Drugs and Diseases: hematopoiesis

Question 1

describe microcytic, hypochromic anemias?

Answer 1

• impaired Hb synthesis
• Fe deficiency
• lead poisoning
• thalassemia

Question 2

describe macrocytic, normochromic anemias?

Answer 2

• impaired DNA synthesis

- B12 or B9 (folate) deficiency

Question 3

describe normocytic, normochromic anemias?

Answer 3

• red cell loss
• severe bleeding
• sickle cell anemia
• pyruvate kinase deficiency
• G6PDH deficiency

Question 4

what is thrombycytopenia?

Answer 4

low platelet count

Question 5

name 2 congenital bleeding disorders

Answer 5

1. Bernard-Soulier syndrome

2. fibrinogen deficiency

Question 6

what is bernard-soulier syndrome?

Answer 6

GPIb-IX deficiency

Question 7

name an acquired bleeding disorder

Answer 7

thrombocytopenia:
- defective formation of megakaryocytes (leukemia)
- excessive destruction of platelets (anti-platelet Abs)

Question 8

what are 3 antiplatelet drugs and how do these function?

Answer 8

plavix: inhibit receptor for ADP
ticlopidine: inhibit receptor for ADP
dipyridamole: bind ADP, prevent binding to receptor

used to treat/prevent arteriral thrombosis

Question 9

what do leeches have that inhibits clot formation?

Answer 9

hirudin

Question 10

what is dicoumarol?

Answer 10

vitamin K antagonist -> prevents binding to Ca2+ (spoiled clover)

Question 11

what is warfarin?

Answer 11

vitamin K antagonist -> anticoagulant

Question 12

aPTT: what does it test, what does long time mean, what is it used to monitor?

Answer 12

activated partial thromboplastin time

• test of INTRINSIC pathway
• long time: deficiency in VIII, IX, XI, XII
• monitor intravenous heparin

Question 13

PT: what does it test, what does long time mean, what is it used to monitor?

Answer 13

prothrombin time

• test of EXTRINSIC pathway
• factor III added to plasma -> specific for reduced VII, but also X, II
• monitor warfarin

Question 14

what is bleeding time used to measure?

Answer 14

platelet fxn

Question 15

what is PT used to measure?

Answer 15

• vitamin K deficiency
• warfarin/oral anticoagulant
• liver disease (good marker for liver failure after acetaminophen overdose)

Question 16

what is aPTT used to measure?

Answer 16

• heparin therapy

- hemophilia A

Question 17

what does congenital deficiency in antithrombin III cause?

Answer 17

-increased risk of venous thromboembolism (DVT, PE)

Question 18

what does factor V leiden mean?

Answer 18

variant factor V - resistant to protein C -> increase in clotting

Question 19

what is hemophilia A/classic hemophilia?

Answer 19

• deficiency in VIIIa (which activates Xa)
• x-linked, many mutations
• prolonged wound bleeding + easy bruising

Question 20

treatment for hemophilia?

Answer 20

• human plasma

- recombinant factor VIII

Question 21

what is von Willebrand disease?

Answer 21

• defective platelet adhesion -> increased bleeding time

- more common than hemophilia

Question 22

what two deficiencies can cause hemolytic anemia?

Answer 22

• pyruvate kinase deficiency

- G6PDH deficiency

Question 23

how does pyruvate kinase deficiency cause hemolytic anemia?

Answer 23

less ATP -> failed cation gradient -> lose K+, H2O -> cell dehydration -> hemolytic anemia

Question 24

why are symptoms of pyruvate kinase hemolytic anemia less severe than expected?

Answer 24

2,3-BPG results in greater release of O2 to tissues

Question 25

treatment for pyruvate kinase deficiency?

Answer 25

• transfusions

- splenectomy (to prevent hemolytic anemia)