Facial symmetry evaluation after experimentally displaced condylar process fracture in methotrexate treated rats

PURPOSE: To investigate the facial symmetry of high and low dose methotrexate (MTX) treated rats submitted to experimentally displaced mandibular condyle fracture through the recording of cephalometric measurements. METHODS: One hundred male Wistar rats underwent surgery using an experimental model of right condylar fracture. Animals were divided into four groups: A - saline solution (1mL/week); B - dexamethasone (DEX) (0,15mg/Kg); C - MTX low dose (3 mg/Kg/week); D - MTX high dose (30 mg/Kg). Animals were sacrificed at 1, 7, 15, 30 and 90 days postoperatively (n=5). Body weight was recorded. Specimens were submitted to axial radiographic incidence, and cephalometric mensurations were made using a computer system. Linear measurements of skull and mandible, as well as angular measurements of mandibular deviation were taken. Data were subjected to statistical analyses among the groups, periods of sacrifice and between the sides in each group (alpha=0.05). RESULTS: Animals regained body weight over time, except in group D. There was reduction in the mandibular length and also changes in the maxilla as well as progressive deviation in the mandible in relation to the skull basis in group D. CONCLUSION: Treatment with high dose methotrexate had deleterious effect on facial symmetry of rats submitted to experimentally displaced condylar process fracture.

The influence of anthropometric factors on postural balance: the relationship between body composition and posturographic measurements in young adults

OBJECTIVE: The aim of the present study was to evaluate the influence of anthropometric characteristics and gender on postural balance in adults. One hundred individuals were examined (50 males, 50 females; age range 20-40 years). METHODS: The following body composition measurements were collected (using bone densitometry measurements): fat percentage (% fat), tissue (g), fat (g), lean mass (g), bone mineral content (g), and bone mineral density (g/cm(2)). In addition, the following anthropometric measurements were collected: body mass (kg), height (cm), length of the trunk-cephalic region (cm), length of the lower limbs (cm) and length of the upper limbs (cm). The following indices were calculated: body mass index (kg/m(2)), waist-hip ratio and the support base (cm 2). Also, a postural balance test was performed using posturography variables with open and closed eyes. RESULTS: The analysis revealed poor correlations between postural balance and the anthropometric variables. A multiple linear regression analysis demonstrated that the whole group (female and male) height explained 12% of the medial-lateral displacement, 10% of the speed of oscillation, and 11% of the displacement area. The length of the trunk-cephalic length explained 6% of the displacement in the anteroposterior direction. With eyes closed, the support base and height explained 18% of the medial displacement, and the lateral height explained 10% of the displacement speed and 5% of the scroll area. CONCLUSION: Measured using posturography, the postural balance was only slightly influenced by the anthropometric variables, both with open and closed eyes. Height was the anthropometric variable that most influenced postural balance, both in the whole group and separately for each gender. Postural balance was more influenced by anthropometric factors in males than females.

Variations in peak expiratory flow measurements associated to air pollution and allergic sensitization in children in Sao Paulo, Brazil

Background In the last 20 years, there has been an increase in the incidence of allergic respiratory diseases worldwide and exposure to air pollution has been discussed as one of the factors associated with this increase. The objective of this study was to investigate the effects of air pollution on peak expiratory flow (PEF) and FEV1 in children with and without allergic sensitization. Methods Ninety-six children were followed from April to July, 2004 with spirometry measurements. They were tested for allergic sensitization (IgE, skin prick test, eosinophilia) and asked about allergic symptoms. Air pollution, temperature, and relative humidity data were available. Results Decrements in PEF were observed with previous 24-hr average exposure to air pollution, as well as with 310-day average exposure and were associated mainly with PM10, NO2, and O3 in all three categories of allergic sensitization. Even though allergic sensitized children tended to present larger decrements in the PEF measurements they were not statistically different from the non-allergic sensitized. Decrements in FEV1 were observed mainly with previous 24-hr average exposure and 3-day moving average. Conclusions Decrements in PEF associated with air pollution were observed in children independent from their allergic sensitization status. Their daily exposure to air pollution can be responsible for a chronic inflammatory process that might impair their lung growth and later their lung function in adulthood. Am. J. Ind. Med. 55:10871098, 2012. (c) 2012 Wiley Periodicals, Inc.

Linear viscoelasticity of immiscible blends: The application of creep

A new method to characterize the long-time linear relaxation mechanisms of immiscible blends based on creep experiment was developed. Small-amplitude oscillatory shear and incomplete creep/recovery experiments were combined to characterize immiscible blends of polypropylene with dispersed droplets of polystyrene. An experimental protocol was defined such that the full creep compliance function could be obtained while minimizing morphological changes. Dynamic experiments were performed to characterize the shorter time relaxation processes, and creep and recovery measurements were used to detect the longer time portions of the relaxation spectra. Extended retardation and relaxation spectra were constructed by combining these data. It was found that using this technique, very long-time relaxation peaks which were inaccessible with dynamic experiments alone could be detected. (C) 2012 The Society of Rheology. [http://dx.doi.org/10.1122/1.4720081]