Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0038187 (starvation)
 24,951 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

When islets from mice were incubated with 16.7 mM-glucose, previous starvation for 48 h decreased the rate of insulin release by approx. 50% and glucose utilization was decreased by approx. 35%. The maximally extractable activity of glucose 6-phosphate dehydrogenase was diminished by 28% after starvation. The formation of 14CO2 from both [1-14C]glucose was, however, higher than the rate of oxidation of [6-14C]-glucose in islets from both fed and starved mice. The fraction of glucose utilized that was oxidized (specific 14CO2 yield) ranged from one-fifth to one-third and was higher in islets from starved mice with both [1-14C]glucose and [6-14C]glucose as substrate. The contribution of pentose-cycle oxidation to total glucose metabolism was small (3% in the fed state and 4% in the starved state). The absolute rates of glucose carbon metabolism via the pentose-cycle oxidation to total glucose metabolism was small (3% in the fed state and 4% in the starved state). The absolute rates of glucose carbon metabolism via the pentose cycle and the turnover of NADPH in this pathway were identical in islets from fed and starved animals. After incubation at 16.7 mM-glucose for 30 min the contents of glucose (6-phosphate and 6-phosphogluconate were both unchanged by starvation. It is concluded that there is no correlation between the decreased sensitivity of the insulin secretory mechanism during starvation and the metabolism of glucose via the pentose cycle, the islet content of glucose 6-phosphate or 6-phosphogluconate.
Biochem J 1975 Dec
PMID:The pentose cycle and insulin release in isolated mouse pancreatic islets during starvation. 77 71

Pacaud and Uriel described an enzyme from Escherichia coli ("protease I") that hydrolyzes acetyl phenylalanine naphthyl ester (APNE). We examined the possible involvement of this enzyme in intracellular protein degradation, its subcellular distribution, and its proteolytic activity. Although the APNE-hydrolyzing activity is localized primarily in the periplasm, proteolytic activity against casein was found in the periplasm, membrane, and cytoplasm with similar specific activities. The APNE-hydrolyzing enzyme did not appear to contribute to the proteolytic activity of the periplasm. A mutant deficient in APNE-hydrolyzing activity lacked all activity in the periplasm but showed a slight percentage of residual activity in the cytoplasm. Extracts of such cells were normal in their ability to hydrolyze casein. The mutant was indistinguishable from wild-type cells in its rate of protein degradation during growth or glucose starvation and in the ability to rapidly degrade puromycin-containing polypeptides. Nitrogen starvation, which increased protein breakdown severalfold, affected neither the total amount nor the distribution of APNE-hydrolyzing activity. The mutant showed no defect in its ability to cleave small phenylalanine-containing peptides released during protein degradation. The mutant and wild-type cells are equally able to hydrolyze exogenously supplied phenylalanyl peptides. These experiments suggest that the APNE-hydrolyzing enzyme is not required for protein degradation and that "protease I" is probably not a protease.
J Bacteriol 1976 Dec
PMID:Role and location of "protease I" from Escherichia coli. 79 31

Three distinct sections of the ultraviolet mutation frequency response (MFR) curve toward tryptophan prototrophy have been demonstrated in Excherichia coli B/r WP2 trp thy and its uvrA derivative in log-phase growth in minimal medium. The initial section, which appears fluence-squared, may reflect the necessity, if mutation is to result, for induction of two lesions, one located within the potentially mutated genetic locus and the other damaging deoxyribonucleic acid replication and resulting in inducation of the error-prone SOS repair function. A second linear section is ascribed to the continued induction, after exposure above that sufficient for complete SOS expression, of isolated lesions which lead to mutation in potentially mutated loci. The third section demonstrates an increased rate of mutagenesis and suggests the induction of two lesions in proximity which result in additional mutations. Split-exposure studies support the inducible nature of the SOS function and suggest that mutation frequency decline (MFD) is due to exicion resulting from or related to the prevention of SOS induction by inhibition of protein synthesis. Preirradiation tryptophan starvation of the uvr+ strain for 30 min decrease MFR in the first and second sections of the curve. Reduction of MFR in the third section requires more prestarvation time and is blocked by nalidixic acid. The decreased MFR of the first and second sections ascribed to promotion of postirradiation MFD based on excision and that of third section to completion of the chromosome during the prestarvation period.
J Bacteriol 1976 Dec
PMID:Complexity of the ultraviolet mutation frequency response curve in Escherichia coli B/r: SOS induction, one-lesion and two-lesion mutagenesis. 79 35

Some methods for measuring the uptake of sugars by yeasts were investigated critically. A study was made of the effects of starvation of Pichia pinus, Candida utilis, Saccharomyces cerevisiae and Rhodosporidium toruloides on their uptake of D-glucose and 2-deoxy-D-glucose. Marked changes in the rates of uptake of these sugars occured during 10 h of starvation, including (a) an immediate increase of up to 75% above that for growing cells and (b) a continuous decline to as little as 4%. Each yeast behaved differently. The rates did not remain constant during the periods of starvation often used for studies on the transport of sugars into yeasts. For Pichia pinus, there were striking differences, associated with starvation, between the transport of 2-deoxy-D-glucose and D-glucose, despite evidence that the two sugars enter this yeast by means of the same carrier. Some physiological explanations for these findings are discussed.
Arch Microbiol 1976 Dec 01
PMID:Some physiological observations on the uptake of D-glucose and 2-deoxy-D-glucose by starving and exponentially-growing yeasts. 79 35

An isogenic pair of Escherichia coli mutants (relA+ tufB valSts and relA1 tufB valSts) has been cultured at several temperatures to establish various degrees of limitation for valyl-tRNA synthetase. The biosynthetic rate of 16 identifiable proteins, most of which are components of the transcription and translation apparatus, was measured by pulse-labelling with [35S]-methionine, followed by protein separation using two-dimensional gel electrophoresis (O'Farrell, 1975). No single pattern of response to amino acid starvation of biosynthetic rate was observed. EF-Ts, L12 and S6 were found to be under strong stringent and relaxed regulation; EF-G, EF-Tu-A and S1 are under strong stringent, but weak relaxed regulation; EF-Tu-B, alpha, VRS, IRS and ARS are under week stringent and weak relaxed regulation; beta is under weak stringent regulation and does not respond at all to relaxed conditions; the biosynthetic rate of a protein called stringent starvation protein is strongly stimulated, relative to other proteins, in the starved stringent strain.
Mol Gen Genet 1976 Dec 22
PMID:Biosynthetic regulation of individual proteins in relA+ and relA strains of Escherichia coli during amino acid starvation. 79 46

The ciliated protozoan, Tetrahymena pyriformis strain GL-C, has been used to study the effect of cell population density during starvation on the synchrony obtained after refeeding and on the number of cells arrested in G2 phase of the cell cycle. At high cell densities two peaks of division indices were observed after refeeding while only one was observed at low cell densities. Cell division began earlier in cultures starved at high cell densities. Most importantly, the proportion of cells in G2 was considerably higher in populations starved at high cell densities. When tritiated thymidine was present during the refeeding period, radioautographs of cell samples at different times showed that the first cells to exhibit division furrows contained unlabeled nuclei. The first peak in the division index after refeeding was observed only at higher cell densities and is attributed to the cells arrested in G2. These results suggest that Tetrahymena is an excellent organism to study the concept of resting stages in the cell cycle and their control.
J Cell Biol 1975 Dec
PMID:Effect of cell population density on G2 arrest in Tetrahymena. 81 69

Using histochemical techniques the glycogen content and the activities of glycogen synthetase (UDPGGT) and phosphorylase were studied in the livers of 106 golden hamsters under following experimental conditions; a) starvation of 16, 36, 48, 72, and 96 hours: b) alloxan-diabetes. Starvation leads to a depletion of liver glycogen during the first 48 hours, which is finally restricted to zone 3 of the liver acinus. After starvation of 72 and 96 hours a new glycogen accumulation is demonstrable in the microvasculatory periphery of the acinus (zone 3 and 2). The process of glycogen depletion is characterized in the beginning by a high phosphorylase activity in all zones of the acinus, later only in the forefield of glycogen content. The weak activity of glycogen synthetase is mainly restricted to zone 3. All phases of glycogen depletion are to be found in alloxan diabetic animals, too. Out of 45 hamsters 23 showed an extreme depletion of glycogen; typical for this situation is a weak or absent glycogen synthetase activity in zone 3 and a broad field of phosphorylase activity in zones 1 and 2. The short stimulation by insulin leads to a considerable increase of glycogen synthetase activity at the portally oriented border of the glycogen area and to a shift of the moderate phosphorylase activity of zone 1. Thus the histochemical characteristics of glycogen depletion are: a shift of the reduced glycogen content in direction of the microvasculatory periphery of the liver acinus (zone 3), caused by a high phosphorylase activity in the portal forefield, while glycogen synthetase activity is low in the glycogen area. The histochemical characteristics of glycogen accumulation are: after a short phase of glycogen synthesis in all hepatocytes a moderate phosphorylase activity in zone 1 leads to a mobilization of the portal glycogen deposits and to an increasing accumulation of glycogen in the peripheral part of the acinus. At the portally oriented border of the glycogen area a high synthetase activity leads to a broadening of the glycogen area in direction of the portal branches. At the end of this process the "normal" pattern of the liver acinus occurs: all hepatocytes are filled with glycogen, the glycogen enzymes are restricted to the periportal border of zone 1.
Histochemistry 1975 Dec 08
PMID:Dynamics of liver glycogen: the topochemistry of glycogen synthesis, glycogen content and glycogenolysis under the experimental conditions of glycogen accumulation and depletion. 81 13

Twenty-three postoperative patients were divided into three groups to evaluate the peripheral vein administration of solutions containing glucose, amino acids, or glucose and amino acids. Serum insulin, glucose, and nitrogen balances were monitored in each patient. Serum insulin concentrations rose on the first postoperative day in all three groups, then fell to near preoperative levels by the third day after surgery. Negative nitrogen balance was most pronounced in patients recieving glucose only. Patients receiving only amino acids had a reduction in nitrogen balance, but some protein catabolism was present. The mean nitrogen balance in patients who received a combination of these solutions was positive on days one and two after surgery and slightly negative on the third postoperative day. These changes were not significantly better than the amino acid group. However, the combination group had 12 to 21 days of positive balance, as compared to seven of 20 days in the amino acid group. Since starvation adaptation accurs gradually, it is concluded that the simplest and safest way to reduce protein catabolism in the immediate postoperative period is by the peripheral intravenous administration of both glucose and amino acids.
Arch Surg 1976 Dec
PMID:Endogenous caloric sources and nitrogen balance: regulation in postoperative patients. 82 36

1. Accumulation of glycogen up to a constant amount per cell was observed during the postexponential phase of growth, in the presence of an excess of a utilizable carbon source. Cell multiplication was reproducibly controlled by growth of the organism in a nitrogen-limiting medium under photoautotrophic conditions (presence of light, air plus CO2). 2. Temporary starvation, i.e. by removal of light or by the addition to an illuminated culture of DCMU, 3-(3',4'-dichlorophenyl)-1,1'-dimethylurea, a specific inhibitor of photosystem II, lead to a mobilization of glycogen in the cell. Furthermore, Anacystis nidulans, having accumulated glycogen by virtue of preculture under nitrogen-limiting conditions, will resume cell division when the culture medium is complemented with a nitrogen source. The ability of the organism to use glycogen as an endogenous carbon source for growth was observed by addition of a nitrogen source to nitrogen-starving cells and simultaneous removal of CO2. 3. During the period of constant amount of glycogen per cell the reserve polysaccharide was subject to turnover as demonstrated with a pulse chase-labelling technique. The demonstration of a turnover--for the first time with a bacterial species--indicated a strict balance in the relative rate of synthesis and degradation.
Arch Microbiol 1976 Dec 01
PMID:Accumulation, mobilization and turn-over of glycogen in the blue-green bacterium Anacystis nidulans. 82 31

The complex problems of microbiological degradation of synthetic plastics and a fairly wide variety of 62 testing materials, belonging to 14 major groups of plastics, are described. Adaequate and reliable testing techniques had to be devised. Drawing on the experiences of H. Braun, 1930, and of Bushnell and Haas, 1941, as to the metabolism of bacteria and the utilization of certain hydrocarbons by microorganisms, and previous research work by A. Schwartz in Berlin, 1959-60, on microbial corrosion of plastics, methods of laboratory testing were developed. The bacteriological technique was based on selection of aerobic microorganisms, which were, by starvation, adapted to use the plastic materials as their only carbon source; foreign carbon sources had to be strictly eliminated; emphasis was laid on proper, double control cultures. The test organisms involved included P. aeruginosa and fluorescens strains, also a certain species of Candida, and mixtures of soil, sewage and garbage organisms grown on exposed plastic surfaces. By means of series of passages the selective adaptation and conservation of these organisms was continued up to 4 1/2 years. An anaerobic adaptation method for Desulfovibrio desulfuricans was developed and used successfully. After preliminary experimentation (Soil burial, sewage and garbage exposure tests) in the laboratory as well as in the open, a large scale Field testing programme under realistic and to some extent extreme conditions was implemented: Nine different plastic materials comprising eight plain high polymer plastics and for comparison one synthetic Cellulose derivate, together with glass control samples, were exposed in twelve different sewage, garbage, and soil media over a period of 3 months to 2 years, and subsequently examined. On the basis of the bacteriological results obtained from the adaptation series the test materials were classified into three categories, corresponding to the stimulation of bacterial growth: Group one, which allowed strong proliferation, included certain types of plasticized P.V.C. and Cellulose esters, as expected, and, as a new result, Polyurethane rubber; the latter showed clear signs of surface corrosion. Group two, which induced a clear but moderate growth, comprised a nylon trade type of Polyamide. Gruop three, allowing weak but still recognisable growth, included Formaldehyde pressure resing (Bakelite). This was surprising as it was thought that the formaldehyde and phenol components would exert a bacteriocidic or at least bacteriostatic effect. The results of the long and time consuming adaptation series with Pseudomonas aeruginosa were confirmed by the manometric dissimilation method of O. Warburg by means of the Braun/Melsungen apparatus. With this subtle but elegant procedure results and graphical recordings were obtained within hours and days...
Zentralbl Bakteriol Orig B 1976 Dec
PMID:[Mutual relations between plastic materials and bacteria (author's transl)]. 82 69


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