Abstract

Future of Capsule Endoscopy (Small Bowel, Colon, Gastric)

Jean Francois Rey

Small Bowel Capsule (SBE) has been introduced 10 years ago by Given Imaging and is becoming a gold standard for small bowel exploration. It was a major step in digestive field and it opened promising non-invasive explorations for esophagus, stomach and colon. SBE is challenging especially enteroscopy in the West, as capsule is available since 2001. Obscure GI bleeding remains the most important indication after normal upper and lower endoscopies. Suspected Crohn’s disease is also a well accepted indication of course in case of findings therapeutic endoscopy is requested but SBE avoids in many cases this useful but time consuming endoscopy. Colon capsule is under clinical trial for colorectal cancer screening when traditional colonoscopy is contraindicated or impossible. The preparation remains the most important drawback. First results seem promising but control of colonic motility is still cumbersome. Finally, gastric guided capsule, as we have performed the 1st clinical trial on humans, offers possibilities of capsule exploration with a guidance system. Today we have performed more than 400 patients or volunteers with interesting results compared to high definition gastroscopy. Even if endoscopy remains the most important tool in the GI field, capsules offer promising new possibilities.

Regulation of Oxidative Stress and Inflammation by MicroRNAs

Paul Holvoet

A primary event in atherogenesis is the infiltration of activated monocytes into the arterial wall. Activation of the inflammatory toll-like receptor/nuclear factor κB signaling in monocytes contributes to inflammation. This is associated with secretion of reactive oxygen species and oxidation of lipoproteins, and induction of foam cells and endothelial cell apoptosis, which in turn lead to plaque growth and rupture. Importantly, this vicious circle between oxidative stress and inflammation does also occur in adipose tissues during obesity. There, oxidative stress and inflammation impair adipocyte maturation resulting in defective insulin action and adipocytokine signaling. This observation raises question what molecules are likely common regulators of these pathogenic processes in adipose and vascular tissues. Candidates are small, non-coding, microRNAs which control gene expression by inducing mRNA degradation or blocking translation. For example, microRNA-181a, a possible regulator of the toll-like receptor/nuclear factor κB signaling, is decreased in obese monocytes and weight loss normalizes its expression. It is associated with a higher number of metabolic syndrome components and with CAD even after adjustment for traditional risk factors, obesity and the metabolic syndrome. MicroRNA-146b-5p is also decreased in monocytes during obesity and is a major mediator of the anti-inflammatory action of globular adiponectin. In addition, the activation of monocytes is associated with the release of microRNA-containing microvesicles which mediate the communication between different cell types within the same tissue. When they are secreted in the circulation they may also mediate the communication between different tissues, for example adipose and vascular tissues, possibly explaining the similarity and the simultaneity of molecular changes and interactions in those tissues.