The etiopathology of inflammatory bowel disease (IBD) remains elusive. Accumulating evidence suggests that the abnormality of innate and adaptive immunity responses plays an important role in intestinal inflammation. IBD including Crohn's disease (CD) and ulcerative colitis (UC) is a chronic inflammatory disease of the gastrointestinal tract, which is implicated in an inappropriate and overactive mucosal immune response to luminal flora. Traditionally, CD is regarded as a Th1-mediated inflammatory disorder while UC is regarded as a Th2-like disease. Recently, Th17 cells were identified as a new subset of T helper cells unrelated to Th1 or Th2 cells, and several cytokines [e.g. interleukin (IL)-21, IL-23] are involved in regulating their activation and differentiation. They not only play an important role in host defense against extracellular pathogens, but are also associated with the development of autoimmunity and inflammatory response such as IBD. The identification of Th17 cells helps us to explain some of the anomalies seen in the Th1/Th2 axis and has broadened our understanding of the immunopathological effects of Th17 cells in the development of IBD.

This study analyzed IL-23p19 expression in inflamed mucosa of IBD and the role in the induction of IEL and NK cell activation as well as Th17 cell differentiation. Expression of IL-23p19 was performed by immunohistochemistry and quantitative real-time PCR. Expression of IL-23R was assessed by flow cytometry. Cytolytic activities of IEL and NK cells by IL-23 were determined by a standard (51)Cr-release assay. Cytokine levels were analyzed by ELISA and quantitative real-time PCR. Expression of IL-23p19 was increased significantly in inflamed mucosa of CD compared with that in UC and healthy controls. Double-staining confirmed that IL-23p19(+) cells were mainly CD68(+) macrophages/DCs. IL-23R(+) cells were increased significantly in PB- and LP-CD4(+) and -CD8(+) T and NK cells. IL-23 markedly promoted IBD IEL and NK cell activation and cytotoxicity and triggered IBD PB- and LP-T cells to secrete significantly higher levels of IFN-γ, TNF, IL-2, and IL-17A compared with controls. Importantly, IL-23 promoted IBD PB- or LP-CD4(+) T cells to differentiate into Th17 cells, characterized by increased expression of IL-17A and RORC. Anti-TNF treatment could markedly reduce IL-23 expression and Th17 cell infiltration in inflamed mucosa of CD patients. These data indicate that IL-23 is highly expressed in inflamed mucosa of IBD and plays an important role in the induction of IEL, NK, and T cell activation, proinflammatory cytokine secretion, and Th17 cell differentiation. Targeted therapy directed against IL-23p19 may have a therapeutic role in treatment of IBD.

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BackgroundHyperlipidaemia may be a potential risk factor for the occurrence of intestinal polyps. This study aimed to evaluate correlation between lipidaemia and the formation of colorectal polyps.MethodsOne hundred and fourteen patients with colorectal polyps and forty-eight healthy controls were included in this study. Colonoscopies were performed for all patients and controls within 1 week before blood samples were taken. The concentrations of serum lipids and lipoproteins were measured simultaneously using an automatic biochemical analyser. The colorectal lesions were classified based on pathological characteristics, and four types were identified in the study: hyperplastic polyp (HP), tubular adenoma (TA), tubulovillous adenoma (TVA) and adenoma with high-grade dysplasia (A-HGD). Advanced adenoma was classified according to the number, size and histological type of polyps.ResultsThe value of low-density lipoprotein cholesterol (LDL-C) was significantly higher in the group with advanced adenoma than in the controls (p < 0.05). Moreover, the LDL-C values in the HP and TA groups were higher when compared to that of controls (p < 0.05). Obesity, age, and increased TG and LDL-C were independent risk factors for the formation of colorectal polyps. The cut-off values of triglyceride (TG) and LDL-C to distinguish polyp patients from healthy controls were 0.96 mmol/L (AUC = 0.604, p = 0.036) and 3.05 mmol/L (AUC = 0.654, p = 0.002). The combined use of increased LDL-C and TG levels to distinguish polyp patients was effective, with a sensitivity of 50.0% and a specificity of 89.6% (AUC = 0.733, p < 0.01).ConclusionsColorectal polyps are more often found in obese and older patients. Increased LDL-C and TG were correlated with the occurrence of polyps. Combination of the two serum indicators was useful to assess risk of colorectal lesions, maybe more effective in screening hyperplastic polyp, tubular adenoma and advanced adenoma.

Background:The deregulation of immune responses plays a critical role in inflammatory bowel disease (IBD). Results: The levels of IgA and IL-10 were significantly lower, whereas the levels of IL-23 were higher, in IBD specimens. Conclusion: IL-23 can suppress IL-10 in the IBD intestinal mucosa. Significance: IL-23 may be a potential target in the treatment of IBD.

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Abstract. Using Laplace transform method, semi-analytical solutions are presented for transient electroosmotic flow of Maxwell fluids between micro-parallel plates. The solution involves solving the linearized Poisson-Boltzmann equation, together with the Cauchy momentum equation and the Maxwell constitutive equation considering the depletion effect produced by the interaction between macro-molecules of the Maxwell fluids and the channel surface. The overall flow is divided into depletion layer and bulk flow outside of depletion layer. In addition, the Maxwell stress is incorporated to describe the boundary condition at the interface. The velocity expressions of these two layers were obtained respectively. By numerical computations of inverse Laplace transform, the influences of viscosity ratio μ, density ratio ρ, dielectric constant ratio ε of layer II to layer I, relaxation timeλ 1 , interface charge density jump Q, and interface zeta potential difference Δψ on transient velocity amplitude are presented. Mathematics Subject Classification (2000). 76A05 · 76D05 · 76W05.