Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: 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)

The value of a modified 13C-urea breath test for the detection of Helicobacter pylori was analysed in a prospective study of 50 consecutive patients (28 women, 22 men, aged 20-90 years) with unknown Helicobacter pylori status about to undergo upper intestinal endoscopy. Four biopsies each were obtained in each patient from the antrum and the body of the stomach and examined for Helicobacter pylori infection of the gastric mucosa histologically (haematoxylin-eosin and Giemsa stain), with the rapid urease test and by culture. The patients then underwent a modified 13C-urea breath test. Results were positive histologically and(or) by culture in 29 patients, while the breath test was positive in 28 (sensitivity 96.3%). The breath test was falsely positive in two (specificity 91.3%). The biopsy urease test had a sensitivity of 96.3% with a 100% specificity. These results demonstrate that the modified 13C-urea breath test is a simple and accurate way of demonstrating Helicobacter pylori infection, equal in diagnostic value to the biopsy urease test.
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PMID:[The modified 13C-urea breath test in the diagnosis of Helicobacter pylori colonization of the gastric mucosa]. 760 Sep 35

The histological gastritis classification according to the Sydney system is a standardisation of different classification systems used so far. It is based on the principles of etiology, topography and course of the disease, as well as morphological changes of the gastric mucosa in gastritis. Histological examination represents the practical gold standard of Helicobacter pylori detection and can be used on routinely formaldehyde-fixed biopsy material and hematoxylin-eosin stained slides. Histology is therefore also of practical diagnostic value for the control of the eradication therapy of Helicobacter pylori. The sensitivity of histological Helicobacter detection is on average higher than that of other methods including microbiology. Nevertheless, additional bacterial cultures are useful in cases of therapy resistant Helicobacter pylori infections. For routine diagnosis histological Helicobacter pylori detection is often combined with the so-called rapid urease test, which can be used in the endoscopy outpatient department, frequently offering an interim diagnosis of Helicobacter pylori infection. Furthermore, histological examination enables not only exact gastritis classification with Helicobacter pylori detection, but also the diagnosis of precancerous lesions and gastric carcinomas, as well as primary gastric lymphomas. Biopsy material for histological examination can be taken during the routinely necessary gastroscopic examination of patients with gastric symptoms without much additional burden.
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PMID:[Therapeutic relevance of the classification of gastritis]. 797 70

Helicobacter pylori infection has been associated with stimulation of gastric mucosal reactive oxygen metabolite production. To provide further evidence of a causal relationship we looked for a dose-response relationship. We studied antral biopsy material from 110 patients. Quantitative H. pylori assessments were made using histologic and microbiologic methods. Reactive oxygen metabolite production was measured by luminol-dependent chemiluminescence. The usefulness of timed urease test colour changes as a guide to infective load was assessed. There was a positive association between mucosal reactive oxygen metabolite production and histologic (p = 0.002, n = 69) and microbiologic (Spearman's R = +0.6, p = 0.05, n = 18) quantitative H. pylori assessments. H. pylori infective load varied markedly over small areas (coefficient of repeatability of paired cultures (in colony-forming units/mg) = 1.9 x 10(6). Urease test timing correlated with histologic (p = 0.01) and microbiologic (p = 0.03) H. pylori quantitation. Histologically assessed mucosal damage was related to quantitative H. pylori assessment and to mucosal reactive oxygen metabolite production (p = 0.0001). These results support the hypothesis that H. pylori stimulates gastric mucosal reactive oxygen metabolite production and that this phenomenon is of pathogenic importance.
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PMID:Relationship between infective load of Helicobacter pylori and reactive oxygen metabolite production in antral mucosa. 803 57

Gastric acid secretion has been considered to decline with increasing age but this view is being re-evaluated as the importance of Helicobacter pylori infection emerges. This study aimed to determine the effect of age, H pylori, and gastritis with atrophy on the serum gastrin concentration, gastric secretory volumes, and acid output in healthy, asymptomatic men. Young men (mean (SD) age 22.9 (0.6) years; n = 22) were compared with old men (72.9 (1.2) years; n = 28) in respect of basal serum gastrin and basal, sham fed, pentagastrin stimulated maximal and peak acid secretion. Antral, corpus, and fundal biopsy specimens were taken for histology and H pylori status (histology, culture, and rapid urease test). H pylori associated gastritis was present in three of 22 young (13.6%) and 16 of 28 old (57.1%) men. Gastritis with atrophy was present in 11 old subjects, 10 of whom were H pylori positive. These subjects had higher mean (SD) serum gastrin concentrations than old subjects without atrophy and young subjects (61.8 (9.2); 40.0 (2.9); 36.8 (2.3) pmol/l respectively; p < 0.001). H pylori infected subjects had higher gastrin values than uninfected subjects, overall (55.3 (5.9); 36.0 (1.8) pmol/l; p < 0.001) and in subjects without atrophy (45.3 (4.2); 36.0 (1.8) pmol/l; p < 0.03). In subjects without H pylori infection, gastrin values did not differ with age (old 37.1 (1.7); young 35.4 (2.1) pmol/l). The maximal gastric secretory volume was lower in old subjects with atrophy. Acid output (mmol/h) in subjects with atrophy was lower than in subjects with no atrophy (basal: 3.0(1.1); 5.1(0.7); p=NS; sham led: 5.4 (1.4); 9.3 (0.8); p<0.02; maximal: 18.9 (4.0); 31.4(1.8); p<0.002; peak: 25.1(5.3); 43.4(2.7); p<0.003). However, acid secretion in old subjects without atrophy was not different to that in young subjects, irrespective of H pylori status. These results did not differ when acid output was expressed as mmol/h/kg lean body mass or mmol/h/kg fat free body weight. Using multiple linear regression analysis, gastritis with atrophy was the only factor that had an independent negative effect on acid secretion. In healthy men without atrophy, gastric acid secretion is preserved with ageing and is independent of H pylori status. Atrophy, which is closely related to H pylori infection, is associated with a decline in acid secretion. Increased basal serum gastrin is related to both atrophy and H pylori infection but not to ageing per se.
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PMID:Effect of age, Helicobacter pylori infection, and gastritis with atrophy on serum gastrin and gastric acid secretion in healthy men. 817 48

One hundred and ninety-six symptomatic Saudi patients with dyspepsia underwent gastroscopy, and multiple biopsies were taken from the antrum of the stomach for identification of Helicobacter pylori. Three methods were studied for diagnosis of Helicobacter pylori, including urease test, culture and histopathology. The commonest gastroscopic findings were gastritis in 82 patients (41.84%) and duodenal ulcer in 40 patients (20.41%). Among the 196 patients, Helicobacter pylori was identified by histopathology in 145 patients (73.98%), the urease test was positive in 126 patients (64.29%), and a positive culture was obtained in 102 patients (52.04%). These results show that there is a high incidence of Helicobacter infection among Saudi patients with peptic ulcer disease or non-ulcer dyspepsia. Helicobacter pylori identification was more successful by histopathology than by the urease test or culture.
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PMID:Helicobacter pylori: incidence and comparison of three diagnostic methods in 196 Saudi patients with dyspepsia. 817 15

An immunoblot method has been evaluated to diagnose Helicobacter pylori infection serologically by comparing 69 serum specimens from patients with a positive Gram stain and/or culture result and a positive urease test on biopsy material, as well as 51 serum specimens from patients with at least 4 negative urease tests, and negative microscopy and culture results. Sensitivity and specificity was found to be 100%. Recognition of the cross-reacting flagellin (66 kDa), flagellar sheath protein (51 kDa), and a 14 kDa protein are not a criterion for a current H. pylori infection. On the other hand, any combination of at least two of the 180, 120, 90, 75, 67, 29.5 and 19 kDa bands were diagnostic of infection. Three H. pylori strains, which were compared with both gel electrophoretic analyses and immunoblot reactivity, exhibited in part strong qualitative and quantitative differences that particularly affect the 120 kDa pathogenic factor, the large urease subunit and other proteins especially in the molecular mass range from 50 to 67 kDa. IgG immunoblot patterns showed that the choice of H. pylori strain, as well as a reproducible and standardizable antigen preparation, is of great importance for the reliability of serodiagnostic tests. The immunoblot method was found to be a valuable tool for the semi-quantitative confirmation of results achieved with other serological methods as well as optimization and quality control of the antigens used for serodiagnostic purposes.
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PMID:Humoral immune response against Helicobacter pylori as determined by immunoblot. 822 5

Helicobacter pylori infection is found world-wide although the epidemiology of infection has not been well defined in many geographical areas. The aims of this study were to determine the prevalence of H. pylori infection and chronic gastritis and the demographic correlates of infection in a single racial group in southern India. The sample population was selected randomly from the male population register of a Tibetan refugee settlement. Demographic data and results of endoscopy with antral mucosal biopsy were evaluated in 197 subjects (median age 28, range 21-81 years). H. pylori was present in 77.2% of subjects by histology and/or urease test. Chronic gastritis and H. pylori were closely related and there was an association between the number of bacteria present and the severity of the gastritis (P < 0.04). Infection with H. pylori was inversely associated with socio-economic factors, specifically educational level (P < 0.02) and occupation (P < 0.02). Unlike other studies, the prevalence of H. pylori was not found to rise with age, being lower in those older than 40 years (P < 0.005). This difference was still apparent when adjusted for socio-economic status. The major demographic difference between younger and older subjects of low socio-economic status was the greater proportion of early life spent outside India (and in Tibet) by older subjects. Among younger subjects, residence in India for 20 years or more was associated with a greater risk of H. pylori infection (P < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:An evaluation of factors affecting Helicobacter pylori prevalence in Tibetans exiled in India. 824 63

The authors review recent progresses made in the understanding of the disturbed gastrin homeostasis in Helicobacter pylori infection and in pernicious anaemia. Regulation of gastrin release in a complex mechanism involving inhibition by a low gastric pH and several peptides including somatostatin, and stimulation by different factors, mainly alimentary peptides and amino-acids. The hypergastrinaemia observed in patients with Helicobacter pylori infection occurs despite a normal intraluminal pH. This may be through alkalinisation of the gastric mucus layer due to the production of ammonia by the bacterial urease or through local release of inflammatory mediators. In pernicious anaemia a factor present in the antacid gastric juice could explain the important hypergastrinaemia observed. The gastrin releasing activity of the gastric juice itself was demonstrated by a decrease of the patients' plasma gastrin concentration during a neutral gastric lavage and by a rise of the gastrin levels in rats whose stomachs were perfused with gastric juice from pernicious anaemia patients. A better understanding of the relation between gastric pH and gastrin release is important not only for these pathological states but also for treatments which suppress acid secretion.
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PMID:[Mechanisms in hypergastrinemia in autoimmune atrophic gastritis and Helicobacter pylori infection]. 826 64

A sensitive and specific serological diagnostic test for Helicobacter pylori infection has been developed and validated in 120 patients with dyspeptic symptoms undergoing endoscopy. This test is to use urease, a protein unique to H. pylori, as the basis for the enzyme linked immunosorbent assay (ELISA) that detects serum H. pylori urease antibodies. The ELISA mean optical density (OD) in H. pylori-positive group is higher than that in H. pylori-negative group (0.57 +/- 0.23 vs 0.24 +/- 0.15, P < 0.001), a cut-off 0.3 OD yields a sensitivity of 95% and a specificity of 93%. Serum absorption test showed that Escherichia coli, Klebsiella pneumonia, Proteus mirabilis, Yersinia enterocolotica, Pseudomonas aeruginosa cell lysate do not influence serum H. pylori urease antibody level, though they all have urease except E. coli. The result implied that H. pylori urease can be a good antigen to detect serum H. pylori antibody and it would be useful for epidemiological survey and routine diagnostic approach. Nearly half of the blood donors showed positive result with H. pylori urease antibody. It is suggested that H. pylori infection is quite common in the asymptomatic population.
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PMID:[An urease enzyme linked immunosorbent assay for detection of Helicobacter pylori infection]. 826 56

One hundred consecutive patients with Helicobacter pylori infection, as proven by culture, were treated with 120 mg colloidal bismuth subcitrate (CBS) four times daily, 250 mg tetracycline four times daily, and 250 mg metronidazole four times daily during 15 days. The patients were amply instructed in how to take the medicine and strongly urged to complete the prescribed course. In 66 of the 100 patients pretreatment metronidazole susceptibility was determined. Endoscopy was performed 3 months after cessation of treatment to check for H. pylori eradication by culture, urease testing, and histology. Side effects of the treatment were registered and classified into five groups on the basis of severity. Eradication was achieved in 93 of 100 patients (93%), in 61 of 62 patients with a metronidazole-sensitive strain (98.4%), and in 2 of 4 patients with a metronidazole-resistant strain (50%). Eighty-two per cent of the patients experienced no or just minor side effects; 15% had moderate side effects, and just 3% had severe side effects. Non-ulcer dyspepsia patients reported significantly more side effects than patients with peptic ulcer disease. With proper patient instruction, this treatment regimen is well tolerated and very effective for the eradication of metronidazole-sensitive H. pylori strains.
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PMID:Efficacy and side effects of a triple drug regimen for the eradication of Helicobacter pylori. 828 26


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