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Background: Anti-TNF exposure has been linked to demyelination events. We sought to describe the clinical features of demyelination events following anti-TNF treatment and to test whether affected patients were genetically predisposed to multiple sclerosis [MS]., Methods: We conducted a case-control study to describe the clinical features of demyelination events following anti-TNF exposure. We compared genetic risk scores [GRS], calculated using carriage of 43 susceptibility loci for MS, in 48 cases with 1219 patients exposed to anti-TNF who did not develop demyelination., Results: Overall, 39 [74%] cases were female. The median age [range] of patients at time of demyelination was 41.5 years [20.7-63.2]. The median duration of anti-TNF treatment was 21.3 months [0.5-99.4] and 19 [36%] patients were receiving concomitant immunomodulators. Most patients had central demyelination affecting the brain, spinal cord, or both. Complete recovery was reported in 12 [23%] patients after a median time of 6.8 months [0.1-28.7]. After 33.0 months of follow-up, partial recovery was observed in 29 [55%] patients, relapsing and remitting episodes in nine [17%], progressive symptoms in three [6%]: two [4%] patients were diagnosed with MS. There was no significant difference between MS GRS scores in cases (mean -3.5 × 10-4, standard deviation [SD] 0.0039) and controls [mean -1.1 × 10-3, SD 0.0042] [p = 0.23]., Conclusions: Patients who experienced demyelination events following anti-TNF exposure were more likely female, less frequently treated with an immunomodulator, and had a similar genetic risk to anti-TNF exposed controls who did not experience demyelination events. Large prospective studies with pre-treatment neuroimaging are required to identify genetic susceptibility loci., (© The Author(s) 2020. Published by Oxford University Press on behalf of European Crohn’s and Colitis Organisation. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Background: Glucocorticosteroids (GC) are long-established, widely used agents for induction of remission in inflammatory bowel disease (IBD). Hyperglycaemia is a known complication of GC treatment with implications for morbidity and mortality. Published data on prevalence and risk factors for GC-induced hyperglycaemia in the IBD population are limited. We prospectively characterise this complication in our cohort, employing machine-learning methods to identify key predictors of risk., Methods: We conducted a prospective observational study of IBD patients receiving intravenous hydrocortisone (IVH). Electronically triggered three times daily capillary blood glucose (CBG) monitoring was recorded alongside diabetes mellitus (DM) history, IBD biomarkers, nutritional and IBD clinical activity scores. Hyperglycaemia was defined as CBG ≥11.1 mmol/L and undiagnosed DM as glycated haemoglobin ≥48 mmol/mol. Random forest (RF) regression models were used to extract predictor-patterns present within the dataset., Results: 94 consecutive IBD patients treated with IVH were included. 60% (56/94) of the cohort recorded an episode of hyperglycaemia, including 57% (50/88) of those with no history of DM, of which 19% (17/88) and 5% (4/88) recorded a CBG ≥14 mmol/L and ≥20 mmol/L, respectively. The RF models identified increased C-reactive protein (CRP) followed by a longer IBD duration as leading risk predictors for significant hyperglycaemia., Conclusion: Hyperglycaemia is common in IBD patients treated with intravenous GC. Therefore, CBG monitoring should be included in routine clinical practice. Machine learning methods can identify key risk factors for clinical complications. Steroid-sparing treatment strategies may be considered for those IBD patients with higher admission CRP and greater disease duration, who appear to be at the greatest risk of hyperglycaemia., Competing Interests: Competing interests: MM: received non-financial support from Falk, MSD, Janssen and Takeda. RJH: personal fees from AbbVie and Janssen; non-financial support from Falk. LD: non-financial support from Janssen. SD: personal fees and non-financial support from Janssen; personal fees from Falk, MSD and AbbVie. JRFC: personal fees and research and/or educational support from Abbot, AbbVie, Amgen, Astra Zeneca, Biogen, Celltrion, GlaxoSmithKline, Janssen, Norgine, Pfizer, Pharmacosmos, Samsung, Shield Therapeutics, Shire, Takeda and Vifor. MG: personal fees from AbbVie, MSD and Takeda; non-financial support from AbbVie and Takeda., (© Author(s) (or their employer(s)) 2020. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Objective: COVID-19 has disrupted the normal way of life in the UK, but for some patients with inflammatory bowel disease (IBD), the impact of this unprecedented global emergency was far greater. We aimed to assess the experience of patients with IBD during the COVID-19 lockdown., Design: We designed a survey focused on the impact of COVID-19 on IBD healthcare, social and psychological well-being and quality of life. To capture those most likely to be affected we targeted survey invitations at our British Society of Gastroenterology (BSG) defined high and moderate-risk IBD population. Access to the survey was also available via our trust's social media pages., Results: 685 responses were received. 76% of respondents categorised themselves in BSG defined moderate or high-risk groups, requiring stringent social distancing or shielding. 87% did not change their IBD medication, with most reported changes initiated by the IBD team. 39% were worried about their IBD care, but most services were largely uninterrupted. 90% received 'at-risk' notification often from multiple sources, but 17% not until May. The majority reported a negative impact of COVID-19 on their quality of life and significantly increased perceived stress. Patients expressed a strong wish of having future care delivered remotely., Conclusion: COVID-19 has had a significant negative impact on psychological well-being of patients with IBD. Local IBD services must have a robust data set of vulnerable patients and be designated future responsibility for prompt communication of advice to avoid delayed and sometimes conflicting information. Remote patient management systems should be further developed and embedded in clinical practice., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2020. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Background and Aims: Mucosal healing is important in Crohn's disease therapies. Epithelial homeostasis becomes dysregulated in Crohn's, with increased permeability, inflammation, and diarrhoea. MicroRNAs are small non-coding RNAs that regulate gene expression and show changes in inflammatory bowel disease. Tumour necrosis factor alpha [TNFα] inhibitor protein 3 is raised in Crohn's and regulates TNFα-mediated activation of NFκB. We investigated TNFα regulation by microRNA in Crohn's disease [CD], and studied effects on epithelial permeability and inflammation., Methods: Colonic epithelium from CD and healthy donor biopsies was isolated using laser capture microdissection, and microRNA was quantified. Tumour necrosis factor alpha inhibitor protein 3 was characterised immunohistochemically on serial sections. Expression effect of microRNA was confirmed with luciferase reporter assays. Functional barrier permeability studies and innate cytokine release were investigated with cell and explant culture studies., Results: MicroRNA23a levels significantly increased in colonic Crohn's epithelium compared with healthy epithelium. Luciferase reporter assays in transfected epithelial cells confirmed that microRNA23a repressed expression via the 3' untranslated region of tumour necrosis factor alpha inhibitor protein 3 mRNA, coinciding with increased NFκB-mediated transcription. Immunohistochemical staining of TNFAIP3 protein in colonic biopsies was reduced or absent in adjacent Crohn's sections, correlating inversely with microRNA23a levels and encompassing some intercohort variation. Overexpression of microRNA23a increased epithelial barrier permeability in a colonic epithelial model and increased inflammatory cytokine release in cultured explant biopsies, mimicking Crohn's disease characteristics., Conclusions: MicroRNA23a overexpression in colonic Crohn's epithelium represses tumour necrosis factor alpha inhibitor protein 3, enhancing sensitivity to TNFα, with increased intestinal permeability and cytokine release., (Copyright © 2019 European Crohn’s and Colitis Organisation (ECCO). Published by Oxford University Press. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Background & Aims: Anti-tumor necrosis factor (anti-TNF) therapies are the most widely used biologic drugs for treating immune-mediated diseases, but repeated administration can induce the formation of anti-drug antibodies. The ability to identify patients at increased risk for development of anti-drug antibodies would facilitate selection of therapy and use of preventative strategies., Methods: We performed a genome-wide association study to identify variants associated with time to development of anti-drug antibodies in a discovery cohort of 1240 biologic-naïve patients with Crohn's disease starting infliximab or adalimumab therapy. Immunogenicity was defined as an anti-drug antibody titer ≥10 AU/mL using a drug-tolerant enzyme-linked immunosorbent assay. Significant association signals were confirmed in a replication cohort of 178 patients with inflammatory bowel disease., Results: The HLA-DQA1*05 allele, carried by approximately 40% of Europeans, significantly increased the rate of immunogenicity (hazard ratio [HR], 1.90; 95% confidence interval [CI], 1.60-2.25; P = 5.88 × 10 -13 ). The highest rates of immunogenicity, 92% at 1 year, were observed in patients treated with infliximab monotherapy who carried HLA-DQA1*05; conversely the lowest rates of immunogenicity, 10% at 1 year, were observed in patients treated with adalimumab combination therapy who did not carry HLA-DQA1*05. We confirmed this finding in the replication cohort (HR, 2.00; 95% CI, 1.35-2.98; P = 6.60 × 10 -4 ). This association was consistent for patients treated with adalimumab (HR, 1.89; 95% CI, 1.32-2.70) or infliximab (HR, 1.92; 95% CI, 1.57-2.33), and for patients treated with anti-TNF therapy alone (HR, 1.75; 95% CI, 1.37-2.22) or in combination with an immunomodulator (HR, 2.01; 95% CI, 1.57-2.58)., Conclusions: In an observational study, we found a genome-wide significant association between HLA-DQA1*05 and the development of antibodies against anti-TNF agents. A randomized controlled biomarker trial is required to determine whether pretreatment testing for HLA-DQA1*05 improves patient outcomes by helping physicians select anti-TNF and combination therapies. ClinicalTrials.gov ID: NCT03088449., (Copyright © 2020 AGA Institute. Published by Elsevier Inc. All rights reserved.)

Adalimumab, the first fully humanised monoclonal antibody against tumour necrosis factor alpha (TNF-α), has played a leading role in the revolution brought about by the introduction of biologics, and has received the widest range of indications among TNF-α inhibitors. Post-registration, observational and registry studies of real-life use have largely supported the outcomes seen in registrational clinical trials. With the recent loss of exclusivity for the originator medicinal product in Europe, a number of biosimilar adalimumab molecules have been licensed for use in the same indications as the originator molecule across rheumatology, dermatology, gastroenterology and ophthalmology. Clinicians in these areas first gained experience with biosimilar infliximab, followed by etanercept and rituximab. However, adalimumab is likely to present unique challenges given the numbers of patients treated and the range of biosimilar adalimumab products available. The biosimilar approval pathway has an emphasis on the pre-clinical analytic data in combination with clinical studies conducted to confirm therapeutic equivalence. To date, several adalimumab biosimilars have entered the EU market following successful marketing authorisation applications and recent expiration of originator patent protection. This overview covers the extent of use of adalimumab and summarises the regulatory process involved in the development of biosimilars as well as their use in clinical practice. The authors also discuss clinical data available so far on adalimumab biosimilars and their envisaged impact in the field of immune-mediated inflammatory diseases.

Objective: To understand the effectiveness of ustekinumab in treating Crohn's disease (CD) in a UK real-world setting., Design: Retrospective cohort study using prospectively maintained clinical records., Setting: Single UK inflammatory bowel disease centre., Patients: Adult patients with an established diagnosis of CD prescribed ustekinumab outside of clinical trials at University Hospital Southampton (UHS)., Interventions: Ustekinumab, a monoclonal antibody to the shared p40 subunit of interleukin (IL) 12 and IL-23 as part of routine clinical care., Main Outcome Measures: Effectiveness as measured by an improvement in physician's global assessment, drug persistence and improvement in biomarkers (C-reactive protein (CRP), albumin and calprotectin)., Results: 84 patients were included, 72 had a postinduction review and 49 had 1-year data. At postinduction clinical review, clinical response occurred in 53% of patients and clinical remission occurred in 8%. For patients on ustekinumab at 1 year, clinical response occurred in 71% and remission in 14%. Adverse events included four patients with infections requiring admission, one drug-related rash, five CD surgeries and two CD exacerbations., Conclusions: Ustekinumab was well tolerated in a complex UK CD population and demonstrated benefit to patients in terms of clinical response and improvement of biomarkers and with some patients attaining clinical remission. No unexpected safety signals were seen., Competing Interests: Competing interests: Outside the submitted work the following interests are declared. RJH: personal fees from Abbvie & Janssen; non-financial support from Falk. MM: non-financial support from Falk, MSD, Janssen & Takeda. MB: Personal fees from Abbvie, Falk, Hospira, Janssen, MSD, Napp, Takeda & Pfizer. MG: personal fees and non-financial support from Abbvie & MSD; personal fees from Takeda; non-financial support from Falk & Janssen. JRFC: grants and personal fees from Samsung, Pfizer & Biogen; personal fees and non-financial support from Janssen & Abbvie; grants, personal fees and non-financial support from Takeda; personal fees from MSD, Sandoz, Celltrion & NAPP., (© Author(s) (or their employer(s)) 2020. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Anti-TNF drugs are effective treatments for the management of Crohn's disease but treatment failure is common. We aimed to identify clinical and pharmacokinetic factors that predict primary non-response at week 14 after starting treatment, non-remission at week 54, and adverse events leading to drug withdrawal., Methods: The personalised anti-TNF therapy in Crohn's disease study (PANTS) is a prospective observational UK-wide study. We enrolled anti-TNF-naive patients (aged ≥6 years) with active luminal Crohn's disease at the time of first exposure to infliximab or adalimumab between March 7, 2013, and July 15, 2016. Patients were evaluated for 12 months or until drug withdrawal. Demographic data, smoking status, age at diagnosis, disease duration, location, and behaviour, previous medical and drug history, and previous Crohn's disease-related surgeries were recorded at baseline. At every visit, disease activity score, weight, therapy, and adverse events were recorded; drug and total anti-drug antibody concentrations were also measured. Treatment failure endpoints were primary non-response at week 14, non-remission at week 54, and adverse events leading to drug withdrawal. We used regression analyses to identify which factors were associated with treatment failure., Findings: We enrolled 955 patients treated with infliximab (753 with originator; 202 with biosimilar) and 655 treated with adalimumab. Primary non-response occurred in 295 (23·8%, 95% CI 21·4-26·2) of 1241 patients who were assessable at week 14. Non-remission at week 54 occurred in 764 (63·1%, 60·3-65·8) of 1211 patients who were assessable, and adverse events curtailed treatment in 126 (7·8%, 6·6-9·2) of 1610 patients. In multivariable analysis, the only factor independently associated with primary non-response was low drug concentration at week 14 (infliximab: odds ratio 0·35 [95% CI 0·20-0·62], p=0·00038; adalimumab: 0·13 [0·06-0·28], p<0·0001); the optimal week 14 drug concentrations associated with remission at both week 14 and week 54 were 7 mg/L for infliximab and 12 mg/L for adalimumab. Continuing standard dosing regimens after primary non-response was rarely helpful; only 14 (12·4% [95% CI 6·9-19·9]) of 113 patients entered remission by week 54. Similarly, week 14 drug concentration was also independently associated with non-remission at week 54 (0·29 [0·16-0·52] for infliximab; 0·03 [0·01-0·12] for adalimumab; p<0·0001 for both). The proportion of patients who developed anti-drug antibodies (immunogenicity) was 62·8% (95% CI 59·0-66·3) for infliximab and 28·5% (24·0-32·7) for adalimumab. For both drugs, suboptimal week 14 drug concentrations predicted immunogenicity, and the development of anti-drug antibodies predicted subsequent low drug concentrations. Combination immunomodulator (thiopurine or methotrexate) therapy mitigated the risk of developing anti-drug antibodies (hazard ratio 0·39 [95% CI 0·32-0·46] for infliximab; 0·44 [0·31-0·64] for adalimumab; p<0·0001 for both). For infliximab, multivariable analysis of immunododulator use, and week 14 drug and anti-drug antibody concentrations showed an independent effect of immunomodulator use on week 54 non-remission (odds ratio 0·56 [95% CI 0·38-0·83], p=0·004)., Interpretation: Anti-TNF treatment failure is common and is predicted by low drug concentrations, mediated in part by immunogenicity. Clinical trials are required to investigate whether personalised induction regimens and treatment-to-target dose intensification improve outcomes., Funding: Guts UK, Crohn's and Colitis UK, Cure Crohn's Colitis, AbbVie, Merck Sharp and Dohme, Napp Pharmaceuticals, Pfizer, and Celltrion., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Background: Ulcerative colitis (UC) is characterized by disruption of the mucosal intestinal barrier. MicroRNAs, single-stranded noncoding RNAs of approximately 22nt, are dysregulated in UC. MicroRNAs targeting thymic stromal lymphopoietin (TSLP), a cytokine involved in T-cell maturation and polarization, may be involved in regulating UC inflammation and mucosal healing., Methods: Biopsy samples from non-UC (n = 38), inactive UC (n = 18), and active UC (n = 23) patients were analyzed for mRNA (real-time quantitative polymerase chain reaction) or TSLP protein expression (enzyme-linked immunosorbent assay). Flow cytometry was used to isolate CD4+ T cells from biopsies. The functional mechanism was shown using luciferase assays and antago-miR transfections. The TSLP/miR-31 association was analyzed on 196 subjects from a previous clinical trial that tested the anti-IL-13 drug tralokinumab, whereas mucosal healing effects were studied on a subset of patients (n = 13) from this trial., Results: We found that TSLP is reduced at both mRNA and protein levels in inflamed UC patients when compared with healthy subjects, in both whole biopsies and biopsy-isolated CD4+ CD25+ T cells. The expression of miR-31, predicted to target TSLP, inversely co-related to the levels of TSLP mRNA in T cells. Blocking miR-31 in vitro in T cells increased both TSLP mRNA expression and protein secretion. Luciferase assays showed that miR-31 directly targeted TSLP mRNA, suggesting a direct mechanistic link. We also found that TSLP is increased in patients who achieve mucosal healing, comparing biopsies before and after treatment from the tralokinumab trial., Conclusions: Our data suggest a role for TSLP in promoting mucosal healing and regulating inflammation in UC, whereas miR-31 can directly block this effect.

MicroRNAs (miRNAs) are single-stranded RNA molecules, which influence the translation of messenger RNA and hence protein synthesis. The altered expression of miRNAs in disease states in cancer and autoimmune diseases including inflammatory bowel disease is providing new insights into disease pathogenesis. This understanding is leading to consideration of the utility of miRNAs in diagnostics, prognostics, and therapeutics in inflammatory bowel disease. A literature search was conducted using the MEDLINE/PubMed databases using search terms inflammatory bowel disease, miRNA, treatment, and biomarkers.

Background: Previous work reports an association between familial risk factors stemming from parental characteristics and offspring disruptive behavior disorders (DBDs). This association may reflect (a) the direct effects of familial environment and (b) a passive gene-environment correlation (r(GE)), wherein the parents provide both the genes and the environment. The current study examined the contributions of direct environmental influences and passive r(GE) by comparing the effects of familial risk factors on child DBDs in genetically related (biological) and non-related (adoptive) families., Method: Participants were 402 adoptive and 204 biological families. Familial environment was defined as maternal and paternal maladaptive parenting and antisociality, marital conflict and divorce; offspring DBDs included attention deficit hyperactivity disorder (ADHD), conduct disorder (CD) and oppositional defiant disorder (ODD). Mixed-level regressions estimated the main effects of familial environment, adoption status and the familial environment by adoption status interaction term, which tested for the presence of passive r(GE)., Results: There was a main effect of maternal and paternal maladaptive parenting and marital discord on child DBDs, indicating a direct environmental effect. There was no direct environmental effect of maternal or paternal antisociality, but maternal and paternal antisociality had stronger associations with child DBDs in biological families than adoptive families, indicating the presence of a passive r(GE)., Conclusions: Many familial risk factors affected children equally across genetically related and non-related families, providing evidence for direct environmental effects. The relationship of parental antisociality and offspring DBDs was best explained by a passive r(GE), where a general vulnerability toward externalizing psychopathology is passed down by the parents to the children.

The observations of the exceptionally bright gamma-ray burst (GRB) 130427A by the Large Area Telescope aboard the Fermi Gamma-ray Space Telescope provide constraints on the nature of these unique astrophysical sources. GRB 130427A had the largest fluence, highest-energy photon (95 GeV), longest γ-ray duration (20 hours), and one of the largest isotropic energy releases ever observed from a GRB. Temporal and spectral analyses of GRB 130427A challenge the widely accepted model that the nonthermal high-energy emission in the afterglow phase of GRBs is synchrotron emission radiated by electrons accelerated at an external shock.

Purpose of Review: Our understanding of the importance of nutrition in inflammatory bowel disease (IBD) continues to improve. With increasing evidence or cumulative evidence, this article reviews the current data for the role of nutrition in IBD pathogenesis, disease exacerbation and its use in the treatment of IBD in a clinically relevant context., Recent Findings: Irritable bowel syndrome and obesity prevalence is rising, and is increasingly being recognized in patients with IBD. Exclusive enteral nutrition remains highly relevant because of its efficacy and superior side-effect profile, even when considered against new pharmacological treatments, but requires patient motivation. We are now beginning to understand the importance of micronutrients such as iron and vitamin D, which may not only alter the bowel flora but also have an immune-modulatory effect. More recently, a prebiotic and probiotic combination has been used in a randomized trial for the treatment of IBD., Summary: Macronutrient and micronutrient assessment should be an essential part of nutritional assessment of all patients with IBD. Although research is needed to further our understanding of the immune-modulatory effects of nutrients and supplements, better and more effective therapies combining nutrition and drug treatments like immune-suppressants should be explored.

Background: Genetic variation in myosin IXB (MYO9B) was found to be associated with ulcerative colitis (UC) in a recent collaborative study. A nonsynonymous single nucleotide polymorphism (SNP) rs1545620 at the 3' end of the gene was found to be significantly associated with UC and weakly associated with Crohn's disease (CD). The aim of our current study was to replicate these findings in an independent UC cohort and to investigate association with CD. We also investigated subphenotype association and interactions with CARD15, IL23R, ATG16L1, and the IBD5 risk haplotype., Methods: In all, 652 CD patients, 650 UC patients, and 1190 controls were genotyped for 8 MYO9B SNPs. Haplotype testing, epistasis testing with known polymorphisms, and subphenotype analysis were performed., Results: An intronic SNP rs2305767 in the MYO9B gene was associated with inflammatory bowel disease (IBD) overall (corrected P-value 0.002, odds ratio [OR] 0.76, 95% confidence interval [CI] 0.67-0.86). On individual disease analysis an association was found with CD (corrected P-value 0.001, OR 0.62, 95% CI 0.53-0.73) but not with UC. Analysis of the common MYO9B haplotypes showed significant association for CD and UC alone and IBD overall. No subphenotypic association was found. These data support an association between CD and SNPs in MYO9B independent of the established effects of SNPs in CARD15, IL23R, ATG16L1, and the IBD5 haplotype. There was no evidence of epistasis between SNPs in MYO9B and these established genes., Conclusions: MYO9B variants may be involved in IBD pathogenesis.

Background: Genomewide linkage studies identified chromosome 3p21 as an IBD locus. Genomewide association studies have supported this locus and the Wellcome Trust Case Control Consortium (WTCCC) study narrowed it to a 0.6 Mb region. Our objectives were to perform a 2-stage candidate gene association study of the 3p locus and to identify linkage disequilibrium (LD) between significant single-nucleotide polymorphisms (SNPs) and an Oxfordshire subset (n = 282) of the WTCCC as well as the HapMap SNPs., Methods: A total of 197 SNPs in 53 genes from the 3p locus were genotyped on the Illumina platform in a screening cohort of 469 Crohn's disease (CD) patients and 461 controls. Significant associations were then genotyped on the iPLEX platform in the original as well as a second cohort of 139 CD patients, 670 ulcerative colitis (UC) patients, and 1131 controls. All cases and controls were Caucasian and from the Oxfordshire region of the UK., Results: An intronic SNP rs1128535 in the TRAIP gene was associated with CD in the screening and validation cohorts (combined [n = 608] P = 0.0004 [corrected 0.002], odds ratio [OR] 0.77, 95% confidence interval [CI], 0.67-0.89]). No association was seen for UC. Epistasis was seen with the common CARD15 mutations (P = 0.00003 [corrected 0.0006], OR 0.48, 95% CI, 0.34-0.68). No LD was demonstrated with the WTCCC SNPs. Strong LD was demonstrated with 2 nonsynonymous HapMap SNPs in the MST1R gene in an adjacent LD block to the peak WTCCC association, suggesting a distinct association signal., Conclusions: The LD with these functional MST1R variants implicate this gene as having a possible role in CD pathogenesis.

Background: A North American genome-wide single nucleotide polymorphism (SNP) association study identified IL23R as a novel inflammatory bowel disease (IBD) susceptibility gene. Association was reported with multiple risk variants in the centromeric portion of IL23R in 3 large independent cohorts. The aims of this study were to replicate the association of IL23R with Crohn's disease (CD), examine subphenotype relationships, and look for evidence of epistasis with the known CD susceptibility gene CARD15 and susceptibility haplotype IBD5 in a large collection of CD patients. We further investigated the relationship between IL23R and ulcerative colitis (UC)., Methods: In all, 604 CD and 647 UC patients who had been rigorously phenotyped and who had been recruited from a single UK center were used in this study. Controls were either spouses of patients (141) or were recruited from well-person clinics (993). Eight SNPs were genotyped using MassArray (Sequenom). All 8 SNPs genotyped were significantly associated with CD., Results: The association with the nonsynonymous SNP rs11209026 was confirmed (P=6.65x10(-6), odds ratio [OR], 0.43, 95% confidence interval [CI]: 0.29-0.64). The most significant SNP in our study was rs7517847 (P=4.9x10(-9), OR 0.65, 0.56-0.75), which is statistically independent of rs11209026. Preliminary evidence suggests an epistatic interaction with the IBD5 risk haplotype. The effects of mutations in this IL23R appear weaker in UC (P=0.008, OR 0.63, 0.45-0.89 and 0.005 OR, 0.81, 0.71-0.94, respectively). No subphenotype associations were identified., Conclusions: We confirmed the findings that IL23R is a susceptibility gene for IBD with suggestive epistasis with the IBD5 locus in the CD population.

Background: A German genome-wide nonsynonymous single nucleotide polymorphism (nsSNP) association study identified ATG16L1 as a Crohn's disease (CD) susceptibility gene. The association appeared to be confined to the nsSNP rs2,241,880 and was confirmed in 2 German independent case-control collections (combined P = 4.0 x 10(-8), odds ratio [OR] 1.45; 95% confidence interval [CI]: 1.21-1.74), a CD transmission disequilibrium test (TDT) collection, and an independent UK cohort. A weak statistical interaction with CARD15 was demonstrated. No association with ulcerative colitis (UC) was demonstrated. The aims of the study were to replicate the association with CD, examine subphenotype associations and statistical interactions with CARD15, IL23R, and the IBD5 risk haplotype, as well as explore the association with UC., Methods: The study included 645 CD and 676 UC rigorously phenotyped patients recruited from a single UK center. Unaffected controls comprised either spouses of patients (141) or individuals recruited from well-person clinics (1,049). The nsSNP rs2,241,880 was genotyped using MassArray (Sequenom)., Results: A strong association with CD was demonstrated (P = 2.33 x 10(-7), OR 1.45 [1.25-1.67]), but no significant association was demonstrated with any subphenotype. We failed to replicate the reported interaction between rs2,241,880 and the CARD15 low-risk haplotypes dd and Dd. No significant statistical interaction with the 3 known CD susceptibility genes was seen. No association with UC susceptibility (P = 0.37, OR 1.06 [0.93-1.22]), or any UC subphenotype was identified., Conclusions: We confirmed the findings that ATG16L1 is a CD susceptibility gene and found no evidence of interaction with CARD15, IL23R, or IBD5.

Two short (< 2 s) gamma-ray bursts (GRBs) have recently been localized and fading afterglow counterparts detected. The combination of these two results left unclear the nature of the host galaxies of the bursts, because one was a star-forming dwarf, while the other was probably an elliptical galaxy. Here we report the X-ray localization of a short burst (GRB 050724) with unusual gamma-ray and X-ray properties. The X-ray afterglow lies off the centre of an elliptical galaxy at a redshift of z = 0.258 (ref. 5), coincident with the position determined by ground-based optical and radio observations. The low level of star formation typical for elliptical galaxies makes it unlikely that the burst originated in a supernova explosion. A supernova origin was also ruled out for GRB 050709 (refs 3, 31), even though that burst took place in a galaxy with current star formation. The isotropic energy for the short bursts is 2-3 orders of magnitude lower than that for the long bursts. Our results therefore suggest that an alternative source of bursts--the coalescence of binary systems of neutron stars or a neutron star-black hole pair--are the progenitors of short bursts.

Gamma-ray bursts (GRBs) come in two classes: long (> 2 s), soft-spectrum bursts and short, hard events. Most progress has been made on understanding the long GRBs, which are typically observed at high redshift (z approximately 1) and found in subluminous star-forming host galaxies. They are likely to be produced in core-collapse explosions of massive stars. In contrast, no short GRB had been accurately (< 10'') and rapidly (minutes) located. Here we report the detection of the X-ray afterglow from--and the localization of--the short burst GRB 050509B. Its position on the sky is near a luminous, non-star-forming elliptical galaxy at a redshift of 0.225, which is the location one would expect if the origin of this GRB is through the merger of neutron-star or black-hole binaries. The X-ray afterglow was weak and faded below the detection limit within a few hours; no optical afterglow was detected to stringent limits, explaining the past difficulty in localizing short GRBs.

Objectives: Methotrexate (MTX) is an effective immunosuppressive treatment in inflammatory bowel disease (IBD) but its use is limited by unpredictable toxicity and efficacy. MTX metabolism is complex involving a number of enzymes. An individual's response to MTX may in part be genetically determined by functional genetic variation in genes encoding these enzymes. We report a pharmacogenetic evaluation of MTX therapy in IBD., Methods: We studied 102 IBD patients treated with MTX, and 202 patients with Crohn's disease (CD), 205 patients with ulcerative colitis (UC) and 189 healthy volunteers served as controls to assess allele frequencies in the disease and healthy populations. All subjects were genotyped for four polymorphisms: G80A in the reduced folate carrier (RFC1) gene, G452T in the gamma-glutamyl hydrolase (GGH) gene and C677T and A1298C in the methylenetetrahydrofolate reductase (MTHFR) gene. Three non-conservative SNPs in the RFC1 and the MTHFR gene could not be detected in our patient cohort. Genotype-phenotype associations were evaluated with respect to efficacy and toxicity of MTX therapy., Results: No significant differences in the allele frequencies between CD, UC and healthy controls were detected. Overall 21% of patients experienced MTX side effects. Patients homozygous for the MTHFR 1298C allele were more likely to experience one or more side effects compared to patients with the wild-type 1298AA genotype (21.0 vs. 6.3%, P < 0.05). None of the genotyped SNPs or haplotypes, either alone or in combination, was associated with short-term efficacy or sustained response., Conclusions: Side effects of MTX in IBD are associated with a SNP in the MTHFR gene but response cannot be predicted by any of the investigated SNPs.

The explosion that results in a cosmic gamma-ray burst (GRB) is thought to produce emission from two physical processes: the central engine gives rise to the high-energy emission of the burst through internal shocking, and the subsequent interaction of the flow with the external environment produces long-wavelength afterglows. Although observations of afterglows continue to refine our understanding of GRB progenitors and relativistic shocks, gamma-ray observations alone have not yielded a clear picture of the origin of the prompt emission nor details of the central engine. Only one concurrent visible-light transient has been found and it was associated with emission from an external shock. Here we report the discovery of infrared emission contemporaneous with a GRB, beginning 7.2 minutes after the onset of GRB 041219a (ref. 8). We acquired 21 images during the active phase of the burst, yielding early multi-colour observations. Our analysis of the initial infrared pulse suggests an origin consistent with internal shocks.

The prompt optical emission that arrives with the gamma-rays from a cosmic gamma-ray burst (GRB) is a signature of the engine powering the burst, the properties of the ultra-relativistic ejecta of the explosion, and the ejecta's interactions with the surroundings. Until now, only GRB 990123 had been detected at optical wavelengths during the burst phase. Its prompt optical emission was variable and uncorrelated with the prompt gamma-ray emission, suggesting that the optical emission was generated by a reverse shock arising from the ejecta's collision with surrounding material. Here we report prompt optical emission from GRB 041219a. It is variable and correlated with the prompt gamma-rays, indicating a common origin for the optical light and the gamma-rays. Within the context of the standard fireball model of GRBs, we attribute this new optical component to internal shocks driven into the burst ejecta by variations of the inner engine. The correlated optical emission is a direct probe of the jet isolated from the medium. The timing of the uncorrelated optical emission is strongly dependent on the nature of the medium.

The genetic revolution has been with us for over a decade now. We have yet to see this impacting the care of patients except in a few rare examples. However, progress has been made in the field of inflammatory bowel disease (IBD) that could soon be translated to the bedside, both in terms of predicting the disease course as well as in the response to therapy. IBD traditionally has been classified as ulcerative colitis and Crohn's disease, with 10% of patients classified as having indeterminate colitis on the basis of clinical, radiologic, endoscopic, and histologic findings. However, this traditional view is now being challenged. Developments in genetics and serological markers, as well as an appreciation of the disease course, have led to an understanding that IBD is a heterogeneous group of diseases with some common genetic and environmental factors but different clinical manifestations in terms of disease behavior, location, and response to treatment. Data are now emerging that may allow us to more objectively select the correct therapy for the correct patient, rather than the current approach, which is based on clinical experience backed up by a less-than-perfect evidence base. In this article, we will review the evidence for this.

The effects of actodigin were studied in dogs with decreased cardiac contractility or atrail flutter. When injected at 30 min invervals into dogs with barbiturate-induced heart failure, actodigin caused a marked positive inotropic action of short duration. Actodigin's pronounced but fleeting effect appears to be related to the novel attachment of its steroid nucleus alpha to the carboxyl function in the lactone. Cardiac glycosides with a conventional beta linkage of the lactone ring to the steroid nucleus (e.g., AY-22,248) had positive inotropic actions which were both slower in onset and cumulative when injected every 30 min. Apparently because of its short duration of action, actodigin was not as cardiotoxic as its isomer, AY-22,248. Lastly, a sustained atrail flutter was induced by intercaval crush and faradic atrial stimulation. Both actodigin and ouabain converted this arrhythmia to normal sinus rhythm.

Butaclamol is a member of a new chemical class for which antipsychotic activity in humans has been demonstrated. Butaclamol, a racemate, has been resolved into its optical isomers and a separation of activities was found to occur between the (+) and (-) enantiomers. The present experiments show that at doses ranging from 0.1 to 0.3 mg/kg the (+) enantiomer abolished amphetamine-induced (a) stereotyped behavior and (b) rotational behavior in rats with unilateral lesions in the substantia nigra. It also inhibited the lever-pressing response in the continuous (Sidman) avoidance procedure, blocked discriminated avoidance behavior, and decreased ambulation and rearing in the open field. In contrast, the (-) enantiomer was devoid of behavioral activity at 100-500 times larger doses. At considerably higher doses (+)-butaclamol antagonized epinephrine-induced mortality. Again, the (-)-butaclamol was devoid of this activity as well. The significance of absolute optical specifity manifested by a neuroleptic drug is discussed in the light of dopaminergic and adrenergic mechanisms.

Cetamolol, a new beta-adrenoceptor blocker with partial agonist activity and cardioselectivity, was studied in vivo to determine its membrane-stabilizing effects. Comparisons were carried out with atenolol, pindolol, practolol, propranolol, timolol, dexpropranolol, lidocaine, and procaine. The following results indicated that cetamolol lacked membrane-stabilizing activity: (i) failure to cause local anesthesia on the rabbit cornea and motor nerve of the rat tail; (ii) ineffectiveness in reversing ventricular arrhythmias induced by coronary artery litigation in dogs; (iii) failure to reduce cardiac automaticity in catecholamine-depleted dogs as determined by the rate of a subatrial rhythm during ventricular (vagal) escape; and (iv) lack of a significant increase in atrioventricular conduction time in vagotomized or atropinized dogs in contrast to the effect in normal dogs indicating a reflex effect of cetamolol. Other results include a restoration of sinus rhythm in dogs with ventricular tachycardia induced by ouabain, and a dose-related decline in the force of cardiac contraction in anesthetized dogs at doses from 3 to 15 mg/kg, which occurred after an initial increase in force owing to intrinsic sympathomimetic activity. Although the mechanisms for the latter two effects are not clear at this time, explanations other than membrane-stabilizing activity have been considered in view of the other findings. It is concluded that cetamolol lacks membrane-stabilizing activity even at inordinately high doses.

In vitro studies on the new beta-adrenoceptor antagonist, cetamolol (Betacor), have demonstrated that the compound is a potent antagonist of the chronotropic effects of isoproterenol on guinea pig atria. The pA2 value (8.05) of cetamolol was slightly lower than that of propranolol (8.44). The compound was shown to possess a moderate degree of cardioselectivity as indicated by a lower pA2 value for the antagonism of isoproterenol-induced relaxation of the isolated guinea pig trachea (pA2 = 7.67) compared with that derived from atrial experiments (pA2 = 8.05). Up to concentrations of 10(-4) M, cetamolol displayed negligible negative inotropic activity relative to propranolol in the electrically stimulated guinea pig left atrial preparation. When applied to isolated right atria from reserpinized rats, cetamolol had a positive chronotropic effect (approximately 75% of that displayed by practolol) which was antagonized by pretreatment with propranolol, thus indicating intrinsic sympathomimetic activity. Specificity experiments in a number of isolated tissues indicated that cetamolol had very little antihistaminic, anticholinergic, alpha 1-adrenergic blocking, or calcium antagonistic properties. Biochemical receptor binding studies are in general agreement with the observations from the isolated tissue experiments.

The ability of dioxychlorane to depress cortical activity in rats with implanted electrodes was compared to that reported previously for methoxyflurane, halothane and enflurane. Dioxychlorane was eight times more potent than enflurane, five times more potent than halothane and twice as potent as methoxyflurane. Serum fluoride concentrations after the administration of dioxychlorane and enflurane were not different from controls. In contrast, serum fluoride concentrations after methoxyflurane reached a value of 105 mumol litre-1 and remained increased for at least the next 48 h. Urine fluoride concentrations in the dioxychlorane and enflurane groups were a half and a quarter, respectively, of those recorded in the methoxyflurane group. Polyuria and polydipsia were observed only in the methoxyflurane group. Dilatation of the proximal convoluted tubules was noted in the rats anesthetized with methoxyflurane. These changes were most marked at the 6- and 24-h periods following anaesthesia. Haemorrhage and ulcerative cystitis were noted in the bladders of the rats subjected to methoxyflurane. Cellular swelling in the proximal tubule was observed in the rats sacrificed 24 h after the administration of dioxychlorane. Enflurane produced no pathological changes.