Colon Length (colon + length)

Distribution by Scientific Domains

Selected Abstracts

Angiopoietin-2 in experimental colitis

Vijay C. Ganta PhD
Abstract Background: The pathophysiology of inflammatory bowel disease (IBD) includes leukocyte infiltration, blood and lymphatic remodeling, weight loss and protein enteropathy. The roles of angiopoietin-2 (Ang-2) in initiating gut inflammation, leukocyte infiltration and angiogenesis are not well understood. Methods: Disease activity index, histopathological scoring, myeloperoxidase assay, immunohistochemistry and sodium dodecyl sulphate- polyacrylamide gel electrophoretic methods were employed in the present study to addess the roles of Ang-2 in experimental colitis. Results: Several important differences were seen in the development of experimental IBD in Ang-2,/, mice. Although weight change and disease activity differ only slightly in WT and Ang-2,/, + DSS treated mice, leukocyte infiltration, inflammation and blood and lymphatic vessel density is significantly attenuated compared to WT + DSS mice. Gut capillary fragility and water export (stool blood and form) appear significantly earlier in Ang-2,/, + DSS mice vs. WT. Colon lengths were also significantly reduced in Ang-2,/, and gut histopathology was less severe in Ang-2,/, compared to WT + DSS. Lastly, the decrease in serum protein content in WT + DSS was less severe in Ang-2,/, + DSS, thus protein losing enteropathy (PLE) a feature of IBD is relieved by Ang-2,/,. Conclusion: These data demonstrate that in DSS colitis, Ang-2 mediates inflammatory hemangiogenesis, lymphangiogenesis and neutrophil infiltration to reduce some, but not all clinical features of IBD. The implications for Ang-2 manipulation in the development of IBD and other inflammatory diseases and treatments involving Ang-2 are discussed. (Inflamm Bowel Dis 2009) [source]

How to manage difficulties with colonoscope insertion

Masaaki Miyaoka
Unsuccessful insertion of a colonoscope is usually as a result of bending or looping of the scope. Looping of the colonoscope increases when too much air is insufflated or the scope is inserted with undue force, resulting in increased pain and risk of perforation. Successful insertion therefore requires careful handling of the scope to keep it straight, careful regulation of air levels, shortening of the colon length by gathering of the colon folds and rapid correction of any looping that should occur. This can be complicated in cases with an unusually long colon or with adhesion. The use of a colonoscope with variable rigidity or a small-caliber colonoscope is recommended to increase the rate of successful insertion to relieve pain and to prevent accidents. [source]

Bifidobacterium lactis inhibits NF-,B in intestinal epithelial cells and prevents acute colitis and colitis-associated colon cancer in mice,,

Seung Won Kim MS
Abstract Background: The aim of this study was to investigate the antiinflammatory effects of Bifidobacterium lactis on intestinal epithelial cells (IECs) and on experimental acute murine colitis and its tumor prevention effects on colitis-associated cancer (CAC) in mice. Methods: Human HT-29 cells were stimulated with IL-1,, lipopolysaccharides, or tumor necrosis factor-, with and without B. lactis, and the effects of B. lactis on nuclear factor kappa B (NF-,B) signaling in IEC were examined. For in vivo study, dextran sulfate sodium (DSS)-treated mice were fed with and without B. lactis. Finally, we induced colonic tumors in mice by azoxymethane (AOM) and DSS and evaluated the effects of B. lactis on tumor growth. Results: B. lactis significantly suppressed NF-,B activation, including NF-,B-binding activity and NF-,B-dependent reporter gene expression in a dose-dependent manner, and suppressed I,B-, degradation, which correlated with the downregulation of NF-,B-dependent gene products. Moreover, B. lactis suppressed the development of acute colitis in mice. Compared with the DSS group, the severity of DSS-induced colitis as assessed by disease activity index, colon length, and histological score was reduced in the B. lactis -treated group. In the CAC model, the mean number and size of tumors in the B. lactis -treated group were significantly lower than those in the AOM group. Conclusions: Our data demonstrate that B. lactis inhibits NF-,B and NF-,B-regulated genes in IEC and prevents acute colitis and CAC in mice. These results suggest that B. lactis could be a potential preventive agent for CAC as well as a therapeutic agent for inflammatory bowel disease. (Inflamm Bowel Dis 2010) [source]

Plant sterol guggulsterone inhibits nuclear factor-,B signaling in intestinal epithelial cells by blocking I,B kinase and ameliorates acute murine colitis

Jae Hee Cheon MD
Abstract Background/Aims: The plant sterol guggulsterone has been shown to have anti-inflammatory properties. It remains unknown, however, whether guggulsterone is effective for the treatment of inflammatory bowel disease (IBD). Therefore, we investigated anti-inflammatory effects of guggulsterone on intestinal epithelial cells (IEC) and on experimental murine colitis models and elucidated its molecular mechanisms. Methods: Human Caco-2 cells and rat non-transformed IEC-18 cells were stimulated with interleukin (IL)-1, or lipopolysaccharide (LPS) with or without guggulsterone. The effects of guggulsterone on nuclear factor (NF)-,B signaling in IEC were examined by intercellular adhesion molecule (ICAM)-1 real-time reverse-transcription polymerase chain reaction, NF-,B transcriptional activity assay, Western blotting for I,B phosphorylation/degradation, electrophoretic mobility shift assay, and in vitro I,B kinase (IKK) assay. For in vivo study, dextran sulfate sodium (DSS)-treated mice were fed with or without guggulsterone. Colitis was quantified by disease activity index and evaluation of macroscopic and microscopic findings. Phosphorylation of I,B and IKK in colon mucosa was assessed by Western blotting and immunohistochemistry. Results: Guggulsterone significantly inhibited LPS- or IL-1,-induced ICAM-1 gene expression, NF-,B transcriptional activity, I,B phosphorylation/degradation, and NF-,B DNA binding activity in IEC. Moreover, guggulsterone strongly blocked IKK activity. Administration of guggulsterone significantly reduced the severity of DSS-induced murine colitis as assessed by clinical disease activity score, colon length, and histology. Furthermore, tissue upregulation of I,B and IKK phosphorylation induced by DSS was attenuated in guggulsterone-treated mice. Conclusion: Guggulsterone blocks NF-,B signaling pathway by targeting IKK complex in IEC and attenuates DSS-induced acute murine colitis, which suggests that guggulsterone could be an attractive therapeutic option in the treatment of IBD. [source]

Interleukin-18 overproduction exacerbates the development of colitis with markedly infiltrated macrophages in interleukin-18 transgenic mice

Abstract Background and Aim:, The authors have previously shown that production of interleukin (IL)-18 was increased in the inflamed mucosa of patients with Crohn's disease (CD) and blockade of IL-18 ameliorated the murine model of CD. This demonstrated that IL-18 plays a significant role during intestinal inflammation. However, the initial role of IL-18 during intestinal inflammation was unclear; therefore the susceptibility of IL-18 transgenic (Tg) mice to acute dextran sulfate sodium (DSS)-induced colitis was examined. Methods:, Interleukin-18 Tg and wild-type (WT) mice were fed 2.0% of DSS for 8 days. The total clinical scores (bodyweight loss, stool consistency, and rectal bleeding), colon length and histological scores were assessed. The expressions of surface markers and IL-18 on infiltrating lamina propria mononuclear cells were analyzed immunohistochemistrically. Mesenteric lymph node (MLN) cells were isolated and the expressions of CD4+ T-cell activation markers (CD69, CD25 and IL18R) were analyzed by flow cytometry. Results:, The IL-18 Tg mice exhibited an increased susceptibility to DSS-induced colitis, as shown by significantly increased clinical, histological scores, and more severe colonic shortening compared with WT mice. Immunohistochemical analysis revealed a significant increase of IL-18 production and CD11b+ macrophages but not CD4+ T cells in the inflamed mucosa in DSS-fed IL-18 Tg compared with DSS-fed WT mice. Furthermore, MLN cells revealed no evidence of increased CD4+ T-cell activation in DSS-fed IL-18 Tg. Conclusions:, These findings suggest that IL-18 overproduction in the mucosa plays an important role in the marked infiltration of macrophages and exacerbates colitis in IL-18 Tg mice. [source]

Effect of oral iron supplementation on oxidative stress and colonic inflammation in rats with induced colitis

J. Carrier
Background: Iron supplementation may increase disease activity in ulcerative colitis, possibly through the production of reactive oxygen species from the Fenton reaction. Aim: To assess the effects of two doses of oral iron on intestinal inflammation and oxidative stress in experimental colitis. Methods: Colitis was induced in rats by giving 5% dextran sulphate sodium in drinking water for 7 days. First, using a 2 2 factorial design, rats with or without dextran sulphate sodium received the regular diet or a diet containing iron 3%/kg diet. Second, rats with dextran sulphate sodium-induced colitis were supplemented with iron 0.3%/kg diet and compared with rats on dextran sulphate sodium and regular diet. The body weight change, histological scores, colon length, rectal bleeding, plasma and colonic lipid peroxides, colonic glutathione peroxidase and plasma vitamin E and C were measured. Faecal analysis for haem and total, free and ethylenediaminetetra-acetic acid-chelatable iron was also performed. Results: Iron 3% and iron 0.3% increased the activity of dextran sulphate sodium-induced colitis, as demonstrated by higher histological scores, heavier rectal bleeding and further shortening of the colon. This was associated with increased lipid peroxidation and decreased antioxidant vitamins. Faecal iron available to the Fenton reaction was increased in a dose-dependent manner. Conclusions: Iron supplementation taken orally enhanced the activity of dextran sulphate sodium-induced colitis and is associated with an increase in oxidative stress. [source]