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Gene therapy used to turn back clock on Parkinson's (October 27, 2000 12:01 a.m. EDT http://www.nandotimes.com) - Researchers at a Chicago medical center have successfully used gene therapy to reverse the damage of Parkinson's disease in the brains of aged monkeys, and to stop the progression of the disease in its early stages in younger animals. By inserting a gene that increases the production of the chemical nerve transmitter dopamine directly into the animals' brains, scientists at Rush-Presbyterian-St. Luke's Medical Center and Lausanne University in Switzerland were able to significantly reverse the cellular brain damage. Doctors now usually try to make up for the loss of dopamine with a drug that helps the brain produce it, but the effect eventually wears off. Some success has been achieved by grafting fetal nerve tissue into brains of Parkinson's patients, but this doesn't stop the loss of the original cells. The big hope lies in some way of stopping the loss of the critical dopamine-producing cells before the disease advances too far. "The study suggests a new approach to forestall disease progression in newly diagnosed Parkinson's disease patients," said Jeffrey Kordower, director of the Research Center for Brain Repair at Rush and lead author of a report on the research published in the journal Science on Friday. Key to the treatment is a special virus, called lenti-GDNF, developed by Swiss researchers, that can deliver the gene for glial-derived neurotrophic factor into the brains of the primates. Kordower said it is expected that clinical testing of the lenti viral delivery system for GDNF on humans will begin in Switzerland and the United States in less than five years, depending on the outcome of a safety review by the Food and Drug Administration. Parkinson's is a slowly progressive disease that degenerates a small part of the mid-brain called the substantia nigra, which causes production of dopamine to slump. That chemical sends signals in the brain that allows people to move smoothly. The disease can cause tremors, limb stiffness, balance and gait problems, and contribute to dementia. Parkinson's affects nearly 1 million Americans, most of them over the age of 60, although some people develop the disease much earlier. The cause of the disease is unknown, but thought to have both genetic and environmental factors. There is no known cure. In the study, researchers found that the GDNF gene not only boosted dopamine production, but also the production of GDNF itself, a nutrient that strengthens and protects the brain cells that die due to Parkinson's. Two groups of monkeys were tested. The first group of eight monkeys, each about 25 years old, all had brains that displayed cellular changes associated with early Parkinson's - the cells are still intact, but have either stopped making dopamine or are making very little. They got six injections of the special delivery virus, lenti-GDNF. After three months of treatment, tests showed a dramatic increase in dopamine production, similar to the levels found in the brains of young monkeys. The second group consisted of 20 young adult monkeys with no symptoms. These primates had been trained to perform a specific hand-reach task for a food reward. They were given a chemical that initiates Parkinson's-like symptoms, then were retested, and then treated with lenti-GDNF. The animals showed great difficulty in performing the tasks after receiving the chemical. Following three months of treatment, their performance returned to near-normal. Brain scans showed the treatment had completely prevented degeneration of the monkeys' dopamine-producing system, with brain cells and their fibers preserved. By LEE BOWMAN, Scripps Howard News Service Copyright 2000 Nando Media Copyright 2000 Scripps Howard News Service http://www.nandotimes.com/noframes/story/0,2107,500273007-500426081-50266605 2-0,00.html janet paterson 53 now / 44 dx cd / 43 onset cd / 41 dx pd / 37 onset pd TEL: 613 256 8340 URL: http://www.geocities.com/janet313/ EMAIL: [log in to unmask] SMAIL: PO Box 171 Almonte Ontario K0A 1A0 Canada