Miscellaneous

Question 1

54 year old male with anorexia, hematuria, and abomindal discomfort. CT of abdomen shows multiple liver and kidney cysts (homogenous with regular outline and nonenhancing on contrast CT).

Answer 1

ADPKD

• Born with multiple bilateral renal cysts, asx until 4th or 5th decade of life
• CT differentiates from solid metastasis

Question 2

Mitochondrial diseases

Answer 2

MERRF
Kerns-Sayre syndrome
Leber’s hereditary optic neuropathy

Question 3

HMG-CoA reductase

Answer 3

Cholesterol synthesis

Increased by estrogen (incr risk of cholesterol gallstones)

Question 4

Beta-glucuronidase

Answer 4

Deconjugates bilirubin
- If increased (e.g. released by damaged hepatocytes), can complex Ca2+ and precipitate w/n bile –> pigmented gallstones (not chloesterol)

Question 5

7alpha-hydroxylase

Answer 5

Converts cholesterol into bile salts, decreased activity with fibrate drugs

Question 6

Recurrent fever, dyspnea, and productive cough in elderly pt after flu (fever, HA, myalgia, malaise for 2-5 days)

Answer 6

Secondary bacterial PNA

• Viral induced damage to mucociliary mechanisms of respiratory epithelium
• CXR with pulmonary consolidation
• S. pneumo > S. aureus > H. flu

Question 7

Molecular pathogenesis of sickle cell disease

Answer 7

Single substitution: valine (uncharged, hydrophobic) replaces glutamic acid (acidic, negative charge, hydrophilic) at position 6

Question 8

Mechanism of angioedema

Answer 8

Bradykinin accumulation

Question 9

S4

Answer 9

“ASTIFF-WALL”

• S4 in younger pts always pathologic (unlike S3)
• Represents atrial contraction, produced by resultant onrush of blood striking a stiff LV (decr LV compliance), e.g. restrictive cardiomyopathy and LVH

Question 10

Rapidly growing mass resected from the liver of 35 year old Australian immigrant. Mass is encapsulated and calcified.

Answer 10

Tapeworm Echinococcus granulosus infection resulting in hyatid cyst disease.

• Hepatomegaly, RUQ pain, N/V
• E. ganulosus; unilocular
• E. multiocularis: multilocular

Don’t aspirate or disrupt, may cause ANAPHYLAXIS from spilling of cyst contents! (Prevent with EtOH injection to kill daughter cells)

Question 11

Pupillary light reflex

Answer 11

CN II –> CN III

Other CN II functions

• Somatic: IR, SR, MR, IO, levator palpebrae (palsy = unopposed LR of VI and SO of IV)
• PSNS: iris sphincter and ciliary muscle

Question 12

Cutaneous sensation to external auditor canal

Answer 12

Posterior: CN X via small auricular branch
Rest: CN V3

Question 13

Taste to anterior 2/3 tongue

Other functions of this nerve?

Answer 13

CN VII via chorda tympani
Also carries efferent PSNS preganglionic fibers to innervate submandibular and sublingual salivary glands
Small motor component to stapedius and posterior ear, no sensory

Question 14

AR disorder of bilirubin metabolism caused by lack of uridine diphosphate-glucuronyltransferase (UGT)

Answer 14

Crigler-Najjar

• unconjugated hyperbilirubinemia
• Kernicterus and death :(

Question 15

AR absence of biliary transport protein, MRP2 (multidrug resistance protein 2) used in hepatocellular excretion

Answer 15

Dubin-Johnson

• cannot excrete BR blucuronides into bile canaliculi
• Liver is darkly pigmented but typically asx pt

Question 16

AR asx conjugated hyperBR from defect in hepatic uptake and excretion of BR pigments

Answer 16

Rotor syndrome

Question 17

Components of the JGA

Answer 17

1) Macula densa: tall columnar cells in the distal tubule

2) Modified smooth muscle cells around the afferent arteriole

Question 18

Pathogenesis of calcium nephrolithiasis

Answer 18

Ca stones are most common (75-80%)

• 50% of cases associated with idiopathic hypercalciuria - incr urine Ca with nl serum Ca
• Other causes: primary hyper PTH (high serum and urine Ca), low Ca diet leading to hyperozaluria (e.g. malabs like Crohn’s), hyperuricosuria (e.g. high protein diets), tumor lysis syndrome with hyperuricemia and hyperuricosuria which stimulated ca oxalate stone formation as well as uric acid stones

Question 19

Vitiligo vs. albinsim

Answer 19

Vitiligo: decr number of melanocytes
Albinsm: nl number, but decr tyrosinase activity. Or abnl NCC migration in development

Question 20

Parvovirus in kids vs. adults

Answer 20

Kids: erythemia infectiosum (5th disease)
Adults: RA mimic, symmetric arthritis involving the proximal interphalangeal, metacarpal, knee, and ankle joints