Search results for "Coliti"

IMPLICAZIONI NEUROENDOCRINE, IMMUNOFENOTIPICHE E CELLULARI DELLE COLITI MICROSCOPICHE

Vascular Microarchitecture of Murine Colitis-Associated Lymphoid Angiogenesis

2009

In permissive tissues, such as the gut and synovium, chronic inflammation can result in the ectopic development of anatomic structures that resemble lymph nodes. These inflammation-induced structures, termed lymphoid neogenesis or tertiary lymphoid organs, may reflect differential stromal responsiveness to the process of lymphoid neogenesis. To investigate the structural reorganization of the microcirculation involved in colonic lymphoid neogenesis, we studied a murine model of dextran sodium sulfate (DSS)-induced colitis. Standard 2-dimensional histology demonstrated both submucosal and intramucosal lymphoid structures in DSS-induced colitis. A spatial frequency analysis of serial histolog…

New Insights of Oral Colonic Drug Delivery Systems for Inflammatory Bowel Disease Therapy

2020

[EN] Colonic Drug Delivery Systems (CDDS) are especially advantageous for local treatment of inflammatory bowel diseases (IBD). Site-targeted drug release allows to obtain a high drug concentration in injured tissues and less systemic adverse effects, as consequence of less/null drug absorption in small intestine. This review focused on the reported contributions in the last four years to improve the effectiveness of treatments of inflammatory bowel diseases. The work concludes that there has been an increase in the development of CDDS in which pH, specific enzymes, reactive oxygen species (ROS), or a combination of all of these triggers the release. These delivery systems demonstrated a th…

Epithelial NEMO links innate immunity to chronic intestinal inflammation

2007

Deregulation of intestinal immune responses seems to have a principal function in the pathogenesis of inflammatory bowel disease(1-4). The gut epithelium is critically involved in the maintenance of intestinal immune homeostasis-acting as a physical barrier separating luminal bacteria and immune cells, and also expressing antimicrobial peptides(3,5,6). However, the molecular mechanisms that control this function of gut epithelial cells are poorly understood. Here we show that the transcription factor NF kappa B, a master regulator of pro-inflammatory responses(7,8), functions in gut epithelial cells to control epithelial integrity and the interaction between the mucosal immune system and gu…

Tolerance towards resident intestinal flora in mice is abrogated in experimental colitis and restored by treatment with interleukin-10 or antibodies …

1996

There is now increasing evidence that hyperresponsiveness towards intestinal flora is a crucial event in the pathogenesis of inflammatory bowel disease (IBD). In support of this hypothesis, we recently described in humans that tolerance exists towards indigenous intestinal flora but is broken in active IBD lesions. In the present study, we have attempted to transfer this model into mice from different genetic backgrounds (BALB/c, SJL/J, C3H/HeJ). We found that mononuclear cells from spleen, small bowel and large bowel of mice do not proliferate, i.e. are tolerant when exposed to bacterial sonicates derived from autologous intestine (BsA) but do proliferate, i.e. are immune when exposed to b…

Efficient gene delivery to the inflamed colon by local administration of recombinant adenoviruses with normal or modified fibre structure

1999

BACKGROUND/AIMSReplication deficient recombinant adenoviruses represent an efficient means of transferring genes in vivo into a wide variety of dividing and quiescent cells from many different organs. Although the gastrointestinal tract is a potentially attractive target for gene therapy approaches, only a few studies on the use of viral gene transfer vehicles in the gut have been reported. The prospects of using recombinant adenoviruses for gene delivery into epithelial and subepithelial cells of the normal and inflamed colon are here analysed.METHODSAn E1/E3 deleted recombinant adenovirus (denoted AdCMVβGal) and an adenovirus with modified fibre structure (denoted AdZ.F(pk7)) both express…

Exposure to Gastric Acid Inhibitors Increases the Risk of Infection in Preterm Very Low Birth Weight Infants but Concomitant Administration of Lactof…

2018

Objective: To investigate whether exposure to inhibitors of gastric acidity, such as H2 blockers or proton pump inhibitors, can independently increase the risk of infections in very low birth weight (VLBW) preterm infants in the neonatal intensive care unit. Study design: This is a secondary analysis of prospectively collected data from a multicenter, randomized controlled trial of bovine lactoferrin (BLF) supplementation (with or without the probiotic Lactobacillus rhamnosus GG) vs placebo in prevention of late-onset sepsis (LOS) and necrotizing enterocolitis (NEC) in preterm infants. Inhibitors of gastric acidity were used at the recommended dosages/schedules based on the clinical judgmen…

Cytokines in Colitis-Associated Cancer: Potential Drug Targets?

2008

In inflammatory bowel disease (IBD), such as UC and CD, the development of colorectal carcinoma can be initiated through chronic inflammation, depending on the duration and severity of the disease. Growing evidence supports a role for various cytokines, released by epithelial and immune cells, in the pathogenesis of colitis associated cancer (CAC). For instance, TNF-alpha has been recently shown to promote tumor development in experimental colitis. Due to its role in the pathogenesis of IBD, TNF-alpha blockade has become one of the cornerstones of IBD therapy. Thus, anti-TNF-alpha strategies could also provide effective anti-tumor therapies. TGF-beta has been shown to attenuate an anti-tumo…

A variant of Smurf2 protects mice against colitis-associated colon cancer by inducing transforming growth factor β signaling.

2011

Background & Aims Transforming growth factor (TGF)-β signaling, which is down-regulated by the E3 ubiquitin ligase Smad ubiquitin regulating factor 2 (Smurf2), promotes development of cancer. We identified a splice variant of Smurf2 (ΔE2Smurf2) and investigated its role in colon carcinogenesis in mice. Methods Colitis-associated colon cancer was induced in mice by administration of azoxymethane, followed by 3 cycles of oral administration of dextran sodium sulfate. Messenger RNA levels of Smurf2 in colon tumors and control tissue were measured by quantitative polymerase chain reaction; lymphocyte and cytokine levels were measured in tumor and tissue samples. Results Tumor-infiltrating CD4 +…

Mucosal immunology and probiotics.

2013

The cross-talk between the mucosa-associated immune system and microbiota is critical in mucosal tissue homeostasis as well as in protection against infectious and inflammatory diseases occurring at mucosal sites. This recent evidence has paved the way to therapeutic approaches aimed at modulating the mucosa-associated immune system using probiotics. Different strains of probiotics possess the ability to finely regulate dendritic cell (DC) activation, polarizing the subsequent T cell activity toward Th1 (e.g. Lactobacillus (Lb) acidophilus), Th2 (Lb.reuteri and Bifidobacterium bifidum) or, as more recently demonstrated, Th17 responses induced by specific strains such as Lb.rhamnosus GG and …