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A γ-glutamyl hydroxymethyl rhodamine green probe (gGlu-HMRG) reacts with γ-glutamyltranspeptidase (GGT) and immediately produces fluorescence, is clinically applied for real-time cancers' visualization. Since Helicobacter pylori produces GGT, this study aimed to investigate whether gGlu-HMRG can be used to detect H. pylori infections. A wild-type H. pylori strain and the ggt gene-disrupted mutant were cultured and treated with gGlu-HMRG. This fluorescent probe assay was used to quantify GGT activity of H. pylori ex vivo using gastric biopsy specimens. The H. pylori diagnostic capabilities of the assay were determined from altered fluorescence intensity (FI) values at 5 min (FIV-5) and 15 minutes (FIV-15). Distinct fluorescence was identified in wild H. pylori strain, using gGlu-HMRG, whereas no fluorescence was observed in ggt gene-disrupted mutant strain. On ex vivo imaging of gGlu-HMRG, fluorescence intensity increased markedly with time in H. pylori-positive specimens; however, the H. pylori-negative specimens displayed a slight increase in FI. FIV-5 and FIV-15 differed significantly between H. pylori-positive and -negative specimens. FIV-15 differed significantly between H. pylori-positive and -eradicated group. This assay sensitivity and specificity were 75.0% and 83.3% in the antrum and 82.6% and 89.5% in the stomach body. GGT-activatable fluorescence probe is applicable for rapid diagnosis of H. pylori.

BH3-only protein, Bim, is a pro-apoptotic protein that mediates mitochondria-dependent cell death. However, the role of Bim in Helicobacter pylori-associated gastritis remains unclear. This study aimed to assess the cellular localization of Bim and its possible role in H. pylori-induced gastritis. The study was conducted on biopsy specimens obtained from 80 patients who underwent upper gastrointestinal endoscopy (H. pylori-negative: n=30, positive: n=50). Association between Bim mRNA expression and severity of gastritis was evaluated and the localization of Bim was examined by immunofluorescence. Bim mRNA expression was positively correlated with the degree of gastritis, as defined by the Sydney system. Immunohistochemical analysis confirmed increased Bim expression in H. pylori-infected gastric mucosa compared with uninfected mucosa in both humans and mice. Bim localized in myeloperoxidase- and CD138-positive cells of H. pylori-infected lamina propria and submucosa of the gastric tract, indicating that this protein is predominantly expressed in neutrophils and plasma cells. In contrast, Bim did not localize in CD20-, CD3-, or CD68-positive cells. Bim was expressed in the mitochondria, where it was partially co-localized with activated Bax and cleaved-PARP. In conclusion, Bim is expressed in neutrophils and plasma cells in H. pylori-associated gastritis, where it may participate in the termination of inflammatory response by causing mitochondria-mediated apoptosis in specific leucocytes., (Copyright © 2015 Elsevier GmbH. All rights reserved.)

Background: The gastric lesions of various lymphomas were observed at the cellular level using endocytoscopy., Methods: Endocytoscopy and magnifying endoscopy with narrow band imaging (NBI) were performed in 17 patients with lymphomas of the stomach. The lesions consisted of 7 with low-grade mucosa-associated lymphoid tissue (MALT), 5 with gastric involvement by adult T-cell leukemia/lymphoma (ATLL), 4 with diffuse large B-cell lymphoma (DLBCL), and 1 with peripheral T-cell lymphoma., Results: On conventional endoscopy, 9 were classified as having superficial spreading type, 7 were mass-forming type, and 1 was diffuse infiltrating type. Anti-H. pylori treatment was given in the 7 MALT lymphoma cases. NBI magnification endoscopy invariably showed dilatation or ballooning and destruction of gastric pits and elongation and distortion in microvessels. Endocytoscopy showed mucosal aggregation of interstitial cellular elements in almost all gastric lymphoma cases. The nuclear diversity in size and configuration was exclusively seen in gastric lymphomas other than MALT lymphoma, whereas the nuclei of MALT lymphoma cells were regular and small to moderate in size. Inter-glandular infiltration by lymphomatous cell elements was frequently observed in MALT lymphoma and DLBCL, but it was uncommon in peripheral gastric T-cell malignancies. Endocytoscopy could identify the disease-specific histology, the lymphoepithelial origin, as inter-glandular infiltration of cellular components in MALT lymphoma and the possibly related DLBCL cases. Complete regression (CR) was observed in 2 of the 7 MALT lymphoma patients. In the 2 patients with CR who underwent repeat endocytoscopy, the ultra-high magnification abnormalities returned to normal, while they were unchanged in those without tumor regression., Conclusions: On endocytoscopy, intra-glandular aggregation of cellular components was invariably identified in lymphomas of the stomach. Nuclear regularity in size and configuration may indicate the cytological grade, differentiating the indolent low-grade from aggressive lymphoproliferative diseases. The inter-glandular infiltration seen on endocytoscopy can indicate the lymphoepithelial lesions seen in MALT lymphoma and related DLBCL. Endocytoscopy would be applicable for virtual histopathological diagnosis of different lymphoproliferative disorders and their clinical assessment during ongoing endoscopy.

Vacuolating cytotoxin A (VacA) is one of the important virulence factors produced by H. pylori. VacA induces apoptotic cell death, which is potentiated by ammonia. VacA also causes cell death by mitochondrial damage, via signaling pathways that are not fully defined. Our aim was to determine whether endoplasmic reticulum (ER) stress is associated with VacA-induced mitochondrial dysfunction and apoptosis. We found that C/EBP homologous protein (CHOP), a key signaling protein of ER stress-induced apoptosis, was transcriptionally up-regulated following incubation of gastric epithelial cells with VacA. The effect of VacA on CHOP induction was significantly enhanced by co-incubation with ammonium chloride. Phosphorylation of eukaryotic initiation factor 2 (eIF2)-alpha, which is known to occur downstream of the ER stress sensor PKR-like ER-localized eIF2-alpha kinase (PERK) and to regulate CHOP expression, was also observed following incubation with VacA in the presence of ammonium chloride. Knockdown of CHOP by siRNA resulted in inhibition of VacA-induced apoptosis. Further studies showed that silencing of the PERK gene with siRNA attenuated VacA-mediated phosphorylation of eIF2-alpha, CHOP induction, expression of BH3-only protein Bim and Bax activation, and cell death induced by VacA with ammonium chloride, indicating that ER stress may lead to mitochondrial dysfunction during VacA-induced toxicity. Activation of ER stress and up-regulation of BH3-only proteins were also observed in human H. pylori-infected gastric mucosa. Collectively, this study reveals a possible association between VacA-induced apoptosis in gastric epithelial cells, and activation of ER stress in H. pylori-positive gastric mucosa.

A 37-year-old woman was evaluated at our hospital for a treatment-resistant proctosigmoiditis. Fifteen years previously, ulcerative colitis was suspected and she was cured by steroid therapy. Colonoscopy revealed multiple sessile polyps covered with white exudate from the rectum to the sigmoid colon. Histopathological examination revealed a mucosal surface cover of granulation tissue. Based on these findings, cap polyposis was diagnosed. She underwent Helicobacter pylori eradication therapy, and at 1 month after therapy, her symptoms had improved. We present a case of cap polyposis relapsing 15 years after remission with steroid therapy, and that was improved by H. pylori eradication therapy.

Background and Aims: Chemokine CXC ligand 13 (CXCL13) and CXC receptor type 5 (CXCR5) are constitutively expressed in tertiary lymphoid follicles where the CXCL13/CXCR5 system regulates B lymphocytes homing. In this study, we sought to examine CXCL13 expression in the H. pylori-infected and -uninfected gastric mucosa and to elucidate the implication in the pathogenesis of HAG in humans., Methods: Using endoscopic biopsies taken from the gastric antrum of 29 subjects infected with Helicobacter pylori and 22 uninfected subjects, mucosal CXCL13 mRNA and protein levels were measured by real-time polymerase chain reaction and enzyme-linked immunosorbent assay, respectively., Results: The CXCL13 expression levels were significantly more elevated in H. pylori-positive patients than uninfected ones. The CXCL13 expression levels correlated with the degree of chronic gastritis and bacterial colonization. Immunohistochemistry and in vitro infection assay showed that CXCL13 was not produced by the gastric epithelium, but the α-smooth muscle antigen expressing mesenchymal cells were the possible source of CXCL13 within H. pylori-infected gastric mucosa. CXCR5 immunostaining was seen in the CD20-positive lymphoid aggregates., Conclusions: The enhanced induction of CXCL13 may be involved in the pathogenesis of H. pylori-associated gastritis.

Background/aims: Recent studies have shown that focal active gastritis seems to be the typical gastric pathology in Crohn's disease. The aim of this study was to compare the incidence of focal active gastritis, Helicobacter pylori infection and distribution of gastric mast cells and macrophages in patients with Crohn's disease, ulcerative colitis and H. pylori gastritis without inflammatory bowel disease., Methodology: Patients with histologically confirmed Crohn's disease (n = 25) or ulcerative colitis (n = 25) and control patients without inflammatory bowel disease (n = 25) were included in this study. Biopsy specimens were obtained from the antrum and corpus of each patient, and stained with hematoxylin and eosin and immunostained using antibodies to tryptase (AA1) and CD68. The number of mast cells and macrophages located in the lamina propria was determined., Results: Focal active gastritis was detected in 54% of H. pylori-negative patients with Crohn's disease, but it was not found in patients with ulcerative colitis nor in the control group. The density of mast cells and macrophages in the lamina propria of H. pylori-positive patients was significantly higher than in H. pylori-negative patients in all groups. In the Crohn's disease group, the number of mast cells (antrum; 83 +/- 11, body; 89 +/- 11/mm2) and macrophages (antrum; 94 +/- 22, body; 92 +/- 17/mm2) in the lamina propria of H. pylori-negative patients with focal active gastritis was halfway between that in H. pylori-positive and H. pylori-negative patients. In focal active gastritis, mast cells accumulated at the border of focal active gastritis, whereas macrophages accumulated in the center of such lesions., Conclusions: Our findings indicated that the diagnosis of focal active gastritis, using immunostain for mast cells and macrophages, is the histological hallmark of gastric Crohn's disease. Macrophages might be associated with the formation of focal active gastritis in patients with Crohn's disease.

Background: It has recently been proposed that disturbed gastric adaptive relaxation may play a role in functional dyspepsia (FD). However, the effect of Helicobacter pylori infection, which may be one of multiple factors associated with FD, on gastric relaxation is not clear. The aim of this study was to clarify the influence of H. pylori infection on the responsiveness of smooth muscles of the gastric fundus to agonists or to stimulation of enteric nerves, with particular emphasis on nonadrenergic noncholinergic (NANC) relaxation., Methods: We investigated myogenic responses to carbachol (CCH) and sodium nitroprusside (SNP), and neural responses to electrical field stimulation (EFS), in the absence or presence of atropine and guanethidine, in the tissues of the gastric fundus of H. pylori-infected Mongolian gerbils (MGs)., Results: H. pylori-infected MGs showed typical gastritis, with H. pylori colonization in the antrum and body. The gastric fundus adjacent to the body was composed of thin gastric mucosa with mild inflammation, which was covered with stratified squamous epithelium, and the muscle layer communicated with that of the gastric body. In the gastric fundus, CCH- and SNP-induced responses were not different in controls and H. pylori-infected MGs. In the absence of any antagonists, EFS-evoked contraction tended to be reduced in H. pylori-infected MGs compared with that in control MGs, albeit that the difference was statistically nonsignificant. N(omega)-nitro- l-arginine methyl ester inhibited NANC relaxation in the tissues in both groups. EFS-evoked NANC relaxation remained intact in H. pylori-infected MGs., Conclusions: Mild inflammation in gastric fundus associated with H. pylori infection does not cause enteric neuromuscular dysfunction of the site in vitro.

Objective: Transcription factor NF-kappaB plays a pivotal role in inflammatory responses by up-regulating mRNA expression of bioactive molecules such as chemokines and adhesion molecules. The present study was designed to elucidate the implication of NF-kappaB in Helicobacter pylori-associated gastritis (HAG)., Methods: We examined 41 patients with HAG and 18 H. pylori-negative control subjects. Expression of activated NF-kappaB was studied in situ by immunohistochemistry using alpha-p65 mouse monoclonal antibody (alpha-p65 mAb), which recognizes activated NF-kappaB. To identify the cell types in which NF-kappaB was activated, we performed immunohistochemical analysis using antibodies against vascular endothelial cells, macrophages, and B and T lymphocytes. We also examined the colocalization of activated NF-kappaB with the of intercellular expression adhesion molecule-1 (ICAM-1) on endothelial cells. We measured the levels of NF-kappaB-dependent chemokines including interleukin-8 (IL-8) and monocyte chemoattractant protein-1 (MCP-1), regulated on activation normal T-cell expressed and secreted (RANTES) and macrophage inflammatory protein-1alpha (MIP-1alpha) in antral mucosa by ELISA (ELISA)., Results: Activated NF-kappaB was detected in the nuclei of epithelial cells in antral mucosa, especially of patients with HAG. NF-kappaB positivity index (NF-kappaB PI), representing the percentages of epithelial cells with positive nuclear staining for activated NF-kappaB, was significantly higher in patients with HAG than in H. pylori-negative controls. NF-kappaB PI correlated significantly with histological scores of gastritis. Moreover, activated NF-kappaB was identified in the nuclei of vascular endothelial cells, macrophages, and B lymphocytes within the lamina propria in HAG. Colocalization of activated NF-kappaB with ICAM-1 expression in the same endothelial cells was demonstrated. The IL-8 levels significantly correlated with the NF-kappaB PI., Conclusions: In addition to epithelial cells, macrophages, vascular endothelial cells, and B lymphocytes contained activated NF-kappaB. In these cells, activated NF-kappaB may be involved in the inflammation process in HAG through the up-regulation of chemokines or adhesion molecules.

Background: The transcription factor nuclear factor-kappaB (NF-kappaB) plays a pivotal role in inflammatory responses by upregulating mRNA expression of, for example, proinflammatory cytokines and chemokines. Although in vitro studies have shown that Helicobacter pylori can induce NF-kappaB activation in gastric cancer cell lines, there is little information on cellular localization of NF-kappaB in H. pylori-infected gastric mucosa., Methods: H. pylori-infected and -negative patients with various endoscopic findings were examined. NF-kappaB expression was studied by means of Southwestern histochemistry, a new method of localizing transcription factors. Labeled double-stranded oligo-DNA with specific consensus sequence for the NF-kappaB binding site was reacted with frozen sections from gastric biopsy specimens. We compared mucosal interleukin-8 (IL-8) and IL-1beta levels as measured with enzyme-linked immunosorbent assay with the degree of NF-kappaB expression., Results: NF-kappaB expression was often evident in nuclei of epithelial cells in H. pylori-infected gastric mucosa. The degree of NF-kappaB expression on the epithelium was significantly more severe in H. pylori-infected than in -negative mucosa. The degree of NF-kappaB expression also correlated with mucosal IL-8 levels but not with IL-8., Conclusions: H. pylori infection increases the expression of NF-kappaB in gastric mucosa, suggesting that NF-kappaB is involved in inflammatory responses to H. pylori.

Background: The prevalence of Helicobacter pylori in HIV-positive individuals is significantly lower than in HIV-negative controls. However, its prevalence in individuals infected with human T-cell leukaemia virus type I (HTLV-I), another important member of the human retrovirus family, has not been previously investigated., Objective: To establish the prevalence of H. pylori in HTLV-I-positive individuals in the Nagasaki Prefecture, which is an area endemic for HTLV-I., Methods: We examined sera from 146 HTLV-I-positive individuals with a mean age of 56.7 years, consisting of 45 adult T-cell leukaemia (ATL) patients, 13 HTLV-I-associated myelopathy (HAM) patients and 88 healthy carriers. Serum samples of 292 age- and sex-matched HTLV-I-negative controls were also examined. Serum anti-H. pylori immunoglobulin (Ig) G antibody was examined using an enzyme-linked immunosorbent assay kit. Twenty-eight HTLV-I-positive patients were examined endoscopically, assessed for H. pylori by culture, histology and CLO test using gastric biopsy specimens, and gastritis in these patients was also graded histologically., Results: The seroprevalence of H. pylori was 48% in HTLV-I-positive individuals versus 64% in HTLV-I-negative controls (P < 0.01). In the three HTLV-I-positive groups, ATL patients and carriers had significantly lower seroprevalence of H. pylori than the HTLV-I-negative controls (P < 0.05). Assessment of H. pylori using gastric biopsy specimens also showed a significantly lower prevalence of H. pylori infection in HTLV-I-positive patients than controls (46% versus 70%, P < 0.05). Histological examination showed a significantly higher degree of activity, inflammation and glandular atrophy in the antrum and corpus in H. pylori-positive patients compared to H. pylori-negative patients. H. pylori-positive patients with HTLV-I infection had a more severe degree of glandular atrophy in the corpus than H. pylori-positive controls without HTLV-I infection., Conclusion: We have found a reduced prevalence of H. pylori in HTLV-I-positive individuals. Whatever the explanation, infection with HTLV-I does not predispose to the risk of H. pylori infection.

Background: Although the pathogenesis of gastric xanthoma (GX) remains unclear, an association of GX with atrophic gastritis has been reported. Helicobacter pylori is closely related to atrophic gastritis. The aim of this study was to investigate the relationship among GX, H. pylori, and atrophic gastritis., Methods: Sixty-seven patients with GX were assessed for H. pylori infection by serum anti-H. pylori IgG antibody, in addition to the rapid urease test, culture, and histologic examination using biopsy specimens of the antrum and corpus. The findings were compared with 67 age- and sex-matched control subjects without GX. The distribution of atrophic gastritis was assessed endoscopically. The severity of atrophic gastritis was determined endoscopically and histologically. Serum pepsinogen (PG) levels were also measured. Immunohistochemical staining of GX samples for H. pylori antigen was performed. H. pylori clinical isolates from patients with GX and controls were assessed for cagA by means of polymerase chain reaction., Results: The prevalence of H. pylori was significantly higher in patients with GX than in controls (94% and 72%, respectively). A significantly more extensive atrophic gastritis was present in patients with GX, as determined endoscopically and histologically, than in controls. Serum PG-I levels and the PG-I/PG-II ratio were significantly lower in the GX group than in the control group. H. pylori antigens were frequently identified in the cytoplasm of xanthoma cells in H. pylori-positive specimens of GX (54 of 63 specimens, 86%), whereas no immunoreactivity for H. pylori antigens was detected in H. pylori-negative specimens of GX. There was no significant difference in the positive rate of cagA between the two groups., Conclusions: Our results identified a close relationship among H. pylori infection, GX, and atrophic gastritis. A proportion of GXs may be provoked by H. pylori infection.