Estudio de factibilidad para la creación de una empresa de asesoría gerencial para proyectos de construccción inmobiliarios en la ciudad de Quito y Valles aledaños

El desarrollo del sector de la construcción afecta a toda la actividad económica del país de diversas maneras. En primer lugar influye de manera directa en las empresas constructoras que a su vez producen un impacto en las empresas suministradoras de materiales para la construcción las cuales traen consigo una repercusión amplia de actividades productivas, así como también afecta de manera directa a los sectores para los cuales constituye un punto de partida para el desarrollo de sus actividades

3-Methylcholanthrene impacts on the female germ cells of rats without causing systemic toxicity

We have previously shown that daily exposure to the environmental pollutant 3-methylcholanthrene (3MC) alters the ovarian function by affecting follicle growth and ovulation. To extend our findings, the aims of this work were to study the effects of daily and non-daily exposure to 3MC on oocyte morphology and integrity and the meiosis process. To this end, immature female rats were daily (0.1–1.0 mg/kg) and non-daily (0.1 mg/kg, three times a week) exposed to 3MC and/or α-naphthoflavone (αNF) (80 mg/kg) for 19 and 20 days, respectively. The latter was used to study its ability to prevent the 3MC action. Follicular growth was examined by histology, apoptosis by in situ cell death detection, oocyte integrity by morphological parameters and fluorescent dyes, and the meiotic spindle by immunostaining. Compared with controls (C), and in a dose-dependent manner, all 3MC-treated rats showed i) increased presence of apoptotic cells in antral follicles and decreased percentage of healthy oocytes, ii) increased oocyte area, perimeter and perivitelline space and decreased thickness of the zona pellucida, and ii) increased percentage of oocytes with abnormal meiotic spindle. In addition, the non-daily dose of 3MC caused DNA damage in oocytes, but not in blood or bone marrow cells. All 3MC-induced changes were prevented with the co-treatment with αNF. These results suggest that low doses of 3MC severely disrupt the ovarian function and that germ cells seem to be more sensitive to this environmental pollutant than other cells such as peripheral blood and bone marrow cells.Fil: Rhon Calderón, Eric Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Centro de Estudios Farmacológicos y Botánicos. Universidad de Buenos Aires. Facultad de Medicina. Centro de Estudios Farmacológicos y Botánicos; ArgentinaFil: Galarza, Rocío Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Centro de Estudios Farmacológicos y Botánicos. Universidad de Buenos Aires. Facultad de Medicina. Centro de Estudios Farmacológicos y Botánicos; ArgentinaFil: Faletti, Alicia Graciela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Centro de Estudios Farmacológicos y Botánicos. Universidad de Buenos Aires. Facultad de Medicina. Centro de Estudios Farmacológicos y Botánicos; Argentin

The systemic and gonadal toxicity of 3-methylcholanthrene is prevented by daily administration of α-naphthoflavone

In the present study, we investigated the effect of 3-methylcholanthrene (3MC) on sexual maturity and the ability of α-naphthoflavone (αNF) to prevent this action. To this end, immature rats were daily injected intraperitoneally with 3MC (0.1 or 1 mg/kg) and/or αNF (80 mg/kg). Body weight, vaginal opening and estrous cycle were recorded and ovaries were obtained on the day of estrus. Ovarian weight, ovulation rate (measured by the number of oocytes within oviducts), and follicular development (determined by histology) were studied. No differences were found in body weight, ovarian weight, day of vaginal opening, or the establishment of the estrous cycle among the different groups of rats. However, animals treated with 3MC, at both doses, exhibited a lower number of primordial, primary, preantral and antral follicles than controls. Also, 3MC inhibited the ovulation rate and induced an overexpression of both the Cyp1a1 and Cyp1b1 genes, measured by chromatin immunoprecipitation assay. The daily treatment with αNF alone increased the number of follicles in most of the stages analyzed when compared with controls. Moreover, the αNF treatment prevented completely not only the 3MC-induced decrease in all types of follicles but also the 3MC-induced overexpression of Cyp enzymes and the genetic damage in bone marrow cells and oocytes. These results suggest that (i) daily exposure to 3MC during the pubertal period destroys the follicle reserve and alters the ovulation rate; (ii) the 3MC action seems to be mediated by an aryl hydrocarbon receptor-dependent mechanism; (iii) daily administration of αNF has a clear stimulatory action on the ovarian function; and (iv) αNF may prevent both the systemic and gonadal 3MC-induced toxicity.Fil: Rhon Calderón, Eric Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Centro de Estudios Farmacológicos y Botánicos. Universidad de Buenos Aires. Facultad de Medicina. Centro de Estudios Farmacológicos y Botánicos; ArgentinaFil: Galarza, Rocío Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Centro de Estudios Farmacológicos y Botánicos. Universidad de Buenos Aires. Facultad de Medicina. Centro de Estudios Farmacológicos y Botánicos; ArgentinaFil: Lomniczi, Alejandro. Oregon National Primate Research Center; Estados UnidosFil: Faletti, Alicia Graciela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Centro de Estudios Farmacológicos y Botánicos. Universidad de Buenos Aires. Facultad de Medicina. Centro de Estudios Farmacológicos y Botánicos; Argentin

Maternal overweight disrupts the sexual maturation of the offspring

The aims of the present work were to study the effect of maternal overweight and obesity on the ovarian reserve, follicular development, and ovulation of the offspring and to assess whether this maternal condition alters oocyte integrity. To this end, female offspring from rats fed standard (OSD) or cafeteria (OCD) diet were used. Body weight, vaginal opening, and estrous cycle were recorded and ovaries were obtained on the day of the second estrus. In addition, ovarian weight, ovulation rate (measured by the number of oocytes within oviducts), follicular development (determined by histology), and oocyte integrity were examined. The OCD were divided into 2 groups: offspring from rats with 17% and 28% of overweight (OCD17 and OCD28, respectively). Both OCD groups showed higher body weight, but OCD28 also exhibited early vaginal opening and higher ovarian weight and glycemia at euthanasia compared with OSD. Both OCD17 and OCD28 had lower number of primordial and primary follicles, and only OCD28 exhibited lower number of antral follicles, all compared with OSD rats. In addition, both OCD17 and OCD28 had higher ovulation rate than controls, and OCD28 had lower number of healthy oocytes, which, in turn, exhibited morphological alterations such as larger perivitelline space and zona pellucida than those of control animals. These results suggest that maternal overweight may severely affect the reproductive ability of the offspring, likely as a result of altering the organogenesis.Fil: Galarza, Rocío Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Centro de Estudios Farmacológicos y Botánicos. Universidad de Buenos Aires. Facultad de Medicina. Centro de Estudios Farmacológicos y Botánicos; Argentina. Universidad de Buenos Aires. Facultad de Medicina; ArgentinaFil: Rhon Calderón, Eric Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Centro de Estudios Farmacológicos y Botánicos. Universidad de Buenos Aires. Facultad de Medicina. Centro de Estudios Farmacológicos y Botánicos; ArgentinaFil: Cortez, Analía Elizabeth. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Centro de Estudios Farmacológicos y Botánicos. Universidad de Buenos Aires. Facultad de Medicina. Centro de Estudios Farmacológicos y Botánicos; Argentina. Universidad de Buenos Aires. Facultad de Medicina; ArgentinaFil: Faletti, Alicia Graciela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Centro de Estudios Farmacológicos y Botánicos. Universidad de Buenos Aires. Facultad de Medicina. Centro de Estudios Farmacológicos y Botánicos; Argentina. Universidad de Buenos Aires. Facultad de Medicina; Argentin

Changes in the expression of genes involved in the ovarian function of rats caused by daily exposure to 3-methylcholanthrene and their prevention by α-naphthoflavone

Daily exposure to low doses of 3-methylcholanthrene (3MC) during the pubertal period in rats disrupts both follicular growth and ovulation. Thus, to provide new insights into the toxicity mechanism of 3MC in the ovary, here we investigated the effect of daily exposure to 3MC on selected ovarian genes, the role of the aryl hydrocarbon receptor (AhR) and the level of epigenetic remodeling of histone post-transcriptional modifications. Immature rats were daily injected with 3MC (0.1 or 1 mg/kg) and mRNA expression of genes involved in different ovarian processes were evaluated. Of the 29 genes studied, 18 were up-regulated, five were down-regulated and six were not altered. To assess whether AhR was involved in these changes, we used the chromatin immunoprecipitation assay. 3MC increased AhR binding to promoter regions of genes involved in Notch signaling (Hes1, Jag1), activation of primordial follicles (Cdk2), cell adhesion (Icam1), stress and tumor progression (Dnajb6), apoptosis (Bax, Caspase-9) and expression of growth and transcription factors (Igf2, Sp1). Studying the trimethylation and acetylation of histone 3 (H3K4me3 and H3K9Ac, respectively) of these genes, we found that 3MC increased H3K4me3 in Cyp1a1, Jag1, Dnajb6, Igf2, Notch2, Adamts1, Bax and Caspase-9, and H3K9Ac in Cyp1a1, Jag1, Cdk2, Dnajb6, Igf2, Icam1, and Sp1. Co-treatment with α-naphthoflavone (αNF), a specific antagonist of AhR, prevented almost every 3MC-induced changes. Despite the low dose used in these experiments, daily exposure to 3MC induced changes in both gene expression and epigenomic remodeling, which may lead to premature ovarian failure.Fil: Rhon Calderón, Eric Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Centro de Estudios Farmacológicos y Botánicos. Universidad de Buenos Aires. Facultad de Medicina. Centro de Estudios Farmacológicos y Botánicos; ArgentinaFil: Toro, Carlos Alejandro. Oregon National Primate Research Cente; Estados UnidosFil: Lomniczi, Alejandro. Oregon National Primate Research Cente; Estados UnidosFil: Galarza, Rocío Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Centro de Estudios Farmacológicos y Botánicos. Universidad de Buenos Aires. Facultad de Medicina. Centro de Estudios Farmacológicos y Botánicos; ArgentinaFil: Faletti, Alicia Graciela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Centro de Estudios Farmacológicos y Botánicos. Universidad de Buenos Aires. Facultad de Medicina. Centro de Estudios Farmacológicos y Botánicos; Argentin

Regulation of the ovarian oxidative status by leptin during the ovulatory process in rats

Leptin exerts both stimulatory and inhibitory effects on the ovulatory process. In this study, we investigated whether these opposite effects involve changes in the oxidative status in response to different levels of leptin. To this end, we performed both in vivo and in vitro assays using ovaries of immature rats primed with gonadotropins to induce ovulation. Superoxide dismutase (SOD) and catalase (CAT) activity, lipid peroxidation, glutathione (GSH) content, and reactive oxygen species (ROS) were studied as oxidative damage-related parameters. The expression of BCL2, BAX, and caspase 3 were measured by western blot as apoptosis-related biomarkers. The acute treatment with leptin, which inhibits ovulation, decreased SOD activity and increased active caspase 3 expression. No differences were found in CAT activity, lipid peroxidation, or total GSH. In contrast, the daily administration of leptin, which induces ovulation, decreased GSH content, ROS levels, and Bax and active caspase 3 expression, but caused no changes in other parameters. In addition, the daily administration of leptin induced follicular growth, measured by the number of antral follicles in ovarian sections. Using ovarian explant cultures, we found increased BCL2 expression and decreased SOD activity at low and high concentrations of leptin respectively. Thus, leptin can modulate the oxidative status of the ovarian tissue, during the ovulatory process, by acting on different targets according to its circulating levels. At low concentration, leptin seems to play a protective role against the oxidative stress, whereas at high concentrations, this protein seems to be involved in cell death.Fil: Bilbao, María Guillermina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Centro de Estudios Farmacológicos y Botánicos; Argentina. Universidad de Buenos Aires. Facultad de Medicina; ArgentinaFil: Di Yorio, María Paula. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Centro de Estudios Farmacológicos y Botánicos; Argentina. Universidad de Buenos Aires. Facultad de Medicina; ArgentinaFil: Galarza, Rocío Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Centro de Estudios Farmacológicos y Botánicos; Argentina. Universidad de Buenos Aires. Facultad de Medicina; ArgentinaFil: Varone, Cecilia Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Faletti, Alicia Graciela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Centro de Estudios Farmacológicos y Botánicos; Argentina. Universidad de Buenos Aires. Facultad de Medicina; Argentin

Impact of maternal overweight on the sexual maturity of male offspring in rats

The aims of the present work were to study the effect of maternal overweight on both the count and quality of sperm of the offspring and to assess whether this maternal condition is able to alter testicular integrity and spermatogenic process. To this end, male offspring from rats fed a standard (OSD) or cafeteria (OCD) diet were used. Body and testis weight, length, preputial separation and ano-genital distance (AGD) were recorded and testes were removed at 60 days of age. In addition, the number of germ, Leydig and Sertoli cells, spermatogenesis and sperm integrity were examined. The OCD rats were divided into two groups: offspring from rats with 25% and≥35% of overweight (OCD25 and OCD35, respectively). Both OCD groups showed higher body and testis weight, higher length, and greater AGD than OSD rats. OCD25 also showed early preputial separation and OCD35 exhibited a high level of testosterone with normal glycemia. Both OCD25 and OCD35 rats had a lower number of spermatozoa and Leydig cells than OSD rats, and OCD35 also exhibited a lower number of spermatogonia and Sertoli cells than OSD rats. In addition, both OCD groups exhibited lower number of sperm cells with normal morphology and sperm motility, and OCD35 showed changes in both the seminiferous epithelium and spermatogenic process. These results suggest that maternal overweight severely affects the reproductive capacity of male offspring, likely leading to a subfertility condition and a premature reduction of the reproductive life span.Fil: Galarza, Rocío Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Centro de Estudios Farmacológicos y Botánicos. Universidad de Buenos Aires. Facultad de Medicina. Centro de Estudios Farmacológicos y Botánicos; ArgentinaFil: Rhon Calderón, Eric Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Centro de Estudios Farmacológicos y Botánicos. Universidad de Buenos Aires. Facultad de Medicina. Centro de Estudios Farmacológicos y Botánicos; ArgentinaFil: Bizzozero, Marianne. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Meneghini, María Agustina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Centro de Estudios Farmacológicos y Botánicos. Universidad de Buenos Aires. Facultad de Medicina. Centro de Estudios Farmacológicos y Botánicos; ArgentinaFil: Cortez, Analía Elisabeth. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Centro de Estudios Farmacológicos y Botánicos. Universidad de Buenos Aires. Facultad de Medicina. Centro de Estudios Farmacológicos y Botánicos; ArgentinaFil: Lux Lantos, Victoria Adela. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Faletti, Alicia Graciela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Centro de Estudios Farmacológicos y Botánicos. Universidad de Buenos Aires. Facultad de Medicina. Centro de Estudios Farmacológicos y Botánicos; Argentin

Mujeres y trabajo en América Latina: Desafíos para las políticas laborales

"Mujeres y trabajo en América Latina: Desafíos para las políticas laborales" reseña los avances realizados por las mujeres de la región en el mercado laboral y los desafíos que tienen por delante, al tiempo que propone recomendaciones sobre políticas en este campo. El libro presenta una serie de estudios empíricos en los que se utilizan datos de encuestas familiares para analizar las tendencias de las tasas de participación femenina, el impacto de la liberalización del comercio en el trabajo de las mujeres, las tendencias de las disparidades salariales por motivos de género y la segregación ocupacional, y las repercusiones de la reforma del sistema de pensiones en las situación de la mujer.