ABSTRACT
ABSTRACT Introduction: Articular cartilage is an essential structure for joint weight-bearing and movement. If it is always under a specific mechanical stimulation, it will cause osteoarthritis (OA) and even involve the articular cartilage. Sports can affect articular cartilage thickness, cartilage surface morphology, and cartilage cell metabolism. Objective: This thesis studies the cell metabolism of knee cartilage tissue with exercises of different intensities. Methods: We divided 40 rats into four groups according to exercise intensity. The control group exercised freely, while the experimental group exercised with different intensities. After eight weeks of exercise, we extracted the knee joint cartilage to observe its cell metabolism. Results: We found that the cartilage surface of the rats was complete after exercise, and the thickness of the cartilage layer was significantly greater than that of rats without exercise. Conclusion: Exercises of different intensities have different effects on the metabolism of cartilage cells in the knee joint of rats. Level of evidence II; Therapeutic studies - investigation of treatment results.
RESUMO Introdução: A cartilagem articular é uma estrutura essencial para o suporte de peso e movimento de juntas. Quando a articulação está constantemente sob estímulos mecânicos específicos, a osteoartrite (OA) pode resultar, envolvendo inclusive a cartilagem articular. O esporte pode afetar a espessura da cartilagem articular, a morfologia da superfície da cartilagem e o metabolismo celular da cartilagem. Objetivo: Este estudo analisa o metabolismo celular do tecido cartilaginoso do joelho com exercícios de diferentes intensidades. Métodos: Dividimos 40 ratos em quatro grupos de acordo com a intensidade do exercício. O grupo de controle praticou exercícios livremente, enquanto o grupo experimental exercitou com diferentes intensidades. Após oito semanas de exercícios, extraímos a cartilagem da junta do joelho para observar seu metabolismo celular. Resultados: Descobrimos que a superfície cartilaginosa dos ratos se desenvolveu após o exercício, e que a espessura da camada de cartilagem aumentou muito mais do que aquela dos ratos sem exercício. Conclusão: Exercícios de diferentes intensidades tem diferentes efeitos no metabolismo de células cartilaginosas nas juntas de joelhos de ratos. Nível de evidência II; Estudos terapêuticos - investigação de resultados de tratamento.
Resumen Introducción: El cartílago articular es una estructura esencial para el soporte de peso y movimientos de articulaciones. Cuando la articulación está constantemente bajo estímulos mecánicos específicos, puede causar la osteoartritis (OA) e incluso involucrar el cartílago articular. El deporte puede afectar el espesor del cartílago articular, la morfología de la superficie del cartílago y el metabolismo celular del cartílago. Objetivo: Este estudio analiza el metabolismo celular del tejido cartilaginoso de la rodilla con ejercicios de diferentes intensidades. Métodos: Dividimos 40 ratones en cuatro grupos de acuerdo a la intensidad del ejercicio. El grupo de control practicó ejercicios libremente, mientras el grupo experimental ejercitó con diferentes intensidades. Tras ocho semanas de ejercicios, extraemos el cartílago de la articulación de la rodilla para observar su metabolismo celular. Resultados: Descubrimos que la superficie cartilaginosa de los ratones se desarrolló tras el ejercicio, y que el espesor de la camada de cartílago aumentó mucho más que aquella de los ratones sin ejercicio. Conclusiones: Ejercicios de distintas intensidades tienen diferentes efectos en el metabolismo de células cartilaginosas en las articulaciones de rodillas de ratones. Nivel de evidencia II; Estudios terapéuticos - investigación de resultados de tratamiento.
ABSTRACT
Corneal opacity is one of the most commonly used parameters for estimating postmortem interval(PMI).This paper proposes a new method to study the relationship between changes of corneal opacity and PMI by processing and analyzing cornea images.Corneal regions were extracted from images of rabbits' eyes and described by color-based and texture-based features,which could represent the changes of cornea at different PMI.A KNN classifier was used to reveal the association of image features and PMI.The result of the classification showed that the new method was reliable and effective.
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To study the relationship between changes of microbial ATP in four kinds of murine tissues and the postmortem interval (PMI),healthy SD rats were sacrificed and their muscles,livers,spleens and kidneys were sampled at different postmortem intervals. The concentration of microbial ATP was detected using bioluminescent assay and the data was statistically analyzed. The concentration of microbial ATP in muscle increased with PMI time. The peak appeared at the 7th day after death,and at the 10th day,microbial ATP in muscle tissue increased again. In internal organs,the peaks of microbial ATP were observed at the 8th day after death and the level decreased during 8-10 d. The differences in microbial ATP concentration in liver,spleen and kidney were not statisticallysignificant. During day 0 to day 9 after death,the correlation was best between PMI and microbial ATP in muscle. With PMI as the independent variable,the cubic polynomial regression equation was Y=0.02X3-0.166X2-0.666X+13.412 (R2=0.989,P＜0.01). In internal organs,the best correlation was found between PMI and microbial ATP during day 0 to day 10. With PMI as the independent variable,the cubic polynomial regression equation was Y=0.016X3-0.127X2-0.809X+13.324 (R2=0.986,P＜0.01). There existed high correlations between PMI and microbial ATP concentration in rat tissues.Since only a small amount of tissue was needed for the detection and the sample was not affected by self-decomposition,the method may extend the time range of PMI estimation.
ABSTRACT
To study the relationship between the late postmortem interval (PMI) and trimethylamine-nitrogen (TMA-N) in postmortem tissues of cadaver, TMA-N in muscles, livers and kidneys of rats was measured at different postmortem intervals (PMD by using a modified spectrophotometric method. The results indicated that the detection sensitivity of TMA-N was 1 mg/L, and there was a good linear correlation between the value of absorbance (A value) and TMA-N at the concentration of 1-10 mg/L (R2 =0.9991). Although TMA variation in muscles was different from that in inner organs during the time since death, TMA-N changes in cadaver tissues was positively correlated with PMI. During 2 to 7 d since death, the best correlation between PMI and TMA-N concentration was found in muscles.With PMI as an independent variable, the cubic polynomial regression equation was y= --0.457x3+6.519x2-24.574x+27.207 (R2=0.969). During 3 to 8 days since death, PMI was best correlated with TMA-N concentration in inner organs. With PMI as the independent variable, the cubic polynomial regression equation was y=0.509x3-9.153x2+55.727x-95.819 (R2=0.953). It was concluded that TMA-N in tissues could be used as a new estimator for late PMI. The method used in this study offered advantages such as accuracy, sensitivity, little samples required and wide PMI estimation.