NIH says that adult stem cells were difficult to replicate. Ironically, research funded by NIH itself and the Christopher Reeve Paralysis Foundation, which advocates using surplus human embryos for research, reported in August that adult human bone-marrow cells grew rapidly in culture and formed nerve cells. Such new nerve cells have huge potential for treating paralysis and diseases of the nervous system, such as Parkinson's. A growing supply of umbilical-cord blood, donated after childbirth, also provides a rich source of stem cells. As early as 2001, when new grants are awarded, the direction of federal research will be clearer.
Some critics suspect that the issue is partly psychological.
That frontier includes research using human embryos, but not necessarily stem cells from adult donors, which is merely a transplant technology. Another key concern of critics is that the large and growing supply of unclaimed embryos will be used for purposes other than research into life-threatening diseases. The Senate may vote on the measure by the end of this year. Related Elsewhere Visit the NIH homepage . Read more about bioethics concerns at Trinity's Center for Bioethics and Human Dignity .