Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:6.3.4.6 (urease)
 7,490 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Infection with Helicobacter pylori strains containing the cag Pathogenicity Island (cag PAI) is strongly correlated with the development of severe gastric disease, including gastric and duodenal ulceration, mucosa-associated lymphoid tissue lymphoma, and gastric carcinoma. Although in vitro studies have demonstrated that the expression of genes within the cag PAI leads to the activation of a strong host inflammatory response, the functions of most cag gene products and how they work in concert to promote an immunological response are unknown. We developed a transcriptional reporter that utilizes urease activity and in which nine putative regulatory sequences from the cag PAI were fused to the H. pylori ureB gene. These fusions were introduced in single copies onto the H. pylori chromosome without disruption of the cag PAI. Our analysis indicated that while each regulatory region confers a reproducible amount of promoter activity under laboratory conditions, they differ widely in levels of expression. Transcription initiating upstream of cag15 and upstream of cag21 is induced when the respective fusion strains are cocultured with an epithelial cell monolayer. Results of mouse colonization experiments with an H. pylori strain carrying the cag15-ureB fusion suggested that this putative regulatory region appears to be induced in vivo, demonstrating the importance of the urease reporter as a significant development toward identifying in vivo-induced gene expression in H. pylori.
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PMID:Differential gene expression from two transcriptional units in the cag pathogenicity island of Helicobacter pylori. 1140 55

Helicobacter pylori has acquired great importance during the last two decades, after being recognized as an important pathogen that infects a great portion of the human population. This microorganism is recognized as the main causal agent of chronic gastritis and duodenal ulcers, and it is associated with the subsequent development of gastric carcinoma. The pathogenic mechanisms of H. pylori and their relation to gastric ailments have not been clearly defined. However, at present it is well established that urease, vacuolating cytotoxin VacA, and the pathogenicity island (cag PAI) gene products, are the main factors of virulence of this organism. Thus, individuals infected with strains that express these virulence factors probably develop a severe local inflammation that may induce the development of peptic ulcer and gastric cancer. The way the infection spreads throughout the world suggests the possibility that there are multiple pathways of transmission. Due to the importance that H. pylori has acquired as a human pathogen, laboratories worldwide are attempting to develop a vaccine that confers long-term immunological protection against infection by this microorganism. Hence, the objective of this review is to present the most relevant findings of the biology of H. Pylori and its interaction with the human host.
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PMID:Helicobacter pylori: recent advances in the study of its pathogenicity and prevention. 1145 1

Hp diagnostic is made by invasive methods using gastric biopsy of antrum, for culture and histological study. Non invasive are serology and urea breath test. 152 Hp from 19 children's with acute gastritis (46. 1%); 9 Hp from an adult. There had ampicillin resistance, 27. 4%, claritromicin 21. 8%, metronidazol 58. 4% and tetracycline 31. 5%, the 21 % susceptible to four anti-microbial. RAPD-PCR with 4 primers gave 44 profiles, related with clinical profile. In 7 children, there were two profiles RAPD. Three were similar but different each other. AFLP 23 adults 151 Hp; cagA and vacA genotypes gave unique patterns for each patient. The genes cagA, babA and oipA, secuencing and compared with reported Hp (Genbank); gave high polymorfism. Everything indicates that there are colonization with multiple Hp strains in Mexicans. In 645 sera from 352 children: 36.9% with Hp, the 46. 9% gave him/her anti-shits and 16. 2% antibodies to urease. Adults 293 (89. 1%) with Hp, 78. 9% gave anti-CagA and 59% antibodies to urease. The expression of IL-8 was bigger in infected children that in not infected and more significant in peptic ulcer. Genomic library Cag-PAI revealed 90% (Hp) positive, they had the complete PAI, 2 were incomplete and three negatives. PCR -LiPA LiPA (LineProbe Assay) is suggestive for genotyping assays.
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PMID:[Microbiologic, serologic diagnosis, and genotypification of Helicobacter pylori isolated from biopsies in children and adult people. Molecular detection of the cag pathogenicity island of Helicobacter pylori]. 1757 80