Heme/Onc 1 Flashcards Preview

ID/LC Step Review > Heme/Onc 1 > Flashcards

Flashcards in Heme/Onc 1 Deck (20):
1

MOA of desmopressin

- Increases circulating Factor 8 levels
- Also stimulates vWF secretion from endothelial cells

Used in hemophilia A and VW disease

2

Methotrexate MOA

- Inhibits dihydrofolate reductase (DHFR)
- Folic acid analog
- Functions as a chemo agent --- inhibits DNA synthesis
- Anti-psoriasis agent

3

SEs of methotrexate

Death of rapidly dividing cells in GI and bone marrow

causes ulcers and pancytopenia

4

Folinic acid

- Reverses methotrexate toxicity if given early
- Only in non-cancerous cells (GI and bone marrow)

5

Reperfusion arrythmias

Fibrinolytics (eg tPA) can cause these when the artery is re-opened

usually *benign*

6

What is the Haldane effect?

Binding of oxygen to Hb => H+ and CO2 release from Hb

7

What is the Bohr effect?

High [CO2] and [H+] => O2 unloading from Hb

8

Describe the effects of CO on Hb

- CO binds Hb w/ affinity 220 times that of O2
- Binding of CO and O2 are reversible => CO2 competitively binds Hb

9

What form of retinoblastoma (Rb) protein allows transition from G1 --> S phase?

**Phosphorylated** Rb or **inactive**
- Means Rb is inactive meaning it cannot stop cells in G1

10

Candida albicans

- Most common cause of opportunistic mycosis (think HIV and chemo)
- Affects any organ
- Yeasts and pseudohyphae on light microscopy
- (+) germ tube test

11

Anti-Rh(D) immunoglobin is given to Rh(-) moms of Rh(+) babies. What type of Abs are these?

IgG

12

Describe the role of folate in erythroid precursor cells

Folate helps produce dTMP

Without it, you get limited DNA synthesis, megaloblastosis, and erythroid precursor cell apoptosis

13

What supplement helps convert folate derivatives into dTMP?

Thymidine

Supplement used only during limited denovo synthesis (that causes deficiency)

14

How is 6-mercaptopurine degraded?

In liver via xanthine oxidase

XO inhibitors = allopurinol

15

AML cytogenetic defect and fusion gene

t(15;17)

PML/RARa => inhibits differentiation of myeloblasts and triggers AML

Think retinoic acid

16

von Willebrand disease labs

- Increased PTT (b/c of decreased factor 8 activity)

- Increased BT (b/c of impaired platelet function)

17

Characteristic findings of AML

- Auer rods in myeloblast's cytoplasm
- Stains for myeloperoxidase

18

Clinical signs of metastatic prostate cancer

- Urinary urgency and frequency
- Constant back pain --- worse at night
- Pain non-responsive to position ∆s or analgesics
- Hx or risk factors for malignancy

19

What are the 2 major mechanisms of therapeutic ionizing radiation?

1) DNA ds breakage

2) Free radical formation

20

Labs of iron deficiency anemia

- Low MCV
- Low Hb
- Low ferritin
- High transferrin
- High TIBC