1,272 research outputs found

    Viruses disrupt functions of human lymphocytes. Effects of measles virus and influenza virus on lymphocyte-mediated killing and antibody production.

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    We present experimental data that offer, in part, a better understanding of the immunosuppression that accompanies measles virus infection. We note that measles virus "silently" infects human lymphocytes and that the infection does not alter lymphocyte survival in vitro. Yet such infected lymphocytes fail to generate natural killer (NK) cell activity or synthesize immunoglobulins (Ig). Thus, the presence of virus within lymphocytes impairs their specific immune functions in the absence of cytolysis. Influenza virus also infects human lymphocytes. In contrast to measles virus infection of resting lymphocytes in which viral antigen is rarely expressed, influenza virus infection of these cells yields viral antigens expressed in the cytoplasm and on the cell surface. Influenza virus-infected lymphocytes have normal NK cell activity but fail to synthesize IgG or IgM

    Estimating tibial stress throughout the duration of a treadmill run

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    This is the author accepted manuscript. The final version is available from Lippincott, Williams & Wilkins via the DOI in this record.Introduction: Stress fractures of the tibia are a problematic injury amongst runners of all levels. Quantifying tibial stress using a modelling approach provides an alternative to invasive assessments that may be used to detect changes in tibial stress during running. This study aimed to assess the repeatability of a tibial stress model and to use this model to quantify changes in tibial stress that occur throughout the course of a 40-minute prolonged treadmill run. Methods: Synchronised force and kinematic data were collected during prolonged treadmill running from fourteen recreational male rearfoot runners on two separate occasions. During each session, participants ran at their preferred speed for two consecutive 20-minute runs, separated by a 2-minute pause. The tibia was modelled as a hollow ellipse and bending moments and stresses at the distal 1/3 of the tibia were estimated using beam theory combined with inverse dynamics and musculoskeletal modelling. Results: Intraclass correlation coefficients indicated good-to-excellent repeatability for peak stress values between sessions. Peak anterior and posterior stresses increased following 20 minutes of prolonged treadmill running and were 15% and 12% greater respectively after 40 minutes of running compared with the start of the run. Conclusion: The hollow elliptical tibial model presented is a repeatable tool that can be utilised to assess within-participant changes in peak tibial stress during running. The increased stresses observed during a prolonged treadmill run may have implications for the development of tibial stress fracture.Brooks Running Company, Seattle, WA, USA

    Inertia based microfluidic capture and characterisation of circulating tumour cells for the diagnosis of lung cancer

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    Background: Routine clinical application of circulating tumour cells (CTCs) for blood based diagnostics is yet to be established. Despite growing evidence of their clinical utility for diagnosis, prognosis and treatment monitoring, the efficacy of a robust platform and universally accepted diagnostic criteria remain uncertain. We evaluate the diagnostic performance of a microfluidic CTC isolation platform using cytomorphologic criteria in patients undergoing lung cancer surgery. Methods: Blood was processed from 51 patients undergoing surgery for known or suspected lung cancer using the ClearBridge ClearCell FX systemTM (ClearBridge Biomedics, Singapore). Captured cells were stained on slides with haematoxylin and eosin (H&E) and independently assessed by two pathologist teams. Diagnostic performance was evaluated against the pathologists reported diagnosis of cancer from surgically obtained specimens. Results: Cancer was diagnosed in 43.1% and 54.9% of all cases. In early stage primary lung cancer, between the two reporting teams, a positive diagnosis of CTCs was made for 50% and 66.7% of patients. The agreement between the reporting teams was 80.4%, corresponding to a kappa-statistic of 0.61±0.11 (P<0.001), indicating substantial agreement. Sensitivity levels for the two teams were calculated as 59% (95% CI, 41–76%) and 41% (95% CI, 24–59%), with a specificity of 53% for both. Conclusions: The performance of the tested microfluidic antibody independent device to capture CTCs using standard cytomorphological criteria provides the potential of a diagnostic blood test for lung cancer

    Nanosilver and the microbiological activity of the particulate solids versus the leached soluble silver.

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    Nanosilver (Ag NPs) is currently one of the most commercialized antimicrobial nanoparticles with as yet, still unresolved cytotoxicity origins. To date, research efforts have mostly described the antimicrobial contribution from the leaching of soluble silver, while the undissolved solid Ag particulates are often considered as being microbiologically inert, serving only as source of the cytotoxic Ag ions. Here, we show the rapid stimulation of lethal cellular oxidative stress in bacteria by the presence of the undissolved Ag particulates. The cytotoxicity characteristics are distinct from those arising from the leached soluble Ag, the latter being locked in organic complexes. The work also highlights the unique oxidative stress-independent bacterial toxicity of silver salt. Taken together, the findings advocate that future enquiries on the antimicrobial potency and also importantly, the environmental and clinical impact of Ag NPs use, should pay attention to the potential bacterial toxicological responses to the undissolved Ag particulates, rather than just to the leaching of soluble silver. The findings also put into question the common use of silver salt as model material for evaluating bacterial toxicity of Ag NPs

    Development of practice principles for the management of ongoing suicidal ideation in young people diagnosed with major depressive disorder

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    Objectives: There is a lack of clear guidance regarding the management of ongoing suicidality in young people experiencing major depressive disorder. This study utilised an expert consensus approach in identifying practice principles to complement relevant clinical guidelines for the treatment of major depressive disorder in young people. The study also sought to outline a broad treatment framework for clinical intervention with young people experiencing ongoing suicidal ideation. Methods: In-depth focus groups were undertaken with a specialist multidisciplinary clinical team (the Youth Mood Clinic at Orygen Youth Health Clinical Program, Melbourne) working with young people aged 15–25 years experiencing ongoing suicidal ideation. Each focus group was audio recorded and transcribed verbatim using orthographic conventions. Principles of grounded theory and thematic analysis were used to analyse and code the resultant data. Results: The identified codes were subsequently synthesised into eight practice principles reflecting engagement and consistency of care, ongoing risk assessment and documentation, individualised crisis planning, engaging systems of support, engendering hopefulness, development of adaptive coping, management of acute risk, and consultation and supervision. Conclusions: The identified practice principles provide a broad management framework, and may assist to improve treatment consistency and clinical management of young people experiencing ongoing suicidal ideation. The practice principles may be of use to health professionals working within a team-based setting involved in the provision of care, even if peripherally, to young people with ongoing suicidal ideation. Findings address the lack of treatment consistency and shared terminology and may provide containment and guidance to multidisciplinary clinicians working with this at-risk group

    Enterococcus faecalis Adapts to Antimicrobial Conjugated Oligoelectrolytes by Lipid Rearrangement and Differential Expression of Membrane Stress Response Genes.

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    Conjugated oligoelectrolytes (COEs) are emerging antimicrobials with broad spectrum activity against Gram positive and Gram negative bacteria as well as fungi. Our previous in vitro evolution studies using Enterococcus faecalis grown in the presence of two related COEs (COE1-3C and COE1-3Py) led to the emergence of mutants (changes in liaF and liaR) with a moderate 4- to16-fold increased resistance to COEs. The contribution of liaF and liaR mutations to COE resistance was confirmed by complementation of the mutants, which restored sensitivity to COEs. To better understand the cellular target of COEs, and the mechanism of resistance to COEs, transcriptional changes associated with resistance in the evolved mutants were investigated in this study. The differentially transcribed genes encoded membrane transporters, in addition to proteins associated with cell envelope synthesis and stress responses. Genes encoding membrane transport proteins from the ATP binding cassette superfamily were the most significantly induced or repressed in COE tolerant mutants compared to the wild type when exposed to COEs. Additionally, differences in the membrane localization of a lipophilic dye in E. faecalis exposed to COEs suggested that resistance was associated with lipid rearrangement in the cell membrane. The membrane adaptation to COEs in EFC3C and EFC3Py resulted in an improved tolerance to bile salt and sodium chloride stress. Overall, this study showed that bacterial cell membranes are the primary target of COEs and that E. faecalis adapts to membrane interacting COE molecules by both lipid rearrangement and changes in membrane transporter activity. The level of resistance to COEs suggests that E. faecalis does not have a specific response pathway to elicit resistance against these molecules and this is supported by the rather broad and diverse suite of genes that are induced upon COE exposure as well as cross-resistance to membrane perturbing stressors

    Corporate Social Responsibility and Islamic Financial Institutions (IFIs): Management Perceptions from IFIs in Bahrain

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    Islamic finance is gaining greater attention in the finance industry, and this paper analyses how Islamic financial institutions (IFIs) are responding to the welfare needs of society. Using interview data with managers and content analysis of the disclosures, this study attempts to understand management perceptions of corporate social responsibility (CSR) in IFIs. A thorough understanding of CSR by managers, as evident in the interviews, has not been translated fully into practice. The partial use of IFIs’ potential role in social welfare would add further challenges in the era of financialisation

    Sexual selection protects against extinction

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    Reproduction through sex carries substantial costs, mainly because only half of sexual adults produce offspring. It has been theorised that these costs could be countered if sex allows sexual selection to clear the universal fitness constraint of mutation load. Under sexual selection, competition between (usually) males, and mate choice by (usually) females create important intraspecific filters for reproductive success, so that only a subset of males gains paternity. If reproductive success under sexual selection is dependent on individual condition, which depends on mutation load, then sexually selected filtering through ‘genic capture’ could offset the costs of sex because it provides genetic benefits to populations. Here, we test this theory experimentally by comparing whether populations with histories of strong versus weak sexual selection purge mutation load and resist extinction differently. After evolving replicate populations of the flour beetle Tribolium castaneum for ~7 years under conditions that differed solely in the strengths of sexual selection, we revealed mutation load using inbreeding. Lineages from populations that had previously experienced strong sexual selection were resilient to extinction and maintained fitness under inbreeding, with some families continuing to survive after 20 generations of sib × sib mating. By contrast, lineages derived from populations that experienced weak or non-existent sexual selection showed rapid fitness declines under inbreeding, and all were extinct after generation 10. Multiple mutations across the genome with individually small effects can be difficult to clear, yet sum to a significant fitness load; our findings reveal that sexual selection reduces this load, improving population viability in the face of genetic stress

    Universality, limits and predictability of gold-medal performances at the Olympic Games

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    Inspired by the Games held in ancient Greece, modern Olympics represent the world's largest pageant of athletic skill and competitive spirit. Performances of athletes at the Olympic Games mirror, since 1896, human potentialities in sports, and thus provide an optimal source of information for studying the evolution of sport achievements and predicting the limits that athletes can reach. Unfortunately, the models introduced so far for the description of athlete performances at the Olympics are either sophisticated or unrealistic, and more importantly, do not provide a unified theory for sport performances. Here, we address this issue by showing that relative performance improvements of medal winners at the Olympics are normally distributed, implying that the evolution of performance values can be described in good approximation as an exponential approach to an a priori unknown limiting performance value. This law holds for all specialties in athletics-including running, jumping, and throwing-and swimming. We present a self-consistent method, based on normality hypothesis testing, able to predict limiting performance values in all specialties. We further quantify the most likely years in which athletes will breach challenging performance walls in running, jumping, throwing, and swimming events, as well as the probability that new world records will be established at the next edition of the Olympic Games.Comment: 8 pages, 3 figures, 1 table. Supporting information files and data are available at filrad.homelinux.or
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