101 research outputs found

    Transcriptomic Analysis Reveals Novel Mechanistic Insight into Murine Biological Responses to Multi-Walled Carbon Nanotubes in Lungs and Cultured Lung Epithelial Cells

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    There is great interest in substituting animal work with in vitro experimentation in human health risk assessment; however, there are only few comparisons of in vitro and in vivo biological responses to engineered nanomaterials. We used high-content genomics tools to compare in vivo pulmonary responses of multiwalled carbon nanotubes (MWCNT) to those in vitro in cultured lung epithelial cells (FE1) at the global transcriptomic level. Primary size, surface area and other properties of MWCNT- XNRI -7 (Mitsui7) were characterized using DLS, SEM and TEM. Mice were exposed via a single intratracheal instillation to 18, 54, or 162 μg of Mitsui7/mouse. FE1 cells were incubated with 12.5, 25 and 100 μg/ml of Mitsui7. Tissue and cell samples were collected at 24 hours post-exposure. DNA microarrays were employed to establish mechanistic differences and similarities between the two models. Microarray results were confirmed using gene-specific RT-qPCR. Bronchoalveolar lavage (BAL) fluid was assessed for indications of inflammation in vivo. A strong dose-dependent activation of acute phase and inflammation response was observed in mouse lungs reflective mainly of an inflammatory response as observed in BAL. In vitro, a wide variety of core cellular functions were affected including transcription, cell cycle, and cellular growth and proliferation. Oxidative stress, fibrosis and inflammation processes were altered in both models. Although there were similarities observed between the two models at the pathway-level, the specific genes altered under these pathways were different, suggesting that the underlying mechanisms of responses are different in cells in culture and the lung tissue. Our results suggest that careful consideration should be given in selecting relevant endpoints when substituting animal with in vitro testing

    The association between weekly hours of physical activity and mental health: A three-year follow-up study of 15–16-year-old students in the city of Oslo, Norway

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    <p>Abstract</p> <p>Background</p> <p>Mental health problems are a worldwide public health burden. The literature concerning the mental health benefits from physical activity among adults has grown. Adolescents are less studied, and especially longitudinal studies are lacking. This paper investigates the associations between weekly hours of physical activity at age 15–16 and mental health three years later.</p> <p>Methods</p> <p>Longitudinal self-reported health survey. The baseline study consisted of participants from the youth section of the Oslo Health Study, carried out in schools in 2000–2001 (<it>n </it>= 3811). The follow-up in 2003–2004 was conducted partly at school and partly through mail. A total of 2489 (1112 boys and 1377 girls) participated in the follow-up. Mental health was measured by the Strengths and Difficulties Questionnaire with an impact supplement. Physical activity was measured by a question on weekly hours of physical activity outside of school, defined as exertion 'to an extent that made you sweat and/or out of breath'. Adjustments were made for well-documented confounders and mental health at baseline.</p> <p>Results</p> <p>In boys, the number of hours spent on physical activity per week at age 15–16 was negatively associated with emotional symptoms [B (95%CI) = -0.09 (-0.15, -0.03)] and peer problems [B (95%CI) = -0.08 (-0.14, -0.03)] at age 18–19 after adjustments. In girls, there were no significant differences in SDQ subscales at age 18–19 according to weekly hours of physical activity at age 15–16 after adjustments. Boys and girls with five to seven hours of physical activity per week at age 15–16 had the lowest mean scores for total difficulties and the lowest percentage with high impact score at age 18–19, but the differences were not statistically significant after adjustments.</p> <p>Conclusion</p> <p>Weekly hours of physical activity at age 15–16 years was weakly associated with mental health at three-year follow-up in boys. Results encourage a search for further knowledge about physical activity as a possible protective factor in relation to mental health problems in adolescence.</p

    Characterising paediatric mortality during and after acute illness in Sub-Saharan Africa and South Asia: a secondary analysis of the CHAIN cohort using a machine learning approach

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    Background A better understanding of which children are likely to die during acute illness will help clinicians and policy makers target resources at the most vulnerable children. We used machine learning to characterise mortality in the 30-days following admission and the 180-days after discharge from nine hospitals in low and middle-income countries (LMIC). Methods A cohort of 3101 children aged 2–24 months were recruited at admission to hospital for any acute illness in Bangladesh (Dhaka and Matlab Hospitals), Pakistan (Civil Hospital Karachi), Kenya (Kilifi, Mbagathi, and Migori Hospitals), Uganda (Mulago Hospital), Malawi (Queen Elizabeth Central Hospital), and Burkina Faso (Banfora Hospital) from November 2016 to January 2019. To record mortality, children were observed during their hospitalisation and for 180 days post-discharge. Extreme gradient boosted models of death within 30 days of admission and mortality in the 180 days following discharge were built. Clusters of mortality sharing similar characteristics were identified from the models using Shapley additive values with spectral clustering. Findings Anthropometric and laboratory parameters were the most influential predictors of both 30-day and post-discharge mortality. No WHO/IMCI syndromes were among the 25 most influential mortality predictors of mortality. For 30-day mortality, two lower-risk clusters (N = 1915, 61%) included children with higher-than-average anthropometry (1% died, 95% CI: 0–2), and children without signs of severe illness (3% died, 95% CI: 2–4%). The two highest risk 30-day mortality clusters (N = 118, 4%) were characterised by high urea and creatinine (70% died, 95% CI: 62–82%); and nutritional oedema with low platelets and reduced consciousness (97% died, 95% CI: 92–100%). For post-discharge mortality risk, two low-risk clusters (N = 1753, 61%) were defined by higher-than-average anthropometry (0% died, 95% CI: 0–1%), and gastroenteritis with lower-than-average anthropometry and without major laboratory abnormalities (0% died, 95% CI: 0–1%). Two highest risk post-discharge clusters (N = 267, 9%) included children leaving against medical advice (30% died, 95% CI: 25–37%), and severely-low anthropometry with signs of illness at discharge (46% died, 95% CI: 34–62%). Interpretation WHO clinical syndromes are not sufficient at predicting risk. Integrating basic laboratory features such as urea, creatinine, red blood cell, lymphocyte and platelet counts into guidelines may strengthen efforts to identify high-risk children during paediatric hospitalisations. Funding Bill & Melinda Gates Foundation OPP1131320

    Antioxidant Defenses Predict Long-Term Survival in a Passerine Bird

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    Normal and pathological processes entail the production of oxidative substances that can damage biological molecules and harm physiological functions. Organisms have evolved complex mechanisms of antioxidant defense, and any imbalance between oxidative challenge and antioxidant protection can depress fitness components and accelerate senescence. While the role of oxidative stress in pathogenesis and aging has been studied intensively in humans and model animal species under laboratory conditions, there is a dearth of knowledge on its role in shaping life-histories of animals under natural selection regimes. Yet, given the pervasive nature and likely fitness consequences of oxidative damage, it can be expected that the need to secure efficient antioxidant protection is powerful in molding the evolutionary ecology of animals. Here, we test whether overall antioxidant defense varies with age and predicts long-term survival, using a wild population of a migratory passerine bird, the barn swallow (Hirundo rustica), as a model.Plasma antioxidant capacity (AOC) of breeding individuals was measured using standard protocols and annual survival was monitored over five years (2006-2010) on a large sample of selection episodes. AOC did not covary with age in longitudinal analyses after discounting the effect of selection. AOC positively predicted annual survival independently of sex. Individuals were highly consistent in their relative levels of AOC, implying the existence of additive genetic variance and/or environmental (including early maternal) components consistently acting through their lives.Using longitudinal data we showed that high levels of antioxidant protection positively predict long-term survival in a wild animal population. Present results are therefore novel in disclosing a role for antioxidant protection in determining survival under natural conditions, strongly demanding for more longitudinal eco-physiological studies of life-histories in relation to oxidative stress in wild populations

    Asthma control in adolescents 10 to 11 y after exposure to the World Trade Center disaster

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    Background: Little is known about asthma control in adolescents who were exposed to the World Trade Center (WTC) attacks of 11 September 2001 and diagnosed with asthma after 9/11. This report examines asthma and asthma control 10–11 y after 9/11 among exposed adolescents. Methods: The WTC Health Registry adolescent Wave 3 survey (2011–2012) collected data on asthma diagnosed by a physician after 11 September 2001, extent of asthma control based on modified National Asthma Education and Prevention Program criteria, probable mental health conditions, and behavior problems. Parents reported healthcare needs and 9/11-exposures. Logistic regression was used to evaluate associations between asthma and level of asthma control and 9/11-exposure, mental health and behavioral problems, and unmet healthcare needs. Results: Poorly/very poorly controlled asthma was significantly associated with a household income of ≤$75,000 (adjusted odds ratio (AOR): 3.0; 95% confidence interval (CI): 1.1–8.8), having unmet healthcare needs (AOR: 6.2; 95% CI: 1.4–27.1), and screening positive for at least one mental health condition (AOR: 5.0; 95% CI: 1.4–17.7), but not with behavioral problems. The impact of having at least one mental health condition on the level of asthma control was substantially greater in females than in males. Conclusions: Comprehensive care of post-9/11 asthma in adolescents should include management of mental health-related comorbidities. The collapse and burning of the World Trade Center (WTC) towers on 11 September 2001 (9/11) exposed hundreds of thousands of people to a complex mixture of dust, debris, and jet fuel combustion byproducts (1). It is estimated that over 25,000 persons in lower Manhattan developed asthma symptoms after exposure to the WTC terrorist attacks and the subsequent rescue and recovery efforts (1). In the years immediately following 9/11, new-onset asthma rates were elevated among exposed adults and many of those affected continued to experience respiratory symptoms (i.e., coughing, shortness of breath) years later (1,2). An estimated 25,000 children were living or attending school in lower Manhattan near the WTC on 9/11, and potentially were in the path of the dust cloud of building debris and smoke after the collapse of the towers, as well as for several months following the attacks, and could have inhaled particulate matter and toxic substances (3,4). Associations between 9/11-related exposures and both asthma diagnosis and persistent respiratory symptoms among children and adolescents have been documented (4,5,6). A previous report found that 2 to 3 y after 9/11, over half of children under 18 y of age who were enrolled in the World Trade Center Health Registry (Registry) reported new or worsening respiratory symptoms (53%), and 5.7% reported a post-9/11 diagnosis of asthma, both of which were associated with exposure to the dust cloud that resulted from the collapse of buildings on 9/11 (4). A subsequent study of Registry enrollees under 18 y old found that respiratory symptoms persisted up to 7 y post-9/11 (5). The WTC Environmental Health Center which collected clinical data on a sample of children an average of 7.8 y after 9/11, reported new onset provider-diagnosed asthma in 21.4% of children, and found that dust cloud exposure was associated with pulmonary function abnormalities, such as isolated low forced vital capacity pattern and an obstructive pattern consistent with asthma (6). Although the association between asthma and 9/11-exposure in children and adolescents has been documented, little is known about asthma control in this population. Large population-based surveys consistently show that poor asthma control is common in many children with asthma (7,8). Asthma control is affected by many factors, including healthcare access (9,10), socioeconomic status (9,10), and comorbid mental health conditions (11,12,13). It has been observed that adolescents with symptomatic asthma are more likely than adolescents without asthma to have lower perceived well-being, more negative behaviors, and a greater number of physical and mental health comorbidities (14). Several studies found that depression has been associated with uncontrolled asthma (11,12). In adults with 9/11-related asthma, having at least one mental health condition has been associated with poorly controlled asthma (15). However, little is known about the association between mental health conditions and the level of asthma control especially among 9/11-exposed adolescents. Previous studies of adult Registry enrollees found that those with unmet healthcare needs are more likely to have severe mental health symptoms, comorbid mental and physical health problems, and have lower quality of life (1,16). Unmet healthcare needs among adolescents have been shown to be associated with poorer health status and functioning, including asthma control (17). Poorly controlled asthma has also been associated with unmet healthcare needs related to cost or access barriers (18), such as an inability to pay for asthma medications and not having access to asthma specialists (19). The goal of this study was to evaluate asthma control 10–11 y after 9/11 among Registry as children, and to determine whether poor asthma control is associated with specific factors including adolescent 9/11-exposure, adverse mental health, behavior problems, and unmet healthcare needs

    Structure-Function Analysis of STRUBBELIG, an Arabidopsis Atypical Receptor-Like Kinase Involved in Tissue Morphogenesis

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    Tissue morphogenesis in plants requires the coordination of cellular behavior across clonally distinct histogenic layers. The underlying signaling mechanisms are presently being unraveled and are known to include the cell surface leucine-rich repeat receptor-like kinase STRUBBELIG in Arabidopsis. To understand better its mode of action an extensive structure-function analysis of STRUBBELIG was performed. The phenotypes of 20 EMS and T-DNA-induced strubbelig alleles were assessed and homology modeling was applied to rationalize their possible effects on STRUBBELIG protein structure. The analysis was complemented by phenotypic, cell biological, and pharmacological investigations of a strubbelig null allele carrying genomic rescue constructs encoding fusions between various mutated STRUBBELIG proteins and GFP. The results indicate that STRUBBELIG accepts quite some sequence variation, reveal the biological importance for the STRUBBELIG N-capping domain, and reinforce the notion that kinase activity is not essential for its function in vivo. Furthermore, individual protein domains of STRUBBELIG cannot be related to specific STRUBBELIG-dependent biological processes suggesting that process specificity is mediated by factors acting together with or downstream of STRUBBELIG. In addition, the evidence indicates that biogenesis of a functional STRUBBELIG receptor is subject to endoplasmic reticulum-mediated quality control, and that an MG132-sensitive process regulates its stability. Finally, STRUBBELIG and the receptor-like kinase gene ERECTA interact synergistically in the control of internode length. The data provide genetic and molecular insight into how STRUBBELIG regulates intercellular communication in tissue morphogenesis

    Determination of sin2 θeff w using jet charge measurements in hadronic Z decays

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    The electroweak mixing angle is determined with high precision from measurements of the mean difference between forward and backward hemisphere charges in hadronic decays of the Z. A data sample of 2.5 million hadronic Z decays recorded over the period 1990 to 1994 in the ALEPH detector at LEP is used. The mean charge separation between event hemispheres containing the original quark and antiquark is measured for bb̄ and cc̄ events in subsamples selected by their long lifetimes or using fast D*'s. The corresponding average charge separation for light quarks is measured in an inclusive sample from the anticorrelation between charges of opposite hemispheres and agrees with predictions of hadronisation models with a precision of 2%. It is shown that differences between light quark charge separations and the measured average can be determined using hadronisation models, with systematic uncertainties constrained by measurements of inclusive production of kaons, protons and A's. The separations are used to measure the electroweak mixing angle precisely as sin2 θeff w = 0.2322 ± 0.0008(exp. stat.) ±0.0007(exp. syst.) ± 0.0008(sep.). The first two errors are due to purely experimental sources whereas the third stems from uncertainties in the quark charge separations

    Small Theropod Teeth from the Late Cretaceous of the San Juan Basin, Northwestern New Mexico and Their Implications for Understanding Latest Cretaceous Dinosaur Evolution

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    Studying the evolution and biogeographic distribution of dinosaurs during the latest Cretaceous is critical for better understanding the end-Cretaceous extinction event that killed off all non-avian dinosaurs. Western North America contains among the best records of Late Cretaceous terrestrial vertebrates in the world, but is biased against small-bodied dinosaurs. Isolated teeth are the primary evidence for understanding the diversity and evolution of small-bodied theropod dinosaurs during the Late Cretaceous, but few such specimens have been well documented from outside of the northern Rockies, making it difficult to assess Late Cretaceous dinosaur diversity and biogeographic patterns. We describe small theropod teeth from the San Juan Basin of northwestern New Mexico. These specimens were collected from strata spanning Santonian - Maastrichtian. We grouped isolated theropod teeth into several morphotypes, which we assigned to higher-level theropod clades based on possession of phylogenetic synapomorphies. We then used principal components analysis and discriminant function analyses to gauge whether the San Juan Basin teeth overlap with, or are quantitatively distinct from, similar tooth morphotypes from other geographic areas. The San Juan Basin contains a diverse record of small theropods. Late Campanian assemblages differ from approximately coeval assemblages of the northern Rockies in being less diverse with only rare representatives of troodontids and a Dromaeosaurus-like taxon. We also provide evidence that erect and recurved morphs of a Richardoestesia-like taxon represent a single heterodont species. A late Maastrichtian assemblage is dominated by a distinct troodontid. The differences between northern and southern faunas based on isolated theropod teeth provide evidence for provinciality in the late Campanian and the late Maastrichtian of North America. However, there is no indication that major components of small-bodied theropod diversity were lost during the Maastrichtian in New Mexico. The same pattern seen in northern faunas, which may provide evidence for an abrupt dinosaur extinction
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