uworld assessment block #4 4.15 Flashcards
infectious arthritis causes? presentation
most common (1) n. gonorrhea (disseminated). can also be (2) s. aureus (2) streptococcus
STD triad: synovitis (arthralgia, knee), tenosynovitis (hand), dermatitis
(note, no eye symptoms. compared to reiter’s – conjunctivitis)
differentiate infectious arthritis from reactive arthritis ‘reiter’s’
infectious agents:
infectious arthritis: gonorrhea, s. aureus, strep
reactive arthritis: nongonococcual urethritis (chlamydia) and GI bugs (campylobacter, salmonella, shigella, yersinia)
eye involvement:
infectious: tenosynovitis, synovitis, dermatitis
reactive: conjunctivitis, seroneg arthritis, urethritis
viral arthritis
symmetric polyarticular disease. associated w/ parvovirus, hep B, hep C, rubella, alphavirus
prader-willi presentation
neonatal hypotonia, extreme hyperphagia, morbid obesity, ultimately DM type II, short, small hands & feet, hypogonadism, characteristic facies.
pathophysiology of prader-willi
imprinting.
normal: mom’s gene 15q11 region SILENT. express ONLY PAPA.
disease:
(1) delete papa’s gene
(2) 25% uniparental disomy (only inherit mom’s imprinted gene)
would detect microdeltion of papa’s chr 15 on FISH. if FISH is normal = uniparental disomy.
pathophysiology of angelman’s syndrome
imprinting
normal: papa’s gene is normally SILENT. express ONLY MOM.
disease:
(1) delete mom’s gene
(2) 5% uniparental disomy. (only inherit papa’s imprinted gene)
presentation of angelman’s syndrome
inappropriate laughter “happy puppet”, seizure, ataxia, severe intellectual disability
paracentric inversions
inversions of chromosomal DNA in one arm of chromosome not including centromere
GI presentation of celiac’s disease
(1) blunting of villi (2) lymphocytes in lamina propria (3) hyperplasia of crypts
CD8+ T cells infiltrate surface epithelilum, while CD4+ in lamina propria.
distal duodenum
Ab found in celiac’s disease
anti-transglutaminase, anti-gliadin, anti-endomysial
presentation of dermatitis herpatiformis? pathophysiology?
PRUITIC erythematous urticarial plaques on extensor surfaces of elbow, knee, buttocks, back.
caused by CROSS-REACTION of gliadin IgG and IgA with RETICULIN
–> component of fibrils that anchor the epidermal basement membrane to superficial dermis.
neutrophils at dermal tips –> microabscesses –> subepidermal blisters
normal thickness of right ventricle? left ventricle?
right: 3-4mm
left: 1 cm
layers of epidermis
corneum lucidium granulosum spinosum basale
describe stratum corneum
15-20 layers of dead squamous cells that lack nuclei.
generally thickest in regions exposed to friction (soles of feet)
callus
painless thickening of stratum corneum, at locations of repeated of external pressure / friction
essential characterestics of PCOS
amenorrhea, obesity, hirsuitism, virilization, peripheral insulin resistance, dyslipidemia
ovaries in PCOS
bilateral enlargement and smooth thickened capsules.
subcapsular follicles in diff stages of atresia.
hyperplastic theca stroma cells rim arrested follicles
hormone imbalance in PCOS
elevation in everything EXCEPT FSH
think: high LH makes theca cells produce more androgens.
FSH is diminished, so granulosa cells can’t make as much estrogen.
lesch-nyhan inheritance? presentation?
X-linked recessive.
self-mutilating behavior, mild mental retardation, involuntary movement, delayed motor development, nephrolithiasis, gout
FROST on skin under diaper –> hyperuricuria
rx: allopurinol
HGPRT fxn
purine salvage.
convert hypoxanthine and guanine to inosine monophosphate (IMP) and guanine mono phosphate (GMP).
absence: increased purine synthesis, hyperuricemia, hyperuricuria
ADA deficiency
impt for purine catabolism. deficiency: build up dATP, inhibit ribonucleotide redutase, inhibit DNA synthesis.
adenine phosphoribosyltransferase (APRT)
involved in purine salvage. converts adenine to AMP.
deficiency: hyperuricemia and adenine stone urolithiasis.
autosomal recessive. no neurological symptoms
erythromyocin drug effect
block translocation.
prevent tRNA release from donor site after peptide bond formation. 50S.
chloramphenicol drug effect
bind to 50S
block peptidyltransferase action
puromycin
aminonucleoside, structure analogus to aminoacyl-tRNA.
leads to premature release of unfinished polypeptide chains and polypeptidyl-puromycin derivatives.
differentiation of a cell primarily depends on
transcription factor: favors expression of only those genes required for cell to perform function.
specific for each individual tissue.
cytokine vs. growth factor
growth factor = type of cytokine. stimulate GROWTH and DIFFERENTIATION of various lines. regulates synthesis of transcription factor.
timolol for glaucoma?
block b2 receptor mediated secretion of aqueous humor from ciliary epithelium
what GI hormone would be elevated in a patient with pernicious anemia?
GASTRIN. autoimmune destruction of parietal cells.
parietal cells secrete instrinic factor (bind to b12) AND HCl!
low HCl will prompt Gastrin secretion
pernicious anemia
results in atrophic gastritis w/ profound hypochloridia and increased serum gastrin levels
what leads to varicoele (left)
compression of renal vein between SMA and aorta
recumbent position allows blood to drain fine
spermatocele
cystic masses, arise from caput of epididymis. measuring between 2-5cm in diameter. usu do not cause symptoms
transillumination of varicoele
NEGATIVE. will not.
where does fluid accumulate in hydrocoele?
between parietal and visceral layers of tunica vaginalis
Peutz-Jegher’s
rare, autosomal dominant. pigmented mucocutaneous macules and hamartomatous polyps in GI tract.
acanthos nigricans suggests (2)
underlying GI malignancy (gastric) and / or insulin resistance
neurofibromas that undergo malignant degeneration?
malignant peripheral nerve sheath tumors
rx after mechanical valve surgery (chronically)
warfarin (antagonize vitamin K-dependent gamma-carboxylation)
antiplatelets are not enough!
when are gbIIb/IIIa blockers used?
acute coronary syndrome
what origin is melanocytes
neural crest cell
at what stage to oocytes arrest in development
primary oocytes in prophase
cardiac problem seen in diGeorge?
truncus arteriosus, tetrology of fallot, interrupted aortic arch
3rd and 4th pharyngeal pouch important for
parathyroids, thymus, and ultimobranchial body
sinus venosus in utero
receives blood from vitelline vein, umbilical vein, and common cardinal vein
eventually forms coronary sinus, oblique vein of left atrium, and sinus venarum of right atrium
cardinal veins return blood from abdominal walls and wolffian bodies
which nucleotide is methylated in hypermethylated DNA
cytosine-guanine dinucleotide repeat sequences.
gaucher’s disease presentation
hepatosplenomegaly. anemia, thrombocytopenia, bleeding, BONE PAIN and FRACTURES.
macrophages with crinkled-tissue paper appearance
enzyme deficiency in gaucher’s disease
glucocerebrosidase.
increase in glucocerebroside.
most prevalent genetic disorder among ashkenazi jews
gaucher’s disease
wrinkled-tissue paper in macrophage
gaucher’s disease
built up product in fabry’s
x-linked recessive. defect alpha-galactosidase. retention of ceramide trihexose
build up of ceramide trihexose in..
fabry’s, defect in alpha-galactosidase
defect in arylsulfatase
metachromatic leukodystrophy
accumulation in metachromatic leukodystrophy
defect in arylsulfatase
cerebroside sulfate accumulates
peripheral neuropathy and motor skill difficulties
what is S-adenosylmethionine
SAM. produced by condensation of methionine with ATP.
functions as methyl group donor. involved in several reactions.
in adrenergic system: SAM important for conversion of NE to E by PNMT
rx against TNF-alpha (etanercept and infliximab) used for..
autoimmune processes like rheumatoid arthritis, crohn’s, ankylosing spondylitis, psoriasis
tacrolimus
suppress T-lymphocyte activation by binding to FKBP-12. used in transplants
acute coronary syndrome characterized by…
occlusion of coronary vasculature, typically by thrombus, which arises secondary to increased platelet deposition & clotting factor activity at the site of a disrupted atherosclerotic plaque.
desired aspirin effect in stable angina?
block acute coronary syndrome (thrombus formation). block cox-1 (low dose aspirin)
limits platelet aggregation! (also affects GI system)
desired aspirin effect in inflammatory conditions (like rheumatoid arthritis)
block inflammation, cox-2!
selective cox-2 were generated b/c high dose also blocks cox-1 –> GI bleeds
aspergillus fungus histology
methenamine silver stain. septate hyphae out of which asexual fruiting structures known as conidiophores project.
conidiophores – each have terminal vesicle w/ outwardly radiating phialides and condiospores attached – giving ‘broom like appearance’
generally, pts w/ history of TB may develop aspergillus in lung cavities previous formed by TB. fungus balls.
pneumocystis jiroveci on silver stain
cup or disc-shaped organisms.
examples of competent bacteria (able to undergo transformation)
haemophilus, streptococcus, bacillus, neisseria
FSGS associated w/ what demographic?
HIV infection, heroin addiction, sickle cell (black & hispanic)
in FSGC, describe the focally sclerosed parts (3)
basement membrane collapse, increased matrix production, hyalinosis
FSGS can progress to.. (esp with HIV-associated nephropathy)
collapsing glomerulonephropathy. usual FSGS lesions with collapse and sclerosis of whole glomerular tuft.
glomerular epithelial cells proliferate & hypertrophy. marked tubular injury (accompanying microcyst formation)
goodpasture’s nephropathy is a form of…
RPGN
describe deposits in membranous glomerulonephropathy
diffuse glomerular capillary wall thickening w/ spike subepithelial IgG deposits
describe membranoproliferative glomerulonephritis
enlarged, hypercellular glomeruli w/ PMNs & monocytes.
increased mesangial cellularity –> capillary basement membrane thickening.
granular IgG and/or C3 deposits
postinfectious glomerulonephritis
diffuse hypercellularity (PMNs and monocytes)
diffuse granular deposits of IgG and C3 along glomerular capillary wall & mesangium.
IgA nephropathy
diffuse mesangian proliferation & expansion of ECM. granular IgA in mesangium & capillary walls
see collapsed lung w/
absence of lung markings along peripheral edge.
white visceral pleural line on chest radiograph.
heart & trachea moved away from affected side.
rx for collapsed lung (tension pneumothorax)
needle aspiration or chest tube placement (remove air from chest space)
homeobox genes
highly conserved set of genes (animals, fungi, plants).
code for protein TRANSCRIPTION FACTORS (homeodomain proteins).
GUIDE morphogenesis.
(mutation = structural defects)
modulate expression of other genes in cells. guide development from earliest stages of embryogenesis to final differentiation of cells.
HoxA-13 mutation
hand-foot-genital syndrome.
characterized by clinodactyly (curavture of finger), shortened thumbs, small feet, short great toes, urinary tract abnormalities. GI abnormalities: duplications in reproductive tact of women. hyposadias in men.
Pax-3 mutations
Waardenburg syndrome
Waardenburg syndrome
mutation in Pax-3.
heterochromia irides, poliosis, dystopia canthorum, sensorineural DEAFNESS.
dystopia canthorum: lateral displacement of inner canthorum of eye – widened nasal bridge.
VHL mutation
predisposition to retinal, cerebellar, spinal hemangioblastomas.
renal cell carcinoma, pheochromocytoma, pancreatic tumor.
major effects of active vitamin D (1,25 dihydroxycholecaliferol)
- increased intestinal absorption of orally ingested Ca2+ and PO4-
- this lowers PTH
- enhanced bone resorption and release of bone Ca2+ and PO4- when serum levels of one of these are low
what contributes to serum anion gap? what is normal?
Na - (Cl + HCO3) = 12-16meq/ml
> 30 = unaccounted acidic anions
sudden onset back pain, hematuria, oliguria, and anion gap metabolic acidosis
ethylene glycol posioning –> causes calcium oxalate crystals in renal tubules –> renal failure
basic steps of thermal cycling PCR
heating - DNA strand denature
cooling - primer hybridization
rewarming - primer extension & DNA synthesis
which facial sinus is most commonly affected during URI?
maxillary, bc drainage is located SUPERIOR to the floor of the sinus (gravity doesn’t help)
drainage of ethmoid air cells
superior meatus
Virchow’s node
left supraclavicular (between clavicle and trapezius).
receives drainage from thoracic duct – samples lymph from
- all abdominal viscera
- viscera of left hemithorax
- all tissues inferior to umbilicus
- all left-sided tissues superior to umbilicus.
can be enlarged in abdominal malignancy, breast cancer, lung cancer, lymphoproliferative disorders
deep cervical lymph nodes drain
head & neck
axillary lymph nodes involved in..
classical metastatic breast cancer (could also go to parasternal nodes)
deltopectoral (infraclavicular) lymph nodes
participates in draining lymph from arm. groove between deltoid and pectoralis.
epitrochlear nodes
near elbow. drain lymph from ulnar aspect of forearm and hand.
enlarge w/ skin or soft-tissue infection distal to elbow.
circadian sleep rhythm sleep disorder
intrinsic abnormal suprachiasmatic nucleus. sleep/wake cycles off sync with time. i.e. want to go to bed at 3am and wake much later.
present: excessive daytime sleepiness during the school week in an otherwise health child (due to inability to attain needed amount of sleep when social demands require premature waking)
narcolepsy (3 features)
(1) daytime REM attacks and (2) cataplexy (sudden loss in antigravity muscle tone)
auditory or visual hallucinations of a hynagogic (upon falling asleep, more common) or hypnopompic (upon wakeing, less common) may occur
pathway of hormone secretion from suprachiasmatic nucleus
SCN –> NE –> pineal gland –> melatonin.
SCN regulated by light.
progression of EEG waves awake (eyes open) awake (eyes closed) non-REM 1 (5%): non-REM 2 (45%): non-REM 3 (25%):
REM (25%):
BATS Drink Blood
awake (eyes open): beta
awake (eyes closed) alpha
non-REM 1: theta
non-REM 2: sleep spindles & k complex
non-REM 3: delta waves
REM: beta waves
in which stage of sleep does bed-wetting occur?
stage 3: delta waves. deepest
in which stage does teeth clenching (bruxism) occur?
stage 2: sleep spindles & k complexes. longest sleep
rx for narcolepsy
- daytime stimulants (amphetamines and modafinil)
- nightime sodium oxybate (GHB) GABA-b agonist
fatal familial insomnia
autosomal dominant prion disease. severe intractable insomnia and death
preload on contraction velocity
initial muscle fiber length prior to contractin.
amount of stretch placed on fiber before contraction occurs.
increasing preload increases contractile velocity up to a maximum value. beyond which –> actin/myosin becomes ineffient.
passive tension exerted by skeletal myocyte positively correlated with
resting length.
decrease in passive tension implies decrease in fiber length (decrease in maximal contraction velocity)
afterload on skeletal muscle contraction velocity
maximal velocity of contraction increases as afterload decreases
how does giardia look in GI system? what does it cause?
binucleate flagellated trophozite (looks like it’s looking at you)
kite-like, owl’s eyes
attaches to small bowel mucosa w/ ventral sucking disk.
does NOT damage or invade mucosa.
greasy, frothy, foul-smelling, nonbloody diarrhea. excessive flatulence.
malabsorption due to dysfunction of brush border enzymes.
usu camping / travel abroad
identification of entamoeba histolytica
serology or stool:
(1) trophozites w. RBCs in cytoplasm
(2) cysts w/ up to 4 nuclei
acute leukemia presents w/ (3)
PANCYTOPENIA:
anemia: fatigue
leukopenia: opportunistic infxn
thrombocytopenia: bleeding
3 cases where basophilic stipling is seem
ribosomal aggregates
- alcohol abuse
- lead poisoning
- thalasemia
virulence factor for aspergillus
vascular invasion
aspergillus is associated w/
aflatoxin – carcinogen related to hepatocellular carcinoma
felty syndrome
triad of (1) rheumatoid arthritis (2) splenomegaly (3) neutropenia
rx for esophageal variceal hemorrhage?
ocretotide (somatostatin analogue)
reduce splanchnic blood flow & divert blood from portal system to systemic circulation
indirectly induces splanchnic vasoconstriction via inhibition of glucagon and VIP (which vasodilate splanchnic vasculature)
also good bc doesn’t cause systemic vasoconstriction
use of pentagastrin (2)
synthethetic gastric analogue:
(1) screen for carcinoid syndrome (stimulate 5HT secretion)
(2) screen for medullary carcinoma of thyroid (stimulate calcitonin secretion)
glucagon & VIP on splanchnic vasculature
vasodilation
