3,267 research outputs found

    The Mini‐Organo: A rapid high‐throughput 3D coculture organotypic assay for oncology screening and drug development

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    Background: The use of in vitro cell cultures is a powerful tool for obtaining key insights into the behaviour and response of cells to interventions in normal and disease situations. Unlike in vivo settings, in vitro experiments allow a fine-tuned control of a range of microenvironmental elements independently within an isolated setting. The recent expansion in the use of three-dimensional (3D) in vitro assays has created a number of representative tools to study cell behaviour in a more physiologically 3D relevant microenvironment. Complex 3D in vitro models that can recapitulate human tissue biology are essential for understanding the pathophysiology of disease. Aim: The development of the 3D coculture collagen contraction and invasion assay, the "organotypic assay," has been widely adopted as a powerful approach to bridge the gap between standard two-dimensional tissue culture and in vivo mouse models. In the cancer setting, these assays can then be used to dissect how stromal cells, such as cancer-associated fibroblasts (CAFs), drive extracellular matrix (ECM) remodelling to alter cancer cell behaviour and response to intervention. However, to date, many of the published organotypic protocols are low-throughput, time-consuming (up to several weeks), and work-intensive with often limited scalability. Our aim was to develop a fast, high-throughput, scalable 3D organotypic assay for use in oncology screening and drug development. Methods and results Here, we describe a modified 96-well organotypic assay, the "Mini-Organo," which can be easily completed within 5 days. We demonstrate its application in a wide range of mouse and human cancer biology approaches including evaluation of stromal cell 3D ECM remodelling, 3D cancer cell invasion, and the assessment of efficacy of potential anticancer therapeutic targets. Furthermore, the organotypic assay described is highly amenable to customisation using different cell types under diverse experimental conditions. Conclusions: The Mini-Organo high-throughput 3D organotypic assay allows the rapid screening of potential cancer therapeutics in human and mouse models in a time-efficient manner

    The role of Comprehension in Requirements and Implications for Use Case Descriptions

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    Within requirements engineering it is generally accepted that in writing specifications (or indeed any requirements phase document), one attempts to produce an artefact which will be simple to comprehend for the user. That is, whether the document is intended for customers to validate requirements, or engineers to understand what the design must deliver, comprehension is an important goal for the author. Indeed, advice on producing ‘readable’ or ‘understandable’ documents is often included in courses on requirements engineering. However, few researchers, particularly within the software engineering domain, have attempted either to define or to understand the nature of comprehension and it’s implications for guidance on the production of quality requirements. Therefore, this paper examines thoroughly the nature of textual comprehension, drawing heavily from research in discourse process, and suggests some implications for requirements (and other) software documentation. In essence, we find that the guidance on writing requirements, often prevalent within software engineering, may be based upon assumptions which are an oversimplification of the nature of comprehension. Hence, the paper examines guidelines which have been proposed, in this case for use case descriptions, and the extent to which they agree with discourse process theory; before suggesting refinements to the guidelines which attempt to utilise lessons learned from our richer understanding of the underlying discourse process theory. For example, we suggest subtly different sets of writing guidelines for the different tasks of requirements, specification and design

    Development and preliminary evaluation of EMPOWER for surrogate decision-makers of critically ill patients

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    OBJECTIVE: The objectives of this study were to develop and refine EMPOWER (Enhancing and Mobilizing the POtential for Wellness and Resilience), a brief manualized cognitive-behavioral, acceptance-based intervention for surrogate decision-makers of critically ill patients and to evaluate its preliminary feasibility, acceptability, and promise in improving surrogates' mental health and patient outcomes. METHOD: Part 1 involved obtaining qualitative stakeholder feedback from 5 bereaved surrogates and 10 critical care and mental health clinicians. Stakeholders were provided with the manual and prompted for feedback on its content, format, and language. Feedback was organized and incorporated into the manual, which was then re-circulated until consensus. In Part 2, surrogates of critically ill patients admitted to an intensive care unit (ICU) reporting moderate anxiety or close attachment were enrolled in an open trial of EMPOWER. Surrogates completed six, 15-20 min modules, totaling 1.5-2 h. Surrogates were administered measures of peritraumatic distress, experiential avoidance, prolonged grief, distress tolerance, anxiety, and depression at pre-intervention, post-intervention, and at 1-month and 3-month follow-up assessments. RESULTS: Part 1 resulted in changes to the EMPOWER manual, including reducing jargon, improving navigability, making EMPOWER applicable for a range of illness scenarios, rearranging the modules, and adding further instructions and psychoeducation. Part 2 findings suggested that EMPOWER is feasible, with 100% of participants completing all modules. The acceptability of EMPOWER appeared strong, with high ratings of effectiveness and helpfulness (M = 8/10). Results showed immediate post-intervention improvements in anxiety (d = -0.41), peritraumatic distress (d = -0.24), and experiential avoidance (d = -0.23). At the 3-month follow-up assessments, surrogates exhibited improvements in prolonged grief symptoms (d = -0.94), depression (d = -0.23), anxiety (d = -0.29), and experiential avoidance (d = -0.30). SIGNIFICANCE OF RESULTS: Preliminary data suggest that EMPOWER is feasible, acceptable, and associated with notable improvements in psychological symptoms among surrogates. Future research should examine EMPOWER with a larger sample in a randomized controlled trial

    Preparation of Primary Rat Hepatocyte Spheroids Utilizing the Liquid-Overlay Technique.

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    Herein, we describe a protocol for the preparation and analysis of primary isolated rat hepatocytes in a 3D cell culture format described as spheroids. The hepatocyte cells spontaneously self-aggregate into spheroids without the need for synthetic extracellular matrices or hydrogels. Primary rat hepatocytes (PRHs) are a readily available source of primary differentiated liver cells and therefore conserve many of the required liver-specific functional markers, and elicit the natural in vivo phenotype when compared with common hepatic cells lines. We describe the liquid-overlay technique which provides an ultra-low attachment surface on which PRHs can be cultured as spheroids. © 2019 The Authors. Basic Protocol 1: Preparation of agarose-coated plates Basic Protocol 2: Primary rat hepatocyte isolation procedure Basic Protocol 3: Primary rat hepatocyte spheroid culture Basic Protocol 4: Immunofluorescent analysis of PRH spheroids

    Simpson's Paradox, Lord's Paradox, and Suppression Effects are the same phenomenon – the reversal paradox

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    This article discusses three statistical paradoxes that pervade epidemiological research: Simpson's paradox, Lord's paradox, and suppression. These paradoxes have important implications for the interpretation of evidence from observational studies. This article uses hypothetical scenarios to illustrate how the three paradoxes are different manifestations of one phenomenon – the reversal paradox – depending on whether the outcome and explanatory variables are categorical, continuous or a combination of both; this renders the issues and remedies for any one to be similar for all three. Although the three statistical paradoxes occur in different types of variables, they share the same characteristic: the association between two variables can be reversed, diminished, or enhanced when another variable is statistically controlled for. Understanding the concepts and theory behind these paradoxes provides insights into some controversial or contradictory research findings. These paradoxes show that prior knowledge and underlying causal theory play an important role in the statistical modelling of epidemiological data, where incorrect use of statistical models might produce consistent, replicable, yet erroneous results

    Interleukin-1 polymorphisms associated with increased risk of gastric cancer

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    Helicobacter pylori infection is associated with a variety of clinical outcomes including gastric cancer and duodenal ulcer disease. The reasons for this variation are not clear, but the gastric physiological response is influenced by the severity and anatomical distribution of gastritis induced by H. pylori. Thus, individuals with gastritis predominantly localized to the antrum retain normal (or even high) acid secretion, whereas individuals with extensive corpus gastritis develop hypochlorhydria and gastric atrophy, which are presumptive precursors of gastric cancer. Here we report that interleukin-1 gene cluster polymorphisms suspected of enhancing production of interleukin-1-beta are associated with an increased risk of both hypochlorhydria induced by H. pylori and gastric cancer. Two of these polymorphism are in near-complete linkage disequilibrium and one is a TATA-box polymorphism that markedly affects DNA-protein interactions in vitro. The association with disease may be explained by the biological properties of interleukin-1-beta, which is an important pro-inflammatory cytokine and a powerful inhibitor of gastric acid secretion. Host genetic factors that affect interleukin-1-beta may determine why some individuals infected with H. pylori develop gastric cancer while others do no

    Walks4work: Rationale and study design to investigate walking at lunchtime in the workplace setting

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    Background: Following recruitment of a private sector company, an 8week lunchtime walking intervention was implemented to examine the effect of the intervention on modifiable cardiovascular disease risk factors, and further to see if walking environment had any further effect on the cardiovascular disease risk factors. Methods. For phase 1 of the study participants were divided into three groups, two lunchtime walking intervention groups to walk around either an urban or natural environment twice a week during their lunch break over an 8week period. The third group was a waiting-list control who would be invited to join the walking groups after phase 1. In phase 2 all participants were encouraged to walk during their lunch break on self-selecting routes. Health checks were completed at baseline, end of phase 1 and end of phase 2 in order to measure the impact of the intervention on cardiovascular disease risk. The primary outcome variables of heart rate and heart rate variability were measured to assess autonomic function associated with cardiovascular disease. Secondary outcome variables (Body mass index, blood pressure, fitness, autonomic response to a stressor) related to cardiovascular disease were also measured. The efficacy of the intervention in increasing physical activity was objectively monitored throughout the 8-weeks using an accelerometer device. Discussion. The results of this study will help in developing interventions with low researcher input with high participant output that may be implemented in the workplace. If effective, this study will highlight the contribution that natural environments can make in the reduction of modifiable cardiovascular disease risk factors within the workplace. © 2012 Brown et al.; licensee BioMed Central Ltd

    The pharmaceutical use of permethrin: Sources and behavior during municipal sewage treatment

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    This is the author's accepted manuscript. The final published article is available from the link below. Copyright @ 2010 Springer Science+Business Media, LLC.Permethrin entered use in the 1970s as an insecticide in a wide range of applications, including agriculture, horticultural, and forestry, and has since been restricted. In the 21st century, the presence of permethrin in the aquatic environment has been attributed to its use as a human and veterinary pharmaceutical, in particular as a pedeculicide, in addition to other uses, such as a moth-proofing agent. However, as a consequence of its toxicity to fish, sources of permethrin and its fate and behavior during wastewater treatment are topics of concern. This study has established that high overall removal of permethrin (approximately 90%) was achieved during wastewater treatment and that this was strongly dependent on the extent of biological degradation in secondary treatment, with more limited subsequent removal in tertiary treatment processes. Sources of permethrin in the catchment matched well with measured values in crude sewage and indicated that domestic use accounted for more than half of the load to the treatment works. However, removal may not be consistent enough to achieve the environmental quality standards now being derived in many countries even where tertiary treatment processes are applied.United Utilities PL
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