Protective effect of the APOE-e3 allele in Alzheimer’s disease

Although several alleles of susceptibility to Alzheimer’s disease (AD) have been studied in the last decades, few polymorphisms have been considered as risk factors for the disease. Among them, the APOE-e4 allele appears to be the major genetic risk factor for the onset of the disease. However, it is important to confirm the potential susceptibility of these genetic variants in different populations in order to establish a genetic profile for the disease in specific communities. This study analyzed the APOE polymorphisms regarding susceptibility to AD in a sample of 264 individuals (primarily Caucasians; 82 cases and 182 controls) in the population from Vitória, ES, Brazil, by PCR restriction fragment length polymorphism (PCR-RFLP) methods. The patients were selected according to clinical criteria for probable AD. Whereas the e4 allele showed statistically significant positive association with susceptibility to AD (OR = 3.01, 95 percentCI = 1.96-4.61; P < 0.0001), the e2 allele did not. The results of the e4 allele confirm the role of this polymorphism as a risk factor for AD in the sample studied as observed in other populations. Although the e3 allele has been considered neutral in several studies, our results suggest that it acts as a protective factor against AD in the population studied (OR = 0.46, 95 percentCI = 0.30-0.67; P < 0.0001). This study may provide a new insight into the role of the APOE-e3 allele in the etiology of AD and might help to estabilish a profile of risk for AD in the population from Vitória, ES.

Traumatismo de tercio medio facial en pacientes pediátricos y adolescentes / Midface trauma in pediatric and adolescents patients

El objetivo de este estudio fue realizar un análisis retrospectivo de la etiología, incidencia, uso de dispositivos de seguridad, tipo y severidad de las fracturas, tratamiento y complicaciones de los traumatismos del tercio medio facial en una población pediátrica e adolescente del Estado de São Paulo. La muestra fue seleccionada a partir del análisis de historias clínicas de 2986 pacientes víctimas de traumatismos faciales atendidos entre 1999 y 2008 por el Área de Cirugía Buco-Maxilo-Facial de la Facultad de Odontología de Piracicaba, Universidad Estatal de Campinas, Estado de São Paulo-Brasil. Durante este periodo, 757 pacientes menores de 18 años fueron víctimas de traumatismos maxilofaciales. De éstos, 138 pacientes presentaron 148 fracturas nasales y de tercio medio. Los adolescentes fueron el grupo etario más afectado, mientras que el género masculino fue el de mayor prevalencia. Los accidentes ciclísticos se constituyeron en la principal etiología (21.7%). El tratamiento conservador fue utilizado en la gran mayoría de los casos (118 pacientes, 85.5%). Veinte pacientes (14.5%) recibieron tratamiento quirúrgico y solo un caso de complicación pos-operatoria fue reportado. La incidencia de traumatismos y fracturas del tercio medio fue alta en la región de estudio. Los accidentes ciclísticos y las agresiones físicas fueron los principales factores etiológicos, siendo el género masculino predominante en todos los grupos etarios evaluados. Las fracturas nasales y del complejo zigomático orbitario fueron las más prevalentes, mientras que el tratamiento conservador fue instituido en la gran mayoría de los casos

This study showed a retrospective analysis of the etiology, incidence, use of safety devices, type and severity of fractures, treatment and complications of midface trauma in a pediatric and adolescent population of São Paulo - Brazil. We analyzed 2986 medical records of facial trauma patients treated by the Division of Oral and Maxillofacial Surgery Piracicaba Dental School, State University of Campinas, São Paulo - Brazil between 1999 and 2008. During this period, 757 patients under 18 were identified and 138 had 148 nasal and midface fractures. The adolescents were the most affected age group, male gender being the most prevalent. The most common injury causes were bicycle accident (21.74%) and violence (19.6%). Conservative treatment was used in the majority of cases (118 patients, 85.5%). Twenty patients (14.5%) received surgical treatment and only one case of postoperative complication was reported. The incidence of trauma and middle third fractures in pediatric and adolescents patients was high in the study area, being the main etiological factors the bicycle accidents and violence. The male were most affected in all age groups tested. Nasal fractures and zygomatic complex were most prevalent, while conservative treatment was instituted in most cases

Análisis de microdureza de dos diferentes resinas relacionadas a la intensidad de fotopolimerización dependiendo de la distancia utilizada / Microhardness of two different composite resind related to light curing intensity depending on distance

Objetivo: El presente estudio evaluó la microdureza de dos distintas resinas que fueron fotopolimerizadas a cuatro distancias diferentes. Materiales y Métodos: Se obtuvieron cuarenta muestras utilizando una matriz metálica de acero y dos resinas fotopolimerizables (Filtek-A110, Filtek-Z250). Las muestras se prepararon de forma aleatoria constituyendo 8 grupos, 4 por cada resina fotopolimerizable (n igual que 5), las cuales fueron polimerizadas a 0, 2, 4 y 8 mm de distancia de la fuente de luz, usando la misma intensidad de energía. Posteriormente, las medidas de microdureza Vickers fueron obtenidas en la superficie superior e inferior de las muestras. Los datos resultantes fueron sometidos al t test o ANOVA y al test Tukey (alfa igual que 0.05). Resultados: La microdureza de la resina microhíbrida (Filtek-Z250), fue superior en todas las distancias analizadas en relación con la resina de microrelleno (Filtek-A110). Para la resina Filtek-Z250, la distancia de polimerización no influyó en la dureza de la parte superior o inferior, excepto a 8mm de la distancia inferior, donde se encontró el menor valor de microdureza. En la resina Filtek-A110, se observó una disminución progresiva de la microdureza con el incremento de la distancia, en la parte superior e inferior. En general, la microdureza en la parte superior fue significativamente mayor que en la parte inferior de ambas resinas. Conclusiones: El incremento en la distancia de fotopolimerización no modificó el grado de polimerización de la resina microhíbrida. Sin embargo, esta distancia es un factor importante a ser considerado durante la polimerización de las resinas de microrelleno.

Objetive: This study investigated the surface microhardness of two different composite resins light cured at four different distance. Material and methods: Forty specimens were obtained sin composites (Filtek-A110 and Filtek-Z250). The samples were randomly prepared, constituting 8 groups, 4 for each resin composite (n=5), which were light cured at 0,2,4 or 8 mm distances, using the same output power. Afterwards, Vickers microhardness measurements were obtained on top and botton surfaces of the samples. Data were submitted to t test or ANOVA followed by Turkey test (a=0.05). Results: The microhardness of the microhybrid resin, Filtek-Z250, was superior in all distances analyzed in relation to the microfilled resin, Filtek-A110. Filtek-Z250, the distance of polymerization did not influence the hardness at top or bottom, except for 8 mm distance at bottom, where the lowest microharness was found. For Filtek-A110, a progressive decrease in microhardness with the increase of distance was observed at both top and bottom. At general, hardness at top was significantly higher than at bottom for both resins. Conclusions: In the conditions of this study, the increase in the distance of polymerization did no change microhybrid composite resin polymerization. However, this distance is an important factor to be observed in polymerization of microfilled composite resins.

Características tridimensionais da camada aprismática de fissuras de premolares humanos: estudo ao microscópio eletrônico de varredura / Three-dimensional characteristics of enamel \"prismless\" layer of the human premolar fissurae: a scanning electron microscopy study

A estrutura de esmalte aprismático de fissuras de premolares humanos foi observada através de superfícies fraturadas vestíbulo-lingualmente. Os resultados mostraram que a camada aprismática margeia a superfície da fissura em toda extensão. A espessura da camada aprismática é aumentada na porção média da fissura a qual é semelhante aquela encontrada nas superfícies vestibular e lingual. Os cristais de hidroxiapatita dispondo-se paralelamente são claramente vistos em aspectos tridimensionais