uworld Flashcards
What preceeds development of Acute Rheumatic Fever?
untreated bacterial infection (group A streptococcal pharyngeal inf)
What histology is pathognomonic for ARF?
interstitial myocardial granuloma/Aschoff body
What histology is seen in a viral myocarditis?
lymphocytic interstitial infiltrate with focal necrosis of myocytes. No Aschoff bodies
Anterograde axonal transport mediated by what protein?
kinesin
Imaging, labs and pathology for Sarcoidosis?
Bilateral hilar adenopathy and pulmonary reticular infiltrates. Labs: hyperCa, elevated ACE (granulomas prod 1,25-dihydroxycholecalciferol and ACE). Bx shows noncaseating granulomas stain neg for fungi and acid fast bacili.
Predomimant lymphocyte in sarcoid granulomas?
CD4+
Midsystolic click followed by a mid to late systolic murmur at cardiac apex that disappears with squating?
mitral valve prolapse with mitral regurgitation. Click due to tensing of chordae tendinae as pulled by ballooning valve leaflets. Murmur due to malalignment of valve margins udring systole. Squatting increases venous return and LV volume, helping to bring valve leaflets into more normal anatomic arrangement.
Altered gene and chromosome in renal cell carcinoma?
VHL gene, chr 3p (seen in both sporadic and hereditary – von hippel lindau dz)
What amino acid is not formed in homocystinuria?
inability to form cysteine from homocysteine
What are the clinical features of homocystinuria?
Prothrombotic state (premature acute coronary syn), ectopia lentis, intellectual disability.
In LV P-V loop, what would show a rightward widening of the loop?
increase in circulating volume increases preload.
Triad of ataxia telangiectasia?
Cerebellar ataxia, telangiectasias (superficial blanching nests of distended capillaries), increased risk of sinopulmonary infections.
Signs of PKU?
Intellectual disability, gait/posture abnormality, eczema, musty body odor in toddler.
What passes through the jugular foramen?
CN IX, X, XI
Drugs that reduce size of prostate in bph?
5-alpha reductase inhibitors (finasteride, dutasteride) block conversion of T to DHT in prostate thus reducing volume of prostate in BPH.
Most significant risk factor for catheter associated UTI?
duration of catheterization. Prevent by avoiding unecessary catheterization, using sterile technique when inserting and removing promptly when no longer needed.
What is cord factor?
Is a mycoside and it’s presence correlates with virulence of mycobacteria (if not present, can’t cause disease). Inactivates neutrophils, damages mito, induces release of TNF.
What is the virulence factor of Haemophilus influenzae type b?
Its polysaccharide capsule, which is composed of the polymer polyribosylribitol phosphate. PRP capsul protects the bacterium from phagocytosis and complement mediated lysis by binding factor H which prevents complement deposition on host cells.
How do you dx Trichomonas vaginalis?
Saline microscopy (wet mount) of discharge to identify trichomonads.
Sx of HepB?
Systemic, skin (pruritic urticarial vasculitis rash) and joit sx; hepatomegaly; elevated transaminase levels – often 10x norm.
Mutated Hb with lowered 2,3-BPG binding affinity?
mutations that result in loss of 2,3-BPG binding pocket’s pos charge cause Hb A to resemble fetal Hb which binds oxygen with higher affinity due to inability to interact w/ 2,3-BPG.
How to use Absolute risk?
AR (of tx) = AR (of control) - {RRR x AR control}
How to treat severe hypoglycemia?
severe hypoglycemia (unconsciousness) requires parenteral tx - emergency glucagon kits in nonmedical setting, IV glucose in medical setting.
What is a cohort study?
Organized by selecting group of individuals (cohort), determining their exposure status, then following over time for development of dz of interest.
Indwelling bladder catheters increases risk of UTI by what orgs?
Typical (E. coli, Klebsiella pneumoniae, Staph saphrophyticus, Proteus mirabilis) and opportunistic (Pseudomonas, Enterococcus, other Staphylococci, fungal) orgs.
What org is non-lactose fermenting, oxidase pos, gram negative rod?
Pseudomonas
Insulin binding to R activates what cascade?
R has intrinsic tyrosine kinase activity –> phosphorylation of insulin R substrate 1 –> activates MAP kinase pathway (dna syn, cell growth), activates PI3K pathway (translocation of GLUT 4 to cell memb, glycogen syn via activation of protein phosphatase which dephosphorylates thus activates glycogen synthase, fat syn)
Cytokines involved in formation/maintence of granulomas in TB?
IFN gamma, IL12, TNF alpha
Hormones that bind G protein coupled R on memb, activate adenylyl cyclase, converts ATP to cAMP, activates PKA?
PTH, ACTH, TSH, ADH (V2 R)
Hormones that bind G protein couple Rs that activate phospholipase C, hydrolyzes phosphatidylinositol bisphosphate to IP3 and DAG, IP3 mobilizes Ca from ER, DAG directly activates PKC?
GnRH, TRH, Ang II, ADH (V1 R)
MOA of Nevirapine?
Nonnucleoside reverse transcriptase inhibitor. Does not req activation via intracellular phosphorylation. Prevent syn of viral dna from rna template.
Location of Great Saphenous vein?
Accessed at medial leg, or near point of termination in femoral triangle of upper thigh a few cm inferolateral to pubic triangle (superiorly infuinal ligament, laterally sartorious muscle, medially adductor longus muscle).
