 |
 |
New study a setback to fetal cell treatment The study, involving a USF neurosurgeon, found Parkinson's disease patients treated with the cells did not improve. By LISA GREENE, Times Staff Writer © St. Petersburg Times published August 23, 2003 TAMPA - A new study involving a prominent University of South Florida neurosurgeon casts more doubt on the hope that fetal tissue transplants could be the key to beating Parkinson's disease. Transplanting cells into the brains of Parkinson's patients failed to improve their symptoms overall. More troubling, more than half the patients developed uncontrolled movements in their limbs. Researchers concluded they could not recommend the cell transplants, taken from brain cells of aborted fetuses, to treat Parkinson's. Even so, researchers say they remain optimistic about the transplants and say the study offered clues for future research. "What we've found is that cell therapies are coming closer and closer to being useful," said Dr. Thomas Freeman, a USF neurosurgery professor, co-author of the study and medical director of USF's Center for Aging and Brain Repair. The research "came close, very close," said Dr. Warren Olanow, lead author of the study and neurology department chairman at Mount Sinai School of Medicine in New York. "This is a brand new field." To advocates, cell transplants seem a common-sense solution: In Parkinson's, neurons that produce a chemical called dopamine begin to die. Without dopamine to transmit signals in the brain, patients can't control their movements. Many shake and tremble, become rigid, or have trouble balancing. Even simple jobs - signing a document or opening a jar - become challenges. Researchers said if fetal brain cells could be implanted into a Parkinson's patient, they could produce new dopamine and reverse the disease. The theory has been controversial because many abortion opponents say fetal cells have no place in medical treatment. Some preliminary studies showed promise. But this study, published Friday in the Annals of Neurology, is the second carefully controlled trial that failed to show positive results. The first study, in 2001, also caused some patients to suffer uncontrollable movements. "That, to me, is the big obstacle," Olanow said. "If we don't know why these people are having a potentially serious side effect, we got trouble." Olanow and Freeman said the next step will be to return to the lab and find ways to minimize the side effects. They say the type of movements patients suffered could mean they need more transplanted cells, thus allowing the brain to make more dopamine. In the long run, Freeman said, researchers likely will abandon fetal cells and turn to stem cells, derived from bone marrow or the blood of the umbilical cord. "We have to get a more reliable cell source," Freeman said. Dr. Curt Freed, director of the Parkinson's transplant program at the University of Colorado, was a research leader on the 2001 study. He said he was disappointed with the results of the new study. But Freed said it will help show which patients are more suited for transplants. "These studies represent the first steps in learning how to repair the brain," he said. Freed and Olanow said the study also underlines the validity of a controversial surgical technique: so-called sham surgeries. In the early transplant studies, doctors and patients knew they had received transplanted cells. Researchers worried that the knowledge could skew how patients viewed their symptoms, and how doctors evaluated them. In the recent study, 34 patients underwent surgery and had dime-sized holes drilled in their skulls. Twenty-three patients had liquid droplets containing thousands of fetal brain cells placed deep inside their brains. The other 11 had holes drilled only partly through the skull, so they never got the droplets. Only Freeman knew which patients were which. Other doctors followed and evaluated the patients. In testing new drugs, researchers often find it valuable to give some patients dummy pills and compare their reactions with those of patients taking the real drug. Applying the same principle to surgical tests has always raised ethical questions. The new study, Olanow said, reinforces the validity of this type of testing with surgeries. "There aren't many surgeons who could do this," Olanow said, praising Freeman. Patients with milder Parkinson's showed some improvement. Many patients also showed some initial improvement, but that stopped after they stopped receiving a drug to keep their bodies from rejecting the transplanted cells. Freeman and Olanow said that's another area to investigate. SOURCE: The St. Petersburg Times, Fl http://tinyurl.com/kxuy * * * ---------------------------------------------------------------------- To sign-off Parkinsn send a message to: mailto:[log in to unmask] In the body of the message put: signoff parkinsn