The Mast Cell Degranulator Compound 48/80 Directly Activates Neurons

Background Compound 48/80 is widely used in animal and tissue models as a “selective” mast cell activator. With this study we demonstrate that compound 48/80 also directly activates enteric neurons and visceral afferents. Methodology/Principal Findings We used in vivo recordings from extrinsic intestinal afferents together with Ca++ imaging from primary cultures of DRG and nodose neurons. Enteric neuronal activation was examined by Ca++ and voltage sensitive dye imaging in isolated gut preparations and primary cultures of enteric neurons. Intraluminal application of compound 48/80 evoked marked afferent firing which desensitized on subsequent administration. In egg albumen-sensitized animals, intraluminal antigen evoked a similar pattern of afferent activation which also desensitized on subsequent exposure to antigen. In cross-desensitization experiments prior administration of compound 48/80 failed to influence the mast cell mediated response. Application of 1 and 10 µg/ml compound 48/80 evoked spike discharge and Ca++ transients in enteric neurons. The same nerve activating effect was observed in primary cultures of DRG and nodose ganglion cells. Enteric neuron cultures were devoid of mast cells confirmed by negative staining for c-kit or toluidine blue. In addition, in cultured enteric neurons the excitatory action of compound 48/80 was preserved in the presence of histamine H1 and H2 antagonists. The mast cell stabilizer cromolyn attenuated compound 48/80 and nicotine evoked Ca++ transients in mast cell-free enteric neuron cultures. Conclusions/Significance The results showed direct excitatory action of compound 48/80 on enteric neurons and visceral afferents. Therefore, functional changes measured in tissue or animal models may involve a mast cell independent effect of compound 48/80 and cromolyn

A mechanistic multi-centre, parallel group, randomised placebo controlled trial of Mesalazine for treatment of irritable bowel syndrome with diarrhoea (IBS-D)

Introduction: Immune activation has been reported in the mucosa of irritable bowel syndrome patients with diarrhoea (IBS-D) and some small studies have suggested that Mesalazine may reduce symptoms. We performed a double blind, randomised placebo controlled trial of 2g Mesalazine twice daily versus placebo for 3 months in Rome III criteria IBS-D patients. Primary outcome was daily average stool frequency during weeks 11-12; secondary outcomes were abdominal pain, stool consistency, urgency and satisfactory relief of IBS symptoms. Methods: Participants were randomised after a 2-week baseline stool diary. All participants completed a 12-week stool diary and at the end of each week recorded the presence of “satisfactory relief of IBS symptoms”. Results: 136 patients with IBS-D (82 F, 54 M) were randomised, 10 patients withdrew from each group. Analysis by intention to treat showed the daily average stool frequency during weeks 11 and 12 were mean (SD), 2.8 (1.2) in Mesalazine and 2.7 (1.9) in placebo group with no significant group difference (95% confidence interval) 0.1 (-0.33,0.53); p=0.66. Mesalazine did not improve abdominal pain, stool consistency nor percentage with satisfactory relief compared to placebo during the last 2 weeks follow up. Conclusion: This study does not support any clinically meaningful benefit or harm of Mesalazine compared with placebo in unselected IBS with diarrhoea. More precise subtyping based on underlying disease mechanisms is needed to allow more effective targeting of treatment in IBS. (ClinicalTrials.gov number NCT01316718

Characterisation of faecal protease activity in irritable bowel syndrome with diarrhoea: origin and effect of gut transit

OBJECTIVES: Faecal serine proteases (FSPs) may play a role in irritable bowel syndrome with diarrhoea (IBS-D), but their origin is unclear. We aimed to structurally characterise them and define the impact of colonic cleansing and transit time. DESIGN: Faecal samples were obtained from 30 healthy volunteers (HV) and 79 patients with IBS-D participating in a trial of ondansetron versus placebo. Colonic transit was measured using radio-opaque markers. Samples were also obtained from 24 HV before and after colonic cleansing with the osmotic laxative MoviPrep. FSPs were purified from faecal extracts using benzamidine-Sepharose affinity chromatography. SDS-PAGE profiled components were identified using trypsinolysis and tandem mass spectrometry. Functional protease activity in faecal extracts was measured using a colorimetric assay based on the proteolysis of azo-casein. RESULTS: Protein analysis identified the most abundant FSPs as being of human origin and probably derived from pancreatic juice. Functional assays showed increased faecal protease (FP) and amylase in patients with IBS-D compared with HV. Those with higher amylase had significantly higher FP and greater anxiety. FP activity correlated negatively with whole gut transit in patients with IBS-D (Spearman r=−0.32, p=0.005) and HV (r=−0.55, p=0.014). Colon cleansing caused a significant rise in FP activity in HV from a baseline of median (IQR) 253 (140–426) to 1031 (435–2296), levels similar to those seen in patients with IBS-D. FSP activity correlated positively with days/week with urgency. CONCLUSIONS: The most abundant FSPs are of human origin. Rapid transit through the colon and/or decreased (possibly bacterial) proteolytic degradation increases their faecal concentration and could contribute to visceral hypersensitivity in patients with IBS-D. CLINICALTRIALS.GOV: NCT00745004

Efficacy and mode of action of mesalazine in the treatment of diarrhoea-predominant irritable bowel syndrome (IBS-D): a multicentre, parallel-group, randomised placebo-controlled trial

BackgroundDiarrhoea-predominant irritable bowel syndrome (IBS-D) is a common outcome after inflammation due to bacterial gastroenteritis. Several studies have shown ongoing immune activation in the mucosa of patients with IBS-D and a number of studies have suggested that mesalazine slow-release granule formulation (2?g; PENTASA®, Ferring Pharmaceuticals Ltd) may provide benefit including a reduction in stool frequency.ObjectivesOur primary aim was to compare the effect of mesalazine with placebo on stool frequency. Our secondary aims were to assess the effect of mesalazine on abdominal pain, stool consistency, urgency and satisfactory relief of irritable bowel syndrome (IBS) symptoms.Design/participants/interventionWe performed a double-blind, randomised placebo-controlled trial of 2?g mesalazine twice daily compared with placebo for 3 months in Rome III criteria patients with IBS-D.SettingsParticipants were recruited from the primary care research network and secondary care hospitals. Participants were randomised after a 2-week baseline stool diary. All participants completed a 12-week stool diary and at the end of each week recorded the presence of ‘satisfactory relief of IBS symptoms’. Those recruited in Nottingham had sigmoid biopsies and/or magnetic resonance imaging of the abdomen at the start and end of the trial.ResultsA total of 136 patients with IBS-D (82 female, 54 male) were randomised; 10 patients withdrew from each group. Analysis by intention to treat showed that the mean daily average stool frequency during weeks 11 and 12 was 2.8 [standard deviation (SD) 1.2] in the mesalazine group and 2.7 (SD 1.9) in the placebo group, with a group difference of 0.1 (95% confidence interval –0.33 to 0.53); p?=?0.66.ConclusionsMesalazine did not improve abdominal pain, stool consistency or percentage with satisfactory relief compared with placebo during the last 2 weeks’ follow-up. A post hoc analysis in 13 postinfectious patients with IBS appeared to show benefit but this needs confirmation in a larger group. More precise subtyping based on underlying disease mechanisms may allow more effective targeting of treatment in IBS.Trial registrationCurrent Controlled Trials ISRCTN76612274.FundingThis project was funded by the Efficacy and Mechanism Evaluation (EME) programme, a MRC and NIHR partnership.<br/

Immune activation in irritable bowel syndrome: can neuroimmune interactions explain symptoms?

Irritable bowel syndrome (IBS) is a functional disorder of the gastrointestinal (GI) tract characterized by pain or discomfort from the lower abdominal region, which is associated with altered bowel habit. Despite its prevalence, there is currently a lack of effective treatment options for patients. IBS has long been considered as a neurological condition resulting from alterations in the brain gut axis, but immunological alterations are increasingly reported in IBS patients, consistent with the hypothesis that there is a chronic, but low-grade, immune activation. Mediators released by immune cells act to either dampen or amplify the activity of GI nerves. Release of a number of these mediators correlates with symptoms of IBS, highlighting the importance of interactions between the immune and the nervous systems. Investigation of the role of microbiota in these interactions is in its early stages, but may provide many answers regarding the mechanisms underlying activation of the immune system in IBS. Identifying what the key changes in the GI immune system are in IBS and how these changes modulate viscerosensory nervous function is essential for the development of novel therapies for the underlying disorder.Patrick A. Hughes, Heddy Zola, Irmeli A. Penttila, L. Ashley Blackshaw, Jane M. Andrews, and Doreen Krumbiege

Meme Discourse as an Object of Linguocognitive Modelling

Introduction. The  goal  of  this  study  is  to  gain  new  insights  into  meme  discourse  by reconstructing  its  linguocognitive  model,  based  on  the  properties  and  characteristics  of memes, relevant for Internet communicators.Methodology and sources. In order to reconstruct the meme-discourse model the authors combine  the  method  of  linguocognitive  modelling  with  the  technique  of  fragmenting  the respondents'  answers  into  motivational  explications  as  units  of  measurement  for  the obtained  data.  The  meme  discourse  model  is  based  on  the  answers  of  100  students  at I.I. Polzunov Altai State Technical University – “Why do you use memes when communicating?” The  choice  of  respondents  is  determined  by  their studying  at  the  Faculty  of  Information Technology and being advanced Internet users.Results  and  discussion. Motivational  explications  of  Internet  users  of  why  they  resort  to memes to communicate serve as language material for inferring cognitive foundations for using memes. The most  significant  cognitive  foundation  for  the  use  of  memes  by communicators is the effectiveness of the impact they make (47.3 %). The second cognitive foundation is related to communication productivity: memes help to establish and maintain communication  (20,9 %).  The  third  one  is  the  functionality  of  memes,  which  facilitates  the transmission of content (17,1 %). The fourth one is the format suitable for conveying thoughts and feelings (14,7 %). Based on the concept of discourse, proposed by T. van Dijk and the reconstructed model the authors gain new insights into the nature of meme-discourse.Conclusion. The  main  conceptual  conclusion  regarding  meme-discourse  is  that,  as  a complex communicative phenomenon, it appears to be an important component of sociocultural interaction for its participants. Both the goal and the result of this interaction is to create  a  positive  type  of  social  context  maintained  and  preserved  through  mutual understanding  between  the  communicants.  Memes  facilitate  finding  common  points  of contact serving as a “package” of  positive  emotions  for  communicators’  thoughts  and feelings.  In  this  way  communicants  produce  meme-discourse  as  an  actual  referential context to share their worldview

Intestinal Epithelial Cell-Specific Deletion of PLD2 Alleviates DSS-Induced Colitis by Regulating Occludin

Ulcerative colitis is a multi-factorial disease involving a dysregulated immune response. Disruptions to the intestinal epithelial barrier and translocation of bacteria, resulting in inflammation, are common in colitis. The mechanisms underlying epithelial barrier dysfunction or regulation of tight junction proteins during disease progression of colitis have not been clearly elucidated. Increase in phospholipase D (PLD) activity is associated with disease severity in colitis animal models. However, the role of PLD2 in the maintenance of intestinal barrier integrity remains elusive. We have generated intestinal specific Pld2 knockout mice (Pld2 IEC-KO) to investigate the mechanism of intestinal epithelial PLD2 in colitis. We show that the knockout of Pld2 confers protection against dextran sodium sulphate (DSS)-induced colitis in mice. Treatment with DSS induced the expression of PLD2 and downregulated occludin in colon epithelial cells. PLD2 was shown to mediate phosphorylation of occludin and induce its proteasomal degradation in a c-Src kinase-dependent pathway. Additionally, we have shown that treatment with an inhibitor of PLD2 can rescue mice from DSS-induced colitis. To our knowledge, this is the first report showing that PLD2 is pivotal in the regulation of the integrity of epithelial tight junctions and occludin turn over, thereby implicating it in the pathogenesis of colitis

Replication of an emergency department-based recovery coaching intervention and pilot testing of pragmatic trial protocols within the context of Indiana's Opioid State Targeted Response plan

Solving the opioid crisis requires immediate, innovative, and sustainable solutions. A number of promising strategies are being carried out by U.S. states and territories as part of their Opioid State Targeted Response (STR) plans funded through the 21st Century Cures Act, and they provide an opportunity for researchers to assess effectiveness of these interventions using pragmatic approaches. This paper describes a pilot study of Project Planned Outreach, Intervention, Naloxone, and Treatment (POINT), the intervention that served as the basis for Indiana's STR-funded, emergency department (ED)-based peer specialist expansion that was conducted in preparation for a larger, multisite pragmatic trial. Through the pilot, we identified, documented, and corrected for challenges encountered while implementing planned study protocols. Per the project's funding mechanism, the ability to move to the larger trial was determined by the achievement of 3 milestones: (1) successful replication of the intervention; (2) demonstrated ability to obtain the necessary sample size; and (3) observe a higher level of engagement in medication for addiction treatment in the POINT group compared to standard care. Overall implementation of the study protocols was successful, with only minor refinements to proposed procedures being required in light of challenges with (1) data access, (2) recruitment, and (3) identification of the expansion hospitals. All three milestones were reached. Challenges in implementing protocols and reaching milestones resulted in refinements that improved the study design overall. The subsequent trial will add to the limited but growing evidence on ED-based peer supports. Capitalizing on STR efforts to study an already scaling and promising intervention is likely to lead to faster and more sustainable results with greater generalizability than traditional, efficacy-focused clinical research

Low-Complexity Feedback Data Compression for Closed-Loop Digital Predistortion

This paper proposes sample combining as a low-complex and effective feedback data compression technique that allows to significantly reduce the computational effort and buffering needs for parameter adaptation in a closed-loop digital predistortion (DPD) system. Compression is achieved by applying an integrate & dump operation to an undersampled feedback signal. The proposed method is experimentally validated for RF measurement based behavioral modeling as well as closed-loop DPD of a 3.5 GHz GaN Doherty PA, taking also quantization effects of the feedback path into account. Our results demonstrate that the proposed technique is as capable as state-of-the-art histogram-based sample selection, however, at a much lower complexity.Peer reviewe

NANOPARTICLE-MODIFICATION OF NICU-BASED ALLOY 400 FOR LASER POWDER BED FUSION

NiCu-based Alloy 400 is a material being frequently used in corrosive environments wherefore it is applied in several industries like the maritime sector or chemical processing [1]. Numerous functional parts made of this alloy, like heat exchangers or liquid-carrying tubes for instance, may withstand harsh environments to a certain extend but still, at high temperatures and especially in carbon-rich atmospheres, component failure occurs due to poor metal dusting and creep resistance [2–5]. Reinforcing the base alloy system with nanoparticles using gas atomization and subsequent laser powder bed fusion (LPBF) can counteract such material failure [6]. Hence, in this work, titanium was added to Alloy 400 and atomized under nitrogen atmosphere in order to cause TiN nanoparticle formation in the microstructure of printed components.Mechanical Engineerin