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Biomedical subjects

S Miwa

Publications and source records attributed to S Miwa.

At least 415 records · Page 23Linked to original sources

Three new electrophoretically normal glucose-6-phosphate dehydrogenase variants associated with congenital nonspherocytic hemolytic anemia found in Japan: G6PD Ogikubo, Yokohama, and Akita.

Three new glucose-6-phosphate dehydrogenase (G6PD) variants, which showed electrophoretically normal mobility and were associated with chronic nonspherocytic hemolytic anemia, were found in Japan. G6PD Ogikubo, found in a 17-year-old male whose red cells contained 3% of normal enzyme activity, had normal Km G6P, normal Km NADP, normal utilization of deamino-NADP, decreased heat stability, and a normal pH curve. G6PD Yokohama, characterized from a 15-year-old male, had 1.9% of normal enzyme activity, normal Km G6P, normal Km NADP, low Ki NADPH, normal utilizations of both 2-deoxy-G6P and deamino-NADP, decreased heat stability, and normal pH curve. G6PD Akita, characterized from a 56-year-old male, had an undetectably low activity when hemolysate was examined, normal Km G6P, normal Km NADP, normal Ki NADPH, normal utilizations of both 2-deoxy-G6P and deamino-NADP, decreased heat stability, and normal pH curve. The degree of hemolytic anemia was moderate to mild in all three patients.

Adolescent↗

Glutathione reductase deficiency in a kindred with hereditary spherocytosis.

A kindred with hereditary spherocytosis was found to have erythrocyte glutathione reductase deficiency. The glutathione reductase was evaluated enzymatically and immunologically. The enzyme activity could not be restored either by flavin adenine dinucleotide (FAD) in vitro, or by oral administration of FAD. Kinetic and electrophoretic studies, heat stability tests, and pH curves revealed no evidence of a varient enzyme. The results of electroimmunodiffusion and neutralization tests using an antiserum indicated that the deficiency is caused by a diminished production of enzyme protein. Hereditary spherocytosis and glutathione reductase deficiency traits segregated independently. The amount of reduced glutathione in the erythrocyte was normal, and the deficiency state without hereditary spherocytosis was asymptomatic. All deficient members in this kindred were heterozygous and the residual enzyme activity in the heterozygote might be sufficient to maintain the reduced glutathione level to prevent oxidative stress.

Antigens↗

A case of red-cell adenosine deaminase overproduction associated with hereditary hemolytic anemia found in Japan.

A case of red cell adenosine deaminase (ADA) overproduction associated with hereditary hemolytic anemia is reported here. This appears to be the second report. Proband is a 38-year-old Japanese male who had hemoglobin, 15.8 g/100 ml; reticulocyte count, 4.5%; serum indirect bilirubin, 4.9 mg/100 ml; 51Cr-labeled red cell half-life, 12 days; red cells showed moderate stomatocytosis. His red cell ADA activity showed 40-fold increase while that of the mother showed 4-fold increase. The mother was hematologically normal. The father had a normal enzyme activity. The proband and the mother showed slightly high serum uric acid levels. The proband's red cell showed: ATP, 628 nmoles/ml (normal, 1,010--1,550); adenine nucleotide pool, 46% of the normal mean; 2,3-diphosphoglycerate content, 3,782 nmoles/ml (normal 4,170--5,300); increased oxygen affinity of hemoglobin, P50 of intact erythrocytes being 21.8 mmHg (normal, 24.1--26.1). Red cell glycolytic intermediates in the proband were low in general, and the rate of lactate production was low. Kinetic studies using crude hemolysate revealed a normal Km for adenosine, normal electrophoretic mobility but slightly abnormal pH curve and slightly low utilization of 2-deoxyadenosine. The ADA activity of lymphocytes was nearly normal.

Adenosine Deaminase↗

Fine structure of the spleen in autoimmune hemolytic anemia associated with systemic lupus erythematosus.

The fine structures of the red pulp of the spleen and the liver of a patient with autoimmune hemolytic anemia, neutropenia and thrombocytopenia associated with systemic lupus erythematosus are described. The red blood cells were phagocytized in toto by the splenic macrophages. These also contained neutrophils and platelets in various stages of degradation. Sinus endothelial cells revealed occasional erythrophagocytosis. The Kupffer cells in the liver occasionally contained red cells and platelets. These morphological findings and marked improvement of hematological abnormalities following splenectomy suggested that the spleen was the major site of destruction of blood cells. Undulating tubules associated with the endoplasmic reticulum were present in the sinus endothelial cells of the spleen.

Anemia, Hemolytic, Autoimmune↗