Communalities for rates of diaphyseal elongation of short bones of the hand of children with Down syndrome

Communality indices for rates of elongation of diaphyses of short bones of the hand were computed from serial data for children with Down syndrome, 7 to 14 years of age. Communalities were larger for adjacent than for nonadjacent bones and also larger for bones grouped in rows rather than rays of the hand. This pattern is similar to that reported for normal children. Communality indices for rates of diaphyseal elongation for girls with Down syndrome were lower than those of boys with Down syndrome and normal children.     

The effects of wrist motion and hand orientation on muscle forces: A physiologic wrist simulator study

Although the orientations of the hand and forearm vary for different wrist rehabilitation protocols, their effect on muscle forces has not been quantified. Physiologic simulators enable a biomechanical evaluation of the joint by recreating functional motions in cadaveric specimens. Control strategies used to actuate joints in physiologic simulators usually employ position or force feedback alone to achieve optimum load distribution across the muscles. After successful tests on a phantom limb, unique combinations of position and force feedback – hybrid control and cascade control – were used to simulate multiple cyclic wrist motions of flexion-extension, radioulnar deviation, dart thrower’s motion, and circumduction using six muscles in ten cadaveric specimens. Low kinematic errors and coefficients of variation of muscle forces were observed for planar and complex wrist motions using both novel control strategies. The effect of gravity was most pronounced when the hand was in the horizontal orientation, resulting in higher extensor forces (p < 0.017) and higher out-of-plane kinematic errors (p < 0.007), as compared to the vertically upward or downward orientations. Muscle forces were also affected by the direction of rotation during circumduction. The peak force of flexor carpi radialis was higher in clockwise circumduction (p = 0.017), while that of flexor carpi ulnaris was higher in anticlockwise circumduction (p = 0.013). Thus, the physiologic wrist simulator accurately replicated cyclic planar and complex motions in cadaveric specimens. Moreover, the dependence of muscle forces on the hand orientation and the direction of circumduction could be vital in the specification of such parameters during wrist rehabilitation.     

Tactile-spatial and cross-modal attention effects in the second somatosensory and 7b cortical areas of rhesus monkeys

Abstract This study analyzed neuronal responses in the second somatosensory (SII) and 7b cortical areas during a selective attention task. Cues directed attention to one of three simultaneous stimuli: vibrotactile stimuli applied to mirror sites on both hands or to a similarly timed auditory tone. Two stimulus patterns appeared with equal probability for the cued stimulus: a constant amplitude sinewave or the latter with a superimposed brief amplitude pulse midway in the trial. Uncued stimuli always contained amplitude pulses. Monkeys demonstrated whether an amplitude pulse at the cued location was present or absent by making appropriately rewarded up and down foot pedal movements. Cue location and stimulus pattern varied trial-wise and pseudo-randomly. Average firing rates to vibrotactile stimuli in 82 of 181 SII cells and 13 of 22 area 7b cells differed significantly during at least one epoch for trials cued to the contralateral hand when compared to trials cued to the ipsilateral hand or auditory stimulus. Predominant were relatively suppressed firing rates during times prior to the epoch containing the amplitude pulses or enhanced activity during and after these pulses. Generally, different cells showed suppression early vs enhancement later in a trial. Analyses of the ratio between firing rates before and during the amplitude pulses suggested improved evoked signals to the amplitude pulses. The discussion considers attention as a mechanism for reducing distractions, early in the trial through suppressing these signals, or for selectively increasing response magnitudes in the cued channel, especially around times when amplitude pulses were present or absent.     

手足温针灸联合步行阶梯训练对老年糖尿病周围神经病变患者步态异常、血流动力学和感觉及运动神经传导的影响

摘要 目的：观察手足温针灸联合步行阶梯训练对老年糖尿病周围神经病变（DPN）患者步态异常、血流动力学和感觉及运动神经传导的影响。方法：按照随机数字表法将上海市第六人民医院2020年3月~2022年1月期间收治的119例老年DPN患者分为对照组（n=59,步行阶梯训练）和研究组（n=60,手足温针灸联合步行阶梯训练）。对比两组疗效、步态异常、血流动力学、临床症状改善情况和感觉及运动神经传导变化情况。结果：研究组91.67%的临床总有效率高于对照组72.88%（P<0.05）。研究组干预后的密歇根糖尿病神经病变评分（MDNS）和多伦多临床评分系统（TCSS）评分低于对照组（P<0.05）。研究组干预后的腓总神经及胫神经的感觉神经传导速度（SNCV）、运动神经传导速度（MNCV）高于对照组（P<0.05）。研究组干预后的全血黏度、血浆比黏度、纤维蛋白原低于对照组（P<0.05）。研究组足底压力中心轨迹（COP）曲线异常、全足平衡性曲线异常、全足压力变化曲线异常例数少于对照组（P<0.05）。结论：手足温针灸联合步行阶梯训练可促进老年DPN患者步态异常、血流动力学和感觉及运动神经传导恢复,疗效较好。     

Biomechanical model predicts directional tuning of spindles in finger muscles facilitates precision pinch and power grasp

Humans have a sense of static limb position derived primarily from the output of secondary muscle spindle endings. The features of finger pose these proprioceptors signal best were predicted by singular value decomposition of a kinematic model of the human long finger and the six muscles that actuate it. The analysis indicated that muscle spindles signal the location of the fingertip with less error than they signal angles of individual finger joints. The fingertip displacements for which proprioceptors have greatest sensitivity were also predicted. These fingertip displacements seem to correspond to the fine positioning of an object pinched between the fingertip and distal phalanx of the thumb. The analysis also predicted the directions in which subjects can displace the fingertip most rapidly. The directions seem to correspond to rapid closure of precision pinch or power grasp.     

CV-A16感染沙鼠细胞因子和趋化因子的动态变化分析

柯萨奇病毒A组16型(Coxsackievirus A16,CV-A16)是导致手足口病的病原体之一,CV-A16感染后宿主的外周血细胞的细胞因子表达变化的报道较少,也未见有关血清中细胞因子含量在感染前后的表达变化。为了分析CV-A16感染的不同严重程度的沙鼠细胞因子和趋化因子的动态变化。通过腹腔注射CV-A16构建CV-A16感染发病模型,应用流式细胞术、实时荧光定量RT-PCR和ELISA法检测病毒载量、血清炎症因子和趋化因子水平动态变化。CV-A16感染后重症沙鼠的临床症状,包括体重下降程度、临床症状分值以及死亡率均显著高于轻症沙鼠,并且重症沙鼠外周血白细胞比例和升高趋势总体上高于轻症感染沙鼠;重症感染沙鼠全血中细胞因子IL-2、IL-12、IFN-γ和TNF-α的mRNA转录水平上调,IL-4、IL-10、IL-8和IP-10的mRNA转录水平下调;并且CV-A16感染后重症沙鼠血清中的TNF-α和IFN-γ含量显著上升,IL-8和IP-10的含量显著下降。结论为重症沙鼠全血和血清中存在多种趋化和炎症因子上调,可能与Th1炎症失调有关。     

2017年湖北省襄阳市手足口病患者柯萨奇病毒A2型分离株的突变和重组分析

目的通过对2016-2017年襄阳市手足口病(hand, foot and mouth disease, HFMD)样品的分离与鉴定,了解主要病原之一的柯萨奇病毒A2型(Coxsackievirus, CV-A2)的分子生物学特征。方法收集2016年9月-2017年12月襄阳市HFMD患儿肛拭子样品,用人类横纹肌肉瘤细胞(RD细胞)培养,分离病毒。RT-PCR扩增CV-A2 VP1基因,Megalign软件分析VP1基因同源性,MEGA6软件构建系统发育树。比较3种疾病(急性迟缓性麻痹、手足口病和急性呼吸道感染)CV-A2分离株VP1氨基酸序列,分析可能的致病位点。扩增CV-A2代表株基因组全长序列,用SimPlot软件分析可能的重组事件。结果 2016-2017年CV-A2襄阳株之间VP1核苷酸及氨基酸同源性分别为96.4%~99.8%,98.0%~100.0%;襄阳株与CV-A2原型株(Fleetwood株)之间的核苷酸及氨基酸同源性分别为80.8%~81.9%,95.3%~95.9%。与襄阳株同源性最高的为2017年江西株(GenBank:MG926784),核苷酸及氨基酸同源性分别为96.7%~98.8%,98.0%~98.6%。襄阳市HFMD主要病原之一的CV-A2 VP1基因系统发育树显示,襄阳株与国内主要流行株同属于基因型D。3种疾病分离株的VP1氨基酸比对发现,急性迟缓性麻痹分离株和HFMD分离株在第21、60、82和215位存在差异;而HFMD分离株与呼吸道感染分离株之间只在167位存在差异,由谷氨酸变成天冬氨酸。CV-A2重组分析提示,襄阳株在P1区域与Fleetwood株同属一分支,在P2区域与CV-A5 Swartz株亲缘性最高,但在P3区域与CV-A16 G-10株有较高的相似度。结论虽然CV-A2襄阳株与其他流行株在VP1区序列上亲缘性较高,但其VP1氨基酸突变或与其他肠道病毒的型间重组可能导致其致病特性与流行病学特点发生变化。     

人工育幼非洲狮、孟加拉虎、豹幼仔的生长曲线拟合比较

<正>生长曲线(Growth curve)是揭示动物生长发育规律的有效手段之一,反映动物发育指标(包括体重、体尺、体表面积等度量值)与时间之间的关系(盛志廉和吴常信,1995)。生长曲线方程大致可以分为三类：第一类是表示报酬递减规律的方程,如指数函数;第二类是描述光滑S型曲线,     

Performance on a manual tracking task differentiates individuals at risk of developing carpal tunnel syndrome from those not at risk

Introduction

The purpose of this study was to determine whether sensorimotor abnormalities are detectable in asymptomatic individuals deemed at risk of developing carpal tunnel syndrome (CTS)

Methods

Seventeen individuals deemed at risk of developing CTS and 16 asymptomatic individuals deemed to be at minimal risk of developing CTS participated. Nerve conduction velocity, two-point discrimination ability, pressure acuity, Purdue Pegboard Test performance and tracking error and tracking variance on a manual tracking task performed at two different speeds were measured in all participants and compared between the groups.

Results

None of the measures of nerve conduction, sensory perception, or Purdue Pegboard task performance were different between the groups. The error in the manual tracking tasks was significantly different between the groups, where the at-risk group demonstrated more error than the control group.

Conclusion

These results suggest that manual tracking tasks may be useful in the identification of those individuals at risk of developing CTS before they develop any measurable sensorimotor impairment.