March 14 - Heme/onc Flashcards Preview

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Flashcards in March 14 - Heme/onc Deck (62):
1

Haldane effect

O2 affects affinity of hemoglobin for CO2/H+. Serves to increase CO2 delivery to lungs. Increase in PO2 increases CO2 and H+ offloading from Hb.

2

LMWH compared with UH

Better bioavailability
Can give SC
Less monitoring
Longer half half
Less easily reversible

3

Direct thrombin inhibitors

Argatroban, dabigatran, bivalirudin

4

Direct factor Xa inhibitors

Apixaban, rivaroxaban. Oral, don't require monitoing but not as easily reversible.

5

Fondaparinux

Factor Xa inhibitor

6

Antiemetics used for chemo-induced vomiting

1) 5-HT3 antagonists: ondansetron and granisetron
2) Dopamine antagonists: metoclopromide, prochlorperazine
3) Neurokinin1 antagonists which prevent substance P release: aprepitant, fosaprepitant

7

Mutation in polycythemia vera (specifics)

Mutation in JAK2, which is involved in EPO signaling.

Normal pathway: EPO binds receptor. Receptor interacts with JAK2, which is a cytoplasmic tyrosine kinase receptor. Leads to downstream signling and activation of STATs.

Mutated pathway: JAK2 constitutively active resulting in overproduction of red cell.

8

Labs in sickle cell trait

Normal retic count, HGB, RBC indices and morphology

9

Integrins

Bind collagen, laminin, and fibronectin in the ECM to facilitate adhesion

10

Acute intermittent porphyria: presentation, pathophysiology, prevention, treatment of acute attacks

Presentation: episodes of abdominal pain, N/V, peripheral neuropathy, neuropsych derancements, red urine that darkens on exposure to light and air due to exccess PBG

Pathophys: AD defect in porphobilinogen deaminase in heme synthesis pathway. Causes early heme intermediates to accumulate and cause NS damage.

Prevention: avoid alcohol, smoking, and CYP inducing drugs which increase ALA synthase activity

Treatment : dextrose and IV heme which decrease ALA synthase activity

11

Cutaneous porphyrias

Caused by defect later in pathway than AIP. Photosensitivity

12

Heme synthesis pathway

Glycine and succinyl coA
ALA
Porphobiolinogen
many steps
Porphyrin IX
Heme

13

Osteoblastic vs osteolytic bone mets: which cancers

Osteoblastic: prostate, small cell lung, hodgkin
Osteolytic: multiple myeloma, non-small cell lung, non-hodkin lymphoma, RCC, melanoma

14

Congenital parvovirus B infection, type of virus

Mom: arthritis
Fetus: hydrops fetalis due to interruption of erythropoiesis in bone marrow
Virus type: ssDNA

15

Congenital infections causing chorioretinitis

CMV or toxoplasma

16

Congenital infections causing sensorineural hearing loss

Rubella, CMV

17

Presentation of follicular lymphoma

Indolent, waxing and waning course. Painles LAD

18

Auer rods

Indicate myeloid differentation. Stain for peroxidase

19

RhoGAM: MOA

Anti-Rh(D) IgG pooled from donor plasma (polyclonal antibody). Binds to Rh-pos fetal RBCs that enter maternal circulation to prevent them from interacting with the maternal immune system and being sequestered in the spleen. Amount given is small enough that there is no significant transplacental fetal hemolysis.

IgG is given because that is what is produced against Rh antigens (vs IgM made against ABO)

20

Stop codons

UAA, UAG, UGA

21

Sickle cell mutation

Valine sub for glutamic acid

22

HMP shunt: location, products, key enzymes

In cytoplasm.
Produces ribose 5-phosphate and NADPH
Enzymes: transaldolase and transketolase

23

Blood cells in EBV infectious mono

Infects B cells by binding CD21 receptor
CD8+ cells clonally expand to kill the virus-infected cells. Appear larger than usual with abundant cytoplasm, eccentrically placed nuclei, membrane that appears to adhere to neighboring cells

24

Cyanide poisoning: pathophys, presentation, treatment

Pathophysiology: binds iron-containing cytochrome enzymes, inhibiting aerobic metabolism

Presentation: flushing, increased RR and HR, headache

Antidote: nitrites which induce formation of methemoglobin. Methemoglobin has high affinity for cyanide and sequesters it in blood

25

Beta thalassemia: mutation

Multiple mutaitons that affect mRNA

26

Abciximab

GPIIb/IIIa receptor antagonist. Used for acute coronary syndrome, especially if undergoing percutaneous intervention

27

Aspirin OD treatment

Alkalinize urine with sodium bicarb

28

ADP receptor inhibitors: names, MOA, kinetics

Names: clopidogrel, ticagrelor, ticlopidine

MOA: block ADP receptor preventing GIIb/IIIa expression

Kinetics: prodrugs with slow onset of action, with exception of ticagrelor

29

Phosphodiesterase III inhibitors: names, effects

Names: cilostazol, dipyridamole

Effects: inhibit platelet aggregation, vasodilate

30

Inflammatory carcinoma: presentation and pathophys

Presentation: itchy, generalized erythematous rash on breast with thick and coarse skin texture and breast edema. Underlying mass may or may not be present.

Pathophys: cancer cells obstructing lymphatic drainage

31

Cryoprecipitate vs fresh frozen palsma

FFP has all coag factors; cryoprecipitate only has cold-soluble proteins

32

5-fluorouracil: MOA

pyrimidine analog that inhibits DNA synthesis by inhibiting thymidylate synthetase

33

Leucovorin: MOA and effects

Tetrahydrofolate derivative that doesn't require dihydrofolate reductase. USed to rescue normal cells from methotrexate. Can potentiate effects of 5-fluorouracil which uses THF as cofactor

34

Vinca alkyloids: MOA and toxicity

MOA: M phase specific, inhibit microtubule formation
Toxicity: peripheral neuropathy

35

G2 phase cancer drugs

Bleomycin and doxorubicin

36

Why mature RBCs can't make heme

Heme occurs partly in cytoplasm, partly in mitochondria. Mautre red cells have lost their mitochondria

37

Warfarin induced skin necrosis

Complication seenin first few days of warfarin therapy due to transident hypercoagulable state

38

Hairy cell leukemia: presentation and diagnosis

Presentation: pancytopenia and massive splenomegaly in middle aged male

Diagnosis: often a dry tap due to bone marrow fibrosis, massive splenomegaly due to cancer in the reticuloendothelial system as well as the marrow

39

Ringed sideroblasts

Seen in myelodysplastic syndrome due to mitochondrial iron accumulaiton around the nucleus

40

Tumor lysis syndrome

Emergency seen during chemo treatment of leukemia/lymphoma. Destroy a ton of cells at once resulting in release of ions and nucleic acids into the blood. Prevent with aggressive hdyration and medications.

41

Rasburicase

Recombinant urate oxidase. Promotes conversino of uric acid to soluble metabolites that are excreted in urine.

42

Translocation seen in burkitt lymphoma

t(8;14), c myc and IgH

43

desmopressin: two uses

1. Hemophilia A and von willebrand disease: increases factor VIII and vWF to stop bleeding
2. Central DI: binds V2 receptors on renal tubular cells, increasing water reabsorption and decreasing urine production

44

Leukemoid reaction

Benign leukocytosis in response to severe infection, malignancy, acute hemolysis. Presents with normal to elevates leukocyte alk phosphatase and basophilic granules in neutrophils on smear

45

Myoglobin O2 binding curve

Monomeric without cooperative binding. Saturates at much lwoer pO2 than HGB (higher O2 affinity)

46

Basis for hemoglobin electrophoresis: looking for HbS and HbC

Distinguishes based on charge. HbA has neg charged glutamate, HbS has nonpolar valine. HbC has pos charged lysine. Thus, HbA migrates farthest, HbC migrates the least toward the pos end of gel.

47

6-mercaptopurine

Inactivated by xanthine oxidase. Azathioprine is pro-drug

48

Distinguishing three types of childhood brain tumors

1. Pilocytic astrocytoma: low grade, usually in cerebellum, presents with headache and balance problems, solid and cystic components on imaging, rosenthal fibers on path

2. Medulloblastoma: high grade, always in cerebellum, solid mass, sheets of small blue cells

3. Ependymoma: obstructive hydrocephalus, rosettes

49

N-myc: what associated with

neuroblastoma, small cell lung cancer

50

Bleomycin MOA

Forms radicals that damage DNA and produce double strand breaks; acts in G2

51

Thyroid cancer with psammoma bodies

papillary carcinoma

52

cancer associated with myasthenic syndrome

small cell lung cancer

53

cancer associated with paraneoplastic hypercalcemia

squamous cell carcinoma

54

cisplatin toxicity

Nephrotoxicity, acoustic nerve damage. Prevent nephrotoxicity with aggressive hydration

55

von hippel lindau disease: cause and manifestationa

Caused by AD mutation on chromosome 3

Causes hemangioblastomas of retina, cerebellum, medulla; renal cell carcinoma

56

Meningioma vs ependymoma (path and population(

Meningioma: psammoma bodies, middle aged woman

Ependymoma: perivascular pseeudorosettes, kids

57

Sacrococcygeal teratoma

Most common fetal neoplasm, benign, primitive streak remnant

58

Wilms tumor

Arises from embryonic renal cells due to WT del on chromosome 11. Presents as large palpable flank mass that distorts renal calyces

59

Doxorubicin MOA

DNA intercalater

60

Raltegravir MOA

integrase inhibitor for HIV

61

DIC in pregnancy

mediated by tissue factor release from placental trophoblasts

62

Metalloproteinases

enzymes that degrade ECM and basement membrane