After more than 15 years of failures by scientists around the world and one outright fraud, biologists have finally created human stem cells by the same technique that produced Dolly the cloned sheep in 1996: They transplanted genetic material from an adult cell into an egg whose own DNA had been removed. The result is a harvest of human embryonic stem cells, the seemingly magic cells capable of morphing into any of the 200-plus kinds that make up a person. The feat, reported on Wednesday in the journal Cell, could re-ignite the field of stem-cell medicine, which has been hobbled by technical challenges as well as ethical issues. Until now, the most natural sources of human stem cells have been human embryos, whose use in research poses ethical quandaries. The technique announced on Wednesday, by scientists at Oregon Health & Science University and the Oregon National Primate Research Center, uses unfertilized human eggs.
