The result of acute induced psychosocial stress on pain sensitivity and modulation in healthy people

Background: Pain can be influenced by several factors, including stress. Stress can have various reactions on pain. These reactions are influenced by several internal factors such as gender, age, and experience with stress or pain. Objectives: To determine the effect of acute stress on mechanical hyperalgesia (with pressure pain thresholds [PPT]), endogenous pain facilitation (measured by temporal summation [TS]), and inhibition (measured by conditioned pain modulation [CPM]) in healthy people and to determine which factors are responsible for this stress result. Study Design: Pre-posttest design. Setting: Healthy volunteers from Belgium. Methods: One hundred and one healthy pain-free patients underwent a modified Trier Social Stress Test. Prior and following the stress manipulation, PPT, TS, and CPM efficacy were determined in the mm. trapezius and quadriceps and overall. Furthermore, possible explanatory factors, such as fear of pain, pain catastrophizing, pain hypervigilance, and daily activity levels, were assessed using questionnaires. Results: We found a significant stress result on widespread pain sensitivity, with an increase of PPT (P 0.05), and a decrease in CPM efficacy (P < 0.001). Factors associated with the stress result were age, previous surgery, attentional focus on the conditioning stimulus during CPM, fear of pain, and daily activity levels. Limitations: The efficacy of the stress manipulation was not examined, and the lack of a control group prevented to examine a real stress-effect. Furthermore, no physiologic parameters were measured as possibly influencing internal factors for the stress-result. Conclusions: The increase in PPT was not a clinically significant change, whereas the decrease in CPM was meaningful. None of the factors predicted the stress result in all experimental pain measurements, and the predictions that were observed only explained a small proportion of the observed effects

Overview: On the transport and transformation of pollutants in the outflow of major population centres – observational data from the EMeRGe European intensive operational period in summer 2017

Megacities and other major population centres (MPCs) worldwide are major sources of air pollution, both locally as well as downwind. The overall assessment and prediction of the impact of MPC pollution on tropospheric chemistry are challenging. The present work provides an overview of the highlights of a major new contribution to the understanding of this issue based on the data and analysis of the EMeRGe (Effect of Megacities on the transport and transformation of pollutants on the Regional to Global scales) international project. EMeRGe focuses on atmospheric chemistry, dynamics, and transport of local and regional pollution originating in MPCs. Airborne measurements, taking advantage of the long range capabilities of the High Altitude and LOng Range Research Aircraft (HALO, https://www.halo-spp.de, last access: 22 March 2022), are a central part of the project. The synergistic use and consistent interpretation of observational data sets of different spatial and temporal resolution (e.g. from ground-based networks, airborne campaigns, and satellite measurements) supported by modelling within EMeRGe provide unique insight to test the current understanding of MPC pollution outflows. In order to obtain an adequate set of measurements at different spatial scales, two field experiments were positioned in time and space to contrast situations when the photochemical transformation of plumes emerging from MPCs is large. These experiments were conducted in summer 2017 over Europe and in the inter-monsoon period over Asia in spring 2018. The intensive observational periods (IOPs) involved HALO airborne measurements of ozone and its precursors, volatile organic compounds, aerosol particles, and related species as well as coordinated ground-based ancillary observations at different sites. Perfluorocarbon (PFC) tracer releases and model forecasts supported the flight planning, the identification of pollution plumes, and the analysis of chemical transformations during transport. This paper describes the experimental deployment and scientific questions of the IOP in Europe. The MPC targets – London (United Kingdom; UK), the Benelux/Ruhr area (Belgium, the Netherlands, Luxembourg and Germany), Paris (France), Rome and the Po Valley (Italy), and Madrid and Barcelona (Spain) – were investigated during seven HALO research flights with an aircraft base in Germany for a total of 53 flight hours. An in-flight comparison of HALO with the collaborating UK-airborne platform Facility for Airborne Atmospheric Measurements (FAAM) took place to assure accuracy and comparability of the instrumentation on board. Overall, EMeRGe unites measurements of near- and far-field emissions and hence deals with complex air masses of local and distant sources. Regional transport of several European MPC outflows was successfully identified and measured. Chemical processing of the MPC emissions was inferred from airborne observations of primary and secondary pollutants and the ratios between species having different chemical lifetimes. Photochemical processing of aerosol and secondary formation or organic acids was evident during the transport of MPC plumes. Urban plumes mix efficiently with natural sources as mineral dust and with biomass burning emissions from vegetation and forest fires. This confirms the importance of wildland fire emissions in Europe and indicates an important but discontinuous contribution to the European emission budget that might be of relevance in the design of efficient mitigation strategies. The present work provides an overview of the most salient results in the European context, with these being addressed in more detail within additional dedicated EMeRGe studies. The deployment and results obtained in Asia will be the subject of separate publications

Presbyopia:Effectiveness of correction strategies

Presbyopia is a global problem affecting over a billion people worldwide. The prevalence of unmanaged presbyopia is as high as 50% of those over 50 years of age in developing world populations due to a lack of awareness and accessibility to affordable treatment, and is even as high as 34% in developed countries. Definitions of presbyopia are inconsistent and varied, so we propose a redefinition that states “presbyopia occurs when the physiologically normal age-related reduction in the eye's focusing range reaches a point, when optimally corrected for distance vision, that the clarity of vision at near is insufficient to satisfy an individual's requirements”. Presbyopia is inevitable if one lives long enough, but intrinsic and extrinsic risk factors including cigarette smoking, pregnancy history, hyperopic or astigmatic refractive error, ultraviolet radiation, female sex (although accommodation is similar to males), hotter climates and some medical conditions such as diabetes can accelerate the onset of presbyopic symptoms. Whilst clinicians can ameliorate the symptoms of presbyopia with near vision spectacle correction, bifocal and progressive spectacle lenses, monovision, translating or multifocal contact lenses, monovision, extended depth of focus, multifocal (refractive, diffractive and asymmetric designs) or ‘accommodating’ intraocular lenses, corneal inlays, scleral expansion, laser refractive surgery (corneal monovision, corneal shrinkage, corneal multifocal profiles and lenticular softening), pharmacologic agents, and electro-stimulation of the ciliary muscle, none fully overcome presbyopia in all patients. While the restoration of natural accommodation or an equivalent remains elusive, guidance is gives on presbyopic correction evaluation techniques

Treatment of central sensitization in patients with rheumatoid arthritis : a narrative overview

Purpose of reviewCentral sensitization (CS) is present in a variety of chronic pain conditions including rheumatoid arthritis (RA). An overview of the treatment options for desensitizing the central nervous system in RA patients, with CS as their dominant pain mechanism, is provided.Recent findingsThe treatment of pain in RA patients has mostly focused on treating inflammation to indirectly treat pain. Unfortunately, little research has focused on treating CS, which appears to be present in some patients with RA.Summary"Treating the brain without ignoring the joints" should be the leading principle in the management of CS in RA patients. Pain neuroscience education, graded activity, and a time-contingent exercise approach are important interventions to implement in clinical practice. Further research is necessary to evaluate the effectiveness of these promising treatments for diminishing hyperexcitability of the central nervous system in RA patients with CS as their dominant pain mechanism