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Biomedical subjects

V Moses

Publications and source records attributed to V Moses.

12 recordsLinked to original sources
PubMed1987

A thirty-year review of maternal mortality in Oklahoma, 1950 through 1979.

Oklahoma's Maternal Mortality Committee has been active since 1941. During the 30-year period 1950 through 1979, the committee reviewed in detail 75.9% of the pregnancy-related deaths that occurred in Oklahoma. The maternal mortality ratio in 1950 was 95.1/100,000 live births, and for 1979 it was 8.1/100,000 live births, a decrease of 91.5%. The risk of death from childbearing remained greater for black women than for American Indian or white women throughout the three decades. For American Indian women, the risk of death associated with pregnancy has decreased and is almost equal to the risk for white women. The Maternal Mortality Committee estimated that two thirds of Oklahoma's maternal deaths were preventable. The proportion of deaths judged preventable did not vary substantially during the study period. We conclude that maternal mortality in Oklahoma can be reduced to fewer than three deaths per 100,000 live births. Intensive monitoring and investigation of deaths and their causes by local maternal mortality committees continues to be an important mechanism for obtaining information to assist health workers in the prevention of deaths.

Black or African American↗
PubMed1987

Microbes and oil recovery.

Conventional oilfield operations recover, on average, about a third of the crude oil originally present in a reservoir. Improving the yield depends both on overcoming macro- and micro-geological problems and on progressively compensating for the pressure drop in the reservoir as it is depleted of oil. In some cases this may be achieved by treating the oil-bearing matrix with certain chemicals, most commonly surfactants and viscous or insoluble polymers. One effective way of introducing the chemicals is by employing a population of bacteria in the reservoir as synthetic agents. Some of these processes are shown in the Centrespread illustration.

Bacteria↗
PubMed1986

Lymphocyte transformation in lepromatous leprosy: a study of the influence of disease activity and symptom duration.

The lymphocyte hyporesponsiveness to M. leprae of patients with active lepromatous leprosy has been well described. This immune defect is less well understood in terms of its time of origin, possible reversibility and specificity. To further examine the persistence and specificity of this abnormality, lymphocyte transformation tests of 93 leprosy patients to lepromin, BCG and PHA were studied. Among lepromatous patients, a decreased response to M. leprae was seen, whether the disease was active or inactive. Decreased responses to BCG were found in lepromatous patients with active disease, but not in those with inactive disease. The duration of patient symptoms was not associated with differences in LTT responses among the active lepromatous patients.

Adolescent↗
PubMed1978

Proline biosynthesis by cell-free extracts of Escherichia coli and potential errors arising from the use of a bioradiological assay procedure.

1. The growth of Escherichia coli proline auxotrophs on medium containing L-proline (50 microgram/ml) induces catabolic enzymes. A bioradiological assay system for proline, using proB cells of E. coli, might give erroneous results owing to proline catabolism by the proline auxotrophs on which the assay depends. 2. Differential utilization of proline and 1-pyrroline-5-carboxylate by the proB cells for the synthesis of protein, and failure of the method to distinguish between these two possible products of the proline-biosynthetic enzymes, might also give rise to error. 3. The proline-dependent incorporation of [14C]phenylalanine into the protein of proline-starved proB auxotrophs was to some degree directly influenced by the presence of crude cell extract from E. coli, even though this was not supplied with substrate and cofactors, and could thus not itself synthesize proline. 4. The kinetics of proline biosynthesis by cell-free extracts were linear and biphasic, only the last phase being affected by the concentrations of substrate and extract. This phenomenon is not understood. 5. Proline biosynthesis is inhibited, not only by high concentrations of ATP, but also by aspartate, glycine, alanine and serine, aspartate having the greatest effect. 6. Attempts at complementation in vitro between extracts of proline auxotrophic mutants were not successful, suggesting the possibility that strain X680 (proA) and/or X278 (proB) may be a double mutant. 7. The enzymes of proline biosyntehsis are co-eluted from a column of Bio-Gel A1.5M in a position corresponding to a mol.wt. of 350000. 8. Comparisons between rates of proline biosynthesis in vivo and in vitro were made.

Adenosine Triphosphate↗
PubMed1978

The enzymes of proline biosynthesis in Escherichia coli. Their molecular weights and the problem of enzyme aggregation.

1. By using Bio-Gel A1.5M and Sephadex G-150 columns, crude cell-free extracts of Escherichia coli were fractionated to demonstrate the existence of a proline-biosynthetic aggregate. 2. Sephadex G-150 resolves two glutamyl kinases that are inhibited by proline, with mol.wts. of 125000 and 38000, the reactions of which are Mg2+-dependent. The heavier species is more sensitive to inhibition by proline. 3. Gamma-Glutamyl phosphate reductase and 1-pyrroline-5-carboxylate reductase (EC 1.5.1.2) have mol.wts. of approx. 125000 and 190000 respectively, the specific activity of the latter being 5 X 10(3)-fold greater than either of the other two biosynthetic enzymes or of the total pathway in vivo. 4. Bio-Gel A1.5M chromatography gave a single glutamyl kinase of mol.wt. 250000, and the possibility of this being a constituent of an enzyme complex is discussed.

Aldehyde Oxidoreductases↗
PubMed1976

The tentative identification in Escherichia coli of a multienzyme complex with glycolytic activity.

Penicillin spheroplasts of Escherichia coli were ruptured osmotically, by freezing and thawing, or mechanically. Differential centrifugation sedimented 20-30% of the glycolytic enzymes without increasing their specific activities. There was, however, evidence of distinct groups of sedimenting enzymes; growth on different carbon sources could influence the distribution. Sucrose gradient studies gave no evidence of enzyme association but provided estimations of the molecular weight of each enzyme which were close to those subsequently observed on gel filtration. Using the determined molecular weight and a literature value for specific activity, the measured activity ratio of the enzymes was compared with that expected from an equimolar mixture. All values agreed within a factor of five, except for hexokinase. The relative roles of hexokinase and phosphotransferase in E. coli are briefly considered. An equimolar multienzyme aggregate of all the enzymes of glycolysis would have a molecular weight of about 1.6 X 10(6). Chromatography on a Biogel column yielded one fraction, corresponding to a molecular weight of 1.6 X 10(6), which contained a proportion of all the glycolytic enzyme studied; the remaining portion of each enzyme activity was eluted from the column at the position expected from its individual molecular weight. The fraction of mol. wt 1 600 000 was tested for complete glycolysis pathway activity and found not to be different from a reconcentrated mixture of the separated enzymes. Both the eluted and the reconstructed systems showed unexpected activity changes at different protein concentrations. The specific radioactivity of pyruvate formed by these systems from [14C]glucose 6-phosphate was reduced by the presence of unlabelled 3-phosphoglycerate, but by less than would have been expected had the latter been able to participate fully in glycolytic activity. This result indicates that these preparations were capable of selectivity compartmenting glycolytic intermediates. Electron microscope investigation of both systems showed large numbers of regular 30 nm diameter particles which, on disruption, appeared to be composed of smaller units: it is possible that these particles may have been aggregates containing glycolytic enzymes. The possible advantages of a glycolytic multienzyme complex are briefly discussed.

Carbohydrate Epimerases↗
PubMed1976

Concerning cyclic AMP.

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3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1967

The regulatory process in the de-repression of enzyme synthesis. Alkaline phosphatase of Bacillus subtilis.

1. The kinetics of de-repression of alkaline phosphatase in Bacillus subtilis were studied after the removal of P(i). Enzyme activity appeared about 10min. after removal of P(i), whereas ;enzyme-forming potential' appeared after 6min. 2. Protein synthesis is not impaired for at least 20min. on removal of P(i), but RNA synthesis is considerably diminished. 3. Adding chloramphenicol to cells without P(i), just at the time they start to make enzyme-forming potential, does not affect the differential rate of enzyme synthesis compared with total protein. Enzyme-forming potential accumulates to about normal levels in the presence of chloramphenicol, even though peptide-bond formation is inhibited by more than 95%. 4. Similar experiments performed with actinomycin C show more complex effects. Actinomycin initially prevents RNA synthesis and also the synthesis of enzyme-forming potential. After some minutes RNA synthesis resumes at a low rate, to be followed 4min. later by enzyme synthesis. Enzyme-forming potential can accumulate in the presence of actinomycin after the resumption of RNA synthesis. Protein synthesis, initially inhibited by actinomycin as a consequence of the effect on RNA synthesis, is later directly inhibited by actinomycin. 5. Adding actinomycin to de-repressed cells already making enzyme stops enzyme synthesis within 4-5min. Enzyme synthesis resumes, as before, 4min. after the resumption of RNA synthesis. 6. Adding P(i) together with actinomycin to de-repressed cells synthesizing enzyme does not result in a lower yield of enzyme compared with actinomycin alone. 7. Actinomycin is less effective an inhibitor of RNA and protein synthesis in P(i)-starved cells if P(i) is also added. 8. These results are discussed in view of the three main models for the regulation of enzyme induction: regulation at the level of transcription only, at translation only, or a coupled model in which transcription requires concomitant translation. It is concluded that the present evidence most powerfully supports the model of transcriptional regulation.

Alkaline Phosphatase↗