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Life Line

A page on the latest in medical science

The Parasite Killer
New Scientist

This is great news for India, home to half the victims of leishmaniasis in the world. Although injectable drugs are available, 80 per cent of the patients in India are resistant to even the most effective of these. Still worse, about 9 per cent of treated patients die from heart-related side-effects. Not surprisingly, India has become the first to license it and the drug is expected to hit the market this September. India plans to eliminate the disease by 2010.

Leishmaniasis is a parasitic disease transmitted to humans through the bite of a sandfly. The visceral form—also known as black fever and kala azar—is the most deadly of its four forms, killing about 60,000 people every year. The parasite attacks cells in the spleen, liver and lymph nodes, causing immune system damage and death within one to two years.The new drug, called miltefosine, has been developed by teams at the German biopharmaceutical company Zentaris and the WHO-sponsored Tropical Diseases Research programme (TDR). It is 95 per cent effective at curing the disease, with "manageable" side-effects. WHO researchers say "the other great advantage of this drug is that it is in a tablet form, so people do not have to stay in hospitals or make daily visits to clinics in order to take it."

Miltefosine works by attacking the parasite’s cell membrane—although the researchers say they do not fully understand how.

Efforts are also on to develop a vaccine against this dreaded pestilence. Recently, US scientists at the National Institute of Allergy and Infectious Diseases near Washington DC found that a vaccine against a protein found in the insect’s saliva can protect mice. Vaccinated animals developed only minor skin lesions that cleared in a few weeks. In contrast, unprotected animals develop persistent ulcers that destroyed tissue.

Human trials, however, are still at least three years away, but the scientists are close to testing a vaccine in monkeys and in dogs, the natural reservoirs for the parasite. In the meantime, patients can look forward to a better life, thanks to the new drug.

Food For Thought

Anti-ageing products are a multibillion-dollar industry. But the marketing of these often misrepresents the science. Lest they be accused of tacit approval, 51 of the top researchers in the field of ageing have collectively authored a position paper that sets out the current state of the science. They aver that there are no lifestyle changes, surgical procedures, vitamins, antioxidants, hormones or techniques of genetic engineering available today that have been demonstrated to influence the processes of ageing. "We strongly urge the general public to avoid buying or using products or other interventions from anyone claiming that they will slow, stop or reverse ageing." To dig more, go to www.sciam.com

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The Good News

Scientists at the University of Pennsylvania School of Medicine have discovered that a simple urine test could be used to predict a person’s chances of developing Alzheimer’s disease. They say the breakthrough will now make it easier to track and treat the condition.

The test detects isoprostanes, chemicals which scientists believe are released in the brain as a result of Alzheimer’s damage. Within four years of being diagnosed with mild cognitive impairment (MCI), the precursor to the disease, up to half the sufferers will go on to develop Alzheimer’s.

The researchers claim this "is the first non-invasive test that can predict a clinical diagnosis of Alzheimer’s disease." Since there is no cure for Alzheimer’s, physicians could slow down its progress if caught early. In their study, published in the Archives of Neurology, the scientists studied 123 people, 50 of whom had Alzheimer’s and 33 who had MCI. The new test is not widely available at the moment, but the team is developing a more user-friendly version.

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The Bad News

Several authors in the recent edition of the Journal of the American Medical Assocation (JAMA) suggest that the reporting of medical and other research is highly flawed. According to the journal, research presentations often receive an unwarranted amount of media coverage. It also says that media releases can play up the importance of the findings, and that the views presented in research papers often do not represent the opinions of all the concerned scientists. Lisa Schwartz from the Department of Veterans Affairs Medical Center, Vermont, writes that media reports "may leave the public with the false impression that the data are in fact mature, the methods valid, and the findings widely accepted. Patients may thus experience undue hope or anxiety, or may seek unproven, nay dangerous, tests and treatments".

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