Effects of rebamipide, a gastro-protective drug on the Helicobacter pylori status and inflammation in the gastric mucosa of patients with gastric ulcer: a randomized double-blind placebo-controlled multicentre trial

AIMS

To investigate the effects of rebamipide on the Helicobacter pylori eradication rate with amoxicillin and omeprazole. The trial also examined its histological effects on gastro-mucosal inflammation after eradication.

METHODS

Two hundred and six H. pylori-positive patients with active gastric ulcer underwent 8-week based therapy (OA) consisting of 2-week amoxicillin with omeprazole and subsequent 6-week omeprazole. They randomly received either rebamipide (OA-R) or placebo (OA-P) for 16 weeks: combined with the OA based therapy, and subsequently for another 8 weeks. Besides eradication rate, inflammatory findings of gastric mucosa after eradication were evaluated histologically.

RESULTS

Per Protocol Set analysis showed no significant difference in eradication rate between OA-R (64.6%; 95% confidence interval, 54.3-75.0%) and OA-P (67.9%; 95% CI, 57.6-78.3%). Histological findings in the gastric mucosa of the ulcer region, however, indicated a significant improvement (P = 0.017) in inflammation scores in OA-R (1.84 +/- 0.41) compared with that in OA-P (2.02 +/- 0.39) after 16-weeks of treatment. This suppressive effect on inflammation was observed even in the OA-R patients unsuccessfully eradicated.

CONCLUSION

Rebamipide demonstrated a suppressive effect on the persistent and possibly chronic inflammation in the gastric mucosa of the ulcer region after eradication, but the drug did not improve the eradication rate.

Effects of ecabet sodium, an antiulcer drug, on gastric adaptive relaxation in isolated guinea-pig stomachs

Disturbances in the reservoir function of the stomach may cause epigastric fullness or early satiety, which are the main symptoms in patients with dysmotility-like functional dyspepsia. Gastric adaptive relaxation is involved in the reservoir function of the proximal stomach. Ecabet sodium, synthesized from abietic acid, is widely used in Japan as an antiulcer drug. The purpose of this study was to evaluate the effects of ecabet on gastric adaptive relaxation in isolated guinea-pig stomachs. Changes in intragastric volume and pressure were recorded in the presence of atropine and guanethidine. Gastric adaptive relaxation was triggered by luminal distention. Ecabet at the dose of 20 mmol/l in solutions at two pHs (pH 3.0 and 7.4) significantly lowered the threshold pressure needed for such relaxation and increased intragastric volume, but lower doses had little or no effect. The results suggested that this antiulcer drug might improve symptoms in patients with dysmotility-like functional dyspepsia.

Platelet recovery after eradication of Helicobacter pylori in patients with idiopathic thrombocytopenic purpura

The association between Helicobacter pylori ( H. pylori) infection and idiopathic thrombocytopenic purpura (ITP) has been reported by several groups. We investigated the prevalence of H. pylori infection and the effectiveness of its eradication in Japanese patients with ITP. H. pylori infection was found in 21 of 30 patients (70.0%) by (13)C urea breath test and presence of serum antibodies to H. pylori. H. pylori was eradicated in 18 of the 21 infected patients (85.7%) by administration of a proton pump inhibitor and two kinds of antibiotics. In only one patient was medication discontinued due to skin rash on the 4th day of treatment. Platelet recovery was obtained in ten patients (55.6%). In two patients with treatment failure, platelet recovery was obtained after successful re-eradication. In three patients without H. pylori infection, platelet counts did not significantly increase with the same treatment. On the other hand, eradication therapy did not affect platelet counts in patients with gastric ulcer. In conclusion, H. pylori eradication can be used for initial treatment with tolerable adverse effects in some ITP patients.

Is eradication sufficient to heal gastric ulcers in patients infected with Helicobacter pylori? A randomized, controlled, prospective study

BACKGROUND

In Helicobacter pylori infection, the effect of short-term triple therapy with proton pump inhibitor plus two antibiotics on gastric ulcer healing is not well known.

AIM

To compare 1-week triple therapy with 8-week proton pump inhibitor therapy on gastric ulcer healing in infected patients.

PATIENTS AND METHODS

We randomly assigned 120 patients with H. pylori and gastric ulcers to proton pump inhibitor plus amoxicillin and clarithromycin for 1 week (n = 61) or proton pump inhibitor alone for 8 weeks (n = 59), with endoscopic assessment of ulcer healing 8 weeks after the start of treatment.

RESULTS

Triple therapy eradicated H. pylori in 51 patients [intention-to-treat, 84%; 95% confidence interval (CI), 75-93%]. At 8 weeks, gastric ulcers were healed in 30 patients given triple therapy (49%; 95% CI, 37-62%) and in 49 patients given proton pump inhibitor (83%; 95% CI, 73-93%, P < 0.001). Healing rates in the triple therapy and proton pump inhibitor-only groups were 89% and 100%, respectively, for ulcers of < 1.0 cm in diameter, 54% and 77% for ulcers of 1.0 to < 1.5 cm in diameter, and 5% and 77% (P < 0.001) for ulcers of > or = 1.5 cm in diameter.

CONCLUSIONS

One-week triple therapy healed most ulcers of < 1.0 cm, but not ulcers of > or = 1.5 cm. Short-term therapy is effective for gastric ulcers of < 1.0 cm, but, for larger ulcers, follow-up therapy to suppress acid is needed.

Analysis of the mouse transcriptome based on functional annotation of 60,770 full-length cDNAs

Only a small proportion of the mouse genome is transcribed into mature messenger RNA transcripts. There is an international collaborative effort to identify all full-length mRNA transcripts from the mouse, and to ensure that each is represented in a physical collection of clones. Here we report the manual annotation of 60,770 full-length mouse complementary DNA sequences. These are clustered into 33,409 'transcriptional units', contributing 90.1% of a newly established mouse transcriptome database. Of these transcriptional units, 4,258 are new protein-coding and 11,665 are new non-coding messages, indicating that non-coding RNA is a major component of the transcriptome. 41% of all transcriptional units showed evidence of alternative splicing. In protein-coding transcripts, 79% of splice variations altered the protein product. Whole-transcriptome analyses resulted in the identification of 2,431 sense-antisense pairs. The present work, completely supported by physical clones, provides the most comprehensive survey of a mammalian transcriptome so far, and is a valuable resource for functional genomics.

Endoscopic resection of a cavernous haemangioma of the stomach

A lesion, suspected, from the endoscopic appearance, to be an isolated gastric haemangioma was incidentally detected in a 66-year-old male. At follow-up endoscopy, 5 years later, tumour size had increased and its appearance had changed with respect to previous examinations. On endoscopic ultrasonography, the tumour was solid and confined mainly to the submucosal layer of the gastric wall. Examination of biopsy specimens failed to provide any useful information. After biopsy, tumour size and the area of reddish discoloration decreased and endoscopic ultrasonography revealed multiple small cystic lesions in the tumour. Endoscopic resection was then performed with complete excision of the tumour without complications or recurrence. Pathological examination of resected tissue demonstrated cavernous haemangioma of the stomach.

Differential gene expression of vascular endothelial growth factor isoforms and their receptors in the development of the rat masseter muscle

The capillary network in the masseter muscle develops dramatically with the differentiation of muscle fibres after birth, especially around weaning. Here, developmental changes in mRNA expression for four splicing variants of vascular endothelial growth factor (VEGF) and for two distinct VEGF receptors (Fms-like tyrosine kinase (Flt-1) and kinase insert domain-containing receptor/fetal liver kinase-1 (KDR/Flk-1)) were studied in rat masseter. The relative abundance of VEGF (120) mRNA was the highest, representing 35% of total VEGF mRNA on day 7 after birth and gradually decreased with age to become approximately 5% on day 37. In contrast, VEGF (188) mRNA was very low in the newborn rat, but increased sharply before weaning and reached 40-50% of the total on day 50. Neither VEGF (144) nor VEGF(164) mRNA showed any significant change in abundance after birth. The expression of KDR/Flk-1 mRNA was transiently high in the early postnatal stage and gradually decreased with age, Flt-1 mRNA was stably expressed at a constant level after birth. These findings suggest that different combinations of VEGF isoforms and their receptors regulate angiogenesis in the development of the masseter muscle.

Inhibitory effect of sofalcone on tumor necrosis factor-alpha and interleukin-1 beta production in human monocytes stimulated by Helicobacter pylori water extract

We investigated the effect of sofalcone, a synthetic flavonoid derivative of sophoradin, on tumor necrosis factor (TNF)-alpha and interleukin (IL)-1 beta production in human monocytes stimulated by Helicobacter pylori water extract. H. pylori water extract significantly stimulated TNF-alpha and IL-1 beta production by monocytes while incubation with sofalcone (10 micrograms/ml and 50 micrograms/ml) significantly inhibited this increase in TNF-alpha and IL-1 beta production. These results suggest that sofalcone could be used to improve H. pylori-associated gastric mucosal inflammation through inhibition of proinflammatory cytokine production.

Increased expression of epidermal growth factor receptors in basal cell hyperplasia of the oesophagus after acid reflux oesophagitis in rats

BACKGROUND

Epidermal growth factor (EGF), which binds to EGF receptors (EGF-R), stimulates oesophageal epithelial cell proliferation, enabling rapid repair after mucosal injury. In the normal human oesophageal epithelium, EGF-R expression is present and confined to the basal layer.

AIM

To examine histological changes in and dynamics of EGF-R expression during healing after acid reflux oesophagitis in a rat model.

METHODS

Gastric acid reflux oesophagitis was induced in Wistar rats by ligation of the pylorus and the transitional region between the forestomach and the grandular portion for 5 h, followed by release of both ligations. Rats were killed 7 and 14 days after production of oesophagitis to examine macroscopic and histological changes as well as dynamics of EGF-R expression. Epithelial cell proliferation was assessed by bromodeoxyuridine (BrdU) uptake, and expression of EGF-R mRNA and protein by RT-PCR and Western blotting or immunohistochemistry.

RESULTS

Gastric acid reflux induced erosive and ulcerative mucosal lesions in the lower and middle part of the oesophagus. These lesions were healed by 14 days and histologically showed thickening of the oesophageal epithelium from 41.11 +/- 3.09 microm in controls to 142.73 +/- 11.59 microm (P < 0.001) in ligated rats, as well as elongation of papillae and basal cell hyperplasia. The number of BrdU-positive cells among basal cells on day 14 was significantly increased from 7.1 +/- 0.8/field in controls to 30.9 +/- 3.0/field in ligated rats. Expression of EGF-R mRNA and protein was significantly increased on day 14 and most basal cells were immunohistochemically positive in both BrdU and EGF-R staining.

CONCLUSION

Acid reflux-induced oesophageal injury caused basal cell hyperplasia with an increase in cell proliferation and EGF-R expression. Activation of EGF-R gene and protein in response to acid reflux-induced injury may facilitate mucosal healing. These results suggest that epidermal growth factor receptors play a crucial role in healing after acid reflux oesophagitis in rats.

High molecular protein of Helicobacter pylori responsible for inhibition of ornithine decarboxylase activity of human gastric cultured cells

BACKGROUND

Ornithine decarboxylase (ODC), a rate-limiting enzyme of polyamine biosynthesis, mediates epithelial cell proliferation and plays a critical role in the optimal repair of gastric mucosal damage. Several studies have shown that Helicobacter pylori inhibits the growth and proliferation of gastric cells in vitro.

AIM

To test whether H. pylori extract affects ODC mRNA expression and its enzyme activity in gastric cells and to examine the partial characterization of the molecule responsible for this effect.

METHODS

Human gastric cells (MKN-45) were used. Bacterial extracts from various E. coli or H. pylori strains, namely (1) cagA+, vacA+, CagA+, VacA+; (2) cagA+, vacA+, CagA+ VacA-; or (3) cagA-, vacA+, CagA-, VacA- were added to the cells. Cell proliferation was assessed by [3H]-thymidine incorporation, viability by MTT assay and LDH release test, ODC enzyme activity by 14CO2 counts from L-[1(14)C]ornithine, and ODC mRNA by Northern blotting.

RESULTS

H. pylori and E. coli extract did not affect viability of gastric cells. H. pylori extract, especially extracts containing a protein greater than 50 kDa, significantly inhibited proliferation and ODC activity of gastric cells while E. coli extract had no effect. Inhibition of ODC activity was found in extracts of all H. pylori strains, irrespective of CagA and VacA protein expression. Serum stimulation induces an increase in ODC mRNA while H. pylori extract did not affect ODC mRNA expression.

CONCLUSION

High molecular weight (greater than 50 kDa) proteins of H. pylori extract without CagA or VacA protein inhibited proliferation and ODC activity of human gastric cells, but did not affect ODC mRNA expression, suggesting that inhibition of ODC activity is regulated at the post-transcriptional level.

Prevalence of Helicobacter pylori infection in gastric remnant after distal gastrectomy for primary gastric cancer

BACKGROUND

The development of a second primary cancer in the gastric remnant after gastrectomy for early gastric carcinoma is a problem, and eradication of Helicobacter pylori after the operation has been recommended. However, to date, practical indications for H. pylori eradication after gastric cancer surgery have not yet been reported.

METHODS

We examined H. pylori infection in the gastric remnant after distal gastrectomy for primary gastric cancer. One hundred and nine patients who had had a gastrectomy were studied. Endoscopic findings and results from the urease test, bacteriologic assessment, serological test, and histopathological examination were analyzed.

RESULTS

Seventy-one patients (65.1%) were judged to be positive for H. pylori infection. The prevalence of H. pylori infection was found to be significantly decreased in older patients, patients in whom the operation had been performed a long time before examination, patients with symptoms, and patients with severe reflux gastritis. On the other hand, histologically, chronic and acute gastritis correlated significantly with H. pylori infection. H. pylori prevalence was highest in mildly atrophic mucosa and decreased with more extensive atrophic changes of the mucosa.

CONCLUSIONS

The persistence of H. pylori-related active gastritis in the gastric remnant after gastric cancer surgery was suggested in younger patients with mild atrophic gastritis and without reflux gastritis. These patients may be the best candidates for H. pylori eradication therapy.

Determination of carbohydrate contents from excess light scattering

In the light scattering technique, glycosylation gives rise to excess light scattering for glycoproteins. Assuming additivity of refractive index and using an appropriate refractive index increment for carbohydrate, one can determine the degree of glycosylation from the excess light scattering. Here we have used size-exclusion chromatography in combination with online light scattering, UV absorbance, and refractive index. The results show that the technique accurately determines the carbohydrate content of recombinant stem cell factor.

The membrane-anchored MMP inhibitor RECK is a key regulator of extracellular matrix integrity and angiogenesis

Matrix metalloproteinases (MMPs) are essential for proper extracellular matrix remodeling. We previously found that a membrane-anchored glycoprotein, RECK, negatively regulates MMP-9 and inhibits tumor invasion and metastasis. Here we show that RECK regulates two other MMPs, MMP-2 and MT1-MMP, known to be involved in cancer progression, that mice lacking a functional RECK gene die around E10.5 with defects in collagen fibrils, the basal lamina, and vascular development, and that this phenotype is partially suppressed by MMP-2 null mutation. Also, vascular sprouting is dramatically suppressed in tumors derived from RECK-expressing fibrosarcoma cells grown in nude mice. These results support a role for RECK in the regulation of MMP-2 in vivo and implicate RECK downregulation in tumor angiogenesis.

Prevalence of Helicobacter pylori infection in gastric remnant after distal gastrectomy for primary gastric cancer

BACKGROUND

The development of a second primary cancer in the gastric remnant after gastrectomy for early gastric carcinoma is a problem, and eradication of Helicobacter pylori after the operation has been recommended. However, to date, practical indications for H. pylori eradication after gastric cancer surgery have not yet been reported.

METHODS

We examined H. pylori infection in the gastric remnant after distal gastrectomy for primary gastric cancer. One hundred and nine patients who had had a gastrectomy were studied. Endoscopic findings and results from the urease test, bacteriologic assessment, serological test, and histopathological examination were analyzed.

RESULTS

Seventy-one patients (65.1%) were judged to be positive for H. pylori infection. The prevalence of H. pylori infection was found to be significantly decreased in older patients, patients in whom the operation had been performed a long time before examination, patients with symptoms, and patients with severe reflux gastritis. On the other hand, histologically, chronic and acute gastritis correlated significantly with H. pylori infection. H. pylori prevalence was highest in mildly atrophic mucosa and decreased with more extensive atrophic changes of the mucosa.

CONCLUSIONS

The persistence of H. pylori-related active gastritis in the gastric remnant after gastric cancer surgery was suggested in younger patients with mild atrophic gastritis and without reflux gastritis. These patients may be the best candidates for H. pylori eradication therapy.

Intranasal immunization with recombinant Ascaris suum 14-kilodalton antigen coupled with cholera toxin B subunit induces protective immunity to A. suum infection in mice

Animals can be rendered immune to Ascaris parasites by immunization with infectious-stage larvae. The specific parasite gene products that mediate protective responses in ascariasis are unknown. We have identified a cDNA encoding Ascaris suum 14-kDa antigen (As14) and evaluated the vaccinal effect of the Escherichia coli-expressed recombinant protein (rAs14). GenBank analysis showed that As14 has low similarity at the amino acid level to a Caenorhabditis elegans gene product and to antigens of the filarial nematodes but not to other known proteins. In addition, As14 homologues were found to be expressed in human and dog roundworms. In mice that received intranasal administration of rAs14 coupled with cholera toxin B subunit (rAs14-CTB), there was a 64% reduction of recovery of larvae compared with that in the nontreated group. The vaccinated mice showed a significant increase in the total serum immunoglobulin G (IgG) levels and the mucosal IgA responses. Elevation of the rAs14-specific IgE response was also seen. Measurement of the IgG subclasses showed a higher level of IgG1 and a lower level of IgG2a antibody response in the sera of the immunized mice, suggesting that protection was associated with a type II immune response. As14 is the first protective antigen against A. suum infection to be identified. Our immunization trial results in laboratory animals suggest the possibility of developing a mucosal vaccine for parasitic diseases caused by ascarid nematodes.

Mechanisms and roles of neutrophil infiltration in stress-induced gastric injury in rats

Water-immersion and restraint stress is associated with an increase in neutrophil infiltration into the gastric mucosa, but the mechanism responsible for this infiltration is unclear. We investigated the involvement of intercellular adhesion molecule-1 (ICAM-1) and tumor necrosis factor-alpha (TNF-alpha) in neutrophil infiltration in stress-induced gastric injury in rats. Rats were administered neutralizing antibody against ICAM-1 or TNF-alpha and were subjected to induction of gastric injury by 6-hr water-immersion and restraint stress. To evaluate the relationship between gastric acid and neutrophil infiltration, some rats were given cimetidine before administration of stress. Neutralizing antibodies inhibited both the lesion formation and the increase in myeloperoxidase activity induced by stress. Expression of ICAM-1 on endothelial cells was increased by stress, accompanied by an increase of TNF-alpha-positive cells. Antibody against TNF-alpha inhibited this increase in ICAM-1 expression. Cimetidine almost completely inhibited gastric lesions, but did not affect myeloperoxidase activity. In conclusion, neutrophil infiltration in stress-induced gastric injury may be mediated by ICAM-1 and TNF-alpha, but not gastric acid, and may play crucial roles in the progression of gastric injury.

Effect of Helicobacter pylori culture supernatant on acute reflux esophagitis in a rat model

BACKGROUND/AIMS

Prevalence of Helicobacter pylori, especially cagA-positive strains is inversely related to gastroesophageal reflux disease. The aim of this study was to examine whether H. pylori culture supernatants affect acute esophagitis induced by acid or mixed reflux in rats.

METHODOLOGY

Three different H. pylori strains were used. Acute esophagitis was induced in 59 male Wistar rats by ligation of both the transitional regions between the forestomach and glandular portion, and the pylorus or the lower part of duodenum. After operation, the rats were either left untreated or treated with intragastric injection of either vehicle or H. pylori culture supernatants and were sacrificed 6 or 24 hours later. Esophagitis index, depth of esophageal lesions, esophageal epithelial degeneration, and infiltration of inflammatory cells were examined.

RESULTS

Gross esophageal erosions and ulcers were observed up to mid-esophagus in all animals. H. pylori culture supernatants did not affect esophageal mucosal injury and no histologically significant differences were found among rats.

CONCLUSIONS

H. pylori culture supernatants, regardless of cagA gene expression, did not affect acute esophagitis induced by acid or mixed reflux. This finding suggests that no powerful protective factors against reflux-induced mucosal injury were produced by H. pylori.

Removal of polyA tails from full-length cDNA libraries for high-efficiency sequencing

We have developed a method to overcome sequencing problems caused by the presence of homopolymer stretches, such as polyA/T, in cDNA libraries. PolyA tails are shortened by cleaving before cDNA cloning with type IIS restriction enzymes, such as GsuI, placed next to the oligo-dT used to prime the polyA tails of mRNAs. We constructed four rice Cap-Trapper-selected, full-length normalized cDNA libraries, of which the average residual polyA tail was 4 bases or shorter in most of the clones analyzed Because of the removal of homopolymeric stretches, libraries prepared with this method can be used for direct sequencing and transcriptional sequencing without the slippage observed for libraries prepared with currently available methods, thus improving sequencing accuracy, operations, and throughput.

Sorbicillinol, a key intermediate of bisorbicillinoid biosynthesis in Trichoderma sp. USF-2690

In the course of our screening program for free radical scavengers from Trichoderma sp. USF-2690, we found an unidentified metabolite (1) that appeared by the method used for HPLC analysis. Metabolite 1 gradually decreased with the production of bisorbicillinoids and was easily missed during the general isolation procedure. The LC-ESI-MS (negative) analysis for 1 gave m/z 247 as the (M-1)- ion peak. The hydrolysis of synthetic 6-O-acetylsorbicillinol (+/- -2) by 0.05 M KOH and acetylation of product 1 in an aqueous solution indicated that the structure of 1 was (6S)-4-(2,4-hexadienoyl)-3,6-dihydroxy-2,6-dimethyl-2,4-cyclohexadien-1-one, designated sorbicillinol, a quinol that has been postulated to be important in bisorbicillinoid biosynthesis.

PPAR-gamma ligands inhibit growth of human esophageal adenocarcinoma cells through induction of apoptosis, cell cycle arrest and reduction of ornithine decarboxylase activity

Peroxisome proliferator-activated receptor gamma (PPAR-gamma), a member of the nuclear hormone receptor superfamily, is involved in suppression of growth of several types of tumors such as liposarcoma, breast cancer, prostate cancer, and colon cancer, possibly through induction of cell cycle arrest and/or apoptosis. In this study, we demonstrated expression of PPAR-gamma mRNA and protein in human esophageal carcinoma cells. Expression of PPAR-gamma protein was higher in an adenocarcinoma cell line (TE-7 cells) than in a squamous cell carcinoma cell line (TE-1 cells). PPAR-gamma ligands such as 15-deoxy-Delta12,14-prostaglandin J2 and troglitazone significantly inhibited the growth of TE-7 cells but had less or no effect on growth of TE-1 cells. 15d-PGJ2 and troglitazone induced apoptosis in TE-7 cells but not in TE-1 cells. Troglitazone caused G1 cell cycle arrest and reduced ornithine decarboxylase activity (ODC) in TE-7 cells but not in TE-1 cells. Inhibition by PPAR-gamma ligands of growth of esophageal adenocarcinoma cells may thus be due to induction of apoptosis, G1 cell cycle arrest and reduction of ODC activity.