53 research outputs found

    Elucidating the Mechanisms of Thromboembolism and Structural Arterial Disease in Children with Inflammatory Bowel Disease

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    Inflammatory bowel disease (IBD) is a group of life-long relapsing and remitting inflammations of the gastrointestinal (GI) tract, with complex aetiology and no known cure. Incidence world-wide is increasing, especially among paediatric-onset cases. In addition to known primary morbidities, recent epidemiological evidence suggests an increased life-time risk of cardiovascular events in IBD patients, however the mechanism for this is unknown. This thesis attempts to investigate the hypothesis that chronic inflammation in IBD promotes vascular dysfunction, which leads to increased cardiovascular risk, and is detectable in paediatric IBD. Mechanisms of endothelial microparticle (MP) formation were investigated, and it was found cytokines associated with IBD stimulate MP release in a synergistic manner. Additionally, markers of endothelial injury, hypercoagulability and circulating microparticles (MPs) were assessed in paediatric IBD patients and compared to healthy controls. Circulating endothelial cells (CECs) were raised in paediatric IBD, with even inactive patients having significantly higher CECs. This was corroborated by increased circulating levels of MPs, particularly those derived from neutrophils, the endothelium and those expressing tissue factor (TF). Paradoxically, plasma from patients showed delayed thrombin generation, as well as MP-mediated thrombin generation, measured by an in vitro assay. Patients also showed increased plasma activity of TF and derangement of the TF/TFPI axis. Patients were assessed for structural arterial disease by assessment of carotid-femoral pulse wave velocity (PWV), but showed no difference to healthy controls. Finally, assessment of plasma cytokines and vascular injury markers by multi-plex electrochemiluminescent assay showed an increase in multiple pro-inflammatory cytokines in paediatric IBD. In summary, these novel findings suggest an increase in vascular injury in paediatric IBD along with promotion of a pro-thrombotic state. These findings provide a unique insight into the cardiovascular complications of IBD patients

    Can auditors be independent? – Experimental evidence on the effects of client type

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    Recent regulatory initiatives stress that an independent oversight board, rather than the management board, should be the client of the auditor. In an experiment, we test whether the type of client affects auditors’ independence. Unique features of the German institutional setting enable us to realistically vary the type of auditors’ client as our treatment variable: we portray the client either as the management preferring aggressive accounting or the oversight board preferring conservative accounting. We measure auditors’ perceived client retention incentives and accountability pressure in a post-experiment questionnaire to capture potential threats to independence. We find that the type of auditors’ client affects auditors’ behaviour contingent on the degree of the perceived threats to independence. Our findings imply that both client retention incentives and accountability pressure represent distinctive threats to auditors’ independence and that the effectiveness of an oversight board in enhancing auditors’ independence depends on the underlying threat

    Say on Pay: A wolf in sheep’s clothing?

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    This paper debates whether Say on Pay can fix executive pay. We argue that Say on Pay benefits executive pay when shareholders’ voice offsets CEO power and mitigates directors’ information deficiencies. We admonish however that Say on Pay may raise novel problems. The pay resulting from Say on Pay can harm stakeholders whose interests differ from those of shareholders influential in pay- setting. Moreover, boards may resist shareholders’ intervention in pay-setting and, accordingly, manage compensation disclosures to ensure a passing shareholder vote. Consequently, Say on Pay may not only fail to remedy suboptimal pay but also legitimize it

    Smoking cessation for people with severe mental illness (SCIMITAR+) : a pragmatic randomised controlled trial

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    BACKGROUND: People with severe mental illnesses such as schizophrenia are three times more likely to smoke than the wider population, contributing to widening health inequalities. Smoking remains the largest modifiable risk factor for this health inequality, but people with severe mental illness have not historically engaged with smoking cessation services. We aimed to test the effectiveness of a combined behavioural and pharmacological smoking cessation intervention targeted specifically at people with severe mental illness. METHODS: In the smoking cessation intervention for severe mental illness (SCIMITAR+) trial, a pragmatic, randomised controlled study, we recruited heavy smokers with bipolar disorder or schizophrenia from 16 primary care and 21 community-based mental health sites in the UK. Participants were eligible if they were aged 18 years or older, and smoked at least five cigarettes per day. Exclusion criteria included substantial comorbid drug or alcohol problems and people who lacked capacity to consent at the time of recruitment. Using computer-generated random numbers, participants were randomly assigned (1:1) to a bespoke smoking cessation intervention or to usual care. Participants, mental health specialists, and primary care physicians were unmasked to assignment. The bespoke smoking cessation intervention consisted of behavioural support from a mental health smoking cessation practitioner and pharmacological aids for smoking cessation, with adaptations for people with severe mental illness-such as, extended pre-quit sessions, cut down to quit, and home visits. Access to pharmacotherapy was via primary care after discussion with the smoking cessation specialist. Under usual care participants were offered access to local smoking cessation services not specifically designed for people with severe mental illnesses. The primary endpoint was smoking cessation at 12 months ascertained via carbon monoxide measurements below 10 parts per million and self-reported cessation for the past 7 days. Secondary endpoints were biologically verified smoking cessation at 6 months; number of cigarettes smoked per day, Fagerström Test for Nicotine Dependence (FTND) and Motivation to Quit (MTQ) questionnaire; general and mental health functioning determined via the Patient Health Questionnaire-9 (PHQ-9), the Generalised Anxiety Disorder-7 (GAD-7) questionnaire, and 12-Item Short Form Health Survey (SF-12); and body-mass index (BMI). This trial was registerd with the ISRCTN registry, number ISRCTN72955454, and is complete. FINDINGS: Between Oct 7, 2015, and Dec 16, 2016, 526 eligible patients were randomly assigned to the bespoke smoking cessation intervention (n=265) or usual care (n=261). 309 (59%) participants were male, median age was 47·2 years (IQR 36·3-54·5), with high nicotine dependence (mean 24 cigarettes per day [SD 13·2]), and the most common severe mental disorders were schizophrenia or other psychotic illness (n=343 [65%]), bipolar disorder (n=115 [22%]), and schizoaffective disorder (n=66 [13%]). 234 (88%) of intervention participants engaged with the treatment programme and attended 6·4 (SD 3·5) quit smoking sessions, with an average duration of 39 min (SD 17; median 35 min, range 5-120). Verified quit data at 12 months were available for 219 (84%) of 261 usual care and 223 (84%) of 265 intervention participants. The proportion of participants who had quit at 12 months was higher in the intervention group than in the usual care group, but non-significantly (34 [15%] of 223 [13% of those assigned to group] vs 22 [10%] of 219 [8% of those assigned to group], risk difference 5·2%, 95% CI -1·0 to 11·4; odds ratio [OR] 1·6, 95% CI 0·9 to 2·9; p=0·10). The proportion of participants who quit at 6 months was significantly higher in the intervention group than in the usual care group (32 [14%] of 226 vs 14 [6%] of 217; risk difference 7·7%, 95% CI 2·1 to 13·3; OR 2·4, 95% CI 1·2 to 4·6; p=0·010). The incidence rate ratio for number of cigarettes smoked per day at 6 months was 0·90 (95% CI 0·80 to 1·01; p=0·079), and at 12 months was 1·00 (0·89 to 1·13; p=0·95). At both 6 months and 12 months, the intervention group was non-significantly favoured in the FTND (adjusted mean difference 6 months -0·18, 95% CI -0·53 to 0·17, p=0·32; and 12 months -0·01, -0·39 to 0·38, p=0·97) and MTQ questionnaire (adjusted mean difference 0·58, -0·01 to 1·17, p=0·056; and 12 months 0·64, 0·04 to 1·24, p=0·038). The PHQ-9 showed no difference between the groups (adjusted mean difference at 6 months 0·20, 95% CI -0·85 to 1·24 vs 12 months -0·12, -1·18 to 0·94). For the SF-12 survey, we saw evidence of improvement in physical health in the intervention group at 6 months (adjusted mean difference 1·75, 95% CI 0·21 to 3·28), but this difference was not evident at 12 months (0·59, -1·07 to 2·26); and we saw no difference in mental health between the groups at 6 or 12 months (adjusted mean difference at 6 months -0·73, 95% CI -2·82 to 1·36, and 12 months -0·41, -2·35 to 1·53). The GAD-7 questionnaire showed no difference between the groups (adjusted mean difference at 6 months -0·32 95% CI -1·26 to 0·62 vs 12 months -0·10, -1·05 to 0·86). No difference in BMI was seen between the groups (adjusted mean difference 6 months 0·16, 95% CI -0·54 to 0·85; 12 months 0·25, -0·62 to 1·13). INTERPRETATION: This bespoke intervention is a candidate model of smoking cessation for clinicians and policy makers to address high prevalence of smoking. The incidence of quitting at 6 months shows that smoking cessation can be achieved, but the waning of this effect by 12 months means more effort is needed for sustained quitting. FUNDING: National Institute for Health Research Health Technology Assessment Programme

    Whole-genome sequencing reveals host factors underlying critical COVID-19

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    Critical COVID-19 is caused by immune-mediated inflammatory lung injury. Host genetic variation influences the development of illness requiring critical care1 or hospitalization2–4 after infection with SARS-CoV-2. The GenOMICC (Genetics of Mortality in Critical Care) study enables the comparison of genomes from individuals who are critically ill with those of population controls to find underlying disease mechanisms. Here we use whole-genome sequencing in 7,491 critically ill individuals compared with 48,400 controls to discover and replicate 23 independent variants that significantly predispose to critical COVID-19. We identify 16 new independent associations, including variants within genes that are involved in interferon signalling (IL10RB and PLSCR1), leucocyte differentiation (BCL11A) and blood-type antigen secretor status (FUT2). Using transcriptome-wide association and colocalization to infer the effect of gene expression on disease severity, we find evidence that implicates multiple genes—including reduced expression of a membrane flippase (ATP11A), and increased expression of a mucin (MUC1)—in critical disease. Mendelian randomization provides evidence in support of causal roles for myeloid cell adhesion molecules (SELE, ICAM5 and CD209) and the coagulation factor F8, all of which are potentially druggable targets. Our results are broadly consistent with a multi-component model of COVID-19 pathophysiology, in which at least two distinct mechanisms can predispose to life-threatening disease: failure to control viral replication; or an enhanced tendency towards pulmonary inflammation and intravascular coagulation. We show that comparison between cases of critical illness and population controls is highly efficient for the detection of therapeutically relevant mechanisms of disease

    SARS-CoV-2 Omicron is an immune escape variant with an altered cell entry pathway

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    Vaccines based on the spike protein of SARS-CoV-2 are a cornerstone of the public health response to COVID-19. The emergence of hypermutated, increasingly transmissible variants of concern (VOCs) threaten this strategy. Omicron (B.1.1.529), the fifth VOC to be described, harbours multiple amino acid mutations in spike, half of which lie within the receptor-binding domain. Here we demonstrate substantial evasion of neutralization by Omicron BA.1 and BA.2 variants in vitro using sera from individuals vaccinated with ChAdOx1, BNT162b2 and mRNA-1273. These data were mirrored by a substantial reduction in real-world vaccine effectiveness that was partially restored by booster vaccination. The Omicron variants BA.1 and BA.2 did not induce cell syncytia in vitro and favoured a TMPRSS2-independent endosomal entry pathway, these phenotypes mapping to distinct regions of the spike protein. Impaired cell fusion was determined by the receptor-binding domain, while endosomal entry mapped to the S2 domain. Such marked changes in antigenicity and replicative biology may underlie the rapid global spread and altered pathogenicity of the Omicron variant

    Whole-genome sequencing reveals host factors underlying critical COVID-19

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    Critical COVID-19 is caused by immune-mediated inflammatory lung injury. Host genetic variation influences the development of illness requiring critical care1 or hospitalization2,3,4 after infection with SARS-CoV-2. The GenOMICC (Genetics of Mortality in Critical Care) study enables the comparison of genomes from individuals who are critically ill with those of population controls to find underlying disease mechanisms. Here we use whole-genome sequencing in 7,491 critically ill individuals compared with 48,400 controls to discover and replicate 23 independent variants that significantly predispose to critical COVID-19. We identify 16 new independent associations, including variants within genes that are involved in interferon signalling (IL10RB and PLSCR1), leucocyte differentiation (BCL11A) and blood-type antigen secretor status (FUT2). Using transcriptome-wide association and colocalization to infer the effect of gene expression on disease severity, we find evidence that implicates multiple genes—including reduced expression of a membrane flippase (ATP11A), and increased expression of a mucin (MUC1)—in critical disease. Mendelian randomization provides evidence in support of causal roles for myeloid cell adhesion molecules (SELE, ICAM5 and CD209) and the coagulation factor F8, all of which are potentially druggable targets. Our results are broadly consistent with a multi-component model of COVID-19 pathophysiology, in which at least two distinct mechanisms can predispose to life-threatening disease: failure to control viral replication; or an enhanced tendency towards pulmonary inflammation and intravascular coagulation. We show that comparison between cases of critical illness and population controls is highly efficient for the detection of therapeutically relevant mechanisms of disease
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