UWorld Test Review 7 Flashcards

1
Q

name a drug that acts by inhibiting cyclic nucleotide phosphodiesterase

A

milrinone: phosphodiesterase inhibitor, increases cAMP levels —> vasodilation and positive inotropy

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2
Q

which drugs act by activating soluble guanylate cyclase?

A

nitrates: provide free radical NO, which activates guanylate cyclase and increases cGMP —> dephosphorylation of myosin light chains causes vascular smooth muscle relaxation

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3
Q

what do tumor cells of small cell carcinoma express?

A

small cell carcinoma is of neuroendocrine origin - cells express neural cell adhesion molecule (NCAM), chromogranin, synaptophysin

associated paraneoplastic syndromes = SIADH, Cushing syndrome, LEMS

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4
Q

which drugs are used to treat patent ductus arteriosus (PDA)?

A

NSAIDS (indomethacin, ibuprofen) - inhibit cyclooxygenase, which normally synthesizes prostaglandins (like PGE2, which keeps PDA open)

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5
Q

which component of the coagulation cascade performs each of the following functions?
a. anchoring platelets to subendothelial collagen
b. cleaving vWF multimers
c. cross-linking fibrin molecules
d. linking factors IXa and X to create activated X (Xa)

A

a. anchoring platelets to subendothelial collagen = vWF
b. cleaving vWF multimers = ADAMTS13
c. cross-linking fibrin molecules = factor XIIIa
d. linking factors IXa and X to create activated X (Xa) = factor VIII

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6
Q

MOA emicizumab

A

emicizumab = bispecific mAb, mimics normal function of Factor VIII

one site binds Factor IXa, other binds Factor X - brings them into close proximity so IXa can cleave X into Xa (normal function of Factor VIII)

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7
Q

which of the following agents causes slowly progressive, rather than rapidly progressing, CNS infection?
a. cytomegalovirus
b. herpes simplex virus
c. measles virus

A

c. measles virus - subacute, sclerosing panencephalitis —> slowly worsening neurologic symptoms and multifocal, enhancing, white matter lesions

a. cytomegalovirus - CMV encephalitis —> rapidly progressive altered mental status and focal neuro deficits; highly inflammatory, causing enhancing lesions

b. herpes simplex virus - HSV encephalitis —> rapid onset (<1week) of focal neuro deficits and altered mental status; enhancing temporal lobe lesion with mass effect

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8
Q

what is the role of Rb protein vs p27 protein in the cell cycle?

A

p27 protein acts during G1 phase to inhibit cyclin-dependent kinases

Rb protein prevents transition from G1 to S phase when it is dephosphorylated (active)

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9
Q

how do levels of sex hormone-binding globulin (SHBG) change with aging?

A

increased hepatic synthesis of SHBG

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10
Q

which of the following can be used to increase uterine tone?
a. indomethacin
b. terbutaline
c. misoprostol
d. magnesium sulfate

A

c. misoprostol: PGE1 agonist (Gq)

DECREASE uterine tone (stop premature contractions):
a. indomethacin - inhibits cyclooxygenase, therefore also prostaglandin production
b. terbutaline - beta2 agonist (Gs)
d. magnesium sulfate - inhibits L-type Ca2+ channels [nifedipine works this way also]

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11
Q

which of the following therapies for supraventricular arrhythmias causes flushing and burning chest as a side effect?
a. adenosine
b. amiodarone
c. digoxin
d. ibutilide
e. verapamil

A

a. adenosine - flushing, hypotension, bronchospasm (burning chest), AV block

b. amiodarone (class III) - hepatic toxicity, thyroid dysfunction, photodermatitis, blue/grey skin color, pulmonary fibrosis
c. digoxin - bradycardia, N/V, yellow vision, confusion
d. ibutilide (class III) - QT prolongation (torsades de pointes)
e. verapamil (class IV) - bradycardia, constipation

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12
Q

what kind of acid-base imbalance does salicylate toxicity cause?

A

stimulates central respiratory drive —> primary respiratory alkalosis

also disrupts cellular metabolism (inhibit TCA, uncouple ox/phos) —> primary anion gap metabolic acidosis

net effect is mixed acid-base disturbance and blood pH may be within normal range

presents as fever + tinnitus + tachypnea

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13
Q

episodic flushing, secretory diarrhea, and wheezing + plaque-like deposits of fibrous tissue on R-sided endocardium (causing tricuspid regurgitation) =

A

carcinoid syndrome: neuroendocrine tumors in distal small intestine/ proximal colon, secrete histamine, serotonin, vasoactive intestinal peptide

serotonin stimulates fibroblast growth —> pathognomonic plaque-like deposits of fibrous tissue on endocardium in R heart

urinary labs show elevated 5-hydroxyindoleacetic acid (5-HIAA), which is end produce of serotonin metabolism

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14
Q

This enzyme is blocked by some chemotherapy agents used to treat lymphocyte-derived cancers. Inherited mutations of this enzyme also causes the autosomal recessive form of SCID. What is?

A

adenosine deaminase (ADA) - inhibition/absence is lymphocytotoxic because these cells are very mitotically active

[cladribine = ADA inhibitor]

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15
Q

with which cancers are the following proto-oncogenes associated?
a. BRAF
b. HER1
c. RET
d. MYC

A

a. BRAF - melanoma
b. HER1 - squamous cell lung cancer
c. RET - medullary thyroid cancer, pheochromocytoma
d. MYC - neuroblastoma, small cell lung cancer

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16
Q

what is the CSF findings in bacterial vs viral meningitis?

A

bacterial: elevated opening pressure, neutrophils, decreased glucose, elevated protein

viral: normal glucose, mildly elevated protein (<150mg/dL), leukocyte count <250

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17
Q

name 2 non-nucleoside reverse transcriptase inhibitors (NNRTIs)

A
  1. nevirapine
  2. efavirenz
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18
Q

which 4 classes of drugs are associated with gout due to reduced uric acid excretion?

A
  1. diuretics - hydrochlorothiazide, furosemide
  2. salicylates - low dose aspirin
  3. ACE inhibitors - lisinopril
  4. cyclosporine
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19
Q

acute vision loss/ metamorphopsia + grey-green subretinal membrane on funduscopy =

A

wet age-related macular degeneration: retinal neovascularization due to VEGF

tx: ranibizumab/bevacizumab (VEGF inhibitors) + smoking cessation

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20
Q

what is the MOA of the drug used to treat trigeminal neuralgia?

A

trigeminal neuralgia (tic douloureux): episodic, severe, unilateral, electric shock-like pain in distribution of CN V

first-line tx = carbamazepine: inhibits Na+ channels

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21
Q

why are patients undergoing chemotherapy more at risk for Candida infection specifically?

A

Neutrophils are the most important immune cell in the protection against invasive candida – patients undergoing chemotherapy develop neutropenia

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22
Q

in which patients can pulsus paradoxus be seen? (4)

A
  1. cardiac tamponade - most commonly

also severe asthma, COPD, constrictive pericarditis

Pulsus paradoxus = decrease in systolic blood pressure greater than 10mmHg with inspiration

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23
Q

what differentiates Klebsiella pneumoniae and Legionella pneumophila, respectively, from other causes of pneumonia?

A

both important causes of nosocomial (hospital-acquired) pneumonia, both show alveolar opacification on CXR

Klebsiella - characterized by hemorrhagic lung necrosis (currant-jelly sputum) and early abscess formation

Legionella - characterized by pulmonary symptoms + febrile gastroenteritis

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24
Q

what are the most common viral (3) and bacterial (3) causes of acute exacerbation of COPD (AECOPD)?

A

viral: rhinovirus, influenza, RSV

bacterial: Haemophilus influenzae (nontypeable), Moraxella catarrhalis, Streptococcus pneumoniae

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25
Q

what is elevated in the following inherited hyperlipoproteinemias?
a. familial chylomicronemia (type I)
b. familial hypercholesterolemia (type II)
c. familial dysbetalipoproteinemia (type III)
d. familial hypertriglyceridemia (type IV)

A

a. familial chylomicronemia (type I): LPL and ApoC-2 defect —> chylomicrons

b. familial hypercholesterolemia (type II): LDLR and ApoB-100 defect —> LDL

c. familial dysbetalipoproteinemia (type III): ApoE defect —> chylomicron + VLDL remnants

d. familial hypertriglyceridemia (type IV): polygenic —> VLDL

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26
Q

child w/ restlessness and jerking movements 3 months after sore throat =

A

Sydenham chorea: hyperkinetic extrapyramidal movement disorder; neuro manifestation of acute rheumatic fever that occurs 1-8 months after group A beta-hemolytic Strep infection

caused by delayed onset autoimmune rxn against basal ganglia (molecular mimicry)

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27
Q

where do descending aortic dissections typically originate?

A

close to the left subclavian artery (last artery branching off aortic arch)

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28
Q

anthracycline chemotherapy agents may cause [dilated/restrictive] cardiomyopathy, while radiation therapy may cause [dilated/restrictive] cardiomyopathy

A

anthracycline chemo (doxorubicin, daunorubicin) —> dilated cardiomyopathy

radiation —> restrictive cardiomyopathy

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29
Q

which 3 drug classes reduce mortality in patients with reduced ejection fraction HF by reducing cardiac remodeling?

A
  1. ACE inhibitors (lisinopril)
  2. ARBs (losartan)
  3. mineralocorticoid receptor antagonists (spironolactone, epleronone)

these are the major ones, but also note beta blockers and SGLT2 inhibitors also have mortality benefits

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30
Q

MOA of evolocumab and alirocumab

A

PCSK9 inhibitors - decrease LDL receptor degradation

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31
Q

patient exhibiting disinhibition, loss of empathy, and compulsive behaviors + accumulation of ubiquitinated TDP-43 =

A

frontotemporal dementia (FTD) - degeneration of prefrontal cortex due to accumulation of Tau and TDP-43 (transcription inhibitor or DNA repair protein)

[TDP-43 also see in ALS]

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32
Q

the intestinal absorption of what other amino acids besides cystine is decreased in patients with cystinuria?

A

COLA: Cystine (cysteine homodimer forming disulfide bonds) + Ornithine + Lysine + *Arginine**

these dibasic amino acids share a common transporter in the GI lumen and kidneys (in cystinuria, this transporter is defective)

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33
Q

which 2 enzymes are released from mast cells during anaphylaxis?

A

histamine and tryptase (specific to mast cells)

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34
Q

which molecules (3) stimulate the JAK-STAT pathway?

A
  1. growth hormone
  2. cytokines (interferon)
  3. hematopoietic growth factors (EPO, G-CSF)
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35
Q

which nerves are found in the anterior, lateral, and deep posterior compartments of the leg?

A

anterior compartment - deep peroneal nerve
lateral compartment - superficial peroneal nerve
deep posterior compartment - tibial nerve

superficial posterior compartment - no major nerves (big area, mostly made of calf muscles)

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36
Q

Pt presents with fever. They returned from a mission trip 3 weeks ago and developed a rising fever. A week following, they began experiencing abdominal pain and noticed a rash on their trunk and abdominal. This week, in your office, you note hepatosplenomegaly, and labs show mild normocytic anemia. What was the route of transmission of the patient’s infection?

A

dx = typhoid fever (Salmonella Typhi or Paratyphi): gram neg. enteric pathogens which only reside in GI tract of humans

invades enterocytes, enters GI submucosa, impairs respiratory burst via capsular antigen, replicates unchecked within macrophages

ROT is fecal-oral - travels to developing countries are at risk if not vaccinated with typhoid vaccine

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37
Q

what is the mechanism by which testicular germ cell tumors cause gynecomastia?

A

secrete hCG, which suppresses testosterone production in Leydig cells while increasing aromatase activity —> increased conversion to estradiol

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38
Q

diarrhea and flushing can be caused by a _____-secreting tumor

A

serotonin (5-HT) -secreting tumor (carcinoid syndrome) - rare, derived from neuroendocrine cells of GI tract

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39
Q

clinical use of calcipotriene

A

calcipotriene: vitamin D analog used to treat plaque psoriasis

inhibits T cell and keratinocyte proliferation, stimulates keratinocyte differentiation

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40
Q

clinical use of topical salicylic acid

A

salicylic acid: keratolytic agent, increases sloughing of virus-infected epidermal cells

used to treat common warts

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41
Q

clinical use of silver nitrate

A

silver nitrate: coagulates cellular proteins to form an eschar

used to cauterize wounds to stop bleeding (ex, epistaxis) and to remove excess granulation tissue

42
Q

cystic hygromas are associated with which 2 genetic disorders?

A
  1. Turner syndrome
  2. Down syndrome

comprised of lymphatic cysts lined by thin endothelium, present at birth, found on posterior neck and lateral chest wall

43
Q

what stage of maturity of RBC do the following strains of Plasmodium infect?
a. P falciparum
b. P vivax
c. P ovale
d. P malariae

A

a. P falciparum - all ages of RBC
b. P vivax - reticulocytes
c. P ovale - reticulocytes
d. P malariae - old RBC

44
Q

which lymph nodes drain the testis, penis, and scrotum, respectively?

A

testis - para-aortic nodes

penis - deep inguinal nodes

scrotum - superficial inguinal nodes

45
Q

what are symptoms of salicylate toxicity? (5)

A

aka aspirin intoxication - causes primary respiratory alkalosis + primary metabolic acidosis with anion gap (lactate)

symptoms: tinnitus, tachypnea, hyperthermia, vomiting, altered mental status

46
Q

STI causing painful ulcers with ragged borders and grey exudate

A

Haemophilus ducreyi chancroids

47
Q

genital vesicular rash + positive Tzanck smear =

A

genital herpes simplex virus (HSV): causes recurrent, episodic symptoms due to latent virus within dorsal root ganglia

prevent recurrence with daily oral valacyclovir (preferred), acyclovir, or famciclovir - suppress viral multiplication during reactivation (do not eliminate latent form)

48
Q

which nerve(s) are stimulated by carotid sinus hypersensitivity?

A

carotid sinus = dilation of the internal carotid artery just above bifurcation of common carotid artery

afferent limb = glossopharyngeal nerve (CN IX), activated in carotid sinus

efferent limb = vagus nerve (CN X), firing from aortic arch baroreceptors

49
Q

first-line non-stimulant for treatment of ADHD

A

atomoxetine: NE reuptake inhibitor, lacks abuse potential

50
Q

which 2 enzymes inactivate 6-mercaptopurine (6-MP)?

A

6-MP (prodrug = azathioprine): purine analog that act as false nucleotides to disrupt DNA/RNA synthesis, used to treat autoimmune disease/ organ transplant rejection/ some cancers

metabolized via xanthine oxidase and thipurine methyltransferase (TPMT)

51
Q

which muscles are worked by Kegel exercises?

A

levator ani muscle complex (iliococcygeus, pubococcygeus, puborectalis)

[don’t think detrusor muscle! this is overactive in urge incontinence and is a smooth muscle - can’t be voluntarily exercised!]

52
Q

which antihypertensive medications may cause peripheral edema and dizziness/light-headedness?

A

dihydropyridine Ca2+ channel blockers - amlodipine, nifedipine

53
Q

enhancer vs promoter sequences

A

enhancers: can be located up/down/within transcribed gene (can be far away) and increase rate of transcription

promoters: located just upstream of their associated gene and function to initiate transcription

54
Q

some patients are homozygous for an atypical plasma cholinesterase, resulting in paralysis that can last for hours following adminstration of ______

A

succinylcholine: depolarizing blocker used for rapid-sequence intubation due to its rapid onset (<1 minute)

duration of action is typically <10 mins, except for patients with cholinesterase mutation (breaks down succinylcholine) —> must be maintained on mechanical ventilation until spontaneous respirations resume

55
Q

which type of ovarian tumor looks like an oily cystic mass on gross examination?

A

struma ovarii: germ cell tumor composed mostly of mature thyroid tissue (endoderm), secretes thyroid hormone

histology shows thyroid follicles with colloid and surrounded by ovarian stroma

56
Q

actin within cells is anchored via integrin-mediated binding to _____ in the extracellular matrix

A

actin (in cytosol) is bound to integrin (transmembrane), which binds fibronectin, collagen, and laminin in the ECM

57
Q

erythema nodosum + hilar adenopathy + elevated ACE =

A

sarcoidosis: systemic inflammatory disorder of noncaseating granulomas

58
Q

what type of anticonvulsants are most appropriate for juvenile myoclonic epilepsy?

A

juvenile myoclonic epilepsy: generalized onset epilepsy causing brief, involuntary jerking movements during first hour of awakening (and provoked by lack of sleep)

tx = broad-spectrum anticonvulsants (valproate, levetiracetam)

59
Q

which type of hematoma presents with a lucid interval?

A

epidural hematoma: due to rupture of middle meningeal artery

60
Q

which conventional infection may cause metaphyseal erosions and periosteal inflammation of long bones?

A

congenital syphilis caused by Treponema pallidum

also causes focal necrosis of umbilical cord, copious rhinorrhea (snuffles), desquamating rash involving palms/soles, fissures near orifices, jaundice, anemia

61
Q

what is the antidote for poisoning with the toxin that causes garlic breath?

A

arsenic poisoning: found in pesticides/insecticides or well water, binds sulfhydryl groups —> impaired cellular respiration via inhibition of pyruvate dehydrogenase (disrupted gluconeogenesis and glutathione metabolism)

—> vomiting, severe watery diarrhea, delirium, hypotension (dehydration), QT prolongation, garlic breath

antidote = dimercaprol (chelating agent)

62
Q

preferred chelating agent for iron overdose or overload due to multiple blood transfusions

A

deferoxamine

63
Q

methylene blue is antidote for…

A

methemoglobinemia - causes grey/blue skin, SOB, “chocolate” colored blood

methylene blue acts as artificial electron transporter for reduction of methemoglobin through NADPH pathway

64
Q

which tumors occur with each type of MEN syndrome? (3 each)

A

MEN1: parathyroid adenoma/hyperplasia + pituitary tumor + pancreatic tumor [3 P’s]

MEN2A: medullary thyroid cancer (calcitonin) + pheochromocytoma (adrenal medulla) + parathyroid hyperplasia [medullary tumors]

MEN2B: medullary thyroid cancer (calcitonin) + pheochromocytoma (adrenal medulla) + mucosal neuromas/ marfanoid habitus

65
Q

oral thrush (candidiasis) in a patient with no other risk factors for thrush (dentures, inhaled corticosteroid use, etc) should raise suspicion for…

A

HIV infection

66
Q

what is seen on mount microscopy with bacterial vaginosis infection?

A

[due to Gardnerella vaginalis]

microscopy shows clue cells: squamous epithelial cells covered with bacteria

there will be increase in vaginal pH + fishy-smelling discharge

67
Q

MOA flutamide

A

non-steroid anti-androgen - acts as competitive inhibitor of testosterone receptors

used in combination with long-acting gonadotropin-releasing hormone agonists for treatment of prostate cancer

68
Q

MOA of vecuronium/rocuronium vs succinylcholine

A

vecuronium and rocuronium = non-depolarizing neuromuscular blocking agents, competitive antagonists of nicotinic ACh receptors

succinylcholine = depolarizing neuromuscular blocking agent, competitive agonist of nicotinic ACh receptors - persistent depolarization leads to desensitization of motor end plate

69
Q

secreted in response to hyperphosphatemia, reduces intestinal absorption and renal reabsorption of phosphate

A

fibroblast growth factor 23 (FGF23)

70
Q

Menkes vs Wilson’s Disease

A

Menkes disease is an X-linked disorder (ATP7A) of copper metabolism resulting in growth failure and severe neurodegenerative disease in early childhood.

Wilson’s disease is an autosomal recessive disorder (ATP7B) of copper metabolism resulting in hepatic cirrhosis and neuronal degeneration.

71
Q

which vasculitis diseases do the following represent?
a. granulomatous inflammation of large arteries
b. necrotizing inflammation of medium-sized arteries
c. segmental inflammation of medium-sized arteries and veins

A

a. granulomatous inflammation of large arteries = giant cell (temporal) arteritis if 50+; Takayasu arteritis if young female

b. necrotizing inflammation of medium-sized arteries = polyarteritis nodosa

c. segmental inflammation of medium-sized arteries and veins = thromboangiitis obliterans (Buerger disease) - always seen with heavy smoking

72
Q

which intracellular pathway is activated by growth hormone?

A

JAK-STAT

73
Q

what is a physical exam finding of testicular torsion?

A

scrotal edema + erythema + absent cremasteric reflex (cremaster muscle lies within spermatic cord)

testicle is also high-riding due to cord shortening with rotation

74
Q

which drug class may cause syncope in elderly patients with underlying age-ratted degeneration of the conduction system?

A

acetylcholinesterase inhibitors (donepezil, rivastigmine) - can precipitate bradycardia and AV block, reducing CO and manifesting as syncope

75
Q

retroverted uterus =

A

endometriosis - retroverted uterus due to scarring from continues cyclic shedding of ectopic endometrial tissue that has no outlet

76
Q

what is the mechanism by which hepatitis B virus causes liver injury?

A

HepB virus does not have cytotoxic effect itself - presence of HBsAg and HBcAg on cell surface stimulates host cytotoxic CD8+ T cells to destroy infected hepatocytes

77
Q

barking cough =

A

croup (parainfluenza virus) - causes edema of proximal trachea —> inspiratory strider + hoarseness + barking cough

X-ray will show steeple sign (subglottic narrowing)

78
Q

during remodeling phase of wound healing, matrix ________ facilitate degradation of ECM proteins and replacement of type ____ collagen to type ___ collagen

A

during remodeling phase of wound healing, matrix metalloproteinases facilitate degradation of ECM proteins and replacement of type III collagen to type I collagen (cross-linked, better tensile strength)

this leads to flattening of raised scars

79
Q

temporomandibular joint disorder (TMD) causes hypersensitivity of which nerve?

A

temporomandibular joint disorder (TMD): jaw misalignment, jaw clenching, teeth grinding, hypersensitivity to mandibular nerve (CN V3) (contributes sensory innervation to external auditory canal)

—> dull wax/waning face/jaw pain (worse with chewing), clicking/popping noises with jaw movement, ear pain/stuffiness, tinnitus

80
Q

dry tap bone marrow + nucleated RBC and dacrocytes (tear-drop cells) on peripheral smear =

A

primary myelofibrosis: clonal expansion of megakaryocytes, which secrete TGF-beta, stimulating bone marrow fibroblasts to fill space with collagen

bone marrow aspiration is dry, but bone marrow biopsy shows marked fibrosis with clusters of megakaryocytes

81
Q

deficiency of which vitamin can cause ataxia, loss of proprioception, hyporeflexia, myopathic, weakness, and hemolytic anemia?

A

vitamin E - responsible for preventing oxidative damage

deficiency via fat malabsorption (cystic fibrosis, pancreatitis, cholestasis) or genetic via abetalipoproteinemia

82
Q

28 year old woman with recent episode of hemoptysis. Patient has had ongoing vagina bleeding after uncomplicated vagina delivery nine weeks ago. Has not resumed sexual intercourse. On PE, patient’s uterus is enlarged and the adnexa are normal. Labs show markedly increased beta hCG levels. Chest radiograph shows multiple bilateral lung nodules. Diagnosis?

A

gestational choriocarcinoma: malignant tumor arising from the trophoblast, most commonly preceded by a normal pregnancy, but can follow any pregnancy (molar, ectopic, abortive)

Tumor causes vaginal bleeding, uterine enlargement, very high beta hCG levels

Choriocarcinoma is aggressive and has hematogenous spread - lungs are most common site of distal metastasis

Histology shows proliferation of mononuclear cytotrophoblast and multinucleate synctiotrophoblasts with no villi

83
Q

What kind of acid base disturbance is caused by chronic kidney disease?

A

anion gap metabolic acidosis with respiratory compensation due to uremia (elevated BUN)

84
Q

which pediatric abdominal wall defects do the following describe?
a. incomplete closure of the umbilical ring.
b. Incomplete recanalization of the fetal intestinal tract
c. Incomplete rotation of the midgut in utero.
d. Failure of the extraembryonic got to return to the abdominal cavity.
e. Persistent processes vaginalis.

A

a. incomplete closure of the umbilical ring = congenital umbilical hernia (associated with Down’s)

b. Incomplete recanalization of the fetal intestinal tract = duodenal atresia (associated with Down’s)

c. Incomplete rotation of the midgut in utero = malrotation, which may lead to volvulus (intestinal torsion)

d. Failure of the extraembryonic gut to return to the abdominal cavity = omphalocele

e. Persistent processes vaginalis = indirect inguinal hernia

85
Q

Which of the following physiologic changes in kidney function would be seen in a patient with hypovolemic shock?
a. Decreased chloride reabsorption.
b. Decreased urine osmolarity
c. Increased renal blood flow.
d. Increased urea reabsorption.

A

d. Increased urea reabsorption.

compensatory mechanisms for hypovolemia include activation of the RAAS system and increased ADH release —> increased renal sodium, chloride, water, and urea reabsorption with increased potassium excretion

86
Q

______ infection causes the hepatocellular cytoplasm to fill with _____ surface antigen, resulting in the appearance of homogenous, pale eosinophilic (pale pink) cytoplasm (ground-glass hepatocyte)

A

Hepatitis B - chronic infection causes accumulation of hep B surface antigen

pale pink (eosinophilic) inclusions are high specific for Hep B

87
Q

patient with very flexible body and siblings who also have flexible bodies = inherited mutation in which of the following proteins?
a. collagen.
b. Elastin.
c. fibrillin 1
d. Hyaluronic acid.
e. Laminin.
f. Proteoglycan.

A

a. collagen.

dx = Ehrler’s Danlos syndrome: hypermobile joints and overelastic skin due to deficiencies of lysyl hydroxylase and procollagen peptidase enzymes responsible for collagen synthesis

Collagen consists of three polypeptide alpha chains held together by hydrogen bond to form a triple helix (tropocollagen) - lysyl oxidase forms covalent bonds between individual tropocollagen molecules, generating mature collagen fibers

88
Q

22-year-old woman with six month history of increasing neck and low back pain that is most severe in the morning. Pain improves as the day passes. PE shows tenderness over lumbosacral area and at the insertion site of the Achilles tendon. Regulation of which cytokine is most likely responsible? What is the diagnosis?

A

ankylosing spondylitis: increased production of IL-17, TNF-alpha, prostaglandins (increased risk with HLA-B27)
[remember B27 —> high IL-17]

—> inflammatory back pain, enthesitis (tenderness at tendon insertions), dactylitis, uveitis

rx = NSAIDS (ibuprofen, naproxen), anti-TNFalpha (etanercept, infliximab), anti-IL17 (secukinumab)

89
Q

name two long acting beta-2 agonists

A
  1. Salmeterol.
  2. Formoterol.

Used for maintenance therapy in COPD or with inhaled corticosteroids in asthma

Have lipophilic side chains, which allows them to attach to the plasma membrane and diffuse laterally across to the beta2 receptor —> extended duration of action, but slow onset of action

90
Q

25-year-old woman with newly diagnosed seizures comes to ED with fever and skin rash. She was started on phenytoin 4 weeks ago. There is diffuse confluent it erythema involving 60% of the body, palpable, generalized lymphadenopathy, and symmetrical facial swelling. Oral mucosa is normal. Which of the following laboratory findings is most likely?
A. Anti-neutrophils cytoplasmic antibodies.
B. Cryoglobulinemia.
C. Eosinophilia
d. Microangiopathic hemolytic anemia.

A

C. Eosinophilia

dx = DRESS syndrome (drug reaction with eosinophilia and systemic symptoms): occurs 2 to 8 weeks after exposure to high risk drugs, such as anticonvulsants (phenytoin, carbamazepine), allopurinol, sulfonamides, vancomycin

Patients develop fever, generalized lymphadenopathy, facial edema, diffuse skin rash, internal organ dysfunction, eosinophilia

91
Q

abnormal separation of the dorsal and ventral foregut =

A

esophageal atresia (with or without tracheoesophageal fistula) - causes respiratory distress + choking with feeds

dorsal foregut = GI tract
ventral foregut = respiratory tract

92
Q

newborn with respiratory distress + unilateral decreased breath sounds + scaphoid abdomen + cystic structures on CXR =

A

Congenital diaphragmatic hernia: failure of the pleuroperitoneal folds to close —> abnormal communication between the thorax and abdomen

Compression of the developing lung causes pulmonary hyperplasia

CXR shows mediastinal shift and thoracic bowel loops, which appear as cystic, fluid filled structures

93
Q

Injections in which region of the butt have a high risk of injuring the superior gluteal nerve, resulting in _____ weakness and Trendelenburg gait?

A

Injections in the superomedial quadrant of the butt have a high risk of injuring the superior gluteal nerve, resulting in gluteus medius weakness and Trendelenburg gait (hip drop on contralateral/unaffected side)

injections should be placed in superior-lateral quadrant

94
Q

abnormal bleeding in a patient with end stage renal disease due to type one diabetes mellitus is most likely due to…

A

uremia - impairs platelet aggregation and adhesion, resulting in a qualitative platelet disorder characterized by prolonged bleeding time with normal platelet count, PT, and PTT

95
Q

what are the steps (and mediators of each) of leukocyte migration? (5)

A
  1. margination - via vascular leakage
  2. rolling - via selectins (E/P)
  3. activation - via inflammatory cytokines
  4. tight adhesion/ crawling - via integrins (LFA-1, ICAM-1)
  5. transmigration - via PECAM-1 (adhesion molecule)
96
Q

which 2 drugs for hyperlipidemia decrease production of VLDL?

A
  1. fibrates - activate PPAR-alpha, decreasing VLDL production and increasing LPL activity
  2. fish oil - decrease VLDL and apolipoprotein B production
97
Q

what is the cause of duodenal vs intestinal (midgut) atresia?

A

duodenal atresia - failure of recanalization

midgut atresia (jejunum, ileum, proximal colon) - vascular occlusion (SMA)

98
Q

CSF shows normal glucose + marginally elevated protein + lymphocytic predominance =

A

aseptic meningitis - usually viral, and most commonly caused by enterovirus

99
Q

what is the most common cause of viral meningitis?

A

enterovirus - coxsackievirus, echovirus, poliovirus

CSF will show normal glucose + elevated protein + lymphocytes

100
Q

function of muscle spindles vs Golgi tendon organs

A

muscle spindles (intrafusal muscle fibers): connected in parallel with extrafusal fibers, innervated by group Ia and II sensory axons, sensitive to changes in muscle length

Golgi tendon organs: located at junction of muscle and tendon, innervated by group Ib sensory axons, connected in series with extrafusal fibers, sensitive to changes in force