13

Question 1

50% infectious dose (very high for salmonella) low for

Answer 1

shigella
campy
Very low for entamoeba histolytica and giardia (1-10 organisms)

Question 2

3–>5 exonuclease activity of DNA pol. Mismatch repair during dna replication. Disease associated =

Answer 2

Heriditary nonpolposis colon cancer (AD)
80% get CRC
Associated with endometrial, skin, and ovarian cancers
MLH1, MSH2, MSH6 (microstallite instability)

Question 3

Triad of arthritis, dermatitis and tenosynovitis in sexually active woman

Answer 3

N. gonorrhoeae

Question 4

Secretory IgA (dimer joined by peptide j-chain) bind pili and other membrane proteins involved in bacterial adherence to mucosa

Answer 4

inhibiting mucosal colonization

Question 5

IgA proteases (cleave a hing region leaving Fab and Fc fragments)

Answer 5

N. gonorrhoeae, N. meningitidis, step pneumo, H. flue

Question 6

May cause reperfusion arrhythmia on arterial re-opening, usually benign

Answer 6

fibrinolytics (tPA)

Question 7

Neuroprotective agent that may slow functional losses in AD

Answer 7

Vitamin E (alpha-tochopherol)

Question 8

NMDA receptor antagonist. CNS NMDA- overstimulation by glutamate may contribute to AD symptoms thus this drug is used in AD treatment

Answer 8

Memantine

Question 9

High concentration of serum ferritin are found in

Answer 9

Hemochromatosis

Question 10

Hyperoxaluria is seen in Crohns disease. Causes

Answer 10

calcium oxalate RENAL stones due to increased absorption
Gallstones are due to decreased reabsorption of bile salts
Don’t confuse these two

Question 11

Accelerated bone remodeling with eventual bony overgrowth. The disease is thought to be caused by gene mutation (affecting RANK, osteoprotegerin) that result in excessive RANK signaling and NF-kB activation—> osteoclast differentiation and activity.

Answer 11

Paget disease of the bone

Question 12

ALAS is upregulated by what?

ALAS is downregulated by what?

Answer 12

Upregulated by CYP450 Inducers (antiepileptics, griseofulvin, rifampin, etc)
Downregulated by HEME AND GLUCOSE (dextrose)

Question 13

Three mutations associated with early onset (

Answer 13

1) APP gene on chromosome 21
2) Presenilin 1 gene on chromosome 14
3) Presenilin 2 gene on chromosome 1

All promote production of A Beta-amyloid

Question 14

Echocardiogram showing an aorta lying anterior to the pulmonary artery is diagnostic of

Answer 14

TGA (transposition of great arteries)

Failure of fetal aorticopulmonary septum to spiral normally during septation of the truncus arteriosus

Question 15

ACE inhibitor cough due to increased

Answer 15

bradykinin, Substance P, prostoglandins

Bradykinin and substance P accumulation can cause inflammation and stimulate lung irritation

Question 16

Immunochemistry of hydatidiform mole
p57 negative =
p57+ =

Answer 16

p57 negative= complete (due to absent maternal genome)

p57 positive = partial (due to maternal genome presence)

Question 17

Hyperemesis gravidarum and formation of theca-lutein cysts in setting of molar pregnancy is due to?
Preeclampsia, anemia and hyperthyroidism can also be present in complete moles

Answer 17

Increased beta hCG secretion by proliferating trophoblast

Note: b-HCG stimulates ovarian growth leading to cysts

Question 18

Decrease in SYSTOLIC pressure of > 10mm Hg with inspiration. MC seen in patients with severe asthma, COPD, constrictive pericarditis

Answer 18

Pulsus paradoxus

Question 19

Medication induced muscle atrophy is most commonly seen with ___________. _________ can cause a similar condition too.

Answer 19

MC= chronic corticosteroid therapy

Chloroquine can also do this

Question 20

Uveoscleral pathway- a small amount of AH can diffuse through the ciliary muscle and adjacent sclera

Answer 20

Prostaglandin agonist work on this pathway for tx of glaucoma

Question 21

Diffusion through a trabecular network in Schlemm’s Canal (scleral venous sinus) and drains into EPISCLERA and CONJUCTIVAL VEINS

Answer 21

Trabecular outflow pathway (muscarinic agonists work here)

Question 22

Progressive loss of ganglion cell axons, pale opitic disc and enlarged optic cup. Symptoms evolve over decades with progressive loss of peripheral visual fields

Answer 22

Open-angle glaucoma caused by increased secretion or decreased outflow of AH

Question 23

Traumatic aortic rupture (rapid deceleration in car wreck)

Answer 23

Injury is to the aortic isthmus (tethered by ligamentum arteriosum and relatively fixed and immobile compared to adjacent distal aorta

Question 24

Pneumobilia (air in biliary tract)

Answer 24

Gallstone illeus

Radiograph = dilated bowel loops with air-fluid levels and pneumobilia due to retrograde passage of intestinal gas through fistula

Question 25

Overproduction of which cytokine is implicated in direct damage to podocytes (ex: minimal change disease)

Answer 25

IL-13

Question 26

Renal veins join the IVC at what level?

Common iliac veins merge to become the IVC at the level of

Answer 26

Renal veins join IVC at L1/L2

Common iliac veins merge to become IVC at L4

Question 27

IVC filters are placed in patients with DVT or PE who have

Answer 27

contraindications to antioagulation

Question 28

S. gallolyticus endocarditis is unique in that most cases occur in patients without preexisting valvular abnormality

Answer 28

Check patient for colonic cancer (25% positive)

Question 29

Nickel is a carcinogen and occupational exposure is associated with nasal and lung cancer. Nickel mining is also suggestive of

Answer 29

silica dust exposure

Question 30

Thicken bronchial walls, lymphocytic infiltration, mucous glands enlargment, patchy squamous metaplasia of the bronchial mucosa

Answer 30

Chronic bronchitis (MC cause= smoking)

Question 31

Major immune mechanisms against Giardia

Answer 31

CD4+ T-help cells and secretory IgA production

Question 32

Chronic giardiasis? who are the players?

Answer 32

IgA deficiency, X-linked agammablobulinemia, CVID

Question 33

Increase in pH effect on calcium

Answer 33

Hypocalcemia–> Increase affinity of albumin (anion) to bind Ca2++ (less H+ around to compete with it)

In decrease pH (acidosis) more H+ to bind Ca2+ which leads to more free calcium and hypercalcemia