93 resultados para In vivo produced embryos
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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The present study was designed to investigate the effectiveness of different ultrasonic instruments on the root surface. Fourteen patients with 35 single root teeth designated for extraction were recruited to the present study. Teeth were assigned to four experimental groups: group 1, piezoelectric ultrasonic device; group 2, magnetostrictive ultrasonic device; group 3, hand instrumentation; and group 4, untreated teeth (control). After instrumentation, the teeth were extracted and the presence of residual deposits (roughness and root surfaces characteristics) were analyzed. The results showed that residual deposits were similar in all tested groups: piezoelectric, 8.7%; magnetostrictive, 9.7%; hand instrumentation, 11.1% and control, 76.4%. There were statistically significant differences between control and all the experimental groups (p < 0.0001). With respect to roughness parameters evaluation, R(a) and R(z) of the roots treated with the different instruments showed a similar pattern (p > 0.05), but for R(t) and R(y), a significant difference was observed (p < 0.05) among hand instrumentation and ultrasonic devices. SEM analysis revealed a similar root surface pattern for the ultrasonic devices, but curettes showed many instrumental scratches, deep gouges, and a relatively large amount of dentin was removed. Within the limits of the study, although the instruments produced similar results, root surfaces instrumentated with curettes were rougher and had more root surface tissue removed than with the ultrasonic device.
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CONTEXTUALIZAÇÃO: O Ultrassom (US) é um dos recursos físicos amplamente utilizado e pesquisado nos tratamentos de fisioterapia. Sabe-se que diante de uma escassa literatura sobre efeitos do US em tecidos sadios, muitos profissionais fisioterapeutas acabam realizando aplicações infundadas de métodos e parâmetros. OBJETIVO: Avaliar possíveis alterações histológicas e morfométricas do tecido sadio in vivo de ratos Wistar irradiados com diferentes intensidades de US. MÉTODOS: Trinta ratos da linhagem Wistar, distribuídos aleatoriamente em cinco grupos de seis animais cada foram tratados na região dorsal do lado direito numa área de 4cm². O lado esquerdo serviu como controle. O tratamento foi feito durante quatro dias com 2 minutos de irradiação. Verificou-se a intensidade de saída com dosímetro de precisão antes das aplicações. Analisou-se a histologia e a morfometria por meio do software Image Tool. RESULTADOS: Observou-se um discreto infiltrado inflamatório e adelgaçamento das fibras da derme, principalmente dos grupos irradiados com 1.5 e 2W/cm². Notou-se também um aumento na espessura da epiderme nas amostras dos animais irradiados. Para avaliar os resultados quantitativos, utilizou-se como análise estatística ANOVA one way e o teste post hoc de Tukey. Na espessura da epiderme, obtiveram-se diferenças significativas entre grupo controle e os grupos irradiados com 1.0, 1.5 e 2.0W/cm². CONCLUSÃO: Sob ação do US nas doses maiores houve alterações na epiderme e derme, respectivamente, o aumento da espessura e proliferação com adelgaçamento das fibras colágenas, o que alerta para possíveis implicações do uso do US em estética.
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Water contaminants have a high potential risk for the health of populations. Protection from toxic effects of environmental water pollutants primarily involves considering the mechanism of low level toxicity and likely biological effects in organisms who live in these polluted waters. The biomarkers assessment of oxidative stress and metabolic alterations to cadmium exposure were evaluated in Nile tilapia, Oreochromis niloticus. The fish were exposed to 0.35, 0.75, 1.5, and 3.0 mg/l concentrations of Cd2+ (CdCl2) in water for 60 days. Fish that survived cadmium exposure showed a metabolic shift and a compensatory development for maintenance of the body weight gain. We observed a decreased glycogen content and decreased glucose uptake in white muscle. Lactate dehydrogenase (LDH) and creatine phosphokinase (CK) activities were also decreased, indicating that the glycolytic capacity was decreased in this tissue. No alterations were observed in total protein content in white muscle due to cadmium exposure suggesting a metabolic shift of carbohydrate metabolism to maintenance of the muscle protein reserve. There was an increase in glucose uptake, CK increased activity, and a clear increase of LDH activity in red muscle of fish with cadmium exposure. Since no alterations were observed in lipoperoxide concentration, while antioxidant enzymes glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) were changed in the liver and the red and white muscle of fish with cadmium exposure, we can conclude that oxygen free radicals are produced as a mediator of cadmium toxicity. Resistance development is related with increased activities of antioxidant enzymes, which were important in the protection against cadmium damage, inhibiting lipoperoxide formation. (C) 2002 Elsevier B.V. Ltd. All rights reserved.
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The purpose of this study was to evaluate the influence of intrapulpal pressure and dentin depth on bond strengths of an etch-and-rinse and a self-etching bonding agent to dentin in vitro and in vivo. Twenty-four pairs of premolars were randomly divided into four groups (n = 6) according to the dentin bonding agent, Single Bond and Clearfil SE Bond, and intrapulpal pressure, null or positive. Each tooth of the pair was further designated to be treated in vivo or in vitro. The intrapulpal pressure was controlled in vivo by the delivery of local anesthetics containing or not a vasoconstrictor, while in vitro, it was achieved by keeping the teeth under hydrostatic pressure. Class I cavities were prepared and the dentin bonding agents were applied followed by incremental resin restoration. For the teeth treated in vitro, the same restorative procedures were performed after a 6 month-storage period. Beams with I mm 2 cross-sectional area were prepared and, microtensile tested. Clearfil SE Bond was not influenced by any of the variables of the study, while bond strengths produced in vitro were significatly higher for Single Bond. Overall, lower bond strengths were produced in deep dentin, which reached statistical significance when Single Bond was applied under physiological or simulated intrapulpal pressure. In conclusion, in vitro bonding may overestimate the immediate adhesive performance of more technique-sensitive dentin bonding systems. The impact of intrapulpal pressure on bond strength seems to be more adhesive dependent than dentin morphological characteristics related to depth. (C) 2007 Wiley Periodicals, Inc.
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4-Methylesculetin (4-ME) is a synthetic derivative of coumarin that displays a potent reactive oxygen species (ROS) scavenger and metal chelating agent and therefore has been produced to help reduce the risk of human disease. The main objective of this study was to investigate the in vivo genotoxicity of 4-ME and initially to verify its potential antigenotoxicity on doxorubicin (DXR)-induced DNA damage. Different doses of 4-ME (500, 1000 and 2000mgkg -1 body weight) were administered by gavage only or with a simultaneous intraperitoneal (i.p.) injection of DXR (80mgkg -1). The following endpoints were analyzed: DNA damage in peripheral blood, liver, bone marrow, brain and testicle cells according to an alkaline (pH>13) comet assay and micronucleus induction in bone marrow cells. Cytotoxicity was assessed by scoring polychromatic (PCE) and normochromatic (NCE) erythrocytes (PCE/NCE ratio). No differences were observed between the negative control and the groups treated with a 4-ME dose for any of the endpoints analyzed, indicating that it lacks genotoxic and cytotoxic effects. Moreover, 4-ME demonstrated protective effects against DXR-induced DNA damage at all tested doses and in all analyzed cell types, which ranged from 34.1% to 93.3% in the comet assay and 54.4% to 65.9% in the micronucleus test.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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O objetivo do presente estudo foi investigar a influência da pressão intrapulpar e da profundidade dentinária sobre o desempenho adesivo de dois agentes de união à dentina, Single Bond (3M ESPE, St. Paul, MN, EUA) e Clearfil SE Bond (Kuraray, Tokyo, Japão), aplicados in vitro e in vivo. Quarenta e oito prémolares superiores hígidos foram selecionados e os pares pertencentes aos mesmos pacientes foram aleatoriamente distribuídos em 4 grupos experimentais de acordo com o sistema adesivo e a pressão intrapulpar, presente ou ausente. Dos dentes pertencentes ao mesmo par, um foi tratado in vivo e o outro in vitro. A ausência ou presença de pressão intra-pulpar foi determinada in vivo pelo uso de anestésicos locais com ou sem vasoconstritor, respectivamente. In vitro, os dentes foram mantidos sob pressão hidrostática de 15 cm de água por 24 horas. Cavidades de classe I foram preparadas e os sistemas adesivos aplicados de acordo com a recomendação dos fabricantes, seguidos da restauração incremental em resina composta. Para os dentes tratados in vitro, os mesmos procedimentos restauradores foram realizados após 6 meses de armazenagem em solução contendo timol 0,1%. Espécimes com área de secção transversal de 1 mm2 foram obtidos e submetidos ao ensaio mecânico de microtração. In vivo, ambos os sistemas adesivos apresentaram desempenho adesivo comparável, enquanto in vitro, o sistema Single Bond foi superior ao sistema Clearfil SE Bond. Esse último não foi influenciado por nenhuma das variáveis estabelecidas no estudo, ou seja, aplicação in vitro ou in vitro, presença de pressão intrapulpar e profundidade em dentina. O sistema Single Bond aplicado sob pressão intrapulpar positiva sofreu variação significante de resistência de união em função da profundidade da dentina, ou seja, em dentina profunda seu desempenho adesivo... (Resumo completo, clicar acesso eletrônico abaixo)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)