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Tadao Bamba

Publications and source records attributed to Tadao Bamba.

At least 37 records · Page 2Linked to original sources
PubMed2003

Effects of the soluble fibre pectin on intestinal cell proliferation, fecal short chain fatty acid production and microbial population.

AIM: Although pectin, a dietary fibre, has been suggested to possess some trophic effects on the intestine, the mechanisms involved remain unclear. This study aimed to evaluate the effects of pectin on rat intestinal cell proliferation and the intraluminal environment. METHODS: Control and pectin-fed rats were given a fibre-free elemental diet (ED) and an ED containing 2.5% pectin, respectively. On the 15th day, the length, weight and number of Ki-67-positive cells from each intestinal segment, and the short chain fatty acids (SCFAs) and microbial population in the caecum were measured. Plasma glucagon-like peptide-2 (GLP-2) concentration and GLP-2 receptor (GLP-2R) mRNA levels in the epithelium were also determined. RESULTS: Pectin supplementation resulted in significant increases in the length, weight, and number of Ki-67-positive cells in the ileum, caecum and colon. Although pectin supplementation did not affect the caecal microbial flora that produced SCFAs, the caecal SCFA content was significantly increased. Pectin supplementation also induced an increase in the plasma GLP-2 concentration, but did not affect the GLP-2R mRNA levels in the small intestine. CONCLUSIONS: The increases in the caecal SCFAs and plasma GLP-2 levels induced by pectin supplementation may cause mucosal proliferation in the lower intestinal tract.

Animals↗
PubMed2003

Treatment of ulcerative colitis patients by long-term administration of germinated barley foodstuff: multi-center open trial.

Germinated barley foodstuff (GBF), which mainly consists of dietary fiber and glutamine-rich protein, is a prebiotic for ulcerative colitis (UC). In our previous study, we carried out a clinical trial of GBF with mildly to moderately active UC patients and showed that GBF treatment was able to attenuate the symptoms of UC in a relatively short-term. The aim of this study was to investigate the efficacy of long-term administration of GBF in the treatment of UC in a multi-center open trial. Twenty-one patients with mildly to moderately active UC received 20-30 g of GBF for 24 weeks in an open-label protocol while baseline treatments (5-amino-salicyrate compounds and/or steroids) were continued. The response to the GBF treatment was evaluated using a clinical scoring and after 24 weeks of observation, the GBF group showed a significant decrease in clinical activity index (especially, the degree of visible blood in stools and the presence of nocturnal diarrhea) compared with the control group (p<0.05). No side effects related to GBF were observed. In conclusion, GBF can reduce the clinical activity of UC over long-term as well as short-term administration. Nutraceutical GBF therapy may have a place in long-term management of UC, but controlled studies are needed to demonstrate its efficacy in the treatment of this disorder.

Adult↗
PubMed2002

Extracellular signal-regulated kinases 1 and 2 participate in interleukin-17 plus tumor necrosis factor-alpha-induced stabilization of interleukin-6 mRNA in human pancreatic myofibroblasts.

In human pancreatic myofibroblasts, interleukin (IL)-17 markedly enhances tumor necrosis factor (TNF)-alpha-induced IL-6 secretion through the induction of IL-6 mRNA stabilization. Induced stability of IL-6 mRNA was markedly decreased by the inhibitors of extracellular signal-regulated kinase (ERKs), PD98059 and U0216. This indicates that activation of the ERK pathway is involved in the induction of IL-6 mRNA stabilization by IL-17 plus TNF-alpha.

Cells, Cultured↗
PubMed2002

IL-17 selectively down-regulates TNF-alpha-induced RANTES gene expression in human colonic subepithelial myofibroblasts.

IL-17 enhances the TNF-alpha-induced IL-6 and IL-8 secretion in human colonic subepithelial myofibroblasts. In this study, we investigated how IL-17 modulates RANTES secretion in these cells. TNF-alpha potently induced RANTES secretion, but IL-17 dose-dependently inhibited the TNF-alpha-induced RANTES secretion. This was also observed at the mRNA level. Even after pretreatment with TNF-alpha for 12 h, the inhibitory effect of IL-17 was detectable. IL-17 did not affect the TNF-alpha-induced stability of the RANTES gene. IL-17 significantly decreased the TNF-alpha-induced increase in RANTES promoter activity, and IL-17 actually blocked the TNF-alpha-induced RANTES gene transcription. EMSAs demonstrated that IL-17 did not modulate the TNF-alpha-induced NF-kappaB DNA-binding activity, but markedly decreased TNF-alpha-induced IFN regulatory factor-1 (IRF-1) DNA-binding activity. Because cooperation between NF-kappaB and IRF-1 is important in the TNF-alpha-induced RANTES gene expression, the major mechanism mediating the inhibitory effect of IL-17 may be achieved by the inhibition of IRF-1 DNA-binding activity.

Base Sequence↗
PubMed2002

In vivo cytokine responses in gut-associated lymphoid tissue (GALT) and spleen following oral administration of staphylococcal enterotoxin B.

The mechanisms responsible for oral tolerance have been analyzed using various antigens. The induction of oral nonresponsiveness to low doses of Staphylococcal Enterotoxin B (SEB), in which SEB-reactive clonal anergy and deletion are involved, has also been confirmed. However, few reports have examined the cytokine milieu of the mucosal and peripheral lymphoid tissue during tolerance induction after the oral administration of SEB. In this study, to elucidate the mechanism responsible for the oral tolerance to low dose of SEB, the cytokine responses of the gut-associated lymphoid tissues (GALT) and the spleen were examined using the reverse transcription-polymerase chain reaction (RT-PCR) method. After the oral administration of a single low dose of SEB, the expressions of Th2 and TGF-beta, and to a lesser extent Th1 mRNA were observed in the mucosa. In contrast, following repeated oral low doses of SEB, in a manner different from previous results using conventional antigens, no cytokine enhancements were demonstrated in the GALT or the spleen. In conclusion, the involvement of unknown inhibitory or regulatory cytokines, together with SEB-reactive clonal anergy and deletion, is suggested in the induction of oral tolerance to low dose SEB.

Animals↗
PubMed2002

Effect of a conserved mutation in uridine diphosphate glucuronosyltransferase 1A1 and 1A6 on glucuronidation of a metabolite of flutamide.

OBJECTIVE: We investigated how the conserved mutation (Y486D) changed the kinetic parameters of uridine diphosphate glucuronosyltransferase 1A1 and 1A6 (UGT1A1 and 1A6) for 2-amino-5-nitro-4-trifluoromethylphenol, which is a major metabolite of flutamide, a nonsteroidal antiandrogenic agent. METHODS: The wild-type or mutant cDNA-expressed UGT was co-incubated with 2-amino-5-nitro-4-trifluoromethylphenol (aglycone) and uridine diphosphate-glucuronic acid (UDP-GA, donor substrate). The glucuronidation of the aglycone was determined. RESULTS: The maximum velocities of the mutant UGT1A1 and UGT1A6 were about 12% and less than 1% of the corresponding wild-type, respectively. The Michaelis constant (K(M)) for the aglycone of the wild-type UGT1A1 was double that of the mutant, but the K(M) for UDP-GA of the wild-type UGT1A1 was not significantly different from that of the mutant. CONCLUSION: Patients with Y486D may accumulate excessive 2-amino-5-nitro-4-trifluoromethylphenol, which might lead to unexpected toxicity.

Androgen Antagonists↗
PubMed2002

Analysis of alpha-amylase-derived pyridylamino-dextran sulfate oligomers by the combination of size-exclusion and reversed-phase high-performance liquid chromatography.

In a previous study, we reported a novel method for the separation and quantification of a strong negatively charged material, dextran sulfate sodium (DSS), using fluorometric labeling with 2-aminopyridine and size-exclusion high-performance liquid chromatography. In the present study, we developed a method for the separation of pyridylamino-DSS (PA-DSS) using reversed-phase high-performance liquid chromatography (RPLC). In vitro enzymatic degradation of the PA-DSS was carried out using alpha-amylase. In RPLC, depolymerized PA-DSS was eluted on the basis of molecular mass (in the order pentamer, trimer, dimer, and monomer of PA-DSS) and separations were more sharply than in size-exclusion chromatography. The combination of RPLC and size-exclusion chromatography also separated depolymerized PA-DSS as effectively as RPLC alone.

Chromatography, Gel↗
PubMed2002

IL-6 secretion by human pancreatic periacinar myofibroblasts in response to inflammatory mediators.

There is increasing evidence that IL-6 plays an important role in the pathophysiology of acute pancreatitis via its broad proinflammatory actions. To identify the local biosynthetic site for IL-6 in human pancreas, we investigated IL-6 secretion in human pancreatic periacinar myofibroblasts. IL-6 secretion was determined by ELISA and Northern blotting. The activation of NF-kappaB was assessed by EMSA. The activation of mitogen-activated protein kinase (MAPK) was assessed by immunoblotting. IL-6 secretion was rapidly induced by IL-17, IL-1beta, and TNF-alpha. EMSAs demonstrated that IL-17, IL-1beta, and TNF-alpha induced NF-kappaB activation within 1.5 h after stimulation, and a blockade of NF-kappaB activation by the pyrrolidine derivative of dithiocarbamate and tosyl-phe-chloromethylketone markedly reduced the IL-17-, IL-1beta-, or TNF-alpha-induced IL-6 gene expression. Furthermore, IL-17, IL-1beta, and TNF-alpha induced a rapid activation of extracellular signal-related kinase p42/44 and p38 MAPKs, and specific MAPK inhibitors (SB203580, PD98059, and U0216) significantly reduced IL-17-, IL-1beta-, or TNF-alpha-induced IL-6 secretion, indicating the role of MAPKs in the induction of IL-6. The combination of either IL-17 plus IL-1beta or IL-17 plus TNF-alpha enhanced IL-6 secretion and IL-6 mRNA expression; in particular, the effects of IL-17 plus TNF-alpha were much stronger than those induced by IL-17 plus IL-1beta. TNF-alpha-induced IL-6 mRNA degraded rapidly at any concentrations, and the combination of IL-17 and TNF-alpha markedly enhanced IL-6 mRNA stability. This indicates that the effects of IL-17 plus TNF-alpha were regulated at the post-transcriptional level. In conclusion, pancreatic periacinar myofibroblasts secreted a large amount of IL-6 in response to proinflammatory cytokines. These cells might play an important role in the pathogenesis of acute pancreatitis via IL-6 secretion.

Cells, Cultured↗
PubMed2002

Intestinal subepithelial myofibroblasts in inflammatory bowel diseases.

Colonic subepithelial myofibroblasts (SEMFs) may play a role in the regulation of a number of epithelial cell functions and in the mucosal repair process. In this study, we evaluated the changes in alpha-smooth muscle actin (SMA)- and vimentin-positive SEMFs in the inflamed mucosa of inflammatory bowel disease (IBD) patients. Tissue samples were surgically obtained from patients with active ulcerative colitis (UC) (n = 5) and active Crohn's disease (CD) (n = 5). Normal intestinal tissues were also obtained (n = 5). The SMA and vimentin expression was evaluated by standard immunohistochemical procedures. In normal intestinal mucosa, SMA- and vimentin-positive SEMFs were located immediately subjacent to the basement membrane, juxtaposed against the bottom site of the epithelial cells. In the inflamed mucosa of active UC patients, there were relatively more SMA-positive cells compared with normal mucosa. In particular, the increase in SMA-positive cells was greatest at the marginal area of deep ulcers of UC patients. In active CD mucosa, SMA-positive cells were increased in all samples, and a marked increase was observed in two samples. The number of SMA-positive SEMFs was relatively higher in CD mucosa than in UC mucosa. An [3H]thymidine incorporation study demonstrated that platelet-derived growth factor (PDGF)-BB, basic fibroblast growth factor (bFGF), and insulin-like growth factor (IGF)-I significantly increased the uptake of [3H]thymidine into isolated SEMFs. In particular, PDGF had a strong stimulatory effect. We concluded that colonic SEMFs may play an important role in the repair process of IBD.

Actins↗
PubMed2002

Treatment of ulcerative colitis by feeding with germinated barley foodstuff: first report of a multicenter open control trial.

BACKGROUND: Germinated barley foodstuff (GBF) is a prebiotic foodstuff that effectively increases luminal butyrate production by stimulating the growth of protective bacteria. In the first pilot study, GBF has been shown to reduce both clinical activity and mucosal inflammation in ulcerative colitis (UC). The aim of this study was to investigate the efficacy of GBF in the treatment of UC in a multicenter open control trial. METHODS: Eighteen patients with mildly to moderately active UC were divided into two groups using a random allocation protocol. The control group (n = 7) were given a baseline anti-inflammatory therapy for 4 weeks. In the GBF-treated group (n = 11), patients received 20-30 g GBF daily, together with the baseline treatment, for 4 weeks. The response to the treatments was evaluated clinically and endoscopically. Fecal microflora were also analyzed. RESULTS: After 4 weeks of observation, the GBF-treated group showed a significant decrease in clinical activity index scores compared with the control group (P < 0.05). No side effects related to GBF were observed. GBF therapy increased fecal concentrations of Bifidobacterium and Eubacterium limosum. CONCLUSIONS: Oral GBF therapy may have the potency to reduce clinical activity of UC. We believe that these results support the use of GBF administration as a new adjunct therapy for UC.

Adult↗
PubMed2002

Luminal polyamines upregulate transmural glucose transport in the rat small intestine.

BACKGROUND: Polyamines, which are contained in many foods, play an important role in the growth and differentiation of the enterocyte, but their role in glucose transport is unclear. Using isolated rat small intestine and a nonrecirculating perfusion system, we studied the effect of luminal polyamines on glucose uptake and on the concentration of sodium-glucose transporter 1 (SGLT1) and glucose transporter 5 (GLUT5) proteins. METHODS: In the control group, 300mg glucose solution was administered through the jejunum, and the glucose concentration in the portal vein was measured for 15 min. In treatment groups, various concentrations of polyamine (putrescine [Put] or spermine [Spm]) were administered simultaneously with the glucose. At the end of the perfusion period, the amount of SGLT1, GLUT5, and aminopeptidase N (APN) in the brush border membrane was subjected to Western blot analysis. RESULTS: Glucose concentration in the portal vein increased after the simultaneous administration of glucose and polyamines, and the area under the curve (AUC) after the 15-min perfusion was enhandced to 188%, 196%, 132%, and 192% by 0.5mM Spm, 4mM Spm, 1 mM Put, and 8 mM Put, respectively. The brush border membrane concentration of SGLT1 protein 15 min after polyamine administration was also enhanced in all treatment groups, and it correlated with the AUC. The concentration of GLUT5, on the other hand, was reduced by 4mM Spm, and the concentration of APN was not affected by polyamine administration. CONCLUSIONS: Luminal polyamines increase glucose absorption in the small intestine via the rapid enhancement of SGLT1 protein in the brush border membrane.

Animals↗
PubMed2002

Immunohistochemical analysis of cell cycle-regulating-protein (p21, p27, and Ki-67) expression in gastroesophageal reflux disease.

BACKGROUND: The aim of this study was to carry out an immunohistochemical analysis of cell cycle-regulating-protein (p21, p27, and Ki-67) expression in endoscopic biopsy samples obtained using angled biopsy forceps. METHODS: The study was based on the examination of endoscopic esophageal biopsy specimens obtained from 46 patients with evidence of reflux and from 10 normal control subjects without clinical reflux. RESULTS: The percentage of samples containing the lamina propria was 5.7% using standard forceps ( n = 53) and 83.3% using the angled forceps ( n= 67). The use of angled forceps allowed the detection of inflammatory cell accumulation in the lamina propria even in patients with modified Los Angeles (LA) system grades N and M. In normal esophageal mucosa, Ki-67-positive cells were detected within the lower parts of the basal zone, and p21- and p27-positive cells were not detected. In samples from grade N and M patients, no histological changes were detectable by standard H&E staining. However, the area of Ki-67-positive cells was slightly expanded compared with normal mucosa, and p21- and p27-positive cells were clearly detectable from the lower to middle part of the epithelium. The area of Ki-67-, p21-, and p27-positive cells tended to expand upward in the epithelium with gastroesophageal reflux disease (GERD) severity based on the LA classification grading. CONCLUSIONS: The use of angled biopsy forceps allows the evaluation of inflammatory responses at the level of the lamina propria and makes it possible to assess the expression of cell cycle-regulating proteins in the entire epithelium. The evaluation of these responses may be helpful in the diagnosis of endoscopically negative GERD.

Basement Membrane↗
PubMed2002

Stem cell factor expressed in human gastric mucosa in relation to mast cell increase in Helicobacter pylori-infected gastritis.

We previously reported mast cell increases in H. pylori gastritis. To determine the mechanism, we investigated the kinetics of mast cells and mast cell growth factor (stem cell factor, SCF) in H. pylori-positive and -negative gastric mucosa. Biopsy specimens from 12 H. pylori-negative and 28 positive subjects were examined. Sections were stained for mast cells, proliferating cell nuclear antigen (PCNA), and SCF. Densities of mast cells, PCNA-positive mast cells, and SCF-positive cells were significantly greater in H. pylori-positive than -negative subjects. SCF was expressed in mast cells and fibroblasts. The density of SCF-positive fibroblasts increased in H. pylori-positive gastritis and decreased after cure of infection. SCF mRNA was detected in H. pylori-positive gastric mucosa. Fibroblasts isolated from the normal gastric mucosa expressed SCF mRNA after incubation with H. pylori water extract. SCF may be one of the factors for mast cell increase. Fibroblasts may participate in mast cell increase and inflammation in H. pylori infection.

Adult↗
PubMed2002

Potentiation of slow component of delayed rectifier K(+) current by cGMP via two distinct mechanisms: inhibition of phosphodiesterase 3 and activation of protein kinase G.

1. Regulation of the slowly activating component of delayed rectifier K(+) current (I(Ks)) by intracellular guanosine 3'5' cyclic monophosphate (cGMP) was investigated in guinea-pig sino-atrial (SA) node cells using the whole-cell patch-clamp method. 2. When a cell was dialyzed with pipette solution containing 100 micro M cGMP, I(Ks) started to gradually increase and reached a maximum increase of a factor of 2.37 +/- 0.39 (n = 4) about 10-15 min after rupture of patch membrane. Atrial natriuretic peptide (ANP, 100 nM) also potentiated I(Ks), consistent with intracellular cGMP-induced enhancement of I(Ks). 3. Bath application of a selective blocker of the cGMP-inhibited phosphodiesterase (PDE3) milrinone (100 microM) enhanced I(Ks) by a factor of 1.50 +/- 0.09 (n = 4) but failed to further enhance I(Ks) after a maximum stimulation by intracellular cGMP (100 microM), suggesting that blockade of PDE3 activity is involved in the enhancement of I(Ks). A potent but nonspecific PDE inhibitor 3-isobutyl-1-methylxanthine (IBMX, 100 microM) further increased I(Ks) stimulated by 100 microM milrinone, indicating that PDE subtypes other than PDE3 are also involved in the regulation of basal I(Ks) in guinea-pig SA node cells. 4. Bath application of 100 microM 8-bromoguanosine 3'5' cyclic monophosphate (8-Br-cGMP) increased I(Ks) by a factor of 1.48 +/- 0.11 (n = 5) and this stimulatory effect was totally abolished by cGMP-dependent protein kinase (PKG) inhibitor KT-5823 (500 nM), suggesting that the activation of PKG also mediates cGMP-induced potentiation of I(Ks). 5. These results strongly suggest that intracellular cGMP potentiates I(Ks) not only by blocking PDE3 but also by activating PKG in guinea-pig SA node cells.

1-Methyl-3-isobutylxanthine↗
PubMed2002

A new prebiotic from germinated barley for nutraceutical treatment of ulcerative colitis.

A germinated barley foodstuff (GBF) containing glutamine-rich protein and hemicellulose-rich fiber was made from brewer's spent grain, by physical isolation. Our previous studies demonstrated that GBF supported maintenance of epithelial cell populations, facilitated epithelial repair, and suppressed epithelial nuclear factor kappaB-DNA-binding activity through generating increased short-chain fatty acid (especially butyrate) production by luminal microflora, which includes Bifidobacterium and Eubacterium, thereby preventing experimental colonic injury. The fiber fraction also modulates stool water content because of its high water-holding capacity. The patients with mild to moderate active ulcerative colitis who had been unresponsive to or intolerant of standard treatment received 20-30 g GBF, feeding daily in a non-randomized, open-label fashion. At 4 weeks, this treatment resulted in a significant clinical and endoscopic improvement. The improvement was associated with an increase in stool butyrate concentrations. These results indicate that GBF feeding is a potentially new, attractive prebiotic treatment in patients with ulcerative colitis. The potency of GBF on modulating microflora, as well as the high water-holding capacity, may play an important role in treatment and prolongation of remission in ulcerative colitis.

Colitis, Ulcerative↗
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↗