Exam IV: Lecture 16 Flashcards
What are Koch’s modified postulates?
- Pathogen must be present in every case of the disease
- Pathogen must be isolated from the host with the disease and grown in cells in culture
- Disease must be reproduced when a pure culture of the pathogen is inoculated or tissue into a healthy susceptible host
- Pathogen must be recoverable from the experimentally infected host
What does TSE stand for?
Transmissible spongiform encephalopathies
What is TSE?
Progressive, fatal disease of humans and other animals
Characterized by neuronal loss > spongiform degeneration in brain tissue
Can also be accompanied by amyloid plaques or fibrils
What are some examples of diseases that are TSEs? (4)
- Kuru
- CJD (Creutzfeldt-Jakob Disease)
- Gerstmann-Straussler-Scheinker Syndrom
- Fatal Familial Insomnia
What is the fatality rate of TSE diseases?
100%
Death occurs withing 6mo-1 year
How does one contract TSE?
- Acquired (Ingestion of infected tissue or iatogenic)
- Sporadic mutation
- Inherited
A mutation in what gene can cause someone to be predisposed to sporadic TSEs? What chromosome is it located on?
PRNP gene
Chromosome 20
What 3 human TSEs are inherited?
- CJD
- GSS
- FFI
What is scrapie? When was it first described? How was it transmitted? What is its namesake? Does it spread to humans?
Scrapie was first described in 18th C
Sheep contracted the disease by eating the grass contaminated by afterbirth
Sheep would become “itchy” and scrape off their wool
it is not known to spread to humans
What does scrapie cause in the sheep?
Degeneration of brain tissue
There is a similar disease to scrapie in deer and elk. What is it called?
Chronic wasting disease
What is Kuru? Where was it found? How was it transmitted? What is its namesake?
Disease found in New Guinea
Fore people eat part of dead bodies of relatives
Kuru = to be afraid/to shiver
Why were the women and children affected differently by Kuru than the men? What did that signify?
Only the women and children would get Kuru because they were the only ones that ate the brain of the relatives
Told researchers that the disease existed in the brain
What was the pathology of Kuru?
Blurred speech, dementia, inability to walk, speak, see
Eventual death
Is Kuru an old disease? Is Kuru still a problem today?
Kuru is not an old disease, someone from the tribe acquired a mutation (1900) > Kuru
It is not still a problem today because researchers convinced the Fore people to stop cannibalism and Kuru went away (1950)
What are the 3 stages of Kuru?
- Ambulatn stage
- Sedentary stage
- Terminal stage
What is the life span of someone with Kuru?
Adults: 12-18 months
Children: 3-12 months
Transmission of Kuru to primates in the lab from brain extracts was the first demonstration of TSE diseases
True