RESUMO
BACKGROUND: Mucopolysaccharidoses (MPS) are a group of inherited metabolic diseases caused by impaired function or absence of lysosomal enzymes involved in degradation of glycosaminoglycans. Clinically, MPS are skeletal dysplasias, characterized by cartilage abnormalities and disturbances in the process of endochondral ossification. Histologic abnormalities of growth cartilage have been reported at advanced stages of the disease, but information regarding growth plate pathology progression either in humans or in animal models, as well as its pathophysiology, is limited. METHODS: Histological analyses of distal femur growth plates of wild type (WT) and mucopolysaccharidosis type VI (MPS VI) rats at different stages of development were performed, including quantitative data. Experimental findings were then analyzed in a theoretical scenario. RESULTS: Histological evaluation showed a progressive loss of histological architecture within the growth plate. Furthermore, in silico simulation suggest the abnormal cell distribution in the tissue may lead to alterations in biochemical gradients, which may be one of the factors contributing to the growth plate abnormalities observed, highlighting aspects that must be the focus of future experimental works. CONCLUSION: The results presented shed some light on the progression of growth plate alterations observed in MPS VI and evidence the potentiality of combined theoretical and experimental approaches to better understand pathological scenarios, which is a necessary step to improve the search for novel therapeutic approaches.
RESUMO
OBJECTIVE: Hyaline cartilage degenerative pathologies induce morphologic and biomechanical changes resulting in cartilage tissue damage. In pursuit of therapeutic options, electrical and mechanical stimulation have been proposed for improving tissue engineering approaches for cartilage repair. The purpose of this review was to highlight the effect of electrical stimulation and mechanical stimuli in chondrocyte behavior. DESIGN: Different information sources and the MEDLINE database were systematically revised to summarize the different contributions for the past 40 years. RESULTS: It has been shown that electric stimulation may increase cell proliferation and stimulate the synthesis of molecules associated with the extracellular matrix of the articular cartilage, such as collagen type II, aggrecan and glycosaminoglycans, while mechanical loads trigger anabolic and catabolic responses in chondrocytes. CONCLUSION: The biophysical stimuli can increase cell proliferation and stimulate molecules associated with hyaline cartilage extracellular matrix maintenance.
Assuntos
Cartilagem Articular/citologia , Condrócitos/fisiologia , Cartilagem Hialina/citologia , Osteoartrite/fisiopatologia , Estimulação Física/métodos , Agrecanas/fisiologia , Animais , Cartilagem Articular/fisiopatologia , Proliferação de Células/fisiologia , Colágeno Tipo II/fisiologia , Estimulação Elétrica/métodos , Terapia por Estimulação Elétrica/métodos , Matriz Extracelular/fisiologia , Glicosaminoglicanos/fisiologia , Humanos , Cartilagem Hialina/fisiopatologia , Engenharia Tecidual/métodosRESUMO
Slipped capital femoral epiphysis (SCFE) is an orthopedic pathology in which damage of the growth plate leads to the anterosuperior displacement of the femoral body in respect to the femoral head. Despite being a widely studied disease, its etiology is still unknown. This study was carried out to determine the influence of the physeal-diaphysis angle, body mass, the presence of the perichondrial ring, the type of physical activity, and physeal thickness on SCFE. For this purpose, a finite element analysis of the hip joint and the femur-physis interface was carried out. With the computational model, the Von Mises stresses along the growth plate were calculated and subsequently analyzed statistically to find their correlation with the studied factors. It was found that body mass, the type of physical activity, and the presence of the perichondrial ring had more statistical relevance for the physeal stresses than the physeal-diaphysis angle and the physeal thickness. Thus, our work suggests that changes in growth plate inclination and thickness do not influence the etiology of SCFE.
Assuntos
Epífises , Cabeça do Fêmur , Lâmina de Crescimento , Escorregamento das Epífises Proximais do Fêmur/etiologia , Análise de Variância , Fenômenos Biomecânicos , Peso Corporal , Criança , Epífises/anatomia & histologia , Epífises/fisiologia , Cabeça do Fêmur/anatomia & histologia , Cabeça do Fêmur/fisiologia , Análise de Elementos Finitos , Lâmina de Crescimento/anatomia & histologia , Lâmina de Crescimento/fisiologia , Articulação do Quadril/anatomia & histologia , Articulação do Quadril/diagnóstico por imagem , Articulação do Quadril/fisiologia , Humanos , Masculino , Atividade Motora , Fatores de Risco , Tomografia Computadorizada por Raios XRESUMO
Objetivo: desarrollar un análisis por elementos finitos de la influencia del ángulo fisis-diáfisis, la masa corporal y la actividad física con el fin de observar su predominancia en la incidencia de deslizamiento epifisiario. Métodos: se elaboraron los modelos correspondientes a las combinaciones entre cada uno de los parámetros definidos (ángulo, masa y actividad física), generando 20 casos diferentes, y se evaluaron los esfuerzos presentes a lo largo de la placa de crecimiento. Resultados: se muestra un comportamiento uniforme y similar entre cada combinación, así como un aumento en las tensiones en la medida en que se incrementaba el valor de la carga y del ángulo. Conclusiones: el esfuerzo tiende a aumentar cuando se incrementa tanto el ángulo como la masa física, lo cual sugiere que estos dos factores podrían influir de manera decisiva en el origen del deslizamiento epifisiario(AU)
Objective: to develop a finite element analysis of the influence of physis-diaphysis angle, body mass and physical activity to observe its predominance in the incidence of epiphyseal gliding. Methods: models corresponding to the combinations among each of the defined parameters (angle, mass and physical activity) were developed, generating 20 different cases and efforts present through the growth plate were evaluated. Results: a similar and uniform behaviour between each of the combinations is shown as well as an increase in tension at the same time as the value of the load and angle increases. Conclusions: effort tends to increase when there is an increment in both the angle and the physical mass what suggests that these two factors could have a decisive influence on the origin of the epiphyseal gliding(AU)
But: en s'appuyant sur la technique des éléments finis, une analyse de l'influence de l'angle physe-diaphyse, la masse corporelle et l'activité physique a été réalisée afin d'observer cette influence sur l'incidence du déplacement épiphysaire. Méthodes: des modèles correspondant aux combinaisons entre chaque paramètre défini (angle, masse et activité physique), en résultant 20 cas différents, ont été élaborés, et les efforts présents tout au long de la plaque de croissance ont été évalués. Résultats: un comportement uniforme et similaire entre chaque combinaison est montré, ainsi qu'une élevée des tensions au fur et à mesure que la valeur de la charge et l'angle augmentaient. Conclusions: l'effort tend à augmenter lorsque l'angle et la masse physique s'accroissent, ce qui indique que ces deux facteurs pourraient influer certainement sur l'origine du déplacement épiphysaire(AU)