Sensitivity of intervertebral joint forces to center of rotation location and trends along its migration path

Translational vertebral motion during functional tasks manifests itself in dynamic loci for center of rotation (COR). A shift of COR affects moment arms of muscles and ligaments; consequently, muscle and joint forces are altered. Based on posture- and level-specific trends of COR migration revealed by in vivo dynamic radiography during functional activities, it was postulated that the instantaneous COR location for a particular joint is optimized in order to minimize the joint reaction forces. A musculoskeletal multi-body model was employed to investigate the hypotheses that (1) a posterior COR in upright standing and (2) an anterior COR in forward flexed posture leads to optimized lumbar joint loads. Moreover, it was hypothesized that (3) lower lumbar levels benefit from a more superiorly located COR.The COR in the model was varied from its initial position in posterior-anterior and inferior-superior direction up to ±6 mm in steps of 2 mm. Movement from upright standing to 45° forward bending and backwards was simulated for all configurations. Joint reaction forces were computed at levels L2L3 to L5S1. Results clearly confirmed hypotheses (1) and (2) and provided evidence for the validity of hypothesis (3), hence offering a biomechanical rationale behind the migration paths of CORs observed during functional flexion/extension movement. Average sensitivity of joint force magnitudes to an anterior shift of COR was +6 N/mm in upright and −21 N/mm in 30° forward flexed posture, while sensitivity to a superior shift in upright standing was +7 N/mm and −8 N/mm in 30° flexion. The relation between COR loci and joint loading in upright and flexed postures could be mainly attributed to altered muscle moment arms and consequences on muscle exertion. These findings are considered relevant for the interpretation of COR migration data, the development of numerical models, and could have an implication on clinical diagnosis and treatment or the development of spinal implants.     

Plasma N-glycome composition associates with chronic low back pain

Background

Low back pain (LBP) is the symptom of a group of syndromes with heterogeneous underlying mechanisms and molecular pathologies, making treatment selection and patient prognosis very challenging. Moreover, symptoms and prognosis of LBP are influenced by age, gender, occupation, habits, and psychological factors. LBP may be characterized by an underlying inflammatory process. Previous studies indicated a connection between inflammatory response and total plasma N-glycosylation. We wanted to identify potential changes in total plasma N-glycosylation pattern connected with chronic low back pain (CLBP), which could give an insight into the pathogenic mechanisms of the disease.

放射线引导下经椎间盘入路内脏大小神经毁损术治疗上腹部癌痛的临床分析

目的:观察放射线引导下经椎间盘入路毁损内脏神经治疗上腹部癌痛的疗效及安全性。方法:选择上腹部癌痛患者26例,在放射线引导下经T11~12椎间盘入路穿刺,注射无水乙醇5.0 mL毁损内脏大、小神经,观察穿刺成功率,并记录术前、术后1天、1周、2周、1月、2月的疼痛强度(NRS评分)、生活质量评分(QOL),阿片类药物的用量以及手术不良反应的发生情况。结果:所有患者均穿刺到位,无严重并发症出现。和术前相比,术后各时点的NRS评分、每日吗啡消耗量下降,QOL评分增加(P0.05)。其中,6例患者发生暂时性腹泻,一周内恢复;5例患者出现不同程度的腹背部烧灼感,未经特殊处理24 h后症状消失。结论:在放射线引导下经椎间盘入路毁损内脏神经治疗上腹部癌痛的操作简单,疗效好,可显著提高患者的生活质量,且安全性高。     

不同浓度的右美托咪定对老年腰椎术患者的镇静效果、氧化应激和血流动力学的影响

目的:探讨不同浓度的右美托咪定对老年腰椎术患者的镇静效果、氧化应激和血流动力学的影响。方法:选取2013年3月-2018年4月期间我院收治的老年腰椎术患者90例为研究对象。根据随机数字表法将患者分为对照组(n=30)、低浓度组(n=30)以及高浓度组(n=30)。低浓度组麻醉诱导前输注0.5μg/kg右美托咪定,高浓度组输注1μg/kg右美托咪定,对照组不输注右美托咪定。比较给药前(T0)、给药后10 min(T1)、给药后30 min(T2)、给药后60 min(T3)的听觉诱发电位指数(AAI)、改良/镇静视觉评分(OAA/S)。比较T0、T3、手术后24h(T4)的三组患者丙二醛(MDA)、超氧化物歧化酶(SOD)水平。比较T0-T3时间点三组患者的心率(HR)、平均动脉压(MAP)情况。观察三组患者术后不良反应发生情况。结果:与T0时间点比较,三组T1-T3时间点AAI、OAA/S均显著降低(P0.05);与对照组相比,低浓度组与高浓度组T1-T3时间点AAI、OAA/S均较低,且高浓度组低于低浓度组(P0.05)。与T0时间点比较,三组T3、T4时间点MDA均显著升高,T3时间点SOD显著降低(P0.05);与对照组相比,低浓度组与高浓度组T3、T4时间点MDA均降低,且高浓度组低于低浓度组(P0.05);高浓度组T3、T4时间点SOD高于低浓度组和对照组(P0.05)。与T0时间点比较,三组T2、T3时间点HR、MAP均降低(P0.05);与对照组相比,低浓度组、高浓度组T2、T3时间点HR均降低,且高浓度组低于低浓度组(P0.05);与对照组相比,低浓度组、高浓度组T2、T3时间点MAP均降低,但高浓度组高于低浓度组(P0.05)。三组患者术后不良反应总发生率比较差异无统计学意义(P0.05)。结论:1μg/kg右美托咪定对老年腰椎术患者的镇静效果较好,可有效维持血流动力学稳定,减轻氧化应激反应。     

Spermidine promotes nucleus pulposus autophagy as a protective mechanism against apoptosis and ameliorates disc degeneration

Spermidine has therapeutic effects in many diseases including as heart diastolic function, myopathic defects and neurodegenerative disorders via autophagy activation. Autophagy has been found to mitigate cell apoptosis in intervertebral disc degeneration (IDD). Accordingly, we theorize that spermidine may have beneficial effects on IDD via autophagy stimulation. In this study, spermidine's effect on IDD was evaluated in tert‐butyl hydroperoxide (TBHP)‐treated nucleus pulposus cells of SD rats in vitro as well as in a puncture‐induced rat IDD model. We found that autophagy was actuated by spermidine in nucleus pulposus cells. In addition, spermidine treatment weakened the apoptotic effects of TBHP in nucleus pulposus cells. Spermidine increased the expression of anabolic proteins including Collagen‐II and aggrecan and decreased the expression of catabolic proteins including MMP13 and Adamts‐5. Additionally, autophagy blockade using 3‐MA reversed the beneficial impact of spermidine against nucleus pulposus cell apoptosis. Autophagy was thus important for spermidine's therapeutic effect on IDD. Spermidine‐treated rats had an accentuated T2‐weighted signal and a diminished histological degenerative grade than vehicle‐treated rats, showing that spermidine inhibited intervertebral disc degeneration in vivo. Thus, spermidine protects nucleus pulposus cells against apoptosis through autophagy activation and improves disc, which may be beneficial for the treatment of IDD.     

winged eye Induces Transdetermination of Drosophila Imaginal Disc by Acting in Concert with a Histone Methyltransferase,Su(var)3-9

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Expression of serglycin in human disc is increased in degenerated discs and up-regulated in vitro by exposure to IL-1ß or TNF-α

We investigated whether the multifunctional intercellular proteoglycan, serglycin, is expressed in human intervertebral disc cells and assessed its localization. We also investigated expression levels of serglycin in human annulus fibrosus (annulus) cells exposed to IL-1ß and TNF-α, which are two proinflammatory cytokines that are expressed during disc degeneration. Immunolocalization of serglycin was common in many cells of the human annulus, but less common in the nucleus pulposus (nucleus). Both intracellular and cell membrane localization were observed. Annulus cells from Thompson grades III, IV and V degenerated discs exhibited a 4.69 fold up-regulation in serglycin expression vs. cells from healthier grades I and II discs. In monolayer annulus cell culture, cells from more degenerated discs exhibited a 9.4 fold up-regulation of serglycin expression compared to cells from healthier discs. Exposure of cultured cells to IL-1ß or TNF-α caused significant up-regulation of serglycin expression. We found that serglycin expression increased with increasing disc degeneration both in vivo and in vitro, and also increased with exposure in vitro to IL-1ß and TNF-α.     

一种基于视网膜主血管方向的视盘定位及提取方法

为分割出眼底图像中的视盘,构建基于眼底图像的计算机辅助诊断系统,提出了一种基于视网膜主血管方向的视盘定位及提取方法。首先,利用Otsu阈值分割眼底图像R通道获取视盘候选区域;然后利用彩色眼底图像的HSV空间的H通道提取视网膜主血管并确定主血管方向;在此基础上,通过在方向图内寻找出对加权匹配滤波器响应值最高的点确定视盘中心位置;最后,利用该位置信息从视盘候选区域中"挑选"出真正的视盘。利用该方法对100幅不同颜色、不同亮度的眼底图像进行视盘分割,得到准确率98%,平均每幅图像处理时间1.3 s。结果表明:该方法稳定可靠,能快速、有效分割出眼底图像中的视盘。