Campylobacter like organisms in duodenal and antral endoscopic biopsies: relationship to inflammation

Gastric foveolar metaplasia and gastric heterotopia in the duodenum: no evidence of an etiologic role for Helicobacter pylori

Gastric-type epithelium and islands of oxyntic mucosa in duodenal biopsies are considered by some to be part of a spectrum of metaplastic change related to peptic disorders. This study was designed to assess prevalence and associations of metaplastic-heterotopic gastric mucosa in the duodenum. Demographic, clinical, and histopathologic data from patients who had duodenal biopsy specimens for a 12-month period were collected from a national database. The duodenal findings of patients with duodenitis, gastric metaplasia, and gastric heterotopia were correlated with gastric pathology, Helicobacter pylori status, and clinical information. Of 28,210 patients with duodenal biopsy specimens, 80.9% were healthy, 2.1% had active duodenitis, 2.2% gastric foveolar metaplasia without active inflammation ("peptic duodenopathy"), 4.8% gastric foveolar metaplasia with active inflammation ("peptic duodenitis"), and 1.9% gastric heterotopia. Helicobacter pylori was documented in 9.8% of patients with normal duodenum, 6.9% of those with gastric metaplasia without active inflammation, 15.8% of those with active duodenitis, and 29.1% of those with gastric foveolar metaplasia with active inflammation; 2.2% of 543 patients with gastric heterotopia had H pylori gastritis. Helicobacter pylori was detected in the metaplastic epithelium of 67.6% of patients with active inflammation and in 16.4% of those with metaplasia without inflammation. Gastric heterotopia was strongly associated with concurrent fundic gland polyps. In conclusion, active duodenitis was more common in patients with H pylori infection, but gastric metaplasia was not. We suggest that there is insufficient evidence to ascribe duodenitis with foveolar metaplasia to a "peptic" disorder, as "peptic duodenopathy" and "peptic duodenitis" seem to imply. Gastric heterotopia is likely a congenital lesion; its association with fundic gland polyps suggests that use of proton pump inhibitors may enhance its endoscopic detection.

Significance of Campylobacter pylori

There is an explosion of interest in the role of Campylobacter pylori as a cause of active chronic gastritis. This curved spiraled microorganism can readily be detected within the mucus gel covering the stomach mucosa, especially in patients suffering from peptic ulcer disease or non-ulcer dyspepsia. To what extent this intriguing microorganism is causally related to peptic ulcer disease remains to be elucidated, but all the evidence which is available so far supports a pathogenetically important role. There appears to be a striking discordance between in-vitro sensitivity and in-vivo efficacy of antibiotic therapy. At present, the combination of colloidal bismuth subcitrate and amoxycillin or tinidazole appears most effective in temporary elimination of these microorganisms.

Is it really more difficult to treat prepyloric ulcers?

Prepyloric and duodenal ulcers have some common characteristics: gastric acid secretion is increased and there is an association with blood group O. Many, therefore, have considered prepyloric ulcers to be a variety of duodenal ulcer disease. From an anatomical point of view, however, prepyloric ulcers are clearly gastric ulcers. After proximal selective vagotomy, the recurrence rate is very high, amounting to more than 30% in 5 years; this is significantly higher than the rate for duodenal ulcers. Better results are obtained in prepyloric ulcers, if vagotomy is combined with a drainage procedure. In recent years, some evidence, primarily from Scandinavia, has accumulated indicating that prepyloric ulcers are more resistant to treatment with histamine H2-receptor antagonists than duodenal ulcers or ulcers located in other parts of the stomach. In addition, the recurrence rate is particularly high in prepyloric ulcers. One must, however, consider that not only have all of these studies included relatively small numbers of patients, but also the prepyloric ulcer healing rates in other studies were similar to those observed for both duodenal ulcers and ulcers located elsewhere in the stomach. Prospective studies with large numbers of patients are, therefore, necessary before a clear-cut conclusion can be reached. There are several reasons why prepyloric ulcers could be more resistant to treatment. Impaired gastric emptying, duodeno-gastric reflux or chronic gastritis, especially in conjunction with Campylobacter pylori infection, must be considered. At present, one can only speculate on the validity of any of these hypotheses.

Association between interleukin-1beta-511C/T polymorphism and reflux esophagitis in Japan

BACKGROUND

Interleukin-1beta (IL-1beta) gene polymorphisms are related to hypochlorhydria and increase the risk of gastric cancer in the presence of Helicobacter pylori infection. However, little information is available about the genetic risk factors of reflux esophagitis. In this study we investigated its association with the IL-1beta polymorphisms.

METHODS

We examined 48 patients with reflux esophagitis and 96 control subjects, 89 with gastric cancer. IL-1beta-511C/T genotyping was performed by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method.

RESULTS

The frequency of IL-1beta-511T alleles was significantly higher in reflux esophagitis patients (57.3%) than in controls (41.1%) (P = 0.0215, chi(2) = 5.289). The frequency of IL-1beta-511T/T genotypes was also significantly higher in reflux esophagitis patients (31.3%) than in controls (15.6%). The odds ratio and the 95% confidence interval were 4.000 and 1.393-11.486, respectively. The frequency of IL-1beta-511T/T genotypes was significantly higher in reflux esophagitis patients (31.3%) than in gastric cancer patients (21.4%). The odds ratio and the 95% confidence interval were 2.961 and 1.054-8.316, respectively.

CONCLUSIONS

IL-1beta-511T was associated with reflux esophagitis having hyperacidity. Differences of genetic background regarding gastric acid secretion may exist between Japanese and Caucasians.

Helicobacter pylori infection inhibits healing of the wounded duodenal epithelium in vitro

Helicobacter pylori (Hp) infection causes duodenal ulcers, delays the healing of such ulcers, and is associated with ulcer recurrence. The pathogenic mechanisms involved in Hp-induced duodenal mucosal injury and delay in ulcer healing remain unclear. In this study we sought to investigate the possible pathogenic actions of Hp infection and vacuolating cytotoxin (Vac A) on duodenal epithelial wound healing, using an in vitro wound model consisting of excisionally scraped or eroded IEC-6 duodenal monolayers. Two isogenic strains of Hp were used: wild-type strain 60190, producing Vac A; and an isogenic mutant strain, 60190-v1, that lacks the gene to produce the cytotoxin. The addition of Vac A-positive or Vac A-negative Hp (50:1 ratio of bacterial to epithelial cells) to the eroded or "wounded" IEC-6 monolayers resulted in significant inhibition of wound reepithelialization. The Vac A-positive Hp produced significantly greater inhibition than did the Vac A-negative Hp (70% and 35% inhibition, respectively; P <.001). Additionally, the bacterial supernatant containing Vac A (but not the supernatant lacking the cytotoxin) caused significant inhibition of IEC-6 wound reepithelialization in the absence of Hp infection, indicating that Vac A has an independent inhibitory action on wound reepithelialization. The Vac A inhibition of IEC-6 reepithelialization correlated with down-regulation of actin stress fibers in the migrating cells. Epidermal growth factor (EGF) stimulated IEC-6 wound reepithelialization with a corresponding increase in the formation of actin stress fiber. Vac A-positive bacterial supernatant (but not Vac A-negative supernatant) prevented the EGF-stimulated increase in IEC-6 actin stress fiber formation and wound reepithelialization. These findings demonstrate that Hp infection inhibits the process of duodenal epithelial wound healing. Hp inhibition of duodenal wound healing may therefore be an important pathogenic factor contributing to duodenal mucosal injury and delay in ulcer healing in vivo.

Does colonization of Helicobacter pylori in the heterotopic gastric mucosa play a role in bleeding of Meckel's diverticulum?

BACKGROUND/PURPOSE

Helicobacter pylori is a microorganism known to colonize in gastric type of mucosa and is associated with gastritis and peptic ulceration. The aim of the study was to determine whether colonization of H pylori in heterotopic gastric mucosa plays a role in bleeding of Meckel's diverticulum.

METHODS

Histopathologic slides of patients who had undergone resection of Meckel's diverticulum in recent 5 years were reexamined for the presence of H pylori in heterotopic gastric mucosa. Polimerase chain reaction (PCR) test was used to trace the genetic material of urease gene and 16s rDNA amplifications for H pylori.

RESULTS

Thirteen of the 30 histopathologic slides of Meckel's diverticula had heterotopic gastric mucosa. Ten of the 13 patients presented with acute bleeding of the diverticula, whereas 3 of them were asymptomatic. None of the 13 gastric mucosa bearing diverticula were colonized with H pylori. PCR was unable to show any trace of genetic material for H pylori.

CONCLUSION

Although the role of H pylori is well established in the gastric mucosal ulceration, its presence is not essentially required to induce "heterotopic gastritis" that may result in bleeding of the Meckel's diverticulum. .

Eradication of Helicobacter pylori infection induces an increase in body mass index

BACKGROUND

The relationship between H. pylori infection and body mass indices is controversial.

AIM

To investigate the relationship between H. pylori infection and body indices, and to examine the effect of H. pylori eradication therapy on body indices.

METHODS

Nine-hundred and thirty-two employees of an industrial corporation were examined for H. pylori infection and body mass indices. Three hundred and two H. pylori-positive cases diagnosed with chronic gastritis by upper gastrointestinal endoscopy or radiography underwent eradication therapy. Body mass indices, serum total cholesterol levels and symptom scores were obtained before and at 12 months after eradication therapy.

RESULTS

There was no significant difference in body weight, body mass index (BMI) or serum total cholesterol level between the H. pylori-positive and H. pylori-negative groups. However, body weight and BMI increased significantly 12 months after eradication of H. pylori infection. In contrast, there was no significant difference in body weight and BMI 12 months after eradication therapy in the non-eradication group. Serum total cholesterol levels did not change after eradication therapy in either the eradication or non-eradication groups.

CONCLUSION

Eradication of H. pylori infection induced an increase in BMI in industrial workers with chronic gastritis in Japan.

Familial clustering of Helicobacter pylori infection: population based study

OBJECTIVES

To assess the rate of intrafamilial transmission of Helicobacter pylori infection in the general population and the role of a family's social background.

DESIGN

Population survey.

SETTING

Campogalliano, a town in northern Italy with about 5000 residents.

PARTICIPANTS

3289 residents, accounting for 416 families.

MAIN OUTCOME MEASURES

Prevalence of H pylori infection assessed by presence of IgG antibodies to H pylori.

RESULTS

The overall prevalence of H pylori infection was 58%. Children belonging to families with both parents infected had a significantly higher prevalence of H pylori infection (44%) than children from families with only one (30%) or no parents (21%) infected (P<0.001). Multivariate analyses confirmed that children with both parents positive had double the risk of being infected by H pylori than those from families in which both parents were negative. Family social status was independently related to infection in children, with those from blue collar or farming families showing an increased risk of infection compared with children of white collars workers (odds ratio 2.02, 95% confidence interval 1.16 to 3.49).

CONCLUSIONS

H pylori infection clusters within families belonging to the same population. Social status may also be a risk factor. This suggests either a person to person transmission or a common source of exposure for H pylori infection.

A prospective randomised trial of a "test and treat" policy versus endoscopy based management in young Helicobacter pylori positive patients with ulcer-like dyspepsia, referred to a hospital clinic

BACKGROUND

Management of dyspepsia remains a controversial area. Although the European Helicobacter pylori study group has advised empirical eradication therapy without oesophagogastroduodenoscopy (OGD) in young H pylori positive dyspeptic patients who do not exhibit alarm symptoms, this strategy has not been subjected to clinical trial.

AIMS

To compare a "test and treat" eradication policy against management by OGD.

PATIENTS

Consecutive subjects were prospectively recruited from open access OGD and outpatient referrals.

METHODS

H pylori status was assessed using the carbon-13 urea breath test. H pylori positive patients were randomised to either empirical eradication or OGD. Symptoms and quality of life scores were assessed at baseline and subsequent reviews over a 12 month period.

RESULTS

A total of 104 H pylori positive patients aged under 45 years were recruited. Fifty two were randomised to receive empirical eradication therapy and 52 to OGD. Results were analysed using an intention to treat policy. Dyspepsia scores significantly improved in both groups over 12 months compared with baseline; however, dyspepsia scores were significantly better in the empirical eradication group. Quality of life showed significant improvements in both groups at 12 months; however, physical role functioning was significantly improved in the empirical eradication group. Fourteen (27%) in the empirical eradication group subsequently proceeded to OGD because of no improvement in dyspepsia.

CONCLUSIONS

This randomised study strongly supports the use of empirical H pylori eradication in patients referred to secondary practice; it is estimated that 73% of OGDs in this group would have been avoided with no detriment to clinical outcome.

Rising incidence of oesophageal adenocarcinoma in men in Australia

Adenocarcinomas of the oesophagus and of the gastric cardia have been reported to be increasing in incidence in many countries, while the incidence of squamous cell carcinoma of the oesophagus is stable and non-cardia gastric cancers are decreasing in incidence. Age-standardized incidence rates for the years 1982-1993 for oesophageal adenocarcinoma and non-adenocarcinoma, and gastric cardia and non-cardia cancers were calculated based on state cancer registry incidence data. Time trends in the age-standardized rates were assessed using linear regression. A consistent increasing trend in the incidence of oesophageal adenocarcinoma in men was seen in all states of Australia and was statistically significant in all states except South Australia. There were no consistent nationwide trends in the incidence of oesophageal adenocarcinoma in women, although a trend towards an increase in the incidence of this cancer reached statistical significance (P < 0.05) in three states (New South Wales, Victoria, Queensland). There were no important trends in the incidence of oesophageal non-adenocarcinoma in either men or women. There were no consistent nationwide changes in the incidence of gastric cardia cancer in either men or women, although this cancer was significantly increasing in Tasmania in both men and women. The incidence of cancer of the stomach not arising at the gastric cardia was significantly decreasing in men in all states and was also decreasing in women in all states, although in women this decrease was statistically significant only in New South Wales, Victoria and Western Australia. There has been a dramatic increase in the incidence of oesophageal adenocarcinoma in men in Australia. The incidence of this cancer in men is now approximately equal with that of non-adenocarcinoma of the oesophagus. The incidence of non-cardia stomach cancer continues to fall.

Effects of Helicobacter pylori eradication therapy on hyperammonaemia in patients with liver cirrhosis

BACKGROUND AND AIMS

Helicobacter pylori has strong urease activity. Ammonia produced by H pylori in the stomach can be a source of systemic ammonia in patients with hepatic dysfunction. The effect of the eradication of H pylori on hyperammonaemia was examined in patients with liver cirrhosis.

SUBJECTS AND METHODS

Ammonia concentrations in blood and gastric juice were analysed in 50 patients with liver cirrhosis and hyperammonaemia. All patients were first treated with a low protein diet, kanamycin, lactulose, and branched chain enriched amino acid solution. Hyperammonaemia remained in 18 patients. These 18 patients were divided into three groups according to the status of H pylori infection; those with a diffuse distribution of H pylori in the stomach (group I), those with a regional distribution (group II), and those without H pylori (group III). These patients were given 30 mg iansoprazole, 1000 mg amoxicillin, and 400 mg clarithromycin or 500 mg metronidazole for two weeks to eradicate H pylori.

RESULTS

In group I ammonia concentrations in blood and gastric juice were significantly reduced after H pylori eradication. The blood ammonia concentration at 12 weeks after the eradication was still significantly lower than that before eradication. In groups II and III the ammonia concentrations in blood and gastric juice were not significantly reduced after eradication therapy.

CONCLUSIONS

The diffuse distribution of H-pylori in the stomach contributes partly to hyperammonaemia in patients with liver cirrhosis, and the eradication of H pylori is effective in patients with hyperammonaemia with diffuse H pylori infection in the stomach.

Helicobacter pylori duodenal colonization in children

To investigate the prevalence and the significance of Helicobacter pylori duodenal colonization, endoscopic duodenal biopsies were performed in 168 children with chronic abdominal pain, gastroesophageal reflux, gastrointestinal bleeding, and malabsorption syndrome. Helicobacter pylori infection was detected in 68 children (40.4%): in 31 of them H. pylori was present in the gastric antrum, and in 37 in the duodenum also. Duodenitis was observed in 25 children with duodenal H. pylori; gastric metaplasia in 3. Scanning electron microscopy revealed the presence of the micro-organism in 3/13 cases; the bacteria were located in the intercellular spaces and alterations of the epithelial surface were found. In conclusion, H. pylori gastritis in children is often associated with duodenal colonization which can cause duodenitis, and also without gastric metaplasia, which indicates a possible role of the micro-organism in the pathogenesis of the lesions.

The British Society of Gastroenterology Diamond Jubilee. March 1997

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Pathophysiology of Helicobacter pylori-induced gastritis and peptic ulcer disease

Helicobacter pylori causes persistent infection and inflammation in the human stomach, yet only a small fraction of persons harboring this organism develop peptic ulcer disease. An important question is why this variation in infection outcome exists. Recent studies have demonstrated that H pylori isolates possess substantial phenotypic and genotypic diversity that may engender differential host inflammatory responses that influence clinical outcome. Further investigation in this field may help to define which H pylori-infected persons bear the highest risk for subsequent development of peptic ulcer disease, and thus enable physicians to focus eradication therapy.

Evaluation of Helicobacter pylori in reflux oesophagitis and Barrett's oesophagus

BACKGROUND

One of the major pathophysiological abnormalities in patients with gastro-oesophageal reflux disease is thought to involve transient lower oesophageal sphincter (LOS) relaxations. One component of the neural mechanism controlling the LOS appears to be a reflex are whose afferent limb originates in the gastric fundus. As inflammation is known to be associated with neural activation an investigation was made to determine whether gastric infection with H pylori is altered in prevalence or distribution in patients with reflux disease.

METHODS

Five groups of subjects referred for endoscopy-group 1: 25 controls (asymptomatic individuals with anaemia and normal endoscopy); group 2: 36 subjects with erosive oesophagitis alone (Savary-Millar grades I-III); group 3: 16 subjects with duodenal ulcer alone; group 4: 15 subjects with oesophagitis with duodenal ulcer; group 5: 16 subjects with Barrett's oesophagus. No patients were receiving acid suppressants or antibiotics. An antral biopsy specimen was taken for a rapid urease test, and two biopsy specimens were taken from the antrum, fundus, and oesophagus (inflamed and non-inflamed) for histological evidence of inflammation and presence of H pylori using a Giemsa stain.

RESULTS

Nine (36%) controls had H pylori. Patients with duodenal ulcer alone had a significantly higher incidence of colonisation by H pylori than other groups (duodenal ulcer 15 (94%); oesophagitis 13 (36%); oesophagitis+duodenal ulcer 6 (40%); Barrett's oesophagus 4 (25%)). H pylori was not more common in oesophagitis. When H pylori colonised the gastric antrum it was usually found in the gastric fundus. There was no difference in anatomical distribution of H pylori in the different patient groups. In Barrett's oesophagus H pylori was found in two of 16 in the metaplastic epithelium.

CONCLUSION

H pylori is not more common and its distribution does not differ in those with oesophagitis compared with control subjects, and is therefore unlikely to be aetiologically important in these patients. H pylori, however, can colonise Barrett's epithelium.

Helicobacter pylori and the surface mucous gel layer of the human stomach

BACKGROUND

The colonization of Helicobacter pylori in the surface mucous gel layer (SMGL) was investigated.

MATERIALS AND METHODS

Surgically removed stomachs were obtained from patients and included gastric ulcer (4 cases), duodenal ulcer (2), and gastric cancer (24). Five of these cases were examined at 8, 19, 28, 143, and 171 days after the end of eradication therapy. For the preservation of the SMGL, these specimens were fixed in cold Carnoy's solution, cleared in xylene, and embedded in paraffin. Serial sections were obtained and were stained by dual staining with the galactose oxidase-cold thionin Schiff reaction followed by paradoxical Concanavalin A staining and immunostaining for H. pylori.

RESULTS

H. pylori characteristically attached to surface mucous cells and colonized in the SMGL H. pylori in the SMGL was more abundant than that attached to the surface mucous cells. The degree of H. pylori infection both on the surface of surface mucous cells and in the SMGL correlated well with the severity of gastritis. In the SMGL, this organism obviously preferred to colonize in the layer of surface mucous cell-type mucins, and the multilaminated structure of the SMGL deteriorated markedly. Eradication of H. pylori restored the structure of the SMGL, and the inflammatory reaction decreased gradually.

CONCLUSION

The SMGL is an indispensable site of H. pylori colonization, and this organism damaged the gastric mucosa partially by causing deterioration of the SMGL. Removal of the organism from the SMGL should be considered for eradication of this organism.

Upper gastrointestinal endoscopic and histologic findings before and after vertical banded gastroplasty

BACKGROUND

A total of 30 consecutive morbidly obese patients, six males and 24 females, who underwent vertical banded gastroplasty (VBG) between January 1992 and December 1994 and were followed up by endoscopy and biopsy were included in this study with the aim to determine the short- and mid-term complications and to investigate alterations in esophageal, gastric, and duodenal mucosa after surgery.

METHODS

All patients underwent endoscopy before operation. Postoperatively, 28 patients were reendoscoped at 6 months, 26 at 12 months, and 22 at 18 months. Biopsies were taken from the lower part of esophagus, just below the esophagogastric junction (vertical part of the partitioned stomach), corpus, antrum, and duodenal bulb.

RESULTS

Before operation 5 patients (16.6%) had a hiatus hernia and four of them (13.3%) had esophagitis. Endoscopic gastritis was diagnosed in nine patients (30%) and endoscopic duodenitis in two (6. 6%). Histologically, in 15 patients (50%) esophagitis was recognized; in 24 patients (80%) corpus gastritis; in 27 patients (90%) antral gastritis; and in 23 (76.6%) duodenitis. Helicobacter pylori was found in 20 (66.6%) patients. Postoperatively, three patients developed a mild stoma stenosis and were treated only by passing the endoscope 6 months after operation; one patient, with a severe stoma stenosis, was treated by Eder-Puestow dilatations and surgery. Gastric ulcer was found in two patients 6 and 12 months after surgery. One patient developed an endostomach channel because of staple line dehiscence 18 months after VBG. An increasing incidence of esophagitis and gastritis of the vertical part of the stomach was found at 6 and 12 months. Endoscopic and histologic gastritis of the corpus and antrum, as well as endoscopic and histologic duodenitis decreased gradually after surgery.

CONCLUSIONS

Our findings suggest that postoperative complications of VBG can be diagnosed by endoscopy, and some of them can easily be managed. Vertical banded gastroplasty causes not only no harm to the esophageal, gastric, and duodenal mucosa but also influences them favorably.

Diagnosis of Helicobacter pylori infection

A number of diagnostic tests have been developed for the detection of H. pylori. Diagnostic techniques can be divided into invasive and noninvasive methods. The invasive methods require upper gastrointestinal endoscopy and involve culture of gastric biopsy specimens, examination of stained biopsies and detection of urease activity in the biopsies themselves. In addition, we have developed endoscopic diagnosis of H. pylori infection in gastric mucosa using phenol red dye-spraying. The noninvasive methods include urea breath test and serological techniques. Although there has been considerable improvement in the techniques, a combination of at least two different techniques should be used in order to optimize the diagnostic yield. We recommend the use of one rapid test in the combination. The rapid urease test, cytology and the phenol red dye-spraying endoscopy give results available before the patient leaves the endoscopy suite.

Production of reactive oxygen species by gastric cells in association with Helicobacter pylori

Reactive oxygen species (ROS) and Helicobacter pylori have been identified as pathogenic factors in several gastrointestinal disorders. Since little information is available regarding the mechanistic pathways of H. pylori-induced gastric injury, the potential role of ROS was investigated. The induction of ROS in gastric cells (GC) by H. pylori was assessed using chemiluminescence, cytochrome c reduction, nitrobluetetrazolium (NBT) reduction and lactate dehydrogenase (LDH) leakage. The dose-dependent protective abilities of selected ROS scavengers on LDH leakage were determined. Following incubation of GC with three strains of H. pylori (1:1), approximately 5.7-8.0 and 3.8-4.3 fold increases were observed in cytochrome c and NBT reduction, respectively, demonstrating production of ROS. Enhanced chemiluminescence responses of 2.1- and 3.7-fold were observed following incubation of GC with H. pylori (ATCC 43504) at ratios of 1:1 and 1:10, respectively. Approximately 2.2- and 3.5-fold increases in LDH leakage were observed at GC:H. pylori (ATCC 43504) ratios of 1:1 and 1:10, respectively. Substantial inhibition of LDH leakage from GC in the presence of H. pylori was observed following co-incubations with selected ROS scavengers with cimetidine serving as the best chemoprotectant. The antioxidants and H2-receptor antagonists had no effect on growth of H. pylori cells. This study demonstrates that H. pylori induces enhanced production of ROS in GC, and enhances membrane damage.

Helicobacter pylori infection and its role in human disease--an overview

Helicobacter pylori (H. pylori) is probably the commonest chronic bacterial infection in humans. The bacterium colonizes the gastric epithelium and induces inflammation of the underlying mucosa. The recognition that this infection is the most important acquired factor in the pathogenesis of duodenal and gastric ulcers has transformed the management of these common disorders. Most patients with ulcers can be cured by a 1-week course of anti-H. pylori therapy, thereby removing the need for long-term acid inhibitory therapy. Eradication of the infection involves taking complex combinations of drugs and simpler eradication regimens are required. Recent epidemiological data indicate an association between H. pylori infection and the subsequent development of gastric carcinoma. If this association is established as causal, then widespread eradication of the infection may be indicated. Global eradication of H. pylori will probably rely on prophylactic or therapeutic vaccination and this approach is being actively investigated.

Gastric emptying and Helicobacter pylori infection in duodenal ulcer disease

The pathogenetic link between Helicobacter pylori gastritis and duodenal ulcer is still unknown. Fast gastric emptying of liquids might be important in the pathogenesis of gastric metaplasia of the duodenum and duodenal ulcer through an increased exposure of the duodenum to gastric acid. In H. pylori-infected subjects, an abnormal gastric emptying could affect urea breath test results and correlate with histological gastritis. This study was performed to evaluate the gastric emptying of liquids in duodenal ulcer patients with H. pylori infection and the possible relation between the bacterial load, gastric emptying, and urea breath test results. Seventeen duodenal ulcer patients with H. pylori gastritis and 15 healthy volunteers were studied by a [14C]octanoic acid and [13C]urea breath test to evaluate gastric emptying rate and H. pylori status simultaneously. Endoscopy with antral biopsies were performed in all duodenal ulcer patients. Duodenal ulcer patients with H. pylori infection have a normal liquid gastric emptying that is unrelated with histological severity of gastritis. The urea breath test results and the gastric emptying parameters do not correlate with histology. A significant correlation between the gastric emptying and the urea hydrolysis rate is found. It is concluded that H. pylori infection and duodenal ulcer disease is not associated with abnormally fast liquid gastric emptying, and this finding should be taken into account when a casual link between H. pylori infection and duodenal ulcer disease is searched for. The correlation between gastric emptying and urea hydrolysis rate explains why no conclusions on intragastric bacterial load can be drawn from the urea breath test results.

Inverse relation of serum Helicobacter pylori antibody titres and extent of intestinal metaplasia

AIMS

To clarify the relation between the serum titre of anti-Helicobacter pylori (H pylori) antibody and the extent of intestinal metaplasia of the gastric mucosa.

METHODS

The serum anti-H pylori IgG titres of 95 asymptomatic individuals (mean age 65 years) undergoing an annual health examination were measured and compared with the extent of intestinal metaplasia (absent, moderate, or extensive), determined by examination of multiple endoscopic mucosal biopsy specimens. Serum pepsinogen I (PGI) levels, as a marker for gastric atrophy, were also measured.

RESULTS

The prevalence of seropositivity for H pylori antibody was high (> 80%), regardless of the extent of metaplasia. However, there was a negative association between the extent of metaplasia and the anti-H pylori titre: 75% of the subjects in the group without metaplasia had high (3+) antibody levels, as did 43% with moderate, and 37% with extensive metaplasia (absent v extensive). The inverse relation between the titre and the extent of metaplasia was evident when examined in those with normal PGI (> 30 ng/ml), whereas no such relation was apparent in subjects with low PGI (< or = 30 ng/ml).

CONCLUSIONS

The anti-H pylori titre correlates inversely with the extent of intestinal metaplasia, particularly in subjects with less marked gastric atrophy.

Organic and psychosocial risk factors for duodenal ulcer

Duodenal ulcer (DU) is a common medical disorder which frequently becomes chronic. The factors involved in the aetiology of DU are poorly understood. Evidence for the contribution of psychosocial factors to the onset of DU is reviewed in the context of evidence of organic factors, genetic and environmental, with special reference to new evidence of infectious agents in the aetiology of DU. Recent progress in understanding of biological forces of duodenal ulcer disease has lead to a substantially revised view of psychosomatic factors. Although these may be of significance, their relative contribution to aetiology is likely to be modest.

Barrett's oesophagus and Helicobacter pylori

In order to demonstrate the presence of Helicobacter pylori in the metaplastic epithelium of Barrett's oesophagus and to evaluate its possible association with this entity, we examined 29 cases of Barrett's oesophagus where concomitant antral biopsies were also available. These cases were compared with an equal number of age and sex matched controls of uncomplicated reflux oesophagitis. H. pylori was present in 11 of 29 cases of Barrett's oesophagus (38%). No increase in the frequency of H. pylori antral gastritis was found in patients of Barrett's oesophagus compared to the control group of uncomplicated reflux oesophagitis. The positivity of Barrett's oesophagus for H. pylori correlated with the presence of H. pylori antral gastritis (P < 0.05), although in two cases of H. pylori-positive Barrett's oesophagus antral biopsies were negative for H. pylori. No difference was found in the severity of inflammatory and dysplastic changes of H. pylori-positive and H. pylori-negative Barrett's oesophagus. Presence of H. pylori does not seem to alter the natural history of Barrett's oesophagus.

Pathophysiological effects of long-term acid suppression in man

A critical evaluation has been made of the available evidence in man of the effects of prolonged low acid states on the structure and function of the stomach. Various human models have been examined. 1. Ageing does not affect acid output from the normal male stomach, and there may be an increase in women. With progressive atrophy of the corpus mucosa, which is more frequent and rapid in patients with gastric ulcer, there is an associated loss of secretory function. Chronic gastritis and atrophy are the most important age-related changes, which in many cultures are hypothesized to develop via a prior Helicobacter pylori-related gastritis. However, H. pylori colonization of the mucosa decreases with increasing grades of gastric atrophy probably because intestinal metaplasia provides a hostile environment. Atrophy and intestinal metaplasia are associated with precancerous lesions and gastric cancer. Apparent hyperplasia of the gastric argyrophil endocrine cells is a common and spontaneous phenomenon in patients with atrophic gastritis, which in part may be related to the preferential loss of nonendocrine cells. 2. Pernicious anemia is associated with a complete lack of acid production, marked hypergastrinemia, and endocrine cell hyperplasia in the majority of patients. ECL-cell carcinoids and gastric cancer occur with a prevalence of 3-7%, and endoscopic surveillance in routine clinical practice is not warranted. 3. Gastric ECL-cell carcinoids are rare events that have been described in association with two diseases in man, pernicious anemia and Zollinger-Ellison syndrome as part of multiple endocrine neoplasia syndrome type I, and usually relate to marked hypergastrinemia and the presence of chronic atrophic gastritis with gastric antibodies or a genetic defect rather than the presence or absence of acid. Regression or disappearance of ECL-cell carcinoids, either spontaneously or after removal of the gastrin drive, has been recorded. Lymph node, and rarely hepatic, metastases are documented but death in these cases has been anecdotal. 4. Therapy with H2 antagonists may result in up to a twofold rise in serum gastrin levels but in man no endocrine cell hyperplasia has been recorded. However, the data for H2 antagonists on these aspects are very limited. There is no drug-related risk of gastric or esophageal cancer, although the incidence of the latter may be raised. Long-term treatment with omeprazole is associated with a two- to fourfold increase in gastrin levels over baseline values in one third of patients and apparent endocrine cell hyperplasia in 7% of cases overall.(ABSTRACT TRUNCATED AT 400 WORDS)

Primary antral gastritis in young American children. Low prevalence of Helicobacter pylori infections

Although Helicobacter pylori (H. pylori) is considered by many to be the major cause of primary antral gastritis (PAG), several important questions concerning its pathogenetic role remain unanswered. The most basic unresolved issue relates to the low prevalence of H. pylori in children in developed countries. If H. pylori is the cause of PAG, the prevalence of PAG should also be low, but previous studies have not provided data on this issue. To answer this question, we prospectively studied 408 children who underwent esophagogastroduodenoscopy and biopsy from January 1, 1988, to December 31, 1990, for symptoms consistent with peptic disease or immunocompromise. Although the prevalence of PAG was similar (about 20%) in the four age groups of patients studied (< 5, 5-9, 10-14, and 15-20 years), the prevalence of H. pylori infections was significantly greater in the oldest age group (67%, P < 0.0001). Only four of 39 children < 10 years old with PAG had evidence of H. pylori. H. pylori is an uncommon finding in our population of young American children with PAG, indicating that it does not play an important role in the pathogenesis of this disorder in this age group.

Duodenal ulcer treatment: progress from pH to HP

The treatment of duodenal ulcer has evolved from ineffective medical treatments through an era of surgical management, back to increasingly effective medical treatment. The advent of H2-receptor antagonists changed the outlook for ulcer patients. More recently, Helicobacter pylori, an organism which inhabits gastric mucosa exclusively, has been implicated in the pathogenesis of peptic ulcer. This bacterium is found in the stomachs of around 95% of duodenal ulcer patients. Its eradication is shown dramatically to improve the rate at which ulcers relapse. The mechanisms whereby it may cause ulceration are not established--we review current hypotheses. No method of eradication is 100% effective, and many different dual or triple therapy regimens have been tried. Metronidazole resistance is reported but its importance is not yet known. Helicobacter eradication is likely to prove a cost-effective and acceptable treatment for duodenal ulcer, and once its value has gained acceptance widespread uptake of this option is anticipated.

Role of the systemic cellular immune response in the pathogenesis of Helicobacter pylori-associated duodenal ulcer

20 patients colonized by H. pylori (9 with duodenal ulcer, 11 with antral gastritis) were examined for the presence of a systemic cellular immune response to H. pylori using an in vitro lymphocyte transformation assay. Infiltration of the antral mucosa by myelomonocytic cells was assessed by immunohistology as a parameter of local cellular immune response. A systemic H. pylori-induced cellular reaction could be demonstrated in 11 patients all of whom showed an intense myelomonocytic infiltration of the antral mucosa. In this group 7 of 9 duodenal ulcers occurred. The findings support the hypothesis, that a specific cellular immune response might be involved in the pathogenesis of H. pylori-associated gastritis and duodenal ulcer. A protective role of systemic cellular immunity to H. pylori seems rather unlikely.

Helicobacter pylori associated dyspepsia in 208 patients from southern Saudi Arabia

The frequency of Helicobacter pylori (HP) infection in 208 patients with upper gastrointestinal tract symptoms from the Southern Province of Saudi Arabia was studied prospectively. The occurrence of HP was documented histologically and using a rapid urease test in antral endoscopic biopsies. Our results showed that 82.2% of the 208 patients included were positive for HP with a male:female ratio of approximately 1:1 (88:83). The age range was 14 to 80 years and the median age was 38.2 years. The frequencies of HP infection among Saudi and non-Saudi patients were 86% and 71%, respectively. Frequencies of HP infection were 88%, 77.5%, and 93% during the second, third, and fourth decades of life. Among the 140 patients with histologically proven antral gastritis, 128 cases (91%) were positive for HP whereas 29 cases (17%) of the 171 patients positive for HP did not show histologic evidence of antral gastritis. Our data showed that HP was present in 92.5% of patients with endoscopic diagnosis of duodenal ulceration, 81% of patients with duodenitis, 80% of patients with both duodenitis and gastritis, 69% of patients with gastric antral erythema, and 81% of patients with non-ulcer dyspepsia (normal upper gastrointestinal endoscopy). Histologically proven antral gastritis was seen in 80% of patients with endoscopic diagnosis of duodenal ulceration, 76% of patients with antral erythema, 70% of patients with both duodenitis and gastritis, 33% of patients with duodenitis only, and 66% of patients with non-ulcer dyspepsia. Among the 208 patients included in the study, gastric ulcerationw as only seen in two cases, both positive for HP.

Link between Helicobacter pylori-associated gastritis and duodenal ulcer

We examined the interrelationships among the degree of fundic mucosal atrophy, the prevalence of Helicobacter pylori in the gastric antrum, the gastric juice, and the duodenum with and without gastric metaplasia, in 20 duodenal ulcer patients and 20 non-duodenal ulcer patients. The detection rates of H. pylori in the antrum, the gastric juice, and the duodenum were significantly higher in duodenal ulcer patients (80%, 65%, and 60%) than in non-duodenal ulcer subjects (50%, 20%, and 5%). The frequency of H. pylori was significantly lower in the gastric juice (30%) and the duodenum (10%) in non-duodenal ulcer patients with antral H. pylori, compared with those in duodenal ulcer patients with antral H. pylori. All of seven patients with both gastric metaplasia and H. pylori infection in the duodenum had duodenal ulcer, whereas only 1 of 14 patients without either gastric metaplasia or H. pylori infection in the duodenum had duodenal ulcer. There was normal or mild atrophic mucosa in the fundus of duodenal ulcer patients with H. pylori in the antrum, whereas moderate or severe atrophic mucosa in non-duodenal ulcer patients with H. pylori gastritis. These results suggest that the preserved fundic mucosa, gastric metaplasia in the duodenum, and a greater load of H. pylori to the duodenum through the gastric juice may be prerequisites for the formation of duodenal ulcers.

Study of Helicobacter pylori colonization of patches of heterotopic gastric mucosa (HGM) at the upper esophagus

Helicobacter pylori (HP), known to cause active chronic gastritis, has primarily been found in gastric-type mucosa. Even in the duodenum, the organism was detected in islands of metaplastic gastric mucosa. HP has also been found in gastric metaplasia of Barrett's esophagus in 15-50%. The aim of our study was to determine: (1) the frequency with which HP is found on histopathological sections of heterotopic gastric mucosa (HGM) patch(es) at the upper esophagus, as compared to that of the stomach proper, and (2) the histopathological significance of infection in the HGM patches. From 63 patients with HGM patches at the upper esophagus, 48 patients were found to have concurrent adequate specimen from the stomach for modified Steiner's stain. In 22 patients (45.8%), pair sections from HGM and stomach were negative for HP. Of 26 patients (54.1%) HP-positive on sections from the antrum and/or body (both in 21 cases) nine patients (18.7%) demonstrated HP in the HGM patches. Whereas focal acute inflammatory changes on the H&E section of HGM was present in six patients, HP was detected in HGM only in one. Chronic inflammatory cell infiltration was detected in all nine HP-positive HGM patches and in 37 of 39 HP-negative patches. A mixed acute and chronic inflammatory cell infiltration was found in five of these 37 patients. Our data demonstrate that HP infection of HGM patches at the upper esophagus is part of the HP gastritis and an independent colonization of HGM patches without gastric infection does not occur.(ABSTRACT TRUNCATED AT 250 WORDS)

Treatment of Helicobacter pylori-associated gastroduodenal disease in children. Clinical evaluation of antisecretory vs antibacterial therapy

The charts of 54 children diagnosed with antral H. pylori were reviewed, to establish the incidence of gastroduodenal inflammation and compare therapeutic efficacies of antisecretory vs. antibacterial therapy. Histology demonstrated normal mucosa in three cases (6%) and gastric/duodenal inflammation (> or = Whitehead grade 3) in 51 biopsies (94%). 23/43 children (53%) initially responded to H2-blockers; however, by 10 mo, 13 had relapsed clinically. All of these patients subsequently responded to amoxicillin plus bismuth subsalicylate. Of the 20 children who failed to enter remission after an initial course of H2-blockers, all became symptom-free after treatment with amoxicillin/bismuth. Compared to antisecretory agents, antibacterial treatment induced clinical remission in 11/11 patients (p < 0.001), who remained symptom-free for 10 +/- 0.2 mo. Clinical remissions were maintained in significantly more patients following amoxicillin/bismuth vs. H2-blockers (44/54 vs. 10/43 courses, p < 0.001); and, the cumulative probability of remaining asymptomatic was significantly greater in the antibiotic group (p < 0.001). These data suggest that gastric colonization by H. pylori is highly predictive of mucosal pathology in children. Initial therapy should be directed toward achieving bacterial eradication, as opposed to gastric acid suppression.

Pathophysiology and treatment of functional dyspepsia

Functional dyspepsia (or 'non-ulcer') is usually defined as chronic or intermittent upper abdominal symptoms for which no organic cause can be found. Division of functional dyspepsia into subgroups such as reflux-like, ulcer-like, dysmotility-like and non-specific dyspepsia has been proposed, but lacks a scientific basis. Gastric acid hypersecretion, Helicobacter pylori-associated gastritis, gastric and small intestinal motor disorders, psychological and neurohormonal factors all might play a role in the pathogenesis. The heterogeneity of the underlying abnormalities makes it unlikely that one single treatment modality will ever be beneficial to all patients. In general practice, a therapeutic trial, with either a prokinetic or an acid secretion inhibiting drug, is usually carried out before diagnostic procedures are performed to exclude organic abnormalities. In the choice of the initial therapy, some guidance can be derived from the prominent symptoms. In a study in 30 H. pylori-negative patients with functional dyspepsia ranitidine (150 mg bid) significantly reduced the severity of heartburn. The effect was most pronounced in patients of the reflux-like subgroup.

Helicobacter colonization and histopathological profile of chronic gastritis in patients with or without dyspepsia, mucosal erosion and peptic ulcer: a morphological approach to the study of ulcerogenesis in man

Helicobacter pylori colonization and the incidence, severity, activity and topography of gastritis were investigated systematically in antrum and corpus mucosal biopsies of 1177 subjects undergoing endoscopy in the absence of gastric complaints (asymptomatic, 49) or for non-ulcer dyspepsia (NUD; 631 patients, 72 of whom had gastric and/or duodenal erosions), active gastric ulcer (GU, 76 patients), active duodenal ulcer (DU, 138 patients), and healed gastric (HGU, 39 cases) or duodenal ulcer (HDU, 230 cases). In the antrum, H. pylori colonization and the incidence, severity and activity of gastritis increased progressively in the sequence asymptomatic, erosion-free NUD, erosive NUD, healed ulcer and active ulcer. The same trend was observed in the corpus as regards H. pylori and gastritis incidence, whereas the severity and activity of gastritis were lower in active DU and erosive NUD and higher in active, proximal GU than in the remaining patients. Active DU and erosive NUD showed the highest incidence of non-atrophic gastritis and lowest type-A or AB atrophic gastritis, while active GU had lowest normal mucosa or type-A gastritis and highest type-B atrophic gastritis. In conclusion, H. pylori colonization and gastritis incidence, severity and, especially, activity of the antrum might all contribute to mucosal erosion and ulceration, whereas the same factors, at least in part and with the exception of proximal GU, seem to have a preventive role when affecting corpus mucosa.

Effect of Helicobacter pylori infection on colloidal bismuth subcitrate concentration in gastric mucus

Necropsy gastric mucus infected with Helicobacter pylori has a reduced capacity to concentrate colloidal bismuth subcitrate when compared with non-infected mucus. Mucus mounted in a modified in vitro diffusion chamber was bathed with colloidal bismuth subcitrate solutions at different concentrations and pH levels. Bismuth was measured by atomic absorption spectrophotometry to assess intramucus colloidal bismuth subcitrate concentrations. Bismuth concentrations in non-infected mucus were higher than in Helicobacter pylori infected mucus at all experimental colloidal bismuth subcitrate concentrations and pH levels. Regardless of the infection status, the intramucus concentration of colloidal bismuth subcitrate was dependent upon the concentration of the bathing solution and independent of the pH and the mucus thickness. Colloidal bismuth subcitrate solubility in saline solution varied with pH, and was least soluble in the pH range 1.1 to 3.25 and more soluble above and below this pH range. This study suggests that Helicobacter pylori infection is associated with physicochemical changes in the gastric mucus with a reduction in its capacity to concentrate colloidal bismuth subcitrate. Such a reduction may compromise the attainment of optimum colloidal bismuth subcitrate concentrations necessary for its bactericidal activity.

Helicobacter pylori affects the quality of experimental gastric ulcer healing in a new animal model

Helicobacter pylori has been implicated in the genesis of human gastritis, dyspepsia, and peptic ulcers. However, its influence in the quality of experimental gastric ulcer healing has not been previously investigated. Standardized gastric fundic ulcers were produced in 50 male Sprague-Dawley rats (150-200 g) by a 4 mm in diameter focal, serosal application of 100% acetic acid. Thirty rats were administered 2 ml H. pylori suspension (urease producing, ATCC 43504) in normal saline (10(8) CFU/ml) 2x/day for 7 days. Twenty rats (controls) received 2 ml normal saline 2x/day for 7 days. Gastric ulcer surface area was measured under a dissecting microscope and mucosal specimens were obtained for qualitative and quantitative histology. No gross or microscopic duodenal abnormalities were identified at sacrifice. Ninety percent of control rats showed grossly and microscopically entirely healed ulcers. The remaining 10% showed partially reepithelialized ulcers (area, 0.78 to 1.77 mm2; mean, 1.27 +/- 0.7 mm2). The grossly "healed" mucosa demonstrated marked dilatation of gastric glands lined with mature surface epithelial cells. Parietal cells were scanty (5-10% of all cells). One hundred percent of the H. pylori-exposed rats showed persistence of chronic active ulcers (area, 1.76 to 19.63 mm2; mean, 8.95 +/- 6.15 mm2). The ulcer beds were infiltrated by acute and chronic inflammatory cells, abundant fibroblasts, and capillary networks. The raised ulcer borders were characterized by dilated glands lined by mature surface epithelial cells. Various special stains demonstrated the presence of H. pylori in the surface mucus and within the crypts.(ABSTRACT TRUNCATED AT 250 WORDS)

Is Helicobacter pylori a cause of duodenal ulcer? A methodologic critique of current evidence

INTRODUCTION

Helicobacter pylori (HP) in the gastric antrum has been strongly associated with both duodenal ulcer (DU) and chronic active gastritis (CAG). The relationship between HP and DU has been interpreted as causal by many observers. An alternate hypothesis is that HP coincidently colonizes CAG, which is independently associated with DU by some yet-unknown mechanism.

PURPOSE

To assess the extent to which a causal relationship between HP and DU has been demonstrated, we performed a methodologic critique of published clinical studies. We carried out a literature search to identify clinical studies that included at least 25 subjects. Of the eight studies we identified, six used a cross-sectional design and two used a prospective cohort design. We applied methodologic criteria to assess causation: strength of association, biologic gradient, temporality, and experiment.

METHODS

A strong association between HP and DU was demonstrated in all eight studies. Biologic gradient and temporality were not assessed in any study. In the two experimental studies of therapy, loss of antral HP was associated with a decreased rate of DU relapse; however, we did not interpret this as sufficient to support causality because the effect may have been due to a direct mucosal action rather than eradication of HP.

CONCLUSION

We conclude that published evidence does not establish HP as a cause of DU. One approach to address causality would be an observational cohort study of ulcer relapse to assess the temporal relationships between HP, CAG, and DU.

Helicobacter pylori: a Jordanian study

The prevalence of Helicobacter pylori in patients with upper gastrointestinal symptoms in the north of Jordan was studied prospectively. The occurrence of H. pylori was documented histologically and bacteriologically in 169 patients attending endoscopy for upper gastrointestinal symptoms. Our results showed that H. pylori was present in 70% of patients with acute gastritis, 73% of patients with chronic gastritis, 68% of patients with acute on chronic gastritis, 83% of patients with duodenal ulceration, 75% of the patients with gastric ulceration, 64% of patients with no pathology, and 68% of patients regardless of the pathology found. There was a sharp rise in the prevalence of H. pylori with age, up to the age of 40 years with an annual increase in the prevalence of 2%. This study shows that the prevalence of H. pylori in Jordan is similar to that seen in other developing countries with infections occurring at a lower age and with the annual infection rate being double that seen in developed countries.

Mucosal humoral immune response to Helicobacter pylori in patients with duodenitis

The humoral immune response to Helicobacter pylori infection in the duodenum has been investigated by short-term in vitro culture, ELISA, and immunoblotting techniques. H. pylori IgA secretion by duodenal bulb biopsies was significantly increased (P less than 0.001) in patients with duodenitis. The IgA response to H. pylori in patients with duodenitis was restricted to the first part of the duodenum; second part duodenal biopsies secreting significantly (P less than 0.001) less IgA during culture in vitro. H. pylori IgG antibody secretion by cultured biopsies was also significantly increased (P less than 0.01) in patients with duodenitis and those with gastric H. pylori infection but without duodenitis. Immunoblotting of duodenal bulb culture supernatants showed positive recognition by the mucosal IgA response of H. pylori antigens in the region of 120, 90, 61, and 31-26 kDa in patients with duodenitis. Serologically, such patients showed little evidence of IgA H. pylori antibodies by immunoblotting. These results demonstrate that the inflammatory response in the duodenal mucosa of patients with duodenitis represents a specific highly localized humoral response to H. pylori.

Helicobacter pylori and chronic gastritis

One hundred forty-eight Arab patients of both sexes who had dyspeptic symptoms were histologically examined for the existence of chronic gastritis and the presence of Helicobacter pylori. This study further confirms this association and suggests an etiological link between these two conditions. The infestation of Helicobacter pylori adjacent to atrophic gastritis warrants prolonged follow-up of affected cases to prove any relationship to the development of gastric cancer.

Peptic ulcer pathophysiology

Despite extensive research, the etiology of peptic ulcer disease remains unclear. Given the multiple processes that control acid and pepsin secretion and defense and repair of the gastroduodenal mucosa, it is likely that the cause of ulceration differs between individuals. Acid and pepsin appear to be necessary but not sufficient ingredients in the ulcerative process. It is clear that the majority of gastric ulcers and a substantial number of duodenal ulcers do not have increased gastric acid secretion. Recent research has focused more on protection and repair of the stomach and duodenum. NSAIDs cause a significant number of gastric and duodenal ulcers; this is probably due to inhibition of prostaglandin production with loss of its protective effects. In the absence of NSAIDs and gastrinoma, it appears that most gastric ulcers and all duodenal ulcers occur in the setting of H. pylori infection. Evidence is mounting in support of H. pylori as a necessary ingredient in the ulcerative process, similar to acid and pepsin. It is not known whether the bacteria or the accompanying inflammation is the more important factor in the pathophysiology. Although the pathophysiology of gastric ulcer and duodenal ulcer is similar, there are clearly differences between the two groups. Duodenal ulcer is typified by H. pylori infection and duodenitis and in many cases impaired duodenal bicarbonate secretion in the face of moderate increases in acid and peptic activity. These facts suggest the following process: increased peptic activity coupled with decreased duodenal buffering capacity may lead to increased mucosal injury and result in gastric metaplasia. In the presence of antral H. pylori, the gastric metaplasia can become colonized and inflamed. The inflammation or the infection itself then disrupts the process of mucosal defense or regeneration resulting in ulceration. A cycle of further injury and increased inflammation with loss of the framework for regeneration may then cause a chronic ulcer. Gastric ulcer often occurs with decreased acid-peptic activity, suggesting that mucosal defensive impairments are more important. The combination of inflammation, protective deficiencies, and moderate amounts of acid and pepsin may be enough to induce ulceration. Many questions remain in understanding the pathophysiology of peptic ulcer disease. The physiology and pathophysiology of mucosal regeneration and the mechanisms by which H. pylori and inflammation disrupt normal gastroduodenal function will be fruitful areas of future investigation.

Effect of omeprazole on duodenal ulcer-associated antral gastritis and Helicobacter pylori

This study set out to investigate the effects of omeprazole or ranitidine on the progression of antral gastritis and Helicobacter pylori in patients with active duodenal ulcer. A double-blind, double-dummy trial was performed in 270 patients, 241 of whom were studied histologically for the presence of H. pylori. Patients were randomized to receive omeprazole, 10 mg every morning, omeprazole, 20 mg every morning, or ranitidine, 150 mg twice a day, for four weeks. Endoscopy was performed on entry and at weekly intervals during the study; at least two antral biopsies were taken on each occasion to assess the activity and degree of chronic inflammation, as reflected by the degree of polymorphonuclear leukocyte infiltration and mononuclear cell infiltration, respectively. Biopsy specimens also were assessed histologically for H. pylori. The sex, age and maximal acid output were comparable in the three treatment groups. The percentages of patients showing an improvement in the activity of gastritis in the four consecutive weeks of treatment were 9%, 40%, 51%, and 53% for omeprazole, 10 mg (N = 78); 14%, 42%, 49%, and 53% for omeprazole, 20 mg (N = 81); and 2%, 23%, 30%, and 33% for ranitidine, 150 mg twice a day (N = 82) (life table analysis gave P less than 0.01 for both omeprazole regimens compared with ranitidine). The degree of chronic inflammation showed similar changes. The density of H. pylori decreased significantly after treatment with omeprazole, 10 mg or 20 mg, (both, P less than 0.00001) but not with ranitidine.(ABSTRACT TRUNCATED AT 250 WORDS)

A comparison of symptoms between non-ulcer dyspepsia patients positive and negative for Helicobacter pylori

The role of Helicobacter pylori infection in the symptom complex associated with non-ulcer dyspepsia is uncertain, despite the presence of the organism in a high proportion of these patients. In order to exclude physician bias in history taking, 18 patients (9 female) diagnosed as non-ulcer dyspepsia, after endoscopy and gallbladder ultrasonography, underwent computer interrogation using the Glasgow Diagnostic System for Dyspepsia (GLADYS). Five antral and 3 fundal endoscopic biopsies from these patients were also histologically examined for the presence of Helicobacter pylori and quantitatively analysed for polymorph and chronic inflammatory cell densities per mm2 of lamina propria using computer-linked image analysis. In the group of 9/18 patients who were positive for Helicobacter pylori, there were significantly higher antral and fundal inflammatory cell counts than in negative patients. However, analysis of the GLADYS interrogation data showed no significant positive relationships between Helicobacter pylori positivity and any gastrointestinal symptoms. These results confirm a significant association between Helicobacter pylori and superficial gastritis but suggest that non-ulcer dyspepsia in patients with Helicobacter pylori colonisation is probably not a clinically identifiable and distinct syndrome.

Is gastroduodenitis a cause of chronic dyspepsia?

The role of Helicobacter pylori infection in causing chronic dyspepsia is in need of further clarification. More well-designed prospective studies are necessary to ascertain whether and to what extent H. pylori-related chronic inflammation in the stomach and the duodenum causes dyspeptic symptoms; whether and to what extent there is a symptom cluster characteristic for H. pylori-related gastroduodenitis; whether and to what extent H. pylori infection is demonstrable in the chronic dyspeptic population; and whether and to what extent H. pylori infection interferes with gastrin homoeostasis and acid secretion or induces motor disturbances. Well-designed prospective H. pylori-eradication studies may further contribute in unravelling its role in chronic dyspepsia, especially in patients with active polymorphonuclear gastroduodenitis and hyperacidity.