Targeted expression of plasminogen activator inhibitor(PAI)-1 to the stomach inhibits gut-brain signalling by the satiety hormone cholecystokinin (CCK)

Energy homeostasis is a tightly regulated system that is vital for survival involving anorectic and orexigenic signals. Obesity is a maladaptive response where the balance becomes disrupted. Obesity is one of the most concerning health problems of our time. It is no longer considered a consequence of a western lifestyle, with more developing countries now reporting an increased incidence of obesity and associated illnesses. While obesity itself can be debilitating and decrease quality of life, it is the associated comorbidities that are the main cause for concern; including type two diabetes, cancer and thrombo-occlusive diseases. One of the molecules thought to be responsible for occlusive events is plasminogen activator inhibitor (PAI)-1. This inhibitor of the plasminogen system is also reported to be up to 5 fold higher in obese subjects in plasma, and similar to leptin, is released from adipose tissue. PAI-1 is considered to play a protective role in circumstances of gastric mucosal attack, thus a transgenic mouse (PAI-1HKβ) was generated, with targeted expression of PAI-1 to the gastric parietal cells, to study this. However, an unexpected phenotype emerged, most notably hyperphagia and increased body weight, which formed the basis of these present studies. The gut-brain axis is a major and well-studied regulator of energy homeostasis and this was the focus of this project. The PAI-1HKβ mice when compared to wild-type had decreased brain stem responses to the satiety hormone, Cholecystokinin (CCK). Brainstem responses were also attenuated in wild types pre-treated with exogenous PAI-1. Furthermore, it was shown that the urokinase plasminogen activator (uPA) receptor by which PAI-1 binds, was required to influence the observed decrease in brainstem responses. CCK also has other physiological functions in the role of energy homeostasis, including gastric emptying. While delayed gastric emptying was observed following a protein rich liquid test meal in C57BL/6 mice, PAI-1HKβ mice had a blunted response. Blockade of the CCK1 receptor in C57BL/6 mice also attenuated the delay in gastric emptying. Moreover, exogenous PAI-1 attenuated CCK-mediated inhibition of gastric emptying. The PAI-1HKβ mice had an attenuated inhibition of gastric emptying of a non-nutrient containing liquid test meal in response to CCK. Treatment with gastrin was shown to increase plasma PAI-1 and attenuated delayed gastric emptying in C57BL/6 mice. Food intake is stimulated by orexigens, most notably ghrelin, working via appetite-stimulating neurons in the arcuate nucleus. While ghrelin stimulated feeding in fed ad libitum C57BL/6 mice, PAI-1 increased feeding in previously fasted C57BL/6 mice only. This response to ghrelin and PAI-1 was also replicated in PAI-1 -/- mice, suggesting PAI-1 is not required for the orexigenic effect of ghrelin. Moreover, intrapertoneal (ip.) administered ghrelin increased fos expression in arcuate neurons of both C57BL/6 and PAI-1 -/- mice, whereas ip. PAI-1 did not. Weight loss in the PAI-1HKβ mice appeared to reverse the insensitivity to CCK in terms of gastric emptying. PAI-1HKβ mice were also found to be insensitive to other gut-derived satiety hormones, suggesting gastric PAI-1 is an anti-satiety factor. However, mice null for wild-type gastric PAI-1 responded normally to CCK prior to feeding, indicating that wild type is necessary for CCK insensitivity in the PAI-1HKβ mice. The current findings demonstrate that PAI-1 plays a role in the control of food intake. PAI-1 is an example of a novel anti-satiety factor that can modulate gut-brain signalling via the vagus nerve in order to preserve nutrient intake. This work provides a platform for future investigations into novel pathways implicated in the development and treatment of obesity

Measurement of HbA1c in multicentre diabetes trials - should blood samples be tested locally or sent to a central laboratory: an agreement analysis (vol 17, pg 517, 2016)

Background Glycated haemoglobin (HbA1c) is an important outcome measure in diabetes clinical trials. For multicentre designs, HbA1c can be measured locally at participating centres or by sending blood samples to a central laboratory. This study analyses the agreement between local and central measurements, using 1-year follow-up data collected in a multicentre randomised controlled trial (RCT) of newly diagnosed children with type I diabetes. Methods HbA1c measurements were routinely analysed both locally and centrally at baseline and then at 3, 6, 9 and 12 months and the data reported in mmol/mol. Agreement was assessed by calculating the bias and 95 % limits of agreement, using the Bland-Altman analysis method. A predetermined benchmark for clinically acceptable margin of error between measurements was subjectively set as ±10 % for HbA1c. The percentage of pairs of measurements that were classified as clinically acceptable was calculated. Descriptive statistics were used to examine the agreement within centres. Treatment group was not considered. Results Five hundred and ninety pairs of measurement, representing 255 children and 15 trial centres across four follow-up time points, were compared. There was no significant bias: local measurements were an average of 0.16 mmol/mol (SD = 4.5, 95 % CI −0.2 to 0.5) higher than central. The 95 % limits of agreement were −8.6 to 9.0 mmol/mol (local minus central). Eighty percent of local measurements were within ±10 % of corresponding central measurements. Some trial centres were more varied in the differences observed between local and central measurements: IQRs ranging from 3 to 9 mmol/mol; none indicated systematic bias. Conclusions Variation in agreement between HbA1c measurements was greater than had been expected although no overall bias was detected and standard deviations were similar. Discrepancies were present across all participating centres. These findings have implications for the comparison of standards of clinical care between centres, the design of future multicentre RCTs and existing quality assurance processes for HbA1c measurements. We recommend that centralised HbA1c measurement is preferable in the multicentre clinical trial setting

Enhancing practitioners’ confidence in recruitment and consent in the EcLiPSE trial: A mixed-method evaluation of site training – a Paediatric Emergency Research in the United Kingdom and Ireland (PERUKI) study

Background: EcLiPSE (Emergency treatment with Levetiracetam or Phenytoin in Status Epilepticus in children) is a randomised controlled trial (RCT) in the United Kingdom. Challenges to success include the need to immediately administer an intervention without informed consent and changes in staffing during trial conduct, mainly due to physician rotations. Using literature on parents' perspectives and research without prior consent (RWPC) guidance, we developed an interactive training package (including videos, simulation and question and answer sessions) and evaluated its dissemination and impact upon on practitioners' confidence in recruitment and consent. Methods: Questionnaires were administered before and immediately after training followed by telephone interviews (mean 11 months later), focus groups (mean 14 months later) and an online questionnaire (8 months before trial closure).Results: One hundred and twenty-five practitioners from 26/30 (87%) participating hospitals completed a questionnaire before and after training. We conducted 10 interviews and six focus groups (comprising 36 practitioners); 199 practitioners working in all recruiting hospitals completed the online questionnaire. Before training, practitioners were concerned about recruitment and consent. Confidence increased after training for explaining (all scale 0-5, 95% CIs above 0 and p values < 0.05): the study (66% improved mean score before 3.28 and after 4.52), randomisation (47% improvement, 3.86 to 4.63), RWPC (72% improvement, 2.98 to 4.39), and addressing parents' objections to randomisation (51% improvement, 3.37 to 4.25). Practitioners rated highly the content and clarity of the training, which was successfully disseminated. Some concerns about staff availability for training and consent discussions remained.Conclusions: Training improved practitioners' confidence in recruitment and RWPC. Our findings highlight the value of using parents' perspectives to inform training and to engage practitioners in trials that are at high risk of being too challenging to conduct

Continuous subcutaneous insulin infusion versus multiple daily injection regimens in children and young people at diagnosis of type 1 diabetes: pragmatic randomised controlled trial and economic evaluation

ObjectiveTo compare the efficacy, safety, and cost utility of continuous subcutaneous insulin infusion (CSII) with multiple daily injection (MDI) regimens during the first year following diagnosis of type 1 diabetes in children and young people.DesignPragmatic, multicentre, open label, parallel group, randomised controlled trial and economic evaluation.Setting15 paediatric National Health Service (NHS) diabetes services in England and Wales. The study opened to recruitment in May 2011 and closed in January 2017.ParticipantsPatients aged between 7 months and 15 years, with a new diagnosis of type 1 diabetes were eligible to participate. Patients who had a sibling with the disease, and those who took drug treatments or had additional diagnoses that could have affected glycaemic control were ineligible.InterventionsParticipants were randomised, stratified by age and treating centre, to start treatment with CSII or MDI within 14 days of diagnosis. Starting doses of aspart (CSII and MDI) and glargine or detemir (MDI) were calculated according to weight and age, and titrated according to blood glucose measurements and according to local clinical practice.Main outcome measuresPrimary outcome was glycaemic control (as measured by glycated haemoglobin; HbA1c) at 12 months. Secondary outcomes were percentage of patients in each treatment arm with HbA1c within the national target range, incidence of severe hypoglycaemia and diabetic ketoacidosis, change in height and body mass index (as measured by standard deviation scores), insulin requirements (units/kg/day), partial remission rate (insulin dose adjusted HbA1c Results294 participants were randomised and 293 included in intention to treat analyses (CSI, n=144; MDI, n=149). At 12 months, mean HbA1c was comparable with clinically unimportant differences between CSII and MDI participants (60.9 mmol/mol v 58.5 mmol/mol, mean difference 2.4 mmol/mol (95% confidence interval -0.4 to 5.3), P=0.09). Achievement of HbA1c lower than 58 mmol/mol was low among the two groups (66/143 (46%) CSII participants v 78/142 (55%) MDI participants; relative risk 0.84 (95% confidence interval 0.67 to 1.06)). Incidence of severe hypoglycaemia and diabetic ketoacidosis were low in both groups. Fifty four non-serious and 14 serious adverse events were reported during CSII treatment, and 17 non-serious and eight serious adverse events during MDI treatment. Parents (but not children) reported superior PedsQL scores for those patients treated with CSII compared to those treated with MDI. CSII was more expensive than MDI by £1863 (€2179; $2474; 95% confidence interval £1620 to £2137) per patient, with no additional QALY gains (difference -0.006 (95% confidence interval -0.031 to 0.018)).ConclusionDuring the first year following type 1 diabetes diagnosis, no clinical benefit of CSII over MDI was identified in children and young people in the UK setting, and treatment with either regimen was suboptimal in achieving HbA1c thresholds. CSII was not cost effective.Trial registrationCurrent Controlled Trials ISRCTN29255275; European Clinical Trials Database 2010-023792-25

Seven-step framework to enhance practitioner explanations and parental understandings of research without prior consent in paediatric emergency and critical care trials

Background: Alternatives to prospective informed consent enable the conduct of paediatric emergency and critical care trials. Research without prior consent (RWPC) involves practitioners approaching parents after an intervention has been given and seeking consent for their child to continue in the trial. As part of an embedded study in the 'Emergency treatment with Levetiracetam or Phenytoin in Status Epilepticus in children' (EcLiPSE) trial, we explored how practitioners described the trial and RWPC during recruitment discussions, and how well this information was understood by parents. We aimed to develop a framework to assist trial conversations in future paediatric emergency and critical care trials using RWPC. Methods: Qualitative methods embedded within the EcLiPSE trial processes, including audiorecorded practitioner-parent trial discussions and telephone interviews with parents. We analysed data using thematic analysis, drawing on the Realpe et al (2016) model for recruitment to trials. Results: We analysed 76 recorded trial discussions and conducted 30 parent telephone interviews. For 19 parents, we had recorded trial discussion and interview data, which were matched for analysis. Parental understanding of the EcLiPSE trial was enhanced when practitioners: provided a comprehensive description of trial aims; explained the reasons for RWPC; discussed uncertainty about which intervention was best; provided a balanced description of trial intervention; provided a clear explanation about randomisation and provided an opportunity for questions. We present a seven-step framework to assist recruitment practice in trials involving RWPC. Conclusion: This study provides a framework to enhance recruitment practice and parental understanding in paediatric emergency and critical care trials involving RWPC. Further testing of this framework is required

Ultrafiltration versus diuretics on prognostic cardiac and renal biomarkers in acute decompensated heart failure : a systematic review and meta-analysis

Peer reviewedPublisher PD

Antibiotic or silver versus standard ventriculoperitoneal shunts (BASICS): a multi-centre, single-blinded, randomised trial and economic evaluation

Background Insertion of a ventriculoperitoneal shunt for hydrocephalus is one of the commonest neurosurgical procedures worldwide. Infection of the implanted shunt affects up to 15% of these patients, resulting in prolonged hospital treatment, multiple surgeries, and reduced cognition and quality of life. Our aim was to determine the clinical and cost-effectiveness of antibiotic (rifampicin and clindamycin) or silver shunts compared with standard shunts at reducing infection. Methods In this parallel, multicentre, single-blind, randomised controlled trial, we included patients with hydrocephalus of any aetiology undergoing insertion of their first ventriculoperitoneal shunt irrespective of age at 21 regional adult and paediatric neurosurgery centres in the UK and Ireland. Patients were randomly assigned (1:1:1 in random permuted blocks of three or six) to receive standard shunts (standard shunt group), antibiotic-impregnated (0·15% clindamycin and 0·054% rifampicin; antibiotic shunt group), or silver-impregnated shunts (silver shunt group) through a randomisation sequence generated by an independent statistician. All patients and investigators who recorded and analysed the data were masked for group assignment, which was only disclosed to the neurosurgical staff at the time of operation. Participants receiving a shunt without evidence of infection at the time of insertion were followed up for at least 6 months and a maximum of 2 years. The primary outcome was time to shunt failure due the infection and was analysed with Fine and Gray survival regression models for competing risk by intention to treat. This trial is registered with ISRCTN 49474281. Findings Between June 26, 2013, and Oct 9, 2017, we assessed 3505 patients, of whom 1605 aged up to 91 years were randomly assigned to receive either a standard shunt (n=536), an antibiotic-impregnated shunt (n=538), or a silver shunt (n=531). 1594 had a shunt inserted without evidence of infection at the time of insertion (533 in the standard shunt group, 535 in the antibiotic shunt group, and 526 in the silver shunt group) and were followed up for a median of 22 months (IQR 10–24; 53 withdrew from follow-up). 32 (6%) of 533 evaluable patients in the standard shunt group had a shunt revision for infection, compared with 12 (2%) of 535 evaluable patients in the antibiotic shunt group (cause-specific hazard ratio [csHR] 0·38, 97·5% CI 0·18–0·80, p=0·0038) and 31 (6%) of 526 patients in the silver shunt group (0·99, 0·56–1·74, p=0·96). 135 (25%) patients in the standard shunt group, 127 (23%) in the antibiotic shunt group, and 134 (36%) in the silver shunt group had adverse events, which were not life-threatening and were mostly related to valve or catheter function. Interpretation The BASICS trial provides evidence to support the adoption of antibiotic shunts in UK patients who are having their first ventriculoperitoneal shunt insertion. This practice will benefit patients of all ages by reducing the risk and harm of shunt infection. Funding UK National Institute for Health Research Health Technology Assessment programme