Mix2 Flashcards
If a patient presents with recurrent diarrhea, cutaneous flushing, wheezing, and tricuspid regurg (R sided valvular heart Dz) then what is the most likely Dx?
Carcinoid Syndrome
This is a metastatic small bowel tumor that secretes high levels of 5HT.
Aside from surgery, how would carcinoid syndrome be treated?
Admin of octreotide (SS analog)
What’s the role of cabergoline in treating GH secreting pituitary tumors?
Cabergoline = dopamine agonist.
** Can also be used to treat prolactinomas.
Leuprolide is a synthetic analog of:
GnRH
Pheochromocytoma is the most common tumor of the adrenal medulla in adults. It is derived from what cell type?
chromaffin cells (from neural crest)
What is the MOA of using phenoxybenzamine in treating pheochromocytoma?
Phenoxybenzamine is an irreversible alpha antagonist.
** Should give a-antagonist followed by B-blocker. Alpha block must be achieved before giving beta blocker to prevent hypertensive crisis.
Since both E coli and Enterobacter cloacae are both G(-) lactose fermenting bacilli, how could you distinguish them in a case of UTI?
Can check for indole positivity. E coli = indole pos (+)
Indole positivity = ability to convert tryptophan to indole
The omphalomesenteric (vitelline) duct connects the midgut lumen with the ___ in early fetal life. It normally obliterates during the ___ week of development.
yolk sac, 7th week
What event at birth could indicate that the vitelline duct has failed to close?
Passage of meconium discharge from the umbilicus soon after birth.
___ is a defense mechanism in which an individual transforms unacceptable feelings or impulses into their extreme opposites:
reaction formation
What are the 4 major structures contained in the carpal tunnel?
- flexor digitorum profundus tendons
- flexor digitorum superficialis “
- flexor pollicus longus tendon
- median nerve
The sciatic nerve is derived from ___ branches but compression most often occurs at ___
L4-S3. Compression at L5 or S1 (via vertebral disc herniation)
What electrolyte disturbances can be caused by foscarnet use?
Foscarnet = pyrophosphate analog (binds PP site on viral DNA polymerase) that is used for acyclovir resistant CMV.
Foscarnet chelates Ca2+, induces renal Mg2+ wasting, and causes release of PTH. End result is hypocalcemia and hypomagnesemia»_space; SEIZURE
What are the 2 major toxicities assoc with acyclovir use?
- Obstructive Crystal nephropathy»_space; renal failure
2. Neurotoxicity (delirium and tremor)
What infection is acyclovir predominantly used to treat and what is the MOA?
Acyclovir = guanosine analog»_space; inhibition of viral DNA Pol»_space; chain termination
Used to treat HSV/VZV. Monophosphorylated by HSV/VZV thymidine kinase (so few adverse effects in uninfected cells)
What infection is sofosbuvir predominantly used to treat and what is the MOA?
Sofosbuvir = inhibits HCV RNA dependent RNA polymerase (NS5B) and acts as a chain terminator.
Generally used in combination therapy with ribavirin, simeprevir, and ledipasvir for chronic HepC infection.
What infection is ganciclovir predominantly used to treat and what is the MOA?
Ganciclovir = Guanosine analog (5’monophosphate). Preferentially inhibits CMV viral kinase (viral DNA polymerase)
What are 3 common first line meds for bipolar maintenance therapy?
Lithium
Valproate (anticonvulsant)
Quietapine (2nd gen antipsychotic)
** Lamotrigine (another anticonvulsant) can be used in maintenance Rx for preventing depression in bipolar.
Methylphenidate is used to treat what psychiatric condition?
ADHD. Methylphenidate is a psychostimulant.
Why can’t cephalosporins be used to treat Listeria infections?
Cephalosporins = block PBP (penicillin binding protein)
Listeria is motile and a facultative intracellular organism so it is able to avoid phagocytosis and can spread intracellularly. Listeria is resistant to cephalosporins because it has an altered PBP. It is still sensitive to ampicillin though.
What’s the rate limiting step in the pentose phosphate pathway?
G6PD. Catalyzes conversion of G6P to 6-phosphogluconate
PPP is used to generate NADPH and ribose5-P (nucleotide synth precursor).
IF NADPH isn’t produced, glutathione can’t be reduced, cell suffers free radical damage»_space; hemolysis
Why are the elderly predisposed to UTI?
Urinary obstruction (BPH), fecal incontinence, neurogenic bladder (due to DM), and frequent or indwelling catheterization.
