F r o m
g l o w - i n - t h e - d a r k
m o n k e y s , l a t e s t k e y
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d o g s
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j e l l y f i s h
x e n o t r a n s p l a n t a t i o n
F r a n k e n s t e i n u n l o c k i n g m i s s t e p W o r d s
n e w
i n t o b y
s c i e n c e . m e d i c a l
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J a m e s
ou are 5’9”, weighing 13 stone. Every day you eat a nutritious diet. You exercise daily – running, jumping, lifting and stretching. Your body is a temple. So the doctor breaks the news slowly: you have a rare heart defect and, like many others, you are on a long transplant list. You’re going to die before you get your turn and there’s nothing you can do about it. Except, now, there is. While in recent years scientific scare stories have centred on nightmare visions regarding the ethical concerns of stem cell research, it’s xenotransplantation that has proved the most intriguing, and potentially controversial, of all modern-day medical breakthroughs. According to official NHS figures, more than 10,000 people in the UK are waiting for a transplant. Of these, 10 percent – three a day – will die before they receive an organ. However, through xenotransplantation, the process of harvesting organs from transgenic animals, a lack of donors could become a thing of the past. The procedure involves introducing a foreign gene into a living organism – which could be anything from a pig to baboon – in the hope that it will eventually exhibit a new property in its gene sequence and transmit that property to its offspring. It’s delicate and complicated stuff, but potentially xenotransplants could alleviate shortfalls around the world and save thousands of lives by increasing the number of available donor organs. “Right now, there just aren’t enough hearts for all the patients who need them,” Dr Barry Starr of Stanford’s Biomedical Sciences programme explained to a visiting student. “Many people die while they’re on the waiting list and clearly we need a new supply of hearts;
m o r a l
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m a r v e l s , m a z e ?
W r i g h t
pigs may be just the supplier we’re looking for.” So what are we waiting for? “Unfortunately, there are lots of problems with putting pig hearts into humans,” he continued. “First off, our bodies hate pig hearts. Our immune system immediately attacks it, like trying to get rid of a foreign invader. Rejection is a big problem with all transplants, even the human-to-human ones; patients need to take medicine that weakens their immune system for the rest of their lives just for it to work. But a pig’s heart is just too different for this medicine to work. This is where genetics can help. Scientists are trying to make pig hearts our bodies won’t reject by fiddling with the pig’s genes. “A second problem,” revealed Dr Starr, “has to do with hidden viruses. Animals have harmless viruses [called ‘endogenous retroviruses’] that hang out in their DNA. These viruses don’t infect other animals and are passed down from parents to children. But we don’t know if the viruses will stay harmless if they’re moved into another animal. This means we don’t know what pig viruses will do in people; it’s possible they might do nothing and stay in the pig heart. The worry, though, is that they might spread into the patient’s cells and make the patient sick. The even bigger worry is that they might gain the ability to move easily from person to person. Then we’d have a worldwide epidemic on our hands. We might have another case like the Spanish Flu that struck right after World War I. That virus probably came from a bird and it killed 25 million people worldwide in a single year, so scientists, rightfully, need to do everything they can to make sure it won’t happen.” “There are also real moral and ethical issues here,” argued Alan Berger, Executive Director of the Animal Protection Institute, in a panel
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