Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: DrugBank:EXPT00568 (ascorbate)
 23,072 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In adults supplemental parenteral nutrition (PN) is advisable in burns over 40% especially when weight loss exceeds 10% of body weight. In children with smaller reserves and higher requirement of proteins and energy no rigid scheme for parenteral supplementation is used at our unit. In a young infant it may be added already at a 20-30% deep burn, especially with connected gastrointestinal tract problems, infection etc. Metabolic and protein requirements are estimated 50-100% in addition to their normal needs. Hypertonic glucose (gradually increased from 20-40%), covered with insulin in the early phase, is used as source of carbohydrates. L-amino acid mixture containing the "pediatric essential amino acids" histidine and cysteine is given as a nitrogen source. 20% Intralipid is given in a gradually increased amount of 2-4 g/kg per day to provide calories and essential fatty acids. Among electrolytes K, Ca, P and Mg must be added. Increased amounts of vitamin C and folate are needed by burned children. Vitamin E is also required during prolonged lipid administration. Trace elements (Zn. Fe, etc.) are supplied orally or i.v. with special solutions or fresh plasma infusions. Our experience with parenteral nutrition in severely burned children will be presented. There were no severe metabolic side-effects but sepsis represented the major problem. The concomitant heat preservation by warming the room and use of infra-red heaters is emphasized.
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PMID:Parenteral nutrition in severely burned children. 10 12

The artificial electron-donor system, phenazine methosulfate (PMS) ascorbate, inhibited active transport of glucose by Pseudomonas aeruginosa irrespective of whether the incubation systems were in air, flushed with oxygen, or gassed with nitrogen under anaerobic denitrifying conditions. Active transport of glucose by P. aeruginosa was also inhibited by reduced 5-N-methyl-phenazonium-3-sulfonate, a membrane-impermeable electron donor. PMS-ascorbate caused rapid depletion of intracellular adenosine triphosphate (ATP) when added to respiring cell suspensions of P. aeruginosa either in the presence or absence of glucose or succinate as oxidizable energy sources. In contrast, under identical conditions, Escherichia coli formed ATP with PMS-ascorbate as the sole oxidizable energy source and ATP formation continued when glucose or succinate was present in addition to PMS-ascorbate in the incubation system.
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PMID:The effect of phenazine methosulfate-ascorbate on bacterial active transport and adenosine triphosphate formation: inhibition of Pseudomonas aeruginosa and stimulation of Escherichia coli. 11 71

The composition of rhesus monkey aqueous humor has been studied in large-volume, pooled samples. Replicate determinations of the concentrations of a number of constituents have been carried out for both aqueous humor and serum from large veins by means of automatic analyzing equipment. Since aqueous humor has been obtained by anterior chamber paracentesis, it is a mixture of anterior and posterior chamber aqueous. When compared to serum, the pooled aqueous contains an excess of chloride, bicarbonate, ascorbate, lactate, uric acid, and several neutral amino acids. Rhesus monkey aqueous humor is deficient in calcium, urea nitrogen, phosphates, glucose, protein, creatinine, iron, bilirubin, cholesterol, triglycerides, a number of serum enzymes, acidic and basic amino acids, and several neutral amino acids. Sodium, potassium, magnesium, and two neutral amino acids (cysteine and valine) are of equal concentration in aqueous humor and serum. Glutathione concentration is very low in both aqueous humor and serum. Pooled rhesus monkey aqueous humor and serum are isosmolar, with measured osmolality being about 303 mOsm. Based upon the chemical analysis, a new solution has been formulated to substitute for primate aqueous humor during anterior ocular perfusion. This new solution causes very little change in the physiologic integrity of the outflow pathways during prolonged, repeated perfusion. In this respect, its effects are very similar to those of pooled rhesus monkey aqueous humor during perfusion of rhesus monkey eyes. In contrast, perfusion of rhesus monkey eyes with glutathione-bicarbonate-Ringer's solution has been shown to cause progressive increase of the total facility. To minimize physiologic alterations during operative procedures, a solution similar to this new one could be formulated for irrigation of the inside of the human eye.
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PMID:Rhesus monkey aqueous humor composition and a primate ocular perfusate. 11 68

It was possible to quantitate the tetramethyl-p-phenylenediamine (TMPD) oxidase reaction in Azotobacter vinelandii strain O using turbidimetrically standarized resting cell suspensions. The Q(O2) value obtained for whole cell oxidation of ascorbate-TMPD appeared to reflect the full measure of the high respiratory oxidative capability usually exhibited by this genera of organisms. The Q(O2) value for the TMPD oxidase reaction ranged from 1,700 to 2,000 and this value was equivalent to that obtained for the oxidation of the growth substrate, e.g., acetate. The kinetic analyses for TMPD oxidation by whole cells was similar to that obtained for the "particulate" A. vinelandii electron transport particle, that fraction which TMPD oxidase activity is exclusively associated with. Under the conditions used, there appeared to be no permeability problems; TMPD (reduced by ascorbate) readily penetrated the cell and oxidized at a rate comparable to that of the growth substrate. This, however, was not true for the oxidation of another electron donor, 2,6-dichloroindophenol, whose whole cell Q(O2) values, under comparable conditions, were twofold lower. The TMPD oxidase activity in A. vinelandii whole cells was found to be affected by the physiological growth conditions, and resting cells obtained from cells grown on sucrose, either under nitrogen-fixing conditions or on nitrate as the combined nitrogen source, exhibited low TMPD oxidase rates. Such low TMPD oxidase rates were also noted for chemically induced pleomorphic A. vinelandii cells, which suggests that modified growth conditions can (i) alter the nature of the intracellular terminal oxidase formed (or induced), or (ii) alter surface permeability, depending upon the growth conditions used. Preliminary studies on the quantitative TMPD oxidation reaction in mutant whole cells of both Azotobacter and a well-known Mucor bacilliformis strain AY1, deficient in cytochrome oxidase activity, showed this assay can be very useful for detecting respiratory deficiencies in the metabolism of whole cells.
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PMID:Tetramethyl-p-phenylenediamine oxidase reaction in Azotobacter vinelandii. 17 91

The nitrogen metabolism in rats with toxic affection of the liver caused by administration of CCl4 was studied as affected by the amino acid mixture moriamine S-2. It is established that with toxic hepatitis the nitrogen metabolism is sharply disturbed, especially during protein deficiency. The following evidences for this fact: a rise in the depth of the nitrogen negative balance, an increase in the intensity of amine nitrogen and ammonia excretion with urea as well as an increase in the amount of amine nitrogen in blood and tissues with a simultaneous decrease in the content of protein. The parenteral administration of the amino acid mixture for eight days to the animals with a toxic affection of the liver is more effective when nitrogen preparation is combined with the group B vitamin, vitamin C, insulin, nerobolyl and sirepar.
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PMID:[Correction of nitrogen metabolism in rats with toxic hepatitis by parenteral administration of an amino acid mixture]. 42 34

Cytochrome b-562.5 (Ulva pertusa) was extracted from a green alga, U. pertusa, by homogenization of the thalli in phosphate buffer solution. Purification was carried out by acrinol treatment, ammonium sulfate fractionation, DEAE-cellulose and DEAE-Sephadex column chromatographies, and Sephadex gel filtration. Cytochrome b-562.5 has absorption maxima at 562.5 (alpha), 530.5 (beta), 429 (gamma), and 326 nm (delta) in the reduced form and at 537, 415 (gamma), and 275 nm in the oxidized form. The alpha-band of the reduced form is asymmetric with a shoulder at 560 nm, at liquid nitrogen temperature this band splits into two distinct peaks at 562 and 556.5 nm. The absorption maxima of the pyridine ferrohemochrome appear at 556 (alpha), 523 (beta), and 418 nm (gamma). The cytochrome does not combine with carbon monoxide or cyanide. The preparation of the cytochrome shows little peroxidase activity. The cytochrome is oxidized by ferricyanide and reduced by cysteine, ascorbate, and hydrosulfite. Autoxidation of the cytochrome was found to be very slow. The midpoint potential (Em) of the cytochrome was determined by equilibration with the ferro- and ferri-EDTA system to be +0.20 V at pH7.0. The molecular weight of the cytochrome was estimated by Sephadex gel filtration to be 23x10(3).
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PMID:Purification and properties of cytochrome b-562.5 from Ulva pertusa. 42 58

1. The age-related decrease in hydroxyproline : creatinine ratio in young guinea pigs was significantly smaller in vitamin C-deficient animals than in pair-fed controls. The same was true for proline : creatinine and total amino nitrogen : creatinine ratios, but hydroxyproline : total amino nitrogen and proline : total amino nitrogen ratios were not significantly affected by deficiency. 2. Although the proline : hydroxyproline ratio was unaffected in unfractionated urine, acute or chronic deficiency produced a small but significant increase in this ratio in collagenase digests of the acetone-insoluble fraction. 3. In scorbutic animals, therefore, collagen probably turns over more rapidly than in animals matched for inanition. Some at least, of this increase could represent the rapid turnover of underhydroxylated nascent collagen. Because it contains the degradation products from collagen from many tissues, differing widely in sensitivity to vitamin C status, the urine is unlikely, however, to provide a specific and sensitive functional index of vitamin C status.
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PMID:Vitamin C deficiency in guinea pigs: changes in urinary excretion of proline, hydroxyproline and total amino nitrogen. 46 70

Chlorophyll a monolayers are studied at a nitrogen-water interface in the presence of a reducing or oxidizing agent: sodium ascorbate and benzyl viologen, respectively. Absorption spectra of the films are measured directly on the aqueous surface. With the aid of a computer, fourth derivative and difference spectra are determined. In the presence of ascorbate, a bathochromic shift of the absorption maximum to 693 nm can be induced as compared to 683 nm for a chlorophyll monolayer without any additives. In the presence of ascorbate, chlorophyll species at 676, 712 and 750 nm (present in a pure chlorophyll monolayer) are decreased or diminished. Illumination causes no change in the position of these absorption maxima; however, there is an increase of the absorbance of the main red absorption band. In the presence of benzyl viologen there is a hypsochromic shift of the red absorption maximum to 679 nm. Chlorophyll species at 670, 694, 712 and 740 nm (present in pure chlorophyll monolayers) are decreased or diminished upon addition of benzyl viologen. Upon illumination, there is a decrease in absorbance at 686 nm. It appears that the redox reagents induce the formation of specific chlorophyll aggregates, in the interfacial system, which might be analogous to the various chlorophyll species observed in green plant photosynthesis.
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PMID:Spectral properties of chlorophyll a monolayers in the presence of an exogenous electron donor and acceptor. 69 13

It has been suggested that glycogen depletion followed by a protein-fat diet and a carbohydrate-rich diet improves performance. This study was designed to determine the nutritional and metabolic effects of a carbohydrate-rich diet in a glycogen supercompensation training regimen. Four male subjects participated in a 5-week protocol of which the first 3 weeks were devoted to a control period and the last 2 weeks to the experimental phase of the study. The variables measured before, during, and following the experimental phase included anthropometric and basal metabolic rate measurements, urinary and serum analysis for vitamins, SMA 12/60 blood profile and aerobic performance (VO2max). Results indicated an appreciable modification of the metabolic and nutritional profile of the subjects as a result of the diets. During the protein-fat diet there was a decrease in serum glucose and resting respiratory quotient and an increase in cholesterol, blood urea nitrogen, riboflavin, and N1-methylnicotinamide excretion. Subsequent to the carbohydrate-rich diet there was an increase in triglycerides and vitamin C, riboflavin, and thiamin excretion while there was a decrease in serum blood urea nitrogen, and N1-methylnicotinamide excretion. Aerobic performance was slightly decreased and the mean postexercise lactate levels were slightly higher after the carbohydrate-rich diet. It was hypothesized that the reduced niacin intake during the carohydrate-rich diet may hamper the aerobic oxidative pathways.
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PMID:The nutritional and metabolic effects of a carbohydrate-rich diet in a glycogen supercompensation training regimen. 72 61

Rat thyroid lobes or hemilobes have been incubated in Krebs-Ringer phosphate buffer containing labeled T4 and/or T3, and the products were separated by paper chromatography. Labeled T4 was actively degraded; about half of the T4 metabolized was recovered as T3. Labeled T3 was also metabolized, but less rapidly than T4. Other than T3 produced from T4, the major products from both hormones were inorganic iodide and iodoprotein; the latter was presumably a secondary product of iodide organification because its formation was inhibited by hypoxia and methimazole. Feeding the animals a low iodine diet increased their hormone-metabolizing activity. Incubation under nitrogen did not affect the rate of T4 degradation, but partially inhibited T3 degradation. Degradation of both hormones was unchanged in the presence of methimazole and ascorbate, was markedly inhibited by 1 mM propylthiouracil (PTU), and was partially inhibited by azide and cyanide. Thyroid tissues concentrated both hormones, tissue to medium gradients averaging 5.4 for T4 and 20.7 for T3; none of the conditions affecting hormone degradation (incubation under nitrogen or with azide, cyanide, or PTU) significantly altered these gradients. It is concluded that the thyroid can metabolize both of its major hormones by a system distinct from thyroidal peroxidase. Hormone metabolism, therefore, is a potentially important factor in net hormone secretion. In its resistance to hypoxia, methimazole, and ascorbate and its sensitivity to PTU, the thyroid's system for generating T3 from T4 resembles T3-forming systems of liver and kidney. The thyroid, because T3 formation is its dominant pathway for T4 metabolism, may provide a useful model for study of this reaction.
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PMID:Metabolism of thyroid hormones by rat thyroid tissue in vitro. 74 19


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