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)

Oxidative DNA damage is thought to play an important part in the pathogenesis of H. pylori-induced mucosal damage. 8-OHdG is a sensitive marker of DNA oxidation and is repaired by a polymorphic glycosylase (OGG1) more effectively than by OGG1-Cys(326). The aims of this study were to ascertain the respective roles of H. pylori, cagA status and OGG1 polymorphism in determining 8-OHdG levels in benign and premalignant stomach diseases and in gastric cancer (GC). The study involved 50 GC patients (for whom both neoplastic tissue and surrounding mucosa were available), 35 with intestinal metaplasia and atrophy (IMA) and 43 controls. H. pylori and cagA status were determined by histology and polymerase chain reaction for urease and cagA. 8-OHdG was assayed using HPLC with an electrochemical detector (HPLC-ED). The OGG1 1245C-->G transversion was identified using RFLP analyses. 8-OHdG levels were significantly higher in GC, with no differences in relation to H. pylori or cagA status. OGG1 polymorphism was documented in 34% of GC (15 Ser/Cys, 2 Cys/Cys). OGG1 1245C-->G polymorphism was detected in 54% of IMA patients, but only 16% of controls (p = 0.0004) and coincided with significantly higher 8-OHdG levels. In the multivariate analysis, 8-OHdG levels were predicted by histotype and OGG1 status. OGG1 1245C-->G polymorphism was common in both GC and IMA, but very rare in controls, and correlated more closely with 8-OHdG levels than do H. pylori infection or cagA status.
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PMID:Oxidative DNA damage in gastric cancer: CagA status and OGG1 gene polymorphism. 1836 59

The effect of high salt environments on biological characteristics of Helicobacter pylori is still unclear. In the present study, we therefore investigated biological characteristics of the bacterium exposed to high salt concentrations. H. pylori strain, L301, was cultured in media supplemented with different concentrations (3%, 15% and 30%) of sodium chloride (NaCl) under microaerophilic conditions for 48 h. Morphology was assessed by light microscopy, the ATP content was quantitated by single-tube fluorescent light-emission and the levels of CagA and UreB proteins were determined by Western blotting. After exposure to NaCl, H. pylori transformed from common spiral shape to U or even coccoid shapes. The ATP content was significantly higher in 30% NaCl group than in 15% and 3% NaCl group and the level of CagA protein increased with the salt concentration. The urease reaction was all strongly positive in H. pylori exposed to different salt concentrations. The level of 8-OHdG expression was significantly increased in GES-1 cells co-cultured with H. pylori exposed to high salt, compared with the level in uninfected cells. H. pylori survives under exposure to high salt concentrations up to 30%, exhibiting changes in mobility, morphology and CagA expression, associated with increased 8-OHdG in the gastric epithelial cells, indicative of DNA damage.
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PMID:Changes in biological and virulent characteristics of Helicobacter pylori exposed to high salt. 2232 Sep 66

Helicobacter Pylori infection is a common gastrointestinal infection that can cause pathological effects, increase oxidative stress and induce an inflammatory response in gastric mucosa. Inflammatory aspects may prompt the production of radical oxygen substance (ROS) which may damage cells and release 8-hydroxydyoxyguanosine (8-OHdG) to serum. In this study, we evaluate the prevalence of H. pylori virulence factors and the association between serum level of 8-OHdG, H. pylori infection, and its various virulence factors. The presence of H. pylori and prevalence of cagA, babA and oipA genes in samples were determined by rapid urease test (RUT), histopathological exam (HE) and polymerase chain reaction (PCR) and oxidative DNA damage situation were assessed by using serum level of 8-OHdG. There was not any direct relation between H. pylori negative and H. pylori oipA+specimens by 8-OHdG serum level (P>0.05). In all clinical observations, the presence of cagA and oipA genes was common. There was a statistical relationship between the presence of cagA, babA factors, and high serum level of 8-OHdG (P<0.05). The presence of cagA and babA virulence factors may be associated with increased serum 8-OHdG in dyspeptic patients and may induce the damage to gastric cells.
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PMID:Helicobacter pylori and Its Virulence Factors' Effect on Serum Oxidative DNA Damages in Adults With Dyspepsia. 2803 92