Browsing by Subject "Toxicology"
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- PublicationOpen AccessCadmium toxicity on cultured neonatal rat hepatocytes: Biochemical and ultrastructural analyses(Murcia : F. Hernández, 1991) Takeshi Hirano; Hiroshi Ueda; Kawahara, Akio; Fujimoto, Sunao
- PublicationOpen AccessDo court sentences reflect the reality of wildlife poisoning in the natural environment? The Spanish case.(2020-07-12) Navas Ruiz, Isabel María; Simal, Jorge; María Mójica, Pedro; Jiménez, Pedro; García Fernández, Antonio Juan; Ciencias SociosanitariasAlthough poisoning of wildlife is considered, since 1995, as a crime by the Spanish Penal Code, it is a deeply rooted habit of the population. The illegal use of poisoned baits to kill “unwanted” animals, such as predators, and specially birds of prey is a great threat for both domestic and wild animals. Poisons to kill animals are not selective; therefore animals poisoned by baits or other legally used pesticides, may suffer secondary poisonings. In Spain, according to WWF, between 1992-2013, the number of animals poisoned reached 18,503 individuals, including kites, vultures, eagles, wolves and bears. According to the Life+Veneno Project, 80 Court sentences about wildlife poisoning have been pronounced in Spain between 1994 and 2019. The aim of this study was to review these sentences comparing the data with epidemiologic data reported by the regional authorities, in order to evaluate if the court sentences reflect the real situation of wildlife poisoning in Spain. The compounds involved in poisonings in those sentences partly match with those found in the document published in 2016 by WWF and SEO/Birdlife. Aldicarb and carbofuran are the compounds most commonly used to kill wildlife, followed to a lesser extent, by two convulsivant compounds (strychnine and endosulfan), other cholinesterase inhibitors and a second generation anticoagulant rodenticide, bromadiolone. The court sentences handed down in Spain include 439 poisoned animals, mainly birds (72%) and mammals (25%). Fifty percent of these animals (n=215) are necrophagous: 114 Black kites (Milvus migrans), 42 Red kites (Milvus milvus), 41 Griffon vultures (Gyps fulvus), 10 Cinereous vulture (Aegypius monachus), 6 Spanish Imperial Eagle (Aquila adalberti), 1 Bearded vulture (Gypaetus barbatus) and 1 Golden Eagle (Aquila chrysaetos). The mean time elapsed between the crime and delivery of the judgment of the Court of First Instance is close to 3 years (median, 2 years). According to the Spanish Penal Code, this offence carries a maximum prison sentence of two years and/or economic fines. Moreover the poisoner can be disqualified from exercising the right to passive suffrage and the right to practice hunting activities. The vast majority of the Court sentences concluded with guilty verdicts (n=74, 92.5%). Imprisonment sentences were imposed in 32 of the trials; while economic fines and disqualification to hunting activities were imposed in 60 of them.
- PublicationOpen AccessEffects of chronic low-level copper exposure on ultrastructure of the olfactory system in rain bow trout (Oncorhynchus mykiss)(Murcia : F. Hernández, 1993) Julliard, A.K.; Saucier, D.; Astic, L.This study investigated the effects of a chronic exposure to a low level of copper on cell populations of the olfactory system in yearling rainbow trout. Fish were sacrificed after 15, 30 and 60 days of copper exposure. Transmission electron microscopy was used to describe the sequence of subcellular changes occurring in three tissues, the sensory epithelium, the olfactory nerve and the olfactory bulb. Data show that a 15-day exposure to 20 pg/l of copper causes specific degeneration of al1 mature receptor cells as well as numerous immature neurons. Moreover, degenerating receptor cells exhibited morphological features of a cell death by apoptosis. After 30 days, and more specifically after 60 days of exposure, numerous clusters of cells were observed in the basa1 region of the epithelium, suggesting a great mitotic activity in this area. In parallel, an increased number of maturing receptor cells and goblet cells were observed, but no fully mature neurons were noted even after 60 days of exposure. In both the olfactory nerve and the olfactory bulb, the number of degenerating axons and terminals, which was high at 15 days, decreased with time and some process of glomerular reinnervation was detected after 60 days. A reactive hypertrophy of supporting, ensheathing and astrocytic cells was also observed in exposed fish, which demonstrates that these cell types are actively involved in the process of tissue scarring. Even though some signs of neurona1 regeneration were reported during the time-course of exposure, indicating some fish acclimation, results raise the question of the olfactory function during such environmental stress.
- PublicationOpen AccessExploring in the classroom the relationship between alcohol intake and behavioral disorders through an animal model(Wiley, International Union of Biochemistry and Molecular Biology (IUBMB), 2024-03-19) Hernández García, Samanta; Guerrero-Rubio, M. Alejandra; Henarejos Escudero, Paula; Martínez Rodríguez, Pedro; Gandía Herrero, Fernando; Bioquímica y Biología Molecular AAlcohol consumption has profound effects on behavior, such as impaired judg-ment, addiction or even death. It is estimated that alcohol contributes to around three million deaths worldwide, 13.5% of them in young people with ages between 20 and 39 years. Consequently, it is necessary to raise awareness among college and high school students of the risk related to alcohol drinking. The small nematode Caenorhabditis elegans is an animal widely used as amodel organism to study nearly all aspects of Biochemistry. It is a powerfultool to test the potential bioactivity and molecular mechanisms of natural com-pounds and drugs in vivo. Therefore, it is an interesting topic to include in an undergraduate course of Biotechnology, Biochemistry or Biology students among other scientific vocations. C. elegans is also used as a neurobiological model to evaluate substances´ neurotoxicity and behavioral effects. The pro-posed experiment introduces students to the handling of this preclinical modeland to the evaluation of behavioral alterations induced by chemicals in scien-tific research. The effects of different doses of ethanol on C. elegans behavior are studied using a versatile chemotaxis assay. This laboratory experiment issuitable for an undergraduate course. The practical session can be used in theglobal strategies of information and awareness of educational centres to miti-gate the impact of alcohol abuse among students, both in formal courses or inScience fairs or exhibitions
- PublicationOpen AccessHistopathology of the male reproductive system induced by the fungicide benomyl(Murcia : F. Hernández, 2000) Hess, R.A.; Nakai, M.Benomyl is an effective fungicide that has been in use for many years. This chemical and its primary metabolite, carbendazim, are microtubule poisons that are relatively nontoxic to all mammalian organs, except for the male reproductive system. Its primary effects, at moderate to low dosages, are on the testis, where it causes sloughing of germ cells in a stagedependent manner. Sloughing is caused by the effects of the chemical on microtubules and intermediate filaments of the Sertoli cell. These effects spread to dividing germ cells and also lead to abnormal development of the head of elongating spermatids. At higher dosages, it causes occlusion of the efferent ducts, blocking passage of sperm from the rete testis to epididymis. The mechanism of occlusion appears to be related to fluid reabsorption, sperm stasis, followed by leukocyte chemotaxis, sperm granulomas, fibrosis and often the formation of abnormal microcanals. The occlusion results in a rapid swelling of the testis and ultimately seminiferous tubular atrophy and infertility. In conclusion, studies that reveal long term testicular atrophy following chronic or subchronic exposure to a toxicant should be re-examined for histopathological lesions in the efferent ductules and head of the epididymis. Lesions in the male track that cause blockage may induce permanent testicular damage and a decrease in sperm production.
- PublicationOpen AccessImmunotoxicological Effects of Environmental Contaminants in Teleost Fish Reared for Aquaculture(2011-10-10) Meseguer, José; Cuesta Peñafiel, Alberto; Esteban Abad, María de los Ángeles; Biología Celular e Histología