Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0847097 (acidity)
 15,165 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Recent studies have been reviewed to establish the possible importance of the interaction between Helicobacter pylori infection and gastric acid secretion. H. pylori infection results in increased gastrin release, but this does not lead to gastric acid hypersecretion and gastrin normalizes after eradication of the infection. An optimal, well-tolerated treatment strategy against H. pylori infection has not yet been clearly defined. One potentially useful approach may be to improve the antibacterial efficacy of antibiotics by effectively regulating gastric acidity. H2-receptor antagonists have no effect against H. pylori infection, while omeprazole (an acid pump inhibitor) appears to have a bacteriostatic action. Combination therapy with omeprazole and amoxycillin has been found to eradicate H. pylori in 50-80% of patients with duodenal ulcer, leading to a significant reduction in ulcer recurrence.
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PMID:Helicobacter pylori, peptic ulcer disease and inhibition of gastric acid secretion. 139 40

New concepts in the pathophysiology of peptic ulcers must acknowledge 1. the close association of ulcers and Helicobacter pylori infection, 2. the protective role of endogenous prostaglandins, 3. the scarcity of new data on the importance of acidity (though presence of gastric acid remains indispensible for ulcer development). The different pathophysiologically relevant factors closely interact with each other. However, many not of actual concepts are still experimental and--apart from Helicobacter pylori--have not yet led to new therapeutical approaches.
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PMID:[Current pathogenetic principles in peptic ulcer]. 149 2

Helicobacter pylori infection may be associated with duodenal ulcer (DU) and accompanied by enhanced gastrin release but the mechanism of this H pylori related hypergastrinaemia in DU patients is unclear. Cholecystokinin (CCK) has been implicated in the feedback control of gastrin release and gastric acid secretion in healthy subjects. This study therefore investigated if CCK participates in the impairment of postprandial gastrin release and gastric secretion in six DU patients. Tests were undertaken with and without elimination of endogenous CCK by loxiglumide, a selective CCK-A receptors antagonist, before and after eradication of H pylori with triple therapy (omeprazole, amoxicyllin, bismuth). In H pylori positive DU patients, the post-prandial decline in pH (with median pH 3.5) was accompanied by a pronounced increment in plasma gastrin but the administration of loxiglumide did not affect significantly this postprandial rise in plasma gastrin and gastric pH profile. After eradication of H pylori, the plasma gastrin concentration was reduced while the median postprandial pH was significantly increased (median pH 4.3). The administration of loxiglumide resulted in significantly greater increase in postprandial plasma gastrin and greater decrease in pH (median pH 3.1) in these patients. This study shows that (a) infection with H pylori is accompanied by an enhanced gastrin release and gastric acidity in DU patients, (b) the failure of loxiglumide to affect plasma gastrin or gastric acid secretion in H pylori infected DU patients could be attributed, at least in part, to the failure of endogenous CCK to control gastrin release and gastric secretion by releasing somatostatin, and (c) the test with loxiglumide may be useful in the identification of patients with impaired feedback control of gastrin release and gastric secretion resulting from infection with H pylori.
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PMID:Eradication of Helicobacter pylori restores the inhibitory effect of cholecystokinin on postprandial gastrin release in duodenal ulcer patients. 748 32

We studied the action on acid secretion of lansoprazole compared with famotidine by 24-h intragastric pH monitoring, evaluated its clinical effects prospectively, and assessed the importance of acid inhibition in gastric ulcer patients. Twenty symptomatic patients with active gastric ulcers diagnosed by endoscopy were assigned to a lansoprazole (LAN) group (lansoprazole 30 mg q.d., n = 10) or a famotidine (FAM) group (famotidine 20 mg b.i.d., n = 10). There were no differences between the groups in pretreatment pH profiles or background factors such as age, sex, smoking, previous ulcer therapy, ulcer site, or Helicobacter pylori infection. The FAM group showed a continuous increase in intragastric pH during the night, with low pH values except for a transient increase associated with food intake during the day. However, the LAN group showed a more neutral pH throughout the day, with pH-3 holding time ratios of 99.0% for 24 h, 98.3% at night, and 99.8% during the day, compared with 68.0, 76.5, and 59.4%, respectively, in the FAM group. The healing rate was also higher in the LAN group. We conclude that inhibition of gastric acidity is important in ulcer therapy and that lansoprazole is superior to famotidine in promoting ulcer healing.
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PMID:Suppressive action of lansoprazole on gastric acidity and its clinical effect in patients with gastric ulcers: comparison with famotidine. 759 34

Omeprazole plus amoxicillin cures Helicobacter pylori infection. The hypothesis was tested that low acidity is a predictor of outcome. Fifty patients with relapsing or complicated, or both H pylori positive duodenal (n = 25) or gastric ulcer (n = 25) were randomly treated with either omeprazole 20 mg twice daily plus amoxicillin 1 g twice daily or with omeprazole 40 mg twice daily plus amoxicillin 1 g twice daily over two weeks. After one week of combined treatment, a 24 hour gastric pH measurement was performed in all patients. H pylori cure rate was 67%. Patients who later turned out to be cured had higher pH values during night time and after meals (p < 0.05). In an explorative analysis drug compliance, smoking, location of the ulcer (duodenum versus stomach), age, and grade of body gastritis were additional predictors of the outcome. Smoking (p = 0.006), compliance (p = 0.037), duodenal ulcer disease (p = 0.065), and young age (p = 0.021) were related to high acidity. In conclusion, the success of eradication treatment with omeprazole and amoxicillin in ulcer patients infected with H pylori depends on intragastric pH. Drug compliance, smoking habits, location of ulcer, age, and activity of body gastritis are other predictors and in part related to intragastric acidity.
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PMID:Intragastric acidity as a predictor of the success of Helicobacter pylori eradication: a study in peptic ulcer patients with omeprazole and amoxicillin. 767 77

To test the hypothesis that Helicobacter pylori infection is associated with a decreased intragastric acidity during omeprazole therapy, ambulatory 24 hour dual point gastric pH recordings were performed in 18 H pylori positive and 14 H pylori negative subjects. There was a four to six week washout period between the two pH recordings made in each subject after one week courses of placebo or omeprazole, 20 mg daily. During placebo, median 24 hour pH values were not different in the corpus (H pylori positive = 1.5, negative = 1.4; p = 0.9) or antrum (H pylori positive = 1.3, negative = 1.2; p = 0.1). However, during omeprazole treatment, median 24 hour pH values were higher in H pylori positive subjects, both in the corpus (H pylori positive = 5.5, negative = 4.0; p = 0.001) and antrum (H pylori positive = 5.5, negative = 3.5; p = 0.0004). During placebo treatment, the only difference between the two groups was a higher later nocturnal pH in the antrum in the H pylori positive group. During omeprazole treatment, gastric pH was higher both in the corpus and in the antrum in the H pylori positive group for all periods, except for mealtime in the corpus. These data indicate that omeprazole produces a greater decrease in gastric acidity in subjects with H pylori infection than in those who are H pylori negative. It is not, however, known whether there is a causal relationship between H pylori infection and increased omeprazole efficacy.
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PMID:Effect of Helicobacter pylori status on intragastric pH during treatment with omeprazole. 773 60

The present strategies for the management of peptic ulceration are well tolerated and clinically effective. Histamine H2-receptor antagonists can be used for mild to moderate disease, and proton pump inhibitors are of particular benefit for patients with severe peptic ulceration and the Zollinger-Ellison syndrome. However, none of these treatments provides protection against recurrent ulceration, except when taken as long-term continuous treatment. Long-term exposure to pharmacological agents raises problems of safety, particularly relating to a lack of intragastric acidity. In addition, the accelerated development of atrophic gastritis in patients receiving omeprazole requires investigation and assessment. It is unlikely that there will be any major development in the area of control of gastric acid secretion, except perhaps the introduction of specific immunization against gastrin. However, the clinical benefit of this strategy awaits assessment. The main area for development must be the introduction of convenient and effective regimens for the eradication of Helicobacter pylori infection. Existing regimens are either simpler and relatively ineffective, or too complicated for widespread application. Bearing in mind the long gestation period of any new drug, it seems likely that the only innovative drug that will be introduced for the management of peptic ulceration before the millennium will be ranitidine bismuth citrate, an antisecretory anti-H. pylori drug that will usually be used in combination with an antibiotic.
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PMID:Treatment of peptic ulcers from now to the millennium. 794 62

Thirty-three consecutive patients with idiopathic gastric acid hypersecretion (defined as a basal acid output > 10.0 meq/hr with a normal fasting serum gastrin level and negative secretin stimulation test) who were being treated for duodenal ulcer disease and other acid-peptic disorders were evaluated for the presence of Helicobacter pylori by means of a rapid urease test. Fourteen patients had duodenal ulcer and 19 had other acid-peptic disorders (gastroesophageal reflux in 14, including six with Barrett's esophagus; four with nonulcer dyspepsia; and one with erosive gastritis). Helicobacter pylori was present in 12 of the 14 ulcer patients (86%) compared to only two of the 19 nonulcer patients (11%) (P < 0.0001). The distribution of basal acid output for patients with duodenal ulcer was similar to that for nonulcer patients, and no significant difference in the mean basal acid output was found among Helicobacter pylori-positive compared to Helicobacter pylori-negative patients. Seven of the duodenal ulcer patients with a basal acid output greater than 15.0 meq/hr were Helicobacter pylori-positive, suggesting that the organism can withstand even extreme levels of gastric acidity. In conclusion, this study demonstrates that the prevalence of Helicobacter pylori infection in patients with duodenal ulcer disease associated with idiopathic gastric acid hypersecretion is not different from a majority of ulcer patients with normal acid secretory profiles and offers additional evidence that extreme levels of gastric acid are not bactericidal for the organism.
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PMID:Helicobacter pylori in duodenal ulcer patients with idiopathic gastric acid hypersecretion. 842 Jul 45

The occurrence of duodenal ulcer is characterized by seasonal variation, for poorly understood reasons. No previous study has assessed whether 24-h intragastric acidity and Helicobacter pylori infection have similar seasonal fluctuations in patients with this disorder. For this reason, we evaluated retrospectively the circadian gastric pH in 319 new patients (226 men and 93 women, mean age 45.2 years) with endoscopically proven duodenal ulcer, who agreed to undergo this examination during the years 1987-1992 in our center. The month-by-month occurrence of the disease over the global 6-year period was assessed, and the mean pH values were calculated for each patient during three time intervals of interest: 24 h, daytime (08:00-19:59 h), and nighttime (20:00-07:59 h). The mean pH values of these three time periods were then calculated month by month throughout the annual cycle. H. pylori infection was sought by histology in 171 patients examined in the period from 1990 to 1992. The percentage of H. pylori-positive duodenal ulcer patients was then calculated for each season. The calendar fluctuation of duodenal ulcer occurrence showed an evident increase (p < 0.001) in fall (October-December) and in winter (January-March) compared with spring (April-June) and summer (July-September). Both 24-h and nighttime gastric acidity showed no significant variation by month, whereas daytime gastric pH varied significantly (p < 0.05) with two evident decreases, meaning higher acidity, in April and August. H. pylori infection was detected in 152 of 171 patients (89%), and the percentage of H. pylori-positive duodenal ulcers did not differ from season to season. We conclude that there was no parallel circannual fluctuation of duodenal ulcer, gastric acidity, and H. pylori infection in the restricted sample of patients we studied. This reduces the apparent relevance of acid in inducing ulcer seasonal fluctuation. Also, the responsibility of H. pylori in this phenomenon can be excluded until a reliable diagnostic method capable of distinguishing recent from old infection is found.
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PMID:Are duodenal ulcer seasonal fluctuations paralleled by seasonal changes in 24-hour gastric acidity and Helicobacter pylori infection? 941 62

Symptomatic gastro-oesophageal reflux disease is a common disorder characterized by pathological exposure of the distal oesophagus to acid. The management requires the control of symptoms, prevention of relapse and complications. Proton pump inhibitors are without doubt the most effective agents in the management of gastro-oesophageal reflux disease. In Helicobacter pylori-negative individuals the efficacy of ranitidine, but more pronounced of omeprazole, on the nocturnal intragastric acidity, is less than in Helicobacter pylori-positive patients. Curing the Helicobacter pylori infection in gastro-oesophageal reflux disease patients might, therefore, have the disadvantage of losing efficacy of antisecretory therapy. Conversely, several studies have shown that long-term use of proton pump inhibitors is associated with progression and worsening of body gastritis exclusively in Helicobacter pylori-positives. This observation makes Helicobacter pylori eradication indicated before starting long-term treatment with proton pump inhibitors for gastro-oesophageal reflux disease and other acid-related diseases. The data reported, so far, however, are not conclusive. The Federal Drugs Administration Advisory Committee concluded on available data, that there is no evidence that longterm proton pump inhibitors treatment leads to gastric atrophy, intestinal metaplasia or gastric cancer. Eradication of Helicobacter pylori infection might lead to reduction in the efficacy of antisecretory agents, but might prevent worsening of the gastric corpus gastritis. More data are needed to really answer these clinically relevant questions.
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PMID:Should Helicobacter pylori be eradicated before starting long-term proton pump inhibitors? 951 35


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