Persistant viral infections of the central nervous system Genomes either integrate or persist as episoms Mechanism of persistance is not yet understood Avoid detection and elimination by the host ID: 1012373
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1. Persistant viral infections of the central nervous system
2. Persistant viral infections of the central nervous systemGenomes either integrate or persist as episomsMechanism of persistance is not yet understoodAvoid detection and elimination by the hostProgresiveConventional virusesprions
3. Conventional virusesSubacute Sclerosing panencephalitis (SSPE): MeaslesRubellaJC virusEnterovirus
4. Prion (Unconventional Diseases)HumansCreutzfeld-Jacob, variant CJDGertsmann-Straüssler-Scheinker DiseaseKuruFatal Familial insomniaAnimalsScrapie(sheep)Bovine spongioform encephalopaty (BSE:cows)
5. Basic properties of prionsProgresisive without remissionNo inflamatory diseaseNo alteration in pathogenesis by immunosuppresion or immunopotentiationSize estimated 5-100nmNo virionlike structure by elctronmicroscopyTransmissible to experimental animalsNo interferon production or interferans by virusesUnusual resistance to UV irradiation, alohol,boiling,proteasesCan be inactivated by prolonged exposure to steam autoclaving or 1N or 2 N NaoH
6. Nobel Prize for Medicine 1997Stanley PrusinerIdentified the role of prions in diseaseAcuolar changes in cortex and cerebellumSpongiophorm encephalopathyPrion : small proteinaceous particleNo nucleic acidPrion protien is encoded by normal cellular gene PrP in the brain.
7. Proposed mechanism
8. PreventionNo contact with the infected tissue1h with 2 N NAOH60-90 min autoclaveGenetically engineered growth hormone