Interactions of human galectins with Trypanosoma cruzi: binding profile correlate with genetic clustering of lineages

This is a pre-copyedited, author-produced PDF of an article accepted for publication in Glycobiology following peer review. The version of record Pineda, M.A. et al. Interactions of human galectins with Trypanosoma cruzi: binding profile correlate with genetic clustering of lineages. Glycobiology 25.2 (2015): 197-210 is available online at: http://dx.doi.org/10.1093/glycob/cwu103We report here the specific interaction between several members of the human galectin family with the three developmental stages of several genetic lineages of the protozoan parasite Trypanosoma cruzi. We provide data of specific and differential binding of human galectins-1, 3, 4, 7 and 8 to 14 strains of T. cruzi that belong to the six genetic lineages representing the genetic diversity of the parasite. It is shown that galectins preferentially bind forms present in the host, trypomastigotes and amastigotes, compared to the non-infective epimastigote present on the intestinal tract of the vector, reflecting the changes on glycosylation that occur during the metacyclogenesis and amastigogenesis process. Also, it is evidenced that galectin binding to the parasites promotes binding to the host cells and higher infection rates. In addition evidence is provided indicating that the intracellular amastigotes may take over the cytosolic pool of some galectins when released to the extracellular medium. Finaly, by applying unweighted pair group method analysis to the galectin binding profile to either cell-derived trypomastigotes or amastigotes we show that the differential binding profile by the host galectins to the six lineages resembles the clustering based in genetic data. Therefore, the differential binding profile for the six lineages could have implications in the immunopathology of Chagas’ disease, affecting the complex network of immune responses on which galectins mediate, thus providing linkage clues to the notion that different lineages may be related to different clnical forms of the disease.This work was supported by grants from the Fondo de Investigaciones Sanitarias-Ministerio de Sanidad (FIS-PI11/00033) to PB and (FIS-PI11/0095) to MS, and grant ChagasEpiNet (European VII framework Program) to MF. The financial support Network RICET from the FIS, Ministerio de Sanidad and Fundacion Ramon Areces is acknowledge

Evaluación de autofertilidad en diferentes híbridos de girasol en el ambiente de Santa Rosa, La Pampa

Durante la campaña agrícola 1999/00 se llevó a cabo un ensayo en el campo experimental de la Facultad de Agronomía de la UNLPam con el fin de evaluar el nivel de autofertilidad en híbridos comerciales de girasol (Helianthus annus, L.) y la incidencia de los polinizadores en el rendimiento y sus componentes. El ensayo se realizó en bloques completamente aleatorizados, con tres repeticiones. Los cultivares utilizados son: Paihuen, TC200l, Uranus, Contiflor 7, CF2I, Agrobel 975 y Agrobel 920, los cuales fueron sometidos a dos tratamientos: capítulos tapados (sin acceso de polinizadores) y capítulos libres (con acceso de polinizadores). Estos materiales se compararon entre si para cada tratamiento y entre tratamientos. Los resultados obtenidos manifiestan diferencias significativas en la comparación de capítulos tapados y capítulos libres para las variables diámetro improductivo, semillas por plantas y rendimiento, no habiendo encontrado diferencias en el peso de 1000 granos, índice de cosecha y materia seca. En la comparación entre híbridos para el tratamientos: capítulos tapados, se encontraron diferencias significativas para todas las variables analizadas, exceptuando el diámetro total del capítulo y el rendimiento que no manifestaron diferencias significativas para las variables diámetro improductivo, índice de cosecha y el peso de 1000 granos.Director: Ing. Agr. Hugo Mirasson, Cátedra de Cultivos II

Estudio de la fracción glucídica de la semilla de annana cherimolia mil

We have isolated two glucidic compounds from Annona cherimolia deffated seed. The first one was identificated as Sucrose and the second as β-sitosterol-3-glucoside.De la fracción etanólica de la semilla de chirimoyo (Annona cherimolia Mi11.) se han aislado dos glúcidos. El primero ha sido identificado como SACAROSA y el segundo como el                     3-CLUCOSIDO del β-SITOSTEROL

Efecto de la suplementación con ciclodextrinas cargadas con colesterol al semen sexado bovino post-descongelación para su uso en producción in vitro de embriones

Los espermatozoides bovinos presentan una bajo relación de colesterol/fosfolípidos en la membrana plasmática. Esta característica es importante ya que el colesterol juega un papel fundamental en el mantenimiento de la estructura y funcionalidad de la membrana espermática tras la congelación, y, por lo tanto, en la supervivencia del espermatozoide tras el proceso de criopreservación. El proceso de sexado podría agravar todavía aún más esta situación. El objetivo de este trabajo es estabilizar las membranas plasmáticas de espermatozoides sexados mediante el agregado de ciclodextrinas cargadas con colesterol (CLC) post-descongelado y consecuentemente, prolongar su funcionalidad, aumentar su capacidad de fecundar ovocitos in vitro y producción de embriones. Para ello se trataron espermatozoides sexados con CLC a diferentes concentraciones e incubados por 15 minutos antes de evaluar el patrón de motilidad mediante un sistema computarizado CASA y fertilizar ovocitos in vitro. Los espermatozoides tratados con 3 mg de metil-β-ciclodextrina saturada de colesterol cada 120x106 espermatozoides presentaron mejor motilidad y vigor y se mantuvieron elevados durante el tiempo analizado. La concentración de 3 mg de CLC también produjo mayor clivaje, MOR/eBL, BL y embriones totales.Bovine sperm have a low cholesterol/phospholipids ratio in the sperm plasma membrane. This characteristic is important due to cholesterol plays a key role in maintaining the structure and function of sperm membrane after freezing, and therefore, increasing sperm survival. This situation could be amplified in case of sexed semen. The aim of this study is to stabilize the plasma membranes of sperm sexed by adding cholesterol-loaded cyclodextrins (CLC) post-thaw and consequently extend their functionality, increase their ability to fertilize oocytes and produce embryos in vitro. Sexed sperm were treated with CLC at different concentrations and incubated for 15 minutes before evaluating different motility parameters by a computerized system (CASA) and fertilize oocytes in vitro. Sperm treated with 3 mg of methyl-β-cyclodextrin saturated cholesterol for each 120x106 of sperm, showed higher motility parameters and remained high during the analyzed period. The concentration of 3 mg of CLC also increased cleavage rate, early (MOR/eBL), late (BL) and total embryo development.EEA RafaelaFil: Ferre, Luis Bernardo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Rafaela; Argentina.Fil: Grötter, L. Universidad Nacional del Litoral. Facultad de Ciencias Veterinarias; ArgentinaFil: Fresno, C. National Institute of Genomic Medicine (INMEGEN). Computational Genomics Division; MéxicoFil: Cattáneo, Luciano. Universidad Nacional del Litoral. Facultad de Ciencias Veterinarias; Argentin

Selective Inhibition of Vascular Endothelial Growth Factor–mediated Angiogenesis by Cyclosporin A: Roles of the Nuclear Factor of Activated T Cells and Cyclooxygenase 2

Cyclosporin A (CsA) is an immunosuppressive drug that inhibits the activity of transcription factors of the nuclear factor of activated T cells (NFAT) family, interfering with the induction of cytokines and other inducible genes required for the immune response. Here we show that CsA inhibits migration of primary endothelial cells and angiogenesis induced by vascular endothelial growth factor (VEGF); this effect appears to be mediated through the inhibition of cyclooxygenase (Cox)-2, the transcription of which is activated by VEGF in primary endothelial cells. Consistent with this, we show that the induction of Cox-2 gene expression by VEGF requires NFAT activation. Most important, the CsA-mediated inhibition of angiogenesis both in vitro and in vivo was comparable to the Cox-2 inhibitor NS-398, and reversed by prostaglandin E2. Furthermore, the in vivo corneal angiogenesis induced by VEGF, but not by basic fibroblast growth factor, was selectively inhibited in mice treated with CsA systemically. These findings involve NFAT in the regulation of Cox-2 in endothelial cells, point to a role for this transcription factor in angiogenesis, and may provide a novel mechanism underlying the beneficial effects of CsA in angiogenesis-related diseases such as rheumatoid arthritis and psoriasis.This work was supported by grant PM99-0116 from Ministerio de Educación y Cultura (MEC-DGES) of Spain (to J.M. Redondo) and grants FEDER 1FD97-0514-CO2-01 and FEDER FD97-0275 from MEC-DGES and the European Community to J.M. Redondo and M. Fresno, respectively. G.L. Hernández was supported by grants from Consejo Superior de Investigaciones Científicas y Tecnológicas (CONICET) of Argentina and Comunidad Autónoma de Madrid grant 8.3/0024/2000, and M. Fresno by grant PM97-0130, O. Volpert by American Heart Association grant AHA SDG 0030023N, and S. Martínez-Martínez by grant 8.3/19/1998 from the Comunidad Autónoma de Madrid. The Centro de Biología Molecular "Severo Ochoa" is supported by a grant from the Fundación Ramón ArecesPeer reviewe

Selective Inhibition of Vascular Endothelial Growth Factor–Mediated Angiogenesis by Cyclosporin a: Roles of the Nuclear Factor of Activated T Cells and Cyclooxygenase 2

Cyclosporin A (CsA) is an immunosuppressive drug that inhibits the activity of transcription factors of the nuclear factor of activated T cells (NFAT) family, interfering with the induction of cytokines and other inducible genes required for the immune response. Here we show that CsA inhibits migration of primary endothelial cells and angiogenesis induced by vascular endothelial growth factor (VEGF); this effect appears to be mediated through the inhibition of cyclooxygenase (Cox)-2, the transcription of which is activated by VEGF in primary endothelial cells. Consistent with this, we show that the induction of Cox-2 gene expression by VEGF requires NFAT activation. Most important, the CsA-mediated inhibition of angiogenesis both in vitro and in vivo was comparable to the Cox-2 inhibitor NS-398, and reversed by prostaglandin E2. Furthermore, the in vivo corneal angiogenesis induced by VEGF, but not by basic fibroblast growth factor, was selectively inhibited in mice treated with CsA systemically. These findings involve NFAT in the regulation of Cox-2 in endothelial cells, point to a role for this transcription factor in angiogenesis, and may provide a novel mechanism underlying the beneficial effects of CsA in angiogenesis-related diseases such as rheumatoid arthritis and psoriasis

Extracción de objetos en imágenes médicas tridimensionales basada en características texturales

En este trabajo se propone un algoritmo basado en texturas para la segmentación de imágenes médicas tridimensionales. En particular, se utilizan indicadores de textura calculados a partir de estadísticas de segundo orden, recabadas mediante matrices de coocurrencia de niveles de gris. Esta información es utilizada para guiar la evolución de un algoritmo de crecimiento de regiones, que realiza una segmentación inicial restrictiva con la cual es inicializado un modelo de Superficies Activas. El resultado obtenido consiste en un conjunto de mallas de superficie asociadas a los objetos de interés dentro de la imagen. Para estudiar la robustez del método propuesto se realizó un análisis experimental para la segmentación de tumores cerebrales en MRI artificiales y órganos abdominales de CT, obteniendo resultados más que satisfactorios en ambos casos.Sociedad Argentina de Informática e Investigación Operativ

Un enfoque para la compresión de imágenes médicas basado en regiones de interés y compensación de movimiento

Con el incremento del uso de imágenes digitales en los ambientes clínicos, se ha vuelto necesaria la utilización de métodos de compresión a fin de reducir su costo de almacenamiento o transmisión. Si bien las alternativas de compresión con pérdida permiten obtener altas tasas de compresión, existen limitaciones legales en cuanto a que los estudios deben almacenarse en un formato sin pérdida de información. En este trabajo se propone un mecanismo de compresión de imágenes digitales compatible con el estándar DICOM que aprovecha las capacidades de JPEG2000 para preservar la calidad diagnóstica de las regiones de interés, mediante codificación sin pérdida, mientras que el resto de la imagen, compuesta por zonas menos relevantes, se comprime con pérdida. Además, se presenta una técnica que permite almacenar las secciones transversales pertenecientes a un estudio 3D en un único archivo, aprovechando las características de compensación de movimiento provistas por el estándar MPEG-4 y se comparan los resultados con la técnica de empaquetado intraframe Motion JPEG-2000.Sociedad Argentina de Informática e Investigación Operativ

Influence of surface density on the CO2 photoreduction activity of a DC magnetron sputtered TiO2 catalyst

Advancing in the photocatalyst scale-up is crucial for the development of highly efficient solar fuels production at industrial scale. Here, we report DC-magnetron sputtering as a suitable technique to produce photocatalytic TiO2 coatings for CO2 reduction with a view on process scalability. The crystallinity of the obtained TiO2 coatings varies with surface density, with amorphous or quasi-amorphous coatings obtained with very low densities, while UV light absorption coefficients show the opposite trend, which has been related to the proportionally higher abundace of surface defects and grain boundaries associated to the small crystal size and/or amorphicity of the lightest coatings. The as-prepared samples lead to the reduction of CO2 as demonstrated by 13C isotope tracing. An optimum catalyst area density of 1 g/m2 (by geometric area) is obtained in terms of CO2 photoreduction production, which is ascribed to a compromise situation between crystallinity and absorption coefficient. Selectivity to the different reaction products also varies with the coating characteristics, with amorphous or quasi-amorphous light coatings favouring methanol formation, in contrast with the preferred CO evolution in heavier, crystalline ones. Raman spectroscopy reveals the formation of peroxo and peroxocarbonate species on the photocatalyst surface as oxidation products during the CO2 reduction, the accummulation of which is proposed to be related to the observed catalyst deactivation