Antioxidant capacity and mineral content of pulp and peel from commercial cultivars of citrus from Brazil

Four Citrus species (C. sinensis, cvs. Pera and Lima; C. latifolia Tanaka cv. Tahiti; C limettioides Tanaka cv. Sweet lime and C. reticulate, cv. Ponkan) grown in Brazil were characterised in relation to contents of minerals, ascorbic acid, total polyphenols and antioxidant capacity of pulps and peels. In general, the peels demonstrated significantly higher contents of all compounds than the pulps (p < 0.05), with the exception of the Pera orange pulp that presented the highest acid ascorbic content (68 mg/100 ml), while the Tahiti lime peel presented the lowest (8 mg/100 g). Citrus showed high levels of potassium, calcium and magnesium, and the peels were considered sources of these minerals. The Ponkan mandarin peel presented the highest antioxidant capacity. The antioxidant capacity of citrus was correlated both to vitamin C and phenolics. Aside from citrus pulps, the peels are also good sources of bioactive compounds and minerals, and can be explored for their health promoting values in food products. (C) 2012 Elsevier Ltd. All rights reserved.

Different protocols to produce artificial dentine carious lesions in vitro and in situ: hardness and mineral content correlation

This study compared dentine demineralization induced by in vitro and in situ models, and correlated dentine surface hardness (SH), cross-sectional hardness (CSH) and mineral content by transverse microradiography (TMR). Bovine dentine specimens (n = 15/group) were demineralized in vitro with the following: MC gel (6% carboxymethylcellulose gel and 0.1 m lactic acid, pH 5.0, 14 days); buffer I (0.05 m acetic acid solution with calcium, phosphate and fluoride, pH 4.5, 7 days); buffer II (0.05 m acetic acid solution with calcium and phosphate, pH 5.0, 7 days), and TEMDP (0.05 m lactic acid with calcium, phosphate and tetraethyl methyl diphosphonate, pH 5.0, 7 days). In an in situ study, 11 volunteers wore palatal appliances containing 2 bovine dentine specimens, protected with a plastic mesh to allow biofilm development. The volunteers dripped a 20% sucrose solution on each specimen 4 times a day for 14 days. In vitro and in situ lesions were analyzed using TMR and statistically compared by ANOVA. TMR and CSH/SH were submitted to regression and correlation analysis (p < 0.05). The in situ model produced a deep lesion with a high R value, but with a thin surface layer. Regarding the in vitro models, MC gel produced only a shallow lesion, while buffers I and II as well as TEMDP induced a pronounced subsurface lesion with deep demineralization. The relationship between CSH and TMR was weak and not linear. The artificial dentine carious lesions induced by the different models differed significantly, which in turn might influence further de- and remineralization processes. Hardness analysis should not be interpreted with respect to dentine mineral loss

Sedentary behaviours and its association with bone mass in adolescents: the HELENA cross-sectional study

Background: We aimed to examine whether time spent on different sedentary behaviours is associated with bone mineral content (BMC) in adolescents, after controlling for relevant confounders such as lean mass and objectively measured physical activity (PA), and if so, whether extra-curricular participation in osteogenic sports could have a role in this association. Methods: Participants were 359 Spanish adolescents (12.5-17.5 yr, 178 boys,) from the HELENA-CSS (2006-07). Relationships of sedentary behaviours with bone variables were analysed by linear regression. The prevalence of low BMC (at least 1SD below the mean) and time spent on sedentary behaviours according to extracurricular sport participation was analysed by Chi-square tests. Results: In boys, the use of internet for non-study was negatively associated with whole body BMC after adjustment for lean mass and moderate to vigorous PA (MVPA). In girls, the time spent studying was negatively associated with femoral neck BMC. Additional adjustment for lean mass slightly reduced the negative association between time spent studying and femoral neck BMC. The additional adjustment for MVPA did not change the results at this site. The percentage of girls having low femoral neck BMC was significantly smaller in those participating in osteogenic sports (>= 3 h/week) than in the rest, independently of the cut-off selected for the time spent studying. Conclusions: The use of internet for non-study (in boys) and the time spent studying (in girls) are negatively associated with whole body and femoral neck BMC, respectively. In addition, at least 3 h/week of extra-curricular osteogenic sports may help to counteract the negative association of time spent studying on bone health in girls.

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.

A Modified Technique of Rat Tail Suspension for Longer Periods of Observation

FALCAI MJ, LOUZADA MJQ, DE PAULA FJA, OKUBO R, VOLPON JB. A modified technique of rat tail suspension for longer periods of observation. Aviat Space Environ Med 2012; 83:1176-80. Background: Rat tail suspension is an accepted method to create experimental osteopenia. However, suspension periods longer than 3 wk may cause tail skin sloughing or rat slippage. The hypothesis was that a traction system with skeletal anchorage through one tail vertebra would prolong the suspension time without significant complications. Methods: There were 80 young adult female Wistar rats that were submitted to one of the following interventions: skeletal tail suspension (N = 20), skin tail suspension (N = 20), no intervention (N = 20), and a baseline control (N = 20). All animals were followed up either for 3 (N = 10) or 6 (N = 10) wk. Animals were assessed for clinical signs of stress and tolerance to suspension. The femur evaluation was in terms of mineral density content, mechanical resistance, and histomorphometry. Results/Discussion: All animals reached the 3-wk end point. However, for the 6-wk period, seven animals suspended by the skin traction method were discarded (70%) because of signs of stress and skin sloughing. In contrast, there was one loss in the skeletal suspension group (10%). All suspended animals developed similar osteopenia at 3 wk characterized by decreased bone mineral content, weakened bone resistance, and loss of femoral mass. At 6 wk, all suspended animals had similar osteopenic parameters, but they were not statistically different from those of the rats in the 3-wk groups. Therefore, suspension longer than 3 wk did not increase the bone deterioration in the femur.

Temporal modifications in bone following spinal cord injury in rats

Introduction: The aim of this study was to investigate the temporal modifications in bone mass, bone biomechanical properties and bone morphology in spinal cord injured rats 2, 4 and 6 weeks after a transection. Material and methods: Control animals were randomly distributed into four groups (n = 10 each group): control group (CG) - control animals sacrificed immediately after surgery; spinal cord-injured 2 weeks (2W) - spinal cord-injured animals sacrificed 2 weeks after surgery; spinal cord-injured 4 weeks (4W) - spinal cord-injured animals sacrificed 4 weeks after surgery; spinal cord-injured 6 weeks (6W) - spinal cord-injured animals sacrificed 6 weeks after surgery. Results: Biomechanical properties of the right tibia were determined by a threepoint bending test and injured animals showed a statistically significant decrease in maximal load compared to control animals. The right femur was used for densitometric analysis and bone mineral content of the animals sacrificed 4 and 6 weeks after surgery was significantly higher compared to the control animals and animals sacrificed 2 weeks after surgery. Histopathological and morphological analysis of tibiae revealed intense resorptive areas in the group 2 weeks after injury only. Conclusions: The results of this study show that this rat model is a valuable tool to investigate bone remodeling processes specifically associated with SCI. Taken together, our results suggest that spinal cord injury induced bone loss within 2 weeks after injury in rats.

Rehabilitation with forage grasses of an area degraded by urban solid waste deposits

Dry matter yield and chemical composition of forage grasses harvested from an area degraded by urban solid waste deposits were evaluated. A split-plot scheme in a randomized block design with four replicates was used, with five grasses in the plots and three harvests in the subplots. The mineral content and extraction and heavy metal concentration were evaluated in the second cut, using a randomized block design with five grasses and four replicates. The grasses were Brachiaria decumbens cv. Basilisk, Brachiaria ruziziensis, Brachiaria brizantha cv. Marandu and cv. Xaraés, and Panicum maximum cv. Tanzânia, cut at 42 days of regrowth. The dry matter yield per cut reached 1,480 kg ha-1; the minimum crude protein content was 9.5% and the average neutral detergent fiber content was 62.3%. The dry matter yield of grasses was satisfactory, and may be an alternative for rehabilitating areas degraded by solid waste deposits. The concentration of heavy metals in the plants was below toxicity levels; the chemical composition was appropriate, except for phosphorus. The rehabilitated areas may therefore be used for grazing.