Tim Radford and Michael White Monday August 14, 2000 The scientists who led the world in cloning animals are withdrawing from controversial research into pigs that could provide organs for human transplant. Just as the government cautiously prepares to endorse the use of human embryos for research into "therapeutic cloning", Ian Wilmut of the Roslin Institute, near Edinburgh, which partners a commercial venture with the US biotechnology giant Geron, revealed that research into pigs-for-transplant was to end at Roslin. The decision follows widely voiced fears that new diseases could be passed to humans through the use of animal organs. On Wednesday the government is expected to publish a report by the chief medical officer, Liam Donaldson, giving the all-clear to very limited use of human embryos for studies which could end in an entirely different kind of tissue transplant. The final decision will be left to a free vote of MPs. Humans are made of more than 200 kinds of specialised cells for nerves, skin, liver, heart, blood, bone, and so on. All of these stem from a ball of embryonic cells that develops to form a foetus. There is a worldwide race to harness embryonic stem cells to repair nerve damage and halt degenerative diseases - and eventually to replace failing organs. In the meantime, victims of heart, liver and kidney failure are dying because there are too few human transplant donors, and groups in Britain and the US have been working to develop a line of genetically engineered pigs with human-compatible hearts to provide a steady supply of organs that would survive immediate rejection. Although firms such as Imutran, the Cambridge-based group, and more lately Geron Bio-Med at Roslin and in the US have been working on "xenotransplantation" - transplants from a foreign source - the British government has blocked any human trials. There have been increasing fears that unknown pig viruses might enter the human population. Microbes that do no apparent harm to one natural host can wreak havoc when they transfer to another. Prof Wilmut said the decision to end pig research was disappointing. He told Scotland on Sunday: "We are reducing pig work. It has not quite finished but it will be before long. "I think the concern is mainly unknown viruses. That's the frightening thing. If you know what the disease is you know how to look for it." David White, co-founder of Imutran, who developed Astrid, the world's first pig with a human-compatible heart, said he was disappointed to hear the Scottish group was no longer in the field. "The technology Ian Wilmut and his group developed is a major advance and I think the question of the safety issues can be resolved." But even as one door closed for Roslin, another is about to open. Geron Bio-Med was formed to marry the technique that led to Scotland's Dolly the sheep with the research into stem cells pioneered by the Geron Corporation. The usage of donated embryos in Britain is strictly controlled, and is only permitted for fertility research. But for more than a year, British scientists have been hoping for permission to use surplus embryos to provide stem cells which could provide the basis of a new kind of cure. On Wednesday, they are likely to get it, providing MPs back the Donaldson report in a free vote. The cautious approach implied in a free vote will disappoint some MPs who would like to see Tony Blair being "bold in defence of science" and whipping Labour MPs through the lobbies after first exposing the hollowness of the mainly-religious opposition. _______________________________________________ Crashlist resources: http://website.lineone.net/~resource_base To change your options or unsubscribe go to: http://lists.wwpublish.com/mailman/listinfo/crashlist
