Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P00790 (PGA)
 2,475 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

1. The influence of replacing 10% of the urea nitrogen in a purified diet with casein, maize gluten or white fish meal on the efficiency of conversion of dietary-N into microbial N was examined using sheep equipped with rumen fistulas and duodenal re-entrant cannulas. 2. Total nitrogen (TN), non-ammonia nitrogen (NAN) and amino acid nitrogen (AAN) flowing to the proximal duodenum were significantly higher (P smaller than 0.05) when maize gluten was added to the diet, and this appeared to be due to an increased efficiency of microbial protein production. 3. Pepsin secretion was not significantly different between treatments and the daily amount of pepsin N flowing to the proximal duodenum was very small (40-53 mg). The peak of pepsin activity in duodenal digesta was reached 6-8 h after feeding. 4. The possible practical implications of the results are discussed.
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PMID:The effect of partially replacing urea nitrogen with protein N on N capture in the rumen of sheep fed a purified diet. 33 43

The derivatization of prostaglandins of the A series with 1:1 mixtures of bis-(trimethylsilyl)trifluoroacetamide and nitrogen-containing non-aromatic heterocyclics such as piperidine, pyrrolidine, morpholine and hexamethylenimine (1--4 h at 60--70 degrees C) gives new types of derivatives, designated as 11-heterocycle, 9-enol PGA (TMS)3. These derivatives show very simplified and characteristic mass spectral patterns strikingly dominated by a common [M-173]+ fragment ion and easily detectable by selected ion monitoring. This feature allows the concurrent analytical detection of both prostaglandin A's and 19-hydroxy prostaglandin A's in biological samples. In this case 2 ml samples of human semen were extracted by direct ultrafiltration on a Pellicon membrane with a nominal molecular weight limit of 1000. The prostaglandins in the approximately or equal to 1.6 ml of ultrafiltrate thus obtained were recovered in ethyl acetate, derivatized as indicated above and detected by monitoring of the corresponding [M-173]+ ions.
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PMID:New derivatives of prostaglandin A1 and specific detection of prostaglandin A's and 190hydroxylated prostaglandin A's in human semen. 70 54

The measurement of 13,14-dihydro-15-keto prostaglandin E2 [PGEM] is complicated by the artefactual formation of compounds of the corresponding A series which are reactive towards protein. Existing methods of assay depend on the deliberate dehydration to the 'A' form followed by cyclization in alkaline solution to a bicyclic derivative which is stable and can be measured by radioimmunoassay. We report an alternative approach using methyl oximation of the 9- and 15-keto groups which confer stability on the molecule. This derivatization is simple and does not involve an active intermediate such as those of the PGA series. The antiserum for radioimmunoassay is raised against the methyl oxime form. The label is the methyl oxime of PGEM coupled to a tripeptide Pro-gly-tyr through the nitrogen in the proline ring. This is a linkage distinct from that used to raise the antiserum and thus is not preferentially recognized over the endogenous analyte; this results in a high sensitivity assay. The results correlated well with those from the bicyclic assay when both assays were used to measure the same samples of peripheral blood from women receiving a sustained release PGE pessary for ripening the cervix. The technique provides a rapid and reliable method for determining prostaglandin E metabolites.
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PMID:The measurement of the main PGE metabolite, 13,14-dihydro-15-keto prostaglandin E by radioimmunoassay using methyl oxime stabilization. 158 44

Despite blockade and neutralization of gastric acid, acute gastric lesions cause substantial morbidity and mortality in critically ill patients. Pepsinogen release in response to noxious stimuli such as hypoxia and endotoxin might contribute to mucosal damage. Guinea pig fundic mucosa was mounted in Ussing chambers. Acid secretion, pepsinogen release, potential difference (PD), and resistance were monitored. Gassing with room air or nitrogen diminished acid secretion and PD but increased pepsinogen release 9.7- and 15.5-fold, respectively (both p less than 0.001). Similarly, endotoxin (0.01 and 0.1 units/ml) dose-dependently inhibited acid secretion and PD but increased pepsinogen release 3.3- and 6.1-fold (both p less than 0.05). Endotoxic and air-gassed tissues were edematous with scattered cellular damage by light and transmission electron microscopy; nitrogen-exposed membranes appeared necrotic. Pepsin release may therefore have resulted from cell damage rather than exocytosis. Intragastric peptic activity in critically ill H2-receptor-blocked patients (n = 20) was 5490 +/- 1701 U/ml. The gastric juice of H2-blocked convalescing surgical patients (n = 20) contained 315 +/- 101 U/ml (p less than 0.0001). Occult blood correlated with intragastric peptic activity (r = 0.59, p less than 0.0001) but not with gastric pH (r = 0.04, p = 0.6). These data suggest that the complex of pathophysiologic abnormalities common in critical illness causes substantial pepsin release. Efflux of this potent mucolytic barrier breaker may damage gastric mucosa in severely stressed patients.
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PMID:Pepsinogen release and acid secretion from human and guinea pig gastric mucosa compromised by hypoxia, endotoxin, or critical illness. 221 92

1. The use of a nylon-bag technique for pig feed digestibility determination was studied. Bags, measuring 25 x 40 mm and containing feed samples, were introduced into the pig gastrointestinal tract through a duodenal cannula, and recovered in the faeces between 23 and 69 h later. The disappearance of organic matter and crude protein (nitrogen x 6.25) from the bags was compared with in vivo apparent digestibility, determined by conventional faecal-collection methods, and neutral-detergent-fibre content for eleven feeds. The residues left in the bags after passage through the intestine from whole-crop-pea (Pisum sativum) and barley-grain samples were analysed for starch, non-starch polysaccharide residues, Klason lignin, crude protein and ash. 2. Dry matter disappearance of barley or whole-crop peas was not influenced by increasing bag pore size from 10 to 36 microns or sample weight from 250 to 1000 mg. Pepsin (EC 3.4.2.1) pretreatment had no effect on the degradation in the bags of the feeds investigated. 3. Organic matter and crude protein disappearance from the bags exceeded in vivo apparent digestibility by up to 0.10 and 0.42 units respectively. In vivo apparent organic matter digestibility could be predicted (P less than 0.001) by the organic matter disappearance from the bags and the neutral-detergent-fibre content of the feed, while in vivo apparent crude protein digestibility was highly correlated (P less than 0.001) to all these indices but poorly to crude protein disappearance from the bags. 4. Klason lignin was the least degraded component measured in the whole-crop-pea and barley residues from the bags, while starch was completely digested.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Use of a nylon-bag technique for pig feed digestibility studies. 387 Jun 93

The pools of Arg, Gly, His, Ile, Ser, Glu, Leu, Val and Asp were lower during photosynthesis at 1% O2 concentration. At the same time specific radioactivity of a number of amino acids--following 14CO2 incorporation--was different than that at atmospheric O2 concentration. This is probably due to the inhibition of the photorespiratory nitrogen cycle and the resulting NH+4 deficiency. The pattern of response to O2 concentration suggests that in rye plants in the light, all Gly and a part of Ser are synthesized by an O2-sensitive pathway, i.e. via the glycolate pathway, but most of Ser is probably formed from 3-phosphoglycerate (3-PGA) via the O2-insensitive pathway. Changes in the pool size and specific radioactivity after 6 h incubation in darkness suggest that synthesis of Gly is strongly light-dependent, whereas synthesis of Ser was substantial also in darkness. The specific radioactivity of Ala, Asp, Ser and Glu indicates that in darkness those amino acids are formed from a common precursor, i.e. glycolytic 3-PGA, and undergo rapid metabolic turnover.
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PMID:Photosynthesis in detached rye leaves at normal and low oxygen concentration. II. Incorporation of 14CO2 into amino acids. 681

1. Pigs (sixteen/diet) were weaned at 2 d of age and given liquid diets (200 g dry matter/l) during a 26 d experiment. The pigs were fed on a scale based on live weight. Dried skim-milk was the only source of protein in diet U and was partially or totally replaced by a soya-bean isolate (diet B) or a concentrate (diets C and D). Soya-bean protein provided 500, 700 or 350 g/kg total crude protein (nitrogen x 6.25) in diets B, C and D respectively. 2. Performance was similar for diets B and D, but poorer than that of pigs given diet U. The apparent digestibility and retention of N of these diets was similar. Pigs given diet C scoured severely and twelve died. 3. Protein digestion was studied in pigs given diets U, B and D, killed at 28 d of age, at the termination of the feeding experiment. The dry matter content and proportion of N in the digesta in the stomach were reduced in pigs given soya-bean protein. Pepsin concentrations in digesta and stomach tissue were unchanged. 4. The concentrations of trypsin and chymotrypsin in the pancreas were greater in pigs given the soya-bean protein concentrate compared with milk protein, but only the increase in trypsin was significant (P less than 0.01). Digesta from the small intestine of pigs given the soya-bean-protein isolate contained less chymotrypsin (P less than 0.05). There were no differences in the proportion of non-protein-N in the total N in the digesta, suggesting that proteolysis of the milk and soya-bean proteins were equally by 28 d of age.
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PMID:Artificial rearing of pigs. 12. Effect of replacement of dried skim-milk by either a soya-protein isolate or concentrate on the performance of the pigs and digestion of protein. 720 50

Bacillus licheniformis ATCC 9945a is one of the bacterial strains that produce gamma-poly(glutamic acid) (gamma-PGA). The use of carbohydrate medium components for gamma-PGA production was explored. Cells were grown in shake flasks or in controlled pH fermentors using medium formulations that contain different carbon sources. During the cultivations, aliquots were removed to monitor cell growth, carbon utilization, polymer production, and polymer molecular weight. Glucose was a better carbon source than glycerol for cell growth. Furthermore, glucose was utilized at a faster rate than glycerol, citrate, or glutamate. However, by using mixtures of glucose and glycerol in medium formulations, the efficiency of gamma-PGA production increased. For example, by increasing the glycerol in medium formulations from 0 to 40 g/L, the gamma-PGA broth concentration after 96 h increased from 5.7 to 20.5 g/L. Considering that glycerol utilization was low for the glucose/glycerol mixtures studied, it was unclear as to the mechanism by which glycerol leads to enhanced product formation. Cell growth and concomitant gamma-PGA production (12 g/L) at pH 6.5 was possible using glucose as a carbon source if trace amounts (0.5 g/L each) of citrate and glutamate were present in the medium. We suggested that citrate and glutamate were useful in preventing salt precipitation from the medium. In addition, glutamate may be preferred relative to ammonium chloride as a nitrogen source. The conversion of glucose to gamma-PGA by the strain ATCC 9945a was believed to occur by glycolysis of glucose to acetyl-CoA and tricarboxylic acid (TCA) cycle intermediates that were then metabolized via the TCA cycle to form alpha-ketoglutarate, which is a direct glutamate precursor.
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PMID:Effects of glucose and glycerol on gamma-poly(glutamic acid) formation by Bacillus licheniformis ATCC 9945a. 1009 19

Poly(gamma-D-glutamic acid) (PGA)-producing strains of Bacillus species were investigated to determine their ability to contribute to reducing the amount of ammonium nitrogen in liquid manures and their ability to convert some of the ammonium into this polyamino acid as a transient depot for nitrogen. Organisms that do these things should help solve the serious environmental problems which are caused by the use of large amounts of liquid manure resulting from intensified agriculture; these problems are mainly due to the high content of ammonium nitrogen. Bacillus licheniformis ATCC 9945 and Bacillus subtilis were able to grow in liquid manure and to produce PGA in the presence of sodium gluconate. On artificial liquid manure these two strains were able to produce 0.85 and 0.79 g of PGA per liter, respectively. Under conditions that are found in intensified farming situations the ammonia content was reduced within 48 h from 1.3 to 0.75 g/liter. One mutant of B. subtilis 1551 impaired in the catabolism of PGA was obtained after nitrosoguanidine mutagenesis. This mutant produced PGA at a final concentration of 4.8 g/liter, whereas the wild type produced only 3.7 g/liter.
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PMID:Cultivation of bacteria producing polyamino acids with liquid manure as carbon and nitrogen source. 1115 24

Mediators of cholera toxin (CT)-induced fluid secretion include 3',5'-adenosine monophosphate (cAMP), prostaglandin E(2) (PGE(2)), and 5-hydroxytryptamine (5-HT). Administration of L-histidine significantly reduced the net secretory response of the small intestine of mice challenged with CT and reduced the capacity of PGE(2) to stimulate Na+ transport in Ussing chambers. We demonstrated that L-histidine chemically modified the structure of PGE(2) but had no direct effect on cAMP or 5-HT. L-Histidine and imidazole reacted with PGE(2) in vitro in cell-free mixtures incubated at 37 degrees C and pH 7.0 under an atmosphere of N(2) with the formation of PGE(2)-imidazole and PGE(2)-histidine covalent adducts. Nuclear magnetic resonance (NMR) spectroscopy and mass spectrometry (MS) analysis of the purified adduct showed that imidazole catalyzed the dehydration of PGE(2). A Michael adduct then was formed between C11 of 11-deoxy-Delta(10) PGE(2) (PGA(2)) and the tau nitrogen in the imidazole ring of L-histidine. Importantly, the isolated PGE(2)-imidazole and PGE(2)-histidine adducts inhibited CT-induced fluid loss and cAMP accumulation in mouse intestinal loops. The protection provided by PGE(2)-imidazole, PGE(2)-histidine, and L-histidine against intestinal fluid loss could provide a basis for future therapy against cholera.
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PMID:Cholera toxin-induced PGE(2) activity is reduced by chemical reaction with L-histidine. 1147 60


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