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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)

The urease method developed by Noone et al. for rapid bioassay of aminoglycoside antibiotics in serum is described in detail. The accuracy of the method was improved by using a BM 1-09 electrode assembly (Metrohm, CH-9100 Herisau, Switzerland) in conjunction with a digital pH-Meter (Metrohm E 500). The mean difference between spiked serum samples and measured concentrations was +0.37 +/-0.78 microgram/ml. The coefficient of determination between the urease and agar diffusion method was 0.94. Disadvantages of the method are a low sensitivity at concentrations below 1.5 microgram/ml and a large serum sample (1.5 ml). Advantages are its simplicity and rapidity.
Infection 1977
PMID:[Assay of aminoglycosides in serum using the urease method (author's transl)]. 1 6

The role of urease in induction of pyelonephritis was studied by treatment of proteus-infected rats with acetohydroxamic acid, a potent inhibitor of urease. Infection was produced by introduction of Proteus mirabilis into the bladder along with a zinc disk. Controls were treated identically but received no acetohydroxamic acid. The number of bacteria per milliliter of urine was the same in both groups. The number of bacteria in the kidneys and the extent of renal damage was much greater in controls. Common enterobacteraceal antigen was not detected in the renal parenchyma of rats treated with acetohydroxamic acid. Treatment with acetohydroxamic acid thus prevented invasion of and damage to kidney tissue without reduction of urinary infection. Thus new evidence was found that the invasive properties of Proteus in the urinary tract are dependent on alkalinization of urine by urease and the resulting damage to the renal epithelium.
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PMID:Role of urease in pyelonephritis resulting from urinary tract infection with Proteus. 23 93

In the course of a systematic search for Bacteroides corrodents and Eikenella corrodens in clinical specimens submitted for microbiological analysis, 61% of the specimens from anal abscesses, 6% of the vaginal specimens and none of the pharyngeal specimens yielded B. corrodens, whereas E. corrodens was recovered from only 9% of the pharyngeal specimens. Some characteristics were found to be useful in differentiating between the two species: B. corrodens strains were strictly anaerobic, cytochrome-oxidase-negative, urease-positive and gelatinase-positive; they were sensitive to lincomycin but resistant to vancomycin. E. corrodens strains on the other hand were facultatively anaerobic, oxidase-positive, urease-negative and gelatinase-negative; they were resistant to lincomycin but sensitive to vancomycin. The pathogenicity of the two species was difficult to assess as in most cases they were recovered from mixed cultures.
Infection 1977
PMID:Isolation of Bacteroides corrodens and Eikenella corrodens from human clinical specimens. Comparative study of incidence and methods of identification. 33 72

A prospective study was conducted to determine the frequency of occurrence of Helicobacter pylori infection in outpatients presenting with upper gastro intestinal symptoms to Arba Minch Hospital over a one year period. Four hundred and forty four patient, 309 males and 135 females, underwent upper gastro intestinal fiberoptic endoscopy between March 1989 and April 1990. The age range was 14 to 75 years (mean = 35). All 444 patients were examined and tested for infection. Sixty per cent had abnormal endoscopy results. The major endoscopic findings were gastritis in 23% and peptic ulcer disease in 20% of the patients. To identify H. pylori infection, 2 biopsy specimens were taken from the greater curve of the gastric antral mucosa of all patients. The specimens were examined using the urease diagnostic test and Loeffler Methylene Blue stain. Infection was considered present when either of the tests were positive. Infection by H. pylori was found in 324 patients (73%). Among the 173 patients without endoscopic findings, 63% had infection. Of 271 patients with abnormal endoscopic findings, 79% were infected. The results of this study show that H. pylori infection is a common finding in patients with upper gastrointestinal symptoms in Ethiopia. There is a higher prevalence of infection among patients with endoscopic findings. Thus the management of patients with upper gastro-intestinal symptoms in Ethiopia should take H. pylori infection into consideration.
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PMID:Helicobacter pylori infection in patients with upper gastrointestinal symptoms in Arba Minch Hospital: southwestern Ethiopia. 156 64

Infection stones in the urinary tract are always associated with infection with a urease-producing, urea-splitting organism. The most common of these organisms are easy to culture and identify and can be treated early either with an appropriate antibiotic or with an anti-urease agent. Ureaplasma urealyticum and Corynebacterium urealyticum are urease-producing organisms which are difficult to grow; their presence and effects frequently go undetected and untreated. Other organisms, as yet unknown, may also be involved in the same process. We report the first series of 8 patients with recurrent infection-type stones likely to have been caused by a "hard to grow" organism. Five patients never had a positive culture; in 2 patients 1 of 10 urine cultures grew a coagulase-negative Staphylococcus and in 1 patient the same organism was grown from a stone but never in the urine. The clinical course of all of these patients was significantly improved after blind treatment with antibiotics and in one case with an anti-urease agent.
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PMID:Recurrent infection stones with apparently negative cultures. The case for blind antibacterial treatment. 156 95

Four barrier-born pigs were inoculated with Helicobacter pylori during gastroscopy. Infection in all pigs was established after 3 weeks, and the animals were kept isolated from other pigs in ordinary experimental sites. The pigs were sacrificed and examined 3, 5, 6, and 6.5 months postinoculation. A detailed urease mapping of the pig stomachs showed a patchy distribution of H. pylori. The bacteria colonized in all pigs, with a concentration of H. pylori-positive areas in the antrum and fundus. Furthermore, the number of colonized areas tended to increase with time, and some of these areas showed a strong urease reaction, indicating a heavy colonization with H. pylori. Biopsies from these areas contained 10(2) to 10(5) CFU per 2-mm-wide biopsy. We conclude that persistence of H. pylori infection in barrier-born pigs can be demonstrated for at least 6.5 months. The patchy distribution and the variability of viable bacteria were similar to those described for humans.
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PMID:Topographic mapping of Helicobacter pylori colonization in long-term-infected pigs. 173 Apr 99

Infection stones have an outstanding position in childhood urolithiasis. In non-infection stones one can mostly find a certain--for example metabolic--causes of stone formation. In infection stones, the urease-producing and thus urea-cleaving properties of some gram-negative bacteria are responsible for alkalization of the urine and lead especially in combination with disturbances of urine transport to the staghorn calculi. Therefore in such children early diagnosis, adequate therapy and consequent maintenance is the crucial point for good life quality in future. Preliminary condition for therapeutic success is a close coworking between pediatric nephrologist, pediatric urologist, family doctor and parents.
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PMID:[Infection-induced urinary calculi in children; current therapeutic schedule and prevention of recurrence]. 307 Jan 41

Campylobacter pylori has recently been isolated from gastric mucosal biopsy specimens. Campylobacter pylori has many attributes in common with other campylobacters but it may represent a new genus. It produces abundant quantities of urease, and this property has been used to develop a rapid diagnostic test. The organism is found predominantly beneath the gastric mucus layer that lines the surface epithelium of the stomach. Infection with C. pylori causes an acute histologic gastritis which may become chronic. The bacterium is the etiologic agent in type-B gastritis. Prevalence of the organism in asymptomatic persons appears to be age related. Campylobacter pylori is found commonly in patients with peptic ulcer disease, always in association with chronic gastritis. Eradication of the organism is associated with healing of the gastritis and a lower relapse rate in duodenal ulcer disease. A role for the organism in other upper gastrointestinal diseases is unproven.
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PMID:The clinical significance of Campylobacter pylori. 327 66

Apart from urine supersaturation with respect to struvite and calcium phosphate, crystal retention is considered to be necessary for the formation of infection stones. This study was performed to investigate the role of the mucous coat in rat bladders in the adhesion of sterile urease-induced crystals and to determine to what extent the adhesion was influenced by infection. Elimination of the mucous coat with 0.1 M HCl increased the adherence of crystals six times compared to that in bladders with an intact mucous coat. Infection with Proteus mirabilis, Escherichia coli, enterococci and Ureaplasma urealyticum increased the adherence six, five, four and two times, respectively. Injury to the mucous coat may thus be one mechanism by which microorganisms can contribute to the formation of infection stones in the urinary tract.
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PMID:Adherence of urease-induced crystals to rat bladder epithelium following acute infection with different uropathogenic microorganisms. 329 48

Infection-induced stones in man probably form solely as a consequence of urealysis which is catalyzed by the bacterial protein urease. Urease stones composed of struvite and carbonate-apatite may form primarily, or as secondary stones or pre-existent metabolic stones. Struvite stones form and grow rapidly owing to (a) supersaturation of urine with stone forming salts, (b) 'salting out' of poorly soluble organic substances normally dissolved in urine and (c) ammonia-induced destruction of the normally protective urothelial glycosaminoglycan layer. Immature (predominantly organic) matrix stones mature into densely mineralized stones. Curative treatment is possible only by eliminating all of the stone and by eradicating all urinary and parenchymal infection. A variety of operative and pharmaceutical approaches are available. Patient treatment must be individualized inasmuch as some patients are better candidates for one type of treatment than another.
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PMID:Infection (urease) stones. 330 21


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