The political debate over controversial cell research shifted significantly on Thursday when researchers announced that a study in which tissue from aborted fetuses was used to treat Parkinson's disease proved to have disastrous results. Only hours after the findings were released, a pro-life organization filed a lawsuit against the federal government, seeking to block federal financing of embryonic stem cell research. The timing of the two events was merely coincidental, but critics of the fledging research field used the opportunity to galvanize their position, calling for an end to all experimentation with cells derived from fetal tissue and discarded embryos.

The first blow came when long-awaited results from the Parkinson's study hit the media. The study involved 40 patients between the ages of 34 and 75 with Parkinson's. Half of them received "sham" surgery, and the other half, the transplant of cells from the "substantia nigra." After following the patients for one year, researchers found that there were devastating side effects in 15 percent of those who received the transplant.

Meanwhile, Nightlight Christian Adoptions and several couples interested in adopting embryos filed their lawsuit, which demands that the National Institutes of Health stop the grant application process and appropriation of money to scientists doing research with stem cells harvested from human embryos.

These developments have motivated anti-abortion groups to say that they are no longer pinning all their hopes on President Bush's signing an executive order banning federal funding of this type of research. They believe that the new scientific evidence, and the impact of the lawsuit, could end the practice of controversial cell research without presidential intervention.

"The study took everybody by surprise," says Scott Weinberg, spokesman for the American Life League, which supports the suit but is not named as a plaintiff. "This completely undercuts the scientific claims that this kind of research is necessary. We've always strongly opposed these unsubstantiated claims, and [the research] merely proves that this is deleterious not only for the patient but for the embryonic person."

The groups listed as plaintiffs in the suit, along with Nightlight Christian Adoptions, which facilitates the adoption by infertile couples of unwanted frozen embryos stored at fertility clinics, include the Christian Medical Association; a woman from Arizona who is pregnant with an adopted embryo; and California and Colorado couples who want to adopt embryos and contend that stem cell research curtails the availability of embryos for adoption.

"We have an ethical alternative which is scientifically better than the embryonic stem cells," says Dr. David Prentice, a professor of life sciences at Indiana State University and a plaintiff in the suit. "There is no reason to do this research that destroys human embryos and, especially, to use human tax dollars to fund that research."

The current guidelines for stem cell research, which are at the center of the debate, were issued in August by the Clinton administration. While it is still illegal to use federal money to extract stem cells from discarded embryos, the regulations allow research with embryonic cells as long as they are obtained from and paid for by private sources.

The lawsuit alleges that these regulations are contrary to "ethical norms that protect human life from medical experimentation," and that the government has ignored other viable sources from which stem cells can be derived, such as adult bone marrow.

Last week, Tommy Thompson, the newly appointed secretary of the Department of Health and Human Services, said that government scientists would evaluate the guidelines and issue a decision on their propriety sometime this summer. But the impetus for Thursday's lawsuit was another statement by Thompson indicating that the NIH will continue to accept applications for grants in this area of research until March 15. Thompson, HHS, NIH and its acting director were all named in the suit. A spokesman for HHS said he could not comment on the complaint, and a call to the White House for comment was not returned.

A quick look at Thompson's position on this issue shows how fractured the debate over stem cell research is, and how the sides are not necessarily drawn along political lines. Thompson is against abortion, yet has expressed his support for embryonic research in the past. And his latest announcement that he will accept grant applications has pushed critics of embryonic stem cell research over the edge. They say they can't wait any longer for the president to overturn the regulations.

"We said, 'No way, this is the fox guarding the henhouse,' and we sprung into action and mobilized a grass-roots campaign urging the president to issue an executive order immediately," says Weinberg of the American Life League. "In fact, [Bush] should have done this already. This [lawsuit] is a serious vote of no confidence in regards to the pro-life credentials of this administration."

The issue of using embryos for research is emotionally charged, largely because it pits many patients with debilitating diseases like Parkinson's, Alzheimer's and diabetes against those who believe any tampering with embryos -- which are destroyed during the cell extraction process -- is unethical. Those who point to the promise of stem cells believe they can be manipulated to develop almost any type of tissue in the human body. (They are taken from the inner sphere of a fertilized egg.)

Many physicians, researchers and patients -- including actor Christopher Reeve, who suffers from spinal cord injuries -- believe that stem cell research will one day lead to a cure for their ailments, and they insist that the field of embryonic stem cell research needs time -- and funding -- in order to be successful. (While there is also great hope for adult stem cell research, those cells are considered to have less plasticity than cells from embryos.)

Sen. Patty Murray, D-Wash., is among those who strongly support stem cell research. She says she and her family have always hoped it might provide a cure for multiple sclerosis, a disease her father had until he passed away a few years ago. Thursday's complaint by a "small extremist group," she says, should not be allowed to thwart the progress in this area of medicine.

"This is not about destroying human lives, it's about saving human lives," says Sen. Murray. "I think it's outrageous that they have gone to such extremes to stop research that is going on in the most bioethical way possible." The senator also warns that if the federal government stops funding embryonic stem cell research, the field will become dependent on funding from private sources, which may not have the public's best interest at heart.

But those who oppose the controversial extraction of cells from sources such as embryos and aborted fetuses were definitely in control of the debate as the details from the disastrous study on the fetal cell treatment for Parkinson's disease came out.

In the double-blind study, led by Curt Freed from Denver's Health Sciences Center, cells from aborted fetuses were transplanted into the brains of patients with the disease. While the study, published in the New England Journal of Medicine, found that there were benefits from the transplant of fetal tissue, horrifying side effects were also experienced by some of those who received the dopamine neurons. For example, some patients could not stop chewing or flexing their wrists. One even ended up on a feeding tube.

"It's a nightmare," said Dr. Paul Greene, one of the study's researchers and a neurologist at Columbia University, in an interview with the New York Times. "And we can't selectively turn it off."

The publication of the results of the Parkinson's study came as a shock -- albeit a fortuitous one -- to anti-abortion activists. For supporters of fetal tissue research like neurologist Dr. Jeffrey Kordower, it was a huge blow. A researcher in the midst of a study looking at the effects of transplanted fetal cells in Parkinson's patients, Kordower is gravely concerned that critics will use the NEJM report as a political tool to halt all research using fetal tissue. He says that the techniques employed in the Parkinson's study were unusual, including everything from where the cells were implanted (the forehead) to the small number of fetuses used to the way the tissue was prepared. (A researcher in the study did not return a call seeking comment.)

"They will use this study as a basis to prevent stem cell research and it's inappropriate," says Kordower, who works at Rush-Presbyterian-St. Luke's Medical Center. "This is just one study." In his research so far, he says, he has not encountered any serious side effects such as the ones experienced in the study reported in the NEJM. He hopes that the results of his study of 34 Parkinson's patients, to be completed later this year, will somehow provide a fresh and convincing argument for research in his now fragile field of medicine.