Irritable bowel syndrome and visceral hypersensitivity : risk factors and pathophysiological mechanisms.

Irritable bowel syndrome (IBS) is a common functional gastro-intestinal disorder, characterized by abdominal pain and altered intestinal motility. Visceral hypersensitivity is an important hallmark feature of IBS and is believed to underlie abdominal pain in patients with IBS. The two main risk factors associated with the development of IBS are gastrointestinal inflammation and psychological distress.

Mechanisms contributing to visceral hypersensitivity: focus on splanchnic afferent nerve signaling.

Background: Visceral hypersensitivity is a main characteristic of functional bowel disorders and is mediated by both peripheral and central factors. We investigated whether enhanced splanchnic afferent signaling in vitro is associated with visceral hypersensitivity in vivo in an acute and postinflammatory rat model of colitis.

Methods: Trinitrobenzene sulfonic acid (TNBS)-colitis was monitored individually by colonoscopy to confirm colitis and follow convalescence and endoscopic healing in each rat.

CD4+ROR γ t++ and Tregs in a Mouse Model of Diet-Induced Nonalcoholic Steatohepatitis.

Background And Aims: Inflammatory mediators that cross-talk in different metabolically active organs are thought to play a crucial role in the pathogenesis of Nonalcoholic Steatohepatitis (NASH). This study was aimed at investigating the CD4+RORγt+ T-helper cells and their counterpart, the CD4+CD25+FOXP3+ regulatory T cells in the liver, subcutaneous adipose tissue (SAT), and abdominal adipose tissue (AAT) in a high fat diet (HFD) mouse model.

Methods: C57BL6 mice were fed a HFD or a normal diet (ND).

P2X3 receptors mediate visceral hypersensitivity during acute chemically-induced colitis and in the post-inflammatory phase via different mechanisms of sensitization.

Objectives: Experiments using P2X3 knock-out mice or more general P2X receptor antagonists suggest that P2X3 receptors contribute to visceral hypersensitivity. We aimed to investigate the effect of the selective P2X3 antagonist A-317491 on visceral sensitivity under physiological conditions, during acute colitis and in the post-inflammatory phase of colitis.

Methods: Trinitrobenzene sulphonic-acid colitis was monitored by colonoscopy: on day 3 to confirm the presence of colitis and then every 4 days, starting from day 10, to monitor convalescence and determine the exact timepoint of endoscopic healing in each rat.

Treatment with egg antigens of Schistosoma mansoni ameliorates experimental colitis in mice through a colonic T-cell-dependent mechanism.

Background: Helminth-derived molecules are being identified as a new therapeutic approach for immune-mediated diseases. We investigated the anti-inflammatory effect and the immunological mechanisms of Schistosoma mansoni soluble egg antigens (SmSEA) in a mouse model of chronic colitis.

Methods: Colitis was induced in immunocompromised severe combined immunodeficiency mice by the adoptive transfer of CD4CD25CD62L T cells.

Histamine H₄ receptors in the gastrointestinal tract.

Histamine is a well-established mediator involved in a variety of physiological and pathophysiological mechanisms and exerts its effect through activation of four histamine receptors (H1-H₄). The histamine H₄ receptor is the newest member of this histamine receptor family, and is expressed throughout the gastrointestinal tract as well as in the liver, pancreas and bile ducts. Functional studies using a combination of selective and non-selective H₄ receptor ligands have rapidly increased our knowledge of H₄ receptor involvement in gastrointestinal processes both under physiological conditions and in models of disease.

Worm proteins of Schistosoma mansoni reduce the severity of experimental chronic colitis in mice by suppressing colonic proinflammatory immune responses.

Although helminthic therapy as a possible new option to treat inflammatory bowel disease is a well-established concept by now, the search for immunomodulatory helminth-derived compounds and their mechanisms of action is still ongoing. We investigated the therapeutic potential and the underlying immunological mechanisms of Schistosoma mansoni soluble worm proteins (SmSWP) in an adoptive T cell transfer mouse model of chronic colitis. Both a curative and a preventive treatment protocol were included in this study.

Exploring associations between lower urinary tract symptoms (LUTS) and gastrointestinal (GI) problems in women: a study in women with urological and GI problems vs a control population.

Objectives: To study the prevalence of self-reported lower urinary tract symptoms (LUTS) in women consulting a Gastroenterology clinic with complaints of functional constipation (FC), fecal incontinence (FI) or both, compared with a female control population. Also, to study the influence of FC, FI, or both on self-reported LUTS in women attending a Urology clinic.

Patients And Methods: We present a retrospective study of data collected through a validated self-administered bladder and bowel symptom questionnaire in a tertiary referral hospital from three different female populations: 104 controls, 159 gastroenterological patients and 410 urological patients.

The effect of chemically induced colitis, psychological stress and their combination on visceral pain in female Wistar rats.

Visceral sensitivity is of pathophysiological importance in abdominal pain disorders and can be modulated by inflammation and stress. However, it is unclear whether inflammation and stress alter visceral perception independently of each other or in conjunction through neuroendocrine interactions. Therefore, we compared the short- and long-term effects of experimental colitis and water avoidance stress (WAS), alone or in combination, on visceral sensitivity in female Wistar rats.

Belgian consensus on chronic pancreatitis in adults and children: statements on diagnosis and nutritional, medical, and surgical treatment.

Chronic pancreatitis (CP) is an inflammatory disorder characterized by inflammation and fibrosis, resulting in a progressive and irreversible destruction of exocrine and endocrine pancreatic tissue. Clinicians should attempt to classify patients into one of the six etiologic groups according to the TIGARO classification system. MRI/MRCP, if possible with secretin enhancement, is considered the imaging modality of choice for the diagnosis of early-stage disease.

Of worms, mice and man: an overview of experimental and clinical helminth-based therapy for inflammatory bowel disease.

The incidence of inflammatory and autoimmune disorders is highest in well-developed countries which is directly related to their higher hygienic standards: it is suggested that the lack of exposure to helminths contributes to the susceptibility for immune-related diseases. Epidemiological, experimental and clinical data support the idea that helminths provide protection against immune-mediated diseases such as inflammatory bowel disease (IBD). The most likely mechanism for the suppression of immune responses by helminths is the release of helminth-derived immunomodulatory molecules.

Neuroanatomy of lower gastrointestinal pain disorders.

Chronic abdominal pain accompanying intestinal inflammation emerges from the hyperresponsiveness of neuronal, immune and endocrine signaling pathways within the intestines, the peripheral and the central nervous system. In this article we review how the sensory nerve information from the healthy and the hypersensitive bowel is encoded and conveyed to the brain. The gut milieu is continuously monitored by intrinsic enteric afferents, and an extrinsic nervous network comprising vagal, pelvic and splanchnic afferents.

Histamine H4 and H1 receptors contribute to postinflammatory visceral hypersensitivity.

Objectives: Substantial evidence implicates mast cells and their main constituent histamine in the pathogenesis of visceral hypersensitivity. We explored the specific contribution of histamine H4 (H4R) and H1 (H1R) receptors to visceral hypersensitivity in a postinflammatory rat model.

Design: Trinitrobenzenesulfonic acid (TNBS)-colitis was monitored individually by colonoscopy: first on day 3 to confirm the presence of colitis and then every 4 days, starting from day 10, to monitor convalescence and determine the exact timepoint of endoscopic healing in each rat.

Renewed attention for overtube-assisted colonoscopy to prevent incomplete endoscopic examination of the colon.

Background: Colonoscopy is the standard examination to detect mucosal pathology in the colon. However, failure to complete colonoscopy may reach more than 10% in population-based endoscopy practices. The reasons for incomplete conventional colonoscopy are diverse and result in missed diagnosis of colonic polyps and carcinoma.

Infliximab induces remission in cryptogenic multifocal ulcerous stenosing enteritis: first case.

We present the case of a 29-year-old patient with a history of abdominal pain and vomiting. Based on wireless video capsule findings he was previously diagnosed with ileal Crohn's disease at a different institution, although the clinical and radiological picture was not typical and the response to corticosteroids was poor. We performed a single-balloon enteroscopy showing a short, ulcerous stenosis 50 cm proximal from Bauhin's valve.

Mechanisms of pelvic organ crosstalk: 1. Peripheral modulation of bladder inhibition by colorectal distention in rats.

Purpose: Bladder activity can be inhibited by afferent input from the colorectum (inhibitory rectovesical reflex). We evaluated the functional response of the rat bladder to nonnoxious and noxious colorectal distention, and investigated the mechanical and pharmacological peripheral modulation of this response.

Materials And Methods: In 70 female Sprague-Dawley® rats we evaluated the effect of nonnoxious (20 mm Hg) and noxious (40 and 60 mm Hg) colorectal distention on the micturition volume threshold and on bladder activity in a filled bladder.

Colonoscopy and µPET/CT are valid techniques to monitor inflammation in the adoptive transfer colitis model in mice.

Background: Preclinical in vivo research on inflammatory bowel diseases requires proper animal models and techniques allowing longitudinal monitoring of colonic inflammation without the need to kill animals. We evaluated colonoscopy and μ-positron emission tomography/computed tomography (μPET/CT) as monitoring tools in a model for chronic colitis in mice.

Methods: Colitis was induced by adoptive transfer of CD4(+)CD25(-)CD62L(+) T cells in immunocompromised severe combined immunodeficient mice.

Role of TRPV1 and TRPA1 in visceral hypersensitivity to colorectal distension during experimental colitis in rats.

The aim of the present study is to investigate the effects of TRPV1 and TRPA1 receptor antagonists and their synergism on the visceromotor responses during experimental colitis in rats. Colitis was induced in rats by a TNBS/ethanol enema at day 0 and was assessed at day 3 using endoscopy, histology and a myeloperoxidase assay. The visceromotor response to colorectal distension (10-80 mmHg) was evaluated in conscious rats before (control condition) and 3 days after 2,4,6-trinitrobenzene sulfonic acid (TNBS) administration (colitis condition).

Increased intrahepatic resistance in severe steatosis: endothelial dysfunction, vasoconstrictor overproduction and altered microvascular architecture.

Non-alcoholic fatty liver disease can progress to steatohepatitis and fibrosis, and is also associated with impaired liver regeneration. The pathophysiology remains elusive. We recently showed that severe steatosis is associated with an increase in portal pressure, suggesting liver flow impairment.

Noninvasive assessment of nonalcoholic fatty liver disease in obese or overweight patients.

Background & Aims: Reliable noninvasive tools are needed for staging nonalcoholic fatty liver disease (NAFLD). Published scoring systems have not been validated in prospective assessments of unselected patients. We aimed to identify factors that predicted development of nonalcoholic steatohepatitis (NASH) in a large group of overweight or obese patients and compared these with established factors.

The use of colonoscopy to follow the inflammatory time course of TNBS colitis in rats.

Background And Study Aims: Animal models of colitis are widely used to study the pathogenesis of inflammatory bowel diseases (IBD) and irritable bowel syndrome (IBS). However techniques allowing sequential assessment of colonic inflammation over time, without the need to sacrifice the animal, are required. This study evaluated in vive colonoscopy to follow the evolution of colitis in rats in comparison with the more commonly used post-mortem macroscopic, microscopic and biochemical assays of inflammation.

Development and psychometric evaluation of a dutch questionnaire for the assessment of anorectal and lower urinary tract symptoms.

Background And Study Aims: Epidemiological studies have shown a frequent coexistence of symptoms and diseases affecting the anorectum and lower urinary tract. To further investigate combined symptoms and pathology of both pelvic viscera we developed a self-reported questionnaire, in Dutch, which extensively evaluates habits, complaints and symptoms of both viscera. We describe the construction and the psychometric properties of this questionnaire.