Lessons from prolonged gastric pH monitoring

Intragastric pH monitoring has shown that the distribution of acidity within the stomach is not homogeneous. Not only is it affected by meals but it also has a circadian rhythm in which nocturnal pH falls to very acid levels in normal subjects. Although results of pH monitoring are highly reproducible within individuals, considerable inter-individual variation has been shown. Duodenal ulcer patients do not appear to possess the normal buffering reaction to meals, but their night-time acidity is within the normal range. In these patients, antacids and pirenzepine have a small acid-neutralizing effect in the stomach; cimetidine is less potent than ranitidine and famotidine. Clinicians can choose between a single dose of either ranitidine or famotidine in the evening with dinner and a twice-daily regimen.

[Symptom- versus endoscopy-based diagnosis and treatment of gastroesophageal reflux disease (GERD)]

The current guidelines of the German Society for Digestive Diseases (DGVS) endoscopy recommends for patients representing with reflux symptoms. In daily routine as well as in Guidelines from other countries and international guidelines, however, a symptom-based strategy for the management of patients with reflux disease is favoured. Since either strategies is dependent on specific clinical findings, neither can be recommended. The preference for one or the other strategy depends on the prevalence of so-called alarm symptoms, risk factors for a reflux carcinoma or Barrett's metaplasia, demographic factors, e. g., age and gender, patient's wish and initial response to empirical therapy with proton pump inhibitors (PPI). However, most patients with characteristic reflux symptoms without any alarm symptoms and/or other risk factors can be safely managed with a symptom-based strategy in acute and long-term care.

Is early endoscopy in the emergency room beneficial in patients with bleeding peptic ulcer? A "fortuitously controlled" study

BACKGROUND AND STUDY AIMS

In previous randomized trials, early endoscopy improved the outcome in patients with bleeding peptic ulcer, though most of these studies defined "early" as endoscopy performed within 24 hours after admission. Using the length of hospital stay as the primary criterion for the clinical outcome, we compared the results of endoscopy done immediately after admission (early endoscopy in the emergency room, EEE) with endoscopy postponed to a time within the first 24 hours after hospitalization, but still during normal working hours ("delayed" endoscopy in the endoscopy unit, DEU).

PATIENTS AND METHODS

We conducted a retrospective analysis of data from 81 consecutive patients with bleeding peptic ulcer admitted in 1997 and 1998 (age range 16 - 90 years). Of these 81 patients, 38 underwent DEU (the standard therapy at the hospital) and 43 underwent EEE. Patients in the two groups were comparable with regard to admission criteria, were equally distributed with respect to their risk of adverse outcome (assessed using the Baylor bleeding score and the Rockall score), and differed only in the treatment they received. Endoscopic hemostasis was performed whenever possible in all patients with Forrest types I, IIa, and IIb ulcer bleeding.

RESULTS

We found similar rates in the two groups for recurrent bleeding (16 % in DEU patients vs. 14 % in EEE patients), persistent bleeding (8 % in DEU patients vs. none in EEE patients), medical complications (21 % in DEU patients vs. 26 % in EEE patients), the need for surgery (8 % in DEU patients vs. 9 % in EEE patients), and the length of hospital stay (5.1 days for DEU patients vs. 5.9 days for EEE patients). None of the differences between the two groups in these parameters were statistically significant. None of the patients died.

CONCLUSIONS

Early endoscopy in an emergency room did not improve the clinical outcome in our 81 consecutive patients with bleeding peptic ulcer.

Meta-analysis: The treatment of irritable bowel syndrome

To evaluate therapies available for the treatment of irritable bowel syndrome, and provide consensus recommendations for their use, a total of 51 double-blind clinical trials using bulking agents, prokinetics, antispasmodics, alosetron, tegaserod and antidepressants were selected. The quality of studies was assessed using 5-point scale. Meta-analyses were performed on all studies, and on 'high-quality studies'. The efficacy of fibre in the global irritable bowel syndrome symptoms relief (OR: 1.9; 95% CI:1.5-2.4) was lost after exclusion of low-quality trials (OR: 1.4; 95% CI: 1.0-2.0, P = 0.06). When excluding the low-quality trials, an improvement of global irritable bowel syndrome symptoms with all antispasmodics (OR: 2.1; 95% CI:1.8-2.9) was maintained only for octylonium bromide, but on the basis of only two studies. Antidepressants were effective (OR: 2.6, 95% CI: 1.9-3.5), even after exclusion of low-quality studies (OR: 1.9, 95% CI: 1.3-2.7). Alosetron (OR: 2.2; 95% CI: 1.9-2.6) and tegaserod (OR: 1.4; 95% CI: 1.2-1.5) showed a significant effect in women. We recommend the use of tegaserod for women with irritable bowel syndrome with constipation and alosetron for women with severe irritable bowel syndrome with diarrhoea. Antidepressants can be beneficial for irritable bowel syndrome with diarrhoea patients with severe symptoms. Loperamide can be recommended in painless diarrhoea. Evidence is weak to recommend the use of bulking agents in the treatment of irritable bowel syndrome with constipation.

Personal view: rationale and proposed algorithms for symptom-based proton pump inhibitor therapy for gastro-oesophageal reflux disease

Gastro-oesophageal reflux disease and non-erosive reflux disease are chronic, highly prevalent conditions requiring long-term treatment that is both effective and practical. On-demand therapy with a proton pump inhibitor may meet that need. It is becoming a mainstay of long-term treatment because it reduces the risk of over- and under-treatment, is cost-effective and user friendly. Epidemiological and clinical observations speak also in its favour. However, for the anticipated benefits of on-demand therapy to accrue in clinical practice, on-demand treatment algorithms are required. These algorithms must specify the initial evaluation and treatment of candidates, and follow-up protocols for an on-demand strategy. Our group has developed such algorithms, which are presented here.

Favourable effect of regular intake of fermented milk containing Lactobacillus johnsonii on Helicobacter pylori associated gastritis

BACKGROUND

Lactobacillus johnsonii (Lj1) had an in vitro and in vivo inhibitory effect on Helicobacter pylori. Fermented milk containing Lj1 (LC1), coadministered with antibiotics had a favourable effect on H. pylori gastritis.

AIM

Evaluate the effect of LC1 intake without antibiotics on H. pylori gastritis.

METHODS

Fifty H. pylori positive healthy volunteers were randomised in a double-blind study to LC1 or placebo. Gastric biopsies from the antrum and corpus were obtained before, and after 3 and 16 weeks of treatment, for histology and quantitative cultures.

RESULTS

Severity and activity of antral gastritis was reduced after 16-week LC1 intake (pretreatment and 16-week inflammatory cell score: 6.0 +/- 0.8 vs. 5.3 +/- 0.1; P=0.04). H. pylori density decreased in the antrum after LC1 intake (3-week: 4.4 +/- 0.6; 16-week: 4.3 +/- 0.5 log10 colony forming units (cfu) vs. pretreatment 4.5 +/- 0.4 log10 cfu; P=0.04, respectively). Mucus thickness increased after 16 weeks of LC1 consumption (change of mucus thickness with LC1 and placebo in the antrum: 0.6 +/- 1.3 vs. -0.2 +/- 1.0, P=0.01; in the corpus: 0.3 +/- 1.1 vs. -0.6 +/- 1.5, P=0.03).

CONCLUSION

LC1 intake had a favourable, albeit weak, effect on H. pylori associated gastritis, particularly in the antrum. Regular ingestion of fermented milk containing L. johnsonii may reduce the risk of developing disorders associated with high degrees of gastric inflammation and mucus depletion.

Favourable effect of regular intake of fermented milk containing Lactobacillus johnsonii on Helicobacter pylori associated gastritis

BACKGROUND

Lactobacillus johnsonii (Lj1) had an in vitro and in vivo inhibitory effect on Helicobacter pylori. Fermented milk containing Lj1 (LC1), coadministered with antibiotics had a favourable effect on H. pylori gastritis.

AIM

Evaluate the effect of LC1 intake without antibiotics on H. pylori gastritis.

METHODS

Fifty H. pylori positive healthy volunteers were randomised in a double-blind study to LC1 or placebo. Gastric biopsies from the antrum and corpus were obtained before, and after 3 and 16 weeks of treatment, for histology and quantitative cultures.

RESULTS

Severity and activity of antral gastritis was reduced after 16-week LC1 intake (pretreatment and 16-week inflammatory cell score: 6.0 +/- 0.8 vs. 5.3 +/- 0.1; P=0.04). H. pylori density decreased in the antrum after LC1 intake (3-week: 4.4 +/- 0.6; 16-week: 4.3 +/- 0.5 log10 colony forming units (cfu) vs. pretreatment 4.5 +/- 0.4 log10 cfu; P=0.04, respectively). Mucus thickness increased after 16 weeks of LC1 consumption (change of mucus thickness with LC1 and placebo in the antrum: 0.6 +/- 1.3 vs. -0.2 +/- 1.0, P=0.01; in the corpus: 0.3 +/- 1.1 vs. -0.6 +/- 1.5, P=0.03).

CONCLUSION

LC1 intake had a favourable, albeit weak, effect on H. pylori associated gastritis, particularly in the antrum. Regular ingestion of fermented milk containing L. johnsonii may reduce the risk of developing disorders associated with high degrees of gastric inflammation and mucus depletion.

13C urea breath test (UBT) in the diagnosis of Helicobacter pylori: why does it work better with acid test meals?

BACKGROUND

Acid test meals may improve the accuracy of the (13)C urea breath test (UBT). This has been attributed to changes in gastric emptying rather than to the effects of gastric pH on Helicobacter pylori urease.

AIMS

To determine whether enhancement of (13)CO(2) excretion in the UBT in H pylori infected volunteers by acidification of a test meal is due to a delay in gastric emptying.

METHODS

Urease activity in vitro was measured in intact bacteria and in bacterial homogenates. Urease activity in vivo was assessed by means of the UBT. Eleven H pylori infected subjects underwent UBTs with neutral Ensure (pH 7.0), acidified Ensure (pH 3.0), and apple juice (pH 3.0). Gastric emptying was assessed by (13)C sodium acetate breath test.

RESULTS

From pH 7 to pH 3, the in vitro urease activity of intact bacteria increased sixfold. In contrast, urease activity of bacterial homogenates was inactivated by low pH. In vivo, urease activity, as measured by the UBT 20 minutes after meal ingestion, was higher with apple juice (delta (13)CO(2)=21.1; p=0.03) and acidified Ensure (delta (13)CO(2)=25.5; p=0.01) than with neutral Ensure (delta (13)CO(2)=12.5). Gastric emptying was faster with apple juice (T(max)=36.7 (8) minutes) but not with acidified Ensure (T(max)=63.3 (5) minutes; p=0.06) than with neutral Ensure (T(max)=65.0 (3) minutes; p=0.04).

CONCLUSIONS

The higher UBT found with acidified compared with neutral test meals was independent of the emptying rates of the test meals but may have been due to medium acidity dependent activation of intra-bacterial urease in intact H pylori.

Acid inhibition on the first day of dosing: comparison of four proton pump inhibitors

BACKGROUND

Rapid and consistent acid suppression on the first day of dosing may be important in treating acid-related disorders.

AIM

To compare the antisecretory activity and onset of action of single doses of rabeprazole, lansoprazole, pantoprazole, omeprazole capsule, omeprazole multiple unit pellet system (MUPS) tablet and placebo in healthy Helicobacter pylori-negative subjects.

METHODS

This cross-over, double-blind, randomized study was performed in 18 H. pylori-negative subjects. Twenty-four-hour intragastric pH monitoring was performed on the day of treatment (once-daily dose of rabeprazole 20 mg, lansoprazole 30 mg, pantoprazole 40 mg, omeprazole capsule 20 mg, omeprazole MUPS tablet 20 mg or placebo).

RESULTS

The intragastric pH (3.4) and time at pH > 4 during the 24 h post-dose (8.0 h) were significantly greater with rabeprazole than with lansoprazole, pantoprazole, omeprazole capsule, omeprazole MUPS tablet or placebo (P <or= 0.04 for rabeprazole vs. the others). Daytime and night-time pH values were higher with rabeprazole and lansoprazole than with pantoprazole, omeprazole capsule and omeprazole MUPS tablet (P </= 0.04).

CONCLUSION

Rabeprazole was the most potent acid inhibitor of all the proton pump inhibitors tested during the first day of dosing.

Clinical and pathological implications of IgG antibody responses to Helicobacter pylori and its virulence factors in non-ulcer dyspepsia

AIM

To determine whether pre-treatment antibody response to Helicobacter pylori virulence factors predicts eradication success and symptom relief 12 months after triple therapy in non-ulcer dyspepsia.

METHODS

H. pylori-positive patients with non-ulcer dyspepsia received 1-week omeprazole-based triple therapy, or omeprazole plus placebos. Symptoms were assessed using a validated Likert scale. Gastric biopsies taken before and 12 months after treatment were used for histological examination. Pre-treatment blood samples were used for the detection of anti-H. pylori immunoglobulin G (IgG) antibodies, and specific IgG antibodies to 19.5-, 26.5-, 30-, 35-, 89- (VacA) and 116-kDa (CagA) antigens of H. pylori.

RESULTS

IgG antibodies to the six antigens were detected in 62%, 96%, 88%, 47%, 54% and 78% of patients, respectively. The presence of antibody to 19.5-, 26.5- or 30-kDa antigen was associated with an increased anti-H. pylori IgG absorbance index. IgG absorbance indices were greater in those with H. pylori eradication (vs. persistent infection). The prevalence of antibodies to the six antigens was not significantly different between those with symptom relief vs. those without. The 19.5-kDa antigen (P = 0.018) and VacA (P = 0.001) were independent risk factors for body gastritis.

CONCLUSIONS

An increased pre-treatment anti-H. pylori IgG absorbance index may be a useful predictor of the success of eradication therapy. Although the 19.5-kDa antigen and VacA were associated with body gastritis, none of the six antigens tested predicted symptom relief after triple therapy.

Effect of omeprazole on regional and temporal variations in intragastric acidity

BACKGROUND

Conventional techniques for measuring gastric acidity have demonstrated the decrease in gastric acidity produced by proton pump inhibitors (PPI); however, such techniques do not detect transient or localized pH changes which may modify the intragastric environment without affecting the therapeutic efficacy of PPIs.

AIM

To investigate local and temporal variations in intragastric pH and to test the hypothesis that omeprazole produces prolonged, generalized gastric anacidity (pH >6).

METHODS

A single-blind study was conducted with triple-point 24-hour gastric pH-metry on days 7, 14 and 21 in 14 healthy, Helicobacter pylori-negative volunteers (7 M; 20-46 years) who received placebo for 7 days, followed by omeprazole 20 mg daily for 14 days.

RESULTS

Omeprazole increased the median 24-hour pH significantly in the distal corpus (placebo: 1.3 (95% CI 1.1 to 1.6); omeprazole week 1: 4.0 (2.6-5.0); omeprazole week 2: 4.0 (2.8-4.6)) and at all other gastric recording sites (p < 0.01). At both corpus sites, nocturnal pH was lower and mealtime pH was higher than the non-meal daytime pH during placebo and both omeprazole administration periods; in the antrum, however, the major difference noted was that meal-time pH was higher than non-meal daytime pH. Antral pH was lower during meals and higher at night than proximal corpus pH. During placebo, gastric pH >6.0 was observed at 1 site only for 1.7% (median; 95% CI 0.4-3.3%), at 2 sites simultaneously for 0.24% (0.0-1.0%) and at 3 sites for 0.0% (0.0-0.28%), respectively, of the recording periods; during the second week of omeprazole, the equivalent results were 7.7% (1.4-14.0%), 4.9% (0.21-15.7%) and 4.7% (0.0-9.9%), respectively.

CONCLUSIONS

Omeprazole, 20 mg daily, does not produce gastric anacidity despite significant increases in median 24-hour pH values. The time-, meal- and site-related variations in gastric pH observed under normal physiological conditions are seen to persist, with prolonged periods of low pH throughout the stomach and preservation of the normal, meal-related rise and nocturnal fall in gastric pH during omeprazole administration.

Treatment of Helicobacter pylori in functional dyspepsia resistant to conventional management: a double blind randomised trial with a six month follow up

BACKGROUND

Previous studies on the treatment of Helicobacter pylori infection in functional dyspepsia have shown little, if any, effect on dyspeptic symptoms. However, whether such treatment might be of benefit in patients resistant to acid inhibitors has not been formally tested.

AIM

The present study investigated the effect of H pylori treatment in patients with functional dyspepsia resistant to conventional treatment.

PATIENTS

A total of 181 H pylori positive patients with chronic functional dyspepsia who had not responded to a one week antacid run-in and two week double blind antisecretory or placebo treatment were included.

METHODS

Patients were randomised to two weeks of treatment with omeprazole 40 mg twice daily combined with amoxicillin 1 g twice daily or omeprazole 20 mg once daily alone. The primary outcome variable ("response") was defined as no need for further therapy or investigations for dyspeptic symptoms 4-6 months after treatment.

RESULTS

H pylori infection was healed in 10% of patients after omeprazole and in 52% after omeprazole plus amoxicillin. The respective "response" rates were 66% and 62% (NS). H pylori treatment and cure of H pylori infection had no effect on complete resolution of all dyspeptic symptoms, individual symptoms, or various aspects of quality of life.

CONCLUSION

In functional dyspepsia, H pylori treatment and cure of H pylori are no more effective for symptoms over six months than short term acid inhibition. These results do not support treatment of H pylori in functional dyspepsia.

Primary prevention of diclofenac associated ulcers and dyspepsia by omeprazole or triple therapy in Helicobacter pylori positive patients: a randomised, double blind, placebo controlled, clinical trial

BACKGROUND

There is much controversy as to whether or not treatment of Helicobacter pylori reduces the occurrence of peptic ulcers during therapy with a non-steroidal anti-inflammatory drug (NSAID).

AIM

To assess the efficacy of triple therapy or omeprazole on the occurrence of diclofenac associated ulcers in H pylori positive patients.

METHODS

This was a randomised, double blind, placebo controlled, multicentre trial in H pylori positive patients requiring NSAID therapy who had no past or current peptic ulcer. They received diclofenac 50 mg twice daily for five weeks in combination with one of the four randomly assigned treatments: anti-H pylori treatment for one week (omeprazole 20 mg+clarithromycin 500 mg+amoxicillin 1 g, all twice daily) followed by placebo for four weeks (OAC-P); anti-H pylori treatment for one week followed by antisecretory treatment with omeprazole 20 mg once daily for four weeks (OAC-O); omeprazole 20 mg once daily for five weeks (O-O); or placebo for five weeks (P-P). Patients were endoscoped before and after treatment.

RESULTS

Data from 660 patients were included in an intention to treat analysis. The occurrence of peptic ulcers in the four treatment groups during the study period was: 1.2% for OAC-P, 1.2% for OAC-O, 0% for O-O, and 5.8% for P-P (p<0.05 between placebo and all active treatment groups). Patients who received active treatment developed therapy requiring dyspeptic symptoms less frequently than those who received placebo (p<0.05 between placebo and all active treatment groups).

CONCLUSIONS

In H pylori infected patients, all three active therapies reduced the occurrence of NSAID associated peptic ulcer and dyspeptic symptoms requiring therapy.

Combined analysis of the ORCHID and OCAY studies: does eradication of Helicobacter pylori lead to sustained improvement in functional dyspepsia symptoms?

Currently, one of the most important unresolved questions concerning Helicobacter pylori is whether eradication of the organism leads to a sustained improvement in symptoms in patients diagnosed with functional (non-ulcer) dyspepsia. Recently, two very similar studies, the ORCHID and OCAY studies, have been completed and the combined results of these two multicentre, multinational, randomised, double blind, controlled clinical trials are reviewed.

Antibiotic prophylaxis of infective endocarditis during digestive endoscopy: over- and underuse in Switzerland despite professed adherence to guidelines

BACKGROUND AND STUDY AIMS

Guidelines for antibiotic prophylaxis of infective endocarditis associated with gastrointestinal endoscopy are not uniform. Though based on weak scientific evidence, they do represent an attempt to unify the management of antibiotic prophylaxis. We investigated whether physicians who profess to adhere to these guidelines actually do apply them correctly.

MATERIALS AND METHODS

A questionnaire was sent to all 195 Swiss gastroenterologists asking whether they adhered to antibiotic prophylaxis guidelines and under what conditions did they apply antibiotic prophylaxis in gastrointestinal endoscopy. We analysed whether the Swiss gastroenterologists who claim to adhere to these guidelines actually do so in practice.

RESULTS

The response rate to our questionnaire was 95%. Of the Swiss gastroenterologists, 60% correctly employ antibiotic prophylaxis guidelines in gastroscopy, as do 47% in colonoscopy. In therapeutic endoscopy, the percentage of correct antibiotic prophylaxis use depends upon the type of intervention and varies between 21 and 58%. Overuse of antibiotic prophylaxis is at least twice as frequent in colonoscopy and therapeutic endoscopy than in gastroscopy.

CONCLUSIONS

Guidelines for antibiotic prophylaxis are not well applied and do not lead to uniform management despite a high degree of professed adherence to them. This phenomenon can be explained by "cognitive dissonance" and "reactance." We conclude that guidelines based on unconvincing data may even prove harmful.

A randomized, double-blind, comparative study of standard-dose rabeprazole and high-dose omeprazole in gastro-oesophageal reflux disease

BACKGROUND

Rabeprazole has a faster onset of antisecretory action than omeprazole, and it is of interest to determine whether this translates into faster symptom relief in patients with gastro-oesophageal reflux disease.

AIMS

To assess the relief from heartburn after 3 days of treatment with standard-dose rabeprazole or high-dose omeprazole (primary end-point). Secondary end-points included the decrease in score for other symptoms of gastro-oesophageal reflux disease, healing rates and quantification of antacid use.

METHODS

Patients with endoscopically confirmed erosive oesophagitis were randomized to receive 4 weeks of double-blind treatment with rabeprazole (20 mg) or omeprazole (40 mg). Patients who were not healed after 4 weeks received a further 4 weeks of treatment.

RESULTS

Two hundred and seventy-four patients were screened, 251 patients were randomized and 230 patients completed the trial. The numbers of patients with relief from heartburn on day 4 were similar in the two groups (84% for rabeprazole; 95% confidence interval, 76-90%; 83% for omeprazole; 95% confidence interval, 75-89%). There were no significant differences between the treatments in the relief from other gastro-oesophageal reflux disease symptoms or in healing rates. The number of reports of severe heartburn during the first 3 days was higher in the omeprazole group (daytime heartburn: 4.7% for rabeprazole vs. 10.3% for omeprazole, P=0.005; night-time heartburn: 4.7% for rabeprazole vs. 9.8% for omeprazole, P=0.01; statistical comparisons defined post hoc).

CONCLUSIONS

Standard-dose rabeprazole was as effective as high-dose omeprazole in relieving symptoms by day 4 of treatment and in healing oesophageal lesions, but had a faster onset of action in patients with severe heartburn. This suggests that the improved pharmacological properties of rabeprazole translate into a clinically relevant advantage.

Cholestatic hepatitis A complicated by acute renal insufficiency

31 cases of non-fulminant hepatitis A complicated by acute renal insufficiency are reported in the literature. Two-thirds of those patients needed dialysis, usually when depending on the severity of their hyperbilirubinemia. This report concerns the first published case of non-fulminant cholestatic hepatitis A complicated by acute renal insufficiency in which a spontaneous remission of renal function occurred without need for dialysis despite a very severe hyperbilirubinemia.

Favourable effect of an acidified milk (LC-1) on Helicobacter pylori gastritis in man

OBJECTIVE

The supernatant of Lactobacillus johnsonii La1 culture was shown to be bactericidal and to have a partial, acid-independent suppressive effect on Helicobacter pylori in humans. The aim of the present study was to investigate the effect of L. johnsonii La1-acidified milk (LC-1) on H. pylori infection.

DESIGN AND METHODS

Fifty-three volunteers infected with H. pylori as determined by positive 13C-urea breath test and positive serology were randomized to receive either LC-1 or a placebo 180 ml twice a day for 3 weeks. All subjects also received clarithromycin 500 mg bid during the last two weeks of acidified milk therapy. Oesophagogastroduodenoscopy and biopsies were performed at inclusion and repeated 4-8 weeks after the end of the treatment. H. pylori infection was confirmed by urease test and histology. H. pylori density and inflammation were scored using a modified Sydney classification.

RESULTS

LC-1 ingestion induced a decrease in H. pylori density in the antrum (P= 0.02) and the corpus (P= 0.04). LC-1 also reduced inflammation and gastritis activity in the antrum (P= 0.02 and P= 0.01, respectively) and of activity in the corpus (P= 0.02). Clarithromycin eradicated H. pylori in 26% of the subjects; LC-1 did not improve the antibiotic effect.

CONCLUSION

These results suggest that H. pylori infection and gastritis can be down-regulated by LC-1.

Short course acid suppressive treatment for patients with functional dyspepsia: results depend on Helicobacter pylori status. The Frosch Study Group

BACKGROUND AND AIMS

Treatment of functional dyspepsia with acid inhibitors is controversial and it is not known if the presence of Helicobacter pylori infection influences the response.

METHODS

After a complete diagnostic workup, 792 patients with functional dyspepsia unresponsive to one week of low dose antacid treatment were randomised to two weeks of treatment with placebo, ranitidine 150 mg, omeprazole 10 mg, or omeprazole 20 mg daily. Individual dyspeptic and other abdominal symptoms were evaluated before and after treatment according to H pylori status.

RESULTS

The proportions of patients considered to be in remission (intention to treat) at the end of treatment with placebo, ranitidine 150 mg, omeprazole 10 mg, and omeprazole 20 mg were, respectively, 42%, 50%, 48%, and 59% in the H pylori positive group and 66%, 73%, 64%, and 71% in the H pylori negative group. In H pylori positive patients, the therapeutic gain over placebo was significant for omeprazole 20 mg (17.6%, 95% confidence intervals (CI) 4.2-31.0; p<0.014 using the Bonferroni-adjusted p level of 0.017) but not for omeprazole 10 mg (6.8%, 95% CI -6.7-20.4) or ranitidine 150 mg (8.9%, 95% CI -4.2-21. 9). There was no significant therapeutic gain from active treatment over placebo in H pylori negative patients. Complete disappearance of symptoms and improvement in quality of life also occurred most frequently with omeprazole 20 mg and was significant in both H pylori positive and H pylori negative groups. The six month relapse rate of symptoms requiring treatment was low (<20%) in all groups.

CONCLUSIONS

Omeprazole 20 mg per day had a small but significant favourable effect on outcome in H pylori positive patients. The differential response in these patients may be explained by an enhanced antisecretory response in the presence of H pylori. The effect of weaker acid inhibition was unsatisfactory.

Cushing's syndrome in an 81-year-old patient treated with budesonide and amiodarone

This is the first report of Cushing's syndrome under oral budesonide treatment. An 81-year-old man known for paroxysmal atrial fibrillation and chronic renal insufficiency, treated with 6 mg budesonide for collagenous colitis, developed Cushing's syndrome under co-administration of amiodarone. The Cushing's syndrome disappeared after discontinuation of the amiodarone treatment. Metabolism of the two medications by hepatic cytochrome P 450 3A may explain the development of Cushing's syndrome.

Helicobacter pylori in the oral cavity reflects handling of contaminants but not gastric infection

Helicobacter pylori colonises the gastric mucosa, but can also be found within the oral cavity. The presence of H. pylori was monitored in the oral cavity of 22 patients with duodenal ulcer, before and after antibiotic treatment and of 24 hospital employees who were or were not professionally exposed to H. pylori. Gastric infection was determined by breath test. Bacteria in the oral cavity were detected by nested PCR of samples containing saliva and dental plaque, using primers specific for 16S rRNA and ureC genes. Before treatment, 9 out of 22 infected ulcer patients harbored H. pylori in their oral cavity. Bacteria disappeared from the oral cavity of 3 of 7 cured patients. Twelve of 17 exposed subjects harbored H. pylori in their oral cavity, while no bacteria could be detected in the mouths of the 7 nonexposed subjects. Presence of bacteria in the oral cavity reflects handling of contaminants; it does not correlate with gastric infection and does not seem to promote it.

Effect of whey-based culture supernatant of Lactobacillus acidophilus (johnsonii) La1 on Helicobacter pylori infection in humans

BACKGROUND

Specific strains of Lactobacillus acidophilus are known to inhibit intestinal cell adhesion and invasion by enterovirulent bacteria. As L. acidophilus can survive transiently in the human stomach, it may downregulate Helicobacter pylori infection.

METHODS

The ability of L. acidophilus (johnsonii) La1 supernatant to interfere with H. pylori bacterial growth, urease activity, and adhesion to epithelial cells was tested in vitro. Its effect on H. pylori infection in volunteers was monitored in a randomized, double-blind, controlled clinical trial, using a drinkable, whey-based, La1 culture supernatant. H. pylori infected volunteers were treated 14 days with 50 ml of La1 supernatant four times a day combined with either omeprazole 20 mg four times a day or with placebo. Infection was assessed by breath test, endoscopy, and biopsy sampling, performed at inclusion, immediately at the end of the treatment (breath test only), and 4 weeks after the end of the treatment.

RESULTS

La1 supernatant inhibited H. pylori growth in vitro, regardless of previous binding of H. pylori to epithelial cells. In 20 subjects (8 females, 12 males, mean age 33.1 years) a marked decrease in breath test values was observed immediately after treatment with La1 supernatant, both in the omeprazole and in the placebo group (median 12.3 vs. 28.8 and 9.4 vs. 20.4, respectively; p < 0.03). In both treatment groups, breath test values remained low 6 weeks after treatment (omeprazole treated 19.2, placebo treated 8. 3; p < 0.03 vs. pretreatment), but the persistence of H. pylori infection was confirmed in gastric biopsies.

CONCLUSION

La1 culture supernatant shown to be effective in vitro has a partial, acid-independent long-term suppressive effect on H. pylori in humans.

Quantitative analysis of intestinal motor patterns: spatiotemporal organization of nonneural pacemaker sites in the rat ileum

BACKGROUND & AIMS

Intestinal contractions are triggered by electric activity of pacemaker cells within the smooth muscle. However, the precise spatial organization of the pacemaker system is unknown. We directly assessed the spatiotemporal organization of pacemakers by video image analysis combined with manometry and electromyography.

METHODS

Isolated segments of rat ileum were perfused arterially with oxygenated fluorocarbon solution and luminally with saline. Luminal end pressures, extracellular electric activity, and images of the intestine were recorded simultaneously. Tetrodotoxin, N(G)-nitro-L-arginine methyl ester (L-NAME), L-arginine, and eserine were administered arterially.

RESULTS

Myogenic contractions originated in discrete areas (dominant pacemakers) and propagated faster in aboral than in oral direction. Dominant pacemakers were distributed along the intestine at regular intervals. The preparations were mostly driven by 1 pacemaker at the time, but 2 or 3 pacemakers with different frequencies could be active simultaneously. Tetrodotoxin decreased aboral propagation velocity and revealed multiple regularly spaced pacemaker areas. Eserine increased, whereas L-arginine decreased, their frequency. After L-NAME, pacemaker activity increased and isolated pacemakers with higher frequency appeared.

CONCLUSIONS

Nonneural pacemakers in rat ileum are functionally organized not as a continuous system but show a segmental arrangement, spatially and temporally modulated by neural activity.

Diagnostic accuracy and interobserver agreement of CT colonography (virtual colonoscopy)

BACKGROUND AND AIMS

Computed tomographic (CT) colonography or virtual colonoscopy (VC) is a non-invasive imaging method proposed for screening patients with colorectal neoplasias. Our aims were to study the diagnostic accuracy and interobserver agreement of VC for correct patient identification compared with conventional colonoscopy (CC).

METHODS

This was a prospective study of 50 patients successively undergoing VC and CC. Multiplanar two dimensional CT images and three dimensional VC were constructed using surface rendering software and interpreted by two independent investigator teams. VC findings were compared with those of CC. Interobserver agreement was determined using kappa statistics.

RESULTS

CC found 65 polyps in 24 patients. For identification of patients with polyps > or =10 mm, the sensitivity of VC was 38% and 63%, and specificity was 74% and 74% for teams 1 and team 2. Interobserver agreement was good (kappa 0.72). For patients with polyps of any size, the sensitivity of VC was 75% and 71%, and specificity was 62% and 69% for teams 1 and 2. Interobserver agreement was fair (kappa 0.56). Accuracy improved when comparing the results of the first 24 with the last 26 patients.

CONCLUSIONS

In our experience, VC had a low diagnostic value for identification of patients with colorectal neoplasias. Interobserver agreement for VC interpretation was fair. These results may be explained by software imperfections and a learning curve effect.

The effects of omeprazole on healing and appearance of small gastric and duodenal lesions during dosing with diclofenac in healthy subjects

BACKGROUND

Non-steroidal anti-inflammatory drugs (NSAIDs) are associated with gastrointestinal mucosal damage. Omeprazole prevents the formation, and accelerates the healing, of NSAID-induced ulcers.

AIM

To test whether omeprazole accelerates healing of standardized gastroduodenal lesions in the presence of diclofenac.

METHODS

In a double-blind, double-dummy, placebo-controlled, crossover study, 12 healthy volunteers received consecutive, 2-week courses of omeprazole (40 mg o.d.) and placebo, in random order, with an intervening, 4-week washout period; diclofenac (50 mg t.d.s.), was given for the second week of each course. Five endoscopies were performed, one at the outset and the others before and after each course of diclofenac. Biopsies were taken from the endoscopically normal mucosa of the corpus, antrum and duodenum and also from any new mucosal lesion that developed after diclofenac. The sites of biopsies taken before each course of diclofenac were evaluated endoscopically after each course to assess the extent of healing according to a predetermined healing score scale.

RESULTS

The healing scores observed after administration of placebo/diclofenac (median=0; range 0-6) and after omeprazole/diclofenac (median=0; range 0-6; P=0.17) did not differ. Small gastroduodenal lesions developed de novo in six subjects during placebo/diclofenac and in seven during omeprazole/diclofenac. Focal chemical gastropathy was observed only in close proximity to macroscopic lesions.

CONCLUSIONS

In healthy subjects, omeprazole does not accelerate the healing of pre-existing mucosal lesions or prevent the development of small diclofenac-induced mucosal lesions.

The effect of ammonia on omeprazole-induced reduction of gastric acidity in subjects with Helicobacter pylori infection

OBJECTIVE

Omeprazole produces a higher intragastric pH during Helicobacter pylori (H. pylori) infection than after cure. We tested the hypothesis that this difference is due to the production of ammonia by H. pylori.

METHODS

Gastric acidity and acid output (AO) were measured overnight in 12 subjects, with and without omeprazole, before and 1 and 6 months after cure of H. pylori infection. Gastric ammonia ([NH3]), total bile acid ([TBA]) and protein concentrations and plasma omeprazole levels were measured.

RESULTS

During omeprazole, median AO were 0.0 mmol/h before, 0.86 mmol/h (p = 0.003 vs before cure) at 1 month, and 0.34 mmol/h (p = 0.02) at 6 months after cure; median NH3 output was 0.17 mmol/h before, 0.03 mmol/h (p = 0.002) at 1 month, and 0.02 mmol/h (p = 0.005) at 6 months after cure. AO and NH3 output were similar 1 and 6 months after cure. When corrected for [NH3], AO and gastric pH curves were similar before and after cure. Omeprazole plasma levels increased after cure and gastric [TBA] were unchanged.

CONCLUSIONS

The higher pH observed before cure of H. pylori during omeprazole administration is attributable, in large part, to ammonia production. Other acid-neutralizing substances and changes in acid secretion may also be important, but duodenogastric reflux and omeprazole pharmacokinetics are not involved.

Oral administration of antigens from intestinal flora anaerobic bacteria reduces the severity of experimental acute colitis in BALB/c mice

Homeostasis between indigenous intestinal flora and host response may be broken in inflammatory bowel disease. The present study explores whether repeated oral administration of intestinal flora antigens can protect mice against dextran sodium sulphate (DSS)-induced colitis. Sonicates of Gram-positive, Gram-negative, or anaerobic resident bacteria isolated from mouse intestinal flora were fed to BALB/c mice by gastric gavage, with or without cholera toxin. After four weekly doses of 1 mg of these antigen preparations (or of PBS as control), DSS colitis was induced. One week later colitis was evaluated by clinical scores and histology. Mice fed a pool of the three sonicates had decreased inflammation scores (5 (1-14); median (range)) compared with PBS-fed control animals (15 (7-19); P < 0.05). Decreased inflammation was observed in mice fed anaerobic bacteria antigens (7 (6-11); P < 0.05 versus control), but not in mice fed a pool of Gram-positive and -negative sonicates (16 (12-16)). Inflammation scores of mice fed antigens with cholera toxin were similar to those of PBS-fed control animals. DSS-induced colitis can be suppressed by oral administration of normal intestinal flora antigens containing anaerobes.

The effect of intra-gastric acidity and flora on the concentration of N-nitroso compounds in the stomach

BACKGROUND

Correa's hypothesis proposes that gastric carcinogenesis is due to atrophic gastritis and hypochlorhydria which permit gastric bacterial colonization, the reduction of dietary nitrates to nitrites and the formation of potentially carcinogenic N-nitroso compounds (NOCs).

OBJECTIVE

To test the hypothesis that omeprazole-induced hypochlorhydria is associated with increased intra-gastric concentrations of nitrate-reducing bacteria (NRB), nitrites and NOCs.

DESIGN

Single-blind study in healthy volunteers.

PARTICIPANTS

Fourteen healthy subjects (seven female, mean age 24 years), free of Helicobacter pylori infection, received a one-week course of placebo followed by a two-week course of omeprazole, 20 mg daily.

METHODS

Fasted gastric samples, aspirated using a sterile double-lumen nasogastric tube at the end of the 1 st week (placebo) and the 2nd and 3rd weeks (omeprazole), were cultured aerobically and anaerobically; gastric pH and intra-gastric concentrations of nitrates, nitrites and NOCs were also determined.

RESULTS

After weeks 1, 2 and 3, the intra-gastric concentrations of nitrate-reducing bacteria exceeded 10(5) colony-forming units (c.f.u.)/ml in 3, 7 and 9 subjects, respectively (P > 0.05). A gastric pH greater than 4.0 was associated with increased NRB (P < 0.05); however, neither increased gastric pH nor increased NRB, alone or in combination, was associated with increased intra-gastric concentrations of nitrites or NOCs (P > 0.05).

CONCLUSIONS

A two-week increase in gastric pH in healthy, H. pylori-negative subjects was associated with increased intra-gastric concentrations of nitrate-reducing bacteria but not of nitrites or N-nitroso compounds. These data suggest that reduced gastric acid secretion is not a necessary precursor to the formation of carcinogenic N-nitroso compounds and that other mechanisms should be invoked to explain gastric carcinogenesis.

Urease-based mucosal immunization against Helicobacter heilmannii infection induces corpus atrophy in mice

Mucosal immunization with Helicobacter heilmannii urease B or Helicobacter pylori urease, given nasally with cholera toxin, protects BALB/c mice against H. heilmannii infection and significantly reduces a preexisting infection. However, immunization aggravates gastric corpus atrophy. Our results underline the necessity of defining immunization regimens that do not enhance mucosal damage.

Endoscopic assessment of oesophagitis: clinical and functional correlates and further validation of the Los Angeles classification

BACKGROUND

Endoscopic oesophageal changes are diagnostically helpful and identify patients exposed to the risk of disease chronicity. However, there is a serious lack of agreement about how to describe and classify the appearance of reflux oesophagitis

AIMS

To examine the reliability of criteria that describe the circumferential extent of mucosal breaks and to evaluate the functional and clinical correlates of patients with reflux disease whose oesophagitis was graded according to the Los Angeles system.

METHODS

Forty six endoscopists from different countries used a detailed worksheet to evaluate endoscopic video recordings from 22 patients with the full range of severity of reflux oesophagitis. In separate studies, Los Angeles system gradings were correlated with 24 hour oesophageal pH monitoring (178 patients), and with clinical trials of omeprazole treatment (277 patients).

RESULTS

Evaluation of circumferential extent of oesophagitis by the criterion of whether mucosal breaks extended between the tops of mucosal folds, gave acceptable agreement (mean kappa value 0.4) among observers. This approach is used in the Los Angeles system. An alternative approach of grouping the circumferential extent of mucosal breaks as occupying 0-25%, 26-50%, 51-75%, 76-99%, or 100% of the oesophageal circumference, gave unacceptably high interobserver variation (mean kappa values 0-0.15) for all but the lowest category of extent (mean kappa value 0.4). Severity of oesophageal acid exposure was significantly (p<0.001) related to the severity grade of oesophagitis. Preteatment oesophagitis grades A-C were related to heartburn severity (p<0.01), outcomes of omeprazole (10 mg daily) treatment (p<0.01), and the risk for symptom relapse off therapy over six months (p<0.05).

CONCLUSIONS

Results add further support to previous studies for the clinical utility of the Los Angeles system for endoscopic grading of oesophagitis.

Oral immunization with urease and Escherichia coli heat-labile enterotoxin is safe and immunogenic in Helicobacter pylori-infected adults

BACKGROUND & AIMS

Oral immunization with Helicobacter pylori urease can cure Helicobacter infection in animals. As a step toward therapeutic immunization in humans, the safety and immunogenicity of oral immunization with recombinant H. pylori urease were tested in H. pylori-infected adults.

METHODS

Twenty-six H. pylori-infected volunteers were randomized in a double-blind study to four weekly oral doses of 180, 60, or 20 mg of urease with 5 microg heat-labile enterotoxin of Escherichia coli (LT), LT alone, or placebo. Side effects and immune responses were evaluated weekly after immunization, and gastric biopsy specimens were obtained after 1 month and 6 months for histology and quantitative cultures.

RESULTS

Diarrhea was noted in 16 of 24 (66%) of the volunteers who completed the study. Antiurease serum immunoglobulin A titers increased 1. 58-fold +/- 0.37-fold and 3.66-fold +/- 1.5-fold (mean +/- SEM) after immunization with 60 and 180 mg urease, respectively, whereas no change occurred in the placebo +/- LT groups (P = 0.005). Circulating antiurease immunoglobulin A-producing cells increased in volunteers exposed to urease compared with placebo (38.9 +/- 13. 6/10(6) vs. 5.4 +/- 3.1; P = 0.018). Eradication of H. pylori infection was not observed, but urease immunization induced a significant decrease in gastric H. pylori density.

CONCLUSIONS

H. pylori urease with LT is well tolerated and immunogenic in H. pylori-infected individuals. An improved vaccine formulation may induce curative immunity.

Effects of pumaprazole (BY841), a novel reversible proton pump antagonist, and of omeprazole, on intragastric acidity before and after cure of Helicobacter pylori infection

BACKGROUND

Omeprazole produces a higher intragastric pH in the presence of Helicobacter pylori infection than after cure.

AIM

To investigate whether this effect also occurs with pumaprazole (BY841), a reversible proton pump antagonist which, in contrast to omeprazole, does not require activation in the acid compartment of the parietal cell.

METHODS

In a randomized, crossover, double-blind study, 24-h intragastric pH was measured in 13 H. pylori-positive subjects before and after a 1-week course of omeprazole (20 mg o.d.) or of pumaprazole (100 mg b.d.). The studies were repeated after the infection was cured.

RESULTS

In the absence of drug administration, the median 24-h pH values before cure (median 2.0, 90% CI: 1.2-3.2) did not differ from those after cure (median 1.5, 90% CI: 1.3-2.2; P = 0.115). The 24-h pH values were higher before cure of the infection than after during both pumaprazole (6.0, 4.8-6.7 vs. 4.3, 2.6-5.7; P = 0.002) and omeprazole (5.8, 4.0-6.2 vs. 3.6, 2.8-5; P = 0.004). Both before and after cure, there were no significant differences between the two drugs with respect to acid inhibition over the 24-h period. The median decrease in acid inhibition after cure of the infection (calculated as the difference in H+ activity in mmol/L) during pumaprazole (median 0.05, 90% CI: 6 x 10-4- 2.3) was no different from that during omeprazole (median 0.2, 90% CI: 3 x 10-3-1.5; P = 0.6).

CONCLUSIONS

Both before and after cure of H. pylori infection, pumaprazole raised the intragastric pH over a 24-h period to a similar degree as omeprazole. H. pylori infection similarly augments the pH-increasing effect of both drugs. This effect is related to H. pylori infection and not to an increased activation of acid inhibitory agents in the parietal cell compartment.

Lack of effect of treating Helicobacter pylori infection in patients with nonulcer dyspepsia. Omeprazole plus Clarithromycin and Amoxicillin Effect One Year after Treatment (OCAY) Study Group

BACKGROUND

It is uncertain whether treatment of Helicobacter pylori infection relieves symptoms in patients with nonulcer, or functional, dyspepsia.

METHODS

We conducted a double-blind, multicenter trial of patients with H. pylori infection and dyspeptic symptoms (moderate-to-very-severe pain and discomfort centered in the upper abdomen). Patients were excluded if they had a history of peptic ulcer disease or gastroesophageal reflux disease and had abnormal findings on upper endoscopy. Patients were randomly assigned to seven days of treatment with 20 mg of omeprazole twice daily, 1000 mg of amoxicillin twice daily, and 500 mg of clarithromycin twice daily or with omeprazole alone and then followed up for one year. Treatment success was defined as the absence of dyspeptic symptoms or the presence of minimal symptoms on any of the 7 days preceding the 12-month visit.

RESULTS

Twenty of the 348 patients were excluded after randomization because they were not infected with H. pylori, were not treated, or had no data available. For the remaining 328 patients (164 in each group), treatment was successful for 27.4 percent of those assigned to receive omeprazole and antibiotics and 20.7 percent of those assigned to receive omeprazole alone (P=0.17; absolute difference between groups, 6.7 percent; 95 percent confidence interval, -2.6 to 16.0). After 12 months, gastritis had healed in 75.0 percent of the patients in the group given omeprazole and antibiotics and in 3.0 percent of the patients in the omeprazole group (P<0.001); the respective rates of H. pylori eradication were 79 percent and 2 percent. In the group given omeprazole and antibiotics, the rate of treatment success among patients with persistent H. pylori infection was similar to that among patients in whom the infection was eradicated (26 percent vs. 31 percent). There were no significant differences between the groups in the quality of life after treatment.

CONCLUSIONS

In patients with nonulcer dyspepsia, the eradication of H. pylori infection is not likely to relieve symptoms.

Immunization of BALB/c mice with Helicobacter urease B induces a T helper 2 response absent in Helicobacter infection

BACKGROUND & AIMS

Infection with Helicobacter induces a T helper type 1 response in mice and humans. Mice can be cured or protected from infection with Helicobacter by mucosal immunization with recombinant H. pylori urease B subunit (rUreB). This study characterizes the immune response of infected mice immunized with rUreB.

METHODS

BALB/c mice were infected with H. felis. Two weeks later, they were orally immunized four times with rUreB and cholera toxin (CT) at weekly intervals. Controls were only infected or sham-immunized with CT. Animals were killed at various times after immunization. Splenic CD4(+) cells were obtained and cultured in vitro with rUreB to evaluate antigen-specific proliferation and induction of interferon gamma and interleukin 4 secretion.

RESULTS

All rUreB-immunized mice (n = 8) were cured from infection 3 weeks after the fourth immunization. Immunization induced a proliferative response of splenic CD4(+) cells, a progressive decrease in interferon gamma secretion, and a concomitant increase in interleukin 4 secretion after each immunization. A simultaneous increase in rUreB specific serum immunoglobulin G1 levels was observed in infected/immunized mice.

CONCLUSIONS

In BALB/c mice, therapeutic mucosal immunization with rUreB induces progressively a Th2 CD4(+) T cell response resulting in the elimination of the pathogen.

Differential expression of laminin-5 subunits and integrin receptors in human colorectal neoplasia

Cell-matrix interactions contribute to regulating the adhesion, growth, migration, and differentiation of epithelial intestinal cells. Alterations in matrix components and their cellular receptors have been found in tumours but their specific roles remain unclear. The tissue patterns of laminin-5 and alpha 3, beta 3 and gamma 2 subunits, as well as those of the alpha 3, alpha 6, beta 1, and beta 4 integrin chains, were determined by immunofluorescence on frozen sections of 12 colorectal mucosal samples from four patients, 15 adenomas, 29 adenocarcinomas, and eight metastases. Distinct patterns of laminin-5 and integrin expression were found along the mucosa-adenoma, and adenoma-carcinoma transitions. Expression of basement membrane laminin-5 and subunits was continuous and gradient-like in normal mucosa, enhanced at the periphery of adenomas, and discontinuous in places in carcinomas and metastases. Decrease of the alpha 3 integrin chain was found in adenomas, together with that of alpha 6 and beta 4 chains in carcinomas. A subpopulation of carcinoma cells dissociating (budding) from neoplastic tubules was found to accumulate the laminin-5 beta 3 gamma 2 heterodimer in the cytoplasm, with progressive loss of surface integrin expression. These results suggest that in colorectal cancer, an abnormal expression of laminin-5 subunits and integrin chains may identify a subset of carcinoma cells prone to invade focally and to contribute to disease aggressiveness.

Helicobacter pylori and functional dyspepsia: a real causal link?

This chapter reviews the evidence for a link between functional dyspepsia and Helicobacter pylori infection from three angles. In the section on pathophysiology, we evaluate how H. pylori could theoretically produce dyspeptic symptoms: many mechanisms can be proposed. In the discussion on epidemiology, we evaluate possible associations between the occurrence of symptoms and infection. Here, many studies claiming a coincidence or chronological sequence of infection and symptoms are criticized because of their poor design. In the section on the improvement of functional dyspepsia by the treatment of H. pylori infection, the conclusion is reached that if such an effect occurs at all--which is unlikely--it is very weak. The controversy on the link between H. pylori infection and functional dyspepsia is presently ongoing. Some authors are still trying to save an elegant concept that once looked so plausible but now has the facts against it.

High concentrations of ammonia, but not volatile amines, in gastric juice of subjects with Helicobacter pylori infection

BACKGROUND

Helicobacter pylori (H. pylori) produces large amounts of ammonia. Based on higher readings obtained with an ammonia-sensitive electrode when compared to a specific enzymatic assay, it has been claimed that H. pylori also produces potentially toxic volatile amines.

METHOD

We measured ammonia concentrations (NH3) in gastric aspirates from 11 H. pylori positive subjects (22-40 y, 6 M), using an ammonia electrode sensitive to ammonia and amines, and an enzymatic assay specific for ammonia. Continuous aspiration was performed overnight and 220 aspirates were analyzed before and 6 weeks after cure of H. pylori. Gastric samples were diluted 1:3 (before cure) and 1:1 (after cure) according to dilution curves constructed prior to the assays.

RESULTS

Median (95% CI) NH3 detected by the electrode/enzymatic assay were 4.34 mM[4.12-4.61]/4.50 mM [4.28-4.68] (p > .05) before cure and 0.54 mM[0.42-0.60]/0.73 mM[0.71-0.81] after cure (p > .05). Intra-class correlation coefficient between the two methods was 0.91 before cure and 0.90 after cure (p < .001). Without dilution, the enzymatic assay was linear for NH3 from 0.01 to 1 mM and saturated at 2.5 mM; the electrode was linear for NH3 from 0.01 to 20 mM. When appropriate dilutions were performed, the enzymatic assay was accurate for NH3 greater than 2.5 mM.

CONCLUSION

In subjects with H. pylori infection there is a high NH3 in gastric juice; production of volatile amines appears to be negligible in vivo. An ammonia-sensitive electrode and a specific enzymatic assay are both suitable methods for determining NH3 in the gastric juice of subjects with H. pylori infection.

Differential expression of laminin-5 subunits and integrin receptors in human colorectal neoplasia

Cell-matrix interactions contribute to regulating the adhesion, growth, migration, and differentiation of epithelial intestinal cells. Alterations in matrix components and their cellular receptors have been found in tumours but their specific roles remain unclear. The tissue patterns of laminin-5 and alpha 3, beta 3 and gamma 2 subunits, as well as those of the alpha 3, alpha 6, beta 1, and beta 4 integrin chains, were determined by immunofluorescence on frozen sections of 12 colorectal mucosal samples from four patients, 15 adenomas, 29 adenocarcinomas, and eight metastases. Distinct patterns of laminin-5 and integrin expression were found along the mucosa-adenoma, and adenoma-carcinoma transitions. Expression of basement membrane laminin-5 and subunits was continuous and gradient-like in normal mucosa, enhanced at the periphery of adenomas, and discontinuous in places in carcinomas and metastases. Decrease of the alpha 3 integrin chain was found in adenomas, together with that of alpha 6 and beta 4 chains in carcinomas. A subpopulation of carcinoma cells dissociating (budding) from neoplastic tubules was found to accumulate the laminin-5 beta 3 gamma 2 heterodimer in the cytoplasm, with progressive loss of surface integrin expression. These results suggest that in colorectal cancer, an abnormal expression of laminin-5 subunits and integrin chains may identify a subset of carcinoma cells prone to invade focally and to contribute to disease aggressiveness.

[Helicobacter pylori infection and ulcer]

Our understanding of ulcer pathogenesis has dramatically changed since the discovery of Heliobacter pylori. Peptic ulcer is now recognized as a chronic gastric infectious disease. H. pylori can be considered the pacemaker, with other known risk factors ultimately contributing to the ulcer formation. Treatment of H. pylori in peptic ulcer disease cures the acute lesion and prevents relapse and complications. In clinical management a positive diagnosis of H. pylori is required and other potential causes for ulcer formation must be excluded before starting treatment. The standard treatment in H. pylori positive ulcer consists of PPI in standard dose and two antibiotics either clarithromycin 2 x 500 mg and amoxycillin 2 x 1 g or metronidazole 2 x 400 mg and clarithromycin 2 x 250 mg (or 500 mg) for 7 days. The simultaneous presence of H. pylori and NSAID intake requires distinct management. Following bleeding complication a PPI needs to be given beyond 7 days until ulcer healing is endoscopically confirmed.

Mice are protected from Helicobacter pylori infection by nasal immunization with attenuated Salmonella typhimurium phoPc expressing urease A and B subunits

Live Salmonella typhimurium phoPc bacteria were tested as mucosal vaccine vectors to deliver Helicobacter pylori antigens. The genes encoding the A and B subunits of H. pylori urease were introduced into S. typhimurium phoPc and expressed under the control of a constitutive tac promoter (tac-ureAB) or a two-phase T7 expression system (cT7-ureAB). Both recombinant Salmonella strains expressed the two urease subunits in vitro and were used to nasally immunize BALB/c mice. The plasmid carrying cT7-ureAB was stably inherited by bacteria growing or persisting in the spleen, lungs, mesenteric or cervical lymph nodes, and Peyer's patches of immunized mice, while the plasmid carrying tac-ureAB was rapidly lost. Spleen and Peyer's patch CD4+ lymphocytes from mice immunized with S. typhimurium phopc cT7-ureAB proliferated in vitro in response to urease, whereas cells from mice given S. typhimurium phoPc alone did not. Splenic CD4+ cells from mice immunized with phoPc cT7-ureAB secreted gamma interferon and interleukin 10, while Peyer's patch CD4+ cells did not secrete either cytokine. Specific H. pylori anti-urease immunoglobulin G1 (IgG1) and IgG2A antibodies were detected following immunization, confirming that both Th1- and Th2-type immune responses were generated by the live vaccine. Sixty percent of the mice (9 of 15) immunized with S. typhimurium phoPc cT7-ureAB were found to be resistant to infection by H. pylori, while all mice immunized with phoPc tac-ureAB (15 of 15) or phoPc (15 of 15) were infected. Our data demonstrate that H. pylori urease delivered nasally by using a vaccine strain of S. typhimurium can trigger Th1- and Th2-type responses and induce protective immunity against Helicobacter infection.

Alterations in plasminogen activation correlate with epithelial cell dysplasia grading in colorectal adenomas

Proteases are important for neoplastic invasion but a specific role for the plasminogen activator system in the progression of colorectal epithelial dysplasia to adenomatous lesions remains unclear. Consecutive tissue cryosections of 51 adenomas, 49 distant mucosa samples and five mucosa samples from control subjects were histopathologically analysed for dysplasia grade and tissue type, urokinase plasminogen activator levels and plasminogen activator inhibitor type 1 (PAI-1) using immunosorbent methods. Plasminogen activation and urokinase-mediated proteolytic activity levels were assessed using in situ zymography. Plasminogen activation and tissue-type activator levels were lower in adenomas than in mucosae (P < 0.001). PAI-1 concentration and urokinase levels were higher in adenomas than in mucosae (P < 0.001 and P < 0.001 respectively). In adenomas, urokinase concentration increased in parallel with PAI-1, but only the urokinase levels correlated with the dysplasia grade (P < 0.01). Thus, the alterations in plasminogen activation correlated with epithelial cell dysplasia grading. In the mucosa to adenoma transition, a marked decrease in tissue-type plasminogen activator occurred. In adenomas, this decrease was accompanied by a concomitant increase in urokinase and PAI-1. The urokinase level only continued to rise in parallel with the dysplasia grade. Resulting protease-antiprotease imbalance in high-grade dysplasia may represent the phenotypic change associated with malignant transformation and invasive behaviour.

Gastro-oesophageal reflux disease: medical or surgical treatment? Report of an interactive workshop

Gastroesophageal reflux disease (GERD) is the most common disease of the upper gastrointestinal tract. With the introduction of proton pump inhibitors medical treatment of GERD has been significantly improved. However, the development of laparoscopic antireflux surgery resulted in an increasing interest of surgeons in this disease. An interactive meeting was organized in order to develop an agreement between gastoenterologists and surgeons regarding therapeutic decisions and this is the main topic of this paper.

[Gastroenterology. II: Acid research and ulcer therapy]

Three discoveries of the last thirty years have revolutionized acid research and ulcer therapy: H2-receptors and their competitive inhibition, the acid pump and its blockade and, finally, Helicobacter pylori and its central role in ulcer disease. Today the problem of ulcer treatment is more or less solved by the correct use of antibiotics, while the cure of reflux disease is still problematic: pump blockers accelerate the healing of mucosal breaks and prevent, when given at long term, recurrences but they cannot change the natural history of reflux disease. These facts form the basis for future research.