Lab challenges usual theory on mad cow...
From the
Seattle Post Intelligencer:
bq. At the eastern edge of the Bitterroot Mountains, a craggy range of peaks that defines the border between Idaho and Montana, is a lab full of skeptics who don't hold with the majority scientific consensus on mad cow disease.
bq. They are world-class researchers on these kinds of diseases, categorically called "transmissible spongiform encephalopathies" -- or TSEs.
bq. Some of these diseases have been recognized for a long time, but they captured wide public attention only when it appeared -- first in Britain -- that the disease could get passed on to people who eat beef from a cow with this type of brain infection, which eats holes in the brain.
And more:
bq. Most of the scientists here at the Rocky Mountain Laboratories, a branch of the National Institutes of Health, accept that this kind of "cross-species" transfer of a TSE can, on rare occasions, take place. They were some of the first to show it, in fact, in experimental animals.
bq. But try to make any other simple statement of fact about mad cow or Creutzfeldt-Jakob disease, CJD, and you will encounter a stubborn refusal to let you move even one step beyond the evidence.
bq. "These diseases are real, fundamental scientific mysteries," said Dr. Byron Caughey, a biochemist searching for drug compounds to combat TSEs. "We don't really know how they work. ... We only know enough to say they're weird."
And more:
bq. The diseases are weird because a misshapen protein appears to spread the infection by causing other proteins in the brain to warp as well. Other kinds of infections, by viruses or bacteria, require transfer of genetic material. Proteins don't do that.
bq. And the scientific inquiry is made more complicated by the fact that this infectious protein process has never been successfully demonstrated in the many laboratory attempts to prove it.
bq. Evidence for the infectious protein theory has been indirect, based mostly on the injection of infected brain tissue into laboratory animals watched for later signs of disease.
bq. "All these diseases are diagnosed based on the presence of these abnormal proteins" in the brain, said Dr. Susan Priola, another Rocky Mountain Labs scientist working on developing vaccines against TSEs.
bq. It is still possible, Priola said, that these bad proteins are a product of viral or bacterial infection -- possibly the real cause of mad cow, scrapie or other TSEs. Although it is possible to fight an infectious disease without knowing its ultimate cause, she said, generally it's a good idea to find the primary infectious agent.
bq. "Everybody says no virus or bacteria has ever been found, but really nobody is looking for it anymore," Priola said. "It's difficult to get funding for such a project."
This is a complex issue - it has gotten a lot of publicity despite the fact that nobody died from vCJD last year but yet 555 people contracted Hepatitis A and three people died
from eating Green Onions.
Standard CJD is scary but it is not related to Mad Cow - it affects older people and has a very rapid onset. vCJD which has an anecdotal connection to Mad Cow affects much younger people and has a slow onset.
Posted by DaveH at January 23, 2004 9:37 AM