Cell proliferation in the gastric corpus in Helicobacter pylori associated gastritis and after gastric resection

Appraisal of gastric stump carcinoma and current state of affairs

Gastric stump carcinoma, also known as remnant gastric carcinoma, is a malignancy arising in the remnant stomach following gastrectomy for a benign or malignant condition. Enterogastric reflux and preexisting risk factors in a patient with gastric cancer are the major contributors to the development of gastric stump carcinoma. The occurrence of gastric stump carcinoma is time-dependent and seen earlier in patients operated on for malignant rather than benign diseases. The tumor location is predominantly at the anastomotic site towards the stomach. However, it can occur anywhere in the remnant stomach. The pattern of lymph node involvement and the type of surgery required is distinctly different compared to primary gastric cancer. Gastric stump carcinoma is traditionally considered a malignancy with a dismal outcome. However, recent advances in diagnostic and therapeutic strategies have improved outcomes. Recent advances in molecular profiling of gastric stump carcinoma have identified distinct molecular subtypes, thereby providing novel therapeutic targets. Also, reports of gastric stump carcinoma following pancreatoduodenectomy and bariatric surgery highlight the need for more research to standardize the diagnosis, staging, and treatment of these tumors. The present review aims to provide an overview of gastric stump carcinoma highlighting the differences in clinicopathological profile and management compared to primary gastric carcinoma.

Prevalence and characteristics of gastric remnant cancer: A systematic review and meta-analysis

The incidence and outcomes of GRC remain variable. Minority published researches have paid attention to the characteristics of GRC. This study aimed to make a systematic review and meta-analysis of the prevalence of GRC, with a focus on characteristics and survival rates of GRC. PubMed, EMBASE, and CENTRAL were searched for related clinical studies. Data were pooled using Stata 11.0, and subgroup and sensitivity analyses were performed if necessary and feasible. Moreover, SPSS (version 19.0) was used for comparing the clinical characteristics of GRC. Twenty studies were selected in this meta-analysis. The results indicated that the pooled prevalence of GRC was 2.6% (95% confidence interval (CI), 2.2-3.0%, p = 0.000). European population and American populations have a higher rate of prevalence of GRC than Chinese populations and Japan. There is no significant difference in histology and the TNM stage between the benign group and the malignant group. The five-year survival rate for GRC cases with benign primary gastric diseases is poorer than the primary gastric diseases malignant. Gastric remnant cancer is not a very rare clinical problem, especially for European and American patients. Active treatment and regular follow-up are conductive to increase 5-years survival rate.

Clinicopathological Features of Remnant Gastric Cancer (RGC): Detection of RGC after Five Years of Follow-Up Was Associated with a Poor Prognosis

The purpose of this study was to evaluate the clinicopathological features and prognosis of patients who underwent surgery for remnant gastric cancer (RGC) during/after the regular five-year follow-up period after initial distal gastrectomy for gastric cancer that is recommended by the Japanese gastric cancer treatment guidelines. Between January 2007 and December 2017, 40 patients underwent surgery for RGC after distal gastrectomy. Twenty-eight of the 40 patients underwent initial gastrectomy for cancer. We divided the 28 patients into two groups: patients who were diagnosed with RGC during/after the five-year follow-up period after initial gastrectomy, and analyzed their retrospectively collected data. Among the 28 patients, 15 patients were diagnosed with RGC within five years and 13 patients were diagnosed with RGC after five years. There were significant differences in the reconstruction of the initial operation, curative resection, pathological depth of the tumor, and pathological stage of the two groups. Multivariate analyses revealed that the interval between initial gastrectomy and RGC and the pathological TNM stage were significant risk factors for shorter cancer-specific survival. Kaplan-Meier analyses demonstrated that patients with RGC after the five-year follow-up period had a significantly worse prognosis in terms of cancer-specific survival than those who developed RGC within five years. This study suggested surveillance by using the annual endoscopy might be necessary beyond the initial five-year period for patients who underwent gastrectomy for gastric cancer.

Carcinoma in the Remnant Stomach During Long-Term Follow-up After Distal Gastrectomy for Gastric Cancer: Analysis of Cumulative Incidence and Associated Risk Factors

BACKGROUND

The number of patients with remnant gastric cancer following resection of gastric cancer may increase. The aims of this study were to investigate the development of remnant gastric cancer after distal gastrectomy for gastric cancer and to examine its cumulative incidence, clinicopathological characteristics, and risk factors.

METHODS

We examined 437 patients with relapse-free survival for 5 years or more after distal gastrectomy with Billroth I reconstruction for gastric cancer performed between 1985 and 2005.

RESULTS

A total of 17 patients suffered from remnant gastric cancer. The cumulative incidence was 3.7% at 10 years and 5.4% at 20 years. The median time until development of remnant gastric cancer was 79 months (range 30-209 months). The presence of synchronous multiple gastric cancers was a significant independent risk factor for remnant gastric cancer (hazard ratio 4.036; 95% confidence interval 1.478-11.02; P = 0.006). Of the 17 patients, the 13 whose remnant gastric cancer was detected via regular endoscopy showed better prognoses than the patients detected by other means (P < 0.001).

CONCLUSION

The cumulative incidence of remnant gastric cancer was 5.4% at 20 years. In particular, patients who had multiple gastric cancers at initial gastrectomy were at higher risk for remnant gastric cancer. Therefore, long-term endoscopic surveillance is important.

Effect of Helicobacter pylori Eradication on Long-Term Survival after Distal Gastrectomy for Gastric Cancer

Purpose

Negative Helicobacter pylori status has been identified as a poor prognostic factor for survival in gastric cancer (GC) patients who underwent surgery. The aim of this study was to examine the effect of H. pylori eradication on long-term outcomes after distal gastrectomy for GC.

Materials and Methods

We analyzed the survival of 169 distal GC patients enrolled in a prospective randomized trial evaluating histologic changes of gastric mucosa after H. pylori eradication in the remnant stomach. The outcomes measured were overall survival (OS) and GC recurrence rates.

Results

The median follow-up duration was 9.4 years. In the modified intention-to-treat analysis including patients who underwent H. pylori treatment (n=87) or placebo (n=82), 5-year OS rates were 98.9% in the treatment group and 91.5% in the placebo group, and Kaplan-Meier analysis showed no significant difference in OS (p=0.957) between groups. In multivariate analysis, no difference in overall mortality was observed between groups (adjusted hazard ratio [aHR] for H. pylori treatment, 0.75; p=0.495) or H. pylori-eradicated status (aHR for positive H. pylori status, 1.16; p=0.715), while old age, male sex, and advanced stage ≥ IIIa were independent risk factors. Six patients in the treatment group (6.9%) and seven patients in the placebo group (8.5%) had GC recurrences, and GC recurrence rates were not different according to H. pylori treatment (5-year GC recurrence rates, 4.6% in the treatment group vs. 8.5% in the placebo group; p=0.652).

Conclusion

H. pylori eradication for GC patients who underwent distal gastrectomy did not compromise long-term survival after surgery.

Diagnostic performance of urea breath test, rapid urea test, and histology for Helicobacter pylori infection in patients with partial gastrectomy: a meta-analysis

BACKGROUND

Helicobacter pylori infection has been implicated in the pathogenesis of gastroduodenal diseases such as recurrent peptic ulceration and particularly residual stomach cancer in the postoperative stomach.

AIM

To determine the performance of different commonly used tests for the diagnosis of H. pylori infection in patients after partial gastrectomy.

METHODS

A systematic literature search was conducted by searching the PubMed, EMBASE and ScienceDirect databases with relevant key words. Data extraction was independently performed by two reviewers. Meta-analyses were performed for the performance of the different tests including the sensitivities, specificities, likelihood ratios (LRs), diagnostic odds ratio diagnostic odds ratio, and the summary receiver operating characteristic summary receiver operating characteristic curve. The meta-analysis was performed by Meta-DiSc software.

RESULTS

Studies showed a high degree of heterogeneity. Pooled sensitivity, specificity, LR+, LR- and diagnostic odds ratio for the different methods were: Urea breath test (9 studies): 0.77 (95% CI, 0.72-0.82), 0.89 (95% CI, 0.85-0.93), 6.32 (95% CI, 3.22-12.42), 0.27 (95% CI, 0.17-0.43), and 27.86 (95% CI, 13.27-58.49). Rapid urease test (7 studies): 0.79 (95% CI, 0.72-0.84), 0.94 (95% CI, 0.90-0.97), 10.21 (95% CI, 5.94-17.54), 0.28 (95% CI, 0.22-0.36) and 49.02 (95% CI, 24.24-99.14). Histology (3 studies): 0.93 (95% CI, 0.88-0.97), 0.85 (95% CI, 0.73-0.93), 5.88 (95% CI, 3.26-10.60), 0.09 (95% CI, 0.05- 0.15), and 97.28 (95% CI, 34.30-275.95). The corresponding summary receiver operating characteristic curves showed areas under the curves of 0.91, 0.93 and 0.96 and Q* values of 0.84, 0.86 and 0.91, respectively

CONCLUSION

Among the three commonly used tests, histological examination performs the best, followed by the rapid urease test, for the diagnosis of H. pylori infection after partial gastrectomy. Thus, histology, preferably after the rapid urease test, is recommended for the diagnosis of H. pylori infection after partial gastrectomy.

Gastric reddish streaks in the intact stomach: endoscopic feature of reactive gastropathy

The pathogenesis of reddish streaks in the intact stomach is unclear. Sixty-three functional dyspeptic patients with gastric reddish streaks were recruited for the study. Fifty-five patients (group I) had only reddish streaks while nine patients (group II) had additional lesions such as reddish patches or spots randomly scattered throughout the stomach. Updated Sydney system and parameters of reactive gastropathy were used to score the biopsy specimens from reddish streaks separately. Helicobacter pylori infection rate was found to be markedly lower in group I than group II patients (13% vs 89%, P < 0.001). H. pylori-infected patients had higher scores for acute and chronic inflammation (P < 0.001) and foveolar hyperplasia (P < 0.005) than non-infected patients, while other parameters for gastritis and gastropathy were similar between infected and non-infected patients. In H. pylori-non-infected patients all biopsy specimens had at least one histological feature of reactive gastropathy. Bile reflux was observed in 54% of patients (34/63). Only 7.9% used non-steroidal anti-inflammatory drugs and 4.9% drank alcohol. The present data indicate that the fundamental histological features of gastric reddish streaks are reactive gastropathy with low H. pylori infection, and are probably enterogastric reflux related in etiology. Coincidental H. pylori infection increased acute and chronic inflammatory cell infiltration, and enhanced the grade of foveolar hyperplasia.

Helicobacter pylori infection and expression of DNA mismatch repair proteins

AIM: To determine the expression of DNA (MMR) proteins, including hMLH1 and hMSH2, in gastric epithelial cells in the patients with or without Helicobacter pylori (H pylori)-infected gastritis.

METHODS: Fifty H pylori-positive patients and 50 H pylori-negative patients were enrolled in the study. During endoscopy of patients with non-ulcer dyspepsia, two antral and two corpus biopsies were taken for histological examination (Giemsa stain) and for immunohistochemical staining of hMLH1 and hMSH2.

RESULTS: The percentage of epithelial cell nuclei that demonstrated positivity for hMLH1 staining was 84.14 ± 7.32% in H pylori-negative patients, while it was 73.34 ± 10.10% in H pylori-positive patients (P < 0.0001). No significant difference was seen between the two groups regarding the percentage of epithelial cell nuclei that demonstrated positivity for hMSH2 staining (81.16 ± 8.32% in H pylori-negative versus 78.24 ± 8.71% in H pylori-positive patients; P = 0.09).

CONCLUSION: This study indicates that H pylori might promote development of gastric carcinoma at least in part through its ability to affect the DNA MMR system.

Effects of aspirin on the development of Helicobacter pylori-induced gastric inflammation and heterotopic proliferative glands in Mongolian gerbils

BACKGROUND

Helicobacter pylori infection is a major cause of gastritis and gastric carcinoma. Aspirin has anti-inflammatory and antineoplastic activity. The aim of the present study was to determine the effects of aspirin on H. pylori-induced gastritis and the development of heterotopic proliferative glands.

METHODS

H. pylori strain SS1 was inoculated into the stomachs of Mongolian gerbils. Two weeks after inoculation, the animals were fed with the powder diets containing 0 p.p.m. (n = 10), 150 p.p.m. (n = 10), or 500 p.p.m. (n = 10) aspirin. Mongolian gerbils were killed after 36 weeks of infection. Uninfected Mongolian gerbils (n = 10) were used as controls. Histologic changes, epithelial cell proliferation and apoptosis, and prostaglandin E(2) (PGE(2)) levels of gastric tissue were determined.

RESULTS

H. pylori infection induced gastric inflammation. Administration of aspirin did not change H. pylori-induced gastritis, but alleviated H. pylori-induced hyperplasia and the development of heterotopic proliferative glands. Administration of aspirin accelerated H. pylori-associated apoptosis but decreased H. pylori-associated cell proliferation. In addition, the increased gastric PGE(2) levels due to H. pylori infection were suppressed by treatment with aspirin, especially at the dose of 500 p.p.m.

CONCLUSIONS

Aspirin alleviates H. pylori-induced hyperplasia and the development of heterotopic proliferative glands. Moreover, aspirin increases H. pylori-induced apoptosis. We demonstrated the antineoplastic activities of aspirin in H. pylori-related gastric carcinogenesis.

Roux-en-Y reconstruction after distal gastrectomy to reduce enterogastric reflux and Helicobacter pylori infection

Enterogastric reflux (EGR) is regarded as an unavoidable consequence of distal gastrectomy. We evaluated the efficacy of Roux-en-Y (RY) gastrojejunostomy and Braun enteroenterostomy (BEE) for preventing EGR. Between January 2002 and January 2005, 60 patients who underwent distal gastrectomy for gastric cancer or peptic ulcers were divided into RY, Billroth II reconstruction (BII) without or with BEE (BII+B) according to reconstructive method. After 12 months, EGR and mucosal alterations of the remnant stomach were evaluated using biliary scintigraphy, endoscopy, and histology. Scintigraphy showed fasting and postprandial EGR into the remnant stomach occurred in 5.3% and 21.1% of the RY group, 62.1% and 93.1% of the BII group, and 50.0% and 91.7% of the BII+B group, respectively. Endoscopy showed bile reflux occurred in 15.8% of the RY group, 75.9% of the BII group, and 83.3% of the BII+B group. In addition, the prevalence of Helicobacter pylori (HP) infection in the RY group was less than in the other groups (P<0.02). Therefore, RY after distal gastrectomy was effective in reducing EGR and HP infection. BEE was ineffective in diverting bile flow away from the gastric remnant.

What to expect in the excluded stomach mucosa after vertical banded Roux-en-Y gastric bypass for morbid obesity

Mucosal alterations after vertical banded Roux-en-Y gastric bypass have not been clearly evaluated. The aim of this paper was to analyze the histological findings and the presence of Helicobacter pylori in the excluded stomach. Forty consecutive patients who underwent Roux-en-Y gastric bypass longer than 36 months were selected for double-balloon enteroscopy. The excluded stomach was reached in 35/40 patients (88%). Morphological alterations were analyzed through hematoxilin and eosin and the presence of H. pylori was confirmed with Giemsa staining. Thirty patients (86%) were female, and the mean age was 43 years old. The mean postoperative time was 78 months (36-110 months). Histologically, all patients had chronic gastritis in the bypassed stomach, with pangastritis in 33/35 (94%). Five cases (5/35, 14%) presented atrophy and four of them also had intestinal metaplasia. Helicobacter pylori was detected in 7/35 (20%) of the excluded stomach and in 12/35 (34%) of the functional pouch. All patients positive for H. pylori in the excluded stomach were also positive in the functional pouch, p = 0.0005. Helicobacter pylori is still present in the excluded stomach after Roux-en-Y gastric bypass and might be considered for treatment. Histological findings indicated high prevalence of atrophy and intestinal metaplasia in this selected population.

Gastric cancer precursor lesions and Helicobacter pylori infection in patients with partial gastrectomy for peptic ulcer

The mucosa of the gastric stump is considered at greater risk of dysplastic and neoplastic changes than that of the intact stomach. The combination of enteric reflux and Helicobacter pylori infection may have a synergistic damaging effect on the mucosa of the gastric remnant, both producing and increasing mucosal proliferation. The aim of this study was to assess whether the occurrence of H. pylori infection in the remnant mucosa of partially gastrectomized subjects for peptic ulcer disease is associated with an increase of the mucosal precursor lesions of malignancy. A series of 151 subjects who underwent partial gastrectomy for peptic ulcer disease were submitted to upper digestive endoscopy for long-term surveillance. Biopsy specimens of the gastric stump were tested for the occurrence of H. pylori infection and for the presence of precancerous mucosal lesions. The prevalence of H. pylori colonization in the remnant stomach was less than 30% and similar in subjects with different time intervals between gastrectomy and endoscopy. Age at surgery (chi(2): p = 0.03) and H. pylori infection (chi(2): p = 0.002) were significantly associated with the grading of mucosal lesions. The prevalence of normal mucosa was 10 times higher in H. pylori-negative patients as in H. pylori-positive ones (22.0% vs. 2.4%), and the prevalence of intestinal metaplasia was four times higher in H. pylori-positive patients than in H. pylori-negative ones (19.6% vs. 4.6%). We concluded that H. pylori infection may play a causal role in the development of gastric lesions in the operated stomach.

Dietary supplementation of carbonate promotes spontaneous tumorigenesis in a rat gastric stump model

OBJECTIVE

Food supplements are known to affect the development of gastric adenocarcinoma. In this study, an animal model of gastric resection was used to investigate the effects of calcium carbonate on spontaneous development of gastric adenocarcinoma.

MATERIAL AND METHODS

Ninety-two Wistar rats with gastric resections (performed to induce spontaneous gastric cancer) and 60 without resections (controls) were used to analyse the carcinogenic potential of different ion supplements in food.

RESULTS

Among the resected rats, cancer developed in 3 out of 18 (17%, NS) given NaCl but in 11 out of 18 (61%, p<0.01) exposed to calcium carbonate. No tumours were found in the unresected (unoperated) animals. These findings were further analysed by separately investigating the effects of calcium and carbonate ions on tumorigenesis in the gastric stump model. Cancer developed in one of 26 (4%) resected animals given a diet supplemented with CaHPO(4), which was lower than the rate observed in the resected control group fed a normal diet, although this difference was not statistically significant. However, tumour development increased significantly in the resected animals given a diet supplemented with NaHCO(3) (tumours in 13 out of 24 rats, 54%; p<0.01).

CONCLUSIONS

The present results reveal a significant role for carbonate in the induction of gastric carcinoma in the rat. The relevance of this finding is underlined by the fact that carbonate is a major constituent of intestinal reflux into the stomach, and that such reflux is considered to be one of the major causes of gastric cancer.

Histological changes in the gastric mucosa after Helicobacter pylori eradication

BACKGROUND AND AIM

Correa described a stepwise model of changes in the gastric mucosa after Helicobacter pylori infection, from the normal gastric epithelium to chronic gastritis, atrophy, intestinal metaplasia, dysplasia and adenocarcinoma. The aim of this study is to assess the reversibility of these mucosal changes after H. pylori eradication.

METHODS

The study sample consisted of 89 patients who underwent at least two gastric biopsies from 1990 to 2000, with a positive finding for H. pylori in the first and a negative finding in the second. Specimens were evaluated for acute and chronic inflammation, lymphoid aggregates, proliferation, mucosal atrophy, intestinal metaplasia, dysplasia, and MUC5AC and MUC6 expression using histochemical and immunohistochemical methods.

RESULTS

The average time between biopsies was 23.15 +/- 26.30 months. There was a significant decrease in acute and chronic inflammation scores, from 1.48 +/- 1.10 to 0.23 +/- 0.63 and from 2.67 +/- 0.68 to 1.44 +/- 1.04, respectively (P < 0.001), and in a number of lymphoid follicles, from 42.68% to 21.95% of cases (P < 0.008). The number of glands increased from 39.08 +/- 16.67/mm to 48.86 +/- 17.93/mm after eradication (P = 0.062). Intestinal metaplasia was found in 17.07% of the cases, with no change over time. Dysplasia appeared in one case 2 years after eradication. In 27 patients, the Ki67 labeling index decreased significantly after eradication, while MUC5AC and MUC6 expression increased.

CONCLUSION

Our findings, although not conclusive for arrest of the malignant potential, support the importance of H. pylori eradication in the prevention of gastric cancer.

Does eradication of Helicobacter pylori reduce the risk of carcinogenesis in the residual stomach after gastrectomy for early gastric cancer?

BACKGROUND AND AIMS

After partial gastrectomy, the mucosa of the residual stomach usually undergoes severe changes, and these lesions are known to be pre-cancerous. Recently, Helicobacter pylori has been highlighted as an agent that induces such mucosal alterations. In the present study, we evaluated whether eradication of H. pylori reduced the risk of carcinogenesis.

PATIENTS AND METHODS

The subjects were 12 patients who underwent distal gastrectomy with Billroth I anastomosis for early gastric cancer and were positive for H. pylori. We performed endoscopy and biopsy both before and after H. pylori eradication therapy to assess changes in the gastric mucosa.

RESULTS

After eradication therapy, no mucosal edema or erythema was detected. On histological examination, mononuclear cell infiltration had decreased and there was complete absence of neutrophil infiltration. The Ki-67 labeling index and the tissue IL-8 level had also decreased significantly, compared with before eradication.

CONCLUSION

Before H. pylori eradication, the mucosa of the residual stomach may be at high risk of carcinogenesis due to induction of mucosal damage and active gastritis by H. pylori. Such changes were almost completely normalized by eradication therapy, so the eradication of H. pylori may reduce the risk of H. pylori-associated carcinogenesis in patients who have undergone gastrectomy for early gastric cancer.

Duodenogastric reflux and Helicobacter pylori infection synergistically increase gastric mucosal cell proliferative activity in Mongolian gerbils

BACKGROUND

Helicobacter pylori and duodenogastric reflux (DGR) are both recognized as aetiological factors in chronic gastritis and gastric carcinogenesis. In this study, a Mongolian gerbil (MG) model was used to investigate the histopathological changes in the gastric mucosa resulting from DGR and/or H. pylori infection.

METHODS

One-hundred-and-eleven 7-week-old, specific-pathogen-free, male MGs were divided into four groups: normal controls, gerbils with surgically induced DGR, and H. pylori-infected gerbils with and without DGR. Gerbils were killed 4, 12 and 26 weeks after DGR surgery, their stomachs removed and sections prepared. Sections were fixed immediately in 20% phosphate-buffered formalin and subjected to haematoxylin and eosin staining, Alcian blue at pH 2.5/periodic acid-Schiff staining, and immunostaining for smooth muscle cells, H. pylori and 5'-bromo-2'-deoxyuridine (BrdU).

RESULTS

The gastric mucosa of H. pylori-infected gerbils showed chronic active gastritis irrespective of DGR throughout the experimental period. The gastric mucosa of H. pylori-infected gerbils with DGR demonstrated higher BrdU labelling than in the other groups.

CONCLUSIONS

In MGs, DGR and H. pylori infection synergistically increased gastric mucosal cell proliferative activity. DGR and H. pylori infection may be involved synergistically in gastric carcinogenesis by increasing cell proliferative activity.

Family history of gastric cancer: should we test and treat for Helicobacter pylori?

A close link has been established between infection and gastric cancer. In this article, we suggest that using a risk stratification technique (like that for colorectal cancer), the high-risk group of first-degree relatives of patients with gastric cancer can be separated out for testing and treatment. This would be more manageable and more cost-effective than screening the whole population, in which the mortality from distal gastric cancer has declined concomitant with the eradication of infection. Support for the feasibility of this approach is derived from studies showing that the family is the core unit of transmission and that childhood colonization, especially with a virulent strain, is apparently a major risk factor for disease progression to the neoplastic stage. When there is a case of gastric cancer in the family, first-degree relatives, who might be infected by a bacterium with an identical genetic fingerprint, are at higher risk than normal for developing gastric cancer. Furthermore, genetic and epidemiologic studies based on the Correa model have shown that both primary and secondary prevention of gastric cancer is possible. Calculations done in high-risk populations, such as Japanese-Americans, confirm the savings in cost and the safety of the test-and-treat strategy. Considering that eradication should be done as early as possible, at a point in the cascade when the changes are still reversible, and that gastric cancer is associated with a high mortality rate, we suggest that this strategy be applied to this high-risk population.

Mucosal changes in the gastric remnant: long-term effects of bile reflux diversion and Helicobacter pylori infection

OBJECTIVE

Bile reflux is thought to be responsible for reflux gastritis and stump carcinoma occurring after partial gastrectomy for peptic ulcer. Gastritis and gastric carcinoma are also correlated with Helicobacter pylori. The aim of this study was to investigate whether diversion of enteric reflux and the presence of H. pylori infection alter long-term histological developments in the gastric remnant.

METHODS

Twenty-nine patients partially gastrectomized for peptic ulcer were reoperated on with re-resection and a Roux-en-Y reconstruction because of reflux gastritis (12 patients) or severe dysplasia/early gastric cancer (17 patients). The resected specimens and subsequent biopsies from the new anastomotic region taken at endoscopies 5-17 years after reoperation were evaluated regarding the presence of H. pylori, the grade of active and non-active chronic gastritis, and the premalignant changes--atrophy, intestinal metaplasia and dysplasia.

RESULTS

A progression of active chronic gastritis, atrophy, intestinal metaplasia and dysplasia was seen after re-resection and Roux-en-Y reconstruction. Non-active chronic gastritis remained unchanged. The development was, in general, independent of H. pylori infection.

CONCLUSIONS

Enteric reflux may perhaps induce a histological transformation of the gastric mucosa that cannot be reversed, even if the reflux is diverted. In our study, H. pylori infection had no impact on the histological development. Factors other than enteric reflux and H. pylori infection might also be of importance.

Effect of interlukin-1beta on proliferation of gastric epithelial cells in culture

BACKGROUND

Helicobacter pylori is the main risk factor for the development of non-cardia gastric cancer. Increased proliferation of the gastric mucosa is a feature of H. pylori infection. Mucosal interkeukin-1beta production is increased in H. pylori infection and IL-1beta genotypes associated with increased pro-inflammatory activity are risk factors for the development of gastric cancer. The effect of IL-1beta on gastric epithelial cell proliferation has been examined in this study.

METHODS

AGS cells were cultured with IL-1beta. DNA synthesis was assed by [3H]thymidine incorporation and total viable cell numbers by MTT assay.

RESULTS

IL-1beta dose dependently increased DNA synthesis and cell numbers. The enhanced proliferation was blocked by interleukin-1 receptor antagonist. Addition of neutralising antibody to GM-CSF reduced IL-1beta-stimulated proliferation by 31 +/- 4 %. GM-CSF alone significantly stimulated proliferation. Addition or neutralisation of IL-8 had no effect on basal or IL-1beta-stimulated proliferation. The tyrosine kinase inhibitor genistein completely blocked IL-1beta-stimulated proliferation and inhibition of the extracellular signal related kinase pathway with PD 98059 inhibited IL-1beta stimulated proliferation by 58 +/- 5 %.

CONCLUSIONS

IL-1beta stimulates proliferation in gastric epithelial cells. Autocrine stimulation by GM-CSF contributes to this proliferative response. Signalling via tyrosine kinase activity is essential to the mitogenic response to IL-1beta. The extracellular signal related kinase pathway is involved in, but not essential to downstream signalling. IL-1beta may contribute to the hyperproliferation seen in H. pylori- infected gastric mucosa, and be involved in the carcinogenic process.

Reactive oxygen species activity, mucosal lipoperoxidation and glutathione in Helicobacter pylori-infected gastric mucosa

BACKGROUND AND AIM

Helicobacter pylori is considered as the major pathogen in Helicobacter pylori-associated gastroduodenal disease, but the mechanism of its action has not been fully explained. This study was performed to assess the reactive oxygen species activity and the damage in Helicobacter pylori-infected gastric mucosa.

METHODS

Gastric biopsy specimens were obtained from 308 patients undergoing endoscopy. Gastric mucosal damage was assessed by using luminol enhanced chemiluminescence, thiobarbituric acid-reactive substance, and mucosal glutathione.

RESULTS

The chemiluminescence and thiobarbituric acid-reactive substance-equivalent levels in the mucosa of patients with Helicobacter pylori-positive gastric mucosa (43.8 +/- 134.9 c.p.m./microg tissue, 157.0 +/- 96.2 nmol/g tissue, respectively) were significantly higher than in those with Helicobacter pylori-negative mucosa (6.8 +/- 20.3 c.p.m./microg tissue, 110.0 +/- 51.6 nmol/g tissue, respectively; P=0.000, P=0.016, respectively). The glutathione levels in the mucosa of patients with Helicobacter pylori-positive gastric mucosa (159.3 +/- 76.6 nmol/microg tissue) were significantly lower than in those with Helicobacter pylori-negative gastric mucosa (212.3 +/- 134.3 nmol/microg tissue; P=0.008). After the data were divided according to the presence of Helicobacter pylori, there were no significant differences in chemiluminescence, thiobarbituric acid-reactive substance, and glutathione among the different macroscopic findings within Helicobacter pylori-positive and -negative gastric mucosa.

CONCLUSIONS

Helicobacter pylori infection plays a pathological role in many gastrointestinal diseases through excessive mucosal-reactive oxygen species production, pronounced membrane damage, and the depletion of gastric anti-oxidants.

Influence of pantoprazole on oesophageal motility, and bile and acid reflux in patients with oesophagitis

BACKGROUND

Reflux of duodeno-gastric juice into the oesophagus appears to be involved in the pathogenesis of both reflux oesophagitis and oesophageal adenocarcinoma. Although proton pump inhibitors have been shown to decrease acid reflux and heal oesophagitis, their effect on biliary reflux and motility is less clear.

AIM

To investigate whether pantoprazole also reduces bile reflux and whether this is paralleled by a change in oesophageal motility.

METHODS

Combined 24-h measurements of intraoesophageal bilirubin concentration, pH and pressure were performed in 18 symptomatic patients with endoscopically proven reflux oesophagitis before and on day 28 of treatment with pantoprazole, 40 mg/day, under standardized conditions. A reflux symptom score was determined initially and every 2 weeks thereafter. After 56 days on medication, a control endoscopy was performed.

RESULTS

The symptom score and the acid and bile reflux improved significantly, whereas the motility parameters did not change during the study period. Helicobacter pylori-positive patients had a significantly higher bile reflux time (32.1 +/- 4.3%) than H. pylori-negative patients (16.3 +/- 3.1%) (P=0.009). The endoscopic healing rate was 89%. The cough symptoms disappeared in three of four patients.

CONCLUSIONS

The proton pump inhibitor pantoprazole decreases both acid and bile reflux. The decrease of bile reflux cannot be explained by increased oesophageal clearance as oesophageal motility did not improve with therapy. Interestingly, H. pylori infection of the stomach was associated with higher levels of oesophageal bile reflux.

Involvement of cyclooxygenase-2 in hyperplastic gastritis induced by Helicobacter pylori infection in C57BL/6 mice

BACKGROUND AND AIMS

The hyperplastic changes observed in Helicobacter pylori-associated gastritis have been considered to increase the risk of gastric cancer. The aim of this study was to determine whether cyclooxygenase-2 is involved in the hyperplastic changes in mice infected with H. pylori.

METHODS

Seven-week-old, male C57BL/6 mice (n=40) were inoculated with the Sydney strain of H. pylori. Control mice (n=40) were treated with vehicle only. Half of the infected and control mice were fed an experimental diet containing etodolac (10 mg/kg/day) from 1 week after inoculation until the end of the experiment. The thickness of gastric pits, COX-2 mRNA and protein levels, and prostaglandin E2 (PGE2) levels in the gastric mucosa were determined before and 12, and 24 weeks after inoculation.

RESULTS

The thickness of gastric pits, COX-2 mRNA and protein levels, and PGE2 levels were significantly increased at 24 weeks after inoculation of H. pylori compared with the control groups. Treatment with etodolac resulted in significant decreases in PGE2 production and in the thickness of gastric pits in the infected groups at 24 weeks after inoculation.

CONCLUSIONS

Our findings suggest that COX-2 is involved in the development of hyperplastic gastritis caused by H. pylori infection via the production of PGE2.

Gastric carcinoma after surgical treatment of peptic ulcer: an analysis of morphologic features and a comparison with cancer in the nonoperated stomach

BACKGROUND

Surgery for peptic ulcer is associated with an increased risk of later development of gastric carcinoma. This risk applies to cancer occurring in the distal stomach, not at the cardia. Mucosal alterations occurring in the nonneoplastic mucosa, adjacent to postgastrectomy carcinomas, are currently poorly defined.

METHODS

Between 1975 and 1995, the authors collected records of 76 patients with gastric carcinoma developing after previous ulcer surgery. Thirty-three gastrectomy specimens were available for study and were compared with a control series of gastric carcinomas occurring in the intact stomach. Morphologic features studied were macroscopic findings, tumor type, extent of inflammation, atrophy, intestinal metaplasia, reactive gastropathy, and presence of Helicobacter pylori. When possible, a semiquantitative grading system (Sydney system) was used.

RESULTS

The 33 patients with resected carcinoma after ulcer surgery were representative of the total 76 patients. There were no differences between the seven postulcer surgery cardia carcinomas and the control cardia carcinomas. The 18 distal carcinomas occurring after prior gastrectomy had significantly less intestinal metaplasia and Helicobacter pylori in the nonneoplastic mucosa than did the controls. Eight distal carcinomas occurring after a vagotomy and pyloroplasty had adjacent mucosa with findings intermediate between the gastrectomy carcinomas and the controls.

CONCLUSIONS

The differences shown suggest that for distally located postgastrectomy carcinomas Helicobacter pylori infection with extensive intestinal metaplasia may be relatively less important in pathogenesis and that intestinal reflux with reactive gastropathy more important. There was no evidence to support a different mechanism of pathogenesis for postsurgical carcinomas occurring at the cardia from that of control cardia carcinomas.

Cell proliferation in type C gastritis affecting the intact stomach

AIMS

Type C gastritis caused by bile reflux has a characteristic appearance, similar to that seen in other forms of chemical gastritis, such as those associated with NSAIDs or alcohol. An increase in mucosal cell proliferation increases the likelihood of a neoplastic clone of epithelial cells emerging, particularly where there is chronic epithelial injury associated with bile reflux. It has been shown previously that type C gastritis is associated with increased cell proliferation in the postsurgical stomach. The aim of this study was to determine cell proliferation in type C gastritis caused by bile reflux affecting the intact stomach.

METHODS

Specimens from 15 patients with a histological diagnosis of type C gastritis on antral biopsy were obtained from the pathology archives between 1994 and 1997. A control group of nine normal antral biopsies was also selected and all underwent MIB-1 immunostaining. The gastric glands were divided into three zones (zone 1, gastric pit; zone 2, isthmus; and zone 3, gland base) and the numbers of positively staining nuclei for 500 epithelial cell nuclei were counted in each zone to determine the percentage labelling index (LI%).

RESULTS

Cell proliferation was significantly higher in all three zones of the gastric glands with type C gastritis compared with controls as follows: zone 1, median LI% in type C gastritis 64.7 (range, 7.8-99.2), controls 4.7 (range, 2.0-11.3); zone 2, median LI% in type C gastritis 94.7 (range, 28.8-98.7), controls 40.2 (range, 23.1-70.3); and zone 3, median LI% in type C gastritis 20.0 (range, 1.3-96.0), controls 2.6 (range, 0.9-8.7).

CONCLUSIONS

Bile reflux is thought to act as a promoter of gastric carcinogenesis in the postsurgical stomach. The same may be true in the intact stomach.

Induction and maintenance of immune effector cells in the gastric tissue of mice orally immunized to Helicobacter pylori requires salivary glands

BACKGROUND & AIMS

Helicobactor pylori mostly colonizes the gastric mucus that contains salivary antibodies. We studied the role of saliva in the induction and maintenance of gastric immunity conferred by oral vaccination against H. pylori.

METHODS

C57BL/6 mice underwent a sialoadenectomy before and after intragastric immunization using whole-cell sonicates of H. pylori and cholera toxin as an adjuvant. At 1 and 6 months after oral inoculation, we assessed the density of the H. pylori colonizing the stomach, specific antibodies in gastric secretion and sera, and the constituents of cellular infiltrates in the tissue.

RESULTS

A sialoadenectomy before, but not after, immunization abrogated protection by the vaccination at 1 month after inoculation. Protected mice had more neutrophils, plasma cells, and lymphocytes, but fewer eosinophils, in the gastric tissue than nonprotected mice. Protected mice had a greater increase of immunoglobulin (Ig) G1 specific to H. pylori than IgG2a in sera. At 6 months after inoculation, oral immunization was less effective in mice who had a sialoadenectomy than in control immunized mice. The antibody titers in both gastric secretion and in sera did not correlate with the density of bacteria colonizing the stomach.

CONCLUSIONS

It is suggested that, in intragastric immunization against H. pylori, saliva is necessary for both the induction and maintenance of optimal immunity in the stomach. Effective immunity was associated with an increased number of neutrophils and lymphocytes in gastric tissue.

Sustained increase in gastric antral epithelial cell proliferation despite cure of Helicobacter pylori infection

OBJECTIVE

Studies of the effect of Helicobacter pylori treatment on gastric mucosa proliferation have yielded inconsistent results. We compared gastric mucosa cell proliferation posttherapy and in uninfected controls.

METHODS

Biopsies were obtained from patients with H. pylori infection before treatment and at intervals for up to 33 months. Epithelial cell proliferation was determined using Ki-67 immunostaining. The labeling index (LI) is the proportion of positively labeled cells with respect to the total number of cells. The proliferative index was calculated by multiplying the labeling index (LI) and the proliferation zone PZ (PZ = length of the area between the uppermost and lowest labeled cells).

RESULTS

The study included 27 patients with H. pylori gastritis and 35 controls. Epithelial cell proliferation (LI) was greater with H. pylori infection than without in both the antrum and corpus (65+/-5 vs 91+/-8 in the antrum and 44+/-4 vs 72+/-8 in the corpus, for uninfected controls vs H. pylori gastritis, respectively) (p = 0.0001). In the antrum there was no significant decrease in epithelial cell proliferation after cure of the H. pylori infection despite follow-up for >2 yr (labeling index = 83+/-10). In contrast, epithelial cell proliferation decreased in the corpus and became similar to that in controls after 7-13 months.

CONCLUSIONS

Patients with H. pylori infection have sustained high epithelial cell proliferation in the antrum compared to that in uninfected subjects. A continued increase in proliferation in the antrum after cure of H. pylori infection suggests continuing damage.

Role of apoptosis in gastric epithelial turnover

Gastric epithelial turnover is a dynamic process. It is characterized by continuous cell proliferation, which is counterbalanced by cell loss. The biological principle that mediates the homeostasis of epithelium is programmed cell death, or apoptosis. Currently, several subtypes of apoptosis are distinguished, which are mediated by different mechanisms. Various subtypes of apoptosis also occur in the gastric epithelium under various conditions. In the normal stomach, apoptosis due to cell isolation (anoikis) mediates the physiological epithelial turnover. Albeit rarely seen in routine histology, approximately 2% of epithelial cells in the normal stomach are apoptotic. In Helicobacter pylori-induced gastritis, apoptosis and epithelial proliferation are moderately increased, with approximately 8% apoptotic epithelial cells. In gastritis, factors such as CD95 ligand or tumor necrosis factor (TNF) alpha act as death factors. They bind to specific receptors, CD95 and TNF-R, which are induced either by other cytokines, such as interferon gamma, or by Helicobacter pylori itself. In addition to CD95, H.pylorican also induce upregulation of CD95 ligand expression. Taken together, the upregulated expression of CD95, and the presence of CD95L in the close proximity to apoptotic gastric epithelial cells suggest a functional role of the CD95-CD95L system in the induction of apoptosis in H.pylori-gastritis. The role of other pathways to apoptosis is currently under study. Apart from being a biological phenomenon, apoptosis in the stomach may also have direct clinical consequences. An extreme example is given in gastric graft-vs.-host disease when epithelial denudement occurs.

Management of Helicobacter pylori infection: gastroenterological and surgical perspectives

Diagnosis and treatment of Helicobacter pylori is a crucial point in the management of the different gastroduodenal disorders. Management involves the general practitioner and different specialists such as internists, gastroenterologists and surgeons. Among the most frequent H. pylori-related gastroduodenal disorders of medical interest are some diseases such as dyspepsia and gastroesophageal reflux, where the role of the bacterium is not well defined and therefore the importance H. pylori eradication is still controversial. On the contrary, the relationship of H. pylori and gastric and duodenal peptic ulcer is widely and definitively proven, and there are no doubts regarding the importance of curing the bacterium in these disorders. However, the surgical aspect of peptic ulcer, in particular the relevance and management of its complications, has not been widely investigated so far. In fact, the prevalence of H. pylori in perforated, bleeding and stenotic peptic ulcers seem to be lower that in non-complicated peptic ulcer, and whenever H. pylori eradication virtually prevents the re-bleeding of peptic ulcer in all cases, the effect of curing the bacterium in perforated and stenotic ulcers is still largely unknown. The management of H. pylori infection after gastric surgery is also still controversial. Most studies suggest that H. pylori can persist after gastric surgery whenever its incidence is much lower than that before operation. However it seems most unlikely that the infection plays a major role in the development of ulcer recurrence after gastric surgery or in the induction of gastric carcinoma. In any case, there are no convincing data that its cure may prevent the occurrence of gastric carcinoma following gastrectomy procedures.

Cell proliferation in the post-surgical stomach, dietary salt, and the effect of H pylori eradication

AIMS

To study the epithelial kinetics of the post-surgical stomach with reference to dietary salt intake and H pylori.

METHODS

Endoscopic biopsies of the antrum/anastomosis and corpus were taken for histology and MIB-1 immunostaining. The labelling index (LI%) was determined in the three zones of the gastric glands (zone 1 = surface + gastric pit; zone 2 = isthmus; zone 3 = gland base) in patients with vagotomy and pyloroplasty (n = 12), gastroenterostomy + vagotomy (n = 4), partial gastrectomy (n = 3), and Billroth I operation (n = 3). Dietary salt was determined by urinary sodium/creatinine ratio. Twelve patients were H pylori positive (10 vagotomy and pyloroplasty; 2 partial gastrectomy) and had a repeat biopsy three months after antihelicobacter treatment (10 were H pylori negative after treatment).

RESULTS

There was no correlation between salt intake and antrum/anastomosis (r = -0.34; p = 0.2) or corpus (r = -0.16; p = 0.2) labelling indices. Gastric mucosal proliferation is increased in the antrum/ anastomosis compared to the corpus in H pylori positive (p = 0.014) but not H pylori negative subjects (p = 0.084). This may reflect the different types of post-surgical stomach in each group. Gastric mucosal proliferation is reduced in antrum/anastomosis (p = 0.002) and corpus (p = 0.016) following H pylori eradication.

CONCLUSIONS

Dietary salt does not influence gastric mucosal proliferation in the post-surgical stomach but H pylori may have a role in gastric stump carcinogenesis.

Duodenogastric reflux: clinical and therapeutic aspects

BACKGROUND

Duodenogastric reflux is believed to cause damage to gastric mucosa. Most reports on this disorder concern adult patients.

PATIENTS AND METHODS

1120 children with abdominal pain were studied; endoscopic features of duodenogastric reflux were found in 92 patients. To confirm the diagnosis of duodenogastric reflux, cholescintigraphy (Tc99-HEPIDA) was performed. Children with confirmed duodenogastric reflux by scintigraphy were given a prokinetic drug (cisapride).

RESULTS

Endoscopic features of duodenogastric reflux were found in 92 children; the diagnosis was confirmed by scintigraphy in 59 patients. There was no significant difference in the severity of inflammation in gastric mucosa compared with the control group, whereas significantly fewer of these patients were infected with Helicobacter pylori. There was no correlation between regions of isotope accumulation and inflammatory lesions in the stomach. The prokinetic drug (cisapride) helped eliminate or greatly reduce duodenogastric reflux in children.

CONCLUSIONS

When endoscopic features of duodenogastric reflux are found the final diagnosis should be based on an examination that does not itself influence the motility of the gastrointestinal tract: cholescintigraphy seems to be a useful method. However, because the use of milk as a test meal affects the scintigraphic image, there was no correlation between the area of isotope accumulation and the localisation of inflammatory lesions in the stomach. Duodenogastric reflux seems to be less important as a cause of inflammatory lesions than other factors (such as genetic predisposition, stress, etc). Prokinetic drugs have a beneficial influence on treatment results in children with inflammatory lesions of gastric mucosa with duodenogastric reflux.

Effect of Helicobacter pylori infection and its eradication on cell proliferation, DNA status, and oncogene expression in patients with chronic gastritis

BACKGROUND

Helicobacter pylori, the main cause of chronic gastritis, is a class I gastric carcinogen. Chronic gastritis progresses to cancer through atrophy, metaplasia, and dysplasia. Precancerous phenotypic expression is generally associated with acquired genomic instability.

AIM

To evaluate the effect of H pylori infection and its eradication on gastric histology, cell proliferation, DNA status, and oncogene expression.

METHODS/SUBJECTS

Morphometric and immunohistochemical techniques were used to examine gastric mucosal biopsy specimens from eight controls, 10 patients with H pylori negative chronic gastritis, 53 with H pylori positive chronic gastritis, and 11 with gastric cancer.

RESULTS

All patients with chronic gastritis were in a hyperproliferative state related to mucosal inflammation, regardless of H pylori infection. Atrophy was present in three of 10 patients with H pylori negative chronic gastritis and in 26 of 53 with H pylori positive chronic gastritis, associated in 18 with intestinal metaplasia. DNA content was abnormal in only 11 patients with atrophy and H pylori infection; eight of these also had c-Myc expression, associated in six cases with p53 expression. Fifty three patients with H pylori positive chronic gastritis were monitored for 12 months after antibiotic treatment: three dropped out; infection was eradicated in 45, in whom cell proliferation decreased in parallel with the reduction in gastritis activity; atrophy previously detected in 21/45 disappeared in five, regressed from moderate to mild in nine, and remained unchanged in seven; complete metaplasia disappeared in 4/14, and markers of genomic instability disappeared where previously present. In the five patients in whom H pylori persisted, atrophy, metaplasia, dysplasia, and markers of genomic instability remained unchanged.

CONCLUSIONS

Chronic H pylori infection seems to be responsible for genomic instability in a subset of cases of H pylori positive chronic atrophic gastritis; eradication of H pylori infection can reverse inflammation and the related atrophy, metaplasia, and genomic instability.

Correlation between epithelial cell proliferation and histological grading in gastric mucosa

AIM

To determine if there is a correlation between the histological findings in the gastric mucosa and the degree of cell proliferation in gastric antral biopsies.

METHODS

Cell proliferation in gastric antral biopsies was determined by in vitro bromodeoxyuridine labelling. Histological sections were assessed using the Sydney System.

RESULTS

There was a positive correlation between antral mucosal cell proliferation and the acute inflammatory cell infiltrate (r = 0.29; p = 0.03). There was a stronger correlation with the chronic inflammatory cell infiltrate (r = 0.53; p < 0.0001) and the density of H pylori colonisation (r = 0.54; p < 0.0001). There was no correlation between gastric epithelial proliferation and the degree of atrophy. Stepwise multiple regression indicates that the only independent predictor of epithelial cell proliferation is the density of H pylori colonisation (p < 0.0001).

CONCLUSIONS

H pylori increases gastric epithelial cell proliferation through the mucosal inflammatory response and probably by other means. The strong correlation between epithelial proliferation, the chronic inflammatory cell infiltrate, and the density of H pylori colonization may have implications for gastric carcinogenesis.

Helicobacter pylori infection and risk of cardia cancer and non-cardia gastric cancer. A nested case-control study

BACKGROUND

Helicobacter pylori infection is an established risk factor for gastric adenocarcinoma. Potential confounding by socioeconomic factors has not been adequately assessed, and the magnitude of the relative risk in relation to gastric subsites, morphologic subtypes, sex, age, and follow-up time need further study.

METHODS

We conducted a serologic case-control study nested within the Norwegian JANUS cohort. Between 1972 and 1986 serum was collected from 101,601 subjects who were followed up with regard to cancer development through 1992.

RESULTS

Among 208 gastric adenocarcinoma cases, we found a strong positive association between H. pylori infection and non-cardia gastric cancer (odds ratio (OR), 5.15; 95% confidence interval (CI), 2.83-9.37), and a statistically significant negative association with cardia cancer (OR, 0.40; 95% CI, 0.20-0.77). Adjustment for socioeconomic factors and smoking did not materially alter the effect estimates. The association between the infection and non-cardia cancer was stronger for tumors distal to the angulus and tended to be stronger in women than in men. The results were similar across Laurén morphologic subtypes.

CONCLUSIONS

These results strengthen the evidence of H. pylori infection as a risk factor in non-cardia gastric cancer. A negative association with H. pylori infection was found for cardia cancer.

Relationship between persistence of Helicobacter pylori and dysplasia, intestinal metaplasia, atrophy, inflammation, and cell proliferation following partial gastrectomy

Helicobacter pylori and partial gastric resection are risk factors for gastric cancer. Our aims were to investigate the presence of H. pylori in postgastrectomy patients and to correlate that with alterations in mucosal architecture and cell proliferation. One hundred fifty-one endoscopic biopsies from 22 patients, (15-47 years of age, mean 29.2 years) following partial gastrectomy with Billroth II reconstruction for peptic ulcer disease, were examined for the presence of H. pylori using Giemsa staining. Sections were scored for grade of hyperplasia, intestinal metaplasia, dysplasia, inflammation, and atrophy. Immunohistochemistry for proliferative cell nuclear antigen (PCNA) was used to characterize cell proliferation. H. pylori was observed in 17/22 (77.3%) of patients or in 57/151 (37.7%) of biopsies. Metaplasia was seen in 18/22, chronic atrophic gastritis in 20/22, and cystic glandular dilation in 21/22 patients. The highest type of metaplasia in each patient was: four Type I, five Type IIA and nine Type IIB. Dysplasia was present in 16 biopsies from nine patients. H. pylori was more prevalent in intestinal metaplasia type I (44.8% of biopsies), than in type IIA (32.7%) or type IIB (25%). No H. pylori was detected in regions showing dysplasia or cystic glandular dilation. H. pylori colonization was associated with degree of inflammation (P = 0.00001) and cell proliferation (P = 0.0001). In conclusion, H. pylori is commonly seen many years after gastrectomy, it is associated with an increased epithelial cell proliferation, and it is not present in areas of histologic markers of premalignancy (type IIB metaplasia and dysplasia).

Diagnosis of Helicobacter pylori infection after gastric surgery for peptic ulcer: is the rapid urease test useful?

BACKGROUND

The usefulness of the rapid urease test (RUT) in diagnosing Helicobacter pylori infection after peptic ulcer surgery is unknown.

METHODS

Patients who had undergone peptic ulcer surgery were offered endoscopic examination if they presented with dyspepsia or gastrointestinal bleeding. Biopsy specimens were taken for RUT and histology from the corpus and the stoma in patients who had undergone partial gastrectomy or from the corpus and the antrum in patients who had undergone vagotomy. Histologic examination using haematoxylin and eosin stain and Warthin-Starry stain were used as the gold standard.

RESULTS

Ninety patients were studied (69 had partial gastrectomy and 21 had vagotomy). Forty-three patients (32 in the partial gastrectomy group and 11 in the vagotomy group) were positive for H. pylori by histology. The respective sensitivity of RUT was 59% (stoma) and 75% (corpus) in the partial gastrectomy group (P = 0.36) and 55% (antrum) and 73% (corpus) in the vagotomy group (P = 0.51).

CONCLUSIONS

RUT is not sensitive for detecting H. pylori after acid reduction surgery.

Significance of cell proliferation measurement in gastric cancer

Cell kinetic data may be important indicators of clinical behaviour in many types of cancer. Recently, several antibodies to cell-cycle associated antigens have been characterised. This overview summarises the advantages and disadvantages of different methods for the assessment of cell proliferation. Moreover, the prognostic value of proliferative activity in gastric cancer is discussed and suggestions for future research are given.

Helicobacter pylori gastritis and epithelial cell proliferation in patients with reflux oesophagitis after treatment with lansoprazole

BACKGROUND

Helicobacter pylori gastritis may spread proximally in the stomach during profound acid inhibition.

AIMS

To examine histological gastric body changes and epithelial cell proliferation before and after treatment with lansoprazole.

PATIENTS AND METHODS

Patients diagnosed as having reflux oesophagitis grade 1 or 2 were enrolled and treated for 12 weeks with lansoprazole (30 mg every morning). After 12 weeks, 103 of the 118 patients appeared endoscopically healed and were asymptomatic; they then received maintenance treatment with 15 or 30 mg lansoprazole daily. Biopsy specimens obtained from similar sites before and after treatment, were available from 90 patients after a median of 64 weeks (range 15-73 weeks). Epithelial cell proliferation was determined by the number of Ki-67 antigen positive cells per gland.

RESULTS

Of these 90 patients, 44 (49%) were found to be infected with H pylori. Their median inflammation score had increased from grade 1 before to grade 2 after treatment (p < 0.0001). Initially, the number of Ki-67 antigen positive cells per gland was significantly higher in the H pylori infected than in the uninfected group and increased further after treatment (p < 0.0001). In uninfected patients, no significant change in inflammation or proliferation occurred during treatment.

CONCLUSIONS

A marked increase in body gastritis was observed in H pylori infected individuals during long term treatment with the proton pump inhibitor lansoprazole. Epithelial cell proliferation and atrophy also increased in infected but not in uninfected patients.

Structural changes in the gastric foveolar epithelium in Helicobacter pylori-positive gastritis revealed by keratin immunohistochemistry

To clarify structural changes in the gastric foveolar epithelium in Helicobacter pylori (Hp)-positive gastritis, the expression rates of keratins 8, 18, 19, and 20 were assessed immunohistochemically in normal tissue and chronic gastritis. In normal tissue, keratin 8 was found in 100% of the cells. Staining for keratins 18 and 19 was abundantly positive. Keratin 20 was not expressed in the deep foveolae, but present in the upper foveolae and on the tips. No differences were found between the antrum and the body. In chronic gastritis, both Hp-positive and -negative, keratins 8, 18, and 19 were expressed comparably to normal tissue. Keratin 20 expression in the antrum was significantly lower in Hp-positive compared with Hp-negative gastritis (P < .05) and normal tissue (P < .05). In the body, staining for keratin 20 did not differ significantly between all groups. The difference in keratin 20 expression between the antrum and the body in Hp-positive gastritis was significant (P < .05). After successful eradication, staining for keratin 20 in the antrum normalized within 6 months (P < .05). These findings indicate structural changes in the gastric foveolar epithelium in Hp-positive gastritis. They predominantly include the antral region and show full reversibility after eradication.

Synchronous mucosa-associated lymphoid tissue lymphoma and adenocarcinoma of the stomach

The development of simultaneous primary gastric lymphoma and carcinoma is a rare event for which a possible etiopathogenetic role for Helicobacter pylori (HP) recently has been postulated. We report a series of eight such cases diagnosed from 1980 to 1995. In two cases, both tumors arose in a gastric stump, at 26 and 34 years, respectively, after gastric resection for a duodenal ulcer. Grossly, the lymphoma and carcinoma formed a single lesion in four cases (collision tumor); they were separated in the other four cases. Histologically, all the lymphomas fit into the category of B-cell mucosa-associated lymphoid tissue lymphoma; six of them were low-grade lymphomas and two were low-grade lymphomas with a high-grade component. The adenocarcinomas were intestinal-type in four cases, diffuse in three, and mixed in one. Regarding the depth of infiltration, four carcinomas were early gastric cancers and four were advanced. All the collision tumors contained an early gastric cancer. Our observations confirmed the association of HP with gastric lymphoma and carcinoma in 4 cases. Spiral bacteria with the features of Helicobacter heilmannii were found in one case. The occurrence of two different tumors in a gastric stump, which has not been reported previously, suggests that postgastrectomy gastritis might contribute to the development of both gastric lymphoma and carcinoma.

Helicobacter pylori infection accelerates human gastric mucosal cell proliferation

Helicobacter pylori causes chronic atrophic gastritis and intestinal type gastric cancer arises against a background of atrophic gastritis. Increased proliferation of epithelial cells is an important indicator of increased risk for gastric adenocarcinoma. We investigated gastric mucosal cell proliferation in H. pylori-associated gastritis and the effect of eradication therapy on this proliferation in 45 patients endoscopically diagnosed (31 with persistent eradication and 14 in whom H. pylori) recurred. H. pylori status was determined by culture and histology in biopsied specimens from the gastric antrum and corpus. Eradication of the infection was defined as reversal to negative on both tests. In vitro Ki-67 immunostaining of endoscopic biopsy specimens was used to measure mucosal cell proliferation in H. pylori-associated gastritis before and after therapy. The proliferative zone was defined as the distance of Ki-67-positive gastric epithelial cells between the highest and the lowest cells. In patients in whom H. pylori was eradicated, cell proliferation in both the antral and corpus mucosa had decreased 4 weeks after completion of the eradication therapy (P < 0.01, P < 0.001), and 6 months later, it had markedly decreased (P < 0.05, P < 0.05) and returned to normal. In patients in whom H. pylori recurred, only antral epithelial cell proliferation was reduced 4 weeks after eradication therapy, but when H. pylori recurred, determined by culture and histology, cell proliferation level was the same as that before eradication. These results suggest that H. pylori infection accelerates cell proliferation in gastric mucosa and may play a causal role in the chain of events leading to gastric carcinoma.

Mucosal expression and luminal release of epidermal and transforming growth factors in patients with duodenal ulcer before and after eradication of Helicobacter pylori

BACKGROUND

Epidermal growth factor (EGF) and transforming growth factor-alpha (TGF alpha) are potent gastric acid inhibitors and stimuli of mucosal growth and protection but their involvement in Helicobacter pylori associated duodenal ulcer has been little examined.

AIM

To assess gastric acid secretion, plasma gastrin concentrations, mucosal content of EGF and TGF alpha, and mucosal expression of these peptides and their receptor (EGFr) as well as salivary and gastric luminal release of EGF under basal conditions and after pentagastrin stimulation in 10 healthy subjects and in 25 H pylori positive patients with duodenal ulcer before and after two weeks of triple anti-H pylori therapy and four weeks after the termination of this therapy.

RESULTS

Pentagastrin stimulation caused a significant increase in salivary and gastric release of EGF both in healthy controls and patients with duodenal ulcers but in the patients, the eradication of H pylori resulted in several fold higher gastric luminal (but not salivary) EGF release than before the anti-H pylori therapy. Mucosal contents of immunoreactive EGF and TGF alpha and mucosal expression of EGF, TGF alpha, and EGFr in H pylori positive patients with duodenal ulcer were significantly higher than those in healthy H pylori negative controls and this increase persisted after eradication of H pylori. Basal plasma gastrin was significantly reduced after two weeks of triple therapy and four weeks after the H pylori eradication all ulcers were completely healed.

CONCLUSIONS

(1) H pylori infection in patients with duodenal ulcer was accompanied by enhanced plasma gastrin and increased mucosal content and expression of TGF alpha, EGF, and EGFr; (2) H pylori eradication resulted in ulcer healing, reduction in plasma gastrin, and enhancement of gastric (but not salivary) luminal release of EGF, particularly after pentagastrin stimulation; and (3) enhanced mucosal content and expression of TGF alpha, EGF, and EGFr and increased luminal release of EGF may contribute to ulcer healing after eradication of H pylori.

Partial characterization of a cell proliferation-inhibiting protein produced by Helicobacter pylori

Despite the induction of an immunological reaction, Helicobacter pylori-associated gastritis is a chronic disease, suggesting that this microbe can evade the host immune defense. Previous studies by our group showed that H. pylori suppresses the in vitro proliferative response of human mononuclear cells to mitogens and antigens. Here we demonstrate that the antiproliferative activity of H. pylori also affects the proliferation of various mammalian cell lines (U937, Jurkat, AGS, Kato-3, HEP-2, and P388D1). This effect is detectable in the first 16 h of incubation and maximal between 24 and 48 h. In addition, the presence of H. pylori significantly diminished the protein synthesis of cells in the first 6 h of incubation, comparable to the results with cycloheximide and diphtheria toxin. The urease enzyme, the cagA gene product, and the vacuolizing cytotoxin of H. pylori were excluded as causative agents of the antiproliferative effect by using isogenic knockout mutant strains. The inhibitory effect was not due to a lytic activity of this bacterium. The results reported here indicate that the responsible factor is a protein with an apparent native molecular mass of 100 +/- 10 kDa. Our work implicates the presence of a protein factor in H. pylori (termed PIP [for proliferation-inhibiting protein]) with antiproliferative activity for mammalian cells, including immunocompetent and epithelial cells. Thus, it is reasonable to presume that this property may contribute to the pathogenesis of H. pylori-induced diseases. It may be involved on the one hand in immune response evasion and on the other hand in the suppression of epithelial repair mechanisms.