Heme/onc

Question 1

Which types of malaria have a dormant hypnozoite stage?

Answer 1

P. vivax and P. ovale

Question 2

What are Scuffner dots?

Answer 2

multiple brick-red dots that appear in erythrocytes infected with P. vivax/ovale

Question 3

What are the characteristics of cat-scratch disease?

Answer 3

1. development of a pustule at site of infection
2. tender regional adenopathy
3. stellate granulomas with central necrosis and gram-negative bacilli

Question 4

What is the mechanism of inheritance of G6PD deficiency?

Answer 4

X-linked recessive

Question 5

Why do patients with beta thalassemia often present at 7 months

Answer 5

infants switch from hemoglobin F (α2y2) to hemoglobin A (α2β2) at about 6 months, and they do not synthesize enough β

Question 6

What are the toxicities of chloroquine?

Answer 6

1. Chloroquine-retinopathy
2. Worsens symptoms of psoriasis
3. Pruritis (especially in dark-skinned individuals)

Question 7

What are the diseases that can arise from deletion of 1, 2, 3, and 4 alpha alleles of the hemoglobin gene?

Answer 7

1 deletion - benign carrier
2 deletions - alpha thalassemia trait
3 deletions - HbH
4 deletions - hydrops fetalis

Question 8

What is the difference between measures of fibrin degradation products (FDP) and D-dimer?

Answer 8

FDP measures breakdown products of both fibrin and fibrinogen whereas D-dimer only arises from fibrin

Question 9

What cells are found in mononucleosis?

Answer 9

reactive T lymphocytes that are CD8+

Question 10

What is a potential consequence of warfarin administration with macrolides?

Answer 10

Macrolides ↑ activity of warfarin by inhibiting P450 → bleeding including hematuria

Question 11

What does a t(15:17) lead to?

Answer 11

defective retinoic acid receptor → inhibits myeloblast differentiation → AML

Question 12

What is the most significant cause of humoral hypercalcemia of malignancy?

Answer 12

PTHrP

Question 13

Is pica common in pregnancy?

Answer 13

Yes, usually manifests as eating lots of ice

Question 14

What is the cell marker for Mø’s?

Answer 14

CD14

Question 15

What does CD20 mark? What other CD’s are present on B cells?

Answer 15

B cells are CD19+, CD20+, CD21+

Question 16

What is the advantage of COX-2 selective inhibitors? Name an example.

Answer 16

They don’t cause ulceration and bleeding; Celecoxib

Question 17

What are the symptoms and treatment of orotic aciduria?

Answer 17

megaloblastic anemia, failure to thrive; uridine monophosphate tx to bypass mutated enzyme

Question 18

What is the primary virulence factor in mycobacterium TB?

Answer 18

Cord factor (w/out→ can’t cause infxn); presence → serpentine growth pattern; inhibits IFN-α, neutrophils, damage mitochondria. (Note: another virulence factor is sulfatides which inhibit phagolysosomal fusion)

Question 19

What is tryptase?

Answer 19

A substance released during mast cell degranulation (e.g. during allergic reactions) that is often used as a marker for mast cell activation.

Question 20

What are three categories of polycythemia?

How can you differentiate these?

Answer 20

1. Absolute vs. relative - ↑ RBC mass in absolute
2. Hypoxic vs. non-hypoxic - O2 saturation
3. Primary vs. secondary - ↓ EPO levels in primary

Question 21

What causes sickle cells to sickle?

Answer 21

release of O2, which can be precipitated my many factors associated with anoxia s.a. ↓ pH and ↑ 2,3-DPG

Question 22

Addition of what factor to hemophilic patients will lead to clotting?

Answer 22

thrombin

Question 23

What substitution is responsible for HbS (sickle cell)? HbC?

Answer 23

HbS: valine for glutamic acid
HbC: lysine for glutamic acid

Question 24

What kind of disease is myelofibrosis? What causes it?

Answer 24

a chronic myeloproliferative disorder caused by an activating mutation of a cytoplasmic tyrosine kinase (JAK) → ↑ JAK-STAT pathway activation

Question 25

What abnormal bleeding findings can patients with uremia (e.g. dialysis patients who haven’t been dialyzed on time) present with?

Answer 25

isolated ↑ BT due to a qualitative platelet defect induced by uric acid