Two research groups managed to obtain stem cells without the ethical problems posed by destroying human embryos. Through different techniques, they managed to turn human skin cells into cvasi-stem cells which appear to be pluripotent, having theoretically the ability to develop into any cell type. Still, we are years away from producing stem cells which could be used on a patient, the scientists warned.

The research, by U.S. and Japanese scientists, has been published in the journals Science and Cell.

"It's not the time to say human embryonic stem cell research is dead," James Thomson, a biologist at the University of Wisconsin in Madison, who is behind a study appearing in the journal Science, told MSNBC.

One set of experiments was published today in the journal Cell. That team was led by Shinya Yamanaka of Kyoto University. A second paper was published in Science by researchers at Thomson's lab at the University of Wisconsin. Thomson created the first human stem-cell line in 1998.

Both experiments essentially replaced four genes in adult cells to make them behave like they were still embryonic stem cells. The two teams used viruses to force these genes into the cells' DNA and reprogram them. These results which used human tissue are a big step up from similar breakthroughs in mice, separately reported this summer by Dr. Yamanaka's group and two other research teams in the U.S.

"We can now envisage a time when a simple approach can be used to produce stem cells that are able to form any tissue from a small sample taken from any of us," Ian Wilmut of the Scottish Centre for Regenerative Medicine at the University of Edinburgh, said in a statement. Wilmut led the research that gave rise to Dolly, the first cloned sheep. While Wilmut was not involved in either of the two research projects, he recently declared that he decided not to pursue a license to clone human embryos following the new research by the Japanese team.

"The work which was described from Japan of using a technique to change cells from a patient directly into stem cells without making an embryo has got so much more potential." Wilmut said for BBC a couple of days ago.