Isokinetic external rotation strength of shoulder : correlation with age and muscle size.

The purpose of this study was to determine the correlation between quantitative (cross sectional areas) evaluation of the posterior cuff muscles and mechanical strength in asymptomatic shoulders with special reference to aging. The cross-sectional area of the combined infraspinatus and teres minor muscles were measured, in the sagittal oblique magnetic resonance images, in eighty-one patients with a mean age of 44.06 years (range 19 - 74). These areas were correlated with the measured isokinetic strength in external rotation at angular velocities of 60 deg/s and 180 deg/s using Cybex 770 NORM. The results show that there was a gradual decrease in size of the muscles as the age of the individual increases. A strong correlation was found between aging and combined cross-sectional area and peak torque as well. The correlation between combined cross-sectional area and peak torques at both angular velocities were less strong. Further, the correlation between the peak torque/cross-sectional area ratio with aging was also less significant, which may imply that the decrease in the muscle strength was greater than the change in muscle area. Our results suggest that there may be other qualitative and biochemical factors that may determine the true strength of the muscles in the aged population.

A study on the reproducibility of a stable, lyophilized reagent for the Chagas' disease hemagglutination test: proposals for quality control analysis.

Para se efetuar rigoroso controle de partidas sucessivas de reagentes liofilizados, usados na reacao de hemaglutinacao passiva, sao aqui propostos processos estatisticos simples. Para se avaliar qualitativamente os niveis de sensibilidade e de especificidade do reagente foi empregada a analise sequencial truncada.Os criterios adotados na avaliacao foram definidos com base em estudos comparativos efetuados com o teste de hemaglutinacao passiva em relacao as reacoes de imunofluorescencia, fixacao do complemento e floculacao de 3.264 soros de individuos, infectados ou nao pelo T. cruzi. Onze partidas de reagente de hemaglutinacao, produzidas durante um periodo de 3 anos, foram submetidas a esta analise de qualidade. O processo aqui proposto mostrou-se satisfatorio para selecionar reagentes que forneceram resultados reprodutiveis. Esta observacao foi confirmada quando se procedeu a analise de variancia dos resultados obtidos com 7 partidas de reagentes, aprovados pela analise de qualidade, contra 20 soros de pacientes chagasicos titulados em duplicata