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24 Cards in this Set
- Front
- Back
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what does uremia do to the bone marrow?
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makes it less responsive to EPO
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what is hydroxyurea used for?
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increases production of fetal hemoglobin HbF
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what are Howell Jolly bodies?
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inclusions of nuclear chromatin remnants seen in RBCs of pts with hypoactive splenic function
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why should sickle cell patients consider prophylactice cholecystectomy?
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70% of sickle cell patients develop symptomatic cholelithiasis
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why does hepatosplenomegaly develop in thalassemia pts?
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increased hemolysis of abnormal RBCs by macrophages in the spleen and liver; extramedullary hematopoiesis
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where is dietary iron absorbed and in what form?
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absorbed in proximal duodenum; we eat Fe+++ and absorb as Fe++
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why do pts with chronic disease develop anemia?
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1. chronic inflammation leads to more cytokines in blood and resulting increase in phagocytic activity destroying RBCs
2. cytokines inhibit renal secretion of EPO 3. lactoferrin released by inflammatory cells binds serum iron and makes it unavailable for erythropoiesis |
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what's the big picture problem in anemia of chronic disease and iron?
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high iron stores, but unavailable to the body
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what does B12 do?
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1. catalyzes conversion of homocysteine to methionine
2. catalyzes conversion of methyltetrahydrofolate to tetrahydrofolate 3. converts methylmalonic acid to succinyl CoA |
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what is tetrahydrofolate?
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form of folic acid used in DNA synthesis
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what is G6PD?
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the rate-limiting step in HMP pathway for NADPH production
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what is glutathione?
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after reduction by NADPH, it combats oxidatative damage in cells
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what is primary hemostasis?
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production of the temporary platelet plug
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how does tPA work as a clot buster?
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it's an enzyme that activates plasminogen, converting it to plasmin which cleaves fibrin strands
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how does heparin work?
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stimulates antithrombin III, which inhibits thrombin (factor II)
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what is microangiopathic hemolytic anemia?
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hemolytic anemia due to intravascular fracture of RBCs
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E. coli 0157 and Shigella species are known for causing what heme dysfunction?
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TTP or HUS
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what's the main problem in TTP or HUS?
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endothelial damage leads to platelet consumption
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what does desmopressin acetate (DDAVP) do?
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stimulates the liver to produce plasma clotting factors
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what are 2 common causes of acquired platelet dysfunction?
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uremia and NSAIDs
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how do clopidogrel and ticlopidine work?
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these 2 antiplatelet drugs block platelet-ADP receptor activation
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how do abciximab, eptifibatide and tirofiban work?
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inhibit platelet GpIIb-IIIa receptor which mediates aggregation via a "fibrinogen bridge"
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what anticoagulant can cause thrombocytopenia?
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heparin in 1-3% of pts;
can cause 2 syndromes: HITS: heparin induced thrombocytopenia syndrome HITT: heparin induced thrombocytopenia thrombosis |
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how can ITP be treated?
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prednisone to slow the immune-mediated destruction of platelets
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