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As the first line of defense against intestinal bacteria and toxins, intestinal epithelial cells are always exposed to bacteria or lipopolysaccharide (LPS), whereas pathogenic bacteria or LPS can cause intestinal epithelial cell damage. Previous studies have shown that konjac mannan oligosaccharides (KMOS) have a positive effect on maintaining intestinal integrity, and Bacillus subtilis (BS) can promote the barrier effect of the intestine. However, it is still unknown whether KMOS and BS have a synergistic protective effect on the intestines. In this study, we used the LPS-induced Caco-2 cell injury model and mouse intestinal injury model to study the synergistic effects of KMOS and BS. Compared with KMOS or BS alone, co-treatment with KMOS and BS significantly enhanced the activity and antioxidant capacity of Caco-2 cell, protected mouse liver and ileum from LPS-induced oxidative damage, and repaired tight junction and mucus barrier damage by up-regulating the expression of Claudin-1, ZO-1 and MUC-2. Our results demonstrate that the combination of KMOS and BS has a synergistic repair effect on inflammatory and oxidative damage of Caco-2 cells and aIIeviates LPS-induced acute intestinal injury in mice., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Chen, Zhang, Wu, Ren, Liu and Wu.)

Purpose: Idiopathic intussusception is one of the most common causes of small bowel obstruction in children. To decrease subsequent recurrence and to detect a lead point, an early laparoscopy was performed for children with multiple recurrent ileocolic intussusception., Materials and Methods: Between January 2014 and July 2017, a total of 2561 consecutive children with intussusception were treated and followed. There were 110 patients with multiple recurrences, 61 were treated with ileocolic pexy and 49 were not and the results were compared. Using a 5-mm laparoscope and 2 additional transabdominal wall stab incisions, an appendectomy and an ileocolic pexy with nonabsorbable sutures were performed simultaneously for the children after the last successful enema reduction., Results: The mean operative time was 59.4±13.1 minutes (range, 45 to 85 min). No cases required conversion to an open surgery, blood loss was minimal. There was no operative morbidity. Two patients were found with a Meckel's diverticulum, and were removed by slightly enlarged transumbilical incision. The 61 cases were followed up for 4 to 42 months (mean, 19.3±1.1 mo). In the ileocolic pexy group, 2 of 61 (3.2%) got 2 episodes of recurrences. Among the 25 patients with 3 recurrences without undergoing ileocolic pexy, 18 (72%) had 22 episodes of recurrence. Of the 16 patients with 4 recurrences and without ileocolic pexy, 14 (87.5%) had 17 episodes of recurrence. There was statistical difference in recurrent rate among the 3 groups (ileocolonic pexy group vs. 3 recurrences group, P<0.01; ileocolic pexy group vs. 4 recurrences group, P<0.01)., Conclusions: Early preventive laparoscopic ileocolic pexy should be undertaken for the patients with multiple recurrences after the last nonsurgical reduction had been attempted successfully.

Background: Intestinal ischemia-reperfusion (I/R) injury can lead to multiple organ failure and death. The aim of this study was to investigate the effects of pentoxifylline and iloprost administered before reperfusion in intestinal ischemia., Methods: In total, 25 male Wistar Albino rats weighing 250-300 g were divided into five groups each comprising five subjects: control group (n=5), sham group (n=5, no I/R), I/R group (n=5, 45 min ischemia, and 120 min reperfusion), I/R + pentoxifylline group (n=5, 45 min ischemia following intraperitoneal 50 mg/kg pentoxifylline and 120 min reperfusion), and I/R + iloprast group (n=5, 45 min ischemia followed by intraperitoneal 2 mcg /kg iloprost and 120 min reperfusion). At the end of the experiment, ileum specimens were stained using hematoxylin-eosin and histopathologically evaluated using the Chiu score. Isometric contraction-relaxation responses were recorded using organ baths for contraction-relaxation responses., Results: Pentoxifylline provided a significant improvement in response to histopathological and contraction-relaxation responses. Although iloprost provided recovery in reperfusion injury, it was not statistically significant., Conclusion: Our findings demonstrate that pentoxifylline may be promising in preventing small bowel ischemia-reperfusion injury. We concluded that further clinical and experimental studies for iloprost are needed.

Aim: To investigate the protective effect of bifidobacterium in endotoxin-induced intestinal injury in preweaning rats., Methods: Preweaning rats were randomly divided into three groups (n = 40 for each): a control group (group C), a model group (group E) and a treatment group (group T). Both groups E and T were intraperitoneally injected with lipopolysaccharide (LPS) at a dose of 5 mg/kg (5 mg/L in normal saline), and group T was intragastrically administrated with bifidobacterium suspension (2.0 × 10(9) CFU/mL, 0.5 mL each time, twice a day, until the end of the experiment) 7 d before LPS administration. Group C was intraperitoneally injected with normal saline. After intraperitoneal injection and intragastric administration, the rats were placed back to the initial cage to receive breast feeding. The rats were killed at 2, 6, 12, 24 or 72 h, respectively, after endotoxin or physiological saline injection to collect serum and ileal tissue samples. Myeloperoxidase (MPO) contents in serum and ileum were detected at different times, and expression of ileal defensin-5 mRNA was evaluated by reverse transcription-polymerase chain reaction., Results: Serum and ileal MPO contents in group E were significantly higher than those in group C (serum contents: 107.50 ± 17.70 vs 157.14 ± 24.67, P < 0.05; ileal contents: 1.03 ± 0.21 vs 1.57 ± 0.33, P < 0.05), which peaked at 12 h and 6 h, respectively. MPO contents in group T were significantly lower than those in group E (serum contents: 114.38 ± 24.56 vs 145.25 ± 23.62, P < 0.05; ileal contents: 1.25 ± 0.24 vs 1.57 ± 0.33, P < 0.05). The expression of defensin-5 mRNA in group E was significantly higher than that in group C (0.953 ± 0.238 vs 0.631 ± 0.146, P < 0.05), which peaked at 2 h, and then decreased gradually. The expression of defensin-5 mRNA in group T was significantly lower than that in group E (0.487 ± 0.149 vs 0.758 ± 0.160, P < 0.05) apparently in 24 h. The expression of defensin-5 mRNA at 2 h in group T was significantly higher than that in group C (0.824 ± 0.158 vs 0.631 ± 0.146, P < 0.05)., Conclusion: MPO and defensin-5 mRNA increase in preweaning rats with LPS-induced intestinal injury. Bifidobacterium protects the gut by inhibiting MPO activity, not by increasing defensin-5 secretion.

It has been previously shown that acetylcholine (ACh) may affect pro-inflammatory and anti-inflammatory cytokines. The role of the cholinergic system in radiation-induced inflammatory responses and tissue damage remains unclear. Therefore, the present study was designed to determine the radio-protective properties of the cholinergic system in the ileum and the liver of rats. Rats were exposed to 8-Gy single-fraction whole-abdominal irradiation and were then decapitated at either 36 h or 10 d post-irradiation. The rats were treated either with intraperitoneal physiological saline (1 ml/kg), physostigmine (80 µg/kg) or atropine (50 μg/kg) twice daily for 36 h or 10 d. Cardiac blood samples and liver and ileal tissues were obtained in which TNF-α, IL-1β and IL-10 levels were assayed using ELISA. In the liver and ileal homogenates, caspase-3 immunoblots were performed and myeloperoxidase (MPO) activity was analyzed. Plasma levels of IL-1β and TNF-α increased significantly following radiation (P < 0.01 and P < 0.001, respectively) as compared with non-irradiated controls, and physostigmine treatment prevented the increase in the pro-inflammatory cytokines (P < 0.01 and P < 0.001, respectively). Plasma IL-10 levels were not found to be significantly changed following radiation, whereas physostigmine augmented IL-10 levels during the late phase (P < 0.01). In the liver and ileum homogenates, IL-1β and TNF-α levels were also elevated following radiation, and this effect was inhibited by physostigmine treatment but not by atropine. Similarly, physostigmine also reversed the changes in MPO activity and in the caspase-3 levels in the liver and ileum. Histological examination revealed related changes. Physostigmine experiments suggested that ACh has a radio-protective effect not involving the muscarinic receptors., (© The Author 2014. Published by Oxford University Press on behalf of The Japan Radiation Research Society and Japanese Society for Radiation Oncology.)

Objectives: Ischaemia-reperfusion (I/R) injury is encountered in conditions that diminish intestinal blood flow. There is no clinically feasible technique available for mucosal preservation., Methods: One hundred Wistar rats were subjected to intestinal ischaemia for 15 and 60 min (I15', I60'), followed by 1 and 7 days of reperfusion (R1d, R7d). Rats were subjected to ischaemia by clamping the superior mesenteric artery. Prostaglandin E1 (PGE1) (2.500 ng/kg intra-arterial bolus or 20 ng/kg intravenous infusion) was administered immediately prior to the commencement of the experimental period. Animals were divided into 20 groups: sham (laparotomy alone), sacrificed at 1 or 7 days; saline administration, 15 or 60 min of ischaemia, 1 or 7 days of reperfusion; prostaglandin E1 administration, 15 or 60 min of ischaemia, 1 or 7 days of reperfusion, each one for intra-arterial or intravenous administration. Ileal segments were excised and assessed for histopathological score, polymorphonuclear (PMN) leucocytes encountered and myeloperoxidase (MPO) activity measurement., Results: I/R caused deterioration of histological characteristics. Prophylactic administration of PGE1 resulted in a significant decrease in the histological score compared with the respective saline group (analysis of variance, P < 0.005). In groups treated with PGE1, PMN leucocyte infiltration was lower for the 60 min of ischaemia group (I60'/R1d *P = 0.026; I60'/R7d P = 0.015). I15'/R7d did not lead to a significant reduction in PMN infiltration (P = 0.061). Pretreatment with PGE1 attenuates MPO levels after intestinal I/R injury (P < 0.05). No differences were encountered between types of administration., Conclusions: Results of this study showed that administration of prostaglandin E1 prevents I/R injury by diminishing histological damage parameters, inhibiting PMN leucocyte infiltration and attenuating MPO activity.

Background: Neutrophil migration, one of the major factors predisposing to nonsteroidal anti-inflammatory drugs (NSAIDs)-induced intestinal lesions, consists of several steps, including interaction with P-selectin from platelets. Cilostazol, a specific phosphodiesterase (PDE)-3 inhibitor, suppresses the expression of P-selectin from platelets and reduces interaction between platelets and leukocytes, leading to inflammatory amelioration in several disease models. We tried to clarify the therapeutic effectiveness of cilostazol for NSAID-induced small intestinal lesions., Subjects and Methods: 1) Anti-PSGL-1 antibody (2 mg/kg) or cilostazol (100 mg/kg) was administered to mice one hour before Indomethacin (IND, 2.5 mg/kg) administration for 4 days to evaluate small intestinal lesions. 2) IND-induced migratory behaviors of neutrophils and platelets were evaluated in intestinal vessels by an intravital microscopy., Results: i) IND induced small intestinal lesions with an increase in MPO activity. Anti-PSGL-1 antibody and cilostazol ameliorated intestinal lesions along with suppression of MPO activity. ii) Intravital microscopy revealed that administration of IND increased migration of platelet-bearing neutrophils. Cilostazol treatment ameliorated neutrophil migration by blocking interaction between platelets and neutrophils., Conclusion: Our results suggest that enhanced platelets-bearing neutrophil migration is critically involved in the pathogenesis of IND-induced small intestinal lesions and suggest a potential application of cilostazol for prevention of NSAID-induced small intestinal lesions.

Purpose: High doses of anticancer drugs often damage the intestinal mucosa. The purpose of the present study was to examine the effect of glutamine on mucosal damage induced by cyclophosphamide in a rat model, and to elucidate the mechanisms responsible for its protective effects., Method: Rats were randomly assigned to one of the three experimental groups. Group A (control) (n = 8): intraperitoneal injection of saline, group B (n = 8): intraperitoneal injection of cyclophosphamide (300 mg/kg), group C (n = 8): intraperitoneal injection of cyclophosphamide (300 mg/kg) and oral glutamine (1.0 g/kg). After 3 days, the ileal segment was removed for morphological and the biochemical analyses. We also evaluated the level of mucosal apoptosis by the TUNEL method and enterocyte proliferation using bromodeoxyuridine (BrdU)., Results: Mucosal atrophy was observed in group B but not in groups A or C. The mucosal wet weight, protein and glutathione levels were significantly decreased in group B compared with group A, and were increased significantly in group C compared with group B. While enterocyte proliferation significantly decreased and the apoptotic index significantly increased in group B compared with group A, a significant increase in the enterocyte proliferation and a significant decrease in apoptosis were observed in group C compared with group B., Conclusions: Glutamine prevented intestinal mucosal injury induced by cyclophosphamide via increased glutathione, decreased apoptosis and increased proliferation of intestinal epithelial cells.

Most cases of Meckel's diverticulum (MD) are asymptomatic and discovered by chance. Management of MD is controversial. The authors describe an exceptional case of intestinal obstruction caused by a giant MD in a patient who had previously undergone appendectomy. A review of the contradictory literature on this subject leads to the conclusion that careful consideration of clinical and morphological data (patient's age, ASA score, the surgical procedure to be performed, morphology and position of the MD, any fibrotic bands) is required before deciding whether or not to resect an asymptomatic MD.

Background: The purpose of this study is to investigate the protective effects of Ginkgo biloba extract (EGb 761) in rat pups with hypoxia/reoxygenation (H/R)-induced bowel injury., Methods: One-day-old Wistar albino rat pups (n = 21) were randomly divided into 3 groups: group 1 (control, untreated and not exposed to H/R, n = 7), group 2 (untreated but exposed to H/R, n = 7), and group 3 (EGb 761 + H/R, n = 7). Ginkgo biloba extract was administered (100 mg/kg per day, subcutaneously) to group 3 for 3 days. On the fourth day, all animals except controls were exposed to H/R and were killed 6 hours after H/R. Histopathologic injury scores (HIS), malondialdehyde, glutathione (GSH), GSH-peroxidase (Px) activities, and nitric oxide (NO) levels were measured on intestinal samples., Results: Although the control group had normal HIS, group 2 had grade 3 HIS. In contrast, group 3 had minimal HIS, and these results were significantly better than those of group 2 (P < .001). Malondialdehyde and NO levels of group 3 were significantly lower than those of group 2 (P < .01). Glutathione and GSH-Px activities of group 1 were higher than those of groups 2 and 3 (P < .05). However, there were no significant differences for GSH and GSH-Px activities between groups 2 and 3., Conclusions: This study showed that hypoxia and NO contributed to the pathogenesis of H/R-induced intestinal injury and that prophylactically administered EGb 761 had a protective effect on bowel injury., (Crown Copyright © 2011. Published by Elsevier Inc. All rights reserved.)

Intestinal ischemia/reperfusion causes tissue hypoxia and damage, leading to the pathophysiology of inflammation. The aim of this study was to investigate the effects of glutamine on the tissue injury caused by ischemia/reperfusion of the gut. Ischemia/reperfusion injury of the intestine was caused by clamping both the superior mesenteric artery and the celiac trunk for 30 min followed by the release of the clamp allowing reperfusion for 1h. This procedure results in splanchnic artery occlusion-injury. Based on our findings we propose that the amino acid glutamine, administered 15 min before reperfusion at the dose of 1.5mg/kg, i.v. may be useful in the treatment of various ischemia and reperfusion diseases. The present study was performed in order to determine the pharmacological effects of glutamine ischemia/reperfusion-induced intestinal injury in rats. In particular, to gain a better insight into the mechanism(s) of action of glutamine, we evaluated the following endpoints of the inflammatory response: (1) histological damage; (2) neutrophil infiltration of the reperfused intestine (MPO activity); (3) NF-kappaB activation and cytokines production; (4) expression of ICAM-1 and P-selectin during reperfusion; (5) nitrotyrosine and poly-ADP-ribose formation; (6) pro-inflammatory cytokine production; (7) inducible nitric oxide synthase expression; (8) apoptosis as shown by TUNEL staining and (9) Bax/Bcl-2 expression., (2010 Elsevier B.V. All rights reserved.)

Background: Traumatic brain injury (TBI) causes gastrointestinal dysfunction and increased intestinal permeability. Regulation of the gut barrier may involve the central nervous system. We hypothesize that vagal nerve stimulation prevents an increase in intestinal permeability after TBI., Methods: Balb/c mice underwent a weight drop TBI. Selected mice had electrical stimulation of the cervical vagus nerve before TBI. Intestinal permeability to 4.4 kDa FITC-Dextran was measured 6 hours after injury. Ileum was harvested and intestinal tumor necrosis factor-alpha and glial fibrillary acidic protein (GFAP), a marker of glial activity, were measured., Results: TBI increased intestinal permeability compared with sham, 6 hours after injury (98.5 microg/mL +/- 12.5 vs. 29.5 microg/mL +/- 5.9 microg/mL; p < 0.01). Vagal stimulation prevented TBI-induced intestinal permeability (55.8 +/- 4.8 microg/mL vs. 98.49 microg/mL +/- 12.5; p < 0.02). TBI animals had an increase in intestinal tumor necrosis factor-alpha 6 hours after injury compared with vagal stimulation + TBI (45.6 +/- 8.6 pg/mL vs. 24.1 +/- 1.4 pg/mL; p < 0.001). TBI increased intestinal GFAP 6.2-fold higher than sham at 2 hours and 11.5-fold higher at 4 hours after injury (p < 0.05). Intestinal GFAP in vagal stimulation + TBI animals was also 6.7-fold higher than sham at 2 hours, however, intestinal GFAP was 18.0-fold higher at 4 hours compared with sham and 1.6-fold higher than TBI alone (p < 0.05)., Conclusion: In a mouse model of TBI, vagal stimulation prevented TBI-induced intestinal permeability. Furthermore, vagal stimulation increased enteric glial activity and may represent the pathway for central nervous system regulation of intestinal permeability.

Enteric fluids produced by enterocutaneous fistulae can cause severe inflammation in the surrounding skin. By removing these corrosive fluids, topical negative pressure can help maintain skin integrity and promote spontaneous closure.

Background: Intestinal barrier failure during acute pancreatitis (AP) is associated with translocation of luminal bacteria, resulting in infectious complications. We examined the effects of multispecies probiotics on the intestinal barrier impairment in a murine model of AP., Methods: Mice were injected with cerulein to induce AP and were sacrificed 11 (early AP) or 72 hours (late AP) after start of induction. AP and associated systemic effects were confirmed by histology of pancreas and lung. Animals received daily probiotics starting 2 days prior to AP induction (pretreatment) or at the moment of AP induction (treatment). Mucosal barrier function of the distal ileum was assessed in Ussing chambers by measurement of the epithelial electrical resistance and the permeability to Na-fluorescein., Results: Histological analysis revealed pancreatic injury in both phases of AP, and lung damage in the early phase. Epithelial resistance of the ileum was reduced and permeability increased in both phases of AP, indicating impairment of the intestinal barrier. Pretreatment had no effect on resistance or permeability in the early phase of AP. In the late phase of AP, pretreatment but not treatment abolished the AP induced resistance decrease and permeability increase. Administration of probiotics as such (ie, without induction of AP) had no effect on intestinal barrier function., Conclusion: Pretreatment with multispecies probiotics for 2 days abolishes intestinal barrier dysfunction in the late phase of AP, while treatment does not. The effectiveness of probiotics in this model depends on the timing of administration. Clinical trials with probiotics should seek conditions where treatment can be started prior to onset of disease or elective surgical intervention.

Background: The role of polymorphonuclear neutrophil granulocytes (PMNs) and the PMN-derived protease, which is called matrix metalloproteinase-9 (MMP-9), for the gut barrier dysfunction in severe acute pancreatitis (SAP) has not yet been clarified. The aim of this study was to evaluate the effects of PMNs and MMP-9 on gut barrier dysfunction in rat SAP., Methods: SAP was induced by the injection of 5% sodium taurocholate, and anti-rat PMN serum or BB-94 were administered 48 h and 24 h, respectively, before the induction of acute pancreatitis. Twenty-four hours after the induction of acute pancreatitis, the gut barrier dysfunction and the incidence of bacterial translocation (BT) and PMN transmigration were investigated by bacterial, histologic, and biochemical (MPO) analysis. Inhibition of MMP-9 was achieved by depletion of PMNs or inhibition of MMP-activity by a broad-spectrum MMP inhibitor and confirmed by zymography. In addition, reactive oxygen species were evaluated by spin trap assay., Results: The mucosal injury and the infiltration of PMNs into the gut tissue of rats with SAP were significantly increased in comparison with rats treated with anti-rat PMN serum or BB-94. The levels of MMP-9 and reactive oxygen species in the gut of rats with SAP were significantly higher than those of the rats treated with anti-rat PMN serum or BB-94. Pretreatment with anti-rat PMN serum or BB-94 reduced the incidence of BT in SAP., Conclusion: The incidence of BT in SAP was prevented by the depletion of PMNs or less pronounced by the injection of the MMP inhibitor BB-94. PMNs play an important pathophysiologic role in the occurrence of BT, and MMP-9 is involved in both BT and PMN transmigration in rat SAP.

The present study was undertaken to determine whether resveratrol (RVT) could ameliorate ionizing radiation-induced oxidative injury. After a 10-days pre-treatment with RVT (10 mg/kg/day p.o.), rats were exposed to whole-body IR (800 cGy) and the RVT treatment was continued for 10 more days after the irradiation. Irradiation caused a significant decrease in glutathione level, while malondialdehyde levels, myeloperoxidase activity and collagen content were increased in the liver and ileum tissues. Similarly, plasma lactate dehydrogenase and pro-inflammatory cytokine levels, 8-hydroxy-2'-deoxyguanosine and leukocyte apoptosis were elevated, while antioxidant-capacity was reduced in the irradiated rats as compared with the control group. Furthermore, Na(+), K(+)-ATPase activity was inhibited and DNA fragmentation was increased in the ileal tissues. Resveratrol treatment reversed all these biochemical indices, as well as histopathological alterations induced by irradiation. In conclusion, supplementing cancer patients with adjuvant therapy of resveratrol may have some benefit for a more successful radiotherapy.

Purpose: Open ileal pouch surgery leads to high rates of adhesive small-bowel obstruction (SBO). A laparoscopic approach may reduce these complications. We aimed to review the incidence of adhesive SBO-related complications after open pouch surgery and to model the potential financial impact of a laparoscopic approach purely as an adhesion prevention strategy., Materials and Methods: We reviewed cases of open ileal pouch patients kept on a database and examined annually. Case notes were studied for episodes of adhesive SBO requiring admission or reoperation. Similar parameters were studied in a small series undergoing laparoscopic pouch surgery. The financial burden of the open access complications was estimated and potential financial impact of a laparoscopic approach modeled., Results: Two hundred seventy-six patients were followed up after open surgery (median, 6.3; range, 0.2-20.1 years). There were 76 (28%) readmissions (median length of stay, 7.4 days) in 53 patients (19%) and 28 (10%) reoperations (43% within 1 year). Laparoscopic patients required less adhesiolysis at second-stage surgery (0% vs 36%, p < 0.0001) and had less SBO episodes within 12 months of surgery (0% vs 14%, p < 0.0001) than open patients. Modeling a laparoscopic approach cost $1,450 and saved $3,282, thus netting $1,832 per pouch constructed., Conclusion: Open ileal pouch surgery results in significant cumulative long-term access-related complications, particularly adhesions. These impose a large medical burden on patients and financial burden on health-care systems, all of which may be recouped by a laparoscopic approach, despite higher theater costs.

Background: Hernia surgery, in particular parastomal hernia mesh repair and new techniques for hernia prevention, require novel biomaterials that avoid fibrosis and potential bowel erosion, while retaining adequate strength for their intended purpose. The aim was to evaluate the human host response to an acellular porcine-derived cross-linked collagen implant., Methods: In a prospective pilot study on prevention of parastomal herniation, 15 patients undergoing loop stoma formation had an implant placed within the anterior abdominal wall. Histopathology and immunohistochemistry were performed to analyse the implant qualitatively and, where appropriate, quantitatively for biocompatibility, degradation, cellular infiltration, neo-extracellular matrix (ECM) formation and neovascularization., Results: At a median of 7 (range 1-8) months, 12 of 15 patients had stoma reversal and 11 implant biopsies were obtained. In biopsies from ten of the 11 patients all responses were limited to the periphery of the implant and native pores. There was a minimal inflammatory response and minimal degradation of the implant. Fibroblastic and neovascular infiltration were noted, as was matrix metalloproteinase 1 activity with organized deposition of host collagen, fibronectin and laminin., Conclusion: The collagen implant demonstrated excellent biocompatibility and resistance to degradation in most patients. However, fibrovascular in-growth and ECM deposition were limited. This implant has excellent potential for soft tissue reinforcement., (2008 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd.)

Rats receiving intracolonic administration of indomethacin develop longitudinal ulcers on the mesenteric side of the small intestine that are similar to those seen in the acute phase of Crohn's disease. To investigate the causative role of microcirculatory disturbances and to elucidate the therapeutic effect of antioxidants on this enteropathy in rats, we serially evaluated changes in regional blood flow of the small intestine using laser Doppler perfusion imaging and the colored microsphere injection method. Both methods disclosed stepwise hyperperfusion limited to the mesenteric side of the small intestine following transient ischemia during the initial 30-60 minutes. In addition, both a radical scavenger and a radical production inhibitor significantly ameliorated the mesenteric longitudinal ulcers. We concluded that ischemia-reperfusion on the mesenteric side accompanying excessive production of radicals might be strongly involved in indomethacin-induced longitudinal ulcers of the small intestine in rats.

We evaluated the effects of N-hexacosanol, a cyclohexenonic long-chain fatty alcohol, on muscarinic receptors in diabetic rat ileal dysfunction. Eight-week-old male SD rats were divided into four groups. After induction of diabetes (streptozotocin 50 mg/kg, i.p.), three groups were maintained for eight weeks with treatment by N-hexacosanol (0, 2 or 8 mg/kg, s.c. every day). Ileum function was investigated by organ bath studies using carbachol and KCl, and the expression levels of muscarinic M(2) and M(3) receptors were investigated by real-time polymerase chain reaction. Various concentrations of subtype-selective muscarinic antagonists, i.e., atropine (non-selective), pirenzepine (M(1) selective), methoctramine (M(2) selective), and 4-diphenylacetoxy-N-methylpiperidine methiodide (4-DAMP, M(1)/M(3) selective), were used in this study. In the presence and absence of these antagonists, contractile response curves to increasing concentrations of carbachol were investigated. Treatment with N-hexacosanol did not alter the diabetic status of the rats, but did significantly prevent the carbachol-induced hypercontractility in diabetic rat ileum. Estimation of the pA(2) values for atropine, pirenzepine, methoctramine, and 4-DAMP indicated that the carbacholinduced contractile response in the ileum is mainly mediated through the muscarinic M(3) receptor subtype in all groups. Furthermore, N-hexacosanol significantly prevented the diabetes-induced up-regulation of intestinal muscarinic M(2) and M(3) receptor mRNAs in streptozotocin-diabetic rats. Our data indicated that N-hexacosanol exerts preventive effects with respect to carbachol-induced hypercontractility in the diabetic rat ileum without qualitative alteration of the muscarinic receptor system.

Medical countermeasures provide a key role in the UK integrated approach to chemical defence and are aimed at preventing or mitigating the effects of exposure to nerve agents. It is UK policy that medical countermeasures will be licensed products. Demonstration of efficacy relies on extrapolation of animal-derived data to man which means that species selection is extremely important. For the foreseeable future it is likely that a combination of pretreatment and therapy will be required to provide protection against nerve agent poisoning. There is a longer-term aspiration to develop a post poisoning-therapy which would reduce the reliance on pretreatment, prevent or mitigate the effects of exposure to all nerve agents and decrease the requirement for three autoinjectors. Immediate therapy comprising physostigmine (0.2mg/kg), hyoscine hydrobromide (4mg/kg) and HI-6 (93.6mg/kg) protected all animals against the lethal effects of a supralethal dose of GD, when given 1min after nerve agent poisoning in the absence of any pretreatment. In contrast when hyoscine hydrobromide was replaced with hyoscine methyl nitrate most of the animals died within 24h, whereas when an equal mixture of hyoscine hydrobromide and hyoscine methyl nitrate was used all the animals survived. None of these animals had an intussusception. It would not be possible to deliver these doses of HI-6 to a human from a single autoinjector device. Recent studies have shown that a lower dose of HI-6 (7mg/kg) which can be delivered via an autoinjector, in combination with physostigmine and hyoscine hydrobromide provides good protection against the lethal effects of a supralethal dose of GD. A number of animals died between 6 and 24h and had an intussusception. The surviving animals did not begin to regain weight until 48h after poisoning. In contrast when a mixture of hyoscine hydrobromide and hyoscine methyl nitrate was used, one animal died within 15min, the other animals all survived, regained weight from 24h and did not have an intussusception. These studies will now be extended to include other agents and will be taken forward to studies in non-human primates where the incidence of intussusception will be closely monitored.

Background/purpose: The study investigates the effect of airway instrumentation on the histopathology of the intestine, contribution of bacterial translocation, and whether oxygen supplementation may counteract the possible detrimental effects of this procedure., Methods: Fifty-five Wistar rats were assigned to 3 groups. Group 1 served as control. Groups 2 and 3 underwent airway instrumentation. In addition, group 3 received oxygen supplementation during the procedure. Arterial blood gases were measured after the procedure. Samples of mesenteric lymph nodes ileum, cecum, spleen, liver, and blood were harvested for determination of bacterial growth after 24 hours. Ileum was evaluated histologically., Results: In group 2, the rats presented a decrease in oxygen saturation (90% +/- 0.3%, P < .0001), hypoxemia (PaO2, 73 +/- 1.5 mm Hg; P < .0001), and respiratory acidosis (pH 7.27 +/- 0.01; PaCO2, 48 +/- 1.5 mm Hg; P < .0001) after airway instrumentation. These rats also showed evidence of intestinal injury (P < .0001) and bacterial translocation to mesenteric lymph nodes in 10 of 20 rats compared with 0 of 15 in the controls (P = .004). In group 3, oxygen supplementation provided normal arterial blood gas parameters, and led to minimal histologic changes and bacterial translocation in only 1 of 20 rats, compared with group 2 (P < .0001 and P = .005, respectively)., Conclusions: The study suggests that oxygen supplementation during airway instrumentation prevents hypoxemia, intestinal damage, and bacterial translocation.

Clostridium difficile is a spore-forming, anaerobic, gram-positive bacillus that releases two main virulence factors: toxins A and B. Toxin A plays an important pathogenic role in antibiotic-induced diarrhea and pseudomembranous colitis, a condition characterized by intense mucosal inflammation and secretion. Agonist activity at A2A adenosine receptors attenuates inflammation and damage in many tissues. This study evaluated the effects of a new selective A2A adenosine receptor agonist (ATL 313) on toxin A-induced injury in murine ileal loops. ATL 313 (0.5 to 5 nM) and/or the A2A adenosine receptor antagonist (ZM241385; 5 nM) or phosphate-buffered saline (PBS) were injected into ileal loops immediately prior to challenge with toxin A (1 to 10 microg/loop) or PBS. Intestinal fluid volume/length and weight/length ratios were calculated 3 h later. Ileal tissues were collected for the measurement of myeloperoxidase, adenosine deaminase activity, tumor necrosis factor alpha (TNF-alpha) production, histopathology, and detection of cell death by the TUNEL (terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling) method. Toxin A significantly increased volume/length and weight/length ratios in a dose-dependent fashion. ATL 313 treatment significantly (P < 0.05) reduced toxin A-induced secretion and edema, prevented mucosal disruption, and neutrophil infiltration as measured by myeloperoxidase activity. ATL 313 also reduced the toxin A-induced TNF-alpha production and adenosine deaminase activity and prevented toxin A-induced cell death. These protective effects of ATL 313 were reversed by ZM241385. In conclusion, the A2A adenosine receptor agonist, ATL 313, reduces tissue injury and inflammation in mice with toxin A-induced enteritis. The finding of increased ileal adenosine deaminase activity following the administration of toxin A is new and might contribute to the pathogenesis of the toxin A-induced enteritis by deaminating endogenous adenosine.

Background: Sepsis is a generalized inflammatory response, which involves organ systems remote from the locus of the initial infectious insult, involves the release of cytokines and the subsequent formation of reactive oxygen and nitrogen species., Objective: The aim of this study was to investigate the possible protective effect of montelukast, a leukotriene receptor blocker, against oxidative damage in the liver and ileum of septic rats., Methods: Sepsis was induced by cecal ligation and puncture method in female Wistar albino rats. Sepsis and sham operated (control) groups received either saline or montelukast (10 mg/kg, ip) immediately after the operation and at 12 h. Twenty-four hours after the surgery, rats were decapitated and malondialdehyde (MDA) content--an index of lipid peroxidation, glutathione (GSH) levels--a key antioxidant, myeloperoxidase (MPO) activity--an index of neutrophil infiltration, and collagen contents were determined in the liver and ileum. Formation of reactive oxygen species in liver and ileal tissue samples was monitored by using chemiluminescence (CL) technique with luminol and lucigenin probes. Both tissues were also analyzed histologically. Serum lactate dehydrogenase (LDH) and tumor necrosis factor-alpha (TNF-alpha) level were assessed in trunk blood., Results: Sepsis resulted in decreased GSH levels, and increased MDA levels, MPO activity, CL levels and collagen contents in both the liver and the ileum (P < 0.05-P < 0.001) indicating the presence of the oxidative damage. Similarly, serum TNF-alpha and LDH were elevated in the sepsis group as compared to control group. On the other hand, montelukast treatment reversed all these biochemical indices, as well as histopathological alterations, which were induced by sepsis., Conclusion: Findings of the present study suggest that montelukast possesses an anti-inflammatory effect on sepsis-induced hepatic and intestinal damage and protects against oxidative injury by a neutrophil-dependent mechanism.

Background: The formation of further adhesions after adhesiolysis is a major problem. Not all agents that are supposed to reduce de novo adhesions can reduce further adhesion formation. The efficacy and safety of intraperitoneally applied phospholipids has been shown previously. This study evaluated the influence of phospholipids and icodextrin on adhesion re-formation., Methods: In an experimental study on 60 Chinchilla rabbits adhesions were induced by standardized abrasion of defined areas of the ventral abdominal wall, the caecum and the ileum. Open adhesiolysis was performed 10 days later. The animals randomly received either 1.5 per cent phospholipids, 4 per cent icodextrin or Ringer's lactate intraperitoneally. Half of the animals in each group were killed after a further 10 days and the remainder at 20 days. Adhesion formation was assessed by computer-aided planimetry and histopathological examination., Results: Phospholipids (10 days: P = 0.001; 20 days: P = 0.012) and icodextrin (10 days: P = 0.006; 20 days: P = 0.055) reduced adhesion re-formation after both intervals compared with Ringer's lactate controls., Conclusion: Phospholipids and icodextrin were effective in preventing re-formation of adhesions., (Copyright 2003 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd.)

Intestinal intussusception is a frequent problem after experimental transplantation in dogs. This report describes the safety and efficacy of performing a modified Noble plication for the prevention of intussusception. Heterotopic renal transplantation and plication was performed in 20 dogs. Dogs were killed when the serum creatinine concentration exceeded 7 mg/dL because of acute rejection (19 dogs) or venous occlusion (1 dog). Gastrointestinal signs were commonly observed, but no dog experienced an intestinal intussusception, compared to 3 of 14 dogs (21%) previously treated using a similar immunosuppressive regimen. This study supports the routine use of enteroplication in dogs undergoing renal transplantation.

The aim of the present study was to determine whether the ET(A) receptor antagonist LU135252 can protect the mesenterium against ischaemia/reperfusion (I/R) damage. Direct occlusion of the superior mesenteric artery was performed for 30 min in two groups of dogs. Declamping was followed by 90 min of reperfusion. Mesenteric release of ET-1 was studied in series 1 (n=6). In series 2, 5 min before cross-clamping, the treated group (n=7) received an intravenous bolus of LU135252 (5 mg/kg), whereas the control group (n=6) was given vehicle. Mean arterial blood pressure and mesenteric blood flow were recorded. Mesenteric venous and systemic arterial serum lactate and glucose, plasma creatine kinase and free radical concentrations were determined at 15 min intervals. Ischaemia for 30 min induced a significant increase (P<0.05) in mesenteric ET-1 release (1594+/-526 pg/min, compared with 343+/-258 pg/min at baseline), which had returned to baseline after 20 min of reperfusion. LU135252 administration significantly decreased mesenteric blood flow during ischaemia (204+/-23%) compared with controls (320+/-34%, P<0.05). In contrast, mesenteric blood flow was higher in the treated group (120+/-19% compared with 82+/-7%; P<0.05) after 90 min of reperfusion. Mesenteric lactate production was reduced by ET(A) antagonist administration under ischaemia (0.77+/-0.02 mmol/l) compared with controls (1.36+/-0.04 mmol/l; P<0.01). Lower levels of venous creatine kinase were present in the treated group during ischaemia as well as after reperfusion (120+/-7% compared with 150+/-16%; P<0.01). Administration of LU135252 also improved the total scavenger capacity of the mesenteric bed during ischaemia [(15.9+/-3.9)x10(6) compared with (6.4+/-3.6)x10(6) relative light units; P<0.05] and early reperfusion [(8.7+/-3.1)x10(6) compared with (1.1+/-2.9)x10(6) relative light units]. Thus ET-1 is involved in I/R-induced disturbances in the intestine. LU135252 seems to counteract these changes, in part by increasing the antioxidant capacity of the mesenterium.

The pathogenesis of postoperative ileus (PI) is multifactorial, and includes activation of inhibitory reflexes, inflammatory mediators and opioids (endogenous and exogenous). Accordingly, various strategies have been employed to prevent PI. As single-modality treatment, continuous postoperative epidural analgesia including local anaesthetics has been most effective in the prevention of PI. Choice of anaesthetic technique has no major impact on PI. Minimally invasive surgery reduces PI, in accordance with the sustained reduction in the inflammatory responses, while the effects of early institution of oral nutrition on PI per se are minor. Several pharmacological agents have been employed to resolve PI (propranolol, dihydroergotamine, neostigmine, erythromycin, cisapride, metoclopramide, cholecystokinin, ceruletide and vasopressin), most with either limited effect or limited applicability because of adverse effects. The development of new peripheral selective opioid antagonists is promising and has been demonstrated to shorten PI significantly. A multi-modal rehabilitation programme including continuous epidural analgesia with local anaesthetics, enforced nutrition and mobilisation may reduce PI to 1-2 days after colonic surgery.

Objective: To investigate the effect of octreotide, a long-acting analogue of somatostatin, on postoperative adhesion formation, because somatostatin inhibits secretion of some growth factors that have modulatory effects on collagen synthesis., Design: An experimental study., Setting: Surgical Research and Biochemistry laboratories at Hacettepe University, Ankara, Turkey., Subjects: Male Swiss albino mice., Interventions: Both sides of a 5-cm ileal segment from Swiss albino mice were scraped 10 times, and transient ischemia was induced by clamping the segmental artery. Animals were injected subcutaneously with 1 mL/d of saline for 3 days (group 1), a single 5-mL intraperitoneal dose of saline (group 2), subcutaneously with 10 micrograms/kg daily of octreotide for 3 days (group 3) or a single 10 micrograms/kg intraperitoneal dose of octreotide (group 4). In half of the animals repeat laparotomy was performed on postoperative day 5. After adhesions were graded, the scraped ileal segments were excised for determination of hydroxyproline quantity. The same procedure was repeated on postoperative day 14 for the remaining animals., Outcome Measures: Adhesion grading, hydroxyproline levels., Results: On postoperative day 5, the intraperitoneal octreotide group (group 4) had a significantly lower median adhesion score than groups 1 and 2. On postoperative day 14, both octreotide groups (3 and 4) had a significantly lower median adhesion grading than both saline groups (1 and 2). Hydroxyproline levels of the groups were not significantly different on either day 5 or day 14., Conclusion: Octreotide has a beneficial effect in decreasing adhesion formation in the early postoperative period.

The aim of the present study was to investigate the protective effect of the pineal secretary product melatonin in a model of splanchnic artery occlusion shock (SAO). SAO shock was induced in rats by clamping both the superior mesenteric artery and the celiac trunk for 45 min, followed thereafter by release of the clamp (reperfusion). At 60 min after reperfusion, animals were sacrificed for tissue histological examination and biochemical studies. There was a marked increase in the oxidation of dihydrorhodamine 123 to rhodamine (a marker of peroxynitrite-induced oxidative processes) in the plasma of the SAO-shocked rats after reperfusion, but not during ischemia alone. Immunohistochemical examination demonstrated a marked increase in the immunoreactivity to nitrotyrosine, an index of nitrogen species such as peroxynitrite, in the necrotic ileum in shocked rats. SAO-shocked rats developed a significant increase of tissue myeloperoxidase and malondialdehyde activity, and marked histological injury to the distal ileum. SAO shock was also associated with a significant mortality (0% survival at 2 hr after reperfusion). Reperfused ileum tissue sections from SAO-shocked rats showed positive staining for P-selectin, which was mainly localized in the vascular endothelial cells. Ileum tissue sections obtained from SAO-shocked rats with anti-intercellular adhesion molecule (ICAM-1) antibody showed a diffuse staining. Melatonin (applied at 3 mg/kg, 5 min prior to reperfusion, followed by an infusion of 3 mg/kg per hr), significantly reduced ischemia reperfusion injury in the bowel as evaluated by histological examination. This prevented the infiltration of neutrophils into the reperfused intestine, is evidenced by reduced myeloperoxidase activity and reduced lipid peroxidation. This was evaluated by malondialdehyde activity which reduced the production of peroxynitrite during reperfusion, markedly reduced the intensity and degree of P-selectin and ICAM-1 in tissue section from SAO-shocked rats and improved their survival. Taken together, our results clearly demonstrate that melatonin treatment exerts a protective effect and part of this effect may be due to inhibition of the expression of adhesion molecule and peroxynitrite-related pathways and subsequent reduction of neutrophil-mediated cellular injury.

Ileal ulcers and thiobarbituric acid (TBA)-reactive substances in the ileal mucosa were induced in rats treated with a nonsteroidal antiinflammatory drug, 5-bromo-2-(4-fluorophenyl)-3-(4-methylsulfonylphenyl)thiophene (BFMeT), at a dose of 1,000 mg/kg administered with tap water as drinking water. However, the formation of ileal ulcers and TBA-reactive substances in the ileal mucosa was repressed by giving the animals a culture supernatant of Lactobacillus acidophilus as drinking water. We measured the antioxidative activity of the culture supernatant and found that the supernatant inhibited the formation of t-butyl hydroperoxide-induced TBA-reactive substances in erythrocyte membrane ghosts. Therefore, the effects of various known antioxidative compounds on the ileal ulcer formation induced by BFMeT were investigated. While alpha-tocopherol, t-butyl-1,4-hydroxyanisole and allopurinol did not repress ulcer formation after BFMeT treatment, ascorbic acid, dimethyl sulfoxide, glutathione and beta-carotene significantly inhibited formation. Among these compounds, ascorbic acid was the most effective. Accumulation of TBA-reactive substances in the ileal mucosa after BFMeT treatment also decreased significantly in rats treated with ascorbic acid. In addition, the percentage of gram-negative rods in the ileal contents of rats treated with BFMeT and tap water was dramatically increased, but it was not increased in rats treated with BFMeT and these antioxidants. A positive correlation between the percentage of gram-negative rods and the number of ileal ulcers was also observed. These results suggest that lipid peroxidation mediated by oxygen radicals plays an important role in the induction of ileal ulcers by BFMeT in rats, and that lipopolysaccharide-activated neutrophils probably produce highly reactive hypochlorous acid and hydrogen peroxide, which are inactivated by ascorbic acid and glutathione, respectively.

The role of intestinal bacteria in induction and repression of ulcer formation in the ileum of rats treated with one of the nonsteroidal antiinflammatory drugs (NSAIDs), 5-bromo-2-(4-fluorophenyl)-3-(4-methylsulfonylphenyl) thiophene (BFMeT), was examined in this study. BFMeT was administered by intragastric gavage once at doses of 500-1,500 mg/kg of body weight to Wistar rats treated with and without antibiotics (bacitracin, neomycin, streptomycin), germ-free rats and gnotobiotic rats, and 72 hr later their gastrointestinal tracts were examined for ulcer formation. A single oral administration of BFMeT induced ileal ulcers in specific pathogen-free rats. However, the rats given antibiotics to reduce the intestinal bacteria had no ulcers. BFMeT-treated germ-free rats and gnotobiotic rats mono-associated with Bifidobacterium adolescentis or Lactobacillus acidophilus also had no intestinal ulcers. However, the drug induced ileal ulcers in gnotobiotic rats mono-associated with Eubacterium limosum or Escherichia coli. An overnight culture of B. adolescentis or L. acidophilus or yogurt containing Bifidobacterium breve and Streptococcus thermophilus, when given as drinking water, inhibited ulcer formation in the ileum of rats treated with BFMeT. Gram staining of the ileal contents of normal rats revealed that 97.4% of the stained microorganisms were Gram-positive rods and only 1.2% were Gram-negative rods. In the group of rats with ulcers induced by BFMeT, the Gram-positive rods decreased by 56.4% and the Gram-negative rods including Escherichia coli, Klebsiella, Proteus and Bacteroides increased by 37.3%. However, in the group of rats administered the Bifidobacterium culture, the Lactobacillus culture or yogurt, the percentages of the Gram-negative rods were decreased. Although Lactobacillus was a major bacterium in the ileum of normal rats, the Gram-negative facultatively anaerobic rods E.coli, Klebsiella and Proteus were increased in the ulcerated ileum of rats treated with BFMeT, suggesting that these bacteria are associated with ulcer formation in rats treated with NSAIDs, and that Lactobacillus and Bifidobacterium inhibit it by repressing the growth of ulcer-inducing bacteria.

Neutrophils have been implicated in the acute formation of gastric mucosal erosions induced by nonsteroidal antiinflammatory drugs. The aims of the present study were to determine, in rats, the role of neutrophils in the pathogenesis of etodolac- and indomethacin-induced gastrointestinal ulceration and blood loss. Both drugs caused gastrointestinal ulceration, which was associated with increased blood loss, a rise in plasma haptoglobin concentration, and a rise in the number of circulating neutrophils. A marked infiltration of neutrophils occurred only in ileal tissue. Pretreatment with a selective antineutrophil serum induced a significant neutropenia, which failed to inhibit either etodolac- or indomethacin-induced gastrointestinal ulceration and blood loss. A further study demonstrated that the antineutrophil serum did not prevent gastric erosions induced by indomethacin, but it inhibited carrageenan paw edema, which is dependent, in part, on neutrophil infiltration and activation. It is concluded that neutrophils do not contribute to gastrointestinal ulceration and blood loss induced by nonsteroidal antiinflammatory drugs. Furthermore, in contrast with previous studies, our results provide no evidence that neutrophils contribute to indomethacin-induced acute gastric erosion formation.

Intra-abdominal adhesions were created by localized serosal trauma in 11 adult ponies at three locations on the small intestine. Six ponies received verapamil hydrochloride (0.2 mg/kg) subcutaneously every eight hours for three days, and five ponies received an equal volume of saline solution at the same intervals. The investigators were not informed which treatments the ponies received. Systolic, diastolic, and mean carotid arterial pressures and heart rates were measured six hours before surgery, and then 0.5, 1, 1.5, and 8 hours after the first treatment on each day for three days. One pony was euthanatized on day 13 because of colic, and the other 10 ponies were euthanatized 14 days after surgery. Scoring methods were used to assess the severity of adhesion formation and to grade the histologic appearance of the abraded sites. No significant differences were found for rectal temperature, packed cell volume, total plasma proteins, heart rate, and systolic, diastolic, or mean arterial pressures between control and verapamil-treated ponies. No significant differences were detected between the treatment groups for adhesion scores per abraded site, total adhesion scores per pony, the total number of adhesions per pony, or in the histologic scores.

Background: Clostridium difficile toxin A is the principal mediator of inflammatory enterocolitis in experimental animals. The purpose of this study was to explore the effect of ketotifen, an anti-inflammatory drug, on toxin A-induced enterotoxicity in rat ileum., Methods: The effects of intragastric administration of ketotifen on secretion, mannitol permeability, histological damage, and mucosal levels of leukotriene B4, leukotriene C4, and platelet activating factor in toxin A-exposed rat ileal loops were measured in vivo. The effects of ketotifen on toxin A-mediated release of rat mast cell protease II (rat mucosa mast cell product) release were also measured in rat ileal explants in vitro. The effect of ketotifen on neutrophil migration in vitro was also evaluated., Results: Ketotifen pretreatment inhibited toxin A-associated intestinal secretion by 42.5% and mannitol permeability by 56.3% and reduced epithelial cell inflammation and necrosis. These effects were associated with reduced levels of leukotriene B4 by 65.8%, leukotriene C4 by 88.8%, platelet activating factor by 77.8%, and inhibition of rat mast cell protease II by 58.4%. In addition, pretreatment of neutrophils with ketotifen inhibited neutrophil migration in vitro., Conclusions: The protective effect of ketotifen in this animal model was associated with significant inhibition of release of mast cells and neutrophil derived mediators, supporting their involvement in C. difficile enteritis.

We earlier described an experimental model to create recurring chronic ileal inflammation with ulceration in the rat. A 2 cm segment of the distal ileum is excised but left attached to its intact mesentery; the ileum is reanastomosed. The ileal segment will seal off its open ends and a cyst-like structure of varying size will be formed, containing mucus, cell debris and bacteria. Approximately two thirds of the animals develop chronic inflammation with ulceration proximal to the ileal anastomosis. The ileal cyst and the surgical procedure on the distal ileum were shown to be prerequisites of the rat model for the development of lesions. We recently described that, in contrast to rats fed a standard diet, rats fed a hydrolyzed formula diet never developed inflammation or ulceration when subjected to the experimental procedure. In the present study we confirmed these observations and showed that the normal ileal flora (NIF) and the ileal cyst flora (ICF) were significantly influenced by the diets. The bacterial counts of both the aerobic and anaerobic NIF were 2 10log lower, i.e. > or = 99%, in rat fed the formula diet as compared to in those fed standard rat pellets. The NIF of the former group was represented by more aerobic species than the NIF of rats on the standard diet. Compared to the NIF there was a parallel increase in the bacterial counts of the ICF by approximately 2 10log CFU values in both groups of rats. The mean number of anaerobic species, mainly Gram-negative rods of the ICF, increased by approximately 70% in the rats on the standard diet that developed ileal ulceration, whereas identified aerobic species of the ICF decreased by 61% in rats on the formula diet and by 46% in those on the standard diet that did not develop ileal ulceration. The number of anaerobes in those groups of rats remained unchanged. The significant bacteriological differences between the rats that developed ileal ulcers and those which did not indicate that bacteria may be involved, directly or indirectly, in the development of chronic ileal ulceration.

We recently described an experimental model in the rat to create recurring chronic ileal inflammation including ulceration. This model is dependent on an "in vivo culture" of normal intestinal contents. In the present experimental study we examined the effect of a polymeric and a hydrolyzed formula diet on the formation of ulcerating lesions using our rat model. Two groups of rats (twenty in each group) were fed either one of these formula diets eight weeks prior to the experimental procedure and this diet was continued until sacrifice eight weeks later. Twenty control rats also underwent the experimental procedure but were fed standard rat pellets for the same time periods. At sacrifice 60% of the control rats had developed ileal ulcers. None of the rats fed the formula diets developed macroscopic ileal inflammation or ulceration. The effectiveness of formula diets in inducing remission in Crohn's disease in humans may be linked to alterations in the intestinal microflora. We hypothesize that the formula diets in this experiment exerted a protective effect against ileal ulceration by altering the ileal microflora. Preliminary studies support this hypothesis but need to be expanded.

Construction of a continent ileal urinary reservoir is associated with a high incidence of late complications because of malfunction of the nipple valve. Three important modifications in the operative procedures for the construction of the nipple valve were developed with significant improvements in late complication rates and end results. First is the use of Dacron (polyester fiber) fabric as a collar instead of Marlex mesh (polypropylene), which frequently causes erosion. The second is treatment of the mesentery using a CUSA (Cavitron Ultrasonic Surgical Aspirator) (Cavitron Co. Ltd.) instead of making Deaver's windows, thus preserving the blood supply to the nipple valves. Third is anchoring of the nipple valves to the anterior wall of the reservoir, preventing prolapse, the most frequent malfunction of the nipple valve. The incidence of malfunction of the nipple valve and the end results of this innovative urinary diversion using an internal reservoir were analyzed in relation to these modifications of the operative technique among 71 patients. To date, with an established mode of operation, the success rate is more than 95 per cent.