613 research outputs found

    Plasma cytokine profiles in HIV-1 infected patients developing neuropathic symptoms shortly after commencing antiretroviral therapy: a case-control study

    Get PDF
    Abstract Background In patients infected with human immunodeficiency virus 1 (HIV-1) neuropathic symptoms may develop within weeks of starting combination antiretroviral therapy (cART). This timing coincides with the occurrence of immune reconstitution inflammatory syndrome. Our objective was to investigate the longitudinal association of plasma cytokine and soluble receptor concentrations with incident neuropathic symptoms within 12 weeks of starting programme-based cART in a nested case-control study. Methods One hundred and twenty adults without neuropathic symptoms and about to initiate cART were followed longitudinally for 24 weeks after cART initiation. Subjects were examined for peripheral neuropathy at baseline (pre-cART) and 2-, 4-, 12- and 24 weeks thereafter. Individuals developing neuropathic symptoms within 12 weeks of starting cART were matched in a nested case-control design with those remaining symptom-free for at least 24 weeks. Plasma was collected at each visit. Cytokines and soluble receptors were quantified using multiplex immunometric assays. Results Incident neuropathic symptoms occurred in 32 (27%) individuals within 12 weeks of starting cART for the first time. Cytokine concentrations increased at 2 weeks, irrespective of symptom-status, returning to baseline concentrations at 12 weeks. Compared to the control group, the symptomatic group had higher baseline levels of interleukin-1 receptor (IL-1R)-antagonist. The symptomatic group also showed greater increases in soluble interleukin-2 receptor-alpha and tumour necrosis factor (TNF) receptor-II levels at week 2 and soluble interleukin-6 receptor levels at week 12. Ratios of pro-inflammatory- vs anti-inflammatory cytokines were higher for TNF-alpha/IL-4 (p = 0.022) and interferon-gamma/IL-10 (p = 0.044) in those developing symptoms. After 24 weeks of cART, the symptomatic group showed higher CD4+ counts (p = 0.002). Conclusions The initiation of cART in previously treatment naïve individuals was associated with a cytokine 'burst’ between 2- and 4 weeks compared with pre-cART levels. Individuals developing neuropathic symptoms within 12 weeks of starting cART showed evidence of altered cytokine concentrations even prior to initiating cART, most notably higher circulating IL-1R-antagonist levels, and altered ratios of “pain-associated” cytokine and soluble receptors shortly after cART initiation

    Direct activation of NADPH oxidase 2 by 2-deoxyribose-1-phosphate triggers nuclear factor kappa B-dependent angiogenesis.

    Get PDF
    AbstractAims: Deoxyribose-1-phosphate (dRP) is a proangiogenic paracrine stimulus released by cancer cells, platelets, and macrophages and acting on endothelial cells. The objective of this study was to clarify how dRP stimulates angiogenic responses in human endothelial cells.Results: Live cell imaging, electron paramagnetic resonance, pull-down of dRP-interacting proteins, followed by immunoblotting, gene silencing of different NADPH oxidases (NOXs), and their regulatory cosubunits by small interfering RNA (siRNA) transfection, and experiments with inhibitors of the sugar transporter glucose transporter 1 (GLUT1) were utilized to demonstrate that dRP acts intracellularly by directly activating the endothelial NOX2 complex, but not NOX4. Increased reactive oxygen species generation in response to NOX2 activity leads to redox-dependent activation of the transcription factor nuclear factor kappa B (NF-κB), which, in turn, induces vascular endothelial growth factor receptor 2 (VEGFR2) upregulation. Using endothelial tube formation assays, gene silencing by siRNA, and antibody-based receptor inhibition, we demonstrate that the activation of NF-κB and VEGFR2 is necessary for the angiogenic responses elicited by dRP. The upregulation of VEGFR2 and NOX2-dependent stimulation of angiogenesis by dRP were confirmed in excisional wound and Matrigel plug vascularization assays in vivo using NOX2−/− mice.Innovation: For the first time, we demonstrate that dRP acts intracellularly and stimulates superoxide anion generation by direct binding and activation of the NOX2 enzymatic complex.Conclusions: This study describes a novel molecular mechanism underlying the proangiogenic activity of dRP, which involves the sequential activation of NOX2 and NF-κB and upregulation of VEGFR2. Antioxid. Redox Signal. 28, 110–130

    Breath Regulation and yogic Exercise An online Therapy for calm and Happiness (BREATH) for frontline hospital and long-term care home staff managing the COVID-19 pandemic: A structured summary of a study protocol for a feasibility study for a randomised controlled trial

    Get PDF
    OBJECTIVES: Objective 1: To determine if it is feasible to conduct an RCT of online Sudarshan Kriya Yoga (SKY) for frontline hospital and long-term care home staff under the constraints imposed by the COVID-19 pandemic and need for remote trial monitoring. Objective 2: To assess whether online versions of SKY and/or Health Enhancement Program (HEP) result in improvement in self-rated measures of insomnia, anxiety, depression, and resilience. TRIAL DESIGN: This is an open-label feasibility randomized controlled trial (RCT), comparing an online breath based yogic intervention SKY versus an online control mind-body intervention HEP in frontline hospital and long-term care home staff managing the COVID-19 pandemic. PARTICIPANTS: Participants will include frontline hospital and long-term care home staff that are involved in the management of COVID-19 patients in London, Ontario, Canada. Participants will be willing and able to attend via online video conferencing software to participate in the study interventions. Participants must have an adequate understanding of English and be able to sit without physical discomfort for 60 minutes. INTERVENTION AND COMPARATOR: Sudarshan Kriya Yoga (SKY): The online version of SKY will be delivered by at least one certified Canadian SKY teacher, with at least one back up teacher at all times, under the supervision of Ms. Ronnie Newman, Director of Research and Health Promotion, Art of Living Foundation, USA. The online version of SKY for healthcare workers has a total duration of 3 hours. Phase I will consist of 5 self-paced online modules of 4-10 minutes each to learn the breath control techniques. Participants will be sent an online survey in REDCap requesting that they self-confirm completion of the Phase I modules. In Phase II, 2 interactive online sessions of 1 hour each will be held on consecutive days with a certified SKY teacher, during which participants will learn the fast, medium and slow breaths. For ease of scheduling, multiple time windows will be offered for Phase II. There will be at least one back up teacher at all times. Both Phase I and II will be completed in the first week. Health Enhancement Program (HEP): The active control arm, HEP, will consist of time-matched online self-paced modules for Phase I. Phase II will consist of mindfulness-based meditation sessions delivered by mental health staff. HEP will be an active treatment program that incorporates mind-body interventions. HEP will consist of time-matched online self-paced modules with psychoeducation on healthy active living as well as interactive modules comprising of guided de-stressing exercises including music therapy, mindfulness and progressive muscle relaxation. Weekly follow up sessions will be offered to all recruited participants for 30 minutes each for the subsequent 4 weeks in both study arms. MAIN OUTCOMES: The following feasibility outcomes will be measured at the end of the study: (1) rate of participant recruitment, (2) rate of retention, (3) completeness of data entry, (4) cost of interventions, and (5) unexpected costs. Such measures will be collected on a daily basis through-out the study and tabulated 5 weeks later at the end of the study. RANDOMISATION: Participants will be randomized after they have electronically signed the consent form and the research staff have confirmed eligibility. We will use REDCap to perform randomization in a 1:1 ratio as well as allocation concealment. REDCap is widely used by health researchers worldwide to significantly reduce data entry and study management errors to improve data fidelity. BLINDING (MASKING): All study participants will be blinded to the study hypotheses so as to prevent any expectation bias. Group allocation will be masked during analysis. NUMBERS TO BE RANDOMISED (SAMPLE SIZE): This study will randomize a total of 60 participants in a 1:1 ratio to either SKY or HEP interventions. TRIAL STATUS: Protocol version number 2.0 (June 5, 2020). Recruitment is currently ongoing (starting June 25, 2020). We anticipate to complete recruitment by June 30, 2021 and complete the study by September 30, 2021. TRIAL REGISTRATION: ClinicalTrials.gov protocol ID NCT04368676 (posted April 30, 2020). FULL PROTOCOL: The full protocol is attached as an additional file, accessible from the Trials website (Additional file 1). In the interest in expediting dissemination of this material, the familiar formatting has been eliminated; this Letter serves as a summary of the key elements of the full protocol

    Joint associations of blood plasma proteins with overwinter survival of a large mammal

    Get PDF
    In many wild animal populations, hosts are at risk of parasites and malnutrition and resource costs of defence may be difficult to afford. We postulate that proteins, important in homeostasis and immunity, play a complex but central role in condition dependence and resource costs of mammalian immune defence. To test this, we measured plasma concentrations of albumin, total proteins. Self-reactive antibodies and parasite-specific IgG in female Soay sheep. Using a principal component analysis, we found a new metric of condition reflecting individual variation in acquisition, assimilation and/or recycling of plasma proteins that predicted overwinter survival. Controlling for this metric, an age-dependent trade-off between antibody titres and protein reserves emerged, indicating costs of mounting an antibody response: younger individuals survived best when prioritising immunity while older individuals fared better when maintaining high-protein nutritional plane. These findings suggest fascinating roles for protein acquisition and allocation in influencing survival in wild animal populations.RG was supported by a Princeton University Health Grand Challenges grant to ALG

    Comparison and relative utility of inequality measurements: as applied to Scotland’s child dental health

    Get PDF
    This study compared and assessed the utility of tests of inequality on a series of very large population caries datasets. National cross-sectional caries datasets for Scotland’s 5-year-olds in 1993/94 (n = 5,078); 1995/96 (n = 6,240); 1997/98 (n = 6,584); 1999/00 (n = 6,781); 2002/03 (n = 9,747); 2003/04 (n = 10,956); 2005/06 (n = 10,945) and 2007/08 (n = 12,067) were obtained. Outcomes were based on the d3mft metric (i.e. the number of decayed, missing and filled teeth). An area-based deprivation category (DepCat) measured the subjects’ socioeconomic status (SES). Simple absolute and relative inequality, Odds Ratios and the Significant Caries Index (SIC) as advocated by the World Health Organization were calculated. The measures of complex inequality applied to data were: the Slope Index of Inequality (absolute) and a variety of relative inequality tests i.e. Gini coefficient; Relative Index of Inequality; concentration curve; Koolman and Doorslaer’s transformed Concentration Index; Receiver Operator Curve and Population Attributable Risk (PAR). Additional tests used were plots of SIC deciles (SIC10) and a Scottish Caries Inequality Metric (SCIM10). Over the period, mean d3mft improved from 3.1(95%CI 3.0–3.2) to 1.9(95%CI 1.8–1.9) and d3mft = 0% from 41.1(95%CI 39.8–42.3) to 58.3(95%CI 57.8–59.7). Absolute simple and complex inequality decreased. Relative simple and complex inequality remained comparatively stable. Our results support the use of the SII and RII to measure complex absolute and relative SES inequalities alongside additional tests of complex relative inequality such as PAR and Koolman and Doorslaer’s transformed CI. The latter two have clear interpretations which may influence policy makers. Specialised dental metrics (i.e. SIC, SIC10 and SCIM10) permit the exploration of other important inequalities not determined by SES, and could be applied to many other types of disease where ranking of morbidity is possible e.g. obesity. More generally, the approaches described may be applied to study patterns of health inequality affecting worldwide populations

    Argumentation in school science : Breaking the tradition of authoritative exposition through a pedagogy that promotes discussion and reasoning

    Get PDF
    The value of argumentation in science education has become internationally recognised and has been the subject of many research studies in recent years. Successful introduction of argumentation activities in learning contexts involves extending teaching goals beyond the understanding of facts and concepts, to include an emphasis on cognitive and metacognitive processes, epistemic criteria and reasoning. The authors focus on the difficulties inherent in shifting a tradition of teaching from one dominated by authoritative exposition to one that is more dialogic, involving small-group discussion based on tasks that stimulate argumentation. The paper builds on previous research on enhancing the quality of argument in school science, to focus on how argumentation activities have been designed, with appropriate strategies, resources and modelling, for pedagogical purposes. The paper analyses design frameworks, their contexts and lesson plans, to evaluate their potential for enhancing reasoning through foregrounding the processes of argumentation. Examples of classroom dialogue where teachers adopt the frameworks/plans are analysed to show how argumentation processes are scaffolded. The analysis shows that several layers of interpretation are needed and these layers need to be aligned for successful implementation. The analysis serves to highlight the potential and limitations of the design frameworks

    Modelling chemistry in the nocturnal boundary layer above tropical rainforest and a generalised effective nocturnal ozone deposition velocity for sub-ppbv NOx conditions

    Get PDF
    Measurements of atmospheric composition have been made over a remote rainforest landscape. A box model has previously been demonstrated to model the observed daytime chemistry well. However the box model is unable to explain the nocturnal measurements of relatively high [NO] and [O3], but relatively low observed [NO2]. It is shown that a one-dimensional (1-D) column model with simple O3 -NOx chemistry and a simple representation of vertical transport is able to explain the observed nocturnal concentrations and predict the likely vertical profiles of these species in the nocturnal boundary layer (NBL). Concentrations of tracers carried over from the end of the night can affect the atmospheric chemistry of the following day. To ascertain the anomaly introduced by using the box model to represent the NBL, vertically-averaged NBL concentrations at the end of the night are compared between the 1-D model and the box model. It is found that, under low to medium [NOx] conditions (NOx <1 ppbv), a simple parametrisation can be used to modify the box model deposition velocity of ozone, in order to achieve good agreement between the box and 1-D models for these end-of-night concentrations of NOx and O3. This parametrisation would could also be used in global climate-chemistry models with limited vertical resolution near the surface. Box-model results for the following day differ significantly if this effective nocturnal deposition velocity for ozone is implemented; for instance, there is a 9% increase in the following day’s peak ozone concentration. However under medium to high [NOx] conditions (NOx > 1 ppbv), the effect on the chemistry due to the vertical distribution of the species means no box model can adequately represent chemistry in the NBL without modifying reaction rate constants

    Impacts of climate change on plant diseases – opinions and trends

    Get PDF
    There has been a remarkable scientific output on the topic of how climate change is likely to affect plant diseases in the coming decades. This review addresses the need for review of this burgeoning literature by summarizing opinions of previous reviews and trends in recent studies on the impacts of climate change on plant health. Sudden Oak Death is used as an introductory case study: Californian forests could become even more susceptible to this emerging plant disease, if spring precipitations will be accompanied by warmer temperatures, although climate shifts may also affect the current synchronicity between host cambium activity and pathogen colonization rate. A summary of observed and predicted climate changes, as well as of direct effects of climate change on pathosystems, is provided. Prediction and management of climate change effects on plant health are complicated by indirect effects and the interactions with global change drivers. Uncertainty in models of plant disease development under climate change calls for a diversity of management strategies, from more participatory approaches to interdisciplinary science. Involvement of stakeholders and scientists from outside plant pathology shows the importance of trade-offs, for example in the land-sharing vs. sparing debate. Further research is needed on climate change and plant health in mountain, boreal, Mediterranean and tropical regions, with multiple climate change factors and scenarios (including our responses to it, e.g. the assisted migration of plants), in relation to endophytes, viruses and mycorrhiza, using long-term and large-scale datasets and considering various plant disease control methods
    corecore