Path Suggested for Mad Cow Study

Rogue proteins that cause mad cow and other brain-destroying diseases become toxic by latching on to the outside of cell membranes, say government scientists studying how the mysterious substances work.

If scientists could break the fatty Velcro-like bond that anchors these prion proteins, they might devise a treatment for the deadly illnesses, the research, published in today's edition of the journal Science, suggests.

"We need to focus on that as a target for drug therapy," said the lead researcher, Bruce W. Chesebro, a virologist at the National Institutes of Health's Rocky Mountain Laboratories.

Related diseases -- including bovine spongiform encephalopathy (commonly known as mad cow), scrapie in sheep and the human Creutzfeldt-Jakob disease -- are believed to arise when a protein that the body normally harbors folds into an abnormal shape, called a prion, and sets off a chain reaction of misfolds.

When enough abnormal prions accumulate, they deposit plaque on the brain and eventually leave clumps of dead brain cells -- the diseases' hallmark spongy holes.

If the abnormal prions are not bound to cells' surfaces, they may be unable to disrupt signaling between cells, a leading theory behind their toxicity, neuropathologist Adriano Aguzzi of the University Hospital of Zurich said in an accompanying editorial.

Targeted Mosquito Spraying Is Safe

Light, targeted spraying to control mosquitoes that might spread West Nile virus did not lead to raised pesticide levels in people, U.S. health researchers reported yesterday.

An expert at the Centers for Disease Control and Prevention said he was reassured by the studies done in three states where local health officials sprayed the insecticides.

"These findings suggest that ultra low-volume application of naled, permethrin, and d-phenothrin is safe to humans," the CDC said in its weekly report on death and illness.

Whooping Cough Booster Passes Test

An experimental booster shot designed to protect adults and adolescents from whooping cough proved safe and effective in a study released yesterday, offering a vital new tool for fighting a dangerous resurgence of the disease over the past few years.

The vaccine, developed by Sanofi Pasteur and already widely given to teenagers in Canada, appears likely to win U.S. government approval this month.

The vaccine is needed "to prevent the disease in teenagers and adults themselves and, secondly, take away their ability to be contagious," said Michael E. Pichichero, a professor at the University of Rochester Medical Center who has headed clinical trials of the vaccine.

Cases of whooping cough, an ancient scourge that effective vaccination of babies and toddlers was meant to wipe out, have quadrupled in the United States over the past three years to 18,957 cases in 2004, according to the Centers for Disease Control and Prevention. It turns out that the vaccine that babies get starts wearing off by adolescence.

The study, funded by Sanofi Pasteur, was released early by the Journal of the American Medical Association, ahead of its scheduled publication in the June 22-29 issue, because the results were considered so important.

-- From News Services