Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0017168 (gastroesophageal reflux disease)
 11,783 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Helicobacter pylori causes chronic gastritis and plays important roles in peptic ulcer disease, gastric carcinoma, and mucosa-associated lymphoid tissue (MALT) lymphoma. It is believed that H. pylori infects over 50% of the worlds' population. However, only a small subset of infected people experience H. pylori-associated illnesses. Associations with disease-specific factors remain enigmatic. The contribution of comparative genomics to our understanding of the genome organisation and diversity of H. pylori is exemplified herein. The discovery of the cag pathogenicity island has revolutionised our understanding of the molecular pathogenesis of gastroduodenal ulcers. Another type IV secretion system, the comB gene cluster, provides a novel transformation system. Identification of this cluster has boosted our perception of horizontal gene transfer and gene mosaicism in H. pylori as a result of natural competence. Recent discovery of a third type IV secretion system called tfs3 encoding cluster in the so called plasticity zone of the H. pylori has gained significant attention, although its role is not clear. Study of the evolution of polymorphisms and sequence variation in H. pylori populations on a global basis is contributing to understanding of the history of human population migration and co-evolution of this pathogen with its human host. Possible symbiotic relationships were debated since the discovery of this pathogen. The debate has been further intensified as recent studies have posed the intriguing possibility that H. pylori infection may be advantageous in some humans. This analogy is based on increased incidence of diseases like gastro-oesophageal reflux disease (GERD), Barrett's oesophagus and adenocarcinoma of the oesophagus following H. pylori eradication in some patients.
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PMID:Revisiting the pestilence of Helicobacter pylori: insights into geographical genomics and pathogen evolution. 1515 25

Helicobacter pylori is prevalent worldwide, especially in developing countries, and is associated with several upper gastrointestinal diseases. Since it is present in over 90% of duodenal ulcer patients, empirical eradication in these patients is often recommended. In gastric ulcer patients, eradication is indicated only after the infection is confirmed. Testing for H. pylori infection should be carried out in patients with peptic ulcer hemorrhage, because eradication has been shown to reduce recurrent bleeding. Both H. pylori and NSAIDs are risk factors for peptic ulceration, and it is reasonable to screen for and eradicate H. pylori infection in peptic ulcer patients taking NSAIDs. H. pylori is a group I carcinogen for gastric adenocarcinoma, and should be eradicated for the primary prevention of this cancer. Eradication of this organism has been reported to result in regression of early low-grade mucosa-associated lymphoid tissue lymphoma. The role of H. pylori infection in the causation of gastroesophageal reflux and non-ulcer dyspepsia is not clearly established. Several tests are available for the diagnosis of H. pylori infection. These include invasive tests, such as histology, culture and urease test, and non-invasive tests, such as serology, urea breath test and stool antigen test. The choice of test is determined by clinical indication, pretest probability of infection, as well as the availability, cost, sensitivity and specificity of the test. H. pylori eradication therapy using proton pump inhibitor with clarithromycin and amoxycillin for 7 days has a success rate of 85-90%. Improved living standard and sanitation are vital in the control of H. pylori transmission and infection. Future development may include the use of vaccines against H. pylori, and therapies specifically targeting cagA strains of the bacteria.
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PMID:Eradication of Helicobacter pylori in clinical situations. 1559 83

The human gastric pathogen Helicobacter pylori causes chronic gastritis, peptic ulcer disease, gastric carcinoma, and mucosa-associated lymphoid tissue (MALT) lymphoma. It infects over 50% of the worlds' population, however, only a small subset of infected people experience H. pylori-associated illnesses. Associations with disease-specific factors remain enigmatic years after the genome sequences were deciphered. Infection with strains of Helicobacter pylori that carry the cytotoxin-associated antigen A (cagA) gene is associated with gastric carcinoma. Recent studies revealed mechanisms through which the cagA protein triggers oncopathogenic activities. Other candidate genes such as some members of the so-called plasticity region cluster are also implicated to be associated with carcinoma of stomach. Study of the evolution of polymorphisms and sequence variation in H. pylori populations on a global basis has provided a window into the history of human population migration and co-evolution of this pathogen with its host. Possible symbiotic relationships were debated since the discovery of this pathogen. The debate has been further intensified as some studies have posed the possibility that H. pylori infection may be beneficial in some humans. This assumption is based on increased incidence of gastro-oesophageal reflux disease (GERD), Barrett's oesophagus and adenocarcinoma of the oesophagus following H. pylori eradication in some countries. The contribution of comparative genomics to our understanding of the genome organisation and diversity of H. pylori and its pathophysiological importance to human healthcare is exemplified in this review.
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PMID:Helicobacter pylori and gastroduodenal pathology: new threats of the old friend. 1563 57

Helicobacter pylori infection has been recognized as the most important pathogenetic principal of peptic ulcer disease, atrophic gastritis, gastric adenocarcinoma and MALT lymphoma. At the moment efforts are made to clarify it's role in functional dyspepsia, and gastro-esophageal reflux disease. The complex interactions between H. pylori infection and NSAIDs is another field of ongoing research. Diagnosis and eradication therapy are standardized. Established indications are peptic ulcer disease, low-grade gastric MALT lymphoma, early gastric cancer treated by mucosal resection and partial gastrectomy for gastric cancer. Atrophic gastritis, known to be a precancerous lesion, as well as first degree relatives of patients with gastric cancer is another widely accepted indication for eradication therapy. The recommended eradication regimens combine a proton pump inhibitor with clarithromycin and either amoxicillin or metronidazole--for a week.
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PMID:[Helicobacter pylori: reasons for eradication]. 1567 64

Clinical relevance of infection with different Helicobacter pylori strains was reviewed in this paper. Helicobacter pylori (H. pylori) infection plays a role in pathogenesis of chronic gastritis, peptic ulcer disease, gastric adenocarcinoma and MALT lymphoma. Extragastric manifestations of H. pylori infection most probably include acne rosacea and chronic urticaria, while the importance of H. pylori infection for pathogenesis of growth retardation in children, iron deficiency anemia, coronary heart disease, stroke and idiopathic thrombocytopenic purpura remains vague. The expression of two H. pylori proteins, cytotoxin associated protein (cag A) and vacuolization cytotoxin (vac A) is considered to be related with pathogenicity of the bacterium. It is clear that presence of cag A+ strains is important for development of peptic ulcer; nevertheless, it is also protective against esophageal reflux disease. On the other hand, cag A+ strains are common in gastric adenocarcinoma and MALT lymphoma patients, but it seems that certain subtypes of vac A cytotoxin are more important risk factors. Infection with cag A+ strains is more common in patients with acne rosacea, stroke and coronary heart disease.
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PMID:[Clinical significance of infection with cag A and vac A positive Helicobacter pylori strains]. 1593 30

Lifestyles of Japanese, including eating habits, have been similar to those in Western countries, which might be related to an increase in gastroesophageal reflux disease (GERD) in Japan. Barrett's esophagus is generally accepted as a complication of chronic and severe GERD. Helicobacter pylori (H. pylori) is a pathogen that is associated with atrophic gastritis, peptic ulcer disease, gastric adenocarcinoma, mucosa-associated lymphoid tissue lymphoma, and so on. The relationship between H. pylori and GERD+ Barrett's esophagus is controversial. H. pylori eradication therapy may increase the risk for the development of GERD, which may lead to increase a risk factor of Barrett's esophagus and esophageal adenocarcinoma. This review gives the outline regarding GERD and the relation between Barrett's esophagus and H. pylori infection.
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PMID:[Barrett's esophagus and Helicobacter pylori]. 1610 Dec 26

It has been 2 decades since the rediscovery of Helicobacter pylori. Since that time, enormous advances have occurred: H. pylori is clearly felt to be a cause of peptic ulcer disease and gastric malignancies such as mucosa associated lymphoid tissue (MALT) lymphoma and a carcinogenic factor for gastric adenocarcinoma. These associations have led to clear indications for H. pylori treatment in certain conditions, but in other diseases where the associations are not as clear, the indications also remain relatively controversial. Clear indications for H. pylori treatment include patients with duodenal and gastric H. pylori associated ulcers and MALT lymphoma. In uninvestigated dyspepsia, there are also very clear benefits to H. pylori treatment whereas in non-ulcer dyspepsia, the benefits are controversial. H. pylori is certainly a risk factor for gastric adenocarcinoma but eradication of this infection has not yet been shown to reduce or eliminate the risk of developing this condition. The effect of H. pylori treatment in patients with gastroesophageal reflux disease is also unclear. There is a potential benefit in the prevention of atrophic gastritis but a potential disadvantage is the worsening of reflux disease, which has been suggested by certain studies. In addition, the interaction between H. pylori and nonsteroidal anti-inflammatory drugs (NSAIDs) appears quite complicated. Although there have been several advances in the last 2 decades with regards to the treatment of H. pylori, several controversies still exist, attesting to the requirement for further research.
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PMID:Treatment of Helicobacter pylori infection. 1648 66

Helicobacter pylori infection is basically acquired during infancy. H. pylori is associated with a great number of pathologies including gastritis, gastroduodenal peptic ulcer, gastric adenocarcinoma and MALT lymphoma. Its association with abdominal pain in children remains controversial. An association with iron deficiency anemia was recently described. The reference method for diagnosis still remains culture and histology of gastric biopsies realized during endoscopy. A few years ago, a lot of studies have shown the reliability of non-invasive tests (urea breath test 13C and the H. pylori stool antigen) for the diagnosis of the H. pylori infection in children. The treatment associating a proton pump inhibitor with two antibiotics (depending on the antimicrobial susceptibility when it's available) is recommended every time infection is proved. In children, the reinfection rate after H. pylori eradication is often higher than in adults. The eradication of H. pylori infection does not seem to produce the advent or the aggravation of gastro-oesophageal reflux oesophagitis. The eradication of this pathogen, in children as well as in adults, should theoretically lead to the disappearance of gastric cancer.
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PMID:[Helicobacter pylori infection in children]. 1654 42

Scientific evidence based on controlled clinical research confirm substantial benefits resulting from the eradication of H. pylori infection in such pathologies of the alimentary tract as: gastric peptic and duodenal ulcer (active or confirmed in the future and ulcer disease complications), MALT (Mucosa Associated Limphoid Tissue) lymphoma, atrophic gastritis, past stomach resection, gastric cancer in the family. The above group of indications is strongly recommended for eradicative treatment. During the last several years there have been many guidelines made by international and national specialist groups. "Test and treat" strategy of undiagnosed dyspepsia treatment is based on possibility to carry out non-invasive tests confirming H. pylori infection. First symptoms of dyspepsia in people over 45 years of age constitute recommendation for endoscopy, as well as symptoms assumed to be "alarming" (loss of weight, anaemia, bloody vomiting, tarry stool, dysphagia) regardless of patient age. An individual approach to eradication is proposed in gastroesophageal reflux disease, and use of non-steroid anti-inflammatory drugs. Antibacterial activity towards H. pylori is shown by many antibiotics (amoxicillin, macrolides, tetracyclines) and some other chemotherapeutic agents (nitroimidazoles) and bismuth. PPIs are recommended, because through increase of pH in stomach they create conditions to act for antibiotics. During the stage of first line triple therapy, it is advised to apply PPI and two antibacterial medicines at the same time (PPI + amoxicillin+metronidazole or clarithromycin). Such therapeutic action ensures achievement of eradication of H. pylori infection in 80-90% of cases. In case of lack of treatment efficiency in the first-line therapy, 7-14 day treatment may be repeated using triple therapies (PPI + 2 antibiotics) substituting the antibiotic with the metronidazole or tetracycline, or quadruple therapies (PPI + bismuth citrate + 2 antibiotics). Side effects during eradicative treatments occur quite rarely (from 15 to 30%).
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PMID:Guidelines in the medical treatment of Helicobacter pylori infection. 1703 12

Helicobacter pylori (H. pylori) remains a prevalent, worldwide, chronic infection. Though the prevalence of this infection appears to be decreasing in many parts of the world, H. pylori remains an important factor linked to the development of peptic ulcer disease, gastric malignanc and dyspeptic symptoms. Whether to test for H. pylori in patients with functional dyspepsia, gastroesophageal reflux disease (GERD), patients taking nonsteroidal antiinflammatory drugs, with iron deficiency anemia, or who are at greater risk of developing gastric cancer remains controversial. H. pylori can be diagnosed by endoscopic or nonendoscopic methods. A variety of factors including the need for endoscopy, pretest probability of infection, local availability, and an understanding of the performance characteristics and cost of the individual tests influences choice of evaluation in a given patient. Testing to prove eradication should be performed in patients who receive treatment of H. pylori for peptic ulcer disease, individuals with persistent dyspeptic symptoms despite the test-and-treat strategy, those with H. pylori-associated MALT lymphoma, and individuals who have undergone resection of early gastric cancer. Recent studies suggest that eradication rates achieved by first-line treatment with a proton pump inhibitor (PPI), clarithromycin, and amoxicillin have decreased to 70-85%, in part due to increasing clarithromycin resistance. Eradication rates may also be lower with 7 versus 14-day regimens. Bismuth-containing quadruple regimens for 7-14 days are another first-line treatment option. Sequential therapy for 10 days has shown promise in Europe but requires validation in North America. The most commonly used salvage regimen in patients with persistent H. pylori is bismuth quadruple therapy. Recent data suggest that a PPI, levofloxacin, and amoxicillin for 10 days is more effective and better tolerated than bismuth quadruple therapy for persistent H. pylori infection, though this needs to be validated in the United States.
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PMID:American College of Gastroenterology guideline on the management of Helicobacter pylori infection. 1760 75


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