March 25 - Other

Question 1

Hepatitis B immunopathogenesis

Answer 1

Hep B has NO viral cytopathic effect. Immune system is what does damage.

1. Proliferative phase: HBsAg and HBcAg are expressed on MHC class I. CD8+ cells kill the infected hepatocytes.
2. Integrative phase: HBV DNA is incorporated into the genome of surviving hepatocytes. What causes risk for hepatocellular carcinoma.

Antibody response neutralizes virus before it enters hepatocytes, so is protective but does not cause hepatocellular damage.

Immune complexes cause some of non-hepatic symptoms such as arthralgias of acute disease and glomerulonephritis and vasculitis of chronic disease

Question 2

Hereditary angioedema

Answer 2

Autosomal dominant. Episodes of painless non-pitting edema. Low serum C1 esterase inhibitor- can’t inactivate C1 or kallikrein. Kallikrein converts kininogen to bradykinin which causes the angioedema

Question 3

Calcineurin inhibitors

Answer 3

Cyclosporine and tacrolimus. Normally calcineurin is activated and then dephosphorylates NFAT. NFAT can then enter nucleus and stimulate IL-2 production. IL-2 stimulates the growth and differentiation of T cells. Calcineurin inhibitors thus block T cell proliferation

Question 4

Scarlet fever presentation

Answer 4

Fever, malaise, abdominal pain, sore throat.
Swollen edematous pharynx that may be covered by gray-white exudate.
Strawberry tongue due to inflammation of the papillae.
Red rash with sandpaper like feel

Question 5

Tryptase

Answer 5

Enzyme released by mast cells in anaphylaxis. Can be measured after event to support diagnosis

Question 6

Hypertensive retinopathy findings

Answer 6

Flame hemorrhages
Thickened retinal arteriolar walls and AV nicking
Cotton-wool spots: small white foci of retinal ischemia

Question 7

Wilson disease

Answer 7

Kayser fleischer rings: copper deposition in cornea

Damage and atrophy of basal ganglia

Question 8

Aqueous humor flow

Answer 8

Secreted by ciliary body to posterior eye chamber. Then flows through pupil to anterior chamber. Then diffuses through trabecular network to canal that drains to veins.

Question 9

Open angle glaucoma pathophysiology

Answer 9

Increased IOP due ot problem with travecular meshwork that blocks outflow of aqueous humor. Results in increased IOP that is painless, chronic, and slowly progressive. Pale optic disc and enlarged optic cup on eye exam.

Question 10

Closed angle glaucoma pathophysiology

Answer 10

Increased IOP due to physical obstruction of outflow canals by the narrow angle between the iris and the cornea. Results in painful, acute, sudden vision loss.

Question 11

Treatment of closed angle glaucoma

Answer 11

Mannitol or carbonic anhydrase inhibitor to rapidly lower IOP. Laser or surgery if ineffective.

Cholinergic agonist
-M receptors in ciliary body and iris. Agonist casuses constriction which opens the angle, increasing aqueous humor outflow

Question 12

Treatment of open angle glaucoma

Answer 12

1. Beta blockers
   - decrease aqueous humor production by antagonizing B1 receptors in ciliary body
2. Latanoprost
   - prostaglandin analog. Opens canal improving outflow.
   - side effect is darkening of iris