UWorld Flashcards
IFN-gamma
released by T cells
use it to test for latent TB (how much IFN-gamma is released by T cells when exposed to TB antigens?)
Enteric bacteremia = most likely to be caused by
E coli, Salmonella typhi, Klebsiella, proteus (shigella is rarely phagocytosed and destroyed when it enters bloodstream, so no bacteremia)
DSM5 personality disorders
Paranoid = suspicious, distrustful, hypervigilant
Schizoid = loner, detached, unemotional
Schizotypal = eccentric; odd thoughts, perceptions and behavior
Antisocial = disregard and violation of rights of others
Borderline = chaotic relationships, labile mood, inner emptiness, self harm etc
Histrionic = dramatic, superficial, attention seeking
Narcissistic = grandiose, lack empathy
avoidant = avoid b/c of fears of criticism and rejection
Dependent = submissive, clingy
Obsessive-compulsive = rigid, controlling, perfectionistic
To locate appendix intra-op?
follow tenia coli band of muscle to where it attaches to cecum
Stimulation of pancreatic bicarb release?
Enzyme release?
Bicarb = from secretin (secreted by S-cels in response to increasing H+ conc)
Enzymes = from CCK and cholinergic stim
Wiskoff-Aldrich
eczema, recurrent infxns, thrombocytopenia
mut on X chrom (males) - combo B and T lymphocyte disorder
tx = hla-matched bone marrow transplant
HUS
microangiopathic hemolytic anemia, thrombocytopenia, acute renal failure
usually caused by enteroinvasive infxn –> toxin binds renal endothelium –> damage –> thrombosis and inactivation of ADAMTS13 (as in TTP) –> growing thrombi –> RBC lysis (schistocytes) and AKI (uremia)
causes of aplastic anemia
chloramphenicol use
infection of SCD pts with parvo
Chediak-Higashi syndrome
albinism, peripheral neuropathy, immunodeficiency
phagocyte dysfxn
ataxia-telangectasia syndrome
B/T cell defect –> ataxia and telangectasia
3’–> 5’ exonuclease vs 5’ –> 3’ exonuclease
Prokaryotes have 3 DNA polymerases and all have 5’-to-3’ polymerase and 3’ to 5’ proofreading exonuclease activity, but DNA pol 1 also has 5’ to 3’ exonuclease activity
5’–>3’ allows DNA pol1 to do nick translation (DNA repair and removal of RNA primers)
3’–>5’ is the usual virus-encoded proofreader; absent in HCV so it makes lots of replication errors –> lots of subspecies of HCV
Lithium effects on kidney
induces DI by antagonizing vasopressin/ADH (–> polydipsia, polyuria, inappropriately dilute urine after water restriction)
in addition to kidney damage, can cause hypothyroidism (monitor BUN, Cr, and thyroid fxn)
*lithium toxicity enhanced by anything that decreases GFR –> increased PT lithium reabs (lithium follows Na) –> increased lithium floating around in the body, and it has a really narrow therapeutic window
**ACEi, NSAIDs and nondihydropyridine CCBs can also increase lithium conc and toxicity
Abciximab is used for…
GPIIb/IIIa antag, used for unstable angina and ACS
Direct thrombin inhibitors are used in
argatroban (HIT), dabigatran (afib, venous thromboembolism)
so anticoag
clopidogrel vs abciximab
clopidogrel blocks ADP receptors on plts
abciximab blocks GPIIb/IIIa
Symptoms of Patau syndrome
holoprosencephaly (ranging from cleft lip to cyclops), microceph, microphthalmia, ID
Markedly elevated AFP levels associated with ___
open neural tube and ventral wall defects (eg opmhalocele, gastroschisis)
vs low AFP associated with Down syndrome
Parinaud syndrome
dorsal midbrain problem (paralysis of upward gasze, kptosis and pupillary abnormalities) due to compression of pretectal region of midbrain, eg from pineal gland mass
most common pineal gland mass?
germinoma (from embryonic germ cells); most common in young boys
also seen in suprasellar region (less common) –> endocrine problems
Ventral vs dorsal pancreatic buds
dorsal forms majority of pancreatic tissue, + accessory duct (which usually fuses with ventral duct and rest of it usually degenerates, except in pancreas divisum, when the buds fail to fuse, so there are two ducts into duod; usu asymptomatic but can –> recurrent pancreatitis)
ventral = major duct + inferior/posterior portion of head and uncinate process
Myotonia
abnormally slow relaxation of muscles
Sx: difficulty loosening one’s grip, cataracts, frontal balding, gonadal atrophy
myotonic muscular dystrophy (second most common inherited muscle disorder, aut dom trinucleotide repeat expansion of gene for myotonia protein kinase)
type 1 fibers = esp atrophied
Inflammatory myopathies
Dermatomyositis, polymyositis
Ion channel myopathies
sx: myotonia (abnormally slow relaxation of mm) + episodes of hypotonoic paralysis, esp with exercise; no muscle atrophy
mitochondrial myopathies
aka oxidative phosphorylation disease
sx: myopathy, lactic acid buildup, CNS disease
ragged red fibers
mitochondrial inheritance
Inheritance pattern of achondroplasia
autosomal dominant (homozygous form = lethal)
usu starts as sporadic mutation due to advanced paternal age
mech: GOF mutation in FGFR3 gene
Patients with deficiencies in complement factors that form MAC get …
recurrent Neisseria infxns
Effect of pCO2 on cerebral blood flow
Increased pCO2 increases CBF via cerebral vasodil (vs pO2 has less effect on CBF)
cystocele
prolapse of anterior vaginal wall, may occur with pelvic floor injury (levator ani muscle injury)
Kegels
squeeze and release levator ani muscles to strengthen pelvic floor
Causes of incontinence (urinary)
stress urinary incontinence (with increased abd pressure) - pelvic floor (levator ani) injury, external urethral sphincter injury (eg prolonged labor)
urge incontinence (detrusor overactivity)
overflow incontinence (detrusor underactivity)
Control of urination
To urinate: Parasympathetics contract detrusor, relax internal urethral sphincter; somatic: pudendal relaxes external urethral sphincter
To not urinate: Sympathetics relax detrusor, contract internal urethral sphincter; pudendal contracts external urethral sphincter
STD ulcers - initial pain vs no pain
pain: chancroid, genital herpes (HSV1 and 2 - more common; lesions heal within 10 days)
no pain: Klebsiella, syphilis (lesion self resolves within weeks), lymphogranuloma venereum
Large, painful inguinal lymph nodes in which STD?
lymphogranuloma venereum (chlamydia)
also painless initial ulcer, ulcers = small and shallow
OBLIGATE INTRACELLULAR
characteristic feature sof granuloma inguinale (Klebsiella)
extensive and progressive ulcerative lesions, nonpainful, with granulation tissue at base
NO LAD (Distinguishes it from chlamydia buboes)
deeply staining gram neg intracytoplasmic cysts (Donovan bodies)
What do chancroid ulcers look like?
multiple, deep, painfull, with gray/yellow exudate at base
histo: organisms = clumped in parallel strands (schools of fish)
vs syphilis = single, indurated, well circ, painless ulcer with clean base and thin, corkscrew organismss on darkfield mic
Cowdry bodies
pink/purple intranuclear (not cytoplasmic) inclusions seen in HSV
also histo: multinucleated gina cells
HbH vs Hb Barts
HbH is in alpha-thal 3 allele deletion, when have very little alpha and get excess beta in tetramers
Hb Barts (lethal) = no alpha globin (4 allele deletion), so get gamma tetramers
HbA vs HbA2
HbA = 2 alpha, 2 beta
HbA2 = 2 alpha, 2 delta (increased in beta thal minor)
Drug of choice for paroxysmal SVT
adenosine (blocks AV node), fast acting with short t1/2
side effects = flushing, chest burning (bronchospasm), hypotension, and AV block
antiarrhythmic used for ventricular arrythmias
lidocaine (class IB)
tox = neuro sx
preferentially affects ischemic tissue, so often preferred post-MI
Anti-serotonin drugs
Cyrpoheptadine (oral 5-ht1a and 2a antag used to treat ser syndrome)
Ondansetron (5-ht3 antag to treat nausea/vomiting)
Nitrite positive urine = what kind of organism causing the UTI?
gram negative
arteriovenous nicking
funduscopic finding in patients with chronic htn (early manifestation of retinopathy due to exudative vascular changes from endothelial damage)
looks like arteriole overlying squished vein
end-organ damage in pre-eclampsia = due to ?
endothelial damage secondary to release of inflamm factors from abnormal placentation
difference b/w clotting factor deficiency-induced bleeding and VWD bleeding
clotting factor def (eg hemophilia) = deep tissue bleeding
vs VWD = skin and mucosal bleeding (gingivae, nasal mucosa, GI tract, endometrium)
ITP bleeding also = mucocutaneous
Cheyne-Stokes breathing
cyclic breathing pattern in which apnea is follwed by gradually increasing then decreasing tidal volumes until the next apneic period
seen in CHF (chronic hypervent with ypocapnia induces apnea during sleep –> buildup of CO2 –> ventilation overshoots)
Erythematous childhood rashes
Chickenpox (pruritic vesicles in different stages of dev)
Erythemia infectiosum (parvo; malar rash) - worry about aplastic anemia as sequela in IC or SCD pts
Rubella (occipital and postauricular lad; rash starts on head and moves down)
Rubeola (measles) - rash from head down, cough, coryza, conjunc, koplik spots; can –> bronchopna, encephalitis
roseola (HHV) - fever –> rash, self-lim; rash starts on trunk
scarlet fever (strep pyogenes) - sandpaper like rash starts on neck and then generalizes; may –> RF, glomerulonephritis
P450 inducers
barbs, rifampin, carbamazepine, griseofulvin, chronic alcohol
p450 inhibitors
isoniazid, cimetidine/omeprazole, macrolides, azoles, grapefruit juice
phenytoin toxicity
it’s a p450 inducer, and will be metabolized faster in liver if administered with other p450 inducers
it’s breakdown is dose-dependent so if give higher doses and saturate the enzyme, can quickly get tox
Cherry red spot
on macula with diffuse retinal ischemia of central retinal artery occlusion
usually with acute monocular vision loss
Hiatal hernia - two types?
para-esophageal (GE jxn stays attached at level of diaph, but part of stomach passes or bulges into chest)
sliding (GE jxn protrudes into chest –> dysphagia, GERD but normal manometry)
Phenotypic mixing in viruses
host cell is coinfected with 2 viral strains and progeny virions contain genome from one strain and nucleocapsid or envelope proteins from other
BUT their offspring will go back to original traits, since genome is unchanged
Reassortment vs recombination vs transformation in viruses
Reassortment requires segmented genomes, exchange whole genome segments (eg flu) - mechanism of genetic shift in flu
Recombination = nonsegmented, dsDNA genomes (exchange genes between 2 chromosomes via crossing over of homologous regions); can result in traits in progeny that weren’t present in either progeny strain
Transformation = uptake of naked DNA by prokaryotic or eukaryotic host cell (doesn’t change virus genome) - eg bacteria uptaking DNA from its environment, or host cell incorporating viral DNA into its own genome
mold vs. yeast
mold = branching (eg germ tubes of candida in the body)
yeast = spore-like (unicellular, can assemble into strings, aka “pseudohyphae”) - most infxs fungi = “yeast in the heat” (aka in the human body), except candida
ecological study
unit of analysis = populations, not individuals
if try to make conclusions about individuals within the populations, that’s the “ecological fallacy”
vs. eg cross sectional study (exposures and outcomes in INDIVIDUALS at given pt in time)
lab test for fat in stool
sudan III stain (stool should normally contain no measurable fat)
Adverse effects of anthracyclines and prevention of that a/e
chemo drugs
main a/e = cardiotoxicity due to generation of free radicals –> DCM (swelling of SR and loss of cardiomyocytes –> CHF sx)
tx: dexrazoxane (Fe chelation)
Mutation in SCD vs HbC defect
SCD: glutamic acid to valine in beta chain
HbC: glutamic acid to lysine in beta chain
Mechanism of action of most N. meng vaccines
target the polysaccharide capsule to facilitate bacterial opsonization, phagocytosis, and clearance of organism from blood to prevent hematogenous dissemination
what would be even better is targeting pilus (mechanism of invading nasopharyngeal epithelium to get access to blood in first place)
Diphenoxylate
opioid mu receptor agonist used in low doses to slow GI motility and decrease diarrhea symptoms in uncomplicated diarrhea
often combined with atropine to lead to a/es if taken in high doses (discourage abuse)
Three areas of portosystemic shunt in portal htn and veins involved
caput medusae: paraumbilical veins (portal) –> superficial and inferior epigastric veins (systemic)
hemorrhoids: superior rectal vv (portal) –> middle and inferior rectal vv (systemic)
esophageal varices: left gastric (portal) –> esophageal (systemic)
Rare mu opioid a/e that causes abd pain
contraction of smooth muscle cells in sphincter of oddi –> spasm and increase in common bile duct pressure, may –> biliary colic in pressure in gallbladder increases
d/c
isolated atrial amyloidosis is due to ___
deposition of abnormally folded ANP-derived proteins (increased incidence with age)
can also happen in pancreas with DM, in pituitary with prolactin-derived proteins, in thyroid with calcitonin-derived proteins in medullary thyroid cancer etc
Urine is diluted in the ____
concentrated in the ____
diluted in ascending loop of henle (electrolytes, but not water, are reabs) - concentrated on way down LoH, diluted on way back up
concentrated in collecting duct (via ADH –> aquaporin translocation and water reabs driven by high osm of medullary interstitium)
porphyria
deficiencies in heme synthesis enzymes
urinary porphobilingoen may = elevated
HIT
IgG against heparin-platelet factor 4 –> Fc of IgG binds and activates plts –> clotting and depletion of plts
hot tub folliculitis
pseudomonas
Campylobacter can be acquired from…
domestic animals or contaminated food
DRESS syndrome
drug rxn with eosinophilia and systemic symptoms
rare, can be life-threatening, 2-8 weeks after start antiseizure, allopurinol, sulfonamides, abx (eg minocycline, vanc)
prob causes herpesvirus reactivation –> clonal expansion of T cells that cross react with drug
sx: fever, LAD, facial edema, skin rash
tx: d/c drug
drugs most commonly linked to anca-associated vasculitis
hyperthyroidism drugs and hydralazine
mixed cryoglobulinemia
small- to medium-vessel vasculitis caused by circulating Ig-complement complexes
often assoc with chronic inflamm state
glucogenic amino acids vs ketogenic AAs
both: phenylalanine, isoleucine, tryptophan
ketogenic: leucine, lysine
glucogenic: alanine, serine, asparagine, aspartate
glucogenic = producing intermiediates of TCA cycle or pyruvate
2nd gen antipsychotics with greatest risk of…
metabolic syndrome/weight gain?
QT prolongation
agranulocytosis?
prolactin elevation?
onazapine and clozapine
ziprasidone (QT)
clozapine (agran)
risperidone (prolactin)
cervicofacial actinomycosis
slow growing mass that –> chronic face and neck abscesses complicated by cutaneous sinus tracts due to actinomyces infxn (often after dental work etc)
tx: parenteral pcn and surgical debridement
diuretics that can –> hypercalcemia and hyperuricemia
thiazides
infliximab
anti-tnf-alpha used for RA, AS, Crohn’s
IL-2 as treatment
activates T cells to aid in tumor cell destruction, used in RCCA and melanoma
T cells then secrete more IL-2
also promotes growth of B cells and activation of NK cells and monocytes
aldosterone escape
high aldo levels –> increased intravasc volume –> increased RBF and increased ANP –> compensatory increase in Na excretion from kidneys, so net sodium in body doesn’t increase much, and pt doesn’t get too volume overloaded
RPF vs RBF
RPF = RBF*(1-Hct)
need RPF to calculate FF (=GFR/RPF)
Alemtuzumab
anti-CD52 used to treat CLL (binds CD52 and initiates direct cytotoxic killing through complement and Ig-dependent, CMI)
IFN-gamma
increases expression of MHC I and II –> improved antigen presentation
symptoms of serotonin syndrome
abnormal mental status, autonomic hyperactivity, muscular rigidity with hyperreflexia
seen with SSRIs
Epistasis
allele of one gene affects phenotypic expression of alleles in another gene
congenital torticollis
due to birth trauma (eg breech) or malposition of head in utero –> SCM injjury and fibrosis (may come with other MS anomalies, like hip dysplasia, clubfoot etc)
clinical diag: noticed around 2-4 weeks, head = tilted toward affected side with chin pointed away and soft tissue mass over affected SCM
tx = stretching exercises
maternal htn can cause?
asymmetric IUGR (normal or almost-normal head size with reduced abdominal circumference)
Pneumoconioses vs. hypersensitivity pneumonitis
Asbestosis - ferruginous bodies, pleural plaques, interstitial infiltrate in lower lobes (CXR)
Berylliosis - ill-definednodular opacities on CXR; histo: noncaseating epithelioid granulomas (looks like sarcoid)
Coal - nodualr interstitial opacities; histo: coal dust-laden macrophages
Silica - eggshell calcification of hilar lymph nodes; histo: birefringent silica particles surrounded by fibrosis
hypersensitivity pneumonitis - diffuse interstitial infiltrates on CXR; histo: noncaseating granulomas
can all present with DOE
E Coli feature that allows some strains to colonize and ascend urinary tract?
fimbriae (adhesive proteins) –> pyelo, bacteremia/sepsis
PNH
sx: hemolytic anemia, pancytopenia, hypercoagulability
pathophys: due to acquired mutation of PIGA gene within clonal population of multippotent hematopopietic stem cells, so can’t make GPI anchor, and thus can’t attach CD55 (DAF) and CD59 (MAC inhibitory protein) – diag based on flow –, so can’t inactivate complement, which will cause MAC to form on normal cells –» comp-mediated hemolysis
thrombotic complications (eg budd chiari) due to release of free hgb and oother prothrombotic factors from lysed RBCs and plts
fundamentally a stem cell disorder, which is why you get pancytopenia
tx: eculizumab (complement inhibitor)
consequence of cardiac rupture and timing post-MI
usually 5-14 days, when coag necrosis, PMN/macrophage infiltration, and enzymatic lysis of CT is going on
consequence: severe hypotension and shock –> pulseless electrical activity and death (due to tamponade and hemopericardium in free wall rupture - most common site of rupture)
vs true aneurysm = late complication (>1month) - rarely rupture b/c surrounded by tough epicardium
pre-op treatment of carcinoid
octreotide (decrease diarrhea since it inhibits GI hormones)
cabergoline
DA agonist (used to treat GH-secreting or PRL-secreting tumors)
only DNA pol ___ has 5’ to 3’ exonuclease
1, used to remove RNA primer
all three DNA pols have 3’ to 5’ exonuclease for proofreading
these = in prokaryotes
if see bloody diarrhea with microangiopathic hemolytic anemia, thrombocytopenia, and renal insufficiency?
think HUS, usually due to E Coli O157:H7
usually undercooked ground beef, person-to-person contact, raw unpasteurized milk, sewage-contam water
lysogenization
bacteriophage infects host bacterium and integrates its genome into host bacterium genome
ex: Shiga-like toxin, botulinum toxin, cholera toxin, diphtheria toxin, erythrogenic toxin of Strep pyogenes (scarlet fever)
Transformation
abitility to take up naked dna from environment
eg Strep pneumo acquires its capsule machinery that way (thus becoming pathogenic)
also H flu, Neisseria
patients with inherited terminal complement defects (can’t form MAC) have increased susc to ____
Neisseria
patients with decreased CMI have increased susc to ___
intracellular bacteria (Salmonella, shigella, M TB, listeria), viruses, fungi
Mallory Weiss vs. Boerhaave syndrome
Mallory-weiss = upper GI mucosal tear
Boerhaave = esophageal transmural tear –> vomiting, chest/upper abd pain, and rapid fever, dyspnea and septic shock
Three causes of nausea/vomiting with different antiemetcs
GI-related (eg traveler’s diarrhea) - use serotonin antagonist (GI irritation –> ser release) - eg ondansetron
Central nausea (eg migraines) = da induced, so can use DA antag (eg metoclopramide, promethazine)
Vestibular nausea (eg motion sickness) - use first-gen (cross BBB) H1 receptor antag (eg diphenhydramine, meclizine) or mAChR antagonists (eg scopolamine)
When would you use atropine in MI?
inferior MI (right coronary artery blockage –> decreased perfusion to SA and AV node), so give atropine to decrease vagal influence on AV and SA nodes and thus increase HR
but comes with usual atropine a/es (eg angle closure glaucoma due to mydriasis)
also used to treat other causes of bradycardia (eg heart block)
Increased optic cup:disc ratio
sign of open angle glaucoma (pale disc, big cup)
progressiv eloss of ganglion cell axons causes the change, causing progressive loss of peripheral visual fields
tx: decrease aqueous production (eg CA inhibitors, alpha agonistis [eg brimonidine - vasocon in ciliary body], beta blockers [eg timolol]) or increase outflow (eg with prostaglandins)
Drugs to decrease aqueous humor production
CA inhibitors (decrease formation of bicarb in ciliary body)
alpha agonists (eg brimonidine) - vasocon of ciliary body
beta antag (eg timolol)
Drugs to increase aq humor drainage
topical prostaglandins (eg latanoprost) - ?mech
HPV has predilection for _____ type of epithelium, so mostly found as warts on _____
stratified sq epithelium - anal canal, vagina, cervix, and true vocal cords (only part of resp tract with strat sq epith to protect from constant friction of speech)
may see these vocal cord warts in babies born to infected moms
Positive likelihood ratio
prob of diseased person testing positive (sensitivity) / prob of nondiseased person testing positive (1-specificity)
Negative likelihood ratio
likelihood of having the disease given a negative result
prob of diseased person testing negative (1-sensitivity) / prob of nondiseased person testing negative (specificity)
Fragile X
physical sx: macroorchidism, dysmorphic (long) facies
neuropsych: ID, dev delay, ASD, ADHD
cause: mutation of FMR1 gene on X chrom (expanded trinucleotide repeat) –> gene hypermethylation (so gene is inactivated)
Rheumatoid factor
IgM antibody specific for Fc component of self IgG
binds IgG and forms ICs that circulate in serum and deposit in synovium and cartilage –> complement activation and chronic inflamm
produced when CD4 cells are activated by collagen proteins and stimulate B cells to make RF
anti-centromere vs anti-dsDNA
centromere = CREST
dsDNA = SLE
Effect of IFN-alpha and beta on virally infected cells
synthesized in most cells in response to viral infection, but antiviral enzymes that are made when they bind their receptors are only activated in presence of dsRNA (virally infected cells) –> prevent protein synth and thus viral replication
IFN alpha, beta, gamma
alpha and beta are made by all cells in response to viral infection –> antiviral enzymes that are activated only in presence of dsRNA (viral) and decrease protein synth to stop viral replication
- alpha and beta also induce MHC I expression –> more NK and cytotoxic T cells –> more apop of infected cells
- gamma is produced by NK and T cells –> Th1 differentiation, increased MHC2 expression, and improved intracellular killing ability of macrophages
anterolateral humeral fracture injures the ____
radial nerve (pushes humerus anterior and laterally, where radial runs, eg falling on outstretched hand/hyperextension)
sx: wrist drop
vs if injure the radial as it passes through supinator canal (eg due to repetitive pronation/supination, trauma, dislocation of radius), then get weakness on finger and thumb extension, but triceps and wrist extensor = OK (branches come off before the deep branch of the radial nerve passes around lateral epicondyle of humerus and into forearm through the canal)
anteromedial humeral fracture - caused by what and injures what?
caused by hyperextension (eg falling on outstretched hand) that pushes humerus medially and forward
injures brachial artery and median nerve
hyperflexion injures what nerve?
ulnar (runs posterior to medial epicondyle, so when humerus is displaced posteriorly, it gets injured)
biceps tendon injury happens how, usually?
older people who are lifting something (so biceps is flexed) and then rapidly extend
hemorrhagic cystisis is side effect of what chemo?
Cyclophosphamide/ifosfamide
chemo that can cause CHF?
doxorubicin (anthracycline + chemo)
pulmonary toxicity induced by which chemo drug?
bleomycin (progressive pulm fibrosis)
Cholestasis and hepatitis associated with which chemo drug?
mercaptopurine
ToF is primarily a ____ defect
abnormal neural crest cell migration –> deviation of infundibular septum (so get malaligned VSD and overriding aorta)
Endocardial cushion defect results in ___
ASD or VSD with left-to-right shunting; eventually reverses (Eisenmenger) and get late-presentation cyanosis
Somatomedin C
insulin-like growth factor (released in response to GH a nd stimulates growth)
POMC = precursor to ____
beta-endorphin, ACTH, MSH
Spread of H. flu vs N. meng to brain
H. Flu: pharynx –> lymphatics –> meninges
N. meng: pharynx –> blood via mucosal epithelium –> choroid plexus –> meninges
Musculocutaneous innervates
biceps and brachialis (elbow flexion)
Suprascapular n innervates
supraspinatus and infraspinatus (shoulder abduction and lateral rotation)
grabbing from above –>
lower brachial plexus (ulnar and median) injury
fall on outstretched hand
usually injures radial (anterolateral fracture; also with middle humerus fracture)
anteromedial fracture can injure median nerve/brachial artery
Zolpidem
short-acting hypnotic, used for insomnia b/c less addiction/tol potential, no anticonvulsant properties or muscle relaxing effects
otherwise similar to benzos (and sometimes long-acting benzos like furazepam are used for insomnia, but increased risk of dependence)
How does epi make glucose available?
- adipose: increased breakdwon of TGs –> gluconeo
- liver: increased glycogenolysis and gluconeo
- skel muscle: decreased glucose uptake and increased alanine release (source for gluconeo)
with starvation, renal gluconeo starts (epi stimulates it more than glucagon)
Side effects of TB drugs
Rifampin - red/orange fluids, GI, cytopenias
Isoniazid - B6 deficiency, hepatotox
Pyrazinamide - hepatotox, hyperuricemia
Ethambutol - optic neuropathy (central scotoma, decreased acuity, color blindness)
Viruses that acquire envelope by budding through host cell nuclear membrane (most bud through plasma membrane of host)
herpesviruses
CD21
receptor for C3d on B cells (so CD21 b cells are infected with EBV and proliferate, though not as much as activated CD8 T cells)
Thoracic outlet syndrome
compression of the lower trunk of the brachial plexus and/or subclavian vein and/or subclavian artery as it passes through scalene triangle (between scalene mm and first rib) –> UE nubmness, tingling, weakness +/- swelling (vein compression) +/- exertional pain (artery compression)
may be caused by anomalous cervical rib, scalene muscle abnormalities, or injury (eg repetitive overhead arm mvmts)
methylmalonic acidemia
aut rec deficiency in methylmalonyl-CoA mutase
so threonine, methionine, valine, isoleucine, and odd-chain FAs are converted to propionyl CoA, which is converted to methylmalonyl CoA, but no enzyme to convert that to Succinyl CoA to run TCA –> buiild up of propionic and methylmalonic acid
acidemia –> inhibits urea cycle and gluconeo
also overall increased metabolic rate -> decreased glucose, increased FFA metabolism and ketone production
overall: anion gap metabolic acidosis, hypoglycemia, ketosis, and hyperammonemia
confirm diag with elevatred urine MMA and propionic acid
Causes of sma syndrome
transverse duodenum gets stuck between aorta and SMA if angle between them decreases
eg due to sudden weight loss, severe burns or othe rinducers of catabolism, prolonged bedrest, lordosis etc (all diminish fat between aorta and sma)
Intrapartum infections
HSV, Chlaymydia, Neisseria, viruses (all can cause ophthalmia neonaturm/conjunctivitis), GBS sepsis
Most common presentation of post-procedure atheroembolism?
acute kidney injury (chol-containing debris from deposits in bigger arteries is dislodged and lands in kidney vasculature)
tumor like pheo but that’s outside adrenal medulla?
paraganglioma
Rule of 10’s: 10% of pheos are:
bilateral
extra-adrenal (paragang)
malignant
acute, painless loss of vision is due to ___
central retinal artery occlusion
findings: pale retina, cherry-red macula (fovea gets own blood supply from choroid, which you can see underneath)
amaurosis fugax
painless, transiet (few sec), monocular vision loss due to small embolus to ephthalmic artery
activation of glycogen phosphorylase in liver vs. muscle
to be activated, needs to be phosphorylated by phosphorylase kinase
in liver, that happesn when epi and glucagon increase cAMP via Gs
in skel muscle, no glucagon receptors, so epi –> increased cAMP but more potently, ACh with skeletal muscle contraction –> CICR from SR –> glycogen breakdown (synchronizing muscle contraction and glycogen breakdown so mm have adequate energy to contract)
C1 esterase inhibitor deficiency causes _____?
c/i drug?
hereditary angioedema
ACEi are contraindicated (further increase bradykinin)
Central regulator of Fe homeostasis and wher eis it made?
hepcidin, made in liver
hepicidin (released with high Fe and inflamm) –> less ferroporptin –> decreased intestinal iron abs and less Fe released from macrophages
Metyrapone stimulation test
indicator of HPA axis integrity
give metyrapone, which prevents conversion of deoxycortisol to cortisol, so decreased cortisol should –> increased CRH and ACTH –> increased 11-deoxycortisol (trying to make cortisol)
11-deoxycortisol builds up in blood and is excreted in urine as 17-hydroxycorticosteroid, so measure these to make sure they increase; sign that axis works
if they don’t increase, either pituitary isn’t releasing ACTH or adrenal isn’t responding to it (2ary or 1ary adrenal insufficiency; distinguish by whether or not there’s ACTH - if yes, then it’s primary)
Adenoma carcinoma mutation sequence in CRC
APC mut -> polyp –> KRAS mut (unregulated cell cycle prolif) –> bigger adenoma –> p53 and DCC/other tumor suppressor mutation –> carcinoma
Three features that determine malig potential of adenomatous polyps
size, villous histo, dyplasia
Nitrogen dioxide poisoning
toxic product of combustion (eg firefighters = at risk)
sx: similar to asthma or COPD, imaging may reveal pulm edema
Elderly pt with hip fracture - worry about osteonecrosis b/c of which vessel?
blood supply to femoral neck is mainly medial circumflex artery - esp vulnerable to damage from fractures
____ forms from fusion of 2 medial nasal prominences; failure –> ______
the product of that fusion then fuses with the ______ to form the upper lip and primary palate; failure –> cleft lip
cleft palate results from ____
intermaxillary segment from fusion of 2 medial nasal prominences; failure –> severe midline defects (eg holoprosencephaly)
intermax segment then fuses with left and right maxillary prominences to form upper lip and primary palate
cleft palate if maxillarty promeinences –> palatine shelves, and the shelves don’t fuse
Pierre-Robin sequence
Severe micrognathia from hypoplasia of mandibular prominence –> posterior displacement of tongue and no fusion of secondary palate (so cleft palate)
“Ragged red fibers”
mitochondrial myopathies (can’t run ox phos so present with myopathy, lactic acidosis, NS dysfxn)
heteroplasmy
IL-12 receptor deficiency - consequences and tx?
consequences: can’t stimulate helper T to differentiate into Th1, so no IFN-gamma –> activated macrophages and thus can’t defend against intracellular bugs (eg mycobacteria)
tx = IFN-gamma
How does TNF-alpha (and also catecholamines, glucocorticoids, and glucagon) induce insulin resistance?
active serine kinases –> phophorylation of serines on insulin receptor and its substrate –> inhibit downstream signaling upon insulin binding
Vessels with lowest O2 content in the body?
Coronary sinus (coronary venous blood - myocardial O2 extraction is very high, so by the time it’s done, O2 content is lower than in vena cavae)
Sturge Weber syndrome
Enc phalotrigeminal angiomatosis
Cut facial and leptomeningeal angiomas, ID, seizures, hemiplegic, skull radioopacities
Tuberous sclerosis
CNS Hamartomas, cutaneous angiofibromas, visceral cysts, renal angiomyolipoma S, cardiac Rhabdomyomas, seizures
Aut dom
Bortezomib
proteasome inhibitor used to treat MM
b/c B cells are pumping out lots of Ig (protein), so especially susc to proteasome inhib (–> accum of toxic proteins that can’t be broken down + pro-apoptotic factors –> apop)
____ inhibit macrophage elastase in the lungs
____ inhibit PMN elastase
TIMPs inhibit macrophages
alpha1-antitrypsin inhibits PMNs
when both PMNs and macrophages are releasing their elastases, can degrade each others’ inhibitors and get excess protease activity –> emphysema
Club cells
nonciliated cells mostly in terminal bronchioles; secrete protein that protects against airway inflamm and oxidative stress and surfactant components that prevent bronchiolar collapse
Ras overexpression
Ras protein is part of MAP-kinase pathway; overexpression –> cells = more senstiive to mitogenic stimuli
see mutations in pancreatic, gallbladder, colon, endometrial, thyroid, and lung cancer
Prolactin is inhibited by ____
progesterone
so lactation is suppressed during pregnancy b/c of high progesterone levels inhibiting anterior pituitary; at delivery, progesterone suddenly drops –> PRL stimulates lactation
restless leg syndrome - tx and drugs that worsen sx?
tx: DA agonists (eg ropinirole, pramipexole)
drugs that worsen: steroids, SSRIs, lithium
Nutcracker effect
compression of left renal vein between aorta and SMA
may elevate pressure in left renal vein –> left renal vein entrapment syndrome (elevated pressure, flank/abd pain, hematuria)
can –> blood backup and varicocele
Most common ankle sprain
anterolateral ligament (anterior talofibular ligament) - medial ligaments (“tibio-“) = stronger and less commonly injured
Terbutaline, ritodrine
beta 2 selective agonists
relax the uterus (tocolysis)
alpha 1 selective agonists
phenylephrine, methoxamine, mitodrine (used to dilate pupil during opthalm exam)
Leucovorin
folinic acid
given to reverse myelosupp from methotrexate or with sulfadiazine (antifolate abx)
How to diagnose primary CNS lymphoma?
EBV PCR in CSF; definitive diag requires brain bx
2nd most common cause of ring-enhancing lesions with mass effect in HIV (after toxo)
Langerhans cell histiocytosis
proliferative disorders of dendritic cells (APCs/macrophages of skin and mucosa) and macrophages
cells contain tennis-racket shaped Birbeck granules
sx: lytic bone lesions, skin rash, recurrent otitis media with mastoid mass (kids), defective antigen presentation
Bohr vs. haldane effects
Bohr: in periphery, increased CO2 + H2) –> H+ and bicarb, and H+ –> O2 unloading
Haldane (in lungs): increased O2 –> H+ pops off Hgb, combines with bicarb –> CO2 that’s exhaled
Treatment for beta blocker overdose
Glucagon –> G protein coupled receptor activation on cardiac myocytes –> act AC –> increased cAMP –> increased [Ca]i and contraction independent of adrenergic receptors
Glaucoma - drugs that decrease aq humor secretion or increase outflow
decrease secretion: CA inhibitors (eg acetazolamide), beta blockers (eg timolol)
increase outflow: prostaglandins, cholinomimetics (eg pilocarpine, carbachol)
Ramelteon
melatonin agonist used for insomnia in elderly (very safe)
Quetiapine
second-gen antipsychotic
2 most common risk fx for ARDS
sepsis and pulmonary infections
with sepsis (eg due to UTI) –> cytokines that circulate and activate pulmonary epithelium –> inflamm –> capillary damage and exudate in alveolar space –> hypoxia and respiratory failure
usu presents fast
achondroplasia
constitutive activation of FGFR3 –> too much inhibition of chondrocytes, so endochondral ossification is screwed up
vs intramembranous ossification (skull, ribs, pelvis) = ok, since no cartilage precursor to bone
autosomal dominant
vs. GH deficiency –> proportional short stature (both long and flat bones = affected)
CD7
T cell marker
CD14
surface marker of monocyte-macrophage cell lineage
Reaction formation
responding in a manner opposite to one’s actual feelings (eg going to church when have sexual impulses)
projection vs displacement
projection = coming up with outside cause for one’s feelings (eg want to have an affair and so believe that partner is cheating on you, justifying your own desire)
displacement = transferring feeling or idea to unrelated person (mom yells at kid because she’s angry at dad)
both immature defense mech
sublimation
channeling impulses into socially acceptable behavior (action is similar to desire, but acceptable given personal values - eg feel aggressive toward parent, but channel that aggression into sports)
vs. reaction formation is doing opposite of desire
suppression vs. repression
suppression = conscious effort, temporary
repression = involuntarily ignoring idea or feeling
Why don’t we mount effective immune response to Hep C?
b/c no proofreading 3’–>5’ exonuclease, so infected with one genotype but high mutation rate –> many different “quasispecies” within given infected individual, esp in hypervariable genomic regions, eg those that code for envelope glycoproteins
lots of new envelope proteins means host can’t mount effective immuen response (just as kill off one quasispecies, new one appears)
t(14; 18)
t(8;14)
14;18 = follicular lymphoma (BCL2 act)
8;14 = Burkitt lymphoma (c-myc activation)
Familial conditions that increase risk of ALL
Down syndrome, ataxia-telangectasia, NF1
17 alpha hydroxylase deficiency
lots of aldo (high BP), ambig sexual char
21-hydroxylase deficiency
lots of sex hormones, aldo and cortisol are down
salt wasting, precocious puberty, virilization in girls
Mutations in transthyretin gene cause ?
hereditary form of cardiac amyloidosis –> cardiomyopathy, progressive dyspnea, peripheral edema , ascites
Quellung reaction
abs bind capsule of encapsulated bacterial organisms, and positive rxn turns capsule opaque and swollen
allows bugs to be visualized under microscope
used to diagnose strep pneumo
Treatment of choice for strep pneumo in pt with pcn allergy
macrolides
Most common cause of congenital adrenal hyperplasia (90%)
21-hydroxylase deficiency –> buildup of 17-OH progesterone (can test serum levels) shunted to androgens
Long-chain FA degradation - how does it work and congenital defect?
carnitine shuttle gets Fatty acyl-CoA into mitochondria
there, oxidation into acyl CoA –> ketone bodies or TCA cycle, if odd chain
systemic primary carnitine deficiency –> can’t get long-chain FAs into mitochondria, so get toxic accum of FAs –> weakness, hypotonia, hypoketotic hypoglycemia
Sarcoid granulomas produce ____
ACE and 1,25-vitD (–> hypercalcemia)
BAL results for sarcoidosis vs hypersensitivity pneumonitis
sarcoidosis: accum of CD4+ T cells and increased CD4:CD8 ratio
hypersensitivity: accum of CD8+ T cells
Chiari I vs. Chiari II
Chiari I = ectopic CBL that extends below foramen magnum into verebral canal; presents late with parox occipital headaches and CBL dysfxn
vs. Chiari II = way worse - CBL and medulla herniate through foramen magnum –> aqueductal stenosis and hydrocephalus + sx from compression of medulla; may present neonatatlly with lumbar myelomeningocele that causes LE paralysis
Lesion most commonly underlying stable angina (resolves within 5 min after exertion)
fixed atheromatous obstruction of coronary artery(ies) occluding >=75% of lumen
vs ulcerated plaque or thrombus would –> unstable angina (single episode of prolonged pain)
Factors that shift O2-hg dissociation curve to the left
Decreased H+ (increased pH)
Decreased temperature (stabilizes bonds and thus increases O2 affinity)
Decreased 2,3 DPG (vs at high altitude, RBCs make more 2,3 DPG –> O2 dumping)
Where is H pylori colonization density the highest?
antrum of stomach
(H pylori can only colonize gastric-like areas; may get gastric metaplasia in the duodenum due to increased acid production stimulated by H pylori, in which case bug can colonize that part of duod, but otherwise, not much bug in duod despite common ulcers there from increased acid)
achrocordon
skin tag (often seen in areas of friction)
beta blockers - mech of action in thyrotoxicosis
- decrease adrenergic excitation (excess thyroid hormones upregualate beta receptor expression, so block receptor activation with beta blockers)
- decrease peripheral conversion of T4 to more potent T3
vs. propylthiouracil and methimazole decrease thyroid hormone SYNTHESIS
vs. iodide can prevent I uptake and thyroid hormone release
Ghon focus vs. Ghon complex
focus = initial infection (focal lesion in mid-to-lower lungs)
complex = when TB spreads to hilar ln + lesion gets walled off and calcified (dormant infxn in lungs)
Rhanke complex
benign, calcified complex that forms from resolution of Ghon complex
bronchus more prone to aspiration?
R > L
DNAase is produced by which bug
Strep pyogenes (GAS)
degrades DNA in pus to facilitate spread of the organism
serum tryptase
released from mast cells, so increased in anaphylaxis
QRS vs QT effects in class 1A, 1B, and 1C anti-arrhythmics
1A (procainamide): prolong QRS and QT (block Na and some K)
1B (lidocaine): no effect on QRS or QT (block Na but very transiently)
1C (flecainide, propafenone): prolong QRS, no effect on QT (block Na; not K)
vs class 3 (sotalol, amiodarone) specifically block K channels and thus work by prolonging QT
use dependence vs. reverse use-dependence
use dependence - class I anti-arrhythmics (more effect with increased heart rate, esp class IC (flecainide, propafenone), which has slow dissociation, so with increased hr it’s all still attached to receptors and having effect - so more prolonged QRS/depolarization time with increased HR)
reverse use dependence - class III antiarrhythmics (K blockers) - the slower the heart rate, the more the QT prolongation
Th1 vs Th2 CD4+ cells
Th1 –> cell mediated immunity (eg granulomas of sarcoidosis; driven by IL2 and IFN-gamma (–> macrophage activation))
Th2 –> humoral immunity (IgE [IL4] and IgA [IL5])
polyarteritis nodosa mostly affects ___ and spares ____
affects medium-small vessels; generally spares pulmonary vasculature
it’s a segmental, necrotizing, transmural inflamm of arteries anywhere except lungs, but esp in heart, kidneys, liver, and GI tract with common cutaneous sx (eg livedo reticularis)
Tocolytic drugs (to stop preterm labor)
nifedipine (CCB) and indomethacin (COX inhibitor so decreases PGs that –> cervical softening and uterine contractions)
also terbutaline (beta ag –> increased cAMP, which inhibits MLCK and keeps myosin in inactive form)
Partial opioid agonist that can provoke opioid withdrawal if taken with full opioids on board
buprenorphine (low efficacy, but high affinity/potency, so kicks out any full opioid and can bring person down from high with a crash)
given with naloxone to treat heroin addiction - if taken orally, still get partial agonist effects (“half a high”), but if crush and inject, naloxone becomes bioavailable (opioid antagonist –> no effect/crash)
Best drug to inhibit Xa vs thrombin?
Xa - LMWH (eg enoxaparin)
thrombin - unfractionated heparin (long enough to bind both thrombin and antithrombin)
enoxaparin
LMWH
also dalteparin (“-parin”)
fondaparinux
direct factor Xa inhibitor (also apixaban, rivaroxaban)
these don’t inactivate thrombin, just inhibit Xa
Calcipotriene
topical Vitamin D analog used to treat psoriasis
others: calcitriol, tacalcitol
bind to and activate vit D receptor –> inhibition of keratinocyte proliferation, stimulation of keratinocyte differentiation; also inhibits T cell proliferation and inflamm
Ustekinumab
monoclonal antibody that targets IL-12 and IL-23, inhibiting differentiation and activation of CD4+ Th1 and Th17 cells
tx of psoriasis
Calcipotriene
topical Vitamin D analog used to treat psoriasis
others: calcitriol, tacalcitol
bind to and activate vit D receptor –> inhibition of keratinocyte proliferation, stimulation of keratinocyte differentiation; also inhibits T cell proliferation and inflamm
Ustekinumab
monoclonal antibody that targets IL-12 and IL-23, inhibiting differentiation and activation of CD4+ Th1 and Th17 cells
tx of psoriasis
Kallmann syndrome
decreased synth of GnRH in HT + anosmia
hypogonadotropic hypogonadism (rare in females - primary amenorrhea, no 2ary sexual char, olfaction deficit)
embyronic vs fetal hgb
embryonic/Gower: 2 zeta, 2 epsilon
fetal: 2 alpha, 2 gamma
so fetal can make up for beta thal in late gestation and early postnatal life, when have lots of HbF; only when gamma chain production starts to wane does infant become symptomatic
vs. HbA2 = 2 alpha, 2 delta (very low levels)
Hypoglycemia with high insulin, low C-peptide
Hypoglycemia with high insulin and C-peptide
high insulin, low C-peptide = exogenous insulin abuse
both high = excess endogenous insulin due to sulfonylurea use or insulinoma
somatostatin
inhibits release of insulin, gastrin, secretin, HCl in stomach, CCK (stimulates gastric motility)
Before starting TNFalpha inhibitor, test for ____
TB
TNF-alpha is necessary for CMI, especially for sequestration of mycobacteria in granulomas, so treating with inhibitor can –> reactivation (and increased susceptibility tofungi and other mycobacteria)
TNFalpha inhibitors: infliximab, adalimumab [antibodies to TNF-alpha], etanercept (decoy receptor for TNF-alpha)
Baseline and f/u:
opthalmologic exams with ____
echo with ____
PFTs with ____
FOBT with ____
eye: hydroxychloroquine (retinal damage can occur with long-term use)
heart: anthracyclines (eg doxorubicin)
lung: amiodarone, methotrexate (lung + liver)
GI bleed: NSAIDs
Recurrent hemarthroses =
Petechiae and ecchymoses =
DVT, cerebral vein thrombosis, and recurrent pregnancy loss =
hemarthroses = hemophilia
petechiae/bruising = plt problem
DVT and other thrombotic stuff = FActor V leiden
Polymyalgia rheumatica vs fibromyalgia
PR: pain and stiffness in shoulders and hips, often with fever, malaise, weight loss; age >=50yo; evidence of inflamm (increased ESR, CRP)
Fibromyalgia: chronic, widespread stiffness, paresthesias, fatigue; often associated with neuropsych disturbances; no evidence of inflamm
Coronary artery that supplies AV node
AV nodal branch off of PDA (usually arises from right coronary artery, except in left dominant people - 10% of pop)
Supplies lateral/posterior walls of LV and anterolateral papillary muscle
vs. posterior interventricular septum, posterior ventricles, posteromedial papillary muscle, AV node
left circumflex coronary artery = lateral/posterior LV
PDA = posterior interventricular septum + posterior ventricles and AV node
coronary artery that supplies anterior interventricular septum, anterolateral papillary muscle, anterior surface of LV
LAD - most commonly occluded in CAD
aka the anterior interventricular artery
coronary artery that supplies the SA node branches off the ?
right coronary (atrial branch)
vs marginal branch supplies RV
B12 CNS/PNS degeneration sites
dorsal columns
lateral corticospinal tracts (so get UMN signs)
axonal degeneration of peripheral nn (numbness/paresthesias)
subacute COMBINED neurodegen
Polio primarily affects the ___ of the spinal cord
anterior horns
ovary torsion around ____ cuts off its blood supply
ovarian artery, vein, and nerve pleus run in infundibulopelvic ligament (aka suspensory ligament of the ovary)
connects ovaries to lateral pelvic wall
___ ligament connects the uterus to the pelvic walls bilaterally
broad ligament (peritoneal tissue
mesosalpinx = part of it that connects fallopian tubes to pelvic wall
mesometrium = part that connects uterus to pelvic walls
mesovarium = part that connects ovary to lateral pelvic wall
connects ovary to uterus
ovarian ligament
ligament that maintains uterine anteflexion
round ligament (runs from lower uterus through inguinal ring to labia majora)
lichen sclerosus
patchy, whitish thinning of the skin
Serotonin is made in the _____
ACh is made in the ______
NE is made in the _______
DA is made in the _______
serotonin = raphe (midbrain, pons, medulla)
ACh = nucleus basalis of meynert
fast-acting insulins
aspart, glulisine, lispro
used for postprandial glucose control, given subQ an dpeak within 45-75min
give ____ insulin via IV in DKA
regular insulin (don’t want to do subQ b/c pts are dehydrated, and IV regular insulin onsets as quickly as IV aspart, glulisine, and lispro, all of which are more expensive)
Central vs. peripheral chemreceptors
Central = in medulla and sense increased PCO2 (not H+, which can’t cross BBB); O2 has relatively small effect if PaO2 >70 (so only contributes significantly to resp drive in COPD pts with decreased sensitivity to PaCO2 and way decreased PaO2)
Peripheral (aortic and carotid bodies) sense decreased O2, increased CO2, and increased H+
Sx of beta blocker overdose
hypoglycemia (if nonspecific), bronchospasm, bradycardia
sx of digoxin overdose
screwed up color vision, hyperkalemia (though hypokalemia increases risk of toxicity by facilitating Na/K blocking effects of digoxin), arrhythmia, n/v, abdominal pain, confusion etc
Where does alanine come from and what does it do?
main fxn = transport nitrogen to liver for disposal
- glutamine utilization in tissues –> alanine –> circulation
- cahill cycle: skeletal muscle protein breakdown puts excess nitrogen in alanine, so that it can be transported to liver; N is added to pyruvate, making alanine (and that N comes off of glutamate, turning it into alpha ketoglutarate) - this is reversed in the liver, so alanine gives its N to alpha-ketoglutarate, forming glutamate; NH3 pulled off glutamate, regenerating alpha-keto and that NH3 enters the urea cycle in teh liver –> urea that can be excreted in the urine
most common source of nosebleed (esp in kids)
anterior - most in anterior vascular watershed area of nasal septum known as kiesselbach’s plexus (septum is highly vascular and that plexus has 3 anastamoses)
immediate effect of ACEi that subsequently resolves?
GFR decreases b/c efferent arteriole can’t constrict
normalizes with time, and Cr will come back down; benefits outweigh risks unless Cr rises by >30%
anterior 2/3 of posterior limb of IC is mostly ___ fibers
posterior 1/3 of posterior limb is mostly ____ fibers
anterior = motor (from corticospinal, corticobulbar, corticopontine)
posterior = sensory (from thalamocortical)
so most IC lesions = pure motor or mixed
lacunes
small cavitary infarcts in the BG, posterior limb of the IC, pons, and CBL from occlusion of small penetrating arteries (lenticulostriate), usu with chronic htn or DM
primary cause of lacunary infarcts?
lipohyalinosis - plasma proteins leak through endothelium damaged by htn etc –> sclerosis, hyaline thickening of wall from collagen deposn, and accum of foamy macrophages
microatheromas - accum of lipid-laden macrophages in intima of vessel where it branches off parent vessel
together –> small vessel occlusion
vs. embolisms usually cause cortical infarcts
PCWP is an indirect measure of…
LA pressure
Osteogenesis imperfecta - defect and mode of inheritance?
defect in type I collagen - bones have no flexibility, prone to fracture
usually autosomal dominant
mechanism of action of fibrates vs niacin
fibrates activate ppar-alpha, which activates LPL (breaking down TGs) and decreases VLDL production
NB - fish oil supplements with lots of omega 3’s also lower TGs by decreasing production of VLDLs and Apolipoprotein B (on VLDLs)
Niacin - decreased hormone-sensitive lipase –> less free FA pulled off circulating chylomicrons –> less VLDL made; also decreases ApoA1 clearance –> increased HDL
most common sites of nonocclusive ischemia in the colon
splenic flexure and rectosigmoid junction (esp in hypotensive state, eg during surgery, or with underlying arterial insufficiency)
complications of ischemia = acidosis, sepsis, gangrene, perf; see pale mucosa and petechial hemorrhages on colonoscopy
Three types of groin hernias
- indirect inguinal - male infants, goes through deep inguinal ring, lateral to inferior epigastric vessels
- direct inguinal - older men, goes through hesselbach’s triantle, medial to inferior epigastric vessels
- femoral - women, through femoral ring, inferior to inguinal ligament (medial to femoral artery and vein); prone to incarceration
Coffee ground emesis
blood in vomit where heme iron is oxidized b/c it’s exposed to gastric acid - sign of peptic ulcer
Differences in presentation between PSGN and IgA nephropathy
PSGN: no recurrence, 1-3 weeks after strep pharyngitis
IgA: also after mucosal infection (esp URI); hematuria for several days starting within 5 days of infxn, frequent recurrence every few months or with next infxn
stain that gives dense black reaction?
osmium tetroxide - stains fat
Humoral vs Cellular mediated acute rejection - histo
humoral: neutrophil infiltrate, necrotizing vasculitis, complement activation
cellular: lymphocytic infiltrate, endothelitis
“salt and pepper” chromatin
carcinoid tumors
Treatment of peripheral artery disease
sx management: cilostazol/dipyridamole (PDE inhibitor to increase cAMP –> vasodil and decreased plt aggregation to relieve claudication sx)
antiplt agent (aspirin, clopidogrel etc) to prevent coronary heart dz and stroke
central line is placed where?
venous system and advanced into SVC for rapid infusion of fluids
Treatment of pregnancy-related VTE
LMWH (best balance of risks and benefits to mom and fetus - easily reversed at delivery, good F, doesn’t cross placenta)
eg dalteparin, enoxaparin
Treatment of pregnancy-related VTE
LMWH (best balance of risks and benefits to mom and fetus - easily reversed at delivery, good F, doesn’t cross placenta)
eg dalteparin, enoxaparin
pralidoxime
“regenerates” AChE, so reverses effects of mACh and nACh overstimulation (eg with organophosphate poisoning)
vs. atropine etc is a mAChR blocker, so only reverses effect of poisoning at mACh receptors
SD vs SEM
SD = spread of individual values in given population; indication of how far the individual mean is from the sample mean
SEM = SD/(n^1/2) to estimate true mean of underlying, whole population; indication of how far the sample mean is from the population mean
Treacher-Collins syndrome
abnormal development of first and second pharyngeal arches –>craniofacial abnormalities (mandibular, maxillary, zygomatic bone hypoplasia that can –> airway compromise and feeding difficulty), absent/abnormal ossicles (conductive hearing loss)
scrofula
cervical lymphadenitis in kids caused by mycobacterium scrofulaceum in/around environmental water sources
Common variable immunodeficiency
defieciency of B and T cells –> hypogammaglobulinemia
- many causes, usually becomes symptomatic in older kids/adults
CMI isn’t as affected as in SCID, don’t see thymic aplasia
Bupropion is contraindicated in ___-
pts with seizure disorders or eating disorders (lowers seizure threshold, esp bad if already have some kind of electrolyte imbalance)
but pts like it because less likely to cause weight gain or sexual dysfxn than other depression treatments (eg SSRIs)
most common cause of spontaneous lobar/cortical hemorrhage in the elderly?
cerebral amyloid angiopathy
Charcot-Bouchard aneurysm rupture?
chronic htn = cause –> hemorrhagic cortical stroke of deep brain structures
CT: hyperdense focus
neprilysin
MMP that inactivates endogenous peptides (BNP, ANP, glucagon, oxytocin, bradykinin etc)
inhibit it to increase levels of endogenous natriuretic peptides to treat HF
Osgood-Schlatter disease
overuse injury of secondary ossification center of tibial tubercle, usually in adolescent after growth spurt and repetitive contraction of quads –> patellar tendon separates from tibial tubercle –> healing causes patella to become elevated and prominent
pes anserinus bursitis
common injury in runners, causes anteromedial knee pain
pes anserinus = where sartorius inserts on anteromedial tibia shaft
Iron absorption occurs in _____
duodenum and proximal jejunum
also B12 and folate
vitamin C is abosrbed in the _____
distal small bowel (ileum) via active transport
B6 absorption occurs in the ____-
jejunum and ileum
B5 and B7 absorption occurs in the _____
small and large intestine via sodium-dependent multivitamin transporter, so deficiency with resection is rare
Stomach ulcer vs erosion
erosion is confined to mucosa (doesn’t go through muscularis mucosa) - usually due to acute, severe mucosal injury (eg burn, surgery, NSAIDs, smoking, alcohol) - can still cause upper GI hemorrhage and melena; usually pain, n/v that subside after withdrawing offending agent
ulcer goes through mucosa into submucosa
urticaria vs. angioedema - location of inflamm/edema
urticaria = superficial dermis edema and inflamm (with normal epidermis)
angioedema = deep dermis edema and inflamm
acantholysis
loss of cohesion between keratinocytes in the epidermis
found in pemphigus
nonbacterial thrombotic endocarditis is most commonly associated with _____
advanced malignancy, chronic inflamm disorders (eg APLS, SLE), and DIC
usually asymptomatic, but thrombi = easier to dislodge than in IE –> infarction
Most laryngeal muscles are innervated by the ____
recurrent laryngeal nerve (mm = cricoarytenoids, arytenoids, tyroarytenoids)
Nerve at risk of injury during thyroidectomy?
external branch of superior laryngeal - runs with superior thyroid artery and vein, and innervates the cricothyroid muscle, so injuring it can –> hoarseness
Barbiturates vs benzos - mechanism?
Barbiturates prolong Cl channel opening in response to GABA; at high conc, act as GABA receptor agonists
Benzos –> increased frequency of Cl channel opening
so both bind allosterically to GABA receptor and modulate effect of GABA on it
GABA-A vs GABA-B receptors and drugs that modify each?
A = Cl- channels, modulated by benzos and barbs
B = GPCRs on skeletal muscle, modulated by baclofen (muscle relaxant)
theophylline - mech and use?
mech: adenosine antagonist and indirect adrenergic agent
used for bronchodilation (increases intracellular cAMP), anti-inflamm, in asthma and COPD
affected by P450 inhibitors and inducers
treatment of drug-induced parkinsonism
centrally-acting antimuscarinic agent (eg benztropine, trihyxyphenidyl)
levodopa, but not in psychosis! can induce psychosis
Treatment for extrapyramidal symptoms of antipsychotics
dystonia from DA-cholinergic balance, so use M1 antagonists (eg benztropine or diphenhydramine)
most common site of blunt aortic trauma (traumatic rupture)
aortic isthmus (where ligamentum arteriosum connects the aorta and the pulmonary trunk, making the aort relatively fixed and immobile there)
route of spermatic cord
goes through deep inguinal ring (opening in transveralis fascia, which thus becomes internal spermatic fascia) –> through inguinal canal –> through suyperficial inguinal ring (formed by opening in external oblique muscel aponeurosis, which thus forms the external spermatic fascia)
**cremasteric muscle (between internal spermatic fascia and external spermatic fascia) arises from internal oblique muscle
Benzos should not be used with what other drugs?
Indications for long-acting benzos?
Indications: GAD, insomnia, anticonvulsant in SE, muscle relaxant with UMN lesion
Don’t use with other drugs that can cause CNS depression/sedation: alcohol, barbs, neuroleptics, 1st gen antihistamines
Promethazine, hydroxyzine, chlorpheniramine - drug type?
first-gen antihistamines
often used to prevent/treat allergic rxns, motion sickness, anti-emetics despite sedation ae
vs. loratadine = second-gen antihistamine (H1) - no CNS effects b/c doesn’t cross BBB
Live vaccines?
Toxoid-based vaccines?
Live = zoster, varicella, yellow fever, BCG, typhoid
Toxoids = Tdap (useful for dzs where toxin is the main cause of dz morbidity and mortality)
Docosanol
topical agent that prevents viral entry and is used in herpes labialis (usually type 1)
why is acyclovir only effective against viral (not host) cells?
- uptake into host cells is poor
- has to be phosphorylated by viral thymidine kinase
- host cell DNA pol has lower affinity for acyclovir than viral DNA pol
bugs that can cause cellulitis related to freshwater or seawater exposure?
Vibrio vulnificans, Aeromonas (both bacteria)
Vitamin E deficiency sx
hemolytic anemia and neuro abnormalities (eg ataxia)
Parasites capable of autoinfxn?
strongyloides
stool: rhab. larvae (noninfxs form)
intestine: eggs + adults
lungs: filariform (infxs)
autoinfxn –> hyperinfxn, esp in those with compromised Th2 immunity –> multiorgan dysfxn and septic shock
Detection of parasite eggs in stool is used to diag ___?
schistosoma
Detect proglottids in the stool with ____?
intestinal tapeworms (eg taenia, diphyllobothrium)
trophozoites and cysts in stool = used to diagnose ___?
intestinal protozoal infxns (giardia, entamoeba)
C3 vs C4 in PSGN
Decreased C3 (alternative pathway activation); normal (or slightly decreased) C4 (classical pathway)
IC deposition –> alternative pathway activation (not ag-Ig-mediated)
vs in SLE, both C3 and C4 are down (activation of both classical and alternative pathways)
Deficiency in aldolase B causes…
vs. aldose reductase fxn?
fructose intolerance
aldose reductase converts galactose to galactitol
enzymes involved in galactose metabolism
galactokinase (deficiency = mild)
then galactose 1phosphate uridyl transferase (GALT - causes classic galactosemia; very severe); get similar sx with much rarer deficiency in udp galactose-4-epimerase, which converts udp galactose to udp glucose, thus allowing galactose-1-p to be converted to glucose-1-p and enter glycolysis
beta-2 microglobulin
little protein associated with MHC1 (non-transmembrane component)
vs. invariant chain is associated with MHC2 and is lost when MHC2 finds antigen in phagolysosome, allowing complex to move to cell membrane
germ tube test
candida test - grow out candida albicans on serum at body temp and it forms true hyphae from yeast (germ tubes)
look like circles with long bits coming off them
major basic protein
found in eosinophil granules, defends against parasites
tartrate resistant acid phosphatase
hairy cell leukemia cell marker (B lymphocyte precursors)
Auer rods stain positively for ___ and are found in ____
stain for myeloperoxidase
indicate myeloid differentiation, seen in AML
Fidaxomicin
related to macrolides
oral drug, bacteriocidal, minimal systemic abs, and narrow spectrum so doesn’t wipe out normal colonic flora as much as vanc or metronidazole, making it good for RECURRENT C DIFF (decreases recurrence rates than with vanc)
vs use metronidazole for initial treatment of c diff or first recurrence
and use oral vanc for severe initial or recurrent c diff
skeletal system mets get there how?
hematogenous spread
vertebral venous plexus is connected to lots of local venous plexuses and runs stragiht into venous supply of the brain
neuroleptic malignant syndrome vs. serotonin syndrome
both: mental status changes, hyperthermia, autonomic instability
NMS: diffuse rigidity and bradyreflexia; tx = direct muscle relaxant (dantrolene)
serotonin synd: neuromusc hyperactivity (hyperreflxia, clonus), n/v/d; tx = serotonin antag (cyproheptadine)
treatment of delirium
primary: treat underlying cause
for acute treatment of agitation and psychosis associated with delirium: high-potency first-gen antipsychotics (eg haloperidos)
DON’T USE BENZOS! can worsen confusion
Fast acetylators of isoniazid also acetylate ____ quickly
dapsone, hydralazine, and procainamide –> need higher doses
fever + tinnitus + tachypnea
suspect aspirin intoxication
mixed resp alk + metabolic acidosis
sequence of reproductive system development
- gonadal (testes vs ovaries)
- genital duct
- external genitalia
Infarct types from small vs. large PEs
small: go into peripheral branches of pulm artery and produce wedge-shaped infarct
big: wedge in pulmonary artery bifurcation (saddle emboli)
dual blood supply to lungs –> hemorrhagic infarcts (red) - bronchial blood hemorhagges into area infarcted by pulmonary arteries
22q11 deletion - two syndromes
Di George - thymus, parathyroid (and hypoCa), and cardiac defects (ToF, interrupted aortic arch etc)
Velocardiofacial syndrome - cleft palate, cardiac anomalies, dysmorphic facies (orbital hypertelorism, short palpebral fissures and philtrum, cleft palate, bifid uvula)
mut = chromosomal microdeletion (see it with FISH)
Liver synthetic fxn abnormal in acute hepatic failure
coagulation (b/c factor 7 has short t1/2, vs albumin has long t1/2)
Effect of PPIs on serum Ca
decrease Ca and Mg abs –> increased risk of osteoporosis
escitalopram
SSRI
Factitious vs malingering vs conversion disorders
Factitious = intentional falsification or inducement of sx with goal of assuming SICK ROLE; no conscious awareness of why they’re doing it
malingering = falsification or exaggeration of sx to obtain EXTERNAL INCENTIVES
conversion disorder = neuro sx incompatible with any known neuro dz; often onset with acute stress (genuine sx, no effort to deceive)
Chronic renal vs pulm rejection
kidney: vascular damage
lung: bronchiole damage - bronchiolitis obliterans, (vs acute rejection = CD8 T cell-mediated damage of vessels)
marker for OB activity? OC activity?
OB: alk phos (distinguish from liver alk phos by electrophoresis, specific monoclonal Ig, and heat denaturation)
OCs: urinary deoxypyridinoline (released into circ when collagen cross links are broken) and hydroxyproline (also collagen breakdown product, but not as specific b/c found in lots of meat products)
chronic mesenteric ischemia
similar to exertional angina - atherosclerotic decrease in bloodflow to GI tract only presents as problem within an hour after meals when more blood is needed for digestion/absorption
Medicare covers ?
pts > 65yo who are US citizens, residents, and have paid into system (taxes)
also younger pts with disabilities, ESRD, and ALS
vs. pregnant women and babies = covered by medicaid
