Navegando por Palavras-chave "intervertebral disc"

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    Effects of Training and Overtraining on Intervertebral Disc Proteoglycans
    (Lippincott Williams & Wilkins, 2018) Ueta, Renato H. S. [UNIFESP]; Tarini, Victor A. F. [UNIFESP]; Franciozi, Carlos E. S. [UNIFESP]; Tamaoki, Marcel J. S. [UNIFESP]; Medeiros, Valquiria P.; Nader, Helena B. [UNIFESP]; Faloppa, Flavio [UNIFESP]
    Study Design. Animal experimental study. Objective. Evaluate the effect of physical activity and overtraining condition on glycosaminoglycan concentration on the intervertebral disc (IVD) using a rat running model. Summary of Background Data. Some guidelines recommend the implementation of a physical exercise program as treatment for low back pain however, cyclic loading impact on the health of the IVD and whether there is a dose-response relationship is still incompletely understood. Methods. Thirty-two rats ages 8 weeks were divided into four groups with eight animals each. The first 8 weeks were the adaptive phase, the overtraining phase was from the ninth to the eleventh week, which consisted of increasing the number of daily training sessions from 1 to 4 and the recovery phase was represented by the 12th and 13th weeks without training. Control group 1 (CG1) did not undergo any kind of training. Control group 2 (CG2) completed just the adaptive phase. Overtraining group 1 (OT1) completed the overtraining phase. Overtraining group 2 (OT2) completed the recovery phase. Running performance tests were used to assess the "overtraining'' status of the animals. IVD glycosaminoglycans were extracted and quantified, and identified by electrophoresis. Results. Glycosaminoglycans showed a distribution between chondroitin sulfate and dermatan sulfate. Glycosaminoglycans quantification showed decreasing concentration at the following order: OT1 > CG2 > OT2 > CG1. Increased expression of dermatan sulfate was verified at the groups submitted to any training. Conclusion. Overtraining condition, as assessed by muscle and cardiovascular endurance did not lessen glycosaminoglycan concentration in the IVD. In fact, physical exercise increased glycosaminoglycan concentration in the IVD in proportion to the training load, even at overtraining condition, returning to normal levels after the recovery phase and glycosaminoglycan production is a reversible acute positive response for mechanical stimulation of the IVD.
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    Expression of Heparanase Isoforms in Intervertebral Discs Classified According to Pfirrmann Grading System for Disc Degeneration
    (Lippincott Williams & Wilkins, 2013-06-01) Reis Rodrigues, Luciano Miller [UNIFESP]; Oliveira, Lilian Zerbinatti de [UNIFESP]; Silva Pinhal, Maria Aparecida da [UNIFESP]; Fac Med Abc; Universidade Federal de São Paulo (UNIFESP); Fac Med ABC
    Study Design. This is a quantitative study of heparanase isoforms expression in degenerative and nondegenerative intervertebral discs (IVDs).Objective. To quantify the expression of both heparanase isoforms (HPSE1 and HPSE2) in IVD tissues as classified by different degeneration grades using the Pfirrmann grading system, and to correlate the expression with the loss of extracellular matrix molecules observed in patients with the disease. Summary of Background Data. the loss of proteoglycans as observed in IVD degeneration may occur due to the enhanced expression of matrix degrading enzymes, such as heparanase. However, the heparanase function in IVD degeneration remains unclear.Methods. This study comprised 53 surgical samples of degenerative discs obtained from patients with lumbar disc degeneration and 12 control samples collected from healthy individuals without any degenerative lumbar disc alterations who had accidental spine fractures.All patients underwent magnetic resonance imaging based on the Pfirrmann grading system for disc degeneration. Only the specimens that were classified according to magnetic resonance imaging evaluations as Pfirrmann grades I, II, III, and IV were analyzed. the tissue sections of the disc samples were subject to immunohistochemical staining with antibodies against the heparanase isoforms and to quantitative real time PCR to amplify heparanase isoforms cDNA. Protein and mRNA expressions were quantified. Analysis of variance and Student t test were used to compare the means of the study populations.Results. the data demonstrated a gradual increase in both the heparanase isoform protein expression and disc degeneration progression. Besides, mRNA expression of both heparanase isoforms were significantly higher in degenerative than nondegenerative IVDs.Conclusion. the overexpression of HPSE1 and HPSE2 in the intervertebral degenerated discs suggests a role for these factors in mediating extracellular matrix remodeling in degenerative discs during disease development.