Fetal tissue grafts reverse Parkinson's.
However, despite enthusiasm about the technique's promise, researchers caution that fetal tissue transplantation is still far from offering a cure for Parkinson's or any other disease. They assert that no one has yet determined the best way to administer such transplants or followed transplant recipients long enough to demonstrate the procedure's long-term risks and benefits.
The results of the new studies are likely to further electrify the already politically charged field of fetal tissue transplantation research, which uses tissue taken from aborted fetuses. While the Bush administration continued a Reagan-era moratorium on the use of federal funds to pay for studies of such transplants (SN: 11/11/89, p.310), many expect President-Elect Bill Clinton to lift the ban following his January inauguration.
Parkinson's disease affects roughly 1 million people in the United States. Symptoms of the disease usually begin with a slight tremor, slowing of voluntary movements, and depression. As Parkinson's progresses, patients develop a characteristic shuffling gait and increasing rigidity. Those with advanced Parkinson's often "freeze" for minutes or hours at a time, sometimes unable even to swallow or open their eyes.
Parkinson's disease results from the unexplained death of cells in the brain that produce dopamine, a key chemical that transmits messages between nerve cells. The only available treatments boost the ability of brain cells to either make or take up dopamine. However, Parkinson's patients must take larger and larger doses of involuntary jerking movements - side effects that some consider worse than the disease itself.
In the first of the new reports - all of which appear in the Nov. 26 NEW ENGLAND JOURNAL OF MEDICINE - D. Eugene Redmond Jr. of the Yale University School of Medicine and his colleagues studied the effects of injecting fetal brain tissue into the brains of four Parkinson's patients. For controls, the researchers followed the health of three other patients who had been selected at random to wait one year before having similar surgery.
A year and a half after their surgery, three of the transplant patients could move more freely and resume some of the normal tasks of daily living, such as dressing and feeding themselves, Redmond's group found. (One of the patients died from complications of a stomach feeding tube inserted before the transplant). In contrast, the controls - who continued to receive medication - maintained their symptoms during their year-long wait.
The second group, led by Curt R. Freed of the University of Colorado Health Sciences Center in Denver, found significant increases in motor function in all seven patients who received transplants of fetal brain tissue. Moreover, Freed's group reports, a positron-emission tomography (PET) scan of one patient revealed that the transplanted tissue was still functioning after nearly three years.
In the third study, Hakan Widner of University Hospital in Lund, Sweden, and his colleagues injected fetal brain tissue into the brains of two patients who developed Parkinson's after injecting themselves with a bad batch of an illicit "designer drug," which killed their dopamine-producing cells. Widner's group reports that both patients regained the ability to care for themselves and walk independently.
In an editorial accompanying the new reports, Stanley Fahn of Columbia University in New York City comments that while many questions remain, the results "will undoubtedly spur optimism." In a second editorial, the journal's top two editors conclude that "there are indeed important benefits to be gained by continuing this work" and call for an end to the federal spending ban.
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|Title Annotation:||success of fetal tissue transplants may cause lift of federal ban|
|Date:||Nov 28, 1992|
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