Term
| Cause and process of megaloblastic maturation in the bone marrow |
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Definition
| Megaloblastic anemia is classified as a nuclear maturation defect, large degree of ineffective Erythropoiesis resulting from disrupted DNA synthesis. Megaloblasts describes any maturation stage of the megaloblastic erythroid series, bone marrow is hypercellular with megaloblastic erythroid precursors and decreased M: E ration |
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Term
| Body’s requirements for vitamin B12 and folate and their physiologic role |
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Definition
| Both are vitamins necessary as coenzymes for nucleic acid synthesis, B12 deficiency is secondary to an intrinsic factor deficiency (factor necessary for absorption of B12). Folic acid deficiency is due to inadequate dietary uptake |
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Term
| Tests used to confirm a diagnosis of vitamin B12 deficiency |
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Definition
| Measurement of increased excretion of methylmalonic acid in the urine indirectly indicated decrease in B12 levels. Homocysteine is increased in people with B12 deficiency |
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Term
| Tests used to confirm a diagnosis of folic acid deficiency |
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Definition
| Serum and erythrocyte folate levels must be decreased |
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Term
| six most common disorders that result in a macrocytic anemia |
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Definition
| (1) Alcoholism (2) liver disease (3)stimulated Erythropoiesis (4) hypothyroidism (5) B12 deficiency and (6) folate deficiency |
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Term
| Pernicious anemia etiology |
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Definition
| absence of IF secondary to gastric atrophy (leads to B12 deficiency) |
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Term
| Pernicious anemia Pathophysiology |
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Definition
| gastric atrophy is thought to result from immune destruction of the acid-secreting portions of the gastric mucosa |
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Term
| Pernicious anemia Clinical symptoms |
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Definition
| gastric atrophy, achlorhydria of gastric juice, IF antibodies, agammaglobulinemia |
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Term
| Pernicious anemia Clinical subtypes |
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Definition
| juvenile pernicious anemia- secondary to a variety of conditions, absence of IF factor |
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Term
| Four causes of a folate deficiency |
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Definition
(1) Inadequate diet
(2) Increased requirement
(3) Malabsorption
(4) Drug inhibition |
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Term
| Laboratory characteristics of Inadequate diet |
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Definition
| vacuolated erythroid precursors, anemia is macrocytic but no megaloblastic |
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Term
| Laboratory characteristics of Increased requirement |
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Definition
| stores are rapidly depleted, hemolytic anemia |
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Term
| Laboratory characteristics of Malabsorption |
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Definition
| intestinal diseases, ileitis, tropical sprune, nontropical sprune |
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Term
| Laboratory characteristics of Drug inhibition |
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Definition
| serum and erythrocyte folate are depressed |
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Term
| Pathophysiology of megaloblastic anemias |
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Definition
| nuclear maturation defect |
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Term
| Peripheral blood of megaloblastic anemias |
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Definition
| macrocytic, normochromic, oval macrocytes, Howell-jolly bodies and hypersegmented neutrophils |
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Term
| Peripheral blood smear for Folate deficiency |
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Definition
| hypersegmented neutrophils |
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Term
| Peripheral blood smears for B12 deficiency |
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Definition
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Term
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Definition
| defects in any step of the vitamin B12 metabolism can lead to vitamin B12 deficiency and megaloblastic anemia. Vitamin B12 is released from food via peptic digestion at a low pH in the stomach; it binds to R-protein. In the duodenum, R-factor is degraded and B12 is released and binds to IF, IF and B12 move to ileum where it binds to IF receptors, entire complex is taken into the cell and then B12 is released |
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Term
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Definition
| absorbed in the intestine, folate is reduced into a form that can circulate in the blood, once inside the cell is has to be demethylated in order to stay inside the cell |
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Term
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Definition
| Deficiency occurs in impaired DNA synthesis and defective fatty acid degradation |
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Term
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Definition
| Deficiency occurs in the decreased synthesis of the circulating form which is a cofactor for DNA synthesis |
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Term
| Macrocytosis associated with a megaloblastic marrow |
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Definition
| macrocytes are not as pronounced; macrocytes are round rather than oval, no hypersegmented neutrophils, normal platelets. Jaundice, glossitis, neuropathy are common |
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Term
| Macrocytosis associated with a normoblastic marrow |
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Definition
| increased membrane lipids, cells usually round |
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Term
| maturation defects that lead to megaloblastosis |
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Definition
| Folate deficiency, B12 deficiency, or chemotherapy, orotic aciduria or CDA |
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Term
| morphologic blood cell abnormalities in meglablastosis |
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Definition
| Macrocytes, normochromic anemia, decreased cell count, Ovalocytes, Howell-jolly bodies, Polychromasia, hypersegmentation of neutrophils |
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Term
| Folate deficiency caused by |
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Definition
| inadequate diet, increased requirement, malabsorption, or drug inhibition |
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Term
| Clincal Symptoms of Folate deficiency |
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Definition
| low income, diseases associated with rapid cell turnover, ileitis, tropical sprune, oral contraceptives, bacteria overgrowth in small intestine |
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Term
| Laboratory results for Folate deficiency |
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Definition
| serum and folate levels decreased |
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Term
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Definition
| impaired DNA synthesis, defective fatty acid degradation |
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Term
| clincal symptoms of B12 deficiency |
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Definition
| pernicious anemia, gastroectomy, crohn’s disease, tropical sprune, intestinal parasite, strict vegan diets, nitrous oxide inhalation |
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Term
| Causes of pernicious anemia |
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Definition
| absence of IF secondary to gastric atrophy |
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Term
| Clinical variations of pernicious anemia |
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Definition
| juvenile pernicious anemia |
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Term
| Causes of Folic acid deficiency |
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Definition
| inadequate diet, increased requirement, malabsorption, drug inhibition |
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Term
| Clinical forms of folic acid deficiency |
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Definition
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Term
| Folate deficiency results in megaloblastic maturation |
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Definition
| due to slowing of DNA synthesis and the S phase if prolonged. Hematopoietic cells show characteristic megaloblastic changes due to folate deficiency. Erythrocytes survive less than 120 days in the peripheral blood |
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Term
| Vitamin B12 deficiency results in megaloblastic maturation |
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Definition
| due to impaired DNA synthesis and defective fatty acid degradation |
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Term
| four laboratory tests used to identify the cause of a macrocytic anemia |
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Definition
| MCV, RBC membrane cholesterol, reticulocytes, morphology |
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Term
| causes of macrocytosis with a normaloblastic marrow |
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Definition
| alcoholism, liver disease, hemolysis, hypothyroidism, aplastic anemia |
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Term
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Definition
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Term
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Definition
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