Fri Jul 10 Flashcards
when a patient comes in with organophosphate poisoning, how do you treat them?
First atropine, then pralidoxime
why do you give atropine before pralidoxime?
you need to give pralidoxime as well, since it treats the nicotinic symptoms of organophosphate poisoning, but it causes a transient rise in Ach so you need to give atropine first
an anteriolateral displacement of a supracondylar humerus fracture may damage which nerve?
RADIAL
an anteriomedial displacement of a supracondylar humerus fracture may damage which nerve?
MEDIAN
which virus causes hand-foot-mouth disease?
enterovirus (coxsacckievirus)
how is coxsackievirus spread?
fecal-oral route
what are anti-jo-1 antibodies?
antibodies against tRNA synthetase
which disease has anti-jo-1-antibodies?
polymyositis
what will be found on biopsy of polymyositis?
endomysial inflammation - mononuclear infiltrate and patchy necrosis
what will be seen on biopsy of someone with dermatomyositis?
perifascicular inflammation
presentation of polymyositis?
symmetrical proximal muscle weakness - difficulty climbing stairs, getting up, carrying heavy objects
which hormone stimulates leydig cells?
LH
which hormone stimulates sertoli cells?
FSH
which vessels does nitroprusside act on?
both veins and arteries - reduces afterload and preload
how is excess ammonia processed in the brain?
Converted to glutamine
what happens when astrocytes have excess glutamine?
they swell up (increased osmolarity) and this leads to impaired glutamine release–> disruption of excitatory neurotransmission
how should you evaluate someone who may have vertebral osteomyelitis?
blood cultures and MRI of the spine
volume overload in the ventricles leads to which type of hypertrophy?
eccentric
the decrease in function KCNH2 mutation is a cause of…
congenital long QT
unfractionated heparin MOA?
binds to both antithrombin and thrombin, forming a complex that inactivates thrombin
also binds to and inhibits Xa
low molecular weight heparin MOA?
binds and inactivates factor Xa
how does shiga and shiga-like toxin work?
binds to 60s ribosomal subunit, inhibiting protein synthesis and leading to cell death
at what CD4 count is someone susceptible to toxoplasmosis?
<100
how does fructose-2,6,BP effect glycolysis?
activates phosphofructokinase-1, promoting the conversion of fructose-6-P to fructose,1,6-P
high concentrations of fructose-2,6 BP inhibit…
gluconeogenesis
what effect does cholesterol have on risk of gallstones?
high cholesterol leads to increased likelihood of cholesterol precipitation and gallstone formation
what effect do bile salts and phosphatidylcholine have on risk of gallstones?
these increase the solubility of cholesterol and thus if they are higher it decreases risk
what antibodies are present in membranous nephropathy?
phospholipase A2 receptor antibodies (PLA2R)
aortic stenosis most commonly results from…
age-related calcific aortic valve disease
pathogenesis of age-related calcific aortic valve disease?
In early stages damage to the valves over time lead to endothelial dysfunction and onset of an atherosclerotic process. The presence of inflammatory mediators eventually leads to fibroblast differentiation into osteoblast-like cells, leading to bone matrix deposition with progressive valvular calficiation
which strain of hepatitis uses reverse transcriptase?
hepatitis B
how do atrial myxomas appear histologically?
scattered cells with a mucopolysaccharide stroma
which type of lung cancer may cause SIADH?
small cell lung carcinoma
which markers are often present in small cell lung carcinoma?
neuroendocrine markers - neural adhesion molecules, chromogranin, neuron-specific enolase, synaptophysin.
what would a biopsy of a white spot in someone with vitiligo show?
no melanocytes or pigment
where does a neuroblastoma occur?
adrenal medulla
presentation of a neuroblastoma?
young child <2 years, abdominal mass, opsoclonus-myoclonus, periorbital ecchymyoses
what will neuroblastoma look like on histology?
small blue cells with homer wright rosettes
what predicts prognosis of a neuroblastoma?
N-myc - poor prognosis
is there blood and leukocytes in the stool of someone with norovirus?
no
how may someone contract campylobacter other than undercooked meats?
contact with warm-blooded animals
where do B cells usually aggregate in lymph nodes?
they usually aggregate in the cortex to form lymphoid follicles
why do loop diuretics cause metabolic alkalosis?
- the loss of Na stimulates aldosterone, leading to increased secretion of H and K
- more Cl- is lost than Na resulting in decreased total body electronegativity, leading to the kidneys holding on to more HCO
if someone on loop diuretics develops metabolic alkalosis, what can you give them?
CA inhibitors
what enzyme do fibrates inhibit?
cholesterol-7-alpha-hydroxylase - the rate limiting step in bile acid synthesis, resulting in decreased bile salt synthesis and increased excretion of cholesterol
fibrates increase the risk for what?
gallstones - increased cholesterol in gallbladder
what property leads to propofols short duration of action?
rapid redistribution of the drug into tissues
how do GLP-1 agonists work?
increase glucose-dependent insulin secretion, decrease glucagon and delay gastric emptying
side effects of GLP-1 agonists?
pancreatitis, weight loss
where does the focal image fall with myopia?
anterior to the retina
where does the focal image fall with hyperopia?
posterior to the retina
