TNES治疗仪的研制及临床应用

神经肌肉电刺激疗法(TNES)在临床应用广泛.其治疗装置种类繁多,但超低频调制低频电脉冲刺激治疗仪的研制国内尚未见报道.我们开发和研制了超低频调制低频电脉冲经皮神经肌肉电刺激治疗仪(简称TNES治疗仪).本治疗仪采用集成电路技术和现代中医理论研制而成,体积小,结构简单,性能稳定,安全可靠,操作方便,应用范围广泛.结构及原理 人体有多种生物电,其频率大部分集中在低频、超低频范围内.患病导致人体生物电磁场紊乱.应用外加的电脉冲刺激,可以调整、激发体内生物电磁场,使其恢复正常.低频、超低频电脉冲可以产生以下生理效应:①兴奋神经、肌肉组织引起肌肉收缩;②镇痛;③促进局部血液循环;④消炎;⑤催眠.整个人体可以看作是一个非均匀介质的导体,人体的心电、脑电、肌电、胃电、眼振电、神经电位     

经皮穴位电刺激改善疲劳的脑电研究

目的 探讨经皮穴位电刺激方法对疲劳的改善效果. 方法 以9名健康男性青年志愿者为研究对象,采用脑电记录额区(F3、Fz、F4)、中央区(C3、Cz、C4)、顶区(P3、Pz、P4)和枕区(O1、Oz、O21)共12导脑电信号在正常状态、疲劳状态和经皮穴位电刺激后状态下的数据,通过计算δ、θ、α、β频段的平均功率谱密度值G,分析经皮穴位电刺激的脑电效果. 结果 对比正常状态,疲劳后δ、θ、α、β频段的G值上升,α频段G值的左右脑区不平衡性增加.经皮穴位电刺激后,δ、θ、α、β频段的G值下降,α频段G值的右脑区不平衡性减小. 结论 经皮穴位电刺激对疲劳的改善有一定效果,脑电有明显的表征.     

噪声和音乐对脑电功率谱的影响

目的：观察飞行员在安静、噪声和音乐３种状态下的脑电功率谱的变化特点,为航天员的心理放松训练提供一客观生理依据。方法：记录了１２名飞行员在安静、噪声和音乐状态下的１６导连续脑电图,并进行了６个频段的功率谱分析。结果：安静状态和噪声状态下以及安静状态和音乐状态下脑电能量变化的比较在统计学上的无显著性差异;噪声状态和音乐状态的比较从频域上看,在音乐状态下,脑电能量在α１频段呈明显减少趋势,在θ频段呈增加趋势;从空间域上看,脑电能量的变化主要集中在前额颞区和中央区。结论：脑电变化与人的情绪变化密切相关,音乐可起到放松作用;声音对脑电的影响有很大的个体差异,放松训练须因人而宜。     

基于Granger因果分析的阿尔兹海默病静息态脑电网络连接特性的研究

目的从多通道脑电(electroencephalography,EEG)的功能性连接角度,研究阿尔兹海默病患者在静息态下的脑网络连接特性。方法收集15例AD患者及15例正常对照组的16导脑电数据,对EEGs进行频域Granger因果分析,计算出因果连接矩阵,平均后得到DTFmean。基于连接矩阵构建因果网络,进一步计算网络特征参数全局效率和集群系数来定量分析脑网络的连接特性。结果在alpha,low-beta和high-beta频段,AD组的DTFmean低于正常对照组(P0.05)。在alpha,low-beta和high-beta频段下AD组的全局效率显著低于正常对照组(P0.01);AD组集群系数显著低于正常对照组(P0.01)。结论阿尔兹海默病患者的静息态脑电在alpha,low-beta和high-beta频段的脑网络连接较弱,表明AD患者的脑功能网络相较于正常老年人有所受损。     

招飞体检异常脑电图及脑电地形图分析

目的探讨将脑电地形图描记术用于招飞体检的价值和可行性。方法将招飞体检中查出的12例脑电图异常者再查脑电地形图,并对照两种检查结果各频段的变化。结果脑电地形图各导联及各频域的参考功率最大值表现的异常与脑电图完全一致,对局限性异常的定位敏感;其功率谱图便于对两侧对称性评估;各频段功率值左右不对称;但不能表现出具体诱发阶段的异常。结论脑电地形图与脑电图相辅相成,前者更直观。但脑电地形图对癫痫的特异性诊断远不如脑电图,不利于诊断癫痫。记录时不能减少导联。     

261名歼击机飞行员脑波α频段涨落图特征的研究

为探讨飞行员脑波α频段涨落图特征，应用脑功能脑电－涨落图（ＥＥＧ－ＥＴ）评价技术，研究了２６１名歼击机飞行员脑波α频段的涨落图特征。结果显示：飞行员的脑波α频段频率涨落竞争结构的主涨落成分为９Ｈｚ，次涨落成分为１０Ｈｚ，７Ｈｚ在涨落优势序排列占第三位。频率涨落竞争结构相对熵值平均为（７２±１４）％，枕区的导联Ｏ１、Ｏ２的相对熵值低，分别为（６９±１７）％和（６７±１８）％。脑波α频段功率涨落功率谱     

急性颅脑损伤脑电地形图的临床研究

分析 14 0例颅脑损伤的临床资料 ,按颅脑损伤分型标准分轻、中、重型 ,分别在伤后不同时期作脑电地形图(BEAM)。结果显示 ,损伤越重 ,昏迷时间越长 ,BEAM功率谱越低 ,如θ、δ频段持续时间越长 ,则预后不良     

5Hz和20Hz磁场对脑反应影响的比较研究

基于在脑电频率范围内的磁场刺激对脑过程可能有调制作用的假设，并在已取得 结构的基础上，本文在２２名正常被试者中比较了５Ｈｚ和２０Ｈｚ的磁场刺激对进行选择反应和选择心算时脑反应的影响。     

急性缺氧条件下轻运动负荷脑电的变化及分布特征

本文实验研究了不同高度急性缺氧条件下运动状态脑电的变化,观察了低压舱内轻体力负荷对人体脑电的影响。结果表明,急性缺氧下轻体力负荷脑电的变化特点是:在以快波节律为主,α波普遍被阻抑的背景下,脑电图随缺氧高度的增加慢波(δ、θ)增加,α波出现并增加,而快波相对减少。经计算处理,δ、θ、α频段功量及分配指数随高度和时间的增加而增加。β频段功量相对稳定,但其分配指数呈降低趋势。这些变化在6000m缺氧高度具有统计学意义。     

轻度认知功能障碍人群工作记忆脑电theta网络缺损模式研究

目的通过分析对比轻度认知功能障碍(mild cognitive impairment,MCI)患者和正常老年人工作记忆脑电的能量密度和网络连接特性,研究MCI工作记忆脑电theta网络缺损模式。方法在视觉工作记忆任务中,对15位MCI患者和15位正常人的34通道脑电数据进行theta振荡,观察行为学特征,利用时频分析计算能量密度,利用频域Granger因果分析网络功能连接。结果 MCI组的工作记忆脑电theta频段平均能量密度为((0.305±0.033)μV2/Hz),显著小于正常对照组((0.468±0.103)μV2/Hz),P0.001)。MCI组的工作记忆脑电theta网络平均连接强度(0.0096±0.0007)显著小于正常对照组(0.0123±0.0006,P0.001)。结论 MCI患者在工作记忆theta频段的活动减弱,theta网络连接下降。     

极低频磁场辐照对细胞间隙连接通讯功能的作用及其阈值研究

目的 探讨极低频（ELF）磁场可能存在的促癌或协同促癌作用。方法 应用光漂白后的恢复技术，观察ELF磁场对细胞间隙连接通讯（GJIC）的作用及其阈值。结果 0.4mT及以上强度的ELF磁场辐照能明显抑制细胞GJIC功能；0.2mT及以上强度的ELF磁场单独虽无抑制GJIC的效应，但可增强TPA所诱导的GJIC的抑制；0.1mT的ELF磁场既无单独抑制作用，也无协同TPA的作用。结论 一定强度的ELF磁场辐照可能具有促癌或协同促癌作用。     

Extremely low frequency (ELF) magnetic fields enhance chemically induced formation of apurinic/apyrimidinic (AP) sites in A172 cells

PURPOSE: To detect the effects of extremely low frequency (ELF) magnetic fields, the number of apurinic/apyrimidinic (AP) sites in human glioma A172 cells was measured following exposure to ELF magnetic fields. MATERIALS AND METHODS: The cells were exposed to an ELF magnetic field alone, to genotoxic agents (methyl methane sulfonate (MMS) and hydrogen peroxide (H2O2)) alone, or to an ELF magnetic field with the genotoxic agents. After exposure, DNA was extracted, and the number of AP sites was measured. RESULTS: There was no difference in the number of AP sites between cells exposed to an ELF magnetic field and sham controls. With MMS or H2O2 alone, the number of AP sites increased with longer treatment times. Exposure to an ELF magnetic field in combination with the genotoxic agents increased AP-site levels compared with the genotoxic agents alone. CONCLUSIONS: Our results suggest that the number of AP sites induced by MMS or H2O2 is enhanced by exposure to ELF magnetic fields at 5 millitesla (mT). This may occur because such exposure can enhance the activity or lengthen the lifetime of radical pairs.     

Inhibition of UV-induced G1 arrest by exposure to 50 Hz magnetic fields in repair-proficient and -deficient yeast strains

PURPOSE: To assess the possibility that extremely low frequency (ELF) magnetic fields obstruct the damage repair process, the gene conversion frequency and cell cycle kinetics in a DNA repair-proficient and nucleotide excision repair (NER)-deficient strain of diploid yeast Saccharomyces cerevisiae. MATERIALS AND METHODS: DNA repair- or NER-deficient cells were irradiated with sublethal doses of ultraviolet light (UV) radiation followed by exposure to 50 Hz magnetic fields up to 30 mT for 48 h. After exposure, colony-forming ability was scored as revertants in which gene conversion had restored the functional allele of the ARG4 gene conversion hotspot. Cell cycle analysis was performed using flow cytometry. RESULTS: Gene conversion rate was increased by the combined exposure in DNA repair-proficient cells, whereas it remained unchanged between UV alone and the combined exposure in NER-deficient cells. The UV-induced G1 arrest was inhibited by exposure to 30 mT ELF magnetic fields in both repair-proficient and -deficient cells. CONCLUSIONS: The results suggest that exposure to high-density (30 mT) ELF magnetic fields decreases the efficiency of NER by suppressing G1 arrest, which in turn led to enhancement of the UV-induced gene conversion.     

Different responses of Drosophila subobscura isofemale lines to extremely low frequency magnetic field (50 Hz, 0.5 mT): fitness components and locomotor activity

Purpose: Extremely low frequency (ELF) magnetic fields as essential ecological factors may induce specific responses in genetically different lines. The object of this study was to investigate the impact of the ELF magnetic field on fitness components and locomotor activity of five Drosophila subobscura isofemale (IF) lines.

Materials and methods: Each D. subobscura IF line, arbitrarily named: B16/1, B24/4, B39/1, B57/2 and B69/5, was maintained in five full-sib inbreeding generations. Their genetic structures were defined based on the mitochondrial DNA variability. Egg-first instar larvae and 1-day-old flies were exposed to an ELF magnetic field (50?Hz, 0.5?mT, 48?h) and thereafter, fitness components and locomotor activity of males and females in an open field test were observed for each selected IF line, respectively.

Results: Exposure of egg-first instar larvae to an ELF magnetic field shortened developmental time, and did not affect the viability and sex ratio of D. subobscura IF lines. Exposure of 1-day-old males and females IF lines B16/1 and B24/4 to an ELF magnetic field significantly decreased their locomotor activity and this effect lasted longer in females than males.

Conclusions: These results indicate various responses of D. subobscura IF lines to the applied ELF magnetic field depending on their genetic background.     

Extremely low frequency magnetic field (50 Hz, 0.5 mT) modifies fitness components and locomotor activity of Drosophila subobscura

Abstract

Purpose: Extremely low frequency (ELF) magnetic fields are essential ecological factors which may induce changes in many organisms. The aim of this study was to examine the effects in Drosophila subobscura exposed for 48 h to ELF magnetic field (50 Hz, 0.5 mT) at different developmental stages.

Materials and methods: Egg-first instar larvae developmental stage of D. subobscura isofemale lines was exposed to ELF magnetic field, and fitness components (developmental time, developmental dynamics, viability and sex ratio) and locomotor activity of three-day-old males and females were monitored. Also, just eclosed D. subobscura isofemale adults were exposed to ELF magnetic field and their locomotor activity was monitored just after.

Results: ELF magnetic field shortens developmental time, increases viability and does not affect sex ratio of D. subobscura. No matter which developmental stage is exposed, ELF magnetic field significantly decreases locomotor activity of adult flies, but after exposure of just eclosed adults observed change lasts longer.

Conclusions: Applied ELF magnetic field modifies fitness components and locomotor activity of D. subobscura. Observed effects can be attributed to the influence of magnetic field on different stages of development where the hormonal and nervous systems play important role in the control of examined parameters.     

Inhibition of UV‐induced G1 arrest by exposure to 50 Hz magnetic fields in repair‐proficient and ‐deficient yeast strains

Purpose: To assess the possibility that extremely low frequency (ELF) magnetic fields obstruct the damage repair process, the gene conversion frequency and cell cycle kinetics in a DNA repair‐proficient and nucleotide excision repair (NER)‐deficient strain of diploid yeast Saccharomyces cerevisiae.

Materials and methods: DNA repair‐ or NER‐deficient cells were irradiated with sublethal doses of ultraviolet light (UV) radiation followed by exposure to 50?Hz magnetic fields up to 30?mT for 48?h. After exposure, colony‐forming ability was scored as revertants in which gene conversion had restored the functional allele of the ARG4 gene conversion hotspot. Cell cycle analysis was performed using flow cytometry.

Results: Gene conversion rate was increased by the combined exposure in DNA repair‐proficient cells, whereas it remained unchanged between UV alone and the combined exposure in NER‐deficient cells. The UV‐induced G1 arrest was inhibited by exposure to 30?mT ELF magnetic fields in both repair‐proficient and ‐deficient cells.

Conclusions: The results suggest that exposure to high‐density (30?mT) ELF magnetic fields decreases the efficiency of NER by suppressing G1 arrest, which in turn led to enhancement of the UV‐induced gene conversion.     

A 700 MHz 1H-NMR study reveals apoptosis-like behavior in human K562 erythroleukemic cells exposed to a 50 Hz sinusoidal magnetic field

PURPOSE: To study cell damage and possible apoptosis in K562 human erythroleukemic cells exposed for 2 h to an extremely low frequency (ELF) 50 Hz sinusoidal magnetic field with a magnetic induction of either 1 or 5 mT using high resolution proton nuclear magnetic resonance (1H-NMR) spectroscopy. MATERIALS AND METHODS: One-dimensional 1H-NMR spectra were obtained on whole K562 cells and perchloric acid extracts of these cells. In addition, two-dimensional 1H-NMR spectra were also acquired. Cell damage was examined by lactate dehydrogenase release and changes in cell growth were monitored by growth curve analyses, bromodeoxyuridine incorporation and Ki67 antigen localization. Cell death (necrosis and apoptosis) were also studied by using the chromatin dye Hoechst 33258. RESULTS: The variations in numerous metabolites observed with 1H-NMR reveal apoptosis-like behavior in response of K562 cells to ELF fields. CONCLUSION: 1H-NMR can be extremely useful in studying the effects of ELF fields on cells. In particular, the variations in metabolites which suggest apoptosis-like behavior occur when the cells are not identifiable as apoptotic by more traditional techniques.     

Observation of changes in neural activity due to the static magnetic field of an MRI scanner

PURPOSE: To clarify whether a strong static magnetic field affects brain activity such as arousal level. MATERIALS AND METHODS: We compared the electroencephalography (EEG) inside an MRI scanner in the presence/absence of the static magnetic field in two different arousal levels of task and rest conditions. Cardiac-related pulsations of head and blood flow induce an electric voltage at each EEG electrode in a static magnetic field. This induced voltage overlaps with the intrinsic EEG signal and becomes a large confounding factor. To extract the information of the intrinsic EEG from the contaminated EEG data measured in a static magnetic field, we developed a new analysis method. RESULTS: No significant difference was observed in the intrinsic EEG in the absence of a magnetic field, whereas in the presence of the static magnetic field, the theta frequency band of the intrinsic EEG increased, especially during the task condition, but other frequency bands did not change. CONCLUSION: Our results demonstrate that a static magnetic field affects brain activity.     

A 700 MHz 1H-NMR study reveals apoptosis-like behavior in human K562 erythroleukemic cells exposed to a 50 Hz sinusoidal magnetic field

Purpose: To study cell damage and possible apoptosis in K562 human erythroleukemic cells exposed for 2?h to an extremely low frequency (ELF) 50 Hz sinusoidal magnetic field with a magnetic induction of either 1 or 5 mT using high resolution proton nuclear magnetic resonance (¹H-NMR) spectroscopy.

Materials and methods: One-dimensional ¹H-NMR spectra were obtained on whole K562 cells and perchloric acid extracts of these cells. In addition, two-dimensional ¹H-NMR spectra were also acquired. Cell damage was examined by lactate dehydrogenase release and changes in cell growth were monitored by growth curve analyses, bromodeoxyuridine incorporation and Ki67 antigen localization. Cell death (necrosis and apoptosis) were also studied by using the chromatin dye Hoechst 33258.

Results: The variations in numerous metabolites observed with ¹H-NMR reveal apoptosis-like behavior in response of K562 cells to ELF fields.

Conclusion: ¹H-NMR can be extremely useful in studying the effects of ELF fields on cells. In particular, the variations in metabolites which suggest apoptosis-like behavior occur when the cells are not identifiable as apoptotic by more traditional techniques.     

Cellular effects of extremely low frequency (ELF) electromagnetic fields

Purpose: The major areas of research that have characterised investigation of the impact of extremely low frequency (ELF) electromagnetic fields on living systems in the past 50 years are discussed. In particular, selected studies examining the role of these fields in cancer, their effects on immune and nerve cells, and the positive influence of these ELF fields on bone and nerve cells, wound healing and ischemia/reperfusion injury are explored.

Conclusions: The literature indicates that there is still no general agreement on the exact biological detrimental effects of ELF fields, on the physical mechanisms that may be behind these effects or on the extent to which these effects may be harmful to humans. Nonetheless, the majority of the in vitro experimental results indicate that ELF fields induce numerous types of changes in cells. Whether or not the perturbations observed at the cellular level can be directly extrapolated to negative effects in humans is still unknown. However, the myriad of effects that ELF fields have on biological systems should not be ignored when evaluating risk to humans from these fields and, consequently, in passing appropriate legislation to safeguard both the general public and professionally-exposed workers. With regard to the positive effects of these fields, the possibility of testing further their efficacy in therapeutic protocols should also not be overlooked.