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To: neverdem
No one doubts whether Verfaillie found the stem cells that she said she did. The problem is that there were mistakes in the reports about how she actually did it and that other labs have had a hard time duplicating her work. From the New Scientist article on the "flaws":

"In her most recent paper, Verfaillie and Irving Weissman, a stem cell biologist at Stanford University in California, showed that MAPCs can give rise to all the cell types found in blood, but it is still unclear whether MAPCs are as versatile as she claimed in the original Nature paper."

Many researchers are unable even to isolate them. “They’re very testy cells,” observes Amy Wagers of Harvard University, who spent a week in Verfaillie’s lab trying in vain to learn the technique.

The problems with the marker profiles may help explain these difficulties. “If I had been following this recipe since 2002, I’d be extremely angry,” says Jeanne Loring, a stem cell biologist at the Burnham Institute for Medical Research in La Jolla, California.

A follow up study published in Journal of Experimental Medicine (I don't have link) and reported on in Science,that included doubter Irving Weissman proved multipotency, if not pleuripotency.

"The work has impressed one skeptic, Stanford blood stem cell researcher Irving Weissman, who collaborated on the new work. Weissman calls the result "remarkable." His skepticism, he adds, "makes me a perfect collaborator, because I insisted on very rigorous criteria for the experiments." He emphasizes, as does Verfaillie, that these cells are clearly not as versatile as ES cells. But despite their limitations, they could prove to be useful therapeutically.

"A lot of people have lost interest in MAP cells by this point," says Weissman. "What our paper will help do is get everybody to look at it again." Others agree. "I'm sure it will revive interest in MAP cells," says stem cell researcher Paul Schiller of the University of Miami, Florida."

Perhaps, now that the "recipe" is corrected, more labs will confirm the original reports.

7 posted on 02/27/2007 11:42:56 AM PST by hocndoc (http://www.lifeethics.org/www.lifeethics.org/index.html)
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To: hocndoc

Thanks for the links.


9 posted on 02/27/2007 12:03:14 PM PST by neverdem (May you be in heaven a half hour before the devil knows that you're dead.)
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