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Competing Interests: TPC declares consultancies, or support for travel or speaker fees, from Takeda, Dr Falk Pharma, Techspert, IQVIA, Sermo, Janssen, Tillots, and M3 Global Research. JS declares grant funding to the University of Oxford from Crohn's Colitis UK, Action Medical Research, ECCO, European Commission, and Leona & M Helmsley Trust; consultancy fees from Janssen; and patent applications to discover diagnostic biomarkers in paediatric inflammatory bowel disease and in developing non-immunogenic anti-TNF therapies. JS is a Director of the UK IBD Registry; Co-Chair of the CCFA Precision Medicine working group; advisor to NICE on precision medicine; Chair of the TRIBUTE trial data & safety committee; and Chair of the steering committee of the MODULATE trial.

Research Question: We previously reported that Deep Brain Stimulation (DBS) of motor thalamus (MT), in a patient with post-stroke tremor, relieved breathlessness associated with chronic obstructive pulmonary disease. This raised the question of whether MT DBS mitigates the ascending dyspnoea signal. We therefore sought to conduct a fully powered cohort study of experimentally induced air hunger (AH), an uncomfortable urge to breathe in patients with MT DBS ON and OFF., Methods: 16 patients (3 females) with DBS of the ventral intermediate nucleus (VIM) as treatment for tremor, underwent hypercapnic AH tests, with DBS "ON" and "OFF". Patients rated AH on a visual analogue scale (VAS) every 15 s. Hypercapnia and ventilation were matched for ON and OFF states (mean±sd 43±4 and 43±4 mmHg for end-tidal P CO 2 , 13.7 and 13.4 L·min -1 for ventilation). Participants ventilation was constrained to baseline levels by breathing from a 3-litre inspiratory reservoir with fixed flow of fresh gas while targeting their resting breathing frequency to a metronome., Results: Overall steady state AH was 52±28%VAS for "ON" and 67±20%VAS for "OFF" (p=0.002; two-tailed paired t-test). The mean reduction in AH during VIM DBS was -14.4%VAS. MT DBS relieved AH in thirteen patients, heightened AH in two and caused no change in one., Conclusion: MT DBS for tremor relief also mitigates the AH component of dyspnoea. We posit that DBS of the MT heightens the gating control of the thalamus modulating the ascending air hunger signal. Extent of relief suggests that thalamic DBS may prove to be a viable therapy for intractable dyspnoea., (Copyright ©The authors 2024.)

Competing Interests: TPC has received educational support from Janssen and Dr Falk Pharma (UK), speaker fees from Janssen, Dr Falk Pharma (UK), and Tillotts Pharma, and consulting fees from Techspert, IQVIA, and Sermo. TA has received educational support from Celltrion Healthcare and Tillotts Pharma, speaker fees from F Hoffmann-La Roche, Pfizer, and Takeda, consulting fees from Amgen, Celltrion Healthcare, Janssen, and Eli Lilly, unrestricted grants from Celltrion Healthcare, Biogen, Nova Pharmaceuticals, Galapagos, Takeda, and Pfizer, and equipment, materials, drugs, medical writing, gifts, or other services from F Hoffmann-La Roche and MAST Group. JS plans a patent application to develop a non-immunogenic anti-TNF biological agent, is director of the UK Inflammatory Bowel Disease Registry, and has received consulting fees from Janssen, grants to Oxford University from the European Community, European Crohn's and Colitis Organisation, Helmsley Trust, Action Medical Research, and Crohn's and Colitis UK.

Better understanding of breathlessness perception addresses an unmet clinical need for more effective treatments for intractable dyspnoea, a prevalent symptom of multiple medical conditions. The insular-cortex is predominantly activated in brain-imaging studies of dyspnoea, but its precise role remains unclear. We measured experimentally-induced hypercapnic air-hunger in three insular-glioma patients before and after surgical resection. Tests involved one-minute increments in inspired CO 2 , raising end-tidal P CO 2 to 7.5 mmHg above baseline (38.5 ± 5.7 mmHg), whilst ventilation was constrained (10.7 ± 2.3 L/min). Patients rated air-hunger on a visual analogue scale (VAS). Patients had lower stimulus-response (2.8 ± 2 vs. 11 ± 4 %VAS/mmHg; p  = 0.004), but similar threshold (40.5 ± 3.9 vs. 43.2 ± 5.1 mmHg), compared to healthy individuals. Volunteered comments implicated diminished affective valence. After surgical resection; sensitivity increased in one patient, decreased in another, and other was unable to tolerate the ventilatory limit before any increase in inspired CO 2 .We suggest that functional insular-cortex is essential to register breathlessness unpleasantness and could be targeted with neuromodulation in chronically-breathless patients. Neurological patients with insula involvement should be monitored for blunted breathlessness to inform clinical management., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The author(s) declared that they were an editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision., (Copyright © 2024 Chapman, Farrell, Plaha, Green and Moosavi.)

Background and Aims: Digital collection of patient-reported outcome measures [PROMs] is largely unexplored as a basis for follow-up for patients with ulcerative colitis [UC]. Our aim was to develop a model to predict the likelihood of escalation of therapy or intervention at an outpatient appointment that may be used to rationalize follow-up., Methods: TrueColours-IBD is a web-based, real-time, remote monitoring software that allows longitudinal collection of ePROMs. Data for prediction modelling were derived from a Development Cohort, guided by the TRIPOD statement. Logistic regression modelling used ten candidate items to predict escalation of therapy or intervention. An Escalation of Therapy or Intervention [ETI] calculator was developed, and applied in a Validation Cohort at the same centre., Results: The Development Cohort [n = 66] was recruited in 2016 and followed for 6 months [208 appointments]. From ten items, four significant predictors of ETI were identified: SCCAI, IBD Control-8, faecal calprotectin, and platelets. For practicality, a model with only SCCAI and IBD Control-8, both entered remotely by the patient, without the need for faecal calprotectin or blood tests was selected. Between 2018 and 2020, a Validation Cohort of 538 patients [1188 appointments] was examined. A 5% threshold on the ETI calculator correctly identified 343/388 [88%] escalations and 274/484 [57%] non-escalations., Conclusions: A calculator based on digital, patient-entered data on symptoms and quality of life can predict whether a patient with UC requires escalation of therapy or intervention at an outpatient appointment. This may be used to streamline outpatient appointments for patients with UC., (© The Author(s) 2023. 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: Current guidelines strongly recommend the use of validated classifications to support optical diagnosis of lesions with advanced endoscopic imaging in the lower gastrointestinal tract. However, the optimal strategy in inflammatory bowel disease (IBD) is still a matter of debate., Objectives: To analyze the accuracy of endoscopic classifications or single predictors for in vivo lesion characterization during endoscopic surveillance of IBD with advanced endoscopic imaging., Design: Systematic review., Data Sources and Methods: Medline and PubMed were used to extract all studies which focused on lesion characterization of neoplastic and non-neoplastic lesions in IBD. The diagnostic accuracy of endoscopic classifications and single endoscopic predictors for lesion characterization were analyzed according to type of patients, lesions, and technology used. When available, the rates of true and false positives or negatives for neoplasia were pooled and the sensitivity (SE), specificity (SP), positive predictive value, and negative predictive value (NPV) were calculated., Results: We included 35 studies (2789 patients; 5925 lesions - 1149 neoplastic). Advanced endoscopic imaging included dye-based chromoendoscopy, virtual chromoendoscopy (VCE), magnification and high-definition endoscopy, confocal laser endomicroscopy (CLE), endocytoscopy, and autofluorescence imaging. The Kudo classification of pit patterns was most frequently used, with pooled SE 83%, SP 83%, and NPV 95%. The endoscopic criteria with the highest accuracy, with minimum SE ⩾ 90%, SP ⩾ 80%, and NPV ⩾ 90% were: the Kudo-IBD classification used with VCE (Fuji Intelligent Color Enhancement and i-SCAN); combined irregular surface and vascular patterns used with narrow band imaging; the Mainz classification used with CLE. Multiple clinical and technical factors were found to influence the accuracy of optical diagnosis in IBD., Conclusion: No single endoscopic factor has yet shown sufficient accuracy for lesion characterization in IBD surveillance. Conventional classifications developed in the non-IBD setting have lower accuracy in IBD. The use of new classifications adapted for IBD (Kudo-IBD), and new technologies based on in vivo microscopic analysis show promise., Competing Interests: The authors declare that there is no conflict of interest., (© The Author(s), 2023.)

Competing Interests: Competing interests: None declared.

Objectives: We aimed to determine whether changes in acute severe colitis (ASC) management have translated to improved outcomes and to develop a simple model predicting steroid non-response on admission., Design: Outcomes of 131 adult ASC admissions (117 patients) in Oxford, UK between 2015 and 2019 were compared with data from 1992 to 1993. All patients received standard treatment with intravenous corticosteroids and endoscopic disease activity scoring (Ulcerative Colitis Endoscopic Index of Severity (UCEIS)). Steroid non-response was defined as receiving medical rescue therapy or surgery. A predictive model developed in the Oxford cohort was validated in Australia and India (Gold Coast University Hospital 2015-2020, n=110; All India Institute of Medical Sciences, New Delhi 2018-2020, n=62)., Results: In the 2015-2019 Oxford cohort, 15% required colectomy during admission vs 29% in 1992-1993 (p=0.033), while 71 (54%) patients received medical rescue therapy (27% ciclosporin, 27% anti-tumour necrosis factor, compared with 27% ciclosporin in 1992-1993 (p=0.0015). Admission C reactive protein (CRP) (false discovery rate, p=0.00066), albumin (0.0066) and UCEIS scores (0.015) predicted steroid non-response. A four-point model was developed involving CRP of ≥100 mg/L (one point), albumin of ≤25 g/L (one point), and UCEIS score of ≥4 (1 point) or ≥7 (2 points). Patients scoring 0, 1, 2, 3 and 4 in the validation cohorts had steroid response rates of 100, 75.0%, 54.9%, 18.2% and 0%, respectively. Scoring of ≥3 was 84% (95% CI 0.70 to 0.98) predictive of steroid failure (OR 11.9, 95% CI 10.8 to 13.0). Colectomy rates in the validation cohorts were were 8%-11%., Conclusions: Emergency colectomy rates for ASC have halved in 25 years to 8%-15% worldwide. Patients who will not respond to corticosteroids are readily identified on admission and may be prioritised for early intensification of therapy., Competing Interests: Competing interests: AW reported personal fees outside the submitted work from Ferring Pharmaceuticals, Janssen and Takeda. SPLT reported outside the submitted work receipt of grants/research support from AbbVie, Buhlmann, Celgene, IOIBD, Janssen, Lilly, Pfizer, Takeda, UCB, Vifor and Norman Collisson Foundation; consulting fees from AbbVie, Allergan, Amgen, Arena, Asahi, Astellas, Biocare, Biogen, Boehringer Ingelheim, Bristol-Myers Squibb, Buhlmann, Celgene, Chemocentryx, Cosmo, Enterome, Ferring, Giuliani SpA, GSK, Genentech, Immunocore, Immunometabolism, Indigo, Janssen, Lexicon, Lilly, Merck, MSD, Neovacs, Novartis, NovoNordisk, NPS Pharmaceuticals, Pfizer, Proximagen, Receptos, Roche, Sensyne, Shire, Sigmoid Pharma, SynDermix, Takeda, Theravance, Tillotts, Topivert, UCB, VHsquared, Vifor and Zeria; speaker fees from AbbVie, Amgen, Biogen, Ferring, Janssen, Lilly, Pfizer, Shire and Takeda; and no stocks or share options. JS received lecture fees from Takeda and from the Falk Foundation., (© Author(s) (or their employer(s)) 2023. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Using two large datasets from Dorset, we previously reported an internally validated multivariable risk model for predicting the risk of GI malignancy in IDA-the IDIOM score. The aim of this retrospective observational study was to validate the IDIOM model using two independent external datasets., Methods: The external validation datasets were collected, in a secondary care setting, by different investigators from cohorts in Oxford and Sheffield derived under different circumstances, comprising 1117 and 474 patients with confirmed IDA respectively. The data were anonymised prior to analysis. The predictive performance of the original model was evaluated by estimating measures of calibration, discrimination and clinical utility using the validation datasets., Results: The discrimination of the original model using the external validation data was 70% (95% CI 65, 75) for the Oxford dataset and 70% (95% CI 61, 79) for the Sheffield dataset. The analysis of mean, weak, flexible and across the risk groups' calibration showed no tendency for under or over-estimated risks in the combined validation data. Decision curve analysis demonstrated the clinical value of the IDIOM model with a net benefit that is higher than 'investigate all' and 'investigate no-one' strategies up to a threshold of 18% in the combined validation data, using a risk cut-off of around 1.2% to categorise patients into the very low risk group showed that none of the patients stratified in this risk group proved to have GI cancer on investigation in the validation datasets., Conclusion: This external validation exercise has shown promising results for the IDIOM model in predicting the risk of underlying GI malignancy in independent IDA datasets collected in different clinical settings., (© 2021. The Author(s).)

Acute severe ulcerative colitis [ASUC] remains a common medical emergency, with 25% of patients with ulcerative colitis experiencing at least one event in their disease course. Despite advances in medical therapy, ASUC continues to be associated with considerable morbidity and mortality, with up to 30% of patients requiring colectomy during initial admission. Our aim was to review the current controversies and recent progress in risk stratification, prediction of outcome, and personalisation of care in ASUC. We re-assess the use of Truelove and Witts' criteria, serum biomarkers, and the use of composite clinical indices in current clinical practice. We explore the potential for endoscopic prediction using defined validated indices for accurate and early prognostication, and the need to define outcome. We also consider the impact of the current COVID-19 pandemic. Finally, we discuss the current research agenda, including the application of new and emerging biomarkers coupled with multi-omics and the implications in management and optimisation of outcome. Research priorities for the prediction of outcome in acute severe colitis include the following. 1. Development of an accurate admission score to guide early medical rescue therapy or colectomy. 2. Utility of point-of-care faecal calprotectin, with determination of optimal cut-off values. 3. Role of serum and faecal infliximab levels to both predict outcome and guide accelerated infliximab dosing. 4. Role of novel biomarkers, including serum calprotectin, in predicting response to corticosteroids or rescue therapy. 5. Specific predictors of response to ciclosporin and infliximab to allow rationalisation of drug use. 6. Utility of validated endoscopic scores. 7. Utility of radiological assessment beyond use of plain abdominal X-ray. 8. The use of multiomics and machine learning to predict risk of Acute Severe Colitis in patients with Ulcerative Colitis., (© The Author(s) 2021. 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: Anti-tumour necrosis factor (anti-TNF) therapy increases the risk of tuberculosis (TB). Given limitations of screening techniques, it remains uncertain if patients receiving anti-TNF in TB endemic regions should be screened for latent infection with chemoprophylaxis restricted to those with proven infection, or if all patients should receive chemoprophylaxis., Aims: To compare the incidence of active TB with infliximab (IFX) following targeted and universal TB chemoprophylaxis, and to determine the rates of adverse events (AE) related to TB chemoprophylaxis METHODS: A multi-centre retrospective cohort study was performed at 18 hospitals in China of 1968 adult patients with IBD receiving IFX from 2009 to 2017. TB screening prior to IFX was performed with chest X-ray and/or computed tomography [CT] and immune reactivity testing (interferon-γ release assay and/or tuberculin skin test). Patients were followed-up for a minimum of 3 months after IFX discontinuation, or until last hospital visit if IFX therapy was ongoing. Targeted strategy was defined as TB chemoprophylaxis only for patients with a positive latent TB screen, with universal strategy defined as TB chemoprophylaxis for all patients., Results: Mean follow-up was 1.07 ± 0.87 years with a total follow-up of 2102 patient-years. There were 1433 patients in the targeted and 483 patients in the universal TB chemoprophylaxis groups, with no significant difference in the incidence rates of active TB between groups (673.3 per 100 000 population per year vs 891.5 per 100 000 population per year, P = 0.60). In the targeted group, 55/1433 patients received TB chemoprophylaxis compared with 483/483 in the universal group, with significantly fewer AEs related to TB chemoprophylaxis in the targeted compared to the universal group (0.35% (5/1433) vs 6.8% (33/483), P < 0.05)., Conclusions: In this study of patients receiving IFX in a TB endemic area, universal chemoprophylaxis was not associated with a reduced risk of active TB when compared to a targeted chemoprophylaxis strategy, and AEs were more common. This supports the use of targeted TB chemoprophylaxis when anti-TNF therapy is initiated in TB endemic regions., (© 2020 The Authors. Alimentary Pharmacology & Therapeutics published by John Wiley & Sons Ltd.)

Treatment strategies for inflammatory bowel disease (IBD) now increasingly target deep remission, yet the resultant more aggressive use of medical therapy is associated with potentially serious adverse events and significant costs. It is, therefore, of vital importance to consider when, how and in whom medical therapy may be safely de-escalated. This issue is of great potential relevance in the current SARS-Cov-2 pandemic. In this review, we first discuss the rationale for drug withdrawal in IBD, before considering the available data on withdrawal of 5-aminosalicylates (5-ASA), immunomodulators (IM) and biological therapy in both ulcerative colitis (UC) and Crohn's Disease (CD). We consider how to identify patients most appropriate for drug withdrawal and outline a potential monitoring strategy for the early detection of relapse following drug withdrawal. We conclude with important future perspectives in this challenging field, and highlight ongoing trials that are likely to shape practice in the years to come., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Background: Tofacitinib is a partially selective Janus kinase inhibitor approved for the treatment of refractory moderate to severe ulcerative colitis [UC]. We sought to define the effectiveness and adverse effects of tofacitinib in a real-world cohort., Methods: We conducted a retrospective observational cohort study of 134 patients with UC [64% male; median age 37 years [range 16-81]; 83% of patients had previously received at least one biologic] treated with tofacitinib from October 2018 to October 2019 in four UK centres. Disease activity was assessed using the Simple Clinical Colitis Activity Index [SCCAI] or partial Mayo score [PMS], depending on study site. Response and remission were defined as a reduction in SCCAI or PMS of ≥3and SCCAI ≤2 or a PMS ≤1, respectively., Results: Overall, 74% (88/119; 95 confidence interval [CI] 65-81%] patients responded to tofacitinib at Week 8 and steroid-free remission was observed in 44% [47/108; 95% CI 3453%] patients at Week 26. Primary non-response was independently associated with younger age [p = 0.014] and higher C-reactive protein [CRP] levels at baseline [p = 0.004]. Only 23% [3/13] of patients who continued tofacitinib in the setting of primary non-response were in steroid-free remission at Week 26. Prior biologic exposure did not influence response or remission rates. Dose escalation, however, recaptured response in approximately half of patients who had lost response. Dyslipidaemia was observed in 20% [27/134; 95% CI 1428%] of patients, but adverse events necessitating drug withdrawal were uncommon and no venous thromboembolic events occurred., Conclusions: In this multicentre real-world cohort, tofacitinib was well tolerated and clinically effective in a treatment-refractory UC population., (© 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: 5-aminosalicylates (5-ASA) are widely used in inflammatory bowel disease (IBD), but emerging evidence suggests that they may be safely withdrawn in significant subsets of patients. This is important to address: 5-ASA therapy accounts for up to 25% of total healthcare costs in ulcerative colitis (UC), while almost a third of patients with Crohn's disease (CD) receive long-term 5-ASA despite no clear evidence of benefit. Further, rationalising medication burden may improve overall adherence and outcome., Aims: To summarise the rationale for 5-ASA withdrawal, review the current evidence in both UC and CD and consider the data surrounding colorectal cancer (CRC) prevention, guiding an evidence-based withdrawal strategy., Methods: PubMed was searched to identify relevant studies. Only papers published in English were reviewed, with priority given to randomised clinical trials and meta-analyses., Results: For patients with UC, consideration of 5-ASA withdrawal should be made on a case-by-case basis, but it appears safest for those in deep remission without any of the following risk factors: younger age (<40 years), remission for less than 2 years, a history of multiple flares, extensive disease. 5-ASA withdrawal should also be considered in patients with UC escalated to biologic therapy who have achieved remission and in all patients with CD. Although 5-ASA therapy may have chemopreventive benefits for CRC, the cost-benefit ratio appears significant, and this indication is not justified by evidence in those who have achieved remission and are continuing therapy with other agents, or in those in sustained remission without a history of extensive disease., Conclusions: Although the majority of patients with IBD receive 5-ASA during their disease course, safe withdrawal appears possible in many, with important implications for both health economics and patient experience. A number of unanswered questions, however, remain., (© 2020 The Authors. Alimentary Pharmacology & Therapeutics published by John Wiley & Sons Ltd.)

Treatment strategies for inflammatory bowel disease (IBD) focus on the induction and long-term maintenance of deep remission to avoid complications of active disease and improve long-term outcomes. Medical therapies for IBD, notably the increasingly widespread use of biological therapy, are often effective at controlling disease, but these drugs are associated with substantial adverse events, which together with other factors-including increasing treatment costs and patient preferences-leads to concerns regarding indefinite use of medical therapy. Consequently, the need to consider the safety and feasibility of drug de-escalation once IBD remission has been achieved is clear. Here, we review the current evidence surrounding de-escalation of immunomodulator and biological therapy in Crohn's disease and ulcerative colitis. We discuss strategies for de-escalation, including the selection of patients who are appropriate for treatment de-escalation and the use of proactive drug monitoring, and review the evidence on subsequent optimal follow-up. We conclude by proposing an algorithm to guide de-escalation decisions, and highlight future perspectives, including the potential effect of emerging medication and personalised medicine for these diseases., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

The interplay between NOD2 and TLR2 following recognition of components of the bacterial cell wall peptidoglycan is well-established, however their role in redirecting metabolic pathways in myeloid cells to degrade pathogens and mount antigen presentation remains unclear. We show NOD2 and TLR2 mediate phosphorylation of the deubiquitinase ataxin-3 via RIPK2 and TBK1. In myeloid cells ataxin-3 associates with the mitochondrial cristae protein MIC60, and is required for oxidative phosphorylation. Depletion of ataxin-3 leads to impaired induction of mitochondrial reactive oxygen species (mROS) and defective bacterial killing. A mass spectrometry analysis of NOD2/TLR2 triggered ataxin-3 deubiquitination targets revealed immunometabolic regulators, including HIF-1α and LAMTOR1 that may contribute to these effects. Thus, we define how ataxin-3 plays an essential role in NOD2 and TLR2 sensing and effector functions in myeloid cells.

Titanium is widely used in demanding applications, such as in aerospace. Its strength-to-weight ratio and corrosion resistance make it well suited to highly stressed rotating components. Zirconium has a no less critical application where its low neutron capture cross section and good corrosion resistance in hot water and steam make it well suited to reactor core use, including fuel cladding and structures. The similar metallurgical behaviour of these alloy systems makes it alluring to compare and contrast their behaviour. This is rarely undertaken, mostly because the industrial and academic communities studying these alloys have little overlap. The similarities with respect to hydrogen are remarkable, albeit potentially unsurprising, and so this paper aims to provide an overview of the role hydrogen has to play through the material life cycle. This includes the relationship between alloy design and manufacturing process windows, the role of hydrogen in degradation and failure mechanisms and some of the underpinning metallurgy. The potential role of some advanced experimental and modelling techniques will also be explored to give a tentative view of potential for advances in this field in the next decade or so.This article is part of the themed issue 'The challenges of hydrogen and metals'., (© 2017 The Author(s).)

Background: Minimising placebo response is essential for drug development., Aim: To conduct a meta-analysis to determine placebo response and remission rates in trials and identify the factors affecting these rates., Methods: MEDLINE, EMBASE and CENTRAL were searched from inception to April 2014 for placebo-controlled trials of pharmacological interventions for Crohn's disease. Placebo response and remission rates for induction and maintenance trials were pooled by random-effects and mixed-effects meta-regression models to evaluate effects of study-level characteristics on these rates., Results: In 100 studies containing 67 induction and 40 maintenance phases and 7638 participants, pooled placebo remission and response rates for induction trials were 18% [95% confidence interval (CI) 16-21%] and 28% (95% CI 24-32%), respectively. Corresponding values for maintenance trials were 32% (95% CI 25-39%) and 26% (95% CI 19-35%), respectively. For remission, trials enrolling patients with more severe disease activity, longer disease duration and more study centres were associated with lower placebo rates, whereas more study visits and longer study duration was associated with higher placebo rates. For response, findings were opposite such that trials enrolling patients with less severe disease activity and longer study duration were associated with lower placebo rates. Placebo rates varied by drug class and route of administration, with the highest placebo response rates observed for biologics., Conclusions: Placebo rates vary according to whether trials are designed for induction or maintenance and the factors influencing them differ for the endpoints of remission and response. These findings have important implications for clinical trial design in Crohn's disease., (© 2017 John Wiley & Sons Ltd.)

Background and Aims: Minimisation of the placebo responses in randomised controlled trials [RCTs] is essential for efficient evaluation of new interventions. Placebo rates have been high in ulcerative colitis [UC] clinical trials, and factors influencing this are poorly understood. We quantify placebo response and remission rates in UC RCTs and identify trial design factors influencing them., Methods: MEDLINE, EMBASE, and the Cochrane Library were searched from inception through April 2014 for placebo-controlled trials in adult patients with UC of a biological agent, corticosteroid, immunosuppressant, or aminosalicylate. Data were independently doubly extracted. Quality was assessed using the Cochrane risk of bias tool., Results: In all, 51 trials [48 induction and 10 maintenance phases] were identified. Placebo response and remission rates were pooled according to random-effects models, and mixed-effects meta-regression models were used to evaluate effects of study-level characteristics on these rates. Pooled estimates of placebo remission and response rates for induction trials were 10% (95% confidence interval [CI] 7-13%) and 33% [95% CI 29-37%], respectively. Corresponding values for maintenance trials were 19% [95% CI 11-30%] and 22% [95% CI 17-28%]. Trials enrolling patients with more active disease confirmed by endoscopy [endoscopy subscore ≥ 2] were associated with lower placebo rates. Conversely, placebo rates increased with increasing trial duration and number of study visits., Conclusions: Objective assessment of greater disease activity at trial entry by endoscopy lowered placebo rates, whereas increasing trial duration and more interactions with healthcare providers increased placebo rates. These findings have important implications for design and conduct of clinical trials., (Copyright © 2016 European Crohn’s and Colitis Organisation (ECCO). Published by Oxford University Press. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Pyogenic liver abscess has a variable clinical presentation. Its management requires input from several disciplines and is often coordinated by a gastroenterologist. This review examines demographics, clinical presentation, aetiology, diagnosis and prognosis; a suggested management approach, including antibiotic selection, radiological intervention and indications for surgery, is offered from a physician's perspective.

Defects in mitochondrial function are increasingly recognised as central to the pathogenesis of many diseases, both inherited and acquired. Many of these mitochondrial defects arise from abnormalities in mitochondrial DNA and can result in multisystem disease, with gastrointestinal involvement common. Moreover, mitochondrial disease may present with a range of non-specific symptoms, and thus can be easily misdiagnosed, or even considered to be non-organic. We describe the clinical, histopathological and genetic findings of six patients from three families with gastrointestinal manifestations of mitochondrial disease. In two of the patients, anorexia nervosa was considered as an initial diagnosis. These cases illustrate the challenges of both diagnosing and managing mitochondrial disease and highlight two important but poorly understood aspects, the clinical and the genetic. The pathophysiology of gastrointestinal involvement in mitochondrial disease is discussed and emerging treatments are described. Finally, we provide a checklist of investigations for the gastroenterologist when mitochondrial disease is suspected., (Copyright © 2013 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.)

In the UK contemporary estimates of dietary Fe intakes rely upon food Fe content data from the 1980s or before. Moreover, there has been speculation that the natural Fe content of foods has fallen over time, predominantly due to changes in agricultural practices. Therefore, we re-analysed common plant-based foods of the UK diet for their Fe content (the '2000s analyses') and compared the values with the most recent published values (the '1980s analyses') and the much older published values (the '1930s analyses'), the latter two being from different editions of the McCance and Widdowson food tables. Overall, there was remarkable consistency between analytical data for foods spanning the 70 years. There was a marginal, but significant, apparent decrease in natural food Fe content from the 1930s to 1980s/2000s. Whether this represents a true difference or is analytical error between the eras is unclear and how it could translate into differences in intake requires clarification. However, fortificant Fe levels (and fortificant Fe intake based upon linked national data) did appear to have increased between the 1980s and 2000s, and deserve further attention in light of recent potential concerns over the long-term safety and effectiveness of fortificant Fe. In conclusion, the overall Fe content of plant-based foods is largely consistent between the 1930s and 2000s, with a fall in natural dietary Fe content negated or even surpassed by a rise in fortificant Fe but for which the long-term effects are uncertain.

Aortic stiffness and chronic kidney disease are closely linked by shared risk factors and associated increased cardiovascular mortality. At lower levels of renal function, aortic stiffness is independently associated with glomerular filtration rate. However, the longitudinal impact of aortic stiffness on renal function has not been reported previously. A cohort of 133 patients with chronic kidney disease stages 3 and 4 (estimated glomerular filtration rate: 15 to 59 mL/min per 1.73 m(2)) underwent prospective measurement of arterial stiffness parameters and monitoring of renal function. Aortic pulse wave velocity measurement was performed in 120 patients. The mean age was 69+/-12 years (mean+/-SD; 103 men, 30 women, and 23.3% diabetic). Mean systolic blood pressure was 155+/-21 mm Hg, and mean diastolic blood pressure was 83+/-11 mm Hg. The mean Modification of Diet in Renal Disease estimated glomerular filtration rate was 32+/-11 mL/min per 1.73 m(2). Change in renal function was measured using reciprocal creatinine plots and the dichotomous combined end point of > or = 25% decline in renal function or start of renal replacement therapy. After stepwise multivariate analysis, aortic pulse wave velocity was independently associated with gradient of reciprocal creatinine plot (r=0.46; P=0.014). In multivariate analysis of the end point of > or = 25% decline in renal function or start of renal replacement therapy, independent predictors were aortic pulse wave velocity (r=0.48; P=0.002), systolic blood pressure (r=0.17; P=0.039), and urine protein:creatinine ratio (r=0.20; P=0.021). We, therefore, conclude that aortic stiffening is independently associated with rate of change in renal function in patients with chronic kidney disease stages 3 and 4.

Cockroaches exploit tactile cues from their antennae to avoid predators. During escape running the same sensors are used to follow walls. We hypothesise that selection of these mutually exclusive behaviours can be explained without representation of the stimulus or an explicit switching mechanism. A neural model is presented that embodies this hypothesis. The model incorporates behavioural and neurophysiological data and is embedded in a mobile robot in order to test the response to stimuli in the real world. The system is shown to account for data on escape direction and high-speed wall-following in the cockroach, including the counter-intuitive observation that faster running cockroaches maintain a closer distance to the wall. The wall-following behaviour is extended to include discrimination of tactile escape cues according to behavioural context. We conclude by highlighting questions arising from the robot experiments that suggest interesting hypotheses to test in the cockroach.

A case of near-fatal nitrogen embolism during hepatic cryosurgery is presented. Modifications of liquid nitrogen probes, which prevent direct contact of liquid nitrogen with the tissue being frozen, can prevent this type of injury.

The advisability of routine allograft nephrectomy following rejection has not been clearly resolved. Rejected transplants may be a source of sepsis, local inflammatory symptoms, and continued antigenic stimulation. Transplant nephrectomy is, however, attended by a surprisingly high incidence of septic complications and death. In an attempt to analyze the occurrence of these, and identify effective prophylactic maneuvers, the authors retrospectively studied 99 consecutive allograft nephrectomies in 252 consecutive renal transplants. Mortality following allograft nephrectomy was 10 per cent, and usually attributable to sepsis. Wound infections occurred in 24 per cent of these patients and were significantly associated with a preoperative site of infection in the wound, urinary tract, or blood (P less than 0.01). Preoperative antibiotics, wound irrigation, drains, and delay in performing allograft nephrectomy were all found to be insignificant variables. Interestingly, total steroid dose was less in patients who developed wound infections than in those who did not (P less than 0.01). A postoperative wound infection approximately doubled the mean number of hospital days. These data suggest that a significant reduction in morbidity and possibly mortality could be accomplished by complete eradication of infection prior to allograft nephrectomy. Consequent delay in removal of the graft is not associated with increased morbidity, and other maneuvers seem to have little beneficial effect.