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Posted within the hour on the Washington Post web site. > > Tony Mazzaschi > AAMC > > Scientists: Stem Cells Colonies Created Without Harming Embryos > > By Rick Weiss > Washington Post Staff Writer > Thursday, January 10, 2008; 12:16 PM > > Scientists in Massachusetts said today they had created several colonies > of human embryonic stem cells without harming the embryos from which > they were derived, the latest in a series of recent advances that could > speed development of stem cell-based treatments for a variety of > diseases. > > In June, scientists in Japan and Wisconsin said they had made cells very > similar to embryonic stem cells from adult skin cells, without involving > embryos. But that technique so far requires the use of gene-altered > viruses that contaminate the cells and limit their biomedical potential. > > By contrast, the new work shows for the first time that healthy, normal > embryonic stem cells can be cultivated directly from embryos without > destroying them. > > That means the work should be eligible for federal financing under > President Bush's six-year-old policy of funding only stem cell research > that does not harm embryos, said study leader Robert Lanza, chief > scientific officer at Advanced Cell Technology in Worcester. > > But that is not likely, said Story Landis, who heads the National > Institutes of Health stem cell task force, which oversees grants for > studies on the medically promising cells. > > The embryos Lanza used, which were donated for research, appear not to > have been damaged, Landis acknowledged. However, she said, "it is > impossible to know definitively" that the embryos were not in some > subtle way harmed by the experiment. And "no harm" is the basis of the > Bush policy, she said. > > Landis said the only way to prove that the technique does not harm > embryos would be to transfer many of them to women's wombs and see if > the resulting babies were normal. But it would be unethical to do that > experiment, she said, so the question cannot be answered. > > That standard has Lanza fuming. By all scientifically recognized > measures, he said, the embryos -- currently frozen in suspended > animation because they were donated for research and not to make babies > -- are normal, he said. > > "I think the burden of proof lies with the NIH and the Bush > administration to show that an embryo was harmed," Lanza said. > > The new technique involves the careful removal of a single cell from a > newly formed eight-cell embryo and coaxing that cell to divide > repeatedly until it forms a self-replenishing colony of embryonic stem > cells. > > Fertility doctors perform such "single-cell biopsies" thousands of times > every year to test the genetic health of embryos conceived by in vitro > fertilization, with little or no apparent effect on the remaining seven > cells' ability to form a normal baby. The idea is to check the removed > cell for DNA defects and transfer to the woman's womb only embryos whose > cells test normal. > > Lanza's team first reported growing stem cells from individual embryo > cells in 2006. But that work was criticized for not showing plainly that > the plucked embryos could develop normally, relying instead on evidence > from the nation's many fertility clinics that embryos can survive the > process. > > In the new experiments, he and his colleagues allowed their seven-cell > embryos to continue growing in laboratory dishes for up to five days -- > the oldest that embryos are typically cultured in fertility clinic labs > before being transferred to a mother's uterus. > > Of 43 embryos biopsied, 36 (or 83 percent) developed into healthy > five-day-old embryos, as determined by various measures used by the > clinics, the team reports in today's online edition of the journal Cell > Stem Cell. > > That's a survival rate as good as or better than occurs with fertility > clinic embryos generally, whether they are biopsied or not, according to > several published reports. > > "The biopsy had no effect on the embryos' development," Lanza said, > adding that the effort produced five new colonies of stem cells. That is > a much higher efficiency than was previously achieved. And because of > improved culture conditions, the new stem cells do not need to be fed > chemicals from destroyed embryos, as was previously the case. > > "It is a technically impressive piece of work," said Douglas A. Melton > of the Harvard Stem Cell Institute. "They've demonstrated their ability > to isolate human embryonic stem cell lines without destruction of the > embryos" -- something few scientists thought possible just a few years > ago. > > "But the fundamental ethical issue remains," said Kathy Hudson, director > of the Genetics and Public Policy Center at Johns Hopkins University -- > namely, how to prove that the approach is inherently harmless. > > Very few studies have looked at the outcomes of fertility treatments in > which biopsies had been performed, Hudson said. And those that have been > done -- including a widely publicized July report that found that > fertility clinic clients who had their embryos biopsied had about a 30 > percent lower chance of giving birth -- are riddled with flaws, she > said. > > But one thing is clear, Hudson said: "Embryo biopsy is tricky and > requires extraordinary good hands and technical skills. And even in the > best hands, embryos are sometimes lost." > > As long as that risk is there, funding under Bush's policy will not be > available, Landis said -- with one possible exception. > > Although NIH will not fund Lanza's method of making stem cells, she > said, the agency might fund studies on the cells themselves once they > are isolated from the embryos with private money and the embryos are > shown to be healthy. > > Asked who would make that funding decision, Landis said it would be up > to NIH officials. But pressed to say whether the White House would have > an influence, she paused. > > "I'm sure they would have an interest in such a decision," she said. >>_______________________________________________ > CAMR.friends mailing list > [log in to unmask] > http://www.freehood.net/mailman/listinfo/camr.friends Rayilyn Brown Board Member AZNPF Arizona Chapter National Parkinson's Foundation [log in to unmask] ---------------------------------------------------------------------- To sign-off Parkinsn send a message to: mailto:[log in to unmask] In the body of the message put: signoff parkinsn