Perda de glicosaminoglicanas da cartilagem após ruptura do ligamento cruzado anterior: influência do tempo de ruptura e da lesão condral

OBJECTIVE: To quantify the concentration of sulfated glycosaminoglycans (GAGs) concentration in the synovial fluid (SF) of knees with chronic anterior cruciate ligament (ACL) rupture and to identify possible associations between GAG concentration in SF and the time elapsed since rupture and degree of chondral injury. METHOD: Fourteen adult male subjects with total unilateral ACL rupture, which had occurred between 5 and 144 months earlier, were assessed. All subjects underwent joint aspiration; it was possible to collect SF from ten individuals. The samples were quantified to determine the GAG concentration using dimethylmethylene blue (DMMB) staining. The degree of chondral injury was macroscopically evaluated using the modified Mankin histological scale. Spearman correlation test (< 0.05) was used to evaluate the association between GAG concentration and chondral injury, and Pearson correlation test (< 0.05) was used to evaluate the association between GAG concentration and the time elapsed since rupture. RESULTS: The GAG concentration in SF showed a mean variation of 73.84 &plusmn; 40.75 µg/ml, with a mean time of 40.4 &plusmn; 40.3 months since the rupture. There was no correlation between GAG concentration and time since the rupture (r= -0.09, p= 0.81). The chondral injury grades found were 0, 1, 4 and 5. There was no correlation between chondral injury grade and GAG concentration in SF (r= -0.41, p= 0.24). CONCLUSION: After at least 5 months, the GAG concentration in SF from knees with ACL rupture is independent of the time elapsed since rupture and/or the severity of chondral injury.OBJETIVO: Quantificar a concentração de glicosaminoglicanas sulfatadas (GAGs) no líquido sinovial (LS) de joelhos com ruptura crônica do ligamento cruzado anterior (LCA) e identificar uma possível correlação entre a concentração de GAGs no LS e o tempo pós-ruptura e grau de lesão condral. MÉTODOS: Foram avaliados 14 indivíduos adultos do sexo masculino com ruptura total unilateral do LCA, ocorrida entre cinco a 144 meses. Todos os sujeitos foram puncionados, sendo possível a coleta de LS em dez indivíduos. As amostras foram quantificadas para determinar a concentração de GAGs usando a coloração azul de dimetilmetileno, método descrito por Farndale21. O grau de lesão condral foi macroscopicamente avaliado pela escala histológica de Mankin modificada por Messner14. As correlações entre concentração de GAGs e lesão condral foram feitas pelo teste de correlação de Sperman (p< 0,05) e a concentração de GAGs e tempo pós-ruptura pelo teste de correlação de Pearson (p< 0,05). RESULTADOS: Concentração de GAGs no LS apresentou variação média de 73,84 &plusmn; 40,75µg/mL, sendo o tempo médio pós-ruptura de 40,4 + 40,3 meses. Não houve correlação entre concentração de GAGs e o tempo pós-ruptura (r= -0,09, p= 0,81). Os graus de lesão condral encontrados foram de 0, 1, 4 e 5. Não houve correlação entre grau de lesão condral e a concentração de GAGs no LS (r= -0,41, p= 0,24). CONCLUSÕES: Após no mínimo cinco meses, a concentração de GAGs no LS de joelhos com ruptura do LCA independe do tempo pós-ruptura e/ou do grau de lesão condral.646

Correlation between the proportion of fast fibers in the biceps brachii muscle and the relative torque during elbow flexion in subjects with clinical hypothesis of myopathy

A produção de força muscular pode estar comprometida em pacientes portadores de miopatias. Estas representam um grupo heterogêneo de doenças com distintas características clínicas e morfológicas. Supõe-se que achados de desempenho funcional estejam relacionados com o tipo predominante de fibra expresso no músculo em análise. OBJETIVO: Correlacionar a proporção das fibras tipo 2 (FT2) do músculo bíceps braquial de sujeitos com hipótese clínica de miopatia (HCM) com picos de torque isométrico e isocinético de flexão do cotovelo. MATERIAIS E MÉTODOS: Participaram deste estudo sete sujeitos com HCM: quatro do sexo feminino com média de idade de 37 anos (dp= 9), peso de 73kg (dp= 26) e altura de 155cm (dp= 6); e três do sexo masculino com média de idade de 39 anos (dp= 1), peso de 88kg (dp= 5) e altura de 172cm (dp= 4). Pela técnica histoquímica de mATPase, foi realizada análise de proporção das fibras musculares. Após um mês da realização das biópsias, os sujeitos realizaram teste de força isométrica e isocinética concêntrica de flexão e extensão do cotovelo em dinamômetro isocinético. Avaliou-se o pico de torque (PT) isométrico a 90°s-¹ e 180°s-¹ e calculou-se o torque relativo 90 (TR90) e 180 (TR180). Para análise estatística, utilizou-se correlação de Spearman (r). RESULTADOS: A proporção de FT2 se correlacionou positivamente com TR180 (r= 0,89, p= 0,01). Uma moderada correlação foi encontrada entre FT2 e TR90 (r= 0,75, p= 0,05). CONCLUSÕES: Os resultados sugerem que o comportamento contrátil das FT2 não foi modificado nestes sujeitos. O dinamômetro isocinético mostrou ser um instrumento que pode avaliar, de forma não invasiva, a predominância do tipo de fibra muscular.Muscular strength production may be impaired in myopathic patients. Myopathies represent a heterogeneous group of diseases with distinct clinical and morphological characteristics. It has been hypothesized that functional performance findings may be related to the predominant fiber type expressed in the muscle analyzed. OBJECTIVE: To correlate the proportion of type 2 fibers in the biceps brachii muscles of subjects with a clinical hypothesis of myopathy with their peak isometric and isokinetic torque during elbow flexion. METHOD: Seven subjects with a clinical hypothesis of myopathy participated in this study: four females of mean age 37 years (sd = 9), weight 73kg (sd= 26) and height 155cm (sd= 6); and three males of mean age 39 years (sd= 1), weight 88kg (sd= 5) and height 172cm (sd= 4). The muscle fiber proportion was analyzed using the mATPase technique. One month after taking biopsies, the subjects performed concentric isometric and isokinetic strength tests for elbow flexion and extension using an isokinetic dynamometer. The isometric and isokinetic peak torques at 90°s-¹ and 180°s-¹ were evaluated and the relative 90° (RT90) and 180° (RT180) torques were calculated. Spearman’s correlation (r) was used for statistical analyses. RESULTS: The proportion of type 2 fibers correlated positively with RT180 (r= 0.89, p= 0.01), and there was a moderate correlation with RT90 (r= 0.75, p= 0.05). CONCLUSIONS: The results suggest that the contractile behavior of type 2 fibers was not modified in these subjects. The isokinetic dynamometer was shown to be an instrument capable of noninvasively evaluating muscle fiber type predominance.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)USP - Fundação de Apoio ao Ensino, Pesquisa e Assistência (Faepa) do Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto (FMRP

Correlation between inflammatory cells and sulfated glycosaminoglycan concentration in synovial fluid of subjects with secondary knee osteoarthritis

Objective. To analyze the presence of inflammatory cells in the synovial fluid (SF) of subjects with osteoarthritis (OA) and correlate them with the concentration of sulfated glycosaminoglycan (GAG). Methods. The degree of chondral injury from 20 subjects (17 men, 3 women, mean age 48.06 +/- 14.35 yrs) was evaluated macroscopically by means of arthroscopy and graded according to the International Cartilage Repair Society classification. All subjects presented anterior cruciate ligament (ACL) injuries, associated or not to menisci injuries. SF was aspirated and centrifuged. Sulfated GAG concentration was quantified by dimethylene blue staining. Manual morphometry was used to determine the inflammatory cell count (mononuclear and poly morphonuclear) by optical microscopy, after staining with May-Grunwald-Giemsa. The time of injury and degree of chondral injury were considered, and correlations among the variables were obtained by Spearman nonparametric correlation test. Results. There was no significant correlation between the amount of mononuclear cells and the GAG concentration. There was a significant positive correlation between the polymorphonuclear cells and the GAG concentration, and a significant negative correlation between the degree of chondral injury and the GAG concentration. Conclusion. Polymorphonuclear cells may be either a cause or an effect in the metabolic and biochemical processes occurring in chondral injuries. The correlations support the hypothesis that inflammatory cells have a significant role in the progression and chronicity of chondral injury in secondary OA.3561096110