65 research outputs found

    In vivo measurement of human brain material properties under quasi-static loading

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    Computational modelling of the brain requires accurate representation of the tissues concerned. Mechanical testing has numerous challenges, in particular for low strain rates, like neurosurgery, where redistribution of fluid is biomechanically important. A finite-element (FE) model was generated in FEBio, incorporating a spring element/fluid–structure interaction representation of the pia–arachnoid complex (PAC). The model was loaded to represent gravity in prone and supine positions. Material parameter identification and sensitivity analysis were performed using statistical software, comparing the FE results to human in vivo measurements. Results for the brain Ogden parameters µ, α and k yielded values of 670 Pa, −19 and 148 kPa, supporting values reported in the literature. Values of the order of 1.2 MPa and 7.7 kPa were obtained for stiffness of the pia mater and out-of-plane tensile stiffness of the PAC, respectively. Positional brain shift was found to be non-rigid and largely driven by redistribution of fluid within the tissue. To the best of our knowledge, this is the first study using in vivo human data and gravitational loading in order to estimate the material properties of intracranial tissues. This model could now be applied to reduce the impact of positional brain shift in stereotactic neurosurgery

    Is dignity therapy feasible to enhance the end of life experience for people with motor neurone disease and their family carers?

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    Background: Development of interventions that address psychosocial and existential distress in people with motor neurone disease (MND) or that alleviate caregiver burden in MND family carers have often been suggested in the research literature. Dignity therapy, which was developed to reduce psychosocial and existential distress at the end of life, has been shown to benefit people dying of cancer and their families. These results may not be transferable to people with MND. The objectives of this study are to assess the feasibility, acceptability and potential effectiveness of dignity therapy to enhance the end of life experience for people with motor neurone disease and their family carers. Methods/design: This is a cross-sectional study utilizing a single treatment group and a pre/post test design. The study population will comprise fifty people diagnosed with MND and their nominated family carers. Primarily quantitative outcomes will be gathered through measures assessed at baseline and at approximately one week after the intervention. Outcomes for participants include hopefulness, spirituality and dignity. Outcomes for family carers include perceived caregiver burden, hopefulness and anxiety/depression. Feedback and satisfaction with the intervention will be gathered through a questionnaire. Discussion: This detailed research will explore if dignity therapy has the potential to enhance the end of life experience for people with MND and their family carers, and fill a gap for professionals who are called on to address the spiritual, existential and psychosocial needs of their MND patients and families

    Antidepressants for the prevention of depression following first-episode psychosis (ADEPP): study protocol for a multi-centre, double-blind, randomised controlled trial

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    Background: Depressive episodes are common after first-episode psychosis (FEP), affecting more than 40% of people, adding to individual burden, poor outcomes, and healthcare costs. If the risks of developing depression were lower, this could have a beneficial effect on morbidity and mortality, as well as improving outcomes. Sertraline is a selective serotonin reuptake inhibitor and a common first-line medication for the treatment of depression in adults. It has been shown to be safe when co-prescribed with antipsychotic medication, and there is evidence that it is an effective treatment for depression in established schizophrenia. We present a protocol for a multi-centre, double-blind, randomised, placebo-controlled clinical trial called ADEPP that aims to investigate the efficacy and cost-effectiveness of sertraline in preventing depression after FEP. Methods: The recruitment target is 452 participants between the ages of 18 and 65 years who are within 12 months of treatment initiation for FEP. Having provided informed consent, participants will be randomised to receive either 50 mg of sertraline daily or matched placebo for 6 months, in addition to treatment as usual. The primary outcome measure will be a comparison of the number of new cases of depression between the treatment and placebo arms over the 6-month intervention phase. Secondary outcomes include suicidal behaviour, anxiety, rates of relapse, functional outcome, quality of life, and resource use. Discussion: The ADEPP trial will test whether the addition of sertraline following FEP is a clinically useful, acceptable, and cost-effective way of improving outcomes following FEP. Trial registration: ISRCTN12682719 registration date 24/11/2020

    Randomized trial of intermittent intraputamenal glial cell line-derived neurotrophic factor in Parkinson's disease

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    We investigated the effects of glial cell line-derived neurotrophic factor (GDNF) in Parkinson’s disease, using intermittent intraputamenal convection-enhanced delivery via a skull-mounted transcutaneous port as a novel administration paradigm to potentially afford putamen-wide therapeutic delivery. This was a single-centre, randomized, double-blind, placebo-controlled trial. Patients were 35–75 years old, had motor symptoms for 5 or more years, and presented with moderate disease severity in the OFF state [Hoehn and Yahr stage 2–3 and Unified Parkinson’s Disease Rating Scale motor score (part III) (UPDRS-III) between 25 and 45] and motor fluctuations. Drug delivery devices were implanted and putamenal volume coverage was required to exceed a predefined threshold at a test infusion prior to randomization. Six pilot stage patients (randomization 2:1) and 35 primary stage patients (randomization 1:1) received bilateral intraputamenal infusions of GDNF (120 mg per putamen) or placebo every 4 weeks for 40 weeks. Efficacy analyses were based on the intention-to-treat principle and included all patients randomized. The primary outcome was the percentage change from baseline to Week 40 in the OFF state (UPDRS-III). The primary analysis was limited to primary stage patients, while further analyses included all patients from both study stages. The mean OFF state UPDRS motor score decreased by 17.3 17.6% in the active group and 11.8 15.8% in the placebo group (least squares mean difference: 4.9%, 95% CI: 16.9, 7.1, P = 0.41). Secondary endpoints did not show significant differences between the groups either. A post hoc analysis found nine (43%) patients in the active group but no placebo patients with a large clinically important motor improvement (510 points) in the OFF state (P = 0.0008). 18F-DOPA PET imaging demonstrated a significantly increased uptake throughout the putamen only in the active group, ranging from 25% (left anterior putamen; P = 0.0009) to 100% (both posterior putamina; P50.0001). GDNF appeared to be well tolerated and safe, and no drug-related serious adverse events were reported. The study did not meet its primary endpoint. 18F-DOPA imaging, however, suggested that intermittent convection-enhanced delivery of GDNF produced a putamen-wide tissue engagement effect, overcoming prior delivery limitations. Potential reasons for not proving clinical benefit at 40 weeks are discussed

    Intraputamenal cerebral dopamine neurotrophic factor in Parkinson's disease: a randomized, double‐blind, multicenter phase 1 trial

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    Background: Cerebral dopamine neurotrophic factor (CDNF) is an unconventional neurotrophic factor that protects dopamine neurons and improves motor function in animal models of Parkinson's disease (PD). Objective: The primary objectives of this study were to assess the safety and tolerability of both CDNF and the drug delivery system (DDS) in patients with PD of moderate severity. Methods: We assessed the safety and tolerability of monthly intraputamenal CDNF infusions in patients with PD using an investigational DDS, a bone‐anchored transcutaneous port connected to four catheters. This phase 1 trial was divided into a placebo‐controlled, double‐blind, 6‐month main study followed by an active‐treatment 6‐month extension. Eligible patients, aged 35 to 75 years, had moderate idiopathic PD for 5 to 15 years and Hoehn and Yahr score ≤ 3 (off state). Seventeen patients were randomized to placebo (n = 6), 0.4 mg CDNF (n = 6), or 1.2 mg CDNF (n = 5). The primary endpoints were safety and tolerability of CDNF and DDS and catheter implantation accuracy. Secondary endpoints were measures of PD symptoms, including Unified Parkinson's Disease Rating Scale, and DDS patency and port stability. Exploratory endpoints included motor symptom assessment (PKG, Global Kinetics Pty Ltd, Melbourne, Australia) and positron emission tomography using dopamine transporter radioligand [18F]FE‐PE2I. Results: Drug‐related adverse events were mild to moderate with no difference between placebo and treatment groups. No severe adverse events were associated with the drug, and device delivery accuracy met specification. The severe adverse events recorded were associated with the infusion procedure and did not reoccur after procedural modification. There were no significant changes between placebo and CDNF treatment groups in secondary endpoints between baseline and the end of the main and extension studies. Conclusions: Intraputamenally administered CDNF was safe and well tolerated, and possible signs of biological response to the drug were observed in individual patients. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society

    Extended Treatment with Glial Cell Line-Derived Neurotrophic Factor in Parkinson's Disease

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    Background: Intraputamenal glial cell line-derived neurotrophic factor (GDNF), administered every 4 weeks to patients with moderately advanced Parkinson’s disease, did not show significant clinical improvements against placebo at 40 weeks, although it significantly increased [18F]DOPA uptake throughout the entire putamen. Objective: This open-label extension study explored the effects of continued (prior GDNF patients) or new (prior placebo patients) exposure to GDNF for another 40 weeks. Methods: Using the infusion protocol of the parent study, all patients received GDNF without disclosing prior treatment allocations (GDNF or placebo). The primary outcome was the percentage change from baseline to Week 80 in the OFF state Unified Parkinson’s Disease Rating Scale (UPDRS) motor score. Results: All 41 parent study participants were enrolled. The primary outcome decreased by 26.7±20.7% in patients on GDNF for 80 weeks (GDNF/GDNF; N = 21) and 27.6±23.6% in patients on placebo for 40 weeks followed by GDNF for 40 weeks (placebo/GDNF, N = 20; least squares mean difference: 0.4%, 95% CI: –13.9, 14.6, p = 0.96). Secondary endpoints did not show significant differences between the groups at Week 80 either. Prespecified comparisons between GDNF/GDNF at Week 80 and placebo/GDNF at Week 40 showed significant differences for mean OFF state UPDRS motor (–9.6±6.7 vs. –3.8±4.2 points, p = 0.0108) and activities of daily living score (–6.9±5.5 vs. –1.0±3.7 points, p = 0.0003). No treatment-emergent safety concerns were identified. Conclusions: The aggregate study results, from the parent and open-label extension suggest that future testing with GDNF will likely require an 80- rather than a 40-week randomized treatment period and/or a higher dose

    Mineralocorticoid and glucocorticoid receptors in the brain. Implications for ion permeability and transmitter systems

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    Customer optimised design analysis : a metric based methodology for conceptual design analysis, selection and optimisation within new product development

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    The systematic creation of product designs that meet specification and are fit-forpurpose has resulted from intensive research investigation undertaken by Western European engineering design theorists, who define design science as four fundamental elements: Technical systems versus design processes and descriptive versus prescriptive statements. It is argued, through a comparison of the parallel emergent design process methodologies of Western European and Eastern Japanese industry, that a fifth element has evolved which should be included within the boundaries of design science - Quality. . The measure of how well new or variant product designs meet customer requirements is critical to the success of a product in a marketplace for which it is intended to compete. As the level of meeting or exceeding customer requirements defines the perceived quality of a design to the customer, it is paramount that design-quality is optimised to ensure maximum customer satisfaction. Quality Function Deployment (QFD) is a dominant, established methodology which translates customer requirements into engineering characteristics. Although the approach is attributed to many well known successes, it also possesses some widely known limitations (subjective in nature; difficult to systematically compare concept design variants; difficult to consider complex design inter-relationships and design' conflicts; complexity of analysis increases proportionally with the size of the matrix; interpretation of matrix information requires high level of experience). Furthermore, although the richness of design information held within a QFD matrix provides a detailed record of design status, this information is' essentially static. To address these limitations, a design hypothesis is presented in which a metric-based theory of coupleddynamic- mapping of information held within the QFD design matrix provides a more sophisticated method of quality-by-design analysis. The hypothesis is tested through the creation of a novel hybrid design methodology- termed CODA (Customer Optimised Design Analysis). CODA methodology simultaneously provides an objective function of overall design merit that denotes optimal design attribute values that represents best design trade-off and optimal customer satisfaction (design quality). Finally, it is' deliberated how CODA is not meant to displace QFD, but to provide the design fraternity with a more sophisticated tool to resolve design conflict and aid decisionmaking within the conceptual design phase.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

    Through Him All Things Were Made

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    The medieval theological worldview was a synthesis of grace and nature that allowed theology and science to act together in a sacred and salvific pursuit of knowledge. This synthesis is beautifully expressed in the Divine Ideas tradition. In this tradition, the tapestry upon which ancient and medieval theology was written, created things existed by reflecting God’s eternal ideas of them. This gave all natural knowledge a Trinitarian dimension because the generation of ideas in the Divine Mind and of created things in the world was isomorphic with the generation of the Son, the uncreated Logos. In my paper, I will argue that just as all things exist as a primordial sacrifice of the Creator offered and known outside Godself through the Son-Logos, so we participate in that primordial gift (in beatitude) when we, recognizing the divine profundity of nature, come to a knowing of God-in-things—to use Meister Eckhart’s phrase. In this tradition, humans, made in God’s image, are ordained to participate in God’s knowing of all things, and to offer creation back up into Divine life by knowing and worshiping God through theology, science, and liturgy. The Divine Ideas model, then, would restore to the sciences a contemplative, salvific power in recognizing the mystical depth of creatures. I will examine theologians like Maximus the Confessor, the Victorines, and modern theologian Mark McIntosh as they see both scientific and theological knowing as a deifying participation in Divine life. I will look at the poetry of St. John the Divine and Thomas Traherne as it lifts the human imagination, illumined by nature and consecrated through liturgy into the life of the world to come. I will close by saying that this tradition becomes especially important in a world confronting the climate crisis. By recognizing the Divine dimensions of creatures, we see how the waste and pollution of the integrity and beauty of the wilderness blemishes the sacrifice of knowing and love that humanity is called to offer to God through theology, the sciences, and the eucharist
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