69 research outputs found
Maternal Smoking in Pregnancy: Do the Effects on Innate (Toll-Like Receptor) Function Have Implications for Subsequent Allergic Disease?
Subtle increases in immaturity of immune function in early infancy have been implicated in the rising susceptibility to allergic disease, particularly relative impairment of type 1 interferon (IFN)-γ responses in the neonatal period. Although genetic predisposition is a clear risk factor, the escalating rates of allergic disease in infancy suggest that environmental factors are also implicated. We previously showed that maternal smoking in pregnancy may impair neonatal IFN-γ responses. Our more recent studies now indicate that this common avoidable toxic exposure is also associated with attenuation of innate immune function, with attenuated Toll-like receptor (TLR)-mediated microbial responses (including TLR-2, -3, -4, and -9 responses). Most notably, the effects were more marked if the mothers were also allergic. In this review, we discuss the significance of these observations in the context of the emerging hypothesis that variations in TLR function in early life may be implicated in allergic propensity. There is now growing evidence that many of the key pathways involved in subsequent T-cell programming and regulation (namely, antigen-presenting cells and regulatory T cells) rely heavily on microbe-driven TLR activation for maturation and function. Factors that influence the function and activity of these innate pathways in early life may contribute to the increasing predisposition for allergic disease. Although "cleaner" environments have been implicated, here we explore the possibility that other common environmental exposures (such as maternal smoking) could also play a role.</p
Reviewing the preclinical curriculum in a problem based learning driven medical program: Challenges and strategies
In order for medical curricula to remain progressive and contemporary, continuous review is critical to ensure that the learners are directed to achieve the intended goals and become workforce ready. We developed a framework for continuous curriculum review at the School of Medicine Fremantle (The University of Notre Dame Australia), taking the key aspects of a curriculum review process into consideration. In planning and implementing the review process we identified several challenges, including management of metadata, work load on staff members, and evaluation. These challenges were addressed successfully by applying necessary strategies using limited resources. The framework we have developed provides a guide to key stakeholders who are involved in medical curriculum review and development
The structure of epitaxial V2O3 films and their surfaces : a medium energy ion scattering study
Medium energy ion scattering, using 100 keV H+ incident ions, has been used to investigate the growth of epitaxial films, up to thicknesses of ~200 Å, of V2O3 on both Pd(111) and Au(111). Scattered-ion energy spectra provide a measure of the average film thickness and the variations in this thickness, and show that, with suitable annealing, the crystalline quality is good. Plots of the scattering yield as a function of scattering angle, so-called blocking curves, have been measured for two different incidence directions and have been used to determine the surface structure. Specifically, scattering simulations for a range of different model structures show poor agreement with experiment for half-metal (….V’O3V) and vanadyl (….V’O3V=O) terminations, with and without surface interlayer relaxations. However, good agreement with experiment is found for the modified oxygen-termination structure, first proposed by Kresse et al., in which a subsurface V half-metal layer is moved up into the outermost V buckled metal layer to produce a VO2 overlayer on the underlying V2O3, with an associated layer structure of ….O3VV’’V’O3
Far-UVC (222 nm) efficiently inactivated an airborne pathogen in a room-sized chamber
Funding: We acknowledge the financial assistance of the United Kingdom’s Department for Health and Social Care (2020/092).Many infectious diseases, including COVID-19, are transmitted by airborne pathogens. There is a need for effective environmental control measures which, ideally, are not reliant on human behaviour. One potential solution is Krypton Chloride (KrCl) excimer lamps (often referred to as Far-UVC), which can efficiently inactivate pathogens, such as coronaviruses and influenza, in air. Research demonstrates that when KrCl lamps are filtered to remove longer-wavelength ultraviolet emissions they do not induce acute reactions in the skin or eyes, nor delayed effects such as skin cancer. While there is laboratory evidence for Far-UVC efficacy, there is limited evidence in full-sized rooms. For the first time, we show that Far-UVC deployed in a room-sized chamber effectively inactivates aerosolised Staphylococcus aureus. At a room ventilation rate of 3 air-changes-per-hour (ACH), with 5 filtered-sources the steady-state pathogen load was reduced by 98.4% providing an additional 184 equivalent air changes (eACH). This reduction was achieved using Far-UVC irradiances consistent with current American Conference of Governmental Industrial Hygienists threshold limit values for skin for a continuous 8-h exposure. Our data indicate that Far-UVC is likely to be more effective against common airborne viruses, including SARS-CoV-2, than bacteria and should thus be an effective and “hands-off” technology to reduce airborne disease transmission. The findings provide room-scale data to support the design and development of effective Far-UVC systems.Publisher PDFPeer reviewe
Pre-cooling for endurance exercise performance in the heat: a systematic review.
PMCID: PMC3568721The electronic version of this article is the complete one and can be found online at: http://www.biomedcentral.com/1741-7015/10/166.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.Endurance exercise capacity diminishes under hot environmental conditions. Time to exhaustion can be increased by lowering body temperature prior to exercise (pre-cooling). This systematic literature review synthesizes the current findings of the effects of pre-cooling on endurance exercise performance, providing guidance for clinical practice and further research
Changes in weight loss, body composition and cardiovascular disease risk after altering macronutrient distributions during a regular exercise program in obese women
<p>Abstract</p> <p>Background</p> <p>This study's purpose investigated the impact of different macronutrient distributions and varying caloric intakes along with regular exercise for metabolic and physiological changes related to weight loss.</p> <p>Methods</p> <p>One hundred forty-one sedentary, obese women (38.7 ± 8.0 yrs, 163.3 ± 6.9 cm, 93.2 ± 16.5 kg, 35.0 ± 6.2 kg•m<sup>-2</sup>, 44.8 ± 4.2% fat) were randomized to either no diet + no exercise control group (CON) a no diet + exercise control (ND), or one of four diet + exercise groups (high-energy diet [HED], very low carbohydrate, high protein diet [VLCHP], low carbohydrate, moderate protein diet [LCMP] and high carbohydrate, low protein [HCLP]) in addition to beginning a 3x•week<sup>-1 </sup>supervised resistance training program. After 0, 1, 10 and 14 weeks, all participants completed testing sessions which included anthropometric, body composition, energy expenditure, fasting blood samples, aerobic and muscular fitness assessments. Data were analyzed using repeated measures ANOVA with an alpha of 0.05 with LSD post-hoc analysis when appropriate.</p> <p>Results</p> <p>All dieting groups exhibited adequate compliance to their prescribed diet regimen as energy and macronutrient amounts and distributions were close to prescribed amounts. Those groups that followed a diet and exercise program reported significantly greater anthropometric (waist circumference and body mass) and body composition via DXA (fat mass and % fat) changes. Caloric restriction initially reduced energy expenditure, but successfully returned to baseline values after 10 weeks of dieting and exercising. Significant fitness improvements (aerobic capacity and maximal strength) occurred in all exercising groups. No significant changes occurred in lipid panel constituents, but serum insulin and HOMA-IR values decreased in the VLCHP group. Significant reductions in serum leptin occurred in all caloric restriction + exercise groups after 14 weeks, which were unchanged in other non-diet/non-exercise groups.</p> <p>Conclusions</p> <p>Overall and over the entire test period, all diet groups which restricted their caloric intake and exercised experienced similar responses to each other. Regular exercise and modest caloric restriction successfully promoted anthropometric and body composition improvements along with various markers of muscular fitness. Significant increases in relative energy expenditure and reductions in circulating leptin were found in response to all exercise and diet groups. Macronutrient distribution may impact circulating levels of insulin and overall ability to improve strength levels in obese women who follow regular exercise.</p
Subjecting Elite Athletes to Inspiratory Breathing Load Reveals Behavioral and Neural Signatures of Optimal Performers in Extreme Environments
Background: It is unclear whether and how elite athletes process physiological or psychological challenges differently than healthy comparison subjects. In general, individuals optimize exercise level as it relates to differences between expected and experienced exertion, which can be conceptualized as a body prediction error. The process of computing a body prediction error involves the insular cortex, which is important for interoception, i.e. the sense of the physiological condition of the body. Thus, optimal performance may be related to efficient minimization of the body prediction error. We examined the hypothesis that elite athletes, compared to control subjects, show attenuated insular cortex activation during an aversive interoceptive challenge. Methodology/Principal Findings: Elite adventure racers (n = 10) and healthy volunteers (n = 11) performed a continuous performance task with varying degrees of a non-hypercapnic breathing load while undergoing functional magnetic resonance imaging. The results indicate that (1) non-hypercapnic inspiratory breathing load is an aversive experience associated with a profound activation of a distributed set of brain areas including bilateral insula, dorsolateral prefrontal cortex and anterior cingulated; (2) adventure racers relative to comparison subjects show greater accuracy on the continuous performance task during the aversive interoceptive condition; and (3) adventure racers show an attenuated right insula cortex response during and following the aversive interoceptive condition of non-hypercapnic inspirator
Life-long Programming Implications of Exposure to Tobacco Smoking and Nicotine Before and Soon After Birth: Evidence for Altered Lung Development
Tobacco smoking during pregnancy remains common, especially in indigenous communities, and likely contributes to respiratory illness in exposed offspring. It is now well established that components of tobacco smoke, notably nicotine, can affect multiple organs in the fetus and newborn, potentially with life-long consequences. Recent studies have shown that nicotine can permanently affect the developing lung such that its final structure and function are adversely affected; these changes can increase the risk of respiratory illness and accelerate the decline in lung function with age. In this review we discuss the impact of maternal smoking on the lungs and consider the evidence that smoking can have life-long, programming consequences for exposed offspring. Exposure to maternal tobacco smoking and nicotine intake during pregnancy and lactation changes the genetic program that controls the development and aging of the lungs of the offspring. Changes in the conducting airways and alveoli reduce lung function in exposed offspring, rendering the lungs more susceptible to obstructive lung disease and accelerating lung aging. Although it is generally accepted that prevention of maternal smoking during pregnancy and lactation is essential, current knowledge of the effects of nicotine on lung development does not support the use of nicotine replacement therapy in this group
Fatigue in neuromuscular disorders: focus on Guillain–Barré syndrome and Pompe disease
Fatigue accounts for an important part of the burden experienced by patients with neuromuscular disorders. Substantial high prevalence rates of fatigue are reported in a wide range of neuromuscular disorders, such as Guillain–Barré syndrome and Pompe disease. Fatigue can be subdivided into experienced fatigue and physiological fatigue. Physiological fatigue in turn can be of central or peripheral origin. Peripheral fatigue is an important contributor to fatigue in neuromuscular disorders, but in reaction to neuromuscular disease fatigue of central origin can be an important protective mechanism to restrict further damage. In most cases, severity of fatigue seems to be related with disease severity, possibly with the exception of fatigue occurring in a monophasic disorder like Guillain–Barré syndrome. Treatment of fatigue in neuromuscular disease starts with symptomatic treatment of the underlying disease. When symptoms of fatigue persist, non-pharmacological interventions, such as exercise and cognitive behavioral therapy, can be initiated
Genetic mechanisms of critical illness in COVID-19.
Host-mediated lung inflammation is present1, and drives mortality2, in the critical illness caused by coronavirus disease 2019 (COVID-19). Host genetic variants associated with critical illness may identify mechanistic targets for therapeutic development3. Here we report the results of the GenOMICC (Genetics Of Mortality In Critical Care) genome-wide association study in 2,244 critically ill patients with COVID-19 from 208 UK intensive care units. We have identified and replicated the following new genome-wide significant associations: on chromosome 12q24.13 (rs10735079, P = 1.65 × 10-8) in a gene cluster that encodes antiviral restriction enzyme activators (OAS1, OAS2 and OAS3); on chromosome 19p13.2 (rs74956615, P = 2.3 × 10-8) near the gene that encodes tyrosine kinase 2 (TYK2); on chromosome 19p13.3 (rs2109069, P = 3.98 × 10-12) within the gene that encodes dipeptidyl peptidase 9 (DPP9); and on chromosome 21q22.1 (rs2236757, P = 4.99 × 10-8) in the interferon receptor gene IFNAR2. We identified potential targets for repurposing of licensed medications: using Mendelian randomization, we found evidence that low expression of IFNAR2, or high expression of TYK2, are associated with life-threatening disease; and transcriptome-wide association in lung tissue revealed that high expression of the monocyte-macrophage chemotactic receptor CCR2 is associated with severe COVID-19. Our results identify robust genetic signals relating to key host antiviral defence mechanisms and mediators of inflammatory organ damage in COVID-19. Both mechanisms may be amenable to targeted treatment with existing drugs. However, large-scale randomized clinical trials will be essential before any change to clinical practice
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