Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.5.1.5 (urease)
 7,257 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Urease (E.C 3.5.1.5) was covalently immobilized on activated methoxypolyethyleneglycol-5000 which is linear, uncharged, soluble in water and nonimmunogenic. mPEG is bound to the epsilon-NH2 groups of Lysin in urease. Previously different molar ratios of urease -Lys/activated-mPEG were searched for immobilization. Storage stabilities, molecular weights and the values of blocked amino groups were determined for each immobilized urease and the best conditions was found 1:3 urease-Lys/activated mPEG. Furthermore physical characterization, kinetic constants (Km, Vmax), heat and temperature stabilites were also determined.
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PMID:Immobilization of urease on activated methoxypolyethyleneglycol-5000. 877 43

In this study, we investigate simple breath test for detection of Helicobacter pylori (HP) infection using 13C-urea. Thirty-nine patients (30 were HP positive, 9 were HP negative) were given three different doses (50, 100 and 150 mg) of 13C-urea at fasting, and keep sitting after mouth washing with water. Breath samples were taken before and 10, 20, 30, 45, and 60 minutes after urea administration. More than 100mg of 13C-urea was necessary for correct diagnosis of HP infection, because 2 HP positive cases were not detected by 50mg 13C-urea administration. In cases with patchy distribution of HP in the stomach, it may be necessary to change the posture to distribute urea within the whole stomach. In most of HP positive cases, peak delta 13CO2 were obtained within 30 minutes, but one HP negative case showed high delta 13CO2 at 10 minutes, which was probably caused by urease activity in the mouth. So it is appropriate to take breath sample at 20 minutes after urea administration. In this study, cut-off value for a positive test can be setted between 4 to 7 delta/1000, it is necessary to investigate much more cases to set exact cut-off value.
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PMID:[Methodological study of 13C-urea breath test for detection of Helicobacter pylori infection]. 881 Aug 9

Vibrio parahaemolyticus is a halophilic bacterium associated with gastroenteritis and traveller's diarrhea. The urease-positive, Kanagawa-negative V. parahaemolyticus had been isolated from patients and the environment in the Pacific Northwest, first reported by Kelly et al. (5). Recently, we purified the urease produced by a clinical isolated of V. parahaemolyticus, and its characterization and pathogenicity has been studied. The urease isolation procedure included a water extraction and anion exchange chromatography. The molecular weight for the native enzyme was 275 KDa, and the three subunits of 85 KDa, 59 KDa, and 33 KDa were determined. The isoelectric focusing of urease was 5.2. The purified urease also can cause intestinal fluid accumulation and demonstrate a positive result in the suckling mouse test. These results suggested that the urease produced by V. parahaemolyticus may be another important indicator for the pathogenesis of the bacteria.
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PMID:Purification, characterization, and pathogenicity of urease produced by Vibrio parahaemolyticus. 885 57

Environmental analysis requires fast and reliable measurement results. Biosensors, which facilitate integral monitoring as well as single substance analysis, achieve high sensitivities in a minimum of measuring time. Four new on-line biosensors, which cover a wide range of environmentally relevant substances, are introduced: A water-quality monitoring bacteria electrode, whose gradual development is described as an example, a heavy-metal screening urease inhibition sensor, a genotoxic potential as well as a immunotoxic potential indicating sensor. Future prospects are given.
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PMID:New biosensors for environmental analysis. 900 99

Electrochemical principle of ion-selective electrodes (ISEs) based on the ion-transfer reactions across a polarizable organic or oil/aqueous or water interface is described; the amperometric ISE and the potentiometric ISE are addressed. Electrochemical sensors and biosensors based on amperometric ISEs are discussed in some details. Amperometric sensors for monitoring ammonia (and other volatile amines) can be constructed on the basis of amperometric ammonium-ISE, where the pulse amperometric technique can successfully be employed. Urea and creatinine biosensors can also be fabricated by immobilizing urease or creatinine deiminase, respectively, on the surface of the amperometric ammonia sensor. Some favored characteristics of amperometric ISE-based sensors and biosensors are discussed with reference to the sensors and biosensors described.
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PMID:Coupling of enzyme reactions to the charge transfer at the interface of two immiscible solvents. 900 14

The object of this review is the genus Proteus, which contains bacteria considered now to belong to the opportunistic pathogens. Widely distributed in nature (in soil, water, and sewage), Proteus species play a significant ecological role. When present in the niches of higher macroorganisms, these species are able to evoke pathological events in different regions of the human body. The invaders (Proteus mirabilis, P. vulgaris, and P. penneri) have numerous factors including fimbriae, flagella, outer membrane proteins, lipopolysaccharide, capsule antigen, urease, immunoglobulin A proteases, hemolysins, amino acid deaminases, and, finally, the most characteristic attribute of Proteus, swarming growth, enabling them to colonize and survive in higher organisms. All these features and factors are described and commented on in detail. The questions important for future investigation of these facultatively pathogenic microorganisms are also discussed.
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PMID:Potential virulence factors of Proteus bacilli. 910 65

A method was developed to detect Ureaplasma urealyticum in urine by the polymerase chain reaction (PCR). A 457-bp fragment of the urease gene of U. urealyticum was amplified by PCR. Before PCR, components disturbing the amplification had to be reduced. This was possible by diluting the urine 1 in 10 with distilled water and by the extraction of the U. urealyticum DNA. Urine specimens from 41 patients with systemic lupus erythematosus (SLE) and 21 healthy individuals were treated by the dilution method and investigated by PCR for U. urealyticum DNA. The results were compared with those obtained by culture and the detection rates of PCR and culture were found to be identical. Also there was no difference in the detection rates of U. urealyticum from urine of SLE patients and healthy individuals; 10 (24.4%) of the 41 urine specimens from SLE patients and five (23.8%) of the 21 urine specimens from healthy individuals gave positive results for U. urealyticum. The results of this study do not indicate a decisive role for U. urealyticum in SLE.
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PMID:Detection of Ureaplasma urealyticum in urine of patients with systemic lupus erythematosus and healthy individuals by culture and polymerase chain reaction. 915 38

This paper presents the construction of various biosensors using thin-film layers incorporated in flow injection devices, providing automated systems for biomedical analysis, process and environmental monitoring. A urease sensor has been developed in conjunction with a flow injection system for the automatic determination of urea. Use of the spraying immobilization technique gives rise to a response time of a few seconds, which allows sample throughputs up to 200 h-1. With a penicillin biosensor adapted in an appropriate cell detection, on-line measurements of penicillin V in the fermentation broth are achieved during the whole fermentation process; the results are compared with the HPLC method. Linearity, sensitivity and reproducibility of the biosensor are studied with regards to sample dilution in a stirred flow detection cell to provide optimal operating conditions. Measurements without any change in parameters are obtained during the whole fermentation process. Acetylcholinesterase sensors have been used in batch systems for the determination of pesticides, but they require large amounts of substrate. When those enzyme sensors are combined with flow injection systems, only small volumes (100 microliters) of substrate are injected into the carrier stream and an automated system can be obtained for continuous control of water quality.
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PMID:Biosensors in flow-injection systems for biomedical analysis, process and environmental monitoring. 917 53

Cattle arriving for slaughter at abattoirs in the Veneto region of N. Italy were examined for intestinal carriage of Escherichia coli O157. Rectal swabs were cultured in modified buffered peptone water and E. coli O157 was concentrated by an immunomagnetic separation technique; the magnetic beads were cultured onto cefixime tellurite sorbitol MacConkey agar. Sorbitol non-fermenting E. coli O157 was isolated from 15 (3.6%) of 419 feedlot cattle but not from 437 veal calves or 65 culled cows. All strains of E. coli O157 hybridized with DNA probes specific for the VT1 or VT2 genes, but two strains did not produce toxin detectable by Vero cell assay. Six different plasmid profiles were observed with all strains harbouring the large 93 kb plasmid characteristic of VTEC. Six strains produced urease but otherwise strains were biochemically typical of E. coli O157. One strain was resistant to streptomycin, tetracycline and sulphonamides but the remainder were sensitive to all antimicrobials tested. This is the first description of the isolation of verocytotoxin-producing E. coli O157 from cattle in Italy. As the contamination of bovine carcasses with E. coli O157 during slaughter and processing has been demonstrated, the risk of transmission of this organism from beef cattle to the human population in the Veneto region, through foods of bovine origin or by other routes, should not be overlooked.
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PMID:Atypical strains of verocytotoxin-producing Escherichia coli O157 in beef cattle at slaughter in Veneto region, Italy. 927 Mar 53

We examined the taxonomic position of seven Aeromonas isolates, recovered from Flemish and Scottish drinking water production plants and reservoirs, which were previously recognized by numerical analysis of genomic AFLP fingerprints as members of an unknown Aeromonas taxon that most closely resembled the species Aeromonas bestiarum (DNA hybridization group [HG] 2). The new phenotypic and DNA-DNA hybridization data obtained in this study show that the A. bestiarum-like strains constitute a separate Aeromonas species, for which the name Aeromonas popoffii sp. nov. is being proposed. The new species exhibited an internal DNA relatedness ranging from 79 to 100% and was 22 to 63% related to the type or reference strains of other Aeromonas spp. The highest DNA binding values were determined with A. bestiarum (51 to 63%), followed by Aeromonas hydrophila sensu stricto (HG1; 50 to 60%) and Aeromonas salmonicida (HG3; 39 to 55%). Although fingerprints generated by ribotyping and cellular fatty acid analysis often were highly similar, minor differences between the respective fingerprints were of significance for the differentiation of A. popoffii from its closest taxonomic neighbors, HG1, HG2, and HG3. Phenotypically, all seven strains of A. popoffii were positive for acid and gas production from D-glucose and glycerol, growth in KCN broth, arginine dihydrolase, DNase, Voges-Proskauer reaction, and resistance to vibriostatic agent O/129 and ampicillin but displayed negative reactions for production of urease, tryptophan deaminase, ornithine decarboxylase, and lysine decarboxylase (LDC). None of the strains displayed strong hemolytic activity. The lack of D-sucrose fermentation and LDC production and the ability to utilize DL-lactate as the sole energy and carbon source were useful characteristics for the biochemical separation of A. popoffii from A. bestiarum. Other Aeromonas spp. could be differentiated phenotypically from the new species by at least two features. The chromosomal G+C content of A. popoffii ranges from 57.7 to 59.6 mol%. Strain LMG 17541 is proposed as the type strain.
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PMID:Aeromonas popoffii sp. nov., a mesophilic bacterium isolated from drinking water production plants and reservoirs. 933 24


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