Science - Snippets From Science News

From Volume 169:

HIV and West Nile virus A genetic mutation that protects against the HIV virus has been shown to increase susceptibility to West Nile virus. Philip M. Murphy, an imunologist at NIAID (National Institute of Allergy and Infectious Diseases) suggests that the protein (chemokine receptor-5, or CCR5) that is eliminated by the mutation might be essential in preventing West Nile virus from attacking the body. The virus causes encephalitis or meningitis in approximately 20 per cent of those infected. According to the CDC (Centers for Disease Control and Prevention), of 2,819 people who became ill as a result of infection with the mosquito-borne virus in 2005, 105 died.

CCR5 is the primary cell-surface receptor that the HIV virus commandeers in order to enter white blood cells. Several companies have designed drugs to block CCR5 in the hope that this will stop HIV from invading white blood cells. The new findings about CCR5 would indicate that individuals using those drugs must take extra precaustions to avoid infection by West Nile virus.


kakapo parrots - sex ratios Female kakapo parrots (Strigops habroptilus) that are too well-fed produce too many male chicks, endangering their already threatened numbers, according to Bruce Robertson of the University of Canterbury in Christchurch, New Zealand. With only 86 of the birds remaining, it is essential that more females be available to produce the coming generations. After putting the heaviest females on short rations, Robertson and his colleagues report that the new diet has ended the excess of male chicks. Kakapos can live for about 60 years.


bisphenol-A and insulin resistance Angel Nadal of Miguel Hernandez University of Elche in Spain reports that bisphenol-A, a synthetic chemical used to make dental sealants, microwavable plastics, linings for metal food and beverage containers, baby bottles, and other consumer products, can mimic estrogen's effects, can leach into food and water, and can contribute to insulin resistance. Nadal believes that this might explain the current global epidemic of diabetes. According to Ana M. Soto of Tufts University School of Medicine in Boston, animal studies have suggested that exposure to bisphenol-A in early life causes obesity. The chemical is also thought to contribute to gestational diabetes in women.


bone replacement and new ceramics Researchers at the Lawrence Berkeley National Laboratory in California have discovered a way to replicate the toughness and strength of nacre (mother-of-pearl) in metal-ceramic composites that might be usable as a scaffold for new bone growth. Simple, inexpensive, and environmentally friendly, the method used by Sylvain Deville and his colleagues involves combining finely ground ceramic powder and polymer binders with water, which is then subjected to carefully controlled subfreezing temperatures. To create bonelike composites, the researches used epoxy mortared between plates of hydroxyapatite, which is the primary ceramic in bones and teeth.


prions and brain disease Glenn Telling, a microbiologist at the University of Kentucky in Lexington, and his colleagues have found that the muscles of deer infected with CWD (Chronic Wasting Disease, which results from malformed prions, like Creutzfeld-Jakob disease and bovine spongiform encephalopathy) can carry the misfolded prions, thus increasing the likelihood that hunters who eat these animals risk infection. Previously, it was assumed that only consumption of the brain or spinal tissue, or contamination by such infected tissue, would carry the disease.

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