Distinct perceptive pathways selected with tonic and bursting patterns of thalamic stimulation

BackgroundNovel patterns of electrical stimulation of the brain and spinal cord hold tremendous promise to improve neuromodulation therapies for diverse disorders, including tremor and pain. To date, there are limited numbers of experimental studies in human subjects to help explain how stimulation patterns impact the clinical response, especially with deep brain stimulation.We propose using novel stimulation patterns during electrical stimulation of somatosensory thalamus in awake deep brain stimulation surgeries and hypothesize that stimulation patterns will influence the sensory percept without moving the electrode.MethodsIn this study of 15 fully awake patients, the threshold of perception as well as perceptual characteristics were compared for tonic (trains of regularly-repeated pulses) and bursting stimulation patterns.ResultsIn a majority of subjects, tonic and burst percepts were located in separate, non-overlapping body regions (i.e., face vs. hand) without moving the stimulating electrode (p < 0.001; binomial test). The qualitative features of burst percepts also differed from those of tonic-evoked percepts as burst patterns were less likely to evoke percepts described as tingling (p = 0.013; Fisher’s exact test).ConclusionsBecause somatosensory thalamus is somatotopically organized, percept location can be related to anatomic thalamocortical pathways. Thus, stimulation pattern may provide a mechanism to select for different thalamocortical pathways. This added control could lead to improvements in neuromodulation - such as improved efficacy and side effect attenuation - and may also improve localization for sensory prostheses.     

Virtual reality doorway and hallway environments alter gait kinematics in people with Parkinson disease and freezing

BackgroundMany people with Parkinson disease (PD) experience freezing of gait (FoG), a transient gait disturbance associated with increased fall risk and reduced quality of life. Head-mounted virtual reality (VR) systems allow overground walking and can create immersive simulations of physical environments that induce FoG.Research questionFor people with PD who experience FoG (PD+FoG), are kinematic gait changes observed in VR simulations of FoG-provoking environments?MethodsIn a cross-sectional experiment, people with PD+FoG walked at their self-selected speed in a physical laboratory and virtual laboratory, doorway, and hallway environments. Motion analysis assessed whole-body kinematics, including lower extremity joint excursions, swing phase toe clearance, trunk flexion, arm swing, sagittal plane inclination angle, and spatiotemporal characteristics. One-way repeated measures analysis of variance was conducted to examine the effects of environment on gait variables, with planned contrasts between laboratory environments and the virtual doorway and hallway.ResultsTwelve participants with PD+FoG (mean age [standard deviation]=72.8 [6.5] years, disease duration=8.8 [8.9] years, 3 females) completed the protocol. The environment had significant and widespread effects on kinematic and spatiotemporal variables. Compared to the physical laboratory, reduced joint excursions were observed in the ankle, knee, and hip when walking in the virtual doorway and in the knee and hip when walking in the virtual hallway. In both the virtual doorway and hallway compared to the physical laboratory, peak swing phase toe clearance, arm swing, and inclination angle were reduced, and walking was slower, with shorter, wider steps.SignificanceVirtual doorway and hallway environments induced kinematic changes commonly associated with FoG episodes, and these kinematic changes are consistent with forward falls that are common during FoG episodes. Combined with the flexibility of emerging VR technology, this research supports the potential of VR applications designed to improve the understanding, assessment, and treatment of FoG.     

姑息性大动脉调转手术的麻醉管理

目的 总结姑息性大动脉调转手术(palliative arterial switch operation,PASO)的麻醉管理. 方法 回顾性总结分析28例于我院行PASO的完全性大动脉转位合并室间隔缺损(transposition of the great arteries with ventricular septal defect,TGA/VSD)或Taussing-Bing综合征患者的临床资料.28例患者年龄中位数为4岁(1月～25岁),体重中位数为12.5 kg(3.6～43kg),术前均诊断为重度肺动脉高压,术前SpO2波动在44％～91％. 结果 所有患者麻醉过程平稳,平均CPB时间为(223±81) min,平均主动脉阻断时间为(153±32) min.平均室间隔补片留孔大小为(5.3±1.5) mm.术后机械辅助通气时间中位数为36 h(7～408 h),ICU停留时间中位数为5.5 d(2～27 d).术后平均SpO2为(96±2)％,与术前比较,差异有统计学意义(P＜0.05).住院死亡5例(18％),余好转出院.出院患者中5例在出院后的1～5年间行介入残余室缺分流堵闭术. 结论 充分的术前准备和评估,平顺的麻醉诱导和维持,围手术期肺动脉高压的处理,早期合理地应用血管活性药物以及出凝血功能的调整,有利于PASO的成功.     

抗肝癌合剂对人肝癌细胞凋亡及间隙连接通讯功能的影响

目的探讨抗肝癌合剂(IPAH)对人肝癌细胞株SMMC-7721细胞凋亡和间隙连接通讯功能的影响。方法制备抗肝癌合剂含药血清,分为高、中、低剂量组,另设阴性对照组和空白血清对照组。培养人肝癌细胞株SMMC-7721进行体外实验,流式细胞仪检测细胞凋亡情况,荧光漂白恢复实验(FRAP)观察对细胞间隙连接通讯功能的影响。结果抗肝癌合剂中剂量组24、48、72h细胞凋亡率分别为(8.07±1.12)%、(12.04±2.12)%、(17.90±1.74)%;高剂量组24、48、72h细胞凋亡率分别为(11.54±2.23)%、(18.29±2.39)%、(22.90±2.43)%,与阴性对照组[(2.42±1.15)%、(2.98±0.92)%、(3.35±0.67)%]及空白对照组[(3.01±1.07)%、(3.88±0.97)%、(4.09±1.23)%]比较,差异有统计学意义(P均0.01)。抗肝癌合剂低、中、高剂量组荧光恢复率分别为(22.43±2.62)%、(42.73±4.36)%、(49.40±5.13)%,随着时间和剂量增加,荧光恢复率明显增加,组间差异有统计学意义(P均0.01)。结论抗肝癌合剂具有诱导肝癌细胞系SMMC-7721细胞凋亡的作用,呈一定的剂量和时间依赖关系。其作用可能与上调细胞间隙连接通讯功能相关。     

Effects of box handle position and carrying range on bi-manual carrying capacity for females

This study utilizes a psychophysical approach to examine the effects on carrying capacity for bi-manual carrying tasks involving different handle positions and carrying ranges. A total of 16 female subjects participated in the experiment in groups of two people, and each group of subjects performed the tasks in a random order with 12 different combinations of carrying task. The independent variables are handle position (upper, middle, lower) and carrying range (F–F: floor height carried to floor height, F–W: floor height carried to waist height, W–W: waist height carried to waist height, W–F: waist height carried to floor height), the dependent variable is the maximum acceptable carried weight (MAWC), heart rate (HR), and the rating of perceived exertion (RPE). The results show that the handle position has a significant effect on MAWC and overall RPE but no significant effect on HR. Carrying range has a significant effect on the MAWC and HR, but no significant effect on overall HR. The handle position and carrying range have a significant interaction on the MAWC and HR. The RPE for different body parts shows significant differences, and the hands feel the most tired. Overall, this study confirms that the lower handle position with the W–W carrying range is the best combination for a two-person carrying task.     

敷料更换的不同次数对穿刺引流术后穿刺口感染的影响

目的 研究敷料更换的不同次数对穿刺引流术后穿刺口感染的影响.方法 随机将该院2013年6月—2014年7月收治的100位进行穿刺引流术的患者分为两组,50例为A组,50例为B组. 为A组患者1周更换1次敷料,B组患者1周更换2次敷料. 对两组患者穿刺口感染的情况进行分析比较. 结果 A组患者穿刺口感染的几率显著低于B组(P<0.05),A组患者的病原菌定植率显著低于B组(P<0.05),两组患者导管相关性血流感染率差异无统计学意义(P>0.05). 结论 穿刺引流术后的患者1周更换1次敷料比较合理,既能降低患者术后穿刺口感染的几率,又能降低医护人员的工作量,但要注意在敷料发生松动或者潮湿时也要及时进行更换.