E-Book Overview
Leading researchers and clinicians describe their state-of-the-art findings and hypotheses arising from a variety of different approaches to this group of diseases. Their approaches include clinical presentations, epidemiology, transgenic methods, and diagnostic tests via transmission electron microscopy and immunoblotting. The diseases treated range from human to animal spongiform encephalopathies and include Creutzfeldt-Jakob disease, mad cow disease, and scrapie.
E-Book Content
1 The Paradox of Prion Disease Rosalind
M. Ridley and Harry F. Baker
1. introduction The study of that group of diseases now collectively known as the prion diseaseshas always been a source of excitement and argument between scientists. These obscure diseases usually have been of extremely rare occurrence and have had little impact on the general public. When an epidemic occurs, however, as in the case of bovme sponglform encephalopathy (BSE) m the United Kmgdom, the bizarreness of the prion diseasesand the profound difference between them and any other “mfectlous” condition can (and did) lead to public consternation. Three features of prlon diseases give them an apparently diabolical quality. 7.1. Their Occurrence Is Largely Unpredictable 1. In acquired casesthere 1sa silent mcubatlon period that can vary from a few weeksto up to 40 yr, dependmgon the speciesand the circumstances 2 During the incubation period there are no symptoms and no detectable signs, e.g., there IS no measurable Immune response that will predict subsequent illness. 3. No mode of transmission could be established for the majority of human cases that appear to occur “out of the blue.”
1.2. They Exhibit Certain Impossible Properties In relation to established principles of microbiology, the prion diseases exhibit certain “impossible” properties. 1 “Infectious” disease seems to arise spontaneously. 2.