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Flashcards in Week 5 Deck (62):
1

von Willebrand Factor

Multimeric glycoprotein that is stored in platelets. binds to subendothelial collagen at sites of vascular injury, and binds to glycoprotein IB at the platelet surface. Also binds to and stabilizes coag. factor VIII

2

Phospholipase A2

after plateets adhere to collagen, and increased intracellular Ca2+, phospholipase A2 is released which hydrolyzes membrane phospholipids liberating arachadonic acid

3

TXA2

is a potent vasoconstrictor and inducer of platelet aggregation that functions by binding to receptors

4

Myosin Light Chain Kinase

Activated by released Ca2+ stores, phosphorylates the light chain of myosin which interacts with actin leading to platelet shape change.

5

GPIIb-GPIIIa

Is a receptor for vonWildebrands factor and fibrinogen leading to fibrinogen induced platelet aggregation. It is inhibited by abciximab.

6

Fibrinogen

Protein which circulates in the blood, also found in platelet granules. Is composed of 3 pairs of polypeptide chains linked by disulfide bonds. Binds platelets helping them bind together.

7

Thrombin

Cleaves fibrinogen to fibrin which polymerize and form a soft clot with platelets. Also activates platelts by binding to specific receptors leading to phospholipase C leading to IP3 (Ca2+ release) and DAG (activates protein kinase C)

8

Extrinsic Pathway

Initiated at the site of injury in response to tissue factor release which is a cofactor in the factor VIIa catalyzed activation of factor X

9

Tissue Factor

is an integral membrane protein that is expressed on surface of activated monocytes, and endothelial cells exposed to cytokines. Not found in plasma

10

Extrinsic pathway steps

Tissue injury leads to tissue factor which binds to and activates factor VII->VIIa. TF-VIIa can activate IX-> IXa. Factors IXa and Xa assemble with their non-enzymatic protein cofactors on the surface of aggregated platelets leading to large amounts of Xa and thrombin(IIa). and conversion of fibrinogen to fibrin... common pathway

11

Intrinsic Pathway

also called the contact activation pathway, much less significant to hemostasis under normal physiological conditions than is the extrinsic. Hyperlipidemia or sepsis can lead to activation of thrombosis via the intrinsic clotting cascade.

12

Intrinsic pathway steps

Factor XII is converted to XIIa by HMWK collagen. Factor XIIa converts XI to XIa. XIa converts IX to IXa which binds VIIIa (which was activated by thrombin). IXa-VIIIa convert X->Xa. common pathway

13

Common Pathway

IXa and VIIIa convert X to Xa in presence of Ca2+. Xa converts prothrombin(II) to thrombin using prothrombinase and factor Va(activated in minute amounts by increasing thrombin). Thrombin(IIa) converts fibrinogen to fibrin. Fibrin is cross linked by XIIIa (also activated by thrombin).

14

Antithrombin III

Most important thrombin inhibitor. inhibits activities of factors IXa, Xa, XIa and XIIa, plasmin, and kallikrein leading to clot dissolution. Activity is potentiated by heparin

15

Heparin Sulfate

Is on the surface of vessel endothelial cells, and regulates antithrombin III.

16

Protein C

Is a trypsin like serine protease It uses Protein S as a cofactor. It, along with activated protein C degrade Va and VIIIa via proteolysis, decreasing thrombin production. Protein S anchors the activated Protein C complex to the clot. Activated protein C also stimulates endothelial cells to increase secretion of prostaglandin I2 which reduces platelet aggregation.

17

Fibrinolysis

Involves the degradation of fibrin in a clot by plasminin.

18

Plasmin

is a serine protease that is formed by plasminogen. It degrades fibrin in a clot.

19

Plasminogen

has a high affinity for fibrin, promoting the incorporation of plaminogen in the developing clot. it is mediated by activators which turn it to plasmin.

20

Tissue Plasminogen activator

Clears up clots especially in central lines.

21

Vitamin K

is required in many factors for blood coagulation. It is needed for gamma carboxylation which occurs in the hepatocyte before clotting factor release.

22

Warfarin

is slow and long acting bloodanticoag. It competes with vitamin K and prevents gamma-carboxylation of glutamate residues in factors II, VII,IX,X, proteinsC and S. The factors cannot bind Ca2+or form the complexes necessary for the coagulation cascade to be initiated. IT DROPS PROTEIN C AND S LEVELS FIRST LEADING TO INCREASED CLOTTING AT FIRST. must bridge with heparin.

23

Heparin

Binds to annd activates ATIII which leads to thrombin inactivation, blocks the activity of factors VIIIa, Ixa, Xa, and Xia by potentiating antithrombin 3 preventing a clot.

24

IL-2

Released from T cells after binding with APC, supports growth and expansion of T, B and NK cell populations, can self activate

25

IL-10

Made by Treg, Th2. Suppressor of T cell effector cells, blocks IL-2 and downregulation of T cell cytokines and MHC class II expression

26

IL-12

(IFN y), made by M1 macrophages after Th1 cells stimulate them them with IFNy. Made by dendritic cells topromote the growth and survival of Th1, CD4+ cells and blocks the growth of Th2 cells

27

IL-35

Also made by T-regs. blocks IL-1 and IL-2 dependant T cell proliferation.

28

IFNy

produced by TH1 and activates M1 macrophages.

29

Anergy

T cell doesn't get proper signaling including B7 from APC and dies off to control population.

30

TGF B

it and IL-35 will turn a TH1 cell to a Treg cell.

31

B cell activation

CD4+ T cell must have CD40 ligand on it which will interact with CD40 on APC to activate them.

32

Thymus independent B cells B1

have CD5 on them, can be activated through TCR or BCR

33

Thymus independent B cells B2

BCR and costimulators, complement

34

CD-44

allows T cells to hone in to migrate to the tymus .

35

Fox3

master transcriptional regulator responds to input signal which then drives transcription of certain genes for Treg cells Tbet=Th1

36

IPEX Syndrome

an inborn lack of Treg cells is the cause of severe autoimmune inflammation in patients with this disease. Mutations in Foxp3.

37

TLR 4 deficiency

Involved in LPS detection, has deficiency found in africa, asia, and europe. results in higher increase in TNFa when stimulated with LPS, is better protection from cerebral forms of malaria.

38

SCID

immunodeficiency caused by a number of different genes, results with lack of T cell response.

39

alpha Granules

contain fibrinogen, vWF

40

delta Granules

contain serotonin, ADP, Calcium

41

Glycoprotein Ia

Binds Collagen

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Glycoprotein Ib

Binds vWF

43

Glycoprotein IIIb-IIIa

binds fibrinogen

44

Tissue factor pathway inhibitor

The way that Xa shuts off the extinsic pathway on the tissue factor VIIa complex.

45

Protein C and S fx.

Shutdown factors VIII and V.

46

Antithrombin III

shuts down almost all parts of the pathway in both the intrinsic, extrinsic and common pathways.

47

Closure Time

Alternate to bleeding time, measures how quickly platelts occlude small holes in a membrane.

48

Platelet aggregation

add aggegating agents to blood sample and see if platelts aggregate. Looking for platelet function abnormalities.

49

Competitive ELISA

have known antigen bound to bottom of tray, and add patient serum which should contain antigen. Then add fluorescent antibody. The less light means the more antigen in the patient sample.

50

Direct ELISA

Have Antibody for antigen on bottom, add antigen/ sample, rinse, and then add same antibody but fluorescently labeled to dish and measure color

51

Rouleaux

Lots of red cells stacked up together mostly only involved with myeloma.

52

Triad of Myeloma

Bone pain, renal failure, and anemia

53

von Willebrand Disease

most common bleeding disorder, autosomal dominant, variable severity. Mucosal bleedin in most patients, deep joint bleeding in severe cases. Prolonged bleeding time, PTT is prolonged, but normalizes with mixing study. INR: normal. Type I is absent vWF, Type II is deformed vWF.

54

Hemophilia A

X- linked recessive disorder. FACTOR VIII deficiency. Sx.- bleeding, deep, with possible joint deformities, and sometimes mucosal hemorrhage. INR, TT, Platelet count, bleeding time, all normal. PTT prolonged and corrected with Mixing study. Factor VIII low. DNA studies abnormal.

55

Hemophilia B

X- linked recessive, FACTOR IX deficiency. much less common than hemophilia A. same clinical findings and sx.

56

Disseminated Intravascular coagulation

Something leads to lots of clotting, using up all the clotting factors and platelets, then have bleeding problems. Have microangiopathic anemia. May be due to obstetric complications, adenocarcinoma, acute promyelocytic leukemia. Also could be from bacterial sepsis, trauma, burns, vasculitis, MOST (malignancy, Ob, Sepsis, and trauma).

57

Idiopathic Thrombocytopenic Purpura

diagnosis of exclusion. have autoantibodies to GP IIb-IIIa, or Ib, binds to platelets, machrophages eat platelts. Chronic: adult women, primary or secondary, see nosebleeds and easy bruising, can bleed on brain
Acute: kids, abrupt after viral ilness, self limiting, may be chronic

58

Thrombotic thrombocytopenic Purpura

pentad: MAHA(MicroAngiopathicHemolyticAnemia), thrombocytopenia, fever, neurologic defects, renal failure. It is a deficiency of ADAMTS13 which metabolizes vWF.

59

Embolis

Is a traveling thrombus, often plugs up an artery.

60

Factor V Leiden

most common cause of unexplained thromboses. Point mutation in factor V gene, factor V cannot be turned off. Need genetic test for diagnosis. Mutated factor V gene. Cannot be cleaved by protein C. normal tests. Can only treat when a thrombus is present, with anticoagulant.

61

Antithrombin III deficiency

- it is a natural anticoagulant inhibiting just about everything, mutated gene produces less ATIII. Heparin doesn't work, antithrombin concentrates required.

62

Protein C and S deficiencies

Inactivates Va and VIIIa, and keeps cytokines low. deficiency from mutation can lead to clotting, can have warfarin induced skin necrosis.