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STEP1 Review > UWorld Test Review 6 > Flashcards

UWorld Test Review 6 Flashcards

1
Q

7yo M w/ sudden onset of facial swelling 2 hours ago w/o itching or pain other than a sore throat over last 2 days, for which he was given acetaminophen. Pt has had similar episodes before which resolved spontaneously. PE shows non-pitting edema of cheeks, lips, and tongue w/o erythema or tenderness. Dx?

A

hereditary angioedema: deficiency of C1 inhibitor —> elevated bradykinin (causes vasodilation + increased permeability)

labs show low C4 because C1 cleaves C4

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2
Q

which infectious causes of GI illness do the following pathological findings represent?
a. blunting of villi in duodenum and proximal jejunum
b. extensive colonic mucosal injury with yellow-white adherent layer
c. flask-shaped ulcerations in the cecum and ascending colon
d. foamy macrophages in the small intestinal lamina propria
e. inflammatory infiltrate and necrosis of the Peyer patches

A

a. blunting of villi in duodenum and proximal jejunum = rotavirus

b. extensive colonic mucosal injury with yellow-white adherent layer = C. diff

c. flask-shaped ulcerations in the cecum and ascending colon = Entamoeba histolytica

d. foamy macrophages in the small intestinal lamina propria = Tropheryma whipplei (Whipple disease)

e. inflammatory infiltrate and necrosis of the Peyer patches = Salmonella typhi

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3
Q

failure of which of the following describes the cause of spina bifida occulta?
a. anterior neural tube closure
b. myelencephalon division
c. neural crest cell migration
d. notochord separation from endoderm
e. vertebral arch fusion

A

e. vertebral arch fusion

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4
Q

how can you differentiate PCP (phencyclidine) vs methamphetamine intoxication?

A

PCP (hallucinogen): violent behavior, hallucinations, ataxia, nystagmus (horizontal or vertical)

methamphetamine (stimulant): violent behavior, psychosis, tachycardia/HTN, choreiform movements, can last up to 20 hours (much longer)

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5
Q

the intercostal vein, artery, and nerve lie along the [upper/lower] border of the rib

A

the intercostal vein, artery, and nerve lie along the LOWER border of the rib (just below each rib)

—> thoracentesis is performed along upper board of rib (just above it)

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6
Q

which drug class may cause angioedema due to excess bradykinin?

A

ACE inhibitors

[ACE is responsible for bradykinin breakdown]

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7
Q

explain the mechanism of insulin release from beta cells (4 steps)

A
  1. glucose enters via GLUT-2
  2. glycolysis produces ATP
  3. ATP binds K+ channel, causing them to close —> membrane depolarization
  4. voltage-gated Ca2+ channels open —> inducing insulin release
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8
Q

describe the steps of the Gq pathway (3)

A
  1. Gq activates phospholipase C (PLC)
  2. PLC breaks PIP2 into IP3 + DAG
  3. DAG stimulates protein kinase C (PKC), while IP3 increases intracellular Ca2+ (also activating PKC)
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9
Q

where in the nephron are uric acid crystals most likely to precipitate and why?

A

uric acid has pKa of 5.4 - soluble at physiologic pH, but precipitates in acidic environment

distal tubules/collecting duct is most acidic part of the nephron

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10
Q

Vitamin A supplementation can be beneficial in the treatment of _____ infection by reducing comorbidities (ocular, keratitis, diarrhea, pneumonia)

A

Vitamin A supplementation can be beneficial in the treatment of MEASLES infection by reducing comorbidities (ocular, keratitis, diarrhea, pneumonia)

measles (paramyxovirus) - exanthema rash (blanching, erythematous) starts on face and spreads to trunk/ extremities while sparing palms/soles

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11
Q

cause of epispadias vs hypospadias

A

epispadias: abnormal opening on DORSAL penis due to faulty positioning of genital tubercle

hypospadias: abnormal opening on VENTRAL penis due to incomplete fusion of the urethral (urogenital) folds

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12
Q

55yo F presents w/ post-menopausal bleeding for the last 6 months. Denies pelvic pain. PMH includes DM2, BMI is 38. Uterus is small and nontender, and there are no palpable adnexal masses. Which of the following is the most likely explanation?
a. autonomous pituitary secretion of prolactin
b. ectopic implantation of endometrial glands and stroma
c. elevated sex-hormone binding globulin levels
d. increased peripheral aromatization of androgens
e. suppression of hypothalamic GnRH secretion

A

d. increased peripheral aromatization of androgens

dx = endometrial hyperplasia or cancer - most common risk factor is chronic unopposed estrogen and associated with obesity

after menopause, some androgens are still produced, and in obese women, peripheral aromatase (adipose tissue) produces a lot of estrogen

a. autonomous pituitary secretion of prolactin - can cause neg. feedback on hypothalamic GnRH, but would see either galactorrhea or mass effect
b. ectopic implantation of endometrial glands and stroma - painful and requires a very high estrogen (pre-menopausal)
c. elevated sex-hormone binding globulin levels - DECREASE after menopause
e. suppression of hypothalamic GnRH secretion - occurs with caloric restriction (not obese) and does not cause bleeding

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13
Q

most common cause of mitral stenosis

A

rheumatic fever (99%!!!) - often latency of 10-20 years (4th/5th decade)

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14
Q

14yo F presents w/ primary amenorrhea. Tanner stage 1, blind vaginal pouch. Imaging reveals absence of uterus and fallopian tubes. Epididymis, vasa deferentia, and testes are present bilaterally. Karyotype is 46,XY. What is the most likely mechanism?
a. absent conversion of testosterone to dihydrotestosterone
b. aplasia of fetal Leydig cells
c. complete defect in androgen receptor function
d. inability to convert 17-hydroxyprogesterone to 11-deoxycortisol
e. loss of sex-determining region of the Y chromosome

A

dx: 5-alpha reductase: a. absent conversion of testosterone to dihydrotestosterone (needed for male external genitalia)

b. aplasia of fetal Leydig cells - Leydig cells secrete testosterone, required for internal male genitalia
c. complete defect in androgen receptor function - internal male genitalia would be absent
d. inability to convert 17-hydroxyprogesterone to 11-deoxycortisol - would have normal male external genitalia
e. loss of sex-determining region of the Y chromosome - would have female internal/external genitalia

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15
Q

what is the function of endothelin 1?

A

stimulated by angiotensin II, increases Na+ and water reabsorption and SVR to maintain BP

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16
Q

how does insulin (specifically) stimulate glycolysis?

A

insulin increases production of fructose 2,6-bisphosphate via phosphofructokinase-2 (PFK2)

fructose 2,6-bisphosphate is the most potent stimulator of phosphofructokinase-1 (PFK1) - the rate-limiting step in glycolysis

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17
Q

how is number needed to harm (NNH) calculated?

A
  1. find absolute risk increase (ARI) by finding difference in rate (risk) of adverse effects between treatment group and control group (placebo)
  2. the NNH is the inverse (1/ARI)
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18
Q

rapid onset of _______ lesions is an indicator of internal malignancy (Leser-Trelat sign), especially [type of cancer]

A

rapid onset of seborrheic keratosis lesions is an indicator of internal malignancy (Leser-Trelat sign), especially gastric adenocarcinoma

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19
Q

what are the leading pathogens causing secondary bacterial pneumonia (for example, following influenza virus) in healthy patients? (3)

A
  1. Streptococcus pneumoniae
  2. Staphylococcus aureus - esp. younger patients
  3. Haemophilus influenzae
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20
Q

loss of sensation in perineal area (saddle anesthesia) indicates…

A

cauda equina syndrome: commonly due to epidural cord compression from malignancy

causes urinary and fecal incontinence late in disease course

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21
Q

lower extremity purpura (buttocks + legs) + colicky abdominal pain + hematuria (renal disease) + joint pain =

A

Henoch-Schonlein purpura: IgA-mediated vasculitis, often follows URI

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22
Q

Industrial worker presents w/ rapid-onset SOB, dizziness, palpitations, and flushed skin. Pt is tachypneic and has reddish skin without cyanosis. Pt is treated with hydroxocobalamin. What were they exposed to, and what is the purpose of this treatment?

A

cyanide poisoning - blocks ETC because CN- binds ferric ion (Fe3+) in cytochrome c oxidase with high affinity

tx:
1. sodium thiosulfate: forms thiocyanate for excretion
2. hydroxocobalamin: forms cyanocobalamin for excretion
3. sodium nitrite: nitrites promote formation of methemoglobin, which binds CN- with greater affinity than cytochrome c oxidase

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23
Q

what is the tx (2) for congenital toxoplasmosis? how do these drugs work?

A

sulfadiazine + pyrimethamine

work synergistically to inhibit protozoal DNA synthesis by blocking subsequent steps in formation of tetrahydrofolate (THF) - cofactor required for purine synthesis

[sulfadiazine inhibits dihydropteroate synthase; pyrimethamine inhibits dihydrofolate reductase]

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24
Q

name 2 complications of incomplete obliteration of the processes vaginalis

A
  1. communicating hydrocele
  2. indirect inguinal hernia
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25
Q

Pt presents with pain in shoulders, hips, and proximal extremities. Labs show elevated erythrocyte sedimentation rate, but x-rays are normal. Dx?

A

polymyalgia rheumatica

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26
Q

what do labs show in Paget disease of bone?

A

Paget disease of bone: excessive and disordered bone formation commonly affecting the skull, long bones, vertebral column —> spinal stenosis, nerve compression, compression fracture

Labs show elevated serum alkaline phosphatase, but normal serum calcium and phosphorus levels due to changes occurring slowly

Radiographs show lytic or mixed lytic – sclerotic lesions, thickening of cortical and trabecular bone, bony deformities

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27
Q

Which three UTI bacteria produce nitrites?

A
  1. E. coli
  2. Klebsiella
  3. Proteus

produce nitrate reductase - reduces normal urinary nitrate (NO3-) to nitrite (NO2-)

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28
Q

what do Abs to the following antigens represent?
a. centromeres
b. dsDNA
c. Fc portion of IgG
d. mitochondrial components
e. nuclear basic proteins
f. phospholipid-binding proteins
g. sheep erythrocytes

A

a. centromeres - CREST

b. dsDNA - SLE

c. Fc portion of IgG = rheumatoid factor (IgM)

d. mitochondrial components - primary biliary cholangitis

e. nuclear basic proteins (antinuclear) - nonspecific finding in many connective tissue disorders

f. phospholipid-binding proteins (beta2 glycoprotein I) - SLE and antiphospholipid syndrome

g. sheep erythrocytes (heterophile Abs) - EBV infection (Monospot test)

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29
Q

what is the function of the nigrostriatal pathway?

A

projects from substantia nigra to the caudate nucleus and putamen and primarily regulates the coordination of voluntary movements

D2 receptor blockade in this pathway results in extra-pyramidal effects (dystonia, akathisia, tardive dyskinesia) and drug-induced parkinsonism

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30
Q

Which two cytokines might tumor cells increase production of two evade immune response?

A
  1. IL-10
  2. TGF-beta

both are immunoinhibitory

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31
Q

which 3 bacteria should come to mind for patients with cystic fibrosis?

A
  1. Haemophilus influenzae
  2. Staphylococcus aureus
  3. Pseudomonas aeruginosa - adults
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32
Q

which cell types are heavily involved in the pathology of centriacinar emphysema?

A

centriacinar emphysema: associated with chronic/heavy smoking, caused by release of proteases (esp. elastase) from infiltrating neutrophils + alveolar macrophages

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33
Q

contrast the 2 disorders of phenylalanine metabolism

A

phenylketonuria (PKU): deficiency of phenylalanine hydroxylase (converts phenylalanine —> tyrosine) —> neuro abnormalities + hypopigmentation + musty odor; tx = restrict phenylalanine + give tyrosine

BH4 deficiency: deficiency of dihydropteridine reductase (regenerates BH4, needed for rxns involving phenylalanine, tyrosine, tryptophan) —> elevated phenylalanine (same symptoms as above) + low dopamine/epinephrine/serotonin; tx = restrict phenylalanine + give BH4

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34
Q

Gram neg. non-lactose-fermenting, nonmotile, rod-shaped =

A

Shigella

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35
Q

name 2 low potency and 2 high potency first-gen. antipsychotics

A

low potency (non-neurological): chlorpromazine, thioridazine
[side effects due to histaminergic/cholinergic/alpha1 blockade]

high potency (neurological): haloperidol, fluphenazine
[side effects due to extrapyramidal symptoms]

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36
Q

how do sulfonylureas work?

A

inhibit ATP-sensitive K+ channel on pancreatic beta cell membrane —> induce depolarization and Ca2+ influx, followed by insulin release independent of blood glucose concentration

therefore, sulfonylureas can cause hypoglycemia because they stimulate insulin secretion even when blood glucose is normal

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37
Q

which muscles does the mandibular nerve (CN V3) supply?

A
  1. muscles of mastication - medial and lateral pterygoid, masseter, temporalis
  2. tensor veli palatini
  3. tensor tympani (middle ear, dampens loud sounds by tensing tympanic membrane)
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38
Q

which 3 metabolic pathways occur in the cytosol, and which 3 occur in the mitochondria?

A

cytosol: glycolysis + fatty acid synthesis + PPP

mitochondria: beta-oxidation + TCA + gluconeogenesis

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39
Q

describe the pathogenesis and associations with hypertrophic osteoarthropathy?

A

painful bone/ soft tissue enlargement in distal extremities —> clubbing, joint pain, periostosis (tender thickening of periosteum)

disruption of normal pulmonary circulation leads to AV shunting —> megakaryocytes bypass lungs into systemic circulation and lodge in peripheral tissues —> release PDGF/VEGF —> fibrovascular hyperplasia and abnormal bone formation

associated w/ lung adenocarcinoma, cystic fibrosis, bronchiectasis, lung abscess, cyanotic heart disease

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40
Q

which of the following may present with regular, heavy menses? (2)
a. adenomyosis
b. chronic endometritis
c. complete hydatidiform mole
d. endometriosis
e. uterine leiomyoma
f. uterine sarcoma

A

a. adenomyosis and e. uterine leiomyoma

b. chronic endometritis - irregular bleeding
c. complete hydatidiform mole - amenorrhea or irregular first-trimester bleeding
d. endometriosis - no heavy menses (extra-uterine implants)
f. uterine sarcoma - irregular, postmenopausal bleeding

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41
Q

differential cyanosis (cyanosis affecting only lower body) suggests…

A

… right to left shunting across patent ductus arteriosus (PDA)

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42
Q

which cytokine is an important driver of the severity of giant cell arteritis?

A

IL-6 - promotes vessel damage and remodeling (intimal hyperplasia)

can target w/ tocilizumab

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43
Q

Pt w/ marfanoid habitus, ectopia lentis, developmental delay, and increased risk for thromboembolism would most likely benefit from supplementation of which vitamin?

A

dx = homocystinuria: AR deficiency of cystathionine synthase (converts homocysteine to cystathionine), which requires B6 (pyridoxine)

responds well to B6 supplements + restriction of methionine

44
Q

which adrenergic agonist binds only alpha1?

A

phenylephrine - increases blood pressure while lowering HR (reflex-mediated)

45
Q

which adrenergic agonist binds beta1 and beta2 equally?

A

isoproterenol - decrease/normal BP and increase HR

46
Q

which of the following combinations is not possible?
a. dichorionic/diamniotic
b. monochorionic/monoamniotic
c. monochorionic/diamniotic
d. dichorionic/monoamniotic

A

d. dichorionic/monoamniotic

monozygotic twins can be:
- dichorionic/diamniotic: days 0-4
- monochorionic/diamniotic: days 4-8
- monochorionic/monoamniotic: days 8-12
- monochorionic/monoamniotic conjoined: >13 days

47
Q

Pt is a 35yo presenting w/ dyspnea on exertion and LE edema that has worsened over the past several weeks. PMH includes episode of fever, runny nose, and myalgia -2mo ago. BP is 112/74, pulse 98. PE reveals JVD, bibasilar lung crackles, 2+ LE pitting edema. Most likely dx?

A

dilated cardiomyopathy (DCM) due to viral myocarditis —> weakened contractibility causes systolic dysfunction and volume overload

viral causes include coxsackievirus, adenovirus, influenza virus

other causes include (not limited to) alcohol, cocaine, Duchenne muscular dystrophy, sarcoidosis, amyloidosis, thiamine or selenium deficiency, peripartum

48
Q

locus heterogeneity vs allelic heterogeneity

A

locus heterogeneity: mutations at different genetic loci (DIFFERENT CHROMOSOMES) result in similar phenotypes - combining these would NOT produce phenotype

allelic heterogeneity: DIFFERENT MUTATIONS at the SAME genetic loci (ALLELE) cause similar phenotypes [seen with cystic fibrosis] - combining these WOULD produce phenotype

49
Q

26yo F, gravida 1 para 0, at 36 weeks gestation presents for routine prenatal visit. Pregnancy is uncomplicated, and pt has no symptoms. BP is 150/100mmHg. Urinalysis shows 2+ protein. Activity of which of the following is decreased in this patient?
a. endothelin
b. hCG
c. prolactin
d. thromboxane A2
e. vascular endothelial growth factor

A

e. vascular endothelial growth factor

pt has preeclampsia - defined as new onset HTN during pregnancy with proteinuria and/or signs of end-organ damage (headache, renal insufficiency), usually during 3rd trimester

abnormal spiral arteries cause chronic placental ischemia, which triggers release of anti-angiogenic factors —> these bind/decrease VEGF and placental growth factor —> widespread endothelial cell dysfunction

[endothelin and thromboxane A2 are vasoconstrictors - activity is increased]

50
Q

this fungus has only a mold form, with broad, ribbon-like hyphae and rare right-angle septations

A

Rhizopus - causes mucormycosis (lung disease) in immunocompromised patients

51
Q

what causes a retroverted uterus?

A

ectopic endometrial glands (endometriosis) —> intraperitoneal blood collection, which undergoes hemolysis and induces pelvic inflammation + adhesion formation

tissue adhesions involving utero-sacral ligaments causes fixed, retroverted uterus

52
Q

patients with 1+ episodes of mania =

A

Bipolar I: most patients have both manic and major depressive episodes, but depressive episodes are not required for dx

manic episodes can occur with our without psychotic features (delusions, hallucinations)… with, it’s called Bipolar I with psychotic features

different from primary psychotic disorders because psychosis only occurs DURING manic episodes (in primary, psychosis occurs in absence of mood symptoms)

53
Q

which bacteria releases a toxin that disrupts cellular membranes?

A

Clostridium perfringens - releases alpha-toxin, aka phospholipase C, which degrades membrane phospholipids

54
Q

6mo M presents w/ 2 week duration of cough and runny nose. Pt is unvaccinated. On PE, pt coughs intermittently and his face turns red. Lungs clear to auscultation. Dx?

A

Bordetella pertussis: gram neg. coccobacilli, secretes AB toxin + adenylate cyclase toxin + tracheal cytotoxin

causes 2-6 weeks of severe coughing spells w/ inspirations whoop and apnea/cyanosis, sometimes followed by emesis

tx = macrolide (azithromycin)

55
Q

what causes LV outflow tract obstruction in patients with hypertrophic cardiomyopathy?

A

hypertrophied interventricular septum causes abnormal systolic anterior motion of the anterior leaflet of the mitral valve

56
Q

what kind of drug is flunisolide?

A

inhaled glucocorticoid - used in treatment of persistent asthma and COPD with frequent exacerbations

57
Q

name a drug that causes bronchodilation by blocking Ca2+ influx into bronchial smooth muscle cells

A

nifedipine

58
Q

name a drug that causes bronchodilation by blocking phosphodiesterase activity, thereby increasing intracellular [cAMP]

A

methylxanthines such as theophylline and aminophylline

59
Q

name 3 bacteria that can cause necrotizing fasciitis

A
  1. Streptococcus pyogenes (Group A Strep)
  2. Staphyloccus aureus
  3. Clostridium perfringens

often polymicrobial though

60
Q

anterior displacement of the vertebral body (spondylolisthesis) can be caused by injury to the…

A

pars interarticularis at the posterior vertebral arch

spondylolysis = fracture of the pars interarticularis

61
Q

patients with maple syrup urine disease (MSUD) have a deficiency in an enzyme that requires which of the following?
a. arginine
b. cobalamin
c. pyridoxine
d. tetrahydrobiopterin
e. thiamine

A

MSUD: AR deficiency in branched-chain alpha-keto acid dehydrogenase complex

enzyme requires thiamine + lipoic acid + CoA + FAD + NAD

62
Q

for which step of vitamin D synthesis is sunlight necessary?

A

7-dehydrocholesterol (provitamin D3) —> cholecalciferol (Vit D3)

cholecalciferol is then converted to 25-hydroxyvitamin D3 (storage form) in liver, then to 1,25-hydroxyvitamin D (active form) in kidneys

63
Q

what is the function of lamellar bodies?

A

organelles in type II pneumocytes which store and release surfactant

64
Q

what arrhythmia does this describe: delayed repolarization of ventricular cardiomyocytes

A

torsade de pointes - form of polymorphic ventricular tachycardia

ECG shows wide QRS which oscillate in height and position

65
Q

what is first-line treatment for Pneumocystis pneumonia?

A

trimethoprim-sulfamethoxazole (usually curative)

66
Q

For which three enzymes of the TCA cycle is niacin required?

A

niacin = vitamin B3, precursor for NAD/NADP

  1. isocitrate dehydrogenase
  2. alpha-ketoglutarate dehydrogenase
  3. malate dehydrogenase
67
Q

name a pharmaceutical agent targeting TNF-alpha from each of the following categories:
a. chimeric monoclonal antibody
b. humanized monoclonal antibody
c. soluble receptor decoy protein

A

a. chimeric monoclonal antibody = infliximab

b. humanized monoclonal antibody = certolizumab (pegylated)

c. soluble receptor decoy protein = etanercept (fusion protein, links TNF-alpha receptor to Fc)

68
Q

what causes the “chloride shift”?

A

within RBC, carbonic anhydrase combines CO2 + H2O —> HCO3-

majority of CO2 produced in tissues is transported as bicarb (HCO3-)

excess bicarb is transferred out of RBC in exchange with chloride (replace negative charge)

for this reason, RBC have high Cl- content in venous blood (lots of HCO3- being sent out)

69
Q

sulfadiazine-pyrimethamine is first line for…

A

toxoplasmosis

70
Q

what is the role of LH and FSH in males?

A

LH – stimulates the release of testosterone from the Leydig cells of the testes

FSH – stimulates the release of inhibin B from the Sertoli cells in the seminiferous tubules

71
Q

Which class of drugs are associated with medication induced esophagitis?

[other than tetracyclines and NSAIDs/aspirin]

A

Bisphosphonates (alendronate, risedronate) – also associated with increased risk of osteonecrosis of the jaw and atypical femoral fractures

esophagitis causes dysphasia and burning pain in chest

72
Q

which viral infection will cause elevated lymphocytes + erythrocytes on CSF analysis?

A

herpes simplex virus (HSV) type 1: most common cause of sporadic encephalitis

CSF shows elevated lymphocytes + erythrocytes, normal glucose, high protein

elevated erythrocytes due to hemorrhagic inflammation of temporal lobes

73
Q

what parts of the body derive from neural crest cells? (8)

A
  1. neural ganglia (dorsal root ganglia, sympathetic/parasympathetic ganglia)
  2. adrenal medulla
  3. Schwann cells
  4. pia and arachnoid mater
  5. aorticopulmonary septum and endocardial cushions
  6. branchial arches (bones and cartilage)
  7. skull bones
  8. melanocytes
74
Q

what does it mean if bacteria turns MacConkey agar pink?

A

able to ferment lactose

75
Q

therapeutic use of aminocaproic acid?

A

antifibrinolytic agent, inhibits plasminogen activators and antiplasmin —> helps achieve hemostasis when fibrinolysis is the cause of bleeding

76
Q

for which blood disorders is desmopressin used?

A

desmopressin = ADH analog, treats diabetes insipidus

at high doses, desmopressin increases factor VIII activity in patients with hemophilia A and von Willebrand disease

77
Q

MOA of milrinone

A

phosphodiesterase 3 (PDE-3) enzyme inhibitor

PDE-3 degrades cAMP, inhibition increases cardiac contractibility (positive inotropy) + vasodilation

78
Q

1 day after receiving an intramuscular injection of benzathine penicillin G for a syphilis infection, a pt begins to experience fever, chills, headache, and myalgias - describe the pathology that caused these symptoms

A

Jarisch-Herxheimer reaction: systemic inflammatory response occurring 6-48h after initiating treatment for spirochete infection (syphilis, Lyme disease, leptospirosis)

due to rapid lysis of spirochetes that spills bacterial lipoproteins

79
Q

Staphylococcus aureus strains which have required the mecA gene are resistant to which antibiotics? (3)

A

mecA gene encodes for penicillin-binding protein (PBP) 2a, which has a low affinity for beta-lactams

therefore, resistant to oxacillin, methicillin, and cephalosporins

80
Q

what is the effect of cystic fibrosis on the pancreas?

A

ductal obstruction by thickened secretions causes buildup of pancreatic enzymes —> pancreatic autolysis, which results in nonselective loss of alpha and beta cells (pancreatogenic diabetes, aka CF-related diabetes)

81
Q

failure of which developmental process causes cleft lip?

A

failed fusion of the L or R maxillary prominence with the intermaxillary segment in early gestation

82
Q

what is the effect of opiates on ion conductance?

A

activate presynaptic mu receptors on primary afferent neuron —> closure of voltage-gated Ca2+ channels and reduced excitatory NT release

bind mu receptors on postsynaptic membranes —> opening of K+ channels and membrane hyperpolarization

83
Q

patient w/ emphysema symptoms + signs of cirrhosis =

A

alpha-1 antitrypsin deficiency: AD deficiency leads to unchecked elastase activity

obstructive pattern on PFT (decreased FEV1/FVC ratio, decreased DLCO)

intrahepatocyte accumulation of polymerized AAT molecules causes cirrhosis (granules of un-secreted AAT seen within periportal hepatocytes, stained with PAS)

84
Q

brain autopsy of a patient w/ HIV shows thick, gelatinous exudate in the base of the brain and marked ventriculomegaly w/ frontal lobe infarcts =

A

tuberculosis meningitis: causes formation of thick, gelatinous exudate in the base of the brain; cerebral vasculitis; and hydrocephalus

frequently presents with subacute, slowly progressive N/V, fever, CN deficits, and strokes

85
Q

which hormone is responsible for paraneoplastic hyperthyroidism in patients w/ testicular masses?

A

choriocarcinomas and germ cell tumors produce hCG

hCG, TSH, FSH, and LH have identical alpha subunits

hCG and TSH share significant sequence homology —> hCG can activate TSH receptors

86
Q

name 3 alpha-1 blockers that can treat both BPH and HTN

A
  1. doxazosin
  2. prazosin
  3. terazosin
87
Q

during bacterial DNA replication, _____ functions to remove RNA primers (via 5’ to 3; exonuclease activity) and replace them with DNA (via 5’ to 3’ polymerase activity)

A

during bacterial DNA replication, DNA polymerase I functions to remove RNA primers (via 5’ to 3; exonuclease activity) and replace them with DNA (via 5’ to 3’ polymerase activity)

88
Q

which muscles of mastication depress the mandible (open the jaw), and may spasm in patients with anterior dislocation of the jaw?

A

lateral pterygoid

89
Q

which 2nd gen. antipsychotic has superior efficacy in treatment-resistant schizophrenia? What side effect is of particular concern?

A

clozapine - requires monitoring of absolute neutrophil count due to risk of neutropenia and agranulocytosis

also associated with weight gain and metabolic effects

90
Q

which cardiac abnormality is associated with increased risk of intracranial hemorrhage?

A

coarctation of the aorta - patients have chronic HTN, high risk for aortic aneurysms (dissection, rupture) and intracranial hemorrhage

pathology - thickened tunica media of aortic arch, associated with Turner syndrome or bicuspid aortic valve

91
Q

place the following in order of increasing duration of action:
a. NPH
b. aspart
c. regular insulin
d. glargine
e. lispro
f. detemir

A
  1. aspart/lispro/glulisine - 45-75 minutes
  2. regular insulin - 5-8 hours (peak 2-4 hours)
  3. NPH - 2x/day (peak 4-6 hours)
  4. detemir - 1/day (<24 hours)
  5. glargine - 1/day (24 hours)
92
Q

which of the following would be best for lowering BP without worsening ECG abnormalities, and why?
a. diltiazem
b. metoprolol
c. nifedipine
d. sotalol
e. verapamil

A

c. nifedipine (dihydropyridine) - primarily cause arterial vasodilation, with little effect on cardiac contractibility or conduction (also includes amlodipine, felodipine)

93
Q

overuse of the _____ muscle can cause avulsion and fragmentation of the tibial tubercle in children

A

overuse of the quadriceps femoris muscle can cause avulsion and fragmentation of the tibial tubercle in children

dx - Osgood-Schlatter disease

94
Q

which immune cells are activated by superantigens such as TSST (toxic shock syndrome toxin)?

A

superantigens interact with MHC on APC (macrophages) and with the variable region of T lymphocyte receptor —> widespread, nonspecific activation of T lymphocytes

this causes release of IL-2 from T cells and IL-1/TNF from macrophages

95
Q

autoantibodies against renal podocyte antigens =

A

membranous nephropathy - nephrotic (proteinuria) syndrome

96
Q

which of the following antibiotics provides the best anaerobic coverage?
a. azithromycin
b. ceftriaxone
c. ciprofloxacin
d. piperacillin-tazobactam
e. vancomycin

A

d. piperacillin-tazobactam: piperacillin is extended-spectrum penicillin, tazobactam is beta-lactamase inhibitor

many anaerobic bacteria (such as Bacteroides) produce beta-lactamase

other beta-lactamase inhibitors include clavulanic acid and sulbactam

97
Q

which drug is given following subarachnoid hemorrhage to prevent ischemia due to cerebral vasospasm?

A

nimodipine: Ca2+ blocker

arterial vasospasm is most common complication following SAH, due to release of vasoconstrictive factors from damaged erythrocytes in subarachnoid space

98
Q

diabetic patient with black necrotic eschar in nasal cavity =

A

mucormycosis (Mucor or Rhizopus) - infection ascends nasal passage to sinuses/orbit and sometimes to brain

histology shows ribbon-like broad non-septate hyphae with right-angle branching

99
Q

which components of the coagulation pathway (2) are inhibited by heparins (LMW)?

which components are affected by vitamin K antagonists? (4)

A

heparin - Xa and IIa (thrombin)

vit K antagonists (warfarin) - VII, IX, X, II

100
Q

MOA bivalirudin

A

direct thrombin (IIa) inhibitor

101
Q

Primigravida at 37w gestation presents with constant, excruciating abdominal pain and sudden vaginal bleeding for past 3 hours. BP is 160/100 and pulse is 118. Uterus is firm and tender. Fetal heart tracing shows baseline of 105/min with no variability. What is the most likely cause of bleeding?

A

third trimester painful vaginal bleeding + tender, firm uterus = abruptio placentae (premature separation of placenta from uterus prior to fetal delivery)

risk factors = HTN, preeclampsia, abdominal trauma, cocaine, tobacco

102
Q

autoantibodies to desmoglein =

A

pemphigus vulgaris

103
Q

what do anti-mitochondrial antibodies vs anti-smooth muscle antibodies indicate?

A

anti-mitochondrial Abs = primary biliary cholangitis (cholestasis + abnormal hepatic enzyme levels)

anti-smooth muscle Abs = autoimmune hepatitis

104
Q

what are anti-Jo-1 antibodies?

A

anti-tRNA synthetase

seen in polymyositis and dermatomyositis

105
Q

MOA dobutamine (include biochemical pathway)

A

predominantly beta1 agonist + some weak beta2 and alpha1 agonism

stimulation of beta1 causes Gs protein GTP binding —> increased cAMP, which causes Ca2+ channel activation and increased contractibility

+ inotropy and chronotropy

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