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USMLE Step 1 > UWorld_3.24 > Flashcards

Flashcards in UWorld_3.24 Deck (23)
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1

Major virulence factor of s. aureus

-Protein A ==> binds Fc of IgG and inhibits compliment, opsonization, and phagocytosis

2

VHL gene locus

3p

3

oncogene loci: Rb, WT-1, NT-1

Rb = 13 WT-1 = 11 NT-1 = 17

4

Candida immune defenses

T-cells = defend against superficial PMNs/phagocytosis = defends against systemic/spread of candida

5

Risks for first-dose rxn to ACE-i

-hypotension, hyponatremia, renal impairment, high renin/aldosterone, heart failure -hypovolemia due to diuretics

6

First arch syndrome

==> malformed structures of first arch: -mandible, maxilla -incus, malleus -temporal bone -zygoma -vomer -palate -associated w/CN V

7

Common cause of coronary sinus dilation

any cause that ==> dilation of right atrium (e.g. pulmonary HTN)

8

common cause of acute eppiglotttis

H. flu <== epiglottitis incidence reduced due to Hib vaccine

9

Electrolytes in adrenal insufficiency

-low aldo ==> decreased Na, increased K -low aldo ==> increased H+ ==> met acidosis = low HCO3- -low HCO3- ==> increased Cl-

10

AR murmur + peak intensity

-early diastolic, high-pitched blowing -best heard leaning forward (valve closer) & during expiration (all L side murmurs) -peak intensity just after closure of the valve

11

Drugs that lead to fat redistribution

-glucocorticoids -HARRT: protease inhibitors (e.g. idinavir)

12

RF = dx of RA =

RF = anti-IgG IgM (but has low specificity) dx = anti-cyclic citrullinated peptide (anti-CCP) = high specificity

13

Recurrent lobar hemorrhages in older adult ==> dx?

-cerebral amyloid angiopathy -beta-amyloid deposited @ vessel wall ==> weak ==> rupture -hemorrhages usually less severe than those due HTN

14

Presentation of sarcoidosis

-typically young, AA female -bilat hilar adenopathy w/non-caseating granulomas -lung parenchymal inflitrates -activated macs ==> elevated Vit D ==> hypercalcemia

15

Example of med that demonstrates tachyphylaxis

-nasal decongestants -negative feedback ==> rebound rhinorrhea after 3 days use

16

BRAF mutation association

-melanoma -BRAF = tyrosine kinase mutation in melanocyte prolif

17

Blood flow to radius of vessel relationship

Flow proportional to 1/r^4

18

flutamide: MOA

-anti-androgen used in prostate cancer tx -competes with T and DHT for binding @ receptor

19

excessive scarring after wound ==>

keloid = excessive collagen

20

Amino acids with 3 titratable protons

- ==> 3 pKa -histadine -arginine -lysine -aspartic acid -glutamic acid -tyrosine -cysteine

21

E. Coli strain that does not ferment + does not produce glucuronidase =

-E. Coli O157:H7 -==> hemorrhagic colitis - has shiga-like toxin ==> inactivation of 60S subunit - ==> HUS

22

Transtentorial herniation ==>

-ipsilateral CNIII lesion = "down and out" -contralateral or ipsilateral hemiparesis -if post. cerebral artery occluded ==> contralateral homonomyous hemianopsia

23

Fendolam: MOA, use

-selective D1 receptor ==> increased cAMP ==> arteriolar dilation -==> increased renal perfusion and natriuresis -used in hypertensive emergencies

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