Anti-Helicobacter pylori therapy significantly reduces Helicobacter pylori -induced gastric mucosal damage in Mongolian gerbils

AIM: To investigate the effectiveness of 4 d‘anti-Helicobacter pyloritherapy on the H pylori-infected Mongolian gerbils based on physiological and pathological changes. METHODS: We used 6-wk-old male gerbils orally inoculated with H pylori (ATCC43504, 2×10^8 CFU/mL). Seven weeks alter Hpyloriinoculation, the animals of study group received 4 d‘arti-H pyloritriple therapy (Hpylorieradicated group). Seven days later, all animals of the H pylori-eradicated and control groups (H pylori-infected & H pylori-uninfected groups) were sacrificed. We examined gastric mucosal lesions macroscopically, studied gastritis microscopically and determined the stomach weight ratio, myeloperoxidase (MPO) activity and prostaglandin (PG) E2 level. RESULTS: The results showed that both macroscopic and histological gastric damages were significantly less in H pylori-eradicated group than H pylori-infected group. Stomach weight ratio, MPO activity and PGE2 levels were significantly higher in H pylori-infected group than those in the other two groups. CONCLUSION: Four days‘anti-H pylori therapy was effective in the improvement of H pylori-induced gastric lesions in Mongolian gerbils.     

Helicobacter pylori infection potentiates aspirin induced gastric mucosal injury in Mongolian gerbils

BACKGROUND: Helicobacter pylori infection and non-steroidal anti-inflammatory drugs are two major causes of gastric ulceration but interactions between H pylori and these drugs in gastric mucosal injury are unclear. AIMS: We studied the influence of experimental H pylori infection on gastric mucosal injury induced by aspirin. SUBJECTS: Male Mongolian gerbils free of specific pathogens were used. METHODS: H pylori ATCC43504 culture broth was administered by oral gavage at seven weeks of age. After three weeks, acidified aspirin (400 mg/kg) was administered orally, and three hours later the total area of gastric erosions, myeloperoxidase (MPO) activity (an index of neutrophil accumulation), thiobarbituric acid reactive substances (TBARS, an index of lipid peroxidation), and KC/GRO (a chemoattractive cytokine in rodents) were measured in gastric mucosa. To determine the role of neutrophils in these circumstances, antigerbil neutrophil rabbit serum (ANS) was administered to some animals 18 hours before aspirin. RESULTS: Aspirin caused more extensive haemorrhagic erosions (33.1 (12.3) mm2) associated with greater MPO activity (1887.7 (598.5) microU/mg protein) and TBARS (0.33 (0.14) nmol/mg protein) and KC/GRO concentrations (28.3 (9.5) pg/mg protein) in infected than in uninfected gerbils (13.7 (2.3); 204.0 (68.9); 0.12 (0.06); 3.1 (0.8), respectively) Pretreatment with ANS inhibited the increases in gastric erosions, MPO activity, and TBARS but not KC/GRO concentration. The reduction in aspirin induced mucosal injury by administration of ANS was much greater in H pylori infected animals (65%) than in uninfected animals (31%). CONCLUSIONS: H pylori infection potentiates aspirin induced gastric mucosal injury by mechanisms that include accumulation of activated neutrophils.     

Acid exposure and altered acid clearance in GERD patients treated for Helicobacter pylori infection

BACKGROUND: After the eradication of Helicobacter pylori, an increased incidence of gastroesophageal reflux disease and acid gastric secretion have been reported. AIM: To evaluate the effect of Helicobacter pylori-eradication on proximal and distal gastroesophageal reflux and acid clearance in patients with gastroesophageal reflux disease. PATIENTS AND METHODS: Sixty-eight gastroesophageal reflux disease patients (age range 18-61 years) were studied by upper endoscopy. All underwent esophageal manometry and dual probe 24-h pH-metry. RESULTS: Percent of time at pH<4 was significantly increased in the proximal esophagus of Helicobacter pylori-eradicated patients compared to Helicobacter pylori-negative (2.4+/-0.5 vs. 1.0+/-0.2; p<0.01); no differences were found in the distal esophagus (14.0+/-3.7 vs. 9.0+/-1.4%, NS). The total number of reflux episodes was significantly higher in the proximal oesophagus of Helicobacter pylori-eradicated patients (37+/-3 vs. 22+/-3, p<0.05). In the distal esophagus, acid clearance was significantly longer, both during total time (1.4+/-0.2 vs. 0.8+/-0.7 min, p<0.01), and in the supine period (8.5+/-2.7 vs. 2.7+/-0.4 min, p<0.05). No differences were reported in the manometric parameters of the two groups of patients. CONCLUSION: In patients with gastroesophageal reflux disease, Helicobacter pylori eradication is associated with increased acid exposure of the proximal esophagus and delayed distal acid clearance.     

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.     

Response of blood endothelin-1 and nitric oxide activity in duodenal ulcer patients undergoing Helicobacter pylori eradication

AIM: To investigate the effect of Helicobacter pylori eradication on endothelin-1 (ET-1) and nitric oxide (NO) in duodenal ulcer (DU) patients. METHODS: Sixty-six Hpylori-infected active DU patients were consecutively enrolled to receive one-week triple therapy (rabeprazole, amoxicillin and metronidazole) and then one-month rabeprazole therapy. They were asked back to determine ulcer and Hpylori status using endoscopy one month later. Thirty-seven healthy controls (H pylori +/-:17/20) were enrolled for comparison. Blood samples were collected in each visit to measure plasma ET-1 and nitrate/nitrite levels using an enzyme immunoassay kit. RESULTS: Sixty DU patients finished trial per protocol. The ulcer healing and Hpylori-eradication rates were 86.7% and 83.3%, respectively. Plasma ET-1 level in DU patients was higher than that of Hpylori-negative and positive controls (3.59±0.96 vs0.89±0.54 vs0.3±0.2 pg/mL,P<0.01), while nitrate/nitrite levels among them were also significantly different (8.55±0.71 vs5.27±0.68 vs 6.39±0.92 μmol/L, P<0.05). H pylori eradication diminished ET-1 levels (3.64±0.55 vs2.64±0.55 pg/mL, P<0.01) but elevated nitrate/ nitrite level (8.16±0.84 vs11.41±1.42 umol/L,P<0.05). CONCLUSION: Both plasma ET-1 and nitrate/nitrite levels increase in active DU patients. After an effective H pylori eradication, DU healing is associated with diminished blood ET-1 level and elevated nitrate/nitrite level.     

Effect of Helicobacter pylori eradication on anti-thrombotic dose aspirin-induced gastroduodenal mucosal injury

BACKGROUND: Helicobacter pylori infection and non-steroidal anti-inflammatory drugs are two major causes of gastric injury but the effect of H. pylori eradication on the development of aspirin-induced gastric mucosal injury is unclear. The aim of the present study was to investigate the effect of Helicobacter pylori eradication on gastroduodenal mucosal injury induced by antithrombotic doses of aspirin. METHODS: Patients who had been planned to start on medium-dose aspirin (300 mg) for any kind of indication were included in the study. All subjects underwent upper gastrointestinal endoscopy for determination of H. pylori status and Lanza score. The H. pylori-positive patients were randomized to receive either aspirin + eradication (omeprazole 20 mg b.i.d. and amoxicillin 500 mg q.i.d. for 2 weeks) or aspirin + placebo eradication. Endoscopic reassessment was done 4 months after the onset of aspirin or when symptoms developed. RESULTS: Thirty-two patients (placebo group n = 16, H. pylori-eradicated group n = 16) completed the study and Lanza scores of both groups were similar before treatment. Lanza scores significantly increased in the placebo group (0.69 +/- 0.87 vs 2.25 +/- 1.3, P < 0.0001) and did not change in the H. pylori-eradicated group after aspirin treatment (0.43 +/- 0.72 vs 0.75 +/- 0.93, P > 0.05). CONCLUSION: Helicobacter pylori eradication may prevent medium-dose aspirin-induced gastroduodenal mucosal injury.     

Eradication of Helicobacter pylori restores the inhibitory effect of cholecystokinin on gastric motility in duodenal ulcer patients

BACKGROUND: Increased gastric emptying and defective action of endogenous cholecystokinin (CCK), that is known to inhibit this emptying, have been implicated in the pathogenesis of duodenal ulcer (DU). The aim of this double blind study was to assess whether CCK and somatostatin participate in the impairment of gastric motility in active DU patients before and after Helicobacter pylori eradication. METHODS: Tests were undertaken in 10 DU patients without or with elimination of the action of endogenous CCK using loxiglumide, a selective CCK-A receptor antagonist, before and 4 weeks after eradication of H. pylori with 1 week triple therapy that resulted in healing of all DUs tested. The gastric emptying rate after feeding was determined using the 13C-acetate breath test. Before each test, samples of gastric juice were obtained by aspiration using a nasogastric tube for determination of somatostatin using specific radioimmunoassay. RESULTS: Prior to H. pylori eradication gastric emptying half-time was 31 +/- 6 min in placebo-treated DU patients and this emptying rate was not significantly affected in tests after pretreatment with loxiglumide (10 mg/kg i.v.). Following eradication of H. pylori, in tests with placebo gastric emptying half-time was significantly longer (48 +/- 9 min) compared to that prior to H. pylori eradication. Pretreatment with loxiglumide in H. pylori eradicated DU patients significantly enhanced the gastric emptying rate with an emptying half-time of only 33 +/- 4 min. Eradication of H. pylori resulted in a significant increase in somatostatin concentration in gastric juice and loxiglumide significantly reduced this luminal somatostatin in H. pylori-eradicated subjects compared to values before anti-H. pylori therapy. CONCLUSIONS: 1) H. pylori infection in DU patients is accompanied by enhanced gastric emptying and reduction in luminal release of somatostatin; 2) the failure of loxiglumide to affect gastric emptying in H. pylori-infected DU patients might be attributed, at least in part, to the failure of endogenous CCK to control gastric motility due to deficient release of somatostatin; and 3) H. pylori-infected patients appear to exhibit a deficient somatostatin release by endogenous CCK that can be reversed by the eradication of H. pylori indicating that both CCK and somatostatin may contribute to normalization of gastric emptying following H. pylori eradication in DU patients.     

Relationship of Helicobacter pylori to serum pepsinogens in an asymptomatic Japanese population.

A seroepidemiologic study of the prevalence of Helicobacter pylori infection in Japan was performed, and the relationship between serum pepsinogen I and II levels (markers of gastritis and gastric atrophy) and H. pylori infection was investigated. Four hundred and eighteen asymptomatic children and adults were studied. The prevalence of anti-H. pylori immunoglobulin G antibody increased with age. For persons born after 1950, the frequency of H. pylori infection increased at approximately 1% per year; for those born before 1950 the prevalence was high (70%-80%) and relatively constant. Serum pepsinogen I and II levels were significantly higher in H. pylori-infected volunteers than in H. pylori-uninfected volunteers [51.6 +/- 3 vs. 42.9 +/- 2 ng/mL (P less than 0.05) for pepsinogen I; 16.0 +/- 1 vs. 7.5 +/- 0.8 ng/mL (P less than 0.001) for pepsinogen II]. The ratio of pepsinogen I to pepsinogen II was significantly lower in H. pylori-infected volunteers (3.5 +/- 0.2) than in uninfected volunteers (6.3 +/- 0.3; P less than 0.001). The apparent decrease in prevalence of H. pylori accompanying the Westernization of Japan may eventually be accompanied by a reduction in the frequency of atrophic gastritis, the precursor lesion of the epidemic form of gastric carcinoma, and ultimately result in a decrease in the incidence of gastric carcinoma in Japan.     

Overexpression of cyclin E in Mongolian gerbil With Helicobacter pylori—induced gastric precancerosis

AIM: To explore dysregulation of cyclin E in malignancies,and to further investigate the role of cyclin E in Helicobacterpylori ( H. pylori)-induced gastric precancerosis.METHODS: Four-week-old specific pathogen-free maleMongolian gerbils were employed in the study. 0.5 mL 1 ×108 cfu@ L- 1 suspension of H. pylori NTCC11637 in Brucellabroth was inoculated orally into each of 20 Mongolian gerbils, and a further 20 gerbils were inoculated with Brucella brothas controls. 10 of the infected gerbils and 10 of the non-infected control gerbils were sacrificed at 25, 45 wk afterinfection. The expression of cyclin E was analyzed by RT-PCR and immunohistochemical studies with monoclonalantibody to cyclin E in Mongolian gerbil of H. pylori-induced gastric precancerosis.RESULTS: H. pylori was constantly detected in all infectedanimals throughout the study. At 25 wk after infection of H.pylori, ulcers were observed in the antral and body ofstomach ( n = 6). Histological examination showed that allanimals developed severe inflammation and multifocallymphoid follicles appeared in the lamina propria andsubmucosa of gastric antrum. At 45 wk after infection of H.pylori, severe atrophic gastritis (n = 10), intestinalmetaplasia (n = 8) and dysplasia (n = 6) could beobserved. Cyclin E mRNA levels were significantly more at25 wk after infection of H. pylori (1.27±0.26), and at45 wkafter infection of H. pylori (1.82 ± 0.39 ) than control-animals (0.59 ± 0.20, P＜ 0.01) ; cyclin E mRNA levels wereevaluated by 2.2-fold at 25 wk ( P ＜ 0.01 ) and 3. 1-fold at 45wk ( P ＜ 0.01 ) precancarosis induced by H. pylori, whencompared with control gastric epithelium of Mongoliangerbil. Immunohistochemical staining revealed exclusivenuclear staining of cyclin E. Furthermore, there wes asequential increase in cyclin E positive cells from normalepithelium to precancerosis.CONCLUSION: Overexpression of cyclin E occurs relativelyearly in gastric tumorigenesis in this model.     

Effect of non-steroidal anti-inflammatory drugs on gastric and duodenal prostaglandin concentrations in patients with Helicobacter pylori infection.

BACKGROUND/AIMS: Both Helicobacter pylori and non-steroidal anti-inflammatory drugs are reported to affect gastroduodenal prostaglandin synthesis. However, their influence on gastric mucosal prostaglandins remains unclear. The aim of this study was to investigate the influence of nonsteroidal anti-inflammatory drugs on mucosal prostaglandin synthesis in patients with Helicobacter pylori infection. METHODOLOGY: We enrolled 87 Helicobacter pylori-infected patients in this study (gastric ulcer: 33, duodenal ulcer: 41, and non-ulcer dyspepsia: 13). Of them, 27 patients received non-steroidal anti-inflammatory drugs. Endoscopy was performed and biospy specimens from gastric body, antrum and duodenal bulb were assessed for Helicobacter pylori and prostaglandin concentration. RESULTS: A significantly lower mucosal prostaglandin E2 level at gastric body (142.2 +/- 28.1 ng/mg vs. 222.0 +/- 12.4 ng/mg, mean +/- SEM) and antrum (131.3 +/- 26.4 ng/mg vs. 226.0 +/- 19.0 ng/mg) was noted in Helicobacter pylori-infected gastric ulcer patients with non-steroidal anti-inflammatory drugs ingestion than in that of patients without non-steroidal anti-inflammatory drugs ingestion (p < 0.05). Using a multivariate analysis, we found that non-steroidal anti-inflammatory drug was an independent variable affecting gastric and duodenal mucosal prostaglandin E2 synthesis in patients with Helicobacter pylori-infected gastric ulcer. CONCLUSIONS: Non-steroidal anti-inflammatory drugs decrease gastroduodenal mucosal prostaglandin E2 synthesis in gastric ulcer patients with Helicobacter pylori infection.     

Long-term treatment with sterigmatocystin,a fungus toxin,enhances the development of intestinal metaplasia of gastric mucosa in Helicobacter pylori-infected Mongolian gerbils

BACKGROUND: Helicobacter pylori is a human gastric carcinogen. Sterigmatocystin (ST), a fungus toxin, is a risk factor of gastric cancer. Cytotoxin-vacuolation toxin A (VacA) present in supernatants of H. pylori suspensions can cause gastritis and ulcer. The aim of this study was to examine the effects of H. pylori, ST and VacA in Mongolian gerbils. METHODS: Male Mongolian gerbils (n = 196) were treated with H. pylori supernatants (10 ml/1000 mg) mixed with diet or inoculated intragastrically with H. pylori alone or with ST (100 or 1000 ppb), and then killed 27 months later. Gastric tissue sections were stained with haematoxylin and eosin (H&E), periodic acid-Schiff (PAS), Alcian blue (AB, pH 2.5) and with immunostaining for PCNA and p53 expression. RESULTS: In H. pylori-infected gerbils, the normal mucosa was replaced by hyperplastic epithelium. Severe gastritis, cystic dilatation of gastric glands, hyperplastic polyps and intestinal metaplasia were observed. In H. pylori + ST (1000 ppb) gerbils, intestinal metaplasia was significantly more frequent than in H. pylori alone animals. No pathological changes were observed in the H. pylori supernatant group. Osseous metaplasia was observed in the H. pylori + ST (100 ppb) group. Serum gastrin levels of the H. pylori + ST (1000 ppb) group were significantly higher than those of the other groups. PCNA labelling index and p53 index of infected gerbils were significantly higher than those of uninfected groups. CONCLUSION: H. pylori causes gastritis, ulcer and intestinal metaplasia. ST enhances the development of intestinal metaplasia and increases gastrin levels in H. pylori-infected Mongolian gerbils.     

Functional and morphological aspects of Helicobacter pylori-induced gastric cancer in Mongolian gerbils

BACKGROUND: Helicobacter pylori infection of Mongolian gerbils is an established model of gastric carcinogenesis, but gastric secretory aspects of this carcinogenesis have not been studied. METHODS: The effects of single intragastric inoculation of gerbils with H. pylori strain (cagA+ vacA+, 5 x 10(6) CFU/ml) or vehicle (saline) were examined at 1, 2, 4, 6, 9, 12 and 30 weeks from inoculation. Gastric morphology, the presence of H. pylori using the rapid urease test, the density of H. pylori and 16S rRNA and the plasma gastrin and somatostatin were determined. RESULTS: H. pylori was detected in gastric mucosa in all infected animals. Basal gastric acid in gerbils was reduced by about 50% after H. pylori inoculation. Early lesions seen at 4 weeks after H. pylori inoculation consisted of chronic gastritis with thickened mucosal folds, oedema, congestion and mucosal lymphocytic infiltration. Adenomatous hyperplasia with cellular atypia with increased mitotic activity and the formation of apoptotic bodies and visible erosions and ulcerations were observed at 12-30 weeks after inoculation. The atypical gastric glands were situated 'back-to-back', suggesting gastric pre-cancer. The gastric blood flow in H. pylori-infected gerbils was significantly lower than that in the controls. Six- to seven-fold increase in plasma gastrin levels combined with significant fall in gastric somatostatin contents and the intraepithelial neoplasia were noticed in gerbils at all tested periods. CONCLUSION: H. pylori-infection in gerbils resulted in gastric pre-cancer associated with functional changes, such as suppression of gastric secretion and impairment of both gastric mucosal microcirculation and the gastrin-somatostatin link.     

Helicobacter pylori infection influences tumor growth of human gastric carcinomas

BACKGROUND: Helicobacter pylori infection is considered a risk factor for gastric carcinoma. However, the effect of eradication therapy in gastric carcinoma patients is not well known. The aim of this study was to investigate the relationship between H. pylori infection and tumor growth of gastric carcinoma. METHODS: Fifty-one patients with gastric carcinoma participated in the study. Thirty-three were H. pylori-positive, 6 were H. pylori-negative, and 12 were diagnosed with gastric carcinoma after eradication of H. pylori. To investigate tumor growth of gastric carcinoma, cell proliferation and angiogenesis of the tumors were evaluated by immunohistochemical techniques using Ki-67 and CD34. RESULTS: The Ki-67 labeling index was 47.9 +/- 2.6 (mean +/- s) in the H. pylori-positive group, 38.1 +/- 3.6 in the H. pylori-eradicated group, and 22.2 +/- 5.5 in the H. pylori-negative group. It was significantly lower in the H. pylori-eradicated and H. pylori-negative groups than in the H. pylori-positive one, and a significant difference was also found between the H. pylori-positive and H. pylori-eradicated groups. The microvessel counts were 62.5 +/- 3.0, 50.2 +/- 4.0, and 66.0 +/- 9.8 in the positive, eradicated, and negative groups, respectively. A significant difference was found between the H. pylori-positive and H. pylori-eradicated groups. CONCLUSION: Our results suggest that H. pylori infection is associated with cell proliferation, and its eradication may influence tumor vascularity of gastric carcinoma. Therefore, H. pylori eradication therapy may contribute to the suppression of tumor growth.     

Expression of mutant type-p53 products in H pylori-associated chronic gastritis

AIM:To investigate the mutation of p 53 immuno-histochemically in non-tumorous gastric mucosa with H pylori infection before and after H pylori eradication therapy.METHODS:53 subjects(36 male,17 female,mean age ± SEM,57.1 ± 12.1)undergoing endoscopic examination were included in this study.42 of 53 patients were H pylori-positive,and 11 were H pylori-negative.All H pylori-positive patients had successful eradication therapy.Biopsy specimens were taken from five points of the stomach,as recommended by the updated Sydney system.Immunohistochemical studies were performed by using primary antibodies against p53(DO-7 and PAb240).RESULTS:p53(DO-7 and PAb240)immunoreactivity was shown in the neck region of the gastric pits,however,quite a few cells were found to be immunopositive for p 53(PAb240)in the H pylori-infected gastric mucosa.The proportion of patients immunopositive for p 53(PAb240)was significantly reduced 6 mo after eradication [28/42(66.7%)to 6/42(14.3%)](P < 0.05),while the biopsies taken from H pylori-negative patients showed no immunoreactivity for p53(PAb240).p53(PAb240)-positive patients were divided into two groups by the number of positive cells detected:one with more than six positive cells per 10 gastric pits(group A,n = 12),and the other with less than five positive cells per 10 gastric pits(group B,n = 30).Atrophy scores in group A were significant higher than those in group B at the greater curvature of the antrum(group A:2.00 ± 0.14 vs group B:1.40 ± 0.15,P = 0.012),the lesser curvature of the corpus(group A:2.00 ± 0.21 vs group B:1.07 ± 0.23,P = 0.017),and the greater curvature of the corpus(group A:1.20 ± 0.30vs group B:0.47 ± 0.21,P = 0.031).Group A showed significant higher intestinal metaplasia scores than group B only at the lesser curvature of the antrum(group A:2.10 ± 0.41 vs group B:1.12 ± 0.29,P = 0.035).CONCLUSION:H pylori-associated chronic gastritis expressed the mutant-type p53,which was significantly associated with more severe atrophic and metaplastic changes.H pylori eradication led to a significant reduction in the expression of the mutant-type p53.It is considered that H pylori-infected chronic gastritis is associated with a genetic instability that leads to gastric carcinogenesis,and H pylori eradication may prevent gastric cancer.     

Impact of Helicobacter pylori infection on gastric and plasma ghrelin dynamics in humans

OBJECTIVES: There are contradictory reports on the relationship between Helicobacter pylori and circulating ghrelin. We sought to clarify the influence of H. pylori infection on gastric and plasma ghrelin dynamics in humans. METHODS: Using endoscopic biopsies from the corpus of 56 H. pylori-infected patients and 25 uninfected subjects, ghrelin mRNA expression levels and gastric ghrelin peptide contents were measured by real-time polymerase chain reaction and radioimmunoassay, respectively. We also measured plasma ghrelin concentrations and analyzed the numbers of ghrelin immunoreactive cells in the fundic gland area. Fifty-one patients with H. pylori infection were treated with a 7-day triple therapy consisting of lansoprazole, clarithromycin, and amoxicillin. RESULTS: The gastric ghrelin mRNA expression level of H. pylori-positive patients (1.64 +/- 1.27 in arbitrary units) was significantly lower than in H. pylori-negative subjects (4.87 +/- 4.1, p < 0.0001). A similar trend was noted for ghrelin peptide contents (31.2 +/- 27.5 vs 81.2 +/- 64.1 ng/mg protein, respectively, p < 0.0001). There was no significant difference in the number of ghrelin immunoreactive cells/mm(2) in terms of H. plyori status. Plasma ghrelin concentrations in H. pylori-infected patients (144.6 +/- 7.8.8 fmol/ml) were significantly lower than in uninfected subjects (196.1 +/- 97.2, p < 0.05) and increased following cure of the infection. Plasma ghrelin levels correlated positively with the expression levels of ghrelin mRNA (r = 0.583, p < 0.0001) and peptide products (r = 0.574, p < 0.0001). There was a significant stepwise decrease in gastric ghrelin mRNA expression (p < 0.05), peptide contents (p < 0.01) and density of ghrelin immunoreactive cells (p < 0.05) with progression of histological severity of glandular atrophy in the corpus. The histological severity of chronic inflammation also negatively influenced the ghrelin mRNA expression (p < 0.001) and peptide production (p < 0.005). CONCLUSIONS: H. pylori infection has a negative impact on gastric and plasma ghrelin dynamics. Chronic inflammatory and atrophic changes associated with the infection may affect gastric ghrelin biosynthesis and contribute to the low circulating levels.     

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

Background & Aims: Oral immunization with Helicobacter pylori urease can cure Helicobacter infection in animals. As a step toward therapeutic immunization in humans, the safety and immunogenicity of oral immunization with recombinant H. pylori urease were tested in H. pylori-infected adults. Methods: Twenty-six H. pylori-infected volunteers were randomized in a double-blind study to four weekly oral doses of 180, 60, or 20 mg of urease with 5 microg heat-labile enterotoxin of Escherichia coli (LT), LT alone, or placebo. Side effects and immune responses were evaluated weekly after immunization, and gastric biopsy specimens were obtained after 1 month and 6 months for histology and quantitative cultures. Results: Diarrhea was noted in 16 of 24 (66%) of the volunteers who completed the study. Antiurease serum immunoglobulin A titers increased 1. 58-fold +/- 0.37-fold and 3.66-fold +/- 1.5-fold (mean +/- SEM) after immunization with 60 and 180 mg urease, respectively, whereas no change occurred in the placebo +/- LT groups (P = 0.005). Circulating antiurease immunoglobulin A-producing cells increased in volunteers exposed to urease compared with placebo (38.9 +/- 13. 6/10(6) vs. 5.4 +/- 3.1; P = 0.018). Eradication of H. pylori infection was not observed, but urease immunization induced a significant decrease in gastric H. pylori density. Conclusions: H. pylori urease with LT is well tolerated and immunogenic in H. pylori-infected individuals. An improved vaccine formulation may induce curative immunity.     

Anti-inflammatory effects of Aloe vera on leukocyte-endothelium interaction in the gastric microcirculation of Helicobacter pylori-infected rats

This research was aimed to investigate anti-inflammatory effects of Aloe vera on leukocyte-endothelium in the gastric microcirculation of Helicobacter pylori (H. pylori)-infected rats. Thirty-six male Sprague-Dawley rats were divided into 3 groups: control, H. pylori-infected, and A. vera-treated group (200 mg/kg b.w., twice daily). H. pylori-inoculation was induced in the rats by the administration of H. pylori solution. Intravital fluorescence videomicroscopy was used to examine leukocyte adhesion in postcapillary venules on the posterior surface of stomach area on different periods after administration of A. vera. Serum tumor necrosis factor-alpha (TNF-alpha) level was measured in blood collected at the end of experiment by using ELISA technique. The results showed that in H. pylori-infected group on day 8, the leukocyte adhesion was 13.40+/-1.00 cells/100 microm vessel length and the TNF-alpha was 76.76+/-23.18 pg/ml, which increased significantly (p < 0.05), compared with the control group (leukocyte adhesion(control) = 2.54+/-0.6 cells/100 microm vessel length and TNF-alpha(control) = 9.92+/-2.62 pg/ml). Treatment with A. vera reduced the leukocyte adhesion (5.5+/-0.5 cells/100 microm vessel length), and TNF-alpha (26.31+/-6.38 pg/ml) significantly (p < 0.05). In conclusion, H. pylori enhanced leukocyte-endothelium interaction in the posterior stomach area markedly. This enhancement in leukocyte-endothelium interaction could be improved by the treatment of A. vera, associated with reduction in TNF-alpha level.     

幽门螺杆菌感染诱导胃黏膜上皮细胞凋亡及端粒酶逆转录酶表达

目的研究幽门螺杆菌（Hp）根除前后胃黏膜上皮细胞凋亡和端粒酶逆转录酶（hTERT）表达及其与bcl-2、c-myc蛋白表达的关系。方法采用脱氧核糖核酸末端转移酶介导的缺口末端标记（TUNEL）技术及免疫组化染色方法检测39例却Hp性患者根除治疗及21例却阴性患者对症治疗前后胃黏膜上皮细胞凋亡、hTERT、bcl-2、c—myc蛋白表达的变化。结果治疗前却阳性者胃黏膜上皮细胞凋亡指数为16．2％，显著高于却阴性者（P〈0．05）；却阳性者hTERT、c—myc蛋白表达显著高于却阴性者（53．8％比23．8％；53．8％比28．6％，P〈0．05）。邯根除者治疗后胃黏膜上皮细胞凋亡、hTERT及bcl-2、c—myc蛋白表达与根除前相比均显著下降（16．9％比9．0％；59．3％比22．2％；59．3％比25．9％；59．3％比14．8％，P〈0．01），且与却阴性对照组相比差异无统计学意义（P〈0．05）；而邯未根治组及对照组上述指标均无显著变化。治疗前bcl-2、c—myc蛋白与hTERT呈显著正相关，秩相关系数r分别为0．269、0．474（P〈0．05）。结论却感染诱导细胞凋亡及hTERT过度表达，使胃黏膜不稳定性增加。根除却可纠正细胞凋亡失调，使hTERT表达下降或消失，从而降低胃癌发生的可能性。bcl-2及c—myc蛋白对hTERT表达可能具有调控作用。     

Role of N-methyl-N-nitrosourea in the induction of intestinal metaplasia and gastric adenocarcinoma in Mongolian gerbils infected with Helicobacter pylori

BACKGROUND: Progression from intestinal metaplasia to neoplasia has not been demonstrated experimentally. The hypothesis that gastric adenocarcinoma arises from intestinal metaplasia was tested in a Mongolian gerbil model of Helicobacter pylori (H. pylori) infection. METHODS: One hundred and fourteen specific pathogen-free gerbils were divided in five groups. A and D: infected with H. pylori and administered the carcinogen N-methyl-N-nitrosourea (MNU); C and E: received MNU; B: H. pylori, but no MNU. Animals were killed at 41 weeks, stomachs were mapped, and the relationship between metaplasia and cancer was assessed. RESULTS: Intestinal metaplasia occurred more frequently in the H. pylori-infected, MNU-treated gerbils than in those receiving H. pylori inoculation only (P < 0.01). Carcinomas arose only in H. pylori-infected animals receiving MNU (8 well differentiated, 2 poorly differentiated, and 10 signet ring). Intestinal metaplasia occurred more frequently in association with intestinal-type carcinoma. CONCLUSIONS: Intestinal metaplasia and adenocarcinoma arise in stomachs subjected to the same injuries (in this study, H. pylori and MNU). Only two intestinal-type carcinomas were contiguous to intestinal metaplasia; all other tumors developed most commonly at non-metaplastic sites. This suggests that in this animal model H. pylori and MNU induce several phenotypes of gastric cancer, but intestinal metaplasia may be a direct precursor only in a subset of the intestinal-type tumors.     

Effect of acid-suppressive therapy on Helicobacter pylori production of interleukin-8 in the gastric mucosa.

BACKGROUND: Recent studies have shown that acid-suppressive therapy increases the severity of Helicobacter pylori- associated gastritis in the corpus. PURPOSE: To evaluate interleukin (IL)-8 production in the gastric corpus mucosa before and during acid-suppressive therapy in H pylori-infected patients. PATIENTS AND METHODS: Ten patients with reflux esophagitis (five H pylori-positive and five H pylori-negative) were treated with omeprazole 20 mg. Serum gastrin concentrations, H pylori colonization density and mucosal IL-8 levels in the corpus were investigated at entry and two weeks after starting therapy. IL-8 levels were measured by ELISA. The organism density was determined, and scored according to area occupied by the bacterial colonies. The presence of H pylori was assessed by rapid urease testing and histological finding of gastric biopsy specimens. RESULTS: In H pylori-positive patients, concentrations of IL-8 during therapy significantly exceeded those before therapy (36.2+/-6. 8 versus 18.3+/-3.8 pg/mg protein; P<0.05) without altering H pylori density. In H pylori-negative patients, IL-8 levels were similar before and during therapy (6.1+/-2.7 versus 6.3+/-3.0 pg/mg protein). Concentrations of gastrin during therapy were significantly higher than those before therapy in all patients. CONCLUSIONS: The results suggest that acid suppression increases mucosal IL-8 levels in H pylori-infected patients with reflux esophagitis.