usmle 2: block 1 Flashcards
note: some are block 2
pulling sensation in groin with..
ascites, hydrothorax, &..
ovarian fibroma: meig’s syndrome
hCG & LDL are elevated in what ovarian neoplasm
dysgerminoma
AFP is elevated in what ovarian neoplasm
yolk sac tumor, endodermal sinus
presentation of yolk sac tumor
in ovaries/testes or saccrococcegeal region
has schiller-duval bodies
drug eluting stents elute..
clopidogrel
paclitaxel
taxol
stabilizes MT, preventing mitosis
schiller-duval bodies
endodermal sinus, yolk sac tumor
call-exner body
granulosa cell tumor (malignant ovarian neoplasm)
resembles primitive follicle
CA-125
monitor progression of all ovarian neoplasms, but not good for screening
most common malignant ovarian neoplasm
serous cystadenocarcinoma
most common benign ovarian
serous cystadenoma
what is the cornea composed of
- endothelial layer: cellular, mitochondrial rich, translucent
- descement’s membrane (location of Cu2+ deposition
basement membrane
probenicid on uric acid? on penicillin?
LOWERS uric acid (inhibits reabsorption) INCREASES penicillin (inhibits secretion)
input to cerebellum?
cortex -> MCP (contralateral) via ipsilateral pontine nuclei spinal cord (proprioception) -> ICP (ipsilateral)
via climbing and mossy fibers
output from cerebellum
purkinje fiber -> deep cerebellar nuclei (DEGF) -> contralateral cortex superior cerebellum peduncle
lateral lesions to cerebellum
voluntary movements of extremities; tendency to fall ipsilaterally
medial lesions to cerebellum?
midline structures;
truncal ataxia, nystagmus, head tilting.
wide-based (cerebellar) gait & defective truncal coordination
usu bilateral
ALCOHOLICS (thiamine-deficiency linked)
alcoholic wide based gait based on..
midline cerebellar defects; thiamine deficiency linked!
xanthomas are most characteristic of..
tendinous more specific for..
increased cholesterol (tendinous more specific)
severely increased triglycerides
urease breath test?
drink radiolabeled urease
H. ployri converts to CO2 + NH3
will breath out radiolabeled CO2
the NH3 raises the pH around bacteria & protects it
low-pitched, rumbling, mid-diastolic murmur in apex LLD
mitral stenosis
most common cause of mitral stenosis
rheumatic heart disease
cardiac manifestation of TB?
tuberculosis pericarditis
peutz-jeghers syndrome
autosomal dominant.
STK11 (serine/threonine kinase chr. 19) mutation
- pigmented mucocutaneous macules
- lips, buccal muscosa (pathognomonic) hands & feet - numerous hamaratomatous polyps in GI tract
usu benign
can: abdominal pain, GI bleed (intussuception, obstruction, malignant transformation)
develop during first few years of life
blue nails & dyspigmentation of lower legs
consider Wilson’s disease (hepatolentincular degeneration)
enzyme deficiency in gilbert’s syndrome
reduced activity of UDP-gluconornyl transferase
atrophic glossitis, megaloblastic anemia, shuffling gait in elderly women of Northern European descent
pernicious anemia presentation
gait: due to degeneration of dorsal column proprioception to cerebellum
liposarcoma vs. lipoma
liposarcoma: LIPOBLAST: nonmembrane bound cytoplasmic lipid characterestically causing nuclear indentations & scalloping of nuclear membrane
lipoma: mature fat cells, without pleomorphism
both present as slow growing, painless masses in deep connective tissue
most common malignant soft tissue tumor in adults? children?
adults: liposarcoma
children: rhabdomyoscarcoma
FAP
osteoma in skull
fibroma (desmoid tumor)
congenital hypertrophy of retinal pigmented epithelium
gardener syndrome (autosomal dominant)
FAP + malignant CNS tumor
turcot syndrome
dermoepidermal junction autoantibodies (against type VII collagen)
epidermolysis bullosa acquisita
basement membrane IgG auto-antibodies in skin
bullous pemphigoid
lung surfactant maturation screen
L/S
lecithin/sphingomyelin 2:1
note: lecithin = DPPC = dipalmitoyl phosphatidyl choline
purpose of surfactant
decrease surface tension of alveoli
reduce pressure needed to keep alveoli inflated
(increased compliance)
sympathetic innervation to eye
3 neuron system
- hypothalamus -> descend to lateral horn spinal cord
- enters sympathetic trunk & ascends to superior cervical trunk
- superior cervical trunk, along internal carotid, joins branches of opthalmic division of CN V
go to pupil dilators & superior tarsal
bulbar vs. pseudobulbar
bulbar:
- LOWER motor neuron
- cranial nuclei from medulla (CN IX, X, XI, XII) & nerves
pseudobulbar:
- UPPER motor neuron
- corticobulbar tracts in mid pons
- for these lesions to be apparent, must be bilateral, as these nuclei receive bilateral input
bromocriptine
dopamine receptor agonist
rx: prolactinoma
clomiphene
SERM
- blocks estrogen receptors in hypothalamus (blocks negative feedback)
- increase release of pituitary gonadotropins
what can be used to trigger ovulatory cascade when follicles are mature? (i.e. in an oocyte donor)
hCG therapy, triggers ovulation
can a person w/ turner have a baby?
w/ IVF
ovaries don’t work, but uterus is fine
lithium side effects
LMNOP
motor (tremors)
nephrogenic diabetes insipidus
hypothyroidism
pregnancy: teratogen: ebstein anomaly
mood disorder history
THINK LITHIUM
3 problems in hypertrophic cardiomyopathy
- diastolic dysfunction: rigid, less volume
- LVOT: increased afterload
- increased cardiac work: MI
2 causes of renal artery stenosis
- atherosclerosis
2. fibromuscular dysplasia (females)
when giving blood to patient w/ IgA deficiency..
must be blood from someone else w/ IgA deficiency!
if IgA is in blood, they will have anaphylaxis (they’ll make anti-IgA)
could be in: RBC, platelet, FFP, IVIG
DNA Pol III? DNA Pol I?
DNA Pol III: continues from RNA primer
DNA Pol I: removes primer (5’-3’ exonuclease), & places new DNA
receiver operating characteric ROC curve? measure of accurary?
sensitivity vs. 1-specificity
want rectangular test
area under curve: accuracy!
true positive rate vs. false positive rate
accuracy formula
TP + TN / all observations
false positive rate
1-specificity
specificity: without disease, test negative
false positive rate: without disease, test negative
true positive rate
sensitivity
with disease, test positive
false negative rate
1-sensitivity
with disease, test negative
CA-125
high specificity,
low sensitivity
(low false + rate, low PPV)
17-hydroxyprogresterone elevation
CAH due to 21-hydroxylase deficiency
PTHrP
squamous cell carcinoma of lung
hypercalcemia
CA-19-9
pancreatic adenocarinoma
cyclosporine
calcineurin inhibitor (binds CYCLOphilin)
prevents IL-2 transcription
– can’t convert NFAT-P to NFAT
[NFAT is TF for IL-2 gene]
use:
transplant rejection prophylaxis
psoriasis
rheumatoid arthritis
tacrolimus
calcineurin inhibitor (binds FKBP)
prevents IL-2 transcription
–can’t convert NFAT-P to NFAT
[NFAT = TF for IL-2 gene)
oprelvekin
IL-11
good for thrombocytopenia
filgrastim
G-CSF (recover bone marrow)
sargramostin
GM-CSF (recover bone marrow)
aldesleukin
IL-2
IFN-a
rx: chronic hep B chronic hep C hairy cell leukemia condyloma acuminatum renal cell carcinoma malignant melanoma
IFN-b
multiple sclerosis
IFN-c
chronic granulomatous disease
IL-2 transcription
calcineurin
NFAT-P -> NFAT
NFAT -> transcription factor for IL-2 gene
cyclosporine toxicity
NEPHROTOXIC HTN hyperlipidemia hyperglycemia tremor hirsuitism gingival hyperplasia
-limus drugs (tacrolimus & sirolimus)
binds FKBP
calcineurin inhibitors (cyclosporine & tacrolimus) are both..
nephrotosix
tacrolimus toxicity
like cyclosporine: MAIN: NEPHROTOXIC
MORE risk of diabetes & neurotoxicity
LESS risk of hirsuitism & gingival hyperplasia
nephrotoxic
hyperlipidemia
tremor
sirolimus (rapamycin)
binds FKBP
mTOR inhibitor
(TF for proliferation genes)
blocks T cell activation & B cell differentiation
prevents IL-2 signal transduction
NON-NEPHROTOXIC
basiliximab
monoclonal Ab to IL-2
like sirolimus / rapamycin, blocks IL-2 reception
immunosuppressant effects of glucocorticoids
inhibits NF-kB
inhibits cytokine transcription
NFAT & NFkB
both transcription factor for IL-2 (cytokine)
azathiopurine blocks
blocks rapidly dividing T & B cells
like 6-MP
PRPP amidotransferase (rate limiting step for purine synthesis)
converts PRPP -> 5-phosphoribosylamine
(then add base + carbon)
cleared by xanthine oxidase
(increase w/ allopurinol rx)
mycophenolate mofetil
like azathiopurine, blocks rapidly dividing T & B cells
blocks IMP dehydrogenase (can’t make de novo GMP)
muromonab
Ab against CD3 on T cells
immunosupressants
gingival hyperplasia (4)
verapamil
phenytoin
cyclosporine
nifidipine
drug induced parkinson’s (3)
anti psychotics
reserpine
metoclopromaide
cog-wheel ARM
metoclopromide
rx: nausea & gastroparesis
D2 receptor antagonist
increase resting tone, contractility, LES tone, motility.
does not influence colonic transport time.
contraindicated in parkinsons
alkaptonuria (ochronosis)
autosomal recessive, bengin.
deficiency of homogentisate oxidase
can’t break down tyrosine -> fumarate
major problem: debilitating arthralgia
(homogentisic acid = toxic to cartilage)
urine black on standing
dark blue/grey on sclerae & ear
(no mental retardation)
major long-term consequence of alkaptonuria?
debilitating arthralgia (3-4th decade)
knee, hip, shoulder, intervertebral joints
parkinsons symptoms mnemonic
TRAPS
resting Tremor Rigiditiy (cogwheel) Akinesia (or brady) Postural instability Shuffling (festinating) gait
degradation of neurons in substantia nigra pars compacta
location of substantia nigra pars compacta
ventral midbrain
near cerebral peduncles (corticobulbar tracts)
‘mickey mouse’ ears
lesion to occipital lobe? lesion to PCA
if occipital lobe: homonymous hemianopsia
if PCA: homonymous hemianopia w/ MACULAR SPARING
can be quadrants if only lingual / cuneate lobe of cortex involved
where are juxtaglomerular cells located
modified smooth muscle cells in afferent arteriole, near glomerulus
in close contact w/ macula densa of DCT
3 stimuli for renin release
- decrease tubular NaCl in macula densa
- B1 receptor sympathetics
- decreased pressure in afferent arteriole
Tamm-Horsfall glycoprotein
exclusively secreted by renal tubular epithelial cells of TAL
if low urine flow, can form hyaline casts
normal albumin excretion in urine
< 30mg/day
amniotic fluid acetylcholinesterase AChE
open neural tube defect
bc its present in blood cells, muscle, and nerve tissue
neural tube defect, elevated..
AFP and AchE
thyroxine deficiency on bone
usu NOT fracture
instead: pain, ache, stiff
presentation of cystathione-beta-synthase deficiency (3)
homocysteinuria from methionine breakdown.
cysteine becomes essential amino acid.
- ectopia lentis (downward lens displacement)
- osteoperosis
- mental retardation
- thin, fair hair & skin: marfanoid
- propensity for arterial & venous thromboelmbolism
presentation of phenylketonuria? (4)
- fair pigmentation
- mousy odor
- seizures
- mental retardation
mutation in phenylalanine hydroxaylase, can’t make tyrosine
presentation of maple syrup urine disease
mutation in branched-chain alpha-keto acid dehydrogenase
can’t decarboxylate the alpha-keto acid derivatives of leucine, isoleucine, valine.
proline synthesized from..
glutamate
level of pancreas
L2
what types of drugs cross placenta? what types of drugs do not?
CROSS: lipid soluble
DO NOT CROSS: water soluble
why can heparin be given during pregnancy but not warfarin
heparin sulfate: charge: water soluble, will not cross placenta
warfarin: lipophilic: will cross palcenta
what type of bilirubin can cross placenta
unconjugated can cross: lipid soluble
conjugated = water soluble = won’t cross
differentiating gonorrhea vs. chlamydia infection
often, treat for both
gonorrhea:
- purulent discharge
- microscopy: multiple WBC w/ intracellular gram - cocci
chlamydia
-microscopy: neutrophils w/ NO pathogens
(bc chlamydia lacks muramic acid, won’t gram stain)
- also causes epididmyitis!
common cause of epididymitis?
chlamydia
unique feature of neisseria (gonococcal & meningococcal LPS
lack repeating O antigen in LPS!
which neisseria ferments maltose & has capsule
meningococcus
gonococcus: NO capsule, NO maltose, NO vaccine
difference between..
acyclovir, famciclovir & ganciclovir
vs.
zidovudine, cytarabine, vidarabine
acyclovir, famciclovir & ganciclovir
activated by viral kinase first (then host)
zidovudine, cytarabine, vidarabine
activated by host cell kinase
CMS retinitis T cell count
<50
PCP pneumonia T cell count
<200
chloroquine mechanism
blocks detoxification of heme into hemozin
heme accumulates & is toxic to plasmodia
note: most falciparium -> resistant
rx for p. falciparium
artemether/lumefantrine
or
atovaquone/proguanil
life threatening, use quinidine or atesunate
what enzyme does ribavarin block
IMP dehydrogenase, can’t make GMP
cidofovir & foscarnet
do not need viral kinase activation
tenovovir
only NRTI that does not need to be phosphorylated by host kinases
is a nucleoTIDe
smoking cessation on lung functoin
will stop further damage, but does not IMPROVE.
WILL decrease risk of lung cancer
is associated w/ weight gain (food to replace smoking)
recidivism
resumption of harmful activity after abstinence / rehab
what allows chicken virus to infect humans
often: genetic reassortment
genetic reassortment
responsible for sudden shifts
2 distinct influenza strains (ie that infect diff animals) infect same cell, HA from 1 and NA from other packaged together –> new virion
novel strain of virus to which we have NO susceptibility
HA and NA are surface proteins, also targets of immune system
antigenic drift
point mutations in HA and NA
slightly alters product proteins
can slightly increase infectivity, etc
gradual drift
phenotypic mixing
2 viruses infect same cell
progeny have coat or envelope proteins not coded for by genetic material packaged within them
hypoglycemia in McArdle?
NO
mutation in muscle glyocgen phosphorylase.
muscle glycogen doesn’t release glucose into circulation anyways.
liver glyocgen phosphorylase is fine –> no hypoglycemia
presentation of McArdle
deficiency muscle glycogen phosphorylase
no hypoglycemia (bc liver fine) muscle pain on exertion, exercise intolerance can have myoglobinuria / renal failure
hyperkalemia on EKG
- peaked T waves
- loss of P
- prolonged PR
- wide QRS
slow HR
hypokalemia on EKG
- flattening T waves
- appearance of U waves
- ST segment depression
can cause Tdp
hypocalcemia on EKG
QT prolongation
hypercalcemia on EKG
QT interval shortening
T-wave flattening or inversion in severe cases
peaked T wave
earliest EKG sign of hyperkalemia
T wave flattening
in hyPO K+
and
hyPER Ca2+
graves disease proptosis/exopathalmosis
- TSH antibodies stimulate fibroblasts to make GAG
- draws in water –> extraocular muscle EDEMA
note: NOT extraocular muscle hypertrophy
communication between suprachiasmatic nucleus & pineal gland
SCN -> NE -> pineal -> melatonin
parinaud syndrome (4)
pinealoma
- upwave gaze palsy,
- absent pupillary light reflex,
- failure of convergence,
- wide-based gait
superior colliculus
oculomotor & trochlear n.
edinger westphal
all involved (mass effect)
where are stem cells located in GI system
crypts of Lieberkuhn
coarse, rhythmic, postural tremor in fingers & arms of alcoholic
thiamine deficiency –> alcoholic cerebellar degeneration
alcoholic cerebellar degeneration pathology
loss of Purkinje cells in anterior lobe & vermis
presentation:
- wide-based gait ataxia
- intention tremor of hands & fingers
- rhythmic parkinsonian tremor of fingers & hands too
- truncal instability
medial medullary lesions cause
- contralateral spastic paralysis
- contralateral paresis
- ipsilateral CN XII (tongue) problems
korsakoff syndrome specifically refers to
temporal lobe damage w/ alcoholics
phenylephrine
alpha-1 agonist
increases PVR
increases systolic BP
decreases PP
decreases HR (reflex)
dobutamin
B1 agonist
increase HR
increase contractility
no effect on SVR
isoproterenol
nonselective B agonist
increase HR increase contractility increase pulse pressure decrease PVR decrease diastolic BP
epinephrine
both alpha & beta agonist
increase HR
increase pulse pressure
decrease PVR (dominant effect on beta 2 over alpha 1)
clonidine
alpha 2-agonist
decreases sympathetic outflow
decreases BP
CAAT & TATA box
both promote transcription intiation
RNA pol II binding
CAAT: 80 bp upstream
TATA: 25 bp upstream
lysyl hydroxylase deficiency
kyphoscoliosis variant of Ehlers-Danlos
autosomal recessive
hypermobile, hyperextensible, fragile joints
similar to vitamin C deficiency (scurvy)
sublimation
convert unacceptable feelings or drives into more socially acceptable
murder -> surgeon
stellate cells in liver
perisinusoidal space, store beitamin A
can differentiate into myofibroblast upon injury -> help produce fibrosis
lambert-eaton associated w/
paraneoplastic syndrome of small cell lung cancer
genetic association w/ small cell lung cancer (note 4 A’s)
ACTH, ADH, Autoimmune (lambert-eaton)
Amplification of myc
genetic associated w/ adenocarcinoma
k-Ras, eGFR, ALK
3 C’s of squamous cell carcinoma
cavitation, cigarretes, hyperCalcemia (PTHrP)
BMI calculation
weight / height^2
what antibiotic binds to 23sRNA
macrolides & clindamycin
maCROlides binds to twenty-THREE
mechanism of chloramphenicol
binds to 50S subunit, blocks peptidyl-transferase
[does not bind to 23s)
mechanism of macrolide & clindamycin
bind 23sRNA in 50S subunit
block translocation
macRO blocks transLOcation
binds to twenty-THREEsubunit
resistance to macrolides
mutation in 23s rRNA subunit of 50s
resistance to chloramphenicol
acetylation of antibiotic
what topoisomerase do fluoroquinolones blocks?
topo II (DNA gyrase topo IV
(like etoposide)
what topoisomerase dose etoposide block?
topo II (like fluoroquinolone)
what topoisomerase does irinotecan, topotecan block
topo !
presentation of cystic hydroma? association!
loose areolar tissue of head and neck, often left side
painless, compressible mass that transilluminates
when lymphatics don’t connect to venous, bud abnoramlly, or retain embryonic growth potential & expand into adjacent structures along facial planes.
associated w/ turner, trisomy 12, 13, 21!
NOT JUST TURNER
what type of patients can have cystic groma (2)
turner
trisomies (13,18, 21)
what ultimately determines amplitude of AP in neurons?
Nernst equation equilibrium potential for Na+
increase: w/ increase extracellular Na+ decrease intracellular Na+
how can amplitude of AP be altered?
how can likelihood of firing be altered?
amplitude: equilibrium potential for Na+ (increase extracellular, decrease intracellular
likelihood of firing: bring membrane potential closer to threshold
- since K+ determines resting potential, decrease intracellular K+
linear erythematous rash after hiking
suggests poisin ivy – hypersensitivity
type IV HSR
drug-induced photosensitivity
SAT For Photo
sulfonamides
amiodarone
tetracylcin
5-FU
presentation of rocky mountain spotted fiber
rash BEGIN: at ankles/wrists,
—->
SPREAD to TRUNK & PALM
dermacentor ticks
where do rickettsiae live
obligate intracellular: need CoA and NAD+, cannot synthesize ATP
ehrlichiosis
monocytes w/ morula
tick vector
anaplasmosis
granulocytes w/ morulae
tick vector
Q fever
no arthropod vector!
coxiella burnetti
tick feces & cattle placenta, aerosol
present: pneumonia + hepatitis
