8/19/12 Flashcards
Hemolytic anemia + hypercoagulability + decreased blood counts =
Paroxysmal Nocturnal Hemoglobinuria
What kind of enzymes require biotin?
carboxylase
What is thought to be the etiology of narcolepsy?
lack of orexin (hypocretin), a stimulatory neurotransmitter involved in wakefulness (suppressing REM sleep).
What is the first line treatment for narcolepsy? Second line?
modafinil (provigil); amphetamines
What happens to the embryonic vitelline veins after birth?
They become the hepatic portal system.
What happens to the embryonic umbilical vv. after birth?
They degenerate; become ligaments.
What happens to the embryonic cardinal vv. after birth?
They become the systemic veins.
Isoniazid is structurally similar to what vitamin?
B6
HGPRT, deficient in Lesch-Nyhan Syndrome, is part of the _______ pathway.
purine salvage
What is enoxaparin?
LMWH
What does enoxaparin bind and inactivate?
Factor Xa
What does unfractionated heparin bind and inactivate?
Factor Xa AND thrombin (by forming a ternary complex w/ it and anti-thrombin).
What is fondaparinux?
a Factor Xa inhibitor
Formula for number needed to treat?
1/ Absolute Risk Reduction (ARR)
Formula for Absolute Risk Reduction (ARR)?
risk in placebo group - risk in tx group
If 25/100 die of disease X w/ placebo and 1/60 die of disease X with drug Y, what is the number needed to treat w/ drug Y vs. placebo?
1/(25/100 - 1/60) = 4.3 ~ 5
Which diuretic will cause Ca++ retention and may be useful in preventing osteoporosis?
thiazides!!!!!!
Aside from osteoporosis prevention, what is another fortuitous side effect of increased Ca++ absorption in certain diuretics?
decreased renal stone formation
What two muscles are present in the inner ear? What are each of their functions?
tensor tympani; stapedius. Both dampen loud sounds, the tensor tympani mainly chewing, and the stapedius mainly one’s own voice.
Which cranial nerves innervates the 2 muscles of the inner ear? Which muscle does each inervate?
tensor tympani - V3
stapedius - facial
Why might a person with Bell’s palsy experience hyperacusis?
Paralysis of CN VII –> stapedius m.
What are the two anti-inflammatory cytokines?
IL-10 and TgF-β
What susbstance regulates the closure of K+ channels in pancreatic β-cells?
ATP
Briefly describe the mechanism by which increased blood glucose causes the release of insulin from the pancreatic beta cell.
Glucose enters beta cell thru GLUT-2 and undergoes glycolysis. ATP produced by this process binds to KATP regulatory subunit of K+ channel to close it and depolarize the cell. Insulin is then released.
What is the mech and effect of the alpha toxin of C. perfringens?
Alpha toxin, aka phospholipase C or lecithinase, cleaves phospholipids causing hemolysis and tissue necrosis.
What is released from the pancreas as a result of stimulation by secretin?
bicarb
What does CCK cause to be released from the pancreas? What else does it cause the secretion of?
pancreatic enzymes and bile from the gallbladder
What does perfringens, as in C. perfringens mean?
to break through, similar to perforate. The alpha toxin of C. perfringens cleaves phospholipids, allowing the bacteria to break through the cell membrane.
