Current concepts in the management of Helicobacter pylori infection--the Maastricht 2-2000 Consensus Report

Significant progress and new insights have been gained in the 4 years since the first Maastricht Consensus Report, necessitating an update of the original guidelines. To achieve this, the European Helicobacter Pylori Study Group organized a meeting of specialists and experts from around the world, representatives from National Gastroenterology Societies and general practitioners from Europe to establish updated guidelines on the current management of Helicobacter pylori infection. The meeting took place on 21-22 September 2000. A "test and treat" approach is recommended in adult patients under the age of 45 years (the age cut-off may vary locally) presenting in primary care with persistent dyspepsia, having excluded those with predominantly gastro-oesophageal reflux disease symptoms, non-steroidal anti-inflammatory drug users and those with alarm symptoms. Diagnosis of infection should be by urea breath test or stool antigen test. As in the previous guidelines, the eradication of H. pylori is strongly recommended in all patients with peptic ulcer, including those with complications, in those with low-grade gastric mucosa-associated lymphoid tissue lymphoma, in those with atrophic gastritis and following gastric cancer resection. It is also strongly recommended in patients who are first-degree relatives of gastric cancer patients and according to patients' wishes after full consultation. It is advised that H. pylori eradication is considered to be an appropriate option in infected patients with functional dyspepsia, as it leads to long-term symptom improvement in a subset of patients. There was consensus that the eradication of H. pylori is not associated with the development of gastro-oesophageal reflux disease in most cases, and does not exacerbate existing gastro-oesophageal reflux disease. It was agreed that the eradication of H. pylori prior to the use of non-steroidal anti-inflammatory drugs reduces the incidence of peptic ulcer, but does not enhance the healing of gastric or duodenal ulcer in patients receiving antisecretory therapy who continue to take non-steroidal anti-inflammatory drugs. Treatment should be thought of as a package which considers first- and second-line eradication therapies together. First-line therapy should be with triple therapy using a proton pump inhibitor or ranitidine bismuth citrate, combined with clarithromycin and amoxicillin or metronidazole. Second-line therapy should use quadruple therapy with a proton pump inhibitor, bismuth, metronidazole and tetracycline. Where bismuth is not available, second-line therapy should be with proton pump inhibitor-based triple therapy. If second-line quadruple therapy fails in primary care, patients should be referred to a specialist. Subsequent failures should be handled on a case-by-case basis by the specialist. In patients with uncomplicated duodenal ulcer, eradication therapy does not need to be followed by further antisecretory treatment. Successful eradication should always be confirmed by urea breath test or an endoscopy-based test if endoscopy is clinically indicated. Stool antigen test is the alternative if urea breath test is not available.

Inhibition of stress-activated MAP kinases induces clinical improvement in moderate to severe Crohn's disease

BACKGROUND & AIMS

We investigated if inhibition of mitogen-activated protein kinases (MAPKs) was beneficial in Crohn's disease.

METHODS

Inhibition of JNK and p38 MAPK activation with CNI-1493, a guanylhydrazone, was tested in vitro. Twelve patients with severe Crohn's disease (mean baseline, CDAI 380) were randomly assigned to receive either 8 or 25 mg/m(2) CNI-1493 daily for 12 days. Clinical endpoints included safety, Crohn's Disease Activity Index (CDAI), Inflammatory Bowel Disease Questionnaire, and the Crohn's Disease Endoscopic Index of Severity.

RESULTS

Colonic biopsies displayed enhanced JNK and p38 MAPK activation. CNI-1493 inhibition of both JNK and p38 phosphorylation was observed in vitro. Treatment resulted in diminished JNK phosphorylation and tumor necrosis factor production as well as significant clinical benefit and rapid endoscopic ulcer healing. No serious adverse events were noted. A CDAI decrease of 120 at week 4 (P = 0.005) and 146.5 at week 8 (P = 0.005) was observed. A clinical response was seen in 67% of patients at 4 weeks and 58% at 8 weeks. Clinical remission was observed in 25% of patients at week 4 and 42% at week 8. Endoscopic improvement occurred in all but 1 patient. Response was seen in 3 of 6 infliximab failures, 2 of whom showed remission. Fistulae healing occurred in 4 of 5 patients, and steroids were tapered in 89% of patients.

CONCLUSIONS

Inflammatory MAPKs are critically involved in the pathogenesis of Crohn's disease and their inhibition provides a novel therapeutic strategy.

Effect of acid suppression on efficacy of treatment for Helicobacter pylori infection

Eradication of Helicobacter pylori from the stomach by triple therapy with bismuth, tetracycline, and metronidazole cures peptic ulcer disease. We investigated whether concomitant acid inhibition with omeprazole would improve the results of triple therapy. 108 consecutive patients with peptic-ulcer disease and biopsy-proven H pylori infection were randomised to 7 days of triple therapy with or without omeprazole 20 mg twice daily. Patients in the omeprazole-treated group were pretreated with 3 days of omeprazole. Eradication of H pylori was assessed by 10 endoscopic biopsies for urease test, histology, and culture 4-6 weeks after treatment. 53 of 54 (98.1%) patients treated with omeprazole were cured compared with 45 of 54 (83.3%) of those not treated (p = 0.02), a difference in efficacy of 14.8% (95% Cl 4.2-25.4%). Most side effects were mild and did not interfere with compliance; 105 patients (97.2%) finished treatment. Gastro-intestinal side effects were significantly fewer in the omeprazole group. We conclude that the addition of omeprazole to triple therapy improves efficacy, lessens side effects, and is sufficiently efficacious to obviate the need for a diagnostic test of cure in compliant patients.

The stool antigen test for detection of Helicobacter pylori after eradication therapy

BACKGROUND

Current noninvasive tests to confirm the eradication of Helicobacter pylori must be performed 4 weeks or more after eradication therapy is completed.

OBJECTIVE

To determine whether the stool antigen test, a relatively new noninvasive test for H. pylori, administered at various times after eradication therapy correctly identifies persons with persistent H. pylori infection.

DESIGN

Prospective blinded study.

SETTING

Six clinical centers in the United States and Europe.

PATIENTS

84 H. pylori --infected patients undergoing endoscopy for upper abdominal symptoms.

MEASUREMENTS

At baseline and on day 35 after the completion of triple eradication therapy, all patients underwent endoscopy with histologic examination, rapid urease test and culture, urea breath test, and a stool antigen test. The stool antigen test was also performed on days 3, 7, 15, 21, 28, and 35 after completion of therapy.

RESULTS

Compared with the gold-standard endoscopic tests on day 35 after antimicrobial therapy, the urea breath test had a sensitivity of 94% (95% CI, 71% to 100%) and a specificity of 100% (CI, 94% to 100%). The stool antigen test had a sensitivity of 94% (CI, 71% to 100%) and a specificity of 97% (CI, 89% to 100%). On day 7 after treatment, the stool antigen test was predictive of eradication (positive predictive value, 100% [CI, 69% to 100%]; negative predictive value, 91% [CI, 82% to 97%]).

CONCLUSION

A positive result on the stool antigen test 7 days after completion of therapy identifies patients in whom eradication of H. pylori was unsuccessful.

Efficacy and safety of single-triple capsules of bismuth biskalcitrate, metronidazole and tetracycline, given with omeprazole, for the eradication of Helicobacter pylori: an international multicentre study

BACKGROUND

The high prevalence of Helicobacter pylori resistance to metronidazole demands treatments more effective than standard bismuth-based triple therapy against these strains.

AIM

To evaluate the H. pylori eradication rate in both metronidazole-sensitive and -resistant strains following quadruple therapy using single-triple capsules of bismuth biskalcitrate, metronidazole and tetracycline, given with omeprazole.

METHODS

One hundred and seventy valid patients with duodenal ulcer, gastric ulcer or non-ulcer dyspepsia were treated in eight centres located in five countries. H. pylori was confirmed at baseline using 13C-urea breath test, histology and/or culture. Patients received three single-triple capsules q.i.d. and omeprazole, 20 mg b.d., for 10 days. Each capsule contained bismuth biskalcitrate, 140 mg (as 40 mg Bi2O3 equivalent), metronidazole, 125 mg, and tetracycline, 125 mg. 13C-Urea breath test was repeated at least 4 and 8 weeks post-treatment.

RESULTS

Overall eradication rates were 93% (158/170) by modified intention-to-treat analysis and 97% (142/146) by per protocol analysis. Eradication rates were 93% (40/43) and 95% (38/40) for strains resistant to metronidazole and 95% (82/86) and 99% (75/76) for strains sensitive to metronidazole by modified intention-to-treat and per protocol analysis, respectively.

CONCLUSION

This omeprazole-bismuth biskalcitrate-metronidazole-tetracycline 10-day regimen is a very effective and well-tolerated treatment, which overcomes metronidazole resistance.

Electrical activity during the 2006 Mount St. Augustine volcanic eruptions

By using a combination of radio frequency time-of-arrival and interferometer measurements, we observed a sequence of lightning and electrical activity during one of Mount St. Augustine's eruptions. The observations indicate that the electrical activity had two modes or phases. First, there was an explosive phase in which the ejecta from the explosion appeared to be highly charged upon exiting the volcano, resulting in numerous apparently disorganized discharges and some simple lightning. The net charge exiting the volcano appears to have been positive. The second phase, which followed the most energetic explosion, produced conventional-type discharges that occurred within plume. Although the plume cloud was undoubtedly charged as a result of the explosion itself, the fact that the lightning onset was delayed and continued after and well downwind of the eruption indicates that in situ charging of some kind was occurring, presumably similar in some respects to that which occurs in normal thunderstorms.

Metabolism of plasminogen in healthy subjects: effect of tranexamic acid

The metabolism of human plasminogen labeled with radioactive iodine was studied in 12 healthy men. The labeled plasminogen had a high specific activity and the same elution on Sephadex G-100 as the plasminogen activity in plasma. Immunoelectrophoresis revealed a single precipitin line. Polyacrylamide gel electrophoresis revealed six main bands, all with plasminogen properties and radioactivity. The purified plasminogen behaved as a homogeneous protein in the turnover experiments. The plasma radioactivity data were adequately approximated by a sum of two exponential terms. The metabolism of plasminogen was therefore represented by a two-compartment mammillary model. Results in the 12 normal subjects were as follows: plasma plasminogen concentration 20.8+/-1.9 mg/100 ml; intravascular plasminogen pool 0.66+/-0.14 g; intravascular fraction 0.59+/-0.06; fractional catabolic rate 0.55+/-0.09 of the plasma pool per day; half-life of the plasma radioactivity 2.21+/-0.29 days. Circulating large-molecular-weight degradation products of labeled plasminogen could not be detected by Sephadex G-100 gel filtration. The plasminogen turnover rate was normal in a patient with Behçet's syndrome and low circulating plasminogen activator activity. This finding supports the concept that under normal conditions the primary pathway of plasminogen catabolism is not via the formation of plasmin. The in vivo effect of tranexamic acid, a potent inhibitor of plasminogen activation, on the turnover of labeled plasminogen was studied in five normal subjects. When 1 g was administered perorally t.i.d. to three of them, one showed an increased plasminogen turnover. A 2 g dose administered t.i.d. to the other two caused markedly increased catabolism in both. This increase may be attributable to a direct reversible effect of tranexamic acid on the plasminogen molecule.

Circumferential and axial distribution of esophageal mucosal damage in reflux disease

The aim of this study was to evaluate the axial and radial distribution of histological markers including hyperplasia of the basal cell layer, elongation of the papillae and dilatation of the intercellular spaces of the squamous epithelium in patients with nonerosive reflux disease compared to controls and to relate this to the macroscopic topography in erosive reflux disease. Two different study populations were included in this report. Endoscopic esophageal biopsies were taken from 21 healthy control subjects and 21 nonerosive reflux disease patients before and after 4 weeks of esomeprazole therapy. Endoscopic still images from 50 erosive reflux disease patients were reviewed for the radial orientation of LA grade A and/or B esophagitis (Los Angeles criteria for grading of reflux esophagitis). The 3 o'clock position of the squamocolumnar junction showed significantly thicker basal cell layer (P=0.011) and more intercellular space dilatation (P=0.01) in nonerosive reflux disease patients compared to the 9 o'clock position. Only a significant difference in dilatation of the intercellular spaces (P=0.018) between nonerosive reflux disease patients and controls were observed in the 3 o'clock region at the squamocolumnar junction, whereas 1-2 cm orally, all three histological criteria differed significantly (P<or=0.01). After treatment, on the contrary, papillary length was significantly less pronounced at the squamocolumnar junction (P<0.01). Endoscopically, erosions were predominantly visualized in the 3 o'clock region (P<0.05). Histological mucosal changes in nonerosive reflux disease patients and visible mucosal erosions in erosive reflux disease patients occur most frequently at the same position, namely in the 3 o'clock quadrant in the distal esophagus. The histological difference between nonerosive reflux disease patients and controls are more distinct 1-2 cm oral to rather than at the squamocolumnar junction. However the effect of therapy is most pronounced at the squamocolumnar junction.

A placebo-controlled trial of the 5-HT1A agonist R-137696 on symptoms, visceral hypersensitivity and on impaired accommodation in functional dyspepsia

Acute studies suggested a therapeutic benefit for fundus-relaxing drugs in functional dyspepsia (FD) with visceral hypersensitivity (VH) to gastric distention or impaired accommodation (IA), but long-term studies are lacking. R-137696 is a serotonin-1A (5-HT(1A)) receptor agonist which relaxes the proximal stomach in man. Our aim was to investigate the influence of R-137696 on symptoms in FD with VH or IA. Randomized, double-blind, placebo-controlled, parallel group study of 4 weeks R-137696 2 mg t.i.d. in FD with VH or IA. Symptoms were assessed using the patient assessment of upper gastrointestinal symptom severity index (PAGI-SYM) total score and individual symptom subscales. Barostat studies were performed before and after 4 weeks of treatment. Fifty-three patients (33 VH and 20 IA), 18 men, mean age 40 +/- 13 years were recruited. Twenty-four received placebo and 29 received R-137696. In VH patients, both placebo and R-137696 improved total symptom scores, with a tendency for superiority of placebo (-1.12 vs-0.51, P = 0.07). Placebo was superior for the subscales of early satiety, bloating, fullness and discomfort (all P < 0.05). In IA, both placebo and R-137696 had no significant influence on total or individual symptom scores (-0.08 and -0.27). In VH, both placebo and R-137696 increased the discomfort volume, without a statistical difference between both arms (+120 and +164 mL). In IA, both placebo and R-137696 enhanced accommodation, without a statistical difference between both (+77 and +159 mL). Adverse events were similar for drug and placebo. A 4-week administration of the fundus-relaxing 5-HT(1A) agonist R-137696 failed to significantly improve symptoms, VH or gastric accommodation compared to placebo.

Magnification endoscopy for diagnosis of nonerosive reflux disease: a proposal of diagnostic criteria and critical analysis of observer variability

BACKGROUND AND STUDY AIMS

This study tested the diagnostic value of high-resolution endoscopy for the recognition of subtle diagnostic esophageal mucosal changes in nonerosive reflux disease.

PATIENTS AND METHODS

Ten control subjects and eleven patients with nonerosive reflux disease confirmed by a validated questionnaire, standard endoscopy, and 24-hour pH-metry participated in the study. Still images were collected by high-resolution endoscopes from the distal esophagus in a standardized manner, incorporating iodine staining. Assessments were repeated in the patients with reflux disease after 4 weeks of esomeprazole therapy. Interobserver variability in the recognition of the proposed criteria was initially evaluated by 27 endoscopists using an Internet-based process. After optimisation of image quality the evaluation was repeated face-to-face with six expert endoscopists.

RESULTS

No criterion was identified in either assessment that was sufficiently sensitive and specific to patients with reflux disease to be clinically useful. The kappa value, used to assess interobserver variation, was acceptably high only for invisibility of palisade vessels (0.59). Triangular indentations, apical mucosal breaks, and pinpoint blood vessels at the squamocolumnar junction were identified more frequently in the patients with reflux disease ( P < 0.05). These changes and the invisibility of the palisade vessels were significantly less prevalent in reflux patients after therapy ( P < 0.01).

CONCLUSIONS

Though some distal esophageal mucosal appearances observed with the high-resolution endoscope appeared to be related to nonerosive esophageal mucosal injury, none of these changes proved to be sufficiently sensitive and specific to justify their use as a diagnostic criterion for nonerosive reflux disease.

Endoscopic screening for malignancy in the gastric remnant: the clinical significance of dysplasia in gastric mucosa

Five hundred and four asymptomatic patients in whom gastrectomy had been performed between 1931 and 1960 were investigated by endoscopy plus biopsy. Ten stump carcinomas were detected (1.98%). In five patients the tumour was limited to the mucosa and was not seen at endoscopy. In three patients with previously noted severe dysplasia intramucosal carcinoma was detected during follow up and in two the carcinoma was found at the site of the preceding severe dysplasia. True regression of severe dysplasia could not be shown. In 23 patients with previous mild or moderate dysplasia no progression was seen during follow up. Severe gastric dysplasia is a serious marker of malignancy demanding close follow up with repeated endoscopy and biopsy. The clinical significance of mild and moderate dysplasia remains unclear. Early detection of stump carcinoma is indeed possible. Physicians should rely not so much on the endoscopic appearance but on the results of multiple biopsies.

Results of the new nitinol self-expandable stents for distal biliary structures

BACKGROUND AND STUDY AIMS

The nitinol stent is a self-expandable spiral stent made of nickel-titanium alloy. We performed a pilot study to evaluate the method of stent insertion and stent efficacy.

PATIENTS AND METHODS

Twenty-eight patients with irresectable malignancy had nitinol stents inserted for obstructive jaundice due to distal biliary strictures. They were followed prospectively for a median of ten weeks (range 1-48) until stent occlusion or death. All patients underwent sphincterotomy prior to stent insertion. Stent deployment was assisted by subsequent balloon dilation of the stent in two patients. Plastic stent insertion was used to temporarily brace the nitinol stent in another three patients.

RESULTS

Short-term relief of jaundice was achieved in 20 of the 28 patients (71%). The remaining eight patients had persistent jaundice due to failure of stent insertion (three patients) or early stent dysfunction (five patients). Long-term success was achieved in 12 of 28 patients (43%). Ten of the 12 patients died without complications after a median of 13.5 weeks (range 3-48). One of the 12 patients is still alive with the stent in place for 40 weeks, and one patient underwent elective bypass surgery, and the stent was removed surgically. Eight of the 28 patients had recurrent symptoms due to late stent dysfunction after a median of 19 weeks (range 6-32).

CONCLUSIONS

Nitinol stents are technically difficult to insert. The problem of stent dysfunction (13 of 28, 46%) is not improved by the use of nitinol stents. Whether improvement of the insertion technique and enhancement of the expanding force of the stent may improve stent efficacy merits further evaluation.

Review article: oesophageal complications and consequences of persistent gastro-oesophageal reflux disease

The major oesophageal complications associated with persistent gastro-oesophageal reflux disease (GERD) include erosive oesophagitis, ulceration, strictures and gastrointestinal (GI) bleeding. Although the causes of these complications are uncertain, studies indicate that erosive oesophagitis may progress to the development of ulcers, strictures and GI bleeding. Pharmacological treatment with proton pump inhibitors is favoured over that with H(2)-receptor antagonists for the treatment of strictures. The treatment of strictures is accomplished with dilation and many favour the concomitant use of proton pump inhibitors. Most gastroenterologists are seeing far fewer oesophageal strictures these days since the introduction of proton pump inhibitors. In addition, research has shown that oesophageal complications have a greater impact on patients suffering from night-time GERD than on those suffering from daytime GERD. Barrett's oesophagus is a significant complication associated with persistent GERD and those at risk generally experience a longer duration of symptoms, especially those with a high degree of severity. In addition, there is a strong relationship between Barrett's oesophagus and oesophageal adenocarcinoma. This is in part due to the association of obesity and the development of hiatal hernias. Furthermore, endoscopic screening is being used to detect Barrett's oesophagus and oesophageal adenocarcinoma in persons suffering from chronic GERD, even though screening may not have an impact on outcomes (Sharma P, McQuaid K, Dent J, et al. A critical review of the diagnosis and management of Barrett's esophagus: The AGA Chicago Workshop. Gastroenterology 2004; 127: 310-30.).

Failure of a cytoprotective dose of arbaprostil to heal acute duodenal ulcers. Results of a multiclinic trial

Previous therapeutic trials with prostaglandins have shown them to be effective in healing duodenal ulcers when used at doses that are highly effective suppressors of gastric acid secretion. We undertook this trial to determine if a cytoprotective dose of arbaprostil (10 micrograms q.i.d. for 4 wk) would also be efficacious in this disease state. Eighty-two patients between the ages of 19 and 72 yr with endoscopically documented duodenal ulcers were entered into this randomized double-blind placebo-controlled trial. The patients were monitored with biweekly endoscopies and laboratory examinations, weekly interviews during the period when drug was administered, and a follow-up interview plus laboratory examinations 1 wk after drug administration was completed. No statistically significant differences between the arbaprostil and placebo treatment groups were found for ulcer healing rates, pain relief, antacid consumption, side effects, or laboratory examinations. It is presumed that this prostaglandin may not have sufficient duodenal cytoprotective capacity to effectively heal duodenal ulcers, or that some suppression of gastric acid secretion may be required to achieve significant clinical efficacy.

Endosonography of gastroesophageal varices: evaluation and follow-up of 76 cases

Endosonography was performed in 76 patients who had endoscopically detected gastroesophageal varices or questionable submucosal lesions, or who were being evaluated for pancreatic carcinoma or pancreatitis. The result were compared with surgery or autopsy results. The patients were divided retrospectively into four groups. Group 1 consisted of 6 patients who underwent surgery or autopsy. Five esophageal varices and 1 fundic varix were diagnosed with endosonography and confirmed histologically. Group 2 consisted of 29 patients undergoing sclerotherapy. Intramural thickening of the esophagus and extramural collaterals were found in 20 of 22 patients, respectively. Endoscopy revealed fibrosis in 10 patients. Group 3 consisted of 16 patients evaluated for pancreatic disease. Fifteen fundic varices, 6 cardiac varices, and 5 extramural collateral veins were found by EUS. Group 4 consisted of 16 patients with questionable submucosal lesions and 9 patients with lesions recognized endoscopically as varices. EUS found varices in all 25 patients. In conclusion, EUS is an important procedure in the diagnosis and follow-up of gastroesophageal varices, and in the identification of questionable abnormalities found endoscopically. The effect of sclerotherapy can be demonstrated as mural thickening with disappearance of submucosal varices.

Does Helicobacter pylori infection influence response rate or speed of symptom control in patients with gastroesophageal reflux disease treated with rabeprazole?

OBJECTIVE

The findings of several studies suggest that proton-pump inhibitors (PPIs) suppress gastric acid more effectively in Helicobacter pylori-infected (Hp +) than in non-infected (Hp -) patients, but there has been no evaluation of the short-term clinical response.

MATERIAL AND METHODS

Results of the first week of treatment with rabeprazole in Hp+ and Hp- patients with gastroesophageal reflux disease (GERD) were compared in a large prospective open-label, multicenter, cohort study in general and specialized practices. GERD patients were recruited on the basis of either typical symptoms alone or endoscopic results, assessed for H. pylori infection and treated with rabeprazole (20 mg). Heartburn and regurgitation symptoms were assessed daily during the first 7 days. Outcome parameters were calculated for both symptoms and compared between Hp+ and Hp- patients.

RESULTS

Data on 1548 patients (74.5% Hp-, 25.5% Hp + ) were available. Mean heartburn and regurgitation scores decreased during the first week. For both symptoms, more than 70% of the patients had "adequate" symptom relief at day 5, and more than 80% at day 7. "Complete" symptom relief was reached in more than 70% of patients. Mean onset of adequate symptom control was about 4 days. In Hp+ and Hp- patients there was no difference in response for any of the parameters.

CONCLUSIONS

Among patients treated with rabeprazole in clinical practice, H. pylori infection or its absence has no effect on the speed or degree of GERD symptom relief. Infected patients and non-infected patients can therefore be treated with a similar dose. When treating heartburn with rabeprazole, physicians do not need to consider the patient's H. pylori status and most patients (>80%) have adequate symptom relief after just a few days of treatment.

Comparative optical coherence tomography imaging of human esophagus: how accurate is localization of the muscularis mucosae?

BACKGROUND

Early diagnosis of esophageal cancer limited to the mucosa allows local endoscopic treatment and thereby improves prognosis. Optical coherence tomography images of normal human esophageal tissue obtained with 2 systems with light sources that provide different wavelengths (800 nm and 1275 nm) were compared with histology to determine which wavelength is best suited for detailed optical coherence tomography imaging of the esophageal wall, and to precisely localize the muscularis mucosae.

METHODS

Within 1 hour of surgical resection, an esophageal specimen was cleaned of excess blood with saline solution and soaked in formalin for a minimum of 48 hours. After optical coherence tomography imaging, the specimen was prepared for routine histologic assessment. To precisely localize the different layers of the esophageal wall on an optical coherence tomography image, well-defined structures within the esophageal wall were sought.

RESULTS

The 1275 nm system with 12 mm resolution was superior in terms of imaging depth. As compared with histology, the 4 microm resolution of the 800 nm system made fine detail more visible. With minimal experience, the muscularis mucosae could be recognized with either system as a hyporeflective layer with a diameter of around 180 microm.

CONCLUSIONS

Based on appearance and location of morphologic landmarks, layers of normal esophageal wall, specifically, the location and extent of the muscularis mucosae, could be recognized by using both the 800 nm and 1275 nm optical coherence tomography system. Although different conditions may be operative in vivo, the present ex vivo study further verifies by precise interpretation that optical coherence tomography provides precise images of the esophageal wall.

Helicobacter pylori: past, present and future

Much has been achieved in Helicobacter pylori research, to the point that the growth of new knowledge is bound to slow down. However, expectations for further developments remain high. Knowledge about the characteristic organism and behaviour is already extensive. Particularly intriguing are the differences in genetic make-up in the various geographical regions. Sadly, detailed knowledge on how the organism spreads is still lacking. The spectrum of clinical presentation in humans is largely known. Helicobacter pylori is disappearing worldwide, allowing the relative frequency of H. pylori-negative ulcer disease to increase. The extent to which H. pylori disappearance and eradication is responsible for decreasing prevalence of gastric cancer remains speculative. Antimicrobial therapy is dominated by proton pump inhibitor triple therapy as first line therapy, with quadruple therapy as second rescue line therapy. The long-term consequences of the rising resistance to the 'key' antimicrobials are so far unknown, because few data are available on therapeutic outcomes in routine practice outside pharmaceutical trials.