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

Initiated spores and vegetative cells of the gramicidin S-producing Bacillus brevis Nagano were compared with respect to their resistance to various forms of stress (osmotic shock-starvation, exposure to ethanol, sonic oscillation, and heat). The resistance of initiated spores to all of these stress situations was considerably greater than that of vegetative cells and approached that of dormant spores. The period during which the initiated spores remained resistant to heat was extended by addition of gramicidin S. The antibiotic may therefore be of survival value to the species in nature by slowing down the development of initiated spores in the outgrowth phase of germination, thereby extending the period during which the cells are resistant to environmental stress.
 ...
PMID:Germination-initiated spores of Bacillus brevis Nagano retain their resistance properties. 257 49

Alcoholic ketoacidosis is a metabolic disorder that occurs in acute-on-chronic ethanol abusers who become acutely starved because of cessation of all caloric intake (including ethanol) owing to gastric intolerance or to an intercurrent acute illness. The precise pathogenesis, and especially the cause of the increased lipolysis, is not known, but several factors known or believed to promote ketogenesis are present in those patients. These are particularly starvation and recent ethanol ingestion. The metabolic disorder responds rapidly to rehydration and administration of glucose intravenously, which stops the ketogenesis. The prognosis in these patients depends on the presence and severity of any underlying illness and the adequacy and effectiveness of treatment for that illness. Patients rarely if ever die from either the ketoacidosis or the lactic acidosis associated with ethanol abuse, but they may succumb to other precipitating or coexisting illnesses.
 ...
PMID:Alcoholism, ketoacidosis, and lactic acidosis. 265 60

In Neurospora crassa, heat shock results in the induction of 9 to 11 heat shock proteins (HSP), of which HSP80 is the most abundant and the first to be synthesized. The induction of HSP80 was investigated during normal growth (2% sucrose) and under sucrose starvation. Transfer of mycelium to a medium supplemented with ethanol stimulated the synthesis of HSP80, even at the normal growth temperature of 28 degrees C. It was also synthesized under carbon starvation conditions, where the medium was supplemented with 0.02% sucrose, 0.3% acetate, 0.2% lactate, or ethanol. A 30-35 kilodalton polypeptide was induced by heat shock in carbon-sufficient media, but in 0.02% sucrose and 0.3% acetate containing media it was synthesized at normal temperatures. While the overall heat shock response remained unaltered in these cultures, the abundance of HSP90 and HSP70, relative to HSP80, was greater. HSP80 appears to be controlled by carbon-catabolite repression as well as heat shock. Another high molecular mass protein (tentatively designated alc'80') was observed to be induced by heat shock, provided carbon starvation conditions prevailed concurrently.
 ...
PMID:Ethanol and carbon-source starvation enhance the accumulation of HSP80 in Neurospora crassa. 296 70

The enzyme ATP:GTP 3'-diphosphotransferase catalyzes the transfer of the beta, gamma-pyrophosphate of ATP to the 3' position of GTP or GDP. The amounts of enzyme were measured in cell extracts of a relA+ strain of E. coli grown at different growth rates between 0.4 and 1.9 generations per hour, using precipitation with specific antibodies to purify the enzyme. The amount of enzyme was found to be a constant fraction of total protein at all growth rates corresponding to about 45 molecules of enzyme per genome equivalent of DNA. The purified enzyme has little catalytic activity by itself but has to be activated either by a complex of 70S ribosomes, mRNA and uncharged tRNA or by a solvent like ethanol at a concentration of about 20%. The kinetic constants of the enzyme for the transfer pyrophosphate from ATP to GTP in the ribosome-activated state were determined. The Vmax was estimated to be 140 mumol/min X mg at 37 degrees C and the S0.5 values for GTP and ATP were 0.35 and 0.53 mM, respectively. The reaction was estimated to have an equilibrium constant of about 300. In the pyrophosphate transfer from ATP to GDP the Vmax was estimated to be 90 mumol/min X mg at 37 degrees C and the S0.5 for GDP as 0.3 mM. During amino acid starvation of a relA+ strain of E. coli the amounts of enzyme and the catalytic capacity of the enzyme are sufficient to maintain the observed ppGpp levels in the cells at all growth rates.
 ...
PMID:The physiology of stringent factor (ATP:GTP 3'-diphosphotransferase) in Escherichia coli. 301 58

Glucose- or nitrogen-starved cultures of Escherichia coli exhibited enhanced resistance to heat (57 degrees C) or H2O2 (15 mM) challenge, compared with their exponentially growing counterparts. The degree of resistance increased with the time for which the cells were starved prior to the challenge, with 4 h of starvation providing the maximal protection. Protein synthesis during starvation was essential for these cross protections, since chloramphenicol addition at the onset of starvation prevented the development of thermal or oxidative resistance. Starved cultures also demonstrated stronger thermal and oxidative resistance than did growing cultures adapted to heat, H2O2, or ethanol prior to the heat or H2O2 challenge. Two-dimensional gel electrophoresis of 35S-pulse-labeled proteins showed that subsets of the 30 glucose starvation proteins were also synthesized during heat or H2O2 adaptation; three proteins were common to all three stresses. Most of the common proteins were among the previously identified Pex proteins (J.E. Schultz, G. I. Latter, and A. Matin, J. Bacteriol. 170:3903-3909, 1988), which are independent of cyclic AMP positive control for their induction during starvation. Induction of starvation proteins dependent on cyclic AMP was not important in these cross protections, since a delta cya strain of E. coli K-12 exhibited the same degree of resistance to heat or H2O2 as the wild-type parent did during both growth and starvation.
 ...
PMID:Starvation-induced cross protection against heat or H2O2 challenge in Escherichia coli. 304 81

Expression of the RAS1 and RAS2 genes of Saccharomyces cerevisiae has been examined at the transcriptional and translational levels. When dextrose is the carbon source, the steady-state amount of RAS1 mRNA and the rate of RAS1 protein synthesis are reduced in parallel as cells approach the mid-exponential phase of growth. RAS1 mRNA levels and protein synthesis are very low at all stages of growth when ethanol rather than dextrose is provided as the sole carbon source. The rate of RAS2 protein synthesis is regulated differently. In cells cultured on dextrose, it is lowest in the early exponential phase, increases approximately 10-fold and remains nearly constant as cells approach stationary phase. By contrast, RAS2 mRNA is found at uniformly high levels at all phases of exponential growth, suggesting that the translational efficiency of RAS2 mRNA is repressed during the early exponential phase. This repression is not observed when ethanol is the sole carbon source. Nutrient starvation, resulting in G1 arrest and sporulation in diploids, leads to greatly decreased amounts of RAS2 mRNA, accomplished in part by selective repression of RAS2 transcripts with particular 5' ends. However, this reduction in RAS2 mRNA levels has little effect on the rate of RAS2 protein synthesis, suggesting that the translational efficiency of RAS2 mRNA is stimulated by nutrient starvation. The combination of transcriptional and translational controls which regulate yeast RAS gene expression seems to ensure that one or the other RAS proteins will be produced over a wide range of physiological states.
 ...
PMID:Multiple regulatory mechanisms control the expression of the RAS1 and RAS2 genes of Saccharomyces cerevisiae. 304 76

To establish a balance between the ATP produced in catabolism and the ATP consumed in net biosynthesis of cellular components the energy metabolism of Saccharomyces cerevisiae utilizing glucose in the absence of a nitrogen source (resting cells) was studied. The following results were obtained. (i) Cell number and biomass increased 2- and 2.5-fold, respectively, during the first 8 h of ammonium starvation. After this period, both values remained constant. (ii) The rate of sugar consumption and ATP production decreased with the duration of starvation to about 20% of the original in 24 h. (iii) About 60% of the sugar consumed was fermented to ethanol and about 10% assimilated as cellular material. Of the assimilated sugar, as much as 80% was accumulated as carbohydrate. (iv) Only 15% of the total ATP produced in catabolism seems to be consumed in net biosynthesis and maintenance of intracellular pH. The fate of the remaining 85% is unknown.
 ...
PMID:Balance of production and consumption of ATP in ammonium-starved Saccharomyces cerevisiae. 307 87

Tumor growth and the incorporation of [3H]thymidine into tumor DNA in vivo are increased about 3 times in adult rats (greater than 250 g) after 1 to 2 days of starvation or the induction of diabetes with streptozotocin. These tumor growth responses require hyperlipemia and are reversed by refeeding or insulin treatment, respectively. They do not occur in young tumor-bearing rats (less than about 150 g) that lack appreciable fat stores. A direct relationship between the increased rates of both [3H]thymidine incorporation and tumor growth and host hyperlipemia suggests that tumor cell renewal in vivo in fed rats is limited by substances that are present in hyperlipemic blood. In this study we used a procedure for perfusion of solid tumors in situ to measure the sensitivity of tumor [3H]thymidine incorporation to hyperlipemic blood and to identify the rate-limiting substances. Tissue-isolated Morris hepatomas (7288CTC) growing in young or adult Buffalo rats were perfused with blood from donor rats. Hyperlipemic blood for perfusion was obtained from 2-day starved tumor-bearing (Buffalo) or non-tumor-bearing (Buffalo or Lewis) rats. At the end of the perfusions the tumors were labeled with a pulse of [3H]thymidine (2 microCi/g estimated tumor wet weight). [3H]Thymidine incorporation in tumors growing in fed adult rats was increased from 80 +/- 5 (SD) dpm/micrograms DNA at zero time (before perfusion) to 209 +/- 9 dpm/micrograms DNA (n = 3) after perfusion for 3 h. Tumors growing in fed or starved young rats showed similar responses, and hyperlipemic blood from non-tumor-bearing rats was as effective as hyperlipemic blood from tumor-bearing rats. Perfusion of tumors growing in starved rats with normolipemic blood from fed adult rats decreased [3H]thymidine incorporation from 211 +/- 13 dpm/micrograms DNA before perfusion to 68 +/- 9 dpm/micrograms DNA (n = 3) after perfusion for 3 h. Cells, plasma, and plasma subfractions from hyperlipemic blood were reconstituted to whole blood using plasma, cells, and whole blood, respectively, from fed rats and the mixtures were perfused into tumors growing in fed adult rats. Mixtures containing hyperlipemic plasma, lipid extracts (ethanol:acetone, 1:1) of hyperlipemic plasma, or albumin from hyperlipemic plasma increased tumor [3H]thymidine incorporation. Free fatty acid concentrations were increased about five times in hyperlipemic plasma and perfusion of tumors with normolipemic blood containing added linoleic and arachidonic acids increased [3H]thymidine incorporation. Blood mixtures containing palmitic, stearic, and oleic acids were inactive.(ABSTRACT TRUNCATED AT 400 WORDS)
 ...
PMID:Identification of linoleic and arachidonic acids as the factors in hyperlipemic blood that increase [3H]thymidine incorporation in hepatoma 7288CTC perfused in situ. 313 Jan 86

To study the role of undernourishment in the negative effects of ethanol during pregnancy and to determine whether maternal ethanol intake modifies metabolic response to starvation at late gestation, female rats receiving ethanol in their drinking water before and during pregnancy (ethanol group) were compared with animals that received the same amount of solid diet as the ethanol group rats (pair-fed group) and with normal rats fed ad libitum (control group). All animals were killed on the 21st day of gestation, either in the fed state or after 24-hours fasting. The body weight of ethanol rats was lower than that of controls but higher than that of pair-fed rats. When compared with controls, ethanol and pair-fed rats had reduced fetal body weights, whereas fetal body length was reduced only in the former. In the fed state, blood glucose concentration was lower in the ethanol and pair-fed rats and fetuses than in controls. Twenty-four-hour starvation caused a reduction in this parameter only in control and ethanol mothers. In the fed state, maternal liver glycogen concentration was lower in ethanol and higher in pair-fed mothers than in controls. Blood beta-hydroxybutyrate levels were higher in ethanol-treated mothers than in the others, and 24-hour starvation increased this parameter in ethanol and control rats to a greater extent than in the pair-fed ones. Liver triacylglyceride concentration was higher in ethanol-treated mothers than in the other two groups, and starvation caused this concentration to increase in ethanol and control groups but not in the pair-fed group.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Metabolic response to starvation at late gestation in chronically ethanol-treated and pair-fed undernourished rats. 318 84

Changes in membrane and periplasmic protein profiles induced by starvation conditions in the marine Vibrio sp. S14 were examined by one-dimensional gel electrophoresis. Analysis by densitometry resolved at least six periplasmic proteins, nine outer membrane proteins, and four cytoplasmic membrane proteins induced at various times during 120 h of nutrient and energy starvation. Eight of these were also synthesized by heat- and/or ethanol-shocked cells. Pulse-labelling indicated that the starvation-induced proteins were not products of degradation, and that their synthesis was differently modulated during starvation. The most pronounced changes occurred during the initial hours of nutrient and energy deprivation. The correlation between the initial changes in protein composition and utilization of the intracellular energy reserve poly-beta-hydroxybutyrate is discussed. The rate of proteolysis during the initial hours of starvation was approximately 16 times greater than that during exponential growth.
 ...
PMID:Synthesis of membrane and periplasmic proteins during starvation of a marine Vibrio sp. 322 Dec 1


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>