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)

1. Clonal theories of disease, particularly progressive clonal growth and selection in tumorogenesis, were briefly cited. 2. Evidence for the clonal nature of PNH was presented. Correlation of red cell hemolysis with (a) G-6-PD type in two female G-6-PD mosaics with PNH and with (b) erythrocyte acetylcholinesterase deficiency, provides strong evidence for the clonal theory of PNH. 3. Possible pitfalls in defining "hidden PNH clones" in other diseases by the use of PNH hemolytic tests were discussed. 4. The potential of PNH as a study model for clonal evolution in human disease was emphasized.
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PMID:Paroxysmal nocturnal hemoglobinuria (PNH) as a clonal disorder. 32 58

The susceptibility to autoxidation of red cell lipids was studied before and after transformation of normal red cells to PNH-like erythrocytes. The transformation was effected by treatment of the red cells with the sulfydryl compounds D-penicillamine (DP) and N-acetyl-L-cysteine (NAC). The autoxidation was induced by incubating the cells with H2O2 and was estimated by measuring the generated malonyl dialdehyde. The susceptibility to autoxidation was significantly higher in DP-treated cells, while the opposite was true for NAC-treated cells. However, both DP- and NAC-treated cells showed a similar sensitivity to lysis by acid serum and about the same degree of acetylcholinesterase (AChE) activity decrease, thus indicating that the susceptibility to autoxidation of lipids is not involved in the determination of complement sensitivity or in the AChE activity decrease of the sulfydryl-treated cells. Finally, since, as evidenced from most of the reported cases in the literature, increased susceptibility to autoxidation is a feature of PNH cells, it seems reasonable to suggest that DP-treated cells should be used in preference to NAC-treated cells as a laboratory substitute for PNH cells.
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PMID:Susceptibility to autoxidation of lipids of paroxysmal nocturnal hemoglobinuria (PNH)-like red cells. 40 34

A 36-year-old white man was found to have low erythrocyte acetylcholinesterase activity. Plasma cholinesterase activity was normal. The propositus had mild anemia and moderate elliptocytosis, but was asymptomatic. A sister, brother, father, and nephew were hematologically normal, but had slightly subnormal red cell acetylcholinesterase activities. There was no exposure to organophosphates, and paroxysmal nocturnal hemoglobinuria was excluded. Mixing experiments failed to demonstrate the absence of an activator or the presence of an inhibitor. The propositus enzyme showed normal kinetics for the substrate and various inhibitors, normal thermostability, and electophoretic migration. Major protein bands of the red cell membrane were normal by electrophoresis. Membrane cholesterol and phospholipid content were also normal. The mild anemia is presumably secondary to the presence of moderate elliptocytosis. The pattern of inheritance of the variant gene is unclear, but the propositus may be homozygous for the abnormal allele, and other family members may be heterozygous.
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PMID:Hereditary deficiency of erythrocyte acetylcholinesterase. 54 20

Normal human red cells incubated with saline extracts of tea develop paroxysmal nocturnal hemoglobinuria-like defects as demonstrated by positive acid and sucrose hemolysis tests. All of a variety of tea preparations tested provoked a sensitivity to complement-dependent hemolysis and, with one exception, a moderate decrease in red cell acetylcholinesterase activity. Complement-dependent hemolysis in teaincubated red cells was inhibited by antisera to C3 and C3 activator, but not by antisera to C4. This suggests that incubation with tea may alter the red cell membrane in a way that specifically potentiates the lytic effects of the alternate pathway of complement, but not the classic pathway. Leupeptin, a protease inhibitor, also prevented complement-dependent hemolysis of red cells incubated with tea. Although the clinical consequences of these observations are unknown, the study was initiated following a report of a young male who had developed an acute limited intravascular hemolytic episode following ingestion of large quantities of a herbal tea.
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PMID:Production paroxysmal nocturnal hemoglobinuria-like red blood cells by tea. 59 68

Erythrocytes from a heterogeneous group of hemolytic anemias have been found to release acetylcholinesterase-enriched fragments and show myelin forms during ATP depletion in vitro. The highest amount of fragmentation was found in hereditary spherocytosis and xerocytosis, two inherited membrane defects. Our data suggest ATP depletion plays a role in producing fragmentation or myelin forms. The addition of external CaCl2 1 mM had no effect on the degree of fragmentation. However, propranolol hydrochloride, a cationic anesthetic that does not prevent ATP depletion, inhibited fragmentation and the appearance of myelin forms in both hereditary spherocytes and xerocytes. A more detailed study of the xerocyte fragments showed that they had the same protein composition as those from normal red cells, primarily integral membrane proteins and glycoproteins. The red cells from patients with PNH and G6PD deficiency had the shortest survival in vivo (51Cr) and produced the smallest amount of fragmentation and myelin forms in vitro, whereas xerocytosis with only mild to moderate hemolysis in vivo was associated with the highest amount of myelin forms and membrane fragments in vitro.
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PMID:Fragmentation and myelin formation in hereditary xerocytosis and other hemolytic anemias. 68 29

Appearance of low molecular components of acetylcholinesterase from erythrocyte membranes was found by gel filtration on Sephadex G-200 and polyacrylamide gel disc electrophoresis. Content of these components was distinctly increased within ghe acute period of Marchiafava-Micheli disease.
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PMID:[Acetylcholinesterase of erythrocytes in various blood diseases]. 102 96

Erythrocytes from patients with paroxysmal nocturnal hemoglobinuria are deficient in decay-accelerating factor (DAF), a factor called C8-binding protein or homologous restriction factor, acetylcholinesterase (AchE), and lymphocyte function-associated antigen 3 (LFA-3). These proteins share a common feature that glycan-inositolphospholipid anchors the protein to the membrane, suggesting that an abnormality related to this glycolipid causes multiple protein deficiencies. The relationship between the DAF, AchE, and LFA-3 defects was studied by fluorescent flow cytometric analysis. In five patients, DAF-negative erythrocytes were also AchE-negative. In three patients, a fraction of DAF-negative erythrocytes expressed subnormal levels of AchE, indicating that AchE was synthesized in these DAF-negative cells. Erythrocytes from the patients having DAF-negative, AchE-positive cells were separated according to density and analyzed for expression of DAF and AchE. Both proteins decreased with increase of cell density, suggesting that DAF-negative, AchE-positive cells become AchE-negative during erythrocyte maturation by losing AchE. A low level of LFA-3 was found on DAF-negative erythrocytes from one patient and decreased with erythrocyte maturation. These results support an idea that complete deficiency of glycan-inositolphospholipid-anchored proteins on erythrocytes could result from abnormally early termination of surface recruitment of these proteins, and subsequent dilution through cell divisions and loss from the surface.
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PMID:Acetylcholinesterase and lymphocyte function-associated antigen 3 found on decay-accelerating factor-negative erythrocytes from some patients with paroxysmal nocturnal hemoglobinuria are lost during erythrocyte aging. 168 24

Red blood cells from patients with paroxysmal nocturnal hemoglobinuria (PNH) were found to be liable to vesiculate, as demonstrated by both DMPC liposome- and CaCl2-induced vesiculation and measured in terms of acetylcholinesterase activity and 3H-inositol radioactivity in the supernatant. Membrane proteins released from the cells during vesiculation included several constituents with molecular weights identical to those of some complement regulating factors (e.g. DAF) which play an essential role in complement-mediated hemolysis. Red blood cells from both normal and PNH patients showed decreased deformability after vesiculation. Liability to vesiculate and the consequential loss of certain essential membrane proteins and decreased deformability might be a factor contributing to the mechanism of hemolysis in PNH.
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PMID:Erythrocyte vesiculation in paroxysmal nocturnal hemoglobinuria. 172 34

A ten-year-old boy with paroxysmal nocturnal hemoglobinuria (PNH) is described. Although hemolytic anemia was evident, Ham's test was negative and the erythrocyte acetylcholinesterase (ACHE) activity was normal at the first admission. The diagnosis of hemolytic anemia of unknown etiology was made. Methylprednisolone pulse therapy was started, but could not prevent the hemolytic crises associated with infections. Twelve months later Ham's test turned positive and ACHE activity decreased. The diagnosis of PNH was confirmed. As the disease is insidious in onset, we emphasize that a high index of suspicion and Ham's test and sucrose water test repeated at regular intervals are required to avoid missing the diagnosis.
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PMID:A case report of paroxysmal nocturnal hemoglobinuria in a child. 185 21

Paroxysmal nocturnal hemoglobinuria, first described in the late 19th century, is an acquired disorder characterized by hemoglobinemia and hemoglobinuria. The major clinical manifestation of PNH is chronic intravascular hemolysis of various severity. Patients-mostly young adults - may also present with episodes of abdominal or back pain. Common cause of death is thrombosis especially of the hepatic veins. Granulocytopenia and thrombocytopenia may be the initial manifestation of PNH, indicating that the disorder is a primary bone-marrow disease, affecting not only the erythrocytes but also other peripheral blood cells and the haematopoietic stem cell. The course of the disease is variable. Partial complete recovery was described, but also fatal thrombosis. The major phenotypic expression of PNH is an increased susceptibility of the erythrocytes to the lytic action of complement in vitro. The enhanced complement susceptibility is most probably due to membrane defects: two membrane proteins regulating the complement cascade in PNH cells were missing, the decay-accelerating factor, DAF, inhibiting the activation of the lytic complement complex and the C8 binding protein, C8bp, which interferes with the lytic process. Aside from the lack of the complement regulators also other membrane defects have been described (e.g. of acetylcholinesterase or alkaline phosphatase). The proteins as well as DAF and C8bp are linked to the cell membrane via a phosphatidylinositol (PI) anchor, leading to the speculation that the disease results from a deficiency in the post-translational PI anchoring mechanism. The diagnosis of PNH is based on the Hamtest, but will be extended to the quantitation of the above described membrane proteins.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Paroxysmal nocturnal hemoglobinuria]. 218 38


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