By Gene Emery BOSTON, May 13 (Reuters) - A Mexican antidote for the sting of the bark scorpion can stop the potentially deadly venom in its tracks within four hours, researchers reported on Wednesday. The study on 15 children, seven of whom received a placebo, produced results so dramatic it is now regarded as unethical to give placebo as part of an experiment, said Dr. Leslie Boyer of the University of Arizona Health Sciences Center, who led the research published in the New England Journal of Medicine. Bark scorpions, found in Arizona and Mexico, typically only cause pain for most adults. But their sting can be deadly to small children. "In effect, what happens with the venom, it locks every nerve in the 'on' position, so the nerves that go to muscles send signals that say 'twitch,' and the nerves that go to glands say 'sweat,' 'drool,' 'pee,' 'cry,'" said Boyer. "The biggest problem is that the nerves that make you breathe are all messed up. So the left side of the chest is saying inhale, while the right side of the chest is saying exhale. At the same time, you're producing a lot of saliva and you don't know how to swallow. You can kind of drown and you don't exchange air as well." Boyer's team has been testing an anti-venom product called Anascorp, made by Instituto Bioclon in Mexico. It is not approved by the U.S. Food and Drug Administration. In the trial, symptoms disappeared in all eight children who got Anascorp within four hours, compared to only one of the seven who received a placebo. The difference was seen in as little as two hours. Stung children typically spend 16 hours in intensive care. After one hour, none of the children who got the anti-venom, also known as antivenin, had any sign of the venom in their blood, while only two placebo patients cleared the venom on their own. Instituto Bioclon sells about a quarter of a million units of the product a year in Mexico. Boyer has been pushing for FDA approval of some new product since 1999, when a researcher at Arizona State University, who had been making a home-grown antivenin for the state, retired. That supply ran out years ago. Boyer said further tests, in which the antivenin has been given to 650 other sting victims at 24 hospitals across the state, are being analyzed to develop safety and effectiveness data for the FDA. (Editing by Maggie Fox)
Children wave on their boat in a street flooded by Mearim river in Bacabal, in the northeastern state of Maranhao May 13, 2009. Floods and mudslides from months of heavy rains ...
