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Archive - Mar 24, 2015

Animal Results with Calcium-Reducing Immunosuppressant Suggest Possibly Major Progress on Parkinson’s Disease

Parkinson's disease, which has stricken such notable figures as actor Michael J. Fox, heavyweight boxing champion Muhammad Ali, and painter Salvador Dalí, could be closer to a cure, thanks to a scientist who has apparently been able to eliminate the disease’s neurological effects with the use of an immunosuppressant. Responsible for the scientific finding is Dr. Gabriela Caraveo Piso, a researcher at the Whitehead Institute for Biomedical Research in the United States in the laboratory of world-renowned scientist Dr. Susan Lindquist (http://lindquistlab.wi.mit.edu/). Dr. Caraveo discovered that the role of calcium as an intracellular messenger can become lethal to brain cells when in high concentration. Her findings were published online on March 23, 2015 in the Spanish-language journal Investigacion y Desarrollo. Neurological diseases called synucleinopathies, such as Parkinson's, are characterized by the aggregation of alpha-synuclein protein. This action triggers a series of events such as the rise in intracellular calcium leading to over-activation of the enzyme calcineurin. This in turn removes phosphates (intracellular communication paths) to alter their functions and kill cells. Dr. Caraveo, a biologist graduated from the National Autonomous University of Mexico (UNAM), sought to nip this problem, after performing a series of analyses in yeast, worms, and neurons of mice, and finding that by reducing the levels of activation of calcineurin, without eliminating it completely, the cells survived.

Malaria Parasite Produces Volatile Terpenes That Attract Other Mosquitoes; Work May Lead to Simple Diagnostic Test

The malaria parasite Plasmodium falciparum produces chemical compounds called terpenes that give off odors that attract mosquitoes, according to new research. The study, published on March 24, 2015 in mBio®, the online open-access journal of the American Society for Microbiology, might explain why the insects are more likely to bite humans or animals already infected with the parasite. The work could lead to new diagnostic tests for malaria, said senior study author Audrey R. Odom, M.D., Ph.D., an Assistant Professor of Pediatrics and of Molecular Microbiology at Washington University School of Medicine in St. Louis. "We hope these kinds of parasite-produced compounds are the sort of thing that you might be able to find in the breath or sweat of children with malaria," Dr. Odom said. "We have studies ongoing to see if we can detect these compounds in children with malaria, because obviously a breathalyzer test would be a lot nicer than the blood-based tests that are currently used." The finding also holds implications for malaria control, she said: "Understanding the molecular basis of mosquito attraction and host choice is important for figuring out how you might prevent people from getting bitten in the first place." Dr. Odom and colleagues have been studying malaria parasite cultures in human red blood cells, grown in airtight bags. For the current study, the researchers sampled the gas on top of the liquid culture in the bags and used a laboratory technique called gas chromatography-mass spectrometry to analyze the chemical components of the gas. They compared gas samples from bags containing malaria-infected red blood cells to gas samples taken from bags containing uninfected red blood cells and from empty bags.

Plexin D1 Appears to Influence Distribution of Visceral Body Fat and May Thus Contribute to Insulin Resistance and Type 2 Diabetes

Scientists have known for some time that people who carry a lot of weight around their bellies are more likely to develop diabetes and heart disease than those who have bigger hips and thighs. But what hasn't been clear is why fat accumulates in different places to produce these classic "apple" and "pear" shapes. Now, researchers have discovered that a gene called Plexin D1 (image of the Plexin D1 protein) appears to control both where fat is stored and how fat cells are shaped, known factors in health and the risk of future disease. Acting on a pattern that emerged in an earlier study (February 2015) of waist-to-hip ratios in 224,000 people, the new study, which was published online on March 23, 2015 in PNAS, found that zebrafish that were missing the Plexin D1 gene had less abdominal or visceral fat, the kind that lends some humans a characteristic apple shape. The researchers also showed that these mutant zebrafish were protected from insulin resistance, a precursor of diabetes, even after eating a high-fat diet. The PNAS article is titled “Plexin D1 Determines Body Fat Distribution by Regulating the Type V Collagen Microenvironment in Visceral Adipose Tissue.” "This work identifies a new molecular pathway that determines how fat is stored in the body, and, as a result, affects overall metabolic health," said John F. Rawls, Ph.D., senior author of the study and Associate Professor of Molecular Genetics and Microbiology at Duke University School of Medicine. "Moving forward, the components of that pathway can become potential targets to address the dangers associated with visceral fat accumulation."