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Components of the plasminogen/plasmin system, known to be present in the oocyte, play a key role in maturation and fertilization. The objective of this study was to examine the effect of plasminogen activation and plasmin inhibition by exogenous supplementation of the IVF medium with streptokinase (SK) or ɛ-aminocaproic acid (ε-ACA), respectively, on fertilization parameters and preimplantation embryo development. After in vitro maturation, bovine cumulus-oocyte complexes (COCs) were inseminated in the presence of SK or ε-ACA. The addition of SK to the IVF medium facilitated the adhesion of the spermatozoa to the zona pellucida without affecting the percentages of monospermy. Cleavage rates and blastocyst yield were similar between the SK and Control groups while they were lower with the ε-ACA treatment. Additionally, we found that the expression levels of embryo quality-related genes (SDHA and DNMT3A) could be modified in blastocysts by the addition of SK or ε-ACA during IVF. The results obtained indicate that supplementation of the IVF medium with SK did not greatly alter the embryonic developmental parameters related to embryo quality in blastocysts. Moreover, we noticed that ε-ACA treatment compromises the success of in vitro embryo development, thus highlighting the importance of the plasminogen/plasmin activity during the early stages of embryogenesis in bovine.

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RESUMO

This study deals with the effect of plasminogen/plasmin on the in vitro maturation (IVM) of bovine cumulus-oocyte complexes (COCs). Exogenous plasminogen activator streptokinase (SK) added to the IVM medium revealed similar values of cumulus expansion and oocyte nuclear maturation compared to controls (standard IVM medium). However, a decrease in both determinations was observed in COCs matured with the supplementation of ɛ-aminocaproic acid (ɛ-ACA), a specific plasmin inhibitor. After in vitro fertilization, no differences were observed in either cleavage or blastocyst rates between SK and control groups; however, ε-ACA treatment caused a decrease in both developmental rates. Zona pellucida (ZP) digestion time decreased in the SK group while it increased in the ε-ACA group. Raman microspectroscopy revealed an increase in the intensity of the band corresponding to the glycerol group of sialic acid in the ZP of oocytes matured with SK, whereas ZP spectra of oocytes treated with ɛ-ACA presented similarities with immature oocytes. The results indicate that although treatment with SK did not alter oocyte developmental competence, it induced modifications in the ZP of oocytes that could modify the folding of glycoproteins. Plasmin inhibition impairs oocyte maturation and has an impact on embryo development, thus evidencing the importance of this protease during IVM.

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BACKGROUND: Violence against health personnel is an understudied phenomenon in Mexico, which has increased during periods of health contingency. OBJECTIVE: To identify the prevalence and type of violence against health professionals before and during the COVID-19 health contingency and determine the characteristics of the worker with the highest exposure. MATERIAL AND METHODS: Cross-sectional descriptive study, carried out during April of 2020, in 562 health workers, who answered a sociodemographic identification card and a questionnaire to know the characteristics, types and consequences of aggression before and during the contingency, through an electronic and anonymous platform. A non-probabilistic sampling (snowball) was used in different states of Mexico. RESULTS: 47.7% of the participants experienced aggressions, 12.8% verbal type and 34.9% verbal/physical aggressions during the last year, where women showed to be more attacked (chi squared = 12.12, p = 0.000). During health contingency, 16.8% perceived aggression, 13.2% verbal type and 3.6% verbal/physical aggression, with nurses being the most attacked (chi squared = 5.57, p = 0.018). A logistic regression model confirmed that being a woman and belonging to nursing profession has, respectively as far as 2.5 and 3 times more risk of suffering violence. CONCLUSIONS: Violence against health personnel requires immediate strategies, especially in critical periods in the community, where aggressions occur inside and outside of hospitals, which have an impact on worker's safety and health institutions.

INTRODUCCIÓN: la violencia hacia el personal de salud es un fenómeno poco estudiado en México, el cual se ha incrementado durante periodos de contingencia sanitaria. OBJETIVO: identificar la prevalencia y el tipo de violencia hacia el personal de salud antes y durante la contingencia sanitaria por COVID-19 y determinar las características laborales del trabajador en mayor exposición. MATERIAL Y MÉTODOS: estudio descriptivo transversal, llevado a cabo en abril de 2020, en 562 trabajadores de la salud, quienes contestaron una cédula de datos sociodemográficos y un cuestionario para indagar características, tipos y consecuencias de las agresiones, antes y durante la contingencia, mediante una plataforma electrónica y anónima. Se empleó un muestreo no probabilístico (en bola de nieve) en distintas entidades de México. RESULTADOS: 47.7% de los participantes experimentó agresiones, 12.8% de tipo verbal y 34.9% verbal/física durante el último año; las mujeres fueron las más agredidas (chi cuadrada = 12.12, p = 0.000). Durante la contingencia sanitaria 16.8% recibió agresión, 13.2% de tipo verbal y 3.6% verbal/física, siendo las enfermeras las más agredidas (chi cuadrada = 5.57, p = 0.018), información que se confirmó mediante un modelo de regresión logística donde ser mujer y pertenecer a enfermería, respectivamente representó hasta 2.5 y 3 veces mayor riesgo de sufrir violencia. CONCLUSIONES: la violencia hacia el personal sanitario requiere estrategias inmediatas, especialmente en periodos críticos en la comunidad, donde las agresiones se presentan dentro y fuera de hospitales, lo cual repercute en la seguridad de los trabajadores e instituciones sanitarias.

RESUMO

Growth and development of ovarian follicles require a series of coordinated events that induce morphological and functional changes within the follicle, leading to cell differentiation and oocyte development. The preantral early antral follicle transition is the stage of follicular development during which gonadotropin dependence is obtained and the progression into growing or atresia of the follicle is made. Follicular growth during this period is tightly regulated by oocyte-granulosatheca cell interactions. A cluster of early expressed genes is required for normal folliculogenesis. Granulosa cell factors stimulate the recruitment of theca cells from cortical stromal cells. Thecal factors promote granulosa cell proliferation and suppress granulosa cell apoptosis. Cell-cell and cell-extracellular matrix interactions influence the production of growth factors in the different follicular compartments (oocyte, granulosa, and theca cells). Several autocrine and paracrine factors are involved in follicular growth and differentiation; their activity is present even at the time of ovulation, decreasing the gap junction communication, and stimulating the theca cell proliferation. In addition, the identification of the factors that promote follicular growth from the preantral stage to the small antral stage may provide important information for the identification for assisted reproduction techniques.

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