Immunohistochemical expression of aromatase cyp19a1a and cyp19a1b in the ovary and brain of zebrafish (Danio rerio) exposed to different concentrations of bisphenol A

Bisphenol A (BPA) is used to produce plastic and plastic derived products in multitude of daily utensils, being one of the industrial compounds most widely used. This endocrine disrupting chemical (EDCs) is a well-known environmental pollutant released into the aquatic environment from industrial wastewater, sewage sludge or landfill leachate. Aromatases are considered potential targets of EDCs with characteristics that make them suitable biomarkers of exposure to their effects. The main objective of our study was to evaluate the expression of cyp19a aromatase as a toxicological endpoint after BPA exposure through the identification and assessment of alterations of the main cells responsible for cyp19a1a and cyp19a1b expression in the zebrafish ovary and brain using different concentrations of BPA in water. Immunohistochemistry was used to analyze the expression of these enzymes in female zebrafish exposed and not exposed to different concentrations of BPA (1, 10, 100 and 1000 μg / L) in water (n = 6/group) for 14 days. The results obtained in this study showed that the cyp19a aromatase system, involved in the synthesis of steroid compounds, is specially located in distinct oocyte stages in the ovary (cyp19a1a) and in radial glial cells of the brain (cyp19a1b). An overexpression of these aromatases was observed after BPA exposure in zebrafish, peaking from a concentration of 10 µg/L and showing to be good biomarkers of exposure to identify the early effects of low BPA concentrations. To our knowledge, this study is the first to localize and quantify the expression of cyp19a1a and cyp19a1b in the cells of brain and ovary after fish exposure to different BPA concentrations in water

An overview of the health effects of bisphenol a from a one health perspective

Bisphenol A (BPA) is a chemical compound, considered as an “emerging pollutant”, that appears ubiquitously, contaminating the environment and food. It is an endocrine disruptor, found in a multitude of consumer products, as it is a constituent of polycarbonate used in the manufacture of plastics and epoxy resins. Many studies have evaluated the effects of BPA, using a wide range of doses and animal models. In this work, we carried out a review of relevant research related to the effects of BPA on health, through studies performed at different doses, in different animal models, and in human monitoring studies. Numerous effects of BPA on health have been described; in different animal species, it has been reported that it interferes with fertility in both females and males and causes alterations in their offspring, as well as being associated with an increase in hormone-dependent pathologies. Similarly, exposure to BPA has been related to other diseases of great relevance in public health such as obesity, hypertension, diabetes, or neurodevelopmental disorders. Its ubiquity and nonmonotonic behavior, triggering effects at exposure levels considered “safe”, make it especially relevant when both animal and human populations are constantly and inadvertently exposed to this compound. Its effects at low exposure levels make it essential to establish safe exposure levels, and research into the effects of BPA must continue and be focused from a “One Health” perspective to take into account all the factors that could intervene in the development of a disease in any exposed organism

Analysis of Indirect Biomarkers of Effect after Exposure to Low Doses of Bisphenol A in a Study of Successive Generations of Mice

Bisphenol A (BPA) is considered as being an emerging pollutant, to which both animal and human populations are continuously and inadvertently exposed. The identification of indirect biomarkers of effect could be a key factor in determining early adverse outcomes from exposure to low doses of BPA. Thus, this study on mice aims to evaluate and identify indirect biomarkers of effect through the analysis of their blood biochemistry, and of certain reproduction parameters after exposure to different BPA concentrations (0.5, 2, 4, 50, and 100 µg/kg BW/day) in drinking water over generations. Our results showed that there were no modifications in the reproductive parameters evaluated, like estrous cycle duration, litter size, or the percentage of the young alive at reaching the weaning stage, at the exposure levels evaluated. However, there were modifications in the biochemical parameters, e.g., alterations in the glucose levels, that increased significantly (p < 0.05) in the breeders at the higher exposure doses (50 and 100 µg/kg BW/day in F1; 50 µg/kg BW/day in F2 and 100 µg/kg BW/day in F3), that would suggest that the BPA could induce hyperglycemia and its complications in adult animals, probably due to some damage in the pancreas cells; albumin, that increased in the breeders exposed to the highest dose in F1 and F3, inferring possible hepatic alterations. Further, total proteins showed a diminution in their values in F1 and F2, except the group exposed to 100 µg/kg BW/day, whereas in F3 the values of this parameter increased with respect to the control group, this aspect likely being related to a possible hepatic and renal alteration. Based on these results, glucose, albumin, and total proteins could initially be considered as early indicators of indirect effect after prolonged exposure to low BPA doses over generations

Using the FVB strain of mice for the evaluation of clinical and experimental ketamine (IP) associated with phenothiazines, benzodiazepines and α2-agonists

El objetivo de este trabajo ha consistido en evaluar el estado fisiológico de los animales mediante el control de las frecuencias respiratoria y cardiaca así como la tasa de saturación de oxígeno durante la anestesia con ketamina asociada a otros fármacos. Para ello hemos utilizado 40 ratones FVB consanguíneos (20 machos y 20 hembras) de 11 semanas de edad, a los que se les administró por vía intraperitoneal ketamina asociada a un depresor del sistema nervioso central: acepromazina, diazepam, medetomidina, midazolam o xilazina. Obtuvimos resultados que difirieron mucho entre sexos, concluyendo que en machos los mejores resultados obtenidos fueron con la asociación a los α2-agonistas, mientras que en las hembras, al menos a las dosis empleadas, no pudimos afirmar que ninguna de las asociaciones fuese óptima.The aim of this work has been to evaluate the physiological status of animals by controlling the respiratory rate and heart rate and oxygen saturation during anesthesia with ketamine in combination with other drugs. We have used 40 consanguine FVB mice (20 males and 20 females) from 11 weeks of age, who were administered intraperitoneally with a ketamine-associated central nervous system depressant:acepromazina, diazepam, medetomidine, midazolam or xylazine. We obtained results that differed greatly between the sexes, in males, concluding that the best results were obtained with the association of α2- agonists, while in females, at least at the doses employed, did not say that none of the associations were optima

Evaluation of the Toxicity of Bisphenol A in Reproduction and Its Effect on Fertility and Embryonic Development in the Zebrafish (Danio rerio)

Bisphenol A (BPA) is a chemical substance commonly used in the manufacture of plastic products. Its inhalation or ingestion from particles in suspension, water, and/or polluted foods can trigger toxic effects related to endocrine disruption, resulting in hormonal, reproduction, and immunological alterations in humans and animals. The zebrafish (Danio rerio) is an ideal experimental model frequently used in toxicity studies. In order to assess the toxic effects of BPA on reproduction and embryonic development in one generation after parental exposure to it, a total of 80 zebrafish, males and females, divided into four groups in duplicate (n = 20) were exposed to BPA concentrations of 500, 50, and 5 µg L−1, along with a control group. The fish were kept in reproduction aquariums for 21 days. The embryos obtained in the crosses were incubated in a BPA-free medium and observed for signs of embryotoxicity. A histopathological study (under optical and electron microscopes) was performed of adult fish gonads. The embryos of reproducers exposed to BPA were those most frequently presenting signs of embryotoxicity, such as mortality and cardiac and musculoskeletal malformations. In the histopathological studies of adult individuals, alterations were found in ovocyte maturation and in spermatazoid formation in the groups exposed to the chemical. Those alterations were directly related to BPA action, affecting fertility in both sexes, as well as the viability of their offspring, proportionally to the BPA levels to which they were exposed, so that our results provide more information by associating toxic effects on the offspring and on the next generation

Proteomic profile of the effects of low-dose bisphenol A on zebrafish ovaries

Human exposure to bisphenol-A (BPA) is largely unavoidable because BPA is an environmental contaminant found in soil, water, food and indoor dust. The safety of authorized BPA amounts in consumer products is under question because new studies have reported adverse effects of BPA at doses far below that previously established by the NOAEL (50 μg/kg per day). To protect public health, the consequences of low-dose BPA exposure in different organs and organismal functions must be further studied to generate relevant data. This study attempted to investigate the effects and potential molecular mechanisms of short-term exposure to 1 μg/L BPA on zebrafish ovarian follicular development. We observed only minor changes at the histopathological level with a small (3 %) increase in follicular atresia. However, a shotgun proteomics approach indicated deep alterations in BPA-exposed ovarian cells, including induction of the oxidative stress response, metabolic shifts and degradome perturbations, which could drive oocytes towards premature maturation. Based on these results, it could be suggested that inadvertent exposure to small concentrations of BPA on a continuous basis causes alteration in biological processes that are essential for healthy reproduction

Development and implementation of a collaborative blog as a co-assessment instrument in Veterinary Medicine Degree

La evaluación educativa pretende comprometer al alumnado en su proceso de enseñanza-aprendizaje mediante el uso de estrategias e instrumentos de coevaluación y autoevaluación. En este sentido, las tecnologías de la información y de la comunicación (TIC) promueven un clima de enseñanza más dinámico a través del aprendizaje activo, siendo los blogs colaborativos una herramienta muy útil de evaluación del alumnado. El objetivo de este proyecto ha sido evaluar la implementación de un blog como instrumento educativo para promover la autorregulación por medio de actividades de coevaluación y/o autoevaluación en el ámbito universitario. Se diseñó un blog de divulgación científica como recurso docente para la asignatura optativa de “el Animal de Laboratorio”, perteneciente al Grado de Veterinaria. Se evaluó mediante cuestionarios tanto la situación inicial del alumnado, como los logros finales respecto al objetivo planteado, siguiendo una metodología descriptiva. Según los resultados obtenidos, es innegable decir que el uso del blog ha sido una práctica innovadora, siendo en muchos casos la primera experiencia con TIC para el alumnado. Respecto a su implementación, los resultados han sido satisfactorios para la mejora motivacional, el aprendizaje y la dinamización metodológica. Todo ello, pone de manifiesto las múltiples ventajas que ofrecen los blogs como herramienta de coevaluación.The educational evaluation aims to engage students in their teaching-learning process through the use of strategies and instruments of co-assessment and self-assessment In this sense, information and communication technologies (ICT) promote a more dynamic teaching environment through active learning, and collaborative blogs appear as a very useful tool for student assessment. The aim of this project has been to evaluate the implementation of a blog as an educational instrument to promote self-regulation through co-evaluation and / or self-evaluation activities at the university. To this end, a scientific dissemination blog was designed as a teaching resource for the optional subject “the Laboratory Animal”, belonging to the Veterinary Science Degree syllabus. The starting point of the learning process of the students was evaluated by questionnaires, as well as the final achievements related to the proposed objective, following a descriptive methodology. According to the obtained results, it is undeniable that the development of the blog has been an innovative practice, being in many cases the first experience with ICT for students. Regarding its implementation, results suggest that students‟ motivation has improved, and the learning procedure and methodologies applied have been dynamized. All this shows the many advantages that blogs offer as a co-assessment tool

Cylindrospermopsin-microcystin-LR combinations may induce genotoxic and histopathological damage in rats

Cylindrospermopsin (CYN) and microcystins (MC) are cyanotoxins that can occur simultaneously in contaminated water and food. CYN/MC-LR mixtures previously investigated in vitro showed an induction of micronucleus (MN) formation only in the presence of the metabolic fraction S9. When this is the case, the European Food Safety Authority recommends a follow up to in vivo testing. Thus, rats were orally exposed to 7.5 + 75, 23.7 + 237, and 75 + 750 μg CYN/MC-LR/kg body weight (b.w.). The MN test in bone marrow was performed, and the standard and modified comet assays were carried out to measure DNA strand breaks or oxidative DNA damage in stomach, liver, and blood cells. The results revealed an increase in MN formation in bone marrow, at all the assayed doses. However, no DNA strand breaks nor oxidative DNA damage were induced, as shown in the comet assays. The histopathological study indicated alterations only in the highest dose group. Liver was the target organ showing fatty degeneration and necrotic hepatocytes in centrilobular areas, as well as a light mononuclear inflammatory periportal infiltrate. Additionally, the stomach had flaking epithelium and mild necrosis of epithelial cells. Therefore, the combined exposure to cyanotoxins may induce genotoxic and histopathological damage in vivo.Ministerio de Economía y Competitividad AGL2015-64558-

Twitter as an educational tool for autonomous and collaborative learning in the Veterinary Degree

Desde el punto de vista educativo, las redes sociales facilitan el intercambio de una gran cantidad de información especializada en tiempo real. Twitter permite el desarrollo de habilidades comunicativas y la capacidad de síntesis por su sencilla y directa forma de comunicación. Nuestro objetivo ha sido determinar el valor de Twitter como instrumento educativo de aprendizaje autónomo y colaborativo. Para ello, se creó una cuenta para la asignatura optativa “el Animal de Laboratorio”, perteneciente al Grado de Veterinaria. Se llevaron a cabo dos actividades; i) la gestión temporal de la cuenta por parte de distintos grupos de trabajo y, ii) el seguimiento e interacción con la cuenta desde los perfiles individuales de cada alumno. Se evaluó mediante cuestionarios tanto la situación inicial del alumnado, así como los logros finales conseguidos. Los resultados obtenidos destacan su funcionalidad como instrumento de aprendizaje autónomo. Además, nos muestran que es una metodología que fomenta el aprendizaje colaborativo, permitiendo interactuar, compartir conclusiones y establecer un reparto de tareas. Igualmente, su uso aumenta el interés y la motivación, al igual que promueve la participación del alumnado. En definitiva, se pone de manifiesto la idoneidad de Twitter como herramienta educativa en el proceso de enseñanza-aprendizaje competencial actual.From an educational standpoint, the use of social networks facilitates the exchange of information, allowing access to a large amount of specialized information in real time. The social network Twitter is characterized by its user-friendly and straightforward way of social interaction. The main objective of this project has been to determine the value of Twitter as an educational tool for autonomous and collaborative learning. To that end, a Twitter account was made for the elective subject "Laboratory Animal", belonging to the Veterinary Degree. Two activities were carried out: i) temporary management of the account profile by different working groups, and ii) interaction with the account profile using students private accounts. The starting point of students, as well as the final achievements regarding the stated objective, were evaluated using questionnaires. It stands out the functionality of the tool as an autonomous learning instrument, as it allows students to be conscious of their learning process. It also came across as a methodology that encourages collaborative learning, as it promotes interaction, sharing conclusions and teamwork building. Finally, it increases interest and motivation, as well as participation. In conclusion, Twitter migh be a reliable tool to facilitate competency-based learning in superior education