by the Way . . .

The infectious proteins that cause chronic wasting disease in cervids such as deer and elk have been isolated in the muscle of deer suffering from the condition, U.S. researchers reported Thursday. Previously federal health officials have assured hunters that they would be OK as long as they did not touch or eat an animal's brain, spinal cord, or other nervous tissue. Now that the proteins have been isolated from the haunch and leg meat ("venison"), the portions favored for eating, hunters are warned to not eat any portion of such animals, even in sausage.

The disease, generally termed transmissible spongiform encephalopathies (translation: things that that you can catch that turn your brain spongy), in deer and elk is known as chronic wasting disease, in sheep, scrapie and in cows, mad cow disease. There is no generally accepted term for the disease in humans, although hunters who consume deer or elk with the wasting disease sometimes develop sporadic Creutzfeldt-Jacob disease, which may or may not be the same thing. If so, it is likely that the popular term will be mad cow, since there is already stuff that sounds like wasting disease and head scrapie in humans. Epidemiologists are now looking for signs of brain wasting among hunters, which you would think should be easy to find. Contraire, it is complicated by the fact that scientists are uncertain of the symptoms, although they seem to include an unusually intense desire to harm animals.

Research into human mad cow disease was given a huge impetous when it was contracted by the popular Boston lawyer Denny Crane. It is not known how humans contract mad cow disease, but the infectious protein appears to be somewhat different according to what type of animal has it. In deer and elk it is known as a misfolded prion, to distinguish it from the normal prion that is around. In sheep it is a misfolded wedgeon, and in humans a misfolded klingon.

Researchers are exploring the disease by inserting the properly folded protein genes of other animals, including humans, in fertilized mouse eggs. This has created mice that possess human, deer and elk folders, respectively. Later the brains of these mice are injected with venison from deer in the final stages of wasting disease. The first procedure apparently made the mice susceptible to misfolding, as every one of them contracted wasting disease (there is no separate term for the mouse version yet, but you still should under no circumstances eat them). To see if the disease can be spread by eating, the investigators next hope to feed the mice feces and urine from infected deer, which is how they think the deer spread it around. So far it has proved difficult to get the mice to eat it, even when spread on cheese. It is also tricky to get the deer to go on the cheese.

In our December 14 post we discussed the ethical questions arising from injecting mice with human stem cells. It is not known whether any of those mice have also been injected in these later experiments, or have become avid hunters.