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At least 19 recordsLinked to original sources
PubMed1979

Chronic myelomonocytic leukemia associated with hereditary pyruvate kinase deficiency and multiple acquired erythrocyte abnormalities.

A congenital erythrocyte pyruvate kinase (PK) deficiency was found in a 72-year old female patient with chronic myelomonocytic leukemia (CMML). Erythrocyte PK deficiency was associated with an increase in the activity of hexokinase, 6-phosphogluconate dehydrogenase and glutathione peroxidase in erythrocytes as well as a decrease in acetylcholinesterase, glutathione reductase and glucosephosphate isomerase activities. The enzymatic abnormalities were accompanied by alterations in hemoglobin and in i antigen content of erythrocyte membrane. In addition, bone marrow ultrastructural studies showed dyshemopoietic changes in all blood cell lines and especially in erythroblasts. The present findings confirm the close relationship between CMML and acquired dyserythropoietic syndromes and constitute a new observation of the infrequent association of hereditary erythrocyte enzymopathies and leukemia. A survey of the literature is presented.

Acetylcholinesterase↗
PubMed1978

Abnormal erythrocyte membrane protein pattern in severe megaloblastic anemia.

The erythrocyte membrane protein pattern of patients with megaloblastic anemia was determined by polyacrylamide gel electrophoresis in sodium dodecyl sulfate. In severe megaloblastic anemia, secondary either to folic acid or vitamin B12 deficiency, the erythrocyte membrane protein pattern was grossly abnormal, lacking bands 1, 2 (spectrin), and 3 and having several diffuse, faster migrating bands. After adequate vitamin replacement therapy, the erythrocyte membrane protein pattern returned to normal. In mild megaloblastic anemia, secondary either to folic acid of vitamin B12 deficiency, and in severe iron deficiency anemia, the erythrocyte membrane protein pattern was normal. Erythrocyte membrane protein pattern of normal membranes did not change after mixing with abnormal membranes before polyacrylamide gel electrophoresis in sodium dodecyl sulfate. Protease activity extracted from membranes of megalocytes was not different from normal. These findings indicate that the erythrocyte membrane protein pattern is abnormal in severe megaloblastic anemia and that this abnormality is not secondary to increased activity of the endogenous erythrocyte membrane proteinase.

Adolescent↗
PubMed1977

The fragility of normal and abnormal erythrocytes in a controlled hydrodynamic shear field.

Fresh human erythrocytes (suspended in a compatible isotonic viscous saline medium containing plasma) were disrupted by the uniform shear stresses generated in the laminar flow field of a conventional cone and plate viscometer. A range of normal fragilities was established and blood samples from patients having certain well-defined haematological abnormalities were found to be partially or completely outside these limits. The present technique is sensitive enough to distinguish between young and old cell fractions isolated from the same original population and also appears to be able to resolve discrete sub-populations having different mechanical fragilities within unfractionated samples from certain patients (e.g. macrocytosis). This technique provides additional information which could aid or facilitate diagnosis and might eventually form the basis of a routine screening test in clinical haematology.

Adolescent↗
PubMed1979

Abnormal erythrocyte metabolism in hepatic disease: effect of NADP repletion.

Erythrocytes from ten patients with severe liver disease displayed low methylene blue-stimulated hexose monophosphate (HMP) shunt activity and glucose recycling despite elevated total glucose consumption when compared to controls. Heinz body formation was increased and reduced glutathione concentration significantly decreased. After hemolysis, no differences in methylene-blue estimulated HMP shunt activity or glucose recycling could be demonstrated between patients and controls. The addition of 2- and 4-mM NADP to the hemolysates produced significantly greater HMP shunt activity and glucose recycling in the patients' hemolysates. The addition of NADPH to the incubation mixture produced no significant stimulation of either HMP shunt activity or glucose recycling, unless methylene blue was also added. Omission of NAD or phosphate from the incubation mixture produced no change in shunt metabolism. The absence of supplemental ATP resulted in extremely low shunt metabolism and refractoriness to NADP stimulation in both patients and controls. In the absence of additional magnesium, a reduction of shunt metabolism was noted. These data suggest that the defect in stimulated shunt metabolism in the intact erythrocytes of patients with hepatic disease does not result from an absolute enzyme deficiency, but rather from an unavailability of NADP or other cofactor.

Adult↗
PubMed1978

Erythrocyte calcium abnormalities and the clinical severity of sickling disorders.

We studied erythrocyte calcium levels and uptake in a group of patients with sickle haemoglobinopathies of different clinical severity in an attempt to relate these measurements to the production of irreversibly sickled cells and disease severity. Erythrocyte calcium levels were measured by atomic absorption spectroscopy and calcium uptake by isotopic means. In sickle cell anaemia, erythrocyte calcium content was elevated and the uptake of isotopic calcium increased under both oxygenated and deoxygenated conditions. There was a direct correlation between the numbers of irreversibly sickled cells and calcium uptake and an inverse relationship between calcium uptake and red cell potassium level. The clinical course of disease was milder in patients with high fetal haemoglobin levels, but there was no relationship between clinical course and calcium levels, calcium flux or irreversibly sickled cells. Our observations suggest that calcium accumulation and irreversibly sickled cell formation are related processes. The absence of good correlation between various biochemical and clinical parameters emphasizes the complexity of factors which modify the clinical course of this disorder.

Adolescent↗
PubMed1977

Radiation-induced erythroleukemia in the beagle dog. A hematologic summary of five cases.

Eleven cases of myeloproliferative disease occurred in a group of 24 beagle dogs placed in a 60Co gamma-ray field at about 13 months of age and irradiated at an exposure rate of 5 R/22-hour day for duratior of life. Of these 11 dogs, 5 (described in this paper) were diagnosed as having erythroleukemia. The bone marrow showed marked erythroblastic hyperplasia, with maturation arrest of the erythroid elements, and increased numbers of myeloblasts and promyelocytes. The terminal peripheral blood was characterized by marked anemia and thrombocytopenia, with circulating erythrocytic precursors and abnormal erythrocyte morphology. Splenomegaly and hepatomegaly occurred in 4 of the 5 animals. In the spleens and livers of all 5, there was extensive leukemic infiltration and proliferation. The extent of leukemic involvement in other tissues and organs varied in individual dogs.

Animals↗
PubMed1976

Phosphorylation in erythrocyte membranes from abnormally shaped cells.

Erythrocyte protein phosphorylation was examined in membrane preparations of 25 patients with hereditary spherocytosis (HS). Reduced phosphorylation in substrate polypeptides was observed in 22 HS erythrocyte membranes for both splenectomized and nonsplenectomized patients. A reduction in labeling was also observed in a polypeptide which was labeled only in the presence of cAMP. No reduction was observed in membranes from immunologically acquired spherocytosis cells or from cells from patients with hereditary elliptocytosis. Heating membranes to 45 degrees C caused negligible inhibition of membrane protein phosphorylation, while heating to 50 degrees C extensively inhibited phosphorylation. Dephosphorylation of membrane protein that occurred in isolated membranes was not dependent upon cAMP.

Cyclic AMP↗
PubMed1979

Erythrocyte spectrofluorometric abnormalities in Duchenne patients and carriers. A new approach to carrier detection.

Duchenne muscular dystrophy (DMD) is a disorder whose pathogenesis is attributed, according to the most recent theories, to generalized membrane abnormalities, including red cell membrane. The study of erythrocyte ghosts in patients affected by DMD showed alterations in ion transport and in various enzymatic activities. Employing a spectrofluorometric method using 1-anilino-8-naphthalene sufonate (1.8-ANS) we have tried to characterize the erythrocyte ghosts of DMD patients, definite DMD carriers and normal controls, matched for age and sex. We found an increase of membrane polarity in DMD and definite DMD-carrier erythrocyte ghosts. Using this new method we were able to: - confirm by means of a different technique the previous observations of many authors on erythrocyte ghost alterations in DMD - find a new technique useful in detecting the DMD carriers. It is noteworthy that in such a way the detection rate of definite DMD carriers was higher than with the CPK test.

Adult↗
PubMed1977

[Erythrocyte membrane protein abnormalities in hereditary hemolytic anemias].

The structural and functional abnormalities of erythrocyte membrane proteins in hereditary hemolytic anemias are reviewed. The authors stress the problems of protein solubilization and the artefacts of the sodium dodecylsulphate polyacrylamide gel electrophoresis; protein abnormalities observed with that method are inconstant and non-specific. Abnormal "spectrin" has been reported in hereditary spherocytosis: however analysis of purified spectrin peptides by isoelectric focusing in 8M urea did not reveal any difference between normal and hereditary spherocytosis spectrin. Deficient autophosphorylation of erythrocyte membrane proteins by endogenous membrane protein-kinases 3'5-cyclic-AMP dependent and independent was pointed out in hereditary spherocytosis and stomatocytosis: the authors' experience was contrary to such results: quantitatively and qualitatively normal activity of membrane protein-kinase was found in five cases of hereditary spherocytosis. The authenticity, frequency and specificity of the various membrane protein abnormalities reported so far, are not firmly established. Many insufficiently verified results published prematurely have been later denied. To date no membrane protein anomaly may be considered as a biochemical cause of any type of hereditary hemolytic anemia.

Anemia, Hemolytic, Congenital↗
PubMed1978

Mechanism for lipid abnormalities of erythrocyte membranes in biliary obstruction: lecithin content and its fatty acyl composition.

The lipid compositions of erythrocyte membranes, plasma and bile of 16 patients with biliary obstruction were analysed to obtain information regarding the origin of excess lecithin which is usually found in the erythrocyte membranes in obstructive jaundice. Phospholipids and free cholesterol were found to be increased proportionally to the degree of biliary obstruction with an elevation in the free cholesterol/phospholipid ratio in the red cell membranes. The increase in phospholipid content is primarily due to lecithin. There was a highly significant alteration in the fatty acid composition of lecithin of erythrocyte membranes, plasma and bile from patients with severe jaundice. Red cell membrane lecithin amounted to more than 40% of the total phospholipid in these patients. Interestingly, the fatty acid composition of lecithin showed a similar pattern in erythrocyte membranes, plasma and bile. In addition, the fatty acyl chain composition of lecithin in lipoprotein-X was very similar to that of the red cell membrane. Freeze-fracture electron microscopy showed an alteration in membrane morphology and a reduced number of membrane-associated particles in the fractured faces. From these findings, we suggest that the lecithin of lipoprotein-X is derived from abnormal bile lecithin, which is incorporated into erythrocyte membranes by fusion with lipoprotein-X. On the other hand, the fatty acid composition of bile lecithin from patients with mild jaundice, whose erythrocyte membrane lecithin amounted to less than 31% of total phospholipid, was not different from that of normal individuals. However, in sharp contrast to the bile content, the fatty acid composition of erythrocyte membranes and plasma in these same patients showed a similar but small change compared to that of patients with severe biliary obstruction. The red cells of patients with mild jaundice were almost normal, biconcave disc-shaped, as observed by scanning electron microscopy and no abnormalities in the distribution or number of membrane particles were detected by freeze-fracturing. We propose that the abnormal lecithin content of erythrocyte membranes in patients with mild jaundice can be explained by the gradual exchange of lecithin between red blood cells and plasma lipoprotein.

Adult↗