Efectos de la genisteína en los niveles del Ca2+ citosólico en células musculares de arteria umbilical humana

Isoflavones are a group of natural phytoestrogens including the compound genistein. Health beneficial effects have been attributed to the consumption of this compound, but the fact that it has estrogen-like activity has raised doubts regarding its potential risk in infants, newborns, or in the fetus and placenta during pregnancy. This work is aimed at studying genistein effects on Ca2+ handling by smooth muscle cells of the human umbilical artery (HUA). Using fluorometric techniques, we found that in these cells genistein reduces the intracellular Ca2+ peak produced by serotonin. The same result could be demonstrated in absence of extracellular Ca2+, suggesting that the isoflavone reduces Ca2+ release from the sarcoplasmic reticulum. Force measurement experiments strengthen these results, since genistein reduced the peak force attained by intact HUA rings stimulated by serotonin in a Ca2+-free solution. Moreover, genistein induced the relaxation of HUA rings precontracted either with serotonin or a depolarizing high-extracellular K+ solution, hinting at a reduction of extracellular Ca2+ entry to the cell. This was confirmed by whole-cell patch-clamp experiments where it was shown that the isoflavone inhibits ionic currents through voltage-operated Ca2+ channels. In summary, we show that genistein inhibits two mechanisms that could increase intracellular Ca2+ in human umbilical smooth muscle cells, behaving in this way as a potential vasorelaxing substance of fetal vessels. Taking into account that genistein is able to cross the placental barrier, these data show that isoflavones may have important implications in the regulation of feto-maternal blood flow in pregnant women who consume soy-derived products as part of their meals.Facultad de Ciencias Exacta

Internet use and academic success in university students

El uso de la tecnología provoca cambios sociales. Esto incluye el trabajo en el ámbito universitario en donde está cambiando tanto la forma de ejercer la docencia como la forma de aprender y se requiere conocer el efecto del uso de la tecnología sobre el rendimiento del alumnado. En este trabajo se investigó la incidencia del uso de Internet sobre el éxito académico del alumnado de cinco universidades de Ecuador. Se levantó una muestra aleatoria de 4.697 personas y se las categorizó en perfiles de uso de Internet para actividades académicas y para entretenimiento, utilizando análisis factorial y análisis clúster. Las categorías resultantes se utilizaron como variables independientes en modelos de regresión logística multinomial que buscaban determinar si el uso de Internet tenía incidencia sobre el éxito académico. Los resultados muestran que quienes realizan actividades interactivas con pares y profesores o quienes utilizan de forma balanceada las distintas herramientas de Internet tienden a un mayor éxito académico que aquellos que solo buscan información. En lo referente al entretenimiento, se encontró una incidencia positiva del uso de Internet sobre el éxito académico. Los estudiantes que realizan descargas de contenido de audio, video y software, y quienes utilizan todas las posibilidades de entretenimiento, presentan menor tendencia a suspender que los estudiantes que utilizan mínimamente Internet. En cuanto al género se presentan diferencias en los usos académicos y de entretenimientoThe use of technology is changing the way things are done, including the work in universities where the teaching and learning process are changing, and it is required to know the effect of technology on student achievement. In this research work, we present the influence of Internet use on academic success of students from five universities in Ecuador. A random sample of 4,697 people was got up and categorized in two groups: the use of Internet in academic activities and entertainment, using factor analysis and cluster analysis; the resulting categories were used as independent variables in multinomial logistic regression model which are seeking to determine if the use of Internet has impacted on academic success. The results show that people who perform interactive activities with peers and teachers or use in a balanced way the different internet tools tend to have more academic success than those who only seeks information. Regarding to the use of Internet in entertainment, a positive impact was found on academic achievement. Students who download audio, video and software, and students who use all the entertainment possibilities show less likely to fail than who using minimally Internet. In terms of gender, it has different effects for entertainment and academic purpose

Development of a protocol for a rat spinal cord proteome

Comunicaciones a congreso

Cloning and heterologous expression of Lactobacillus reuteri uroporphyrinogen III synthase/methyltransferase gene (cobA/hemD): Preliminary characterization

Some strains of Lb. reuteri produce cobalamin (vitamin B12). Cobalamin biosynthesis relies on the sequential action of more than 25 enzymes in a complex metabolic pathway. We have cloned, expressed and characterized the gene in Lb. reuteri that codes for the S-adenosy L-methionine uroprophyrinogen III methyltransferase/synthase (CobA/HemD), a key bifunctional enzyme in the biosynthesis of cobalamin and other tetrapyrrols.Fil: Vannini, María Verónica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaFil: Rodríguez, Adriana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaFil: Vera, José Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaFil: de Valdéz, Graciela F.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; Argentina. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia; ArgentinaFil: Taranto, Maria Pia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaFil: Sesma, Fernando Juan Manuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; Argentin

Physiologic Responses to Infrarenal Aortic Cross-Clamping during Laparoscopic or Conventional Vascular Surgery in Experimental Animal Model: Comparative Study

The aim of this study was to compare the hemodynamic and ventilatory effects of prolonged infrarenal aortic cross-clamping in pigs undergoing either laparotomy or laparoscopy. 18 pigs were used for this study. Infrarenal aortic crossclamping was performed for 60 minutes in groups I (laparotomy, n = 6) and II (laparoscopy, n = 6). Group III (laparoscopy, n = 6) underwent a 120-minute long pneumoperitoneum in absence of aortic clamping (sham group). Ventilatory and hemodynamic parameters and renal function were serially determined in all groups. A significant decrease in pH and significant increase in PaCO2 were observed in group II, whereas no changes in these parameters were seen in group I and III. All variables returned to values similar to baseline in groups I and II 60 minutes after declamping. A significant increase in renal resistive index was evidenced during laparoscopy, with significantly higher values seen in Group II. Thus a synergic effect of pneumoperitoneum and aortic cross-clamping was seen in this study. These two factors together cause decreased renal perfusion and acidosis, thus negatively affecting the patient's general state during this type of surgery

Silencing of Foxp3 enhances the antitumor efficacy of GM-CSF genetically modified tumor cell vaccine against B16 melanoma

The antitumor response after therapeutic vaccination has a limited effect and seems to be related to the presence of T regulatory cells (Treg), which express the immunoregulatory molecules CTLA4 and Foxp3. The blockage of CTLA4 using antibodies has shown an effective antitumor response conducing to the approval of the human anti-CTLA4 antibody ipilimumab by the US Food and Drug Administration. On the other hand, Foxp3 is crucial for Treg development. For this reason, it is an attractive target for cancer treatment. This study aims to evaluate whether combining therapeutic vaccination with CTLA4 or Foxp3 gene silencing enhances the antitumor response. First, the "in vitro" cell entrance and gene silencing efficacy of two tools, 2'-O-methyl phosphorotioate-modified oligonucleotides (2'-OMe-PS-ASOs) and polypurine reverse Hoogsteen hairpins (PPRHs), were evaluated in EL4 cells and cultured primary lymphocytes. Following B16 tumor transplant, C57BL6 mice were vaccinated with irradiated B16 tumor cells engineered to produce granulocyte-macrophage colony-stimulating factor (GM-CSF) and were intraperitoneally treated with CTLA4 and Foxp3 2'-OMe-PS-ASO before and after vaccination. Tumor growth, mice survival, and CTLA4 and Foxp3 expression in blood cells were measured. The following results were obtained: 1) only 2'-OMe-PS-ASO reached gene silencing efficacy "in vitro"; 2) an improved survival effect was achieved combining both therapeutic vaccine and Foxp3 antisense or CTLA4 antisense oligonucleotides (50% and 20%, respectively); 3) The blood CD4+CD25+Foxp3+ (Treg) and CD4+CTLA4+ cell counts were higher in mice that developed tumor on the day of sacrifice. Our data showed that tumor cell vaccine combined with Foxp3 or CTLA4 gene silencing can increase the efficacy of therapeutic antitumor vaccination

Utilización de la técnica de histerectomía para la eliminación de patógenos de una colonia de ratas de experimentación

Se ha demostrado que el uso de animales de experimentación indefinidos desde el punto de vista genético, microbiológico y ambiental, provoca interferencias en los resultados de las pruebas, lo cual implica una perdida de tiempo y de dinero además de una irresponsabilidad desde el punto de vista ético y moral por el hecho de estar utilizando animales vivos. La mayoría de los animales convencionales, que se mantienen en sistemas abiertos con ausencia de barreras sanitarias, están infectados generalmente de forma subclínica, con parásitos, hongos, bacterias y virus; se ha comprobado que estos microorganismos interfieren en las pruebas en las que se utilizan estos animales como reactivo biológico. Uno de los métodos que se ha utilizado para la eliminación de patógenos de colonias de animales de experimentación, es la técnica de derivación por histerectomía en un ambiente controlado. El fundamento de esta técnica se basa en la propiedad de la placenta de actuar como un filtro muy eficiente, protegiendo a los fetos de la transmisión de casi todos los agentes bacterianos, micóticos y virales, presentes en la madre. La técnica, realizada en un ambiente estéril, consiste en la remoción aséptica de los fetos de una madre donadora por medio de una histerectomía programada, y la derivación de los mismos a una madre nodriza SPF (Libre de patógenos específicos). El objetivo de este trabajo fue decontaminar y refundar una colonia de ratas Wistar SHR parasitada, de interés en estudios biomédicos, utilizando la técnica de derivación por histerectomía.Eje: Salud animalFacultad de Ciencias Veterinaria

Caracterización palinológica de la miel de un sector de la región chaqueña de la provincia de Tucumán (Argentina)

Background and aims: Argentina is among the leading producers and exporters of honey worldwide. Export mainly in bulk. To improve competitiveness, it launched a traceability system and quality regulations, based on the knowledge of the composition and availability of resources that allow differentiating honey by their geographical and botanical origin, data provided by the melisopalinological studies. The Chaco ecoregion and its apicultural capacity are the subject of many of these studies. In Tucumán, the Graneros Department located in this ecoregion, is promoted as a provider of beekeeping resources although the history of botanical and geographical characterization of honey is scarce. The objective of this work is the palynological characterization of honey, present in the Department Graneros of the Province of Tucumán.M&M: Honey samples from 3 inter-annual beekeeping campaigns were qualitatively analyzed. The present pollen morphotypes and frequency classes were determined. Data were compared by correspondence analysis.Results: A total of 54 morphological types were identified, 14 at a specific level, 25 generic and 15 family. Of these 11 were classified as very frequent, 10 frequent, 9 infrequent and the remaining rare. 76% of the samples are monofloral, of which 46% are from Atamisquea emarginata, 31% from Sarcomphalus mistol and 23% from Prosopis sp.Conclusions: The interannual analysis of the honey from the Graneros Department (Tucumán), it helps to expand knowledge about the nectariferous resources of a sector of the Chaco Seco.Introducción y objetivos: Argentina se encuentra entre los principales productores y exportadores de miel a nivel mundial. Exporta principalmente a granel. Para mejorar la competitividad puso en marcha un sistema de trazabilidad y normativa de calidad, basado en el conocimiento de la composición y disponibilidad de recursos que permitan diferenciar las mieles por su origen geográfico y botánico, datos aportados por los estudios melisopalinologicos. La ecorregión del Chaco y su capacidad apícola son objeto de muchos de estos estudios. En Tucumán, el Departamento Graneros ubicado en dicha ecorregiòn, se potencia como proveedor de recursos apícolas a pesar de que son escasos los antecedentes de caracterización botánica y geográfica de miel. El objetivo de este trabajo es la caracterización palinológica de las mieles, presente en el Departamento Graneros de la Provincia de Tucumán. M&M: Se analizaron cualitativamente muestras de miel de 3 campañas apícolas interanuales. Se determinaron los morfotipos polínicos presentes y las clases de frecuencia. Los datos fueron comparados mediante un análisis de correspondencia. Resultados: Se identificaron un total de 54 tipos morfológicos, 14 a nivel específico, 25 genérico y 15 familia. De ellos 11 fueron clasificados como muy frecuentes, 10 frecuentes, 9 poco frecuentes y los restantes raros. El 76 % de las muestras son monoflorales, de ellas 46% son de Atamisquea emarginata, 31% de Sarcomphalus mistol y 23% de Prosopis sp. Conclusiones: El análisis interanual de las mieles del Departamento Graneros (Tucumán), contribuye a ampliar el conocimiento sobre los recursos nectaríferos de un sector del Chaco Sec