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Biomedical subjects

Tadao Bamba

Publications and source records attributed to Tadao Bamba.

53 records · Page 3Linked to original sources
PubMed2002

Inhibitory effects of the new anti-inflammatory agent, IS-741, on spontaneous colitis in HLA-B27/beta2-microglobulin transgenic rats.

BACKGROUND: A novel anti-inflammatory drug, IS-741, blocked the adhesion of inflammatory cells to microvascular endothelial cells both in vivo and in vitro. Transgenic rats expressing human leukocyte antigen (HLA)-B27 and human beta2-microglobulin (HLA-B27 rats) spontaneously develop chronic colitis, which resembles human inflammatory bowel disease. In the present study, the authors examined the efficacy of IS-741 against spontaneous colitis in HLA-B27 rats. METHODS: The HLA-B 27 rats were divided in two groups after the development of colitis. IS-741 was dissolved in water and administered orally (10 mg/kg) once per day for 14 days. RESULTS: The HLA-B27 rats treated with IS-741 remained healthy; the wet weight of the colon was significantly lower in the IS-741-treated group. Histological examinations revealed a marked infiltration of inflammatory cells into both the mucosa and the submucosa in the control HLA-B27 rats, but these changes were attenuated in the IS-741-treated group. The mucosal damage score was also significantly reduced by treatment with IS-741. IS-741 significantly reduced the mucosal myeloperoxidase activity and mucosal cytokine-induced neutrophil chemoattractant-1 levels. IS-741 also reduced CD3-positive T-cell infiltration. CONCLUSION: IS-741 suppressed the spontaneous colitis that developed in HLA-B27 rats. Some of the actions of IS-741 may be associated with its inhibitory effects on the adhesion of neutrophils to endothelial cells. The findings from the present study suggest that IS-741 may be a useful new therapeutic agent for inflammatory bowel disease.

Animals↗
PubMed2002

Mast cells may not play a crucial role in the pathogenesis of experimental closed duodenal loop-induced pancreatitis in rats.

INTRODUCTION: Ws/Ws rats have a small deletion of the c-kit gene and are deficient in both mucosal-type mast cells and connective tissue-type mast cells. AIM: To investigate the role of pancreatic mast cells in the development of experimental closed duodenal loop (CDL)-induced pancreatitis using Ws/Ws rats. METHODOLOGY: Pancreatitis was induced by the CDL technique for 5 and 12 hours, and the subsequent ascites volume, wet pancreatic weight, pancreatic myeloperoxidase activities, and serum amylase levels were evaluated. The pancreatic tissue damage was also evaluated histologically. RESULTS: The CDL technique induced equally severe ascites, pancreatic edema and hyperemia, and hyperamylasemia in the Ws/Ws versus the control (+/+) rats. The microscopic mucosal damage score was also equivalent in the Ws/Ws and control (+/+) rats, and there were no significant differences in mucosal myeloperoxidase activity between the Ws/Ws and control (+/+) rats. CONCLUSION: These results indicate that mast cells may not be crucial for the development of CDL-induced pancreatitis.

Amylases↗
PubMed2002

IL-17 stimulates inflammatory responses via NF-kappaB and MAP kinase pathways in human colonic myofibroblasts.

Colonic subepithelial myofibroblasts (SEMFs) may play a role in the modulation of mucosal inflammatory responses. We investigated the effects of interleukin (IL)-17 on IL-6 and chemokine [IL-8 and monocyte chemoattractant protein (MCP)-1] secretion in colonic SEMFs. Cytokine expression was determined by ELISA and Northern blotting. Nuclear factor kappa B (NF-kappaB) DNA-binding activity was evaluated by electrophortetic gel mobility shift assay (EMSA). The activation of mitogen-activated protein kinase (MAPK) was assessed by immunoblotting. IL-6, IL-8, and MCP-1 secretions were rapidly induced by IL-17. IL-17 induced NF-kappaB activation within 45 min after stimulation. A blockade of NF-kappaB activation markedly reduced these responses. MAPK inhibitors (SB-203580, PD-98059, and U-0126) significantly reduced the IL-17-induced IL-6 and chemokine secretion. The combination of either IL-17 + IL-1beta or IL-17 + tumor necrosis factor (TNF)-alpha enhanced cytokine secretion; in particular, the effects of IL-17 + TNF-alpha on IL-6 secretion were much stronger than the other responses. This was dependent on the enhancement of IL-6 mRNA stability. In conclusion, human SEMFs secreted IL-6, IL-8, and MCP-1 in response to IL-17. These responses might play an important role in the pathogenesis of gut inflammation.

Antineoplastic Agents↗
PubMed2002

Oral administration of a product derived from Clostridium butyricum in rats.

Recent studies have suggested that short chain fatty acids (SCFAs) exert a therapeutic effect on some human and experimental animal diseases. Clostridium butyricum produces high levels of SCFAs in the gut lumen. The aim of the present study was to analyze the product derived from Clostridium butyricum in a culture system, and to develop methods to eliminate the odor derived from SCFAs in the product. Clostridium butyricum was incubated in CS medium for 24 h and subsequently in CS broth for 24 h. The suspension of Clostridium butyricum in the broth was centrifugated and the supernatant was analyzed. The results showed this product contained high levels of SCFAs, especially acetic acid and n-butyric acid. Many food materials were tested in order to eliminate the odor derived from SCFAs in the product. Of the food materials tested, yogurt was shown to most effectively eliminate the odor. Using a yogurt base, we prepared a special food additive. Use of the additive completely eliminated the odor of the product derived from Clostridium butyricum. Finally, we administered the product with the additive to Sprague-Dawley rats for 14 days. The rats grew normally for the duration of the experimental period. It is possible that this novel product with the additive exerts therapeutic effects on some gastointestinal disorders.

Acetic Acid↗
PubMed2002

Prebiotic treatment of experimental colitis with germinated barley foodstuff: a comparison with probiotic or antibiotic treatment.

There is increasing evidence that intestinal microflora play an important role in the pathogenesis of ulcerative colitis. Therefore, modification of the microflora by prebiotics, probiotics, and antibiotics may be a rational approach for controlling intestinal inflammation. Germinated barley food-stuff (GBF) is an insoluble mixture of glutamine-rich protein and hemicellulose-rich dietary fiber. GBF is utilized efficiently by Bifidobacterium, Lactobacillus, and Eubacterium and converted by them into lactate, acetate, and butyrate. These bacterial organic acids preserve a favorable intestinal condition. We have previously shown that GBF has attenuated intestinal inflammation in patients with ulcerative colitis and experimental colitis models through prebiotic actions. The aim of this study was to compare the effect of GBF with that of probiotics and antibiotics in an experimental colitis model. Colitis was induced by feeding male SD rats with a diet containing 3.0-3.5% dextran sodium sulfate (DSS). The therapeutic effect of oral administration of a prebiotic (GBF), probiotics (mixture of Lactobacillus and Clostridium butyricum), antibiotics (vancomycin, metronidazole), and the vehicle was determined by assessing clinical and pathological scores on day 6 after initiation of colitis. Butyrate concentrations in the cecal content were also determined. GBF treatment significantly reduced colonic inflammation as assessed by clinical scores with an increase in cecal butyrate levels. Probiotic treatment with a mixture of Lactobacillus and Clostridium butyricum did not show such an effect. Both antibiotic treatments significantly attenuated clinical and pathological scores. However, in contrast to GBF, this treatment led to a significant decrease in cecal butyrate levels. These data suggest that modification of the intestinal microflora by prebiotics, including GBF, may serve as a useful adjunct in the treatment of ulcerative colitis as well as antibiotic treatment.

Animal Feed↗
PubMed2002

Short-term oral administration of a product derived from a probiotic, Clostridium butyricum induced no pathological effects in rats.

Recent studies have suggested that short chain fatty acids (SCFAs) exert a therapeutic effect on some human and experimental animal diseases. In a previous study, we showed that Clostridium butyricum produces high levels of SCFAs in the culture system used. In addition, an additive based on yogurt was effective in eliminating and masking the odor derived from SCFAs in the product. The aim of the present study was to investigate the effects for oral administration of the product, which was derived from Clostridium butyricum and contains a high level of SCFAs, in rats. Male and female Wistar Hannover GALAS rats, 5 weeks old, were allowed a mixture of the standard diet plus the product derived from Clostridium butyricum (50% w/w) with 0.1% additive for 17 days (n=6). The control rats were also allowed a standard diet plus tap water (50% w/w) with 0.1% additive (n=6). After 17 days, a laparotomy was performed. A hemocyte count, and biochemical and electrolyte analyses were subsequently carried out. The esophagus, stomach, small intestine, cecum and large intestine were investigated macroscopically and microscopically. Results showed that the rats grew normally for the duration of the experimental period. In particular, the body weights of the product-fed male rats were significantly increased as compared to those of the control-fed male rats. There were no significant differences in the organic weight between the product-fed and control-fed rats, except for a significantly increased weight of the small intestine in the product-fed female rats. No pathological abnormalities were found in the hemocyte count, the biochemical and electrolyte analyses, or the macroscopic and microscopic findings. It is possible that this novel product with the additive exerts therapeutic effects on some gastrointestinal disorders.

Administration, Oral↗
PubMed2002

[Treatment of Crohn's disease by anti-cytokine monoclonal antibodies].

Pro-inflammatory cytokines such as TNF-alpha and IL-6 play a role in the pathogenesis of inflammatory bowel disease (IBD). Recent advances in the treatment with IBD patients, in particular Crohn's disease, are the use of anti-cytokine monoclonal antibodies against TNF-alpha. Three types of anti-human TNF-alpha antibodies have been developed. Infliximab is a chimeric antibody containing Fab portion of anti-human TNF-alpha mouse IgG and Fc portion of human IgG. CDP571 is a humanized (-95% human residues) monoclonal antibody, and is potentially less immunogenic than chimeric antibody. In this paper, we summarize the recent reports describing the clinical efficacy of these antibodies in the treatment of Crohn's disease.

Animals↗
PubMed2002

Suppressive effects of a new anti-inflammatory agent, IS-741, on dextran sulfate sodium-induced experimental colitis in rats.

A novel anti-inflammatory drug, IS-741, blocked the adhesion of inflammatory cells to microvascular endothelial cells in vivo and in vitro. We examined the efficacy of IS-741 in a dextran sulfate sodium (DSS)-induced colitis model. DSS colitis was induced by the oral administration of 3% DSS for 10 days in rats. The rats were then divided in two groups: a 1% DSS plus IS-741 group and a 1% DSS plus water group. IS-741 was dissolved in water and administered orally (10 mg/kg) once per day for 14 days. The rats treated with DSS plus IS-741 remained healthy, and their body weight increased. The wet weight of the colon was significantly lower and the total colon length was significantly longer in the IS-741-treated group. Histological examinations revealed a marked infiltration of inflammatory cells into both the mucosa and submucosa in the DSS plus water group, but these changes were attenuated in the IS-741-treated group. The mucosal damage score was significantly reduced by treatment with IS-741. IS-741 also significantly reduced the mucosal myeloperoxidase activity. FACS analysis revealed that IS-741 significantly reduced Mac-1 expression on blood neutrophils. In conclusion, IS-741 suppressed DSS-induced experimental colitis in rats. Some of the action of IS-741 may be associated with its inhibitory effects on the Mac-1 expression of neutrophils in association with the blockade of their adhesion to endothelial cells. The findings in this study suggest that IS-741 may be a useful new therapeutic agent for inflammatory bowel disease.

Animals↗
PubMed2002

Elevated serum anti-carbonic anhydrase II antibodies in patients with ulcerative colitis.

An autoimmune mechanism has been postulated for the pathogenesis of ulcerative colitis (UC). The aim of this study was to evaluate the presence of anti-carbonic anhydrase (CA) I and anti-CA II antibodies in a series of inflammatory bowel disease (IBD) patients. We studied 58 IBD patients [36 UC patients and 21 patients with Crohn's disease (CD)]. As a control, 24 healthy individuals and 12 patients with non-IBD diarrheal diseases were tested. Serum anti-CA I and anti-CA II antibodies were quantified by enzyme-linked immunosorbent assay. Anti-CA II antibody was detected in 27.8% of UC patients, whereas anti-CA I antibody was detected in only 5.6% of UC patients. Positive rate of anti-CA II antibody was significantly higher in UC patients as compared to the control. In CD patients and non-IBD diarrheal patients, there were no significant increase in positive rate of either anti-CA I or II antibody. These results suggest that autoimmune responses against CA II may be involved in the pathogenesis of UC, and similar mechanism may participate in the development of pancreatic lesions in UC patients.

Adult↗
PubMed2002

In vitro alterations in fecal short chain fatty acids and organic anions induced by the destruction of intestinal microflora under hypotonic and aerobic conditions.

The pathogenesis of inflammatory bowel disease (IBD) remains unknown. It has been suggested that luminal factors such as the microflora, short chain fatty acids (SCFAs), food antigens and so on play important roles in the disease progression. Many reports have revealed alterations in the SCFA and organic acid concentration of the colon, especially increased lactate and decreased butyrate, in IBD patients. The mechanisms responsible for these alterations, however, remain unclear. Therefore, the effects of aerobic conditions on the alterations in the SCFA and organic anion levels in the feces was evaluated. Fecal specimens were collected from 5 healthy volunteers. Under aerobic condition, a mixture of feces and distilled water was incubated in 37 degrees C for 1 and 3 h. The pH, osmotic pressures, the concentrations of potassium, bicarbonate, SCFA and organic anion, and the activities of alpha-amylase and lactate dehydrogenase (LDH) in the mixture were then measured. We also examined any changes in the microscopic microflora under the hypotonic and aerobic conditions. The results showed the osmotic pressure, and the concentrations of lactate and SCFAs (formate, acetate, propionate and n-valerate) were progressively increased with longer incubation times, and reached a statistically significant difference. In particular, the ratios of lactate, succinate and n-valerate after 1 and 3 h of incubation increased remarkably. In contrast, the electrolyte levels and both alpha-amylase and LDH activities were not altered significantly. Microscopically, the microflora in the mixture decreased with prolonged incubation times. These data suggest that under these in vitro conditions, the organic anion and SCFA levels in the feces easily increased. It is probable that the alterations in the SCFA and organic anion levels in IBD patients may be partly due to intracellular components derived from microflora destroyed under hypotonic and aerobic conditions in the colonic lumen, for example caused by mucosal bleeding. These alterations may influence the pathogenesis and progression of IBD.

Adult↗
PubMed2002

Inhibitory effects of somatostatin on tumor necrosis factor-alpha-induced interleukin-6 secretion in human pancreatic periacinar myofibroblasts.

Pancreatic periacinar myofibroblasts are considered to be therapeutic targets for the suppression of acute pancreatitis. To elucidate the mechanisms mediating the therapeutic actions of somatostatin on acute pancreatitis, we investigated how somatostatin affects the tumor necrosis factor (TNF)-alpha-induced interleukin (IL)-6 and IL-8 secretion from pancreatic myofibroblasts. Cytokine secretion was determined by enzyme-linked immunosorbent assay (ELISA) and Northern blotting. Nuclear factor (NF)-kappaB DNA-binding activity was evaluated by electrophoretic mobility shift assay (EMSAs). The expression of somatostatin receptor (SSTR) mRNA was evaluated by reverse transcription-polymerase chain reaction (RT-PCR). Somatostatin dose-dependently inhibited the TNF-alpha-induced IL-6 secretion. In comparison, the effects on IL-8 secretion were modest. Northern blot analysis demonstrated that somatostatin decreased the TNF-alpha-induced IL-6 mRNA expression, and that this effect was completely blocked by the somatostatin antagonist cyclo-somatostatin. Furthermore, somatostatin suppressed TNF-alpha-induced NF-kappaB activation. These cells bear SSTR subtypes 1 and 2. Somatostatin down-regulated the TNF-alpha-induced IL-6 secretion in human pancreatic periacinar myofibroblasts. These findings suggest that some of the therapeutic actions of somatostatin on acute pancreatitis might be mediated by reducing local IL-6 secretion in the pancreas.

Acute Disease↗
PubMed2002

Alteration in expression of polyamine and glucose-related enzyme mRNA after small bowel resection in the rat residual ileum.

The adaptive hyperplasia of the residual intestine after a massive bowel resection is not fully understood. We investigated the alterations in polyamine and glucose-related enzyme mRNA expression during intestinal adaptation. Six-week-old male Wistar rats underwent an 80% resection of the small intestine. The residual ileum was removed on the preoperative day (control) and on postoperative day (POD) 1, 3, 5 and 7. The total RNA was extracted from the mucosa, and a Northern blot analysis was performed. In the residual small intestine, the expression of polyamine synthesis enzymes, ornithine decarboxylase (ODC) and S-adenosylmethionine decarboxylase (SAMDC) mRNAs were increased on POD 1. The expression of polyamine degradation enzymes diamine oxidase (DAO) and spermidine/spermine N1-acetyltransferase (SSAT) mRNA did not change dramatically. Antizyme-1 (AZ-1) mRNA was significantly increased on POD 1. The mRNA expression of glucose absorption and metabolism-related proteins, including the Na+-dependent D-glucose cotransporter (SGLT1), fructose-6-phosphate,2-kinase/fructose-2,6-bisphosphatase (Fru-6-P,2-kinase/Fru-2,6-Pase) and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) were only slightly changed on POD 1. The enzymes responsible for polyamine biosynthesis but not catabolism were upregulated at the translational level in enterocytes after a small bowel resection. The expression of glucose transport and glycolysis enzyme mRNAs did not increase after a small bowel resection.

Adenosylmethionine Decarboxylase↗
PubMed2002

Interleukin (IL)-4 and IL-17 synergistically stimulate IL-6 secretion in human colonic myofibroblasts.

There is increasing evidence that interleukin (IL)-4 can aid in Th1-type inflammatory responses in chronic colitis models. In this study, we evaluated the effects of IL-4 and/or IL-17 on IL-6 secretion in human colonic myofibroblasts. IL-6 secretion was determined by ELISA and Northern blotting. IL-6 secretion was rapidly induced by either IL-4 or IL-17. IL-17 induced IL-6 mRNA expression within 1 h after stimulation, and reached a maximum at 3 h. IL-6 mRNA induction by IL-4 occurred more rapidly. A maximum induction of IL-6 mRNA by IL-4 was observed at 1 h after stimulation, and this was rapidly decreased. The combination of IL-4 plus IL-17 greatly enhanced IL-6 secretion and mRNA expression. In conclusion, IL-4, in particular IL-4 plus IL-17, induced IL-6 secretion in human colonic myofibroblasts. Th2 immune responses might play an important role in the pathogenesis of gut inflammation.

Cells, Cultured↗
PubMed2001

Sodium butyrate enhances complement-mediated cell injury via down-regulation of decay-accelerating factor expression in colonic cancer cells.

Decay-accelerating factor (DAF) expressed on the surface of colonic cancer cells presents a barrier to complement-mediated clearance by contributing to the ineffectiveness of the humoral immune response. In this study, to investigate the mechanisms responsible for the anti-tumor effects of butyrate, we evaluated how butyrate modulates DAF expression in colonic cancer cells. Three colonic cancer cell lines (HT-29, Caco-2, and T84 cells) were studied. DAF protein expression was assessed by western blot, and DAF mRNA expression was evaluated by northern blot. Complement C3 deposition on the surface of colonic cancer cells was determined by enzyme-linked immunosorbent assay (ELISA). The promoter activity of the DAF gene was assessed by a reporter gene-luciferase assay. Butyrate reduced the basal and interleukin-4 (IL-4)- and tumor necrosis factor-alpha (TNF-alpha)-induced expression of DAF protein and mRNA in HT-29 cells. It increased the susceptibility to complement attack and enhanced C3 deposition on HT-29 cells. The inhibitory effect of butyrate on DAF mRNA expression was also observed in T84 and Caco-2 cells. Butyrate decreased basal DAF expression at both transcriptional and post-transcriptional levels. The inhibitory effect of butyrate on IL-4-induced DAF expression was closely associated with a blockade of IL-4-induced DAF mRNA stability. TNF-alpha-induced transcriptional activation and the increased stability of the DAF gene were also blocked by butyrate. Similar but weak effects were induced by trichostatin A, a potent histone deacetylase inhibitor, suggesting that histone acetylation might participate in butyrate activity. These observations indicate that both a down-regulation of DAF expression and the induction of susceptibility to complement attack contribute to the anti-tumor effects of butyrate in colonic cancer.

Antineoplastic Agents↗
PubMedDate not supplied

Combination of enprostil and cimetidine is more effective than cimetidine alone in treating gastric ulcer: prospective multicenter randomized controlled trial.

BACKGROUND/AIMS: Little is known about the clinical efficacy of co-therapy of enprostil, a prostaglandin E2 analogue, with a histamine H2-receptor antagonist. We aimed to assess the additive benefit of enprostil in combination with cimetidine for treating gastric ulcer in a prospective multicenter randomized controlled trial. METHODOLOGY: In 43 hospitals 171 intention-to-treat (ITT) patients, diagnosed as having gastric ulcer by endoscopy, were randomly allocated to receive either enprostil 25microg b.i.d. and cimetidine 400mg b.i.d. (Group E=85), or cimetidine 400mg b.i.d. alone (Group C=86) for 8 weeks. Healing was examined by endoscopy at 4 and 8 weeks. RESULTS: Per protocol (PP) analysis comprised 166 patients (E=82, C=84). Despite no significant advantage at 4 weeks (E=55.3%, C=42.2%), the combination yielded higher healing rates at 8 weeks by ITT (E=89.4%, C=68.6%; p<0.001) and PP analysis (E=92.7%, C=70.2%; p<0.001). Symptom relief rates [E, C] at 2, 4, and 8 weeks were [80.2%, 68.3%] (not significant), [97.4%, 88.3%] (p<0.05), and [95.6%, 87.0%] (p<0.05), respectively. Significant advantage was observed in the patients aged 40 or older, with solitary ulcer (>5mm in diameter), and without smoking or drinking habits. No adverse effects were critical. CONCLUSIONS: Enprostil safely and significantly augmented gastric ulcer healing and symptom relief by cimetidine.

Adult↗