Evaluación del efecto del ácido cítrico en distintas concentraciones en la permeabilidad dentinaria / Assessment of different citric acid concentrations on dentinal permeability

Objetivos: El objetivo de este estudio fue evaluar in vitro la capacidad de remoción del barrillo dentinário con ácido cítrico al 10, 25 y 50% asociados al hipoclorito sódico al 1% en dientes humanos extraídos. Material y métodos. fueron seleccionados 40 dientes unirradiculares distribuidos en cuatro grupos de 10, intrumentados e irrigados has #40 de acuerdo con los grupos siguientes. Grupo I - hipoclorito de sodio al 1%, Grupo II - ácido cítrico al 10% (pH 1.1), Grupo III - ácido cítrico al 25% (pH 1.1), Grupo VI - ácido cítrico al 50% (pH 1.1). Los conductos radiculares fueron mantenidos en Rodamina B al 2% (pH 7.0) durante 24 horas, seleccionandos longitudinalmente, fotografiados y evaluados en una lupa óptica (40x). Resultados: Test de Kruskal-Wallis (p<0,05) permitieron concluir que el aumento de la concentración del ácido cítrico en el tercio cervical promovió un aumento en la permeabilidad dentinaria. Conclusiones. El ácido cítrico en las concentraciones de 25% y 50% fueron estadisticamente similares

Objective: The aim of this study was to evaluate in vitro the capacity of the smear layer removal of citric acid at 10,25 and 50% associated to the sodium hypochlorite at 1% in human teeth. Material and methods: Forty roots were selected and divided into three groups according to the solution used and were prepared at #40 file: Group I - Sodium hypochlorite at 1%, Group II - Citric acid at 10% (pH 1.1). Group III - Citric acid at 25% (pH 1.1), Group IV - Citric acid at 50% (pH 1.1) . The specimens were submerged in rodamine B at 2% (pH 7.0) for 24 hours and seccionated longitudinally, photographed and evaluated in optical microscopic at 40X. Results: The Krustal-Wallis test (p<0.05) demonstrated that the increased of citric acid concentration in the cervical third promoted the greatest dentin permeability. Conclusions: The citric acid in the concentrations of 25% and 50% were statistically similar

Análisis morfológico del techo y piso de la cámara pulpar en molares superiores e inferiores / Morphological study of both root and pulp chamber floor in maxillary and mandibular molars

El objetivo de este estudio fue evaluar in vitro la distancia entre el techo y el piso de la cámara pulpar en los molares superiores e inferiores a través de estereomicroscopía. Fueron utilizados 200 dientes molares superiores e inferiores con rizogénesis completa, limpios y esterilizados. Los especímenes fueron seccionados longitudinalmente y evaluados en un microscopio óptico por luz reflejada (Leitz Wetzlar - GmBh) a 25 aumentos. La distancia techo-piso de la cámara pulpar en los molares superiores ha sido de 2.1330 mm (+- 0,8469) mientras que en los molares inferiores ha sido de 2.0020 mm (+- 0,8528). La comparación de los promedios entre los dientes superiores y los inferiores a través del test t de Student no ha presentado diferencias estadísticamente significantes (p> 0,05)

The aim of this study was to evaluate in vitro the distance between the roof and the pulp chamber floor in maxillary and mandibular molars through stereoscopic microscope. Two hundred extracted human teeth were selected and were used, cleaned and stored in formol. The specimens were sectioned longitudinally with the purpose of measuring, through optical stereomicroscope (Leitz Wetzlar - GmBh), the relationship of the roof and the pulp chamber floor. The distance of the roof-floor of the pulp chamber in the maxillary molars (2.1330 +- 0.8469) in comparison with the maxillary (2.0020 +- 0.8528) didn't reveal significant difference calculated by Student's t test (p>0.05)

Diabetes mellitus: new therapeutic approaches to treat an old disease

Diabetes mellitus is a widespread disease whose frequency increases constantly and is expected to reach alarming levels by the year 2025. Introduction of insulin therapy represented a major breakthrough; however, a very strict regimen is required to maintain blood glucose levels within the normal range and to prevent or postpone chronic complications associated with this disease. Frequent hyper- and hypoglycemia seriously affect the quality of life of these patients. Reversion of this situation can only be achieved through whole organ (pancreas) transplant or pancreatic islet transplant, the former being a high-risk surgical procedure, while the latter is a much simpler and may be accomplished in only 20-40 min. The advantages and perspectives of islet cell transplantation will be discussed, in the light of tissue engineering and gene therapy. Ongoing research carried out in our laboratory, aimed at developing clinical cell and molecular therapy protocols for diabetes will also be focused

A strategy for obtaining social benefits from the gene revolution.

The strategy described in the present paper offers details about the possibility for Brazil to play a more substantial role in the gene revolution. If successfully applied, the powerful science-based technology currently available in Brazil can contribute to extend the benefits of the gene revolution to the poorest countries, very much like the Green Revolution did in the past, thereby reducing the hunger syndrome which claimed the lives of millions of people in some Asian countries, particularly Pakistan and India, decades ago. In his visit to Brazil in February 2004, Norman Borlaug had the opportunity to witness the success of Brazilian agriculture. At a Conference held at ESALQ - Superior School of Agriculture Luiz de Queiroz in Piracicaba, SP, Brazil, he stated that the 21st century revolution will come from Brazil in the area of agriculture. He also said that reducing hunger is essential for the world to achieve socioeconomic stability. A central question remains unanswered: who will fund this revolution? The FAO 2003-2004 Annual Report listed the barriers preventing the gene revolution from reaching the poorest countries: inadequate regulatory procedures-Intellectual Property Rights and Biosafety, poorly functioning seed delivering systems and weak domestic plant breeding capacity; all are discussed in this paper.

Effect of the employment of biosolids as recovery agent for degraded areas.

The solid residue generated from the sewage treatment receives the denomination of sewage sludge, being also called biosolid. The present work compared the effect of 3 levels of fertilization (sewer sludge, mineral fertilization and proof) in the recovery of areas with 2 levels of soil degradation simulation (removal of 15 cm and 30 cm of soil), plus a proof. In the parcels destined for the biosolid, 40 dry t./ha of aerobic limy stabilized 30% had been used. The content of Ca+Mg, K, V% and CTC in the parcels that received biosolids had its value increased by 11.7%, 28.0%, 8.3% and 6.0% respectively, when compared with the values of the proof at the end of the maize culture. The contents of phosphorus were statistically higher for the Tukey test at 5% of probability in the treatment with biosolid, verifying also the trend of accumulation of phosphorus in the parcels, with the simulated level of degradation of 30 cm. There was a significant increase in carbon content due to the application of biosolids. The production of dry substance was still evaluated, where the biggest productions had been statistically verified in the treatments, being slightly influenced by the different levels of soil degradation, evidencing the great capacity of silt as recovery agent.

Spatial and temporal gene expression patterns occur during corm development.

We investigated gene expression patterns that occur during taro corm development. Two-dimensional gel electrophoresis identified several different prevalent proteins that accumulate during corm development. Microsequencing studies indicated that some of these proteins are related to taste-modifying proteins, such as curculin and miraculin, and proteins found in other storage organs, such as sporamin and the Kunitz trypsin inhibitor. A curculin-encoding cDNA clone, designated as TC1, was identified that corresponds to a highly prevalent 1-kb corm mRNA. The TC1 mRNA accumulates during corm development, is more prevalent in corm apical than basal regions, and is either absent, or present at low concentrations, in other vegetative organs such as the leaf and root. In situ hybridization experiments showed that the TC1 mRNA is highly concentrated in corm storage parenchyma cells and is absent, or present in reduced concentrations, in other corm cells and tissues. Our results show that corm development is associated with the differentiation of specialized cells and tissues, and that these differentiation events are coupled with the temporal and spatial expression of corm-specific genes.