Heme/onc Flashcards
Which types of malaria have a dormant hypnozoite stage?
P. vivax and P. ovale
What are Scuffner dots?
multiple brick-red dots that appear in erythrocytes infected with P. vivax/ovale
What are the characteristics of cat-scratch disease?
- development of a pustule at site of infection
- tender regional adenopathy
- stellate granulomas with central necrosis and gram-negative bacilli
What is the mechanism of inheritance of G6PD deficiency?
X-linked recessive
Why do patients with beta thalassemia often present at 7 months
infants switch from hemoglobin F (α2y2) to hemoglobin A (α2β2) at about 6 months, and they do not synthesize enough β
What are the toxicities of chloroquine?
- Chloroquine-retinopathy
- Worsens symptoms of psoriasis
- Pruritis (especially in dark-skinned individuals)
What are the diseases that can arise from deletion of 1, 2, 3, and 4 alpha alleles of the hemoglobin gene?
1 deletion - benign carrier
2 deletions - alpha thalassemia trait
3 deletions - HbH
4 deletions - hydrops fetalis
What is the difference between measures of fibrin degradation products (FDP) and D-dimer?
FDP measures breakdown products of both fibrin and fibrinogen whereas D-dimer only arises from fibrin
What cells are found in mononucleosis?
reactive T lymphocytes that are CD8+
What is a potential consequence of warfarin administration with macrolides?
Macrolides ↑ activity of warfarin by inhibiting P450 → bleeding including hematuria
What does a t(15:17) lead to?
defective retinoic acid receptor → inhibits myeloblast differentiation → AML
What is the most significant cause of humoral hypercalcemia of malignancy?
PTHrP
Is pica common in pregnancy?
Yes, usually manifests as eating lots of ice
What is the cell marker for Mø’s?
CD14
What does CD20 mark? What other CD’s are present on B cells?
B cells are CD19+, CD20+, CD21+
What is the advantage of COX-2 selective inhibitors? Name an example.
They don’t cause ulceration and bleeding; Celecoxib
What are the symptoms and treatment of orotic aciduria?
megaloblastic anemia, failure to thrive; uridine monophosphate tx to bypass mutated enzyme
What is the primary virulence factor in mycobacterium TB?
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)
What is tryptase?
A substance released during mast cell degranulation (e.g. during allergic reactions) that is often used as a marker for mast cell activation.
What are three categories of polycythemia?
How can you differentiate these?
- Absolute vs. relative - ↑ RBC mass in absolute
- Hypoxic vs. non-hypoxic - O2 saturation
- Primary vs. secondary - ↓ EPO levels in primary
What causes sickle cells to sickle?
release of O2, which can be precipitated my many factors associated with anoxia s.a. ↓ pH and ↑ 2,3-DPG
Addition of what factor to hemophilic patients will lead to clotting?
thrombin
What substitution is responsible for HbS (sickle cell)? HbC?
HbS: valine for glutamic acid
HbC: lysine for glutamic acid
What kind of disease is myelofibrosis? What causes it?
a chronic myeloproliferative disorder caused by an activating mutation of a cytoplasmic tyrosine kinase (JAK) → ↑ JAK-STAT pathway activation
What abnormal bleeding findings can patients with uremia (e.g. dialysis patients who haven’t been dialyzed on time) present with?
isolated ↑ BT due to a qualitative platelet defect induced by uric acid
