Search Results - (Author, Cooperation:H. Kazumori)

2012-05-26

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Computer Science

Medicine

Natural Sciences in General

Physics

Crystallization ; Crystallography, X-Ray ; *Magnesium/chemistry ; Models, Molecular ; Molecular Structure ; Oxides/chemical synthesis/chemistry ; Phthalic Acids/chemical synthesis/chemistry ; Porosity ; *Zinc/chemistry

1365-2036

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Enterochromaffin-like (ECL) cells are the major source of histamine for the regulation of gastric acid secretion, and also contain histidine decarboxylase (HDC), vesicular monoamine transporter 2 (VMAT2), and chromogranin A (CgA). Although gastric acid secretion is suppressed during ulcer healing, the role of ECL cells in that process is not yet fully understood. In the present study, we investigated the changes in ECL cell number during healing of experimental ulcers in rats.〈section xml:id="abs1-2"〉〈title type="main"〉Materials and methods:Seven-week-old male Wistar rats were used. Acetic acid-induced ulcers were caused by an application of 100% acetic acid to the serosal surface of the rat stomachs. At different time points following the induction (12 h-15 days), time-course changes of HDC, VMAT2, and CgA mRNA expression were investigated by Northern blot analysis. The expressions of HDC, VMAT2, and CgA were immunostained on gastric mucosal sections with ulcers.〈section xml:id="abs1-3"〉〈title type="main"〉Results:HDC, VMAT2, and CgA mRNA in gastric mucosa each showed an initial marked transient decrease, followed by an increase on day 10 back to the initial value. HDC, VMAT2, and CgA-immunoreactive cells at the ulcer margin were reduced in number on day 3, compared with those in distant areas. On day 10, however, they returned to levels similar to those in distant areas.〈section xml:id="abs1-4"〉〈title type="main"〉Conclusion:The present study revealed a local down-regulation of HDC, VMAT2, and CgA in ECL cells at the ulcer margin. As a result, we concluded that a suppression of ECL cell activity during ulcer healing may be involved in suppressed gastric acid secretion.

Electronic Resource

1365-2036

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Background : Midkine has been reported to bind to receptor-like protein tyrosine phosphatase (RPTP)-β and to play important roles in growth and differentiation of various cells. Midkine is expressed in rat stomach during experimental ulcer healing, suggesting that the midkine-RPTP-β system has some physiological functions in the stomach. Rebamipide is a mucoprotective drug used for the treatment of gastric ulcers. We have tested the hypothesis that the ulcer healing mechanism stimulated by rebamipide is linked physiologically to the gastric midkine-RPTP-β system.Materials and methods : Seven-week-old-male Wistar rats were used. Midkine and RPTP-β gene expression in rat stomach was investigated by laser capture microdissection coupled with the reverse transcription-polymerase chain reaction (RT-PCR). The effects of rebamipide on midkine and RPTP-β expression in rat stomach and the gastric epithelial cell line RGM1 were evaluated by RT-PCR and Northern blot analyses.Results : Midkine and RPTP-β expression was detected in the gastric mucosal, submucosal and muscle layers. Rebamipide stimulated both midkine and RPTP-β expression in rat stomach and RGM1 cells.Conclusion : Rebamipide may protect the gastric mucosa by regulating midkine and RPTP-β expression.

Electronic Resource

1365-2036

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

There is controversy about the effect of acid-suppressive therapy on Helicobacter pylori density and the severity of histological gastritis in the corpus.〈section xml:id="abs1-2"〉〈title type="main"〉Aim:To evaluate the precise distribution of H. pylori, both on the surface mucus cells and in the surface mucus gel layer, by using Carnoy’s fixation and immunostaining for the detection of bacteria.〈section xml:id="abs1-3"〉〈title type="main"〉Methods:A total of 19 peptic ulcer patients with H. pylori infection were studied. All patients received a 6-week course of treatment with omeprazole (20 mg/day). Before and after the therapy, H. pylori density in Carnoy-fixed tissue sections was examined immunohistochemically. The effect of omeprazole therapy on the severity of gastritis was also evaluated.〈section xml:id="abs1-4"〉〈title type="main"〉Results: H. pylori density and the grade of gastritis significantly decreased in the antrum after omeprazole therapy. In the corpus, however, there were no significant changes in H. pylori density or the severity of gastritis after omeprazole therapy.〈section xml:id="abs1-5"〉〈title type="main"〉Conclusion:Carnoy’s fixation and immunostaining was found to be useful for the detection of H. pylori in the surface mucus gel layer as well as on the surface mucus cells in biopsy tissue sections. By using this method, H. pylori density decreased in the antrum, but remained unchanged in the corpus after a 6-week course of omeprazole therapy.

Electronic Resource

1365-2036

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Background : The attenuated anti-secretory activity of H2 receptor antagonists (H2RA) during continuous administration is referred to as the tolerance phenomenon. However, it is not clarified whether Helicobacter pylori infection affects the occurrence of tolerance to H2RA. It is also not clarified whether the tolerance phenomenon occurs to a new H2RA, lafutidine.Aim : To investigate the occurrence of the tolerance phenomenon in subjects with and without H. pylori infection during the continuous administration of lafutidine and famotidine.Subjects and Methods : Subjects were 20 healthy male volunteers (seven H. pylori positive and 13 H. pylori negative cases). All subjects were examined by ambulatory intragastric pH monitoring five times without medication, on the first and 15th day of the administration of 20 mg b.d. famotidine and 10 mg b.d. lafutidine in a cross-over fashion.Results : The tolerance phenomenon was not observed in H. pylori-positive subjects during the 15-day-long administration of both H2RAs. In contrast, the tolerance phenomenon was observed in H. pylori negative subjects, which has been previously reported.Conclusions : This study demonstrated that H. pylori infection affects the tolerance phenomenon during continuous administration of H2RAs.

Electronic Resource