Unit 12 Flashcards
Describe a Prion
Proteinaceous infectious particles that cause various spongiform encephalopathies, or slow neurodegenerative diseases. They are not antigenic, inflammatory or immunogenic. They affect normal proteins and cause misfolding. Sometimes they are called slow viruses, but this is a misnomer, because they are NOT viruses. Extremely resistant to heat, disinfectants and radiation.
What is the PrP protein?
Amyloid protein which is insoluble and fibrous. Binds on your cells and causes refolding.
What diseases do prions cause?
In humans they cause encephalopathis that have long incubation periods of up to 30 years. Scrapie from sheep. Chronic Wasting Disease from Elk in Colorado. BSE in cattle, but called nvCJD in humans. Kuru in cannibals of New Guinea. CDJ in middle aged people from 40-50 yo. Stands for Creutzfeldt-Jakob disease.
What diseases do prions cause?
In humans they cause encephalopathis that have long incubation periods of up to 30 years. Scrapie from sheep. Chronic Wasting Disease from Elk in Colorado. BSE in cattle, but called nvCJD in humans. Kuru in cannibals of New Guinea. CDJ in middle aged people from 40-50 yo. Stands for Creutzfeldt-Jakob disease.
How are prions transmitted?
Injection, transplantation, contact with medical equipment such as brain electrodes, food and genetics for human familial CJD.
What is the treatment for prions?
There are currently no serotests for diagnosis. You use autopsy and immunohistochemistry on brain following death. Preventing medical spread is very important, but prions are resistant to heat, radiation and disinfectants. Ozone sterilization is a possibility. WHO currently sais 1N NaOH 1 hour, into water and autocave for one hour, clean and sterilization. Or 1 NNaOH 1 hour, rinse in water, open pan for 1 hour in autoclave then clean and sterilize.
