184 research outputs found

    P2X7 receptor is essential for cross-dressing of bone marrow-derived dendritic cells

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    T cell activation requires the processing and presentation of antigenic peptides in the context of a major histocompatibility complex (MHC complex). Cross-dressing is a non-conventional antigen presentation mechanism, involving the transfer of preformed peptide/MHC complexes from whole cells, such as apoptotic cells (ACs) to the cell membrane of professional antigen-presenting cells (APCs), such as dendritic cells (DCs). This is an essential mechanism for the induction of immune response against viral antigens, tumors, and graft rejection, which until now has not been clarified. Here we show for first time that the P2X7 receptor (P2X7R) is crucial to induce cross-dressing between ACs and Bone-Marrow DCs (BMDCs). In controlled ex vivo assays, we found that the P2X7R in both ACs and BMDCs is required to induce membrane and fully functional peptide/MHC complex transfer to BMDCs. These findings show that acquisition of ACs-derived preformed antigen/MHC-I complexes by BMDCs requires P2X7R expression.Fil: Barrera Avalos, Carlos. Universidad de Santiago de Chile; ChileFil: Briceño, Pedro. Universidad de Chile; ChileFil: Valdés, Daniel. Universidad de Santiago de Chile; ChileFil: Imarai, Mónica. Universidad de Santiago de Chile; ChileFil: Leiva Salcedo, Elías. Universidad de Santiago de Chile; ChileFil: Rojo, Leonel E.. Universidad de Santiago de Chile; ChileFil: Milla, Luis A.. Universidad de Santiago de Chile; ChileFil: Huidobro Toro, Juan Pablo. Universidad de Santiago de Chile; ChileFil: Robles Planells, Claudia. Universidad de Santiago de Chile; ChileFil: Escobar, Alejandro. Universidad de Chile; ChileFil: Di Virgilio, Francesco. Università di Ferrara; ItaliaFil: Moron, Victor Gabriel. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Bioquímica Clínica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; ArgentinaFil: Sauma, Daniela. Universidad de Chile; ChileFil: Acuña Castillo, Claudio. Universidad de Santiago de Chile; Chil

    Association between long term exposure to particulate matter and incident hypertension in Spain

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    Exposure to air particulate matter has been linked with hypertension and blood pressure levels. The metabolic risks of air pollution could vary according to the specific characteristics of each area, and has not been sufficiently evaluated in Spain. We analyzed 1103 individuals, participants in a Spanish nationwide population based cohort study ([email protected]), who were free of hypertension at baseline (2008-2010) and completed a follow-up exam of the cohort (2016-2017). Cohort participants were assigned air pollution concentrations for particulate matter < 10 mu m (PM10) and < 2.5 mu m (PM2.5) during follow-up (2008-2016) obtained through modeling combined with measurements taken at air quality stations (CHIMERE chemistry-transport model). Mean and SD concentrations of PM10 and PM2.5 were 20.17 +/- 3.91 mu g/m(3) and 10.83 +/- 2.08 mu g/m(3) respectively. During follow-up 282 cases of incident hypertension were recorded. In the fully adjusted model, compared with the lowest quartile of PM10, the multivariate weighted ORs (95% CIs) for developing hypertension with increasing PM10 exposures were 0.82 (0.59-1.14), 1.28 (0.93-1.78) and 1.45 (1.05-2.01) in quartile 2, 3 and 4 respectively (p for a trend of 0.003). The corresponding weighted ORs according to PM2.5 exposures were 0.80 (0.57-1.13), 1.11 (0.80-1.53) and 1.48 (1.09-2.00) (p for trend 0.004). For each 5-mu g/m(3) increment in PM10 and PM2.5 concentrations, the odds for incident hypertension increased 1.22 (1.06-1.41) p = 0.007 and 1.39 (1.07-1.81) p = 0.02 respectively. In conclusion, our study contributes to assessing the impact of particulate pollution on the incidence of hypertension in Spain, reinforcing the need for improving air quality as much as possible in order to decrease the risk of cardiometabolic disease in the population

    Association between exposure to air pollution and blood lipids in the general population of Spain.

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    Background and Aims: We aimed to assess the associations of exposure to air pollutants and standard and advanced lipoprotein measures, in a nationwide sample representative of the adult population of Spain.Methods: We included 4647 adults (>18 years), participants in the national, cross- sectional, population- based [email protected] study, conducted in 2008– 2010. Standard lipid measurements were analysed on an Architect C8000 Analyzer (Abbott Laboratories SA). Lipoprotein analysis was made by an advanced 1H- NMR lipoprotein test (LiposcaleÂź). Participants were assigned air pollution con-centrations for particulate matter <10 ÎŒm (PM10), <2.5 ÎŒm (PM2.5) and nitrogen dioxide (NO2), corresponding to the health examination year, obtained by mod-elling combined with measurements taken at air quality stations (CHIMERE chemistry- transport model).Results: In multivariate linear regression models, each IQR increase in PM10, PM2.5 and NO2 was associated with 3.3%, 3.3% and 3% lower levels of HDL- c and 1.3%, 1.4% and 1.1% lower HDL particle (HDL- p) concentrations (p< .001 for all associations). In multivariate logistic regression, there was a significant associa-tion between PM10, PM2.5 and NO2 concentrations and the odds of presenting low HDL- c (<40 mg/dL), low HDL- p (<p25) and higher LDL particle (LDL- p) concentrations (≄p75). In subgroup analyses there were stronger associations be-tween PM10 and NO2 and low HDL- p in men (p for interaction .008 and .034), and between NO2 and low HDL- p in individuals with obesity (p for interaction .015).Conclusions: Our study shows an association between the exposure to air pol-lutants and blood lipids in the general population of Spain, suggesting a link to atherosclerosisFunding for open access charge: Universidad de MĂĄlaga / CBU

    Ambient air pollution and thyroid function in Spanish adults. A nationwide population-based study ([email protected] study)

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    Background Recent reports have suggested that air pollution may impact thyroid function, although the evidence is still scarce and inconclusive. In this study we evaluated the association of exposure to air pollutants to thyroid function parameters in a nationwide sample representative of the adult population of Spain. Methods The [email protected] study is a national, cross-sectional, population-based survey which was conducted in 2008-2010 using a random cluster sampling of the Spanish population. The present analyses included 3859 individuals, without a previous thyroid disease diagnosis, and with negative thyroid peroxidase antibodies (TPO Abs) and thyroid-stimulating hormone (TSH) levels of 0.1-20 mIU/L. Participants were assigned air pollution concentrations for particulate matter <2.5 mu m (PM2.5) and Nitrogen Dioxide (NO2), corresponding to the health examination year, obtained by means of modeling combined with measurements taken at air quality stations (CHIMERE chemistry-transport model). TSH, free thyroxine (FT4), free triiodothyronine (FT3) and TPO Abs concentrations were analyzed using an electrochemiluminescence immunoassay (Modular Analytics E170 Roche). Results In multivariate linear regression models, there was a highly significant negative correlation between PM2.5 concentrations and both FT4 (p<0.001), and FT3 levels (p<0.001). In multivariate logistic regression, there was a significant association between PM2.5 concentrations and the odds of presenting high TSH [OR 1.24 (1.01-1.52) p=0.043], lower FT4 [OR 1.25 (1.02-1.54) p=0.032] and low FT3 levels [1.48 (1.19-1.84) p=<0.001] per each IQR increase in PM2.5 (4.86 mu g/m(3)). There was no association between NO2 concentrations and thyroid hormone levels. No significant heterogeneity was seen in the results between groups of men, pre-menopausal and post-menopausal women. Conclusions Exposures to PM2.5 in the general population were associated with mild alterations in thyroid function.CIBERDEM (Ministerio de Economia, Industria y Competitividad-ISCIII), Ministerio de Sanidad, Servicios Sociales e Igualdad-ISCIII, Instituto de Salud Carlos III (PI17/02136, PI20/01322), Consejeria de Salud y familias (PI-0144-2018), European Regional Development Fund (ERDF) "A way to build Europe". GRM belongs to the regional Nicolas Monardes research program of the Consejeria de Salud (RC-0006-2016; Junta de Andalucia, Spain). CMA is recipient of a "Rio Hortega" research contract (CM19/00186, Instituto de Salud Carlos III). VKDG is recipient of a "Rio Hortega" research contract (CM21/00214, Instituto de Salud Carlos III)

    Fatty liver index as a predictor for type 2 diabetes in subjects with normoglycemia in a nationwide cohort study

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    Our aim was to evaluate whether fatty liver index (FLI) is associated with the risk of type 2 diabetes (T2DM) development within the Spanish adult population and according to their prediabetes status; additionally, to examine its incremental predictive value regarding traditional risk factors. A total of 2260 subjects (Prediabetes: 641 subjects, normoglycemia: 1619 subjects) from the [email protected] cohort study were studied. Socio-demographic, anthropometric, clinical data and survey on habits were recorded. An oral glucose tolerance test was performed and fasting determinations of glucose, lipids and insulin were made. FLI was calculated and classified into three categories: Low ( 60). In total, 143 people developed diabetes at follow-up. The presence of a high FLI category was in all cases a significant independent risk factor for the development of diabetes. The inclusion of FLI categories in prediction models based on different conventional T2DM risk factors significantly increase the prediction power of the models when all the population was considered. According to our results, FLI might be considered an early indicator of T2DM development even under normoglycemic condition. The data also suggest that FLI could provide additional information for the prediction of T2DM in models based on conventional risk factors

    Measurement of the cosmic ray spectrum above 4×10184{\times}10^{18} eV using inclined events detected with the Pierre Auger Observatory

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    A measurement of the cosmic-ray spectrum for energies exceeding 4×10184{\times}10^{18} eV is presented, which is based on the analysis of showers with zenith angles greater than 60∘60^{\circ} detected with the Pierre Auger Observatory between 1 January 2004 and 31 December 2013. The measured spectrum confirms a flux suppression at the highest energies. Above 5.3×10185.3{\times}10^{18} eV, the "ankle", the flux can be described by a power law E−γE^{-\gamma} with index Îł=2.70±0.02 (stat)±0.1 (sys)\gamma=2.70 \pm 0.02 \,\text{(stat)} \pm 0.1\,\text{(sys)} followed by a smooth suppression region. For the energy (EsE_\text{s}) at which the spectral flux has fallen to one-half of its extrapolated value in the absence of suppression, we find Es=(5.12±0.25 (stat)−1.2+1.0 (sys))×1019E_\text{s}=(5.12\pm0.25\,\text{(stat)}^{+1.0}_{-1.2}\,\text{(sys)}){\times}10^{19} eV.Comment: Replaced with published version. Added journal reference and DO

    Energy Estimation of Cosmic Rays with the Engineering Radio Array of the Pierre Auger Observatory

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    The Auger Engineering Radio Array (AERA) is part of the Pierre Auger Observatory and is used to detect the radio emission of cosmic-ray air showers. These observations are compared to the data of the surface detector stations of the Observatory, which provide well-calibrated information on the cosmic-ray energies and arrival directions. The response of the radio stations in the 30 to 80 MHz regime has been thoroughly calibrated to enable the reconstruction of the incoming electric field. For the latter, the energy deposit per area is determined from the radio pulses at each observer position and is interpolated using a two-dimensional function that takes into account signal asymmetries due to interference between the geomagnetic and charge-excess emission components. The spatial integral over the signal distribution gives a direct measurement of the energy transferred from the primary cosmic ray into radio emission in the AERA frequency range. We measure 15.8 MeV of radiation energy for a 1 EeV air shower arriving perpendicularly to the geomagnetic field. This radiation energy -- corrected for geometrical effects -- is used as a cosmic-ray energy estimator. Performing an absolute energy calibration against the surface-detector information, we observe that this radio-energy estimator scales quadratically with the cosmic-ray energy as expected for coherent emission. We find an energy resolution of the radio reconstruction of 22% for the data set and 17% for a high-quality subset containing only events with at least five radio stations with signal.Comment: Replaced with published version. Added journal reference and DO

    Measurement of the Radiation Energy in the Radio Signal of Extensive Air Showers as a Universal Estimator of Cosmic-Ray Energy

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    We measure the energy emitted by extensive air showers in the form of radio emission in the frequency range from 30 to 80 MHz. Exploiting the accurate energy scale of the Pierre Auger Observatory, we obtain a radiation energy of 15.8 \pm 0.7 (stat) \pm 6.7 (sys) MeV for cosmic rays with an energy of 1 EeV arriving perpendicularly to a geomagnetic field of 0.24 G, scaling quadratically with the cosmic-ray energy. A comparison with predictions from state-of-the-art first-principle calculations shows agreement with our measurement. The radiation energy provides direct access to the calorimetric energy in the electromagnetic cascade of extensive air showers. Comparison with our result thus allows the direct calibration of any cosmic-ray radio detector against the well-established energy scale of the Pierre Auger Observatory.Comment: Replaced with published version. Added journal reference and DOI. Supplemental material in the ancillary file
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