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Flashcards in Heme/Onc Deck (68):
1

Pyruvate Kinase deficiency has what effect on RBC's?

last step in glycolysis , no PK--> you can't generate the ATP from glycolysis in your RBC's, they become senescent and the spleen removes them Spleen will hypertrophy from this overwork

2

mTOR signaling pathway (the more this is turned on, more cancer)

growth factor binds to Tyrosine Kinase --> autophosphorylation of tyrosine --> activation of PI3K --> activation of PK-B (akt) --> akt activates mTOR --> mTOR goes to nucleus to induce genes involved in cell survival / anti apoptosis

3

Soon after a woman is started on Warfarin, she develops areas of skin and fat necrosis... why?

Warfarin inhibits all the vit. K dep factors (Factors 2,7,9,10 & protein C & S)---> but proteins C & S have shorter half lives & are therefore depleted first this leaves you with a period of time with no protein C (which normally INactivates factor V & VII) and plenty of the other clotting factors this sets you up for clots & " Warfarin Skin Necrosis" ---> so you must always give Heparin too for the 1st few days of warfarin therapy

4

Protein C function

inactivates factors V & VII by proteolysis

5

In HbS -- what causes the Hb to be able to polymerize under low oxygen conditions and therefore "sickle"?

HbS contains a valine in place of the glutamic acid at position 6 in the beta subunit, this promotes HYDROPHOBIC INTERACTION among the Hb molecules and polymerization

6

HbC and Sickle cell disease are result of ________ mutations

Missense mutations (one aa sub'd for another aa) HbC = lysine for glu at position 6 HbS = valine for glu at position 6

7

blasts in peripheral smear w/ TdT + and PAS + material

Lymphoblasts (ex: Acute Lymphoblastic Leukemia) -CD 19 & 10 = B cell blasts -CD 1, 2, 5 = T cell blasts

8

blasts in peripheral smear w/ peroxidase + granules

Auer Rods -- this means Myeloblasts (AML) (found abundantly in AML M3)

9

treatment of Tumor Lysis Syndrome (hyperkalemia, hyperphosphatemia, hyperuricemia)

Rasburicase or Allopurinol

10

anemia with decreased Ferritin, increased Transferrin, increased TIBC, MCV < 80

Iron deficiency anemia (microcytic, hypochromic anemia)

11

reasons for Burr cells on peripheral smear

Uremia, Pyruvate Kinase deficiency, Microangiopathic hemolytic anemias (TTP & HUS), or mechanical trauma to the RBC

12

2,3 BPG effect on O2 binding Hb

2.3 BPG allosterically decreases the affinity of Hb for O2 --> makes it easier to dump oxygen in the tissues

13

a pt with ESRD who has not had dialysis for over a week develops excessive bleeding when changing his catheter

Uremic platelet dysfunction - only the bleeding time will be prolonged

14

most commonly used drug for long term anticoagulation after a PE

Warfarin -inhibits Vit K dependent carboxylation of glutamic acid residues on the Vit K dep clotting factors & inhibits Epoxide Reductase

15

drug of choice for ACUTE management of DVT

Heparin (activates antithrombin III)

16

type of leukemia that is more likely to present with a large mass in the mediastinum or neck, and cause symptoms like dysphagia

T-cell ALL (as apposed to B-cell ALL which presents w/ fever, malaise, bleeding, bone pain, hep/splenomegaly)

17

in a normal distribution, _____% lie within 1 SD, _____% within 2 SD and _______% within 3 SD'd

68% -- 1 SD 95% -- 2 SD 99.7% -- 3 SD

18

most common inherited bleeding disorder, causes a prolonged bleeding time and PTT

von Willebrand disease

19

what has the main control over Iron absorption and excretion in the body?

the liver -- specifically Hepcidin -Hepcidin is increased when you don't need to absorb any more Iron, it binds to and causes downregulation and degradation of Ferroportin

20

What enzyme converts Heme ---> Biliverdin and is thereby responsible for the greenish color of bruises

Heme Oxygenase

21

woman with heavy periods, her platelet count is normal & they aggregate normally in response to ADP but not to Ristocetin

vWF deficiency

22

drug treatment for vWF deficiency

Desmopressin --- b/c ADH stimulates the release of vWF from endothelial cells

23

A man with non-tender cervical lymph nodes has a biopsy shown here, cytogenetic analysis would likely show overexpression of _______________

Q image thumb

Bcl-2 

 

-Follicular lymphoma 

- t(14,18)

24

patient with mild jaundice, RBC peripheral smear is shown, the dx was made by osmotic fragility testing & an increased MCHC

Q image thumb

Hereditary Spherocytosis 

-no central pallor, spherocytes seen on smear 

 

25

megaloblastic anemia with foot numbness, difficulty walking , took years to develop b/c of large stores of _______ in the liver 

B12 (cobalamin) deficiency 

26

t(15,17) -- would likely be associated with a malfunctioning _______ receptor 

-M3 AML (Acute Promyelocytic Leukemia) 

- assoc w/ defect in RETINOIC ACID RECEPTOR

-hence you treat w/ ATRA

27

a mutation 3 bases upstream from the AUG start codon on a mRNA would impair ________

-mutation in the "Kozak sequence" causes impaired mRNA binding to ribosomes and INITIATING translation 

28

What cancer drug's toxicity is increased if given with Allopurinol?

6-Mercaptopurine 

- b/c it's metabolized by Xanthine Oxidase 

29

mechanism of Celecoxib 

-Selective COX 2 inhibitor 

- does not cause GI problems or decr platelet aggregation 

30

Common precipitating factors of G6PD deficiency anemia:

1- Infection

2- Drugs (Dapsone, Malaria drugs, TMP-SMX)

3- DKA

4- Fava beans 

31

a bone marrow sample w/ > 30% plasma cells in diagnostic for ____________

Multiple Myeloma 

32

-IL-1, IL-6 --> bone resorption , "punched out" lytic lesions on Xray 

- Rouleaux formation 

- Bence -Jones proteins (monoclonal light chains) in the urine 

- Amyloid deposits 

all characteristic of Multiple Myeloma 

33

What kind of cancer is associated with this cell?

Q image thumb

Hodgkin's Lymphoma 

 ((Reed Sternberg cell))

34

Use & Mechanism of HYDROXYUREA 

- treatment of Sickle Cell Anemia 

- increases the amount of HbF (which protects against sickling) 

35

tumor with a high Ki-67 fraction (nearing 100%) 

Burkitt's Lymphoma  (as a high mitotic index) 

36

things that can induce Sickling 

-low oxygen states

- acidity or high 2,3 DPG

37

Upper respiratory tract infection + pancytopenia 

Parvovirus (can cause aplastic anemia) 

38

hypocellular marrow filled with fat and fibrosis 

Aplastic anemia 

39

mainstay of DVT treatment in a pregnant woman 

Heparin 

(Warfarin is a teratogen & Aspirin & Clopidogrel are insufficient to treat a DVT)

40

increased indirect bilirubin 

should associate w/ hemolysis / hemolytic anemias 

41

the bluish color of reticulocytes is due to ______

increased r RNA 

42

child w/ Down Syndrome -- at risk for ___________ leukemia before age 5 and _________ leukemias after age 5 

before age 5 = megakaryoblastic leukemia

after age 5 = ALL 

43

Diseases associated with target cells 

"HALT said the hunter to his Target"

-HbC disease

-Asplenia

-Liver disease

-Thalassemia 

44

conditions associated w/ Basophilic stippling of the rbc

"Baste the ox TAIL"

-Thalassemias

-Anemia of chronic dz

-Iron deficiency 

-Lead poisoning 

45

Megaloblastic anemia with INCREASED methylmalonic acid 

B12 deficiency 

 

(folate deficiency has normal mm acid) 

46

Pt w/ pallor, early satiety, splenomegaly, fatigue -- found to have a Jak 2 mutation that causes constitutive tyrosine kinase activity and STAT activation...

Myelofibrosis 

-excess megakaryocytes --> produce PDGF --> causes marrow fibrosis 

-the splenomegaly can cause early satiaty & abd discomfort

((The 2 other chronic myeloproliferative disorders --> Polycythemia Vera & Essential Thrombocythemia also have a Jak2 mutation))

47

Leukemia that classically has increased BASOPHILS

CML

-t(9,22) , Bcr-ABL 

-Basophilia, translocation, and a negative Leukocyte Alk Phos (diff from leukemoid rxn)

48

Beta- Thalassemias are caused by __________

mutations that cause defective mRNA processing & therby low levels of globin chain synthesis 

49

lab abnormalities found in HUS

-prolonged Bleeding Time (due to decrs platelets)  

- incrs BUN, Cr & LDH 

50

bleeding after unfractionated Heparin treatment should be treated w/ ________

Protamine sulfate 

51

increased levels of HbA2 indicate ______

-Beta thalassemia minor (trait)

- or B-Thalassemia intermedia 

52

the _____ will be normal in pt's with CO poisoning, Anemia, Polycythemia, and Methemoglobinemia...

the partial pressure of Oxygen in the blood (the amount dissolved in plasma - doesn't change even if the Hb isn't binding O2) 

53

Pancytopenia in a patient with SLE is due to _______

formation of autoantibodies against blood cells ( a type II hypersensitivity rxn) 

54

a patient with recurrent DVT's and PE's , the PT & PTT are normal, and the PTT does not change with addition of activated protein C...

-Factor V Leiden mutation 

(normally activated protein C would inactivate factor V and prolong the PTT) 

55

Why are patients w/ sickle cell dz (or another chronic hemolytic dz) predisposed to becoming Folic acid deficient and developing macrocytic changes

- b/c they are constantly turning over erythrocytes and making new ones (using up folic acid) 

56

phosphorylation of the Rb gene causes it to be ____________ 

-inactive (ie: let down it's guard of the genome and ALLOW progression from G1 --> S phase) 

57

Her-2/Neu is also known as _________

ERB-B2 

58

the N-myc proto-oncogene is overexpressed in __________

Neuroblastoma 

59

the chemo drug Etoposide, works by ________

inhiibiting the activity of Topoisomerase II (causing double strand breaks to accumulate in the cancer cells) 

60

Small cell carcinoma of the lung is thought to have a ___________ origin

Neuroendocrine (will stain for markers such as chromogranin, synaptophysin...) 

61

How do you calculate Atrributable Risk %

ARP = (RR -1) / RR

 

or (Risk in the exposed - risk in unexposed) / Risk in the exposed 

62

most common indolent (lymph node gets bigger, then smaller in cycles) form of non-Hodgkin's lymphoma in adults 

Follicular lymphoma 

63

T-cell lymphoma, affects skin causing "Pautrier microabscesses"

Mycosis Fungoides

(CD4+ cells invade skin)

64

splenomegaly, pancytopenia in an older man, leukemic cells are + for TRAP (tartrate resistant acid phosphatase)

Hairy Cell Leukemia 

A image thumb
65

formula for "Number needed to harm"

NNH = 1/ Attributable risk 

66

What drug can be used to prevent the nephrotoxicity from Cisplatin (a DNA crosslinker) treatment?

Amifostine (and hydration)

67

mechanism of Cladribine 

-a purine analog that gets to high concentrations within the cell b/c it is resistan to degradation by ADA

- tx of choice for Hairy Cell Leukemia 

68