3.8 (2) Prions Flashcards
prions cause what group of diseases
transmissible spongiform encephalopathies
TSEs are what type of disease
neurodegenerative prion diseases
what are prions
proteinaceous infectious particles
what are 2 characteristics of prion diseases
1) long incubation period (months to decades)
2) always fatal
what is the characteristic lesion of prion diseases
spongiform neuronal degeneration
are there vaccines and treatments for prion diseases
no
what is the normal form of prions and what is the infectious form
normal: PrPc
infectious: PrPSc
what is the normal role of prions
myelin maintenance
what changes in animals infected with prions
alpha helixes change to beta-sheets
how does solubility differ between normal and pathological prion
normal: soluble
pathological: insoluble
how does protease sensitivity differ between normal and pathological prions
normal: protease sensitive
pathological: protease insensitive
what are pathological prions resistant to (3)
boiling, formaldehyde and radiation
T/F there are immune and inflammatory responses against prions
F
what are the 3 main TSEs and what ones are on the OIE list
- scrapie (sheep)
- bovine spongiform encephalopathy
- chronic wasting disease (deer and elk)
what is the incubation period of scrapie
up to 8 years
what is characteristic of scrapie
sheep rub off their wool and lose weight
what is the best treatment of scrapie
destruction of all infected and at-risk animals
what is the accepted route of scrapie infection
oral
where is scrapie infection initiated
gut lymphoid tissue
what are characteristic neuronal lesions of scrapie
vacuolation and degeneration
where did BSE have a significant impact
Britain
T/F BSE has been confirmed in Canada
T
what is the accepted route of BSE infection
oral
what are signs of BSE
nervousness, incoordination, decreased production, weight loss
what is the transmission route of chronic wasting disease
unknown
what is the incubation period of chronic wasting disease
up to 4 years
what are the signs of chronic wasting disease
weight loss and behaviour changes
T/F CWD has been identified in Canada
T
how are TSE diagnosed in lab
1) histopathology of neuronal tissue
2) ELISA
3) immunohistochemistry and western blotting if ELISA positive
