592 research outputs found

    Lymphocyte and Monocyte Hsp72 Responses to Exercise in Athletes with Prior Exertional Heat Illness

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    ABSTRACT Introduction. Exertional heatstroke is a serious disorder that can be fatal especially if treatment is delayed. Heat shock protein 72 (Hsp72) is strongly induced by heat, and can be protective against a subsequent stress that may be the same or of a different form. In animal models it has been shown that upregulation of Hsp72 is protective against heatstroke. There is a natural variability in the amount and/or inducibility of Hsp72 in cells and tissues between individuals, and it is possible that impaired expression levels could make some athletes more prone to heat illness. The purpose of this study was to examine Hsp72 expression in lymphocytes and monocytes of young (\u3c40 years) athletes who had previously experienced, but recovered from serious heatstroke during exercise in the heat. Methods. Fourteen athletes ran on a treadmill for 60 min at 72% maximal oxygen uptake (o2max) in warm conditions (30°C, 40% relative humidity). One group consisted of athletes who had a previous history of exertional heat illness (EHI), while the control group (CON) had no previous history of EHI. Both groups were of similar age (29.7 ± 1.2 and 29.1 ± 2 years, CON vs EHI) and fitness (o2max 65.7 ± 2 and 64.5 ± 3 ml.kg-1.min-1, CON vs EHI). Rectal temperature was measured using a thermistor inserted to a depth of 10 cm past the anal sphincter. Hsp72 levels were measured in both monocytes and lymphocytes by flow cytometry before and immediately after the 60-min run, then after 60 min of recovery at an ambient temperature of 24°C. Results. Rectal temperature increased during the exercise period but there was no difference between groups, demonstrating that the EHI group had recovered from their heat illness and were not heat intolerant. Lymphocyte Hsp72 was lower in the EHI group after 60 min of exercise (p\u3c0.05), while monocyte Hsp72 was not different between groups. Conclusion. Our study found a lower lymphocyte Hsp72 concentration during exercise in athletes who had previously collapsed with serious EHI. Further research is needed to determine whether lower lymphocyte Hsp72 is a factor that may predispose athletes to develop EHI

    Passive immunization during pregnancy for congenital cytomegalovirus infection

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    BACKGROUND Currently, there is no effective intervention for a primary cytomegalovirus (CMV) infection during pregnancy. METHODS We studied pregnant women with a primary CMV infection. The therapy group comprised women whose amniotic fluid contained either CMV or CMV DNA and who were offered intravenous CMV hyperimmune globulin at a dose of 200 U per kilogram of maternal weight. A prevention group, consisting of women with a recent primary infection before 21 weeks\u27 gestation or who declined amniocentesis, was offered monthly hyperimmune globulin (100 U per kilogram intravenously). RESULTS In the therapy group, 31 women received hyperimmune globulin, only 1 (3 percent) of whom gave birth to an infant with CMV disease (symptomatic at birth and handicapped at two or more years of age), as compared with 7 of 14 women who did not receive hyperimmune globulin (50 percent). Thus, hyperimmune globulin therapy was associated with a significantly lower risk of congenital CMV disease (adjusted odds ratio, 0.02; 95 percent confidence interval, ¡∞ to 0.15; P\u3c0.001). In the prevention group, 37 women received hyperimmune globulin, 6 (16 percent) of whom had infants with congenital CMV infection, as compared with 19 of 47 women (40 percent) who did not receive hyperimmune globulin. Thus, hyperimmune globulin therapy was associated with a significantly lower risk of congenital CMV infection (adjusted odds ratio, 0.32; 95 percent confidence interval, 0.10 to 0.94; P=0.04). Hyperimmune globulin therapy significantly (P\u3c0.001) increased CMV-specific IgG concentrations and avidity and decreased natural killer cells and HLA-DR+ cells and had no adverse effects. CONCLUSIONS Treatment of pregnant women with CMV-specific hyperimmune globulin is safe, and the findings of this nonrandomized study suggest that it may be effective in the treatment and prevention of congenital CMV infection. A controlled trial of this agent may now be appropriate

    Global e-Readiness - For What? Readiness for e-Banking (JITD)

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    With the rapid diffusion of the Internet worldwide, there has been considerable interest in the e-potentials of developing countries giving rise to a 1st generation of e-Readiness studies. Moreover, e-Readiness means different things to different people, in different contexts, and for different purposes. Despite strong merits, this first generation of e-Readiness studies assumed a fixed, one-size-fits-all set of requirements, regardless of the characteristics of individual countries, the investment context, or the demands of specific applications. This feature obscures critical information for investors or policy analysts seeking to reduce uncertainties and/or make more educated decisions. But there is very little known about e-Readiness for e-Banking. In particular, based on lessons learnt to date and their implications for emerging realities of the 21st century, we designed and executed a research project with theoretical as well as practical dimensions to answer the question of e-Readiness for What, focusing specifically on e-Banking, based on the very assumption that one size can seldom, if ever, fit all. We propose and develop a conceptual framework for the "next generation" ereadiness - focusing on different e-Business applications in different economic contexts with potentially different pathways - as well as a data model - to explore e-Readiness for e-Banking in ten countries

    The role of discharge variability in determining alluvial stratigraphy

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    We illustrate the potential for using physics-based modeling to link alluvial stratigraphy to large river morphology and dynamics. Model simulations, validated using ground penetrating radar data from the Río Paraná, Argentina, demonstrate a strong relationship between bar-scale set thickness and channel depth, which applies across a wide range of river patterns and bar types. We show that hydrologic regime, indexed by discharge variability and flood duration, exerts a first-order influence on morphodynamics and hence bar set thickness, and that planform morphology alone may be a misleading variable for interpreting deposits. Indeed, our results illustrate that rivers evolving under contrasting hydrologic regimes may have very similar morphology, yet be characterized by marked differences in stratigraphy. This realization represents an important limitation on the application of established theory that links river topography to alluvial deposits, and highlights the need to obtain field evidence of discharge variability when developing paleoenvironmental reconstructions. Model simulations demonstrate the potential for deriving such evidence using metrics of paleocurrent variance

    The tyrosine phosphatase CD148 is an essential positive regulator of platelet activation and thrombosis

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    Platelets play a fundamental role in hemostasis and thrombosis. They are also involved in pathologic conditions resulting from blocked blood vessels, including myocardial infarction and ischemic stroke. Platelet adhesion, activation, and aggregation at sites of vascular injury are regulated by a diverse repertoire of tyrosine kinase–linked and G protein–coupled receptors. Src family kinases (SFKs) play a central role in initiating and propagating signaling from several platelet surface receptors; however, the underlying mechanism of how SFK activity is regulated in platelets remains unclear. CD148 is the only receptor-like protein tyrosine phosphatase identified in platelets to date. In the present study, we show that mutant mice lacking CD148 exhibited a bleeding tendency and defective arterial thrombosis. Basal SFK activity was found to be markedly reduced in CD148-deficient platelets, resulting in a global hyporesponsiveness to agonists that signal through SFKs, including collagen and fibrinogen. G protein–coupled receptor responses to thrombin and other agonists were also marginally reduced. These results highlight CD148 as a global regulator of platelet activation and a novel antithrombotic drug targe

    Probing yield stress fluids with a vibrational rheometer

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    Low volume fraction colloidal gels can possess small yield stresses that are able to trap particles or bubbles within the matrix indefinitely. At rest, the stress applied to the network by a probe particle is limited by the density difference between the probe and continuous phase materials. However, vibration of the sample is an acceleration that causes the inertial particles to impart a stress on the fluid; the stress that results from a vibration is also a function of the frequency and amplitude of the vibration. The microscale fluid properties around the probe particles can be elucidated by studying the effects of vibration on the sample. While applying a vertical mechanical vibration to the sample (1 to 5 mm amplitude, 10 to 100 Hz), we make use of high speed particle tracking to record particle trajectories and measure strain, yielding, flow, and recovery of various complex fluid networks. The measurements enable comparison of the suspension and yielding behaviour of complex fluids with similar rheology but greatly varying microstructures, allowing determination of the optimal approaches to stabilisation of various formulations. Dispersions of colloidal microgels, nanofibres, and wormlike micelles are used in different combinations to explore the robustness of disparate structures to repeated perturbations. Measurements are made of local strain, elasticity, yield stress, and sedimentation rate and compared to continuum predictions for yield stress fluids with more homogeneous microstructures. Please click Additional Files below to see the full abstract

    A tale of two towns: A comparative study exploring the possibilities and pitfalls of social capital among people seeking recovery from substance misuse

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    Background: Social capital has become an influential concept in debating and understanding the modern world. Within the drug and alcohol sector, the concept of ‘recovery capital’ has gained traction with researchers suggesting that people who have access to such capital are better placed to overcome their substance use-related problems than those who do not (Cloud and Granfield, 2008), leading to requests for interventions that focus on building social capital networks (Neale & Stevenson, 2015). While accepting that the concept of social capital has enormous potential for addressing the problems associated with drug use, this paper also considers its ‘dark side’. Methods: Data were drawn from semi-structured interviews with 180 participants including 135 people who use drugs and 45 people who formerly used drugs. Results: High levels of trust, acquired through the establishment of dense social networks, are required to initiate recovery. However, these ‘strong bonds’ may also lead to the emergence of what is perceived by others as an exclusive social network that limits membership to those who qualify and abide by the ‘rules’ of the recovery community, particularly around continuous abstinence. Conclusions: Depending on the nature of the networks and the types of links participants have into them being socially connected can both inhibit and encourage recovery. Therefore, the successful application of social capital within the drugs and alcohol field requires a consideration of not only the presence or absence of social connections but their nature, the value they produce, and the social contexts within which they are developed
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