Influence of low-level laser irradiation on osteocalcin protein and gene expression in bone tissue1

Abstract Purpose: To evaluate osteocalcin gene and protein expression in vitro and in an in vivo model of ostectomy. Methods: Twenty Wistar rats were assigned into two groups A (n=10, laser) and B (n=10, control). Ostectomy was performed in the femur diaphysis; the twenty fragments removed, composed in vitro groups named as in vivo (A and B) and cultivated in CO2 atmosphere for thirteen days. Low-level laser irradiation was performed in groups A (in vivo and in vitro) by an GaAlAs device (λ=808 nm, dose of 2J/cm2, power of 200mW, power density of 0.2W/cm2, total energy of 1.25J, spot diameter of 0.02mm) for 5 seconds, at one point, daily. It was performed immunocytochemistry assays in vivo and in vitro groups. In vitro groups were also submitted to RNA extraction, cDNA synthesis and gene expression by quantitative PCR. Statistical analysis was realized with p<0.05. Results: Immunocytochemistry scores showed no significant differences between control and laser groups either in vivo and in vitro. Gene expression also showed no statistical differences. Conclusion: Low-level laser irradiation did not alter osteocalcin protein and gene expression in vivo and in vitro in the studied period but it may have been expressed them in an earlier period.

Análise eletromiográfica de músculos do quadril em diferentes tipos de apoio monopodálico / Electromyography assessment of hip muscles in different types of monopodal weight bearing

Estudou-se a ação muscular na biomecânica da extremidade proximal do têmur com o intuito de acrescentar um parâmetro objetivo nas decisÒes médicas quanto à sustentação do peso e à reabilitação após fraturas nessa região. Foram avaliadas, por meio da eletromiografia de superfície, as atividades elétricas de cinco músculos da região do quadril de 40 voluntários sadios, nove femininos e 31 masculinos, com idade entre 21 e 55 anos, em quatro situaçÒes diferentes, sendo três com carga e um sem carga. As mediçÒes foram realizadas estaticamente, em ortostase. Observou-se que a situação de apoio total proporcionou atividade elétrica muscular global significativamente menor e melhor distribuída entre os grupos musculares, em comparação com as outras situaçÒes propostas

Método de avaliaçäo da hipotrofia muscular por desuso empregando eletromiografia de superfície / Evaluation method of the muscular hypotrophy caused by lack of use employing surface electromyography

This article presents an evaluation method of muscular atrophy caused by lack of use, employing surface electromyography.Describes a new instrument to measure muscular activity in a practical an reliabe way.For the performance of 96 tests, four muscles were select: wrist flexors, biceps rectus femoris, and the gastrocnemius.These were implemented in two groups: (1) comtrol group and (2) experimental group.The results obtained in all muscular groups measurered showed that the reason reference/affected in group (2) presented a variation of 27 percentage to 142 percentage comparared to reason dominant / contralateral in group (1), confirming the unbalance among the members in the experimental group.In the control group the variabily was much smaller than the difference obtained in the limbs tested, showing this to be an auxiliary instrument in prescription an evolution of rehabilitation treatments