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Biomedical subjects

M Alexander

Publications and source records attributed to M Alexander.

At least 433 records · Page 24Linked to original sources
PubMed1968

Gas chromatography for detection of viral infections.

Gas chromatograms of sertim extracts of dogs inoculated with canine infectious hepatitis virus showed two metabolites not observed in uninoculated animals. Chromatograms of extracts of tissue cultures of dog kidney, inoculated with viruses causing canine hepatitis, herpes, and distemper, and a parainfluenza virus similar to simian virus-5, each showed two or more different metabolites. Two of the distinguishing products from cultures inoculated with hepatitis virus were chromatographically indistinguishable from those found in serums of the animals.

Animals↗
PubMed1968

Rapid and sensitive detection of bacteria by gas chromatography.

A gas chromatograph fitted with electron capture and flame ionization detectors was employed for the rapid detection of bacteria by analysis for their metabolic products. The presence of Proteus vulgaris, Streptococcus faecalis, S. liquefaciens, Escherichia coli B, Bacillus cereus, and B. popilliae was detected in 2 to 4 hr in media inoculated with less than 10(4) cells per ml, whereas a 7- to 12-hr growth period was required for the detection of products formed in cultures of Serratia marcescens, Aerobacter aerogenes, E. coli K-12, Staphylococcus aureus, and Salmonella typhimurium. Metabolites elaborated by the equivalent of less than a single cell of B. cereus, S. faecalis, P. vulgaris, or E. coli B were sensed by the electron capture detector. The flame ionization detector was generally not as sensitive. Volatile metabolites were identified, and their concentrations were determined.

Bacillus↗
PubMed1968

Nitrite formation from hydroxylamine and oximes by Pseudomonas aeruginosa.

Nitrite was formed from hydroxylamine and several oximes by intact cells and extracts of Pseudomonas aeruginosa. The activity was induced by the presence of oximes in the culture medium. Nitroalkanes were not intermediates in the conversion of acetaldoxime, acetone oxime, or butanone oxime to nitrite, since nitromethane inhibited the formation of nitrite from the nitro compounds but not from the corresponding oximes. The oxime apparently functions as a constant source of hydroxylamine during growth of the bacterium. Hydroxylamine at low concentration was converted stoichiometrically to nitrite by extracts of the bacterium; high concentrations were inhibitory. Nicotinamide adenine dinucleotide phosphate, oxygen, and other unidentified cofactors were necessary for the reaction. Actively nitrifying extracts possessed no hydroxylamine-cytochrome c reductase activity. Hyponitrite, nitrous oxide, and nitric oxide were not metabolized.

Hydrogen-Ion Concentration↗