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Biomedical subjects

R Bigley

Publications and source records attributed to R Bigley.

13 recordsLinked to original sources
PubMed1991

The effect of cyanide on vitamin C uptake by human polymorphonuclear leukocytes.

1. Cyanide inhibited the uptake of vitamin C by human polymorphonuclear leukocytes (PMNs). 2. Preincubation of PMNs with cyanide had no effect on cytochalasin B-inhibitable uptake of dehydroascorbic acid (DHA) (the reversibly oxidized and transportable form of vitamin C). 3. Preincubation of DHA with cyanide resulted in inhibition of DHA uptake. 4. Vitamin C uptake was decreased by cyanide to the same degree as it was by glutathione (GSH), which effectively reduces DHA to ascorbic acid. The effects of cyanide and GSH were not additive. 5. The data are consistent with the hypothesis that cyanide inhibition of vitamin C uptake represents the chemical elimination of extracellular DHA rather than the inhibition of active transport in these cells.

Animals↗
PubMed1985

Chronic granulomatous disease in pregnancy.

The ability of phagocytes to kill certain bacteria is impaired in chronic granulomatous disease. This results in frequent infection in the childhood period and frequent death in the early teens. Survival beyond this period is rare and often occurs in patients who have a mild variant of the disease. Reported herein is the obstetric course of a patient with chronic granulomatous disease.

Bacterial Infections↗
PubMed1984

Plasma ascorbate concentrations and blood cell dehydroascorbate transport in patients with diabetes mellitus.

Rates of dehydroascorbate uptake by blood granulocytes and mononuclear cells are slower, and plasma ascorbate concentrations are lower, among persons with diabetes mellitus than in nondiabetic subjects. These measurements do not correlate with one another or with simultaneously measured plasma glucose or glycosylated hemoglobin; they do not differ with type of diabetes or mode of treatment. In those diabetic granulocytes that exhibit slow dehydroascorbate uptake, maximal velocity (Vmax) transport rates for dehydroascorbate, 2-deoxyglucose, and 3-O-methylglucose are decreased, each to the same degree, while Km values for transport of these ligands are not different from those observed in nondiabetic cells. Since diffusion of these ligands is facilitated by a common transporter, these observations may reflect decreased numbers of glucose transporters in the plasma membranes of some diabetic leukocytes.

3-O-Methylglucose↗
PubMed1983

Interaction between glucose and dehydroascorbate transport in human neutrophils and fibroblasts.

Dehydroascorbate (DHA) competitively inhibits the uptake of 2-deoxy-D-glucose and of 3-O-methyl-D-glucose by human blood neutrophils; 2-deoxyglucose and 3-O-methylglucose competitively inhibit dehydroascorbate uptake. Ratios of Km to Kl are near unity for each of these ligands. Exposure of cultured human fibroblasts to insulin enhances cytochalasin B-inhibitable uptake of DHA and of 2-deoxyglucose, both to the same degree. These observations suggest that DHA transport is mediated by glucose transport systems in human neutrophils and fibroblasts.

3-O-Methylglucose↗
PubMed1981

Human cell dehydroascorbate reductase. Kinetic and functional properties.

Dehydroascorbate reductase (glutathione: dehydroascorbate oxidoreductase, EC 1.8.5.1) activity was examined in crude cytosol extracts of human cells. In blood neutrophil and lymphocyte extracts, the Km at pH 6.85 for dehydroascorbate was 1.3 mM, and for reduced glutathione 3.8 mM. Rates of dehydroascorbate uptake by intact human neutrophils, monocytes, lymphocytes and cultured fibroblasts were proportional to cytosol dehydroascorbate reductase activities. Dehydroascorbate reduction during dehydroascorbate uptake by these cells may be entirely enzymatic.

Cells, Cultured↗
PubMed1980

Glutathione-dependent dehydroascorbate reduction: a determinant of dehydroascorbate uptake by human polymorphonuclear leukocytes.

Dehydroascorbate uptake and reduction are impaired in normal human polymorphonuclear leukocytes (PMN) preincubated with N-ethylmaleimide, and in glutathione reductase-deficient cells. We conclude that human PMN dehydroascorbate reduction is glutathione-dependent, and that dehydroascorbate reduction appears to be a necessary condition for cellular dehydroascorbate uptake.

Ascorbic Acid↗
PubMed1975

Synthesis of erythrocyte-specific proteins in cultured friend leukemia cells.

We have studied synthesis of specific proteins in two permanent lines of Friend virus-induced erythroleukemia cells (Friend line 745 and Ostertag line FSD-1, both derived from DBA/2 mice). By 96 hr following treatment with 1-2% dimethyl sulfoxide (Me2SO), up to 25% of the protein being synthesized by both these cultures is hemoglobin. At that time, hemoglobin constitutes up to 10% of the cellular soluble protein. Both lines synthesize heme and globin coordinately, and alpha and beta globin chains in a nearly balanced 1:1 ratio. However, the ratio of betaMajor:betaMinor chains synthesized by these induced Friend leukemia (FL) cells is approximately 9 in the FSD-1 line and 1.3 in the Friend Clone 745 line, whereas it is 4 in normal adult DBA/2 mouse erythrocytes. Evidence for the latter conclusion was obtained by electrophoresis of FL hemoglobins on cellulose acetate membranes, and also by chromatographic separation of alpha, betaMajor, and betaMinor globins on carboxymethylcellulose in 8 M urea at 20 degrees C. Carbonic anhydrase activity per mg protein is 3 times higher in induced than in control cultures. 2,3-diphosphoglyceric acid is not found in induced FL cells. Induced and control FL cells agglutinate strongly and equally with Phaseolus vulgaris phytohemagglutinin. The developmental process in these cultured leukemia cells appears to be an aberrant erythropoiesis.

Agglutination↗