Morphological and functional restoration of parietal cells in helicobacter pylori associated enlarged fold gastritis after eradication

Helicobacter pylori intragastric colonization and migration: Endoscopic manifestations and potential mechanisms

After being ingested and entering the human stomach, Helicobacter pylori (H. pylori) adopts several effective strategies to adhere to and colonize the gastric mucosa and move to different regions of the stomach to obtain more nutrients and escape from the harsher environments of the stomach, leading to acute infection and chronic gastritis, which is the basis of malignant gastric tumors. The endoscopic manifestations and pathological features of H. pylori infection are diverse and vary with the duration of infection. In this review, we describe the endoscopic manifestations of each stage of H. pylori gastritis and then reveal the potential mechanisms of bacterial intragastric colonization and migration from the perspective of endoscopists to provide direction for future research on the effective therapy and management of H. pylori infection.

Consistency between the endoscopic Kyoto classification and pathological updated Sydney system for gastritis: A cross-sectional study

BACKGROUND

Two methods are used to evaluate gastritis: the updated Sydney system (USS) with pathology and Kyoto classification, a new endoscopy-based diagnostic criterion for which evidence is accumulating. However, the consistency of their results is unclear. This study investigated the consistency of their results.

METHODS

Patients who underwent esophagogastroduodenoscopy and were evaluated for Helicobacter pylori infection for the first time were eligible. The association between corpus and antral USS scores (neutrophil activity, chronic inflammation, atrophy, and intestinal metaplasia) and Kyoto classification scores (atrophy, intestinal metaplasia, enlarged folds, nodularity, and diffuse redness) was assessed.

RESULTS

Seven-hundred-seventeen patients (mean age, 49.2 years; female sex, 57.9%; 450 H. pylori-positive and 267 H. pylori-negative patients) were enrolled. All endoscopic gastritis cases in the Kyoto classification were associated with high corpus and antral USS scores for neutrophil activity and chronic inflammation. A subanalysis was performed for H. pylori-positive patients. Regarding atrophy and intestinal metaplasia, endoscopic findings were associated with USS scores. Enlarged folds, nodularity, and diffuse redness were associated with high corpus USS scores for neutrophil activity and chronic inflammation, but with low antral USS scores for atrophy and intestinal metaplasia. The Kyoto classification scores were also associated with the pathological topographic distribution of neutrophil activity and intestinal metaplasia.

CONCLUSIONS

Among H. pylori-positive individuals, endoscopic and pathological diagnoses were consistent with atrophy and intestinal metaplasia. Enlarged folds, nodularity, and diffuse redness were associated with pathological inflammation (neutrophil activity and chronic inflammation) of the corpus; however, they were inversely associated with pathological atrophy and intestinal metaplasia. The endoscopy-based Kyoto classification of gastritis partially reflects pathology.

Enlarged folds on endoscopic gastritis as a predictor for submucosal invasion of gastric cancers

BACKGROUND

Accurate diagnosis of the depth of gastric cancer invasion is crucial in clinical practice. The diagnosis of gastric cancer depth is often made using endoscopic characteristics of the tumor and its margins; however, evaluating invasion depth based on endoscopic background gastritis remains unclear.

AIM

To investigate predicting submucosal invasion using the endoscopy-based Kyoto classification of gastritis.

METHODS

Patients with gastric cancer detected on esophagogastroduodenoscopy at Toyoshima Endoscopy Clinic were enrolled. We analyzed the effects of patient and tumor characteristics, including age, sex, body mass index, surveillance endoscopy within 2 years, current Helicobacter pylori infection, the Kyoto classification, and Lauren’s tumor type, on submucosal tumor invasion and curative endoscopic resection. The Kyoto classification included atrophy, intestinal metaplasia, enlarged folds, nodularity, and diffuse redness. Atrophy was characterized by non-reddish and low mucosa. Intestinal metaplasia was detected as patchy whitish or grayish-white flat elevations, forming an irregular uneven surface. An enlarged fold referred to a fold width ≥ 5 mm in the greater curvature of the corpus. Nodularity was characterized by goosebump-like multiple nodules in the antrum. Diffuse redness was characterized by uniform reddish non-atrophic mucosa in the greater curvature of the corpus.

RESULTS

A total of 266 gastric cancer patients (mean age, 66.7 years; male sex, 58.6%; mean body mass index, 22.8 kg/m²) were enrolled. Ninety-three patients underwent esophagogastroduodenoscopy for surveillance within 2 years, and 140 had current Helicobacter pylori infection. The mean Kyoto score was 4.54. Fifty-eight cancers were diffuse-type, and 87 cancers had invaded the submucosa. Multivariate analysis revealed that low body mass index (odds ratio 0.88, P = 0.02), no surveillance esophagogastroduodenoscopy within 2 years (odds ratio 0.15, P < 0.001), endoscopic enlarged folds of gastritis (odds ratio 3.39, P = 0.001), and Lauren’s diffuse-type (odds ratio 5.09, P < 0.001) were independently associated with submucosal invasion. Similar results were obtained with curative endoscopic resection. Among cancer patients with enlarged folds, severely enlarged folds (width ≥ 10 mm) were more related to submucosal invasion than mildly enlarged folds (width 5-9 mm, P < 0.001).

CONCLUSION

Enlarged folds of gastritis were associated with submucosal invasion. Endoscopic observation of background gastritis as well as the lesion itself may help diagnose the depth of cancer invasion.

Gastric foveolar elongation causes invisibility of regular arrangement of collecting venules in chronic active and inactive gastritis

OBJECTIVES

Helicobacter pylori (H pylori) infection is the most common cause of gastritis. The disappearance of regular arrangement of collecting venules (RAC) is well known as one of the main manifestations of H pylori-affected gastritis while the reason behind it remains obscure. The aim of this study was to investigate the relationship between invisibility of RAC and the length of gastric foveolae.

METHODS

43 RAC-positive and 118 RAC-negative patients were enrolled. Gastric biopsy specimens were obtained from lesser and greater curvature of the corpus with RAC-positive or RAC-negative pattern. Histopathological evaluation was performed based on the updated Sydney System, and foveolar length was derived by a morphometric technique.

RESULTS

The median gastric foveolar length in RAC-positive group (median [IQR], 138.54 μm [120.50, 159.09]) was significantly shorter than that in the RAC-negative group (median [IQR], 260.96 μm [217.40, 315.23], P < .05). The length of gastric foveolae in chronic active gastritis (RAC-negative, activity grades 1, 2, and 3) and inactive gastritis (RAC-negative, activity grade 0) was longer than that in normal group (RAC-positive, activity grade 0) (P < .05). The optimal cutoff value for gastric foveolae length of the corpus mucosa showing RAC-negative pattern was more than 181.53 μm. The sensitivity and specificity of more than cutoff value for predicting the invisibility of RAC were 93.03% and 91.78%, respectively.

CONCLUSIONS

The elongation of gastric foveolae caused the invisibility of RAC in gastric corpus mucosa in chronic active and inactive gastritis on gastroendoscopy.

A single nucleotide polymorphism in Prostate Stem Cell Antigen is associated with endoscopic grading in Kyoto classification of gastritis

The risk allele of a single nucleotide polymorphism (SNP) rs2294008 in the Prostate stem cell antigen (PSCA) gene is strongly associated with gastric cancer. Although the Kyoto classification score is believed to be an indicator of gastric cancer risk, it lacks supporting genetic evidence. We investigated the effect of this risk allele of PSCA SNP on the Kyoto score. Participants without a history of gastric cancer or Helicobacter pylori (H. pylori) eradication underwent esophagogastroduodenoscopy, H. pylori evaluation, and SNP genotyping. The Kyoto score is the sum of scores obtained from endoscopy-based atrophy, intestinal metaplasia, enlarged folds, nodularity, and diffuse redness. The Kyoto score is novel in the light of scoring for gastritis. A total of 323 patients were enrolled (number of individuals with genotype CC: 52; CT: 140; TT: 131, average age: 50.1 years, male: 50.8%). The patient baseline characteristics including age, sex, body mass index, smoking, drinking, family history of gastric cancer, and H. pylori status had no association with PSCA SNP. The Kyoto score was higher in T (CT or TT genotype; risk allele) carriers than in CC carriers. Atrophy, enlarged folds, and diffuse redness scores were higher in T allele carriers (risk allele) than in CC genotype individuals. In multivariate analysis, the Kyoto score was independently associated with PSCA SNP (OR: 1.30, p = 0.012). Thus, the Kyoto score was associated with a genetic predisposition.

Endoscopic Characteristics of Rugal Hyperplasia and Related Acid Condition in Helicobacter pylori-Infected Stomach

Background/Aims

Rugal hyperplastic gastritis (RHG) is associated with Lauren’s diffuse-type gastric cancer (GC) and the accompanying active inflammation is linked to gastric hypoacidity. We tried to establish the steps for identifying high-risk GC patients.

Methods

We included 196 patients with confirmed Helicobacter pylori infection by rapid urease test during screening endoscopy for health check-up from January 2016 to September 2016; all patients underwent blood tests for pepsinogen I and II and fasting serum gastrin. We compared RHG findings with various other endoscopic mucosal images. We also evaluated the relationships between RHG and other mucosal aspects for a given acid status based on serological markers.

Results

Hypoacid and ultra-low-acid (67%) statuses were dominant, with only 18% hyperacid patients. RHG with high acid was related to a less atrophic body type (p=0.001), and RHG with ultra-low acid was associated with body xanthoma (p=0.029) and increased serum gastrin level (p=0.038). However, RHG’s influence on gastric acidity was only seen in closed-type endoscopic atrophic border (EAB), not in open type (p=0.001).

Conclusions

The majority of RHG patients had hypoacid status. RHG frequency showed no difference between closed and opentype EAB, but gastric acidity was influenced by RHG only in closed-type EAB.

Chronic in vivo exposure to Helicobacter pylori VacA: Assessing the efficacy of automated and long-term intragastric toxin infusion

Helicobacter pylori (Hp) secrete VacA, a diffusible pore-forming exotoxin that is epidemiologically linked to gastric disease in humans. In vitro studies indicate that VacA modulates gastric epithelial and immune cells, but the in vivo contributions of VacA as an important determinant of Hp colonization and chronic infection remain poorly understood. To identify perturbations in the stomachs of C57BL/6 or BALB/C mice that result specifically from extended VacA exposure, we evaluated the efficacy of administering purified toxin using automated infusion via surgically-implanted, intragastric catheters. At 3 and 30 days of interrupted infusion, VacA was detected in association with gastric glands. In contrast to previously-reported tissue damage resulting from short term exposure to Hp extracts administered by oral gavage, extended infusion of VacA did not damage stomach, esophageal, intestinal, or liver tissue. However, several alterations previously reported during Hp infection were detected in animals infused with VacA, including reduction of the gastric mucus layer, and increased vacuolation of parietal cells. VacA infusion invoked an immune response, as indicated by the detection of circulating VacA antibodies. These foundational studies support the use of VacA infusion for identifying gastric alterations that are unambiguously attributable to long-term exposure to toxin.

Helicobacter pylori eradication improved the Kyoto classification score on endoscopy

Background and Aim

Endoscopy‐based Kyoto classification predicts the risk of Helicobacter pylori infection and gastric cancer; however, the change in score following H. pylori eradication remains unknown. We retrospectively compared the Kyoto score before and after H. pylori eradication.

Methods

H. pylori‐positive patients who underwent baseline esophagogastroduodenoscopy (EGD), successful H. pylori eradication, and surveillance EGD were enrolled. The Kyoto score is a sum of scores for atrophy (Kimura‐Takemoto atrophic‐border classification none or C1: 0, C‐II or C‐III: 1, O‐I to O‐III: 2), intestinal metaplasia (none: 0, antrum: 1, corpus and antrum: 2), enlarged folds (absence: 0, presence: 1), nodularity (absence: 0, presence: 1), and diffuse redness (none: 0, mild: 1, severe: 2) and ranges from 0 to 8.

Results

Eighty‐three patients (mean age: 54.9 years; 65.1% women) were enrolled. The mean duration from successful eradication to surveillance EGD was 256 days. The Kyoto score significantly decreased from 3.90 to 2.78 following H. pylori eradication (P < 0.001). Scores for endoscopic atrophy (from 1.43 to 1.46, P = 0.638) and endoscopic intestinal metaplasia (from 0.53 to 0.47, P = 0.543) did not change; however, there was significant improvement in the scores for enlarged folds (from 0.14 to 0.00, P = 0.002), nodularity (from 0.18 to 0.04, P = 0.002), and diffuse redness (from 1.61 to 0.82, P < 0.001).

Conclusion

The Kyoto classification score decreased following H. pylori eradication. A decrease in the scores for enlarged folds, nodularity, and diffuse redness contributed to the decrease in Kyoto score.

Risk factors associated with gastric malignancy during chronic Helicobacter pylori Infection

Chronic Helicobacter pylori (Hp) infection is considered to be the single most important risk factor for the development of gastric adenocarcinoma in humans, which is a leading cause of cancer-related death worldwide. Nonetheless, Hp infection does not always progress to malignancy, and, gastric adenocarcinoma can occur in the absence of detectable Hp carriage, highlighting the complex and multifactorial nature of gastric cancer. Here we review known contributors to gastric malignancy, including Hp virulence factors, host genetic variation, and multiple environmental variables. In addition, we assess emerging evidence that resident gastric microflora in humans might impact disease progression in Hp-infected individuals. Molecular approaches for microbe identification have revealed differences in the gastric microbiota composition between cancer and non-cancerous patients, as well as infected and uninfected individuals. Although the reasons underlying differences in microbial community structures are not entirely understood, gastric atrophy and hypochlorhydria that accompany chronic Hp infection may be a critical driver of gastric dysbiosis that promote colonization of microbes that contribute to increased risk of malignancy. Defining the importance and role of the gastric microbiota as a potential risk factor for Hp-associated gastric cancer is a vital and exciting area of current research.

Pediatric Helicobacter pylori gastropathy demonstrates a unique pattern of gastric foveolar hyperplasia

OBJECTIVES

Helicobacter pylori (Hp) are the most common agents causing gastric mucosal injury worldwide. Foveolar hyperplasia is a key component of the stomach's reaction to injury. This study examines histopathologic characteristics associated with Helicobacter pylori and with non- Helicobacter pylori-associated gastropathy in children and adolescents, and compares the prevalence of foveolar hyperplasia among these disease subgroups and normal control subjects.

METHODS

Eighty-one gastric antral and corpus biopsies from subjects 2-19 years of age were studied. Twenty-two subjects with Helicobacter pylori gastritis were compared to 23 with non-Helicobacter pylori gastropathy and to 36 controls (normal biopsies). Foveolar length, full mucosal thickness, and the foveolar length: full mucosal thickness ratio were derived by a morphometric technique previously developed to analyze adult gastric tissue.

RESULTS

Compared to controls, Helicobacter pylori gastritis demonstrated significant increases in antral foveolar length (P < .0001), full mucosal thickness (P < .0001), as well as corpus foveolar length (P < .05) and corpus full mucosal thickness (P < .05). Non-Helicobacter pylori-associated gastropathy also was characterized by increased antral foveolar length (P < .0001) and full mucosal thickness (P < .001) but corresponding corpus measurements did not differ from controls. Antral foveolar length in non-Helicobacter pylori gastropathy was increased, when compared to Helicobacter pylori gastritis (P < .05), while corpus values were not. The non-Helicobacter pylori gastropathy group demonstrated increased antral foveolar length: full mucosal thickness ratios, compared with Helicobacter pylori gastritis (P < .001) and with normal controls (P < .0001).

DISCUSSION

An objective, quantitative approach to measuring foveolar hyperplasia in adults was successfully applied to pediatric biopsies and yielded a richer characterization of gastric pathology in children. Foveolar hyperplasia appears to be a generalized phenomenon in the presence of pediatric Helicobacter pylori gastritis but is limited to the antrum in non-Helicobacter pylori gastropathy.

Nodular gastritis in association with gastric cancer development before and after Helicobacter pylori eradication

Background and Aim

Nodular gastritis is caused by Helicobacter pylori infection and is associated with the development of diffuse-type gastric cancer. This study examined the clinical characteristics of patients with nodular gastritis, including cancer incidence before and after H. pylori eradication.

Methods

This was a retrospective study of patients who underwent upper endoscopy and were positive for H. pylori infection. We examined the clinical findings and follow-up data after H. pylori eradication in patients with and without nodular gastritis.

Results

Of the 674 patients with H. pylori infections, nodular gastritis was observed in 114 (17%). It was more prevalent in women (69%) and young adults. Among patients with nodular gastritis, six (5%) had gastric cancer, all of which were of the diffuse type. Among the 19 (4%) patients with gastric cancer and no nodular gastritis, 16 had intestinal-type cancer. White spot aggregates in the corpus, a specific finding in patients with nodular gastritis, were more frequently observed in patients with gastric cancer than in those without (83% vs 26%, P = 0.0025). Of 82 patients with nodular gastritis who had H. pylori eradicated successfully, none developed gastric cancer over a 3-year follow-up period, while 7 (3%) of 220 patients without nodular gastritis developed gastric cancer after H. pylori eradication.

Conclusions

In patients with nodular gastritis, white spot aggregates in the corpus may indicate a higher risk of developing diffuse-type gastric cancer. Nodular gastritis may be an indication for eradication therapy to reduce the risk of cancer development after H. pylori eradication.

Helicobacter pylori infection in functional dyspepsia

Functional dyspepsia is the most common reason for patients to experience chronic epigastric pain or discomfort. The causes of functional dyspepsia are multifactorial but Helicobacter pylori infection is one likely candidate. Infection with this bacterial pathogen clearly results in chronic mucosal inflammation in the stomach and duodenum, which, in turn, might lead to abnormalities in gastroduodenal motility and sensitivity. Chronic gastritis might also affect a variety of endocrine functions of the stomach including the production of the gastrointestinal hormones and neurotransmitters somatostatin, gastrin and ghrelin. Although these abnormalities might generate symptoms in some patients with functional dyspepsia, the clinical evidence needs to be critically evaluated before this hypothesis can be confirmed. A Cochrane review reported that eradication of H. pylori in these patients had a small but statistically significant long-term effect on symptom relief when compared with placebo, lasting at least 12 months after 1 week of eradication therapy. The efficacy of eradication therapy was seen in all symptom subtypes of functional dyspepsia, but was more marked in Asian than Western patients. This evidence has led to alterations in most of the major guidelines throughout the world, which now recommend H. pylori eradication in patients with functional dyspepsia if they test positive for this bacterium.

Development of gastric cancer in nonatrophic stomach with highly active inflammation identified by serum levels of pepsinogen and Helicobacter pylori antibody together with endoscopic rugal hyperplastic gastritis

This study aimed to elucidate groups at high risk of developing cancer among patients with serologically identified Helicobacter pylori infection and nonatrophic stomach. Annual endoscopy was performed for a mean of 5.4 years in 496 asymptomatic middle-aged men who were H. pylori antibody-positive and pepsinogen (PG) test-negative. Subjects were stratified according to the activity of H. pylori-associated gastritis measured by serum levels of PG and H. pylori antibody, and/or by endoscopic findings of rugal hyperplastic gastritis (RHG), and cancer development was investigated. During the study period, seven cases of cancer developed in the cohort (incidence rate, 261/100,000 person-years), with 85.7% developing in the group showing a PGI/II ratio ≤ 3.0, reflecting active inflammation-based high PGII levels. Cancer incidence was significantly higher in this group (750/100,000 person-years) than in groups with less active gastritis. Furthermore, cancer incidence for this group was significantly higher in the subgroup with high H. pylori antibody titers than in the low-titer subgroup. Meanwhile, endoscopic findings revealed that 11.7% of subjects showed RHG reflecting localized highly active inflammation, and cancer risk was significantly higher in patients with RHG than in patients without. Combining the two serum tests and endoscopic examination for RHG allowed identification of subjects with more active gastritis and higher cancer risk. No cancer development was observed in these high-risk subjects after H. pylori eradication. Subjects with highly active gastritis identified by the two serological tests and endoscopic RHG constitute a group at high risk of cancer development with H. pylori-infected nonatrophic stomach.

Should we still subcategorize helicobacter pylori-associated dyspepsia as functional disease?

Functional dyspepsia is a group of disorders featuring symptoms believed to be derived from the stomach and duodenum such as upper abdominal discomfort, pain, postprandial fullness and early satiety. A key diagnostic requisite is the absence of organic, metabolic, or systemic disorders to explain "dyspeptic symptoms." Therefore, when peptic ulcer diseases (including scars), erosive esophagitis and upper gastrointestinal malignancies are found at endoscopic examinations, the diagnosis of functional dyspepsia is excluded. One notable exception, however, is Helicobacter pylori infection. According to the Rome III definition, H. pylori infection is included in functional dyspepsia. This is an obvious deviation from the diagnostic principle of functional dyspepsia, since H. pylori infection is a definite cause of mucosal inflammation, which affects a number of important gastric physiologies such as acid secretion, gastric endocrine function and motility. The chronic persistent nature of infection also results in more dramatic mucosal changes such as atrophy or intestinal metaplasia, the presence of which in the esophagus (Barrett's esophagus) precludes the diagnosis of functional dyspepsia. Since careful endoscopic examination can diagnose reliably H. pylori infection not only in Japan but also in Western contries, it is now feasible and more logical to exclude patients with chronic gastritis caused by H. pylori infection as having dyspeptic symptoms. It is time to establish the Asian consensus to declare that H. pylori infection should be separated from functional dyspepsia.

Ghrelin cells in the gastrointestinal tract

Ghrelin is 28-amino-acid peptide that was discovered from the rat and human stomach in 1999. Since the discovery of ghrelin, various functions of ghrelin, including growth hormone release, feeding behavior, glucose metabolism, memory, and also antidepressant effects, have been studied. It has also been reported that ghrelin in the gastrointestinal tract has an important physiological effect on gastric acid secretion and gastrointestinal motility. Ghrelin has a unique structure that is modified by O-acylation with n-octanoic acid at third serine residues, and this modification enzyme has recently been identified and named ghrelin O-acyl transferase (GOAT). Ghrelin is considered to be a gut-brain peptide and is abundantly produced from endocrine cells in the gastrointestinal mucosa. In the gastrointestinal tract, ghrelin cells are most abundant in the stomach and are localized in gastric mucosal layers. Ghrelin cells are also widely distributed throughout the gastrointestinal tract. In addition, abundance of ghrelin cells in the gastric mucosa is evolutionally conserved from mammals to lower vertebrates, indicating that gastric ghrelin plays important roles for fundamental physiological functions. Ghrelin cells in the gastrointestinal tract are a major source of circulating plasma ghrelin, and thus understanding the physiology of these cells would reveal the biological significance of ghrelin.

LINE-1 hypomethylation is associated with increased CpG island methylation in Helicobacter pylori-related enlarged-fold gastritis

BACKGROUND

The molecular mechanism by which Helicobacter pylori infection leads to gastric cancer is not fully understood. Similarly, patients with enlarged-fold (EF+) gastritis, one cause of which is H. pylori infection, have an increased risk for gastric cancer, although again molecular mechanism is unclear. In the present study, we analyzed the methylation status of long interspersed nucleotide elements (LINE-1) and three cancer-related genes in a panel of gastric mucosae, with or without EF+ gastritis.

METHODS

We used bisulfite pyrosequencing to assess the levels of LINE-1, CDH1, CDH13, and PGP9.5 methylation in 78 gastric mucosa specimens from 48 patients.

RESULTS

Levels of LINE-1 methylation were significantly reduced in mucosae from patients with EF+ gastritis. This hypomethylation of LINE-1 was associated with increased methylation of the 5' CpG islands of the genes, which suggests that, in EF+ gastritis, the methylation of the promoter regions of certain genes is accompanied by global demethylation of repetitive sequences.

CONCLUSIONS

Our results indicate that genomewide hypomethylation and regional hypermethylation occur in EF+ gastritis and may contribute to the tumorigenesis of diffuse-type gastric cancers.

E-cadherin gene promoter hypermethylation in H. pylori-induced enlarged fold gastritis

BACKGROUND

Promoter hypermethylation of E-cadherin plays an important role on gastric carcinogenesis. We have previously reported that the odds ratio for gastric carcinoma and the prevalence of diffuse-type early gastric carcinoma in Helicobacter pylori-induced enlarged fold gastritis increased with increasing fold width. Thus, we examined E-cadherin methylation in gastric mucosa from H. pylori-induced enlarged fold gastritis before and after H. pylori eradication. Moreover, we analyzed the mechanism of H. pylori infection-induced E-cadherin hypermethylation.

MATERIALS AND METHODS

Twenty-three H. pylori-positive patients with enlarged folds, 18 H. pylori-positive and seven H. pylori-negative patients without enlarged folds, were involved in the study. E-cadherin promoter methylation was studied using quantitative methylation-specific polymerase chain reaction. We investigated methylation percentage and DNA methyltransferase activity in gastric cancer cell lines treated with EGF, TNFalpha, and MG132.

RESULTS

E-cadherin methylation percentage of the gastric antral and body mucosa in H. pylori-positive patients with enlarged folds was much greater than that in both H. pylori-positive and -negative patients without enlarged folds. After H. pylori eradication, the methylation percentage in six patients with enlarged fold gastritis decreased significantly from 15.6 +/- 3.9 to 8.8 +/- 2.2 (p < .05). Moreover, the methylation was induced by TNFalpha, MG132, and EGF treatment, and DNA methyltransferase activity was induced by EGF treatment in MKN-1 cells.

CONCLUSIONS

Our findings suggest that the hypermethylation of E-cadherin promoter might be involved in the process of gastric carcinoma through the specialized factors in H. pylori-induced enlarged fold gastritis.

Rugal hyperplastic gastritis increases the risk of gastric carcinoma, especially diffuse and p53-independent subtypes

OBJECTIVES

Infection with Helicobacter pylori has been linked to chronic gastritis with atrophy or hyperrugosity. The development of noncardia gastric carcinoma, especially the intestinal type in Lauren's classification, has been associated with severe atrophic gastritis and p53 mutations. The objective of this study was to determine the association between hyperrugosity and gastric carcinogenesis, including p53 mutations.

PARTICIPANTS AND METHODS

Barium meal roentgenograms were performed in 395 control participants and 132 gastric carcinoma patients. The fold width was measured at the greater curvature of the middle portion of the gastric body. Serum pepsinogens I and II were determined along with gastrin levels. Complete coding sequences and splice junctions for exons 5-8 of p53 gene were screened for mutations by polymerase chain reaction-based single-strand conformational polymorphism analysis.

RESULTS

Rugal hyperplastic gastritis (gastric body fold width>or=5 mm) increased the risk of gastric carcinoma [odds ratio, 2.60; 95% confidence interval, 1.69-4.01] as compared with the control group, especially diffuse-type gastric carcinoma (odds ratio, 4.13; 95% confidence interval, 2.36-7.24). The p53 mutational rate was significantly lower in gastric carcinoma patients with rugal hyperplastic gastritis. In intestinal-type gastric carcinoma with hyperrugosity, the incidence of p53 gene mutations decreased, but no association was found in diffuse-type gastric carcinoma between p53 mutations and rugal hyperplastic gastritis.

CONCLUSIONS

Rugal hyperplastic gastritis was associated with an elevated risk of gastric carcinoma, especially diffuse-type, and a lower frequency of p53 mutations.

In situ measurement of pH in the secreting canaliculus of the gastric parietal cell and adjacent structures

The gastric H(+)/K(+)-ATPase is located within an infolding (secretory canaliculus) of the apical plasma membrane of gastric parietal cells. Our aim was to measure the pH values in the cytosol and canaliculus of the acid-secreting parietal cell and the adjacent gland lumen in situ. We used ultrafine double-barreled tip-sealed microelectrodes at high acceleration rates for intracellular and canalicular measurements. Immunohistochemical staining of the parietal cells was used to identify the track of the electrode and to estimate the position of the electrode tip at the time of the last intracellular measurement. En route to the deepest regions of the mucosa, where the average gland lumen pH was approximately 3, and on advancing in steps of 2 mum, the electrode entered the cytosol of the parietal cells, where the pH value was 7.4. Advancing the electrode further resulted, in several instances, in a sharp decrease in pH to an average value of 1.7 +/- 0.2, which we interpreted as the measurement within the canaliculus. When the electrode was advanced even further, the pH reading returned to the cytosolic value. From the difference in pH between the secreting canaliculus and the adjacent gland lumen, we concluded that the released acid was immediately buffered. Thus, the only cellular structure directly exposed to the highly acidic canalicular content is the apical membrane forming the canaliculus in the parietal cell.

Dynamic functional and ultrastructural changes of gastric parietal cells induced by water immersion-restraint stress in rats

AIM: To investigate the dynamic functional and ultrastructural changes of gastric parietal cells induced by water immersion-restraint stress (WRS) in rats.

METHODS: WRS model of Sprague-Dawley (SD) rats was established. Fifty-six male SD rats were randomly divided into control group, stress group and post-stress group. The stress group was divided into 1, 2 and 4 h stress subgroups. The post-stress group was divided into 24, 48 and 72 h subgroups. The pH value of gastric juice, ulcer index (UI) of gastric mucosa and H⁺, K⁺-ATPase activity of gastric parietal cells were measured. Ultrastructural change of parietal cells was observed under transmission electron microscope (TEM).

RESULTS: The pH value of gastric juice decreased time-dependently in stress group and increased in post-stress group. The H⁺, K⁺-ATPase activity of gastric parietal cells and the UI of gastric mucosa increased time-dependently in stress group and decreased in post-stress group. Compared to control group, the pH value decreased remarkably (P = 0.0001), the UI and H⁺, K⁺-ATPase activity increased significantly (P = 0.0001, P = 0.0174) in 4 h stress subgroup. UI was positively related with stress time (r = 0.9876, P < 0.01) but negatively with pH value (r = -0.8724, P < 0.05). The parietal cells became active in stress group, especially in 4 h stress subgroup, in which plenty of intracellular canalicular and mitochondria were observed under TEM. In post-stress group, the parietal cells recovered to resting state.

CONCOUSION: The acid secretion of parietal cells is consistent with their ultrastructural changes during the development and healing of stress ulcer induced by WRS and the degree of gastric mucosal lesions, suggesting gastric acid play an important role in the development of stress ulcer and is closely related with the recovery of gastric mucosal lesions induced by WRS.

Hypergastrinemia after Helicobacter pylori infection is associated with bacterial load and related inflammation of the oxyntic corpus mucosa

BACKGROUND AND AIM

Helicobacter pylori infection causes hypergastrinemia. This study aimed to determine the association between serum gastrin and the severity of H. pylori-related gastric histology.

METHODS

A total of 458 dyspeptic patients were included in this study after the absence of gastric malignancy was confirmed using endoscopy. The gastric specimens of each patient were collected from the antrum and corpus for the analysis of H. pylori-related histology changes by updated Sydney's system. Before endoscopy, the fasting blood samples were collected for gastrin analysis.

RESULTS

The H. pylori-infected patients had higher gastrin levels than those without infection (P = 0.01). Gastrin levels were related to H. pylori density and acute and chronic inflammation scores in the corpus mucosa (P < 0.05), but not in the antral mucosa (P = NS). Gastrin levels were also not related to the presence of gastric atrophy. Multivariate regression showed that the gastrin level was only related to acute corpus inflammation. However, in the patients without infection, the gastrin level was also associated with acute corpus inflammation. Nevertheless, the patients with denser H. pylori infection were more likely to have acute corpus gastritis than those with lighter H. pylori infection, and thus presented with higher gastrin levels (P < 0.05).

CONCLUSIONS

The increased level of gastrin of serum after H. pylori infection was associated with acute inflammation in the gastric corpus mucosa, but not in the antral mucosa. Denser H. pylori infection causes more severe corpus gastritis and thus may lead to a higher fasting level of gastrin of serum.

The association between tumour necrosis factor-alpha gene polymorphism and the susceptibility to rugal hyperplastic gastritis and gastric carcinoma

OBJECTIVES

Some subjects infected by Helicobacter pylori have enlarged folds in the gastric body, the precise mechanism of which remains obscure. The aim of this study was to clarify the association of tumour necrosis factor-alpha (TNFA) gene polymorphism with susceptibility to hyper-rugosity. We also examined the association of TNFA polymorphism with gastric carcinoma.

SUBJECTS AND METHODS

Four hundred and seventy-two subjects (male/female = 351/121, aged 26-81 years) without gastric carcinoma (control group), and 300 patients (male/female = 218/82, aged 32-91 years) with gastric carcinoma. Barium meal roentgenograms were performed in 396 subjects in the control group and fold width was measured at the greater curvature of the middle portion of the gastric body. Fasting plasma anti-H. pylori IgG titres, pepsinogens (PGs) I and II were analysed, and TNFA -857 promoter polymorphism was distinguished by the 5' nuclease polymerase chain reaction assay and polymerase chain reaction restriction fragment length polymorphism using HincII in both groups.

RESULTS

Adjusted odds ratios of TNFA -857 T/T genotype and H. pylori seropositivity for hyper-rugosity (fold width = 6.0 mm) were 6.7 (95% confidence interval (CI) 1.5-28, P < 0.01) and 18.2 (95% CI 4.2-78, P < 0.0001), respectively. There were no significant differences in any genotype or allele frequencies between the control and total gastric carcinoma group. In a subgroup of gastric carcinoma patients who were negative for the PG assay, however, the odds ratio of the T allele was 1.4 (95% CI 1.0-2.0, P < 0.05).

CONCLUSION

The TNFA -857 T/T genotype and H. pylori infection were strongly associated with rugal hyperplastic gastritis. The TNFA -857 T allele may promote gastric carcinoma without severe atrophy.

Helicobacter pylori-induced enlarged-fold gastritis is associated with increased mutagenicity of gastric juice, increased oxidative DNA damage, and an increased risk of gastric carcinoma

BACKGROUND AND AIM

The severe inflammation, increased cell proliferation and marked acid inhibition observed in subjects with Helicobacter pylori-associated enlarged-fold gastritis suggest that enlarged-fold gastritis may be a risk factor for gastric carcinoma. The purpose of the present study was to determine whether a relationship exists between enlarged-fold gastritis and gastric carcinoma.

METHODS

One hundred and thirty-five H. pylori-positive patients with early gastric carcinoma and 141 age- and sex-matched H. pylori-positive controls without gastric carcinoma were involved in the study. The widths of gastric body folds were measured by double-contrast radiographs. The mutagenicity of gastric juice was assayed using the Ames test and Salmonella typhimurium TA-98 or TA-100 with S9-mix. Levels of 8-hydroxydeoxyguanosine (8-OHdG) in gastric mucosa were examined using high-performance liquid chromatographic-electrochemical detection.

RESULTS

An upward shift in the distribution of gastric fold widths in H. pylori-positive patients with early gastric carcinoma was found. Enlarged-fold gastritis (fold width >/=5 mm) was observed in 81% of the patients with gastric carcinoma, compared with 46% of H. pylori-positive controls. The odds ratio for gastric carcinoma increased with increasing fold width to a maximum of 35.5 in persons with fold width >/=7 mm. The prevalence of diffuse-type early gastric carcinoma in the body region increased with increasing fold width. The mutagenicity of gastric juice from the patients with enlarged-fold gastritis was significantly higher than that in H. pylori-negative controls and H. pylori-positive patients without enlarged folds. Mucosal 8-OHdG levels in the body region of patients with enlarged-fold gastritis were significantly higher than in H. pylori-negative controls and H. pylori-positive patients without enlarged-fold gastritis. Eradication of H. pylori significantly decreased the mutagenicity of gastric juice and 8-OHdG levels in the gastric mucosa from patients with enlarged-fold gastritis.

CONCLUSION

A significant association is suggested between enlarged-fold gastritis and gastric carcinoma.

The clinical significance of thickened gastric folds found on upper gastrointestinal series

GOALS

To assess the impact of upper endoscopy and biopsy on the outcome of patients with isolated thickened gastric folds found on barium upper gastrointestinal series (UGIS).

STUDY

A total of 8,325 consecutive UGIS reports were reviewed to identify 182 patients who were found to have isolated thickened gastric folds. Patients with other serious radiographic abnormalities were excluded. The 182 patients were studied by a systematic review of the esophagogastroduodenoscopy (EGD) findings, gastric biopsy results, and clinical outcome.

RESULTS

The study included 96 men (52.7%) and 86 women (47.3%) who had isolated thickened gastric folds on the UGIS. Seventy-four patients underwent EGD; 108 patients did not. The two groups were similar in demographic and clinical features. The EGD results were normal, 18 (24.3%); thick gastric folds, 12 (16.2%); hiatal hernia, 12 (16.2%); erythema/inflammation, 11 (14.9%); erosions, 8 (10.8%); portal gastropathy, 3 (4.1%); and gastric ulcer, 1 (1.4%). Forty-eight of the 74 EGD patients had a gastric biopsy. The findings were chronic active gastritis, 39 (81.3%); and chronic gastritis, 5 (10.4%). Evidence for H. pylori infection was present in 91.7% of the gastric biopsies. Outcome (mean follow-up, 28.5 months) was assessed in 49 patients in the EGD group and in 55 patients in the non-EGD group. There were no cases of serious or new UGI problems in either group.

CONCLUSIONS

Isolated thickened gastric folds found on UGIS are frequently associated with H. pylori infection. Performing endoscopy and biopsy did not appear to alter the outcome in these patients.

Gastric mucosal morphological consequences of acid suppression: a balanced view

In the chapter, an analysis of the literature on the relationship between Helicobacter pylori, the use of proton pump inhibitors and the development of atrophic gastritis is presented, and the difficulties of classifying gastritis and the new possibilities of quantifying chronic inflammation by morphometric analysis are discussed. The issue surrounding the necessity of eradicating H. pylori in H. pylori-positive patients has still not been solved. Most studies have now accepted that proton pump inhibitors indeed accelerate the onset of atrophic gastritis in H. pylori-positive patients, but evidence against such an association was published in one recent (Scandinavian) study; conclusions from this study have, however, been challenged by several groups. Some data are available on the efficacy of H. pylori eradication with regard to the prevention of atrophy. The limited significance of the development of parietal cell protrusions and fundic gland cysts is better understood, but much less is known of the development and long-term consequence of H. pylori-induced autoimmune gastritis. Finally, recent studies in H. pylori-positive patients indicate that treatment with proton pump inhibitors may promote bacterial N-nitrosation formation. These data taken together suggest that the eradication of H. pylori may be based not only on morphological arguments, but also on bacterial alterations in the gastric milieu.