Avaliação dos efeitos da exposição crônica ao mercúrio em Hoplias malabaricus (Block, 1794) coletados na usina hidrelétrica de Samuel - Rondonia

Orientador : Ciro Alberto de Oliveira RibeiroCo-orientador : Wanderley Rodrigues BastosDissertação (mestrado) - Universidade Federal do Paraná, Setor de Ciências Biológicas, Programa de Pós-Graduação em Biologia Celular e Molecular. Defesa: Curitiba, 2007Inclui bibliografiaO mercúrio (Hg) tem como características a capacidade de se bioacumular e biomagnificar ao longo da cadeia alimentar. Devido às propriedades tóxicas desse metal e à intensa atividade garimpeira na região Amazônia, aumentou a preocupação com os possíveis danos que o mercúrio empregado nessa atividade pode trazer ao ambiente. Nesse estudo 27 espécimes de Hoplias malabaricus (Block, 1794), foram coletados na Usina Hidrelétrica de Samuel (RO), situada no Rio Jamarí, uma área que sofre influência do garimpo na região. Os peixes foram sacrificados, e amostras foram coletadas para a análise química de Hg (fígado e músculo), avaliações bioquímicas ( Glutationa-S-transferase (GST), Catalase e Peroxidação Lipídica) e morfológicas em brânquia e fígado (Microscopia de Luz, Microscopia Eletrônica de Varredura e Transmissão). Dos valores médios de mercúrio encontrados no músculo dos peixes, 18,5% ultrapassaram a concentração máxima sugerida pela Organização Mundial de Saúde (WHO) que é de 0,5 µg g-¹ de Hg para o consumo humano. Não houve diferença estatística significativa entre a atividade das enzimas (GST e catalase) e os níveis de peroxidação lipídica usados como biomarcadores bioquímicos no fígado de H. malabaricus e as concentrações de mercúrio encontradas neste tecido. Nas análises histopatológicas em fígado foram observadas alterações como: necroses, infiltração leucocitária, grande número de melanomacrófagos e desorganização tecidual. Nas brânquias houve a presença de regiões com intensa proliferação celular, fusão lamelar, presença de aneurismas e parasitas. O estudo com os biomarcadores na Usina Hidrelétrica de Samuel no Rio Jamarí foi pioneiro nessa localidade. Através desse trabalho foi possível avaliar a aplicabilidade dos métodos desenvolvidos em laboratório para o estudo dos efeitos do mercúrio em regiões impactadas pelo garimpo, demonstrando que os biomarcadores morfológicos refletem melhor os danos agudos e cumulativos em detrimento dos danos bioquímicos que podem ser modulados pelas condições ambientais variáveis.Mercury is able to bioaccumulate in live of aquatic organisms and biomagnify along the feed chain. Due to the toxic properties of this metal and its intensive and constant use in goldmining in the Amazon region, more studies have been evidencing the potential damages to nature ecosystem and to the environment. In the present study 27 specimens of the Hoplias malabaricus (Bloch, 1794), were collect in Samuel Hidreletrical Usine (SHU) (RO), situated in Jamarí River, an impacted region by goldmining activities. The individuals were sacrificed and samples of liver and muscle were collect for chemical (total mercury), biochemical (GST, catalase and lipidic peroxidation) and morphological analysis (light microscopy, scanning and transmission electron microscopy). The medium values of mercury found in fishes muscle, 18.5%, passed the maximal concentration established by World Healthy Organization (WHO) (0,5 µg g-¹ of Hg) for human consume. There was no significant statistical difference between the activity of the enzymes used as biochemical biomarchers (GSTs, Catalase) and for the levels of lipidic peroxidation in Hoplias malabaricus livers from SHU on Jamari River and the mercury concentration in the liver. This biochemical study was the first one using this species at Amazon region. Liver histopatological analysis showed damages as necrosis, inflammation, high incidence of melanomacrophages and tissue disorganization. In gills were also observed lesions as the presence cellular proliferation, lamellar junction, aneurisms and parasites occurrence. The present study showed the applicability of methods developed in laboratory under controlled conditions in field studies where the impact of pollutants is evaluated. Also, according the present data was observed that the morphological findings were more efficient to show the chronic effects of mercury in H. malabaricus then the biochemical biomarkers, which tend to be modulated by the environmental conditions

The effects of alcohol consumption on fetal craniofacial development during gestation: a systematic review/ Os efeitos do consumo de álcool no desenvolvimento craniofacial fetal durante a gestação: uma revisão sistemática

The present study used evidence-based dentistry (EBD) to identify clinical studies that described the effects of alcohol on fetal craniofacial development and qualitatively analyze the results found via this systematic review. This systematic review followed the guidelines “Meta-analysis Of Observational Studies in Epidemiology” (MOOSE). As a research strategy, several medical and scientific platforms were chosen, in which studies were sought using keywords defined from medical subject headings (MeSH), following the criterion of choosing keywords that were most related to the proposed theme. A total of 278 studies (116 studies in humans and 162 studies in animals) were identified and, after screening and analysis based on the inclusion criteria, twenty-six observational studies in humans were chosen for the configuration of this systematic review. Studies have reported fetal alterations related to alcohol consumption by mothers such as in the head shape and size, thin upper lip, hypoplastic philtrumbone, short palpebral fissures, micrognathia, flat nasal bridge, among others. These were more often found in patients whose mothers were alcoholics or those who had ingested high doses of alcohol, especially during the first trimester of gestation. Based on the analysis of the results, the impact of maternal alcohol consumption on fetal craniofacial development was evidenced and, as such, these complications can be harmful to the quality of life of the patient, both in childhood and in adulthood, as well as leading to lifelong sequelae. The results also suggest that to avoid craniofacial anatomical abnormalities related to alcohol, the best course of action is to stop alcohol consumption completely or at least reduce it to a minimum level before conception

Ecophysiology, genotoxicity, histopathology, and gene responses of naphthalene injected colossoma macropomum (Cuvier, 1818) exposed to hypoxia

The present study aimed to evaluate the biological responses of Colossoma macropomum to naphthalene injection and subsequent hypoxia exposure, emphasizing the expression of the tumor suppressor gene tp53. Tambaquis were intraperitoneally injected with naphthalene (50 mg/kg) and, after 96 hours, the fish were transferred to respirometry chambers and, submitted to progressive hypoxia for the determination of critical PO2. In a subsequent experiment, the fish received an intraperitoneal injection of naphthalene and were kept for 96 hours under normoxia. Successively, fish were challenged with acute hypoxia (PO2 <PO2 crit) during 6 hours. We observed that the PO2 crit was not affected by naphthalene injection. Moreover, hematological parameters were modulated only in response to hypoxia. Fish with naphthalene injection plus hypoxia exposure presented altered activity of the GST and CAT enzymes. Exposure to naphthalene also resulted in DNA damages, which was not influenced by hypoxia. Hypoxia accentuated the hepatic lesions caused by naphthalene, as well as it also impaired the transcription of tp53 in naphtalene injected fish, demonstrating the risks of contaminating aquatic environments, especially environments where hypoxic conditions are common and occur on a daily or on seasonal basis, as in the Amazon basin. © 2019, Sociedade Brasileira de Genética

A DIDATIC PROPOSAL TO INICIATE THE TEACHING OF HISTOLOGY IN ELEMENTARY EDUCATION

This present report describes a low cost and simple educational proposal to inspire professors from Elementary school for teaching on Histology, with emphasis on concepts of tissue and extracellular matrix. Twenty students from a public elementary school in Manaus city were invited to participate in a social tutoring program from the Federal University of Amazonas, Manaus, Brazil. After observing a lack of information about basic concepts of histology, it was introduced a practice activity using simple material, aiming to create a tridimensional model of a tissue and its basics components. During the activity, students showed excitement and interest in the presented knowledge, especially because they were able to create their own model of a tissue using the provided material. The experience was an exchange of questions and teaching between students and volunteers. Therefore, this present proposal is helpful for professors to develop a simple practice activity in classroom that may clarify the comprehension of student for difficult and abstract histological concepts

Uma proposta didática para iniciar o ensino de histologia na educação básica

This present report describes a low cost and simple educational proposal to inspire professors from Elementary school for teaching on Histology, with emphasis on concepts of tissue and extracellular matrix. Twenty students from a public elementary school in Manaus city were invited to participate in a social tutoring program from the Federal University of Amazonas, Manaus, Brazil. After observing a lack of information about basic concepts of histology, it was introduced a practice activity using simple material, aiming to create a tridimensional model of a tissue and its basics components. During the activity, students showed excitement and interest in the presented knowledge, especially because they were able to create their own model of a tissue using the provided material. The experience was an exchange of questions and teaching between students and volunteers. Therefore, this present proposal is helpful for professors to develop a simple practice activity in classroom that may clarify the comprehension of student for difficult and abstract histological concepts.En este artículo se describe una propuesta didáctica simple y de bajo costo que puede ayudar a los profesores de Educación Básica con la enseñanza de la Histología, haciendo hincapié en el concepto de tejido y la importancia de la matriz extracelular. Se invitó a veinte estudiantes de una escuela pública en la ciudad de Manaus para participar en un proyecto de extensión de la Universidad Federal de Amazonas. Después de las brechas de observación sobre el conocimiento previo de los estudiantes sobre el tema tratado, una actividad de demostración se llevó a cabo utilizando materiales comunes de la construcción del día a día de un modelo tridimensional para representar los componentes básicos de un tejido animal. Durante el desarrollo de la propuesta, los estudiantes mostraron gran interés en la actividad, sobre todo cuando participó activamente en la construcción de sus propios modelos, cuando se podría hablar con la extensión, hacer preguntas y fijar los conceptos aprendidos. Se concluyó que la propuesta que presentamos permite al profesor para reproducir una práctica de la enseñanza simple pero eficaz que se desarrollará en el aula y que se puede cambiar la preconcepción del estudiante de conceptos histológicos considerados abstracto o difícil de entender.O presente artigo descreve uma proposta didática simples e de baixo custo que pode auxiliar professores da educação básica com os ensinamentos de Histologia, enfatizando o conceito de tecido e a importância da matriz extracelular. Vinte estudantes de uma escola pública na cidade de Manaus foram convidados a participar de um projeto de extensão na Universidade Federal do Amazonas. Após a observação de lacunas no conhecimento prévio dos estudantes sobre conceitos básicos de Histologia, foi conduzida uma atividade de demonstração com materiais comuns para a construção de um modelo tridimensional de representação dos constituintes básicos de um tecido animal. Durante o desenvolvimento da proposta, os estudantes demonstraram bastante interesse pela atividade, especialmente quando participaram ativamente da construção de seus próprios modelos. A atividade foi desenvolvida durante uma conversa entre estudantes e os extensionistas para clarificar dúvidas e fixar os conceitos ensinados. Concluiu-se que a proposta que apresentamos possibilita ao professor reproduzir uma prática de ensino simples, porém eficaz, para ser desenvolvida na sala de aula com a finalidade de mudar a concepção do aluno sobre conceitos histológicos considerados abstratos ou de difícil compreensão

Avaliação dos efeitos da exposição crônica ao mercúrio em Hoplias malabaricus (Block, 1794) coletados na usina hidrelétrica de Samuel - Rondonia

Orientador : Ciro Alberto de Oliveira RibeiroCo-orientador : Wanderley Rodrigues BastosDissertação (mestrado) - Universidade Federal do Paraná, Setor de Ciências Biológicas, Programa de Pós-Graduação em Biologia Celular e Molecular. Defesa: Curitiba, 2007Inclui bibliografiaO mercúrio (Hg) tem como características a capacidade de se bioacumular e biomagnificar ao longo da cadeia alimentar. Devido às propriedades tóxicas desse metal e à intensa atividade garimpeira na região Amazônia, aumentou a preocupação com os possíveis danos que o mercúrio empregado nessa atividade pode trazer ao ambiente. Nesse estudo 27 espécimes de Hoplias malabaricus (Block, 1794), foram coletados na Usina Hidrelétrica de Samuel (RO), situada no Rio Jamarí, uma área que sofre influência do garimpo na região. Os peixes foram sacrificados, e amostras foram coletadas para a análise química de Hg (fígado e músculo), avaliações bioquímicas ( Glutationa-S-transferase (GST), Catalase e Peroxidação Lipídica) e morfológicas em brânquia e fígado (Microscopia de Luz, Microscopia Eletrônica de Varredura e Transmissão). Dos valores médios de mercúrio encontrados no músculo dos peixes, 18,5% ultrapassaram a concentração máxima sugerida pela Organização Mundial de Saúde (WHO) que é de 0,5 µg g-¹ de Hg para o consumo humano. Não houve diferença estatística significativa entre a atividade das enzimas (GST e catalase) e os níveis de peroxidação lipídica usados como biomarcadores bioquímicos no fígado de H. malabaricus e as concentrações de mercúrio encontradas neste tecido. Nas análises histopatológicas em fígado foram observadas alterações como: necroses, infiltração leucocitária, grande número de melanomacrófagos e desorganização tecidual. Nas brânquias houve a presença de regiões com intensa proliferação celular, fusão lamelar, presença de aneurismas e parasitas. O estudo com os biomarcadores na Usina Hidrelétrica de Samuel no Rio Jamarí foi pioneiro nessa localidade. Através desse trabalho foi possível avaliar a aplicabilidade dos métodos desenvolvidos em laboratório para o estudo dos efeitos do mercúrio em regiões impactadas pelo garimpo, demonstrando que os biomarcadores morfológicos refletem melhor os danos agudos e cumulativos em detrimento dos danos bioquímicos que podem ser modulados pelas condições ambientais variáveis.Mercury is able to bioaccumulate in live of aquatic organisms and biomagnify along the feed chain. Due to the toxic properties of this metal and its intensive and constant use in goldmining in the Amazon region, more studies have been evidencing the potential damages to nature ecosystem and to the environment. In the present study 27 specimens of the Hoplias malabaricus (Bloch, 1794), were collect in Samuel Hidreletrical Usine (SHU) (RO), situated in Jamarí River, an impacted region by goldmining activities. The individuals were sacrificed and samples of liver and muscle were collect for chemical (total mercury), biochemical (GST, catalase and lipidic peroxidation) and morphological analysis (light microscopy, scanning and transmission electron microscopy). The medium values of mercury found in fishes muscle, 18.5%, passed the maximal concentration established by World Healthy Organization (WHO) (0,5 µg g-¹ of Hg) for human consume. There was no significant statistical difference between the activity of the enzymes used as biochemical biomarchers (GSTs, Catalase) and for the levels of lipidic peroxidation in Hoplias malabaricus livers from SHU on Jamari River and the mercury concentration in the liver. This biochemical study was the first one using this species at Amazon region. Liver histopatological analysis showed damages as necrosis, inflammation, high incidence of melanomacrophages and tissue disorganization. In gills were also observed lesions as the presence cellular proliferation, lamellar junction, aneurisms and parasites occurrence. The present study showed the applicability of methods developed in laboratory under controlled conditions in field studies where the impact of pollutants is evaluated. Also, according the present data was observed that the morphological findings were more efficient to show the chronic effects of mercury in H. malabaricus then the biochemical biomarkers, which tend to be modulated by the environmental conditions

Ras oncogene and Hypoxia-inducible factor-1 alpha (hif-1α) expression in the Amazon fish Colossoma macropomum (Cuvier, 1818) exposed to benzo[a]pyrene.

Abstract Benzo[a]pyrene (B[a]P) is a petroleum derivative capable of inducing cancer in human and animals. In this work, under laboratory conditions, we analyzed the responses of Colossoma macropomum to B[a]P acute exposure through intraperitoneal injection of four different B[a]P concentrations (4, 8, 16 and 32 μmol/kg) or corn oil (control group). We analyzed expression of the ras oncogene and the Hypoxia-inducible factor-1 alpha (hif-1α) gene using quantitative real-time PCR. Additionally, liver histopathological changes and genotoxic effects were evaluated through the comet assay. Ras oncogene was overexpressed in fish exposed to 4, 8 of 16 μmol/kg B[a]P, showing 4.96, 7.10 and 6.78-fold increases, respectively. Overexpression also occurred in hif-1α in fish injected with 4 and 8 μmol/kg B[a]P, showing 8.82 and 4.64-fold increases, respectively. Histopathological damage in fish liver was classified as irreparable in fish exposed to 8, 16 and 32 μmol/kg μM B[a]P. The genotoxic damage increased in fish injected with 8 and 16 μmol/kg in comparison with the control group. Acute exposure of B[a]P was capable to interrupt the expression of ras oncogene and hif-1α, and increase DNA breaks due to tissue damage

Gene expression, genotoxicity, and physiological responses in an Amazonian fish, Colossoma macropomum (CUVIER 1818), exposed to Roundup® and subsequent acute hypoxia

Roundup® (RD)is a glyphosate-based herbicide used to control weeds in agriculture, and fishponds. In the Amazon, hypoxia is a natural phenomenon in flooded areas. Beyond the challenge of hypoxia, fish need to cope with the use of pesticides as RD that increases in the aquatic environment through the leaching of agricultural areas, and in aquaculture fish tanks. Thus, there is a need to better understand the combined effects of hypoxia and RD contamination for aquatic biota. The aim of this study was to investigate the effects of Roundup® (RD)and subsequent acute hypoxia in the gene expression, genotoxicity, histological and physiological responses of Colossoma macropomum. Fish were individually exposed to four different treatments during 96 h: normoxia (N), hypoxia (H), RD plus normoxia (NRD), and RD plus hypoxia (HRD)(RD concentration represents 75% of LC50 - nominal concentration 15 mg L−1 to C. macropomum). HRD fishes presented down-regulation of hif-1α gene and ras oncogene, while NRD fish presented overexpression of ras; no difference occurred in hif-1α gene expression in both normoxia treatments. The glutathione-S-transferase and catalase activities increased in HRD fish liver compared to NRD. Otherwise, there was no difference in lipoperoxidation (LPO)between all treatments. Genetic Damage Index, measured throughout comet assay in erythrocytes of all treatments, presented similar values, excepted by fish exposed to NRD. As regard as hypoxic exposure, hypoxic fish presented significantly lower values, compared to HRD fishes. An increase in liver histological injuries occurred in H and HRD fish groups. In conclusion, we may affirm that C. macropomum is sensitive concerning RD contamination and that this sensitivity increases when combined with hypoxia. © 2019 Elsevier Inc

Ras oncogene and Hypoxia-inducible factor-1 alpha (hif-1α) expression in the Amazon fish Colossoma macropomum (Cuvier, 1818) exposed to benzo[a]pyrene.

Abstract Benzo[a]pyrene (B[a]P) is a petroleum derivative capable of inducing cancer in human and animals. In this work, under laboratory conditions, we analyzed the responses of Colossoma macropomum to B[a]P acute exposure through intraperitoneal injection of four different B[a]P concentrations (4, 8, 16 and 32 μmol/kg) or corn oil (control group). We analyzed expression of the ras oncogene and the Hypoxia-inducible factor-1 alpha (hif-1α) gene using quantitative real-time PCR. Additionally, liver histopathological changes and genotoxic effects were evaluated through the comet assay. Ras oncogene was overexpressed in fish exposed to 4, 8 of 16 μmol/kg B[a]P, showing 4.96, 7.10 and 6.78-fold increases, respectively. Overexpression also occurred in hif-1α in fish injected with 4 and 8 μmol/kg B[a]P, showing 8.82 and 4.64-fold increases, respectively. Histopathological damage in fish liver was classified as irreparable in fish exposed to 8, 16 and 32 μmol/kg μM B[a]P. The genotoxic damage increased in fish injected with 8 and 16 μmol/kg in comparison with the control group. Acute exposure of B[a]P was capable to interrupt the expression of ras oncogene and hif-1α, and increase DNA breaks due to tissue damage