Optimized nanosecond pulsed electric field therapy can cause murine malignant melanomas to self‐destruct with a single treatment

We have identified a new, nanosecond pulsed electric field (nsPEF) therapy capable of eliminating murine melanomas located in the skin with a single treatment. When these optimized parameters are used, nsPEFs initiate apoptosis without hyperthermia. We have developed new suction electrodes that are compatible with human skin and have applied them to a xenograft nude mouse melanoma model system to identify the optimal field strength, pulse frequency and pulse number for the treatment of murine melanomas. A single treatment using the optimal pulse parameters (2,000 pulses, 100 ns in duration, 30 kV/cm in amplitude at a pulse frequency of 5–7 pulses/sec) eliminated all 17 melanomas treated with those parameters in 4 mice. This was the highest pulse frequency that we could use without raising the treated skin tumor temperature above 40°C. We also demonstrate that the effects of nsPEF therapy are highly localized to only cells located between electrodes and results in very little scarring of the nsPEF‐treated skin.     

电疗法对周围神经损伤修复的研究进展

近年来,周围神经损伤的修复和再生有了若干进展。本文分别从低频电疗法与直流电疗法、中频电疗法、高频电疗法（超短波、分米波与毫米波）等角度探讨国内外学者在电疗法对周围神经损伤修复方面的研究及进展。 由于周围神经对不同程度的损伤有不同的病理过程和不同的再生方式,因此,周围神经损伤后,电疗法的选择应按照神经恢复的不同阶段要求来调整治疗方法。但其作用机制仍有待进一步深入研究。     

Electrical estimulation of retinal pigment epithelial cells

We investigated and characterized the effect of externally applied electric fields (EF) on retinal pigment epithelial (RPE) cells by exposing primary cultures of human RPE cells (hRPE) and those from the ARPE19 immortalized cell line to various strengths of EF (EF-treated cells) or to no EF (control cells) under different conditions including presence or absence of serum and gelatin and following wounding. We evaluated changes in RPE cell behavior in response to EF by using a computer based image capture and analysis system (Metamorph). We found that RPE cells responded to externally applied EFs by preferential orientation perpendicular to the EF vector, directed migration towards the anode, and faster translocation rate than control, untreated cells. These responses were voltage-dependent. Responses were observed even at low voltages, of 50-300 mV. Furthermore, the migration of hRPE cell sheets generated by wounding of confluent monolayers of cells at early and late confluence could be manipulated by the application of EF, with directed migration towards the anode observed at both sides of the wounded hRPE. In conclusion, RPE cell behaviour can be controlled by an externally applied EF. The potential for externally applied EF to be used as a therapeutic strategy in the management of selected retinal diseases warrants further investigation.     

Comparison of the Vibration Damping of the Wood Species Used for the Body of an Electric Guitar on the Vibration Response of Open-Strings

Research show that the vibrations of the strings and the radiated sound of the solid body electric guitar depend on the vibrational behavior of its structure in addition to the extended electronic chain. In this regard, most studies focused on the vibro-mechanical properties of the neck of the electric guitar and neglected the coupling of the vibrating strings with the neck and the solid body of the instrument. Therefore, the aim of the study was to understand how the material properties of the solid body could affect the stiffness and vibration damping of the whole instrument when comparing ash (Fraxinus excelsior L.) and walnut (Juglans regia L.) wood. In the electric guitar with identical components, higher modal frequencies were confirmed in the structure of the instrument when the solid body was made of the stiffer ash wood. The use of ash wood for the solid body of the instrument due to coupling effect resulted in a beneficial reduction in the vibration damping of the neck of the guitar. The positive effect of the low damping of the solid body of the electric guitar made of ash wood was also confirmed in the vibration of the open strings. In the specific case of free-free vibration mode, the decay time was longer for higher harmonics of the E₂, A₂ and D₃ strings.     

Auditory Nerve Fiber Responses to Combined Acoustic and Electric Stimulation

Persons with a prosthesis implanted in a cochlea with residual acoustic sensitivity can, in some cases, achieve better speech perception with “hybrid” stimulation than with either acoustic or electric stimulation presented alone. Such improvements may involve “across auditory-nerve fiber” processes within central nuclei of the auditory system and within-fiber interactions at the level of the auditory nerve. Our study explored acoustic–electric interactions within feline auditory nerve fibers (ANFs) so as to address two goals. First, we sought to better understand recent results that showed non-monotonic recovery of the electrically evoked compound action potential (ECAP) following acoustic masking (Nourski et al. 2007, Hear. Res. 232:87–103). We hypothesized that post-masking changes in ANF temporal properties and responsiveness (spike rate) accounted for the ECAP results. We also sought to describe, more broadly, the changes in ANF responses that result from prior acoustic stimulation. Five response properties—spike rate, latency, jitter, spike amplitude, and spontaneous activity—were examined. Post-masking reductions in spike rate, within-fiber jitter and across-fiber variance in latency were found, with the changes in temporal response properties limited to ANFs with high spontaneous rates. Thus, our results suggest how non-monotonic ECAP recovery occurs for ears with spontaneous activity, but cannot account for that pattern of recovery when there is no spontaneous activity, including the results from the presumably deafened ears used in the Nourski et al. (2007) study. Finally, during simultaneous (electric+acoustic) stimulation, the degree of electrically driven spike activity had a strong influence on spike rate, but did not affect spike jitter, which apparently was determined by the acoustic noise stimulus or spontaneous activity.     

Models of Brainstem Responses to Bilateral Electrical Stimulation

A simple, biophysically specified cell model is used to predict responses of binaurally sensitive neurons to patterns of input spikes that represent stimulation by acoustic and electric waveforms. Specifically, the effects of changes in parameters of input spike trains on model responses to interaural time difference (ITD) were studied for low-frequency periodic stimuli, with or without amplitude modulation. Simulations were limited to purely excitatory, bilaterally driven cell models with basic ionic currents and multiple input fibers. Parameters explored include average firing rate, synchrony index, modulation frequency, and latency dispersion of the input trains as well as the excitatory conductance and time constant of individual synapses in the cell model. Results are compared to physiological recordings from the inferior colliculus (IC) and discussed in terms of ITD-discrimination abilities of listeners with cochlear implants. Several empirically observed aspects of ITD sensitivity were simulated without evoking complex neural processing. Specifically, our results show saturation effects in rate–ITD curves, the absence of sustained responses to high-rate unmodulated pulse trains, the renewal of sensitivity to ITD in high-rate trains when inputs are amplitude-modulated, and interactions between envelope and fine-structure delays for some modulation frequencies.     

中频电刺激治疗缺血性脑卒中后吞咽困难疗效观察

目的：观察中频电刺激治疗急性缺血性脑卒中后吞咽困难的临床疗效。方法：选取急性缺血性脑卒中并发生吞咽困难的患者80例,随机分为治疗组和对照组,两组临床用药完全一致,对照组和治疗组分别辅以冰刺激和中频电刺激进行康复治疗,疗程为1月。观察患者吞咽困难的恢复情况。结果：治疗组治愈率为35％,总有效率为90％,与对照组比较差异具显著性。结论：中频电刺激是治疗脑卒中后吞咽困难的一种有效、简便、安全的方法,可推荐临床使用。     

哺乳动物皮层神经元模型的放电模式研究

针对一类三维哺乳动物新皮层神经元模型进行分析。该模型是结合Wilson模型和Hindmarsh-Rose模型而建立 的,得到的快变量遵守欧姆定律。快慢动力学对时间尺度相差很大的系统的分析是非常有效的,因此本研究使用快慢动 力学方法,并结合理论计算和数值模拟来探究该模型的动力学行为。首先,随着系统控制参数的改变,发现了3类簇放电 模式;然后,计算一阶Lyapunov系数,以此确定Hopf分岔是超临界或次临界的;最后,将模型与经典的Morris-Lecar模型 耦合,分析并讨论了耦合强度及外界交流刺激对耦合系统的影响。     

High frequency spectral changes induced by single-pulse electric stimulation: Comparison between physiologic and pathologic networks

Objective

To investigate functional coupling between brain networks using spectral changes induced by single-pulse electric stimulation (SPES).

肌肉松弛疗法对减轻无抽搐电休克治疗术后患者疼痛的疗效研究

目的 探讨肌肉松弛疗法改善无抽搐电休克治疗(modified electric convulsive therapy, MECT)术后患者疼痛、焦虑及睡眠的效果。 方法 选取首次接受MECT治疗的抑郁症患者90例,按随机数字表法分为对照组和研究组各45例。采用长海痛尺、汉密尔顿焦虑量表、匹兹堡睡眠质量指数量表评估干预前后患者疼痛、焦虑及睡眠状况。结果 研究组的疼痛评分明显低于对照组(F_组间=22.772,P＜0.001)。研究组干预后焦虑及睡眠评分均低于对照组(t=-4.743,P<0.001; t=-2.180,P＜0.001)。 结论 肌肉松弛疗法有助于减轻患者MECT术后疼痛,缓解患者的焦虑情绪,提高患者的睡眠质量。