238 research outputs found

    Embedded macrophages induce intravascular coagulation in 3D blood vessel-on-chip

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    Macrophages are innate immune cells that prevent infections and help in wound healing and vascular inflammation. While these cells are natural helper cells, they also contribute to chronic diseases, e.g., by infiltrating the endothelial layer in early atherosclerosis and by promoting vascular inflammation. There is a crosstalk between inflammatory pathways and key players in thrombosis, such as platelets and endothelial cells – a phenomenon known as ‘thromboinflammation’. The role of the embedded macrophages in thromboinflammation in the context of vascular disease is incompletely understood. Blood vessels-on-chips, which are microfluidic vascular cell culture models, have been used extensively to study aspects of vascular disease, like permeability, immune cell adhesion and thrombosis. Blood perfusion assays in blood vessel-on-chip models benefit from multiple unique aspects of the models, such as control of microvessel structure and well-defined flow patterns, as well as the ability to perform live imaging. However, due to their simplified nature, blood vessels-on-chip models have not yet been used to capture the complex cellular crosstalk that is important in thromboinflammation. Using induced pluripotent stem cell-derived endothelial cells and polarized THP-1 monocytes, we have developed and systematically set up a 3D blood vessel-on-chip with embedded (lipid-laden) macrophages, which is created using sequential cell seeding in viscous finger patterned collagen hydrogels. We have set up a human whole blood perfusion assay for these 3D blood vessels-on-chip. An increased deposition of fibrin in the blood vessel-on-chip models containing lipid-laden macrophages was observed. We anticipate the future use of this advanced vascular in vitro model in drug development for early atherosclerosis or aspects of other vascular diseases

    A multi-site single blind clinical study to compare the effects of prolonged exposure, eye movement desensitization and reprocessing and waiting list on patients with a current diagnosis of psychosis and co morbid post traumatic stress disorder: study protocol for the randomized controlled trial Treating Trauma in Psychosis

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    Contains fulltext : 116518.pdf (publisher's version ) (Open Access)Background: Trauma contributes to psychosis and in psychotic disorders post-traumatic stress disorder (PTSD) is often a comorbid disorder. A problem is that PTSD is underdiagnosed and undertreated in people with psychotic disorders. This study's primary goal is to examine the efficacy and safety of prolonged exposure and eye movement desensitization and reprocessing (EMDR) for PTSD in patients with both psychotic disorders and PTSD, as compared to a waiting list. Secondly, the effects of both treatments are determined on (a) symptoms of psychosis, in particular verbal hallucinations, (b) depression and social performance, and (c) economic costs. Thirdly, goals concern links between trauma exposure and psychotic symptomatology and the prevalence of exposure to traumatic events, and of PTSD. Fourthly predictors, moderators, and mediators for treatment success will be explored. These include cognitions and experiences concerning treatment harm, credibility and burden in both participants and therapists. Methods/Design: A short PTSD-screener assesses the possible presence of PTSD in adult patients (21- to 65-years old) with psychotic disorders, while the Clinician Administered PTSD Scale interview will be used for the diagnosis of current PTSD. The M.I.N.I. Plus interview will be used for diagnosing lifetime psychotic disorders and mood disorders with psychotic features. The purpose is to include consenting participants (N = 240) in a multi-site single blind randomized clinical trial. Patients will be allocated to one of three treatment conditions (N = 80 each): prolonged exposure or EMDR (both consisting of eight weekly sessions of 90 minutes each) or a six-month waiting list. All participants are subjected to blind assessments at pre-treatment, twomonths post treatment, and six monthspost treatment. In addition, participants in the experimental conditions will have assessments at mid treatment and at 12 months follow-up. Discussion: The results from the post treatment measurement can be considered strong empirical indicators of the safety and effectiveness of prolonged exposure and EMDR. The six-month and twelve-month follow-up data have the potential of reliably providing documentation of the long-term effects of both treatments on the various outcome variables. Data from pre-treatment and midtreatment can be used to reveal possible pathways of change.19 p

    Multiplexed fluidic circuit board for controlled perfusion of 3D blood vessels-on-a-chip

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    Three-dimensional (3D) blood vessels-on-a-chip (VoC) models integrate the biological complexity of vessel walls with dynamic microenvironmental cues, such as wall shear stress (WSS) and circumferential strain (CS). However, these parameters are difficult to control and are often poorly reproducible due to the high intrinsic diameter variation of individual 3D-VoCs. As a result, the throughput of current 3D systems is one-channel-at-a-time. Here, we developed a fluidic circuit board (FCB) for simultaneous perfusion of up to twelve 3D-VoCs using a single set of control parameters. By designing the internal hydraulic resistances in the FCB appropriately, it was possible to provide a pre-set WSS to all connected 3D-VoCs, despite significant variation in lumen diameters. Using this FCB, we found that variation of CS or WSS induce morphological changes to human induced pluripotent stem cell (hiPSC)-derived endothelial cells (ECs) and conclude that control of these parameters using a FCB is necessary to study 3D-VOCs.Stem cells & developmental biolog

    An old friend who has overstayed their welcome : the ALSFRS-R total score as primary endpoint for ALS clinical trials

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    Objective: The ALSFRS-R is limited by multidimensionality, which originates from the summation of various subscales. This prevents a direct comparison between patients with identical total scores. We aim to evaluate how multidimensionality affects the performance of the ALSFRS-R in clinical trials. Methods: We simulated clinical trial data with different treatment effects for the ALSFRS-R total score and its subscales (i.e. bulbar, fine motor, gross motor and respiratory). We considered scenarios where treatment reduced the rate of ALSFRS-R subscale decline either uniformly (i.e. all subscales respond identically to treatment) or non-uniformly (i.e. subscales respond differently to treatment). Two main analytical strategies were compared: (1) analyzing only the total score or (2) utilizing a subscale-based test (i.e. alternative strategy). For each analytical strategy, we calculated the empirical power and required sample size. Results: Both strategies are valid when there is no treatment benefit and provide adequate control of type 1 error. If all subscales respond identically to treatment, using the total score is the most powerful approach. As the differences in treatment responses between subscales increase, the more the total score becomes affected. For example, to detect a 40% reduction in the bulbar rate of decline with 80% power, the total score requires 1380 patients, whereas this is 336 when using the alternative strategy. Conclusions: Ignoring the multidimensional structure of the ALSFRS-R total score could have negative consequences for ALS clinical trials. We propose determining treatment benefit on a subscale level, prior to stating whether a treatment is generally effective

    Tapering Antidepressants While Receiving Digital Preventive Cognitive Therapy During Pregnancy: An Experience Sampling Methodology Trial

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    Background: Previous studies indicated that affect fluctuations, the use of antidepressant medication (ADM), as well as depression during pregnancy might have adverse effects on offspring outcomes. The aim of the current proof-of-principle study is to explore the effect of tapering ADM while receiving online preventive cognitive therapy (PCT) on pregnant women and the offspring as compared to pregnant women continuing ADM. Objectives: We sought to compare positive and negative affect fluctuations in pregnant women receiving online PCT while tapering ADM vs. pregnant women continuing ADM, and to investigate if affect fluctuations in early pregnancy were related to offspring birth weight. Method: An experience sampling methodology (ESM)-trial ran alongside a Dutch randomized controlled trial (RCT) and prospective observational cohort of women using ADM at the start of pregnancy. In the ESM-trial fluctuations of positive and negative affect were assessed in the first 8 weeks after inclusion. Recurrences of depression were assessed up to 12 weeks post-partum, and birth records were used to assess offspring birth weight. The RCT has been registered at the Netherlands Trial Register (NTR4694, https://www.trialregister.nl/trial/4551). Results: In total, 19 pregnant women using ADM at start of their pregnancy participated in the ESM-trial. There were no significant differences in positive and negative affect fluctuations, nor recurrence rates between women receiving PCT while tapering ADM vs. women continuing ADM. We found no association between affect fluctuations, pre-natal depressive symptoms, and birth weight (all p > 0.05). Conclusion: This explorative study showed that tapering ADM while receiving online PCT may protect pregnant women against recurrences of depression and affect fluctuations, without affecting birth weight. There is a high need for more controlled studies focusing on tapering ADM with (online) psychological interventions during pregnancy

    Innovating clinical trials for amyotrophic lateral sclerosis : challenging the established order

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    Development of effective treatments for amyotrophic lateral sclerosis (ALS) has been hampered by disease heterogeneity, a limited understanding of underlying pathophysiology, and methodologic design challenges. We have evaluated 2 major themes in the design of pivotal, phase 3 clinical trials for ALS—(1) patient selection and (2) analytical strategy—and discussed potential solutions with the European Medicines Agency. Several design considerations were assessed using data from 5 placebo-controlled clinical trials (n = 988), 4 population-based cohorts (n = 5,100), and 2,436 placebo-allocated patients from the Pooled Resource Open-Access ALS Clinical Trials (PRO-ACT) database. The validity of each proposed design modification was confirmed by means of simulation and illustrated for a hypothetical setting. Compared to classical trial design, the proposed design modifications reduce the sample size by 30.5% and placebo exposure time by 35.4%. By making use of prognostic survival models, one creates a potential to include a larger proportion of the population and maximize generalizability. We propose a flexible design framework that naturally adapts the trial duration when inaccurate assumptions are made at the design stage, such as enrollment or survival rate. In case of futility, the follow-up time is shortened and patient exposure to ineffective treatments or placebo is minimized. For diseases such as ALS, optimizing the use of resources, widening eligibility criteria, and minimizing exposure to futile treatments and placebo is critical to the development of effective treatments. Our proposed design modifications could circumvent important pitfalls and may serve as a blueprint for future clinical trials in this population

    Assessing the efficacy and safety of mycophenolate mofetil versus azathioprine in patients with autoimmune hepatitis (CAMARO trial): study protocol for a randomised controlled trial

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    Background: Currently, the standard therapy for autoimmune hepatitis (AIH) consists of a combination of prednisolone and azathioprine. However, 15% of patients are intolerant to azathioprine which necessitates cessation of azathioprine or changes in therapy. In addition, not all patients achieve complete biochemical response (CR). Uncontrolled data indicate that mycophenolate mofetil (MMF) can induce CR in a majority of patients. Better understanding of first-line treatment and robust evidence from randomised clinical trials are needed. The aim of this study was to explore the potential benefits of MMF as compared to azathioprine, both combined with prednisolone, as induction therapy in a randomised controlled trial in patients with treatment-naive AIH. Method:s: CAMARO is a randomised (1:1), open-label, parallel-group, multicentre superiority trial. All patients with AIH are screened for eligibility. Seventy adult patients with AIH from fourteen centres in the Netherlands and Belgium will be randomised to receive MMF or azathioprine. Both treatment arms will start with prednisolone as induction therapy. The primary outcome is biochemical remission, defined as serum levels of alanine aminotransferase and immunoglobulin G below the upper limit of normal. Secondary outcomes include safety and tolerability of MMF and azathioprine, time to remission, changes in Model For End-Stage Liver Disease (MELD)-score, adverse events, and aspects of quality of life. The study period will last for 24 weeks. Discussion: The CAMARO trial investigates whether treatment with MMF and prednisolone increases the proportion of patients in remission compared with azathioprine and prednisolone as the current standard treatment strategy. In addition, we reflect on the challenges of conducting a randomized trial in rare diseases.Cellular mechanisms in basic and clinical gastroenterology and hepatolog
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