Synthesis of fibronectin in normal and osteoarthritic articular cartilage

The content and the biosynthesis of fibronectin was examined in disease-free articular cartilage and in articular cartilage from osteoarthritic canine joints. Fibronectin content was increased in extracts of cartilage from osteoarthritic joints. Incubation of cartilage in vitro with [³H]phenylalanine and subsequent isolation of [³H]fibronectin from a gelatin affinity column and characterization by SDS-polyacrylamide gel electrophoresis and by immunoprecipitation indicated that disease-free and osteoarthritic cartilage explants synthesized fibronectin. About 50% of the [³H]fibronectin was recovered in the incubation medium. The osteoarthritic cartilage synthesized and accumulated up to 5-fold more [³H]fibronectin than disease-free cartilage.     

Aging in the musculoskeletal system of rhesus monkeys: I. Passive joint excursion

In order to describe ontogenetic change in the musculoskeletal system of rhesus monkeys, 126 Macaca mulatta from Cayo Santiago, ranging in age from 7 months to 21 years, were examined under anesthesia. Passive joint excursions were measured at the wrist, elbow, shoulder, hip, and knee. Mean ranges of excursion at these joints differed significantly between age groups and by sex. The potential for most movements appeared to decrease approximately 25 degrees over the first two decades of the macaque life span, and males generally showed less potential for movement than females in all age groups. These results are similar to those obtained for humans and are consistent with patterns of positional behavior, trauma, and osteoarthritis observed in this rhesus monkey population. Thus, to fully describe the locomotor strategy of rhesus monkeys, age- and sex-related variation in locomotor anatomy and functional capacity must be considered.     

Changes in osteoarthritis associated with the development of a maritime economy among southern California Indians

The severity of osteoarthritis was studied in human skeletal remains from archaeological sites in the Santa Barbara Channel area of southern California. These remains were analyzed to better understand changes in activity patterns associated with the economic shift from hunting and gathering to intensive fishing and craft specialization that occurred in this area. The joints of 967 burials from seven archaeological sites occupied between 3500 B.C. and the time of European contact were scored for osteoarthritis. These data show that the rate at which people developed osteoarthritis increased through time. This suggests that the adaptive shift toward more intensive exploitation of the marine environment resulted in an increase in the time people spent in strenuous physical activity. The increase in osteoarthritis affected males to a greater extent than females. One interpretation of this is that the work load of men increased with the economic importance of fishing.     

Osteoarthritis, calcium pyrophosphate deposition disease, and osseous infection in Old World primates.

Uncertainties as to the nature and implications of osteoarthritis and calcium pyrophosphate deposition disease (CPPD) in primates were subject to critical review through examination of 153 prosimians and 1,250 Old World non-prosimian primates. Osteoarthritis, calcium pyrophosphate deposition disease, and infectious arthritis/osteomyelitis were relatively rare phenomena, affecting only 1.7% and 2.5%, respectively, of free-ranging prosimians and other Old World non-prosimian primates. Frequency of infection in Indri and Presbytis appears to reflect a unique susceptibility or exposure. Papio may have a unique predisposition to CPPD. The dichotomy (frequency and joint distribution) between free-ranging and artificially restrained animals suggests caution in interpretation of osteoarthritis or CPPD in non-free-ranging animals.     

Power and work produced in different leg muscle groups when rising from a chair

The aim of this study was to determine the power output and work done by different muscle groups at the hip and knee joints during a rising movement, to be able to tell the degree of activation of the muscle groups and the relationship between concentric and eccentric work. Nine healthy male subjects rose from a chair with the seat at knee level. The moments of force about the hip and knee joints were calculated semidynamically. The power output (P) and work in the different muscle groups surrounding the joints was calculated as moment of force times joint angular velocity. Work was calculated as: work = f Pdt. The mean peak concentric power output was for the hip extensors 49.9 W, hip flexors 7.9 W and knee extensor 89.5 W. This power output corresponded to a net concentric work of 20.7 J, 1.0 J and 55.6 J, respectively. There was no concentric power output from the knee flexor muscles. Energy absorption through eccentric muscle action was produced by the hip extensors and hip flexors with a mean peak power output of 4.8 W and 7.4 W, respectively. It was concluded that during rising, the hip and knee muscles mainly worked concentrically and that the greatest power output and work were produced during concentric contraction of the knee and hip extensor muscles. There was however also a demand for eccentric work by the hip extensors as well as both concentric and eccentric work by the hip flexors. The knee flexor muscles were unloaded.     

放散式体外冲击波穴位治疗联合中药熏洗治疗老年膝骨关节炎的疗效分析

摘要 目的：评价放散式体外冲击波（rESW）穴位治疗联合中药熏洗在老年膝骨关节炎（KOA）中的应用效果。方法：选入2021年2月~2022年8月我院收治的老年KOA患者76例,根据治疗方法不同分为对照组和观察组,各38例,两组均予以中药熏洗,观察组加用rESW穴位治疗。评价两组的治疗效果、膝关节功能、疼痛程度等指标,并进行统计比较。结果：与治疗前相比,两组治疗2周、治疗4周时的VAS评分明显下降（P＜0.05）,而观察组下降幅度更大,与对照组差异显著（P＜0.05）;两组治疗前Lysholm评分无明显差异（P＞0.05）,而观察组治疗2周、治疗4周时的Lysholm评分显著高于对照组（P＜0.05）;观察组治疗显效率和有效率均显著高于对照组（P＜0.05）;观察组治疗2周、4周时的血清IL-1β、TNF-α和MMP-13水平较对照组低（P＜0.05）。结论：rESW穴位联合中药熏洗治疗老年KOA患者疗效显著,可缓解疼痛症状,改善膝关节功能,控制炎症反应,且操作简单,值得推荐。     

长非编码RNA SNAI3-AS1调控人软骨细胞C28/I2增殖能力及退变的机制研究

摘要 目的：为了探究长非编码RNA SNAI3-AS1（LncRNA SNAI3-AS1,即SNAI3-AS1）在骨性关节炎（osteoarthritis,OA）进展中的作用与机制。方法：通过全转录组测序筛选出在OA中差异表达的lncRNA SNAI3-AS1,并通过实时荧光定量PCR（qRT-PCR）检测SNAI3-AS1在软骨细胞退变模型中的表达情况。在软骨细胞C28/I2中分别转染SNAI3-AS1特异性siRNA或真核过表达质粒,分别敲低或过表达SNAI3-AS1,通过MTT、平板克隆形成和EdU掺入实验检测细胞增殖活力,Western Blot检测炎症和细胞外基质蛋白的表达情况。通过生物信息学网站预测SNAI3-AS1相互作用的miRNA和下游靶基因,并通过双荧光素酶报告基因和RIP实验进行验证。结果：相较于正常软骨细胞, SNAI3-AS1的表达水平在OA中显著下调。敲低正常软骨细胞中SNAI3-AS1的表达后,软骨细胞的增殖能力减弱并促进了软骨细胞的退变,而在OA模型的软骨细胞中过表达SNAI3-AS1后,软骨细胞的增殖活力加强并抑制了软骨细胞的退变。在机制上,SNAI3-AS1可充当竞争性内源性RNA（ceRNA）,经海绵吸附miR-2278间接上调PRELP,发挥促进软骨细胞增殖和抑制其退变的作用。结论：LncRNA SNAI3-AS1通过LncRNA SNAI3-AS1/ miR-2278/PRELP轴参与骨性关节炎的发生发展过程。     

超声引导下隐神经联合IPACK阻滞对老年全膝关节置换术患者应激反应、炎性细胞因子及膝关节活动度的影响

摘要 目的：探讨超声引导下隐神经联合腘动脉与膝关节后囊间隙（IPACK）阻滞对老年全膝关节置换术（TKA）患者应激反应、炎性细胞因子及膝关节活动度的影响。方法：根据随机数字表法,将无锡市中医医院2021年3月~2022年9月期间收治的102例初次行TKA的老年患者分为观察组（超声引导下隐神经联合IPACK阻滞镇痛处理）和对照组（超声引导下隐神经镇痛处理）,每组各51例。对比两组疼痛情况、炎性细胞因子、应激反应指标、不良反应发生率、膝关节活动度。结果：观察组术后6 h、术后12 h、术后24 h视觉模拟评分法（VAS）评分低于对照组（P<0.05）。观察组术后48 h肿瘤坏死因子-α（TNF-α）、白细胞介素（IL）-6、IL-1β、β-淀粉样蛋白（Aβ）低于对照组（P<0.05）。观察组术后48 h血管紧张素Ⅱ（AngⅡ）、皮质醇（COR）低于对照组（P<0.05）。观察组术后24 h、术后48 h膝关节活动度大于对照组（P<0.05）。两组不良反应发生率对比无差异（P>0.05）。结论：超声引导下隐神经联合IPACK阻滞用于TKA患者,具有较好的镇痛效果,可减轻应激反应,抑制炎性细胞因子过度分泌,改善膝关节活动度,麻醉效果较好。     

The effects of normalization method on antagonistic activity patterns during eccentric and concentric isokinetic knee extension and flexion

The purpose of this study was to compare different normalization methods of electromyographic (EMG) activity of antagonists during isokinetic eccentric and concentric knee movements. Twelve women performed three maximum knee extensions and flexions isometrically and at isokinetic concentric and eccentric angular velocities of 30 °·s⁻¹, 90 °·s⁻¹, 120 °·s⁻¹ and 150 °·s⁻¹. The EMG activity of the vastus lateralis, rectus femoris, vastus medialis and hamstrings was recorded. The antagonist integrated IEMG values were normalized relative to the EMG of the same muscle during an isometric maximal action (static method). The values were also expressed as a percentage of the EMG activity of the same muscle, at the same angle, angular velocity and muscle action (dynamic method) when the muscle was acting as an agonist. Three-way analysis of variance (ANOVA) designs indicated significantly greater IEMG normalized with the dynamic method compared to the EMG derived using the static method (P < 0.05). These differences were more evident at concentric angular velocities and at the first and last 20 ° of the movement. The present findings demonstrate that the method of normalization significantly influences the conclusions on antagonistic activity during isokinetic maximum voluntary efforts. The dynamic method of normalization is more appropriate because it considers the effects of muscle action, muscle length and angular velocity on antagonist IEMG.     

Motor unit recruitment strategy of knee antagonist muscles in a step-wise, increasing isometric contraction

The purpose of this study was to determine if differences exist between the control strategies of two antagonist thigh muscles during knee flexion and extension muscular coactivation. Surface myoelectric signal (MES) of the quadriceps (rectus femoris) and the hamstrings (semitendinosus) were obtained from both muscles while performing step-wise increasing contractions during flexion and extension with the knee at 1.57 rad of flexion (90 degrees). The median frequency of the power density spectrum, which is related to the average muscle fiber action potential conduction velocity and therefore to motor unit recruitment, was calculated from each MES. The results suggest that, in all the subjects tested, when the muscle acts as antagonist most motor units are recruited up to 50% of the maximal voluntary force, whereas when the muscle acts as antagonist motor units are recruited up to 40% of the maximal voluntary force. The force range past 40–50% of the maximal force is also characterized by differences between the agonist/antagonist.