Misc. UWorld Stuff Flashcards

1
Q

Tx of drug-induced Parkinsonism?

Drug class + 2 examples

A

Anticholinergics

benztropine and trihexyphenidyl

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2
Q

How can left atrial pressure be measured?

A

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
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3
Q

What may be cause of disseminated mycobacterial infection in childhood?

Why?

How can these kids be tx?

A

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
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4
Q

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

A

Normal

(wrongly answered low Ca and high PTH)

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5
Q

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

A

MOTEL PASS:

  • Melanocytes
  • Odontoblasts
  • Tracheal cartilage
  • Enterochromaffin cells
  • Laryngeal cartilage
  • Parafollicular cells (thyroid)
  • Adrenal medulla + all ganglia
  • Schwann cells
  • Spiral membrane
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6
Q

Mutation in primary myelofibrosis

A

JAK2

same as in PV, and ET

(treatable with ruxolitinib, a JAK2 inhibitor)

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7
Q

Mutations in…

acute promyelocytic leukemia?

CLL?

Burkitt?

Mantle cell lymphoma?

A
  • 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
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8
Q

what is cumulative incidence?

A

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

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9
Q

Antidote for cyanide poisoning and its mechanism

A

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)
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10
Q

What structure prevents normal ascent of a horseshoe kidney?

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

A

inferior mesenteric artery

  1. uteropelvic junction obstruction
  2. recurrent infection
  3. urolithiasis
  4. Wilms tumor (kids)
  5. Renal cell cancer (adults)
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11
Q

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

A
  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)
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12
Q

Cryptococcus neoformans

morpho, epidem, infection, dx, tx

A
  • 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
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13
Q

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

A
  • 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
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14
Q

Changes in levels of what molecule are seen in narcolepsy?

where?

A

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
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15
Q

Condition in which tyrosine becomes an essential AA

biochemical consequences + symptoms of the condition?

A

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
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16
Q

Perinatal Hep B infection

  • risk factors
  • clinical findings
  • prevention
A
  • 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
17
Q

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

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

A
  • 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
18
Q

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

A

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
19
Q

Sx of Lithium toxicity (acute vs. chronic)

Conditions / factors which increase Li toxicity

A
  • 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.)
20
Q

what are the 2 main components of “advance directives”?

A
  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
21
Q

What are type I and type II error?

And the “power” of a study?

A
  • 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
22
Q

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

A
  • 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)
23
Q

sensory innervation of tongue

A
  • Anterior 2/3:
    • sensory: lingual nerve (CN V/3)
    • gustatory: chorda tympani (CN VII)
  • Posterior 1/3:
    • sensory + gustatory: glossophar. n. (CN IX)
24
Q

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

What do they become?

A
  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
25
Q

What are the two functions of type II pneumocytes?

A
  • surfactant production
  • proliferation in response to injury (progenitors for type I pneumocytes)
26
Q

what is number-needed-to-harm?

A
  • # ppl who must be treated before 1 additional adverse event occurs
  • calculated using the absolute risk increase:
    • NNH = 1 / ARI
27
Q

What is absolute risk increase?

A

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%