UWORLD practice test Flashcards
Peutz-Jeghers syndrome
- inheritance pattern
- phenotypes
- autosomal dominant
- hyperpigmented lips, multiple harmartomas in GI (abdominal discomfort)
What does desmosome connect?
keratinocytes
- note that keratinocyte span basically entire epidermis layers. I thought it was just startum corneum, but startum corneum is composed of DEAD keratinocytes
postural tremor: what brain lesion?
cerebellum
- postural tremor, tremor during MOVEMENT, is different from resting tremor.
Intussusception vs. Merkel diverticula: how patient presents differently?
- Intussusception: palpable abdominal mass with severe pain, current jelly stool
- Merkel diverticula: occult GI bleeding, but NOT palpable mass, NOT severe pain
- note that Merkel diverticula can be leading point of intussusception
What does primase do?
making RNA primers for DNA replication (lagging strand)
metoclopramide is contraindicated with patient with what disease?
Parkinson
What is color of urine after exposure to air in alkaptouria?
black
- this is the only BLACK urine (not red- nephritic, not orange- rifampin toxicity, not brown- rhabdomyolysis, not portwine- acute intermittent porphyria)
- question presents kid with black wet diaper
phenotypes of alkaptouria?
- black urine
- blue/black spots on skin/sclera
- arthralgia (homogentisic acid is toxic to cartilage)
*OSTEOARTHROPATHY was answer
What is shake test?
mix ethanol with amniotic fluid and shake
=> surfactant foams stable ring with ethanol
=> useful diagnostic test to check enough quantity of surfactant is formed
Why heparin is safe for pregnant?
it is highly water soluble, not crossing placenta
What two types of tissues consist of liver cirrhosis?
- fibrotic tissue (from stellate cells)
- regenerative nodules (proliferating HEPATOCYTES)
female patient who has been failing to concept. regular menstural cycle, normal physical exam, history of unprotected sex. male partner is also normal. what would be possible cause?
history of unprotected sex is key here.
SUBCLINICAL PID (previous PID) can still cause infertility as it could previously damage fellopian tubes.
although patient’s physical exam is normal. ALWAYS think about PREVIOUS/ SUBCLINICAL PID for patient with unprotected sex history
History of field trip. Differentiate morphology of rash
- delayed hypersensitivity
- rocky mountain spotted fever
- delayed hypersensitivity: streaks (scratchy)
- rocky mountain spotted fever: maculopapular rash
What is etiology of later development of lactose intolerance?
decreased GENE EXPRESSION of lactase over the time
commonly affected in Asian, African, native American
Is prolonged bed rest recommended for back pain
no. it can prolong pain.
moderate activity is more recommended
what is pathophysiology of extrapyrimidal side effects upon
up-regulation dopamine receptors or compensatory hypersensitivity of dopamine receptors to dopamine
- remember, dopamine works to enhance movement. extrapyrimidal side effects include crazy movements, that is it is MORE of DOPAMINE ACTIVITY, NOT due to DOPAMINE BLOCKADE
- I picked ACUTE D2 blockade. but question said “years of medication”. meaning that it is more like chronic effect, not acute blockade
What is “contact inhibition” when two cells are growing on petri dish? how do cancer cells behave differently?
As cells are growing and contact each other, cell stops growing. This effect is mediated by cadherin
cancer cells can evade from cadherin, so they can still grow even when two cells contact each other
How can female present hemophila A?
skewed X inactivation
- normally one of female X chromosome is randomly inactivated so that both male and female present with similar gene expression dosage. This inactivation ratio is normally 50:50. But skewed X inactivation may result in 70:30 inactivation. if hemophilia A gene is in 30 inactivation portion, they can present hemophila A
- this applies to any kind of X linked recessive disease
BP while standing: 85/60
BP while sitting: 120/80
what is underlying pathophysiology?
orthostatic hypotension
understimulation of ALPHA receptor to maintain PERIPHERAL blood pressure
- I picked understimulation of beta 1 receptor, but this is not really true. Heart is already pumping (unless there is heart disease). so it is peripheral vasculature that is in charge of maintenance of blood pressure
- remember that common side effect of alpha blocker is orthostatic hypotension
what nephrotic syndrome is commonly associated with solitary tumor?
membranous nephropathy
probenicid usage for
- cidofovir
- gout
- penicillin
for gout and cidofovir probenecid is used for same reason via same mechanism:
probenecid inhibits renal tubular reabsorption so that it reduces toxicity
for penicillin, probenecid is used to increase drug efficacy for exactly opposite mechanism:
probenecid inhibits renal tubular excretion so that it allows penicillin to stay in the system longer, enhancing efficacy
explain physiology how chronic cough results in syncope
cough: sort of exaggerated exhale
- > increase in intrathoracic pressure
- > decreased venous return
what is pathophysiology of spider angiomata in liver cirrhosis
estrogen excess due to decreased estrogen metabolism by liver
*gynecomastia is also same!
Adhesions in pelvic area: diagnosis?
endometriosis
complication of untreated endometriosis?
infertility
Describe how beta-hCG pregnancy test is done
urine is added to test tube coated with antibody against beta-hCG, then latex particles coated with beta-hCG antigen is added.
If pregnant, high beta-hCG in the urine will deplete antibody in test tube, so that addition of latex particles will NOT cause aggultination
If not-pregnant, addition of urine will not do anything to antibody coated in test tube, thus addition of latex particles will cause aggultination
How is paclitaxel is used during coronary stent surgery?
paclitaxel inhibits mitosis by stabilizing microtubuels- prevents anaphase to occur
=> it prevents intimal hyperplasia
What is confabulation? what disease is associated with it?
disturbed memory: talking about stories that never actually happened
seen in Wernicke-Korsakoff syndrom
: not only anterograde amnesia (retrograde is also seen but anterograde is more common) is seen, fabricated/disturbed memory problem is also seen in this disease
breast mass decreased with size after delivery: diagnosis?
fibroadenoma
chest X-ray finding in aortic dissection?
mediastinal widening and abnormal heart contour
- dissected aorta gets messy
chest X-ray finding in pleural effusion?
blunting of costvertebral space
: water feels the bottom first
leucine zipper dimer is characteristic functional unit of what protein?
transcription factor
leucine zipper dimers contain alpha helices that have DNA binding domain
First reaction of de-novo pyrimidine synthesis? what enzyme? where in the cell does it occur?
CO2 + glutamate -> carbamoyl phosphate
mediated by carbamoyl phosphate synthase II (CPSII)
occurs in cytosol
What is underlying physiology of atrophy of other three parathyroid glands in parathyroid adenoma?
negative feedback due to high Ca2+
What is pressure atrophy?
mass COMPRESSING (thus pressure) the structure, limiting blood flow, causing atrophy
dissection between right cruz and IVC in diaphragm increases risk for damaging what structure?
vagus trunks
define
- vasogenic edema
- cytotoxic edema
- vasogenic edema: increased vascular permeability leads to liquid accumulation within interstitium
- cytotoxic edema: cellular injury leads to disruption of Na+/K+-ATPase, leading to accumulation of Na+, within the cell (so does liquid)
