50- HGH I Flashcards
what is hgh, where is it and what does it do
- Somatotropin
- 191 amino acid protein
- Secreted by pituitary gland
- Stimulates growth, cell regeneration
- Important for development, repair
- Larger amounts produced during growth
what does hgh deficiency cause
Hypopituitary dwarfism
Pituitary does not produce enough hGH
what is the earliest treatment for human growth hormone, and why can’t animal cadavers work
- Isolate and purify hGH from human cadavers
- GH from animals is different amino sequence
how did the harvest of hgh from cadavers work and how did using it work
- Remove the brain and cut out pituitary
- Requires approx. 8 cadavers/year/child
- Weekly injections
- Must be continued for 10 to 12 years
- while they are going through puberty
why is it impossible to purify anything 100%? explain proteins and viruses contamination
Proteins from living sources always contain small amounts of contamination
- Proteins
- May cause allergy
- Enzymes (shelf life)
- enzyme might be destroying your drug
- Other functioning protein (various effects)
- Viruses
- May cause infectious disease
- Purifications include special anti-viral steps
- Today this risk is negligible
what is Creutzfeldt–Jakob in hGH patients, and what was noted about them. and how rare is it 3 in one bitches
turns the brain into spongy material, brain tissue gets destroyed
All had been given cadaver-hGH during 1970’s
1 case in >10,000,000 people
what is Transmissible spongiform encephalopathies
- 100 % fatal brain disorders
- Death approx. 1 year after diagnosis
- No treatment
- unstoppable condition
- Dementia, blindness, involuntary movements, strange behaviour
- strange behaviour like scrapie in sheeps they scrape their skin off
Characterized by formation of amyloid plaques
- strange behaviour like scrapie in sheeps they scrape their skin off
what is Bovine spongiform encephalopathy
Mad cow disease (cows)
Does C-J have an infectious component?
- Research in 1970’s indicated infectious agent was a PROTEIN
- protein found in the brains of the animals that get the infection
- Prion
what are prions and what does it cause the alpha helical PrPc cells to undergo
- infectious conformation of proteins
- found in the membranes of nerve cells
- random events will cause the - PrPc protein to randomly undergo a change in conformation changing it into a beta sheet → PrPSc
- beta sheet form is insoluble
- if PrPsc and PrPc come into contact w each other, PrPc will flip and become a PrPSc. and the two will stick together
explain the infectious conformation shape
- exact same protein just different conformation
- conformation is the infectious part
what is PrPc a normal component of
- nerve tissue
- Neurons
- Glial cells
- Membrane-bound protein
- Sequence highly conserved across species
- human sequence is similar to animals
- Important
- Function not fully understood
- Cell adhesion
- Apoptosis
- Cellular stress
explain again how prions arise from conformational changes and the changes made
- Disease arises spontaneously
- One molecule in β conformation randomly changes to β conformation (PrPC to PrPSc)
- β forms bind to β forms and cause them to change conformation to β
- Over time β **fibrils build up disrupting nerve cell structure
- Exponential growth in β forms
is PrPSc a transmissible molecule? what happened to beta sheet form in intestines?
Disease is infectious
Eating nerve tissue (brain) from same species
β sheet form is very robust
normally proteins cant pass through the intestinal lining but this one can
Very long incubation period “slow virus”
what is mad cow disease
- Affects cows 4 to 5 years old
- Very rare
- Exact rates not known
- Likely less than 1 in 1,000,000 animals
- Arises spontaneously
- Affects single animals
- Herd outbreaks very rare
- Possible?
- no one knows if its even possible
- Possible?
