Flashcards in Heme/Onc 1 Deck (20):
MOA of desmopressin
- Increases circulating Factor 8 levels
- Also stimulates vWF secretion from endothelial cells
Used in hemophilia A and VW disease
- Inhibits dihydrofolate reductase (DHFR)
- Folic acid analog
- Functions as a chemo agent --- inhibits DNA synthesis
- Anti-psoriasis agent
SEs of methotrexate
Death of rapidly dividing cells in GI and bone marrow
causes ulcers and pancytopenia
- Reverses methotrexate toxicity if given early
- Only in non-cancerous cells (GI and bone marrow)
Fibrinolytics (eg tPA) can cause these when the artery is re-opened
What is the Haldane effect?
Binding of oxygen to Hb => H+ and CO2 release from Hb
What is the Bohr effect?
High [CO2] and [H+] => O2 unloading from Hb
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
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
- Most common cause of opportunistic mycosis (think HIV and chemo)
- Affects any organ
- Yeasts and pseudohyphae on light microscopy
- (+) germ tube test
Anti-Rh(D) immunoglobin is given to Rh(-) moms of Rh(+) babies. What type of Abs are these?
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
What supplement helps convert folate derivatives into dTMP?
Supplement used only during limited denovo synthesis (that causes deficiency)
How is 6-mercaptopurine degraded?
In liver via xanthine oxidase
XO inhibitors = allopurinol
AML cytogenetic defect and fusion gene
PML/RARa => inhibits differentiation of myeloblasts and triggers AML
Think retinoic acid
von Willebrand disease labs
- Increased PTT (b/c of decreased factor 8 activity)
- Increased BT (b/c of impaired platelet function)
Characteristic findings of AML
- Auer rods in myeloblast's cytoplasm
- Stains for myeloperoxidase
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
What are the 2 major mechanisms of therapeutic ionizing radiation?
1) DNA ds breakage
2) Free radical formation