Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.1.7 (acetylcholinesterase)
 28,390 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A rapid technic for the age-fractionation of human erythrocytes into reticulocyte-enriched (young) red blood cells and reticulocyte-poor (old) red blood cells using an isopycnic density gradient centrifugation through Percoll-Renografin was evaluated for use in autologous red blood cell antigen determinations in multiply-transfused patients. The fractionation was demonstrated by statistically significant density-related changes in pyruvate kinase and acetylcholinesterase activities (P = 0.002 and 0.042, respectively) and by the distribution of reticulocytes on the gradient (P less than 0.005). With initial reticulocyte counts of less than or equal to 1.5%, reticulocyte counts up to 78% were achieved (means = 25%; n = 31). When starting with reticulocyte counts greater than 5%, samples containing up to 98% reticulocytes were obtained (means = 64%; n = 7). The technic requires less than two hours, uses isotonic media, and is nontoxic to red blood cells. Volumes of red blood cells up to 10 mL can be fractionated at one time and the gradient medium is stable when refrigerated at 4 degrees C. Red blood cell typing was performed in six patients who had received from 4-29 units of blood within a 12-hour period. Within 72 hours posttransfusion, typing of the reticulocyte enriched fraction correctly identified the patient's red blood cell antigens with all 16 antisera tested. This technic for typing reticulocyte-enriched samples is of importance for confirmation of antibody specificity in determining whether an antibody is an alloantibody or autoantibody, and in the selection of donor blood for transfusion to patients having autoimmune hemolytic anemia.
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PMID:Erythrocyte age-fractionation using a Percoll-Renografin density gradient: application to autologous red cell antigen determinations in recently transfused patients. 631 92

Acetylcholinesterase of human erythrocytes from healthy donors and from patients with hematological disorders was analysed in a search for differential membrane parameters. Two substrates were used to estimate the exposure of acetylcholinesterase active site in the membrane: phenylacetate, a hydrophobic substrate, to determine total enzyme activity, and acetylcholine, an ionic substrate, to measure the externally reactive enzyme. The sensitivity of acetylcholinesterase to added stearic acid was also analysed. Three categories of the disorders studied were discerned: (a) The erythrocyte acetylcholinesterase profile was indistinguishable from normal control in beta-thalassemia minor and groups of patients with autoimmune hemolytic anemia or congenital dyserythropoietic anemia type II. (b) A marked decline in acetylcholinesterase with both substrates and reduced sensitivity to stearic acid were exhibited by the erythrocytes of paroxysmal nocturnal hemoglobinuria, beta-thalassemia major and other autoimmune hemolytic anemia and congenital dyserythropoietic anemia type II patients. Normal erythrocytes, either aged or pretreated to 50 degrees C, also showed similar characteristics. (c) Hereditary spherocytosis was singly differentiated by an elevated acetylcholinesterase activity with acetylthiocholine and by a vastly diminished sensitivity to stearic acid, while activity with phenylacetate was equal to control. This distinct profile may reflect the unique organization of the erythrocyte membrane in hereditary spherocytosis.
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PMID:Unique profile for erythrocyte membrane acetylcholinesterase in hereditary spherocytosis. 684 70