| Popis: |
Prions (PrP(Sc)) are proteinaceous infectious particles that occur as sporadic (85 percent), infectious (iatrogenic) (5 percent) or hereditary (10 percent) diseases in humans and animals. These unique infectious agents produce a spongiform change in the central nervous system without any inflammation, inclusion bodies or apparent antibody response. A helper (X) protein and genetic predisposition appear to be required to establish the infection, which seems associated with a post-translational change of a normal protein (PrP(C)) encoded by a gene on human chromosome 20. Sporadic human prion disease (Creutzfeldt-Jakob disease) is the most common form of human transmissible spongiform encephalopathy. Nevertheless, it is undoubtedly under-recognized as a result of both low autopsy rates and confusion with other dementing diseases like Alzheimer's disease. Although no therapy is currently available for this infectious dementia, which has a prolonged incubation period, these unfortunate victims should be offered supportive care and postmortem examinations. Universal precautions will protect laboratorians from this infectious, but not contagious, disease. |
