Prions: A Novel Infectious Pathogen Essay -- Medicine Medical Illnesse

Prions: A Novel Infectious Pathogen Prions are novel, transmissible pathogens that differ from viroids, viruses, parasites, fungi, and bacteria, both with respect to the diseases they cause and their structure . They are capable of causing degenerative diseases of the centra1 nervous system both in animals anal in humans. Kuru, Creutzfeldt-Jakob’s disease (CJD) and Gerstmann-Straussler-Sheinker’s (GSS) syndrome illustrate the acquired, sporadic, and genetic manifestation of the -human prion diseases. These transmissible pathogens also cause Scrapie of sheep and goats. Bovine spongiform enphalopathy,(BSE) in cows and transmissible mink encephalopathy, and chronic wasting disease (CWD) of captive mule deer and elk which are thought to result from the ingestion of Scrapie infested animal products (Pruisner, 1991). In addition to these diseases, certain neuropathological changes associated with scrapie disease seem to correlate well with similar changes observed in Alzheimer’s patients (Duguid 1989). T hese similarities have been attributed to similar alterations in gene expression in both of the diseased states (Duguid, 1989). First, in addition to the unique diseases that they cause, prions also exhibit certain novel molecular and structural properties which further differentiate them from other infectious pathogens. The unusual biological properties were first unraveled through experiments performed on scrapie -infested sheep. The isolated scrapie agent from these sheep seem to exhibit certain unusual properties. One such property is the scrapie-agents resistance to nuclease digestion. After being subjected to several rounds of digestion with various nucleases including micrococcal nuclsase, nuclease - P, and deoxyribonucl... ...60-7264.(a) 7. Gabzion, R., McKinley, M. P., Groth, D., Westaway, D., DeArmond, S. J., Carlson, G. A., Prusiner, S. B. (1989) Immunoaffinity purification and neutralization of scrapie prions. Prog. Clin. Biol. Res. 317: 583-600. 8. Hsiao, K., Zeev, M., Kahana, E., Cass, C., Kahana.. I., Avrahemi, D., Scarlato, G.. Abramsky, O., Prusiner, S. B., and Gabizon, R. (1991) Mutation of the Prion Protein in Libyan Jews with Creutzfeldt-Jakob’s disease. N. Engl. J. Med., 324: 1091-1097. 9. Prusiner, S. B. (1991) Molecular Biology of Prion Disease. Science, 252: 1515-1522. 10. Prusiner, S. B. (1982) Novel proteinaceous infectious particles cause scrapie. Science,216: 136-144. 11. Stahl, N. and Pruisner, S. B. (1991) Prions and prion proteins. FASEB J., 5: 2799—2807. 12. Weissmann, C. (1991) A unified theory of prion propagation. Nature., 352: 679-683.