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)

Starved cells of Candida utilis accumulated Zn2+ by two different processes. The first was a rapid, energy- and temperature-independent system that probably represented binding to the cell surface. The cells also possessed an energy-, pH-, and temperature-dependent system that was capable of accumulating much greater quantities of the cation than the binding process. The energy-dependent system was inhibited by KCN, Na2HAsO4, m-chlorophenyl carbonylcyanide hydrazone, N-ethylmaleimide, EDTA and diethylenetriaminepenta-acetic acid. The system was specific inasmuch as Ca2+, Cr3+, Mn2+, Co2+ or Cu2+ did not compete with, inhibit, or enhance the process, Zn2+ uptake was inhibited by Cd2+. The system exhibited saturation kinetics with a half-saturation value of 1.3 muM and a maximum rate of 0.21 (nmol Zn2+) min(-1) (mg dry wt(-1)) at 30 degrees C. Zn2+ uptake required intact membranes since only the binding process was observed in the presence of nystatin, toluene, or sodium dodecyl sulphate. Cells did not exchange recently accumulated toluene, or sodium dodecyl sulphate. Cells did not exchange recently accumulated 65Zn following the addition of a large excess of non-radioactive Zn2+. Similarly, cells pre-loaded with 65Zn did not lose the cation during starvation, and efflux did not occur when glucose and exogenous Zn2+ were supplied after the starvation period. Efflux was only observed after the addition of toluene or nystatin, or when cells were heated to 100 degrees C. Cells fed a large quantity of Zn2+ contained a protein fraction resembling animal cell metallothionein. In batch culture, cells of C. utilis accumulated Zn2+ only during the lag phase and the latter half of the exponential-growth phase.
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PMID:Accumulation and storage of Zn2+ by Candida utilis. 0 25

It was shown that the vital capacity of the mouse kidney tissues quantitatively estimated by the in vitro growth in a plasma-free medium depended upon the condition of the donor organism. Depression of the culture growth was noted after the general X-irradiation of the animals, as well as following prolonged starvation and chloric cadmium poisoning. An increased growth of the kidney tissues was observed both in compensatory hypertrophy caused by unilateral nephrectomy and in subcutaneous inflammation.
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PMID:[Quantitative assessment of the viability of renal tissue when the donor's body is treated differently]. 19 Nov 20

O6-Methylguanine-DNA methyltransferase (MGMT) is decisively involved in protecting mammalian cells against genotoxic effects of alkylating carcinogens. We analysed regulation of MGMT expression after exposing rat hepatoma H4IIE cells to various 'stress' factors. Treatments that damage DNA such as alkylation, hydrogen peroxide, ultraviolet or X-ray exposure, as well as restriction enzymes introduced into cells by electroporation or arrest of replication by hydroxyurea significantly induced MGMT mRNA (2.5 to 5-fold). Slight induction (up to 2.5-fold) was observed after heat shock or cadmium/zinc treatment. No or only a very weak induction (less than 1.5-fold) was observed after treatment with 6-thioguanine, 5-azacytidine, transfection of methylated DNA, depletion of MGMT by feeding with O6-methylguanine or O6-benzylguanine, serum starvation and feeding of starved cells, cAMP, TPA and dexamethasone treatment. Inhibitors of protein kinases, H8 and H9, induced MGMT mRNA. On the other hand, an inhibitor of phosphatases (sodium vanadate) prevented induction of MGMT by N-methyl-N'-nitro-N-nitrosoguanidine. The data indicate that DNA breaks are an ultimate signal for MGMT mRNA induction and that protein phosphorylation is involved in regulating MGMT expression.
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PMID:Stress factors affecting expression of O6-methylguanine-DNA methyltransferase mRNA in rat hepatoma cells. 142 Mar 62

Exposure of growing batch cultures of Escherichia coli to nine different "model micropollutants" (benzene, cadmium chloride, chlorpyrivos, 2,4-dichloroaniline, dioctylphtalate, hexachlorobenzene, pentachlorophenol, trichloroethylene, and tetrapropylbenzosulfonate) led to the induction of 13 to 39 proteins, as analyzed by two-dimensional gel electrophoresis. Some of these proteins overlapped with heat shock and carbon starvation proteins, but at least 50% were unique to a given chemical. The stress protein induction showed a temporal pattern, indicating sequential gene expression. Chemical stress protein synthesis occurred even at concentrations that had no effect on growth. Thus, the synthesis of these proteins can be a sensitive index of stress and the nature of environmental pollution.
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PMID:Unique and overlapping pollutant stress proteins of Escherichia coli. 153 81

The multidrug transporter, initially identified as a multidrug efflux pump responsible for resistance of cultured cells to natural product cytotoxic drugs, is normally expressed on the apical membranes of excretory epithelial cells in the liver, kidney, and intestine. This localization suggests that the multidrug transporter may have a normal physiological role in transporting cytotoxic compounds or metabolites. In the liver, hepatectomy or treatment with chemical carcinogens increases expression of the MDR1 gene which encodes the multidrug transporter. To evaluate conditions which increase MDR1 gene expression, we have investigated the induction of the MDR1 gene by physical and chemical environmental insults in the renal adenocarcinoma cell line HTB-46. There are two strong heat shock consensus elements in the major MDR1 gene promoter. Exposure of HTB-46 cells to heat shock, sodium arsenite, or cadmium chloride led to a 7- to 8-fold increase in MDR1 mRNA levels. MDR1 RNA levels did not change following glucose starvation or treatment with 2-deoxyglucose and the calcium ionophore A23187, conditions which are known to activate the expression of another family of stress proteins, the glucose-regulated proteins. The levels of the multidrug transporter, P-glycoprotein, as measured by immunoprecipitation, were also increased after heat shock and sodium arsenite treatment. This increase in the level of the multidrug transporter in HTB-46 cells correlated with a transient increase in resistance to vinblastine following heat shock and arsenite treatment. These results suggest that the MDR1 gene is regulatable by environmental stress.
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PMID:Heat shock and arsenite increase expression of the multidrug resistance (MDR1) gene in human renal carcinoma cells. 196 74

Emphysema in humans takes several different forms: centrilobular, panacinar, paraseptal, and airspace enlargement with fibrosis. The varying morphologic and background features of these forms of emphysema suggest that they differ in pathogenesis. Elastic fiber rupture and fraying are a feature of emphysema. Experimental emphysema may be induced by human neutrophil elastase and other elastolytic enzymes but not by nonelastolytic proteases. Disruption of elastic fibers also appears to be the underlying feature of lathyrogen-induced airspace enlargement and of the emphysema in the blotchy mouse. However, there is no evidence of elastic fiber destruction in cadmium-induced airspace enlargement with fibrosis or in emphysema associated with hyperoxia or severe starvation. Thus, elastic fiber disruption is not common to all forms of experimental emphysema. We posit that airspace enlargement may be a stereotyped response of the lungs to different injuries. Emphysema can be induced in experimental animals by repeated induction of pulmonary neutrophilia. However, the evidence for involvement of neutrophil elastase in human emphysema is not clear: there are studies using a variety of approaches that weigh on both sides of the question. There is also in vitro evidence that alveolar macrophages can degrade elastin or elastic fibers with which they are in contact by means of a metalloelastase or the cooperative action of plasminogen activator and an acid cysteine protease. We conclude that the pathogenesis of emphysema is complex. Neutrophil elastase likely plays a major role in the development of some forms of emphysema, but our understanding of the interactions between the alveolar walls and neutrophils is still fragmentary.
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PMID:Putative role of neutrophil elastase in the pathogenesis of emphysema. 206 48

Specimens of male and brooding female eider (Somateria mollissima) were collected in Svalbard. Chemical analyses revealed hepatic copper concentrations ranging from 20 to 1050 micrograms per g wet weight. This is in agreement with previous results. The selenium, zinc and cadmium values were equal to or slightly higher than previously recorded. It is suggested that the wide variation in copper concentration is a result of differences in intake of copper-containing food among the birds. High selenium intake may enhance copper accumulation. Starvation influences the concentration of zinc and also copper. Zinc concentrations were significantly higher in females. This may be secondary to starvation. The percentage of copper recovered among the soluble proteins was inversely related to the copper content. The distribution of the soluble proteins reflects a normal copper metabolism. Microscopic studies showed prominent dark granules, positive with the rubeanic acid test for copper, confined to hepatocytes. By electron microscopy, the granules appeared as large irregular, electron-dense bodies that, by X-ray microanalysis, were found to contain copper. There were no signs of liver injuries such as necrosis and fibrosis. Apparently, the eider has evolved a high capacity for copper storage.
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PMID:Chemical and morphological studies of liver from eider (Somateria mollissima) in Svalbard with special reference to the distribution of copper. 236 57

The effects of short term intraperitoneal administration of cadmium chloride and D-galactosamine on liver nuclear and chromatin levels of ribonucleic acid (RNA) and protein as well as the gel patterns of nuclear nonhistone proteins were examined in fed and starved chickens. It was shown that starvation, cadmium chloride and galactosamine caused a decrease of RNA and protein content in the liver nuclei and chromatin. Cadmium had no significant effect on the gel patterns of nuclear proteins whilst D-galactosamine and starvation produced quantitative changes of certain bands of nonhistone proteins. Although D-galactosamine caused an increase of the amount of histones among liver nucleoplasmic proteins both in fed and starved birds, cadmium brought about a similar effect in starved hens only.
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PMID:Effects of cadmium chloride and D-galactosamine on liver nuclear proteins of starved hens. 243 53

The hepatic acid-soluble thiol content of striped mullet (Mugil cephalus) exposed to cadmium (10 mg/liter seawater), mercury (200 micrograms/liter), fluorene (100 micrograms/liter), dibenzofuran (750 micrograms/liter), or a 20% water-soluble fraction of a No. 2 fuel oil, and of winter flounder (Pseudopleuronectes americanus) exposed to pentachlorophenol (200 micrograms/liter) for up to 3 weeks was determined. Exposure to these chemicals caused an elevation of hepatic acid-soluble thiol content over control values. Similarly, the acid-soluble thiol content was 1.75 times control values 24 hr after injection with acetaminophen (40 mg/100 g body wt, ip). In contrast, hepatic acid-soluble thiol concentrations did not fluctuate after feeding or during short-term starvation, or after acute or chronic physical trauma. Thus, the increase in hepatic acid-soluble thiols observed in mullet appears to be a specific response to chemical insult. The effect of chemical exposure on specific thiols can vary with the compound under investigation. Glutathione accounted for most of the acid-soluble thiol increase observed in mullet exposed to oil, whereas other acid-soluble thiols were also elevated after exposure to cadmium. Injection of [14C]glycine into cadmium- and oil-treated mullet showed that hepatic uptake of this amino acid substrate and its incorporation into hepatic glutathione increased after chemical exposure. The proportion of the total [14C]glycine in the liver incorporated into glutathione was unchanged after oil exposure, but was significantly increased in cadmium-exposed fish. These results suggest that chemicals may elevate glutathione content by enhancing the hepatic uptake of amino acid substrates and also the activity of biosynthetic enzymes.
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PMID:Effects of metals and organic compounds on hepatic glutathione, cysteine, and acid-soluble thiol levels in mullet (Mugil cephalus L.). 648 87

As was shown using various reagents (Ag+, Cd2+) and solvents (ethanol, methanol), Thiobacillus ferrooxidans cells accumulate colloidal sulfur when they grow in the medium 9K containing elemental sulfur. Colloidal sulfur is accumulated in the periplasmic space, in large, bipolarly arranged spherical structures and in simple invaginates of the cytoplasmic membrane. T. ferrooxidans cells accumulate the sulfur at a highest rate during the stationary phase of growth and can use it as a source of energy under the conditions of starvation. The factors causing sulfur accumulation in T. ferrooxidans cells are discussed.
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PMID:[Nature of the sulfur-containing component and its function in Thiobacillus ferrooxidans]. 664 91


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