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Volume 3 Issue 193 Published - 14:00 UTC 08:00 EST 16-Oct-2001 Next Update - 14:00 UTC 08:00 EST 17-Oct-2001
| Editor: Susan K. Boyer, RN © RAmEx Ars Medica, Inc. All rights reserved. |
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 Unknown, Toxic Molecule May Hold Key To Early Diagnosis Of Parkinson's Disease
A previously unknown, possibly toxic molecule has been found in key areas of the brains of Parkinson's patients, according to a report presented at the American Neurological Association's 126th annual meeting, earlier this month in Chicago. If the molecule--known by its acronym, ADTIQ--turns out to correlate with the presence or severity of the disease, its presence might be used as a marker to help diagnose the disease. Furthermore, if ADTIQ is found to be instrumental in harming nerve cells and leading to Parkinson's, it might be possible to develop therapies that target the molecule. "The diagnosis of Parkinson's disease is sometimes inaccurate even in the best of hands because there are no definitive laboratory tests, and so the diagnosis is based strictly on clinical assessment," said lead author Yulin Deng, M.D., of the University of Saskatchewan, in Saskatoon, Canada. "If we can detect this compound in fluids such blood or urine, which are easily accessible, and correlate it with the severity of Parkinson's disease, it would become the first biological marker for Parkinson's disease," The direct cause of Parkinson's disease, which afflicts approximately half a million Americans, is the progressive death of nerve cells in an area of the brain called the substantia nigra. These cells produce a chemical called dopamine that helps direct muscle activity. As dopamine is lost, patients experience symptoms such as tremor when at rest, muscle rigidity, and slowness of movement. Scientists have not determined why the substantia nigra dopamine cells die, but they have uncovered some likely suspects. Some of these substances are endogenous, meaning they are normally found in the brain. In particular, the molecule TIQ and its structural relatives have been found to be toxic to dopamine neurons in certain laboratory experiments. Deng and Ali M. Rajput, M.D., along with their colleagues, report that they have found a new variation, termed ADTIQ, which is structurally similar to a neurotoxic TIQ relative called salsolinol. When they compared the brains of deceased Parkinson's patients with those of normal subjects, the researchers found that the Parkinson's patients had elevated levels of ADTIQ, compared to the controls, in all the brain areas they examined. They found particularly high concentrations among the dopamine cells of the substantia nigra, as well as in a brain area called the putamen, where the substantia nigra cells communicate with other nerve cells using dopamine as the chemical messenger. If these results are confirmed, ADTIQ measurement might be used to detect Parkinson's disease at an early stage, allowing time for future therapies to slow or halt the progress of the disease. |
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