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)

Serum aminogram changes were prospectively studied in 95 patients with enteric fistula and intraabdominal infection who was under total parenteral nutrition (TPN) therapy with Anfuming 14s. In patients with sepsis and starvation, the aminogram showed remarkably low total free amino acids before TPN therapy. In 81 survivors, free amino acids increased gradually to normal in 2 weeks after use of TPN and in 14 dead cases increased rapidly to a significantly higher peak at terminal stage. Both in survivors and nonsurvivors, phenylalanine level remained high during the study. In response to infection, proline was also elevated but to a lesser degree; the ratio of branched chain amino acid (BCAA) to aromatic amino acid (AAA) was lower than normal and the decrease of arginine was parallel to the severity of infection. We conclude that the ideal amino acids preparation for the starvated and septic patients should be high in BCAA and arginine but low in phenylalanine, administration of inappropriate exogenous amino acids in decompensated metabolic septic patients may bring about more harm than benefit, and in septic patients that the levels of serum phenylalanine and proline are elevated persistently along with the decrease of arginine level is a useful prognostic indication.
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PMID:[Changes in serum amino acids in total parenteral nutrition supported patients with intra abdominal infection]. 251 49

Plasma aminogram changes were prospectively studied in 95 patients with external enteric fistula and intraabdominal infection who were under total parenteral nutrition (TPN) therapy with anfuming 14s. Plasma amino acids and albumin were determined before the administration of TPN, weekly and at the end of the therapy or 2 to 5 days before death of patients. In patients with sepsis and starvation, the aminogram showed remarkably low total free amino acids before TPN therapy. In survivors, free amino acids increased gradually to normal in 2 weeks after use of TPN and in the dead increased rapidly to a significantly high peak at the terminal stage. In both survivors and deceased, phenylalanine level remained high during the study. In response to infection, proline was also elevated but to a lesser degree; the ratio of branched chain amino acid (BCAA) to aromatic amino acid (AAA) was lower than normal and the decrease of arginine was parallel to the severity of infection. We conclude that the ideal amino acid preparation for the starved, septic patients should be high in BCAA and arginine but low in phenylalanine; the administration of inappropriate exogenous amino acids in metabolically decompensated septic patients may bring about more harm than benefit; and in septic patients the persistently elevated level of plasma phenylalanine and proline along with decrease of arginine is a useful prognostic sign.
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PMID:Changes of plasma amino acids in total parenteral nutrition-supported patients with intraabdominal infection. 251 37

Argininosuccinate synthetase and argininosuccinate lyase catalyze the synthesis of arginine from citrulline in kidney and also serve as components of the urea cycle in liver of ureotelic animals. Dietary and hormonal regulation of mRNAs encoding these enzymes have been well studied in liver but not in kidney. Messenger RNAs for these enzymes are localized within the renal cortex. Starvation and extreme variations in dietary protein content (0% vs 60% casein) produced 2.6- to 3.5-fold increases in mRNA abundance for these two enzymes in rat kidney. Argininosuccinate lyase mRNA was not induced by dibutyryl cAMP, dexamethasone, or a combination of the two agents. In contrast, argininosuccinate synthetase mRNA was induced 2-fold by dibutyryl cAMP but was unresponsive to dexamethasone. Thus, diet and hormones regulate levels of these mRNAs in rat kidney, but the responses are both qualitatively and quantitatively distinct from the responses previously reported for rat liver.
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PMID:Nutritional and hormonal regulation of mRNA abundance for arginine biosynthetic enzymes in kidney. 254 41

In submerged grown hyphae of Penicillium cyclopium the activities of seven transport systems could be distinguished which share in the uptake of L-arginine, L-glutamic acid, L-phenylalanine and L-leucine. They include the specific systems a (accepting L-arginine and L-lysine), b (L-phenylalanine, L-tyrosine), c (L-glutamic acid) and d (L-leucine), system I (a 'general amino-acid permease') and the low-affinity systems II and III, which accept acidic or basic amino acids, respectively, but also L-phenylalanine. In nutrient-sufficient cells, systems I, II and III remain repressed; uptake is dominated by the specific systems b, c, d and a, the latter reaching its maximum activity. Nitrogen starvation is the most powerful signal for the development of systems I, II and III, whereas, in carbon-starved cells, systems b, c and d reach maximum activities. The development of the general amino-acid permease in nitrogen-starved cells requires both translational and--with a few hours delay--transcriptional events as indicated by the influence of cycloheximide and 5-fluorouracil. The uptake of all amino acids is accompanied by a transient acidification of the cellular interior. Short-time preaccumulation of several anions, such as citrate, alpha-oxo-glutarate, glutamate (but not glutamine), increases the initial rate of amino-acid uptake at a pH above the optimum. Uncouplers inhibit the uptake not only under aerobic but also under anaerobic conditions, where the ATP content is not influenced by these compounds. These findings point to an H+/amino acid symport, which is tightly connected with the recycling of the incoming protons by the plasmalemma H+-ATPase.
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PMID:Kinetic properties, nutrient-dependent regulation and energy coupling of amino-acid transport systems in Penicillium cyclopium. 256 28

The arginine-independent, de novo biosynthetic pathway of pyrimidines in Dictyostelium discoideum is initiated by a class II carbamoyl-phosphate synthetase (EC 6.3.5.5) specific for pyrimidine biosynthesis which utilized L-glutamine as its N donor and was partially inhibited by both UTP and CTP. The second step in the de novo pathway was provided by an unregulated aspartate transcarbamoylase (EC 2.1.3.2) which primarily appeared as a multimeric enzyme of 105 kilodaltons. The next enzyme, dihydroorotase (EC 3.5.2.3), was approximately 90-100 kilodaltons. Although the early enzymatic activities of the pyrimidine pathway appeared to reside in independent protein complexes, various unstable molecular species were observed. These structural variants may represent proteolytic fragments of a multienzyme complex. In addition to de novo synthesis, the amoeba demonstrated the capacity for salvage utilization of uracil, uridine, and cytidine. Upon starvation on a solid substratum, axenically grown amoebas began a concerted developmental program accompanied by a restructuring of nucleotide metabolism. The absolute levels of the ribonucleotide pools droppedby 98% within 30 h; however, both the adenylate energy charge and the GTP/ATP ratios were maintained for 50 h after the initiation of development. The maintenance of these metabolic energy parameters required the tight cell-cell contact necessary for development, and the capacity for pyrimidine metabolism was maintained throughout developmental morphogenesis.
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PMID:Characterization of pyrimidine metabolism in the cellular slime mold, Dictyostelium discoideum. 256 62

Tetrahymena thermophila cells grown in a synthetic nutrient medium for 9 h removed 97% of the free L-arginine but less than 50% of any of the other essential amino acids. The major portion of the arginine was degraded rapidly (76-92%) whereas 5-15% was conserved as intact and only 2.5-10% were incorporated into protein. However, if bovine serum albumin (BSA) was present in the medium as a macromolecular arginine source the incorporation of free arginine into protein was reduced to less than 1% but the degraded fraction was increased. Apparently, the uptake mode of arginine determines its fate: arginine taken up by phagocytosis is bound for protein biosynthesis, arginine taken up by membrane receptors is chanelled to degradation. Media without arginine did not support growth of Tetrahymena. Citrulline and ornithine, the precursors of arginine biosynthesis in yeast and vertebrates, were not able to substitute for arginine. Pronounced morphological changes, e.g. greatly reduced ribosome content, were observed in Tetrahymena cells after 24 h of arginine starvation in otherwise complete medium, but not in cells starved in water, salt solution, or buffer. Thus, arginine is an essential nutrient component for Tetrahymena and the rapid degradation of this compound involving the enzymes arginine deiminase (ADI) and citrulline hydrolase (CH) might be of regulatory importance for the unicellular, as it is the case with acetylcholine and catecholamines in mammalian organisms. Since the product of these enzymes, L-ornithine, is the substrate for the regulatory key enzyme of polyamine biosynthesis, ornithine decarboxylase (ODC), the effects of the presence of absence of arginine on the activities of each particular enzyme of the pathway were studied, including ODC and the enzyme ornithine-oxo-acid aminotransferase (O delta T), which is a competitor of ODC for the common substrate. The arginine-degradative pathway was stimulated by extracellular free but not by peptide-bound arginine and was modulated by extracellular protein which induced phagocytosis; O delta T was stimulated with a time lag. The stimulation of ODC was in a reciprocal relation to the arginine concentration and enhanced by phagocytosis and previous arginine starvation.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Stimulation of growth and polyamine biosynthesis of the ciliated protozoan Tetrahymena thermophila. Regulation by L-arginine. 261 Sep 29

The effects of 3-hydroxybutyrate (3-OHB) and hyperosmolarity on glucagon secretion were examined in the isolated perfused canine pancreas. When 3-OHB was infused for 15 min into the pancreas perfused with 2.8 mM glucose, 5 and 20 mM sodium 3-OHB inhibited it after a transient stimulation, whereas a similar transient stimulation was observed also by the infusion of 20 mM NaCl in a control experiment. The above inhibition was not observed under the perfusate condition of 5.5 mM glucose plus 10 mM arginine. When the isolated canine pancreas was perfused under the perfusate condition of acidosis (pH 7.1), ketoacidosis (pH 7.1 and 20 mM 3-OHB) or hyperosmolarity (+60 mOsm/kg with sucrose) throughout the experiment, the glucagon concentrations produced by 2.8 mM glucose under the ketoacidotic and hyperosmolar conditions, were less than half of those obtained under the standard condition. The insulin level was not influenced by the above perfusate conditions. These results suggest that 3-OHB inhibits glucagon secretion stimulated by glucopenia, but does not inhibit it stimulated by amino acids, and that hyperosmolarity inhibits glucagon secretion but does not inhibit insulin secretion. The pathophysiological significance of these results must be slight, considering the presence of hyperglucagonemia during prolonged starvation or diabetic ketoacidosis.
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PMID:Effects of 3-hydroxybutyrate and hyperosmolarity on glucagon release from isolated perfused canine pancreas. 268 20

We constructed Schizosaccharomyces pombe strains that carry phenylalanine, instead of arginine, as residue 116 of calmodulin by site-directed mutagenesis of the cam1 gene. Whereas haploid strains carrying the mutant allele, designated cam1-F116, exhibit no defects in growth and mating, diploid strains homozygous for cam1-F116 are deficient in sporulation. The four nuclei generated by the two serial meiotic divisions are not encapsulated in these diploids. The mutation is recessive. Semiquantitative analysis using polyclonal antibodies showed that vegetatively growing cam1-F116 cells have a smaller amount of calmodulin than wild-type cells. The quantitative difference becomes more remarkable if the cells are starved for nitrogen, which is a condition for induction of sporulation. In addition to this in vivo observation, we showed in vitro that the mutant protein is susceptible to a proteolytic activity induced by nitrogen starvation that hardly affects the wild-type calmodulin. Thus, the sporulation deficiency of the cam1-F116 mutant may be ascribed to shortage of calmodulin due to proteolysis of the mutant molecules under nitrogen starvation. Two other mutations at position 116 resulted in similar but leakier Spo- phenotypes.
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PMID:Substitution at position 116 of Schizosaccharomyces pombe calmodulin decreases its stability under nitrogen starvation and results in a sporulation-deficient phenotype. 269 71

In this article we summarize evidence for a pathway by which cytosolic proteins can be selectively taken up and degraded within lysosomes. Serum deprivation of cells in culture activates this pathway, and only proteins that contain peptide sequences related to KFERQ (lysine, phenylalanine, glutamic acid, arginine, glutamine) are degraded at enhanced rates. Approximately 30% of intracellular proteins contain such peptide sequences, and we speculate about the physiological relevance of the selective degradation of these proteins in response to serum withdrawal. Several rat tissues also contain proteins with peptide sequences related to KFERQ, and the amount of these proteins is reduced in response to starvation. Finally, we present recent results suggesting that this selective uptake of cytosolic proteins by lysosomes is not through classical macroautophagic pathways. Instead, the selective uptake may be similar to other protein sorting pathways such as protein translocation through the endoplasmic reticulum or protein import into mitochondria.
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PMID:Lysosomal degradation of microinjected proteins. 270 96

Crithidia luciliae, a trypanosomatid protozoan readily grown in axenic cultures, was shown to possess low levels of a surface membrane-bound ectoenzyme capable of hydrolyzing both 3'-ribonucleotides and nucleic acids. The specific activities of this 3'-nucleotidase/nuclease, with both mononucleotide and nucleic acid substrates, were greatly enhanced when the protozoa were deprived of purines, an essential nutrient. The catalytic activities were exhibited by a polypeptide which migrated in sodium dodecyl sulfate-polyacrylamide gel electrophoresis with an Mr of 47,000. Starvation of these cells for inorganic phosphate (Pi), in media with or without purines, also led to an increase in the specific activity of the ectoenzyme compared to that of Pi- and purine-replete cells. In contrast, the level of enzyme activity was not increased when the protozoa were starved, under purine-replete conditions, for either arginine or hemin, two other essential nutrients. Cells starved simultaneously for either of the latter two nutrients and for purines also did not show increased levels of the 3'-nucleotidase/nuclease. The activation of the enzyme was also prevented by sodium arsenite, cycloheximide, actinomycin D, and tunicamycin indicating that the activation presumably required metabolic energy as well as new transcription, translation, and protein modification. The results demonstrate that the control of 3'-nucleotidase/nuclease expression is a regulated, adaptive response to growth-limiting levels of essential nutrients.
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PMID:Crithidia luciliae: factors affecting the expression of 3'-nucleotidase/nuclease activity. 283 57


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