201 research outputs found

    Immature rats show ovulatory defects similar to those in adult rats lacking prostaglandin and progesterone actions

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    Gonadotropin-primed immature rats (GPIR) constitute a widely used model for the study of ovulation. Although the equivalence between the ovulatory process in immature and adult rats is generally assumed, the morphological and functional characteristics of ovulation in immature rats have been scarcely considered. We describe herein the morphological aspects of the ovulatory process in GPIR and their response to classical ovulation inhibitors, such as the inhibitor of prostaglandin (PG) synthesis indomethacin (INDO) and a progesterone (P) receptor (PR) antagonist (RU486). Immature Wistar rats were primed with equine chorionic gonadotropin (eCG) at 21, 23 or 25 days of age, injected with human chorionic gonadotropin (hCG) 48 h later, and sacrificed 16 h after hCG treatment, to assess follicle rupture and ovulation. Surprisingly, GPIR showed age-related ovulatory defects close similar to those in adult rats lacking P and PG actions. Rats primed with eCG at 21 or 23 days of age showed abnormally ruptured corpora lutea in which the cumulus-oocyte complex (COC) was trapped or had been released to the ovarian interstitum, invading the ovarian stroma and blood and lymphatic vessels. Supplementation of immature rats with exogenous P and/or PG of the E series did not significantly inhibit abnormal follicle rupture. Otherwise, ovulatory defects were practically absent in rats primed with eCG at 25 days of age. GPIR treated with INDO showed the same ovulatory alterations than vehicle-treated ones, although affecting to a higher proportion of follicles. Blocking P actions with RU486 increased the number of COC trapped inside corpora lutea and decreased ovulation. The presence of ovulatory defects in GPIR, suggests that the capacity of the immature ovary to undergo the coordinate changes leading to effective ovulation is not fully established in Wistar rats primed with eCG before 25 days of age

    Diseño de un modelo de arquitectura empresarial basado en TOGAF para mejorar la gestión de procesos de negocio de Brasas y Parrillas JC, Trujillo, 2020

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    El presente trabajo de investigación tuvo como objetivo analizar las características de la gestión de procesos de negocio y qué aspectos se puede considerar de TOGAF para proponer un modelo de arquitectura empresarial en Brasas y Parrillas JC. Para lo cual, primero se buscó información sobre las características de arquitectura empresarial para una adecuada gestión de procesos de negocios y las bases teóricas del marco de referencia TOGAF para elaborar un modelo de arquitectura empresarial. Seguido, se analizó el estado de los procesos de la empresa en estudio, hallando que estos presentaban retrasos en los tiempos ejecución, acciones redundantes y actividades que podían automatizarse pero que se realizaban manualmente. Teniendo en cuenta esta problemática, se elaboró un modelo de arquitectura empresarial basada en la metodología TOGAF, con la cual se propusieron mejoras en 4 dimensiones: arquitectura de negocio, arquitectura de información, arquitectura de aplicaciones y arquitectura tecnológica. Obteniendo como resultado un modelo de arquitectura empresarial, en el que se integraría sus procesos con la tecnología, que permitiría a la empresa agilizar sus operaciones y estar a la vanguardia frente a la competencia

    Microcystin-LR equivalents and their correlation with Anabaena spp. in the main reservoir of a hydraulic system of Central Mexico

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    The occurrence of cyanobacterial blooms is a characteristic of eutrophic inland water bodies. Valle de Bravo reservoir (Mexico State, Mexico) is the main source of water for the Cutzamala Hydraulic System, which supplies drinking water to the west of Mexico City (~6 million consumers) and suburban areas of Mexico State. The goal of this study was to determine the presence of microcystins (MC-LR equivalents) and their relationship with toxic populations of cyanobacteria recorded some years ago in this important reservoir. We measured the concentration of MC-LR equivalents using a commercial kit (EnviroLogix) based on the ELISA test. The calculation of abundance and biovolume was carried out monthly from February to November 2010. The presence of MC-LR equivalents was related to the biovolume of Anabaena planctonica. The values of this toxin from February to June exceeded the World Health Organization (WHO) provisional guideline (1 µg L-1) for finished drinking water sources, particularly in April when the highest value was recorded (5.56 μg L-1). In addition, in April, May, June, and August, the abundance of cyanobacteria exceeded the WHO moderate risk level (10 × 104 cells mL-1) for recreational activities. This study furthers investigations ranging from the characteristics of the water column to benthic cyanobacteria and molecular biology tests to establish which species are toxic in the reservoir

    Hypothalamic miR-30 regulates puberty onset via repression of the puberty-suppressing factor, Mkrn3.

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    Mkrn3, the maternally imprinted gene encoding the makorin RING-finger protein-3, has recently emerged as putative pubertal repressor, as evidenced by central precocity caused by MKRN3 mutations in humans; yet, the molecular underpinnings of this key regulatory action remain largely unexplored. We report herein that the microRNA, miR-30, with three binding sites in a highly conserved region of its 3' UTR, operates as repressor of Mkrn3 to control pubertal onset. Hypothalamic miR-30b expression increased, while Mkrn3 mRNA and protein content decreased, during rat postnatal maturation. Neonatal estrogen exposure, causing pubertal alterations, enhanced hypothalamic Mkrn3 and suppressed miR-30b expression in female rats. Functional in vitro analyses demonstrated a strong repressive action of miR-30b on Mkrn3 3' UTR. Moreover, central infusion during the juvenile period of target site blockers, tailored to prevent miR-30 binding to Mkrn3 3' UTR, reversed the prepubertal down-regulation of hypothalamic Mkrn3 protein and delayed female puberty. Collectively, our data unveil a novel hypothalamic miRNA pathway, involving miR-30, with a prominent role in the control of puberty via Mkrn3 repression. These findings expand our current understanding of the molecular basis of puberty and its disease states

    Water-soluble gold nanoparticles : from catalytic selective nitroarene reduction in water to refractive index sensing

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    Water-soluble gold nanoparticles (Au NPs) stabilized by a nitrogen-rich PEG-tagged substrate have been prepared by reduction of HAuCl₄ with NaBH₄ in water at room temperature. The morphology and size of the nanoparticles can be controlled by simply varying the gold/stabilizer ratio. The nanoparticles have been fully characterized by TEM, HRTEM, ED, EDS, UV-vis, p-XRD and elemental analysis. The material is efficient as a recyclable catalyst for the selective reduction of nitroarenes with NaBH₄ to yield the corresponding anilines in water at room temperature. Furthermore, the potential ability of the Au NPs as a refractive index sensor due to their localized surface plasmon resonance (LSPR) effect has also been assessed

    Enfrentando los riesgos socionaturales

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    El objetivo del libro es comprender la magnitud de los Riesgos Socionaturales en México y Latinoamérica, para comprender el peligro que existe por algún tipo de desastre, ya sea inundaciones, sismos, remoción en masa, entre otros, además conocer qué medidas preventivas, correctivas y de contingencias existen para estar atentos ante alguna señal que la naturaleza esté enviando y así evitar alguna catástrofe. El libro se enfoca en los aspectos básicos de análisis de los peligros, escenarios de riesgo, vulnerabilidad y resiliencia, importantes para la gestión prospectiva o preventiva

    Dicer ablation in Kiss1 neurons impairs puberty and fertility preferentially in female mice

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    Kiss1 neurons, producing kisspeptins, are essential for puberty and fertility, but their molecular regulatory mechanisms remain unfolded. Here, we report that congenital ablation of the microRNA-synthesizing enzyme, Dicer, in Kiss1 cells, causes late-onset hypogonadotropic hypogonadism in both sexes, but is compatible with pubertal initiation and preserved Kiss1 neuronal populations at the infantile/juvenile period. Yet, failure to complete puberty and attain fertility is observed only in females. Kiss1-specific ablation of Dicer evokes disparate changes of Kiss1-cell numbers and Kiss1/kisspeptin expression between hypothalamic subpopulations during the pubertal-transition, with a predominant decline in arcuate-nucleus Kiss1 levels, linked to enhanced expression of its repressors, Mkrn3, Cbx7 and Eap1. Our data unveil that miRNA-biosynthesis in Kiss1 neurons is essential for pubertal completion and fertility, especially in females, but dispensable for initial reproductive maturation and neuronal survival in both sexes. Our results disclose a predominant miRNA-mediated inhibitory program of repressive signals that is key for precise regulation of Kiss1 expression and, thereby, reproductive function.Kiss1 neurons are essential for puberty and fertility. Here, the authors show that canonical microRNA biosynthesis in Kiss1 neurons plays an essential role in the control of puberty and fertility, especially in females, likely via repression of repressors on the Kiss1 gene.</p

    Hypothalamic miR-30 regulates puberty onset via repression of the puberty-suppressing factor, Mkrn3

    Get PDF
    Mkrn3, the maternally imprinted gene encoding the makorin RING-finger protein-3, has recently emerged as putative pubertal repressor, as evidenced by central precocity caused by MKRN3 mutations in humans; yet, the molecular underpinnings of this key regulatory action remain largely unexplored. We report herein that the microRNA, miR-30, with three binding sites in a highly conserved region of its 3 ' UTR, operates as repressor of Mkrn3 to control pubertal onset. Hypothalamic miR-30b expression increased, while Mkrn3 mRNA and protein content decreased, during rat postnatal maturation. Neonatal estrogen exposure, causing pubertal alterations, enhanced hypothalamic Mkrn3 and suppressed miR-30b expression in female rats. Functional in vitro analyses demonstrated a strong repressive action of miR-30b on Mkrn3 3 ' UTR. Moreover, central infusion during the juvenile period of target site blockers, tailored to prevent miR-30 binding to Mkrn3 3 ' UTR, reversed the prepubertal down-regulation of hypothalamic Mkrn3 protein and delayed female puberty. Collectively, our data unveil a novel hypothalamic miRNA pathway, involving miR-30, with a prominent role in the control of puberty via Mkrn3 repression. These findings expand our current understanding of the molecular basis of puberty and its disease states

    Immune physiology in tissue regeneration and aging, tumor growth, and regenerative medicine

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    The immune system plays an important role in immunity (immune surveillance), but also in the regulation of tissue homeostasis (immune physiology). Lessons from the female reproductive tract indicate that immune system related cells, such as intraepithelial T cells and monocyte-derived cells (MDC) in stratified epithelium, interact amongst themselves and degenerate whereas epithelial cells proliferate and differentiate. In adult ovaries, MDC and T cells are present during oocyte renewal from ovarian stem cells. Activated MDC are also associated with follicular development and atresia, and corpus luteum differentiation. Corpus luteum demise resembles rejection of a graft since it is attended by a massive influx of MDC and T cells resulting in parenchymal and vascular regression. Vascular pericytes play important roles in immune physiology, and their activities (including secretion of the Thy-1 differentiation protein) can be regulated by vascular autonomic innervation. In tumors, MDC regulate proliferation of neoplastic cells and angiogenesis. Tumor infiltrating T cells die among malignant cells. Alterations of immune physiology can result in pathology, such as autoimmune, metabolic, and degenerative diseases, but also in infertility and intrauterine growth retardation, fetal morbidity and mortality. Animal experiments indicate that modification of tissue differentiation (retardation or acceleration) during immune adaptation can cause malfunction (persistent immaturity or premature aging) of such tissue during adulthood. Thus successful stem cell therapy will depend on immune physiology in targeted tissues. From this point of view, regenerative medicine is more likely to be successful in acute rather than chronic tissue disorders
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