105 research outputs found

    Protocol biopsies in renal transplantation: Prognostic value of structural monitoring

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    The natural history of renal allograft damage has been characterized in serial protocol biopsies. The prevalence of subclinical rejection (SCR) is maximal during the first months and it is associated with the progression of interstitial fibrosis/tubular atrophy (IF/TA) and a decreased graft survival. IF/TA rapidly progress during the first months and constitutes an independent predictor of graft survival. IF/TA associated with transplant vasculopathy, SCR, or transplant glomerulopathy implies a poorer prognosis than IF/TA without additional lesions. These observations suggest that protocol biopsies could be considered a surrogate of graft survival. Preliminary data suggest that the predictive value of protocol biopsies is not inferior to acute rejection or renal function. Additionally, protocol biopsies have been employed as a secondary efficacy variable in clinical trials. This strategy has been useful to demonstrate a decrease in the progression of IF/TA in some calcineurin-free regimens. Quantification of renal damage is associated with graft survival suggesting that quantitative parameters might improve the predictive value of protocol biopsies. Validation of protocol biopsies as a surrogate of graft survival is actively pursued, as the utility of classical surrogates of graft outcome such as acute rejection has become less useful because of its decreased prevalence with actual immunosuppression

    Functional polymorphisms of macrophage migration inhibitory factor as predictors of morbidity and mortality of pneumococcal meningitis.

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    Pneumococcal meningitis is the most frequent and critical type of bacterial meningitis. Because cytokines play an important role in the pathogenesis of bacterial meningitis, we examined whether functional polymorphisms of the proinflammatory cytokine macrophage migration inhibitory factor (MIF) were associated with morbidity and mortality of pneumococcal meningitis. Two functional MIF promoter polymorphisms, a microsatellite (-794 CATT5-8; rs5844572) and a single-nucleotide polymorphism (-173 G/C; rs755622) were genotyped in a prospective, nationwide cohort of 405 patients with pneumococcal meningitis and in 329 controls matched for age, gender, and ethnicity. Carriages of the CATT7 and -173 C high-expression MIF alleles were associated with unfavorable outcome (P= 0.005 and 0.003) and death (P= 0.03 and 0.01). In a multivariate logistic regression model, shock [odds ratio (OR) 26.0, P= 0.02] and carriage of the CATT7 allele (OR 5.12,P= 0.04) were the main predictors of mortality. MIF levels in the cerebrospinal fluid were associated with systemic complications and death (P= 0.0002). Streptococcus pneumoniae strongly up-regulated MIF production in whole blood and transcription activity of high-expression MIF promoter Luciferase reporter constructs in THP-1 monocytes. Consistent with these findings, treatment with anti-MIF immunoglogulin G (IgG) antibodies reduced bacterial loads and improved survival in a mouse model of pneumococcal pneumonia and sepsis. The present study provides strong evidence that carriage of high-expression MIF alleles is a genetic marker of morbidity and mortality of pneumococcal meningitis and also suggests a potential role for MIF as a target of immune-modulating adjunctive therapy

    The Carnegie Supernova Project I: photometry data release of low-redshift stripped-envelope supernovae

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    The first phase of the Carnegie Supernova Project (CSP-I) was a dedicated supernova follow-up program based at the Las Campanas Observatory that collected science data of young, low-redshift supernovae between 2004 and 2009. Presented in this paper is the CSP-I photometric data release of low-redshift stripped-envelope core-collapse supernovae. The data consist of optical (uBgVri) photometry of 34 objects, with a subset of 26 having near-infrared (YJH) photometry. Twenty objects have optical pre-maximum coverage with a subset of 12 beginning at least five days prior to the epoch of B-band maximum brightness. In the near-infrared, 17 objects have pre-maximum observations with a subset of 14 beginning at least five days prior to the epoch of J-band maximum brightness. Analysis of this photometric data release is presented in companion papers focusing on techniques to estimate host-galaxy extinction (Stritzinger et al., submitted) and the light-curve and progenitor star properties of the sample (Taddia et al., submitted). The analysis of an accompanying visual-wavelength spectroscopy sample of ~150 spectra will be the subject of a future paper.Comment: Updated a couple of small error

    The Carnegie Supernova Project. I. Third Photometry Data Release of Low-redshift Type Ia Supernovae and Other White Dwarf Explosions

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    We present final natural-system optical (ugriBV) and near-infrared (YJH) photometry of 134 supernovae (SNe) with probable white dwarf progenitors that were observed in 2004-2009 as part of the first stage of the Carnegie Supernova Project (CSP-I). The sample consists of 123 Type Ia SNe, 5 Type Iax SNe, 2 super-Chandrasekhar SN candidates, 2 Type Ia SNe interacting with circumstellar matter, and 2 SN 2006bt-like events. The redshifts of the objects range from to 0.0835; the median redshift is 0.0241. For 120 (90%) of these SNe, near-infrared photometry was obtained. Average optical extinction coefficients and color terms are derived and demonstrated to be stable during the five CSP-I observing campaigns. Measurements of the CSP-I near-infrared bandpasses are also described, and near-infrared color terms are estimated through synthetic photometry of stellar atmosphere models. Optical and near-infrared magnitudes of local sequences of tertiary standard stars for each supernova are given, and a new calibration of Y-band magnitudes of the Persson et al. standards in the CSP-I natural system is presented.Fil: Krisciunas, Kevin. Texas A&M University; Estados UnidosFil: Contreras, Carlos. University Aarhus; Dinamarca. Las Campanas Observatory; ChileFil: Burns, Christopher R.. Las Campanas Observatory; ChileFil: Phillips, M. M.. Las Campanas Observatory; ChileFil: Stritzinger, Maximilian D.. Las Campanas Observatory; Chile. University Aarhus; DinamarcaFil: Morrell, Nidia Irene. Las Campanas Observatory; ChileFil: Hamuy, Mario. Universidad de Chile; ChileFil: Anais, Jorge. Las Campanas Observatory; ChileFil: Boldt, Luis. Las Campanas Observatory; ChileFil: Busta, Luis. Las Campanas Observatory; ChileFil: Campillay, Abdo. Las Campanas Observatory; ChileFil: Castellón, Sergio. Las Campanas Observatory; ChileFil: Folatelli, Gaston. Las Campanas Observatory; Chile. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas; ArgentinaFil: Freedman, Wendy L.. University of Chicago; Estados UnidosFil: González, Consuelo. Las Campanas Observatory; ChileFil: Hsiao, Eric Y.. Florida State University; Estados Unidos. University Aarhus; Dinamarca. Las Campanas Observatory; ChileFil: Krzeminski, Wojtek. Las Campanas Observatory; ChileFil: Persson, Sven Eric. Carnegie Observatories;Fil: Roth, Miguel. Gmto Corporation; Chile. Las Campanas Observatory; ChileFil: Salgado, Francisco. Leiden Observatory Research Institute; . Las Campanas Observatory; ChileFil: Serón, Jacqueline. Las Campanas Observatory; Chile. Cerro Tololo Inter American Observatory; ChileFil: Suntzeff, Nicholas B.. Texas A&M University; Estados UnidosFil: Torres, Simón. Soar Telescope; Chile. Las Campanas Observatory; ChileFil: Filippenko, Alexei V.. University of California at Berkeley; Estados UnidosFil: Li, Weidong. University of California at Berkeley; Estados UnidosFil: Madore, Barry F.. Jet Propulsion Laboratory, California Institute Of Technology; . Las Campanas Observatory; ChileFil: DePoy, D.L.. Texas A&M University; Estados UnidosFil: Marshall, Jennifer L.. Texas A&M University; Estados UnidosFil: Rheault, Jean Philippe. Texas A&M University; Estados UnidosFil: Villanueva, Steven. Texas A&M University; Estados Unidos. Ohio State University; Estados Unido

    Una ruta inteligente y sostenible : Inteligencia aplicada a la recolección de residuos tecnológicos

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    La gestión de los desechos Tecnológicos, es un problema emergente, así como una oportunidad económica, dados los volúmenes de residuos que se generan y el contenido de materiales valiosos que lo componen. La recolección, transporte, tratamiento, reciclaje y eliminación de residuos tecnológicos requiere de soluciones económica y ambientalmente sostenibles. Las soluciones a dichos retos, demandan de enfoques inter-displinarios que incluyen aspectos ambientales, tecnológicos económicos, sociales y legislativos. El paradigma de la economía circular plantea que los residuos al final del ciclo de vida útil de un producto pueden ser materias primas para unos nuevos productos. La programación de la logística de recolección de residuos tecnológicos corresponde al problema de enrutamiento de vehículos (Vehicle Routing Problem, VRP) que presentan una extensa disponibilidad bibliográfica de los problemas de enrutamiento verde de vehículos (GVRP). Los problemas de enrutamiento de VRP en logística describen la complejidad en los casos del mundo real. Particularmente, el propósito de esta línea trabajo es mostrar como la aplicación de un algoritmo basado en inteligencia colectiva mejora la planificación de recolección de residuos tecnológicos para un caso de estudio local sobre con diferentes escenarios e instancias de recolección contenedores de residuos y vehículos con diferentes capacidades.Eje: Agentes y Sistemas Inteligentes.Red de Universidades con Carreras en Informátic

    Una ruta inteligente y sostenible : Inteligencia aplicada a la recolección de residuos tecnológicos

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    La gestión de los desechos Tecnológicos, es un problema emergente, así como una oportunidad económica, dados los volúmenes de residuos que se generan y el contenido de materiales valiosos que lo componen. La recolección, transporte, tratamiento, reciclaje y eliminación de residuos tecnológicos requiere de soluciones económica y ambientalmente sostenibles. Las soluciones a dichos retos, demandan de enfoques inter-displinarios que incluyen aspectos ambientales, tecnológicos económicos, sociales y legislativos. El paradigma de la economía circular plantea que los residuos al final del ciclo de vida útil de un producto pueden ser materias primas para unos nuevos productos. La programación de la logística de recolección de residuos tecnológicos corresponde al problema de enrutamiento de vehículos (Vehicle Routing Problem, VRP) que presentan una extensa disponibilidad bibliográfica de los problemas de enrutamiento verde de vehículos (GVRP). Los problemas de enrutamiento de VRP en logística describen la complejidad en los casos del mundo real. Particularmente, el propósito de esta línea trabajo es mostrar como la aplicación de un algoritmo basado en inteligencia colectiva mejora la planificación de recolección de residuos tecnológicos para un caso de estudio local sobre con diferentes escenarios e instancias de recolección contenedores de residuos y vehículos con diferentes capacidades.Eje: Agentes y Sistemas Inteligentes.Red de Universidades con Carreras en Informátic

    Large scale genomic analysis shows no evidence for pathogen adaptation between the blood and cerebrospinal fluid niches during bacterial meningitis.

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    Recent studies have provided evidence for rapid pathogen genome diversification, some of which could potentially affect the course of disease. We have previously described such variation seen between isolates infecting the blood and cerebrospinal fluid (CSF) of a single patient during a case of bacterial meningitis. Here, we performed whole-genome sequencing of paired isolates from the blood and CSF of 869 meningitis patients to determine whether such variation frequently occurs between these two niches in cases of bacterial meningitis. Using a combination of reference-free variant calling approaches, we show that no genetic adaptation occurs in either invaded niche during bacterial meningitis for two major pathogen species, Streptococcus pneumoniae and Neisseria meningitidis. This study therefore shows that the bacteria capable of causing meningitis are already able to do this upon entering the blood, and no further sequence change is necessary to cross the blood-brain barrier. Our findings place the focus back on bacterial evolution between nasopharyngeal carriage and invasion, or diversity of the host, as likely mechanisms for determining invasiveness

    Carnegie Supernova Project-II: Extending the Near-Infrared Hubble Diagram for Type Ia Supernovae to z0.1z\sim0.1

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    The Carnegie Supernova Project-II (CSP-II) was an NSF-funded, four-year program to obtain optical and near-infrared observations of a "Cosmology" sample of 100\sim100 Type Ia supernovae located in the smooth Hubble flow (0.03z0.100.03 \lesssim z \lesssim 0.10). Light curves were also obtained of a "Physics" sample composed of 90 nearby Type Ia supernovae at z0.04z \leq 0.04 selected for near-infrared spectroscopic time-series observations. The primary emphasis of the CSP-II is to use the combination of optical and near-infrared photometry to achieve a distance precision of better than 5%. In this paper, details of the supernova sample, the observational strategy, and the characteristics of the photometric data are provided. In a companion paper, the near-infrared spectroscopy component of the project is presented.Comment: 43 pages, 10 figures, accepted for publication in PAS

    A wildland fire model with data assimilation

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    A wildfire model is formulated based on balance equations for energy and fuel, where the fuel loss due to combustion corresponds to the fuel reaction rate. The resulting coupled partial differential equations have coefficients that can be approximated from prior measurements of wildfires. An ensemble Kalman filter technique with regularization is then used to assimilate temperatures measured at selected points into running wildfire simulations. The assimilation technique is able to modify the simulations to track the measurements correctly even if the simulations were started with an erroneous ignition location that is quite far away from the correct one.Comment: 35 pages, 12 figures; minor revision January 2008. Original version available from http://www-math.cudenver.edu/ccm/report

    Steroid regulation: An overlooked aspect of tolerance and chronic rejection in kidney transplantation.

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    Steroid conversion (HSD11B1, HSD11B2, H6PD) and receptor genes (NR3C1, NR3C2) were examined in kidney-transplant recipients with "operational tolerance" and chronic rejection (CR), independently and within the context of 88 tolerance-associated genes. Associations with cellular types were explored. Peripheral whole-blood gene-expression levels (RT-qPCR-based) and cell counts were adjusted for immunosuppressant drug intake. Tolerant (n = 17), stable (n = 190) and CR patients (n = 37) were compared. Healthy controls (n = 14) were used as reference. The anti-inflammatory glucocorticoid receptor (NR3C1) and the cortisol-activating HSD11B1 and H6PD genes were up-regulated in CR and were lowest in tolerant patients. The pro-inflammatory mineralocorticoid gene (NR3C2) was downregulated in stable and CR patients. NR3C1 was associated with neutrophils and NR3C2 with T-cells. Steroid conversion and receptor genes, alone, enabled classification of tolerant patients and were major contributors to gene-expression signatures of both, tolerance and CR, alongside known tolerance-associated genes, revealing a key role of steroid regulation and response in kidney transplantation
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