RESUMO
The population of Pará (a state in Brazil) has a very characteristic food culture, as a majority of the carbohydrates consumed are obtained from cassava (Manihot esculenta Crantz) derivatives. Tucupi is the boiled juice of cassava roots that plays a major role in the culinary footprint of Pará. Before boiling, this juice is known as manipueira and contains linamarin, a toxic glycoside that can decompose to hydrogen cyanide. In this study, the cytotoxic and genotoxic effects of tucupi on cultured human lymphocytes were assessed using the comet assay and detection of apoptosis and necrosis by differential fluorescent staining with acridine orange-ethidium bromide. Tucupi concentrations (v/v) were determined using the methylthiazole tetrazolium biochemical test. Concentrations of tucupi that presented no genotoxic effects (2, 4, 8, and 16%) were used in our experiments. The results showed that under our study conditions, tucupi exerted no genotoxic effects; however, cytotoxic effects were observed with cell death mainly induced by necrosis. These effects may be related to the presence of hydrogen cyanide in the juice.
Assuntos
Bebidas , Temperatura Alta , Manihot/química , Mutagênicos/toxicidade , Raízes de Plantas/química , Adulto , Morte Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Ensaio Cometa , Dano ao DNA , Feminino , Fluorescência , Humanos , Masculino , Coloração e Rotulagem , Adulto JovemRESUMO
There is a constant search for new cancer treatments that are less aggressive and economically affordable. In this context, natural products extracted from plants, fungi, and microorganisms are of great interest. Pestheic acid, or dihidromaldoxin, is a chlorinated diphenylic ether extracted from the phytopathogenic fungus Pestalotiopsis guepinii (Amphisphaeriaceae). We assessed the cytotoxic, cytostatic, and genotoxic effects of pestheic acid in a gastric adenocarcinoma cell line (PG100). A decrease in clonogenic survival was observed. Pestheic acid also induced significant increases in both micronucleus and nucleoplasmic bridge frequency. However, we did not observe changes in cell cycle kinetics or apoptosis induction. Reactive oxygen species induced by diphenylic ethers may explain the genotoxicity and mutagenicity of pestheic acid. The absence of repair checkpoints that we observed is probably due to the fact that the PG100 cell line lacks the TP53 gene, which is common in gastric cancers. Even though pestheic acid has had a clear cytotoxic effect, the minimal inhibitory concentration was high, which shows that pestheic acid is not an active anticancer compound under these conditions.
Assuntos
Antineoplásicos/farmacologia , Hidrocarbonetos Clorados/farmacologia , Éteres Fenílicos/farmacologia , Adenocarcinoma , Adulto , Apoptose/efeitos dos fármacos , Ascomicetos/química , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Doxorrubicina/farmacologia , Humanos , Masculino , Testes para Micronúcleos , Neoplasias GástricasRESUMO
PURPOSE: The aim of this study was to investigate the influence of Nd:YAG laser on the shear bond strength to enamel and dentin of total and self-etch adhesives when the laser was applied over the adhesives, before they were photopolymerized, in an attempt to create a new bonding layer by dentin-adhesive melting. MATERIAL AND METHODS: One-hundred twenty bovine incisors were ground to obtain flat surfaces. Specimens were divided into two substrate groups (n=60): substrate E (enamel) and substrate D (dentin). Each substrate group was subdivided into four groups (n=15), according to the surface treatment accomplished: X (Xeno III self-etching adhesive, control), XL (Xeno III + laser Nd:YAG irradiation at 140 mJ/10 Hz for 60 seconds + photopolymerization, experimental), S (acid etching + Single Bond conventional adhesive, Control), and SL (acid etching + Single Bond + laser Nd:YAG at 140 mJ/10 Hz for 60 seconds + photopolymerization, experimental). The bonding area was delimited with 3-mm-diameter adhesive tape for the bonding procedures. Cylinders of composite were fabricated on the bonding area using a Teflon matrix. The teeth were stored in water at 37°C/48 h and submitted to shear testing at a crosshead speed of 0.5 mm/min in a universal testing machine. Results were analyzed with three-way analysis of variance (ANOVA; substrate, adhesive, and treatment) and Tukey tests (α=0.05). ANOVA revealed significant differences for the substrate, adhesive system, and type of treatment: lased or unlased (p<0.05). The mean shear bond strength values (MPa) for the enamel groups were X=20.2 ± 5.61, XL=23.6 ± 4.92, S=20.8 ± 4.55, SL=22.1 ± 5.14 and for the dentin groups were X=14.1 ± 7.51, XL=22.2 ± 6.45, S=11.2 ± 5.77, SL=15.9 ± 3.61. For dentin, Xeno III self-etch adhesive showed significantly higher shear bond strength compared with Single Bond total-etch adhesive; Nd:YAG laser irradiation showed significantly higher shear bond strength compared with control (unlased). CONCLUSION: Nd:YAG laser application prior to photopolymerization of adhesive systems significantly increased the bond strength to dentin.
Assuntos
Colagem Dentária , Esmalte Dentário/ultraestrutura , Adesivos Dentinários/efeitos da radiação , Dentina/ultraestrutura , Lasers de Estado Sólido , Condicionamento Ácido do Dente/métodos , Animais , Bis-Fenol A-Glicidil Metacrilato/química , Bis-Fenol A-Glicidil Metacrilato/efeitos da radiação , Bovinos , Resinas Compostas/química , Materiais Dentários/química , Análise do Estresse Dentário/instrumentação , Adesivos Dentinários/química , Cura Luminosa de Adesivos Dentários/instrumentação , Cura Luminosa de Adesivos Dentários/métodos , Teste de Materiais , Ácidos Fosfóricos/química , Polimerização , Doses de Radiação , Resistência ao Cisalhamento , Estresse Mecânico , Temperatura , Fatores de Tempo , Água/químicaRESUMO
Using a semiotic and hermeneutical approach, the present paper discusses various theoretical elements in the analysis of popular views of schistosomiasis. Based on field work conducted in the State of Bahia, the authors identify two main processes in the construction of meaning related to schistosomiasis and show that depending on the social context of experience the disease may have a primary or secondary meaning for the populations affected by it. The first level of meaning refers to bodily experiences and is shared intersubjectively, whereas the second type is built on the discourse of health professionals. In the latter case, the popular view of the illness is directly linked to discourses and actions previously established by health programs designed for the control of the disease.
Assuntos
Participação da Comunidade , Esquistossomose mansoni/prevenção & controle , Adolescente , Atitude Frente a Saúde , Brasil , Criança , Pré-Escolar , Educação em Saúde , Humanos , Entrevistas como Assunto , População RuralRESUMO
Os AA. comparam dois grupos geograficamente diferentes de pacientes com microtropia, um de Leeds (Inglaterra) e outro de Sao Paulo (Brasil) e comentam as diferencas e semelhancas encontradas
Assuntos
Humanos , EstrabismoRESUMO
Os autores apresentaram um estudo clinico e ecografigo de um irmao e sua irma ambos portadores da sindrome de Weill-Marchesani. A irma apresenta uma alteracao do segmento anterior em ambos os olhos, provavelmente devida seja a uma anteriorizacao-confirmada ecograficamente _ do cristalino com consequente aumento do diametro antero-posteior do espaco vitreo e diminuicao da profundidade da camara anterior, seja a uma disgenesia mesodermal nao caracteristica do segmento anterior
Assuntos
Criança , Humanos , Masculino , Feminino , Anormalidades Múltiplas , Ectopia do Cristalino , UltrassomRESUMO
Trinta e cinco pacientes com microesotropia sao comparados a outros trinta e cinco com microexotropia, todos examinados na Leeds General Infirmary, em Leeds, Inglaterra. Os parametros analisados incluem o tipo de microtropia, distribuicao por sexo, tratamento para ambliopia, tipo de ambliopia, idade de apresentacao, olho fixador, refracao, fusao e sua amplitude e estereopsia. Os resultados mostram nesta populacao uma estereopsia em geral boa em pacientes com microexotropia, justamente onde altas anisometropias e altos astigmatismos sao mais frequentes. Os homens neste trabalho preferem fixar com OE e mulheres com OD. Nao foi encontrado desvio vertical nos pacientes e a microtropia secundaria veio sempre do mesmo tipo de desvio
Assuntos
Humanos , Masculino , Feminino , Ambliopia , EsotropiaRESUMO
Em estudo retrospectivo foram levantados os casos de microtropias vistas no Servico de Motilidade Extrinseca da Clinica Oftalmologica do Hospital das Clinicas da Faculdade de Medicina da Universidade de Sao Paulo no periodo de lo de outubro de 1975 a lo de outubro de 1980, sendo analisados 135. Estudaram-se assim os casos, apos diagnostico baseado em diversos parametros, quanto a incidencia desta entidade; a presenca de componente vertical associado; as diferencas entre primarias e secundarias, microesotropias e microexotropias; a frequencia no sexo masculino e feminino; ao tratamento para ambliopia e seu resultado; a acuidade visual do olho fixador em relacao ao adelfo; a idade de apresentacao a preferencia por OD ou OE como fixador; a refracao; a percepcao macular simultanea; a fusao e sua amplitude e a estereopsia para longe. Os resultados sao discutidos assim como as diferencas entre os diversos subgrupos, baseando-se para isso nos dados obtidos