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)

A 29-year-old woman with short bowel syndrome and prolonged starvation developed hyperchloremic metabolic acidosis after initiation of hyoeralimentation with a casein hydrolysate solution. The acidosis was not due to bicarbonate loss but was associated with diminished ability of the kidney to increase urinary acid excretion, particularly titratable acidity. Supplemental parenteral bicarbonate administration was necessary for two weeks until urinary acid excretion rose to normal.
 ...
PMID:Metabolic acidosis after hyperalimentation with casein hydrolysate. Occurrence in a starved patient. 2 2

The stringent factor from Escherichia coli is the product of the relA locus. It is the enzyme that catalyzes the synthesis of pppGpp and ppGpp eliciting a pyrophosphate transfer from ATP to the 3'--OH of GTP (or GDP). This protein is responsible for the synthesis of pppGpp and ppGpp in stringent strains in response to an amino acid starvation. In vitro it catalyzes the synthesis of these guanosine compounds in either a ribosome-dependent reaction that requires a particular conformation of the ribosome i.e. the presence of an uncharged tRNA recognizing a codon in the acceptor (A) site of the ribosome or in a ribosome-independent reaction at temperatures under 30 degrees in the presence of only buffer, salts, and substrates. Here we report the purification of the stringent factor to near homogeneity. It is a monomeric protein with a molecular weight of 75,000. The properties of the ribosome-independent reaction are studied and it is shown that the presence of certain acidic proteins, such as the 50 S ribosomal proteins L7 and L12 or casein, or 20% methanol or both stimulates the reaction by creating an environment that together with the low temperature further stabilizes the stringent factor.
 ...
PMID:Purification and properties of stringent factor. 16 49

The concentration of insulin and glucagon in peripheral blood and the concentration of cAMP in liver was followed in rats throughout a 48 hour starvation period and up to 6 hours afer refeeding glucose or casein. By so changing the insulin/glucagon molar ratio from minimum to maximum values, simultaneous inverse changes in the concentration of hepatic cAMP could be induced. The study, thus, suggests that during a starvation-refeeding cycle the level of cAMP in the liver is regulated predominantly by the insulin/glucagon ratio in the blood. Possible criticisms of this conclusion are discussed.
 ...
PMID:Concentration of cyclic AMP in rat liver as a function of the insulin/glucagon ratio in blood under standardized physiological conditions. 18 53

The adenosine triphosphate (ATP) content of Arthrobacter crystallopoietes was measured during growth, starvation and recovery from starvation. During exponential growth of the cells as spheres in a glucose slats medium, the level of ATP per cell remained constant at 8.0 x 10(-10) micrograms/cell. Morphogenesis to rodshaped cells and an increased growth rate following addition of casein hydrolysate was accompanied by an almost two-fold increase in the ATP level. As division of the rod-shaped cells proceeded, the level of ATP declined. After growing as rods for 12-14 h the cells underwent fragmentation to spheres during which time the ATP level again increased to the original value of 8.0 x 10(-10) micrograms/cell. As the spherical cells resumed growth on the residual glucose, their ATP content declined for a short period and then remained relatively constant. During starvation of sphere or rod-shaped cells for one week, the ATP level declined by approximately 70% during the first 40-50 h and then remained constant. The endogenous metabolism rate of spherical cells declined during the first 10-20 h of starvation and then remained constant at approximately 0.02% of the cell carbon being utilized per h. Addition of glucose to spherical cells which had been starved for one week increased both the ATP content per cell and their rate of endogenous metabolism. The ATP content fluctuated and then remained at a level higher than maintained during starvation while endogenous metabolism quickly declined.
 ...
PMID:Adenosine triphosphate pool levels and endogenous metabolism in Arthrobacter crystallopoietes during growth and starvation. 51 37

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.
 ...
PMID:Role and location of "protease I" from Escherichia coli. 79 31

The density of the fat-free body mass (FFM) was calculated from carcass composition and density of body components in 148 growing rats under different dietary conditions. These conditions were controlled feeding with 20% and 5% casein diets during 6 and 9 wk, followed by 5 days of starvation, and after starvation with 2 wk refeeding with 20 and 5% casein diets. The results showed that the density of FFM was fairly constant. The means and standard deviations for all conditions were 1.0965 +/- 0.0057 and 1.0956 +/- 0.0075, for the 20% and 5% casein groups, respectively, with a grand mean of 1.0960 +/- 0.0066. It was concluded that the assumption of a constant density of FFM holds very well for many dietary and experimental conditions.
 ...
PMID:Diet and starvation on the composition and calculated density of fat-free body mass. 86 41

It has been shown that the net rate of gluconeogenesis from cysteine was only 10% the rate observed from pyruvate. This suggested that the rate limiting step in gluconeogenesis from cysteine was between cysteine and pyruvate. Evidence is presented showing that the cysteine-sulfinate pathway does not play a regulating role in the conversion of cysteine to glucose. Thus, liver cysteine desulfhydrase (CDS) activity and hydrogen sulfide production were evaluated for their potential effects. Liver CDS activity was increased by a 3 day starvation, by feeding a 90% casein diet or a 4% cysteine + 86% casein diet. In all cases the activity of the enzyme was in excess of that required to account for the rate of conversion of cysteine to glucose observed, thus the potential activity of this enzyme was not a rate limiting factor. The possible effect of H2S, an end product of the CDS reaction, on gluconeogenesis from cysteine was evaluated. The addition of NaHS abolished the glucogenic response observed from cysteine, but had very little effect on glucoeogenesis from lactate, suggesting that accumulated H2S may inhibit CDS, marking CDS rate limiting in the conversion of cysteine to pyruvate.
 ...
PMID:Fractors affecting the rate of gluconeogenesis from L-cysteine in the perfused rat liver. 95 11

The effects of various dietary modifications on the mutagenicity of dimethylnitrosamine (DMNA), N-nitrosomorpholine, and N-methyl-N-nitrosourea for Salmonella typhimurium his G-46 in the host-mediated assay were studied. The diets used were:chow, complete semisynthetic, protein-free, and all-casein, in addition to a 24-hr starvation regimen. The mutagenicity of DMNA and N-nitrosomorpholine, which require metabolic activation for their biological activity, was depressed by the complete semisynthetic diet, as compared to the mutagenicity in mice fed the chow diet. DMNA mutagenicity was depressed by the protein-free diet and enhanced by pure casein as compared with the complete semisynthetic diet. N-Nitrosomorpholine mutagenicity was enhanced by starvation, but results with mice fed the protein-free and all-casein diets were ambiguous. N-Methyl-N-nitrosourea, which does not require metabolic activation for its biological activities, responded in an opposite manner to that of DMNA; its mutagenicity was enhanced by the complete semisynthetic and protein-free diets, but was depressed by the all-casein diet.
 ...
PMID:Dietary modifications affecting the mutagenicity of N-nitroso compounds in the host-mediated assay. 109 77

Experiments were conducted to determine whether the rate of entry of arginine into liver varies with changes in dietary protein or in the protein-catabolic state of the animal. It was first established by liver perfusion with [14C]ureidocitrulline that release of arginine by liver is sufficiently small that it can be ignored and that disappearance of arginine from a perfusion medium can be used to measure entry rate. Disappearance rates of arginine were then determined for rats that had been starved of fed either a stock control diet, a 15% casein diet, a 90% casein diet, or which had been injected with cortisol. There was no difference in arginine uptake between the control and 15% casein groups. The high protein group showed a threefold increase in rate of entry of arginine into liver as compared with the control group. Cortisol treatment and 48 hours of starvation also caused a threefold increase in arginine uptake. Cortisol treatment combined with high protein adaptation resulted in a sevenfold increase over controls. It was concluded that rate of entry of arginine into rat liver varies with nutritional and endocrine states.
 ...
PMID:Effects of protein content of diet and cortisol treatment on uptake of arginine by rat liver. 115 37

1. Sections of small intestine from rats given raw-soya-bean(RS) diets had a decreased capacity to actively accumulate L-methionine when compared to those taken from rats given heated soya bean (HS), and casein-fed controls. The extent of the reduction was small in comparison with pair-fed animals, but was statistically significant in comparison with rats restricted to the same weight gain as the RS groups. 2. The differences in the passive uptake of D-mannitol appear to be directly related to differences in gut thickness between the control and RS groups. 3. Values for water movement and intestinal transmural potentials further support the results found in the active accumulation studies. 4. From this study it was concluded that the degree of starvation directly affects the magnitude of the effect of RS diets when comparisons are made against adequately fed controls.
 ...
PMID:The effect of raw soya bean on in vitro active and passive accumulation by rat small intestine. 116 85


1 2 3 4 5 6 7 Next >>