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Count Your Blessings (12 Apr 97) If you feel living with PD is tough, remember there are other neurodegenerative diseasas that are infinitely worse. In the New Yorker for 14 April, PD therapy pioneer Oliver Sachs reviews "Deadly Feasts" by Richard Rhodes. Rhodes makes a well-grounded case for close kinship between Kuru, Creutzfeldt-Jakob Disease, Scrapie, and Bovine Spongiform Encephalitis (mad cow disease). All of these cause the brain to be riddled with holes, and lead to quick death. They can be spontaneous (CJD incidence is possibly 1 per million), highly infectious, have extremely long latency (as much as 40 yr). The infectious agent is thought to be a prion, which is neither bacterium nor virus, but merely a molecular bit of the body's own protein (hence no immune reaction) that assumes a deviant geometric form. This form reproduces itself in a kind of chain reaction, much as a crystal grows in a particular pattern, until all the protein of the same composition is also perverted. Moreover, prions are almost totally resistant to conventional asepsis technique such as autoclaving or formaldehyde. From evidence that the infectious agents may be alike or closely related, and the long latency which prevents detection of vectors or carriers, Rhodes sees a remote but real possibility of a global plague that could wipe out the human species. The Black Plague killed a third of Europeans, and the Spanish flu in 1918 killed about 25 million, so the threat is not unique. Haven't seen any of those "Where's The Beef?" ads recently, have we? Cheers, Joe Prion Mystery Deepens (18 Oct 98) In April I posted a note about prions, which are prime suspects in both Creutzfeldt-Jakob disease (CJD) and bovine spongiform encephalitis (BSE), probably two forms of the same thing. Rogue prions don't have DNA to reproduce, but multiply by merely altering the form of "normal" prions which are protein building blocks found everywhere in the body. The two forms have exactly the same chemical composition and the same arrangement of bonds between their atoms, but differ only in the way each molecule is "folded". Prions have been in the news lately, with a report of simultaneous illness and death of a man and his cat. BSE- related CJD has so far killed 27 young Britons and a Frenchman. Many questions come to mind: - Why is one form completely benign, and the other so deadly? - Why is conversion always from "good" to "bad" and never reversible? - If interspecies transmission is so easy, and sterilization so difficult, why isn't the human race extinct? - If prions can't perpetuate their characteristics via DNA, why do there seem to be several distinct strains of the bad ones? References: Zanusso G et al; Lancet, 3 Oct 1998;1116-1117 Aguzzi A et al; Nature Medicine 1998;4:1125-1126 Safar J et al; Nature Medicine 1998;4:1157 Stay tuned. Joe -- J. R. Bruman (818) 789-3694 3527 Cody Road Sherman Oaks, CA 91403-5013