Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0009443 (cold)
 92,137 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A semi-automated, metabolite prior-knowledge-based, lineshape fitting analysis has been developed to assess the dynamic biochemical changes found in ex vivo 31P NMR pig liver preservation studies. Due to the inherent experimental limitations of the ex vivo study and the complexity of the composite phosphorus resonances, metabolite information obtained in vitro was incorporated into the ex vivo analysis. This approach has allowed complete metabolite analysis (phosphomonoesters, inorganic phosphate, phosphodiesters and nucleotide triphosphates) in over 2000 spectra in a fraction of the time compared with more conventional analysis methods. The developed analysis will enable complete and rapid assessment of the biochemical changes in ongoing cold preservation studies of the pig liver which will result in thousands of ex vivo 31P NMR spectra. It is also envisaged that comparative studies on human donor livers will be carried out, in which this type of analysis would be the method of choice. Moreover, this kind of analysis approach could be advantageous in many complex in vivo NMR spectroscopy applications.
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PMID:Incorporation of metabolite prior knowledge for data analysis: biochemical implications of dynamic 31P NMR ex vivo pig liver studies. 1042 11

Isolated rat hepatocytes were suspended and stored in either Liebovitz-15 medium (37 degrees C or 4 degrees C) or University of Wisconsin (UW) solution (4 degrees C) containing [(3)H] arachidonic acid (AA). At varying times, membrane phospholipids were separated by thin layer chromatography. AA labeled phospholipids similarly at both 4 degrees C and 37 degrees C. Analysis of the ratios of [(3)H] AA and [(14)C] glycerol incorporated into phosphatidic acid or other phospholipids in dual-labeled cells indicated that the deacylation/reacylation cycle was the major route of AA incorporation at hypothermia. This was supported by showing that blocking phospholipase A(2) (PLA(2)) activity by trifluoperazine suppressed AA incorporation into phospholipids. PLA(2) activity, measured by determining the release of AA, was slow during 48-hour cold storage, but increased significantly when ATP was depleted by inhibition of mitochondria and glycolysis. In the whole rat liver, there was no significant loss of phospholipids during 48-hour storage (total phospholipids [micromol phosphorus/L/mg] : 0.197 +/-. 001 at 0 hours) unless energy blockers were used (0.155 +/-.005 at 48 hours) or glycogen depleted by fasting the rat (0.167 +/-.001 at 48 hours). This study shows that a net PLA(2) stimulated hydrolysis of phospholipids is seen only when ATP is depleted and its generation from anaerobic glycolysis inhibited. Thus, PLA(2) hydrolysis of phospholipids is not a significant cause of liver cell injury during cold storage when livers are obtained in optimal condition. However, conditions affecting the generation of ATP during cold storage could alter PLA(2) leading to membrane damage.
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PMID:Phospholipid metabolism of hypothermically stored rat hepatocytes. 1053 45

To test the hypothesis that a lower mean arterial pressure (MAP) response during voluntary isometric exercise in multiple sclerosis (MS) is related to a dampened muscle metabolic signal, 9 MS and 11 control subjects performed an isometric dorsiflexor contraction at 30% maximal voluntary contraction until target failure (endurance time). We made continuous and noninvasive measurements of heart rate and MAP (Finapres) and of intramuscular pH and P(i) (phosphorus magnetic resonance spectroscopy) in a subset of 6 MS and 10 control subjects. Endurance times and change in heart rate were similar in MS and control subjects. The decrease in pH and increase in P(i) were less throughout exercise in MS compared with control subjects, as was the change in MAP response. Differences in muscle strength accounted for some of the difference in MAP response between groups. Cardiovascular responses during Valsalva and cold pressor tests were similar in MS and control subjects, suggesting that the blunted MAP response during exercise in MS was not due to a generalized dysautonomia. The dampened metabolic response in MS subjects was not explained by inadequate central muscle activation. These data suggest that the blunted pressor response to exercise in MS subjects may be largely appropriate to a blunted muscle metabolic response and differences in contracting muscle mass.
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PMID:Blunted pressor and intramuscular metabolic responses to voluntary isometric exercise in multiple sclerosis. 1143 36

The effect of progressive phosphorylation by phosphorous oxychloride upon the conformation of the 300 kDa storage protein (cruciferin) from rapeseed has been studied using chemical analysis, SDS-PAGE, HPLC, analytical ultracentrifugation, viscometry, fluorescence spectroscopy, and hydrophobicity measurement. The amount of phosphorous in the protein increased with the excess of phosphorous oxychloride and the pH of reaction. The bulk of phosphorus was only loosely bound to the protein and was removed by washing with cold perchloric acid. The more stably bound phosphorus groups after reaction at pH 8 were found to be nearly equally attached to amino and hydroxyl groups, whereas phosphorylation at pH 10-11 led to predominant O-phosphorylation as detected by studying the acid- and alkali-lability of the protein-phosphorous bonds. A 50 kDa component appeared as a product of covalent cross-linking of the constituent alpha- and beta-polypeptide chains. A 2.5S fraction appeared as the main product of dissociation, which takes place after a critical step of modification. The higher the extent of phosphorylation, the larger was the percentage of higher molecular weight products, the percentage of which was most significant after modification under strongly alkaline conditions. They may be attributed both to products of chemical cross-linking and to noncovalently linked aggregates formed by interactions of partially unfolded derivatives exhibiting an increased surface hydrophobicity.
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PMID:Phosphorylation of the 12S globulin from rapeseed (Brassica napus L.) by phosphorous oxychloride: chemical and conformational aspects. 1072 38

Carphedon is a phenyl derivative of nootropil and is effective in increasing physical endurance and cold resistance, and is used for amnesia treatment. Carphedon was extracted from human urine samples by solid-phase microextraction with a 65 microns carbowax-divinylbenzene-coated fiber. This analysis was performed by using capillary gas chromatography with nitrogen-phosphorus detection and optimized at pH 9.6, 30% NaCl, immersion time 10 min and desorption in the GC injector at 250 degrees C for 3 min. The regression equation for carphedon showed good linearity in the range from 0.1 to 10 micrograms ml-1 for human urine samples. The limit of detection was 0.01 microgram ml-1. The developed method is more sensitive and simpler in sample preparation than liquid-liquid extraction and can be applied to doping analysis for stimulants.
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PMID:Determination of carphedon in human urine by solid-phase microextraction using capillary gas chromatography with nitrogen-phosphorus detection. 1074 14

During liver preservation, ATP supplies become depleted, leading to loss of cellular homeostatic controls and a cascade of ensuing harmful changes. Anaerobic glycolysis is unable to prolong ATP production for a significant period because of metabolic blockade. Our aim was to promote glycolysis during liver cold hypoxia by supplying fructose as an additional substrate, compared to supplementation with an equivalent concentration of glucose. Porcine livers (two groups; n = 5 in each) were retrieved by clinical harvesting techniques and subjected to two cycles of cold hypoxia and oxygenated hypothermic reperfusion. In the second cycle of reperfusion, the perfusate was supplemented with either 10 mmol/L glucose (Group 1) or 10 mmol/L fructose (Group 2). During reperfusion in both groups, similar levels of ATP were detected by phosphorus magnetic resonance spectroscopy ((31)P MRS). However, during subsequent hypoxia, ATP was detected for much longer periods in the fructose-perfused group. The rate of ATP loss was sevenfold slower during hypoxia in the presence of fructose than in the presence of glucose (ATP consumption of -7.2 x 10(-3)% total (31)P for Group 1 versus -1.0 x 10(-3)% total (31)P for Group 2; P < 0. 001). The changes in ATP were mirrored by differences in other MRS-detectable intermediates; e.g., inorganic phosphate was significantly higher during subsequent hypoxia in Group 1 (45.7 +/- 2.7% total (31)P) than in Group 2 (33.7 +/- 1.1% total (31)P; P < 0. 01). High-resolution MRS of liver tissue extracts demonstrated that fructose was metabolized mainly via fructose 1-phosphate. We conclude that fructose supplied by brief hypothermic perfusion may improve the bioenergetic status of cold hypoxic livers by sustaining anaerobic glycolysis via a point of entry into the pathway that is different from that for glucose.
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PMID:Bioenergetic targeting during organ preservation: (31)P magnetic resonance spectroscopy investigations into the use of fructose to sustain hepatic ATP turnover during cold hypoxia in porcine livers. 1101 64

The paper contains the results of 19 minerals (Ca, K, P, Na, Mg, Zn, Fe, Mn, Cu, F, Ni, Co, Cr, Li, Sr, Al, Cd, Hg, Pb) determined in green and black species of market teas. The examined minerals (except phosphorus, fluoride and mercury) were determined by ASA-method using air-acetylene flame (aluminium was determined in the nitrous oxide-acetylene flame). Mercury was determined by cold vapour method. The phosphorus and fluoride was determined by spectrophotometry methods (phosphorus in the form of phosphomolybdate blue and fluoride by use microdiffusion procedure where alizarin-fluoride complex was formed). It has been found that the examined teas are important source of potassium and low source of sodium, assuming a daily intake of 4 glasses of tea infusions. Tea drinking may be advantageous for hypertensive persons. The investigated teas are also important source of other examined minerals especially some microelements. The intake of the toxic metals with tea (Cd, Hg, Pb, Al) is low, from a centesimal to a few percent of the PTWI dose accepted by the FAO/WHO Experts. This paper presents also the first findings of the lithium and stronthium contents of examined tea species--whose physiological role still remains unknown.
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PMID:[Amounts of selected minerals in green and black teas]. 1113 81

As part of an effort to examine the possibility of using molecular-beam Fourier-transform microwave spectroscopy to unambiguously detect and monitor chemical warfare agents, we report the first observation and assignment of the rotational spectrum of the nerve agent Sarin (GB) (Methylphosphonofluoridic acid 1-methyl-ethyl ester, CAS #107-44-8) at frequencies between 10 and 22 GHz. Only one of the two low-energy conformers of this organophosphorus compound (C(4)H(10)FO(2)P) was observed in the rotationally cold (T(rot)<2 K) molecular beam. The experimental asymmetric-rotor ground-state rotational constants of this conformer are A=2874.0710(9) MHz, B=1168.5776(4) MHz, C=1056.3363(4) MHz (Type A standard uncertainties are given, i.e., 1sigma), as obtained from a least-squares analysis of 74 a-, b-, and c-type rotational transitions. Several of the transitions are split into doublets due to the internal rotation of the methyl group attached to the phosphorus. The three-fold-symmetry barrier to internal rotation estimated from these splittings is 677.0(4) cm(-1). Ab initio electronic structure calculations using Hartree-Fock, density functional, and Moller-Plesset perturbation theories have also been made. The structure of the lowest-energy conformer determined from a structural optimization at the MP2/6-311G(**) level of theory is consistent with our experimental findings. Copyright 2001 Academic Press.
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PMID:Rotational Spectrum of Sarin. 1133 24

Treatment performance and operational parameters of a pre-coagulation and biofilm process were experimentally discussed with the pilot-scale plant treating actual municipal sewage. Perfect nitrification was accomplished within total hydraulic retention time (HRT) of 4 h at 20% volumetric added ratio of attached-growth media of biofilm in the aerobic tanks under temperature conditions as low as 17 degrees C. Treatment efficiencies in organic matter, T-N and T-P were high and stable with the total HRT of 8 h in the biological reactor. Concentrations of T-N and T-P in effluent were kept about 2 mgN/L and under 1 mgP/L, respectively. Attached growth bacterial mass and the potential activity of nitrification and denitrification in each tank in cold season were high enough to accomplish excellent treatment performance. Then the process was proved to be applicable to municipal sewage treatment for removal of nitrogen and phosphorus as well as organic matter.
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PMID:Advanced treatment of sewage by pre-coagulation and biofilm process. 1137 8

The municipal sewage treatment plant (STP) of the city of Ghent (Belgium) has to be retrofitted to a 43%-increase in the nitrogen treatment capacity and to phosphorus removal. Cold weather, dilute sewage and a critical COD over N ratio make the retrofit a challenge for full biological nutrient removal. The potential for fermentation of primary sludge to alter those critical feed sewage characteristics was experimentally evaluated. The idea was that the pinpoint introduction of fermentate could optimise the available reactors by achieving high-rate denitrification and enhanced biological phosphorus removal. The fermentation process was evaluated with a bench scale apparatus. At 20 degrees C (heated process), the hydrolysis yield--expressed in terms of soluble COD--varied from 11% to 24% of the total sludge COD. The fermentation yield expressed in VFA COD varied from 8% to 13% of the total sludge COD. The efficiency of heated fermentation of primary sludge was lower during cold and wet weather, due to the different sewage characteristics, as a result of extended dilution periods and low temperature. The raw sewage, the primary effluent and the fermentate were fractionated according to the requirements for the IAWQ Activated Sludge Model No. 2d. The results clearly show that fermentation in the sewer played an important role and temperature was the driving parameter for the characteristics of the dissolved COD. Instead, the weather flow conditions were the driving parameter for the characteristics of the suspended COD. The results of the detailed fractionation were used as background for process evaluation. The final scenario choice for the retrofit depends on a cost-efficiency calculation.
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PMID:Impact of cold and dilute sewage on pre-fermentation--a case study. 1144 52


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