Metal-contaminated sediment toxicity in a highly impacted Neotropical river: Insights from zebrafish embryo toxicity assays.

The Fundão dam collapse was one of the largest mining-related disasters globally. It resulted in the release of mining tailings containing heavy metals, which contaminated the Doce River in southeastern Brazil. This study assessed the effects of acute exposure of Danio rerio embryos to sediments contaminated by mine tailings six years after the Fundão dam collapse. The study sites included P2, P3, and P4 in the upper Doce River, as well as site P1 on the Piranga River, an uncontaminated river. Sediment samples were analyzed for 10 metals/metalloid by atomic absorption spectrometry. In the assays, embryos were exposed to sediment from P1-P4 sites, and uncontaminated quartz was used as control sediment. Various biomarkers were applied to assess biological responses, and the integrated biomarker response (IBR) index was calculated for each site. Sediment samples revealed elevated levels of As, Cr, Cu, Hg, and Ni beyond Brazilian legislation limits. At 96-h exposure, embryo mortality rates exceeded 20% in P1, P2, and P3, higher than the control and P4 (p < 0.0001). Hatching rates ranged from 60 to 80% in P1, P2, and P3, lower than the control and P4 (p < 0.001). Larvae exposed to P2 sediment (closest to the Fundão dam) exhibited skeletal, physiological, and sensory malformations. Neurotoxicity was indicated by increased acetylcholinesterase activity and reduced spontaneous movements in embryos exposed to Doce River sediment. Contamination also increased metallothionein and heat shock protein 70 levels, along with changes in cell proliferation and apoptosis. Principal component analysis showed a good correlation between metals/metalloid in the sediment and larval morphometric endpoints. The IBR index highlighted suitable biomarkers for monitoring metal contamination in fish embryos. Overall, our findings suggest that sediment toxicity following the Fundão dam failure may compromise the sustainability of fish communities in the Doce River.

Starvation-induced autophagy modulates spermatogenesis and sperm quality in Nile tilapia.

Spermatogenesis is a finely regulated process that involves the interaction of several cellular mechanisms to ensure the proper development and maturation of germ cells. This study assessed autophagy contribution and its relation to apoptosis in fish spermatogenesis during starvation. To that end, Nile tilapia males were subjected to 0 (control), 7, 14, 21, and 28 days of starvation to induce autophagy. Testes samples were obtained for analyses of spermatogenesis by histology, electron microscopy, immunohistochemistry, and western blotting. Sperm quality was assessed using a computer-assisted sperm analysis (CASA) system. Data indicated a significant reduction in gonadosomatic index, seminiferous tubule area, and spermatozoa proportion in fish subject to starvation compared to the control group. Immunoblotting revealed a reduction of Bcl2 and Beclin 1 associated with increased Bax and Caspase-3, mainly after 21 and 28 days of starvation. LC3 and P62 indicated reduced autophagic flux in these starvation times. Immunolabeling for autophagic and apoptotic proteins occurred in all development stages of the germ cells, but protein expression varied throughout starvation. Beclin 1 and Cathepsin D decreased while Bax and Caspase-3 increased in spermatocytes, spermatids, and spermatozoa after 21 and 28 days. Autophagic and lysosomal proteins colocalization indicated the fusion of autophagosomes with lysosomes and lysosomal degradation in spermatogenic cells. The CASA system indicated reduced sperm motility and velocity in animals subjected to 21 and 28 days of starvation. Altogether, the data support autophagy acting at different spermatogenesis stages in Nile tilapia, with decreased autophagy and increased apoptosis after 21 and 28 days of starvation, which results in a decrease in the spermatozoa number and sperm quality.

Adverse effects of herbicides in freshwater Neotropical fish: A review.

Although herbicides have been developed to act on the physiological processes of plants, they are responsible for causing deleterious effects on animals. These chemical compounds are widely used throughout the world, but especially in countries that export agricultural products such as Central and South America, their use has increased in recent years. Aquatic environments are natural reservoirs of herbicides, which after being applied on crops, run off through the soil reaching rivers, lakes, and oceans. Fish are among the many organisms affected by the contamination of aquatic environments caused by herbicides. These animals play an important ecological role and are a major source of food for humans. However, few studies address the effects of herbicides on fish in this region. Thus, in the present review we discuss the morphophysiological and molecular consequences of herbicide exposure in Neotropical fish systems as well as how the environmental and land use characteristics in this region can influence the toxicity of these pollutants. A toxicity pathway framework was developed summarizing the mechanisms by which herbicides act and endpoints that need to be further investigated.

Biomarker responses induced by bisphenol A on spermatogenesis in a Neotropical teleost fish are temperature-dependent.

Bisphenol A (BPA) is an organic synthetic compound used in the plastic industry with endocrine disrupting activity. Although it is frequently found in surface waters, few studies have investigated its impact on fish gametogenesis, particularly when associated with natural stressors. In this regard, the present study evaluated BPA toxicity on spermatogenesis in the lambari Astyanax bimaculatus under controlled conditions and its interactive effects with water temperature. Adult specimens were exposed in duplicate to 40 µg/L and 400 µg/L BPA at 23 °C and 28 °C for 21 days; the control group did not receive BPA. Testicular samples were collected and analyzed using different cellular and molecular techniques. The results showed a significant reduction in the gonadosomatic index in the BPA-treated groups at both temperatures. A decrease in the testicular levels of 11-ketotestosterone was observed in the 400 µg/L BPA group at 23 °C, 17ß-estradiol increased significantly in the treated groups at 28 °C, and vitellogenin showed no difference between the treatments. The morphometric analysis of spermatogenesis revealed a significant increase in the proportion of spermatogonia, spermatocytes, and Sertoli cells in the treated groups, with a higher proportion at 23 °C than at 28 °C. Otherwise, the proportion of spermatozoa was significantly lower in the BPA-treated groups, with a greater reduction at 23 °C. In addition, BPA also stimulated spermatogonial proliferation in the treated groups, but apoptosis was significantly increased in spermatids at 23 °C. Testis-ova, cell degeneration, and chromatin alterations in spermatids and Sertoli cells were observed in the germinal epithelium of the BPA-treated groups. The integrated biomarker response (IBR) index revealed that the analyzed endpoints are suitable for assessing estrogenic contamination. Taken together, our results indicate that the interactive effects of BPA and temperature contribute to the impairment of spermatogenesis in A. bimaculatus with more severe effects observed on sperm production at 23 °C than at 28 °C.

Effects of metal contamination on liver in two fish species from a highly impacted neotropical river: A case study of the Fundão dam, Brazil.

Environmental disasters such as the rupturing of mine tailings dams are a major concern worldwide. In the present study, we assess the effects of the release of mine waste due to the rupture of the Fundão dam on two native fish species (Hoplias intermedius and Hypostomus affinis) from the Doce River basin. Two sampling sites were chosen: S1, a reference site, and S2, contaminated by mining waste. Water and sediment were collected to evaluate metals concentration. Adult fish were caught to analyse biological parameters, hepatic histopathology, and biomarkers of metal contamination. Compared to site S1, the concentration of manganese was statistically higher in water while lead, nickel, and arsenic were statistically higher in the sediment from site S2, and iron had no significant difference between sites. At site S1, fish of both species presented hepatic tissue with normal architecture. At site S2, hepatic alterations, such as cytoplasmic vacuolization and necrosis were frequently found in both species. Regarding the histopathological index, higher values were found in both species from site S2. The positive antibody reactions for cytochrome P450 1A (CYP1A) and metallothionein (MT) were statistically greater in site S2 for both species. The oxidative stress biomarkers, superoxide dismutase (SOD) and catalase (CAT) were statistically higher in H. intermedius from site S2, but only CAT was statistically greater in H. affinis at site S2. These results demonstrate that the release of mineral residues from the rupture of the Samarco mine dam is provoking hepatic damage in the fish from the Doce River besides inducing the expression of proteins and enzymes related to metal contamination.

Effects of starvation and refeeding cycles on spermatogenesis and sex steroids in the Nile tilapia Oreochromis niloticus.

Food restriction is part of the life cycle of many fish species; however, nutritional deficiency may negatively influence gametogenesis and gonadal maturation. The aim of this study was to evaluate the effects of food restriction on the spermatogenesis of Nile tilapia. For this, adult males were submitted to starvation and refeeding cycles (alternating periods of starvation and feeding) for 7, 14, 21, and 28 days. After 7 days of starvation, glycaemic and lipid levels were significantly reduced, followed by reduction of plasma testosterone (T) and 11-ketotestosterone (11-KT). In addition, reduced proliferation of spermatogonia and increased apoptosis of spermatocytes, spermatids, and spermatozoa was observed in starvation groups. In the refeeding groups, the sex steroids and the proportion of germ cells had no significant alterations compared to the control group, except for spermatozoa. In this sense, the present study suggests that starvation after 7 days progressively reduces T and 11-TK, resulting in damage to the production of spermatogenic cells, while refeeding may delay spermatogenesis but does not lead to testicular impairment.

Autophagy and Cathepsin D mediated apoptosis contributing to ovarian follicular atresia in the Nile tilapia.

Follicular atresia is a hormonally controlled degenerative process involving apoptosis of the somatic and germ cells. Since different signaling pathways can induce cell death, the aim of the present study was to investigate cell death signaling and crosstalk between autophagic, apoptotic, and lysosomal proteins during follicular atresia in Nile tilapia. For this, females were kept in controlled conditions for 21 days, and ovary samples were collected weekly. The atretic follicles (AF) were analyzed in three regression phases: Early, advanced, and late. Under electron microscopy, the follicular cells exhibited numerous protein synthesis organelles in the early AF. Immunoreactivity for Bcl2, Beclin1, Lc3, and Cathepsin D increased significantly in advanced AF (p < .001), when follicular cells were in intense yolk phagocytosis. In this phase, autophagosomes and autolysosomes were frequently observed. In the late AF, follicular cells had a markedly electron-lucid cytoplasm and immunoreactivity for Bax and TUNEL assay indicated an elevated apoptosis rate. Colocalisation of Lamp1/Cathepsin D and Lc3/Caspase-3 suggests dynamic crosstalk between the autophagy, apoptosis, and lysosome pathways. Taken together, the data indicate that autophagy plays a role in the homeostasis and clearance of the follicular cells preceding Cathepsin D mediated apoptosis during follicular atresia in Nile tilapia.

Repetição e contingência na clínica da psicanálise e na arte da performance / Repetition and contingency in the psychoanalytical clinic and in the art of performance / La repetición y la contingencia en el psicoanálisis clínico y en el arte de la performance

Tanto Freud quanto Lacan deixaram um legado peculiar no que diz respeito à interface entre psicanálise e arte: utilizar o material estético como recurso para pensar a clínica psicanalítica. Nesta, os processos de subjetivação implicam o atravessamento da repetição significante pela pulsão. Lacan nomeia tiquê (τύχη) o retorno do real que incide sobre a repetição de signos (autômaton). De maneira análoga, há na arte - especialmente a contemporânea - um modo de apresentação de temas que não se atêm à categoria do sentido, mas que se abrem para o universo dos afetos e pulsões. O objeto estético, nesse sentido, pode ser pensado como objeto pulsional. A partir de alguns exemplos da obra de Marina Abramovic, artista sérvia que vem sendo descrita como a avó da arte da performance, veremos como isso se articula.

Both Freud and Lacan have left a peculiar legacy concerning the interface between psychoanalysis and art: the use of aesthetic material as a resource for thinking the clinic. Subjectivation processes in the psychoanalytical clinic imply the pulsion to traverse the repetition as a significant. Lacan names Tyche (τύχη) the return of the real that bears on the repetition of signs (automaton). In an analogous way, in art - especially contemporary art - there is a way of presenting themes not bound by the category of meaning, but open to the universe of affections and pulsions. One can think the aesthetic object, in this sense, as a pulsional one. By taking some examples from the work of Marina Abramovic, a Serbian artist who has been described as the grandmother of performance art, we will see how these processes connect.

Tanto Freud como Lacan han dejado un legado único en relación con la interfaz entre el psicoanálisis y el arte: el material estético empleado como recurso para pensar la clínica. En esta clínica, los procesos de subjetivación implican que la pulsión atraviese la repetición, en su papel de significante. Lacan nombra tyche (τύχη) el regreso de lo real que incide sobre la repetición de signos (autómata). De modo semejante, existe en el arte - sobre todo en el arte contemporáneo - una manera de presentar los temas que no se atienen a la categoría de sentido, sino que se abren al mundo de las emociones y de las pulsiones. El objeto estético, en este sentido, se puede considerar como un objeto pulsional. A partir de algunos ejemplos de la obra de Marina Abramovic, artista serbia que viene siendo descrita como la abuela del arte de la performance, vamos a ver cómo esto se articula.

Increase in liver cytosolic lipases activities and VLDL-TAG secretion rate do not prevent the non-alcoholic fatty liver disease in cafeteria diet-fed rats.

We have previously shown that the cafeteria diet increases body fat mass, plasma triacylglycerol (TAG) and insulin levels, glucose uptake by white and brown adipose tissues, as well as the sympathetic activity to both adipose tissues in Wistar rats. The metabolic pathways responsible for the development of non-alcoholic fatty liver disease (NAFLD) were examined in cafeteria diet-fed rats. After 3 weeks offering cafeteria diet, we evaluated: (i) activity of the sympathetic nervous system by norepinephrine turnover rates; (ii) de novo fatty acid synthesis in vivo using 3H2O; (iii) secretion of very low density lipoprotein (VLDL)-TAG secretion measuring serum TAG levels after administration of lipase lipoprotein inhibitor, (iv) liver cytosolic lipases activities and (v) liver mRNA expression of enzymes involved in lipids secretion and oxidation by RT-PCR. The cafeteria diet induced an increase in TAG (120%) and cholesterol (30%) liver contents. Cafeteria diet did not change the sympathetic nervous system activity to liver, but induced a marked increase in the lipogenesis (approximately four-fold) and significant increase in cytosolic lipases activities (46%) and VLDL-TAG secretion (22%) compared to control diet-fed rats. The cafeteria diet also increased the microsomal triglyceride transfer protein (30%) and carnitine palmitoyltransferase I (130%) mRNA expression but decreased the apolipoprotein B100 (26%) mRNA expression. Our findings demonstrate that the increase in the cytosolic lipases activities and VLDL-TAG secretion rates were not able to compensate for the increased lipogenesis rates induced by the cafeteria diet, resulting in NAFLD.

Para além do paradigma histérico da anorexia: a ordem de ferro do supereu materno / Beyond the hysterical paradigm of anorexia: the iron order of maternal superego / Más allá del paradigma histérico de la anorexia: el orden de hierro del superyó materno

Interessa-nos interrogar a afinidade estrutural entre anorexia e feminino a partir de um caso para além do paradigma histérico da anorexia. Tal afinidade frequentemente é abordada a partir de sua declinação histérica. Podemos dizer que, dentro desse paradigma, esta relação concerne sobretudo à essência do discurso amoroso: é por amor, para ser a única, que a anoréxica se consome na recusa do alimento. Por meio da recusa daquilo que vem do Outro no registro do ter, ela busca criar uma posição particular no Outro. Está disposta a morrer de fome por amor. Sabemos, contudo, que a busca do amor pode se converter em seu contrário, em uma recusa do Outro. É o que encontramos, por exemplo, nos casos de anorexia não histérica. A que responde a anorexia nos casos em que há uma foraclusão da significação fálica e que, portanto, não são redutíveis à manobra histérica de defesa do desejo? Como situar aí a afinidade entre anorexia e feminino? Tais questões serão colocadas a partir de um caso clínico no qual verificamos uma submissão a uma ordem de ferro do supereu e uma não assunção de uma posição sexuada na dialética amorosa.

We are interested in questioning the structural affinity between anorexia and femaleness from a case beyond the hysterical paradigm of anorexia. Such affinity is often approached from its hysterical decline. It can be said that, in this paradigm, this relation concerns mainly the essence of the amorous discourse: the anorexic is consumed in her refusal of food in order to be the only one. By refusing that which comes from the Other, she seeks to attain a particular place in the Other. She is willing to die of hunger for love. We know, however, that the pursuit of love can turn into its opposite, into a refusal of the Other. It is what we find, for example, in cases of non-hysterical anorexia. To what is anorexy an answer, in the cases in which there is a foreclosure of the phallic signification, and are thereby irreducible to the hysterical manoeuver to preserve the desire? How to locate the affinity between anorexia and femaleness? Such questions will be posed within a clinical case in which we discern a submission to an iron order of the superego and abstaining from a sexual position in the amorous dialectic.

Estamos interesados en cuestionar la afinidad estructural entre la anorexia y la mujer a partir de un caso más allá del paradigma de la anorexia histérica. Esta afinidad a menudo se acercó de su declinación histérica. Podemos decir que, dentro de este paradigma, esta relación se refiere principalmente a la esencia del discurso amoroso: la anoréxica se consume en rechazo a la comida para el amor. Sabemos, sin embargo, que la búsqueda de amor puede convertirse en su contrario, en el rechazo del Otro. Es lo que encontramos, por ejemplo, en casos de anorexia no histérica. Donde hay una exclusión de la significación fálica y por lo tanto no se reduce a maniobra histérica en la defensa del deseo, ¿a lo que responde la anorexia? Entonces, ¿cómo colocar la afinidad entre la anorexia y la mujer? Estas cuestiones serán colocadas a partir de un caso en el que vemos una sumisión a un orden de hierro del superyó y una no asunción de una posición sexual en la dialéctica del amor.

Proliferation, survival and cell death in fish gills remodeling: From injury to recovery.

Pollutants found dispersed in water can cause irritations on the gills, challenge the immune system and prejudice the welfare of the fish. Here we investigated molecules linked to proliferation, survival, and cell death, as well as inflammatory and vascular control, in a model of fish gill remodeling, from injury to recovery. We assessed the gill histology and immunohistochemistry for PCNA, iNOS, HSP70, and Bax in Hypostomus francisci obtained from a river subjected to chronic anthropic influences and then after they were placed in water of good quality. A total of 30 H. francisci adult individuals were collected and distributed into two groups: euthanized on the day of capture (group 1) and maintained for 30 days in an aquarium (group 2). In all the fish from group 1, the primary and secondary lamellae showed hypertrophy of the respiratory epithelium, lamellar fusion, lifting of the epithelium, aneurysm, hyperemia, and vascular congestion. On the other hand, in all the fish from group 2, restoration of gill integrity was observed, and the primary and secondary lamellae showed a simple epithelium, absence of lamellar fusion, hypertrophy, and aneurysm. Gills of fish from group 1 had higher frequency of cells immunopositive for PCNA, iNOS, HSP70, and Bax than those of fish from group 2 (p < 0.05). The molecular and cellular mechanisms from injury to recovery were proposed, with a balance between survival and cell death signals being essential for determining the gill structure. In addition, the findings indicate that recovery of the structural organization of gills is possible if fishes are maintained in good-quality water, indicating the importance of the conservation of aquatic environments.