Monday, January 1, 2007

Scientists develop mad cow resistant beef

On the first day of 2007, The Washington Post reported the development of a line of beef without the protein susceptible to mad cow diseases. The beef would be used for the development of pharmaceuticals, and not for food. The drugs would presumably be safer because they could not transmit an absent protein.

The story is by Rick Weiss and the link is here.

The agent is known as a prion, or protein infectious molecule. The agent cannot be readily destroyed by heat or radiation, as can viruses. It has no genetic RNA or DNA as such. The "infection" is more like crystalization in a high school science lab. A susceptible molecule comes into contact with the surface geometry of the prion, and folds its own surface geometry to fit like a lego toy. This sets up a chain reaction within other similar molecules in the nerve or brain tissues, resulting in disintegration of the tissue into a spongy like substance. Diseases like kuru and Creutzfeldt-Jakob may be caused by such mechanisms. Huntington's, however, seems to be inherited. It is unclear whether such molecules could contribute to Alzheimer's disease or similar dementia in the elderly, particularly early.

In the early 1980s, there were even some wild speculations that prions could cause AIDS, well before HTLV-III (then to be called HIV) were announced as discovered. There was a famous article about prions in Discover magazine in 1983, with discussion of the work of Stanley Prusiner.

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