Effects of anteriorly-loaded treadmill walking on dynamic gait stability in young adults

BackgroundAnteriorly-loaded walking is common in many occupations and may increase fall risk. Dynamic gait stability, defined by the Feasible Stability Region (FSR) theory, quantifies the kinematic relationship between the body’s center of mass (COM) and base of support (BOS). FSR-based dynamic gait stability has been used to evaluate the fall risk.Research questionHow does front load carriage affect dynamic gait stability, step length, and trunk angle among young adults during treadmill walking?MethodsIn this between-subject design study, 30 healthy young adults were evenly randomized into three load groups (0%, 10%, or 20% of body weight). Participants carried their assigned load while walking on a treadmill at a speed of 1.2 m/s. Body kinematics were collected during treadmill walking. Dynamic gait stability (the primary variable) was calculated for two gait events: touchdown and liftoff. Step length and trunk angle were measured as secondary variables. One-way analysis of variance was conducted to detect any group-related differences for all variables. Post-hoc analysis with Bonferroni correction was performed when main group differences were found.ResultsNo significant differences but medium to large effect sizes were found between groups for dynamic gait stability at touchdown (p = 0.194, η² = 0.114) and liftoff (p = 0.122, η² = 0.139). Trunk angle significantly increased (indicating backward lean) with the front load at touchdown (p < 0.001, η² = 0.648) and liftoff (p < 0.001, η² = 0.543). No significant between-group difference was found related to the step length (p = 0.344, η² = 0.076).SignificanceCarrying a front load during walking significantly alters the trunk orientation and may change the COM-BOS kinematic relationship and, therefore, fall risk. The findings could inform the design of future studies focusing on the impact of anterior load carriage on fall risk during different locomotion.     

Analysis of jump load during a volleyball season in terms of player role

ObjectivesThe aim of this study was to analyze the jump load performed by top-level volleyball players during an entire training season in terms of the player role, training period, type of daily training, and quality of opposition in the subsequent match.DesignLongitudinal panel observational study.MethodsThe total number of jumps performed by players was recorded through 174 training days distributed in 32 weeks during the 2016/2017 season (pre-season, 5 weeks; in-season, 27 weeks). The players role were classified as middle-blocker, outside-hitter, opposite and setter (the libero was omitted). A generalized mixed linear model was performed (with Bonferroni post hoc test at p < 0.05) to assess the effect of training variables and the repeated-measures data of players’ jumps along various training days. Additionally, the effect sizes at 95% confidence intervals were calculated to compare the jump load between players’ role and training variables.ResultsThe results showed a significant and moderate higher amount of jumps performed by middle-blockers regardless the type of macro- or micro-cycle, the micro-cycle phase, the type of training and the quality of match opposition. Contrarily, the setter performs the least jump load in all variables analyzed. Only the players’ role, macro-cycle and micro-cycle phase had significant effects on the player's jump load variation along the season.ConclusionsThis information could be useful to guide the monitoring and preparation process for coaches and physical trainers. These values allow differentiating between players’ role and could be used as references values in order to avoid injuries whereas performance increase along the season.     

轴向载荷分担比指导外固定器动力化的临床应用

目的:探讨轴向载荷分担比用于胫腓骨骨干骨折术后指导外固定器轴向动力化促进骨折愈合的有效性。方法:选取外固定器治疗的胫腓骨骨干骨折患者100例,随机分为观察组50例,对照组50例。观察组在轴向载荷分担比指导下行外固定器轴向动力化治疗,对照组未行动力化,随访比较两组的治疗效果。结果:所有患者均获随访,随访时间4～12个月,平均6.5个月,治疗期间所有患者均未出现外固定针断裂、松动及再骨折等并发症,观察组1例骨搬移患者轴向载荷分担比5%,X线片显示骨折断端有连续性骨痂通过,拆除外固定器连接杆后发生移位,恢复原数值行轴向加压再动力化,现已愈合。观察组除外1例骨搬移患者,其余49例患者外固定器固定时间为[(24.4±4.7)周],骨折临床愈合时间为[(22.4±4.7)周],与对照组50例患者外固定器固定时间[(29.3±5.6)周],骨折临床愈合时间[(27.3±5.6)周]比较,显著减少(P0.05)。结论:外固定器轴向载荷分担比指导胫腓骨骨干骨折外固定术后轴向动力化可以加速骨折愈合,但不适合骨搬移截骨端已硬化患者。     

抗PD-(L)1、抗CTLA-4免疫治疗标志物研究进展

免疫检查点抑制剂已经改变了包括肺癌、黑色素瘤等许多肿瘤的治疗情况，并且在一些难治性肿瘤中表现出持久的应答率，然而在部分接受治疗的患者中表现出无反应及严重免疫相关副作用。为了优化免疫疗法的使用，可能需要多种临床应答的预测性标志物。本研究回顾了几种潜在有效生物标志物的可用数据，通过免疫组化检测肿瘤细胞和免疫细胞中PD-L1的表达，提示其是一种临床疗效的良好预测标志物;且PD-L1表达阴性者经免疫治疗后仍可获益。PD-L1表达在肿瘤内是动态和异质性的:在原发性灶和转移灶之间或在穿刺标本和大体标本之间表达不一致。肿瘤突变负荷与新抗原的高比率可获得持久获益。外周血标志物也可作为潜在标志物，增加的绝对淋巴细胞计数（ALC）与疾病控制和生存显著相关。在这篇综述中，我们旨在讨论抗PD-（L）1与抗CTLA-4 免疫治疗相关标志物研究现状，为临床运用提供指导，以便能够准确筛选出从这些治疗中获益更多的患者。     

SYBR Green Ⅰ实时荧光定量RT-PCR测定猴免疫缺陷病毒RNA拷贝数方法的建立

.学者论坛·在动物实验中解决临床难题···························，·······································································……顾玉东(3)基因〕:程     

A comparison of conventional and fast spin-echo sequences for the measurement of lesion load in multiple sclerosis using a semi-automated contour technique

Changes on serial assessments of brain MRI lesion load are used for monitoring therapeutic efficacy in patients with multiple sclerosis (MS). We assessed the accuracy and reliability of conventional spin-echo (CSE) and fast spin-echo (FSE) sequences for measurement of lesion volume using a semiautomated contour technique. Cranial CSE and FSE examinations of 18 patients with secondary progressive MS were studied. The mean lesion load was slightly higher with the CSE sequence (p = 0.002). Intraobserver variability was significantly higher for FSE than for CSE, according to both the coefficient of variation between two measurements (mean 2.48 % and 1.35 % respectively, p < 0.05) and back-transformed 95 % limits of agreement (1.005–1.060 for FSE; 0.988–1.019 for CSE). Although FSE sequences are quicker and the total lesion volume measurements are similar to those obtained with CSE, the poorer reproducibility raises doubts about the use of FSE to replace CSE in clinical trials. Received: 26 March 1996 Accepted: 4 April 1996     

住院脑血管病人主要照顾者负荷

目的 探讨影响住院脑血管病人主要照顾负荷的相关因素。方法采用问卷方式对1997年～2000年60名符合研究对象进行调查。结果脑血管病人的主要照顾中60％为配偶，且年龄较大，知识水平偏低，使其身体、心理、社交方面的负荷增大。同时发现雇用身体及心理压力明显低于家属，但两社交负荷无差异。结论临床护理人员应给予住院病人主要照顾一定的协助及指导，减轻家属的压力，使主要照顾能有效地承担起照顾责任。