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Flashcards in Misc. UWorld Stuff Deck (46):
1

Recurrent bouts of:

  • Diffuse abd. pain (+/- const, naus, decr. sounds)
  • Neuro sx (tingling, sleep issues, diff. concentrating)
  • Dark red urine

Likely dx, pathogenesis, tx

Acute Intermittent Porphyria

  • AD deficiency of porphobilinogen deaminase
  • Tx with hemin or glucose decr. ALA synthase activity

2

Acute intermittent porphyria attacks can be triggered by induction of which enzyme by which inducers?

ALA Synthase

  • drugs: phenobarb, griseofulvin, phenytoin
  • alcohol
  • smoking
  • progesterone (ie puberty)
  • low-calorie diet

3

PSGN immunofluorescence:

Deposition pattern + location? Molecules deposited? 

Subepithelial granular deposits

deposits of IgG, IgM and C3b

4

14 yr old with soft, hyperpigmented non-tender bump below rt breast; has always been there, but got bigger at puberty; becomes tender just before menses

what is it?

 

accessory nipple AKA polythelia / supernumerary nipple

failed involution of mammary ridge; histo same as normal nipple; may swell / be tender during menses, pregnancy or lactation

5

Spina bifida - type of inheritance?

Multifactorial

- many genes play role in neurulation; folic acid deficiency is major factor

- common in first-degree relatives of those affected

6

3 yr old with abd pain, rectal bleeding. Blind pouch from ileum to umbilicus via fibrous band.

What is it? How does it form?

Its layers?

Rule of 2s?

 

Meckel's diverticulum

  • failed obliteration of omphalomesenteric / vitelline duct
  • true diverticulum; all layers (mucosa, sub-, musc- and serosa) (ectopic gastric mucosa / pancreatic tissue common inside --> HCl --> bleeds)
  • 2% population; 2 ft from IC valve; 2 inches long; 2% symptomtic; 2:1 male

7

Tx of drug-induced Parkinsonism?

Drug class + 2 examples

Anticholinergics

benztropine and trihexyphenidyl

8

How can left atrial pressure be measured?

Pulmonary artery occlusion pressure (PAOP)

AKA pulmonary capillary wedge pressure

  • PA catheter (Swan-Ganz) used to dx pulm htn + in critical care
  • Catheter placed in pulmonary artery, inflated, and P backs up to catheter tip from LA + is measured

9

What may be cause of disseminated mycobacterial infection in childhood?

Why?

How can these kids be tx?

Interferon Signaling Deficiency

  • i.e. AR deficiency of IFN-y receptor
  • infected macrophages produce IL-12 > stimulate T/NK production of IFN-y > stimulates macrophage IC killing of mycobacteria (via JAK1/2 > STAT1)
  • tx with life-long anti-mycobacterials

10

Generally, what are serum Ca and PTH levels like in primary osteoporosis patients?

Normal


(wrongly answered low Ca and high PTH)

11

What is the mnemonic for structures arising from neural crest cells?

MOTEL PASS:

  • Melanocytes
  • Odontoblasts
  • Tracheal cartilage
  • Enterochromaffin cells
  • Laryngeal cartilage
  • Parafollicular cells (thyroid)
  • Adrenal medulla + all ganglia
  • Schwann cells
  • Spiral membrane

12

What is the main familial disorder associated with pheochromocytoma?

+ its mutation + other assoc. conditions

MEN type 2 - RET proto-oncogene mutation

  • PCC + medullary thyroid c. (parafollicular cells)
  • Type 2A - parathyroid hyperplasia
  • Type 2B - mucosal neuroma + marfanoid habitus

13

Small underdeveloped ovaries primarily composed of CT with no follicles.

What is this, what disease is it assoc. with + what are the other features?

"Streak ovaries" of Turner Syndrome

  • 45, X - lack of paternal X causes loss of ovarian follicles by age 2 > high FSH and LH with amenorrhea and infertility
  • short stature, shield chest, webbed neck, low posterior hairline
  • lymphedema, bicuspid aortic valve (25%) or aortic coarctation (5%)

14

Mutation in primary myelofibrosis

JAK2

same as in PV, and ET

(treatable with ruxolitinib, a JAK2 inhibitor)

15

Mutations in...

acute promyelocytic leukemia?

CLL?

Burkitt?

Mantle cell lymphoma?

  • APL - t(15;17) PML/RARalpha
  • CLL - increased BCL2 expression
  • Burkitt - t(8;14) involving c-myc via EBV
  • Mantle cell - t(11;14) cyclin D1 overexpression

16

Immune cell receptors which can be blocked by new mAb drugs for cancer therapy

PD-1 and CTLA-4

stimulation of these receptors lead to T-cell inactivation

17

what is cumulative incidence?

total number of new cases of a disease during a given period divided by number of people at risk during that period

18

Antidote for cyanide poisoning and its mechanism

Amyl Nitrate

  • cyanide binds Fe3+, inhibiting mitochondrial cytochrome c oxidase > red skin, tachypnea/-cardia, headache, lactic acidosis + decr. veno-arterial O2 gradient
  • amyl nitrate oxidizes Fe2+ in hemoglobin to form Fe3+ (methemoglobin) which binds + sequesters cyanide
  • hydroxycobalamin and Na Thiosulfate can also be used (make nontoxic metabolites w/ Cn- > urinary excretion)

19

What structure prevents normal ascent of a horseshoe kidney?

What are horseshoe kidney pts at increased risk of (5)?

inferior mesenteric artery

  1. uteropelvic junction obstruction
  2. recurrent infection
  3. urolithiasis
  4. Wilms tumor (kids)
  5. Renal cell cancer (adults)

20

Process of granuloma formation in TB (cell types etc.)

  1. Macrophages phagocytose bacilli
  2. Ms present Ags to T cells
  3. CD4+ cells further stim macrophages
  4. Macros may for Langhans giant cells (mult. nuclei in horseshoe formation)
  5. (Macros also stim fibroblasts which help produce granulomas)

21

physiological vs. patho nipple discharge

#1 cause of pathological

  • physio = bilateral, nonbloody / milky without masses or skin changes
  • patho = bloody or serosanguinous w/ or w/o mass or skin change
  • #1 = intraductal papilloma - usually no mass or skin change, bloody/serosanguinous discharge unilaterally, proliferation of papillary cells in duct/cyst wall with fibrovascular core (twisting of stalk > bleed), with foci of atypia or ductal carcinoma in situ

22

Cryptococcus neoformans

morpho, epidem, infection, dx, tx

  • yeast w/ polysacch capsule; round/oval with narrow-based bud
  • bird poop; inhaled; AIDS pt CD4 < 100
  • meningoencephalitis (fever, HA, confusion)
  • India ink > bubbly budding yeast; latex agg of CSF for polysacch Ag; Sabouraud culture
  • ampho B / flucytosine induction; fluconazole maintenance

23

Newborn girl with posterior neck mass, bilateral nonpitting edema of hands and feet, diminished femoral pulse.

Neck US > cystic spaces separated by CT

What is the mass, why is it there, what causes the condition + explain other findings?

Turner syndrome

  • 45, X due to loss of paternal X
  • cystic hygroma on neck due to abnormal lymph flow
  • edema common to Turner's, diminished femoral pulse due to aorctic coarcation (2nd commonest CV abn in Turner's after bicuspid aortic valve)

24

Ciliary problems + situs inversus 

probably is... ?

Kartagener syndrome - AR inheritance

  • a "primary ciliary dyskinesia" in which dynein problems > impaired ciliary function
  • recurrent respiratory infections; infertility via sperm/fallopian tube problems; situs inversus due to impaired embryogenesis ciliary movement

25

How much of filtered water is absorbed in the different parts of the nephron?

  • PCT - ~60% regardless of hydration status
  • DL henle - ~20% due to corticopapillary gradient
  • AL henle + early DCT - impermeable
  • cortical + medullary CD - up to ~20% based on ADH > aquaporin translocation

26

Changes in levels of what molecule are seen in narcolepsy?

where?

decreased hypocretin-1

  • neuropeptides hypocretin-1 and 2 (orexin 1/2) made in lateral hypothalamus; promote wakefulness and inhibit REM sleep
  • normally detectable in CSF, but not elsewhere

27

Condition in which tyrosine becomes an essential AA

biochemical consequences + symptoms of the condition?

Phenylketonuria

  • AR deficiency of Phe hydroxylase inhibits Phe > Tyr conversion
  • excess Phe inhibits Tyr hydroxylase > decr. melanin (fair skin)/ catecholamine production
  • intellectual disability by 6 mos; seizures, eczema, low pigmentation, "musty" odor

28

Perinatal Hep B infection

  • risk factors
  • clinical findings
  • prevention

  • maternal viral load + HBeAg level
  • immune tolerance (no sx / low-normal LFTs); high chronic risk; high viral load + HBeAg in baby
  • HBsAg vacc + Ig within 12 hrs birth; maternal anti-viral tx; other routine vacc; serology 3 months after 3rd HB vacc dose

29

a holosystolic murmur heard at the apex subsides after diuretic + vasodilator treatment

what was the cause of the murmur + why did the tx help?

  • functional mitral regurgitation due to transient hemodynamic changes (NOT anatomical issues such as deformed cusps, calcified annulus, ruptured papillary muscles, etc.)
  • diuretics > decreased preload and end-diastolic LV volume > less LV dilation > less mitral dysfunction
  • vasodilator > decreased afterload > decreased intraventricular systolic pressure > less mitral dysfunction

30

What is Chediak Higashi syndrome?

  • AR disorder of lysosomal function
  • triad of neuro issues (nystagmus, periph/cranial neuropathy), albinism (partial oculocutaneous), immunodeficiency (defect in neutro phago-lysosome fusion > giant lysosomal inclusions on LM of periph blood + recurrent pyogenic infections by Staph/Strep)

31

How is urinary pH buffered when large amounts of H+ ions must be excreted (as in DKA)?

Buffers such as NH3 and HPO42- in the tubules bind H+ ions to form NH4+ and H2PO4-

  • NH3 (ammonia) is most important as it can be greatly increased via Gln metabolism in acidosis

32

Sx of Lithium toxicity (acute vs. chronic)

Conditions / factors which increase Li toxicity

  • acute = GI > N/V/D
  • chronic = neuro > confusion, agitation, ataxia, tremor, fasciculations (twitch)
  • volume depletion (decr. GFR) and drugs (thiazides, NSAIDs, ACE-I, tetracyclines + metronidazole)
  • (thiazides via decr. DCT Na reabs > stim PCT Na/Li reabs.)

33

what are the 2 main components of "advance directives"?

  1. living will - specifies end-of-life wishes re intubation, CP resuscitation, enteral feeding, etc.
  2. healthcare proxy - specifies individual who will make HC decisions for pt if they are unable to

34

How long does glycogenolysis maintain blood glucose in the fasting state?

12-18 hours

35

When does gluconeogenesis take over in maintenance of blood glucose during fasting?

after 12-18 hours, when glycogen stores are depleted

36

Which 3 enzymatic reactions in glycolysis + TCA are irreversible and must be bypassed by unique enzymes in gluconeogenesis?

 

  1. pyruvate dehydrogenase
  2. phosphofructokinase
  3. hexokinase

37

Which enzymes bypass irreversible glycolysis/TCA steps in gluconeogenesis?

  1. Pyruvate carboxylase - pyruvate > OAA (biotin)
    1. OAA > Malate via MDH, then malate leaves mitoch and > OAA via cytosolic MDH
  2. Phosphoenol Pyruvate (PEP) Carboxykinase - OAA > PEP
  3. Fructose-1,6-bisphosphatase
  4. Glucose-6-phosphatase

38

What are type I and type II error?

And the "power" of a study?

  • Type I error (alpha) - probability of seeing a difference when there is no real difference
  • Type II error (beta) - probability of not seeing a difference when in reality there is one
  • Power is the probability of a study seeing a difference when there is one, so P = 1 - beta

39

What are the 2 clinical tests for hypocalcemia with fancy guys' names?

  • Chvostek sign - tapping facial nerve (CN VII) elicits nose/lip twitching
  • Trousseau sign - bp cuff inflation > carpal spasm (flexion of wrist/thumb, extension of fingers)

40

DiGeorge syndrome

cause, embryo, sx/signs

  • 22q11.2 microdeletion
  • failure of NC cell migration to 3rd + 4th phar. pouch > failed PT and thymic development
  • hypocalcemia > tetany, carpopedal spasm, seizure; T cell deficiency > viral/fungal/protozoal infections; conotruncal abn. (interrupted aortic arch / truncus arteriosus)
  • Chvostek (CN VII tap) and Trousseau (bp cuff) signs + less thymic shadow on CXR
  • if 1st/2nd phar. pouch involved > hypertelorism, short palpebral fissures, micrognathia, bifid uvula, cleft palate

41

sensory innervation of tongue

  • Anterior 2/3:
    • sensory: lingual nerve (CN V/3)
    • gustatory: chorda tympani (CN VII)
  • Posterior 1/3:
    • sensory + gustatory: glossophar. n. (CN IX)

42

What are the 3 sets of nephric systems that arise from the nephrogenic cord?

What do they become?

  1. Pronephros - completely regresses
  2. Mesonephros - Wolffian duct (vas def, epidid); regress > Gartner's duct in females
  3. Metanephros - induced by ureteric bud (>collecting system); becomes all of nephron from glom to DCT

43

IFN types, where they're made + effects

  • Type I - alpha/beta; from virus infected cells; paracrine signal to other infected cells > increased RNAse L and protein kinase R (inhibits eIF-2 + thus translation initiation) in presences of dsRNA
  • Type II - gamma; from T/NK cells; stim Th1 diff, incr MHC-II expression, improves intracellular killing my macros

44

What are the two functions of type II pneumocytes?

  • surfactant production
  • proliferation in response to injury (progenitors for type I pneumocytes)

45

what is number-needed-to-harm?

  • # ppl who must be treated before 1 additional adverse event occurs
  • calculated using the absolute risk increase:
    • NNH = 1 / ARI

46

What is absolute risk increase?

the difference in adverse event rate between two study groups

  • 60/100 people die in a tx grp (60%) and 69/120 in a ctrl grp (57.5%) so ARI is 2.5%