UMLS:C0024623 - FACTA Search

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)

Helicobacter pylori is a gastric-dwelling pathogen responsible, with acid secretion, for peptic ulcer and a 20-fold increase in the risk of gastric cancer. Several transcriptomes have been described after short-term exposure to acidity in vitro, but there are no data identifying the effects of chronic gastric exposure on bacterial gene expression. Comparison of the in vivo to the in vitro transcriptome at pH 7.4 identified several groups of genes of known function that increased expression >2-fold, and three of these respond both to acidity in vitro and to gastric infection. Almost all known acid acclimation genes are highly up-regulated. These include ureA, ureB, and rocF and the pH-gated urea channel, ureI. There is also up-regulation of two groups of motility and chemotaxis genes and for pathogenicity island genes, especially cagA, a predictor for pathogenicity. Most of these genes interact with HP0166, the response element of the pH-sensing two-component histidine kinase, HP0165/HP0166, ArsRS. Based on the pH profile of survival of ureI deletion mutants in vitro and their inability to survive in gastric acidity, the habitat of the organism at the gastric surface is acidic with a pH < or = 4.0. Hence, the pH of the habitat of H. pylori on the surface of the stomach largely determines the regulation of these specific groups of genes.
...
PMID:Gene expression in vivo shows that Helicobacter pylori colonizes an acidic niche on the gastric surface. 1743 79

Helicobacter pylori is strongly associated with peptic ulcer and gastric cancer and may be the most common human bacterial infection. The epidemiology of H. pylori has been poorly studied in Africa, where its relevance to disease has not been fully appreciated. Following a cross-sectional study design, H. pylori infection was measured by (13)C-urea breath test among 857 pregnant women attending antenatal care clinics. Location, water use practices, anthropometry, and social and demographic variables were assessed as covariates. The prevalence of H. pylori infection was 17.5%. Multiple logistic regression showed that H. pylori was positively associated with location of enrollment clinic along the main road leading from the southern seaport (odds ratio (OR)=2.5), presence of costlier household lighting in the home (OR=1.6) and height (10 cm) (OR=1.5). The prevalence of H. pylori infection was unexpectedly low for a developing country population, where prevalence is typically very high. Higher prevalence along the road from the southern seaport suggests that infection was imported from the mainland. The reason for very low prevalence should be investigated further because the discovery of bacterial or dietary factors that limit infection in this population could have useful public health applications.
...
PMID:Unexpectedly low prevalence of Helicobacter pylori infection among pregnant women on Pemba Island, Zanzibar. 1867 80

Helicobacter pylori infection is a chronic gastric gram-negative infection that increases with age worldwide. However, the percentage age of H. pylori-positive elderly patients who are tested and treated for their infection remains very low. It is now demonstrated that H. pylori infection induces a whole cascade of events leading to gastric pathologies, such as peptic ulcer diseases, gastric precancerous lesions and gastric cancer. Recent data also demonstrated that H. pylori chronic infection can play a role in gastric aging, appetite regulation and extradigestive diseases, such as Alzheimer's disease, in the elderly. The diagnosis of H. pylori infection remains difficult to realize in the very old population, and the urea breath test obtains the best performance in this population. 1-week proton pump inhibitor-based triple therapy regimens are highly effective and well tolerated in elderly patients, and antibiotic resistance remains very low. Low compliance is the main factor related to treatment failure in this population.
...
PMID:Current management of Helicobacter pylori infections in the elderly. 1791 18

Aberrant promoter methylation is an important mechanism for gene silencing. Inflammation-related reactive oxygens contribute to this CpG island methylation. The nuclear factor-erythroid 2-related factor 2 gene (Nrf2) is known to regulate the expression of detoxifying and antioxidant genes. We investigated the relationship between promoter polymorphisms of Nrf2 gene and the CpG island methylation in non-cancerous gastric mucosa. The study was performed in 85 subjects (46 without gastric malignancies, non-GC group, and 39 with gastric cancer, GC group). The promoter methylation status of p14(ARF), p16(INK4a) and p21(Waf1) genes was determined by methylation-specific-polymerase chain reaction. The Nrf2 gene genotypes were determined by the PCR-SSCP method. In the 85 subjects, CpG island methylation was found in 25.9% for p14, 15.3% for p16, none for p21. The frequency of the methylated genes was significantly higher in GC group than non-GC group (OR, 2.67; 95% CI, 1.10-6.49; p=0.029). In particular, the frequency of p16 gene methylation was much higher in GC group (p=0.0023). The Nrf2 -686/-684 G/G haplotype was positively associated and A/G haplotype was inversely associated with the development of CpG island methylation, especially p14 gene methylation (OR, 3.28; 95% CI, 1.26-8.59; p=0.015, and OR, 0.38; 95% CI, 0.15-0.96; p=0.040, respectively). In Helicobacter pylori (H. pylori) infected subjects, the number of -686/-684 G/G allele was positively correlated and that of A/G allele was inversely correlated to the methylation status, especially p14 methylation, by the adjusted analysis (OR, 2.90; 95% CI, 1.14-7.36; p=0.026, and OR, 0.33; 95% CI, 0.13-0.88; p=0.027, respectively). Our results suggested that the promoter polymorphisms of Nrf2 gene may affect the methylation status of tumor-related genes, especially the p14 gene, under the influence of H. pylori-induced gastric inflammation.
...
PMID:The influence of promoter polymorphism of nuclear factor-erythroid 2-related factor 2 gene on the aberrant DNA methylation in gastric epithelium. 1809 97

Acute poisoning with corrosive substances can cause severe chemical injuries of the upper part of the gastrointestinal tract. They are most frequently localized in the oesophagus and stomach. If the patient survives the acute phase of poisoning, the regenerative response can result in oesophageal and/or gastric stenosis and a higher risk of oesophageal and stomach cancer. Seven-years clinical material was evaluated for this study (2000-2006) with a total number of 517 patients, hospitalized and treated at the Urgent Internal Medicine and Toxicology Clinic, University Clinical Centre, Skopje, Republic of Macedonia. The evaluation of the caustic poisonings was followed on the basis of anamnesis and hetero-anamnesis, physical examination of the patient, and status of the local changes to the oral mucosae, tongue, palate, and pharynx. The patients were assessed by the following techniques of visualization: urgent oesophagoduodenoscopy in the first 24 hours after the ingestion, control oesophagoduodenoscopy (15 and 25 days after ingestion), X-ray of oesophagus, gaster and duodenum with gastrograph (25-30 days after the ingestion), as well as a routine laboratory examination (blood count, urea, creatinine, enzyme, protein and lipid status, serum transferin, etc), following also the actual body mass index (BMI). The presented results show that the dominating patients were female [n = 368 patients (71.79 %), p < 0.001] and Christian by religion [n = 263 (50.87 %), p > 0.05], with the majority having had secondary education [n = 322 (62.28 %), p = 0.001]. The most frequently misused substance was chlorine hydrogen acid [n = 245 patients (47.38%)]., At the first urgent oesophagoduodenoscopy examination the majority of patients had II A (n = 190) and II B (n = 136) grade damage (x(2) = 44.0; p < 0.05). One hundred patients, or 19.34 %, were dismissed from the hospital with stenosis of the oesophagus and stomach. The high percentage of stenosis was the major factor in the invalidity of these patients. A high mortality of 8.69 % (p > 0.05) was also stated. Of 517 patients, 62 (11.99 %) were poisoned with concentrated acetic acid. In 37 patients (59.67 %) acute renal failure developed as an acute complication and four patients (6.5 %) died as a consequence of the disordered renal function and the need for active dialysis treatment. Recovery of the renal function was established in 93.5 % of the patients. A total number of 138 haemodialyses (3.7/patients) were performed. Acute corrosive poisonings represent a serious socio-economic problem, as well as a diagnostic and therapeutic problem. They appear most frequently in a population that is in a period of life when the person is most creative and efficient in terms of working capacity. The treatment is expensive and is an economic burden on the social community. Despite all the current therapeutic treatments and efforts made to decrease the mortality and late morbidity, intoxication with corrosive substances remains a difficult medical problem.
...
PMID:Epidemiology of severe poisonings caused by ingestion of caustic substances. 1835 88

It is now accepted that peptic ulcer disease, whether duodenal or gastric, is one manifestation of infection with the bacterium Helicobacter pylori. This realization has revolutionized the management of peptic ulcer disease and changed the dictum from no acid no ulcer, to no H. pylori, no ulcer. When confronted with a patient with peptic ulcer disease, the physician must now ask whether H. pylori infection is present and if so, attempt to cure it. The gastric milieu is a very difficult environment for effective antimicrobial therapy. Nevertheless, current multi-drug antimicrobial therapy can be expected to cure the infection in more than 80% of patients. Cure of the infection is associated with a very low rate of recurrence. The continued risk of serious disease or disease complications associated with treatment failure and the availability of the urea breath test to non-invasively assess the results of therapy suggest that post therapy assessment should be routine. Because H. pylori infection causes structural and functional damage to the stomach and is associated with a lifetime risk of peptic or gastric cancer of approximately 16 and 1%, respectively, the infection should be treated whenever it is diagnosed. This paper reviews the current approach to therapy of patients with H. pylori infection, the effective antimicrobial drug combinations end the factors that predict treatment failure. Emergence of antimicrobial resistance may soon undermine the effectiveness of current drug regimens and require pretreatment culture and sensitivity testing as well as development of new drugs and drug regimens.
...
PMID:Antimicrobial therapy of peptic ulcers. 1861 98

The Helicobacter pylori (Hp) infection is common. However, only 10-20% of infected individuals require antibacterial treatment. The main indications to such treatment are peptic ulcer disease, atrophic gastritis, dyspeptic symptoms, previous surgical procedure for gastric cancer, family history of gastric cancer and low-grade gastric mucosa-associated lymphoid tissue (MALT) lymphoma. The treatment may also be undertaken at the patient's request. To detect the infection the urease test (when the patient has indications for gastroscopy), the urea breath test or serologic test are most commonly used. A standard treatment of Hp infection consists of a 7-day administration of one of the proton pump inhibitors and 2 out of 3 antibiotics such as amoxicillin, clarithromycin and metronidazole. After failure of the first-line treatment, the recommended second choice treatment is a quadruple treatment regimen consisting of bismuth salts, tetracycline, metronidazole and proton pump inhibitor. European guidelines (Maastricht III) allow the use of the quadruple treatment regimen already as the first choice treatment and therapy prolongation up to 14 days. Ineffectiveness of the second-line treatment is an indication for antimicrobial susceptibility testing. New antibiotics used for Hp eradication are levofloxacin and rifabutin. Eradication treatment should be obligatorily assessed with the use of the urease or breath test only in patients with peptic ulcer bleeding. The current guidelines do not envisage an active search for Hp infection in an asymptomatic population and treating people infected with this bacterium, for gastric cancer prevention.
...
PMID:Clinical aspects of Helicobacter pylori infection. 1871 38

To investigate the relationship between p16 methylation and Helicobacter pylori infection in precancerous gastric lesions, a population-based study was conducted in Linqu County, a high-risk area of gastric cancer in China. Methylation status of p16 was evaluated by methylation-specific polymerase chain reaction in 920 subjects with precancerous gastric lesions. H. pylori status was determined by 13C-urea breath test and the density of H. pylori in biopsy specimens used for detecting methylation status was assessed by the modified Giemsa stain. The frequency of p16 methylation was significantly higher in subjects with H. pylori positive than those with H. pylori negative in each category of gastric lesion (p<0.001, respectively). Compared with H. pylori negative, the odds ratios (ORs) of p16 methylation were markedly elevated in subjects with H. pylori positive for superficial gastritis (OR, 9.45; 95% confidence interval [CI]: 2.94-30.41), chronic atrophic gastritis (OR, 15.92; 95%CI: 7.60-33.36), intestinal metaplasia (OR, 4.46; 95%CI: 2.44-8.13), indefinite dysplasia (OR, 3.67; 95%CI: 1.90-7.10), and dysplasia (OR, 2.48; 95%CI: 1.02-5.99). Moreover, the frequencies of p16 methylation increased steadily with the severity of H. pylori density in gastric mucosa. Compared with H. pylori negative, the OR of p16 methylation was 1.02-16.13 times higher in subjects with mild H. pylori infection, and 2.69-38.73 times higher in those with moderate/severe infection, respectively. Our findings indicate that p16 methylation was significantly associated with H. pylori infection in precancerous gastric lesions, suggesting that H. pylori infection could potently induce methylation of p16 CpG island.
...
PMID:Promoter methylation of p16 associated with Helicobacter pylori infection in precancerous gastric lesions: a population-based study. 1882 80

The isothiocyanate sulforaphane [SF; 1-isothiocyanato-4(R)-methylsulfinylbutane] is abundant in broccoli sprouts in the form of its glucosinolate precursor (glucoraphanin). SF is powerfully bactericidal against Helicobacter pylori infections, which are strongly associated with the worldwide pandemic of gastric cancer. Oral treatment with SF-rich broccoli sprouts of C57BL/6 female mice infected with H. pylori Sydney strain 1 and maintained on a high-salt (7.5% NaCl) diet reduced gastric bacterial colonization, attenuated mucosal expression of tumor necrosis factor-alpha and interleukin-1beta, mitigated corpus inflammation, and prevented expression of high salt-induced gastric corpus atrophy. This therapeutic effect was not observed in mice in which the nrf2 gene was deleted, strongly implicating the important role of Nrf2-dependent antioxidant and anti-inflammatory proteins in SF-dependent protection. Forty-eight H. pylori-infected patients were randomly assigned to feeding of broccoli sprouts (70 g/d; containing 420 micromol of SF precursor) for 8 weeks or to consumption of an equal weight of alfalfa sprouts (not containing SF) as placebo. Intervention with broccoli sprouts, but not with placebo, decreased the levels of urease measured by the urea breath test and H. pylori stool antigen (both biomarkers of H. pylori colonization) and serum pepsinogens I and II (biomarkers of gastric inflammation). Values recovered to their original levels 2 months after treatment was discontinued. Daily intake of sulforaphane-rich broccoli sprouts for 2 months reduces H. pylori colonization in mice and improves the sequelae of infection in infected mice and in humans. This treatment seems to enhance chemoprotection of the gastric mucosa against H. pylori-induced oxidative stress.
...
PMID:Dietary sulforaphane-rich broccoli sprouts reduce colonization and attenuate gastritis in Helicobacter pylori-infected mice and humans. 1934 90

The main conclusions drawn from the presentations related to Helicobacter pylori at Digestive Diseases Week 2008 are summarized. Several strains of H. pylori frequently infect the same patient, and consequently samples for culture should be obtained from the gastric antrum and body. The test-and-treat strategy in dyspepsia is as effective as empirical antisecretory therapy and is probably cheaper. The benefit of eradication therapy in patients with uninvestigated dyspepsia, although small, seems to be lasting. Eradication in the general population seems to reduce the development of dyspeptic symptoms in the long term and consequently could be cost-effective. The prevalence of H. pylori infection in peptic ulcer is decreasing and the frequency of idiopathic ulcers is increasing. Patients with H. pylori-negative bleeding ulcers have a high probability of hemorrhagic recurrence and should therefore receive maintenance antisecretory therapy. H. pylori eradication reduces the incidence of gastric adenocarcinoma, which could warrant a screening and treatment strategy for this infection in the general population in high risk areas. H. pylori infection should be eradicated in patients undergoing endoscopic mucosal resection for early gastric cancer. To prevent the development of gastric cancer, eradication therapy should be administered early, before gastric atrophy develops. H. pylori-negative and H. pylori-positive gastric lymphomas have an equally favorable prognosis. New diagnostic techniques have been developed: the ultra-rapid urease test, a simpler 14C-urea breath test, and an ELISA method for rapid bacterial susceptibility determination. In patients with gastrointestinal bleeding, the 13C-urea breath test performed immediately after emergency gastroscopy allows early diagnosis of infection. Eradication regimens with double doses of proton pump inhibitors are more effective than those with standard doses. "Sequential" therapy is more effective and cheaper than classical triple-drug therapy, although the superiority of administering therapy sequentially rather than concomitantly has not been established. In penicillin-allergic patients, a combination with levofloxacin and clarithromycin is a promising alternative in rescue therapy. Second-line rescue therapy with levofloxacin is effective and is also simpler and better tolerated than quadruple-drug therapy. The rate of quinolone resistance is increasing as a result of the widespread use of these antibiotics. Third-line treatment with levofloxacin is also a promising alternative. Even after the failure of three previous treatments, a fourth empirical rescue therapy (with levofloxacin or rifabutin) can be effective in more than half of patients. The annual recurrence rate of H. pylori infection is approximately 3% in developed countries and is higher than 10% in developing countries.
...
PMID:[Helicobacter pylori-related diseases: dyspepsia, ulcer and gastric cancer]. 1943 62

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