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)

Gyrocotyle fimbriata isolated from the spiral valve of Hydrolagus colliei were washed, then held in a filtered seawater-penicillin-Tris buffer medium. Ammonia and urea release to the medium declined together and ammonia production was minimal when the urea concentration was below detectable limits. Alanine and smaller amounts of glycine were released to the medium at a more constant rate. After 12 hr the alanine-glycine excretion was more than 20 times the ammonia excretion. L-arginine, L-serine, L-histidine, and urea were most effective in stimulating ammonia production by whole worms; other L-amino acids were essentially ineffective. L-glutamate dehydrogenase, L-amino acid oxidase, uricase, and ornithine transcarbamylase were below detectable levels. L-serine dehydrase, L-arginase, L-histidase, and urease were detected in tissue homogenates and probably account for most of the endogenous ammonia production. L-arginase has a molecular weight of 28,000 by Sehpadex gel filtration. The high levels of glutamate-pyruvate transaminase and lower levels of glutamate-oxalacetate transaminase correlate with the high level of alanine excretion. It is concluded that (1) ammonia production is not strongly linked to the overall energy metabolism of Gyrocotyle and is probably a result of a series of unrelated enzymatic reactions such as the action of urease of urea from the tissue of the rat fish, and (2) alanine and glycine are the major nitrogen excretory products and their production is linked to the energy metabolism of Gyrocotyle.
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PMID:Ammonia formation and amino acid excretion by Gyrocotyle fimbriata (Cestoidea). 111 78

Several lines of evidence suggest that bacterial urease is the primary cause of infection-induced urinary stones. The hydroxamate group of compounds are specific urease inhibitors. Of the cogeners studied, to dat, AHA (acetohydroxamic acid) appears to have the most pharmacologic potential. AHA is rapidly and completely absorbed from the gastrointestinal tract and is concentrated and excreted in the urine. In animals it appears to be relatively nontoxic. Although its toxicity in human beings has not been studied, its similarity to hydroxyurea suggests that reversible toxicity involving the gastrointestinal tract and the hematopoietic systems may result when high doses are administered. The only known metabolite of AHA is acetamide which is nontoxic and rapidly excreted in the urine. Pharmacologic use of AHA is expected to be practical and relatively safe. Use of AHA in patients with urinary infections caused by urea-splitting bacteria may reduce pathogenicity of the infecting organism and may lead to prevention and/or dissolution of stones commonly associated with such infections.
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PMID:Acetohydroxamic acid. Potential use in urinary infection caused by urea-splitting bacteria. 111 89

As a result of reaction of urease with graft copolymer of cellulose and polyglycidyle methacrylate or with carboxymethyl cellulose, products were synthesized, containing about 2% of chemically bound urease. Binding with the cellulose derivatives was accompanied by about two-fold decrease in urease activity. Carboxymethyl cellulose-urease and polyglycidile methacrylate-cellulose-urease might be repeatedly (for 30 cycles) used for hydrolysis of urea; the enzymatic activity of the first compound did not change, but of the second one--was decreased by 30%. Activity of the compounds was not changed after storage within 2 months in 0.1 M phosphate buffer, pH 7.0 at 4 degrees C.
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PMID:[Synthesis and study of the properties of water-insoluble products of the interaction of urease and cellulose derivatives]. 111 15

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

Use of commercially available urea differentiation disks is a rapid and convenient means of determining the urease activity of mycobacteria. In the study performed, paper disks containing Ewing's Urea R Broth were compared with two other methods of testing for urease production. Over 1,500 tests were performed with recent patient isolates from which at least 15 different species of mycobacteria were identified. The tests were read at intervals for 72 h, and a comparison of test results as to rapidity and accuracy for each species was tabulated. The urea disks showed a faster reaction time when compared with the other two methods. They also showed a high percentage (79 to 100%) of reliability for each species on the first run, based on the expected response.
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PMID:Use of urease test disks in the identification of mycobacteria. 117 15

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

In field experiments wheat in the phase of shooting was sprayed with solutions of chlorocholinechloride (CCC) and urea, CCC and ammonium salt MCPA (Aminex) or CCC, urea and Aminex. The effect of the treatment on dry weight of overground parts of wheat, number of bacteria, production of carbon dioxide, urease activity and content of ammonium in the rhizosphere soil was investigated. In all cases evolution of carbon dioxide in the rhizosphere soil was higher than that in the control soil. Highest numbers of bacteria were found in the rhizosphere soil of plants treated with urea, the herbicide and their mixtures. Content of ammonium was higher in the control soil than in the rhizosphere soils, the urease activity was highest in the rhizosphere soil of plants treated with the solution of the herbicide and with the combination of the herbicide with urea.
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PMID:Biological changes in the rhizosphere of wheat after foliar application of chlorocholinechloride, urea and 4-chloro-2-methylphenoxyacetic acid. 119 93

To examine the suitability and reliability in field use of the "Merckognost Harnstoff" method in estimating the concentration of urea in the blood of horses, cattle, goats and dogs, the levels determined by this procedure were compared with those determined by an enzymatic (urease) photometric method widely used in laboratories. It was concluded from the results obtained that estimation using the "Merckognost Harnstoff" is sufficiently reliable for the rapid assay of urea in the blood under field conditions.
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PMID:[Estimation of the concentration of urea in the blood of horses, cattle, goats and dogs using the "Merckognost Harnstoff" method compared with an enzymatic, photometric method (author's transl)]. 119 74

1. Isolated hepatocytes were used to establish the reasons for the accumulation of aspartate, previously observed when the isolated rat liver was perfused with ethanol in the presence of alanine or ammonium lactate. 2. The isolated cells did not form aspartate when incubated with alanine and ethanol, but much aspartate was formed on incubation with ammonium lactate and ethanol. 3. Urea was the main nitrogenous product on incubation with alanine, in contrast with the perfused liver, where major quantities of NH4+ are also formed. When the formation of urea was nullified by the addition of urease, alanine plus ethanol caused aspartate formation, indicating that aspartate formation depends on the presence of critical concentrations of NH4+. 4. The accumulated aspartate was present in the cytosol. Ethanol halved the content of 2-oxoglutarate in the cytosol and more than trebled that of glutamate in the mitochondria. 5. The findings support the assumption that 2-oxoglutarate formed by the mitochondrial aspartate aminotransferase is not translocated to the cytosol in the presence of ethanol and NH4+, because it is rapidly converted into glutamate, the dehydrogenation of ethanol providing the required NADH. Aspartate, however, is translocated to the cytosol and accumulates there because of the lack of stoicheiometric amounts of oxoglutarate.
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PMID:The accumulation of aspartate in the presence of ethanol in rat liver. 120 Oct 7

Seven species of human T-mycoplasmas that grow in Fraction A and 20 mug urea/ml died when the urea was omitted. Two species would not grow in Fraction A broth containing 10 mug/urea/ml. The other five strains grew in broth containing 10 mug urea/ml and were adapted by serial passage in broth containing decreasing concentrations of urea to grow in broth containing 2.5 mug/ml urea, but not in broth containing 1.25 mug/ml. Therefore the minimal urea requirement is not the same for the growth of all strains of T-mycoplasmas. In exponential phase broth cultures, urease was detected only intracellularly, none being found in the medium.
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PMID:The urea requirement and urease production of some human species of T-mycoplasmas. 120


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