19 research outputs found

    Rme-8 depletion perturbs Notch recycling and predisposes to pathogenic signaling.

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    Notch signaling is a major regulator of cell fate, proliferation, and differentiation. Like other signaling pathways, its activity is strongly influenced by intracellular trafficking. Besides contributing to signal activation and down-regulation, differential fluxes between trafficking routes can cause aberrant Notch pathway activation. Investigating the function of the retromer-associated DNAJ protein Rme-8 in vivo, we demonstrate a critical role in regulating Notch receptor recycling. In the absence of Rme-8, Notch accumulated in enlarged tubulated Rab4-positive endosomes, and as a consequence, signaling was compromised. Strikingly, when the retromer component Vps26 was depleted at the same time, Notch no longer accumulated and instead was ectopically activated. Likewise, depletion of ESCRT-0 components Hrs or Stam in combination with Rme-8 also led to high levels of ectopic Notch activity. Together, these results highlight the importance of Rme-8 in coordinating normal endocytic recycling route and reveal that its absence predisposes toward conditions in which pathological Notch signaling can occur.This work was funded by an MRC programme grant [G0800034] to SJB. LAS was the recipient of a BBSRC PhD studentship. ES and TK were funded by the DFG [Sachbeihilfe KL 1028/5-­1].This is the author accepted manuscript. The final version is available from Rockefeller University Press via http://dx.doi.org/10.1083/jcb.20141100

    Costs and staffing resource requirements for adaptive clinical trials: quantitative and qualitative results from the Costing Adaptive Trials project.

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    BACKGROUND: Adaptive designs offer great promise in improving the efficiency and patient-benefit of clinical trials. An important barrier to further increased use is a lack of understanding about which additional resources are required to conduct a high-quality adaptive clinical trial, compared to a traditional fixed design. The Costing Adaptive Trials (CAT) project investigated which additional resources may be required to support adaptive trials. METHODS: We conducted a mock costing exercise amongst seven Clinical Trials Units (CTUs) in the UK. Five scenarios were developed, derived from funded clinical trials, where a non-adaptive version and an adaptive version were described. Each scenario represented a different type of adaptive design. CTU staff were asked to provide the costs and staff time they estimated would be needed to support the trial, categorised into specified areas (e.g. statistics, data management, trial management). This was calculated separately for the non-adaptive and adaptive version of the trial, allowing paired comparisons. Interviews with 10 CTU staff who had completed the costing exercise were conducted by qualitative researchers to explore reasons for similarities and differences. RESULTS: Estimated resources associated with conducting an adaptive trial were always (moderately) higher than for the non-adaptive equivalent. The median increase was between 2 and 4% for all scenarios, except for sample size re-estimation which was 26.5% (as the adaptive design could lead to a lengthened study period). The highest increase was for statistical staff, with lower increases for data management and trial management staff. The percentage increase in resources varied across different CTUs. The interviews identified possible explanations for differences, including (1) experience in adaptive trials, (2) the complexity of the non-adaptive and adaptive design, and (3) the extent of non-trial specific core infrastructure funding the CTU had. CONCLUSIONS: This work sheds light on additional resources required to adequately support a high-quality adaptive trial. The percentage increase in costs for supporting an adaptive trial was generally modest and should not be a barrier to adaptive designs being cost-effective to use in practice. Informed by the results of this research, guidance for investigators and funders will be developed on appropriately resourcing adaptive trials

    PP2A ligand ITH12246 protects against memory impairment and focal cerebral ischemia in mice

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    ITH12246 (ethyl 5-amino-2-methyl-6,7,8,9-tetrahydrobenzo[b][1,8] naphthyridine-3-carboxylate) is a 1,8-naphthyridine described to feature an interesting neuroprotective profile in in vitro models of Alzheimer's disease. These effects were proposed to be due in part to a regulatory action on protein phosphatase 2A inhibition, as it prevented binding of its inhibitor okadaic acid. We decided to investigate the pharmacological properties of ITH12246, evaluating its ability to counteract the memory impairment evoked by scopolamine, a muscarinic antagonist described to promote memory loss, as well as to reduce the infarct volume in mice suffering phototrombosis. Prior to conducting these experiments, we confirmed its in vitro neuroprotective activity against both oxidative stress and Ca2+ overload-derived excitotoxicity, using SH-SY5Y neuroblastoma cells and rat hippocampal slices. Using a predictive model of blood-brain barrier crossing, it seems that the passage of ITH12246 is not hindered. Its potential hepatotoxicity was observed only at very high concentrations, from 0.1 mM. ITH12246, at the concentration of 10 mg/kg i.p., was able to improve the memory index of mice treated with scopolamine, from 0.22 to 0.35, in a similar fashion to the well-known Alzheimer's disease drug galantamine 2.5 mg/kg. On the other hand, ITH12246, at the concentration of 2.5 mg/kg, reduced the phototrombosis-triggered infarct volume by 67%. In the same experimental conditions, 15 mg/kg melatonin, used as control standard, reduced the infarct volume by 30%. All of these findings allow us to consider ITH12246 as a new potential drug for the treatment of neurodegenerative diseases, which would act as a multifactorial neuroprotectant.Peer Reviewe

    Known and unknown requirements in healthcare

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    We report experience in requirements elicitation of domain knowledge from experts in clinical and cognitive neurosciences. The elicitation target was a causal model for early signs of dementia indicated by changes in user behaviour and errors apparent in logs of computer activity. A Delphi-style process consisting of workshops with experts followed by a questionnaire was adopted. The paper describes how the elicitation process had to be adapted to deal with problems encountered in terminology and limited consensus among the experts. In spite of the difficulties encountered, a partial causal model of user behavioural pathologies and errors was elicited. This informed requirements for configuring data- and text-mining tools to search for the specific data patterns. Lessons learned for elicitation from experts are presented, and the implications for requirements are discussed as “unknown unknowns”, as well as configuration requirements for directing data-/text-mining tools towards refining awareness requirements in healthcare applications

    Staying Active with Multimorbidity In Acute hospital settings (StAMInA) trial: protocol for a feasibility randomised controlled trial of allied health assistant mobility rehabilitation for patients with multimorbidity

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    Introduction Key to improving outcomes for patients with multimorbidity is increasing mobility through prescription of a physical activity programme, but this can be difficult to achieve in acute hospital settings. One approach that would assist physiotherapists to increase levels of physical activity is delegation of rehabilitation to allied health assistants. We aim to conduct a randomised controlled trial to determine the feasibility of an allied health assistant providing daily inpatient mobility rehabilitation for patients with multimorbidity.Methods and analysis Using a parallel group randomised controlled design, participants will be allocated to allied health assistant mobility rehabilitation or physiotherapist mobility rehabilitation. Adult inpatients (n=60) in an acute hospital with a diagnosis of multimorbidity who walked independently preadmission will be included. The experimental group will receive routine mobility rehabilitation, including daily mobilisation, from an allied health assistant under the supervision of a physiotherapist. The comparison group will receive routine rehabilitation from a physiotherapist. Feasibility will be determined using the following areas of focus in Bowen’s feasibility framework: Acceptability (patient satisfaction); demand (proportion of patients who participate); implementation (time allied health assistant/physiotherapist spends with participant, occasions of service); and practicality (cost, adverse events). Staff involved in the implementation of allied health assistant rehabilitation will be interviewed to explore their perspectives on feasibility. Secondary outcomes include: Physical activity (daily time spent walking); daily mobilisation (Y/N); discharge destination; hospital readmission; falls; functional activity (Modified Iowa Level of Assistance Scale); and length of stay. Descriptive statistics will be used to describe feasibility. Secondary outcomes will be compared between groups using Poisson or negative binomial regression, Cox proportional hazards regression, survival analysis, linear regression or logistic regression.Ethics and dissemination Ethics approval was obtained from Peninsula Health (HREC/97 431/PH-2023). Findings will be disseminated in peer-reviewed journals and conference presentations.Trial registration number Australian and New Zealand Clinical Trial Registry ACTRN12623000584639p

    Development of an implementation strategy for routine collection of generic patient reported outcome measures: a qualitative study in multidisciplinary community rehabilitation

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    To explore staff perceptions of barriers and enablers towards implementing the EQ-5D-5L in community rehabilitation, and develop a theory-informed implementation approach for routine administration of generic patient-reported outcome measures (PROMs) using implementation science frameworks. A qualitative study was conducted at three sites. Multidisciplinary rehabilitation staff completed individual semi-structured interviews, which were transcribed and coded against the Theoretical Domains Framework (TDF). We identified and selected potentially effective behaviour change techniques using the Behavior Change Wheel. Hypothetical strategies were operationalised. Twenty-one interviews were conducted, and four themes emerged: (1) The Impact of PROMs on patient centered-care; (2) Considerations for validity of PROMs; (3) Service-level impact of embedding PROMs; (4) Practical issues of embedding PROMs within the service. Barriers and enablers were mapped to seven of the TDF domains; relating most to clinicians’ “belief about consequences”, “reinforcement”, and “environmental context and resources”. Five hypothetical strategies were developed to overcome identified barriers and strengthen enablers. Key behaviour change techniques underpinning the strategies include: restructuring the physical environment, incentivisation, persuasion and education, enablement, and, social support. Our implementation approach highlights the importance of automating processes, engaging site champions, routinely reporting, and using PROM data to inform service provision. Implementation of patient reported outcome measures within multidiscipline rehabilitation settings are likely optimised by establishing infrastructure support e.g., information technology systems to automate the process and minimise manual aspects of data collection. Engaging site champions may be an important enabler for the routine collection of patient reported outcome measures Providing feedback to clinicians on aggregated results of patient reported outcome measures are likely to motivate and encourage routine collection.</p

    Practical guidance for planning resources required to support publicly-funded adaptive clinical trials.

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    Adaptive designs are a class of methods for improving efficiency and patient benefit of clinical trials. Although their use has increased in recent years, research suggests they are not used in many situations where they have potential to bring benefit. One barrier to their more widespread use is a lack of understanding about how the choice to use an adaptive design, rather than a traditional design, affects resources (staff and non-staff) required to set-up, conduct and report a trial. The Costing Adaptive Trials project investigated this issue using quantitative and qualitative research amongst UK Clinical Trials Units. Here, we present guidance that is informed by our research, on considering the appropriate resourcing of adaptive trials. We outline a five-step process to estimate the resources required and provide an accompanying costing tool. The process involves understanding the tasks required to undertake a trial, and how the adaptive design affects them. We identify barriers in the publicly funded landscape and provide recommendations to trial funders that would address them. Although our guidance and recommendations are most relevant to UK non-commercial trials, many aspects are relevant more widely
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