Heme/Onc - Stuff Missed Flashcards Preview

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Flashcards in Heme/Onc - Stuff Missed Deck (15)
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1
Q

Methotrexate

A
  • folic acid analog that inhibits dihyrofolate reductase

- inhibits DNA synthesis by preventing syntehsis of purines and thymidylic acid

2
Q

Leucovorin

A

aka Folinic acid

  • can reverse the toxicity of methotrexate in non-cancerous cells in GI mucosa and bone marrow if administered at right time
  • DOES NOT REQUIRE ACTION OF DIHYDROFOLATE REDUCTASE
3
Q

Filgrastim

A

Granulocyte stimuating factor

- used to stimulate proliferation and differentiation of granulocytes with neutropenia

4
Q

Mensa

A

prevents hemorrhagic cystitis in patients receiving cyclophosphamie or ifosfamide chemotherapy
- binds to acrolein, the toxic metabolite formed from cyclophosophamide or ifofsamide

5
Q

Lead poisoning affects which enzymes in heme synthesis pathway

A
  • Zn containing ALA dehydratase
  • Ferrochetolase
  • leads to microcytic anemia as ALA and protoporphyrin IX
6
Q

Rate limiting enzyme in heme synthesis

A

ALA synthase which coverts glycine and succinyl-cOA to ALA

** inhibited by heme and glucose

7
Q

Acute intermittent porphyria

A
  • defect in uroprophyrinogen I synthase
  • acute abdominal pain
  • port-wine colored urine when exposed to sunlight
  • polyneuropathy
  • psych disturbances
  • precipitated by drugs (e.g. barbs, alcohol)
8
Q

Treatment of Acute Intermittent Prophyria

A
  • Glucose and heme which will stop ALA thus stop production of heme
9
Q

Porphyria Cutanea Tarda

A
  • defects in uroprophyrinogen decarboxylase
  • uroprophyrinogen accumulates in urine (tea colored urine)
  • patients experience photosensitivity
  • most common one
10
Q

Cladibrine

A
  • purine analog
  • treatment for hairy leukemia
  • resistant to degradation of adenosine deaminase in high intracellular concentrations
11
Q

How are human tumor cells able to resistt chemotherapy?

A

MDR1 gene which codes for P-glycoprotein, an ATP- dependent efflux transmembrane protein that reduces intracellular concentrations of drugs

12
Q

High nucleotide uptake occurs during which part of cell cycle?

A
  • S phase (preparin to divide)
13
Q

Grade of tumor

A
  • dependent on differentiation (e.g well differentiation or poor differentiation)
14
Q

Stage of tumor

A

extent of tumor expansion

15
Q

Peau d’orange

A
  • pitting edema that is yellow brown in beat

= occurs when neoplastic cells plug dermal lymphatics