Endoscopic and Histological Findings Are Predicted by Fecal Calprotectin in Acute Intestinal Graft-Versus-Host-Disease.

Background: Gastrointestinal graft-versus-host-disease (GI-GVHD) is a major cause of nonrelapse mortality after hematopoietic stem cell transplantation (HSCT) necessitating endoscopic examinations and biopsies for diagnosis. Fecal calprotectin (CPT) has been widely used in gastrointestinal inflammation, but comprehensive data in GI-GVHD are lacking.

Aims: We aimed to identify an association of CPT with endoscopic findings, mucosal damage and symptoms for diagnosing and monitoring acute GI-GVHD.

Candidatus Desulfofervidus auxilii, a hydrogenotrophic sulfate-reducing bacterium involved in the thermophilic anaerobic oxidation of methane.

The anaerobic oxidation of methane (AOM) is mediated by consortia of anaerobic methane-oxidizing archaea (ANME) and their specific partner bacteria. In thermophilic AOM consortia enriched from Guaymas Basin, members of the ANME-1 clade are associated with bacteria of the HotSeep-1 cluster, which likely perform direct electron exchange via nanowires. The partner bacterium was enriched with hydrogen as sole electron donor and sulfate as electron acceptor.

High cell-specific rates of nitrogen and carbon fixation by the cyanobacterium Aphanizomenon sp. at low temperatures in the Baltic Sea.

Aphanizomenon is a widespread genus of nitrogen (N2)-fixing cyanobacteria in lakes and estuaries, accounting for a large fraction of the summer N2-fixation in the Baltic Sea. However, information about its cell-specific carbon (C)- and N2-fixation rates in the early growth season has not previously been reported. We combined various methods to study N2-fixation, photosynthesis and respiration in field-sampled Baltic Sea Aphanizomenon sp.

N2-fixation, ammonium release and N-transfer to the microbial and classical food web within a plankton community.

We investigated the role of N2-fixation by the colony-forming cyanobacterium, Aphanizomenon spp., for the plankton community and N-budget of the N-limited Baltic Sea during summer by using stable isotope tracers combined with novel secondary ion mass spectrometry, conventional mass spectrometry and nutrient analysis. When incubated with (15)N2, Aphanizomenon spp.

Immune derived opioidergic inhibition of viscerosensory afferents is decreased in Irritable Bowel Syndrome patients.

Alterations in the neuro-immune axis contribute toward viscerosensory nerve sensitivity and symptoms in Irritable Bowel Syndrome (IBS). Inhibitory factors secreted from immune cells inhibit colo-rectal afferents in health, and loss of this inhibition may lead to hypersensitivity and symptoms. We aimed to determine the immune cell type(s) responsible for opioid secretion in humans and whether this is altered in patients with IBS.

Host immune response determines visceral hyperalgesia in a rat model of post-inflammatory irritable bowel syndrome.

Background: Irritable bowel syndrome (IBS) is associated with visceral hyperalgesia and frequently occurs after a transient gastrointestinal infection. Only a proportion of patients with acute gastroenteritis develop post-infectious IBS suggesting differences in host response to inflammatory stimuli. We aimed to investigate this concept by characterizing visceral sensitivity in two rat strains, following a chemically induced colitis.

Anaerobic degradation of propane and butane by sulfate-reducing bacteria enriched from marine hydrocarbon cold seeps.

The short-chain, non-methane hydrocarbons propane and butane can contribute significantly to the carbon and sulfur cycles in marine environments affected by oil or natural gas seepage. In the present study, we enriched and identified novel propane and butane-degrading sulfate reducers from marine oil and gas cold seeps in the Gulf of Mexico and Hydrate Ridge. The enrichment cultures obtained were able to degrade simultaneously propane and butane, but not other gaseous alkanes.

HISH-SIMS analysis of bacterial uptake of algal-derived carbon in the Río de la Plata estuary.

One of the main goals of microbial ecologists is to assess the contribution of distinct bacterial groups to biogeochemical processes, e.g. carbon cycling.

Sensory neuro-immune interactions differ between irritable bowel syndrome subtypes.

Objective: The gut is a major site of contact between immune and sensory systems and evidence suggests that patients with irritable bowel syndrome (IBS) have immune dysfunction. Here we show how this dysfunction differs between major IBS subgroups and how immunocytes communicate with sensory nerves.

Design: Peripheral blood mononuclear cell supernatants from 20 diarrhoea predominant IBS (D-IBS) patients, 15 constipation predominant IBS (C-IBS) patients and 36 healthy subjects were applied to mouse colonic sensory nerves and effects on mechanosensitivity assessed.

Look@NanoSIMS--a tool for the analysis of nanoSIMS data in environmental microbiology.

We describe an open-source freeware programme for high throughput analysis of nanoSIMS (nanometre-scale secondary ion mass spectrometry) data. The programme implements basic data processing and analytical functions, including display and drift-corrected accumulation of scanned planes, interactive and semi-automated definition of regions of interest (ROIs), and export of the ROIs' elemental and isotopic composition in graphical and text-based formats. Additionally, the programme offers new functions that were custom-designed to address the needs of environmental microbiologists.

Detecting metabolic activities in single cells, with emphasis on nanoSIMS.

Investigating the contribution of microbial populations to biochemical processes of global significance is challenging as there are few approaches that can detect microbial metabolic activities on single-cell level. Given the widespread distribution and importance of microorganisms in elemental transformations, improved methods for measuring microbial activities in naturally occurring microbial communities is essential. In this article, microautoradiography (MAR), Raman microspectroscopy, and Secondary Ion Mass Spectrometry (SIMS) and their combination with isotope labeling and molecular genetic methods for cell identification (i.

Carbon, nitrogen and O(2) fluxes associated with the cyanobacterium Nodularia spumigena in the Baltic Sea.

Photosynthesis, respiration, N(2) fixation and ammonium release were studied directly in Nodularia spumigena during a bloom in the Baltic Sea using a combination of microsensors, stable isotope tracer experiments combined with nanoscale secondary ion mass spectrometry (nanoSIMS) and fluorometry. Cell-specific net C- and N(2)-fixation rates by N. spumigena were 81.

Small bowel homing T cells are associated with symptoms and delayed gastric emptying in functional dyspepsia.

Objectives: Immune activation may have an important pathogenic role in the irritable bowel syndrome (IBS). While little is known about immunologic function in functional dyspepsia (FD), we have observed an association between cytokine secretion by peripheral blood mononuclear cells (PBMCs) and symptoms in IBS. Upper gastrointestinal inflammatory diseases are characterized by enhanced small bowel homing α4-, β7-integrin, chemokine receptor 9 (CCR9) positive T lymphocytes.

[New drugs for the treatment of constipation].

This review introduces new therapeutic options in the treatment of chronic idiopathic constipation and irritable bowel syndrome with constipation. Therefore, prucalopride and lubiprostone are discussed including their mechanisms and side effects. In addition, other substances that are currently under evaluation such as renzapride and linaclotide are described, since recent results showed a significant effect in patients with constipation.

Carbon and nitrogen fluxes associated with the cyanobacterium Aphanizomenon sp. in the Baltic Sea.

Carbon and nitrogen fluxes in Aphanizomenon sp. colonies in the Baltic Sea were measured using a combination of microsensors, stable isotopes, mass spectrometry, and nanoscale secondary ion mass spectrometry (nanoSIMS). Cell numbers varied between 956 and 33 000 in colonies ranging in volume between 1.

The ion channel TRPA1 is required for normal mechanosensation and is modulated by algesic stimuli.

Background & Aims: The transient receptor potential (TRP) channel family includes transducers of mechanical and chemical stimuli for visceral sensory neurons. TRP ankyrin 1 (TRPA1) is implicated in inflammatory pain; it interacts with G-protein-coupled receptors, but little is known about its role in the gastrointestinal (GI) tract. Sensory information from the GI tract is conducted via 5 afferent subtypes along 3 pathways.

Colonic transit studies with 99mTc-rhenium sulfide colloid in live rats. A preliminary study.

Abnormal colonic motility is associated with clinical relevant conditions such as irritable bowel syndrome or constipation. Accurate assessment of colonic transit in an animal model would be useful in studying these conditions and screen potential drug candidates. The aim of this study was to assess if scintigraphic analyses could reliably evaluate total and segmental colonic transit as a measure of colonic motility of a non-absorbable radiotracer in rats.

Selective role for TRPV4 ion channels in visceral sensory pathways.

Background & Aims: Although there are many candidates as molecular mechanotransducers, so far there has been no evidence for molecular specialization of visceral afferents. Here, we show that colonic afferents express a specific molecular transducer that underlies their specialized mechanosensory function: the transient receptor potential channel, vanilloid 4 (TRPV4).

Methods: We found TRPV4 mRNA is highly enriched in colonic sensory neurons compared with other visceral and somatic sensory neurons.

Immune activation in patients with irritable bowel syndrome.

Background And Aims: We set out to test the hypothesis that irritable bowel syndrome (IBS) is characterized by an augmented cellular immune response with enhanced production of proinflammatory cytokines. We further aimed to explore whether symptoms and psychiatric comorbidity in IBS are linked to the release of proinflammatory cytokines.

Methods: We characterized basal and Escherichia coli lipopolysaccharide (LPS)-induced cytokine production in peripheral blood mononuclear cells (PBMCs) from 55 IBS patients (18 mixed-, 17 constipation-, 20 diarrhea-predominant) and 36 healthy controls (HCs).

Mechanisms of disease: genetics of functional gastrointestinal disorders--searching the genes that matter.

There is evidence to suggest that genetic factors contribute to the manifestation of functional gastrointestinal disorders (FGID). As such, it is important to note that FGID are heterogeneous; they have quite different clinical features and (probably) different underlying pathophysiologic mechanisms. Evidence from family and twin studies indicates that there is clustering of FGID in families and increased concordance in monozygotic compared with dizygotic twins.

Ablation of connexin43 in smooth muscle cells of the mouse intestine: functional insights into physiology and morphology.

Connexin43 (Cx43) gap-junction channels are highly abundant in intestinal smooth muscle but their functional impact has not been studied so far. Here, we have aimed to elucidate the functional role of Cx43 in the tunica muscularis of the mouse intestine in vivo. Transgenic mice with conditional deletion of Cx43 in smooth muscle cells (SMC) were generated.

Severity of mucosal inflammation as a predictor for alterations of visceral sensory function in a rat model.

Transient inflammation is known to alter visceral sensory function and frequently precede the onset of symptoms in a subgroup of patients with irritable bowel syndrome (IBS). Duration and severity of the initial inflammatory stimulus appear to be risk factors for the manifestation of symptoms. Therefore, we aimed to characterize dose-dependent effects of trinitrobenzenesulfonic acid (TNBS)/ethanol on: (1) colonic mucosa, (2) cytokine release and (3) visceral sensory function in a rat model.

Psychological stress and the severity of post-inflammatory visceral hyperalgesia.

Objectives: Lowered visceral sensory thresholds are a key finding in at least a subgroup of patients with functional bowel disorders. Stress and inflammation contribute to this altered visceral sensory function. We aimed to elucidate the role of repetitive stress and acute mucosal inflammation, alone and in combination, on sensory function.

A placebo-controlled trial of itopride in functional dyspepsia.

Background: The treatment of patients with functional dyspepsia remains unsatisfactory. We assessed the efficacy of itopride, a dopamine D2 antagonist with anti-acetylcholinesterase [corrected] effects, in patients with functional dyspepsia.

Methods: Patients with functional dyspepsia were randomly assigned to receive either itopride (50, 100, or 200 mg three times daily) or placebo.

A combination of peppermint oil and caraway oil attenuates the post-inflammatory visceral hyperalgesia in a rat model.

Objective: Visceral hyperalgesia plays a pivotal role in manifestation of symptoms in patients with functional gastrointestinal disorders. In clinical studies combined treatment of peppermint- and caraway oil significantly reduced symptoms. Thus, the aim of this study was to characterize the effects of peppermint- and caraway oil, individually and in combination, on visceral nociception in a rat model of post-inflammatory visceral hyperalgesia.