tag:theconversation.com,2011:/ca/topics/organs-6931/articlesOrgans – The Conversation2023-11-29T20:06:32Ztag:theconversation.com,2011:article/2159802023-11-29T20:06:32Z2023-11-29T20:06:32ZMiniature organs on chips could revolutionize health-care research<iframe style="width: 100%; height: 100px; border: none; position: relative; z-index: 1;" allowtransparency="" allow="clipboard-read; clipboard-write" src="https://narrations.ad-auris.com/widget/the-conversation-canada/miniature-organs-on-chips-could-revolutionize-health-care-research" width="100%" height="400"></iframe>
<p>To understand how bodies work, medical researchers and scientists have created mini models of organs, called organoids. This field of scientific research has had profound impacts on biological discovery and pharmaceutical development.</p>
<p>An organoid is a <a href="https://doi.org/10.1038/s43586-022-00174-y">miniaturized version of an organ</a>. As the name suggests with the Greek suffix <em>oid</em>, meaning “like,” an organoid is designed to mimic the organ it represents. These three-dimensional structures are generated from stem cells and, although only about one millimetre in size, they effectively emulate the morphology or function of the actual organs. </p>
<p>Yet this is only half the narrative. “<a href="https://doi.org/10.1038/s43586-022-00118-6">Organs-on-chips</a>” are a technology that uses intricately carved tunnels (microchannels) on a piece of plastic or polymer that can house cells. These channels facilitate the flow of cell culture media, replicating blood flow in the human body. </p>
<p>Organs-on-chips act like a miniature version of the body’s organs in the lab, making it easier to see if new drugs will work. They act as a dynamic in vitro (artificial) system to better replicate the in vivo (actual living) environment of cells.</p>
<p>These technologies emerged as a solution to the challenges of drug development, which is both time-consuming and exorbitantly expensive.</p>
<h2>Safe drug development</h2>
<p>Developing new drugs has become an arduous and costly process, requiring an average of <a href="https://doi.org/10.1001/jama.2020.1166">14 years and over US$1 billion</a> to bring a drug to market. In addition, developing new drugs includes a high likelihood of failure. </p>
<p>One of the main reasons for the <a href="https://doi.org/10.1038/nrd4539">slow development of new drugs</a> is the inadequate tools for accurately predicting how a drug will work in the human body. To address this, there is a growing recognition of the need for new models, such as organoids and organs-on-chips, which could revolutionize our ability to evaluate drug efficacy more effectively and efficiently.</p>
<h2>Game-changing research</h2>
<p>While both organoids and organs-on-chips hold individual promise, the combination of the two — “organoids-on-chips” — is a game changer. Organoids, despite their excellent biological complexity, lack certain biophysical cues, crucial for a comprehensive representation of human tissues. </p>
<p>On the other hand, organs-on-chips, while incorporating dynamic micro-environments, often incorporate less-than-optimal biological models. Labs often use commercially produced cell lines with genetically altered features.</p>
<p><div data-react-class="InstagramEmbed" data-react-props="{"url":"https://www.instagram.com/p/CwTDM3LRrJJ","accessToken":"127105130696839|b4b75090c9688d81dfd245afe6052f20"}"></div></p>
<p>By combining these technologies, we can leverage the biological accuracy of organoids with the dynamic capabilities of organs-on-chips. This synergy offers a platform that mirrors in vivo physiology, enabling a more accurate study of disease traits and responses to drugs.</p>
<p>In <a href="https://medgen.med.ubc.ca/josef-penninger/">our lab</a>, our primary focus is on incorporating a functional vascular system to organoids. A major breakthrough came in 2019 when we generated <a href="https://doi.org/10.1038/s41586-018-0858-8">blood vessel organoids from human stem cells</a>, providing an unprecedented model for vascular structures. </p>
<p>By integrating these blood vessel models into microfluidic chips and supplying them with blood, immune cells or drugs, we are paving the way for advanced organoids-on-chips that embody the necessary complexity. This enhanced vascular model enables us to vascularize a variety of biological tissues, improving their lifespan, function, growth and maturation.</p>
<h2>Merging physics and biology</h2>
<p>The interdisciplinary foundation of organoids-on-chips combines biology and physics to reflect the intricate interplay of physiological and physical processes in the human body. By integrating principles from both fields, we can develop more sophisticated and accurate physiological models that encompass this inherent complexity.</p>
<p>The pioneering work of researchers at the <a href="https://wyss.harvard.edu/">Wyss Institute at Harvard University</a> is a striking example of the potential of this interdisciplinary approach. In 2010, they developed a “<a href="https://doi.org/10.1126/science.1188302">lung-on-chip</a>” model that not only mimics the biological structure of lung cells, but also replicates the mechanical function of human breathing. </p>
<p>In a remarkable display of innovation, they also created a <a href="https://www.youtube.com/watch?v=VewOqUnwXG0">smoking robot to simulate the effects of cigarette smoke on this lung-on-chip device</a>, and <a href="https://wyss.harvard.edu/news/human-organ-chips-enable-rapid-drug-repurposing-for-covid-19/">tested COVID-19 drugs</a> during the pandemic.</p>
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<iframe width="440" height="260" src="https://www.youtube.com/embed/VewOqUnwXG0?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Researchers at Harvard University look at the impact of smoking on lung cells.</span></figcaption>
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<p>From its initial conception, the field of organs-on-chips has grown exponentially. Highlighting this trend, the geneticist and microbiologist Hans Clevers now leads <a href="https://www.roche.com/about/leadership/hans-clevers">the pharmaceutical giant Roche’s research division</a>. “In 20 years,” Clevers said, “I think organoids will have <a href="https://doi.org/10.1007/s00109-020-02025-3">replaced animal experimentation in toxicology testing</a>.”</p>
<p>In a parallel move, Roche set up <a href="https://institutehumanbiology.com/">the Institute of Human Biology</a>, under the direction of bioengineer <a href="https://doi.org/10.1016/j.stemcr.2021.08.012">Matthias Lutolf</a>. The institute merges the study of organoids with microfluidic technology. </p>
<h2>Future of organoids</h2>
<p>A pivotal development in 2023 was the U.S. <a href="https://doi.org/10.1126/science.adg6264">Food and Drug Administration’s decision to no longer mandate animal testing for new drugs</a> before advancing to human trials. This change underscores the potential of alternatives like organoids and organs-on-chips in early drug testing, and marks a significant milestone for the field.</p>
<p>The <a href="https://doi.org/10.1126/science.aaw7894">potential of organoids-on-chips</a> extends beyond drug screening and toxicity tests. The technology holds promise for a range of exciting applications, including unravelling the fundamental biological principles underlying development and disease. Their applications extend to <a href="https://doi.org/10.1038/s41576-018-0051-9">regenerative medicine</a>, where organs grown from a patient’s own stem cells could be used to replace damaged ones.</p><img src="https://counter.theconversation.com/content/215980/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Clément Quintard does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Organoids — clusters of specialized cells designed to mimic organs — enable researchers to study biological processes and the effects of drugs.Clément Quintard, Postdoctoral fellow, Penninger Lab, University of British ColumbiaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1859162023-06-22T14:25:13Z2023-06-22T14:25:13ZHuman organs for transplant: 5 steps Africa must take to improve the supply chain<figure><img src="https://images.theconversation.com/files/471369/original/file-20220628-20-p4rpam.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Lack of a proper storage and transport medium is a challenge to organ donation in Africa. </span> <span class="attribution"><span class="source">Sean Gallup/Getty Images</span></span></figcaption></figure><p>Medical science has made tremendous advancements over the past 70 years. One of these is the transplant of human organs from one person to another. The first transplant – a kidney – <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8682823/">was in the US</a> in 1954.</p>
<p>Since then, organ transplants have become an <a href="https://latinaer.springeropen.com/articles/10.1186/s40503-019-0068-2">option</a> in a variety of medical cases. Most donated organs come from people who have already died, but people can still give some organs and tissue while they are alive. </p>
<p>The global demand for human organs for transplant has <a href="http://www.transplant-observatory.org/download/2016-activity-data-report/">grown by 7.2%</a> since 2015. That has surpassed supply. The average wait time for organ transplants in developed countries like the US is between two and six years. This results in the loss of <a href="https://www.degruyter.com/document/doi/10.1515/9780804784641/html">over 10,000 lives</a> each year. And in India, every year <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9886047/#:%7E:text=Although%20India%20holds%20second%20place,to%20the%20unavailability%20of%20organs.">500,000 people</a> die because there are not enough organs available. </p>
<p>In sub-Saharan African countries, there has been a <a href="https://dailytrust.com/grey-areas-organ-transplantation-in-nigeria">steady rise</a> in the demand for organ transplantation, with no corresponding increase in the number of <a href="http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S1562-82642017000200002">organ donors</a>. </p>
<p>In South Africa, for example, <a href="http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S1562-82642017000200002">only 18%</a> of families gave permission for organ donation after a death (at a hospital) in 2017. This means 82% of families chose not to support organ donation.</p>
<p>Though the <a href="http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S1562-82642017000200002">first heart transplant in history</a> was performed in an African country, this region has the fewest transplants of any continent. </p>
<p>The median number of kidney transplant facilities in Africa is <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8084720/pdf/main.pdf">0.15 per million population</a> (against 0.42 globally), and transplant-related services are often scarce. Only South Africa, Nigeria, Kenya, Ghana, Tanzania, Sudan, Seychelles, Namibia, Mauritius, Côte d'Ivoire and Ethiopia perform <a href="http://www.transplant-observatory.org/">transplants</a>. </p>
<p>There are a number of reasons for the shortage of donated organs. Religious or cultural beliefs and a lack of <a href="https://www.premiumtimesng.com/news/more-news/470868-nigeria-has-no-regulatory-body-for-organ-harvesting-transplanting-consultant.html">regulatory or policy framework</a> are among them. There is also the challenge of a <a href="https://latinaer.springeropen.com/articles/10.1186/s40503-019-0068-2">poor incentives system</a>, and inadequate <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8314926/">cold-chain facilities</a>. </p>
<p>All these factors have a significant impact on the organ supply chain. They have in turn triggered other serious social problems, such as a flourishing black market for organ sourcing, organ trafficking, and <a href="https://www.bbc.co.uk/news/uk-england-london-61908876">monetising organ donations</a>. For instance, organs, particularly kidneys, are <a href="https://www.bbc.co.uk/news/world-middle-east-36083800">often sold</a> through the black market by poor people in developing countries.</p>
<p>Based on <a href="https://www.emerald.com/insight/content/doi/10.1108/SCM-12-2022-0457/full/html?utm_source=rss&utm_medium=feed&utm_campaign=rss_journalLatest">our research</a>, we provide insights into the challenges confronting Africa’s organ transplant supply chain systems. </p>
<h2>Links in the supply chain</h2>
<p>The organ supply chain is not a simple, linear process. Similar to the <a href="https://theconversation.com/heading-into-the-third-year-of-the-pandemic-the-us-blood-supply-is-at-a-10-year-low-175906">blood supply chain</a>, it involves collecting, testing, distributing, and transfusing donated organs to patients at geographically spread transplant centres. </p>
<p>Having to use a cold chain system for perishable products like organs only makes things worse, especially in sub-Saharan Africa with its inadequate logistical and infrastructure capabilities. </p>
<p>To strengthen the organ supply chains in sub-Saharan Africa, there is a need for collaborative efforts from multiple stakeholders including clinicians, public health experts, supply chain experts, governments, religious bodies, non governmental organisations, academics and the public. </p>
<p>Together, these stakeholders should review and improve current practices of donating and transplanting organs. </p>
<p>As supply chain experts, we have seen that what works in optimising supply chains are strong governance frameworks, partnerships, systems, people, and data. We suggest five actions based on <a href="https://www.emerald.com/insight/content/doi/10.1108/SCM-12-2022-0457/full/html?utm_source=rss&utm_medium=feed&utm_campaign=rss_journalLatest">our research</a>:</p>
<ol>
<li><p><strong>Develop a robust regulatory model:</strong>
Organ donation and transplantation is a well-regulated field. But only a <a href="https://dailytrust.com/grey-areas-organ-transplantation-in-nigeria">few countries</a> in sub-Saharan Africa have a <a href="https://www.intechopen.com/chapters/74329">legal framework</a> in place to monitor and control the sourcing and transplantation of human organs, cells and tissues. The framework should include an organ donation register, clear guidelines, best practices and protocols. There should be clear incentives or compensation mechanisms for living organ donors, consistent with the society’s moral ideals.</p></li>
<li><p><strong>Create local working groups:</strong>
Last-mile access to healthcare in Africa continues to be one of the most <a href="https://link.springer.com/chapter/10.1007/978-1-4614-5885-2_19">difficult obstacles</a> that governments, donors, and businesses must overcome. Therefore, a decentralised approach is needed to manage the database of patients waiting for a transplant in hospitals at various locations, and for making organ matches swiftly. </p></li>
<li><p><strong>Improve medical cold chain systems:</strong>
The safety and quality of human organs will be seriously compromised if temperature monitoring and maintenance logistics systems are insufficient to get them to hospitals in time. The African continent has <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7187137/">suboptimal cold chain capacity</a> to transport blood and components to hospital. </p></li>
</ol>
<p>A cold chain process is required for most food and pharmaceuticals before they can be delivered to the customers. This is an area where sub-Saharan Africa <a href="https://www.forbesafrica.com/opinion/2020/10/20/the-cold-treatment-for-vaccines/">falls short</a>. On average, <a href="https://www.gcca.org/building-cold-chain-africa">50%</a> of the food produced in African countries is wasted due to inadequate temperature-controlled storage facilities. This is also <a href="https://www.pharmaceutical-technology.com/sponsored/africas-last-mile-building-viable-vaccine-supply-chains/">hindering</a> vaccination programmes around the continent. </p>
<ol>
<li><p><strong>Create awareness:</strong>
The socio-demographic characteristics of populations should be taken into consideration when designing programmes to raise awareness about organ donation. Campaigns should be tailored for age, profession, education level, religious affiliation, and cultural sensitivity. </p></li>
<li><p><strong>Establish knowledge exchange hubs:</strong>
Governments should establish centres of excellence on organ donation, logistics and transport, enabling collaboration among government, industry, civil society and academics. Such a forum could evaluate similarities and differences between country practices.</p></li>
</ol><img src="https://counter.theconversation.com/content/185916/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Adegboyega Oyedijo is a Chartered Member of both the Chartered Institute of Procurement and Supply (CIPS) and the Chartered Institute of Logistics and Transport (CILT). He has received funding from The British Academy.</span></em></p><p class="fine-print"><em><span>George Zsidisin does some volunteer work for the Libertarian Party in the U.S. </span></em></p><p class="fine-print"><em><span>Jamal El Baz, Marcia Mkansi, and Temidayo Akenroye do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Demand for human organs has surpassed supply. This is leading to serious problems including a flourishing black market for organ trafficking.Temidayo Akenroye, Associate Professor of Supply Chain & Analytics, University of Missouri-St. LouisAdegboyega Oyedijo, Lecturer in Operations and Supply Chain Management, University of LeicesterGeorge Zsidisin, Professor of Supply Chain Management , University of Missouri-St. LouisJamal El Baz, Associate Professor, Supply Chain Management, Ibn Zohr UniversityMarcia Mkansi, Professor, University of South AfricaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2062982023-06-04T20:04:32Z2023-06-04T20:04:32ZPeople thinking of voluntary assisted dying may be able to donate their organs. We need to start talking about this<figure><img src="https://images.theconversation.com/files/528191/original/file-20230525-23-9njh7.jpg?ixlib=rb-1.1.0&rect=2%2C0%2C995%2C666&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/multiracial-team-professional-medical-surgeons-performs-2089661560">Shutterstock</a></span></figcaption></figure><p>The number of people needing an organ transplant vastly outweighs the number of organs available. </p>
<p><a href="https://www.donatelife.gov.au/sites/default/files/2023-02/OTA%202022%20Donation%20and%20Transplantation%20Activity%20Report.pdf">In 2022</a> there were about 1,800 Australians waiting for an organ but only about 1,200 people received an organ transplant.</p>
<p>But in <a href="https://onlinelibrary.wiley.com/doi/10.1111/imj.16085">a recent paper</a>, I outline one unexplored option for increasing the number of potential organ donors in Australia – transplanting organs from people undergoing voluntary assisted dying. This would involve transplanting organs only after someone had died.</p>
<p>It’s estimated <a href="https://jamanetwork.com/journals/jama/article-abstract/2616383">about 10%</a> of people eligible for voluntary assisted dying are likely to be medically suitable to donate their organs. Based on <a href="https://www.safercare.vic.gov.au/sites/default/files/2022-09/Voluntary%20Assisted%20Dying%20Review%20Board%20Report%20of%20Operations%20July%202021-June%2022_FINAL.pdf">Victorian figures</a> alone, this could lead to about an extra 40 potential organ donors each year.</p>
<p>This type of organ donation has taken place <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9297969/">for more than 20 years</a> in Europe, and more recently in Canada.</p>
<p>Organs transplanted from donors undergoing voluntary assisted dying <a href="https://jamanetwork.com/journals/jamasurgery/article-abstract/2769118">have</a> <a href="https://onlinelibrary.wiley.com/doi/abs/10.1111/ajt.16267">similar</a> <a href="https://onlinelibrary.wiley.com/doi/abs/10.1111/ajt.16971">success rates</a> to more traditional donations.</p>
<p>Yet, this is a discussion we’ve yet to have in Australia. Here are some of the ethical and practical issues we need to start talking about.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/voluntary-assisted-dying-will-be-available-to-more-australians-this-year-heres-what-to-expect-in-2023-196209">Voluntary assisted dying will be available to more Australians this year. Here's what to expect in 2023</a>
</strong>
</em>
</p>
<hr>
<h2>Is this ethical? It’s tricky</h2>
<p>The main ethical challenge is ensuring a person isn’t motivated to end their life prematurely so they can donate their organs.</p>
<p><a href="https://onlinelibrary.wiley.com/doi/abs/10.1111/ajt.13746">Internationally</a>, <a href="https://jme.bmj.com/content/42/8/486.short">this challenge</a> is mainly addressed by having <a href="https://www.sciencedirect.com/science/article/pii/S1600613523000291">independent assessments</a> by multiple doctors. This is to ensure the motivation is genuine and honest, much like assessing someone before voluntary assisted dying.</p>
<p>Similarly, it is important the doctor of someone undergoing voluntary assisted dying isn’t persuading them to donate an organ. This means any doctor overseeing voluntary assisted dying may be limited in how much they can discuss organ donation with their patient. </p>
<p>Again, this <a href="https://onlinelibrary.wiley.com/doi/abs/10.1111/ajt.13746">has been managed internationally</a> by having separate, independent doctors overseeing organ donation and voluntary assisted dying, <a href="https://www.cmaj.ca/content/190/44/E1305.short">without one influencing</a> the other.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/528192/original/file-20230525-27-sjwdaa.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Elderly woman in bed hand on covers" src="https://images.theconversation.com/files/528192/original/file-20230525-27-sjwdaa.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/528192/original/file-20230525-27-sjwdaa.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=437&fit=crop&dpr=1 600w, https://images.theconversation.com/files/528192/original/file-20230525-27-sjwdaa.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=437&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/528192/original/file-20230525-27-sjwdaa.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=437&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/528192/original/file-20230525-27-sjwdaa.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=549&fit=crop&dpr=1 754w, https://images.theconversation.com/files/528192/original/file-20230525-27-sjwdaa.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=549&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/528192/original/file-20230525-27-sjwdaa.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=549&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Is this what people really want, with so little time left?</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/senior-woman-laying-on-bed-hospital-1054837748">Shutterstock</a></span>
</figcaption>
</figure>
<p>Organ donation may also affect the way voluntary assisted dying is conducted, which <a href="https://www.sciencedirect.com/science/article/pii/S1600613523000291">may impact</a> participants’ very limited quality of life. </p>
<p>That’s because determining if someone is eligible to donate an organ involves a number of <a href="https://jme.bmj.com/content/43/9/601.short">investigations</a>. These may include blood tests, radiology (imaging) and numerous clinical encounters to exclude diseases such as cancer, which would prevent someone donating their organs. These investigations may be exhausting but necessary.</p>
<p>This burden must be weighed against the participant’s wishes and motivation to donate their organs. So people must also be informed of the impact organ donation will have on their limited life left. </p>
<p>The choices of people considering this option must be respected and they must be given multiple opportunities to review their decision, without undue influence or bias.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/three-ethical-ways-to-increase-organ-donation-in-australia-42744">Three ethical ways to increase organ donation in Australia</a>
</strong>
</em>
</p>
<hr>
<h2>Practical issues: coordination, location, regulation</h2>
<p>Practically, combining organ donation and voluntary assisted dying is <a href="https://onlinelibrary.wiley.com/doi/abs/10.1111/ajt.13746">challenging</a>. This includes the difficulty organising and coordinating specialists in organ donation, voluntary assisted dying and transplantation.</p>
<p>This is why, internationally, organ donation of this nature mostly occurs in large hospitals, where it’s easier to coordinate.</p>
<p>So if people want to donate an organ this way, they may spend their last moments in an unfamiliar environment.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/528195/original/file-20230525-15-irsqg9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Patient being wheeled on stretcher through hospital corridors" src="https://images.theconversation.com/files/528195/original/file-20230525-15-irsqg9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/528195/original/file-20230525-15-irsqg9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/528195/original/file-20230525-15-irsqg9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/528195/original/file-20230525-15-irsqg9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/528195/original/file-20230525-15-irsqg9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/528195/original/file-20230525-15-irsqg9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/528195/original/file-20230525-15-irsqg9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">People may have to be moved to a large hospital with the facilities and staff on hand.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/surgeon-assistant-team-transport-move-stretcher-2062330820">Shutterstock</a></span>
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<p>Efforts have been made <a href="https://jamanetwork.com/journals/jamasurgery/article-abstract/2776765">internationally</a> to prioritise these valuable last moments by giving people the choice of where voluntary assisted dying occurs (<a href="https://www.cmaj.ca/content/190/44/E1305.short">such as their home</a>). But this currently only occurs in a minority of cases and increases the complexity of organ donation.</p>
<p>Regulating the process is also essential to developing a safe, trustworthy and effective program. Ideally a centralised organisation such as Australia’s national <a href="https://www.donatelife.gov.au">Organ and Tissue Authority</a> would organise, undertake and regulate this.</p>
<p>However, this may be challenging given voluntary assisted dying practices are specific to each state.</p>
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<strong>
Read more:
<a href="https://theconversation.com/an-opt-out-system-isnt-the-solution-to-australias-low-rate-of-organ-donation-108336">An opt-out system isn't the solution to Australia's low rate of organ donation</a>
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<h2>The challenges ahead</h2>
<p>If someone considering voluntary assisted dying wants to donate their organs and is deemed eligible, there is currently <a href="https://onlinelibrary.wiley.com/doi/10.1111/imj.16085">no legal barrier in Australia</a> to stop them.</p>
<p>What might prevent them is how their doctor responds, and whether there are the services and organisations willing to fulfil this request ethically and practically.</p>
<p>The next step in considering this form of organ donation is to discuss the prospect publicly. </p>
<p>Every extra donated organ is potentially lifesaving. So we should make every effort to consider potential safe and ethical ways to increase donation and transplantation rates.</p><img src="https://counter.theconversation.com/content/206298/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Dr Robert Ray is also a physician trainee at Barwon Health, Geelong.</span></em></p>Every extra organ available for donation is potentially lifesaving. And it can be done safely and ethically.Robert Ray, Affiliate Associate Lecturer, School of Medicine, Deakin UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1942072022-12-12T14:15:37Z2022-12-12T14:15:37ZLab-grown blood used in transfusion for first time – here are three other ways that making organs could change healthcare<figure><img src="https://images.theconversation.com/files/500027/original/file-20221209-24-lf5dp9.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C5000%2C3742&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The red blood cells were made by extracting stem cells from a blood sample.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-illustration/3d-rendering-red-blood-cells-vein-516112096">Phonlamai Photo/ Shutterstock</a></span></figcaption></figure><p>Human volunteers have received the first-ever transfusion of <a href="https://www.nhsbt.nhs.uk/news/first-ever-clinical-trial-of-laboratory-grown-red-blood-cells-being-transfused-into-another-person/">lab grown red blood cells</a> in a groundbreaking scientific first. Volunteers received about 5ml-10ml of blood (around 1-2 teaspoons), which contained around 15 billion red blood cells. So far, volunteers who received the lab-grown blood cells are reported to be in good health. </p>
<p>To grow these red blood cells, researchers first extracted stem cells from a blood sample. They then directed these stem cells to grow into red blood cells in the laboratory. It’s hoped that these lab-grown blood cells may be used in the treatment of disorders that affect red blood cells – such as <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6142434/">sickle cell anaemia</a> and <a href="https://www.nhs.uk/conditions/thalassaemia/treatment/">thalassemia</a>.</p>
<p>While this is the first time blood has ever been grown in the lab, it certainly isn’t the first lab-grown innovation. Scientists have used laboratory-based models for years to investigate everything from organ and tissue function, to understand disease processes and to test new treatments. </p>
<p>Here are some of the other most promising lab-grown innovations to date. </p>
<h2>Organoids</h2>
<p>In recent years organoids, derived from various types of <a href="https://www.nature.com/articles/s41580-020-0259-3">stem cells</a>, have become more common in research. Organoids closely match the structure and function of full-size human organs. This allows researchers to study how many different diseases or viruses may affect human health. They also allow researchers to better understand stem cells (which they grown from), which can become almost any cell in the body. </p>
<p>For instance, organoid brains have helped scientists understand the devastating effect of <a href="https://www.science.org/content/article/zika-virus-kills-developing-brain-cells">Zika virus</a> on brain development. They’re also playing a wider key role in understanding different <a href="https://www.nature.com/articles/s41593-021-00923-4">neurological conditions</a>, such as <a href="https://www.ninds.nih.gov/amyotrophic-lateral-sclerosis-als-fact-sheet">ALS</a>. Organoid brains are extremely advantageous because they allow researchers to observe, in real-time, any changes that may occur in the brain as they happen – something not possible with humans. This will help us better know when and how to treat certain diseases.</p>
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<strong>
Read more:
<a href="https://theconversation.com/lab-grown-brain-cells-can-play-pong-so-should-they-have-legal-rights-192549">Lab-grown brain cells can play Pong – so should they have legal rights?</a>
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<p><a href="https://www.science.org/content/article/lab-grown-minihearts-beat-real-thing">Organoid hearts</a> have also been successfully grown in the lab. After a week of development, they’re functionally equivalent to the heart of a 25-day-old embryo, able to beat between 60-100 times per minute. Recent advances have also enabled <a href="https://elifesciences.org/articles/69028">heart cells</a> to be grown from stem cells, paving the way to be able to grow larger and more efficient cardiac organs.</p>
<p>The cells from these organoids have also been shown to improve the performance of <a href="https://link.springer.com/article/10.1007/s00018-012-1078-2">damaged heart muscle</a> when given to animals. Similar work shows that they are also providing <a href="https://stemcellres.biomedcentral.com/articles/10.1186/s13287-021-02340-7">valuable information</a> in what happens in heart attack, heart failure and a number of genetic heart conditions. </p>
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<img alt="A stem cell researcher in a lab coat and mask looks through a microscope." src="https://images.theconversation.com/files/500029/original/file-20221209-33096-p9c7zt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/500029/original/file-20221209-33096-p9c7zt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/500029/original/file-20221209-33096-p9c7zt.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/500029/original/file-20221209-33096-p9c7zt.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/500029/original/file-20221209-33096-p9c7zt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/500029/original/file-20221209-33096-p9c7zt.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/500029/original/file-20221209-33096-p9c7zt.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Lab-grown organoids are made using stem cells.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/stem-cell-researcher-working-laboratory-1126848905">Microgen/ Shutterstock</a></span>
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<p><a href="https://elifesciences.org/articles/66417">Organoid lungs</a> are also proving useful in understanding COVID-19 and testing new therapies, alongside helping scientists <a href="https://www.frontiersin.org/articles/10.3389/fcell.2022.899368/full">understand other diseases</a>, such as chronic obstructive pulmonary disease, asthma and certain types of pulmonary fibrosis. These kind of human lung organoids take approximately <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6531049/">eight weeks</a> to grow in the lab.</p>
<h2>Fully-grown organs</h2>
<p>Scientists have also been able to successfully grow fully-functioning organs in the lab.</p>
<p>For example, a small number of people are actually walking around with <a href="https://www.bbc.co.uk/news/business-45470799">fully-grown, functioning bladders</a> made from their own cells. These are produced in a lab by growing the <a href="https://academic.oup.com/bmb/article/97/1/81/360794#5208779">patient’s own bladder cells</a> and then 3D-printing them into the correct shape. It’s then surgically implanted into the patient. This process takes around two months to complete. But since these are grown from the patient’s own cells, it removes the risk of the body rejecting the new organ.</p>
<p>Lab-grown vaginas are another example. These are usually grown and implanted into women who are born without a vagina – such as those suffering from a rare disease called <a href="https://rarediseases.org/rare-diseases/mayer-rokitansky-kuster-hauser-syndrome/">Mayer-Rokitansky-Küster-Hauser Syndrome</a>. The process is somewhat similar as with bladders, whereby cells from their external genitalia are used to grow the vagina in a bio-reactor. </p>
<p>One of the biggest challenges that researchers now face is developing lab-grown skin. Skin is the largest organ in the body and is composed of three distinct layers. But finding a way of integrating these layers in the same way as they are in the body is proving difficult for scientists. </p>
<p>While skin cells have been successfully grown in labs for many years, it still takes between <a href="https://www.nature.com/articles/eye198831.pdf?origin=ppub">2-3 weeks</a> to grow enough skin cells to fill the area they’re being grafted onto. However, co-culturing them with cells from the underlying dermis (one of the skin’s three layers) has shown to <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3217074/">improve yield and performance</a> of lab-grown skin cells. Another challenge researchers face is growing skin which contains elements such as <a href="https://onlinelibrary.wiley.com/doi/full/10.1002/adhm.202201626">sweat glands and hairs</a>. These are essential as they help the skin perform one of its many important functions: regulating body temperature. </p>
<h2>Ears</h2>
<p>Scientists have successfully grown and 3D-printed <a href="https://www.independent.co.uk/news/science/children-new-ears-grown-own-cells-china-scientists-worlds-first-operation-transplant-a8187776.html">a human ear</a> using a patient’s cartilage cells. </p>
<p>It’s hoped that this development will help in treating people born with <a href="https://www.cdc.gov/ncbddd/birthdefects/anotia-microtia.html">microtia or anotia</a> – a birth defect that causes the ear not to form properly, or not form at all. The condition effects approximately one in every 2,000-10,000 births. But while the external ear improves appearance, there’s still the challenge of overcoming hearing loss due to the initial absence of the ear, which can also impact speech. </p>
<p>Almost <a href="https://www.organdonation.nhs.uk/helping-you-to-decide/about-organ-donation/statistics-about-organ-donation/">6,800 people</a> are waiting for an organ transplant in the UK and more than <a href="https://www.aier.org/article/the-organ-shortage/">15 times</a> that in the US. Advances in lab grown organs may provide an alternative for those waiting for transplants, and can be produced from a patient’s own cells. </p>
<p>Future innovations are looking towards other lab grown organs such as <a href="https://www.nature.com/articles/s41467-022-28226-7">kidneys</a> and <a href="https://www.nihr.ac.uk/news/human-liver-repaired-using-cells-grown-in-a-laboratory-for-the-first-time/27016">livers</a>, as these represent a large portion of the organs that people waiting for transplants need.</p><img src="https://counter.theconversation.com/content/194207/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Adam Taylor is affiliated with the Anatomical Society. </span></em></p>Lab-grown technologies may help change the way certain human diseases are studied and treated.Adam Taylor, Professor and Director of the Clinical Anatomy Learning Centre, Lancaster UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1619992022-07-28T17:39:34Z2022-07-28T17:39:34ZKilling prisoners for transplants: Forced organ harvesting in China<figure><img src="https://images.theconversation.com/files/476240/original/file-20220727-1302-ejyizd.jpg?ixlib=rb-1.1.0&rect=288%2C387%2C2976%2C1938&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A limited supply of donor organs, paired with a massive demand for transplants, has fuelled the global organ trafficking industry, which exploits poor, underprivileged and persecuted members of society as a source of organs to be purchased by wealthy transplant tourists.</span> <span class="attribution"><span class="source">(AP Photo/Ebrahim Noroozi)</span></span></figcaption></figure><iframe style="width: 100%; height: 100px; border: none; position: relative; z-index: 1;" allowtransparency="" allow="clipboard-read; clipboard-write" src="https://narrations.ad-auris.com/widget/the-conversation-canada/killing-prisoners-for-transplants--forced-organ-harvesting-in-china" width="100%" height="400"></iframe>
<p>Organ transplantation is a <a href="https://www.cihi.ca/en/annual-statistics-on-organ-replacement-in-canada-2011-to-2020">life-saving therapy</a> for millions of patients and one of the <a href="https://www.who.int/health-topics/transplantation#tab=tab_1">greatest successes of modern medicine</a>. However, a limited supply of donor organs, paired with a massive demand for transplants, has fuelled the global organ trafficking industry which exploits poor, underprivileged and persecuted members of society as a source of organs to be purchased by wealthy transplant tourists.</p>
<p>Although <a href="https://www.unodc.org/unodc/en/human-trafficking/glo-act2/Countries/unodc-develops-toolkit-on-the-investigation-and-prosecution-of-trafficking-in-persons-for-organ-removal.html">this practice occurs in many countries</a>, the situation in China is particularly concerning. China is the only country in the world to have an industrial-scale organ trafficking practice that harvests organs from executed prisoners of conscience. This practice is known as forced organ harvesting. </p>
<p>To understand forced organ harvesting, it is useful to consider a hypothetical scenario: a patient in Canada with end-stage heart disease is in need of a life-saving cardiac transplant. </p>
<p>Doctors in Canada tell the patient he needs to go on a waiting list until a compatible donor dies under suitable conditions. This process can take weeks, months or even years. The patient then finds a transplant program in China that can schedule a cardiac transplant from a compatible donor weeks in advance. </p>
<p>This raises several important questions. Cardiac transplant can only come from deceased donors, so how can the hospital match this patient with a potential “deceased” donor weeks in advance? How did the hospital find this donor? How do they know when that donor will die? Has the donor consented to have their organs harvested? </p>
<h2>Distressing facts</h2>
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<figcaption><span class="caption">Explainer: China’s multi-billion-dollar murder for organs industry.</span></figcaption>
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<p>The answers to these questions are extremely distressing. China uses incarcerated <a href="https://chinatribunal.com/wp-content/uploads/2020/02/China-Tribunal-SHORT-FORM-CONCLUSION_Final.pdf">prisoners of conscience as an organ donor pool</a> to provide compatible transplants for patients. These prisoners or “donors” are executed and their organs harvested against their will, and used in a prolific and profitable transplant industry. </p>
<p>As transplant nephrologists and medical professionals, we aim to spread awareness about organ trafficking, particularly forced organ harvesting, to colleagues, institutions, patients and the public. We are involved with organizations like <a href="https://dafoh.org">Doctors Against Forced Organ Harvesting</a> and <a href="https://endtransplantabuse.org">International Coalition to End Transplant Abuse in China</a>, which have done considerable work in this area for over a decade.</p>
<p>China currently has the second-largest transplant program in the world. Transplant operations in China increased rapidly in the early 2000s without a corresponding rise in voluntary organ donors, which led to <a href="https://doi.org/10.1186/s12910-019-0406-6">questions about the source of the organs</a>. </p>
<p>During this period of rapid transplant growth, practitioners of the Buddhist Qi gong discipline known as Falun Gong, were being <a href="https://endtransplantabuse.org/introduction/?#introduction">detained, persecuted and killed in large numbers by the Chinese government</a>. Similarly, China in 2017 began a campaign of <a href="https://conservativepartyhumanrightscommission.co.uk/wp-content/uploads/2021/01/CPHRC-China-Report.pdf">mass detention, surveillance, sterilization and forced labour</a> against the Uyghur ethnic group of Xinjiang. </p>
<h2>Human rights investigations</h2>
<p>Concerns about forced organ harvesting began to surface in 2006-7 by the work of two international human rights lawyers, David Kilgour and David Matas, who were later <a href="https://doi.org/10.3325%2Fcmj.2016.57.219">nominated for a Nobel Peace Prize for their work</a>. The <a href="https://chinatribunal.com/">China Tribunal</a>, led by human rights lawyer Sir Geoffrey Nice, was formed in 2019 to independently investigate the claims of forced organ harvesting. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/476244/original/file-20220727-1268-iqbmrs.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A man standing outdoors in front of signs opposing forced organ harvesting in China" src="https://images.theconversation.com/files/476244/original/file-20220727-1268-iqbmrs.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/476244/original/file-20220727-1268-iqbmrs.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/476244/original/file-20220727-1268-iqbmrs.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/476244/original/file-20220727-1268-iqbmrs.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/476244/original/file-20220727-1268-iqbmrs.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/476244/original/file-20220727-1268-iqbmrs.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/476244/original/file-20220727-1268-iqbmrs.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">Human rights lawyer David Kilgour addresses Falun Gong practitioners demonstrating against forced organ harvesting in China outside Australia’s Parliament House in Canberra, Australia in November 2016.</span>
<span class="attribution"><span class="source">(AP Photo/Rod McGuirk)</span></span>
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<p>The Tribunal examined multiple lines of evidence, including transplant numbers, medical testing of detained prisoners, recorded phone calls to transplant hospitals, as well as testimony from surgeons and prisoners. The final conclusion was issued in March of 2020 and “<a href="https://chinatribunal.com/wp-content/uploads/2020/02/China-Tribunal-SHORT-FORM-CONCLUSION_Final.pdf">confirmed beyond reasonable doubt” that China had been using executed prisoners of conscience as a source of transplant organs for many years</a>.</p>
<p>Despite Chinese transplant officials claiming significant transplant reform had taken place since 2015, recent evidence suggests that the barbaric practice of forced organ harvesting has continued. The <em>American Journal of Transplantation</em>, the world’s leading transplant journal, published a paper in April <a href="https://doi.org/10.1111/ajt.16969">that found that brain death had not been declared in many organ retrievals in China</a>, and that retrieval of the donor’s vital organs was the actual cause of death. In other words, these prisoners were being executed by removal of their organs for the purpose of transplantation. </p>
<p>The <a href="https://ishlt.org/">International Society of Heart and Lung Transplantation</a> issued a policy statement in June that excludes submissions that are “<a href="https://doi.org/10.1016/j.healun.2022.05.012">related to transplantation and involving either organs or tissue from human donors in the People’s Republic of China</a>.” </p>
<h2>Raising awareness</h2>
<p>Unfortunately, the use of unethical medical practices against marginalized groups is not new. The <a href="https://wienerholocaustlibrary.org/exhibition/science-and-suffering-victims-and-perpetrators-of-nazi-human-experimentation/">Nazis conducted horrific experiments</a> on Jewish victims in concentration camps. Soviet psychiatrists created a term known as <a href="https://www.bmj.com/content/bmj/293/6548/641.full.pdf">sluggish schizophrenia</a> to label political dissidents, depriving them of civic rights, employment and credibility. American researchers studied the effects of <a href="https://www.cdc.gov/tuskegee/timeline.htm">untreated syphilis in African Americans in the Tuskegee study</a>. </p>
<p>China has been executing prisoners of conscience and using their organs for transplantation for decades. Transplant physicians, medical professionals and the global community must raise awareness and pressure governments, institutions and hospitals to take action. </p>
<p>It is essential that we conduct due diligence and avoid collaborations where transparency regarding the source of organs cannot be guaranteed. We must protest the unjust and <a href="https://www.thestar.com/opinion/contributors/2022/07/25/the-largest-incarceration-of-a-minority-group-since-the-holocaust-canada-must-take-action-to-stop-the-genocide-of-uyghurs-in-china.html">inhumane incarceration and oppression of Uyghurs</a> and marginalized groups around the world. </p>
<p>We must encourage <a href="https://beadonor.ca/outside-ontario">organ donor registration</a> and <a href="https://lop.parl.ca/sites/PublicWebsite/default/en_CA/ResearchPublications/202029E">support initiatives</a> that increase donation to ultimately curb the demand for illegal organ trafficking. </p>
<p><em>Susie Hughes, executive director of End Transplant Abuse in China, co-authored this article.</em></p><img src="https://counter.theconversation.com/content/161999/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Ali Iqbal is affiliated with International Coalition to End Transplant Abuse in China, and Doctors Against Forced Organ Harvesting. </span></em></p><p class="fine-print"><em><span>Aliya Khan receives funding from industry partners for the development of new molecules for osteoporosis and parathyroid disease. Funds received from Amgen, Alexion, Ascendis, Chugai, Radius, Ultragenyx </span></em></p>China’s industrial-scale organ trafficking practice has been executing prisoners of conscience and using their organs for transplantation for decades. This is known as forced organ harvesting.Ali Iqbal, Transplant Nephrologist, Assistant Professor of Medicine, McMaster UniversityAliya Khan, Clinical professor, Faculty of Health Sciences, McMaster UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1826242022-05-10T18:25:19Z2022-05-10T18:25:19ZPig-human transplants may be a misguided attempt to address the organ shortage<figure><img src="https://images.theconversation.com/files/461887/original/file-20220509-20-agjzud.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C6000%2C4500&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Cross-species transplants require us to examine the relationships between humans and animals.</span> <span class="attribution"><span class="source">(Shutterstock)</span></span></figcaption></figure><iframe style="width: 100%; height: 100px; border: none; position: relative; z-index: 1;" allowtransparency="" allow="clipboard-read; clipboard-write" src="https://narrations.ad-auris.com/widget/the-conversation-canada/pig-human-transplants-may-be-a-misguided-attempt-to-address-the-organ-shortage" width="100%" height="400"></iframe>
<p>At the end of 2021, 57-year old David Bennett Sr. was bedridden and on life-support with irreversible heart failure. He was not eligible for a human heart transplant or an implanted mechanical heart pump because of his underlying health condition and, allegedly, “<a href="https://www.technologyreview.com/2022/05/04/1051725/xenotransplant-patient-died-received-heart-infected-with-pig-virus/">a history of disregarding medical advice</a>.”</p>
<p>Certain death was on the horizon and this fatal prognosis made Bennett a candidate for a highly experimental and never-before-attempted surgical procedure involving the transplantation of a heart from a genetically modified pig.</p>
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Read more:
<a href="https://theconversation.com/pig-heart-transplant-was-david-bennett-the-right-person-to-receive-groundbreaking-surgery-174991">Pig heart transplant: was David Bennett the right person to receive groundbreaking surgery?</a>
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<p>The pig-to-human cardiac transplant — or xenotransplant — was <a href="https://www.technologyreview.com/2022/01/11/1043374/gene-edited-pigs-heart-transplant/">authorized by the U.S. Food and Drug Administration on compassionate grounds on New Year’s Eve 2021</a> and the surgery was performed on Jan. 7, 2022.</p>
<p>Initial reports following the experimental surgery suggested that <a href="https://doi.org/10.1038/d41586-022-00111-9">the genetically modified, human-compatible pig heart was functioning well and infection was not a problem</a>. </p>
<p>Bennett died on March 8 — at the time, “no obvious cause” of death was identified. Now, it has been reported that the pig heart was <a href="https://www.newscientist.com/article/2319108-man-who-received-pig-heart-transplant-has-died-after-pig-virus-found/">infected with a virus called porcine cytomegalovirus and that this virus may have contributed to Bennett’s death</a>. </p>
<p>Though the cause of death remains unclear, infection has been implicated in previous xenotransplantation failures involving baboons as the recipients.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/42bwa85g1DM?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">The BBC reports on the initial pig-to-human heart transplant surgery.</span></figcaption>
</figure>
<h2>More demand than supply</h2>
<p>There is an ongoing chronic <a href="https://hillnotes.ca/2021/04/16/organ-donation-in-canada-2/">shortage of suitable human organs for life-saving transplantation</a>. Indeed, many <a href="https://www.cihi.ca/en/organ-transplants-in-canada-2020-donations-and-need-infographic">Canadian transplant candidates die waiting for an organ donation</a>.</p>
<p>Attempts to increase the limited supply of human organs have included changes to consent rules: <a href="https://doi.org/10.1016/S2468-1253(17)30037-7">moving to an opt-out system</a>, <a href="https://doi.org/10.1016/S0140-6736(18)31870-1">introducing directed living donation and deceased donor-initiated chains</a> and, in some countries, <a href="https://doi.org/10.1097/MOT.0000000000000617">offering financial compensation</a>. </p>
<p>Still, patients die on transplant waiting lists. For this reason, there is ever increasing interest in xenotransplantation — an ethically controversial practice. </p>
<h2>Nonhuman primates and pigs</h2>
<p>In 1984, <a href="https://time.com/4086900/baby-fae-history/">the heart of a young baboon was transplanted into Baby Fae</a>, an infant born with a fatal heart defect called <a href="https://www.mayoclinic.org/diseases-conditions/hypoplastic-left-heart-syndrome/symptoms-causes/syc-20350599">hypoplastic left heart syndrome</a>. Baby Fae lived for three weeks, but eventually died of heart failure caused by rejection of the transplanted baboon heart.</p>
<p>Prior to this, there had been three other experimental nonhuman heart transplants, <a href="https://dx.doi.org/10.1080/08998280.2012.11928783">the earliest in 1964 using a chimpanzee heart</a>.</p>
<p>More recent efforts at xenotransplantation have involved the <a href="https://www.uab.edu/news/campus/item/12566-uab-announces-first-clinical-grade-transplant-of-gene-edited-pig-kidneys-into-brain-dead-human">transplantation of pig kidneys into brain-dead humans</a>. The most dramatic recent example, however, remains Bennett’s first-in-human cardiac xenotransplant using a genetically modified pig heart.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/462150/original/file-20220510-17-ol00fx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="a baboon behind a cage" src="https://images.theconversation.com/files/462150/original/file-20220510-17-ol00fx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/462150/original/file-20220510-17-ol00fx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/462150/original/file-20220510-17-ol00fx.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/462150/original/file-20220510-17-ol00fx.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/462150/original/file-20220510-17-ol00fx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/462150/original/file-20220510-17-ol00fx.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/462150/original/file-20220510-17-ol00fx.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">One of the earliest xenotransplants involved a baboon heart transplanted into an infant.</span>
<span class="attribution"><span class="source">(Shutterstock)</span></span>
</figcaption>
</figure>
<p>For some, the use of pig hearts for xenotransplantation may be ethically preferable to the use of nonhuman primate hearts because pigs are already used for medicine: for example, <a href="https://www.npr.org/2021/10/20/1047560631/in-a-major-scientific-advance-a-pig-kidney-is-successfully-transplanted-into-a-h">pig heart valves, corneas and skin are used in various treatments</a>.</p>
<p>Or it could be that pigs are preferable “organ donors” because they are already used for food. When it comes to food animals — those who are consumed by humans — people can be biased against accurately seeing the subjectivity of the animal. This is referred to as the “<a href="https://dx.doi.org/10.3390/ani9121125">meat paradox</a>,” where people perceive food animals as “<a href="https://www.bbc.com/future/article/20190206-what-the-meat-paradox-reveals-about-moral-decision-making">objects and thereby avoid the discomfort caused by knowing about the suffering behind consumer goods</a>.”</p>
<p>A third reason to prefer killing pigs for human benefit instead of killing nonhuman primates is that pigs are biologically less similar to humans.</p>
<h2>Prioritizing humans</h2>
<p>Moral worth — <a href="https://impactethics.ca/2014/09/05/which-lives-are-you-pro/">the value assigned to others in ways that affect how we treat them</a> — is not species specific. Rather, it is associated with specific capacities such as the ability to think, make choices, experience pain, communicate and have social relationships.</p>
<p>Because a human zygote lacks such capacities, not many believe that they have the same moral worth as a human two-year old, and there is nothing obviously irrational about this belief. Though a zygote may have the potential to reach a comparable level of development as a two-year old, they are not yet comparable. Their shared human identity is beside the point. </p>
<p>On occasion, humans may choose to prioritize the interests of their companion animals without doing something obviously wrong. For example, it is not irrational to spend money on the care of pets, even if that money could have gone towards helping fellow humans. This choice may reflect a shared social relationship and the emotional bonds that come with it. It may also reflect a sense of duty toward nonhuman animals that are dependent on the care provided by humans. </p>
<p>Having said this, clearly, there are times when it is appropriate to prioritize the interests of humans over other animals; it is just that <a href="https://aeon.co/essays/human-exceptionalism-is-a-danger-to-all-human-and-nonhuman">this perspective shouldn’t be the default position</a>. In any case, it is not clear, nor is it easy to determine, that Bennett’s extraordinary xenotransplant falls into this category.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/462152/original/file-20220510-16-xxiv1e.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="pigs standing at a trough in a shed" src="https://images.theconversation.com/files/462152/original/file-20220510-16-xxiv1e.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/462152/original/file-20220510-16-xxiv1e.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/462152/original/file-20220510-16-xxiv1e.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/462152/original/file-20220510-16-xxiv1e.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/462152/original/file-20220510-16-xxiv1e.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/462152/original/file-20220510-16-xxiv1e.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/462152/original/file-20220510-16-xxiv1e.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The killing and consumption of pigs is normalized as they are produced for food.</span>
<span class="attribution"><span class="source">(Shutterstock)</span></span>
</figcaption>
</figure>
<h2>Animal welfare</h2>
<p>In Canada, support for animal-based research is anchored in a commitment to <a href="https://www.ccac.ca/Documents/2013_National_Survey.pdf">prevent — or at the very least reduce — unnecessary suffering</a>. The problem with this stance is that current animal welfare considerations do not typically support strong constraints on the scientific use of animals. </p>
<p>Notably, there are pressures to limit, but <a href="https://ccac.ca/en/facts-and-legislation/animal-data/annual-animal-data-reports.html">not to eliminate</a>, the use of animals in research likely to have severe welfare impacts. Also, common animal welfare considerations do not prohibit killing the animals, they just constrain how they are killed. </p>
<p>Part of the problem here is that there are <a href="https://doi.org/10.1017/S0963180119000732">no substantive ethical principles governing animal use in science</a>. The three Rs, which are pervasive in regulated animal use in science, emphasize <em>replacing</em> sentient animals (animals capable of experiencing pain and pleasure) where possible, <em>reducing</em> the number of sentient animals used in studies to a “bare minimum” and <em>refining</em> their experiences of use to minimize suffering. </p>
<p>As such, the three Rs seem to assume something like a principled commitment to non-maleficence — <a href="https://doi.org/10.1093/ilar/ilaa014">avoiding unnecessary harm</a>. However, the continued dependency on harmful animal-based research that almost always ends with the killing of the animals belies this claim, given the known <a href="https://www.cbc.ca/radio/quirks/may-7-endangered-tiny-porpoise-mars-quakes-thermal-batteries-and-more-1.6443011/meet-the-canadian-researcher-determined-to-take-the-animals-out-of-lab-testing-1.6443917">significant problems of extrapolation of research findings</a>.</p>
<p>Given the ethical challenges with animal-based research in general and more specifically the ethical challenges with animal-to-human xenotransplantation, there is good reason to look for <a href="https://www.thehastingscenter.org/xenotransplantation-three-areas-of-concern/">other strategies to increase the supply of organs</a> for transplantation.</p><img src="https://counter.theconversation.com/content/182624/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Andrew Fenton is a member of the (Canadian) Society for Humane Science and is currently serving on a subcommittee for the Canadian Council on Animal Care (revising their core ethics document) and a panel on nonhuman primate research for the National Anti-Vivisection Society. </span></em></p><p class="fine-print"><em><span>Françoise Baylis does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>The heart used in the first pig-human transplant was infected with a pig virus. This reveals that using other species as organ donors may not provide a solution for organ shortages.Françoise Baylis, University Research Professor, Philosophy, Dalhousie UniversityAndrew Fenton, Associate Professor, Philosophy, Dalhousie UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1752902022-02-27T13:08:39Z2022-02-27T13:08:39ZOrgan transplants from pigs: Medical miracle or pandemic in the making?<figure><img src="https://images.theconversation.com/files/447227/original/file-20220218-3064-xtzvrp.jpg?ixlib=rb-1.1.0&rect=422%2C35%2C4922%2C3332&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Xenotransplantation is the transplanting of cells, tissues or organs from animals to humans. Pre-clinical trials of organ transplant from pigs have addressed some of the technical barriers.</span> <span class="attribution"><span class="source">(Shutterstock)</span></span></figcaption></figure><p>Three out of four <a href="https://www.cdc.gov/onehealth/basics/zoonotic-diseases.html">new diseases are zoonotic</a>, meaning they have evolved to infect new host species. For example, a mutated <a href="https://www.cdc.gov/flu/avianflu/virus-transmission.htm">bird-flu virus</a> may jump from wild birds to free-range domestic poultry and then to humans who are in contact with poultry. Similar pathways have led to infection by the pathogens that cause <a href="https://doi.org/10.1038/nrmicro.2017.45">Ebola, Zika, HIV, Lyme disease and likely COVID-19</a>.</p>
<p>If a new medical technology increased the risk of a new zoonotic pandemic — however marginally — how would society decide the balance of risk and benefit? If you needed new lungs that were only available in another country, would a health prohibition on the transplant in your own country stop you? </p>
<p>New developments in organ transplant technology may have streamlined a pathway for new zoonotic diseases, but the biotechnology innovators and medical research institutes have not engaged the public on the risks. Failing to do so may jeopardize the potential of a promising therapy.</p>
<h2>Xenotransplantation</h2>
<p>Over 4,400 Canadians are waitlisted for the lifesaving transplant of a new kidney, liver or lung. In 2019, <a href="https://www.blood.ca/en/stories/data-offers-hope-patients-waiting-organ-transplant">250 died waiting</a>. In the United States and elsewhere, <a href="https://www.organdonor.gov/learn/organ-donation-statistics">the supply gap is more extreme</a> and high hopes ride on xenotransplantation: the transplanting of cells, tissues or organs from animals. </p>
<p>Pre-clinical trials of organ transplants from pigs have addressed the technical barriers to xenotransplantation, reducing the likelihood of rejection. Last summer, Maryland School of Medicine surgeons reported the 31-day survival of a baboon after receiving a <a href="https://doi.org/10.1111/ajt.16809">lung from a genetically modified pig</a>. </p>
<p>Weeks later, a team at New York University transplanted a kidney from a genetically modified pig into a <a href="https://doi.org/10.1111/xen.12718">brain-dead person</a>. In December 2021, surgeons at Maryland School of Medicine transplanted a genetically modified pig heart into a <a href="https://doi.org/10.1038/d41586-022-00111-9">living 57-year-old man</a>. </p>
<p>All projects were approved under U.S. Food and Drug Administration (FDA) regulations, and corporate funding was supplemented by the U.S. National Institutes of Health. The next step with the FDA is to approve clinical trials. Normalization of xenotransplantation could happen before there is informed public acceptance of the benefits and risks.</p>
<h2>A potential zoonotic pathway</h2>
<p>As a developmental geneticist, it has been exciting to track these advances. The revolution in designer gene editing (known as CRISPR-Cas9) makes this stunning progress possible. <a href="https://doi.org/10.1126/science.aan4187">CRISPR allows molecules on the surface of pig cells to be modified</a> so the human immune system will not trigger tissue rejection.</p>
<figure class="align-center ">
<img alt="Illustration in blue tones of a human torso with respiratory tract and lungs in red" src="https://images.theconversation.com/files/447231/original/file-20220218-13070-hep7im.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/447231/original/file-20220218-13070-hep7im.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=465&fit=crop&dpr=1 600w, https://images.theconversation.com/files/447231/original/file-20220218-13070-hep7im.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=465&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/447231/original/file-20220218-13070-hep7im.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=465&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/447231/original/file-20220218-13070-hep7im.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=585&fit=crop&dpr=1 754w, https://images.theconversation.com/files/447231/original/file-20220218-13070-hep7im.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=585&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/447231/original/file-20220218-13070-hep7im.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=585&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Zoonotic bacteria and viruses enter most readily through the delicate surfaces of the respiratory tract.</span>
<span class="attribution"><span class="source">(Shutterstock)</span></span>
</figcaption>
</figure>
<p>To prevent human transplant recipients from being infected with pig <a href="https://www.genome.gov/genetics-glossary/Retrovirus">retroviruses</a> (viruses that can integrate their genetic material into the host’s cells), the retroviruses hiding in the pig genome have been <a href="https://doi.org/10.1111/xen.12595">removed by CRISPR editing</a>. The risk of transferring a disease directly from a genetically modified donor pig to the human host is negligible.</p>
<p>However, disease-free transplanted pig organs could become infected after transplantation. Zoonotic bacteria and viruses enter hosts most readily through the <a href="https://doi.org/10.1051/vetres:2006062">delicate surfaces of the respiratory tract</a>, as with COVID-19. Living pig cells in a transplanted lung could readily be infected by an inhaled pig virus, including a novel virus from a wild animal host that has evolved to infect pigs. </p>
<p>After entering the human body, a replicating zoonotic virus could generate millions of mutations a day, because their mechanism for gene copying <a href="https://doi.org/10.3390/v13091882">is naturally error prone</a>. A pig virus replicating in a lung transplanted into a human could <a href="https://theconversation.com/how-do-viruses-mutate-and-jump-species-and-why-are-spillovers-becoming-more-common-134656">produce variants</a> that may be capable of recognizing and infecting human cells. Although likely a rare event, it is not impossible that this could trigger a new zoonotic pandemic.</p>
<h2>Risk, fear and polarization</h2>
<p>The scenario described above could evoke risk and fear from a complex new medical technology. It parallels the thinking involved in <a href="https://doi.org/10.1038/s41591-021-01459-7">vaccine hesitancy</a> or the <a href="https://www.scientificamerican.com/article/why-people-oppose-gmos-even-though-science-says-they-are-safe/">distrust of genetically modified foods</a>. Both are well anchored in today’s political culture. In both cases, citizens increasingly demand prior consent and the choice to opt out — despite possible risks to public health. <a href="https://doi.org/10.1038/s41598-022-05498-z">Vaccine hesitancy</a> has increased the death toll from COVID-19 and delayed economic recovery from the pandemic.</p>
<p>In contrast, distrust of the industrialization of food has discouraged introduction of genetically modified foods that <a href="https://doi.org/10.4161/21645698.2014.967570">enhance nutrition or sustain agricultural productivity</a> in a warming climate. Consumers question whether genetically modified organisms (GMOs) exist for public benefit or for corporate profit.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/447229/original/file-20220218-19-vy6cvf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A protester wearing a winter hat with their face covered with a scarf, hold a paper plate that says 'No GMOs on my plate'" src="https://images.theconversation.com/files/447229/original/file-20220218-19-vy6cvf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/447229/original/file-20220218-19-vy6cvf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=798&fit=crop&dpr=1 600w, https://images.theconversation.com/files/447229/original/file-20220218-19-vy6cvf.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=798&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/447229/original/file-20220218-19-vy6cvf.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=798&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/447229/original/file-20220218-19-vy6cvf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1003&fit=crop&dpr=1 754w, https://images.theconversation.com/files/447229/original/file-20220218-19-vy6cvf.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1003&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/447229/original/file-20220218-19-vy6cvf.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1003&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Distrust of the industrialization of food has discouraged introduction of GMO foods.</span>
<span class="attribution"><span class="source">(CP PHOTO/Paul Chiasson)</span></span>
</figcaption>
</figure>
<p>Increasingly, health issues such as <a href="https://theconversation.com/politicizing-covid-19-vaccination-efforts-has-fuelled-vaccine-hesitancy-175416">vaccination</a>, vaping or genetic testing generate highly polarized <a href="https://doi.org/10.1093/ntr/ntaa276">platforms for misinformation</a>, debate and political leverage. <a href="https://thedecisionlab.com/insights/society/social-media-and-moral-outrage/">Social media algorithms amplify extreme positions and elicit strong emotional reactions</a> at the <a href="http://dx.doi.org/10.1177/1461444818822813">expense of the middle ground</a>. When communications from the scientific community are reactive, poorly targeted or <a href="https://doi.org/10.1080/02691728.2020.1739778">unintelligible to the average person</a>, the influence of science in the policy process is diminished.</p>
<p>In 2022, progress in xenotransplant technology makes <a href="https://edition.cnn.com/2022/01/15/opinions/pig-heart-transplant-big-deal-reiner/index.html">good news stories</a>. Immense pressure to resolve the growing organ shortage for transplantation may tempt the biotechnology business and public regulators to be insufficiently critical as they seek permission to proceed with clinical studies. They must prepare for the nature and scale of backlash from those tired of experts and mistrustful of corporate motivation and institutional authority. </p>
<p>Concern about zoonosis from transplants was <a href="https://www.nuffieldbioethics.org/publications/xenotransplantation">voiced over twenty years ago</a>, long before CRISPR transformed the field. <a href="https://www.fda.gov/regulatory-information/search-fda-guidance-documents/phs-guideline-infectious-disease-issues-xenotransplantation">Since then</a>, there appear to be no hard facts or even a call for research on zoonotic infection through xenotransplants after transplantation. Bioethicists are <a href="https://www.thehastingscenter.org/xenotransplantation-three-areas-of-concern/">flagging the issue now</a>, but the silence about xenotransplant zoonosis from biotechnology corporations and their affiliated preclinical research institutes leaves an open door to a narrative motivated by skepticism and distrust. It is incumbent on them to lead a public dialogue on managing the risk of novel zoonotic diseases arising from infection after transplantation.</p><img src="https://counter.theconversation.com/content/175290/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>J Roger Jacobs receives funding from the Natural Sciences and Engineering Research Council of Canada.</span></em></p>New developments in organ transplants from animals show promise. However, there has been no public engagement about a potential risk. It may streamline a pathway to humans for new zoonotic diseases.J Roger Jacobs, Professor, Department of Biology, McMaster UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1580052021-04-22T12:25:25Z2021-04-22T12:25:25ZYou don’t have a male or female brain – the more brains scientists study, the weaker the evidence for sex differences<figure><img src="https://images.theconversation.com/files/395082/original/file-20210414-21-x0wfsg.jpg?ixlib=rb-1.1.0&rect=0%2C16%2C5654%2C3732&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Brain sex isn't a thing.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/human-brain-royalty-free-image/520456984">Sunny/Stone via Getty Images</a></span></figcaption></figure><p><a href="https://doi.org/10.1371/journal.pone.0110830">Everyone knows the difference between male and female brains.</a> One is chatty and a little nervous, but never forgets and takes good care of others. The other is calmer, albeit more impulsive, but can tune out gossip to get the job done. </p>
<p>These are stereotypes, of course, but they <a href="https://doi.org/10.1007/s12152-012-9169-1">hold surprising sway</a> over the way actual brain science is designed and interpreted. Since the <a href="https://en.wikipedia.org/wiki/Magnetic_resonance_imaging_of_the_brain">dawn of MRI</a>, neuroscientists have <a href="https://www.theguardian.com/books/2019/mar/05/the-gendered-brain-gina-rippon-review">worked ceaselessly</a> to find differences between men’s and women’s brains. This research attracts lots of attention because it’s just so easy to try to link any particular brain finding to some gender difference in behavior.</p>
<p>But as <a href="https://scholar.google.com/citations?user=tHcqut8AAAAJ&hl=en&oi=ao">a neuroscientist long experienced in the field</a>, I recently completed a painstaking <a href="https://doi.org/10.1016/j.neubiorev.2021.02.026">analysis of 30 years of research on human brain sex differences</a>. And what I found, with the help of excellent collaborators, is that virtually none of these claims has proven reliable. </p>
<p>Except for the simple difference in size, there are no meaningful differences between men’s and women’s brain structure or activity that hold up across diverse populations. Nor do any of the alleged brain differences actually explain the <a href="https://doi.org/10.1037/a0038208">familiar but modest differences</a> in personality and abilities between men and women.</p>
<h2>More alike than not</h2>
<p>My colleagues and I titled our study “Dump the Dimorphism” to debunk the idea that human brains are “sexually dimorphic.” That’s a very science-y term biologists use to describe a structure that comes in two distinct forms in males and females, such as antlers on deer or the genitalia of men and women. </p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/395097/original/file-20210414-19-m4hmqf.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A brightly colored male zebra finch is perched next to a more drab colored female." src="https://images.theconversation.com/files/395097/original/file-20210414-19-m4hmqf.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/395097/original/file-20210414-19-m4hmqf.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=480&fit=crop&dpr=1 600w, https://images.theconversation.com/files/395097/original/file-20210414-19-m4hmqf.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=480&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/395097/original/file-20210414-19-m4hmqf.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=480&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/395097/original/file-20210414-19-m4hmqf.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=603&fit=crop&dpr=1 754w, https://images.theconversation.com/files/395097/original/file-20210414-19-m4hmqf.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=603&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/395097/original/file-20210414-19-m4hmqf.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=603&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A pair of wild zebra finches (<em>Taeniopygia guttata</em>) perch in South Australia. The male is in the foreground, the female behind.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/zebra-finch-pair-australia-royalty-free-image/584502287">Whitworth Images/Moment via Getty Images</a></span>
</figcaption>
</figure>
<p>When it comes to the brain, some animals do indeed exhibit sexual dimorphism, such as certain birds whose brains contain a <a href="https://doi.org/10.1126/science.959852">song-control nucleus that is six times larger</a> in males and is responsible for male-only courtship singing. But as we demonstrate in our exhaustive survey, nothing in human brains comes remotely close to this. </p>
<p>Yes, men’s overall brain size is about 11% bigger than women’s, but unlike some songbirds, no specific brain areas are disproportionately larger in men or women. Brain size is proportional to body size, and the brain difference between sexes is actually smaller than other internal organs, such as the heart, lungs and kidneys, which <a href="https://doi.org/10.1016/s0379-0738(00)00401-1">range from 17% to 25% larger in men</a>.</p>
<p>When overall size is properly controlled, no individual brain region varies by more than <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2782778/">about 1%</a> between men and women, and even these tiny differences are <a href="https://doi.org/10.1016/j.neubiorev.2021.02.026">not found consistently across geographically or ethnically diverse populations</a>.</p>
<p>Other highly touted brain sex differences are also a product of size, not sex. These include the ratio of gray matter to white matter and the ratio of connections between, versus within, the two hemispheres of the brain. Both of these ratios are larger in people with smaller brains, <a href="https://doi.org/10.1016/j.neuroimage.2017.04.029">whether male or female</a>.</p>
<p>What’s more, <a href="https://doi.org/10.1080/1357650X.2018.1497044">recent research has utterly rejected</a> the idea that the tiny difference in connectivity between left and right hemispheres actually explains any behavioral difference between men and women. </p>
<h2>A zombie concept</h2>
<p>Still, “sexual dimorphism” won’t die. It’s a zombie concept, with the latest revival using artificial intelligence to predict whether a given brain scan comes from a man or woman. </p>
<p>Computers can do this with 80% to 90% accuracy except, once again, this accuracy falls to 60% (or not much better than a coin flip) when you <a href="https://theconversation.com/are-there-male-and-female-brains-computers-can-see-a-distinction-but-they-rely-strongly-on-differences-in-head-size-143972">properly control for head size</a>. More troublesome is that these algorithms don’t translate across populations, such as <a href="https://doi.org/10.3389/fnhum.2018.00399">European versus Chinese</a>. Such inconsistency shows there are no universal features that discriminate male and female brains in humans – unlike those deer antlers. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/395103/original/file-20210414-21-pu5nwu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Brain MRI images showing multiple views" src="https://images.theconversation.com/files/395103/original/file-20210414-21-pu5nwu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/395103/original/file-20210414-21-pu5nwu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/395103/original/file-20210414-21-pu5nwu.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/395103/original/file-20210414-21-pu5nwu.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/395103/original/file-20210414-21-pu5nwu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=501&fit=crop&dpr=1 754w, https://images.theconversation.com/files/395103/original/file-20210414-21-pu5nwu.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=501&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/395103/original/file-20210414-21-pu5nwu.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=501&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Human brain structure is the same in males and females.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/head-x-ray-brain-in-mri-royalty-free-image/168715138">Movus/iStock via Getty Images Plus</a></span>
</figcaption>
</figure>
<p>Neuroscientists have long held out hope that bigger studies and better methods would finally uncover the “real” or species-wide sex differences in the brain. But the truth is, as studies have gotten bigger, the <a href="https://doi.org/10.1038/s41598-018-23976-1">sex effects have gotten smaller</a>. </p>
<p>This collapse is a telltale sign of a problem known as <a href="https://doi.org/10.3310/hta14080">publication bias</a>. Small, early studies which found a significant sex difference were <a href="https://doi.org/10.1038/s41598-018-23976-1">likelier to get published</a> than research finding no male-female brain difference.</p>
<h2>Software versus hardware</h2>
<p>We must be doing something right, because our challenge to the dogma of brain sex has received pushback from both ends of the academic spectrum. Some have labeled us as science <a href="https://quillette.com/2019/03/11/science-denial-wont-end-sexism/">“deniers”</a> and deride us for political correctness. On the other extreme, we are dismissed by <a href="https://doi.org/10.1038/d41586-019-01366-5">women’s health advocates</a>, who believe research has overlooked women’s brains – and that neuroscientists should intensify our search for sex differences to better treat female-dominant disorders, such as depression and <a href="https://www.alzdiscovery.org/cognitive-vitality/blog/how-does-alzheimers-affect-women-and-men-differently">Alzheimer’s disease</a>.</p>
<p>But there’s no denying the decades of actual data, which show that brain sex differences are tiny and swamped by the much greater variance in individuals’ brain measures across the population. And the same is true for most behavioral measures. </p>
<p>[<em>Deep knowledge, daily.</em> <a href="https://theconversation.com/us/newsletters/the-daily-3?utm_source=TCUS&utm_medium=inline-link&utm_campaign=newsletter-text&utm_content=deepknowledge">Sign up for The Conversation’s newsletter</a>.]</p>
<p>About a decade ago, teachers were urged to <a href="https://doi.org/10.1007/s11199-011-0037-y">separate boys and girls</a> for math and English classes based on the sexes’ alleged learning differences. Fortunately, <a href="https://www.theguardian.com/commentisfree/2017/jul/14/gender-segregation-state-schools-disaster-damage-children">many refused</a>, arguing the <a href="https://core.ac.uk/download/pdf/4156138.pdf">range of ability</a> is always much greater among boys or among girls than between each gender as a group.</p>
<p>In other words, sex is a very imprecise indicator of what kind of brain a person will have. Another way to think about it is <a href="https://doi.org/10.1016/j.neubiorev.2020.11.018">every individual brain is a mosaic</a> of circuits that control the many dimensions of masculinity and femininity, such as emotional expressiveness, interpersonal style, verbal and analytic reasoning, sexuality and gender identity itself. </p>
<p>Or, to use a computer analogy, gendered behavior comes from running different software on the same basic hardware. </p>
<p>The absence of binary brain sex features also <a href="https://psycnet.apa.org/record/2018-32185-001">resonates</a> with the increasing numbers of people who <a href="https://doi.org/10.1016/j.jadohealth.2017.04.014">identify as nonbinary, queer, nonconforming or transgender</a>. Whatever influence biological sex exerts directly on human brain circuitry is clearly not sufficient to explain the multidimensional behaviors we lump under the complex phenomenon of gender. </p>
<p>Rather than “dimorphic,” the human brain is a sexually monomorphic organ – much more like the heart, kidneys and lungs. As you may have noticed, these can be transplanted between women and men with great success.</p><img src="https://counter.theconversation.com/content/158005/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Lise Eliot receives funding from the Fred B. Snite Foundation. </span></em></p>Rather than distinctly male or female, the human brain is much more like the heart, kidneys and lungs – basically the same no matter the sex of the body it’s in.Lise Eliot, Professor of Neuroscience, Rosalind Franklin University of Medicine and ScienceLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1324912021-04-06T21:15:44Z2021-04-06T21:15:44Z3D-printed organs could save lives by addressing the transplant shortage<figure><img src="https://images.theconversation.com/files/321742/original/file-20200319-22627-p6g975.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C4810%2C3460&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The need for donated organs can be addressed using a novel 3D-printing technique.</span> <span class="attribution"><span class="source">(Shutterstock)</span></span></figcaption></figure><p>Due to the global organ shortage and limited organ donors, thousands of patients are left wanting organs and tissues in cases of <a href="https://doi.org/10.1016/j.jmbbm.2017.11.037">severe injuries</a>, illness or genetic conditions. Many of these patients <a href="http://doi.org/10.1056/NEJM200008103430606">die before transplants are available</a>. </p>
<p>Tissue engineering is an emerging field that works on producing artificial tissue and organ substitutes as permanent solutions to replace or repair damage.</p>
<p>As biomedical engineering researchers, we are developing 3D temporary organ structures — called scaffolds — that may help regenerate damaged tissues and potentially lead to creating artificial organs. These tissues can also be used in various tissue engineering applications, including nerve repair in structures constructed from biomaterials.</p>
<h2>Printing tissue</h2>
<p>Approximately <a href="https://doi.org/10.3171/2017.11.jns171500">22.6 million patients</a> require <a href="https://doi.org/10.1016/j.pneurobio.2018.07.002">neurosurgical interventions</a> annually around the world to treat damage to the peripheral nervous system. This damage is primarily caused by traumatic events such as motor vehicle accidents, violence, workplace injuries or difficult births. It is anticipated that the cost of global nerve repair and regeneration will reach more than <a href="https://www.medgadget.com/2018/10/global-nerve-repair-and-regeneration-market-estimated-to-reach-413-million-by-2025.html">$400 million by 2025</a>.</p>
<p>Current surgical techniques allow surgeons to realign nerve ends and encourage nerve growth. However, the incidence of recovery in the injured nervous system is not guaranteed, and the return of function is almost never complete. </p>
<p>Animal studies on rats have shown that if an injury destroys <a href="https://doi.org/10.3171/jns.2005.103.6.1067">more than two centimetres of nerves</a>, the gap cannot be bridged properly and may result in the loss of muscle function or feeling. In this condition, it is important to use a scaffold to bridge two sides of the damaged nerve, specifically in case of large nerve injuries.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/393603/original/file-20210406-15-rgc2a5.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Illustration showing how a scaffold can bridge an injured nerve" src="https://images.theconversation.com/files/393603/original/file-20210406-15-rgc2a5.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/393603/original/file-20210406-15-rgc2a5.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/393603/original/file-20210406-15-rgc2a5.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/393603/original/file-20210406-15-rgc2a5.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/393603/original/file-20210406-15-rgc2a5.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/393603/original/file-20210406-15-rgc2a5.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/393603/original/file-20210406-15-rgc2a5.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Large nerve injuries (larger than 2 cm) need a scaffold to act as a bridge to connect two sides of the injured nerve.</span>
<span class="attribution"><span class="source">(Saman Naghieh)</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p><a href="https://doi.org/10.1016/j.bprint.2019.e00045">3D bioprinting prints 3D structures layer by layer</a>, similar to 3D printers. Using this technique, our research team created a porous structure made of the patient’s neural cells and a biomaterial to bridge an injured nerve. We used alginate — derived from algae — because the human body does not reject it.</p>
<p>While this technique has not yet been tested in people, once refined, it <a href="https://doi.org/10.1002/biot.201700635">has the potential</a> to help patients waiting for tissues and organs. </p>
<h2>Material challenges</h2>
<p>Alginate is a challenging material to work with because it collapses easily during 3D printing. Our research focuses on the development of new techniques to improve its printability.</p>
<p>For nerve repair, alginate has favourable properties for living cells growth and functions, but its poor 3D printability considerably limits its fabrication. It means that alginate flows easily during the printing process, and results in a collapsed structure. We developed a <a href="https://doi.org/10.1016/j.jmbbm.2019.02.014">fabrication method</a> where cells are contained within a porous alginate structure that is created with a 3D printer. </p>
<p>Previous research used moulding techniques to create a bulk alginate without a porous structure to improve nerve regeneration; the cells do not like such a <a href="https://doi.org/10.1089/ten.tea.2011.0097">solid environment</a>. However, 3D-printing a porous alginate structure is challenging and often impossible.</p>
<p>Our research addresses this issue by printing a porous structure made of alginate layer-by-layer rather than a moulded bulk algiante; such structure has interconnected pores and provides a cell-friendly environment. Cells can easily communicate with each other and start the regeneration while the 3D-printed alginate provides a temporary support for them.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/317655/original/file-20200227-24672-1ryokob.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="an artificial ear made by a 3D printer" src="https://images.theconversation.com/files/317655/original/file-20200227-24672-1ryokob.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/317655/original/file-20200227-24672-1ryokob.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/317655/original/file-20200227-24672-1ryokob.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/317655/original/file-20200227-24672-1ryokob.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/317655/original/file-20200227-24672-1ryokob.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/317655/original/file-20200227-24672-1ryokob.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/317655/original/file-20200227-24672-1ryokob.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">An artificial ear fabricated by a 3D printer: from medical imaging to the creation of a customized scaffold made of biomaterial and cells.</span>
<span class="attribution"><a class="source" href="https://research.usask.ca/our-impact/highlights/images-of-research/gallery/2018/lets-create-an-artificial-organ-with-cells.php">(Saman Naghieh)</a>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Researchers are going towards the <a href="https://doi.org/10.1016/j.pneurobio.2018.07.002">implementation of 3D-printed structures</a> for patients who suffer from nerve injuries as well as other injuries.</p>
<p>After the fabricated alginate structure is implanted in a patient, the big question is if it have enough mechanical stability to tolerate the forces applied by tissues in the body. We developed a <a href="https://doi.org/10.1016/j.jmbbm.2018.01.034">novel numerical model</a> to predict the mechanical behaviour of alginate structures. </p>
<p>Our studies will help to understand cell response, which is the main factor to take into account when evaluating the success of the alginate structures.</p><img src="https://counter.theconversation.com/content/132491/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Saman Naghieh works for the University of Saskatchewan. </span></em></p>Printing organs could reduce the need for human donor organs. And 3D printed organs using a patient’s own cells would increase successful organ transplants by reducing the risk of rejection.Saman Naghieh, Design Engineer & Research Assistant, University of SaskatchewanLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1572112021-03-17T15:18:09Z2021-03-17T15:18:09ZWe grew human tear glands in the lab, and now we’re making them cry<p>Most organs in the adult human body are capable of regeneration, which means they renew their cells to keep the tissue healthy and functional. This capacity is enabled by <a href="https://stemcells.nih.gov/info/2001report/chapter4.htm">adult stem cells</a>, which are present in most organs and divide to create new cells that replace older, damaged ones.</p>
<p>It turns out these stem cells can be <a href="https://www.ibiology.org/development-and-stem-cells/organoids/">isolated and grown in the lab</a>. When we do this, the stem cells form tiny replicants of the organs from which they were extracted, which we call “organoids”.</p>
<p>Alongside our colleague Yorick Post, who recently moved from Utrecht to the Silicon Valley commercial sector, we’ve produced a <a href="https://www.cell.com/cell-stem-cell/fulltext/S1934-5909(21)00075-8">human tear gland organoid</a>, which we’ve been able to make cry organoid tears – not by being nasty, of course, but by subjecting the organoid to adrenaline, which is released in humans when they’re subjected to pain. By studying our organoid tears, we might be able to help develop treatments for dry eye disease, including by transplanting our organoids back into human patients.</p>
<h2>Mini organs</h2>
<p>Until recently, it was very difficult to study stem cells in the lab as they could not be cultured in a Petri dish. Then, in 2009, the perfect recipe was found to culture stem cells of the <a href="https://www.nature.com/articles/nature07935">intestine</a>, which grew into tiny replicates of the intestine: a mini organ. Because of this resemblance, we now call these <em>in vitro</em> models “organoids”.</p>
<p>Since then, most organs have been made in <a href="https://www.sciencedirect.com/topics/medicine-and-dentistry/organoid">organoid form</a>, used to study the physiology and illnesses associated with that particular tissue. More recently, organoids have been used to study how SARS-CoV2 affects different organs, finding that SARS-CoV2 could <a href="https://science.sciencemag.org/content/369/6499/50">infect the human intestine</a>, explaining why some patients with COVID-19 experienced diarrhoea.</p>
<figure class="align-center ">
<img alt="A blue-gloved hand holds a Petri dish" src="https://images.theconversation.com/files/389957/original/file-20210316-15-11vj82c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/389957/original/file-20210316-15-11vj82c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/389957/original/file-20210316-15-11vj82c.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/389957/original/file-20210316-15-11vj82c.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/389957/original/file-20210316-15-11vj82c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/389957/original/file-20210316-15-11vj82c.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/389957/original/file-20210316-15-11vj82c.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Dozens of organoids can be grown in small Petri dishes in our lab.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/male-hand-blue-rubber-gloves-holding-1149877898">arrideo/Shutterstock</a></span>
</figcaption>
</figure>
<p>With more and more organs being created as organoids in the lab, we searched for an organ that hadn’t been considered yet: the tear gland. The tear gland is actually a very important organ: it produces the tears that lubricate the eye and protect it from infections.</p>
<p>When the tear gland doesn’t function properly, people experience itchiness and pain, a disease known as “<a href="https://www.aerzteblatt.de/int/archive/article/167472">dry eye</a>”. This occurs in at least <a href="https://www.tfosdewsreport.org/index.php?lng=en">5% of the adult population</a> worldwide. Until now, studies of this disease were hindered by the lack of a good human tear gland model. We set out to establish one, by creating tear gland organoids.</p>
<h2>Gland designs</h2>
<p>To start an organoid culture, you need tissue directly from a patient. We obtained tear gland samples from the hospital and processed them into small pieces.</p>
<p>These pieces were placed in a droplet of gel, like a cushion. Importantly, this gel allows stem cells to grow in a three-dimensional environment, enabling them to organise into any shape. By stimulating the tear gland stem cells to divide, we made our culture grow. A few days later, we could actually see the first tear gland organoids in a dish, shaped like a sphere.</p>
<figure class="align-center ">
<img alt="The anatomy of a tear duct and tear gland" src="https://images.theconversation.com/files/389958/original/file-20210316-20-g881ir.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/389958/original/file-20210316-20-g881ir.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=435&fit=crop&dpr=1 600w, https://images.theconversation.com/files/389958/original/file-20210316-20-g881ir.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=435&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/389958/original/file-20210316-20-g881ir.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=435&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/389958/original/file-20210316-20-g881ir.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=547&fit=crop&dpr=1 754w, https://images.theconversation.com/files/389958/original/file-20210316-20-g881ir.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=547&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/389958/original/file-20210316-20-g881ir.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=547&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The human tear gland is located above the eye. The tear duct, here in pink, is on the inside edge of the eye.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-illustration/anatomy-drawing-showing-functioning-lacrimal-glands-97867913">Andrea Danti/Shutterstock</a></span>
</figcaption>
</figure>
<p>This was only the first step, as these tear gland organoids mostly contained stem cells. Tear gland stem cells are different from the mature cells that are present in the tear gland. Importantly, the stem cells themselves are not capable of making or shedding tears. </p>
<p>But tear gland stem cells do give rise to mature tear gland cells that are capable of crying. This process is called “<a href="https://www.sciencedirect.com/topics/neuroscience/cellular-differentiation">differentiation</a>”, and it takes place as soon as we stop stimulating stem cells to divide into other stem cells. We found it took at least seven days of culturing before our tear gland organoids could produce tears.</p>
<h2>Tearjerkers</h2>
<p>The final step in our experiments was to make our organoids cry. In humans, crying upon feeling pain is induced by stimuli <a href="https://pitjournal.unc.edu/article/animal-instincts-human-body-psychological-and-skeletal-muscular-analysis-adrenaline-human">such as adrenaline</a>. To recreate this process in a dish, we exposed our tear gland organoids to adrenaline. Adrenaline made our tear gland organoid spheres swell like balloons. The organoids were secreting their tears on the inside: crying, but with nowhere for their tears to go.</p>
<p>What can now be done with these tear gland organoids? First, scientists can use them to study how the tear gland works: how it makes tears, what kind of tears it can make and what happens when the tear gland does not produce tears anymore.</p>
<p>At present, people with dry eye disease must constantly apply eye drops to lubricate the ocular surface. With tear gland organoids, scientists can now screen for better, more effective medicines that could help treat dry eye disease. Tear gland organoids could even eventually be transplanted back into patients with dry eye. </p>
<p>This strategy is already being applied in a clinical trial with <a href="https://umcgresearch.org/-/stem-cell-transplants-should-prevent-a-dry-mouth-after-radiotherapy">salivary gland organoids</a>. Patients treated by radiotherapy following head and neck cancers often lose their salivary glands, resulting in dry mouth. It’s hoped that transplanted salivary gland organoids could treat this affliction.</p>
<p>One other tissue we have our eye on is the tear gland of a crocodile – which is <a href="https://www.frontiersin.org/articles/10.3389/fvets.2020.00574/full">remarkably similar to human tear glands</a>, but with some interesting differences. One day soon we may grow crocodile tear gland organoids in our lab, producing “crocodile tears” in the clinical environment of a Petri dish for the very first time.</p><img src="https://counter.theconversation.com/content/157211/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Hans Clevers is a co-founder and SAB member of Surrozen, a start-up in Silicon Valley, and an SAB member of Merus (Utrecht), Volastra (New York), Decibel (Boston), DImed Inc. (Shanghai), Xilis Inc. (North Carolina). He is non-executive board member of Roche (Basel) and board/SAB member of the Roche subsidiary Genentech (San Francisco). He is a scientific advisor for and investor in Life Sciences Partners, a biotech venture capital firm located in Amsterdam.</span></em></p><p class="fine-print"><em><span>Marie Bannier-Hélaouët does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Next, researchers want to grow the tear glands of a crocodile – seriously.Marie Bannier-Hélaouët, PhD Student, Hubrecht Institute, Utrecht UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1404012020-07-08T12:13:49Z2020-07-08T12:13:49ZWhy are scientists trying to manufacture organs in space?<figure><img src="https://images.theconversation.com/files/344682/original/file-20200630-155312-1d5klwq.jpg?ixlib=rb-1.1.0&rect=0%2C34%2C3790%2C2999&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">This Bioculture System will let biologists learn about how space impacts human health by studying cells grown in the microgravity environment of the International Space Station. </span> <span class="attribution"><a class="source" href="https://www.nasa.gov/sites/default/files/thumbnails/image/cell_science_bioculture_system_acd15-0175-038.jpg">NASA/Ames Research Center/Dominic Hart</a></span></figcaption></figure><p>Gravity can be a real downer when you are trying to grow organs.</p>
<p>That’s why experiments in space are so valuable. They have revealed a new perspective into biological sciences, including insights into making human tissues. </p>
<p>Gravity influences cellular behavior by impacting how protein and genes interact inside the cells, creating tissue that is <a href="https://www.mechanobio.info/development/what-is-cell-polarity/">polarized</a>, a fundamental step for natural organ development. Unfortunately, gravity is against us when we try to reproduce complex three dimensional tissues in the lab for medical transplantation. This is difficult because of the intrinsic limitations of bio-reactors used on Earth. </p>
<p>I am a stem cell biologist and interested on brain health and evolution. My lab studies how the human brain is formed inside the womb and how alterations in this process might have lifelong consequences to human behavior, such as in autism or schizophrenia. Part of that work includes growing brain cells in space.</p>
<h2>Growing tissue and organs in the lab</h2>
<p>To build organized tissues in the lab, scientists use scaffolds to provide a surface for cells to attach based on a predetermined rigid shape. For example, an artificial kidney needs a structure, or scaffold, of a certain shape for kidney cells to grow on. Indeed, this strategy helps the tissue to organize in the early stages but creates problems in the long run, such as eventual immune reactions to these synthetic scaffolds or inaccurate structures. </p>
<p>[<em>Deep knowledge, daily.</em> <a href="https://theconversation.com/us/newsletters/the-daily-3?utm_source=TCUS&utm_medium=inline-link&utm_campaign=newsletter-text&utm_content=deepknowledge">Sign up for The Conversation’s newsletter</a>.]</p>
<p>By contrast, in weightless conditions, cells can freely self-organize into their correct three-dimensional structure without the need for a scaffold substrate. By removing gravity from the equation, we researchers might learn new ways of building human tissues, such as cartilage and blood vessels that are scaffold-free, mimicking their natural cellular arrangement in an artificial setting. While this is not exactly what happens in the womb (after all the womb is also subject to gravity), weightless conditions does give us an advantage. </p>
<p>And this is precisely what is happening at the International Space Station.</p>
<p>These experiments help researchers optimize tissue growth for use in basic science, personalized medicine and organ transplantation.</p>
<p>But there are other reasons why we should manufacture organs in space. Long-term space missions create a series of physiological alterations in the body of astronauts. While some of these alterations are reversible with time, others are not, compromising future human spaceflights.</p>
<p>Studying astronauts’ bodies before and after their mission can reveal what goes wrong on their organs, but provides little insights on the mechanisms responsible for the observed alterations. Thus, growing human tissues in space can complement this type of investigation and reveal ways to counteract it.</p>
<p>Finally, all forms of life that we know about have evolved in the presence of microgravity. Without gravity, our brains might have evolved in a different trajectory, or our livers might not filter liquids as it does on Earth. </p>
<p>By recreating embryonic organ formation in space, we can anticipate how the human body in the womb would develop. There are several research initiatives going on in my lab with human brain organoids at ISS, designed to learn the impact of zero gravity on the developing human brain. These projects will have profound implications for future human colonization (can humans successfully reproduce in space?). These studies will also improve the generation of artificial organs that are used for testing drugs and treatments on Earth. Will better treatments for neurodevelopmental and neurodegenerative conditions that affects millions of people come from research in space?</p><img src="https://counter.theconversation.com/content/140401/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Alysson R. Muotri does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Why are scientists trying to grow organs at the International Space Station? People live on Earth not in zero-gravity. A stem cell expert explains why it is useful to do these experiments in space.Alysson R. Muotri, Professor of Pediatrics and Cellular and Molecular Medicine, University of California, San DiegoLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1337542020-03-26T17:17:58Z2020-03-26T17:17:58ZDuring the Second World War, BBC listeners kept calm and listened to an unlikely star<figure><img src="https://images.theconversation.com/files/322949/original/file-20200325-168903-1gxfxv7.jpg?ixlib=rb-1.1.0&rect=11%2C12%2C613%2C337&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">An image of the popular Sandy Macpherson from circa 1958. Macpherson played soothing music for BBC listeners during Second World War.</span> <span class="attribution"><a class="source" href="https://www.bbc.co.uk/programmes/p009y7yh">(BBC Programming)</a></span></figcaption></figure><p>In Britain, during the first weeks of the Second World War, public entertainment venues closed down. The blackout darkened the streets, and people stuck at home turned to radio as never before. They were seeking news but also diversion — a difficult balance for the BBC to achieve. Many hated what they heard. But the BBC had a seemingly unlikely star: Canadian-born Sandy Macpherson, the BBC’s resident theatre organist. </p>
<p>In September 1939, a listener wrote, “We should like to know if you keep Sandy Macpherson chained up in the dungeons of the BBC.” Indeed, at the end of the first month, Macpherson reported that he had been “on duty more or less continuously,” <a href="https://books.google.ca/books/about/Victory_Through_Harmony.html?id=5XgxJJ4OnwYC&redir_esc=y">having broadcast at least 50 times.</a> </p>
<p>But why? After Britain declared war on Germany on Sept. 1, 1939, the BBC, like the rest of the country, was in emergency mode. It sent its music and entertainment departments outside of London and had to get government clearance for any non-staff entertainers. It shut down its nascent television service and <a href="https://books.google.ca/books?id=6mOotAEACAAJ&dq=briggs+bbc+war+of+words&hl=en&sa=X&ved=0ahUKEwikntbisLPoAhUlUt8KHVLdB34Q6AEIJzAA">reduced radio to a single wavelength</a>. It stopped broadcasting sporting events. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/IKkMNQ21eSQ?wmode=transparent&start=77" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">A clip of Sandy Macpherson from 1939.</span></figcaption>
</figure>
<p>What listeners got was news, announcements, lots of gramophone records and live music <a href="https://books.google.ca/books/about/Victory_Through_Harmony.html?id=5XgxJJ4OnwYC&redir_esc=y">played by a limited pool of staff musicians, including Macpherson</a>. </p>
<p>Had German <a href="https://www.britannica.com/event/the-Blitz">air raids</a> begun immediately, everyone would have understood that it was unrealistic to expect lavish entertainment in an emergency. But instead, listeners at home were anxious and bored and unimpressed by the BBC. Both MPs and critics condemned its lacklustre programming. For some critics, like W.R. Anderson of the <em>Musical Times</em>, Macpherson was part of the problem.</p>
<p>But not everyone agreed. This was not the sort of “fine music” that highbrows like Anderson wanted, but it was extremely popular. Listeners sent thousands of appreciative letters to Macpherson and defended him in the <em>Radio Times</em>, the BBC’s program guide. When one listener complained that he always played the same tunes, another urged him to “continue to fire away with Handel’s ‘Largo,’ ‘the Holy City,’ and ‘The Lost Chord.’” </p>
<h2>History of theatre organists</h2>
<p>Today, we usually associate theatre organs with silent films, but in the United Kingdom they remained popular well into the 1940s — in cinemas, at dance halls and especially on the radio. Starting in the 1920s, the BBC featured theatre organists from cinemas around the country. By the mid-1930s, the broadcasts <a href="https://genome.ch.bbc.co.uk">became an almost daily feature.</a> In 1936, the BBC <a href="http://www.iupress.indiana.edu/product_info.php?products_id=810593">purchased a £8,000 Compton organ and hired its first resident theatre organist, Reginald Foort</a> — chosen from a pool of <a href="https://www.goodreads.com/book/show/2633579-behold-the-mighty-wurlitzer">350 applicants</a>. The <em>London Times</em> reported that theatre organs were the <a href="https://www.thetimes.co.uk/archive/article/1936-02-12/12/5.html?region=global#start%3D1785-01-01%26end%3D1985-12-31%26terms%3Dtheatre%20organ%20for%20b.b.c%26back%3D/tto/archive/find/theatre+organ+for+b.b.c/w:1785-01-01%7E1985-12-31/1%26next%3D/tto/archive/frame/goto/theatre+organ+for+b.b.c/w:1785-01-01%7E1985-12-31/2">most popular form of entertainment on the BBC.</a> </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/qsq1UFHoAbQ?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Reginald Foort, the BBC’s first resident theatre organist in 1936.</span></figcaption>
</figure>
<p>Theatre organs were spectacular technological marvels, <a href="https://www.youtube.com/watch?v=qsq1UFHoAbQ">loaded with special effects</a>. The people who played them became stars. Many theatre organists were virtuosi and arranged their own music. When they played on the BBC, theatre organists went from local celebrities with their names on cinema marquees to national stars. Fans collected their autographs and they sold millions of records. </p>
<p>A theatre organist became popular, not just through musicianship, but through their personality. The goal was to sound friendly and conversational. When the BBC hired Macpherson in November 1938, head of BBC Variety <a href="http://www.iupress.indiana.edu/product_info.php?products_id=810593">John Watt wrote</a>: </p>
<blockquote>
<p>“He has a good personality, simple and straightforward … if he turns out right, we shall have a very good personality there.” </p>
</blockquote>
<h2>A reassuring, relatable friend: liked a pint of beer</h2>
<p>Macpherson came into his own during the early months of the war, a period — called the “Bore War” — of intense anxiety when nothing seemed to happen.</p>
<figure class="align-left zoomable">
<a href="https://images.theconversation.com/files/322658/original/file-20200324-155640-18f25xj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/322658/original/file-20200324-155640-18f25xj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/322658/original/file-20200324-155640-18f25xj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=872&fit=crop&dpr=1 600w, https://images.theconversation.com/files/322658/original/file-20200324-155640-18f25xj.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=872&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/322658/original/file-20200324-155640-18f25xj.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=872&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/322658/original/file-20200324-155640-18f25xj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1096&fit=crop&dpr=1 754w, https://images.theconversation.com/files/322658/original/file-20200324-155640-18f25xj.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1096&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/322658/original/file-20200324-155640-18f25xj.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1096&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The Keep Calm And Carry On motivational poster created by the British government in 1939 was not widely used until the original copy was found in 2000.</span>
<span class="attribution"><span class="source">(Barter Books)</span></span>
</figcaption>
</figure>
<p>Sandy, as listeners called him, spoke like a reassuring, relatable friend. “Sandy Macpherson’s quiet voice is very reassuring at a time when our ears are on the alert for warning sirens,” one family wrote in September 1939. At Christmas, fans showered him with “flowers, mufflers, handkerchiefs, cigarettes, fruit and pots of jam.” </p>
<p>Building on his role, Macpherson started hosting “Sandy Calling” in February 1940. It was a series designed to connect military forces with their families at home. Listeners could write in with a song request and a message for a loved one — and they did so by the thousands. Macpherson even invited senders into the studio to speak for themselves. Eventually, there would be a “Sandy Calling” for Canada, the Middle East and India. </p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/322962/original/file-20200325-168912-1s0cotp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/322962/original/file-20200325-168912-1s0cotp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/322962/original/file-20200325-168912-1s0cotp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=905&fit=crop&dpr=1 600w, https://images.theconversation.com/files/322962/original/file-20200325-168912-1s0cotp.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=905&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/322962/original/file-20200325-168912-1s0cotp.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=905&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/322962/original/file-20200325-168912-1s0cotp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1138&fit=crop&dpr=1 754w, https://images.theconversation.com/files/322962/original/file-20200325-168912-1s0cotp.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1138&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/322962/original/file-20200325-168912-1s0cotp.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1138&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Victory through Harmony: The BBC and Popular Music in the Second World War by Christina L. Baade.</span>
<span class="attribution"><span class="source">(Oxford University Press)</span></span>
</figcaption>
</figure>
<p>Macpherson was at home when a bomb hit the BBC’s St. George’s Hall, destroying the organ and much of his music in September 1940, during the height of the London Blitz. The BBC moved his broadcasting operations to Wales in semi-secrecy, waiting several months to announce the loss.</p>
<p>Throughout the war, the press highlighted Macpherson’s kindness and ordinariness, helped by Canadian stereotypes. He was a “lanky, genial Canadian,” who had “once worked in a lumber camp” and liked “a pint of beer,” wrote the <em>Empire News.</em> The <em>Sunday Pictorial</em> called him “radio’s most human personality” and “probably the BBC’s best contribution to the war so far.” </p>
<h2>During pandemic, listeners searching for comfort</h2>
<p>With social distancing and concern about COVID-19, we are turning to the media for news, but also entertainment and comfort. Musicians, arts organisations, public libraries and media corporations <a href="https://slate.com/culture/2020/03/coronavirus-free-scholastic-met-opera-pbs-ken-burns-baseball-frozen-skywalker-disney-discwoman-dropkick-murphys.html">are responding with creativity and generosity</a>. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/322664/original/file-20200324-155666-1bln60s.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/322664/original/file-20200324-155666-1bln60s.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=257&fit=crop&dpr=1 600w, https://images.theconversation.com/files/322664/original/file-20200324-155666-1bln60s.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=257&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/322664/original/file-20200324-155666-1bln60s.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=257&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/322664/original/file-20200324-155666-1bln60s.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=323&fit=crop&dpr=1 754w, https://images.theconversation.com/files/322664/original/file-20200324-155666-1bln60s.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=323&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/322664/original/file-20200324-155666-1bln60s.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=323&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A scene from Carmen. The Metropolitan Opera House is streaming their shows nightly.</span>
<span class="attribution"><a class="source" href="https://www.metopera.org/user-information/nightly-met-opera-streams/">(Metropolitan Opera)</a></span>
</figcaption>
</figure>
<p>We have so many more choices than Macpherson’s Second World War listeners, but the question of what homebound listeners need and want remains.</p>
<p>The Metropolitan Opera is now <a href="https://slate.com/culture/2020/03/coronavirus-spikes-demand-for-the-mets-streaming-opera-broadcasts.html">streaming for free</a>, as are orchestras, chamber groups and <a href="https://www.wkar.org/post/list-live-streaming-concerts#stream/0">soloists around the world</a>. Classical music lovers and newbies have an exciting opportunity to explore the genre in new ways. </p>
<p>But many people may find themselves turning to familiar pop and lighter entertainment that brings comfort and escape, just as Sandy Macpherson’s listeners did during the Second World War.</p><img src="https://counter.theconversation.com/content/133754/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Christina Baade receives funding from the Canadian Social Sciences and Humanities Research Council. </span></em></p>During the Second World War, anxious but also bored BBC listeners found comfort in the soothing sounds of Sandy Macpherson, Canadian-born organist.Christina Baade, Professor in Communication Studies, McMaster UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1282172020-03-03T19:05:00Z2020-03-03T19:05:00ZCurious Kids: why can some organs regenerate while others can’t?<figure><img src="https://images.theconversation.com/files/315211/original/file-20200213-10980-116rgp5.jpg?ixlib=rb-1.1.0&rect=9%2C0%2C6480%2C3989&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-illustration/cells-under-microscope-research-stem-cellular-1086033461"> Shutterstock</a></span></figcaption></figure><blockquote>
<p><strong>“I would like to know why organs like your liver and brain can regenerate while others can’t?” – Maggie, age 9, Melbourne</strong></p>
</blockquote>
<p><a href="https://theconversation.com/au/topics/curious-kids-36782"><img src="https://images.theconversation.com/files/291898/original/file-20190911-190031-enlxbk.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=90&fit=crop&dpr=1" width="100%"></a></p>
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<p>This is a great question Maggie. Scientists have actually been trying to answer this question for a long time. The good news is after many years of research we now have a good idea of how this works.</p>
<h2>What are cells?</h2>
<p>As you may know, the body is made of cells. We sometimes call these cells “the building blocks of life”. Nature builds all the parts of our bodies with cells. </p>
<p>In other words, you might have played with Lego before. Cells are like pieces of Lego! Just like Lego blocks do, cells come in lots of shapes and colours. Cells can also do lots of different things.</p>
<p>Your skin is made of different cells. Some of them make your hair, and some make your scars when you get a cut, for example.</p>
<p>Even your blood is made of many different cells. The red blood cells give your blood its red colour.</p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/curious-kids-why-dont-burns-bleed-130792">Curious Kids: why don't burns bleed?</a>
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</em>
</p>
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<p>So going back to your question, some cells in our body are very special because they can multiply. Not only that, these special cells can turn into other cells as well. The name of these special cells is “stem cells”, and they are the key to our organs regenerating.</p>
<p>Imagine if your Lego blocks could do that!</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/315215/original/file-20200213-10980-yxkg1n.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/315215/original/file-20200213-10980-yxkg1n.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=505&fit=crop&dpr=1 600w, https://images.theconversation.com/files/315215/original/file-20200213-10980-yxkg1n.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=505&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/315215/original/file-20200213-10980-yxkg1n.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=505&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/315215/original/file-20200213-10980-yxkg1n.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=635&fit=crop&dpr=1 754w, https://images.theconversation.com/files/315215/original/file-20200213-10980-yxkg1n.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=635&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/315215/original/file-20200213-10980-yxkg1n.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=635&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Our liver and skin are better at repairing themselves than our brains.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-illustration/human-body-internal-organs-stomach-lungs-1519743437">Shutterstock</a></span>
</figcaption>
</figure>
<h2>Which organs can regenerate themselves?</h2>
<p>Maggie, you’re very clever at nine to know what “regeneration” means, but in case some other young readers don’t, regeneration is when our organs fix themselves after they’ve been damaged. Our organs might have been damaged if we get injured or we’re very sick.</p>
<p>Organs like our skin (yes, the skin is the biggest organ of the body!) need to regenerate often. The skin’s stem cells produce new cells when the old ones are lost, like when we get a paper cut.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/curious-kids-why-do-we-have-two-kidneys-when-we-can-live-with-only-one-113201">Curious Kids: why do we have two kidneys when we can live with only one?</a>
</strong>
</em>
</p>
<hr>
<p>Our livers are very good at regenerating themselves because they too can make new cells. The cells of the liver are called “hepatocytes”. Hepatocytes start to multiply when the liver is damaged. So hepatocytes work like stem cells.</p>
<p>Intestines are another good example of an organ which regenerates itself. Our intestines regenerate all the time, even when we’re healthy. They lose cells when we digest food, but the stem cells in the intestines multiply to keep this important organ working well.</p>
<h2>Which organs aren’t very good at regenerating?</h2>
<p>The brain actually can’t regenerate itself well because when the brain is damaged its cells find it harder to make new ones. This is because the brain has very few of the special cells, or stem cells.</p>
<p>In recent years, we’ve found some areas of the brain can regenerate. But we still need to do more research to better understand how this works.</p>
<p>We do know the brain is better at regenerating itself when we are young than when we are old.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/curious-kids-how-does-our-brain-send-signals-to-our-body-124950">Curious Kids: how does our brain send signals to our body?</a>
</strong>
</em>
</p>
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<p><em>Hello, curious kids! Have you got a question you’d like an expert to answer? Ask an adult to send your question to curiouskids@theconversation.edu.au.</em></p><img src="https://counter.theconversation.com/content/128217/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jose Polo is a founder of Mogrify. He is an ARC future fellow and receives funding from the NHMRC.</span></em></p>Our bodies are made up of cells that multiply to repair our organs. But organs like our liver and skin are better at regeneration than our brain.Jose Polo, ARC Future Fellow, Anatomy & Developmental Biology, Monash UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1186032019-08-30T02:17:30Z2019-08-30T02:17:30ZCurious Kids: how do wounds heal?<figure><img src="https://images.theconversation.com/files/278847/original/file-20190611-32373-17h8wdw.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C5742%2C3837&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">When you have a wound, your body gets to work straight away to clean it out, kill germs and repair the skin. </span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/pleasant-nice-girl-holding-her-knee-628311236?studio=1">Shutterstock/Yakobchuk Viacheslav</a></span></figcaption></figure><figure class="align-left ">
<img alt="" src="https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=293&fit=crop&dpr=1 600w, https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=293&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=293&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=368&fit=crop&dpr=1 754w, https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=368&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=368&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<p><em>If you have a question you’d like an expert to answer, send it to curiouskids@theconversation.edu.au.</em> </p>
<hr>
<blockquote>
<p><strong>I would like to know how wounds heal. – Simon, age 7.</strong></p>
</blockquote>
<hr>
<p>Thank you for this excellent question, Simon. To explain how the body heals a break in the skin, I first need to explain a bit about how skin works. </p>
<p>Did you know the skin is the largest organ in the body? It has three layers that protect us from germs and help our body keep the right temperature. For example, when our body gets too hot, we have sweat glands in the skin that release salty water to cool us down (it’s like air conditioning in our bodies). Our skin also has a lot of sensors so we can touch and feel hot and cold.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/curious-kids-how-does-our-blood-fight-viruses-like-chicken-pox-and-colds-119394">Curious Kids: how does our blood fight viruses like chicken pox and colds?</a>
</strong>
</em>
</p>
<hr>
<h2>Plugging the wound</h2>
<p>Once we get a wound, the first thing the body tries to do is stop the bleeding. </p>
<p>Within minutes or even seconds, tiny things in your blood called “blood cells” start to group together, protecting and plugging up the wound to stop any more bleeding. A scab will start to form. </p>
<p>The body tries to plug up the wound as quick as it can. It wants to stop germs getting in through broken skin and making you really sick. But even as this happens, the wound may let out a bit of clear fluid that helps to clean the wound.</p>
<p>Your doctor may also decide to close your wound with stitches, special glue or staples to keep the skin together until the body has built new skin to heal.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/281076/original/file-20190625-81754-du1xsq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/281076/original/file-20190625-81754-du1xsq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/281076/original/file-20190625-81754-du1xsq.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/281076/original/file-20190625-81754-du1xsq.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/281076/original/file-20190625-81754-du1xsq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/281076/original/file-20190625-81754-du1xsq.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/281076/original/file-20190625-81754-du1xsq.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Scabs help keep germs out.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/download/confirm/450987034?studio=1&size=huge_jpg">Shutterstock</a></span>
</figcaption>
</figure>
<h2>Behind the scenes</h2>
<p>Under the skin, your body is hard at work cleaning and fixing. </p>
<p>The wound may be swollen, red and painful. Doctors call this “inflammation”. Swelling like this means the body is sending more fluid, oxygen and blood cells to the wound to get to work fixing it. </p>
<p>In your blood there are special “soldier” cells in charge of fighting germs. They are called white blood cells, and as soon as you get a cut, your body will send a lot of white blood cells to the wound to get to work. They eat any germs that may have come in when your skin was broken and they also guide the healing process. </p>
<p>The blood cells in the body then work to start building new skin, layer by layer. One thing they do is tell the body to start producing more of a chemical called “collagen” which helps the skin form new layers.</p>
<p>It usually takes a few days for a wound to heal fully, but it sometimes takes much longer. If you get a really big wound, you might get a scar. A scar is also made out of collagen. It is a mark on your skin. Sometimes they stay there forever, and sometimes they disappear or get lighter over time. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/281069/original/file-20190625-81737-1f1zox7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/281069/original/file-20190625-81737-1f1zox7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=211&fit=crop&dpr=1 600w, https://images.theconversation.com/files/281069/original/file-20190625-81737-1f1zox7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=211&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/281069/original/file-20190625-81737-1f1zox7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=211&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/281069/original/file-20190625-81737-1f1zox7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=265&fit=crop&dpr=1 754w, https://images.theconversation.com/files/281069/original/file-20190625-81737-1f1zox7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=265&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/281069/original/file-20190625-81737-1f1zox7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=265&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">White blood cells will eat any germs that may have come in when your skin was broken.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/search/blood+cells+wound+skin?search_source=base_landing_page">Shutterstock</a></span>
</figcaption>
</figure>
<h2>How to help your body fix a wound</h2>
<p>It is important to keep the wound clean, damp and covered to help it heal quicker. Wounds that are left uncovered are likely to dry out and are not protected from other injuries.</p>
<p>If your wound creates a scab, it might get really itchy. But try not to scratch! Your skin is busy healing underneath. Just let it fall off on its own. Band-aids are perfect to protect small wounds from further injury.</p>
<p>You should eat healthy food to help fuel your body while it fixes itself. Your body needs protein (like meat, milk and cheese), carbohydrates (like bread and pasta) and vitamins (like oranges, carrots and spinach). </p>
<p>These foods supply energy for healing your wound, and help your immune system fight germs.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/curious-kids-why-do-we-have-two-kidneys-when-we-can-live-with-only-one-113201">Curious Kids: why do we have two kidneys when we can live with only one?</a>
</strong>
</em>
</p>
<hr>
<p><em>Hello, curious kids! Have you got a question you’d like an expert to answer? Ask an adult to send your question to curiouskids@theconversation.edu.au</em></p>
<figure class="align-left ">
<img alt="" src="https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=376&fit=crop&dpr=1 600w, https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=376&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=376&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=472&fit=crop&dpr=1 754w, https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=472&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=472&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="attribution"><a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
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<p><em>Please tell us your name, age and which city you live in. We won’t be able to answer every question but we will do our best.</em></p><img src="https://counter.theconversation.com/content/118603/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Christina Parker is a member of Wounds Australia and is the secretary for the QLD committee. </span></em></p><p class="fine-print"><em><span>Helen Edwards receives funding from research grants, including government grants, philanthropic foundation grants and NHMRC grants for wound research. She is a member of Wounds Australia, Fellow, College of Nursing Australia, Fellow, Sigma Theta Tau International and has an Order of Australia Medal.</span></em></p><p class="fine-print"><em><span>Kathleen Finlayson receives funding from government grants, philanthropic foundation grants and NHMRC grants for wound research. She is a member and volunteer for Wounds Australia, the Australian Nursing Council, and Sigma Theta Tau International.
</span></em></p>The body tries to plug a wound quickly to stop germs getting in through broken skin and making you sick. But behind the scenes, your blood is working hard to repair a wound.Christina Parker, Senior Lecturer, Queensland University of TechnologyHelen Edwards, Professor, Queensland University of TechnologyKathleen Finlayson, Lecturer, Queensland University of TechnologyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1177472019-08-06T20:07:46Z2019-08-06T20:07:46ZCurious Kids: why is urine yellow?<figure><img src="https://images.theconversation.com/files/286166/original/file-20190730-43153-osy3ym.jpg?ixlib=rb-1.1.0&rect=11%2C7%2C2486%2C1699&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">If you have been drinking more water than your body needs, the body tells the kidney filters to get rid of the spare water. That's when your urine will look paler.</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><figure class="align-left ">
<img alt="" src="https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=293&fit=crop&dpr=1 600w, https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=293&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=293&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=368&fit=crop&dpr=1 754w, https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=368&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=368&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<p><em>If you have a question you’d like an expert to answer, send it to curiouskids@theconversation.edu.au.</em> </p>
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<blockquote>
<p><strong>Why is urine yellow? – Ronan, aged 9, Greenslopes, Brisbane.</strong> </p>
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<hr>
<p>Thank you for your question, Ronan. </p>
<p>Our bodies use nutrients from the food we eat. But the processes involved in digestion also create what we call “byproducts”. That’s where a new chemical is created along the way. </p>
<p>Some of these byproducts in the body are waste and our bodies have clever waste processing systems to get rid of them. </p>
<p>Some of the waste goes out in your poo. And waste that can be dissolved in water goes out in your wee. We call this “water-soluble” waste. Water-soluble means it can be dissolved in water. </p>
<p>And the parts of your body in charge of “making” the wee are called the kidneys. They’re shaped like kidney beans.</p>
<h2>A delicate balance</h2>
<p>The kidneys work around the clock to make sure the body has the right balance of water, salt and chemicals and not too much water-soluble waste in it. </p>
<p>Kidneys have special filters in them that help sort out the useful bits from the waste. They also are in charge of transporting the water-soluble waste from your kidneys, down two special pipes called “ureters” and into your bladder (which is down near the genitals). </p>
<p>When the bladder gets full, it sends a message along your nerves to your brain that makes you feel like you need to wee. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/286168/original/file-20190730-43118-jirbhy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/286168/original/file-20190730-43118-jirbhy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/286168/original/file-20190730-43118-jirbhy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/286168/original/file-20190730-43118-jirbhy.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/286168/original/file-20190730-43118-jirbhy.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/286168/original/file-20190730-43118-jirbhy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/286168/original/file-20190730-43118-jirbhy.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/286168/original/file-20190730-43118-jirbhy.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">Kidneys also are in charge of transporting the water-soluble waste from your kidneys, down two special pipes called ‘ureters’ and into your bladder.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/curious-kids-why-do-we-have-two-kidneys-when-we-can-live-with-only-one-113201">Curious Kids: why do we have two kidneys when we can live with only one?</a>
</strong>
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</p>
<hr>
<h2>So…. why is it yellow?</h2>
<p>One of the water-soluble waste products that your kidneys put into your urine is a chemical called urobilin, and it is yellow. </p>
<p>The colour of your urine depends on how much urobilin is in it and how much water is in it. </p>
<p>If your urine is light yellow, it means you have been drinking a lot of water and there’s a lot of water in your urine. We call this being “hydrated”.</p>
<p>If your urine is dark yellow, that means there’s less water, and a relatively high amount of urobilin. It probably means you haven’t been drinking enough water and could be dehydrated.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/286167/original/file-20190730-43126-18hz1l7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/286167/original/file-20190730-43126-18hz1l7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/286167/original/file-20190730-43126-18hz1l7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=457&fit=crop&dpr=1 600w, https://images.theconversation.com/files/286167/original/file-20190730-43126-18hz1l7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=457&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/286167/original/file-20190730-43126-18hz1l7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=457&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/286167/original/file-20190730-43126-18hz1l7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=574&fit=crop&dpr=1 754w, https://images.theconversation.com/files/286167/original/file-20190730-43126-18hz1l7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=574&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/286167/original/file-20190730-43126-18hz1l7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=574&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">If your urine is light yellow, it means you have been drinking a lot of water.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
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</figure>
<h2>Too much water versus not enough</h2>
<p>When you haven’t been drinking enough water, the kidneys get a message from your brain to try to keep more water in your body (and out of your bladder). You will also start to feel thirsty. </p>
<p>If people can’t drink water (because they have a vomiting illness, for example), they might need water put directly into their blood. This usually happens in a hospital using a drip (which is where a bag of salt water is put into your blood via a needle in your arm).</p>
<p>If you have been drinking more water than your body needs, the body tells the kidney filters to get rid of the spare water. That’s when your urine will look paler.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/curious-kids-what-is-a-headache-is-it-our-brain-hurting-112951">Curious Kids: what is a headache? Is it our brain hurting?</a>
</strong>
</em>
</p>
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<p><em>Hello, curious kids! Have you got a question you’d like an expert to answer? Ask an adult to send your question to curiouskids@theconversation.edu.au</em></p><img src="https://counter.theconversation.com/content/117747/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Dr Jaqui Hughes is a Torres Strait Islander woman, a specialist physician (kidney doctor) at Royal Darwin Hospital, and a kidney health researcher at Menzies School of Health Research in Darwin. She is employed by the Top End Health Service as a specialist nephrologist, and funded by the National Health and Medical Research Council to lead innovating kidney health research which advances health for Australians.</span></em></p>One of the waste products that your kidneys put into your urine is a chemical called urobilin, and it is yellow.Jaquelyne Hughes, Research Fellow, Menzies School of Health ResearchLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1212282019-08-02T10:27:27Z2019-08-02T10:27:27ZHuman-animal hybrids are coming and could be used to grow organs for transplant – a philosopher weighs in<figure><img src="https://images.theconversation.com/files/286640/original/file-20190801-169688-1mprhc2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Pigs growing human pancreases, coming to a farm near you soon?</span> <span class="attribution"><span class="source">shutterstock</span></span></figcaption></figure><p>Around the world thousands of people are on organ donor waiting lists. While some of those people will receive the <a href="http://www.transplant-observatory.org/">organ transplants</a> they need in time, the sad reality is that many will die waiting. But controversial new research may provide a way to address this crisis.</p>
<p>Japan has recently overturned its ban on the creation of human-animal hybrids, or “chimeras”, and <a href="https://www.nature.com/articles/d41586-019-02275-3">approved a request by researchers from the University of Tokyo</a> to create a <a href="https://theconversation.com/whats-the-benefit-in-making-human-animal-hybrids-72179">human-mouse hybrid</a>.</p>
<p>Scientists will attempt to grow a human pancreas inside a mouse, using a certain kind of stem cell known as “induced pluripotent stem cells”. These are cells that can grow into almost any kind of cell. The stem cells will be injected into a mouse embryo, which has been genetically modified to be incapable of producing a pancreas using its own cells. This hybrid embryo is then implanted in a mouse surrogate and allowed to grow. The goal is to eventually grow a human pancreas in a larger animal – such as a pig – which can be transplanted into a human.</p>
<p><a href="https://theconversation.com/human-pig-chimeras-may-provide-vital-transplant-organs-but-they-raise-ethical-dilemmas-60648">Human-animal hybrids</a> have been created in both the US and UK, but <a href="https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/491496/Animals_Containing_Human_Material_Final_Guidance.pdf">regulations</a> require the embryo to be destroyed usually by 14 days. The new Japanese regulations allow for the embryo to be implanted in a surrogate uterus, and eventually, to be born as a mouse with a “human” pancreas. The mice will then be monitored for up to two years, to see where the human cells travel and how the mice develop.</p>
<h2>Ethical issues</h2>
<p>The idea of <a href="https://theconversation.com/how-long-before-we-can-transplant-an-animals-heart-in-a-human-57701">human-animal hybrids</a> can raise a lot of questions and it’s easy to feel they are “unnatural” because they violate the boundaries between species. But the boundary between species is often fluid, and we don’t seem to have the same reaction to animal hybrids like mules, or the many kinds of plant hybrids humans have produced.</p>
<p><a href="https://www.tandfonline.com/doi/abs/10.1162/15265160360706417">Philosophers</a> believe that negative reactions to human-animal hybrids might be based on our need to have a <a href="https://theconversation.com/wary-of-human-animal-hybrids-its-probably-just-your-own-moral-superiority-72720">clear boundary</a> between things that are “human” and things that are not. This distinction grounds many of our social practices involving animals, and so threatening this boundary could create moral confusion. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/how-much-should-you-be-told-about-your-organ-donor-35118">How much should you be told about your organ donor?</a>
</strong>
</em>
</p>
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<p>Some might feel that human-animal hybrids are a threat to human dignity. But it’s difficult to specify what this claim really amounts to. A stronger objection is the idea that a human-animal hybrid may acquire human characteristics, and as a result, be entitled to human level moral consideration. </p>
<p>If, for example, the injected human stem cells travel to the mouse’s brain, it could develop enhanced cognitive capacities compared to a normal mouse. And on that basis, it may be entitled to a <a href="https://fewd.univie.ac.at/fileadmin/user_upload/inst_ethik_wiss_dialog/Singer__P._2009._Speciesism_and_Moral_Status_44245648.pdf">much higher moral status</a> than a mouse would normally be granted – and possibly make it unethical for use in scientific experimentation.</p>
<h2>Moral status</h2>
<p>Moral status tells us whose interests count, from a moral point of view. Most people would say human beings have full moral status, as do babies, fetuses and the severely disabled, which means we must consider their interests. More controversially, some people also believe that non-human animals – such as <a href="https://www.nonhumanrights.org/blog/cecilia-chimpanzee-legal-person/">chimpanzees</a> or <a href="https://harvardmagazine.com/2007/05/the-moral-status-of-the.html">human embryos</a> – possess a degree of moral status approaching that of human beings. </p>
<p>But pinning down what characteristics confer moral status can be tricky. <a href="https://plato.stanford.edu/entries/grounds-moral-status/#SpecRela">Various criteria have been suggested</a>, including the ability to reason, have self-awareness, the ability to form relationships with others, the capacity for suffering, or simply being a part of the human species. But each of these criteria ends up including some groups who don’t have moral status, or excluding some who do.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/286644/original/file-20190801-169692-1er7dbo.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/286644/original/file-20190801-169692-1er7dbo.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=391&fit=crop&dpr=1 600w, https://images.theconversation.com/files/286644/original/file-20190801-169692-1er7dbo.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=391&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/286644/original/file-20190801-169692-1er7dbo.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=391&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/286644/original/file-20190801-169692-1er7dbo.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=491&fit=crop&dpr=1 754w, https://images.theconversation.com/files/286644/original/file-20190801-169692-1er7dbo.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=491&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/286644/original/file-20190801-169692-1er7dbo.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=491&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A human-animal chimera contains a mixture of human cells and animals cells.</span>
<span class="attribution"><span class="source">Pexels</span></span>
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</figure>
<p>The idea that non-human animals might have sufficient moral status for it to be morally wrong to kill them for food, or use for medical research, has gained significant traction in the philosophical community. Similarly, veganism has grown massively worldwide. There’s been a <a href="https://www.reportbuyer.com/product/4959853/top-trends-in-prepared-foods-2017-exploring-trends-in-meat-fish-and-seafood-pasta-noodles-and-rice-prepared-meals-savory-deli-food-soup-and-meat-substitutes.html">600% increase in people identifying as vegan</a> in the US in just the last three years. While in the UK the number of vegans has risen from <a href="https://www.vegansociety.com/news/media/statistics">150,000 in 2014 to 600,000 in 2018</a>, which suggests people are increasingly willing to take the <a href="https://theconversation.com/vegan-diet-how-your-body-changes-from-day-one-100413">interests of animals</a> seriously.</p>
<p>From a philosophical perspective using non-human animals for food or medical research is unethical because it significantly harms the animal, while providing only a small or insignificant benefit to us. But even those who believe that non-human animals have moral status would likely support sacrificing the life of a non-human animal to save the life of a human – as would be the case in human-animal organ donation. This is because a human can value its life in complex ways that a non-human animal cannot. </p>
<p>But if human-animal hybrids become more like us than non-human animals, it could then be argued that it’s unethical to produce a hybrid simply for the purposes of extracting its organs. That is, harvesting the organs of a non-consenting human-animal hybrid could be morally equivalent to <a href="https://theconversation.com/organ-trafficking-a-protected-crime-16178">harvesting the organs</a> of a non-consenting human. </p>
<p>Of course, for this argument to work, there would need to be strong reasons for thinking not only that a human-animal hybrid has moral status, but that its life has equal moral value to that of a human. And even if a mouse-human hybrid did have a “human-like” brain, it is exceedingly unlikely that it would be human enough to merit equal moral consideration. </p>
<p>So given that this process has the potential to successfully resolve the perpetual lack of organs for transplant, it’s reasonable to think that the use of human-animal hybrids is the right thing to do to <a href="https://theconversation.com/pig-implants-could-deliver-insulin-to-people-with-diabetes-19178">help save human lives</a> – even if it does require some level of animal suffering.</p><img src="https://counter.theconversation.com/content/121228/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Mackenzie Graham does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>The idea of human-animal hybrids can raise a lot of questions and it’s easy to feel they are “unnatural” because they violate the boundaries between species.Mackenzie Graham, Research Fellow of Philosophy, University of OxfordLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1195212019-07-14T19:02:58Z2019-07-14T19:02:58ZWhich body organs are most at risk during a heat wave?<figure><img src="https://images.theconversation.com/files/281862/original/file-20190629-94716-4geooc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">file rc jnf</span> </figcaption></figure><p>In June 2019, much of Europe was struck by early heatwave, with temperatures reaching nearly <a href="https://www.nytimes.com/2019/06/28/world/europe/europe-heat-wave-wildfires.html">46 Centigrade</a> (115 Fahrenheit) in France, an all-time record.</p>
<p>A heat wave is characterised by extremely high temperatures over the course of several days and nights. They have significant impact on our daily lives – we feel overheated and tired. When a heat wave strikes, many governments activate a “heat action plan”, advising those affected to drink water, avoid strenuous exercise, and stay cool. If not, one risks having a heat stroke, which can be potentially life-threatening.</p>
<p>But how exactly does the human body deal with such extreme temperatures, and why is heat so dangerous? Which organs are affected, and when could things take a turn for the worse?</p>
<h2>Staying cool</h2>
<p>The core temperature of the human body usually fluctuates between 36 and 38°C (97 to 99°F). Temperatures within this range allows biochemical reactions to proceed normally, which is vital for proper functioning of cells and organs. The human body is also well equipped to deal with a variety of environmental conditions that might threaten its core temperature.</p>
<p>When the core temperature deviates from the normal range, the body initiates physiological responses that in order to return its temperature return to normal. This <em>thermoregulatory response</em> is comparable to a thermostat at your home; once the in-house temperature strays from the ideal temperature, heating or cooling systems activate to return to the preferred temperature.</p>
<p>In the human body, this thermostat is located at the base of our brain, in a region called the hypothalamus. Information provided by temperature sensors located in our skin, muscles, and other organs is analysed, and when necessary, <a href="https://clinmedjournals.org/articles/iacph/international-archives-of-clinical-physiology-iacph-1-001.php">physiological response</a> is initiated.</p>
<p>The first and most important response to increasing temperatures is heat dissipation via the skin and extremities of our body, such as our hands and feet. We start producing sweat that will evaporate on our skin, shedding heat in the process.</p>
<p>This system is very effective in cooling down the body, but can require up to <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2267797/">2 litres of water per hour in cases of extreme heat</a>. The body adjusts its water housekeeping as much as possible, but to sustain thermoregulation, it’s vital for us to refill the body’s water reservoir. If not, one risks running out of water, and thus losing the ability to sweat and cool down, resulting in overheating of organs. Via the drinking water, we also need to take up electrolytes and salts, which maintain a normal blood acidity, crucial for cells to function.</p>
<h2>From brain to kidneys</h2>
<p>To understand what can go wrong, let’s take a look at how the thermoregulatory response affects the function of multiple organs, and how each organ reacts to extreme heat.</p>
<p>The first is the cardiovascular system. For us to sweat and cool off, blood flow shifts from the central organs to the periphery of the body – you’ve no doubt noticed that people who are overheated are often blushing. The loss of water through sweat and the redistribution of the blood flow causes a fall in blood pressure in the central organs. To maintain blood flow to the vital organs, the heart tries to compensate by elevating the heart rate.</p>
<p>However, if blood flow redistribution is accompanied by too much water loss, blood pressure will drop dangerously and cause fainting, an important sign of a heat stroke. In a worst-case scenario, it can lead to <a href="https://www.aafp.org/afp/2005/0601/p2133.html">heart failure</a> if left untreated.</p>
<p>Another vital organ that suffers under temperature stress is the brain. Increased temperatures disturb communication between nerve cells, as the heat affects DNA and protein structure as well as cellular membrane integrity. Dehydration also causes electrolyte imbalances, which can <a href="https://www.ncbi.nlm.nih.gov/pubmed/16254491">disrupt nerve-muscle cell communication</a>. The longer the overheating lasts, the more serious the consequences can be. Cognitive pathways can be deregulated and provoke emotional alterations such as <a href="https://clinmedjournals.org/articles/iacph/international-archives-of-clinical-physiology-iacph-1-001.php">increased anxiety, headaches and impaired judgement</a>.</p>
<p>Remarkably, one of the ways the brain cools is through the respiratory system. The body increases breathing frequency, cooling the blood flowing to and from the brain. The flowing air can be seen literally as a sort of <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4879782/">natural air-conditioning system</a>. However, an adverse effect is that blood pH rises due to decreases in bicarbonate and CO<sub>2</sub> pressure, which could endanger cell functioning in other organs.</p>
<p>The intestine is another major organ system receiving less blood due to its redistribution to the periphery. It impedes proper functioning, and in extreme cases can cause nausea and vomiting.</p>
<p>Finally, the loss of water and salts also elicits responses in the urinary tract. Under the influence of a special hormone from the brain, <em>antidiuretic hormone</em>, the re-absorption of water and salts is stimulated to counteract the blood pressure loss in the cardiovascular system. As a result, our kidneys produce less but more concentrated urine, which is browner in colour, and we go less frequently to the bathroom. Prolonged periods of high temperatures and dehydration can result in tissue damage in the kidneys.</p>
<h2>Listening to your body</h2>
<p>One can understand now that drinking water, taking up salts and electrolytes, and staying out of the most intense heat is an absolute necessity for our body’s own good. People who do not listen to their bodies, do not drink water and neglect the advice given by health authorities during hot weather can push their bodies to the limits of human physiology. They could suffer exhaustion or heat stroke, which can have potentially fatal consequences.</p>
<p>Those particularly at risk are the elderly and heart patients whose <a href="https://clinmedjournals.org/articles/iacph/international-archives-of-clinical-physiology-iacph-1-001.php?jid=iacph">cardiovascular system is already overstressed</a>. Moreover, elderly might be less aware of the dangers of heat, as their body heat sensors function less well than those of young people. Babies and toddlers depend on their parents to take the necessary measures to protect them.</p>
<p>The best advice during a heat wave is, in essence, to do what we already know:</p>
<ul>
<li><p>Drink plenty of water, while limiting consumption of alcohol and caffeine, which have dehydrating effects on the body.</p></li>
<li><p>Stay out of the sun, seek a cool place, and follow the advice given by health authorities.</p></li>
<li><p>Help those that are particularly vulnerable in hot conditions, in particular infants and the elderly.</p></li>
</ul><img src="https://counter.theconversation.com/content/119521/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Pieter Vancamp ne travaille pas, ne conseille pas, ne possède pas de parts, ne reçoit pas de fonds d'une organisation qui pourrait tirer profit de cet article, et n'a déclaré aucune autre affiliation que son organisme de recherche.</span></em></p>Our body is able to regulate its temperature very effectively, but heat waves can damage certain organs if we are not careful…Pieter Vancamp, Post-doctorant, Muséum national d’histoire naturelle (MNHN)Licensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1126182019-04-07T19:52:53Z2019-04-07T19:52:53ZEdible seaweed can be used to grow blood vessels in the body<figure><img src="https://images.theconversation.com/files/265291/original/file-20190322-36248-4275lc.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C1017%2C1020&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Fluorescence microscopy image of the newly formed blood vessels after injection of our seaweed-derived hydrogel in a muscle. In green are the blood vessels and in blue the cell nuclei.</span> <span class="attribution"><span class="source">Aurelien Forget, Roberto Gianni-Barrera, Andrea Banfi and Prasad Shastri</span>, <span class="license">Author provided</span></span></figcaption></figure><p>When we have small wounds on our skin or muscles they can usually heal by themselves. </p>
<p>But in deeper wounds – such as those in diabetic patients or in muscle tissue after a heart attack – repair is more difficult. These sorts of issues often require more serious treatments, and may eventually need amputation or a transplant if healing is not complete. </p>
<p>While organ transplants save lives, we <a href="https://transplant.org.au/the-facts/">fall short in available organs for this procedure</a>, and alternative methods are needed.</p>
<p>Technology such as <a href="https://www.science.org.au/curious/people-medicine/bioprinting">bioprinting</a> has been proposed to build fully functional organs outside the body. But what if we could boost our own regenerative capabilities? Would it be possible to create the organs inside the body?</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/the-next-pharmaceutical-revolution-could-be-3d-bioprinted-79676">The next pharmaceutical revolution could be 3D bioprinted</a>
</strong>
</em>
</p>
<hr>
<p>In a <a href="https://www.onlinelibrary.wiley.com/doi/full/10.1002/adma.201808050">recent publication</a> we demonstrate that by a simple injection of a gel extracted from edible seaweeds, we can direct the body to create stable blood vessels in a muscle. These vessels are the key in helping tissue to live.</p>
<p>These results are an important step toward regenerative therapies based solely on biomaterials. </p>
<h2>What are regenerative therapies?</h2>
<p><a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4664309/">Regenerative therapy (also called regenerative medicine)</a> is an area of research that combines medicine, molecular biology, and biotechnology. It aims to engineer tissues or organs and restore normal function.</p>
<p>As an example, <a href="https://theconversation.com/the-next-pharmaceutical-revolution-could-be-3d-bioprinted-79676">3D bioprinting</a> has had some success, <a href="https://spectrum.ieee.org/the-human-os/biomedical/devices/human-corneas-could-be-the-first-mainstream-application-of-bioprinting">such as the creation of implantable corneas</a> for the eye. </p>
<p>But this approach requires specialised manufacturing facilities. The cells must be isolated, grown in a bioreactor – a special vessel providing the right environment for tissue growth – and used to create artificial organs under controlled and sterile conditions. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/265151/original/file-20190321-93051-z24b5g.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/265151/original/file-20190321-93051-z24b5g.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/265151/original/file-20190321-93051-z24b5g.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=390&fit=crop&dpr=1 600w, https://images.theconversation.com/files/265151/original/file-20190321-93051-z24b5g.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=390&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/265151/original/file-20190321-93051-z24b5g.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=390&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/265151/original/file-20190321-93051-z24b5g.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=491&fit=crop&dpr=1 754w, https://images.theconversation.com/files/265151/original/file-20190321-93051-z24b5g.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=491&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/265151/original/file-20190321-93051-z24b5g.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=491&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Process of biofabrication of patient specific organs.</span>
<span class="attribution"><span class="source">Steffen Harr</span></span>
</figcaption>
</figure>
<p>A new approach emerged a couple of years ago. This uses the body to produce a particular type of tissue or cells, and is called the <a href="https://www.pnas.org/content/102/32/11450">in vivo (in the body) bioreactor</a>. This was initially developed <a href="https://www.ted.com/talks/molly_stevens_a_new_way_to_grow_bone">to make bones</a>.</p>
<p>To create tissue in the human body, we need to trigger and exploit our own regenerative capabilities. Unfortunately we are not as good as <a href="https://www.livescience.com/34513-how-salamanders-regenerate-lost-limbs.html">salamanders</a>: we can’t regrow a new limb.</p>
<p>But with some help, we could regenerate individual tissues. To achieve this, the help can come in the form of materials that: </p>
<ul>
<li><p>reproduce the tissue properties needed, such as the stiffness of the tissues, and</p></li>
<li><p>carry chemical and biological signals that can direct the tissue growth. </p></li>
</ul>
<p>A tissue is defined as a group of cells working together for a specific function. As an example, muscle tissues are made of cells organised into fibres, forming the so-called muscle fibres.</p>
<h2>Materials that can talk with cells</h2>
<p>Our body’s tissues are made up of many different cell types, and also materials that exist outside the cells. These materials are known as the <a href="https://www.britannica.com/science/cell-biology/Intermediate-filaments#ref313804">extracellular matrix</a> (ECM).</p>
<p>The ECM is made up of several different elements. It holds water, and also stores vital information to help cells move, grow and organise into functional tissues.</p>
<p>We don’t need to go into the details of what the ECM is made of here. But what we can say is that scientists can copy many of its functions using a gel-like material called <a href="https://www.sciencedirect.com/science/article/pii/S2090123213000969">hydrogel</a>. This can be modified to pass specific biological information to cells. </p>
<h2>Edible seaweed to create blood vessels</h2>
<p>We have been developing a new class of injectable hydrogel. </p>
<p>The material making the hydrogel is called agarose, which is also used to <a href="http://www.abc.net.au/tv/pohskitchen/stories/s2848469.htm">make jelly cakes</a> in the kitchen, and in biology laboratories to <a href="https://www.nature.com/scitable/definition/gel-electrophoresis-286">separate DNA</a>. </p>
<p>Agarose is a polysaccharide – a long chain of sugar – that is extracted from <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC170292/">red seaweed</a> found in many oceans <a href="http://www.seaweed.ie/uses_general/agars.php">around the world</a>. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/267345/original/file-20190403-177167-1drmdk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/267345/original/file-20190403-177167-1drmdk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/267345/original/file-20190403-177167-1drmdk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/267345/original/file-20190403-177167-1drmdk.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/267345/original/file-20190403-177167-1drmdk.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/267345/original/file-20190403-177167-1drmdk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/267345/original/file-20190403-177167-1drmdk.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/267345/original/file-20190403-177167-1drmdk.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Agarose powder used in the laboratory for the separation of DNA and agar used to make jelly cakes.</span>
<span class="attribution"><span class="source">Aurelien Forget</span></span>
</figcaption>
</figure>
<p>In <a href="http://www.shastrilab.com">our lab</a>, we can modify agarose by attaching a small molecule (a peptide) that will talk to the cells. Using this approach, we have created a unique formulation of the hydrogel that provides the ideal environment <a href="https://www.pnas.org/content/110/32/12887">for certain cells to organise into blood vessels</a>. </p>
<p>Now in our <a href="https://www.onlinelibrary.wiley.com/doi/full/10.1002/adma.201808050">latest work</a> with <a href="https://biomedizin.unibas.ch/en/research/research-groups/banfi-lab/">collaborators at the University Hospital of Basel</a>, we show that this same hydrogel injected into muscle can “talk” to the body and initiate the formation of new blood vessels.</p>
<p>Previously, only <a href="https://www.pnas.org/content/107/8/3418">cartilage</a> or <a href="https://www.pnas.org/content/102/32/11450">bone</a> could be regenerated within the body.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/266781/original/file-20190401-177187-whhadc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/266781/original/file-20190401-177187-whhadc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/266781/original/file-20190401-177187-whhadc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=371&fit=crop&dpr=1 600w, https://images.theconversation.com/files/266781/original/file-20190401-177187-whhadc.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=371&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/266781/original/file-20190401-177187-whhadc.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=371&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/266781/original/file-20190401-177187-whhadc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=467&fit=crop&dpr=1 754w, https://images.theconversation.com/files/266781/original/file-20190401-177187-whhadc.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=467&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/266781/original/file-20190401-177187-whhadc.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=467&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Formation of new blood vessels induced by an injectable therapeutic material.</span>
<span class="attribution"><span class="source">Steffen Harr</span></span>
</figcaption>
</figure>
<h2>Future therapies</h2>
<p>This approach paves the way for the creation of a new class of therapies in which injectable materials could become as useful as pharmaceutical drugs.</p>
<p>We envision that in certain cases a patient with a defect organ might one day be able to get an injection of a material that will carry with it information to talk to cells and direct their organisation into new functional tissues.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/the-painless-woman-helps-us-see-how-anxiety-and-fear-fit-in-the-big-picture-of-pain-114751">The 'painless woman' helps us see how anxiety and fear fit in the big picture of pain</a>
</strong>
</em>
</p>
<hr>
<p>This approach would let our body do most of the complicated tasks, in contrast to cell therapies or bioprinting of organs outside the body - where cells must be harvested, grown and re-implanted. Materials therapies would be highly valuable for patients in remote location where complex infrastructures are not available. </p>
<p>More speculatively, organ bioprinting is considered as one of the critical technologies for the <a href="https://www.esa.int/Our_Activities/Space_Engineering_Technology/3D_printing_skin_bone_and_body_parts_under_study_for_future_astronauts">expansion of the humans to other planets</a>.</p>
<p>By using regeneration-triggering materials to overcome injuries or disease we could <a href="https://www.nejm.org/doi/full/10.1056/NEJMra1609012">leave the critical repair task for our body</a>. Perhaps one day a person living in space would be able to inject themselves with one of these materials.</p><img src="https://counter.theconversation.com/content/112618/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Aurelien Forget does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Small wounds can usually heal by themselves, but larger wounds can be a problem. With a little help from a seaweed we can help the body regenerate new blood vessels.Aurelien Forget, Lecturer in Macromolecular Chemistry, University of FreiburgLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1132012019-03-18T22:08:03Z2019-03-18T22:08:03ZCurious Kids: why do we have two kidneys when we can live with only one?<figure><img src="https://images.theconversation.com/files/264074/original/file-20190315-28475-1vh4qe0.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C3834%2C2160&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Right now, your kidneys are getting rid of all things your body does not need. They do this by 'cleaning' your blood. </span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p><em><a href="https://theconversation.com/au/topics/curious-kids-36782">Curious Kids</a> is a series for children. If you have a question you’d like an expert to answer, send it to curiouskids@theconversation.edu.au You might also like the podcast <a href="http://www.abc.net.au/kidslisten/imagine-this/">Imagine This</a>, a co-production between ABC KIDS listen and The Conversation, based on Curious Kids.</em> </p>
<blockquote>
<p><strong>Why do we have two kidneys when we can live with only one? – Question from the students of Ms Morris’ Grade 5 class, Ringwood North Primary School, Victoria.</strong> </p>
</blockquote>
<p>This is a really great question. The answer is scientists are not completely sure but we do have some theories. That is often the case with science.</p>
<p>Most of the animals you see above ground on Earth today, including humans, are the same on both sides. We have two eyes, two ears, and even two nostrils. Scientists gave this a fancy name called “<a href="https://nph.onlinelibrary.wiley.com/doi/full/10.1111/nph.13526">bilateral symmetry</a>.”</p>
<p>If you look in the mirror and draw an imaginary line down the middle of your reflection you will see that you have an arm and a leg on each side. If you had goggles that let you see your insides, you would see that you also have a kidney and a lung on each side too. </p>
<p>But it wasn’t always like this. And some <a href="http://molluscs.at/gastropoda/index.html?/gastropoda/morphology/organ_systems.html">animals</a> still only have one kidney.</p>
<p>Around 500 million years ago, our long-lost relatives that were living in the ocean (some of whom probably only had one kidney) decided to leave the water to walk and live on land. </p>
<p>This was a very important moment in our history because on land, animals could change to grow a very complicated body with all of the important organs that are inside you, including two kidneys. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/curious-kids-how-does-my-tummy-turn-food-into-poo-110353">Curious Kids: how does my tummy turn food into poo?</a>
</strong>
</em>
</p>
<hr>
<h2>Two kidneys better than one?</h2>
<p>Right now, your kidneys are getting rid of all things your body does not need. They do this by “cleaning” your blood. </p>
<p>All of this waste will exit your body when you go to the toilet to pee. But your kidneys do a lot more than just clean your blood. They help your bones stay healthy, tell your body when to make new blood cells, and even help you stay upright when you’re walking around all day by taking care of your blood pressure.</p>
<p>With all those important functions, scientist think having two kidneys must be important for our survival. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/264077/original/file-20190315-28471-gblrhk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/264077/original/file-20190315-28471-gblrhk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/264077/original/file-20190315-28471-gblrhk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/264077/original/file-20190315-28471-gblrhk.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/264077/original/file-20190315-28471-gblrhk.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/264077/original/file-20190315-28471-gblrhk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/264077/original/file-20190315-28471-gblrhk.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/264077/original/file-20190315-28471-gblrhk.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Kidneys ‘clean’ your blood and send waste to your bladder, so you can pee it out.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<h2>Growing up with one kidney</h2>
<p>It is true, you <em>can</em> live with only one kidney. Some people are <a href="https://www.ncbi.nlm.nih.gov/pubmed/18612657">born with only one</a> because the other one did not grow properly. Other times, the two kidneys touch each other when they are first growing and join together, making one kidney shaped like a <a href="https://www.ncbi.nlm.nih.gov/pubmed/27324557">horseshoe</a>. People with these types of kidneys have to be very careful because they might get sick more easily than someone who has two kidneys. </p>
<h2>Needing an extra kidney</h2>
<p>Sometimes our kidneys stop working. When this happens our blood cannot be cleaned and we can get very sick. The only way to stay alive is to be attached to a big machine that cleans your blood for you, or have a <a href="https://kidney.org.au/your-kidneys/support/kidney-transplant">kidney transplant</a>. </p>
<p>This happened to me when my kidneys stopped working properly. My dad gave me one of his kidneys. Thanks, Dad.</p>
<p>There are two people involved in a kidney transplant: a donor who is going to give their kidney, and a recipient who will receive the kidney. </p>
<p>After the new kidney is put into the recipient, both the donor and recipient only have one kidney that works properly. Both the donor and the recipient can live long happy lives with only one kidney. They just have to take extra care that they eat healthily and exercise to stay fit. <a href="https://www.heraldsun.com.au/leader/south-east/springvales-twanny-farrugia-marks-45-years-since-receiving-kidney-transplant/news-story/e9ece94308f61042f5f2d9d328823d4c">One person</a> living in Australia has been using a transplanted kidney for 45 years!</p>
<p>So, while your body works best when all of your organs are inside you and working properly, scientists still don’t exactly know why we have two kidneys. However, it is good to know that we have a few spare parts that we can live without.</p>
<p>And if you’re an adult reading this, it’s good to make sure you are <a href="https://donatelife.gov.au/register-donor-today">registered as an organ donor</a> and also chat to your family so they know you want to donate. You may one day save a life.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/curious-kids-why-are-burps-so-loud-108988">Curious Kids: why are burps so loud?</a>
</strong>
</em>
</p>
<hr>
<p><em>Hello, curious kids! Have you got a question you’d like an expert to answer? Ask an adult to send your question to curiouskids@theconversation.edu.au</em></p>
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<p><em>Please tell us your name, age and which city you live in. We won’t be able to answer every question but we will do our best.</em></p><img src="https://counter.theconversation.com/content/113201/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Brooke Huuskes volunteers for Transplant Australia and Kidney Health Australia.</span></em></p>When my kidneys stopped working properly, my dad gave me one of his kidneys. Thanks, Dad.Brooke Huuskes, Lecturer in Human Anatomy, Physiology Anatomy & Microbiology, La Trobe UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1079192019-01-08T12:46:00Z2019-01-08T12:46:00ZThere are many complex reasons for South Africa’s organ donor shortage<figure><img src="https://images.theconversation.com/files/248726/original/file-20181204-34142-1w71r2d.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Many countries around the world can't meet the demand for donor organs.</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>At any given time, there are around <a href="https://www.odf.org.za/info-and-faq-s/statistics.html">4300</a> people waiting for organ donations in South Africa. These patients usually need new livers, kidneys, lungs or hearts. But organ donors are in very short supply. </p>
<p>This isn’t unique to South Africa. Many countries around the world are unable to meet the demand for donor organs. There are a few exceptions, though. One example is <a href="https://journals.lww.com/annalsofsurgery/Abstract/2013/05000/Liver_Transplantation_for_Nonresectable_Liver.3.aspx">Norway</a>, where a surplus of deceased donor livers has been reported. </p>
<p>So what explains South Africa’s organ donor shortage? </p>
<p>Religious and cultural beliefs play a role, because they influence the decisions people make about the remains of their loved ones. Sometimes families prefer that a relative’s body remain whole and intact; in other cases it’s considered important to bury a person within a certain time frame. But attributing the shortages to these factors alone grossly oversimplifies the issue, as <a href="https://journals.sagepub.com/doi/abs/10.1177/1526924818765819?journalCode=pit">research</a> has shown.</p>
<p>There are many complex elements that keep donor numbers low. These permeate the social fabric from a population and legislation level down to the practice of health care workers in hospitals. </p>
<p>It’s important to tackle each of these elements to ease the country’s organ donor shortage.</p>
<h2>Public perception</h2>
<p>At a societal level, religious and socio-cultural practices do play a role in the shortage of donor organs. But in my <a href="https://www.researchgate.net/profile/Harriet_Etheredge">extensive research</a> into the factors influencing low donor numbers, other issues have come to the fore.</p>
<p>These include a suspicion of the biomedical system in South Africa. Sometimes there are perceptions that doctors and hospitals can’t be trusted, or that some aspects of practice are unethical.</p>
<p>Some of these opinions are justified; the so-called <a href="https://mg.co.za/article/2011-04-29-kidneygate-what-the-netcare-bosses-really-knew">kidneygate</a> saga of 2001 is one example of poor medical ethics. This scandal saw “donors” from poor families in Brazil flown to South Africa and paid a nominal sum for a kidney, which was implanted in most cases into wealthy Israeli recipients. The sale of human organs is illegal in South Africa, as it is in most other parts of the world. </p>
<p>The issue is also influenced by a negative and often sensationalist portrayal of organ donation in the <a href="https://www.bloomberg.com/news/articles/2011-11-01/organ-gangs-force-poor-to-sell-kidneys-for-desperate-israelis">media</a>, and <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1119465/">reports</a> of unethical research on the continent. </p>
<p>Suspicion breeds distrust. People question what will happen to their loved ones’ organs should they suspect that doctors and hospitals profit from donations. In the face of these questions, many families find it easier to refuse organ donation, especially in light of the mixed messages which are often communicated to the public.</p>
<h2>Legislation</h2>
<p>South Africa’s organ transplant legislation is vague. The <a href="https://www.gov.za/documents/national-health-act">National Health Act</a> admirably addresses the serious issue of organ trafficking and perverse incentives. It also specifically stipulates that consent to deceased organ donation can be written or oral, and can be given by a mentally competent person in the presence of two witnesses prior to that person’s death. </p>
<p>Technically, this means that a next-of-kin consent to organ donation isn’t actually required where the person stated a preference to donate during his or her lifetime. But the Act doesn’t go any further in adequately addressing the procurement of donor organs from people who are deceased. For example, the law doesn’t make it mandatory to offer all eligible families the option of donating a relative’s organs after brain-stem death, and the conflicts with common law norms are not resolved.</p>
<p>This has left a vacuum. Questions about the legal rights of a person to decide what is done with their remains after they have died need to be weighed against the family’s decision making rights. Families have some common law rights to determine the fate of the remains of their next-of-kin. </p>
<p>As a result, <a href="https://repository.up.ac.za/bitstream/handle/2263/40613/Labuschagne_Analysis_2013.pdf;sequence=1">written family consent</a> for organ donation is required in South Africa, though it is not a legal necessity. </p>
<p>Donors are lost at this point. A number of people who would willingly donate may fail to inform their families of their decision. People think that signing up as a donor is enough to guarantee that their organs will be considered for donation upon their death. But telling one’s family is in fact the most important thing. Even if a person has signed up as an organ donor during their lifetime, the family can still reverse this decision under the current system. They may be more likely to do so if the decision has not been communicated in advance.</p>
<p>Another challenge is that health care workers sometimes face difficult situations, for example, around concepts like brain-stem death. This is an essential step in the organ donation process, because only people who are legally certified as deceased can be deceased organ donors. In South Africa, brain-stem death is a legally accepted definition of death. This can be difficult to understand, especially when the patient is maintained on a mechanical ventilator, still looks pink and feels warm. When such a patient has been declared brain-stem dead they are unequivocally deceased. But it can be hard to believe. </p>
<p>In our <a href="https://journals.sagepub.com/doi/abs/10.1177/1526924818765819?journalCode=pitb">research</a>, we found that this was especially true for nursing staff, for whom the saving and maintenance of life is an imperative goal. There was a sense that the person was being “killed” even though the donor is already dead. </p>
<h2>Finding solutions</h2>
<p>It’s clear, then, that no single factor is keeping organ donor numbers low in South Africa. Policymakers, health care professionals, civil society advocacy groups and academics must work collaboratively to address these issues if the situation is to be improved.</p>
<p>There are a number of countries that have increased their donor numbers by introducing more robust policy. The most notable is <a href="https://mosaicscience.com/story/spain-uk-organ-donation-transplants-liver-kidney-heart-lungs-surgery-nhs/">Spain</a>, where they have adopted an “opt-out” system under which it’s assumed that a person consents to organ donation when they die, unless they have issued a clear, written statement to the contrary.</p><img src="https://counter.theconversation.com/content/107919/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Harriet Etheredge does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Religious and cultural beliefs play a role in the country’s organ donor shortages. But these factors alone grossly oversimplifies the issue.Harriet Etheredge, Bioethicist and Health Communication Specialist, University of the WitwatersrandLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1073882018-11-28T12:57:31Z2018-11-28T12:57:31ZLiver transplant from HIV+ living donor to negative recipient: the unanswered questions<figure><img src="https://images.theconversation.com/files/247683/original/file-20181128-32230-1q19ef7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">More than a year after a groundbreaking liver transplant doctors still can't say if the recipient is HIV-positive or not.</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>A lifesaving partial liver transplant from an HIV-infected mother to her uninfected child – the first of its kind – was conducted last year at the University of the Witwatersrand’s <a href="http://www.dgmc.co.za/">Donald Gordon Medical Centre</a> in Johannesburg. More than a year later, both mother and child are doing well. </p>
<p>But the crucial question of the child’s HIV infection status remains unanswered. And we don’t expect to have a definitive answer any time soon.</p>
<p>Despite this uncertainty, the story of the transplant is inspiring. To date there have been no published reports of a living organ donation by a person with HIV, or of an intentional transplant from an HIV-positive to HIV-negative individual. The operation was driven by a number of factors. These included life-threatening liver failure in the child, no available deceased or suitable live HIV-uninfected donors, and an HIV-positive mother’s continued pleas to be allowed to save her child.</p>
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<p>We’ve learned a great deal from the operation and during the subsequent year. Most importantly, the success of this transplant provides a new therapeutic option for similar cases in high burden HIV countries where deceased donor organs are limited in number, or where access is limited. </p>
<p>But there are still gaps in our knowledge. The biggest is what the long term effect of the transplant will be on the child, and particularly whether the mother’s virus was transferred with the liver.</p>
<h2>The journey</h2>
<p>The child was 13 months old when the transplant happened. The liver has a remarkable ability to regenerate and grows back to its normal size in the donor in about six weeks.</p>
<p>Although born to an HIV-positive mother, the child did not have HIV. The mother was on antiretroviral therapy during pregnancy, and the child received standard preventative treatment. </p>
<p>The mom had an undetectable virus ahead of the transplant. The child also received antiretrovirals ahead of the transplant to try and prevent infection. Both mom and child are still on HIV treatment today. The child is also on immunosuppressive therapy to prevent liver rejection.</p>
<p>After the transplant, the child was tested for HIV. No virus was detected. Very sensitive tests also couldn’t detect traces of the virus within cells. This means that, one year on, there is no direct evidence of virus in the blood or blood cells. </p>
<p>But there is a caveat. Just because we can’t detect the virus doesn’t mean it isn’t hiding in very small amounts.</p>
<p>There’s another reason we can’t conclusively say whether the child is infected or not: 43 days after the operation HIV antibodies were detected in the child using standard diagnostic tests. But these antibodies have since decreased in amount. Normally, the presence of HIV antibodies means a person has been infected. But in this case, we can’t tell if these antibodies belong to the child or the mother (or both) because of the donor cells in the liver. </p>
<p>Because of these uncertainties, treatment is being continued for the moment. Whether this will be lifelong remains one of many open and unanswered questions.</p>
<h2>Unanswered questions</h2>
<p>The operation, and subsequent events, have put us on the cusp of new insights and understanding about HIV and its transmission.</p>
<p>We’ve been able to get some insights from previous events. For example, the transfer of <a href="https://aasldpubs.onlinelibrary.wiley.com/doi/epdf/10.1002/lt.21534">HIV through liver transplantation</a> has accidentally happened where deceased donors unknowingly had HIV. In all cases there was clear evidence of HIV infection in the recipient. </p>
<p>There are lots of other examples – not HIV related – of the transfer of specific immune responses from a donor to the recipient. An interesting one is the transfer of an <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5716392/pdf/jaa-10-307.pdf">allergic reaction to peanuts</a> in cases where the recipients had no prior history of peanut allergy but developed reactions following transplantation. Such transfer of donor immune responses is why we can’t use our standard HIV antibody tests for a conclusive diagnosis of recipient HIV infection in the setting of transplantation.</p>
<p>Two factors make the situation we find ourselves in unique: it’s the first time that liver tissue from an HIV positive living person has been transplanted to a HIV-negative person. The second is that the liver is very different to other organs. </p>
<p>The liver is the major draining organ for substances passing through the gut. Because of its role in metabolism, nutrient storage and detoxification it needs to distinguish foreign particles that are good (food) from those that are bad (pathogens). That’s what makes it immunologically tolerant. Tolerance means the immune system is geared to prevent an overreaction to good molecules. </p>
<p>It’s not known how this tolerance might affect the risk of HIV infection. <a href="https://ac.els-cdn.com/S0042682213004467/1-s2.0-S0042682213004467-main.pdf?_tid=e43f8179-6c5c-4179-b987-73993a086539&acdnat=1543316015_bbbc31f6c2e624b1937f3ad5276edd61">Studies</a> on monkeys have shown an absence of actively infected cells in the liver compared with other organs. The presence of antiretrovirals in our transplant mom-child case would make the presence of actively infected cells even less likely. </p>
<p>On the other hand, latent or “silently” infected cells which are very difficult to detect could be present in small numbers and pose a potential risk of sparking an infection if antiretroviral treatment were ever stopped.</p>
<h2>The way forward</h2>
<p>There are still many gaps in our knowledge. For example, we need to understand HIV in the liver of patients who are on antiretrovirals and virally suppressed. </p>
<p>We also need to have a better understanding of this novel type of HIV exposure so that we can inform best practice in the setting of HIV-positive donor liver transplants. </p>
<p>Studies of this case and of further transplants of this nature will help us to fill in these knowledge gaps. </p>
<p>The ultimate aim is to have the best of both worlds – a life-saving intervention together with successful prevention of HIV infection in the transplant recipient.</p><img src="https://counter.theconversation.com/content/107388/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Caroline T. Tiemessen receives research funding from the South African Medical Research Council (MRC) Strategic Health Innovation Partnerships (SHIP) programme, Department of Science and Technology/National Research Foundation (DST/NRF) South Africans Chair Initiative (SARChI) programme, Poliomyelitis Research Foundation (PRF), and the US National Institutes of Health (NIH).</span></em></p>A liver transplant from an HIV-positive living donor to an HIV-negative recipient is possible, but there are still gaps in our knowledge.Caroline T. Tiemessen, Head: Cell Biology, Centre for HIV and STIs, National Institute for Communicable DiseasesLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1002302018-07-24T07:50:57Z2018-07-24T07:50:57ZHow an ex-Barcelona player’s legal liver transplant is focusing attention on the human organ trade<figure><img src="https://images.theconversation.com/files/228720/original/file-20180722-142435-1khzq5x.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>In surely one of the most bizarre stories of recent weeks, former FC Barcelona president, Sandro Rosell, was forced to deny claims that he illegally purchased a human liver for ex-Barcelona defender Eric Abidal in 2012, after a report in <a href="https://www.elconfidencial.com/espana/2018-07-04/abidal-sandro-rosell-higado-compra-barcelona-trafico-organos_1587537/">Spanish newspaper El Confidencial</a> claimed police had intercepted phone calls of Rosell allegedly admitting the purchase. A statement by FC Barcelona <a href="https://www.sport-english.com/en/news/barca/official-statement-from-barcelona-on-eric-abidals-liver-transplant-story-6924473">flatly denied the allegations</a>, and pointed out that a Catalan court had shelved an investigation into the matter in 2017. Further form denials were issued by Abidal and the hospital in which he underwent surgery, while Spain’s National Transplant Organisation also <a href="http://www.espn.co.uk/football/barcelona/story/3568519/barcelonas-eric-abidal-followed-liver-transplant-protocol-study">came forward</a> to confirm that the operation was performed in accordance with the law.</p>
<p>In this case it appears clear that the transplant was legal, but the incident does shine a spotlight on commercial organ transplantation and the murky worldwide black market for human organs. But what is this trade and how often does it happen?</p>
<h2>What is transplant commercialism?</h2>
<p>Transplant commercialism involves the buying, selling, or otherwise commodifying of human organs. It is recognised as a serious crime in the vast majority of countries, with the <a href="https://www.theguardian.com/society/2015/may/10/kidneys-for-sale-organ-donation-iran">notable exception of Iran</a>.</p>
<p>In practice the term covers a broad spectrum of behaviours. The most troubling cases involve people being trafficked so their organs can be removed. Victims may be held against their will, forced to undergo medical tests, and ultimately operated on without their consent. Thankfully there have not yet been substantiated cases of this occurring in the UK, but we know it happens <a href="https://www.bbc.co.uk/news/health-38722052">elsewhere</a>.</p>
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<img alt="" src="https://images.theconversation.com/files/228870/original/file-20180723-189329-6r5rcy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/228870/original/file-20180723-189329-6r5rcy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=358&fit=crop&dpr=1 600w, https://images.theconversation.com/files/228870/original/file-20180723-189329-6r5rcy.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=358&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/228870/original/file-20180723-189329-6r5rcy.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=358&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/228870/original/file-20180723-189329-6r5rcy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=450&fit=crop&dpr=1 754w, https://images.theconversation.com/files/228870/original/file-20180723-189329-6r5rcy.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=450&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/228870/original/file-20180723-189329-6r5rcy.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=450&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Organ tourism is hard to track and even harder to stop.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-illustration/organ-transportation-concept-open-human-refrigerator-632646452?src=IlS9b5rxckOoYmL37XZMbg-1-26">shutterstock</a></span>
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<p>More common is so-called “transplant tourism”, which sees patients travel abroad for transplants they might struggle to otherwise obtain quickly. Though illegal payments are not always involved – some might have an overseas relative willing to donate – these foreign trips should set off alarm bells.</p>
<p>The global reach of social media makes it increasingly easy for organs to be offered for sale online. Within two days of joining a Facebook group about organ donation, for example, I was messaged by a man in India offering to sell me his kidney.</p>
<p>It should surprise no one that payment for organ “donation” is often associated with the coercion and exploitation of those in poverty. The <a href="http://files.sld.cu/trasplante/files/2010/08/declaracion-estambul.pdf">Declaration of Istanbul</a>, endorsed by transplant organisations around the world, states clearly that trafficking and transplant tourism “violate the principles of equity, justice and respect for human dignity and should be prohibited”. There is an ongoing <a href="https://jme.bmj.com/content/41/6/443.short">academic debate</a> surrounding the ethics of transplant commercialism, but its illegality is clearly established in the laws of most countries.</p>
<h2>An unknown frequency</h2>
<p>Given that lawbreakers rarely report their own crimes, an accurate picture is difficult to ascertain, but it has <a href="https://onlinelibrary.wiley.com/doi/full/10.1111/j.1600-6143.2008.02200.x">been estimated</a> that 5-10% of worldwide organ transplants involve payments. UK figures suggest that <a href="https://nhsbtdbe.blob.core.windows.net/umbraco-assets-corp/4331/79th-meeting-board-report.pdf">nearly 400 patients</a> have received a transplant overseas in the last 16 years, although some of these may have been perfectly legal.</p>
<p>It is also possible that in the UK some donations involve illicit, under-the-table rewards. There are <a href="https://www.hta.gov.uk/sites/default/files/Guidance%20for%20Transplant%20Teams%20and%20Independent%20Assessors.pdf">safeguards</a> in place to counter this and the <a href="https://www.legislation.gov.uk/ukpga/2004/30/contents">Human Tissue Act 2004</a> makes this unequivocally illegal. But once again it is difficult to prove anything: if a grateful recipient buys their donor a new car some months after a transplant, who can draw the line between deferred payment and honest generosity?</p>
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<img alt="" src="https://images.theconversation.com/files/228719/original/file-20180722-142405-o9bk42.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/228719/original/file-20180722-142405-o9bk42.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/228719/original/file-20180722-142405-o9bk42.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/228719/original/file-20180722-142405-o9bk42.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/228719/original/file-20180722-142405-o9bk42.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/228719/original/file-20180722-142405-o9bk42.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/228719/original/file-20180722-142405-o9bk42.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Purloined organs can fetch a pretty penny on the black market.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/kidney-transplant-surgery-illegal-transplantation-human-1044717916?src=7HXBa_CIKKh72wbZjQzCdQ-1-73">shutterstock</a></span>
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</figure>
<p>Inevitably human organs are sometimes in limited supply, so patients on long waiting lists can be tempted to pay for an organ abroad. But when they return to the UK requiring follow up care their doctors will generally have their suspicions. Most medical professionals feel <a href="https://onlinelibrary.wiley.com/doi/abs/10.1111/ajt.13245">bound by patient confidentiality</a> and do not report their suspicions, but this eliminates one of the few potential methods of detecting and prosecuting this murky underworld. The illegal organ trade is complex and illusive, and without doctors reporting cases it will likely remain so.</p><img src="https://counter.theconversation.com/content/100230/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Greg Moorlock is a member of the European Society of Transplantation ELPAT Working Group on Living Organ Donation</span></em></p>I joined a Facebook group about organ donation. Within two days an Indian man offered to sell me his kidney.Greg Moorlock, Senior Teaching Fellow, University of WarwickLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/969372018-06-01T10:43:55Z2018-06-01T10:43:55ZOrgan transplants: knowing more about where donors live could save lives<figure><img src="https://images.theconversation.com/files/221033/original/file-20180530-120511-1k4r38q.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption"></span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/model-human-anatomy-611767448">Panint Jhonlerkieat/Shutterstock</a></span></figcaption></figure><p>In 2017-18, a record number of people (1,575 in total) in the UK donated their organs after death, resulting in more than 5,000 life-saving or life-improving transplants. These figures, released by <a href="https://nhsbtdbe.blob.core.windows.net/umbraco-assets/1616/united_kingdom.pdf">NHS Blood and Transplant</a>, show numbers of deceased donors continue to rise in the UK. The 2017-18 figure was an <a href="https://www.organdonation.nhs.uk/news-and-campaigns/news/record-number-of-organ-donors-and-highest-increase-in-28-years/">11% increase</a> on the previous year, and a near 20% increase in donor numbers since 2013-14.</p>
<p>These numbers are encouraging. More than <a href="https://www.organdonation.nhs.uk/news-and-campaigns/news/more-than-50-000-people-now-alive-thanks-to-organ-donation-and-transplant/">50,000 people</a> are alive in the UK today following organ transplant. Yet <a href="https://nhsbtdbe.blob.core.windows.net/umbraco-assets-corp/4492/section_1_summary_of_transplant_activity.pdf">457 people still died</a> in 2016-17 waiting for a transplant and more than <a href="https://nhsbtdbe.blob.core.windows.net/umbraco-assets/1616/united_kingdom.pdf">6,000 patients</a> remain on the transplant waiting list.</p>
<p>England, Scotland and Northern Ireland operate an opt-in system of consent for organ donation. Willing donors provide consent by actively signing up to the organ donor register. Wales, however, has had an <a href="https://www.bma.org.uk/collective-voice/policy-and-research/ethics/organ-donation/wales">opt-out system</a> since December 2015 (which <a href="https://www.gov.uk/government/news/government-announces-consultation-on-organ-donation-opt-out-system">England</a> and <a href="https://www.organdonationscotland.org/news-events/increasing-organ-and-tissue-donation">Scotland</a> are also expected to implement). All adults in Wales are now presumed to be consenting organ donors unless they explicitly register to opt out of donation, although people can still choose to opt in (known as <a href="https://www.bma.org.uk/collective-voice/policy-and-research/ethics/organ-donation/wales">express consent</a>). </p>
<p>Even given these policy differences, family refusal remains one of the biggest barriers to donation. Under each country’s laws, following the death of a loved one, consent must first be obtained from the family before any organ can be taken for transplant (even in Wales), regardless of the wishes of the deceased. While consent is granted in around two-thirds of cases, this <a href="https://nhsbtdbe.blob.core.windows.net/umbraco-assets-corp/4660/section_13_national_potential_audit_donors.pdf">rises to over 90%</a> when the deceased was a registered donor.</p>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/221040/original/file-20180530-120493-1fxtcz2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/221040/original/file-20180530-120493-1fxtcz2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/221040/original/file-20180530-120493-1fxtcz2.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/221040/original/file-20180530-120493-1fxtcz2.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/221040/original/file-20180530-120493-1fxtcz2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/221040/original/file-20180530-120493-1fxtcz2.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/221040/original/file-20180530-120493-1fxtcz2.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Making a difficult decision.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/doctor-consoling-upset-woman-381286084?src=4MSMWJNDJFL5XFOe-zDo6Q-1-27">XiXinXing/Shutterstock</a></span>
</figcaption>
</figure>
<h2>Donation and location</h2>
<p>At the time of writing, <a href="https://nhsbtdbe.blob.core.windows.net/umbraco-assets/1616/united_kingdom.pdf">more than one-third</a> of the UK’s population (24.9m people) have signed up to the NHS organ donor register, making clear their willingness to donate their organs after death. But <a href="https://nhsbtdbe.blob.core.windows.net/umbraco-assets-corp/4502/section_12_nhs_organ_donor_register.pdf">recent figures</a> show that levels of registration differ across areas of the UK. The number of registered donors is lower in England (35% of the population) than Wales (38%), Northern Ireland (40%) and Scotland (44%). </p>
<p>Between health authorities in England, higher numbers of donors are found in the South (42%), compared to the North (34%), Midlands and East (34%) and London (29%). Similar disparities also exist among <a href="https://nhsbtdbe.blob.core.windows.net/umbraco-assets/1761/wales_la_level.pdf">Welsh local authorities</a>. Whether these figures point to a geography of potential donors is currently unclear, but these numbers surely warrant further investigation – especially given the strong relationship between registered donor status and familial consent for donation.</p>
<p>Research from the US has already identified local differences that correspond to different levels of registered organ donors. <a href="http://journals.sagepub.com/doi/full/10.1177/1526924816640670">In one study</a>, areas characterised by higher income were found to have greater numbers of registered donors, for example. Until recently, however, research linking location factors with organ donation rates had not been conducted in the UK. </p>
<p>In our <a href="https://www.sciencedirect.com/science/article/pii/S1353829218300388">recently published analysis</a> of local patterns in registered organ donors, we found notable difference in rates of sign-up to the organ donor register across Welsh communities in the five years before Wales switched to an opt-out system. Among those aged 16-70, we found levels of new sign-up over this period ranged from as little as 6% of residents in some communities to as much as 24% in others. Higher rates of new sign-up during this period were generally found in and around major urban areas in the south east and north east of Wales, while lower rates were shown in south Wales valley communities.</p>
<p>Exploring the local geography of registered donors will undoubtedly raise questions about whether these differences are caused by variations in people or place – and rightly so. But having a better understanding of the potential geography of registered donors could be of considerable benefit to all the UK nations – especially to those local policymakers and practitioners working within them. </p>
<p>For now, rates of organ donation in the UK are still someway behind high performing countries such as Spain, which had <a href="http://www.irodat.org/?p=database&c=ES#data">46.9 donors per million</a> people in 2017, compared to <a href="http://www.irodat.org/?p=database&c=GB#data">23 donors per million</a> in the UK. Figures for 2017-18 also show the number of people registering a decision to opt-out of organ donation in the UK has increased to more than <a href="https://nhsbtdbe.blob.core.windows.net/umbraco-assets/1616/united_kingdom.pdf">500,000</a>. </p>
<p>Tracking local trends can provide important information that will help identify areas where fewer people are opting in to organ donation, or, in the future (or now in Wales), areas where more people are opting out. Information that could play a vital role in helping specific groups and communities learn about the importance of organ donation, and ultimately help save lives.</p><img src="https://counter.theconversation.com/content/96937/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Nicholas Page does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>To encourage more people to donate, we need to figure out how location has affected their decision.Nicholas Page, Senior Research Assistant, WISERD, University of South WalesLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/947102018-05-30T10:38:17Z2018-05-30T10:38:17ZOrgans-on-chips: Tiny technology helping bring safe new drugs to patients faster<figure><img src="https://images.theconversation.com/files/220515/original/file-20180525-90281-17z2fmg.jpg?ixlib=rb-1.1.0&rect=46%2C84%2C4087%2C3038&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">It doesn't look like a kidney, but this 'kidney-on-a-chip' is a breakthrough for new drug testing.</span> <span class="attribution"><span class="source">Alex Levine</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span></figcaption></figure><p>Getting a new pharmaceutical from an <a href="https://www.fda.gov/ForPatients/Approvals/Drugs/default.htm">idea in the chemistry lab to market</a> takes many years and billions of dollars. Each year just <a href="https://www.fda.gov/Drugs/DevelopmentApprovalProcess/DrugInnovation/ucm537040.htm">several dozen new drugs are approved</a> for use in the United States. </p>
<p>Human “organs-on-chips” are leading a revolution in drug safety testing. These devices use human cells to model the structure and function of human organs and tissues. By testing the potential effects of drugs on different organs faster than traditional methods, organs-on-chips can reduce the need for animal studies and better predict which new drugs will effectively treat human disease.</p>
<p><a href="https://scholar.google.com/citations?user=dHBPovIAAAAJ&hl=en&oi=ao">As part</a> of an interdisciplinary research <a href="http://depts.washington.edu/kellylab/">team</a> with funding support from the National Center for Advancing Translational Sciences, we’re working on a kidney-on-a-chip to improve our understanding of how kidney diseases begin and which drugs can safely treat them. </p>
<h2>Quicker and better testing</h2>
<p>Historically, laboratory testing for new drugs is performed in cells grown in dishes or flasks. If a drug passes initial screening tests in vitro, researchers next test it in vivo in live animals to determine the effects of a new drug on a whole system instead of just one cell type at a time. Finally, after many years of laboratory investigation, researchers will test a promising new drug in people to see if it is safe and effective. </p>
<p>The problem is <a href="https://www.pharmaceutical-technology.com/features/featurecounting-the-cost-of-failure-in-drug-development-5813046/">9 out of 10 of these drugs</a> never make it from small-scale human tests to the patient because they turn out to be ineffective or toxic, even if they showed promising results in early testing.</p>
<p>Organs-on-chips have the potential to completely transform that system. Ranging from the size of a fingernail to that of a credit card, they’re composed of fluid channels and tiny chambers that contain human cell samples. Organs-on-chips <a href="https://ncats.nih.gov/tissuechip/about">in development in labs around the country</a> include kidney, lung, liver, intestine, skin, brain, heart, bone and reproductive systems.</p>
<p>In an organ-on-a-chip, flowing liquid supplies the cells with oxygen and nutrients, similar to the way blood sustains cells in the human body. It’s this constant flow that makes these devices special. Cells grown in organs-on-chips devices act more like cells in a human organ than do cells grown in flat dishes without flow.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/220361/original/file-20180524-51141-1z0jvvy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/220361/original/file-20180524-51141-1z0jvvy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/220361/original/file-20180524-51141-1z0jvvy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/220361/original/file-20180524-51141-1z0jvvy.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/220361/original/file-20180524-51141-1z0jvvy.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/220361/original/file-20180524-51141-1z0jvvy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/220361/original/file-20180524-51141-1z0jvvy.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/220361/original/file-20180524-51141-1z0jvvy.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Fluid circulates through a kidney-on-a-chip.</span>
<span class="attribution"><span class="source">Alex Levine</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<h2>Case of the kidney-on-a-chip</h2>
<p><a href="https://www.niddk.nih.gov/health-information/kidney-disease/kidneys-how-they-work">Kidneys are incredibly important</a> to overall human health. The two fist-sized kidneys remove drugs and unwanted compounds from the body and play a critical role in maintaining proper salt and water balance, blood pressure and vitamin D and bone health. Genetic conditions and even commonly administered medications can, in some circumstances, damage the kidneys.</p>
<p>In the U.S., <a href="https://www.cdc.gov/kidneydisease/pdf/kidney_factsheet.pdf">15 percent of adults have kidney diseases</a>. But most don’t even know it, because kidney diseases often display no symptoms until the condition is very advanced. There’s a pressing need to understand how kidney disease begins, and to develop new safe and effective treatments.</p>
<p>Here at the University of Washington, our kidney-on-a-chip research team is composed of scientists from many different disciplines, including pharmacy, pharmaceutical sciences, nephrology (kidney medicine), toxicology, biochemistry and bioengineering.</p>
<p>In partnership with <a href="https://www.nortisbio.com">Nortis, Inc.</a>, a local biotechnology company, our team has created a small device — the size of a business card — with up to three tiny tubes, each one-thousandth the size of a drop of water, containing 5,000 human kidney cells. When tiny amounts of fluid are pumped through the tubes, the <a href="https://doi.org/10.1016/j.kint.2016.06.011">kidney cells are exposed to important signals</a> that help the cells in the chip behave as if they were in a live kidney.</p>
<p>We’ve found that the kidney cells release signals – called biomarkers – of injury when exposed to known kidney toxins. Our research showed that cells on the chip released markers of injury commonly seen in the urine of people with kidney damage. Testing with the older method, using cells on plates, did not show any damage with the same treatment. This suggests that the <a href="https://doi.org/10.1681/ASN.2015010060">kidney-on-a-chip may be better</a> than existing methods at predicting if a new drug will cause kidney damage in humans.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/215467/original/file-20180418-163975-nzy7ci.jpg?ixlib=rb-1.1.0&rect=60%2C68%2C892%2C589&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/215467/original/file-20180418-163975-nzy7ci.jpg?ixlib=rb-1.1.0&rect=60%2C68%2C892%2C589&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/215467/original/file-20180418-163975-nzy7ci.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/215467/original/file-20180418-163975-nzy7ci.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/215467/original/file-20180418-163975-nzy7ci.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/215467/original/file-20180418-163975-nzy7ci.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/215467/original/file-20180418-163975-nzy7ci.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/215467/original/file-20180418-163975-nzy7ci.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">These devices do a better job of testing how molecules affect living human cells.</span>
<span class="attribution"><span class="source">Alex Levine</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<h2>Connecting organs-on-chips to mimic systems</h2>
<p>Now that we’ve had these promising results, scientific teams across the country are starting to connect different organs together to replicate a more complex, multi-organ system, to give greater insights into how drugs affect people. For example, we were able to connect a <a href="https://doi.org/10.1172/jci.insight.95978">liver-on-a-chip to a kidney-on-a-chip</a> to learn how a plant extract used in some herbal medicines, called aristolochic acid, damages kidney cells. This chip-to-chip investigation reinforces the need for interconnected organs-on-a-chip to replicate the complex mechanics in the human body.</p>
<p>In the coming year, our kidney-on-a-chip project will be one of several <a href="https://ncats.nih.gov/tissuechip/projects/space">sent to the International Space Station</a> where low gravity speeds up changes in cells, sometimes causing health problems for astronauts. The Space Station could be the perfect place to find out more about kidney diseases in weeks, rather than years or decades.</p>
<p>Organs-on-chips can also be used to discover new drug targets. Our team is evaluating the kidney-on-a-chip as a tool to personalize drug selection and dosing in people with kidney cancer, polycystic kidney disease and chronic kidney disease. Other organs-on-chips labs around the country are studying diseases of the immune system, brain, lungs, heart and blood vessels. By working together, dozens of research teams are developing this new technology to revolutionize drug discovery, leading to the development of better and safer medications for all.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/CYBrpCUkdVQ?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">A pocket-size revolution in kidney research.</span></figcaption>
</figure><img src="https://counter.theconversation.com/content/94710/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Catherine Yeung receives funding from The National Institutes of Health (NCATS, NIGMS)</span></em></p><p class="fine-print"><em><span>Edward Kelly receives funding from National Institutes of Health, Environmental Protection Agency and Center for Advancing Science in Space.</span></em></p><p class="fine-print"><em><span>Jonathan Himmelfarb has received relevant grant funding from the U.S. National Institutes of Health and the Center for Advancement of Science in Space.</span></em></p>Researchers who’ve created a kidney-on-a-chip explain why these kinds of devices are an improvement over traditional ways to test new drugs.Catherine Yeung, Research Assistant Professor of Pharmacy, University of WashingtonEdward Kelly, Associate Professor of Pharmaceutics, University of WashingtonJonathan Himmelfarb, Director of the Kidney Research Institute and Professor of Medicine, University of WashingtonLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/765232017-06-13T03:17:26Z2017-06-13T03:17:26ZAn extra organ or body part is more common than you think<figure><img src="https://images.theconversation.com/files/172590/original/file-20170607-3710-vrt3zk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Society has long treated people with extra limbs as anatomical oddities. But having an extra body part or organ is surprisingly common and many people don't know they have them.</span> <span class="attribution"><a class="source" href="https://upload.wikimedia.org/wikipedia/commons/1/1d/The_Peerless_Prodigies_of_Physical_Phenomena.jpg">Ddicksson/Wikimedia Commons</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-sa/4.0/">CC BY-NC-SA</a></span></figcaption></figure><p>Doctors thought they were operating on a malignant tumour when they set about removing an unusual oval lump on the right side of a 40-year-old woman’s body. What they recovered instead was a perfectly normal and fully functioning <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4580026/">extra spleen</a>.</p>
<p>Most of us only have one spleen, an organ involved in immune function and blood filtering. But accessory or extra spleens are quite common, appearing in more than <a href="https://www.ncbi.nlm.nih.gov/pubmed/22764656">one in ten</a> people.</p>
<p>It is not unusual for people with extra organs to be completely unaware of their existence. Often they are discovered accidentally during diagnostic scans for unrelated conditions. While many of these extra organs are rare, others are far more common than many of us believe. Some need to be surgically removed and others can be left alone.</p>
<p>The extra spleen, described above, is an example of what doctors call supernumeracy, when the body has an extra organ, part or structure. </p>
<h2>Supernumeracy in history</h2>
<p>Supernumeracy has long fascinated us, with many obvious and peculiar examples throughout history.</p>
<p>Witch hunters in the 16th and 17th centuries often identified supposed witches by their <a href="https://www.ncbi.nlm.nih.gov/pubmed/17521013">third nipple</a>, although these extra nipples were often mistaken for moles or birthmarks.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/172596/original/file-20170607-3698-1b6re3v.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/172596/original/file-20170607-3698-1b6re3v.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/172596/original/file-20170607-3698-1b6re3v.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=891&fit=crop&dpr=1 600w, https://images.theconversation.com/files/172596/original/file-20170607-3698-1b6re3v.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=891&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/172596/original/file-20170607-3698-1b6re3v.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=891&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/172596/original/file-20170607-3698-1b6re3v.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1120&fit=crop&dpr=1 754w, https://images.theconversation.com/files/172596/original/file-20170607-3698-1b6re3v.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1120&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/172596/original/file-20170607-3698-1b6re3v.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1120&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Myrtle Corbin, with her four legs, was a side-show star. But most examples of supernumeracy are more subtle or hidden.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/Category:Myrtle_Corbin#/media/File:Myrtle_Corbin.jpg">Wikimedia Commons</a></span>
</figcaption>
</figure>
<p>Then there are the famous cases in the era of the <a href="https://www.sheffield.ac.uk/nfca/researchandarticles/freakshows">Barnum and Bailey freak shows</a>, which displayed truly extraordinary examples of supernumeracy. These included the sideshow stars Frank Lentini, the three-legged man, and Myrtle Corbin, the four-legged woman.</p>
<p>Their conditions were the result of being attached to partially formed parasitic twins (also known as an asymmetrical or unequal conjoined twins) that had not fully separated during development. Both went on to marry other people and have normal children.</p>
<p>More recently was the internationally celebrated case of the eight-limbed Indian girl Lakshmi Tatma, born in 2005, who had four arms and four legs. Some considered her to be a reincarnation of a Hindu goddess. A 72-hour operation eventually separated her from her parasitic twin.</p>
<h2>What causes supernumeracy?</h2>
<p>Supernumeracy is caused by errors in how the embryo develops. While some of these conditions can be genetic, most occur spontaneously and have no known cause.</p>
<p>To understand how this happens it helps to think of the development of an embryo into a human as being like a finely tuned orchestra following the directions of a strict conductor.</p>
<p>Every player in the orchestra needs to know when to start playing and when to stop, how fast the pace should be and what instrument needs to dominate in every part of the symphony. If percussion plays too fast or strings come in too soon, it can end in a disaster.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/9DRx8hRb0YI?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Errors in embryonic development led to Indian girl Lakshmi Tatma being born with eight limbs.</span></figcaption>
</figure>
<p>Likewise, when the embryo develops, structures that will eventually make up a human baby need to fold, move, fuse and disappear at exactly the right time. If one structure persists too long or appears too early, it may block the way for another structure migrating to a new position. If a structure duplicates or fails to fuse with its other half, it can end up forming an extra organ.</p>
<p>What is most remarkable about the process of embryonic development is that in the great majority of cases we produce perfectly formed children.</p>
<figure class="align-left zoomable">
<a href="https://images.theconversation.com/files/172592/original/file-20170607-3662-11urvjg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/172592/original/file-20170607-3662-11urvjg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/172592/original/file-20170607-3662-11urvjg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=388&fit=crop&dpr=1 600w, https://images.theconversation.com/files/172592/original/file-20170607-3662-11urvjg.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=388&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/172592/original/file-20170607-3662-11urvjg.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=388&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/172592/original/file-20170607-3662-11urvjg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=488&fit=crop&dpr=1 754w, https://images.theconversation.com/files/172592/original/file-20170607-3662-11urvjg.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=488&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/172592/original/file-20170607-3662-11urvjg.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=488&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">This child developed extra toes as a result of exposure to the drug thalidomide in the womb.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/22719239@N04/2241322031/">Otis Historical Archives, National Museum of Health and Medicine/flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>In many cases of supernumeracy we don’t know what disrupted the development of the embryo, although in some cases a mother’s exposure to certain drugs or chemicals during pregnancy may be the cause.</p>
<p>One of the best known examples is <a href="https://theconversation.com/remind-me-again-what-is-thalidomide-and-how-did-it-cause-so-much-harm-46847">thalidomide</a>, a drug prescribed to pregnant women in the 1950s and 1960s to treat morning sickness but caused some 10,000 children worldwide to be born with significant birth defects.</p>
<p>Although absent or short limbs were among the most common birth defects reported, <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4737249/">some babies had extra toes</a>.</p>
<p>The drug was commonly taken in the first trimester of pregnancy when morning sickness is more common and when, coincidentally, the embryo develops most rapidly.</p>
<h2>Why supernumeracy matters today</h2>
<p>The historical cases highlighted earlier are all examples of extreme supernumeracy. But most cases of supernumeracy are so inconspicuous they are found by chance and have little impact on people’s lives.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/172593/original/file-20170607-3677-blegdr.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/172593/original/file-20170607-3677-blegdr.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/172593/original/file-20170607-3677-blegdr.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/172593/original/file-20170607-3677-blegdr.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/172593/original/file-20170607-3677-blegdr.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/172593/original/file-20170607-3677-blegdr.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/172593/original/file-20170607-3677-blegdr.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/172593/original/file-20170607-3677-blegdr.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Many people have extra teeth, like this 25-year-old man.</span>
<span class="attribution"><a class="source" href="https://radiopaedia.org/cases/supernumerary-tooth-2">Dr Dalia Ibrahim/Radiopaedia.org, rID: 46513</a></span>
</figcaption>
</figure>
<p>In fact, most of the supernumerary organs we see in cadavers in the anatomy laboratory belong to body donors who were unaware of them during their lifetime.</p>
<p>Some supernumerary structures are very rare, including additional <a href="https://www.ncbi.nlm.nih.gov/pubmed/11450783">kidneys</a>, <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3446048/">penises</a> or <a href="https://www.ncbi.nlm.nih.gov/pubmed/17465296">vaginas</a>. Others are relatively common, including extra <a href="https://www.ncbi.nlm.nih.gov/pubmed/9809822">nipples</a> and <a href="https://www.hindawi.com/archive/2014/764050/">teeth</a>. </p>
<p>Understanding these less obvious cases can be very important when diagnosing and treating patients. That’s why medical students learn about them.</p>
<p>One of the supernumerate structures taught in medical school is the cervical rib, an extra rib at the base of the neck above the normal rib cage, which occurs in about one in 200 people. </p>
<p>While not apparent without diagnostic imaging, it can compress nerves and blood vessels that pass between the neck and shoulder, leading to <a href="https://www.ncbi.nlm.nih.gov/pubmed/24316293">numbness and pain</a> in the arms and fingers. So, every medical student is taught about this anatomical variation.</p>
<p>Being aware of supernumerate structures can help doctors make a correct diagnosis.
For example, about one in 2,000 of us have an extra ureter – a muscular tube that carries urine from the kidneys to the bladder, where it is stored until ready to be excreted through the urethra. While an extra ureter does not necessarily cause problems, in some people the ureter connects the kidney <a href="http://www.sciencedirect.com/science/article/pii/S0140673662919736?via%3Dihub">with the wrong structure</a>, for example with the vagina or urethra.</p>
<figure class="align-left zoomable">
<a href="https://images.theconversation.com/files/172594/original/file-20170607-3710-y5aw5n.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/172594/original/file-20170607-3710-y5aw5n.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/172594/original/file-20170607-3710-y5aw5n.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=657&fit=crop&dpr=1 600w, https://images.theconversation.com/files/172594/original/file-20170607-3710-y5aw5n.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=657&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/172594/original/file-20170607-3710-y5aw5n.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=657&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/172594/original/file-20170607-3710-y5aw5n.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=826&fit=crop&dpr=1 754w, https://images.theconversation.com/files/172594/original/file-20170607-3710-y5aw5n.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=826&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/172594/original/file-20170607-3710-y5aw5n.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=826&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Extra nipples are another common example of supernumeracy.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Trzeci_sutek.jpg">Zureks/Wikimedia Commons</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>This means the ureter bypasses the normal mechanism that stops urine from leaking out of the bladder. This anomaly is usually noticed in childhood, as patients who have this type of ureter often have continuous dripping of urine which needs to be surgically corrected.</p>
<p>Doctors also need to be aware that for patients with supernumerary organs, these organs need to be included in cancer screening. </p>
<p>For example, if a patient has supernumerary breasts, these breasts need to be included when screening for lumps or in mammograms. </p>
<p>Even the smallest supernumerary structure may alter some body functions, as it did for a 29-year-old optometry student who in a practical class accidentally discovered she had an <a href="https://www.ncbi.nlm.nih.gov/pubmed/25943682">extra opening in her eyelid</a> known as a punctum. </p>
<p>The punctum helps drain away excessive tears. Usually, we only have one in each eyelid but this student had two in the same eyelid.</p>
<p>This explained why anaesthetic eye drops used for optometry procedures were far less effective in that eye, as the drops drained away twice as fast.</p>
<p>Knowing that she had a supernumerary punctum, doctors told her to press down on it to close off the opening when she needed to use eye drops.</p>
<p>So, while many of us may be aware of supernumerary structures because of the extraordinary examples usually related to parasitic twins, the more subtle supernumerary structures, which are far more common, have an important place in the study of anatomy and medical practice.</p><img src="https://counter.theconversation.com/content/76523/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Michelle Moscova does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Most people don’t know if they have a hidden extra organ. But they’re surprisingly common and often harmless.Michelle Moscova, Senior Lecturer in Anatomy, UNSW SydneyLicensed as Creative Commons – attribution, no derivatives.