379 research outputs found
Regeneración de la superficie ocular: stem cells/células madre y técnicas reconstructivas Regeneration of the ocular
La córnea es un tejido transparente constituido
microscópicamente por 5 capas bien diferenciadas. El
epitelio corneal es esencial para la transparencia corneal
y se encuentra en continua renovación a lo largo
de la vida a partir de la población de células madre limbocorneales.
La localización de estas células madre
limbocorneales parece residir en las capas basales del
epitelio limbocorneal, de vital importancia para mantener
el microambiente de estas células madre limbocorneales,
que depende de una variedad de factores
intrínsecos y extrínsecos. La insuficiencia límbica se
produce cuando ocurre una pérdida parcial o total de
estas células madre limbocorneales. Este cuadro lleva
a una opacificación corneal con la consiguiente pérdida
de visión. En estos casos, el trasplante corneal
supone únicamente un reemplazo temporal del epitelio
corneal; es necesario llevar a cabo un tratamiento
previo con trasplante de limbo autólogo o alogénico,
que permita regenerar la población de células limbocorneales
dañadas. Para disminuir el riesgo que supone
el trasplante de limbo en el ojo donante, se han propuesto
técnicas de cultivo de células limbocorneales a
partir de pequeñas biopsias limbocorneales
Plant-plant competition outcomes are modulated by plant effects on the soil bacterial community
Competition is a key process that determines plant community structure and dynamics, often mediated by nutrients and water availability. However, the role of soil microorganisms on plant competition, and the links between above- and belowground processes, are not well understood. Here we show that the effects of interspecific plant competition on plant performance are mediated by feedbacks between plants and soil bacterial communities. Each plant species selects a singular community of soil microorganisms in its rhizosphere with a specific species composition, abundance and activity. When two plant species interact, the resulting soil bacterial community matches that of the most competitive plant species, suggesting strong competitive interactions between soil bacterial communities as well. We propose a novel mechanism by which changes in belowground bacterial communities promoted by the most competitive plant species influence plant performance and competition outcome. These findings emphasise the strong links between plant and soil communities, paving the way to a better understanding of plant community dynamics and the effects of soil bacterial communities on ecosystem functioning and services
Television viewing and its association with overweight in Colombian children: results from the 2005 National Nutrition Survey: A cross sectional study
<p>Abstract</p> <p>Background</p> <p>There has been an ongoing discussion about the relationship between time spent watching television and childhood obesity. This debate has special relevance in the Latin American region were the globalization process has increased the availability of screen-based entertainment at home. The aim of this study is to examine the association between television viewing and weight status in Colombian children.</p> <p>Methods</p> <p>This cross sectional investigation included children aged 5 to12 yrs from the National Nutrition Survey in Colombia (ENSIN 2005). Weight and height were measured in 11,137 children in order to calculate body mass index. Overweight was defined by international standards. Time spent viewing television was determined for these children through parental reports. Multiple logistic regression analyses were conducted for different subgroups and adjusted for potential confounders in order to study the association between television viewing and weight status in this population.</p> <p>Results</p> <p>Among the surveyed children, 41.5% viewed television less than two hours/day; 36.8% between two and 3.9 hours/day and 21.7% four or more hours/day. The prevalence of overweight (obesity inclusive) in this population was 11.1%. Children who were classified as excessive television viewers (between two and 3.9 hours/day or 4 or more hours/day) were more likely to be overweight (OR: 1.44 95% CI: 1.41–1.47 and OR: 1.32 95% CI: 1.30–1.34, respectively) than children who reported to watch television less than 2 hours/day. Stratified analyses by age, gender and urbanization levels showed similar results.</p> <p>Conclusion</p> <p>Television viewing was positively associated with the presence of overweight in Colombian children. A positive association between urbanization level and television viewing was detected. Considering that the majority of Colombian children lives in densely populated cities and appear to engage in excessive television viewing these findings are of public health relevance for the prevention of childhood obesity.</p
Ciudades biodiversas: mamíferos medianos de la Reserva Forestal Protectora Bosque Oriental de Bogotá D. C., Colombia
In this contribution, we present an updated list of medium-sized mammals present in the Bosque Oriental Protective Forest Reserve of Bogotá. The study area includes the Bogotá Bosque Oriental Protective Forest Reserve that is located east of the city of Bogotá D.C., and commonly known as Eastern Hills.En esta contribución, presentamos un listado actualizado de los mamíferos medianos presentes en la Reserva Forestal Protectora Bosque Oriental de Bogotá. El área de estudio comprende la Reserva Forestal Protectora Bosque Oriental de Bogotá que se localiza al oriente de la ciudad de Bogotá D.C., y comúnmente conocida como Cerros Orientales
Transplantation of mesenchymal stem cells exerts a greater long-term effect than bone marrow mononuclear cells in a chronic myocardial infarction model in rat
The aim of this study is to assess the long-term effect of mesenchymal stem cells (MSC) transplantation in
a rat model of chronic myocardial infarction (MI) in comparison with the effect of bone marrow mononuclear
cells (BM-MNC) transplant. Five weeks after induction of MI, rats were allocated to receive intramyocardial
injection of 106 GFP-expressing cells (BM-MNC or MSC) or medium as control. Heart function
(echocardiography and 18F-FDG-microPET) and histological studies were performed 3 months after transplantation
and cell fate was analyzed along the experiment (1 and 2 weeks and 1 and 3 months). The main
findings of this study were that both BM-derived populations, BM-MNC and MSC, induced a long-lasting
(3 months) improvement in LVEF (BM-MNC: 26.61 ± 2.01% to 46.61 ± 3.7%, p < 0.05; MSC: 27.5 ±
1.28% to 38.8 ± 3.2%, p < 0.05) but remarkably, only MSC improved tissue metabolism quantified by 18FFDG
uptake (71.15 ± 1.27 to 76.31 ± 1.11, p < 0.01), which was thereby associated with a smaller infarct size
and scar collagen content and also with a higher revascularization degree. Altogether, results show that MSC
provides a long-term superior benefit than whole BM-MNC transplantation in a rat model of chronic MI
BioContainers: An open-source and community-driven framework for software standardization
Motivation BioContainers (biocontainers.pro) is an open-source and community-driven framework which provides platform independent executable environments for bioinformatics software. BioContainers allows labs of all sizes to easily install bioinformatics software, maintain multiple versions of the same software and combine tools into powerful analysis pipelines. BioContainers is based on popular open-source projects Docker and rkt frameworks, that allow software to be installed and executed under an isolated and controlled environment. Also, it provides infrastructure and basic guidelines to create, manage and distribute bioinformatics containers with a special focus on omics technologies. These containers can be integrated into more comprehensive bioinformatics pipelines and different architectures (local desktop, cloud environments or HPC clusters). Availability and Implementation The software is freely available at github.com/BioContainers/.publishedVersio
Desafíos y tendencias del México actual
Conjunto de once ensayos cuyo propósito es suscitar la reflexión sobre las tendencias más importantes que marcan el inicio del siglo XXI en México y Jalisco, sin obviar las direcciones que a escala mundial toman la vida social, política y económica.ITESO, A.C
Target product profile for a test for the early assessment of treatment efficacy in Chagas disease patients: An expert consensus.
Six to 7 million people are estimated to be infected by Trypanosoma cruzi, the parasite causing Chagas disease. Thirty to 40% of them, i.e., 1.8 to 2.4 million people, will suffer cardiac disorders and/or digestive clinical manifestations if they are not treated early during the course of the infection [1, 2]. However, only a small fraction of patients are properly diagnosed and treated [3]. Current clinical guidelines recommend treating T. cruzi–infected people if they are asymptomatic or present early symptoms of the disease (Table 1) [4, 5]. Benznidazole (BNZ) and nifurtimox (NFX) are the first-line antiparasitic treatments currently available, both with long administration regimens (60 days) that can produce adverse side effects [6–8]. Despite the fact they are not 100% effective in patients with chronic disease [9–12], they are the only drugs currently registered, and the benefits of their administration have been confirmed in several clinical studies. Currently, clinical trials with new compounds, using alternative regimens that aim to maintain efficacy whilst reducing toxicity, are ongoing and could lead to new therapeutic opportunities and/or policy change
Regeneración de campus para la creación de un laboratorio vivo de sostenibilidad ("living lab") en el Campus de Excelencia Internacional de Moncloa
La Universidad Politécnica de Madrid (UPM) a través de su Centro de Innovación en Tecnología para el Desarrollo Humano (itdUPM) está propiciando la generación de conciencia, conocimiento y soluciones innovadoras que contribuyen al cumplimiento de los Objetivos de Desarrollo Sostenible a través de un edificio que sirve como laboratorio de prueba para nuevas tecnologías verdes y como plataforma de ideación colaborativa y activación social
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