Effect of root morphology on biomechanical behaviour of premolars associated with abfraction lesions and different loading types.

The aim of this study was to investigate the biomechanical behaviour of maxillary premolar teeth regarding root morphology and abfraction depth, submitted to axial and oblique occlusal load. The investigation was conducted using 3D finite element analysis and strain gauge test. Sound maxillary premolar single and double root were selected for 3D model generation. The teeth were scanned for external morphology data acquisition. The 3D geometry was stored in *.STL and exported to Bio-CAD software (Rhinoceros-3D) to model generation. Mesh generation, mechanical properties and boundary conditions were performed in finite element software (Femap, Noran Engineering, USA). Twelve models were generated: sound tooth, 1.25 and 2.5 mm abfraction teeth. 100N compressive static load was applied: axially and 45° angle to the long axis on the palatine surface of the buccal cusp. Two strain gauges were bonded on the teeth mounted in a mechanical testing machine. Von Mises criterion showed that the double-root teeth associated with 2.5 mm abfraction and oblique loading presented higher stress values. Axial loading associated with single-root teeth propitiated the lowest stress rates. Double root sound 1.25 and 2.5 mm abfraction teeth associated with oblique loading showed the highest strain values (µS): 692.6, 1043.31 and 1236.14, respectively. Single root sound 1.25 and 2.5 mm abfraction teeth associated with oblique loading showed 467.10, 401.51 and 420.98 strain values, respectively. Axial loading showed lower strain rates, ranging from 136.12 to 366.91. The association of deep lesions, oblique loading and double-root tooth promoted higher stress and strain concentration.

Types of marriages, population structure and genetic disease.

A high occurrence rate of consanguineous marriages may favour the onset and increased frequency of autosomal recessive diseases in a population. The population of Monte Santo, Bahia, Brazil, has a high frequency of rare genetic diseases such as mucopolysaccharidosis type VI, whose observed frequency in this population is 1:5000, while the incidence of this disease recorded in other regions of the world varies from 1:43,261 in Turkey to 1:1,505,160 in Switzerland. To verify the influence of consanguineous marriage on the increased frequency of observed genetic diseases in this population, the population structure and frequency of different types of marriage during different time periods were evaluated. A total of 9765 marriages were found in an analysis of parish marriage records from the city. Over three periods, 1860-1895, 1950-1961 and 1975-2010, the inbreeding rates were 37.1%, 13.2% and 4.2% respectively. Although there was a high rate of inbreeding, endogamic marriages were the dominant marriage type in all three periods. In the most recent period, there was an increase in the number of exogamous marriages and those among immigrants, but most of these occurred among individuals from cities that neighbour Monte Santo. The low rate of migration and high frequency of endogamic and consanguineous marriages show that growth of this population is predominantly internal and could explain the occurrence, and increase in frequency, of recessive genetic diseases in the city.

Intrauterine growth restriction-induced deleterious adaptations in endothelial progenitor cells: possible mechanism to impair endothelial function.

Intrauterine growth restriction (IUGR) can induce deleterious changes in the modulatory ability of the vascular endothelium, contributing to an increased risk of developing cardiovascular diseases in the long term. However, the mechanisms involved are not fully understood. Emerging evidence has suggested the potential role of endothelial progenitor cells (EPCs) in vascular health and repair. Therefore, we aimed to evaluate the effects of IUGR on vascular reactivity and EPCs derived from the peripheral blood (PB) and bone marrow (BM) in vitro. Pregnant Wistar rats were fed an ad libitum diet (control group) or 50% of the ad libitum diet (restricted group) throughout gestation. We determined vascular reactivity, nitric oxide (NO) concentration, and endothelial nitric oxide synthase (eNOS) protein expression by evaluating the thoracic aorta of adult male offspring from both groups (aged: 19-20 weeks). Moreover, the amount, functional capacity, and senescence of EPCs were assessed in vitro. Our results indicated that IUGR reduced vasodilation via acetylcholine in aorta rings, decreased NO levels, and increased eNOS phosphorylation at Thr495. The amount of EPCs was similar between both groups; however, IUGR decreased the functional capacity of EPCs from the PB and BM. Furthermore, the senescence process was accelerated in BM-derived EPCs from IUGR rats. In summary, our findings demonstrated the deleterious changes in EPCs from IUGR rats, such as reduced EPC function and accelerated senescence in vitro. These findings may contribute towards elucidating the possible mechanisms involved in endothelial dysfunction induced by fetal programming.

Emprego de debrisan no tratamento de feridas infectadas. / Use of debrisan in the treatment of infected wounds

Os autores apresentam os resultados de estudo de 20 pacientes portadores de feridas infectadas, de etiologias variadas, submetidos a tratamento topico com debrisan.Metodo simples de tratamento, diminui rapidamente a reacao inflamatoria, a secrecao, e a dor local, acelerando a formacao de tecido de granulacao, permitindo a cicatrizacao espontanea da ferida, e condicoes para sutura ou enxertia da lesao, diminuindo significativamente o tempo de permanencia hospitalar