A neurokinin 1 receptor antagonist reduces an ongoing ileal pouch inflammation and the response to a subsequent inflammatory stimulus

Ileal pouch-anal anastomosis (IPAA) is an excellent surgical option for patients with chronic ulcerative colitis (CUC) requiring colectomy; however, persistent episodes of ileal pouch inflammation, or pouchitis, may result in debilitating postoperative complications. Because considerable evidence implicates substance P (SP) as an inflammatory mediator of CUC, we investigated whether SP participates in the pathophysiology of pouchitis. With the use of a rat model of IPAA that we developed, we showed that ileal pouch MPO levels and neurokinin 1 receptor (NK-1R) protein expression by Western blot analysis were significantly elevated 28 days after IPAA surgery. In situ hybridization and immunohistochemistry showed that the increase in NK-1R protein expression was localized to the lamina propria and epithelia of pouch ileum. The intraperitoneal administration of the NK-1R antagonist (NK-1RA) CJ-12,255 for 4 days, starting on day 28, was effective in reducing MPO levels. Starting on day 28, animals with IPAA were given 5% dextran sulfate sodium (DSS) in their drinking water for 4 days, which caused histological and physical signs of clinical pouchitis concomitant with significant increases in ileal pouch MPO concentrations as well as NK-1R protein expression by Western blot analysis. In situ hybridization and immunohistochemistry showed that the increase in NK-1R protein expression was especially evident in crypt epithelia of pouch ileum. When the NK-1RA was administered 1 day before starting DSS and continued for the duration of DSS administration, the physical signs of clinical pouchitis and the rise in MPO were prevented. These data implicate SP in the pathophysiology of pouchitis and suggest that NK-1RA may be of therapeutic value in the management of clinical pouchitis.     

Design of a multicentre randomized trial to evaluate CT colonography versus colonoscopy or barium enema for diagnosis of colonic cancer in older symptomatic patients: The SIGGAR study

Clinical trials on novel drug therapies require clear criteria for patient selection and agreed definitions of disease remission. This principle has been successfully applied in the field of rheumatology where agreed disease scoring systems have allowed multi-centre collaborations and facilitated audit across treatment centres. Unfortunately in ulcerative colitis this consensus is lacking. Thirteen scoring systems have been developed but none have been properly validated. Most trials choose different endpoints and activity indices, making comparison of results from different trials extremely difficult. International consensus on endoscopic, clinical and histological scoring systems is essential as these are the key components used to determine entry criteria and outcome measurements in clinical trials on ulcerative colitis. With multiple new therapies under development, there is a pressing need for consensus to be reached.     

Effects of ulcerative colitis activity on plasma and mucosal prostaglandin E2 concentration

The aim of this study was to determine effects of changes in ulcerative colitis activity on mucosal and plasma PGE2 concentrations measured with an EIA in 49 patients who underwent sigmoidoscopy. The disease was diagnosed in 37 patients. Twelve patients with normal colonic mucosa served as controls. Patients were divided into three groups depending on the changes of endoscopic picture during a three-month follow-up. Some laboratory markers of the disease activity, such as C-reactive protein, albumin, gamma-globulin and hemoglobin concentrations, sedimentation rate, and white blood and platelets counts, were also evaluated. Initial examination revealed a significant, positive correlation of mucosal and plasma PGE2 concentration with endoscopic score. Follow-up of patients without significant progression of mucosal changes revealed constant and close to normal concentration of mucosal PGE2. Plasma PGE2 was higher at the second examination, yet without significant difference. Improvement of endoscopic picture resulted in significant decrease of plasma and mucosal PGE2 concentrations. Worsening of mucosal changes reflected endoscopically was associated with significant increase of PGE2. There were no remarkable changes in the values of analyzed laboratory markers of the disease activity. These results indicate the usefulness of mucosal or plasma PGE2 measurement as a possible prognostic marker in patients with ulcerative colitis.     

Beneficial and preventive effect of chitin nanofibrils in a dextran sulfate sodium-induced acute ulcerative colitis model

Chitin nanofibrils, which are prepared from dried crab shells by a grinding method, are newly developed natural materials with uniform widths of approximately 10-20 nm. The bioactivities of chitin nanofibrils have not been investigated. In this study, we examined the preventive effects of chitin nanofibrils in a mouse model of dextran sulfate sodium (DSS)-induced acute ulcerative colitis. The results indicated that chitin nanofibrils improved clinical symptoms and suppressed ulcerative colitis. Furthermore, chitin nanofibrils suppressed myeloperoxidase activation in the colon and decreased serum interleukin-6 concentrations. Conversely, chitin powder did not suppress DSS-induced acute ulcerative colitis. Our results suggested that chitin nanofibrils have potential as a functional substance for inflammatory bowel disease patients.     

Sulfasalazine-induced colitis complicating idiopathic ulcerative colitis.

A diagnosis of idiopathic ulcerative colitis was made in a previously healthy 9-year-old boy. Symptoms persisted despite therapy with sulfasalazine, 50 mg/kg daily, but they eventually responded to treatment with parenteral nutrition and prednisone, 40 mg daily. Metronidazole was also given to eradicate persistent Dientamoeba fragilis from the stools. The symptoms resolved over 3 weeks, and the daily dose of prednisone was tapered. On two subsequent occasions a challenge with sulfasalazine caused an immediate recurrence of loose, blood-streaked stools and of nonspecific histologic features of ulcerative colitis, which resolved when the sulfasalazine was discontinued.     

Oxygen radicals in ulcerative colitis.

This article reviews the pathophysiologic concept that superoxide and hydrogen peroxide, generated by activated leukocytes, together with low-molecular-weight chelate iron derived from fecal sources and from denatured hemoglobin, amplify the inflammatory response and subsequent mucosal damage in patients with active episodes of ulcerative colitis. The putative pathogenic mechanisms reviewed are as follows: (1) Dietary iron is concentrated in fecal material owing to normally limited iron absorption. (2) Mucosal bleeding, characteristic of ulcerative colitis, as well as supplemental oral iron therapy for chronic anemia, further conspire to maintain or elevate mucosal iron concentration in colitis. (3) Fenton chemistry, driven especially by leukocyte-generated superoxide and hydrogen peroxide, leads to formation of hydroxyl radicals. (4) The resultant oxidative stress leads to the extension and propagation of crypt abscesses, either through direct membrane disruption by lipid peroxidation or through generation of secondary toxic oxidants such as chloramines. (5) Chemotactic products of lipid peroxidation, including 4-hydroxynonenal, provide positive feedback to accelerate this inflammatory/oxidative process, leading to acute exacerbations of the disease. (6) Other oxidized products, such as oxidized tryptophan metabolites, created by free radical mechanisms in or near the mucosa, may act as carcinogens or tumor promotors that contribute to the exceedingly high incidence of colon carcinoma in patients suffering from chronic ulcerative colitis. In this way, self-sustaining cycles of oxidant formation may amplify flare-ups of inflammation and mucosal injury in ulcerative colitis. This concept, if proved correct by subsequent research, would provide a rationale for several novel clinical approaches to the management of ulcerative colitis, including use of SOD mimetics, iron chelators, and chain-breaking antioxidants.     

双歧杆菌对小鼠溃疡性结肠炎模型的影响

目的：研究双歧杆菌对小鼠急性溃疡性结肠炎模型的影响。方法：葡聚糖硫酸钠（DSS）制备小鼠溃疡性结肠炎模型。应用实体显微镜观察整段大肠的粘膜改变情况;普通粪便涂片观察小鼠粪便中细菌的变化,梯度稀释法行粪便菌群分析,了解几种代表性的菌群的改变;一般病理切片,行HE染色,观察镜下病理变化,结果：双歧杆菌 DSS组相比,血便不明显,镜下组织病理改变轻微,肠道菌群无明显紊乱。结论：双歧杆菌对溃疡性结肠炎发生有预防作用,并能减轻症状和病变。     

Towards Anatomic Scale Agent-Based Modeling with a Massively Parallel Spatially Explicit General-Purpose Model of Enteric Tissue (SEGMEnT_HPC)

Perhaps the greatest challenge currently facing the biomedical research community is the ability to integrate highly detailed cellular and molecular mechanisms to represent clinical disease states as a pathway to engineer effective therapeutics. This is particularly evident in the representation of organ-level pathophysiology in terms of abnormal tissue structure, which, through histology, remains a mainstay in disease diagnosis and staging. As such, being able to generate anatomic scale simulations is a highly desirable goal. While computational limitations have previously constrained the size and scope of multi-scale computational models, advances in the capacity and availability of high-performance computing (HPC) resources have greatly expanded the ability of computational models of biological systems to achieve anatomic, clinically relevant scale. Diseases of the intestinal tract are exemplary examples of pathophysiological processes that manifest at multiple scales of spatial resolution, with structural abnormalities present at the microscopic, macroscopic and organ-levels. In this paper, we describe a novel, massively parallel computational model of the gut, the Spatially Explicitly General-purpose Model of Enteric Tissue_HPC (SEGMEnT_HPC), which extends an existing model of the gut epithelium, SEGMEnT, in order to create cell-for-cell anatomic scale simulations. We present an example implementation of SEGMEnT_HPC that simulates the pathogenesis of ileal pouchitis, and important clinical entity that affects patients following remedial surgery for ulcerative colitis.     

A novel murine model of inflammatory bowel disease and inflammation-associated colon cancer with ulcerative colitis-like features

Mutations that increase susceptibility to inflammatory bowel disease (IBD) have been identified in a number of genes in both humans and mice, but the factors that govern how these mutations contribute to IBD pathogenesis and result in phenotypic presentation as ulcerative colitis (UC) or Crohn disease (CD) are not well understood. In this study, mice deficient in both TNF and IL-10 (T/I mice) were found to spontaneously develop severe colitis soon after weaning, without the need for exogenous triggers. Colitis in T/I mice had clinical and histologic features similar to human UC, including a markedly increased risk of developing inflammation-associated colon cancer. Importantly, development of spontaneous colitis in these mice was prevented by antibiotic treatment. Consistent with the known role of Th17-driven inflammation in response to bacteria, T/I mice had elevated serumTh17-type cytokines when they developed spontaneous colitis and after systemic bacterial challenge via NSAID-induced degradation of the mucosal barrier. Although TNF production has been widely considered to be be pathogenic in IBD, these data indicate that the ability to produce normal levels of TNF actually protects against the spontaneous development of colitis in response to intestinal colonization by bacteria. The T/I mouse model will be useful for developing new rationally-based therapies to prevent and/or treat IBD and inflammation-associated colon cancer and may further provide important insights into the pathogenesis of UC in humans.     

Presence paf-acether mediator of inflammation in stools of patients with inflammatory enterocolitis

Paf-acether (platelet-activating factor, paf) is one of the most potent inflammatory mediators synthesised by and acting on most inflammatory cells. Paf causes gastric ulcerations and ischemic bowel necrosis. Recently, we described the presence of paf in stools of patients bearing ileal pouch-anal anastomosis with pouchitis. These findings prompted us to search for the presence of paf in stools of patients suffering from inflammatory bowel diseases: Crohn's disease and ulcerative colitis. The fraction corresponding to paf isolated from stools exhibited the same physicochemical and biological characteristics as synthetic paf. Reverse-phase high performance liquid chromatography revealed 80% of C16 and 20% of C18 paf. The presence of a biologically active phospholipid in human stools may bring new perspectives with respect to the study of gastrointestinal diseases as well as the use of paf antagonists in the treatment of inflammatory bowel diseases.     

溃疡性结肠炎患者菌群分析结果的研究

目的：研究溃疡性结肠炎患者肠道菌群的改变。方法：采用梯度稀释法行菌群分析。结果：发现酵母菌和小梭菌数较正常人显著增高,其他细菌数差异无显著性。结论：该结果可以为溃疡性结肠炎的治疗提供参考依据。为溃疡性结肠炎的预后进行评估。     

Adhesive Escherichia coli in inflammatory bowel disease and infective diarrhoea.

The clinical features of ulcerative colitis and Crohn''s disease are similar to those of infections of the bowel, although their cause is uncertain. Many bacteria that cause intestinal diseases adhere to the gut mucosa, and adhesion of pathogenic Escherichia coli is resistant to D-mannose. The adhesive properties of isolates of E coli were assessed by assay of adhesion to buccal epithelial cells with mannose added. The isolates were obtained from patients with inflammatory bowel diseases (50 with a relapse of ulcerative colitis, nine with ulcerative colitis in remission, 13 with Crohn''s disease, and 11 with infectious diarrhoea not due to E coli) and 22 controls. The median index of adhesion to buccal epithelial cells (the proportion of cells with more than 50 adherent bacteria) for E coli from patients with ulcerative colitis in relapse was significantly higher (43%) than that for controls (5%) and patients with infectious diarrhoea (14%). The index was not significantly different among isolates from patients with ulcerative colitis in relapse, Crohn''s disease (53%), and ulcerative colitis in remission (30%). If an index of adhesion of greater than 25% is taken as indicating an adhesive strain 86% of isolates of E coli from patients with inflammatory bowel disease were adhesive compared with 27% from patients with infective diarrhoea and none from controls. The adhesive properties of the isolates from patients with inflammatory bowel disease were similar to those of pathogenic intestinal E coli, raising the possibility that they may have a role in the pathogenesis of the condition; the smaller proportion of adhesive isolates in patients with infective diarrhoea due to other bacteria suggests that the organism may be of primary importance rather than arising secondarily.     

Inducible nitric oxide synthase activity in colon biopsies from inflammatory areas: correlation with inflammation intensity in patients with ulcerative colitis but not with Crohn's disease

Summary. Nitric oxide synthase (NOS) activities are responsible for the enzymatic conversion of L-arginine into NO and L-citrulline. Relatively low amounts of NO are produced in intestinal epithelial cells or are released from nerve endings. The effects of NO production are related to the maintenance of epithelial integrity and permeability. A pathological role of an increased NO production has been suggested to play a role in models of experimental colitis. In humans, NOS activity in colon mucosa from patients with ulcerative colitis is clearly increased when compared with the activity of the control group. In contrast, an increase of NOS activity in the colon mucosa from patients with Crohn's disease remains controversial. In the present work, we have measured NOS activity in colon biopsies originating from the control group (n = 16), from patients with ulcerative colitis (n = 23) and Crohn's disease (n = 17) using the radiochemical method of the conversion of L-[guanido-¹⁴C] arginine into radioactive L-citrulline. In the control group, NOS activity was mainly of the inducible type (88% of total NOS activity) since it was characterised by its insensibility to the absence of calcium in the assay medium. In colon biopsies originating from patients with ulcerative colitis, inducible NOS activity was increased 3 fold (p < 0.005) and in patients with Crohn's disease, inducible NOS activity was increased 5 fold (p < 0.005). Correlations between NOS activity in colon biopsies and the intensity parameters of the disease i.e. Truelove index, endoscopic score and histo-logical parameters were evidenced in patients with ulcerative colitis. In contrast, in patients with Crohn's disease, the high inducible NOS activity was not correlated with any intensity parameters of the disease. From these data, we concluded that although inducible NOS activity was increased several fold in colon biopsies originating from patients with both ulcerative colitis and Crohn's disease, a correlation between this activity and the severity of bowel inflammation was not found in either cases. Received August 7, 1999     

Diagnostic possibilities of roentgeno-endoscopic and morphologic methods of examining the colon in nonspecific colitis

The paper is concerned with comparative assessment of the diagnostic potentialities of the x-ray, endoscopic and pathomorphological methods of investigation. The results of the examination of 100 patients operated upon for nonspecific ulcerative colitis (54) and Crohn's disease (46) were analyzed. The advantages of these methods were demonstrated. A conclusion was made of the necessity of the use of the above methods for specified diagnosis of nonspecific colitis.     

Intestinal fatty acid binding protein (I-FABP) as a possible biomarker of ileitis in patients with ulcerative colitis

BACKGROUND: One of nine types of FABP, intestinal fatty acid binding protein (I-FABP) is primarily limited to the mature enterocytes of the small intestine, with only trace amounts identified in the stomach and large intestine. The aim of this study was to investigate the use of I-FABP as a possible plasma marker of intestinal injury in patients with ulcerative colitis (UC). MATERIAL AND METHODS: The study group consisted of 42 patients (11 females and 31 males) with active ulcerative colitis (UC), aged from 24 to 74 years (mean age: 41.8+/-3.5 years). Plasma I-FABP concentrations and hsCRP were compared using endoscopic pictures scored according to the system developed by Meyers et al., and analysed in the context of inflammatory process extension: pancolitis, or distal or left side colitis. RESULTS: The mean serum I-FABP concentration /mL), whereas individuals with left-side colitis had a mean I-FABP concentration of 61.8+/-8.5 pg/mL. Significant serum I-FABP elevation was observed in UC patients with a severe form of the disease, in contrast to the serum I-FABP concentration in patients with the mild form (260.5+/-60.6 vs. 61.5+/-7.9 pg/mL). CONCLUSION: The elevated serum I-FABP concentration in patients with UC may indicate ileitis. I-FABP may be a useful marker of the extended inflammatory process.     

Azathioprine in Ulcerative Colitis: Final Report on Controlled Therapeutic Trial

Eighty patients, all of whom were suffering from a frank clinical attack of ulcerative colitis, were admitted to the trial. The attack was treated with a standard course of corticosteroids and the patients were immediately placed on treatment with either azathioprine in a dose of 2·5 mg/kg body weight or dummy tablets. The trial tablets were continued for one year while the patients were maintained under regular clinical, sigmoidoscopic, histological, haematological, and biochemical surveillance. If a patient relapsed during such maintenance treatment he or she was treated with a further course of corticosteroids without interrupting maintenance treatment.In the treatment of an actual attack of ulcerative colitis the results in the attacks which brought the 80 patients into the trial show that no benefit came from the addition of azathioprine to a standard course of corticosteroid therapy.Patients admitted in their first attack of ulcerative colitis showed no benefit from the one-year maintenance treatment with azathioprine, the benefits of which were confined to patients admitted in a relapse of established disease. Even in these the difference between the treated group and the control group failed to reach statistical significance, but the difference was big enough to suggest that there is a prima facie case for regarding azathioprine as of some benefit in this group of patients.     

益生菌在炎症性肠病中的治疗作用

炎症性肠病(inflammatory bowel disease,IBD)包括溃疡性结肠炎(ulcerative colitis,UC)和克罗恩病(Crohn’s disease,CD)。随着对肠道微生物群在IBD发病机制中作用的认识不断深入,近年来益生菌广泛应用于IBD治疗。大量临床试验结果表明,益生菌治疗IBD的疗效主要体现在对UC和贮袋炎的治疗,对CD的疗效不明确。益生菌治疗IBD可能通过促进肠道微生物群平衡、改善肠道屏障功能、调节肠道黏膜免疫及营养物质代谢等途径。     

Intestinal bacteria and ulcerative colitis

Convincing evidence from both animal models and the study of patients with ulcerative colitis (UC) implicates the intestinal microflora in the initiation and maintenance of the inflammatory processes in this condition. Despite this, no specific pathogen has been identified as causal and the disease is widely believed to occur as the result of a genetically determined, but abnormal immune response to commensal bacteria. When compared with healthy people, UC patients have increased levels of mucosal IgG directed against the normal microflora. Studies of mucosal bacterial populations in UC indicate that there may be increased numbers of organisms, but reduced counts of "protective" bacteria such as lactobacilli and bifidobacteria. In animal models of colitis, antibiotics, particularly metronidazole, clindamycin, ciprofloxacin and the combination of vancomycin/impinemem protect against UC, especially if given before the onset of inflammation. These antibiotics target anaerobes and some Gram-positive organisms such as enterococci. However, antibiotic use in more than a dozen randomised control trials has been very disappointing, probably because we do not know which species to target, when to give the antibiotics, for how long and in what combinations. Surprisingly, therefore, there is a consistent benefit in the small number of studies reported of probiotics to manage UC and pouchitis. There is scope for more work in this area focussing on the mucosal microflora, its interactions with the gut immune system, its metabolic properties and the potential ways of modifying it.     

Milk fat globule-epidermal growth factor 8 is decreased in intestinal epithelium of ulcerative colitis patients and thereby causes increased apoptosis and impaired wound healing

Milk fat globule-epidermal growth factor 8 (MFG-E8) plays an important role in maintaining intestinal barrier homeostasis and accelerating intestinal restitution. However, studies of MFG-E8 expression in humans with ulcerative colitis are lacking. We examined MFG-E8 expression in colonic mucosal biopsies from ulcerative colitis patients and healthy controls (n = 26 each) by real-time quantitative polymerase chain reaction (PCR), Western blot analysis and immunohistochemistry. MFG-E8 mRNA and protein expression was lower in ulcerative colitis patients than in controls. MFG-E8 expression was inversely correlated with mucosal inflammatory activity and clinical disease activity in patients. MFG-E8 was present in human intestinal epithelial cells both in vivo and in vitro. Apoptosis induction was also detected in the intestinal epithelium of ulcerative colitis patients by terminal-deoxynucleoitidyl transferase mediated nick-end labeling assay. We used lentiviral vectors encoding human MFG-E8 targeting short hairpin RNA to obtain MFG-E8 knockdown intestinal epithelia cell clones. MFG-E8 knockdown could promote apoptosis in intestinal epithelial cell lines, accompanied by a decrease in level of the antiapoptotic protein B-cell lymphoma 2 (BCL-2) and induction of the proapoptotic protein BCL2-associated protein X (BAX). The addition of recombinant human MFG-E8 led to decreased BAX and cleaved caspase-3 levels and induction of BCL-2 level in intestinal epithelia cells. MFG-E8 knockdown also attenuated wound healing on scratch assay of intestinal epithelial cells. The mRNA level of intestinal trefoid factor 3, a pivotal factor in intestinal epithelial cell migration and restitution, was downregulated with MFG-E8 knockdown. In conclusion, we demonstrated that decreased colonic MFG-E8 expression in patients with ulcerative colitis may be associated with mucosal inflammatory activity and clinical disease activity through basal cell apoptosis and preventing tissue healing in the pathogenesis of ulcerative colitis.     

Effect of ulcerative colitis treatment on transforming growth factor beta(1) in plasma and rectal mucosa

The aim of this study was to evaluate the effect of active ulcerative colitis (UC) treatment on transforming growth factor beta(1) (TGF-beta(1)) concentration in plasma and rectal mucosa measured in 28 patients. The highest plasma values were observed in patients with the severe course of the disease (74.2+/-14.0 ng/ml), and they were significantly higher than in the group with mild one (43.7+/-5.6 ng/ml). Mean TGF-beta(1) measured in mucosal samples from patients with severe UC (563+/-146 pg/mg protein) doubled values from patients with mild UC (286+/-65 pg/mg protein). Plasma and mucosal TGF-beta(1) correlated significantly with disease activity index (DAI) and clinical activity index (CAI). Plasma TGF-beta(1) correlated additionally with scored endoscopic degree of mucosal injury. Treatment caused significant decrease of plasma and mucosal TGF-beta(1) concentrations. Patients who responded completely had higher baseline plasma and mucosal TGF-beta(1) that decreased significantly after the treatment. These results show that plasma and mucosal concentrations of transforming growth factor beta(1) are strongly associated with ulcerative colitis activity, and successful treatment of the disease results with decrease of their levels. More effective response to the treatment can be achieved in patients with higher baseline concentrations of TGF-beta(1).