Hiroo Naito

Increased expression of HIP/PAP and regenerating gene III in human inflammatory bowel disease and a murine bacterial reconstitution model.

Although microorganisms play a role in gut inflammation, it remains uncertain which epithelial genes are expressed in response to luminal flora and whether these molecules are also involved in pathologic mucosal inflammation. Germ-free mice were orally challenged with a bacterial suspension prepared from conventionally housed mice (bacterial reconstitution). Thereafter, the differential gene expression in gut epithelial cells was identified by differential display. The expression of the identified genes was also examined in dextran sulfate sodium (DSS)-induced colitis and human inflammatory bowel disease (IBD) epithelial cells. Regenerating gene III (Reg III) was strongly induced in gut epithelial cells following bacterial reconstitution, as well as in the colitis initiated by DSS. The mRNA expression of hepatocarcinoma-intestine-pancreas/pancreatic associated protein (HIP/PAP), a human counterpart of Reg III, was enhanced in colonic epithelial cells of patients with IBD. Reg III mRNA expression was localized in the epithelial cells including goblet cells and columnar cells in mice; on the other hand, HIP/PAP-expressing cells were correlated with Paneth cell metaplasia in human colon. Epithelial expression of Reg III or HIP/PAP was induced under mucosal inflammation initiated by exposure to commensal bacteria or DSS as well as inflamed IBD colon.

The herbal medicine Dai-Kenchu-Tou stimulates upper gut motility through cholinergic and 5-hydroxytryptamine 3 receptors in conscious dogs

BACKGROUND The herbal medicine Dai-Kenchu-To, composed of zanthoxylum fruit, ginseng root, and dried ginger rhizome, is clinically effective for uncomplicated postoperative adhesive intestinal obstruction. We investigated the effect of Dai-Kenchu-To and each ingredient on upper gastrointestinal motility and its mechanism of action. METHODS Five mongrel dogs were equipped with 4-strain gauge-force transducers on the gastric body, antrum, duodenum, and jejunum to measure contractile activity of the circular muscle. Dai-Kenchu-To (1.5 g) or the separate ingredients zanthoxylum fruit, ginseng root, or dried ginger rhizome (1.0 g each) were administered by bolus into the gastric lumen. The effect of atropine, hexamethonium, phentolamine, propranolol, and ondansetron on intragastric Dai-Kenchu-To-induced contractions was studied. RESULTS Intragastric Dai-Kenchu-To induced phasic contractions in the antrum, duodenum, and jejunum. Zanthoxylum fruit elicited phasic contractions mainly in the duodenum and jejunum, whereas dried ginger rhizome induced phasic contractions in the antrum. Ginseng root had no effect. Phasic contractions induced by intragastric Dai-Kenchu-To were inhibited by atropine and hexamethonium at all sites, although ondansetron inhibited these contractions in the antrum and duodenum. CONCLUSIONS Intragastric Dai-Kenchu-To stimulates upper gastrointestinal motility through cholinergic and 5-hydroxytryptamine 3 receptors.

Laparoscope-Assisted Versus Conventional Restorative Proctocolectomy with Rectal Mucosectomy

Abstract To assess the advantages of a laparoscope-assisted proctocolectomy with ileal J-pouch anal anastomosis compared with conventional procedures, we retrospectively analyzed the results of the two procedures as follows: Eleven patients including five patients with familial adenomatous polyposis (FAP) and six with ulcerative colitis (UC) underwent a laparoscope-assisted proctocolectomy and hand-sewn ileal J-pouch anal anastomosis at our department from June 1997 to November 1999. This laparoscope-assisted colectomy (LAC) group was then compared with a group of 13 patients who had undergone conventional ileal pouch anal anastomosis using a standard laparotomy from 1986 to 1997. The median operative time of the LAC group was 8 h 23 min, which was 81 min longer than that of the standard colectomy (SC) group. The number of days during which eating was prohibited were similar in the two groups but the median postoperative hospital stay was significantly shorter in the LAC group (24.1 days). In the LAC group, the small incisions showed better cosmetic results and there was also a remarkable reduction in the degree of postoperative pain. In conclusion, a laparoscope-assisted proctocolectomy with ileal J-pouch anal anastomosis can be employed widely in patients with FAP and also in selected patients with UC.

Outcomes after Pylorus-preserving Gastrectomy for Early Gastric Cancer: A Prospective Multicenter Trial

The aim of the present study was to compare in a prospective, multicenter trial the results early and late after pylorus-preserving gastrectomy (PPG) versus conventional distal gastrectomy (CDG) with Billroth I anastomosis for early gastric cancer. Eighty-one patients with early gastric cancer were randomized and then underwent either PPG or CDG. Duration of operation, intraoperative blood loss, days until removal of the nasogastric tube, days until start of oral intake, and decrease in body weight were studied as parameters for outcomes early after the surgery. Late results were studied in patients followed for longer than 3 years. Change in body weight, status of oral intake, symptoms suggesting early dumping syndrome, and overall satisfaction were addressed in the questionnaire. The presence of gallstones was examined with ultrasonography. There were no differences in early results between PPG and CDG. The incidence of early dumping syndrome was lower in PPG (8%) than in CDG (33%). Other late results including the incidence of gallstones were not different between the 2 groups. These results indicate that PPG is as safe as CDG and has an advantage in terms of early dumping syndrome.

Intraduodenal and Intrajejunal Administration of the Herbal Medicine, Dai-Kenchu-Tou, Stimulates Small Intestinal Motility via Cholinergic Receptors in Conscious Dogs

The aim of the present study was to study the effect and mechanism of action of intraduodenal and intrajejunal dai-kenchu-to, an herbal medicine clinically effective for uncomplicated postoperative adhesive intestinal obstruction, on upper gastrointestinal motility. Five mongrel dogs were equipped with four strain-gauge force transducers on the antrum, duodenum, and proximal and distal jejunum to measure contractile activity. Dai-kenchu-to (0.5, 1.5, and 3.0 g) was administered into the duodenal or proximal jejunal lumen. The effect of atropine, hexamethonium, phentolamine, propranolol, and ondansetron on intraduodenal and intrajejunal dai-kenchu-to-induced contractions was studied. Plasma motilin was measured by specific radioimmunoassay. Intraduodenal and intrajejunal dai-kenchu-to induced phasic contractions in the duodenum and proximal jejunum, respectively, and those contractions migrated distally. Phasic contractions induced by intraduodenal and intrajejunal dai-kenchu-to were inhibited by atropine and hexamethonium at all sites. Plasma motilin was not affected by dai-kenchu-to. Intraduodenal and intrajejunal dai-kenchu-to stimulates upper gastrointestinal motility at and distal to the administration sites through cholinergic receptors.

Non-Pathogenic Bacteria Modulate Colonic Epithelial Gene Expression in Germ-Free Mice

Background: We established a bacterial reconstitution model to investigate epithelial cell-luminal bacteria interaction. The aim of the study was to identify the known genes directly or indirectly modulated by non-pathologic bacterial flora in the colonic epithelia of germ-free mice. Methods: Germ-free mice were orally given a bacterial suspension prepared from specific pathogen-free counterparts (bacterial reconstitution). Colonic epithelial cells were isolated, then total and poly (A) RNA were extracted. We investigated differential gene expression in colonic epithelial cells among germ-free, bacteria-reconstituted, and specific pathogen-free mice by DNA microarray. Finally, differential expression was confirmed by Northern blot or quantitative RT-PCR. Results: Thirty genes were initially selected as differentially expressed genes in DNA microarray analysis. We confirmed that genes associated with growth (Reg III #, Reg III % , guanylate nucleotide binding protein 2), apoptosis (Bcl-associated death promotor), cytoskeleton (tubulin ! 4, erythrocyte protein band 7.2), and immune response (lymphocyte antigen complex 6) were induced by bacterial reconstitution. In contrast, genes possibly participating in extracellular oxidant defence (selenoprotein P, metallothionein 1) and cellular metabolism (cytochrome P450, HMGCoA synthase 2, alcohol dehydrogenase 1 complex, aldehyde dehydrogenase family 1, carbonic anhydrase 1, glycoprotein galactosyltransferase ! 1,3) were down-regulated by bacterial challenge. Conclusion: Non-pathogenic bacteria modulated colonic gene expression in germ-free mice, suggesting that non-pathogenic bacteria possibly initiate epithelial change in genetically normal and/or abnormal hosts. The present study provides a basis for the functional study of each molecule in symbiosis with luminal bacteria in healthy and diseased colon.

The Role of Lipid Peroxidation on Gastric Mucosal Lesions Induced by Water-Immersion-Restraint Stress in Rats

Abstract: This study was designed to determine the effect of water-immersion-restraint stress (WIRS) and pretreatment by reduced glutathione on both the production of gastric mucosal lesions and the content of gastric mucosal phosphatidylcholine hydroperoxide (PCOOH). Sprague-Dawley rats were divided into control and treatment groups (treated with reduced glutathione before stress). After graded durations of WIRS, the macroscopic ulcer index (UI) was measured and the PCOOH content was examined by a chemiluminescence-high performance liquid chromatography assay. The UI in the control group increased significantly in a time-dependent fashion. Elevation of the PCOOH level was observed in combination with the UI for up to 2 h of WIRS, but then showed a declining tendency. Pretreatment with reduced glutathione significantly lowered both the UI and the PCOOH level. Lipid peroxidation is probably involved in the pathogenesis of gastric injury induced by WIRS at least in the early phases. However, in the late phases, other mechanisms causing gastric mucosal lesions may also be involved. We therefore believe this study to be the first to accurately and quantitatively assess the degree of lipid peroxidation in the gastric mucosa as a result of stress.

Induction of epithelial Na+ channel in rat ileum after proctocolectomy.

In patients with colectomy, epithelial transport function in the remnant small intestine can be regulated in response to the increased fecal electrolyte and fluid loss. Using a rat colectomy model, we investigated the Na+ and K+ transport mechanisms underlying the intestinal response. Proctocolectomy with ileoanal anastomosis was performed on rats. The small intestinal mucosa was mounted in Ussing chambers; then short-circuit currents and22Na+fluxes were measured. mRNA expression of the epithelial Na+ channel (ENaC) was determined by Northern blotting. Amiloride-sensitive, electrogenic Na+ absorption appeared in the ileum after proctocolectomy. This functional change was accompanied by the chronological induction of mRNAs for α-, β-, and γ-subunits of the ENaC in the ileum. Tetraethylammonium-sensitive short-circuit current was also activated. We conclude that electrogenic Na+ absorption and probably K+ secretion are induced in the ileum after proctocolectomy. This induction of electrogenic Na+ absorption is probably mediated by the increase in the mRNA levels for all three types of subunits of the ENaC and may contribute to the recovery from the increased fecal Na+ loss.

Sodium Butyrate-Induced Liver-Type Alkaline Phosphatase Activity in a Small Intestinal Epithelial Cell Line, IEC6

Sodium butyrate is a well-recognizeddifferentiating agent inducing alkaline phosphataseactivity, one of the epithelial differentiation markers.When IEC6 cells, a nontransformed, small intestinalepithelial cell line, were cultured with butyrate, thissubstrate induced alkaline phosphate activity in a time-and dose-dependent fashion. However, the type ofisoenzyme involved was a liver-type, not anintestinal-type. Electron microscopy revealed that the inducedactivity was strictly localized in the cytosol and noton the plasma membrane. However, disaccharidaseactivities, another kind of differentiation marker, were also enhanced by sodium butyrate. In addition,the positive cells demonstrating the presence ofalkaline phosphatase activity were preferentiallyobserved in tubular structures. These data show thatbutyrate-induced alkaline phosphatase activity is closelyassociated with differentiation-like phenomena in IEC6cells, although the type of isoenzyme and cellularlocalization of the activity are different from thoseobserved in mucosa.

Effect of Glucagon, Glicentin, Glucagon-like Peptide-1 and-2 on Interdigestive Gastroduodenal Motility in Dogs with a Vagally Denervated Gastric Pouch

Background: We previously reported that inhibition of gastric motility and hypertrophy of the small intestinal mucosa were observed after ileo-jejunal transposition which induced hypersecretion of enteroglucagon. Our aim was to study the effect of four enteroglucagon-related peptides (glucagon, glucagon-like peptide (GLP)-1, -2 and glicentin) on gastroduodenal motility and their mechanisms of action. Methods: The effect of these four peptides on motilin-induced interdigestive contractions was studied in dogs with vagally denervated gastric pouches equipped with four strain gauge force transducers on the pouch, gastric body, antrum and duodenum. Whether or not nitric oxide synthase inhibitor or phentolamine and propranolol reverses the inhibitory effect of those peptides was also studied. Results: Glucagon inhibited contractions in the pouch and stomach but had no effect on duodenal contractility. GLP-1 inhibited contractions at all sites. GLP-2 inhibited contractions in the pouch but did not affect motility in the neurally intact gastroduodenum. Glicentin had no effect on contractions at any site. Pretreatment with either a nitric oxide synthase inhibitor or phentolamine and propranolol reversed the inhibitory effect of glucagon, GLP-1 and GLP-2 on contractions in the pouch, but did not alter the inhibitory effect of glucagon and GLP-1 on motility in the neurally intact stomach and duodenum. Conclusions: These results suggest that the effects of four peptides on gastroduodenal motility differ, and changes occur in the enteric neural modulation of motor activity after chronic surgical extrinsic denervation.BACKGROUND We previously reported that inhibition of gastric motility and hypertrophy of the small intestinal mucosa were observed after ileo-jejunal transposition which induced hypersecretion of enteroglucagon. Our aim was to study the effect of four enteroglucagon-related peptides (glucagon, glucagon-like peptide (GLP)-1, -2 and glicentin) on gastroduodenal motility and their mechanisms of action. METHODS The effect of these four peptides on motilin-induced interdigestive contractions was studied in dogs with vagally denervated gastric pouches equipped with four strain gauge force transducers on the pouch, gastric body, antrum and duodenum. Whether or not nitric oxide synthase inhibitor or phentolamine and propranolol reverses the inhibitory effect of those peptides was also studied. RESULTS Glucagon inhibited contractions in the pouch and stomach but had no effect on duodenal contractility. GLP-1 inhibited contractions at all sites. GLP-2 inhibited contractions in the pouch but did not affect motility in the neurally intact gastroduodenum. Glicentin had no effect on contractions at any site. Pretreatment with either a nitric oxide synthase inhibitor or phentolamine and propranolol reversed the inhibitory effect of glucagon, GLP-1 and GLP-2 on contractions in the pouch, but did not alter the inhibitory effect of glucagon and GLP-1 on motility in the neurally intact stomach and duodenum. CONCLUSIONS These results suggest that the effects of four peptides on gastroduodenal motility differ, and changes occur in the enteric neural modulation of motor activity after chronic surgical extrinsic denervation.