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17 Cards in this Set
- Front
- Back
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factory is on strike or dead
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aplastic anemia
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stem cells mature but proliferate; failure of population control
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myeloproliferative disorders
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factory is working but product is defective
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myelodysplastia (marrow is normal but mature cell counts are low)
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factory is working but children never grow up
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acute leukemias
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define: plasma cell dyscrasias
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arise in ppl with anemia and Ig spikes
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identify sites of hematopoiesis:
-during fetal life - during adult life |
fetal: liver, spleen & thymus (at 3 months), bone marrow (at 6 months), cord blood
adults: vertebrae, ribs, sternum, skull, sacrum/pelvis, proximal ends of femus |
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describe hematopoietic stem cells in 3 phrases
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-can proliferate greatly
-has ability for self-renewal -able to differentiate into mature progeny (pluripotency) |
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what is the next step after hematopoietic stem cells?
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progenitor cells (restricted lineage potential, limited proliferative capacity)
ie. CFU-L (pro-B and Pro-T cell), BFU-E; CFU-Eo, etc. |
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identify maturation sequence for the process of erythropoiesis and genetic factors that influence differentiation
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erythropoiesis - look for basophilic erythroblasts in bone marrow; erythropoietin (EPO) mediates progenitor response to oxygen demand
EPO stim CFU-E --> BFU-E, leading to erythrocyte production various transcription factors effect this pathway |
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identify maturation sequence for myelopoiesis and genetic factors that influence differentiation
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HSC --> GEMML --> GEMM --> GM (PU.1) --> DIFF GRANULOCYTES (GM-CSF) BASED ON ADDITONAL FACTORS
CFU-GM --> CFU-G or CFU-M transcription factors like G-CSF drive myelopoiesis to produce neutrophils specfiically; M-CSF drives monocyte/macrophage differntiation |
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where does the majority of granulocyte maturation take place?
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within bone marrow or tissue
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what drives the process of megakaryopoiesis (making platelets)?
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PHSC (stem cells )becomes megakaryocytes under regulation of TPO (thrombopoietin) and its receptor (c-mpl)
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where is TPO primarily expressed and regulated?
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primary expression by liver; regulated by end organ binding (ie. platelets and megakaryocytes)
when there is low platelets, less TPO is bound and is free to stim maturation of megakaryocytic progenitors |
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name the state where hematopoietic tissue is replaced with fat, resulting in pancytopenia
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bone marrow failure (aplastic anemia)
pancytopenia = 2 or more cell lines are depressed |
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name one type of inherited aplastic anemia (bone marrow failure syndrome) and give its characterisitics
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fanconi anemia (FA)
- autosomal recessive - phenotype: skin hyperpigmentation; short stature; absent thumbs - dz that may evolve into aplastic anemia |
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pathophysiology of acquired severe aplastic anemia
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immune-mediated antigen presentation, activates CD8 t-cells that secretes TNF and gamma-interferon to target CD34+ HSC (hematopoietic tissue), leading to HSC apoptosis and aplastic anemia (destroying bone marrow)
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Describe the mechanisms for acquired pancytopenia and pathophysiology of acquired bone marrow failure and discuss some treatment options
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immune destruction, immune-mediated infectious agents (HIV, parvovirus, etc), hepatitis associated AA
tx: transfusion, G-CSF, bone marrow transplant (in younger children with HLA match); for adults >20 y/o and children without match ==> combined therapy with ATG, CSF, and G-CSF has been historical tx of choice |
