Search results for "Coliti"
showing 10 items of 510 documents
Chromoendoscopy in Inflammatory Bowel Disease
2012
Chromoendoscopy with methylene blue or indigo carmine significantly increases the diagnostic yield of finding intraepithelial neoplasia in patients with longstanding colitis. The number needed to treat is 14 for panchromoendoscopy to identify 1 additional patient with dysplasia. Chromoendoscopy can greatly facilitate the identification of flat lesions harboring intraepithelial neoplasia. Chromoendoscopy can guide biopsies and clearly reduces the amount of biopsies that are needed per patient. Magnifying endoscopy or CLE are additional techniques, which can be used in conjunction with chromoendoscopy to further reduce the amount of biopsies and to further increase the diagnostic yield. Chrom…
Evolving endoscopic strategies for detection and treatment of neoplastic lesions in inflammatory bowel disease
2013
The paradigm for neoplasia surveillance in IBD is rapidly evolving with advancements in endoscopic imaging technology. Modern technology has demonstrated a remarkably improved capacity to detect and characterize subtle neoplastic lesions. As such, practices of obtaining interval random biopsy specimens to identify “invisible”neoplasia and of recommending total proctocolectomy for treatment of early neoplastic lesions are gradually being phased out. Further research is required to confirm the safety and effectiveness of endoscopic resection of more advanced neoplastic lesions, including DALMs and lesions bearing HG-IEN. Moving forward, studies evaluating CRC risk profiles in IBD patients wou…
The transcription factor NFATc2 controls IL-6–dependent T cell activation in experimental colitis
2008
The nuclear factor of activated T cells (NFAT) family of transcription factors controls calcium signaling in T lymphocytes. In this study, we have identified a crucial regulatory role of the transcription factor NFATc2 in T cell–dependent experimental colitis. Similar to ulcerative colitis in humans, the expression of NFATc2 was up-regulated in oxazolone-induced chronic intestinal inflammation. Furthermore, NFATc2 deficiency suppressed colitis induced by oxazolone administration. This finding was associated with enhanced T cell apoptosis in the lamina propria and strikingly reduced production of IL-6, -13, and -17 by mucosal T lymphocytes. Further studies using knockout mice showed that IL-…
RORgamma-expressing Th17 cells induce murine chronic intestinal inflammation via redundant effects of IL-17A and IL-17F.
2008
Background and Aims IL-17–producing CD4 + T-helper cells (Th17) contribute to chronic autoimmune inflammation in the brain, and levels of Th17-derived cytokines increase in patients with colitis, suggesting a role in pathogenesis. We analyzed the roles of Th17 cells and the transcription factor retinoic acid receptor-related organ receptor (ROR)γ, which regulates Th17 differentiation, in chronic intestinal inflammation. Methods Using an adoptive transfer model of colitis, we compared the colitogenic potential of wild-type, interleukin-17A (IL-17A)–, IL-17F–, IL-22–, and RORγ-deficient CD4 + CD25 − T cells in RAG1-null mice. Results Adoptive transfer of IL-17A–, IL-17F–, or IL-22–deficient T…
A Critical Regulatory Role of Leucin Zipper Transcription Factor c-Maf in Th1-Mediated Experimental Colitis
2004
Abstract In this study, we investigated the role of c-Maf, a transcription factor known to induce IL-4 production, in inflammatory bowel diseases and experimental colitis. Although Crohn′s disease (CD) is associated with low IL-4 production by T-bet-expressing Th1 cells in the lamina propria, surprisingly a higher expression of c-Maf in these cells was found as compared with control patients. The relevance of this finding was further evaluated in an animal model of CD induced by adoptive transfer of CD4+CD62L+ T cells in RAG-deficient mice. In this Th1-mediated model, an increase of c-Maf-expressing T lymphocytes in the lamina propria over time was observed. Interestingly, adoptive transfer…
Animal models of intestinal inflammation: new insights into the molecular pathogenesis and immunotherapy of inflammatory bowel disease
2000
Inflammatory bowel diseases (IBDs) in humans are complex chronic inflammatory disorders of largely unknown cause. Several mouse models that in some respects resemble human IBDs have recently been developed and have provided new insights into immunoregulatory processes in the gut. Both genetic and environmental factors have been shown to be involved in chronic intestinal inflammation. In most of the models CD4+ T lymphocytes have been identified as central mediators of inflammation. Inappropriate activation of T(H)1-dominated cytokine pathways upon contact with luminal bacterial antigens and lack of tolerance appear to be crucial for intestinal pathology. We present a brief overview of impor…
IL-21 regulates experimental colitis by modulating the balance between Treg and Th17 cells
2007
Regulatory T (T(reg)) cells play a key role in the maintenance of the immune system homeostasis. T(reg) cells can be generated in the periphery under control of TGF-beta, a cytokine involved in the negative control of the immune system. However, TGF-beta cooperates with IL-6 in the generation of Th17 cells, a novel class of effector cells involved in numerous inflammatory diseases, including colitis. Therefore, TGF-beta emerges as a mediator of both anti-inflammatory and pro-inflammatory processes, depending on the local cytokine milieu. Here we demonstrate that IL-21, a type-1 cytokine produced by T cells and involved in the pathogenesis of immune-mediated diseases, prevents the TGF-beta-d…
FOCAL ACTIVE COLITIS AS A PREDICTOR OF INFLAMMATORY BOWEL DISEASE: RESULTS FROM A SINGLE-CENTER EXPERIENCE.
2017
The term focal active colitis (FAC) is conventionally used to describe the presence of isolated cryptitis, characterized by an inflammatory infiltrate consisting of intraepithelial neutrophils and/or neutrophils invading the lumen of the criptae, with no other microscopic alteration of the colonic mucosa and, in particular, without the presence of signs of chronic inflammation. To date, only four studies, including one conducted in a pediatric population, have been performed to evaluate the clinical significance of this disease. The aim of this retrospective study on prospectively-collected data is to evaluate the clinical implications of the focal active colitis, since there still remains …
The transcription factor IFN regulatory factor–4 controls experimental colitis in mice via T cell–derived IL-6
2008
The proinflammatory cytokine IL-6 seems to have an important role in the intestinal inflammation that characterizes inflammatory bowel diseases (IBDs) such as Crohn disease and ulcerative colitis. However, little is known about the molecular mechanisms regulating IL-6 production in IBD. Here, we assessed the role of the transcriptional regulator IFN regulatory factor-4 (IRF4) in this process. Patients with either Crohn disease or ulcerative colitis exhibited increased IRF4 expression in lamina propria CD3+ T cells as compared with control patients. Consistent with IRF4 having a regulatory function in T cells, in a mouse model of IBD whereby colitis is induced in RAG-deficient mice by transp…
Cellular and humoral immunity to the 60-kD heat shock protein in inflammatory bowel disease.
1997
Background: Mycobacteria have been considered a possible etiological agent in Crohn’s disease. Since cross-reactivity between epitopes of mycobacterial and self-heat shock protein might represent a potential disease mechanism, we determined the cellular and humoral immune responses to the mycobacterial and the human 60-kD heat shock protein, as well as various control antigens. Methods: We studied samples from 19 patients with Crohn’s disease, 12 patients with ulcerative colitis, and from 19 healthy individuals. T cell responses were studied using a standard proliferation assays to purified recombinant mycobacterial and human 60-kD heat shock protein. Antibody levels were measured by establ…