ABSTRACT
Objective:To compare the short-term effects of hip muscles strengthening and quadriceps strengthening on knee osteoarthritis (KOA), and discuss the advantages of hip muscles strengthening. Methods:From October, 2015 to May, 2016, 42 old females with KOA were divided into two groups equally. They received hip strengthening (HS group) and quadriceps strengthening (QS group) for two weeks, respectively. The pain, stiffness and physical function scores of Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) were measured. Isokinetic strength peak torque (PT) was assessed for knee extensors and flexors, and 6-minute Walk Test was also evaluated. They were followed up two months later. Results:Before exercise, there was no significant difference in all the indexes between two groups (P > 0.05). Two weeks after exercise, the knee flexor PT (t = -4.038, P = 0.001) and 6-minute walk distance (t = -2.474, P = 0.022) increased in QS group; the pain, stiffness and physical function scores of WOMAC (t > 2.487, P < 0.05), the knee extensor and flexor PT (|t| > 6.370, P < 0.001), and 6-minute walk distance (t = -2.241, P = 0.037) improved in HS group; the scores of WOMAC were lower (t > 2.087, P < 0.05) and the knee extensor PT was higher (t = -5.028, P < 0.001) in HS group than in QS group. At two-months' follow-up, the drop-out rate was significantly lower in HS group than in QS group (χ2 = 13.480, P < 0.001). Conclusion:Hip muscles strengthening is a good choice for KOA in the early stage of treatment, which could avoid the pain in quadriceps training, increase quadriceps strength and improve physical function.
ABSTRACT
Knee osteoarthritis is a common chronic degenerative disease in the elderly. Its occurrence and development are closely related to biomechanical factors. The force of knee joint is affected by different factors, such as joint morphology, lower limb alignment, muscle contractions, external load, soft tissue traction and so on. Due to the limitation of in vivo measurement, biomechanical parameters based on motion analysis techniques have been widely used in clinical research. At present, biomechanical parameters which are widely studied and applied in clinical research include knee adduction moment, knee adduction impulse, knee flexion moment, and knee varus thrust. It is important to observe the changes of knee joint biomechanical parameters during the occurrence and development of knee osteoarthritis for researching etiology, diagnosis, intervention and treatment.
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<p><b>BACKGROUND</b>Nucleolin (NCL) is the most abundant RNA-binding protein in the cell nucleolus and plays an important role in chromatin stability, ribosome assembly, ribosomal RNA maturation, ribosomal DNA transcription, nucleocytoplasmic transport, and regulation of RNA stability and translation efficiency. In addition to its anti-apoptotic properties, the underlying mechanisms associated with NCL-related roles in different cellular processes remain unclear. In this study, the effect of NCL on microRNA (miRNA) expression was evaluated by generating transgenic mice with myocardial overexpression of NCL and by analyzing microarrays of mature and precursor miRNAs from mice.</p><p><b>METHODS</b>Using microinjection of alpha-MyHc clone 26-NCL plasmids, we generated transgenic mice with myocardial overexpression of NCL firstly, and then mature and precursor miRNAs expression profiles were analyzed in NCL transgenic mice (n = 3) and wild-type (WT) mice (n = 3) by miRNA microarrays. Statistical Package for the Social Sciences version 16.0 software (SPSS, Inc., Chicago, IL, USA) was used to perform Student's t-test, and statistical significance was determined at P < 0.05.</p><p><b>RESULTS</b>Several miRNAs were found to be differentially expressed, of which 11 were upregulated and 4 were downregulated in transgenic mice with myocardial overexpression of NCL compared to those in WT mice. Several differentially expressed miRNAs were subsequently confirmed and quantified by real-time quantitative reverse transcription-polymerase chain reaction. Bioinformatics analysis was used for the prediction of miRNA targets. Furthermore, in vitro experiments showed that NCL regulated miR-21 expression following hydrogen peroxide preconditioning.</p><p><b>CONCLUSIONS</b>Myocardial-protection mechanisms exerted by NCL might be mediated by the miRNAs identified in this study.</p>
ABSTRACT
AIM:To observe the expression of microRNA-126-5p during myocardial injury and its role in myo-cardial cell injury induced by adriamycin(also called doxorubicin, DOX).METHODS: The BALB/c mouse model of DOX-induced acute and chronic myocardial injury was established via intraperitoneal injection of DOX.HE staining was applied to observe the morphological changes of myocardial tissues.Lactate dehydrogenase(LDH)in serum was detected and PowerLab system was used to detect the influence of DOX on the changes of ±dp/dtmax.The expression of microRNA-126-5p in injured myocardial tissues and the H 9c2 cells exposed to DOX was detected by real-time PCR.Gain-and loss-of-function experiments were conducted to detect the role of microRNA-126-5p in H9c2 cells treated with DOX on LDH release and caspase-3 activation.RESULTS:In acute and chronic DOX myocardial damage models in mice,HE staining showed disarranged myocardial fibers, dissolved myofibril and inflammatory cell infiltration.Higher serum LDH level and lower ±dp/dtmaxin DOX-treated mice than those in normal mice were found.Compared with the normal mice, the expression level of microRNA-126-5p was significant increased in the myocardium with DOX-induced injury.Similarly,the expression level of microRNA-126-5p was significant increased in the H9c2 cells treated with DOX.In addition, over-expression of microRNA-126-5p decreased cell viability and promoted apoptosis,while microRNA-126-5p ablation promoted the viability and inhibited the apoptosis of H9c2 cells.CONCLUSION:The microRNA-126-5p expression is up-regulated in myocar-dial injury induced by DOX,and microRNA-126-5p inhibits cell viability and promotes apoptosis induced by DOX.