Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:6.3.4.6 (urease)
 7,490 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Male rats were fed laboratory chow or a purified L-amino acid diet containing 11.2 or 5.6 g arginine/kg. Hyperammonemia was produced by injection of crystalline jackbean urease. Control animals were injected with saline or inactivated urease. Rats injected with 55 U urease activity/kg body wt (an LD50 dose) exhibited acute signs of hyperammonemia and elevated orotate and citrate in their urine. Plasma glucose, lactate, citrate, and alpha-ketoglutarate concentrations were also markedly elevated. Three injections of active urease (10 U/kg body wt) given at intervals of about 10 h produced hyperammonemia, which persisted for 25 h after the first injection. Blood glucose and ammonia concentrations were increased 2.6- and 22-fold, respectively, when compared with controls. Total urinary citrate excretion for 25 h was 371 mueq for active urease-injected rats compared with 62 mueq for rats injected with inactivated urease. Rats fed a purified amino acid diet containing 5.6 g arginine/kg excreted greater quantities of urea, citrate, and orotic acid than rats fed 11.2 g arginine/kg of diet. Injection of active urease increased citrate excretion by rats fed either concentration of dietary arginine. Changes produced with active urease were not observed if inactivated urease was injected.
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PMID:Citric, orotic, and other organic acids in rats injected with active or inactive urease. 111 48

A device, the enzyme thermistor, is described which is capable of measuring changes in heat due to enzymic reactions. The sensor, a thermistor, is in direct contact with the site of reaction through its placement in a microcolumn filled with an immobilised enzyme preparation. The substrate solution flows past the thermistor tip, and as much as approx. one half of the total heat evolved can be registered as temperature change, deltat. Glass-bound glucose oxidase (EC 1.1.3.4), penicillinase (EC 3.5.2.6), trypsin (EC 3.4.21.4) and urease (EC 3.5.1.5) were used for the determination of glucose, penicillin G, benzoyl-L-arginine ethyl ester and urea respectively. Linear relationships between the deltat recorded and the concentration of substrate were obtained in all cases.
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PMID:Determination of heat changes in the proximity of immobilised enzymes with an enzyme thermistor and its use for the assay of metabolites. 117 49

We evaluated the effect of sodium iodoacetate on glycolysis in a series of randomly selected blood samples from patients. Glucose values for serum and for serum with added sodium fluoride (2.5 g/liter) or sodium iodoacetate (2 g and 0.5 g/liter) were compared at room temperature. Respective declines in glucose values averaged 170, 40, 30, and 30 mg/liter after 24 h. Iodoacetate-preserved (0.5 g/liter) samples showed no visible hemolysis. Results of determinations of urea with urease and of other tests on SMA 12/60 (Technicon) panels were unaffected.
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PMID:Sodium iodoacetate as an antiglycolytic agent in blood samples. 118 4

Human red blood cell ghosts were prepared by electrical haemolysis at 0 degrees C in isotonic solutions using a discharge chamber which was part of a high voltage circuit. The size distribution of the ghosts was normally distributed, the modal (=mean) volume was approx. 115 mum3, performing the electrical haemolysis in the following solution: 105 mM KCI, 20 mM NaCL, 4mM MgCl2, 7.6 mM Na2HPO4, 2.94 mM NaH2PO4, 10 mM glucose, pH 7.2. Resealing was carried out at o degrees C for 10 min (after the haemolytic step) and then for further 20 min at 37 degrees C. The mean volume of the ghost preparation could be changed by variation of the phosphate concentration in the above solution replacing a part of NaCl by phosphate (5 mM phosphate: 94 mum3, 15 mM phosphate: 135 mum3). The breakdown voltage of the ghost cell membranes measured with a hydrodynamic focusing Coulter Counter depends on the mean volume (94 mum3 = 1.04 V, 134 mum3 = 1.36 V). On the other hand, the breakdown voltage is constant throughout each size distribution pointing to an "electrically homogeneous" ghost preparation. The sensitiviity of the Coulter Counter to detect electrical inhomogeneities in the membranes of a ghost population is demonstrated by dielectric breakdown measurements of an apparently normally distributed ghost preparation containing two different "electrically homogeneous" ghost population i.e. with two different breakdown voltages. The ghost cells obtained by electrical haemolysis in the above solution containing 10mM phosphate were fairly impermeable to sucrose and behave like an ideal osometer. It is further demonstrated that ghost cells can be loaded with enzymes (e.g. urease) and drugs using this technique and that these loaded ghost cells can be used as bioactive capsules for clinical application.
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PMID:Enzyme loading of electrically homogeneous human red blood cell ghosts prepared by dielelctric breakdown. 127 24

Twenty-seven of 37 non-toxigenic, urease-negative strains originally identified as Clostridium bifermentans that were isolated in the Antarctic are reidentified as C. sordellii by the tests for DNA-DNA homology, by the absence of mannose in the cell wall, and by growth inhibition of mannose. The test for cell wall sugar components of urease-negative and -positive strains of C. sordellii revealed that glucose, mannose, and rhamnose could not be detected in any of eight urease-negative strains used by galactose was detectable in seven of the eight strains and that glucose or galactose or both of the two sugars were present in the urease-positive strains tested.
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PMID:Urease-negative strains of Clostridium sordellii. 127 96

Some staphylococcus and enterococcus strains were used to investigate the effect of culture medium on bacteriocin production. Staphylococcus cohnii SC7, Staphylococcus sp. ZTJ 151, S. saprophyticus SS 877, Enterococcus faecium EF1 and E. faecalis EFG2 were isolated from the rumen wall and contents of lambs, calves and fallow deer, Enterococcus gallinarum EG10 and E. avium EA12 were isolated from the caecum of Japanese quail. The tested bacteria belong to producers with a wide antimicrobial effectiveness spectrum, they have low to medium adherence and urease activity (Tab. III). These culture media were used to test the effect of culture medium on bacteriocin production: nutrient agar no. 2 and VL agar enriched with 2% of glucose and lactose (ZAG, ZAL, VLG, VLL), agar for isolation of faecal streptococci (SA) and the base for blood agar no. 4 and no. 2 (KA4, KA2). The strains Streptococcus bovis AO 24/85 and Staphylococcus aureus Oxford 209 P were used as indicator bacteria. Tables I and II show the results of these tests. The tested strains produced the widest inhibition zones (6 mm) with both indicators on SA medium, and this indicates massive bacteriocin production. On ZAG medium, the zones of enterococci with the AO 24/85 strain were larger size than those of staphylococci, but the zones were dim. All strains with the 209P indicator produced dim zones of the 2mm size. The larger inhibition zones (2-5mm) in comparison with staphylococci were observed in enterococci on the ZAL medium with the AO24/85 strain. The production of tested strains was balanced on VLG agar with respect to the use of both indicators.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[The effect of culture media on bacteriocin production in various strains of bacteria]. 129 43

Single and multisensor field effect transistors (FET) with a pH-sensitive Si/SiO2/Si3N4/Ta2O5-gate and reference electrode (for single sensor) were developed and used for manufacturing the following biological (Bio)-FETs: for glucose analysis, glucose oxidase-FET (GOD-FET); for urea analysis, urease-FET; and for cephalosporin C analysis, cephalosporinase-FET. The GOD-FETs were integrated into flow injection analysis (FIA) of the Eppendorf variables analyser (EVA) system and used for monitoring the glucose concentration in microbial cultivation and production processes with recombinant Escherichia coli K12 MF, recombinant E. coli JM103, Saccharomyces cerevisiae H620, and Candida boidinii. Urease-FET-FIA was used to monitor the urea concentration in a simulated cultivation of Cephalosporium acremonium and urease-FET-FIA and GOD-FET-FIA for the monitoring of urea and glucose concentrations in simulated S. cerevisiae cultivations.
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PMID:Monitoring and control of biotechnological production processes by Bio-FET-FIA-sensors. 136 6

Pasteurella multocida is a pathogen of animals and humans. Most of the patients have been associated with animals but many cases had not contacted them. The failure to diagnose P. multocida infections is mostly due to misidentification on gram stained smears and inadequate laboratory identification techniques. In order to compile detailed characteristics of the organism we studied the physical and biochemical properties of 70 isolates of P. multocida - 17 human, 23 swine and 30 poultry. All isolates produced catalase, oxydase, indol, nitrate reduction and ornithine decarboxylase. They failed to produce urease, gelatinase, methyl red, acetoin and could not grow on MacConkey agar, SS-agar, in nutrient broth with 0% or 6% NaCl. With respect to fermentable sugars, all isolates consistantly produced acid from glucose, mannitol and mannose. None of the cultures fermented lactose, maltose and dulcitol. Marked variations in the patterns of fermentation of arabinose and xylose were found. The characteristics tested are important to facilitate identification of P. multocida but could not be used to differentiate the host of the bacterium.
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PMID:Characteristics of Pasteurella multocida isolated from humans, swine and poultry in Thailand. 148 11

Studies were conducted to evaluate the effect of overcooked soybean meals (SBM) on chick growth and amino acid availability. The SBM were custom-prepared at a commercial processing plant by changing the conditions of a desolventizer-toaster (DT) unit. Six progressively overcooked meals (designated SBM1 to 6 with SBM1 as normal, and SBM6 overcooked) were produced by increasing temperature by up to 50% and extending retention time by up to 75% above normal. The meals measured .05, .03, .01, .09, .00, and .00 delta pH of urease activity; 6.10, 5.01, 4.62, 4.83, 2.32, and 1.78 mg/g SBM of trypsin inhibitor activity; 92, 89, 91, 88, 81, and 81% of protein solubility in .2% KOH; and 46, 43, 41, 40, 23, and 19% of protein solubility in .1 M borate at 40 C, respectively. Glucose content in the hydrolysate of the soluble carbohydrate extract did not differ among the meals, indicating no differences in the degradation of sucrose, raffinose, and stachyose with increasing heat treatment. In a chick growth experiment with a methionine-adequate, low-protein diet, chicks fed SBM1 showed significantly greater weight gain than chicks fed SBM3, 5, or 6. The SBM1, 2, 5, and 6 were chosen for a study of amino acid availability. No differences were observed in amino acid content. There were significant differences in apparent amino acid availability to growing chicks, but not in true amino acid availability by adult roosters among the four meals. The results suggest that the temperature or the retention time of a DT unit may be increased by 50% over the usual operating conditions without reducing amino acid availability from SBM.
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PMID:Effect of overcooked soybean meal on chicken performance and amino acid availability. 156 Dec 16

1. Portacaval shunting in rats results in several metabolic alterations similar to those seen in patients with hepatic encephalopathy. The characteristic changes include: (a) diminution of cerebral function; (b) raised plasma ammonia and brain glutamine levels; (c) increased neutral amino acid transport across the blood-brain barrier; (d) altered brain and plasma amino acid levels; and (e) changes in brain neurotransmitter content. The aetiology of these abnormalities remains unknown. 2. To study the degree to which ammonia could be responsible, rats were made hyperammonaemic by administering 40 units of urease/kg body weight every 12 h and killing the rats 48 h after the first injection. 3. The changes observed in the urease-treated rats were: (a) whole-brain glucose use was significantly depressed, whereas the levels of high-energy phosphates remained unchanged; (b) the permeability of the blood-brain to barrier to two large neutral amino acids, tryptophan and leucine, was increased; (c) blood-brain barrier integrity was maintained, as indicated by the unchanged permeability-to-surface-area product for acetate; (d) plasma and brain amino acid concentrations were altered; and (e) dopamine, 5-hydroxytryptamine (serotonin) and noradrenaline levels in brain were unchanged, but 5-hydroxyindoleacetic acid (5-HIAA), a metabolite of 5-hydroxytryptamine, was elevated. 4. The depressed brain glucose use, increased tryptophan permeability-to-surface-area product, elevated brain tryptophan content and rise in the level of cerebral 5-HIAA were closely correlated with the observed rise in brain glutamine content. 5. These results suggest that many of the metabolic alterations seen in rats with portacaval shunts could be due to elevated ammonia levels. Furthermore, the synthesis or accumulation of glutamine may be closely linked to cerebral dysfunction in hyperammonaemia.
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PMID:Hyperammonaemia causes many of the changes found after portacaval shunting. 170 23


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