Pathoma TidBits Flashcards

1
Q

What factors lead to tumor invasion

A

Downregulation of E-cadherin leads to dissociation, attachment to laminin destroys basement membrane, attachment to fibronectin leads to local spread

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2
Q

What is the first step of primary hemostasis? What is it triggered by?

A

Transient vasoconstriction, by neural stimulation and endothelin release from endothelial cells

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3
Q

Through what receptor does platelet adhesion occur? Aggregation?

A

adhesion to vWF= GP1b. Aggregation: GPIIb/IIIa

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4
Q

What two mediators do platelets release after binding to vWF?

A

ADP- promotes GPIIb/IIIa receptor exposure and TXA2 (COX derivative) to promote aggregation

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5
Q

What’s the presentation of a patient with primary hemostasis disorder? When would you see petechiae?

A

Mucosal and skin bleeding: epistaxis, hemoptysis, GI, hematuria, menorrhagia; Quantitative disorders, not qualitative

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6
Q

ITP is an autoimmune antibody against what?

A

IgG against GPIIb/IIa from plasma cells in spleen

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7
Q

What are the lab findings in ITP: count, PT/PTT, cells

A

Low platelets, normal PT/PTT, inc megakaryocytes (from inc platelet production)

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8
Q

What is caused by TTP? Where are thrombi common?

A

Autoantibody against ADAMS13 (divides multipers to monomers for degradation) leads to abnormal platelet adhesion; CNS

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9
Q

How does HUS lead to platelet microthrombi?

A

E Coli 0157:H7’s verotoxin damages endothelial cells

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10
Q

What are the labs in TTP/HUS: platelet count, bleeding time, PT/PTT,?

A

Thrombocytopenia, inc bleeding time, normal PT/PTT, anemia with schistocytes and megakaryocytes

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11
Q

What is the effect of aspirin and uremia on platelets?

A

Aspirin, blocks COX, leads to no TXA2: platelet aggregation; uremia: adhesion and aggregation

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12
Q

What’s the genetic GP1b def? What’s the important feature? GPIIb/IIIa def?

A

GP1b= Bernard-Soulier (big platelets); GPIIb/IIIa= Glanzmann

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13
Q

How do secondary hemostasis disorders present generally?

A

Deep tissue bleeding into muscles and joints; re-bleeding after surgery

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14
Q

Draw the coagulation cascade

A

INT: 12, 11, 9, 8. Ex: 7. Common: 10, 5, 2, 1.

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15
Q

What activates each pathway? How is it measured?

A

Intrinsic: subendothelial collagen, PTT. Extrinsic: PT, tissue thromboplastin

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16
Q

Cause of hemophilia A? B? How to differentiate between hemophilia A and anti-VIII?

A

A= Eight; B= Nine. Mixing study! PTT doesnt correct if Antibodies are present

17
Q

Labs in vWF def? Treatment?

A

Inc bleeding time (poor adhesion), inc PTT (vWF stabilies factor 8), abnormal ristocetin test. Desmopressin! It induces release from WP bodies

18
Q

How does Vit K assist coagulation?

A

It is activated by epoxide reductase (MOA of warfarin), and once activated gamma carboxylates II, VII, IX, X, C and S