Lipid nanoparticles for cyclosporine a administration: Development, characterization, and in vitro evaluation of their immunosuppression activity

Cyclosporine A (CsA) is an immunosuppressant commonly used in transplantation for prevention of organ rejection as well as in the treatment of several autoimmune disorders. Although commercial formulations are available, they have some stability, bioavailability, and toxicity related problems. Some of these issues are associated with the drug or excipients and others with the dosage forms. With the aim of overcoming these drawbacks, lipid nanoparticles (LN) have been proposed as an alternative, since excipients are biocompatible and also a large amount of surfactants and organic solvents can be avoided. CsA was successfully incorporated into LN using the method of hot homogenization followed by ultrasonication. Three different formulations were optimized for CsA oral administration, using different surfactants: Tween® 80, phosphatidylcholine, taurocholate and Pluronic® F127 (either alone or mixtures). Freshly prepared Precirol nanoparticles showed mean sizes with a narrow size distribution ranging from 121 to 202 nm, and after freeze-drying were between 163 and 270 nm, depending on the stabilizer used. Surface charge was negative in all LN developed. High CsA entrapment efficiency of approximately 100% was achieved. Transmission electron microscopy was used to study the morphology of the optimized LN. Also, the crystallinity of the nanoparticles was studied by X-ray powder diffraction and differential scanning calorimetry. The presence of the drug in LN surfaces was confirmed by X-ray photoelectron spectroscopy. The CsA LN developed preserved their physicochemical properties for 3 months when stored at 4°C. Moreover, when the stabilizer system was composed of two surfactants, the LN formulations were also stable at room temperature. Finally, the new CsA formulations showed in vitro dose-dependent immunosuppressive effects caused by the inhibition of IL-2 levels secreted from stimulated Jurkat cells. The findings obtained in this paper suggest that new lipid nanosystems are a good alternative to produce physicochemically stable CsA formulations for oral administration

Nutrient fluxes through boundaries in the hypolimnion of Sau reservoir : expected patterns and unanticipated processes

By contrast to many natural lakes, the summer hypolimnion in advection-dominated systems like canyon-shaped reservoirs is not isolated from direct inputs from the river. This has important implications in the evolution of limnological features of the hypolimnion through the stratified period, especially if the river water directly plunges as a density current into the hypolimnion as a consequence of temperature differences. Taking the Sau Reservoir (Spain) as a prototype for this kind of systems, we present data from 11 years of monitoring to show how the river water entering the reservoir during summer is the main factor determining hypolimnetic nutrient concentrations. The empirical regression approach used all through the paper also stressed the effect of the improvement in water quality experienced by the river during the studied period on the improvement of the water quality stored in the summer hypolimnion of the reservoir. Since the change in river water quality was the consequence of the implementation of remediation measures at the basin scale, we advocate these solutions to manage reservoir eutrophication problems in this type of systems, which, in addition, had other unexpected benefits for the hypolimnetic water quality in Sau Reservoir.A diferencia de muchos lagos naturales, el hipolimnion que se forma en verano en sistemas dominados por la advección, como los embalses que inundan valles profundos y estrechos, no está aislado de las entradas directas desde el río. Esto tiene importantes implicaciones en la evolución de las características limnológicas del hipolimnion durante el periodo de estratificación, especialmente si el agua del río entra al embalse como una corriente de densidad directamente en el hipolimnion debido a diferencias de temperatura. Tomando el Embalse de Sau (España) como prototipo de este tipo de sistemas, mostramos 11 años de datos de un programa de monitoreo para ejemplificar cómo el agua del río que entra en verano al embalse es el factor determinante de la concentración de nutrientes en el hipolimnion. La aproximación de regresión empírica utilizada en el artículo también puso de manifiesto el efecto de la mejora en la calidad del agua que sufrió el río durante el periodo de estudio en la mejora del agua del agua embalsada en el hipolimnion. Ya que esta mejora en el río fue consecuencia de la implementación de medidas de restauración a nivel de la cuenca, promovemos estas soluciones para la gestión de problemas de eutrofización en este tipo de sistemas, que por otra parte mostraron ventajas inesperadas en el caso del hipolimnion del Embalse de Sau

Valoración de la calidad de ribera en un arroyo pampeano y su relación con las comunidades de macrófitas y peces

An Index of Riparian Quality was applied to a Pampean stream with moderate human impact (Las Flores stream, Luján river basin) to evaluate its degree of conservation. Aquatic macrophyte cover and diversity were also registered in 12 different reaches along the stream to analyze its relationship with the riparian index. In addition, the richness and diversity of the fish community were registered in two reaches with contrasting use of riparian zones and channel morphology. The results of the survey indicate that conservation of the riparian zones is difficult in the stream due to the increase of farming activities, the development of cropland near the margins, the invasion of an alien tree Gleditsia triacanthos (acacio negro) and the development of urban zones. Alteration of the riparian zone also modified the structure of the macrophyte communities and could be associated with a reduction in the richness and diversity of the fish community. We consider that the needs for conservation and recuperation of the riparian zones must be transmitted to the land owners. Activities should be coordinated to maintain the water quality and habitat diversity in order to enhance the basin health.Instituto de Limnología "Raúl A. Ringuelet

Valoración de la calidad de ribera en un arroyo pampeano y su relación con las comunidades de macrófitas y peces

An Index of Riparian Quality was applied to a Pampean stream with moderate human impact (Las Flores stream, Luján river basin) to evaluate its degree of conservation. Aquatic macrophyte cover and diversity were also registered in 12 different reaches along the stream to analyze its relationship with the riparian index. In addition, the richness and diversity of the fish community were registered in two reaches with contrasting use of riparian zones and channel morphology. The results of the survey indicate that conservation of the riparian zones is difficult in the stream due to the increase of farming activities, the development of cropland near the margins, the invasion of an alien tree Gleditsia triacanthos (acacio negro) and the development of urban zones. Alteration of the riparian zone also modified the structure of the macrophyte communities and could be associated with a reduction in the richness and diversity of the fish community. We consider that the needs for conservation and recuperation of the riparian zones must be transmitted to the land owners. Activities should be coordinated to maintain the water quality and habitat diversity in order to enhance the basin health.Instituto de Limnología "Raúl A. Ringuelet

Valoración de la calidad de ribera en un arroyo pampeano y su relación con las comunidades de macrófitas y peces

An Index of Riparian Quality was applied to a Pampean stream with moderate human impact (Las Flores stream, Luján river basin) to evaluate its degree of conservation. Aquatic macrophyte cover and diversity were also registered in 12 different reaches along the stream to analyze its relationship with the riparian index. In addition, the richness and diversity of the fish community were registered in two reaches with contrasting use of riparian zones and channel morphology. The results of the survey indicate that conservation of the riparian zones is difficult in the stream due to the increase of farming activities, the development of cropland near the margins, the invasion of an alien tree Gleditsia triacanthos (acacio negro) and the development of urban zones. Alteration of the riparian zone also modified the structure of the macrophyte communities and could be associated with a reduction in the richness and diversity of the fish community. We consider that the needs for conservation and recuperation of the riparian zones must be transmitted to the land owners. Activities should be coordinated to maintain the water quality and habitat diversity in order to enhance the basin health.Instituto de Limnología "Raúl A. Ringuelet

The CORDEX Flagship Pilot Study in southeastern South America: a comparative study of statistical and dynamical downscaling models in simulating daily extreme precipitation events

The aim of this work is to present preliminary results of the statistical and dynamical simulations carried out within the framework of the Flagship Pilot Study in southeastern South America (FPS-SESA) endorsed by the Coordinated Regional Climate Downscaling Experiments (CORDEX) program. The FPS-SESA initiative seeks to promote inter-institutional collaboration and further networking with focus on extreme rainfall events. The main scientific aim is to study multi-scale processes and interactions most conducive to extreme precipitation events through both statistical and dynamical downscaling techniques, including convection-permitting simulations. To this end, a targeted experiment was designed considering the season October 2009 to March 2010, a period with a record number of extreme precipitation events within SESA. Also, three individual extreme events within that season were chosen as case studies for analyzing specific regional processes and sensitivity to resolutions. Four dynamical and four statistical downscaling models (RCM and ESD respectively) from different institutions contributed to the experiment. In this work, an analysis of the capability of the set of the FPS-SESA downscaling methods in simulating daily precipitation during the selected warm season is presented together with an integrated assessment of multiple sources of observations and available CORDEX Regional Climate Model simulations. Comparisons among all simulations reveal that there is no single model that performs best in all aspects evaluated. The ability in reproducing the different features of daily precipitation depends on the model. However, the evaluation of the sequence of precipitation events, their intensity and timing suggests that FPS-SESA simulations based on both RCM and ESD yield promising results. Most models capture the extreme events selected, although with a considerable spread in accumulated values and the location of heavy precipitation.Thanks to CORDEX for endorsing the FPS-SESA. This work was supported by the University of Buenos Aires 2018- 20020170100117BA grant; JMG, MLB, SAS, RPR funding from the Spanish Research Council (CSIC) I-COOP+ Program “reference COOPB20374”. JMG, JF and AL-G acknowledge support from the Spanish R&D Program through projects MULTI-SDM (CGL2015-66583-R) and INSIGNIA (CGL2016-79210-R), co-funded by the European Regional Development Fund (ERDF/FEDER). AL-G acknowledges support from the Spanish R&D Program through the predoctoral contract BES-2016-078158. Universidad de Cantabria simulations have been carried out on the Altamira Supercomputer at the Instituto de Física de Cantabria (IFCA-CSIC), member of the Spanish Supercomputing Network. MB acknowledges support from the Simons Associateship of the Abdus Salam International Centre for Theoretical Physics. RH acknowledges support from the project LTT17007 funded by the Ministry of Education, Youth, and Sports of the Czech Republic

Relaciones sociales del consumo: el caso de las unidades domésticas de sectores populares

Incluye BibliografíaPlantea el estudio de la dinamica de consumo a partir de la unidad domestica en dos niveles: primero tomandola como organizacion unitaria, dentro del conjunto de instituciones y organizaciones sociales, analiza, para ello, como se van tomando las decisiones y se van organizando las conductas domesticas en unidades domesticas de sectores populares en el area de consumo. El segundo nivel es el de la dinamica intra-domestica, en el se analiza la dinamica interna de la unidad domestica, que esta basada en la division del trabajo y de las responsabilidades, y en la lucha o conflicto entre los miembros en cuanto a la organizacion del gasto y el presupuesto familiar. La investigacion se realizo en la Argentina