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Pig Transplants May Help Parkinson's Patients 04:57 p.m. Feb 27, 1997 EST WASHINGTON (Reuter) - Fetal pig cells have been successfully transplanted into the brains of Parkinson's patients, a turning point in cross-species transplantation and a possible advance toward treating the common neurological disorder, scientists said Thursday. Other scientists have experimented with transplanting human brain cells from aborted fetuses but the supply of such tissue is limited and fraught with ethical complications. So researchers turned to pigs, getting federal approval to do a cross-species transplant, which is rare and controversial because of fears of transferring an animal disease into the human population. Parkinson's afflicts roughly one million Americans and millions more throughout the globe. For reasons not yet understood, they do not have enough of the chemical dopamine in their brains and gradually develop tremors and other motor problems. Drugs can slow the progression but there is no cure. Twelve patients have had the pig cell transplant and early indications are that the procedure is safe and the patients seem to benefit, although it is too soon to know if the treatment will work indefinitely, the researchers said. ``We have measured their activities, their daily living, their complications,'' said Dr. James Shoemacher. ``We have seen measurable improvements. And none has deteriorated.'' One of the 12 died of unrelated causes, giving scientists a chance to study his brain in an autopsy. Shoemacher and his colleagues report Friday in the journal Nature Medicine that the autopsy showed the transplanted cells survived in the human brain and were producing dopamine up to the patient's death. ``We found very clear evidence for surviving dopamine cells that had grown and reconnected themselves with the patient's brain,'' Harvard neuroscientist Ole Isacson said in a telephone interview. Although scientists have to be cautious in drawing conclusions based on only one patient, the team said the results so far were encouraging. ``This is really the extension of a long scientific work in my laboratory and others that show you can replace brain cells that have died, and you can also do it between species,'' Isacson said. ``That creates a reasonable hope that in the future we can create therapies that deal with the structure of the brain, and the brain can accept new cells,'' he added. Although scientists worry about possibly introducing animal diseases into humans via cross-species transplants, Isacson is confident the risk is miniscule when using healthy pig nerve cells that have been extensively screened. Another report in the same journal by Robin Weiss of the Institute of Cancer Research in London says pig retroviruses can infect human cells in laboratory cultures and replicate themselves. Those were cancer cells, which are diseased, while Isacson's experiment used healthy cells. Copyright 1997 Reuters Limited. All rights reserved. Republication and redistribution of Reuters content is expressly prohibited without the prior written consent of Reuters. Reuters shall not be liable for any errors or delays in the content, or for any actions taken in reliance thereon.