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Biomedical subjects

S Miwa

Publications and source records attributed to S Miwa.

At least 433 records · Page 24Linked to original sources
PubMed1977

An ultrastructural study of the red pulp of the spleen and the liver in unstable hemoglobin hemolytic anemia.

Electron microscopic observations on the process of red cell destruction in the spleen and liver of a patient with congenital Heinz body hemolytic anemia, associated with a new variant of unstable hemoglobin, are reported. Two major mechanisms of destruction of Heinz body-containing red cells were noted. One was phagocytosis of these cells in toto by cordal macrophages. The other mechanism though less significant quantitatively, was intravascular hemolysis of injured red cells in the splenic microvasculature. In the liver, phagocytosis of damaged red cells by Kupffer cells was rate and there was no evidence of intravascular hemolysis in this organ. These morphological findings, together with almost complete recovery from hemolysis following splenectomy, indicated that Heinz body-containing red cells were removed from the circulation predominantly by the spleen. In contrast to experimental Heinz body anemia in animals, Heinz bodies were present even in the nucleated cells.

Anemia, Hemolytic↗
PubMed1977

Simultaneous demonstration of peroxidase and lysozyme activities in leukemic cells.

A simple cytochemical and cytobacterial method for the simultaneous demonstration of peroxidase and lysozyme (muramidase) activities in individual cells was devised. In characterization of myeloid and monocyte series, the combination of these myeloid- and monocyte-specific enzymes not only was more informative than a single enzyme but made it easier to differentiate acute myelomonocytic leukemia, with higher lysozyme activity, from acute myeloid leukemia, with higher peroxidase activity. Acute lymphocytic leukemia had no lysozyme or peroxidase activity.

Bone Marrow↗
PubMed1977

G6PD Ube, a glucose-6-phosphate dehydrogenase variant found in four unrelated Japanese families.

A total of 6,120 Japanese males were screened for glucose-6-phosphate dehydrogenase deficiency (G6PD). Five cases with the deficiency were discovered. Two of them and an additional two cases have the same variant, G6PD Ube, characterized by moderate enzyme deficiency, fast moving enzyme activity on electrophoresis, high Ki Nadph, utilization of substrate analogues, kinetics, pH optima, and stability. This variant was distinguished for G6PD A- and from other Oriental variants by biochemical parameters. Differences in the frequency and type of the variants between southern Asia and Japan, suggest that the Japanese who have been isolated on islands where malaria is not endemic, may have developed their own variant traits.

Adult↗
PubMed1977

Characterization of pyruvate kinase from the liver of a patient with aberrant erythrocyte pyruvate kinase, PK Nagasaki.

The characterization of the L-type PK were made of PK extracted from the liver of a patient with congenital hemolytic anemia associated with an erythrocyte PK variant, PK Nagasaki. The L-type PK of PK Nagasaki showed the following parameters: slow migration on electrophoresis, high Km for PEP without F-1,6-P2, less activation by F-1,6-P2, normal Km for ADP, high utilization of UDP, acidic pH optimum, and instability to urea and heat. These tests served to differentiate this L-type PK variant from the other variants previously reported. At the same time, both the Km for PEP with F-1,6-P2 saturation and the electrophoretic mobility of L-type PK were found to be different from those of the erythrocyte PK and PK Nagasaki. Though the liver cell, with regard to L-type PK, has only the less functional and less stable mutant L-type PK there is no evidence of liver dysfunction or damage, although there is chronic hemolytic anemia.

Adolescent↗
PubMed1976

Human erythrocyte glutathione reductase. I. Purification and properties.

1. Glutathione reductase (NAD(P)H:oxidized-glutathione oxidoreductase, EC. 1.6.4.2) from human erythrocytes was purified 49 000-fold with an overall yield of 15% and a 280/460 nm absorbance ratio of 6.03. The procedure used was the method of Worthington and Rosemeyer modified by addition of heating and recrystallization. 2. It was concluded from the results of purification, electrofocusing and inhibition studies that glutathione reductase is a single enzyme which used both NADPH and NADH as hydrogen donors. 3. Apoenzyme cross-reacts with the antibody to the holoenzyme but has a slightly reduced affinity to the antibody. Apoenzyme can be removed from the hemolysate by heating and centrifugation without loss of holoenzyme. 4. Indirect immunological assay of the specific activity of the erythrocyte glutathione reductase is possible in the enzyme saturated with FAD.

Erythrocytes↗
PubMed1976

Isoelectric focussing of normal human erythrocyte pyruvate kinase (PK) and PK variants with abnormal electrophoretic patterns.

Isoelectric points of normal human erythrocyte pyruvate kinase (PK) and PK variants with abnormal electrophoretic patterns, were obtained by means of isoelectric focussing. The obtained isoelectric points of normal, PK Nagasaki, PK Tokyo II, PK Ube, and case T.S. were 7.36, 7.38, 7.05, 6.90, and 7.04, respectively, at 6 degrees C. All of the PKs collected after isoelectric focussing were shown to be not of the L-type PK but to be the erythrocyte PK (by means of thin-layer-polyacrylamide gel electrophoresis). The PKs with fast migration had isoelectric points that were shifted to the acidic side as compared with those of the normal subjects. The PK with slow migration had an isoelectric point that was shifted to the alkaline side, demonstrating that the isoelectric points obtained by isoelectric focussing were consistent with the electrophoretic patterns of the crude hemolysates. Isoelectric focussing also revealed the existence of PK variants with abnormal electric net charge, just as well as thin-layer-polyacrylamide gel electrophoresis.

Erythrocytes↗
PubMed1976

Two new glucose 6-phosphate dehydrogenase variants associated with congenital nonspherocytic hemolytic anemia found in Japan: GD(-) Tokushima and GD(-) Tokyo.

Two new variants of glucose 6-phosphate dehydrogenase (G6PD) deficiency associated with chronic nonspherocytic hemolytic anemia were discovered in Japan. Gd(-) Tokushima was found in a 17-years-old male whose erythrocytes contained 4.4% of normal enzyme activity. Partially purified enzyme revealed a main band of normal electrophoretic mobility with additional two minor bands of different mobility; normal Km G6P, and Km NADP five-to sixfold higher than normal; normal utilization of 2-deoxy-G6P, galactose-6P, and deamino-NADP; marked thermal instability; a normal pH curve; and normal Ki NADPH. The hemolytic anemia was moderate to severe. Gd(-) Tokyo was characterized from a 15-year-old male who had chronic nonspherocytic hemolytic anemia of mild degree. The erythrocytes contained 3% of normal enzyme activity, and partially purified enzyme revealed slow electrophoretic mobility (90% of normal for both a tris-hydrochloride buffer system and a tris-EDTA-borate buffer system, and 70% of normal for a phosphate buffer system); normal Km G6P and Km NADP; normal utilization of 2-deoxy-G6P, galactose-6P, and deamino-NADP; greatly increased thermal instability; a normal pH curve; and normal Ki NADPH. These two variants are clearly different from hitherto described G6PD variants, including the Japanese variants Gd(-) Heian and Gd(-) Kyoto. The mothers of both Gd(-) Tokushima and Gd(-) Tokoyo were found to be heterozygote by an ascorbate-cyanide test.

Adolescent↗
PubMed1976

Extraction of erythrocyte membrane proteins by sulfhydryl inhibitors.

Human red cell membrane proteins were extracted by incubation of the ghost with hypotonic phosphate buffer (pH 7.4), N-ethylmaleimide and p-hydroxy-mercuribenzoate. In paroxysmal nocturnal hemoglobinuria (PNH), hereditary spherocytosis (HS) and hereditary elliptocytosis, the amount of proteins extracted by these procedures was significantly less than the amount extractable from the ghost of normal and aplastic anemia red cells. Polypeptide patterns of red cell membranes in these hematological disorders were essentially similar to those of normal ghosts. Analysis of the supernatant by SDS polyacrylamide gel electrophoresis revealed that this reduction was mainly due to the reduced amount of peripheral proteins extracted. The extraction of peripheral proteins by sulfhydryl reagents was accompanied by shape changes resulting in the formation of membrane vesicles, suggesting an important role of peripheral proteins in the maintenance of ghost shape. It is also suggested that qualitative abnormalities of peripheral proteins such as altered reactivity to sulfhydryl reagents and/or strong binding to the membrane are present in PNH, HS and hereditary elliptocytosis red cells.

Anemia, Hemolytic↗
PubMed1976

A new pyruvate kinase variant (PK Osaka) demonstrated by partial purification and condensation.

A qualitative variant of erythrocyte and liver pyruvate kinases (PK Osaka) was detected in a family in which two siblings have extremely low PK activity by semipurification with DEAE cellulose chromatography and subsequent concentration of the enzyme solutions. This was previously reported to be a quantitative variant based on studies of crude tissue preparations. The molecular aberrations were characterized by slow mobility upon electrophoresis, abnormal kinetics for phosphoenolpyruvate, and low affinity for anti-human erythrocyte PK serum. The mutant PK L was similar both electrophoretically and immunologically to PK R.

Child, Preschool↗