A commonly used organic pesticide called rotenone has been linked with Parkinson's disease. The cause of most cases of the disease is unknown, but epidemiological studies have suggested that chronic exposure to environmental toxins--such as pesticides--may be responsible for the degeneration of neurons containing dopamine. Now Dr Tim Greenmyre and his colleagues at the department of neurology at Emory University in Atlanta have shown that rotenone, administered intravenously over several weeks, reproduces the major features of Parkinson's disease in rats (Nature Neuroscience 2000;3:1301-6).
Postmortem studies suggest that the pathogenesis of Parkinson's disease is initiated by damage to the mitochondria. Previously the best animal model for Parkinson's disease was the "MPTP model," where mice or monkeys are treated with a drug called 1,2,3,6-tetrahydropyridine (MPTP) and the features of Parkinson's disease are faithfully reproduced. The toxicity of MPTP occurs because its derivative MPP+ inhibits one of the mitochondrial enzymes. The team decided to test rotenone because it is known to inhibit the same mitochondrial enzyme as MPP+. This study does not prove that rotenone causes Parkinson's disease in humans, but it does support the hypothesis that exposure to pesticides may contribute to the brain damage seen in the disease.
BMJ has a new ethics committee
The BMJ has formed a new ethics committee. (BMJ 2000; 321:720) Members were recruited from nearly 150 applicants, and their collective expertise spans ethics, law, research, clinical medicine, medical publishing, and journalism. The committee will meet at least four times a year and will report its deliberations and decisions in the BMJ.
The members are Alexander McCall Smith, professor of medical law, University of Edinburgh (chairman); Derick Wade, professor of neurological disability, University of Oxford; Liz Wager, head of international medical publications (UK), GlaxoWellcome; Peter Singer, professor of medicine, and director of joint centre for bioethics, University of Toronto; Anne Sommerville, head of medical ethics, BMA; Tom Wilkie, adviser in bioethics at the Wellcome Trust and editor of Scientific Computing World; Jeffrey Tobias, consultant in radiotherapy and oncology, University College Hospital, London; Richard Smith, editor, BMJ; Alison Tonks, assistant editor, BMJ.
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