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Biomedical subjects

M W Simon

Publications and source records attributed to M W Simon.

43 records · Page 3Linked to original sources
PubMed1976

Enzymes of carbohydrate metabolism in four human species of Leishmania: a comparative survey.

The occurrence and levels of activity of various enzymes of carbohydrate catabolism in culture forms (promastigotes) of 4 human species of Leishmania (L. brasiliensis, L. donovani, L. mexicana, and L. tropica) were compared. These organisms possess enzymes of the Embden-Meyerhof pathway but lack lactate dehydrogenase. No evidence could be found for the production of lactic acid by growing cultures and lactic acid could not be detected either in cell-free preparations or after incubation of cell-free extracts with pyruvate and NADH under appropriate conditions. All 4 species possess alpha-glycerophosphate dehydrogenase and alpha-glycerophosphate phosphatase which together could regenerate NAD, thus compensating for the absence of lactate dehydrogenase. The oxidative and nonoxidative reactions of the hexose monophosphate pathway are present in all 4 species. Cell-free extracts have pyruvate dehydrogenase activity which allows the entry of pyruvate into and its subsequent oxidation through the tricarboxylic acid cycle. All enzymes of this cycle, including a thiamine pyrophosphate dependent alpha-ketoglutarate dehydrogenase, are present. Both NAD and NADP-linked malate dehydrogenase activities are present. The isocitrate dehydrogenase is NADP specific. There is an active glutamate dehydrogenase which could compete with alpha-ketoglutarate dehydrogenase for the common substrate (alpha-ketoglutarate). Replenishment of C4 acids is accomplished by heterotrophic CO2 fixation catalyzed by pyruvate carboxylase. All 4 species have high levels of NADH oxidase activity. Several enzymes thus far not found in any species of Leishmania have been demonstrated. These are: phosphoglucose isomerase, triose phosphate isomerase, fructose-1, 6-diphosphatase, 3-phosphoglycerate kinase, enolase, alpha-glycerophosphate dehydrogenase, alpha-glycerophosphate phosphatase, pyruvate dehydrogenase complex, citrate synthase, aconitase, alpha-ketoglutarate dehydrogenase, glutamate dehydrogenase, and NADH oxidase.

Animals↗
PubMedDate not supplied

Efficacy of nebulized albuterol and cromolyn sulfate for acute wheezing and stridor in children: a prospective, randomized study.

A number of respiratory tract illnesses may produce acute wheezing and stridor in children, and treatment may vary, depending on the specific illness. These illnesses, however, may be difficult to differentiate solely on clinical grounds. A uniform therapeutic approach for children with acute wheezing or stridor independent of the specific etiology can be employed. In this prospective study, 246 children received aerosolized albuterol and cromolyn sulfate. Children who remain in distress after aerosolized medications should be admitted to the hospital. Those with partial improvement may be treated with home aerosol treatments after intramuscular injection of dexamethasone.

Adolescent↗