UWorld_4.5

Question 1

Cardiac consequences of chronic arteriovenous fistula

Answer 1

• acutely: decreased TPR ==> increased CO and increased venous return
• over time ==> increased sympathetic nervous system ==> increased cardiac contractility, vascular tone, and circulating blood volume

Question 2

Characteristics of Paget Disease of the Bone

Answer 2

• problem w/overactive osteoclasts
• osteoclasts originate from hematopoietic progenitor cells
• RANK-L and M-CSF play an important role in osteoclast differention

Question 3

Presentation of HepB

Answer 3

• “serum-like sickness”
• malaise, fever, skin rash, pruritis, lymphadenopathy and joint pain
• anorexia, nausea, jaundice and RUQ pain may ensue
• ALT > AST + bilirubin, alk phos
• vs. Hep C = mild, usually asymptomatic

Question 4

Phenoxybenzamine: MOA

Answer 4

• irreversible alpha 1 & 2 antagonist

Question 5

Listeria characteristics + immune defense

Answer 5

• gram + rods
• tumbling motility @ 22C, can be cultured @ as low as 4C
• narrow zone of beta-hemolysis
• intact cell-mediated immunity is essential for elimination

Question 6

Cells of origin of SCC

Answer 6

• neuroendocrine origin
• markers
  
  • neuron-specific enolase
  • chromogranin
  • synaptophysin
  • neurofilaments

Question 7

Neurblast tumor in children

Answer 7

• non-rhythmic conjugate eye movements + myoclonus
• arises from adrenal medulla
• increased n-myc copies

Question 8

Characteristics of medullary carcinoma of thyroid

Answer 8

• extracellular deposits of amyloid <== formed by calcitonin secreted by parafollicular c-cells
  
  • amyloid stains with congo red
  • nests of uniform/spindle or polygonal cells

Question 9

Migratory thrombophlebitis association

Answer 9

cancer (hypercoag is common paraneoplastic)

Question 10

Extended consumption of appetite suppressants ==>

Answer 10

pulmonary HTN, cor pulmonale, RVH

Question 11

Nitroprusside toxicity + antidote

Answer 11

• nitroprusside ==> cyanide ==> thiocyanate by liver rhodanase
• sodium thiosulfate = antidote for cyanide toxicity
  
  • donates sulfar to help liver rhodanase

Question 12

Drug that can induce prinzmetal angina

Answer 12

• Ergonovine ==> vasoconstriction via alpha-adrenergic and serotonergic mechanisms
• can be used to dx prinzmetal

Question 13

Important tx guideline for hospital tx of alcoholics

Answer 13

No glucose without thiamine in thiamine-deficient patients

Question 14

Characteristics of syndenham’s chorea

Answer 14

• possible sequelae from rheumatic fever
• restless and purposeless jerking movement a few months after sore throat

Question 15

Cause of increased risk for gallstones in Crohn’s patient

Answer 15

• decreased bile reabsorption ==> increased loss in feces
• ==> increased lithogenicity of bile

Question 16

Most common elbow injury in children

Answer 16

• radial head subluxation ==> annular ligament injury
• commonly in younger children (<5)
• little distress unless moving elbow
• hold arm close, extended with pronation

Question 17

MG antibodies =

MS antibodies =

Answer 17

• MG = anti-ACh receptor
• MS = anti-presynp Ca channel
  
  • assoc. with Lambert-Eaton paraneoplastic syndrome

Question 18

Gastric ulcer vs. erosion

Answer 18

• ulcer extends through muscularis mucosa and erosion does not

Question 19

Myoclonus vs. Dystonia

Answer 19

• myoclonus = sudden, brief shock-like contraction
• dystonia = prolonged muscle contraction

Question 20

facial pain + H/A + black necrotic eschar @ pt. w/diabetic ketoacidosis ==> dx?

Answer 20

• mucormycosis
  
  • rhizopus
  • mucor
  • absidia
• dx via biopsy
  
  • broad, nonseptate hyphae w/right angle branching

Question 21

Median n. course

Answer 21

between humeral and ulnar head of pronator teres ==> between flexor digitorum superficial and flexor digitorum profundus =+> carparl tunnel

Question 22

Bell’s palsy =

Answer 22

• CN VII palsy
• facial m. paralysis
• decreased lacrimation
• decreased taste from ant. 2/3

Question 23

Increasing/decreased LVO obstruction murmur intensity

Answer 23

• decreased preload ==> decreased EDV ==> increased intesity
• increased preload/afterload ==> increased EDV ==> decreased intensity

Question 24

Type I vs. Type II Famililal hypercholsterol

Answer 24

• Type I = chylomicrons
  
  • LP lipase is low
  • elevated TGs
  • increased risk for acute pancreatitis
  • skin lesions
• Type II = LDL receptor/apoB100
  
  • tendon xanthomas
  • xanesthesas (e/g/ on eyelids)
  • early CAD

Question 25

Possible CSF complication in meningeal disease

Answer 25

destruction of arachnoid granulations ==> communicating hydrocephalus

Question 26

viruses with segmented genomes

Answer 26

orthomyxoviruses

influenza

rota virus

Question 27

Possible neuro consequences of measles

Answer 27

• encephalitis (days)
• acute dissemenated enchephalomyelitis (weeks)
• subacute sclerosing panencephalitis (years)

Question 28

Lipoic acid is a cofactor for…

Answer 28

• pyruvate DH (deficiency ==> lactic acidosis)
• alpha-ketoglutarate DH
• branched-chain ketoacid DH (deficiency ==> MSUD)

Question 29

Valvular defect association w/inherited HCM

Answer 29

mitral valve has systolic anterior motion ==> comes close to IV septum

Question 30

most common location of anal fissure

Answer 30

posterior midline distal to dentate line

Question 31

menigococcal vaccine composition

Answer 31

capsular protiens

Question 32

glycogen accumulation in lysosomal vacuoles ==> dx?

Answer 32

alpha-glucosidase deficiency

Question 33

Hemophilia A labs

Answer 33

prolonged PTT, normal bleeding time

Question 34

Precursor of Nitric Oxide

Answer 34

arginine

Question 35

Most common lung cancer in gen pop

Answer 35

adenocarcinoma (common @ women, nonsmokers)

Question 36

thiamine is a cofactor for…

Answer 36

alpha-ketoglutarate DH

Question 37

Molecules that use JAK/STAT pathways

Answer 37

• colony-stimulating factors
• prolactin
• growth hormone
• IL-2/cytokines

Question 38

Histo findings in contact dermatitis

Answer 38

spongiosis