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T-593 (osutidine, CAS 140695-21-2) is a new anti-ulcer agent that consists of two enantiomers, (+) (R) T-593 and (-)-(S)-T-593. The present study was designed to investigate the effects of T-593, (+)-(R)-T-593 and (-) (S) T-593 on ethanol-induced gastric damage in rats. Rats were given intraperitoneal administration of vehicle, racemic T-593, (+) (R)-T-593 or (-) (S)-T-593. 30 min later, the rats intragastrically received a 1 ml solution of 40 % ethanol, and 30 min thereafter, they were sacrificed for assessment of gastric damage. Gastric hemodynamics were assessed by reflectance spectrophotometry and laser Doppler flowmetry during the experiment. Gastric damage was significantly suppressed by racemic T-593 in a dose-depenent manner. While 60 mg/kg of (+)-(R) T-593 and (-)-(S) T-593 also suppressed ethanol-induced gastric injury, the same dose of racemic T-593 exerted the most potent anti-ulcerative activity. Both (+) (R) T-593 and racemic T-593 in creased gastric mucosal blood flow and abolished gastric mucosal blood flow stasis induced by 40 % ethanol. Although (-) (S) T-593, which antagonizeshist amine H 2 -receptors, exerts an anti-ulcerative effect, (+) (R) T-593 also protects the gastric mucosa from ethanol induced injury, possibly by influencing gastric mucosal hemodynamics. Thus racemic T-593 may protect the gastric mucosa by antagonizing H 2 receptors and by enhancing gastric circulation in rats.

Interstitial cells of Cajal (ICC) play important roles in autonomic gut motility as electrical pacemakers and mediators of neural regulation of smooth muscle functions. Insufficiency of ICC has been reported in a wide range of gut dysmotilities. Thus, restoration of ICC may be a therapeutic modality in these diseases. Here we provide evidence that transplanted bone marrow (BM) cells can restore gut dysmotility in part via transdifferentiation to ICC. Bone marrow cells obtained from Kit insufficient W/W v mice or syngeneic GFP-transgenic mice with wild-type Kit were transferred to W/W v recipients. Whole gut transit time and gastric emptying were examined 5 and 6 weeks after BM transplantation, respectively, and ICCs were identified in whole mounts, frozen sections and transmission electron immunomicroscopy of the gut smooth muscle layers using specific antibodies. Transplantation of wild-type BM into W/W v mice significantly improved whole gut transit time and gastric emptying. Fluorescent immunohistochemistry revealed GFP+Kit+ cells in the myenteric plexus, deep muscular plexus, and submucosal plexus smooth muscle layers of the stomach, small intestine, and colon, respectively. In the whole mounts, GFP+Kit+ cells were bipolar and spindle shaped, and transmission electron immunomicroscopy showed GFP+ cells rich in mitochondria and endoplasmic reticulum between gut smooth muscle layers, suggesting the presence of GFP+ cells with morphological characteristics of ICC. These results suggest that BM contains cells that may incorporate into ICC networks and improve dysmotility in W/W v mice. Thus, BM transplantation may become to a new therapeutic modality for gut dysmotilities due to ICC insufficiency.

Background: The involvement of bone marrow (BM) in tumor-stroma reactions or tumor development has not been examined in a cancer allograft, which has otherwise been appropriate for assessing therapeutic modalities. We investigated the fate of BM-derived cells in colon cancer allografts and liver metastases in mice. Methods: C57BL/6 mice were irradiated and rescued by BM transplantation from green fluorescent protein (GFP)-transgenic mice. MC38 colon cancer cells were stably transfected with the pDsRed gene in order to identify tumor cells by fluorescence. These were inoculated into the mice to generate subcutaneous allografted tumors or liver metastases. The tumors were observed under confocal microscopy and fluorescent immunohistochemistry to determine the fate of tumor versus BM-derived cells. Results: GFP-positive (GFP+) cells were consistently identified as vimentin+, α-smooth muscle actin (αSMA)+, spindle-shaped stromal cells in both the subcutaneous tumors and the liver metastases. GFP+ cells of leukocyte lineage also infiltrated the tumors. Neither GFP+ CD31+ endothelial cells nor GFP+ DsRed+ cells were detected in the tumor. Conclusions: BM-derived cells frequently and consistently infiltrated the tumor allografts and metastases as interstitial cells and leukocytes. Cells derived from the fusion of BM cells and tumor cells were not observed. This model may be appropriate for the clarification of the effects of anticancer therapies and the study of BM-derived cells in tumor–host interactions.

Musashi-1 (Msi-1), a mammalian neural RNA-binding protein, has been found to play important roles in the maintenance of stem cell states and differentiation in neural stem cells and mouse intestinal cells. We explored Msi-1 expression and its potential implications in the human stomach. Reverse transcription-PCR revealed that Msi-1 levels were significantly higher in the corpus than in antrum in Helicobacter pylori (Hp)-infected patients (n = 49) (P < 0.00001) in paired biopsy samples, whereas they were low and comparable at these two sites in Hp-negative patients (n = 31). Msi-1 levels were significantly higher in the Hp-infected corpus (n = 107) than in the Hp-negative corpus (n = 69) (P < 0.00000001). Immunohistochemistry and in situ hybridization demonstrated that Msi-1 was expressed at the base and neck/isthmus region of the fundic glands and partly co-expressed in Ki-67-positive cells in the corpus and antrum. Msi-1 levels correlated with Hp density (P < 0.05). Based on these results, we conclude that Hp infection strongly induces Msi-1 in the corpus. Given its expression in dividing cells, Msi-1 may modulate the state of gastric progenitor cells.

Background and Aim: Helicobacter pylori (H. pylori)-induced chronic atrophic gastritis is a high-risk factor for gastric cancer. Immune responses to H. pylori are involved in gastric mucosal inflammation, and might affect clinical outcome, including the development of gastric cancer. The present study examines the significance of gene polymorphisms of various cytokines in the development of gastric cancer following H. pylori infection. Methods: One hundred Japanese non-cardia gastric cancer patients and 93 dyspeptic patients as controls were enrolled in the study (age range 50–75 years). All patients were positive for H. pylori. Genomic DNA was extracted from peripheral whole blood leukocytes, and we comprehensively analyzed 207 single nucleotide polymorphisms (SNP) in 11 cytokine genes; interleukin (IL)-1α, IL-1β, IL-1 receptor antagonist (RN), IL-4, IL-4R, IL-8, IL-10, IL-12, TNF-α, TNF-β, and IFN-γ, using either invader assay (163 SNP), direct sequencing (22 SNP), or PCR-restriction fragment length polymorphism (22 SNP). Results: Among the 207 SNP examined, the IL-4 gene diplotypes (984 and 2983 AA/GA) had a significant negative association with gastric cancer development (odds ratio =0.3, 95% confidence interval =0.1–0.9). When we adopted the dyspeptic patients over 66 years of age as the controls, the IL-1RN gene diplotypes (−1102 and 6110 CG/GA) also had a significant negative association (odds ratio =0.2, 95% confidence interval =0.1–0.7). Conclusion: A comprehensive analysis of 207 SNP of 11 cytokine genes revealed that variations in IL-4 and IL-1RN genes are negatively associated with the risk of developing gastric cancer following H. pylori infection. Distinct host cytokine responses in the gastric mucosa might have a role in H. pylori-induced carcinogenesis.

Bone-marrow-derived cells (BMDCs) transdifferentiate into various types of gastrointestinal cells. The precise transdifferentiation of BMDCs in gut regeneration, however, is controversial. In this study, we examined the transdifferentiation of BMDCs in the regeneration of damaged colonic epithelia. Lethally irradiated wild-type female mice (C57BL/6) were rescued by bone marrow transplantation from male green fluorescent protein transgenic mouse donors. Chronic colitis was induced by administering 3% dextran sulfate sodium (DSS) in the drinking water for 5 days on day 28 after the bone marrow transplantation. The mice were killed on day 25 after DSS administration. BMDC phenotypes were examined by confocal microscopy and fluorescence immunohistochemistry. BMDCs were frequently observed in the vimentin-positive colonic interstitial cells, which also expressed α-smooth muscle actin and had a spindle-like morphology, but did not express leukocyte common antigen. Green-fluorescent-protein-positive cells were rarely or less frequently found in Ki-67-positive proliferating cells, cytokeratin-positive epithelial cells, or CD31-positive endothelial cells. BMDCs frequently transdifferentiated into subepithelial myofibroblasts and fibroblasts, and often continued to reside in the colonic subepithelia after the experimental colitis had healed. In conclusion, our data indicate the fate of BMDCs, which might be involved in the healing process of the colon after DSS-induced colitis. Our data show that BMDCs contribute to colonic interstitial cells after the colitis has healed. Understanding the fate of BMDCs may be important for stem cell therapy by BMDCs.

Cyclooxygenase-2 (COX-2) inhibitors are effective chemopreventive agents against colorectal cancers. For treatment of advanced cancers, combination of COX-2 inhibitors and chemotherapy has been attempted, but the results are still controversial. In the present study, the effects of the COX-2 inhibitor celecoxib on the anticancer potential of chemotherapy, and its mechanisms of action were investigated in point of the angiogenesis, using an advanced cancer model in mice. BALB/c mice were inoculated with colon 26 cells. After the allograft grew up to 5 mm in diameter, the animals received celecoxib, 5FU, or a combination of 5FU and celecoxib (5FU/celecoxib). After 21-days of the treatment, 5FU/celecoxib significantly inhibited the tumor growth and the tumor vessel density compared with the other groups. Celecoxib, 5FU or 5FU/celecoxib significantly suppressed the VEGF content in tumor tissues. 5FU/celecoxib also enhanced IFN-γ levels in tumor tissue, which could be involved in the potent antitumor effects of 5FU/celecoxib. This hypothesis was proven, because in IFN-γ knockout (IFN-γ−/−) mice, the inhibitory effects of 5FU/celecoxib on angiogenesis and tumor growth were significantly impaired compared with that in wild type mice. These results suggest that celecoxib enhances the antitumor effect of 5FU against an advanced colon cancer model by suppressing angiogenesis. In addition to VEGF, IFN-γ has pivotal roles in tumor suppression induced by celecoxib. © 2007 Wiley-Liss, Inc.

Background and aim It is known that cyclooxygenase (COX)-2 is over expressed in gastrointestinal neoplasia and Helicobacter pylori (H. pylori) infection is causally linked to gastric cancer. The present study aimed to elucidate the effects of H. pylori on COX-2 expression and prostaglandinE(2) (PGE(2)) production in a gastric epithelial cell line derived from normal rat gastric mucosa (RGM1). Method H. pylori water extracts were prepared from a supernatant of the H. pylori suspension in distilled water. RGM1 cells were cultured with H. pylori water extracts at the final concentration of 2.5, 5, 10 microg/mL for 24 h. For the time sequence study, RGM1 cells were cultured with 10 microg/mL H. pylori water extracts for 0, 6, 12, 24 and 48 h. COX-1 and COX-2 expression in the RGM1 cells was analyzed by western blotting. The levels of PGE(2) in the cultured media were measured by enzyme immunoassay. Results H. pylori did not affect COX-1 expression; whereas COX-2 expression increased by six-fold at 24 h after incubation of RGM1 cells with 10 microg/mL H. pylori water extracts. The increase in COX-2 expression was evident after 12 h of incubation; reached a peak at 24 h and declined at 48 h. H. pylori dose dependently increased COX-2 expression and PGE(2) synthesis in RGM1 cells. Conclusion H. pylori induces COX-2 expression and increases PGE(2) synthesis in RGM1 cells in vitro. These results indicate that H. pylori-associated gastric carcinogenesis may depend on COX-2 expression.

A 39-year-old woman was referred to Osaka Police Hospital and admitted for surgical treatment of gastric cancer. Barium upper gastrointestinal study and endoscopic examination showed a 3.0 × 3.0 cm depressed lesion in the greater curvature of the middle corpus. An unusual miliary pattern resembling ‘goose flesh’ was observed endoscopically in the antrum. Biopsy specimens from the tumor showed poorly differentiated adenocarcinoma, and specimens from the antrum showed many lymphoid follicles with a germinal center. Rapid urease test and histological tests (Giemsa stain) for Helicobacter pylori were both positive. Early gastric cancer with nodular gastritis (NG) was diagnosed and a partial gastrectomy was performed. Histological examination of the resected specimen showed a stage I tumor consisting mainly of signet-ring cell carcinoma restricted to the mucosa. Postoperatively H. pylori eradication therapy was performed and proved to be successful. One year after eradication therapy, endoscopy with biopsy showed no recurrence of gastric cancer and the remarkable regression of antral NG.

Bone marrow contains hematopoietic stem cells, nonhematopoietic mesenchymal stem cells, and several precursor cells for osteoblasts, chondrocytes, adipocytes, myocytes, hepatocytes, and even neural cells. Research findings indicate that multipotent stem cells in the adult body may be used to recover the lost functions of damaged tissues. This study examined the involvement of bone marrow-derived cells in the regeneration of the stomach after experimental gastric ulcers were produced in rats. We transplanted the bone marrow of transgenic rats that expressed green fluorescence protein (GFP) throughout the body. Twenty-one days after the bone marrow transplantation (BMT), gastric ulceration was induced, using absolute ethanol. Control animals received saline. After various observation periods, rats harboring GFP-positive bone marrow-derived cells were killed, and the tissues were removed and processed to prepare paraffin-embedded sections. Cells expressing GFP were identified by conventional immunohistochemistry, using anti-GFP antibody. To identify whether cells expressing GFP were epithelial cells or interstitial cells such as fibroblasts, serial sections were examined with anti-cytokeratin antibody or anti-vimentin antibody, respectively. Furthermore, to confirm that cells expressing GFP were epithelial cells or interstitial cells, we used double-staining analysis with anti-GFP antibody or anti-cytokeratin antibody, respectively. GFP-positive, bone marrow-derived cells were found in the cytokeratin-positive gastrointestinal epithelium, as well as among vimentin-positive interstitial cells. Interestingly, the proportions of GFP-positive, cytokeratin-positive epithelial cells and vimentin-positive interstitial cells were significantly greater in the ethanol-treated damaged stomachs than in the saline-treated controls. The present study clearly demonstrates that bone marrow-derived cells are involved in the regeneration of the stomach after ethanol-induced ulcers in rats.

Bone marrow is reported to contain hematopoietic stem cells and other adult somatic stem cells that have phenotypes of cells composing tissues other than bone marrow. To explore the implication of bone marrow-derived cells in the treatment of inflammatory bowel diseases, experimental colitis was induced in wild-type rats after transplantation of bone marrow from transgenic rats expressing green fluorescence protein (GFP). Chronic colitis was induced 21 days later using 30 mg 2,4,6-trinitrobenzenesulfonic acid (TNBS). Control rats received saline. At 28, 56, and 224 days after TNBS administration, rats were euthanized, and tissues were removed and processed for paraffin-embedded sections. Cells derived from bone marrow were identified by immunohistochemistry using anti-GFP antibody. To identify the phenotypes of the cells expressing GFP, we conducted serial-section analysis and double-staining analysis using antibodies against cytokeratin (epithelial cells) or vimentin (interstitial cells). In the present study, GFP-positive, bone marrow-derived cells occupied 37.6% and 4.25% of the colonic epithelium at 28 days and 56 days after the induction of TNBS-colitis, respectively. Also, significant amounts of mucosal and submucosal interstitial cells were derived from the bone marrow. These findings showed that a large amount of bone marrow-derived cells were involved in regeneration of the colon after experimental colitis in rats.

Background: Biliary tract cancer is a highly fatal disease with poor prognosis, but the aetiology is poorly understood. Aim: We aimed to identify Helicobacter bilis infection in the gallbladder in patients with biliary tract disease. Methods: Archival gallbladder specimens from 34 patients (14 males and 20 females) with an average age of 61.4 ′ 12.2 years (mean ′ SE) were retrieved, consisting of 11 cases of gallbladder cancer, three of bile duct cancer, 16 of cholecystolithiasis and four of pancreatic cancer. DNA was extracted and nested PCR using primers specific for 16S rRNA of H. bilis was performed. Results: Amplification was observed in 3 of 11 gallbladder cancer cases (27.2%) and one of three cases with biliary duct cancer (33.3%). In total, four of 14 cases with biliary tract cancer were positive for H. bilis (28.6%). In addition, the presence of H. bills was shown in two of 16 cases (12.5%) with cholecystolithiasis. Notably, although the number of cases examined was small, none of the four cases with pancreatic cancer showed the presence of H. bilis infection in the gallbladder without apparent abnormalities. Conclusion: H. bilis infection may play a role in biliary tract disease, particularly in biliary tract cancer.

Background and Aim: We examined the incidence of symptomatic gastroesophageal reflux disease (GERD) in patients with type 2 diabetes mellitus (DM). Methods: Patients comprised those with DM or chronic hepatitis C (CHC) who visited Osaka Prefectural General Hospital in the same study period. Reflux symptoms were examined using a self-administered questionnaire. A total score of 4 or more was considered an indication of symptomatic GERD. Disease duration, hemoglobinA1c and diabetic complications were assessed. Results: Patients with DM (n = 241) or CHC (n = 42) were recruited for the study. Of the 241 patients with DM, 100 (41.5%) reported experiencing upper gastrointestinal symptoms, whereas only 9 of 42 (21.4%) patients with CHC reported upper gastrointestinal symptoms (P = 0.0137). Sixty-one patients (25.3%) with DM had reflux symptoms but only four patients (9.5%) with CHC reported reflux symptoms. The incidence of symptomatic GERD was significantly higher in patients with DM than in those with CHC (P = 0.0219). Patients with DM for less than 5 years had a 2.4-fold higher incidence of GERD than patients with CHC. The incidence tended to rise with increased disease duration. Patients with diabetic complications reported reflux symptoms more frequently. The incidence decreased, however, in DM patients who had these conditions for more than 16 years. Conclusions: Type 2 diabetes mellitus is a risk factor for symptomatic GERD. In DM patients, use of oral hypoglycemic agents, body mass index, disease duration and the quality of diabetic control influenced the incidence of GERD. © 2004 Blackwell Publishing Asia Pty Ltd

Background and Aim: Little is known about the clinical efficacy of cotherapy of ecabet sodium, a mucoprotective agent, and a histamine H2-receptor antagonist. The aim of the present study was to assess its additive benefit in combination with cimetidine for gastric ulcer. Methods: In this prospective randomized study, after gastric ulcer was confirmed by endoscopy, 200 patients in 47 hospitals received either ecabet sodium 1 g b.i.d and cimetidine 400 mg b.i.d. (EC), or cimetidine 400 mg b.i.d. alone (C) for 8 weeks. Healing was examined by endoscopy at 4 and 8 weeks. Results: Of the intention-to-treat (ITT) population (EC, 103; C, 97), 181 patients comprised the per protocol (PP) analysis (EC, 93; C, 88). At 4 weeks, healing rates were significantly higher in the EC group (60%) than in the C group (36%) ( p

Chronic inflammation has been reported to accelerate neoplasmas in gastrointestinal tract. Certain bacteria including Helicobacter pylori directly interact with host cells, induce proinflammatory cytokines and stimulate production of free radicals. Free radicals cause mutations in target cells so that neoplastic clones are established. Accumulation of such genetic alterations may cause malignant transformation of some established clones. In addition, inflammatory alterations may promote growth, expansion and invasion of gastrointestinal epithelial cells. The latter changes caused by inflammation may occur even without further genetic mutations or epigenetic alterations, and therefore may be categorized as 'perigenetic alterations' of neoplastic cells. For an example, tumour necrosis factor α (TNF-a) plays pivotal roles not only in the reduction but also in the growth, invasion and metastases of certain neoplasmas. Our studies show that TNF-a increases intracellular radical production, degradates E-cadherin/β-catenin complex and promotes dispersion and migration in epithelial cells transformed with an activated src oncogene (v-src). These data indicate that an inflammatory cytokine induces the malignant potential of src-activated neoplastic cells. Interestingly, TNF-a also induced these phenotypic changes in nonmutated cells whose c-Src was activated by TGF-α, suggesting that the invasive properties of the cell were not necessarily related to gene mutation. Furthermore, certain radical scavengers suppressed the invasive phenotype of the cells. These results indicate that perigenetic alterations are an important target of pharmacological intervention of carcinogenesis.

Dieulafoy's ulcer is a rare form of gastrointestinal bleeding. Although the original descriptions and early reports were of lesions in the proximal stomach, similar lesions have subsequently been reported in the esophagus, duodenum, jejunum, colon and rectum. A 55-year-old man was admitted to hospital for a sudden acute headache. On admission he was conscious, and had severe occipitalgia due to a subarachnoid hemorrhage demonstrated on computed tomography. On the fifteenth hospitalization day, he passed fresh blood together with stool, followed by several further episodes of massive hematochezia. Although no lesion was found by gastroduodenoscopy, colonoscopy revealed fresh blood and clots in the rectum. No obvious source of hemorrhage could be identified until careful irrigation revealed pulsatile bleeding from a protuberant vessel (2 mm in size) in the rectum 5 cm from the anal verge. The patient underwent an endoscopic hemostasis in which the pulsatile vessel was easily sutured with seven clips. The patient did not have another episode of bleeding. The finding of Dieulafoy's ulcer in the elderly-patient group suggests that sclerotic changes to the artery may be associated with this type of rectal ulcer.

Forbidden CD4 + ββ T cells, which produce interleukin (IL)-4 predominantly, are a pathological subset in the development of colitis in T-cell receptor α chain (TCRα)-deficient mice. Stimulation of naive CD4 + T cells with IL-4 induces Th2 development via the activation of signal transducers and activators of transcription (STAT) 6. In the present study, we had found that IL-4 enhanced the expression of STAT6 in CD4 + ββ T cells isolated from TCRα −/− mice with colitis, suggesting that the IL-4 signal in the CD4 + ββ T cells is mediated by STAT6. To further investigate the role of STAT6 in the development of colitis induced by TCRα deficiency, we generated double-deficient mice by crossing TCRα −/− mice and STAT6 −/− mice. Surprisingly, STAT6 deficiency did not result in decreased severity of colitis in TCRα −/− mice. STAT6-deficient CD4 + ββ T cells produced IL-4 and intraperitoneal injection of anti-IL-4 monoclonal antibody in the nondiseased TCRα −/− and STAT6 double-deficient mice prevented the colitis formation, thus indicating that the cells differentiated into the Th2 phenotype have the ability to mediate the development of the colitis in the absence of STAT6.

Gastrin, PGs, and growth factors have important roles in maintaining gastrointestinal mucosal integrity. Cyclooxygenases (COX-1 and COX-2) are the key enzymes involved in PG synthesis. This study aimed to clarify the mechanisms of gastric mucosal protection by gastrin. Fasted rats were administered subcutaneous gastrin 17 with or without gastrin receptor antagonist YM022 pretreatment. Heparin-binding epidermal growth factor-like growth factor (HB-EGF) and COX-2 expression were examined using Western blot analysis. Another series of experiments investigated 1) PGE2 levels in gastric mucosa, 2) the protective action of gastrin against gastric damage by acidified ethanol, 3) the effects of a specific HB-EGF-neutralizing antibody on gastrin-induced COX-2 expression, and 4) the effects of a specific COX-2 inhibitor NS-398 on PGE2 synthesis and the mucosal protection afforded by gastrin. Gastrin dose-dependently increased HB-EGF, COX-2 expression, and PGE2 levels and reduced gastric damage. However, pretreatment with YM022 dose-dependently abolished such effects of gastrin. A specific HB-EGF- neutralizing antibody and an EGF receptor inhibitor decreased gastrin-induced COX-2 expression. NS-398 blocked gastrin-induced PGE2 synthesis and mucosal protection. In conclusion, this study demonstrates that gastrin enhances gastric mucosal integrity through COX-2, which is partially mediated by HB-EGF, and PGE2 upregulation in rats.

Background: Although proton pump inhibitors (PPI) and H2-receptor antagonists (H2-RA) are routinely used in the treatment of reflux esophagitis (RE), no consensus has been reached yet as to whether the first-choice drug should be PPI or H2-RA. In this study, the effects of omeprazole (OMP) and famotidine (FAM) on RE have been examined in a randomized comparative study. Methods: Protocols of OMP 20 mg once daily or FAM 20 mg twice daily for 8 weeks were allocated to 56 cases with RE at random, using an envelope randomization method. Their efficacy in achieving healing was examined endoscopically and a relief from subjective symptoms was compared. Results: Patient's background such as sex, age, recurrence, hiatal hernia, smoking and drinking habits, and complications, and the severity of esophagitis at the time of enrolment were not significantly different between the two groups. Healing in the OMP group and the FAM group was observed in 72 and 32% (P = 0.025) of patients at week 4 and 95 and 53% (P = 0.003) of patients at week 8, respectively. Subjective symptoms were relieved more frequently in the OMP group (at week 2, 67% compared with 29%, P = 0.005; at week 4, 95% compared with 55%, P = 0.009), but this superiority was not significant at week 8 (94% compared with 65%, P = 0.085). No serious adverse events occurred. Conclusions: Omeprazole provided quicker healing and a greater relief from subjective symptoms than did FAM in the treatment of RE, and was considered more suitable as a first-choice drug. © 2002 Blackwell Publishing Asia Pty Ltd

Background and Aims:Helicobacter pylori infection is associated with peptic ulcers; however, it is unclear whether the bacterium delays ulcer healing. We investigated the influence of H. pylori on ulcer healing in mice. We also examined the influence of H. pylori infection on angiogenesis. Methods: An acetic acid ulcer was made in male BALB/c mice. Three days later (day 0), the animals were inoculated with H. pylori SS1 strain. The healing process of the ulcer was examined macroscopically and microscopically on days 0, 6 and 9. The index of angiogenesis was also determined using carmine dye injection. Results: On day 0, angiogenesis began at the ulcer margin while the mucosal epithelia had not yet regenerated. On days 6 and 9, angiogenesis and epithelial regeneration developed and ulcer size reduced. These phenomena were significantly suppressed in mice infected with H. pylori. Conclusion:Helicobacter pylori infection significantly suppressed angiogenesis and delayed ulcer healing. These results indicate that H. pylori plays an important role in ulcer healing. © 2002 Blackwell Publishing Asia Pty Ltd

Background & Aims: Src activation is correlated with progression of colorectal cancer (CRC). CRCs accompanied by ulcerative colitis, chronic inflammation in the colon, often have elevated Src activity, and ulcerative colitis–related CRCs are more likely to become invasive, whereas Ras activation is rarely associated with this disease. The aim of this study was to investigate the effects of a proinflammatory cytokine, tumor necrosis factor α (TNF-α), on the invasive properties of epithelial cells constitutively expressing activated Ras or Src. Methods: A cell line derived from intestinal epithelia was transfected with a v-src – or v-H-ras –expressing vector. The effect of TNF-α on morphologic changes in colonies cultured in soft agar was determined. Src protein kinase activity, peroxide production, E-cadherin expression levels, and the phosphorylation status of β-catenin and E-cadherin were determined. The invasive potential of these cells was determined by measuring cell motility and using an in vitro invasion assay. Results: TNF-α altered the colony morphology of src-, but not ras-expressing cells. TNF-α increased peroxide production, leading to Src protein expression as well as Src activity in src transfectants. Activation of Src by TNF-α led to reduced E-cadherin levels and enhanced invasion of src transfectants. Pyrrolidine dithiocarbamate and herbimycin A inhibited these effects. Conclusion: These results indicate that Src kinase activation enhances the response of epithelial cells to TNF-α leading to increased invasion through mechanisms that involve production of reactive oxygen intermediates. GASTROENTEROLOGY 2002;122:331-339

Transforming growth factor alpha is one of the most potent growth factors for gastrointestinal epithelium. In this study, we examined the roles of cyclooxygenase-2 on proliferation and morphogenesis of RGM1 rat gastric epithelial cells after stimulation with transforming growth factor alpha in vitro, RGM1 cells increased expression of cyclooxygenase-2 messenger RNA 20-60 min after stimulation with transforming growth factor alpha. Transforming growth factor alpha stimulated [3H]thymidine incorporation and tubulogenesis of RGM1 cells in collagen matrix, both of which were significantly suppressed by treatment with a cyclooxygenase-2 specific inhibitor, NS-398 or cyclooxygenase-2 antisense oligonucleotide. Both of the treatment lowered prostanoid production by enzyme immunoassay. The transforming growth factor alpha-induced expression of cyclooxygenase-2 is followed by cell proliferation and development of tubular morphology of RGM1 gastric epithelial cells. Treatment with cyclooxygenase-2 inhibitor and cyclooxygenase-2 antisense oligonucleotide suppressed these responses induced by transforming growth factor alpha suggesting the involvement of cyclooxygenase-2 in proliferation and morphogenesis in gastric mucosal epithelium.

T cell receptor alpha chain-deficient (TCR-alpha(-/-)) mice are known to spontaneously develop inflammatory bowel disease (IBD). The colitis that develops in these mice is associated with increased numbers of T helper cell (Th)2-type CD4(+)TCR-betabeta (CD4(+)betabeta) T cells producing predominantly interleukin (IL)-4. To investigate the role of these Th2-type CD4(+)betabeta T cells, we treated TCR-alpha(-/-) mice with anti-IL-4 monoclonal antibody (mAb). Approximately 60% of TCR-alpha(-/-) mice, including those treated with mock Ab and those left untreated, spontaneously developed IBD. However, anti-IL-4 mAb-treated mice exhibited no clinical or histological signs of IBD, and their levels of mucosal and systemic Ab responses were lower than those of mock Ab-treated mice. Although TCR-alpha(-/-) mice treated with either specific or mock Ab developed CD4(+)betabeta T cells, only those treated with anti-IL-4 mAb showed a decrease in Th2-type cytokine production at the level of mRNA and protein and an increase in interferon gamma-specific expression. These findings suggest that IL-4-producing Th2-type CD4(+)betabeta T cells play a major immunopathological role in the induction of IBD in TCR-alpha(-/-) mice, a role that anti-IL-4 mAb inhibits by causing Th2-type CD4(+)betabeta T cells to shift to the Th1 type.

Recent epidemiological studies indicate that there is reduced risk of all digestive carcinomas in patients who regularly take nonsteroidal anti-inflammatory drugs (NSAIDs) such as aspirin. Cyclooxygenase (COX) is a target enzyme for NSAIDs. We investigated the role of two isoforms, COX-1 and COX-2, in the development and metastasis of gastric carcinoma.Fifteen gastric carcinoma tissue specimens and accompanying adjacent mucosa specimens were obtained from surgical resections. COX-1 and COX-2 protein expression were evaluated using Western blotting analysis, and their relative band densities were semi quantified using standard densitometry scanning techniques.Compared with paired noncancerous specimens, COX-2 was overexpressed in 10 of 15 carcinoma tissue specimens (66.7%). Overall, COX-2 levels in carcinoma tissue were significantly higher. Two early carcinomas (confined to the mucosa and submucosa) and three of 13 advanced carcinomas (extended below the submucosa into the muscular wall) had weak or similar COX-2 expression in paired tissue specimens. COX-2 overexpression in tumors significantly correlated with tumor invasion into the lymphatic vessels in the gastric wall and metastasis to the lymph nodes. Furthermore, the stage grouping in the TNM classification significantly correlated with COX-2 overexpression. In contrast, COX-2 overexpression did not correlate with histopathological grading, surface size, and venous vessel invasion of the tumors. COX-1 levels were similar between paired tissues.COX-2 overexpression might enhance lymphatic invasion and metastasis in patients with gastric carcinoma, implicating a poor prognosis. Therefore, the use of COX-2-specific inhibitor to suppress lymphatic metastasis in humans should be investigated.

Background: Biopsy samples may be erroneously mixed up during endoscopic examination. Although the conventional cassette which we previously reported was opaque before the fixation, it was not hard to confirm biopsy specimens in the cassette after closing the cover because the cover of conventional cassettes used resin which was not resistant against alcohol and xylene, resulting in non-transparent resin. Materials: We developed a new safety cassette for biopsy samples with a transparent cover in collaboration with ANQ (ANQ W-BioTM; ANQ, Ashiya, Japan), and also developed an original plate that allows confirmation of the number of biopsy specimens. Results: Using the new cassettes, we can easily confirm the presence and numbers of biopsy specimens without opening the cover. It is not necessary to open the cover until we fix the biopsy specimens with paraffin. With this newly developed cassette, one can prevent the loss of biopsy specimens, as well as mix-ups, facilitating work efficiency. Conclusion: We developed the new cassette for biopsy samples during endoscopic examination. With the cassette, we were able to confirm the number of biopsy specimens, and reconfirm them at each phase of processing. This new type of cassette for biopsy samples is useful and convenient in comparison to the conventional cassette.

Interstitial cells of Cajal (ICC) are believed to initiate the basic contractile activity of the gastrointestinal tract. Interstitial cells of Cajal express c-kit receptor tyrosine kinase and are deficient in Ws/Ws mutant rats with a small deletion of the c-kit gene. As Ws/Ws rats show remarkable bile reflux to the stomach, the contraction pressure of the pylorus was compared between Ws/Ws and control +/+ rats. The contraction pressure of the pylorus was measured using a microtransducer, which was inserted through a pin-hole in the anterior wall of the stomach under anesthesia. The magnitude of bile reflux was estimated by measuring the content of bile acids in the stomach. The c-kit messenger RNA-expressing cells were detected by in situ hybridization. Frequency and the maximum pressure of the contraction were comparable between Ws/Ws and +/+ rats, but the duration of the contraction was significantly shorter in Ws/Ws rats than in +/+ rats. The number of c-kit messenger RNA-expressing ICC in the pylorus of Ws/Ws rats was 1.7% that of +/+ rats. The bile reflux observed in Ws/Ws rats was attributed to the decrease in the duration of the pyloric contraction, which appeared to result from the deficiency of c-kit messenger RNA-expressing ICC.

To clarify the role of mitogen-inducible cyclooxygenase (COX-2) in the development of malignant tumors, we investigated the effects of COX-2 inhibitors on the growth of gastric cancer xenografts in nude mice in vivo. MKN45 gastric cancer cells (5 × 106cells/animal) that overexpress COX-2 were inoculated subcutaneously into athymic mice. NS-398, a specific COX-2 inhibitor, or indomethacin, a nonspecific COX-2 inhibitor, was administered orally to animals every day for 20 days. These drugs reduced the tumor volume significantly. Immunohistochemistry using bromodeoxyuridine, nick end labeling, and electron microscopy showed that NS-398 induced apoptosis in cancer cells in a dose-dependent manner and inhibited cancer cell replication slightly. Indomethacin also induced apoptosis and suppressed replication of tumor cells. There was a significant negative correlation between tumor volume and apoptotic cell number within the tumor. These results are consistent with the hypothesis that COX-2 inhibitors suppress growth of gastric cancer xenografts mainly by inducing apoptosis and suppressing replication of the neoplastic cells. It follows that COX-2 plays an important role in the development of gastric cancer.

In this study, the effect of different periods of amoxicillin (AMPC) treatment on the eradication rate of Helicobacter pylori in 173 patients with peptic ulcers (gastric ulcer, 109; duodenal ulcer, 64) was investigated. AMPC (1.5 g/day) was administered for 2, 4, or 6 weeks with omeprazole (20 mg/day) and plaunotol (240 mg/day), a mucoprotective drug, for 8 weeks. The H. pylori eradication rate was 46.7% for 2 weeks' treatment, 83.4% for 4 weeks' treatment, and 100% for 6 weeks' treatment. The eradication rate had a good correlation with the period of AMPC treatment. The healing rates of peptic ulcer at 4 and 8 weeks were 93.3% and 100%, respectively, in the 2-week group, 98.0% and 99.3% in the 4-week group, and 85.7% and 100% in the 6-week group. The recurrence rate of gastric and duodenal ulcers was 3.5% and 0% respectively, in the patients in whom H. pylori was eradicated and 30.0% and 40%, respectively, in the patients in whom H. pylori was not eradicated for 12 months after the H. pylori eradication treatment. Adverse effects of this regimen were observed in 5 (2.9%) of the 173 patients. Diarrhea was observed in 3 patients and eruption in 2. These adverse effects disappeared within a few days after only AMPC was withdrawn. Therefore, these may be caused by AMPC. The eradication rate of H. pylori depends on the period of AMPC treatment. This regiment, AMPC (1.5 g/day) + omeprazole (20 mg/day) + plaunotol (240 mg/day), is safe and well tolerated for eradication of H. pylori.

The roles of cyclooxygenase-2 (COX-2) in the development of gastric cancer are unknown. We investigated the effects of nonsteroidal antiinflammatory drugs (NSAIDs). which are specific and nonspecific inhibitors of COX-2, on proliferation of the gastric cancer cell lines KATOIII, MKN28, and MKN45. The protein level of COX-2 was examined in these cell lines by Western analysis, and mRNA levels of COX-1/2 by Northern analysis. These cell lines expressed comparable levels of COX-I mRNA. However, mRNA and protein expression of COX-2 in these cell lines was different. MKN45 expressed higher levels of COX-2 mRNA and protein than KATOIII and MKN28. We also examined the effects of NS-398 and indomethacin. specific and nonspecific inhibitors of COX-2. on the increase in cell number and [ 3 H]thymidine uptake of these cell lines. NS-398 and indomethacin suppressed proliferation of MKN45 cells that overexpressed COX-2, although they exerted minimal effects on proliferation of KATOIII and MKN28, which expressed lower levels of COX-2. These results are consistent with the hypothesis that COX-2 is expressed in certain groups of gastric cancers and is related to their cell proliferation. It was proposed that COX-2 plays an important role in development of gastric cancer cells. Furthermore, NSAIDs may exert antiproliferative activity against gastric adenocarcinomas that overexpress COX-2.

Recent epidemiologic studies have shown a 40–50% reduction in mortality from colorectal cancer in individuals who take nonsteroidal antiinflammatory drugs on a regular basis compared with those not taking these agents. One property shared by all of these drugs is their ability to inhibit cyclooxygenase (COX), a key enzyme in the conversion of arachidonic acid to prostaglandins. Two isoforms of COX have been characterized, COX-1 and COX-2. COX-2 is expressed at high levels in intestinal tumors in humans and rodents. Human colon cancer cells (Caco-2) were permanently transfected with a COX-2 expression vector or the identical vector lacking the COX-2 insert. The Caco-2 cells, which constitutively expressed COX-2, acquired increased invasiveness compared with the parental Caco-2 cells or the vector transfected control cells. Biochemical changes associated with this phenotypic change included activation of metalloproteinase-2 and increased RNA levels for the membrane-type metalloproteinase. Increased invasiveness and prostaglandin production were reversed by treatment with sulindac sulfide, a known COX inhibitor. These studies demonstrate that constitutive expression of COX-2 can lead to phenotypic changes that alter the metastatic potential of colorectal cancer cells.

We recently reported that transrectal or intestinal portal scintigraphy with 123I-iodoamphetamine (IMP) could be a useful method for the non-invasive and quantitative evaluation of the portosystemic shunt in portal hypertension, but what cells in the liver trap IMP has not been clarified. This study was aimed at elucidating whether IMP was extracted by parenchymal cells, sinusoidal endothelial cells, Kupffer cells or fat storing cells. Each type of liver cell was isolated from rats and cultured. The cells were incubated with 125I-IMP and the radioactivity of the lysate was determined. Nonspecific binding was assessed in the presence of an excess of unlabeled IMP, and specific binding was determined by subtracting the nonspecific from total binding. Specific binding observed in parenchymal cells, endothelial cells and Kupffer cells was 70.2 +/- 0.4, 4.2 +/- 1.4 and 2.3 +/- 0.8 pmol/well, respectively, but no specific binding was observed in fat storing cells. The binding in parenchymal cells was much higher than that in endothelial cells or Kupffer cells (p0.005). In addition, the binding to parenchymal cells reached equilibrium within 20 min and was not saturable over the concentration range tested (0.5-10 microM). These findings indicate that IMP is mostly extracted by parenchymal cells in the liver.

Although interleukin (IL)-8 is well known as a chemotactic agent for neutrophil migration in vitro, the relationship between IL-8 activity and the degree of neutrophil infiltration in gastric mucosa is still unclear. In the present study, we investigated IL-8 and myeloperoxidase activity, a marker of neutrophil infiltration, in gastric antral mucosa using biopsy samples in 23 patients with no gastric lesions. The results indicate that there is a good correlation between IL-8 and myeloperoxidase activity (y = 0.173x + 13.9; r = 0.49, P < 0.01). Furthermore, IL-8 and myeloperoxidase activity are significantly higher in Helicobacter pylori-positive patients than in H. pylori-negative patients. In conclusion, an increase of IL-8 activity in the gastric mucosa causes increased neutrophil infiltration in human gastric mucosa and H. pylori infection accelerates these reactions in the mucosa.

A 25-year-old Japanese female was referred to our clinic for the investigation of moderate iron-deficiency anemia and epigastralgia. Endoscopic examination showed diffuse mucosal nodules in the gastric body resembling nodular gastritis, but this pattern was not observed in the antrum. Histology of the gastric biopsies taken from the gastric body showed mild atrophic mucosa with chronic active inflammation. Some of the biopsy specimens showed deposition of patchy, band-like subepithelial collagen. Four years later, the patient showed no clinical symptoms and signs. A follow-up endoscopic examination showed similar findings, which mimicked pseudopolyposis or a cobblestone-like appearance. The biopsy specimens from the depressed mucosa between the nodules revealed a thickened subepithelial collagen band with no improvement, which led to a diagnosis of collagenous gastritis. Treatment with oral administration of proton-pump inhibitors and histamine-2-receptor antagonists had proved ineffective. To make a correct diagnosis of collagenous gastritis, we should determine the characteristic endoscopic findings and take biopsies from the depressed mucosa between the nodules.

The critical injury causing graft failure after prolonged liver storage involves reperfusion-induced killing of sinusoidal endothelial cells and activation of Kupffer cells. Treatment of stored livers with Carolina rinse solution (CRS) prevents endothelial cell killing, reduces Kupffer cell activation, and improves graft survival. Accordingly, our aim was to evaluate the components of CRS and other agents for protection against reperfusion injury to rat livers stored 24 hr in University of Wisconsin solution. CRS virtually abolished endothelial cell killing, prevented denudation of the sinusoidal lining, and decreased structural changes in Kupffer cells indicative of activation. The only component of CRS preventing endothelial cell killing was acidic pH of 6.5. However, when pH was subsequently increased to 7.4, antioxidants (allopurinol, deferoxamine mesylate, and glutathione), vasodilators (adenosine and nicardipine), and possibly energy substrates (fructose, glucose, and insulin) partially blocked pH-dependent cell killing (pH paradox). Na + /H + exchange inhibition, protease inhibition, and Ca 2+ -free buffer did not decrease reperfusion injury, but the amino acid glycine protected strongly. Strychnine, which binds to glycine receptors in the central nervous system, protected equally well. Protection by glycine and CRS was synergistic, virtually eliminating cell killing after 48 hr of storage. Unlike CRS and some of its components (adenosine and Ca 2+ channel blocker), glycine did not block tumor necrosis factor-α release by cultured rat Kupffer cells, although gabexate mesylate, a protease inhibitor, strongly blocked tumor necrosis factor-α release. In conclusion, the combination of CRS and glycine enhanced protection against reperfusion injury to stored livers and may prove beneficial in improving graft function and survival after liver transplantation.

At present, the evaluation of anti-ulcer drugs is generally accomplished simply by calculating the cumulative healing rate at a certain point of time during treatment, which does not implicate any analysis of the healing speed of the ulcer. If the cumulative healing rate of an ulcer is expressed as a function of drug administration time, t, then it will be possible to calculate parameters concerning the healing speed of ulcers and thus evaluate drug efficacy as the time series analysis of the cumulative healing rate. A new method of evaluating anti-ulcer drugs by a statistical analysis of healing speed is proposed. A non-linear regression analysis was performed between two variables, t (time of drug administration : week) and y (non-healing rate : %), to obtain the exponential function y = Ae -kt . The theoretical values calculated from the exponential equation were in close proximity to the observed values. With this analysis, four parameters concerning the healing speed were defined, namely the healing rate constant, the initiation time of healing, the half-life of non-healing rate and the time necessary for 50% healing. With this method, the efficacy of drugs on peptic ulcer healing was dynamically analysed, the non-healing rate (y) being expressed as an exponential function of length of time (t) of treatment, thus obtaining digital parameters for healing speed.

Dichloromethylene diphosphonate (MDPCl2) encapsulated in multilamellar liposomes was selectively incorporated by macrophages, immediately transferred to lysosomes, then released from liposomes into lysosomes by enzymatic digestion of the liposomal lipid layers. From 4 h after ingesting liposome-encapsulated MDPCl2 murine macrophages in vivo and in vitro acquired the ultrastructural features of apoptosis, such as condensed nuclear chromatin, nuclear fragmentation, cell shrinkage, and blebbing of the plasma membrane. Murine peritoneal macrophages and isolated rat Kupffer cells incubated in the medium containing liposome-encapsulated MDPCl2 increased DNA fragmentation in a dose-dependent manner. Electrophoretic analysis of extracted DNA from the isolated Kupffer cells showed DNA fragmentation. Another diphosphonate, Alendronate (4-amino-1-hydroxybutylidene-1,1-diphosphonate) had less potent macrophage cytotoxicity. However, MDPCl2, Alendronate, and gadolinium chloride in solution were not cytotoxic to macrophages. These results implied that the intralysosomal accumulation of MDPCl2 generates signals to induce macrophage apoptosis.

In this article, the effect of NSAIDs on the gastric mucosal microcirculation was reported. Although the precise mechanism of NSAID-induced ulcerogenesis is still unknown, most NSAIDs have been shown to impair gastric mucosal microcirculation and cause gastric mucosal damage.

Long-term storage of liver grafts results in increased adhesion of leukocytes onto the sinusoidal walls. This eventually leads to posttransplant graft damage through disturbances of hepatic microcirculation. Intracellular adhesion molecule-1 (ICAM-1) is known to be involved in attachment of leukocyt

In conclusion, the relationship between smoking and the digestive organs is multifaceted. Cigarettes contain a variety of chemical compounds, and they exhibit variable effects, either directly or via the central nervous system, on tissue microcirculation, motor regulation, and including various systems, the immune system. The influence of smoking on the specific function of an organ may be modified under different experimental conditions. As far as the achievements of previous studies are concerned, some effects of smoking on the digestive system are still controversial. Further investigations are needed.

Although an association is suggested between gastric cancer and prior infection with Helicobacter pylori (HP), the role of HP in gastric carcinogenesis remains obscure. HP has potent urease activity and produces ammonia, a factor causing HP-related gastroduodenal mucosal lesions. In this study, rats were examined in an effort to determine effects of ammonia on gastric carcinogenesis induced by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). After pretreatment with MNNG (83 mg/l) for 24 weeks, a solution of either 0.01% ammonia or plain tap water was administered to the animals as drinking water for an additional 24 weeks. The administration of the 0.01% ammonia solution significantly increased the incidence and number of cancers in the glandular stomach. The numbers of cases in which these cancers penetrated the muscle layer or deeper and of low-grade differentiated adenocarcinomas were significantly higher in rats receiving the ammonia solution. Continuing administration of ammonia accelerated cell proliferation in the gastric mucosa, but had no effect on the serum gastrin level. Therefore, gastric ammonia, which stimulates mucosal cell proliferation, appears to be an important promoter in carcinogenesis in rats and possibly in the HP-related gastric carcinogenesis in humans.

Gastric blood circulation maintains the structure and functions of the stomach, and thereby is closely associated with the pathogenesis and the healing of gastrointestinal lesions. Gastric mucosal blood flow, regulated by systemic neural and humoral factors, is also modified by local metabolic factors such as prostaglandins, leukotrienes. PAF and other endogenous chemical mediators in mucosa. Endothelium-derived factors that are produced by vascular endothelial cells, inducing relaxation or contraction of the blood vessels, are also recognized as basic mediators that regulate the circulation in the stomach.The regionally disturbed gastric circulation in combination with the presence of acid is closely associated with the pathogenesis of NSAIDs and ethanol-induced gastric lesions. Blood flow and oxygenation in the surface mucosa surrounding the peptic ulcer change during healing, depending on the quality of the ulcer healing process: an increased blood circulation with increased oxygen supply to the ulcer margin is important for rapid ulcer healing shown by reflectance spectrophotometry. Factors altering the blood flow during the ulcer healing are discussed.

Background/Aims: Endothelium-derived relaxing factor regulates vascular tone via vasodilation. The relative contribution of endogenous nitric oxide to the pathophysiology of ethanol-induced gastric mucosal microcirculatory disturbances was investigated in anesthetized rats. Methods: Macroscopic and microscopic gastric mucosal damage and gastric mucosal hemodynamics including blood flow and hemoglobin oxygen saturation (ISO2) were assessed by pretreatment with a specific NO synthase inhibitor, Nω-nitro-l-arginine (l-NNA), before and after intragastric administration of ethanol. Results: Pretreatment with l-NNA significantly increased macroscopic (7.7-fold) and microscopic damage caused by 30% ethanol. Concurrent administration of l-arginine, but not d-arginine, significantly reduced the increase in mucosal damage. Similar results were obtained with 60% ethanol. Pretreatment with l-NNA decreased both mucosal blood flow and ISO2 in the basal period and enhanced decreases in both mucosal blood flow (2.7-fold) and ISO2 (4.3-fold) induced by 30% ethanol compared with controls. Concurrent administration of l-arginine, but not d-arginine, significantly inhibited the effect of l-NNA on blood flow and ISO2 in the basal period as well as after intragastric administration of 30% ethanol. Conclusions: Endogenous NO modulates ethanol-induced gastric mucosal injury through the regulation of gastic mucosal microcirculation.

We examined the effects of lansoprazole and famotidine on gastric basic fibroblast growth factor (bFGF) levels and ulcer healing in patients with gastric ulcer. Sixteen patients with active gastric ulcer were divided into two groups and received treatment with lansoprazole 30 mg/day or famotidine 40 mg/day. They were examined endoscopically at 2, 4, and 8 weeks to measure gastric bFGF levels at the ulcer margin and to assess ulcer healing. Helicobacter pylori infection was determined by a rapid urease test. The two groups were comparable with regard to age, male :female ratio, H. pylori infection rates, and bFGF levels. During treatment, bFGF levels did not change significantly in the famotidine group, whereas they increased by a factor of 2.2 to 2.6 in the lansoprazole group. Cumulative healing rates were also significantly lower in the famotidine group than in the lansoprazole group. These results indicate that lansoprazole increases tissue bFGF levels and promotes gastric ulcer healing in humans.

Objective MicroRNAs (miRNAs) act as tumour suppressor genes or oncogenes in the regulation of multiple carcinogenic processes. Aberrant miRNA expression is reported in Helicobacter pylori ( H pylori )-related gastritis and gastric cancer. The cytotoxin-associated gene A (CagA) of H pylori has a pathophysiologically important role in gastric carcinogenesis. A study was undertaken to evaluate the effect of CagA on miRNA expression and its regulatory mechanism. Methods The effect of CagA on miRNA expression was assessed by comprehensive miRNA microarray. The mechanisms of the in vitro and in vivo effects of CagA on histone modification and DNA methylation and the involvement of CagA-dysregulated signal transduction on let-7, an important representative miRNA in gastric carcinogenesis, were investigated. Results In in vitro experiments, CagA significantly attenuated let-7 expression leading to Ras pathway activation. CagA enhanced c-myc, DNA methyltransferase 3B (DNMT3B) and Enhancer of Zeste homologue 2 (EZH2) expression and attenuated miR-26a and miR-101 expression, which resulted in the attenuation of let-7 expression by histone and DNA methylation. Experiments performed in CagA transgenic mice revealed that c-myc, EZH2 and DNMT3B expression were enhanced and let-7 expression was attenuated to induce Ras oncoprotein expression in the stomach, with no associated inflammation. Conclusions H pylori CagA induces aberrant epigenetic silencing of let-7 expression, leading to Ras upregulation.

The purpose of this study was to clarify the role of endogenous nitric oxide in ethanol-induced perturbation of microcirculation and hepatic injury in perfused rat liver. Infusion of ethanol into the portal vein at 25 and 100 mmol/L increased portal pressure, which is an indicator of hepatic vasoconstriction, in a concentration-dependent fashion. Portal pressure started to rise immediately after ethanol load, then decreased gradually and remained at higher than basal levels throughout the period of ethanol infusion. Release of lactate dehydrogenase into the effluent perfusate began to increase after 30 min of ethanol infusion and continued to increase during the 60-min period of ethanol infusion. The lactate dehydrogenase level in the effluent perfusate at 60 min was dependent on the ethanol concentration (0 mmol/L, 8 +/- 3 IU/L; 25 mmol/L, 16 +/- 2 IU/L; 100 mmol/L, 52 +/- 6 IU/L). Simultaneous infusion of NG-monomethyl-L-arginine, a nitric oxide synthesis inhibitor, enhanced significantly the ethanol-induced increase in portal pressure by 100% to 400% and increased lactate dehydrogenase release by 40% to 80%. The effect of NG-monomethyl-L-arginine on the ethanol-induced increase in portal pressure was completely reversed by the co-infusion of an excess dose of L-arginine. Change in portal pressure averaged over 60 min of ethanol infusion correlated with levels of lactate dehydrogenase release 60 min after the initiation of ethanol infusion (r = 0.77, p < 0.01). In conclusion, inhibition of the action of endogenous nitric oxide was associated with an increase in hepatic vasoconstriction and hepatocellular damage.(ABSTRACT TRUNCATED AT 250 WORDS)

In this study, an electronic endoscope was applied for observation of gastric submucosal vessels, with infrared illumination, in anesthetized dogs. An in-vivo spectrophotometry showed that infrared light at 620-820 nm penetrates the abdominal and gastric wall. During the endoscopy performed in dogs, the infrared radiation penetrated the abdominal wall and gastric wall from the outside, and was detected by the endoscope's charge-coupled device. A television monitor displayed a network of gastric vasculature, which was identified as veins in the gastric wall by injecting saline or indocyanine green into the vein. Using this system, it was possible to measure venous diameters of more than 0.2 mm by comparison with a reference wire. The diameter obtained by the image analysis correlated lineally to that of a vascular template prepared from the same stomach. Thus, it may become possible to assess gastric submucosal hemodynamics using infrared endoscopy, a new application in electronic endoscopy.