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Wednesday, August 30, 2006"We have demonstrated, for the first time, that human embryonic stem cells can be generated without interfering with the embryo's potential for life," said lead author Robert Lanza. ...What Lanza's team had done was to biopsy an eight-cell human embryo and gently remove a single cell -- a standard technique nowadays in IVF. With this cell he created a stem cell line while the embryo continued to develop normally. At least that was what he intended. In fact, although 16 embryos were dismembered into 91 separate cells, Lanza produced only two stem cell lines. "It was a very disruptive, very wasteful, very inefficient procedure, and it left all the old embryos dead, just like the old method did," said Doerflinger. He also claimed that it was deceitful to post a picture of a mature healthy embryo which had survived the removal of a single cell. But BioEdge reminds us that there have been some recent developments that might turn out to be a bridge to somewhere: Japanese scientists may be on the track of one of the great dreams of regenerative medicine: making an adult cell revert into an embryonic stem cell. If their results are confirmed and if the technique also works with human cells, it could defuse the bitter ethical and political debate about embryo research. Shinya Yamanaka and Kazutoshi Takahashi, of Kyoto University, found that four factors, or genes, turned the adult cells into cells which behave like embryonic stem cells. These passed the basic ID test: when injected under the skin of healthy mice, they formed teratomas, or tumours from the three germ layers of the body. Up to now it has been thought impossible to create an embryonic stem cell without resorting to cloning. So far, no one's accused them of exaggerating. posted by Sydney on 8/30/2006 08:41:00 PM 0 comments 0 Comments: |
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