234 research outputs found

    Measuring the Integration of Social and Environmental Missions in Hybrid Organizations

    Get PDF
    The authors gratefully acknowledge the excellent suggestions of the Section Editor, Julia Roloff and the three anonymous reviewers. We also thank the many Certified B Corporations for their participation in this study. The first author acknowledges research support from the Initiative for Regulation and Applied Economic Analysis (IRAEA) at Montana State University.Peer reviewedPostprin

    Manipulating prohibitin levels provides evidence for an in vivo role in androgen regulation of prostate tumours

    Get PDF
    Current hormonal therapies for prostate cancer are effective initially, but inevitably tumours progress to an advanced, metastatic stage, often referred to as ‘androgen independent’. However, the androgen receptor (AR) signalling pathway is still key for their growth. It is speculated that tumours escape hormonal control via reduction in corepressor proteins. Manipulating such proteins is thus a potential therapeutic strategy to halt or even reverse tumour progression. We aimed to elucidate the effects of altering levels of the AR corepressor and androgen-target protein prohibitin (PHB) on prostate tumour growth. Prostate cancer cells incorporating an integrated androgen-responsive reporter gene and stably expressing vectors to inducibly overexpress or knockdown PHB were generated and used to assess effects on androgen signalling (by real time imaging) and tumour growth both in culture and in vivo. PHB overexpression inhibited AR activity and prostate-specific antigen (PSA) expression as well as androgen-dependent growth of cells, inducing rapid accumulation in G0/G1. Conversely, reduction in PHB increased AR activity, PSA expression, androgen-mediated growth and S-phase entry. In vivo, doxycycline-induced PHB regulation resulted in marked changes in AR activity, and showed significant effects upon tumour growth. Overexpression led to tumour growth arrest and protection from hormonal starvation, whereas RNAi knockdown resulted in accelerated tumour growth, even in castrated mice. This study provides proof of principle that i) reduction in PHB promotes both androgen-dependent and ‘androgen-independent’ tumour growth, and ii) altering AR activity via increasing levels or activity of corepressors is a valid therapeutic strategy for advanced prostate cancer

    Risk-proportionate clinical trial monitoring: an example approach from a non-commercial trials unit

    Get PDF
    Background Some level of monitoring is usually required during a clinical trial to protect the rights and safety of trial participants and to safeguard the quality and reliability of trial results. Although there is increasing support for the use of risk-proportionate approaches to achieve these aims, the variety of methods and lack of an empirical evidence base can present challenges for clinical trial practitioners. Methods This paper describes the monitoring methods and procedures that are utilised by a noncommercial clinical trials unit which coordinates a range of clinical trials across a variety of clinical areas with different associated risks. Results Monitoring activities and approaches should be selected to be proportionate to the risks identified within a trial. A risk-proportionate approach to monitoring is described giving details of methods that may be considered by clinical trial practitioners during the development of a trial monitoring plan. An example risk assessment and corresponding monitoring plan for a low risk (type A in the Medicines and Healthcare Products Regulatory Agency (MHRA) classification system) pediatric trial is provided for illustration. Conclusion We present ideas for developing a monitoring plan for a clinical trial of an investigational medicinal product based on our experience. Alternative approaches may be relevant or preferable in other settings based on inherent risk

    Priorities for methodological research on patient and public involvement in clinical trials A modified Delphi process

    Get PDF
    Background Despite increasing international interest, there is a lack of evidence about the most efficient, effective and acceptable ways to implement patient and public involvement (PPI) in clinical trials. Objective To identify the priorities of UK PPI stakeholders for methodological research to help resolve uncertainties about PPI in clinical trials. Design A modified Delphi process including a two round online survey and a stakeholder consensus meeting. Participants In total, 237 people registered of whom 219 (92%) completed the first round. One hundred and eighty-seven of 219 (85%) completed the second; 25 stakeholders attended the consensus meeting. Results Round 1 of the survey comprised 36 topics; 42 topics were considered in round 2 and at the consensus meeting. Approximately 96% of meeting participants rated the top three topics as equally important. These were as follows: developing strong and productive working relationships between researchers and PPI contributors; exploring PPI practices in selecting trial outcomes of importance to patients; and a systematic review of PPI activity to improve the accessibility and usefulness of trial information (eg participant information sheets) for participants. Conclusions The prioritized methodological research topics indicate important areas of uncertainty about PPI in trials. Addressing these uncertainties will be critical to enhancing PPI. Our findings should be used in the planning and funding of PPI in clinical trials to help focus research efforts and minimize waste

    Antiandrogens Act as Selective Androgen Receptor Modulators at the Proteome Level in Prostate Cancer Cells*

    Get PDF
    Current therapies for prostate cancer include antiandrogens, inhibitory ligands of the androgen receptor, which repress androgen-stimulated growth. These include the selective androgen receptor modulators cyproterone acetate and hydroxyflutamide and the complete antagonist bicalutamide. Their activity is partly dictated by the presence of androgen receptor mutations, which are commonly detected in patients who relapse while receiving antiandrogens, i.e. in castrate-resistant prostate cancer. To characterize the early proteomic response to these antiandrogens we used the LNCaP prostate cancer cell line, which harbors the androgen receptor mutation most commonly detected in castrate-resistant tumors (T877A), analyzing alterations in the proteome, and comparing these to the effect of these therapeutics upon androgen receptor activity and cell proliferation. The majority are regulated post-transcriptionally, possibly via nongenomic androgen receptor signaling. Differences detected between the exposure groups demonstrate subtle changes in the biological response to each specific ligand, suggesting a spectrum of agonistic and antagonistic effects dependent on the ligand used. Analysis of the crystal structures of the AR in the presence of cyproterone acetate, hydroxyflutamide, and DHT identified important differences in the orientation of key residues located in the AF-2 and BF-3 protein interaction surfaces. This further implies that although there is commonality in the growth responses between androgens and those antiandrogens that stimulate growth in the presence of a mutation, there may also be influential differences in the growth pathways stimulated by the different ligands. This therefore has implications for prostate cancer treatment because tumors may respond differently dependent upon which mutation is present and which ligand is activating growth, also for the design of selective androgen receptor modulators, which aim to elicit differential proteomic responses dependent upon cellular context

    What lies beneath? Reconstructing the primitive magmas fueling voluminous silicic volcanism using olivine-hosted melt inclusions

    Get PDF
    Understanding the origins of the mantle melts that drive voluminous silicic volcanism is challenging because primitive magmas are generally trapped at depth. The central Taupō Volcanic Zone (TVZ; New Zealand) hosts an extraordinarily productive region of rhyolitic caldera volcanism. Accompanying and interspersed with the rhyolitic products, there are traces of basalt to andesite preserved as enclaves or pyroclasts in caldera eruption products and occurring as small monogenetic eruptive centers between calderas. These mafic materials contain MgO-rich olivines (Fo79–86) that host melt inclusions capturing the most primitive basaltic melts fueling the central TVZ. Olivine-hosted melt inclusion compositions associated with the caldera volcanoes (intracaldera samples) contrast with those from the nearby, mafic intercaldera monogenetic centers. Intracaldera melt inclusions from the modern caldera volcanoes of Taupō and Okataina have lower abundances of incompatible elements, reflecting distinct mantle melts. There is a direct link showing that caldera-related silicic volcanism is fueled by basaltic magmas that have resulted from higher degrees of partial melting of a more depleted mantle source, along with distinct subduction signatures. The locations and vigor of Taupō and Okataina are fundamentally related to the degree of melting and flux of basalt from the mantle, and intercaldera mafic eruptive products are thus not representative of the feeder magmas for the caldera volcanoes. Inherited olivines and their melt inclusions provide a unique “window” into the mantle dynamics that drive the active TVZ silicic magmatic systems and may present a useful approach at other volcanoes that show evidence for mafic recharge

    A Mendelian Trait for Olfactory Sensitivity Affects Odor Experience and Food Selection

    Get PDF
    SummaryHumans vary in acuity to many odors [1–4], with variation within olfactory receptor (OR) genes contributing to these differences [5–9]. How such variation also affects odor experience and food selection remains uncertain [10], given that such effects occur for taste [11–15]. Here we investigate β-ionone, which shows extreme sensitivity differences [4, 16, 17]. β-ionone is a key aroma in foods and beverages [18–21] and is added to products in order to give a pleasant floral note [22, 23]. Genome-wide and in vitro assays demonstrate rs6591536 as the causal variant for β-ionone odor sensitivity. rs6591536 encodes a N183D substitution in the second extracellular loop of OR5A1 and explains >96% of the observed phenotypic variation, resembling a monogenic Mendelian trait. Individuals carrying genotypes for β-ionone sensitivity can more easily differentiate between food and beverage stimuli with and without added β-ionone. Sensitive individuals typically describe β-ionone in foods and beverages as “fragrant” and “floral,” whereas less-sensitive individuals describe these stimuli differently. rs6591536 genotype also influences emotional associations and explains differences in food and product choices. These studies demonstrate that an OR variant that influences olfactory sensitivity can affect how people experience and respond to foods, beverages, and other products

    Visualising harms in publications of randomised controlled trials: consensus and recommendations

    Get PDF
    OBJECTIVE: To improve communication of harm in publications of randomised controlled trials via the development of recommendations for visually presenting harm outcomes. DESIGN: Consensus study. SETTING: 15 clinical trials units registered with the UK Clinical Research Collaboration, an academic population health department, Roche Products, and The BMJ. PARTICIPANTS: Experts in clinical trials: 20 academic statisticians, one industry statistician, one academic health economist, one data graphics designer, and two clinicians. MAIN OUTCOME: measures A methodological review of statistical methods identified visualisations along with those recommended by consensus group members. Consensus on visual recommendations was achieved (at least 60% of the available votes) over a series of three meetings with participants. The participants reviewed and critically appraised candidate visualisations against an agreed framework and voted on whether to endorse each visualisation. Scores marginally below this threshold (50-60%) were revisited for further discussions and votes retaken until consensus was reached. RESULTS: 28 visualisations were considered, of which 10 are recommended for researchers to consider in publications of main research findings. The choice of visualisations to present will depend on outcome type (eg, binary, count, time-to-event, or continuous), and the scenario (eg, summarising multiple emerging events or one event of interest). A decision tree is presented to assist trialists in deciding which visualisations to use. Examples are provided of each endorsed visualisation, along with an example interpretation, potential limitations, and signposting to code for implementation across a range of standard statistical software. Clinician feedback was incorporated into the explanatory information provided in the recommendations to aid understanding and interpretation. CONCLUSIONS: Visualisations provide a powerful tool to communicate harms in clinical trials, offering an alternative perspective to the traditional frequency tables. Increasing the use of visualisations for harm outcomes in clinical trial manuscripts and reports will provide clearer presentation of information and enable more informative interpretations. The limitations of each visualisation are discussed and examples of where their use would be inappropriate are given. Although the decision tree aids the choice of visualisation, the statistician and clinical trial team must ultimately decide the most appropriate visualisations for their data and objectives. Trialists should continue to examine crude numbers alongside visualisations to fully understand harm profiles

    What Parents of Children Who Have Received Emergency Care Think about Deferring Consent in Randomised Trials of Emergency Treatments: Postal Survey

    Get PDF
    OBJECTIVE: To investigate parents' views about deferred consent to inform management of trial disclosure after a child's death. METHODS: A postal questionnaire survey was sent to members of the Meningitis Research Foundation UK charity, whose child had suffered from bacterial meningitis or meningococcal septicaemia within the previous 5 years. Main outcome measures were acceptability of deferred consent; timing of requesting consent; and the management of disclosure of the trial after a child's death. RESULTS: 220 families were sent questionnaires of whom 63 (29%) were bereaved. 68 families responded (31%), of whom 19 (28%) were bereaved. The majority (67%) was willing for their child to be involved in the trial without the trial being explained to them beforehand; 70% wanted to be informed about the trial as soon as their child's condition had stabilised. In the event of a child's death before the trial could be discussed the majority of bereaved parents (66% 12/18) anticipated wanting to be told about the trial at some time. This compared with 37% (18/49) of non-bereaved families (p = 0.06). Parents' free text responses indicated that the word 'trial' held strongly negative connotations. A few parents regarded gaps in the evidence base about emergency treatments as indicating staff lacked expertise to care for a critically ill child. Bereaved parents' free text responses indicated the importance of individualised management of disclosure about a trial following a child's death. DISCUSSION: Deferred consent is acceptable to the majority of respondents. Parents whose children had recovered differed in their views compared to bereaved parents. Most bereaved parents would want to be informed about the trial in the aftermath of a child's death, although a minority strongly opposed such disclosure. Distinction should be drawn between the views of bereaved and non-bereaved parents when considering the acceptability of different consent processes
    corecore