Prion Diseases (5) Flashcards
T/F: We can synthesize all amino acids
FALSE - some we cannot synthesize ourselves
What is a prion?
a protein that has been misfolded in multiple, structurally distinct ways, at least one of which is transmissible to other proteins
- similar to viral transmission
What are the sizes of prions?
extremely small - smaller than viruses
Why are prions so hard to break down?
have no nucleic acid
so, they are resistant to procedures that break down nucleic acids
How are prions different from normal proteins?
do not stimulate an immune response (not recognized as non-self)
lacking nucleic acid
How do prions replicate?
stimulates normal cellular protein to refold into a form called PRP^Sc - named after scrapie
How are prions killed?
deactivated by heat, certain chemicals, and by a combination of heat, chemicals, pressure, and time, incubation
highly resistant to infection
How are prion carcasses disposed?
deactivated into a sterile alkaline solution using an alkaline hydrolysis digester
What are some TSEs?
chronic wasting disease
feline spongiform encephalopathy
bovine spongiform encephalitis - mad cow
etc
What are clinical signs of scrapie?
weight loss, despite retention of appetite
behavioral changes
itching and rubbing
T/F: Scrapie cannot infect humans with ‘mad cow disease’
FALSE - can!
What is one of the ways the USA reduces the likelihood that scrapie will spill over to humans?
scrapie flock certification program
What is bovine spongiform encephalopathy?
chronic degenerative (fatal) disease affecting the CNS of cattle
What are the TSEs in humans?
creutzfeldt-jakob disease (CJD)
kuru
variant CJD
What is kuru disease?
caused by an infectious prion in contaminated human brain tissue
New Guinea with cannibalism
“laughing sickness”
How does one acquire variant CJD?
associated with consuming BSE-infected beef (CNS)
How do you diagnosis TSE?
cannot be identified by serology or seroconversion
CANNOT BE CULTURED
antemortem: clinical signs
postmortem: histopathology
To date, the cost of 3 cows with BSE in the United States has been nearly $30 billion primarily in ______
LOST EXPORTS - losses to taxpayers, agricultural sector
What are signs of BSE in cattle?
experience progressive degeneration of the nervous system
may display changes in temperament (nervousness or aggression), abnormal posture, etc
hypersensitive to light
What is the incubation period of BSE?
2 to 8 years
T/F: There is not a vaccine or treatment for BSE
TRUE - have to depopulate entire herds
T/F: BSE can be transmitted in cow’s milk
FALSE - but meat can
How do you prevent BSE?
feed ban - prohibits feeding mammalian proteins to ruminants, including cattle
MOST IMPORTANT
T/F: BSE went down in the UK significantly after BREXIT
TRUE - “politicization of public health”
