Galectin-1: Biphasic growth regulation of Leydig tumor cells

Galectin-1 (Gal-1) is a widely expressed β-galactoside-binding protein that exerts pleiotropic biological functions. To gain insight into the potential role of Gal-1 as a novel modulator of Leydig cells, we investigated its effect on the growth and death of MA-10 tumor Leydig cells. In this study, we identified cytoplasmic Gal-1 expression in these tumor cells by cytofluorometry. DNA fragmentation, caspase-3, -8, and -9 activation, loss of mitochondrial membrane potential (ΔΨ m), cytochrome c (Cyt c) release, and FasL expression suggested that relatively high concentrations of exogenously added recombinant Gal-1 (rGal-1) induced apoptosis by the mitochondrial and death receptor pathways. These pathways were independently activated, as the presence of the inhibitor of caspase-8 or -9 only partially prevented Gal-1-effect. On the contrary, low concentrations of Gal-1 significantly promoted cell proliferation, without inducing cell death. Importantly, the presence of the disaccharide lactose prevented Gal-1 effects, suggesting the involvement of the carbohydrate recognition domain (CRD). This study provides strong evidence that Gal-1 is a novel biphasic regulator of Leydig tumor cell number, suggesting a novel role for Gal-1 in the reproductive physiopathology. © Copyright 2006 Oxford University Press.Fil:Troncoso, M.F. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.Fil:Patrignani, Z.J. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.Fil:Pignataro, O.P. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina

Informe para el Tribunal Constitucional sobre los aspectos científicos y éticos del uso del levonorgestrel como anticonceptivo de emergencia

Las normas de regulación de la fertilidad, propuestas en el documento del Ministerio de Salud de Chile, plantean diversos problemas biomédicos en el contexto de una cierta visión de la procreación humana, de la sexualidad y de la familia. Hay serias objeciones desde una antropología que respeta la naturaleza personal de la mujer y del hombre, especialmente en el riesgo que existe en la promoción de métodos que podrían afectar la vida de seres humanos inocentes en sus etapas iniciales de desarrollo. Del análisis de la literatura se ha concluido que existen antecedentes científicos importantes, que se analizan en este documento, y que indicarían que el uso de la llamada “píldora del día después” podría estar poniendo en riesgo la vida del embrión humano preimplantacional

Political power from elite family networks in colonial Buenos Aires

The aim of this chapter is to show the relationship between the nominations for seats in the Cabildo of Buenos Aires between 1776 and 1810 and the network status of councilmen and their families. To this end, we test hypotheses on the relation of network metrics of elite individuals and families with political positions in the council. We find that actors and families with higher degree of connectedness are statistically associated with entrance and access to more prominent positions in the council as indicators of political power. Specifically, more centralized connections seem to assist individuals on the road to higher positions. In the case of families, a more dense structure of overlapped connections may have assured that more members reached higher positions in the Cabildo.Fil: del Valle, Laura Cristina. Universidad Nacional del Sur. Departamento de Humanidades; ArgentinaFil: Larrosa, Juan Manuel Ceferino. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones Económicas y Sociales del Sur. Universidad Nacional del Sur. Departamento de Economía. Instituto de Investigaciones Económicas y Sociales del Sur; Argentin