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Biomedical subjects

A Terano

Publications and source records attributed to A Terano.

At least 91 records · Page 5Linked to original sources
PubMed1996

Nitric oxide enhances cytotoxicity of cultured rabbit gastric mucosal cells induced by hydrogen peroxide.

While NO has been reported to act as a protective factor to gastric mucosa, it has been shown to be cytotoxic to various cells. NO also has been demonstrated to stimulate prostaglandin (PG) release and mucous glycoprotein secretion which could result in the activation of gastric defensive mechanisms. We examined the effect of NO on cytotoxicity induced by hydrogen peroxide, and mucous glycoprotein secretion and PGE2 release from cultured rabbit gastric mucosal cells. NO enhanced cytotoxicity induced by hydrogen peroxide. Defensive prostaglandin E2 release and mucous glycoprotein secretion were not altered by NO. Under certain circumstances, NO might behave as an aggressive factor in gastric mucosal injury.

Animals↗
PubMed1996

Constitutive expression of hepatocyte growth factor may maintain the sheet construction of gastric epithelial cells through facilitating actin-myosin contractile system.

Previously, we have demonstrated that hepatocyte growth factor (HGF) plays an important role in the repair process of gastric ulcer, showing that HGF expression is specifically increased at gastric ulcer edge. In the present study, we demonstrated the constitutive expression of HGF mRNA in normal mucosa, which is as much as 0.1-1.0 attomole/micrograms total RNA. In order to evaluate the hypothesis that HGF might have some role in maintenance of gastric mucosa or prevention of injury initiation, we developed an in vitro model using rabbit gastric epithelial cell in primary culture. 1% ethanol destroys the cell to cell contact to disrupt the monolayer sheet of the cells without causing any damage to cell viability, indicating that irritants may initiate the mucosal injury. HGF remarkably prevented the disruption induced by the ethanol without eliciting proliferation or migration. This action of HGF was suppressed by actin selective inhibitor, cytochalasin B, indicating that it was mediated by an actin-myosin contractile system. In conclusion, constitutively expressed HGF may prevent the initiation of gastric epithelial disruption, which is dependent on some sort if mobile action of the cells.

Actins↗
PubMed1996

Keratinocyte growth factor is an endogenous stimulant of rabbit gastric epithelial cell proliferation and migration in primary culture.

Mesenchymal-epithelial interactions are important in the gastric mucosal repair. However, specific factors responsible for such interactions have not been established. In the present study, keratinocyte growth factor (KGF) significantly stimulated proliferation of gastric epithelial cells dose dependently and synergistically with hepatocyte growth factor (HGF), epidermal growth factor (EGF) and insulin. Restitution of gastric epithelial monolayers was also assessed, using a round wound restitution model. Keratinocyte growth factor facilitated the restitution of gastric epithelial cells significantly but did not have any effects on gastric fibroblasts. Keratinocyte growth factor receptor mRNA was expressed by gastric epithelial cells, indicating that these effects were elicited by the specific receptor mediated pathway. Northern blot analysis revealed the expression of KGF mRNA in gastric fibroblasts but not in gastric epithelial cells, indicating the production of KGF. These results suggest that KGF might be involved in gastric mucosal repair, through mesenchymal-epithelial interaction.

Animals↗
PubMed1996

[Glucose intolerance after percutaneous ethanol injection therapy (PEI) in liver cirrhosis patients with hepatocellular carcinoma].

We studied the effect of percutaneous ethanol injection therapy (PEI) on glucose tolerance in liver cirrhosis patients with hepatocellular carcinoma. All of 10 patients underwent PEI and aspiration biopsy of the tumor on separate day. Two-time oral glucose tolerance tests (OGTT), before and after PEI, were performed in all patients. There were no significant changes in blood glucose and insulin chronologically measured on aspiration biopsy and PEI. To detect changes in glucose tolerance, we compared the results of OGTT before PEI with those of OGTT after PEI. On the basis of results of OGTT before PEI, patients were classified to impaired glucose tolerance group (4) and diabetes mellitus group (6). Blood glucose at 180 minutes on OGTT after PEI showed significantly higher value than that of OGTT before PEI, but insulin response was not suppressed. From these experiments we speculate that exaggerated insulin resistance due to injected ethanol may be one of the factors influencing glucose tolerance after PEI.

Aged↗
PubMed1996

[Gastric mucosal congestion following endoscopic variceal ligation--analysis using reflectance spectrophotometry].

UNLABELLED: Endoscopic variceal ligation (EVL) has been accepted as a new treatment for esophageal varices in cirrhotic patients, and evaluated to have a lower incidence of complications compared to sclerotherapy. Sclerotherapy may increase the risk of portal hypertensive gastropathy (PHG), which is recognized to be gastric mucosal congestion due to portal hypertension in cirrhotics. However, the gastric mucosal hemodynamics after EVL has not been established yet. The aim of this study is to assess whether EVL could affect the hemodynamics of the gastric mucosa. PATIENTS AND METHODS: Eleven cirrhotic patients with severe esophageal varices, who underwent prophylactic EVL were enrolled in the trial. Age and sex-matched non-cirrhotic patients who had only gastric mucosal atrophy were entered as control to compare the mucosal hemodynamics to that of cirrhotic patient. EVL was performed as described by Stiegmann et al. The gastric mucosal hemodynamics was evaluated with both gastric mucosal blood volume (IHB) and hemoglobin O2 saturation (ISO2), which were measured by reflectance spectrophotometry during endoscopy. These parameters were measured in the three points of the stomach (gastric antrum, lower corpus and upper corpus) just before and after EVL. RESULT: In all patients with cirrhosis, mild PHG was observed endoscopically. ISO2 in cirrhotic patients was significantly lower in all points of the stomach compared with control. IHB in cirrhotic patients was not significantly different from control. ISO2 of post-EVL was significantly lower than that of pre-EVL, whereas IHB of post-EVL revealed significantly higher than that of pre-EVL. However, endoscopic grade of PHG remained mild. The hemodynamics of the mucosa two weeks after the initial EVL showed improvement of the congestion. CONCLUSIONS: The gastric mucosal hemodynamics showed increment of the gastric blood volume and decreased hemoglobin O2 saturation in cirrhotic patients, indicating that cirrhotic gastric mucosa is in congestive condition. EVL for esophageal varices makes the gastric mucosa more congestive soon after the procedure in spite of the same grade of endoscopic PHG. However, the worsened congestion improves within a few weeks.

Aged↗
PubMed1996

Sucralfate and Helicobacter pylori.

Sucralfate enhances the eradication rate of Helicobacter pylori when administered with antibiotics. Sucralfate acts on H. pylori through mucus gel. Whether sucralfate exerts its anti-ulcer action through the eradication of H. pylori is still controversial. As sucralfate itself is an effective, well-tolerated and cost-effective anti-ulcer agent, its mechanisms of action should be investigated further.

Anti-Bacterial Agents↗
PubMed1995

Adaptive cytoprotection in cultured rat gastric mucus-producing cells. Role of mucus and prostaglandin synthesis.

In cultured gastric mucosal cells, we investigated whether: (1) adaptive cytoprotection was associated with stimulation of endogenous prostaglandin synthesis; (2) prostaglandins given exogenously were cytoprotective against ethanol-induced gastric mucosal cell damage; and (3) a relationship existed between cytoprotection and mucus release. Cytolysis was quantified by measuring 51Cr release from prelabeled cells. Mucus release was determined by measurement of [3H]glucosamine release. Concentrations of ethanol > 12% caused cell damage and increased 51Cr release dose dependently. Pretreatment with low concentrations of ethanol (0.5-1.5%) decreased ethanol-induced 51Cr release, but also decreased prostaglandin E2 synthesis. Prostaglandin E2 and 16,16-dimethyl prostaglandin E2 given exogenously were cytoprotective against ethanol-induced gastric mucosal cell damage. Treatment with low concentrations of ethanol (1.5%) increased mucus release from cultured gastric mucosal cells. However, prostaglandin E2 and 16,16-dimethyl prostaglandin E2 did not affect mucus release. We conclude that in cultured gastric mucus-producing cells: (1) adaptive cytoprotection occurs without stimulation of endogenous prostaglandin synthesis but with increase in mucus release; and (2) exogenous prostaglandins are cytoprotective against ethanol-induced gastric mucosal cell damage without stimulating mucus release in vitro. We postulate that adaptive cytoprotection in cultured gastric mucus-producing cells is not mediated by prostaglandin, but by mucus released in response to a mild irritant.

16,16-Dimethylprostaglandin E2↗
PubMed1995

Relationships between metal ions and oxygen free radicals in ethanol-induced damage to cultured rat gastric mucosal cells.

The current study investigated whether metal ions were cytoprotective against ethanol-induced injury to cultured rat gastric mucosal cells in vitro. Secondly, the relationships between oxygen free radicals and cytoprotection by metal ions were examined. Cultured cells exposed to ethanol produced superoxide anion, as assessed by reduction of cytochrome c, in a time-related fashion, and the production of superoxide anion increased dose-dependently as the concentration of ethanol increased. Cellular damage increased proportionately to the production of superoxide anion. ZnCl2, AlCl3, CoCl2, CuCl2, and CdCl2 significantly diminished ethanol-induced injury dose-dependently. All of the agents studied decreased the reduction of cytochrome c in ethanol-induced damage dose-dependently. These results led to the conclusions that: (1) cultured rat gastric mucosal cells exposed to ethanol generate oxygen free radicals; (2) the production of oxygen free radicals is closely linked with ethanol-induced damage to the cells; and (3) metal ions decrease ethanol-induced gastric mucosal cell damage in vitro. Metal ions protect cultured rat gastric mucosal cells from ethanol-induced damage in which oxygen free radicals participate.

Aluminum Chloride↗
PubMed1995

Clinical efficacy of lansoprazole-amoxicillin treatment in eradicating Helicobacter pylori: evaluation by the polymerase chain reaction method.

The clinical efficacy of lansoprazole plus amoxicillin treatment in eradicating Helicobacter pylori was examined in peptic ulcer patients. H. pylori eradication was assessed by the polymerase chain reaction (PCR) method in addition to conventional methods. Fifteen H. pylori-positive patients with active peptic ulcers (10 duodenal ulcer patients and 5 gastric ulcer patients) were given lansoprazole 30 mg/day from day 1 to day 56 and amoxicillin 1,500 mg/day from day 15 to day 28. Four weeks after the end of treatment, no H. pylori organisms were detected in 9 of 15 patients (60%) as assessed by the rapid urease test and in 10 of 15 patients (67%) as assessed by bacterial culture. However, only three patients were negative for H. pylori when evaluated by the PCR method. Therefore, although lansoprazole plus amoxicillin treatment appears to be promising, a very small number of H. pylori organisms are apparently able to survive such treatment, which may result in the recurrence of H. pylori colonization in some patients.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed1995

Hepatocyte growth factor is the most potent endogenous stimulant of rabbit gastric epithelial cell proliferation and migration in primary culture.

Various growth factors are suggested to be involved in gastric mucosal repair. Our previous studies have shown that exogenous hepatocyte growth factor (HGF) has a proliferative effect on gastric epithelial cells. In the present study, comparison of the maximum proliferative effects and the optimum concentrations of several growth factors revealed that HGF was the most potent mitogen for gastric epithelial cells, as is the case for hepatocytes. Restitution of gastric epithelial cell monolayers was assessed using a round wound restitution model. HGF was the most effective agent for facilitating gastric epithelial restitution among those tested. A binding assay revealed specific binding of HGF to its receptor on gastric epithelial cells. Northern blot analysis confirmed the expression of specific HGF receptor mRNA (c-met) by gastric epithelial cells but not by gastric fibroblasts. To investigate endogenous HGF production, we determined the effect of gastric fibroblast-conditioned medium on epithelial proliferation and restitution. The conditioned medium produced similar effects to HGF and its activity was neutralized by an anti-HGF antibody. In addition, expression of HGF mRNA was detected in gastric fibroblasts but not in gastric epithelial cells. Our immunohistochemical study confirmed these in vitro data by means of demonstrating the existence and localization of HGF at human native gastric mucosa. HGF was localized at fibroblasts under the epithelial cell layer around gastric ulcers. These results suggest that HGF may be a potent endogenous promotor of gastric epithelial cell proliferation and migration, and may contribute to gastric mucosal repair through a paracrine mechanism.

Animals↗
PubMed1995

Long-term follow-up study of ulcerative colitis in Japan.

To clarify the long-term prognosis of Japanese patients with ulcerative colitis, we investigated the cumulative colectomy rate and the survival rate, and compared the results with reports from Western countries. The subjects were 778 patients who had visited 8 hospitals from 1973 to 1990. A total of 114 of the 778 patients (14.7%) had required colectomy and 21 (2.7%) had died. These rates were higher in the patients who had total colitis, and in those who had acute fulminant type of severe type. There were no significant differences in these rates according to age of onset (under 29 years, 30-49 years, and more than 50 years). The cumulative colectomy rate increased rapidly within 2 years after onset. Thereafter, the rate increased gradually, by 1%-2% per year. In patients with total colitis, 14.1% required colectomy within 2 years. The age at onset had no effect on this rate. The cumulative survival rate decreased gradually throughout the first 10 years, the rate being 96.2% in the 10th year. No deaths occurred in the 11-18th years after onset. Despite our inclusion of more patients with total or severe colitis, our results were similar to or slightly superior to those reported from Western countries; this may be attributed to a temporal bias.

Adolescent↗
PubMed1995

Therapeutic efficacy of cyclic home elemental enteral alimentation in Crohn's disease: Japanese cooperative Crohn's disease study.

Crohn's disease (CD) often flares up and requires frequent hospitalization and/or surgery. Cyclic home elemental enteral alimentation (C-HEEA) was developed to prevent flare-up of CD and to minimize patient hospitalization. However, its therapeutic efficacy has not been studied in a large patient population. Therefore, questionnaires were sent to members of the Inflammatory Bowel Disease (IBD) Research Group of Japan to evaluate the therapeutic efficacy of C-HEEA and to define the factors that may affect the efficacy of the treatment. Data for 410 patients (C-HEEA-treated n = 322; drug-treated n = 88) were collected from 29 institutions and analysis showed the following results. The cumulative remission and non-hospitalization rates of the C-HEEA treated group were significantly higher than the rates of the drug-treated group in all patients and in those with ileitis and ileo-colitis (P < 0.0001, P < 0.001, and P < 0.01, respectively), but no significant difference was noted in patients with colitis. Cumulative remission and non-hospitalization rates were also influenced by the daily calorie content of the elemental diet (ED); more than 1200 kcal of the ED per day was found to be more effective than lower amounts to maintain remission and to prevent hospitalization. The therapeutic efficacy of C-HEEA was shown to be superior to that of drug treatment in patients with CD with ileal involvement, and it is suggested that more than 1200kcal per day should be supplied by the ED to enhance its therapeutic efficacy.

Case-Control Studies↗