USMLE-RX Flashcards
Failure to synth MHCII antigens
SCID
Leukocyte adhesion deficiency (type 1)
LFA1 integrin on phagocytes is defective and can’t bind ICAM1 –> PMNs can’t migrate, so wound healing is reduced, no pus formation, lots of infxns
Chedak-Higashi syndrome
Microtubule dysfxn in phag-lysosome fusion –> partial albinism, recurrent infxns, peripheral neuropathy
Wiskott-Aldrich syndrome
defective cytoskel organization in T cells –> decreasing lymphocytes over time
Truncal TTP, eczema, recurrent infxns, X-linked
Elevated IgA, IgE; low IgM (vs. hyper IgM: B cells can’t class switch, so get low IgA, E and G)
Nystatin
Used to treat thrush (oral candida)
Haloperidol mech
Blocks D2 receptors, can –> acute dystonia (most likely with haloperidol of all typical antipsychotics [“-azine”])
Treat dystonia by blocking ACh receptors (eg benztropine)
Typical vs. atypical antipsychotic mech
Typical - inhibit D2
Atypical - inhibit D2 and serotonin receptors
Effect of antipsychotics on prolactin
Tonic inhibition of prolactin by DP, so when inhibit DA –> increased PRL –> inhib of GnRH –> decreased LH and FSH –> no ovulation
Brenner tumor
Ovarian tumor, usually benign, cells look like bladder transitional epith in nests with coffee bean-shaped nuclei among fibrous stroma
Classic triad of fibroma, ascites, and hydrothorax
Meigs syndrome - ovarian fibromas (lots of fibroblasts)
Intraperitoneal mucus
Pseudomyxoma peritonei (presentation of ovarian mucinous cystadenomas or mucinous cystadenocarcinomas)
Estrogen-secreting ovarian tumor?
Granulosa cell tumors -> precocious puberty, endometrial hyperplasia, endometrial carcinomas
Histo: ovarian follicles with eo material (Call-Exner bodies)
Schiller-Duval bodies
Look like glomeruli, seen in yolk sac/endodermal sinus ovarian tumors
Krukenberg tumor
GI malig –> mets in ovaries (mucin-secreting signet cell adenoca)
Benzodiazepine mech
Increase GABA receptor action by increasing Cl channel opening in the receptor
Reverse with Flumazenil (competitive antag at benzo binding site on GABA receptor)
Classic triad of MS
Scanning speech
Intention tremor/Incontinence/Internuclear ophthalmoplegia
Nystagmus
“SIN”
MS findings
Increased IgG in CSF (oligoclonal bands)
MRI: periventricular plaques, WM lesions = separated in time and space
Symmetric ascending weakeness
Guillan Barre
IL2 treats…
RCCA and metastatic melanoma
CMV encephalitis MRI findings
Enhancing periventricular WM lesions in cortical and subependymal regions
CMV encephalitis histo findings
Giant cells with eosinophilic inclusions in cyt and nucleus
FAP mutation
Deletions/mut of APC gene on chrom 5 (tumor suppressor gene, mut = aut dom and second hit –> polyps –> adenoca of colon in 100% untreated pts (treat with colon resection))
vs. Hereditary nonpolyposis CRC = assoc with mutations in DNA repair genes (MSH2, MLH1)
Hereditary retinoblastoma increases risk of…
soft tissue sarcomas, osteosarcomas, melanomas, brain cancer
Medullary thyroid carcinoma associated with…
MEN 2A and 2B (Ret gene)
RCC associated with which genetic syndrome?
VHL
Painless hematuria - think of…
Transitional cell carcinoma
assoc with phenacetin, smoking, aniline dyes, cyclophosphamide
4 sx of Gerstmann aphasia
Dyscalculia, agraphia, left/right disorientation, finger nagnosia
Lesion in left parietal lobe
Ethacrynic acid
Loop diuretic that inhibits NKCC in LoH - K wasting diuretic, can –> hyperuricemia
Spironolactone (antag of aldo receptor) and triamterene (inhibits ENac) = K sparing
Birefringence of gout vs. pseudogout crystals
Gout: needle-shaped, negative birefringent (yellow when parallel to axis of polarization and blue when perpendicular)
Pseudogout: rhomboid-shaped (blue when parallel, yellow when perpendicular)
Acute treatment of gout
NSAIDs (indomethacin), steroids, colchicine
HTLV1 cancer assoc
T-lymphocyte leukemia/lymphoma (skin lesions, hyperCa, adenopathy, hepatosplenomegaly)
Job Syndrome
Hyper IgE - helper T cells don’t make IFN-gamma, so neutrophils can’t get where they need to go –> blunted inflamm response and frequent infxn (esp eczematous skin infx and pulm infxn + course facies and bone fractures)
Finasteride
Treats BPH
estradiol levels increase with age and sensitize prostate to DHT; finasteride blocks 5-alpha reductase, decreasing conversion of test to DHT
Side effect: promote hair growth
Gynecomastia is a common side effect of ____
- Flutamide (treats prostatic carcinoma)
Spironolactone, ketoconazole
Loss of blue-green color vision is a common side effect of _____
Sildenafil, vardenafil (treat ED by inhibiting cGMP phosphodiesterase –> increased cGMP)
Common triad of sx with pericarditis
Distant heart sounds, distended jugular vv, hypotension
May –> tamponade, friction rub
Drugs that have survival benefit in decompensated HF
Beta blockers and ACE-i (“-pril”)
Don’t start beta blockers acutely!!
Classic triad of Wernicke-Korsakoff syndrome
Wernicke: Confusion, ataxia, nystagmus
Korsakoff: memory problems and confabulations (irrev)
Seen with thiamine deficiency, esp in alcoholism
First aortic arch –> _____
Second aortic arch –>
Third –>
Fourth –>
Fifth –>
First: Maxillary artery (to deep structures of face)
Second: Stapedial and hyoid aa (usually regress, only important to fetus)
Third: common carotids and proximal internal carotid
Fourth: ascending arch of aorta on L and subclavian on R
Fifth: regresses
Sixth: proximal pulmonary arteries and ductus arteriosus arteries
Diethylstilbestrol exposure assoc with increased risk of _____
vaginal clear cell adenocarcinoma
Used to treat metastatic prostate cancer (used to be used to treat preg-related things)
Scurvy pathophysio
Vit C deficiency –> proline and lysine aren’t hydroxylated in ER during collagen production –> ecchymoses, petechiae, corkscrew hairs
Associations of primary vs. secondary amyloidosis
Primary - multiple myeloma (Ig light chains); that increased serum protein –> rouleaux formation of RBCs
Secondary - chronic dz (TB, RA), serum amyloid-associated protein
Dialysis-associated amyloidosis (accum of MHCI proteins)
Small lymphocytic lymphoma can transform into ___ and they share ___ as a cell marker
DLBCL, CD5 (usually a T cell marker)
vs. Follicular lymphoma (can transform into DLBCL, but doesn’t have CD5)
vs. Mantle cell lymphoma (has CD5 but can’t transform into DLBCL)
LN with cells with open chromatin, prominent nucleoli, moderate amount of cytoplasm - think ___
DLBCL
Most common cause of B12 deficiency
Pernicious anemia
IFN-alpha is used for ____
its leukocytic effects
tx: hep, Kaposi sarcoma, melanoma, leukemia
Lab findings that distinguish thal from Fe-deficiency anemia
Thalassemia: normal serum iron, increased retics
Fe-def anemia: decreased serum iron, so can’t have increased retics b/c have insufficient iron for RBC synth
What is phenobarbital used for, and why is phenobarbital not used outpt?
Anti-seizure drug, works on GABA receptors to increase Cl channel opening
Highly sedating, so only used inpt
Anticonvulsants used for tonic-clonic vs. absence and myoclonic seizures
Tonic-clonic: Gabapentin, Lamotrigine (most likely to cause SJS)
Absence and myoclonic: Clonazepam (benzo)
Down syndrome increases likelihood of this cancer by 20x
ALL
“We ALL fall DOWN”
Presenting sx of ALL
Bone marrow infiltration –> anemia, easy bruising (thrombocytopenia), fatigue etc
Childhood illness that can –> trendelenberg gait, and nerve involved
Superior gluteal nerve damage from polio
Superior gluteal n. innervates gluteus medius and minimus, which do hip abduction and medial rotation of thigh, keeping pelvis level during gait
Pralidoxine
regenerates AChE, so reverses AChE inhibitor in case of ACh poisoning
