WASHINGTON -- In a laboratory in Baltimore, tangles of healthy neurons are sprouting from the spinal cords of mice stricken with a rodent version of Lou Gehrig's disease, a nerve-withering ailment for which there is no cure.
In Boston, mice that normally die in their first six months from the same disease are living a year and a half or longer.
And in a nearby Boston lab, monkeys whose motor neurons have been experimentally destroyed are growing new ones.
In all three cases, the animals were treated with embryonic stem cells, a class of cells found in human embryos and fetuses that can nourish ailing cells and grow into virtually every kind of tissue. Discovered just 18 months ago, the cells appear to have remarkable regenerative powers useful against a host of conditions, including Parkinson's disease, diabetes and, perhaps, even cancer.
But equally remarkable is the speed with which privately funded researchers leading these and other studies are moving to test their stem cells in patients. Meanwhile, publicly funded scientists remain banned from the field because federal guidelines for the ethical conduct of stem cell research languish unfinished, the victim of political wrangling over abortion.
At least one team of privately financed scientists has already met with Food and Drug Administration officials to outline strategies for starting human tests next year. And in Wisconsin, an entire stem cell research facility has just been built without a single federal dollar, to distribute human embryo cells to scientists who plan to test them in volunteers here and abroad.
The accelerating private push is thrilling patients who hope to see medical benefits in their lifetimes. But it's worrisome to some ethicists and others who believe the public would be served better if Clinton administration officials would finish and release their long-awaited rules for how the embryonic cells should be obtained and used.
Among the concerns are that parents may not be told that their embryos are being used in research; scientists may start creating human embryos from scratch just to destroy them for their stem cells; and someone may even try to use the versatile cells to clone human adults.
The rules, which would be designed to prevent these and other abuses, would be binding only on federally funded researchers. But they would serve as the gold standard for everyone in the field. If federal officials don't promulgate them soon, some say, the field of stem cell research could end up a lot like the fertility business, another area of medicine that federal regulators avoided because of abortion politics. That field has long suffered from a reputation as a "Wild West" branch of medicine in which oversight is scarce and abuses common.
"Without rules in place, you're dealing with a black box where nobody knows what's really happening," said John Fletcher, a professor emeritus of biomedical ethics at the University of Virginia in Charlottesville. "The FDA has no oversight mechanisms to look at where these embryos are coming from. You could have a runaway situation where you have embryos being created for research and the worst nightmare of liberals and conservatives coming true."