Extensive burn injury causes bone collagen network alteration and growth delay related to RANK-L immunoexpression change.

PURPOSE: Extensive burn injury mainly affects children, and hypermetabolic state can lead to growth delay. This study aimed to investigate bone histopathological and morphometric aspects, collagen fibers network and the immunoexpression of biological markers related to bone development in a young experimental model for extensive burn. MATERIALS AND METHODS: A total of 28 male Wistar rats were distributed into Control (C) and subjected to scald burn injury (SBI) groups. Sham or injured animals were euthanized 4 or 14 days post-lesion and proximal epiphyses of the femur were submitted to histological, morphometric (thickness epiphyseal plate), and RUNX-2 and receptor activator of nuclear factor kappa- ß ligand (RANK-L) immunoexpression methods. RESULTS: Histopathological femoral findings showed delayed appearance of the secondary ossification center in SBI, 14 days post-injury. Collagen fibers 4 days after injury were observed in articular cartilage as a pantographic network with a transversally oriented lozenge-shaped mesh, but this network was thinner in SBI. Fourteen days after the injury, the pantographic network of collagen presented square-shaped mesh in C, but this aspect was changed to a wider mesh in SBI. Morphometric analysis of epiphyseal plate revealed that the SBI group had less thickness than the respective controls (p<0.05). RUNX-2 showed no difference between groups, but RANK-L score was higher in all SBI groups. CONCLUSIONS: Extensive burn injury causes delayed bone growth and morphological changes. Alterations in collagen network and enhancement in immunoreactivity of RANK-L result in increased osteoclastogenesis.

Effects of concurrent training on muscle strength in older adults with metabolic syndrome: A randomized controlled clinical trial.

INTRODUCTION: Metabolic syndrome is highly prevalent among older adults. Concurrent training comprises muscle strengthening and aerobic exercise. OBJECTIVE: Determine the effects of a concurrent training program on muscle strength, walking function, metabolic profile, cardiovascular risk, use of medications and quality of life among older adults with metabolic syndrome. METHODS: A randomised, controlled, blind, clinical trial was conducted in the city of Santos, state of São Paulo, Brazil, involving 41 male and female older adults. The participants were randomly allocated to a control group (n = 18) and intervention group (n = 23) and were submitted to the following evaluations: strength - 1 maximum repetition (1MR) for 12 muscle groups; the Six-Minute Walk Test (6MWT); blood concentrations of cholesterol and glucose; the use of medications; and the administration of the SF-36 questionnaire. The intervention was conducted twice a week over a total of 24 sessions of concurrent training: 50 min of strength exercises (40-70% 1MR) and 40 min of walking exercises (70-85% maximum heart rate). RESULTS: Increases in muscle strength were found in the upper and lower limbs in the inter-group analysis and a greater distance travelled on the 6MWT was found in the intervention group (p = 0.001). The intervention group demonstrated a reduction in the consumption of biguanides (p = 0.002). No changes were found regarding metabolic profile, cardiovascular risk or self-perceived quality of life. CONCLUSION: The findings of this clinical trial can be used for the prescription of concurrent training for older adults with metabolic syndrome for gains in muscle strength and walking distance as well as a reduction in the use of biguanides.