New insights into irritable bowel syndrome pathophysiological mechanisms: contribution of epigenetics

Irritable bowel syndrome (IBS) is a complex multifactorial condition including alterations of the gut-brain axis, intestinal permeability, mucosal neuro-immune interactions, and microbiota imbalance. Recent advances proposed epigenetic factors as possible regulators of several mechanisms involved in IBS pathophysiology. These epigenetic factors include biomolecular mechanisms inducing chromosome-related and heritable changes in gene expression regardless of DNA coding sequence. Accordingly, altered gut microbiota may increase the production of metabolites such as sodium butyrate, a prominent inhibitor of histone deacetylases. Patients with IBS showed an increased amount of butyrate-producing microbial phila as well as an altered profile of methylated genes and micro-RNAs (miRNAs). Importantly, gene acetylation as well as specific miRNA profiles are involved in different IBS mechanisms and may be applied for future diagnostic purposes, especially to detect increased gut permeability and visceromotor dysfunctions. In this review, we summarize current knowledge of the role of epigenetics in IBS pathophysiology

Pathophysiology of Diverticular Disease: From Diverticula Formation to Symptom Generation

Diverticular disease is a common clinical problem, particularly in industrialized countries. In most cases, colonic diverticula remain asymptomatic throughout life and sometimes are found incidentally during colonic imaging in colorectal cancer screening programs in otherwise healthy subjects. Nonetheless, roughly 25% of patients bearing colonic diverticula develop clinical manifestations. Abdominal symptoms associated with diverticula in the absence of inflammation or complications are termed symptomatic uncomplicated diverticular disease (SUDD). The pathophysiology of diverticular disease as well as the mechanisms involved in the shift from an asymptomatic condition to a symptomatic one is still poorly understood. It is accepted that both genetic factors and environment, as well as intestinal microenvironment alterations, have a role in diverticula development and in the different phenotypic expressions of diverticular disease. In the present review, we will summarize the up-to-date knowledge on the pathophysiology of diverticula and their different clinical setting, including diverticulosis and SUDD

Nerve fiber overgrowth in patients with symptomatic diverticular disease

Background: Colonic diverticulosis is a common condition in industrialized countries. Up to 25% of patients with diverticula develop symptoms, a condition termed symptomatic uncomplicated diverticular disease (SUDD). The aim of the present study was to characterize neuroimmune interactions and nerve fiber plasticity in the colonic mucosa of patients with diverticula. Methods: Controls, patients with diverticulosis and with SUDD were enrolled in the study. Mucosal biopsies were obtained close to diverticula (diverticular region) and in a normal mucosa (distant site), corresponding to sigmoid and descending colon in the controls. Quantitative immunohistochemistry was used to assess mast cells, T cells, macrophages, nerve fibers, and neuronal outgrowth (growth-associated protein 43, GAP43+fibers). Key Results: No difference emerged in mast cells and T cells among the three groups. Macrophages were increased in patients with SUDD and diverticulosis as compared to controls. Nerve fibers were enhanced in patients with SUDD and diverticulosis in comparison with controls in the diverticular region. GAP43+\ua0fibers were increased only in patients with SUDD as compared to controls and to patients with diverticulosis in the diverticular region. In patients with SUDD, GAP43 density was increased in the diverticular region compared to distant site. Macrophages close to GAP43+ fibers were increased in the diverticular region of patients with SUDD. Significant correlations were found between GAP43+ fibers and immune cells. Conclusions and Inferences: Patients with diverticula are characterized by increased macrophage counts, while nerve fiber sprouting is increased only in the diverticular region of patients with SUDD suggesting a role in symptom generation

The Italian Registry of Endovascular Treatment in Acute Stroke: rationale, design and baseline features of patients

Endovascular treatment (ET) showed to be safe in acute stroke, but its superiority over intravenous thrombolysis is debated. As ET is rapidly evolving, it is not clear which role it may deserve in the future of stoke treatments. Based on an observational design, a treatment registry allows to study a broad range of patients, turning into a powerful tool for patients' selection. We report the methodology and a descriptive analysis of patients from a national registry of ET for stroke. The Italian Registry of Endovascular Treatment in Acute Stroke is a multicenter, observational registry running in Italy from 2010. All patients treated with ET in the participating centers were consecutively recorded. Safety measures were symptomatic intracranial hemorrhage, procedural adverse events and death rate. Efficacy measures were arterial recanalization and 3-month good functional outcome. From 2008 to 2012, 960 patients were treated in 25 centers. Median age was 67 years, male gender 57 %. Median baseline NIHSS was 17. The most frequent occlusion site was Middle cerebral artery (46.9 %). Intra-arterial thrombolytics were used in 165 (17.9 %) patients, in 531 (57.5 %) thrombectomy was employed, and 228 (24.7 %) patients received both treatments. Baseline features of this cohort are in line with data from large clinical series and recent trials. This registry allows to collect data from a real practice scenario and to highlight time trends in treatment modalities. It can address unsolved safety and efficacy issues on ET of stroke, providing a useful tool for the planning of new trials