Conservation of body sections and organs of the narrownose smooth-hound, Mustelus schmitti (Pisces, Chondrichthyes), by silicone injection at room temperature to be used in comparative anatomy learning / Conservación de secciones corporales y órganos de gatuzo, Mustelus schmitti (Pisces, Chondrichthyes), por inyección de silicona a temperatura ambiente para ser utilizados en el aprendizaje de anatomía comparada

Comparative Anatomy deals with the study of the ontogenetic and phylogenetic changes of the vertebrates, requiring complementing the theoretical aspects with the observation of structures in specimens belonging to different taxonomic groups. The aim of the present study was to test the injection of silicone at room temperature in organs and trunk sections of Mustelus schmitti as an alternative to the plastination technique. Samples consisted in brain, eyes, heart, proximal end of the ventral aorta, digestive tract, spleen, pancreas, kidneys, testis and cross body section at a pre-caudal level. Material was fixed with formalin (10-5 %), dehydrated with growing concentrations of isopropyl (30 % - 50 % - 70 % - 90 % - 100 % - 100 %), impregnated with diluted commercial silicone and cured at room temperature. The whole process took 66 days. The brain was the unique organ that could not undergo the complete procedure because it did not resist the injection of silicone. The other pieces resulted in materials that characterised by being off-colour, dry, semi-flexible, lightweight, odourless, and non-toxic. They showed no signs of fungal colonization or bacterial degradation after two years of being obtained. Shrinkage was observed, which ranged among 2-25 % for total length, and from 5-26 % for maximum width (mean values: 14 and 15 %, respectively), being testicle the organ that suffered greater shrinkage in both dimensions. The degree of contraction in length and width for each of the samples was generally similar (difference £ 3 %), indicating that not striking deformation occurred. Deformation was observed only for the trunk section, eye, stomach, pancreas and valvular intestine. The technique did not affect the morphology of the structures, allowing the correct visualization of all the basic features required to recognise them. We conclude that this simple and economic method is an adequate alternative to be implemented for the conservation of small-size materials with educational purposes in Comparative Anatomy courses.

La Anatomía Comparada abarca el estudio de los cambios ontogenéticos y filogenéticos sufridos por los vertebrados, requiriendo complementar los aspectos teóricos conla observación de estructuras en especímenes pertenecientes a los distintos grupos taxonómicos. El objetivo del presente trabajo fue testear la inyección de silicona a temperatura ambiente en órganos y secciones corporales de Mustelus schmitti como alternativa a la técnica de plastinación. Las estructuras seleccionadas fueron encéfalo, ojos, corazón, extremo proximal de aorta ventral, tracto digestivo, bazo, páncreas, riñón, testículo y sección transversal del cuerpo a nivel pre-caudal. El material se fijó con formaldehído (10-5 %), se deshidrató con concentraciones crecientes de alcohol isopropílico (30 % - 50 % - 70 % - 90 % - 100 % - 100 %), se impregnó con silicona comercial diluida y se curó a temperatura ambiente. El proceso completo duró 66 días. El encéfalo fue el único órgano que no resistió el tratamiento debido a su friabilidad. Las demás piezas dieron como resultado materiales incoloros, secos, semi-flexibles, livianos, inodoros y no-tóxicos. No se evidenciaron síntomas de colonización fúngica ni bacteriana luego de dos años de obtenidos. Se observó contracción del material que osciló entre 2-25 % para la longitud total, y entre 5-26 % para el ancho máximo (promedios: 14 y 15 %, respectivamente), siendo el testículo el órgano que mayor disminución registró en ambas dimensiones. El grado de contracción en longitud y en ancho fue generalmente similar para cada una de las muestras (diferencia £ 3 %), indicando que no ocurrió una deformación notoria. Solo se observó deformación en la sección corporal, ojo, estómago, páncreas e intestino valvular. La técnica no afectó la morfología de las estructuras, permitiendo la correcta visualización de todas las características diagnósticas requeridas para su reconocimiento. Concluimos que este método simple y económico representa una alternativa adecuada para ser implementada en la conservación de materiales de pequeño tamaño con fines educativos en los cursos de Anatomía Comparada.

Methods for estimating the volume of the tympanic bulla in the big hairy armadillo Chaetophractus villosus (Mammalia, Xenarthra, Dasypodidae) / Métodos para la estimación del volumen de bula timpánica en el quirquincho grande Chaetophractus villosus (Mammalia, Xenarthra, Dasypodidae)

Two methods of measurement of bullar dimensions (callipers and scaling from digital images) and subsequent application of four volume formulae (rectangular prism, cylinder, ellipse and elliptical cone) were tested to find the most appropriate non-destructive method for estimating the bullar volume in Chaetophractus villosus. Material for the study consisted in clean adult skull (n=22). Real volume was obtained from latex casts of the tympanic bulla. Each estimation was corrected by a factor based on the differences between the estimated and the real volumes. Highest accuracy (5-7 % of underestimation) and precision (coefficient of variation: 13.27 %) were obtained from callipers and application of rectangular prism, cylinder and ellipse formulae. The corresponding correction factors were 0.31, 0.39 and 0.58, respectively.

Se evaluaron dos métodos para la obtención de medidas de la bula (calibre y escalado a partir de imágenes digitales), con posterior aplicación de cuatro fórmulas de volumen (prisma rectangular, cilindro, elipse y cono elíptico), a fin de hallar el método no destructivo más adecuado para el cálculo de volumen de bula en Chaetophractus villosus. El material de estudio consistió en cráneos limpios de individuos adultos (n=22). El volumen real fue obtenido a partir de moldes de látex de la bula timpánica. Cada estimación fue corregida mediante un factor basado en las diferencias entre los volúmenes reales y estimados. La mayor precisión (coeficiente de variación: 13,27 %) y exactitud (subestimaciones del 5-7 %) fueron obtenidas a partir de mediciones con calibre y aplicación de fórmulas de prisma rectangular, cilindro y elipse (factores de corrección: 0,31, 0,39 y 0,58, respectivamente).

Experimental Design Applied to the Optimization and Partial Characterization of Pectin Liase from a Newly Isolated Penicillium brasilianum

Penicillium brasilianum was previously isolated from tea and identified by molecular biology technique. A Plackett-Burman design, followed by a complete second order design was used for the screening of most important factors and to maximize the pectin liase (PMGL) activity, respectively. The maximum PMGL activity by P. brasilianum achieved was 9.0 U/mL after 48 h of cultivation in a medium containing pectin (33.0 g/L), yeast extract (30.0 g/L) and potassium phosphate (2.0 g/L) at 30ºC, with a stirring rate of 180 rpm, initial pH 5.5 and 5x106 spores/mL inoculum size. The kinetic evaluation in terms of substrate consumption demonstrated that the maximum production of PMGL was at 72 h, and 40% of the total organic carbon, 25% of the nitrogen, 88% of the magnesium, 13% of the potassium and 66% of the iron were consumed. The pH remained almost stable during the whole period of production (5.33 to 4.9). The partial characterization of the crude PMGL enzyme extract showed optimal pH and temperature of 5.5 and 37°C, respectively.

Radiopacidade do cimento Portland modificado em comparação com o MTA / Radiopacity of the modified Portland cement in comparison with MTA

Objetivo: Este estudo in vitro utilizou imagem digital para medir a radiopacidade do cimento Portland (CP), isoladamente ou associado a substâncias radiopatizantes, com referência à radiopacidade do Agregado do Trióxido Mineral (MTA). Metodologia: Três espécimes foram preparados para cada um dos seguintes grupos: 1) ProRoot MTA (Dentsply); 2) cimento Portland - CP (Goiás); 3) CP + solução de acetato de uranila a 2%; 4) CP + de solução de PTA a 2%; 5) CP + solução de citrato de chumbo. Os espécimes foram armazenados por 28 dias em temperatura ambiente e a radiopacidade foi medida com um sistema de radiografia digital direta (Sens-A-Ray), usando as funções gráfico de perfil de linha e histograma.Resultados: O grupo ProRoot MTA apresentou a maior radiopacidade; a radiopacidade do cimento Portland foi aproximadamente 60% a do MTA. As soluções testadas aumentaram a radiopacidade do cimento Portland nas seguintes taxas: PTA=7%, acetato de uranila=12,5% e citrato de chumbo=11%.Conclusão: A adição de soluções radiopatizantes aumentou a radiopacidade padrão do cimento Portland, mas sem atingir o grau de radiopacidade do cimento ProRoot MTA.

Purpose: This in vitro study used digital images to measure the radiopacity of the Portland cement (PC) containing or not radiopaque substances in relation to the radiopacity of the Mineral Trioxide Aggregate (MTA) cement. Methods: Three specimens were fabricated for each of the following five groups: 1) ProRoot MTA (Dentsply); 2) Portland cement - PC (Goiás); 3) PC + 2% uranyl acetate solution; 4) PC + 2% PTA solution; 5) PC + lead citrate solution. Specimens were stored in room temperature for 28 days and their radiopacity was measured by means of a direct digital radiography system (Sens-A-Ray), using the analytical functions line profile graph and histogram. Results: ProRoot MTA group showed the highest radiopacity; Portland cement radiopacity was approximately 60% of the MTA value. The tested solutions increased the radiopacity of Portland cement in the following rates: PTA=7%, uranyl acetate =12.5% and lead citrate =11%. Conclusion: The addition of radiopaque substances increased radiopacity of the original Portland cement, but it did not reach the level of ProRoot MTA radiopacity.

Hipomineralização molar-incisivo / Molar incisor hypomineralization

A hipomineralização-molar incisivo (HMI) é um defeito de origem sistêmica no esmalte dentário de primeiros molares e incisivos permanentes. Nesta condição, o esmalte hipomineralizado é frágil e pode se destacar facilmente, deixando a dentina exposta e causando, assim, problemas como sensibilidade dentária e maior risco ao estabelecimento de lesões de cárie. A HMI é freqüentemente confundida com fluorose ou amelogênese imperfeita e sua prevalência varia de 3,6 a 25%. Vários fatores etiológicos são citados para a condição e estão freqüentemente relacionados com doenças na infância nos primeiros três anos de vida. O tratamento envolve desde a restauração dos dentes afetados com materiais adesivos ou até mesmo a extração dos mesmos, dependendo da severidade do caso.

Molar-Incisor Hypomineralization (MIH) is a hypomineralization of systemic origin of first permanent molars and incisors. In this condition, hipomineralized dental enamel is fragile and soft and can break easily, leading the dentin exposed and causing problems like dental sensitivity and progression of caries lesions. MIH is frequently misinterpreted as fluorosis or amelogenesis imperfecta and the prevalence ranges from 3,6 to 25%. Several aetiological factors are mentioned as the cause of the condition and they are frequently associated with childhood diseases during the first three years of life. The treatment includes the use of adhesive materials for restorative procedures, or even the extraction of the teeth, according to the severity of the case.