162 research outputs found
HGF -rs12536657 and Ocular Biometric Parameters in Hyperopic Children, Emmetropic Adolescents, and Young Adults: A Multicenter Quantitative Trait Study
Introduction. Even though ocular refractive state is highly heritable and under strong genetic control, the identification of susceptibility genes remains a challenge. Several HGF (hepatocyte growth factor) gene variants have been associated with ocular refractive errors and corneal pathology. Purpose. Here, we assess the association of an HGF gene variant, previously reported as associated with hyperopia, and ocular biometric parameters in a multicenter Spanish cohort.
Methods. An observational prospective multicenter cross-sectional study was designed, including a total of 403 unrelated subjects comprising 188 hyperopic children (5 to 17 years) and 2 control groups: 52 emmetropic adolescents (13 to 17 years) and 163 emmetropic young adults (18 to 28 years). Each individual underwent a comprehensive eye examination including cycloplegic refraction, and topographic and ocular biometric analysis. Genomic DNA was extracted from oral swabs. HGF single nucleotide polymorphism (SNP) rs12536657 was genotyped. Genotypic, allelic, and logistic regression analyses were performed comparing the different groups. A quantitative trait association test analyzing several biometric parameters was also performed using generalized estimating equations (GEEs) adjusting for age and gender.
Results. No association between rs12536657 and hyperopia was found through gender-adjusted logistic regression comparing the hyperopic children with either of the two control groups. Significant associations between mean topographic corneal curvature and rs12536657 for G/A (slope = +0.32; CI 95%: 0.04-0.60; p=0.023) and A/A (slope = +0.76; CI 95%: 0.12-1.40; p=0.020) genotypes were observed with the age- and gender-adjusted univariate GEE model. Both flat and steep corneal topographic meridians were also significantly associated with rs12536657 for the G/A and A/A genotypes. No association was found between rs12536657 and any other topographic or biometric measurements.
Conclusions. Our results support a possible role for HGF gene variant rs12536657 in corneal curvature in our population. To our knowledge, this is the first multicenter quantitative trait association study of HGF genotypes and ocular biometric parameters comprising a pediatric cohort
Engineering of silicon surfaces at the micro- and nanoscales for cell adhesion and migration control
The engineering of surface patterns is a powerful tool for analyzing cellular communication factors involved in the processes of adhesion, migration, and expansion, which can have a notable impact on therapeutic applications including tissue engineering. In this regard, the main objective of this research was to fabricate patterned and textured surfaces at micron- and nanoscale levels, respectively, with very different chemical and topographic characteristics to control cellâsubstrate interactions. For this task, one-dimensional (1-D) and two-dimensional (2-D) patterns combining silicon and nanostructured porous silicon were engineered by ion beam irradiation and subsequent electrochemical etch. The experimental results show that under the influence of chemical and morphological stimuli, human mesenchymal stem cells polarize and move directionally toward or away from the particular stimulus. Furthermore, a computational model was developed aiming at understanding cell behavior by reproducing the surface distribution and migration of human mesenchymal stem cells observed experimentally
Foro de debate: seguridad de las alternativas a la transfusiĂłn alogĂ©nica en el paciente quirĂșrgico y/o crĂtico
Estos Ășltimos años han aparecido alertas de seguridad, no siempre bien sustentadas, que cuestionan el uso de algunas alternativas farmacolĂłgicas a la transfusiĂłn de sangre alogĂ©nica y/o lo restringen en indicaciones establecidas. Asistimos tambiĂ©n a la preconizaciĂłn de otras alternativas, incluyendo productos hemĂĄticos y fĂĄrmacos antifibrinolĂticos, sin que haya una base cientĂfica sĂłlida que lo justifique. Por iniciativa del Grupo de Estudios Multidisciplinares sobre AutotransfusiĂłn y del Anemia Working Group EspanaÂż se reuniĂł a un panel multidisciplinar de 23 expertos del ĂĄrea de cuidados de la salud en un foro de debate para: 1) analizar las diferentes alertas de seguridad en torno a ciertas alternativas a la transfusiĂłn; 2) estudiar los antecedentes que las han propiciado, la evidencia que las sustentan y las consecuencias que conllevan para la prĂĄctica clĂnica, y 3) emitir una valoraciĂłn argumentada de la seguridad de cada alternativa a la transfusiĂłn cuestionada, segĂșn el uso clĂnico de la misma. Los integrantes del foro mantuvieron contactos por vĂa telemĂĄtica y una reuniĂłn presencial en la que presentaron y discutieron las conclusiones sobre cada uno de los elementos examinados. Se elaborĂł un primer documento que fue sometido a 4 rondas de revisiĂłn y actualizaciĂłn hasta alcanzar un consenso, unĂĄnime en la mayorĂa de los casos. Presentamos la versiĂłn final del documento, aprobada por todos los miembros del panel, esperando sea de utilidad para nuestros colegas
2013. Documento Sevilla de Consenso sobre Alternativas a la Transfusión de Sangre Alogénica. Actualización del Documento Sevilla
La transfusiĂłn de sangre alogĂ©nica (TSA) no es inocua, y como consecuencia han surgido mĂșltiples alternativas a la misma (ATSA). Existe variabilidad respecto a las indicaciones y buen uso de las ATSA. Dependiendo de la especialidad de los mĂ©dicos que tratan a los pacientes, el grado de anemia, la polĂtica transfusional, la disponibilidad de las ATSA y el criterio personal, estas se usan de forma variable. Puesto que las ATSA tampoco son inocuas y pueden no cumplir criterios de coste-efectividad, la variabilidad en su uso es inaceptable. Las sociedades españolas de AnestesiologĂa y ReanimaciĂłn (SEDAR), HematologĂa y Hemoterapia (SEHH), Farmacia Hospitalaria (SEFH), Medicina Intensiva y Unidades Coronarias (SEMICYUC), Trombosis y Hemostasia (SETH) y Transfusiones SanguĂneas (SETS) han elaborado un documento de consenso para el buen uso de la ATSA. Un panel de expertos de las 6 sociedades ha llevado a cabo una revisiĂłn sistemĂĄtica de la literatura mĂ©dica y elaborado el 2013. Documento Sevilla de Consenso sobre Alternativas a la TransfusiĂłn de Sangre AlogĂ©nica. Solo se contempla las ATSA dirigidas a disminuir la transfusiĂłn de concentrado de hematĂes. Se definen las ATSA como toda medida farmacolĂłgica y no farmacolĂłgica encaminada a disminuir la transfusiĂłn de concentrado de hematĂes, preservando siempre la seguridad del paciente. La cuestiĂłn principal que se plantea en cada Ătem se formula, en forma positiva o negativa, como: «La ATSA en cuestiĂłn reduce/no reduce la tasa transfusional». Para formular el grado de recomendaciĂłn se ha usado la metodologĂa Grades of Recommendation Assessment, Development and Evaluation (GRADE)
<i>Gaia</i> Data Release 1. Summary of the astrometric, photometric, and survey properties
Context. At about 1000 days after the launch of Gaia we present the first Gaia data release, Gaia DR1, consisting of astrometry and photometry for over 1 billion sources brighter than magnitude 20.7.
Aims. A summary of Gaia DR1 is presented along with illustrations of the scientific quality of the data, followed by a discussion of the limitations due to the preliminary nature of this release.
Methods. The raw data collected by Gaia during the first 14 months of the mission have been processed by the Gaia Data Processing and Analysis Consortium (DPAC) and turned into an astrometric and photometric catalogue.
Results. Gaia DR1 consists of three components: a primary astrometric data set which contains the positions, parallaxes, and mean proper motions for about 2 million of the brightest stars in common with the HIPPARCOS and Tycho-2 catalogues â a realisation of the Tycho-Gaia Astrometric Solution (TGAS) â and a secondary astrometric data set containing the positions for an additional 1.1 billion sources. The second component is the photometric data set, consisting of mean G-band magnitudes for all sources. The G-band light curves and the characteristics of âŒ3000 Cepheid and RR-Lyrae stars, observed at high cadence around the south ecliptic pole, form the third component. For the primary astrometric data set the typical uncertainty is about 0.3 mas for the positions and parallaxes, and about 1 mas yrâ1 for the proper motions. A systematic component of âŒ0.3 mas should be added to the parallax uncertainties. For the subset of âŒ94 000 HIPPARCOS stars in the primary data set, the proper motions are much more precise at about 0.06 mas yrâ1. For the secondary astrometric data set, the typical uncertainty of the positions is âŒ10 mas. The median uncertainties on the mean G-band magnitudes range from the mmag level to âŒ0.03 mag over the magnitude range 5 to 20.7.
Conclusions. Gaia DR1 is an important milestone ahead of the next Gaia data release, which will feature five-parameter astrometry for all sources. Extensive validation shows that Gaia DR1 represents a major advance in the mapping of the heavens and the availability of basic stellar data that underpin observational astrophysics. Nevertheless, the very preliminary nature of this first Gaia data release does lead to a number of important limitations to the data quality which should be carefully considered before drawing conclusions from the data
Spanish Consensus Statement on alternatives to allogeneic blood transfusion: the 2013 update of the 'Seville Document'
Summary of recommendations on alternatives to reduce allogeneic blood transfusion (in descending order of strength)..
Influence of the length of hospitalisation in post-discharge outcomes in patients with acute heart failure: Results of the LOHRCA study
Objective: To investigate the relationship between length of hospitalisation (LOH) and post-discharge outcomes in acute heart failure (AHF) patients and to ascertain whether there are different patterns according to department of initial hospitalisation.
Methods: Consecutive AHF patients hospitalised in 41 Spanish centres were grouped based on the LOH (15 days). Outcomes were defined as 90-day post-discharge all-cause mortality, AHF readmissions, and the combination of both. Hazard ratios (HRs), adjusted by chronic conditions and severity of decompensation, were calculated for groups with LOH >6 days vs. LOH <6 days (reference), and stratified by hospitalisation in cardiology, internal medicine, geriatrics, or short-stay units.
Results: We included 8563 patients (mean age: 80 (SD = 10) years, 55.5% women), with a median LOH of 7 days (IQR 4â11): 2934 (34.3%) had a LOH 15 days. The 90-day post-discharge mortality was 11.4%, readmission 32.2%, and combined endpoint 37.4%. Mortality was increased by 36.5% (95%CI = 13.0â64.9) when LOH was 11â15 days, and by 72.0% (95%CI = 42.6â107.5) when >15 days. Conversely, no differences were found in readmission risk, and the combined endpoint only increased 21.6% (95%CI = 8.4â36.4) for LOH >15 days. Stratified analysis by hospitalisation departments rendered similar post-discharge outcomes, with all exhibiting increased mortality for LOH >15 days and no significant increments in readmission risk.
Conclusions: Short hospitalisations are not associated with worse outcomes. While post-discharge readmissions are not affected by LOH, mortality risk increases as the LOH lengthens. These findings were similar across hospitalisation departments
Gaia Data Release 1: Testing parallaxes with local Cepheids and RR Lyrae stars
Context. Parallaxes for 331 classical Cepheids, 31 Type II Cepheids, and 364 RR Lyrae stars in common between Gaia and the Hipparcos and Tycho-2 catalogues are published in Gaia Data Release 1 (DR1) as part of the Tycho-Gaia Astrometric Solution (TGAS). Aims. In order to test these first parallax measurements of the primary standard candles of the cosmological distance ladder, which involve astrometry collected by Gaia during the initial 14 months of science operation, we compared them with literature estimates and derived new period-luminosity (PL), period-Wesenheit (PW) relations for classical and Type II Cepheids and infrared PL, PL-metallicity (PLZ), and optical luminosity-metallicity (M V -[Fe/H]) relations for the RR Lyrae stars, with zero points based on TGAS. Methods. Classical Cepheids were carefully selected in order to discard known or suspected binary systems. The final sample comprises 102 fundamental mode pulsators with periods ranging from 1.68 to 51.66 days (of which 33 with Ï Î© /Ω < 0.5). The Type II Cepheids include a total of 26 W Virginis and BL Herculis stars spanning the period range from 1.16 to 30.00 days (of which only 7 with Ï Î© /Ω < 0.5). The RR Lyrae stars include 200 sources with pulsation period ranging from 0.27 to 0.80 days (of which 112 with Ï Î© /Ω < 0.5). The new relations were computed using multi-band (V,I,J,K s ) photometry and spectroscopic metal abundances available in the literature, and by applying three alternative approaches: (i) linear least-squares fitting of the absolute magnitudes inferred from direct transformation of the TGAS parallaxes; (ii) adopting astrometry-based luminosities; and (iii) using a Bayesian fitting approach. The last two methods work in parallax space where parallaxes are used directly, thus maintaining symmetrical errors and allowing negative parallaxes to be used. The TGAS-based PL,PW,PLZ, and M V - [Fe/H] relations are discussed by comparing the distance to the Large Magellanic Cloud provided by different types of pulsating stars and alternative fitting methods. Results. Good agreement is found from direct comparison of the parallaxes of RR Lyrae stars for which both TGAS and HST measurements are available. Similarly, very good agreement is found between the TGAS values and the parallaxes inferred from the absolute magnitudes of Cepheids and RR Lyrae stars analysed with the Baade-Wesselink method. TGAS values also compare favourably with the parallaxes inferred by theoretical model fitting of the multi-band light curves for two of the three classical Cepheids and one RR Lyrae star, which were analysed with this technique in our samples. The K-band PL relations show the significant improvement of the TGAS parallaxes for Cepheids and RR Lyrae stars with respect to the Hipparcos measurements. This is particularly true for the RR Lyrae stars for which improvement in quality and statistics is impressive. Conclusions. TGAS parallaxes bring a significant added value to the previous Hipparcos estimates. The relations presented in this paper represent the first Gaia-calibrated relations and form a work-in-progress milestone report in the wait for Gaia-only parallaxes of which a first solution will become available with Gaia Data Release 2 (DR2) in 2018. © ESO, 2017
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