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J C Marchand

Publications and source records attributed to J C Marchand.

At least 19 recordsLinked to original sources
PubMed1989

[Allergy and desensitization to hymenoptera venom in children].

Among 15 children who were stung by hymenoptera, 5 underwent semi-rapid desensitization using the outpatient Molkhou method. This technique was well tolerated; desensitization was stopped when protective IgG levels measured by RIP (radioimmunoprecipitation) reached 50% and skin tests and RASTs became negative. In a comparable series of adults, however, discontinuation of the desensitization was considered only following satisfactory tolerance of an accidental or planned sting. In children, semi-rapid desensitization is very effective and has also been proposed for allergies to air borne allergens such as mites and pollens when increased doses are required to improve protection.

Adolescent↗
PubMed1979

The influence of adenosine on intermediary metabolism of isolated hepatocytes.

The effect of adenosine was tested on the energetic metabolism of fed rat liver cells after isolation. The cells were incubated in a buffered saline medium with glucose (5 mM) and adenosine (1 mM) for 30 minutes at 37 degrees C. This increased the concentration of the adenylic nucleotides ATP (+57 per cent, ADP (+39 per cent). Cyclic AMP was increased (+50 per cent) and the intracellular inorganic phosphate decreased (-22 per cent). These changes were accompaned by a decrease of glycogenolysis, glucose consumption and lactate production. Measurement of glycolytic intermediates showed decreased concentrations of fructose 1,6-bis-phosphate and 3-phosphoglycerate proportional to the increase in ATP concentration. The near-equilibrium of the glyceraldehyde 3-phosphate dehydrogenase-phosphoglycerate kinase system was not modified by adenosine. The decrease of the NAD+/NADH ratio along with the increase of the ATP/ADP X PO4 ratio explains the decrease of 3-phosphoglycerate. The decrease in glucose consumption can be explained by the cross over at the phosphofructokinase stage with the decrease of fructose 1,6-bisphosphate. The major part of adenosine was deaminated as indicated by an increase in the production of ammonia and urea. The effects of inosine, or adenosine along with an inhibitor of adenosine deaminase (pentostatin) suggest that adenosine acts on the glucose consumption through adenylic nucleotides. However the increase of the adenylic nucleotide level cannot totally explain the other metabolic changes: decrease of the NAD+/NADH cytoplasmic ratio, constancy of this ratio in mitochondria, decrease of gluconeogenesis from lactate. A direct action of adenosine can therefore be expected.

Adenosine↗
PubMed1979

[Effect of adenosine on phosphofructokinase and phosphoglycerate kinase of rat liver].

Effects of adenosine on purified rat liver phosphofructokinase and phosphoglycerate kinase activity were investigated in vitro. Stimulation by adenosine of the phosphofructokinase has been observed at low concentrations, but the activity was markedly inhibited at high concentrations. Adenosine was an inhibitor of the phosphoglycerate kinase : Lineweaver-Burk analysis indicated that adenosine inhibition was competitive with ATP and non competitive with 3-phosphoglycerate. An interpretation of these results is proposed.

Adenosine↗
PubMed1979

[Effect of the MgATP2- complex on liver phosphoglycerate kinase activity in the rat].

Effect of Mg ATP2- has been studied on purified rat liver phosphoglycerate kinase in the direction of glycolysis. Lineweaver-Burk analysis indicated that Mg ATP2- inhibition was noncompetitive with Mg ADP1- and 1, 3-diphosphoglycerate; the intersection point is above the 1/[S]-axis and two sites can be suspected for this inhibitor.

Adenosine Triphosphate↗
PubMed1979

[Rat liver phosphoglycerate kinase. I. Purification and kinetic properties in the biosynthesis of 1-3 diphosphoglycerate].

Phosphoglycerate kinase (MgATP 3-phospho-D-glycerate 1-phosphotransferase, EC 2.7.2.3) has been isolated from rat liver with a purification ratio of 960 and a specific activity of 300 IU/mg of protein. The purity of the enzyme preparations was estimated by polyacrylamide gel electrophoresis. The molecular weight, determined by gel filtration is 42 000. The "subunit" size of phosphoglycerate kinase as determined by sodium dodecyl sulfate gel electrophoresis is 46 000, indicating that the enzyme is monomeric. The rate of the enzyme reaction as a function of the concentration of D-3-phosphoglycerate indicated the usual Michaelis Menten relationship. The rate of the enzyme reaction as a function of the concentration of MgATP2- did not fit the usual Michaelis Menten relationship: two distinct regions can be fitted with different straight lines and suggest the presence of two sites for the Mg ATP2-. This hypothesis seems to be confirmed by the study of the action of the free and complexed nucleotides.

Adenosine Diphosphate↗
PubMed1975

The influence of insulin on glucose permeability and metabolism of human granulocytes.

Viable human polymorphonuclear leukocytes isolated from peripheral blood were incubated for 1 h at 37 degrees C with variable concentrations of insulin in a saline medium buffered at pH 7.4. The hormone increased glucose consumption by about 40% without influencing the permeability of the membranes to glucose, whose uptake followed a passive diffusion process. The measurement of intermediates localized activation of glycolysis by insulin, down to 0.36 nM, at the phosphofructokinase step. However, the spectrophotometric measurement showed no activation of phosphofructokinase after preincubation with insulin of either intact granulocytes or crude or ultracentrifuged homogenates. The level of cyclic AMP, which is known to activate phosphofructokinase, was not modified by insulin; cyclic GMP did not activate the enzyme in the granulocyte extracts: neither of the two nucleotides can therefore be considered as a direct messenger of the action of insulin on phosphofructokinase. An important fraction of the extra glucose consumed under the influence of insulin was recovered as neither glycogen nor lactate, nor was it oxidized in the Krebs cycle. It might be assumed to have been converted into glycerolipids. However, insulin produced no detectable accumulation of triglycerides and activated neither the pentose phosphate pathway nor oxidative decarboxylation of pyruvate. The fate of the extra glucose consumed under the influence of insulin therefore remains questionable.

Cell Membrane Permeability↗
PubMed1971

[BCG. Its use].

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BCG Vaccine↗