Procjene strukture i ultrastrukture ovarija vrste Danio rerionakon izlaganja 2, 3, 7, 8 – tetraklorodibenzo-p-dioksinu (TCDD)

The morphological consequences of long-term exposure to low doses of 2, 3, 7, 8-tetrachlo rodibenzo-p-dioxin in the ovaries were nvestigated in 50 adult female zebrafish at structural and ultrastructural levels. Animals were exposed to graded concentrations of 2, 3, 7, 8-tetrachlorodiben zo-p-dioxin (10, 40, 100 and 270 ppb) for 21 days, then zebrafish were sacrificed by an overdose of anaesthetic solution tricaine methanesulfonate, and immediately samples were taken for morphological evaluation. At lower concentrations of exposure there was no evidence of morphological modifications, while at higher concentrations (100 and 270 ppb) we frequently observed degeneration and inflammation. Significant increases in follicular atresia were observed among all groups (p<0.05). These results indicate that long-term exposure to low doses of 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin are able to induce morphological damage on the ovaries, which could then produce adverse effects on fish reproductive health.Morfološke konsekvence ovarija po dugotrajnijem izlaganju niskim dozama 2, 3, 7, 8-tetra klorodibenzo-p-dioksina su utvrđene na 50 odraslih jedinki vrste Danio rerio i to na strukturnoj i ultrastrukturnoj razini. Jedinke su bile izložene stupnjevanim koncentracijama 2, 3, 7, 8-tetraklorodi benzo-p-dioksina (10, 40, 100 i 270 ppb) tijekom 21 dana, i tada su jedinke bile žrtvovane uporabom letalne doze anestetske solucije tricain metansulfonata, i odmah su jedinke uzete za morfološku procjenu. Utvrđeno je da pri nižim koncentracijama izloženosti nema morfoloških modifikacija, dok su pri višim koncentracijama (100 i 270 ppb) utvrđene učestale degeneracije i upale. Značajan porast folikularne atrezije je utvrđen unutar svih grupa (p0.05). Ovi rezultati ukazuju na to se da po dugom izlaganju ovarija niskim dozama 2, 3, 7, 8-tetraklorodibenzo-p-dioksina mogu inducirati morfološkepromjene ovarija, koje tada mogu imati negativni utjecaj na normalnu reprodukciju vrste

Opportunities for training in food safety in the university education context

La formación en Seguridad Alimentaria está creciendo en la actualidad, dadas las necesidades de profesionales con una formación científica sólida, fundamentalmente en el Análisis de riesgos, capaces de resolver los problemas variados que se plantean desde los distintos sectores relacionados con la misma. Se revisan las posibilidades de formación existentes en nuestro país, a nivel de Grado y Postgrado, haciendo especial referencia en las materias, cursos, y másters existentes en las Universidades de Valencia, Córdoba y Sevilla.Food Safety Training is growing nowadays, given the needs of professionals with solid scientific training, especially in Risk Analysis, able to solve the various problems that arise from the different sectors related to food. We review the existing training opportunities in our country, for undergraduate and postgraduate level, with special reference to the subjets, courses and masters existing at the Universities of Valencia, Cordoba and Seville

Evaluation of the Effectiveness of Eugenol and MS-222 as Anesthetics in Zebrafish in Repeated Exposures and Post-Anesthesia Behaviour

The increasing use of the zebrafish (Danio rerio) in scientific experiments has made it necessary to implement anesthesia protocols guaranteeing minimum pain and suffering for these animals and ensuring the reliability of the results obtained from their research. Therefore, we aimed to compare the effectiveness of two anesthetics, eugenol and MS-222, in consecutive administrations and evaluate the zebrafish behaviour after repeated anesthesia. Thus, several zebrafish were anaesthetized with eugenol, MS-222, and buffered MS-222 three times repeatedly with a 24-h interval between each exposure. The induction and recovery periods were also timed. Their swimming frequency was determined after each exposure to assess their behaviour after the anesthesia. Anesthesia induction was quicker with eugenol compared to MS-222. However, eugenol presented longer recovery times, which were prolonged after each exposure. Also, the swimming frequency was reduced after each anesthesia with eugenol. The buffered version of MS-222 was more efficacious than the non-buffered one. Both versions of MS-222 did not affect the swimming frequency. Based on these findings, we recommend the utilization of MS-222 buffered rather than eugenol when repeated, brief-duration anesthesia is necessitated for a study

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

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

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

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