Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0024623 (gastric cancer)
 36,219 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The finding of II pylori in the gastric mucosa has changed the understanding of the pathogenesis of common diseases of the stomach and duodenum. The bacteria causes acute and chronic gastritis and is the precursor of peptic ulcers, gastric lymphoma and gastric cancer. The most common test used to diagnose the infection is the urease test on a gastric biopsy but an endoscopy must be performed to obtain the biopsy. Determination of serum levels of IgG appears the most suitable test to perform in large population studies. Patients with peptic ulcers, gastric lymphoma and early gastric cancer should be treated. Combinations of antibiotics such as amoxicillin, chlarithromycin and a proton pump inhibitor have yielded the best results in irradicating H pylori. Unfortunately this therapy is expensive and new combinations should be explored. Vaccination should be the treatment of choice for prevention and irradication in countries like Chile with high infection rate. Preliminary results are encouraging.
 ...
PMID:[Helicobacter pylori. The bacteriological revolution]. 1075 48

Free radicals (FRs) play an important role in the pathogenesis of gastroduodenal mucosal inflammation, peptic ulcer disease, and probably even gastric cancer. Various micronutrients protect the gastric mucosa by scavenging FRs. Only limited data is available regarding the concentration of micronutrients in the gastric mucosa in patients with gastritis and peptic ulcer disease. Our aim was to analyze micronutrient antioxidant concentrations in the antral mucosa in patients with gastritis and gastric ulcer and to determine the influence of Helicobacter pylori infection on gastric mucosal antioxidants in patients with gastritis and gastric ulcer. Patients who underwent upper endoscopy for evaluation of dyspepsia were included in the study. Ascorbic acid, alpha-tocopherol, alpha-carotene, beta-carotene, total carotenoids, lutein, cryptoxanthin, and lycopene levels were measured in the sera and antral mucosal biopsies in these patients. The diagnosis of H. pylori was confirmed by histology, urease test (CLO) and serology. Patients with negative endoscopic findings and normal histology and no H. pylori infection served as controls. In patients with gastritis, alpha-tocopherol levels were reduced in serum and mucosa irrespective of H. pylori status, whereas carotenoids and ascorbic acid levels were similar to controls. However, in patients with gastric ulcer, serum and mucosal levels of all micronutrient antioxidants were markedly decreased compared with both controls and patients with gastritis. The degree of depletion of antioxidants was similar in patients with either H. pylori-induced or nonsteroidal antiinflammatory drug (NSAID)-induced ulcers. Patients with gastric ulcer have very low gastric antioxidant concentrations compared to patients with gastritis and normal mucosa. This depletion in antioxidants seems to be a nonspecific response and was not related to H. pylori infection.
 ...
PMID:Micronutrient antioxidants in gastric mucosa and serum in patients with gastritis and gastric ulcer: does Helicobacter pylori infection affect the mucosal levels? 1115 82

The Working Party Report on the Management of Helicobacter pylori serves as a clinical practice guideline for Malaysian doctors. H. pylori is not uncommon in the Malaysian population. Marked racial differences and the consistently low prevalence rates amongst Malays are noted. The working party recommends that if endoscopy is to be performed, a rapid urease test should be used for diagnosis. Where suspicion of the infection is strong and the urease test is negative, histology should be performed on gastric biopsies. Culture should be used to monitor resistance patterns to antibiotics and regional laboratories should assume this responsibility. The urea breath tests are highly accurate tests for diagnosis of H. pylori but is as yet not widely available in Malaysia. The working party strongly recommends that all peptic ulcer patients infected with H. pylori whether active, in remission and complicated ulcers should be treated for the infection. Patients with low-grade gastric mucosal lymphoid tissue lymphoma should also be treated for H. pylori infection. It is considered advisable that patients on long term nonsteroidal antinflammatory drug (NSAID) treatment with a history of peptic ulcers or dyspepsia and patients following resection of early gastric cancer or those with a family history of gastric cancer should also be tested and treated for H. pylori. The working party recommends, as first line treatment a 7-day combination therapy of a proton pump inhibitor, clarithromycin and metronidazole or amoxicillin. High metronidazole resistance rates locally may adversely affect regimens containing the antibiotic. It should also be noted that regimens that yield lower eradication rates may result in higher long term expenditure.
 ...
PMID:Management of Helicobacter pylori infection--a Working Party Report of the Malaysian Society of Gastroenterology and Hepatology. 1096 73

Hypochlorous acid, which is one of the reactive oxgen species (ROS) produced from human neutrophils, is converted to cytotoxic NH(2)Cl after reaction with ammonia produced by urease in Helicobacter pylori (HP), increasing gastric mucosal injury and with potential development to gastric cancer. We compared the effects of HP on the production of ROS by human neutrophils between two groups-22 patients with gastric cancer and 16 patients without gastric cancer (control group), in whom HP was isolated from stomach biopsy tissues-using a luminol- and lucigenin-dependent chemiluminescence (LmCL and LgCL, respectively). It was very similar in the mean value or variance of mean maximal chemiluminescence intensities (MCI) and peak time in LmCL and LgCL between the two groups. MCI of LmCL was highly correlated with that of LgCL in both groups. These results indicate that there were no differences in the behaviour of HP on human neutrophil chemiluminescence between two groups. The progression from non-malignant mucosa to cancer may be associated with the time-dependent effects of HP via ROS produced by neutrophils on the gastric mucosa.
 ...
PMID:Effects of Helicobacter pylori in the stomach on neutrophil chemiluminescence in patients with gastric cancer. 1103 83

Helicobacter pylori infection is common in Jamaica. Describing its epidemiology in a population-based study depends largely on serology, but serologic assays have not been validated in this population. To address this issue, we examined the presence of H. pylori infection in 30 sequential adult patients with gastroduodenal symptoms by three biopsy-based methods (rapid urease test, histology, and culture) as well as by one research and two commercial enzyme-linked immunosorbent assays (ELISAs). A patient was considered H. pylori positive if the organism was detected by at least one biopsy-based method. Eighteen (60%) of the 30 patients were H. pylori positive by these criteria, whereas 21 (70%) were seropositive for H. pylori immunoglobulin G by our research ELISA. The presence of H. pylori infection in patients with gastric cancer and those with chronic gastritis was missed by biopsy-based methods but was detected by serologic assays. This observation indicates that serologic assays may be better suited for the detection of this infection in a population in which H. pylori-associated pathology is prevalent. The performance of our research ELISA in detecting biopsy-based H. pylori-positive cases was excellent, with a sensitivity and specificity of 100% and 75%, respectively. Molecular genotyping of the isolates revealed that the predominant H. pylori genotypes in this cohort of Jamaicans were cagA(+) vacA slb-m1, and iceA2. The validated serologic assay enables us to interpret epidemiologic data from population-based studies in Jamaica by comparison to those from other populations.
 ...
PMID:Characteristics of Helicobacter pylori infection in Jamaican adults with gastrointestinal symptoms. 1113 73

Serologic testing is a useful noninvasive testing strategy for H. pylori. It is particularly useful in areas where the prevalence of H. pylori is high and inexpensive point-of-contact fingerprick tests are used. Sensitive tests are valuable ways of excluding H. pylori infection and can be used in conjunction with a direct test (urease histology culture or breath test) to confirm absence of H. pylori if the two methods are concordant. Serologic testing is more definitive and differentiating if the antigenic epitopes of H. pylori can be differentiated based on the antigenic epitopes that specifically associate with gastric cancer, peptic ulcer, and nonulcer dyspepsia. A study by Kawahara's group reported that Hsp 60 may be involved in the development of mucosa-associated lymphoid tissue based on ELISA. The idea of differentiating antigens for H. pylori may open a new area for use of serologic testing in the diagnostic approach of H. pylori infections.
 ...
PMID:Accurate diagnosis of Helicobacter pylori. Serologic testing. 1119 69

Gastric colonization by Helicobacter pylori is a risk factor for noncardia gastric cancer. The association between H. pylori and cancer may be attributable to increased epithelial cell turnover, possibly related to antigastric antibodies. Two previous studies reported a disproportionate increase in proliferation relative to apoptosis in patients with H. pylori strains expressing the virulence-related cagA gene. This has led to the hypothesis that an abrogation of apoptosis by cagA-positive strains may promote neoplasia. We, therefore, examined the effect of H. pylori on gastric epithelial proliferation, apoptosis, and the presence of serum antiparietal cell antibodies in a large prospective study. Proliferation and apoptosis were evaluated "blindly" using validated immunohistochemical methods in two antral and two gastric corpus biopsies from 60 patients with nonulcer dyspepsia, and results were correlated with the presence of serum antiparietal cell antibodies. H. pylori colonization was assessed by histology, biopsy urease test, and serology. Proliferation was increased 2-fold in both antrum and corpus in H. pylori-positive patients, was not related to H. pylori cagA status, and was positively correlated with histological gastritis. Apoptosis was increased in the antrum and body only in patients with cagA-positive H. pylori strains. Antiparietal cell antibodies were not more prevalent in H. pylori colonization, and their presence was inversely related to epithelial apoptosis scores we therefore conclude that in patients with nonulcer dyspepsia, H. pylori carriage is associated with increased proliferation. Futhermore the cag pathogenicity island is associated with increased apoptosis. Our results do not support the hypothesis that there is a relative deficiency of gastric epithelial cell apoptosis associated with the carriage of cagA-positive strains. Host factors may be more important than bacterial products in determining the long-term outcome of H. pylori colonization.
 ...
PMID:Increased gastric epithelial cell apoptosis associated with colonization with cagA + Helicobacter pylori strains. 1124 42

An increased risk for gastric cancer in patients with liver cirrhosis has recently been reported. This study was performed in order to determine gastric epithelial cell proliferation in cirrhotic patients and to evaluate the role of congestive gastropathy (CG) and Helicobacter pylori infection in this process. Thirty-six cirrhotic patients and 18 controls were enrolled in the study. All patients underwent endoscopy and three biopsies were performed in the antrum and three in the gastric body. The presence of H. pylori infection was assessed by a rapid urease test and histology. The antral biopsies were used for gastric cell proliferation assessment by an immunohistochemical analysis (Ki-67). There was no significant difference in epithelial cell proliferation between cirrhotics and controls. Gastric proliferation values were higher in patients with H. pylori infection compared with uninfected patients, both in cirrhotic (P = 0.003) and in control groups (P = 0.06). Among the cirrhotic group, we found a progressive increase in gastric cell proliferation values related to the degree of CG, the highest values being observed in cirrhotic patients with severe CG. Moreover, cirrhotics with both severe CG and H. pylori infection had the highest proliferation values when compared with all other subgroups. In conclusion, this study found that: (1) CG significantly affects epithelial cell proliferation in gastric mucosa in cirrhotic patients, (2) H. pylori infection plays a similar role in gastric cell proliferation in both cirrhotic and non-cirrhotic patients, and (3) CG and H. pylori could act synergistically in this process.
 ...
PMID:Gastric epithelial cell proliferation in patients with liver cirrhosis. 1131 31

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.
 ...
PMID:Helicobacter pylori: recent advances in the study of its pathogenicity and prevention. 1145 1

Considering a suspected link between Helicobacter pylori infection and human stomach cancer, a new H. pylori gene for membrane protein 1 (HP-MP1) was recently cloned. Because HP-MP1 induces release of inflammatory cytokines and tumor necrosis factor-alpha acts as both initiator and tumor promoter, we studied the possible involvement of HP-MP1 in carcinogenesis of H. pylori. Two cell lines, BALB/3T3 cells as control and v-Ha-ras-transfected BALB/3T3 cells (Bhas 42 cells) as putative initiated cells, were each transfected with HP-MP1, urease B genes, or vector alone. All of the Bhas/mpl clones showed strong expression of tumor necrosis factor-alpha gene and produced tumors in 100% of nude mice. Two Bhas/ure clones showed weak tumorigenicity; the other Bhas and BALB clones showed none. Results indicate strong carcinogenic activity of HP-MP1 in cooperation with viral Ras protein and weak activity of urease B.
 ...
PMID:Helicobacter pylori membrane protein 1: a new carcinogenic factor of Helicobacter pylori. 1152 25


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>