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:6.3.4.6 (urease)
7,490 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

With the increasing recognition of the importance of H. pylori in gastrointestinal disease, there is a need for a reliable, efficient and yet inexpensive diagnostic test. The performance of the rapid urease test (RUT) as an endoscopy suite diagnostic test was compared to the established methods of culture, histology and Gram stain of tissue smear, in 274 gastric biopsy samples. Histology had the highest sensitivity of 99.3% followed by the RUT (96.6%). Culture and Gram stain of tissue smear had 100% specificity, while the rapid urease test had 99.2% specificity. The RUT had a positive predictive value of 99.3% and a negative predictive value of 96.2%. The RUT is an inexpensive, rapid and reliable diagnostic test of H. pylori infection.
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PMID:The rapid urease test in the diagnosis of Helicobacter pylori infection. 793 11

The bacterial genus Helicobacter contains a number of species which colonize the gastric mucosa of mammals. Natural and/or experimental gastric pathology has been correlated with colonization in humans and a wide variety of animal species. Historical reports in the literature suggest that a high percentage of cats are colonized by large, spiral, gastric helicobacter-like organisms (GHLOs). One of these bacteria (Helicobacter felis) has been isolated on artificial media and has experimentally caused gastritis in gnotobiotic dogs. This study surveyed the prevalence of helicobacter colonization in random-source cats by using the urease assay. Histologic examination was performed to determine the degree of associated pathology present. GHLOs associated with chronic gastritis were present in 70% of the juvenile and 97% of the adult cats studied. Although further study is needed to determine specifically what role GHLOs play in feline gastrointestinal disease, these results indicate that helicobacter colonization should be considered in the pathogenesis of feline gastroenteropathy. Furthermore, the high prevalence of feline infection is interesting because cats have recently been implicated as a potential reservoir for human infection by helicobacter-like organisms.
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PMID:Animal and public health implications of gastric colonization of cats by Helicobacter-like organisms. 802 8

CURRENT DIAGNOSTIC METHODS: Helicobacter pylori infection plays a central role in the pathophysiology of gastrointestinal disease, and its accurate diagnosis and successful eradication is crucial in a wide range of different circumstances. Currently, serology is recommended for initial screening, followed by histology and/or culture to confirm the diagnosis before treatment. Since H. pylori is developing greater resistance to certain antibiotics, culture is becoming increasingly important in some populations to test for susceptibility to antibiotics. To confirm eradication after treatment, the urea breath test is used. This test is presently the best non-invasive test to determine eradication. NEW APPROACHES: Considerable efforts are being made to improve diagnostic methods, and a host of new or improved approaches can be expected in the near future. For general screening, tests are being developed that use whole blood and can be used by general practitioners to give rapid results in a cost-effective manner. The evidence so far suggests that these new 'office' tests are not as accurate as laboratory tests, but they are nevertheless important for general diagnostic purposes. Serological tests for cagA antibodies and immunoblot tests are also under development. New biopsy-based tests include the development of a true rapid urease test which will give accurate results in 1 h. Polymerase chain reaction/DNA enzyme immunoassay detection is another field receiving attention. Non-invasive direct tests of the future are likely to include the use of the polymerase chain reaction in faeces. This paper reviews current diagnostic modalities for H. pylori and gives an overview of expected future developments.
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PMID:The most important diagnostic modalities for Helicobacter pylori, now and in the future. 2249 1

Kings County Hospital (KCH), and St. John's Episcopal Hospital (SJH) are inner-city hospitals in New York City serving predominantly minority populations. Staten Island University Hospital (SIUH) serves a predominantly middle-class Caucasian population. We examined H. pylori (HP) infection in patients undergoing upper endoscopy at these hospitals. Two gastric biopsies were obtained from each patient. One biopsy was examined by histology or the rapid urease test for the presence of HP. The other was subjected to analysis by PCR to detect HP DNA and to identify putative HP virulence factors. Of 200 subjects, 54% were African-American, 10% were Hispanic, and 36% were Caucasian. HP infection rates in African-American, Hispanic, and Caucasian patients were 43%, 20%, and 11%, respectively. Many of the African-American patients are recent immigrants from the Caribbean Islands. In these patients, an inverse relationship was observed between HP infection and the number of years living in the United States. Higher levels of HP infection were observed in patients with duodenitis and peptic ulcer disease. With respect to HP virulence factors, the vacA s1b and m1 alleles, as well as the iceA2 allele were the predominant alleles expressed in HP-positive samples obtained from African-Americans. The cagA gene was detected in 81% of HP-positive samples. However, CagA positivity was not related to any specific gastrointestinal disorder. Our findings indicate that among several ethnic groups served by three hospitals, African-American patients have the highest rate of HP infection. Moreover, in AfricanAmerican patients undergoing endoscopy: (1) HP infection was inversely related to the number of years the patients have been living in the USA; (2) HP infection rates were higher in patients diagnosed with duodenitis and peptic ulcer disease versus other disorders; (3) expression of the CagA gene was not associated with any specific gastroduodenal disorder; and (4) there was little allelic heterogeneity with respect to VacA and IceA subtypes. These findings suggest that inner-city African-Americans are more likely to be infected with HP and suffer from more serious gastroduodenal disorders than other ethnic groups.
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PMID:H. pylori infection and genotyping in patients undergoing upper endoscopy at inner city hospitals. 1214 19

Ureases are enzymes from plants, fungi and bacteria that catalyze the hydrolysis of urea to form ammonia and carbon dioxide. While fungal and plant ureases are homo-oligomers of 90-kDa subunits, bacterial ureases are multimers of two or three subunit complexes. We showed that some isoforms of jack bean urease, canatoxin and the classical urease, bind to glycoconjugates and induce platelet aggregation. Canatoxin also promotes release of histamine from mast cells, insulin from pancreatic cells and neurotransmitters from brain synaptosomes. In vivo it induces rat paw edema and neutrophil chemotaxis. These effects are independent of ureolytic activity and require activation of eicosanoid metabolism and calcium channels. Helicobacter pylori, a Gram-negative bacterium that colonizes the human stomach mucosa, causes gastric ulcers and cancer by a mechanism that is not understood. H. pylori produces factors that damage gastric epithelial cells, such as the vacuolating cytotoxin VacA, the cytotoxin-associated protein CagA, and a urease (up to 10% of bacterial protein) that neutralizes the acidic medium permitting its survival in the stomach. H. pylori whole cells or extracts of its water-soluble proteins promote inflammation, activate neutrophils and induce the release of cytokines. In this paper we review data from the literature suggesting that H. pylori urease displays many of the biological activities observed for jack bean ureases and show that bacterial ureases have a secretagogue effect modulated by eicosanoid metabolites through lipoxygenase pathways. These findings could be relevant to the elucidation of the role of urease in the pathogenesis of the gastrointestinal disease caused by H. pylori.
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PMID:Ureases display biological effects independent of enzymatic activity: is there a connection to diseases caused by urease-producing bacteria? 1686 75

In the last decade, scientific studies in the field of children's gastroenterology performed in Lithuania explored different problems: pathology of Helicobacter pylori infection and food allergy. Our studies revealed that children with atopic dermatitis had gastrointestinal complaints (abdominal pain, diarrhea, distension and unstable stool, which appeared with the exacerbation of skin rash) more often as compared to nonallergic children of the control group. Abdominal pain in children with atopic dermatitis with local rash was more frequent and lasted longer than in control group children, whereas children with extended rash had stools more frequently. Gastrointestinal disorders in children with atopic dermatitis statistically significantly did not depend on the extent of skin rash and severity of atopic dermatitis. In our scientific research on the importance of H. pylori infection on children's gastrointestinal system, children with chronic dyspepsia were examined. Endoscopy, rapid urease test, biopsies from antrum and corpus of stomach and their histological examination as well as serologic tests were done. According to the results obtained, we recommend to examine children with chronic dyspepsia in a complex way: not only endoscopic examination, but H. pylori diagnostic tests should be performed as well. Serologic test is not suitable for screening H. pylori infection in children. Considering this, we recommend to use no fewer than two different methods to diagnose this infection. The highest frequency of H. pylori infection was found in children with duodenal ulcer; histological changes in their gastric pylorus and corpus mucosa were greatest. More than half of children with nonulcer dyspepsia were infected with H. pylori. After eradication of H. pylori infection, the prevalence of dyspepsia in children with duodenal ulcer decreased.
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PMID:[Relevance of examination and treatment of the most common gastrointestinal disorders in children in Lithuania during the last decade]. 1827 92

Despite elegant regulatory mechanisms, iron deficiency anemia (IDA) remains one of the most common nutritional deficiencies of mankind. Iron deficiency is the result of an interplay between increased host requirements, limited external supply, and increased blood loss. When related to increased physiologic needs associated with normal development, iron deficiency is designated physiologic or nutritional. By contrast, pathological iron deficiency, with the exception of gross menorrhagia, is most often the result of gastrointestinal disease associated with abnormal blood loss or malabsorption. If gastroenterologic evaluation fails to disclose a likely cause of IDA, or in patients refractory to oral iron treatment, screening for celiac disease (anti-tissue transglutaminase antibodies), autoimmune gastritis (gastrin, anti-parietal or anti-intrinsic factor antibodies), and Helicobacter pylori (IgG antibodies and urease breath test) is recommended. Recent studies indicate that 20-27% of patients with unexplained IDA have autoimmune gastritis, about 50% have evidence of active H. pylori infection, and 4-6% have celiac disease. The implications for abnormal iron absorption of celiac disease or autoimmune gastritis are obvious. In patients with unexplained IDA and H. pylori infection, cure of refractory IDA by H. pylori eradication offers strong evidence for a cause-and-effect relation between H. pylori infection and unexplained IDA. Stratification by age cohorts in autoimmune gastritis implies a disease presenting as IDA many years before the establishment of clinical cobalamin deficiency. It is likely caused by an autoimmune process triggered by antigenic mimicry between H. pylori epitopes and major autoantigens of the gastric mucosa. Recognition of the respective roles of H. pylori and autoimmune gastritis in the pathogenesis of iron deficiency may have a strong impact on the diagnostic workup and management of unexplained, or refractory IDA.
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PMID:Iron deficiency, Helicobacter infection and gastritis. 1990 46

CURRENT DIAGNOSTIC METHODS: Helicobacter pylori infection plays a central role in the pathophysiology of gastrointestinal disease, and its accurate diagnosis and successful eradication is crucial in a wide range of different circumstances. Currently, serology is recommended for initial screening, followed by histology and/or culture to confirm the diagnosis before treatment. Since H. pylori is developing greater resistance to certain antibiotics, culture is becoming increasingly important in some populations to test for susceptibility to antibiotics. To confirm eradication after treatment, the urea breath test is used. This test is presently the best non-invasive test to determine eradication. NEW APPROACHES: Considerable efforts are being made to improve diagnostic methods, and a host of new or improved approaches can be expected in the near future. For general screening, tests are being developed that use whole blood and can be used by general practitioners to give rapid results in a cost-effective manner. The evidence so far suggests that these new 'office' tests are not as accurate as laboratory tests, but they are nevertheless important for general diagnostic purposes. Serological tests for cagA antibodies and immunoblot tests are also under development. New biopsy-based tests include the development of a true rapid urease test which will give accurate results in 1 h. Polymerase chain reaction/DNA enzyme immunoassay detection is another field receiving attention. Non-invasive direct tests of the future are likely to include the use of the polymerase chain reaction in faeces. This paper reviews current diagnostic modalities for H. pylori and gives an overview of expected future developments.
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PMID:The most important diagnostic modalities for Helicobacter pylori, now and in the future. 916 Feb 11

Purpose-bred common marmosets from domestic sources housed in a US research facility, and used in multiple drug discovery programmes, were noted to have a high incidence of spontaneous inflammatory bowel disease and sporadic cholecystitis and cholangiohepatitis. Inflammatory infiltrates increased in incidence and severity with age. Because Helicobacter spp. have been linked to gastrointestinal diseases, samples from the gastrointestinal tracts of 39 marmosets were screened for Helicobacter spp. by culture and PCR. Helicobacter spp. were frequently detected in marmosets; 28.2% of the marmosets were positive for a proposed novel species, Helicobacter jaachi sp. nov., by culture, and 48.7% were positive by Helicobacter genus-specific PCR. Seventeen strains of Helicobacter sp. from 11 marmosets were cultured from various gastrointestinal sites. Older animals (age 6-11 years) had a higher helicobacter prevalence rate (57.1%) compared with younger animals (age 3-5 years), which had a 27.2% prevalence rate. Cells of H. jaachi sp. nov. were catalase, urease and oxidase positive and had fusiform morphology, with periplasmic fibres and multiple bipolar, sheathed flagella. All isolates had similar 16S and 23S rRNA sequences, which clustered as representatives of a novel Helicobacter species closely related to 'Helicobacter sanguini' (97%), a species isolated from cotton-top tamarins and 'Helicobacter callitrichis' (96%) isolated previously from the faeces of common marmosets. The whole genome sequence of one of the liver isolates, H. jaachi sp. nov. MIT 09-6949(T), had a 1.9 Mb genome length with a 41 mol% DNA G+C content. The type strain of Helicobacter jaachi sp. nov., MIT 09-6949(T), has been deposited in the BCCM/LMG Bacteria Collection as LMG 28613(T). These findings add to the increasing number of animal species with gastrointestinal disease in which novel enterohepatic Helicobacter spp. have been isolated.
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PMID:Isolation and characterization of a novel Helicobacter species, Helicobacter jaachi sp. nov., from common marmosets (Callithrix jaachus). 2629 46

An 85-year-old woman was admitted to our hospital because of progressive hypoproteinemia and generalised oedema. Technetium-99m human albumin scintigraphy revealed protein leakage in the gastrointestinal tract. Upper gastrointestinal endoscopy revealed small whitish nodules from the gastric body up to the duodenal bulb. The urease test for Helicobacter pylori infection was positive. We diagnosed her as having protein-losing gastroenteropathy (PLGE) caused by H. pylori infection. The patient's hypoproteinemia and clinical symptoms promptly resolved after H. pylori eradication. Our results suggest that a trial of H. pylori eradication is warranted in patients with PLGE, even if endoscopy reveals neither giant rugal folds, erosion of the mucosa, nor polyposis, which are previously reported characteristic endoscopic findings of PLGE.
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PMID:Protein losing gastroenteropathy due to Helicobacter pylori infection without giant rugal folds, erosion or polyposis. 3174 54


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