电磁波的生物学窗效应

本文分别以人的肝癌细胞和动物脑组织为生物学对象，以荧光标记和同位素示踪为实验方法，以激光扫描共聚焦显微镜和液体闪烁计数器为检测仪器，以荧光强度和放射性强度为检测Ca^2 量的特征指标，进行了电磁波生物学非热效应的典型代表--电磁波生物学窗效应的实验研究。两种实验均表明了电磁波生物学频率窗效应和强度窗效应的存在且有相同的窗频率。基于本文的实验研究并结合其他文献的结果，可发现电磁波生物学窗效应具有以下基本特征：(1)不同生物组织都会在15—16Hz左右存在一个频率窗；(2)生物学窗效应既可由ELF(极低频)正弦(调制波)振幅调制的高频电磁波(载波)产生，又可由ELF连续波或ELF脉冲波产生，只是前者的频率窗只体现在调制波频率上而不体现在载波频率上，而且，前者的窗效应频率与后者的窗效应频率是相同的；(3)频率窗分布的一般规律为fn＝(2n 1)fc，式中，n＝0，1，2…，fn为第n个窗频率，fc为基频即最低的那个窗频率。实验研究还表明，这-分布规律在0—135Hz范围内是正确的，且基频fc≈15—16Hz；(4)只有特定频率参数与特定强度参数恰当组合的电磁波才能产生生物学窗效应，或者说，窗效应是电磁波频率和强度的二元函数。     

细胞内自由钙离子浓度变化的时-频分析

了解细胞内自由钙离子浓度([Ca~(2+)]_i)的变化规律是探知细胞乃至相关生物组织生存及健康状况的手段,而采用时-频分析方法则可获得其变化规律中较多的深层次信息.为了更好了解癌细胞与正常细胞内[Ca~(2+)]_i变化规律间的差异以及各自的特征,选取3种癌细胞和4种正常细胞作为实验对象.首先,用荧光试剂对各细胞样品进行负载,再用激光扫描共聚焦显微镜对细胞内的荧光强度进行测量,以获得细胞内[Ca~(2+)]_i的时域数据;接着,对时域数据进行时-频分析,并给出时-频分布函数的等值线图.结果表明,虽然癌细胞和正常细胞内[Ca~(2+)]_i的变化在时-频域内均有连续出现和离散出现的两类谱带,但癌细胞与正常细胞间的差异却是明显的.差异主要表现在:癌细胞中连续谱带的宽度大于正常细胞连续谱带的宽度,癌细胞中只有1条离散谱带,而正常细胞中却有2条离散谱带;不同癌细胞中离散谱带的中心频率相同,而不同正常细胞离散谱带的中心频率却各不同;癌细胞离散谱带中各频谱分量的相对振幅大于正常细胞各频谱分量的相对振幅.这些结果既为鉴别癌细胞提供一个新的指标,也为认识不同正常细胞的健康状况提供新的参考数据,同时可为电磁波的生物学窗效应机理研究奠定生物学自身的内禀依据.     

ELF脉冲电磁场对脑组织钙离子迁移量的影响

目的研究极低频(extremely low frequency,ELF)脉冲电磁场对脑组织钙离子迁移量的影响。方法以鸡脑组织为生物学实验对象,以同位素示踪法为标记方法,用液体闪烁计数器为检测仪器,实验观察ELF脉冲电磁场对脑组织钙离子迁移量的影响。结果不同特征外加ELF脉冲电磁场对脑组织钙离子迁移量影响不同,如频率为16 Hz、场强为42.5 V/m的ELF脉冲电磁场可引起脑组织钙离子迁移量显著变化。频率为16 Hz、场强为62.2 V/m与频率为31 Hz、场强为42.5 V/m的ELF脉冲电磁场却未引起脑组织钙离子迁移量显著改变。结论只有频率和强度恰当组合的ELF电磁场才可引起脑组织钙离子迁移量显著升高,呈现出生物学窗效应。另一方面在既注重物理学分析又注重生物系统特性基础上,从膜通道内的带电粒子动力学方程入手分析讨论生物学窗效应产生机制。     

电磁波对细胞内外离子浓度影响的基本理论

磁波生物学非热效应的一个代表性事例是对离子 ,比如Ca2 穿越细胞膜的影响 ,从而导致细胞内外离子浓度比值发生变化。阐述电磁波对细胞离子浓度影响这一生物学非热效应的基本理论 ,以此为电磁波生物学非热效应机理研究提供理论基础。该基本理论基于两个角度 :一是物理学角度 ,即视生物组织和细胞膜为一般的电磁媒质 ,由物理学角度分析可看出 ,一定参数的电磁波可使细胞内外二价离子浓度的比值发生 10 -6量级的变化 ,这相当于正常细胞内外钙离子浓度在固有比值 10 -4 的基础上发生了 1%的变化 ,与细胞产生动作电位时需要细胞内外电荷密度的比值在固有的 10 -4 基础上发生 1%的变化比较 ,可知基于物理学角度 ,电磁波在引起生物学非热效应方面是有意义的 ;二是生物学角度 ,即视生物组织和细胞膜为特殊的生命物质 ,由生物学角度分析可看出 ,一定参数的电磁波可导致在 1秒钟内有 10 6量级的二价离子穿过细胞膜 ,与用趋化 (趋药 )性试验证明了的要使白细胞的生活状态发生有意义变化需要额外有 10 3 量级的分子通过细胞膜比较 ,可知基于生物学角度 ,电磁波在引起生物学非热效应方面也是有意义的 ,因为无论是细胞内外离子浓度的变化 ,还是电荷穿越细胞膜迁移所携带的信息都会改变细胞自身的生理和生化状态。     

135Hz极低频电磁场对HepG-2细胞内Ca^2＋浓度的影响

目的:研究135 Hz(电场强度为80 V·m-1)极低频电磁场(ELF)暴露对HepG-2细胞内Ca2+浓度的影响.方法:采用荧光探针Fluo-3/AM标记细胞内Ca2+,135 Hz ELF照射HepG-2细胞1 h后,利用激光扫描共聚焦显微镜技术测定细胞内Ca2+浓度,加入L-型Ca2+通道拮抗剂硝苯地平,探讨135 Hz ELF影响HepG-2细胞内Ca2+浓度变化的具体机制.结果:未暴露组细胞荧光强度较弱,ELF暴露组细胞荧光强度增高,与未暴露组有统计学意义(P<0.01);用硝苯地平干预组细胞荧光强度减弱,与未干预组有统计学意义(P<0.01).结论:135 Hz ELF可能通过引起L-型Ca2+通道的开放造成HepG-2细胞发生Ca2+超载.     

线粒体Ca^2＋超载在离体肾脏保存中的作用机制研究

Ca^2＋是许多关键酶和生化过程的调节因子。最新研究证明，线粒体的Ca^2＋超载是导致细胞死亡的根本原因，线粒体内Ca^2＋的过量积累可通过使线粒体通透性转换孔（permeability transition pore,PTP)持久开放，导致线本肿胀破坏从而耗尽细胞能量及释放大量Ca^2＋至胸浆激活多种酶系，使细胞最终崩解死亡。利用X－射线微区分技术结合细胞化学技术，分析离体保存的猫肾脏皮质细胞中的胞浆，线粒体的Ca^2＋浓度变化及线粒体的超微结构。结果显示，离体保存24，48，72小时后胞浆及线粒体中Ca^2＋的峰背比显著增高，且两者呈显著正相关，提示在肾细胞受损死亡过程中，随着胞浆中Ca^2＋浓度的升高，线粒体可积聚大量Ca^2＋，并出现肿胀破坏，最终导致细胞死亡。肾的皮质细胞Ca^2＋－ATPase切片定性也支持这一点。     

电磁波的生物窗效应及其回旋谐振理论

本文列举了电磁波生物学窗效应的典型实验结果,综述了说明频率窗效应的回旋谐振理论。我们在考虑构成细胞膜通道的α-螺旋蛋白质几何参数和化学参数的基础上,改进了膜通道内电位的分布模型,修正了带电粒子在膜通道中运动的回旋本征频率的表达式,并在回旋谐振理论的基础上推导出了一组引起生物学效应的量子态功率密度。     

内源性电场及其生物学效应探讨

生物体内存在跨细胞电势差和跨上皮／内皮电势差，当胚胎发育、组织损伤、肿瘤发生时这些电势差被改变，在细胞外产生一种稳恒直流电场，即内源性电场。暴露于内源性电场中的细胞行为是形态变为狭长、垂直取向和定向迁移，这种趋电性机制是以Ca^2＋流动触发的级联反应，同时处在电场中某些位置的细胞可分裂增殖。内源性电场是胚胎发育和创伤愈合中的重要条件，可使肿瘤细胞趋电性转移。模拟内源性电场已在临床上使用，并显示出初步疗效，但只有对其生物学效应的下游机制等问题更透彻阐明，才能使其有广泛临床应用的可能。     

TNF-α和 LPS对体外培养血脑屏障内皮细胞胞浆内钙离子浓度的影响

目的：观察脂多糖（Lipopolysaccharid，LPS）和肿瘤坏死因子α(Tumor necrosis factor-α，TNF-α)对血脑屏障内皮细胞（Blood-brain barrier endothelial cell，BBBEC）胞浆内钙离子浓度（plasmic inner concentration of calcium，[Ca^2 ]i）的影响。方法：用Fluo-3/AM做为荧光探针对钙离子进行负载，激光扫描共聚焦显微镜观察不同浓度的LPS和TNF-α刺激下BBBEC胞浆内钙离子浓度的变化。结果：在TNF-α刺激下，单个BBBEC[Ca^2 ]i呈浓度依赖性的一过性升高。不同浓度TNF-α引起的BBBEC Ca^2 的荧光强度达高峰的时间基本一致，高峰荧光强度和荧光持续时间随TNF-α浓度的升高而增加。低浓度LPS（1μg/ml和10μg/ml）刺激细胞时，BBBEC[Ca^2 ]i无明显变化，高浓度LPS刺激细胞时，可见[Ca^2 ]i呈短暂性升高，随后下降。结论：TNF-α和LPS在极短的时间内导致BBBEC[Ca^2 ]i的升高，激活BBBEC，这一过程是缺血性脑损伤极早期的重要病理机制之一。     

高频电磁波对脐血淋巴细胞姐妹染色单体互换的影响

目的：探讨高频电磁波辐射对淋巴细胞遗传效应的影响。材料和方法：选取新生儿脐带血为研究对象，通过用频率约为17.8MHz。功率约为1W的高频电磁波对它进行辐射，采用细胞生物学方法，观察其淋巴细胞姐妹染色单体互换SCE频率。结果和结论：随辐射时间（15-75min)及辐射剂量（0.5-1W)的增加，染色单体交换SCE频率有明显增加（10.52-15.37MHz)。说明电磁波辐射能够对机体的生物效应产生影响。     

极低频电磁暴露对钙离子跨膜迁移的影响及机理分析

目的:研究极低频（ELF）电磁暴露对细胞钙离子跨膜迁移的影响。 方法:以人体肝癌细胞为对象,激光扫描共聚焦显微镜为检测手段,研究细胞钙离子跨膜迁移对ELF电磁暴露的响应。 结果:在磁场强度为1.78×10-7 T条件下,与对照组对比,各暴露组均对不同频率和电场强度组合的外加电磁暴露环境有响应,其中[f=16 Hz]且[EP=53 Vm]、[f=45 Hz]且[EP=53 Vm]以及[f=16 Hz]且[EP=80 Vm]的电磁暴露可使钙离子跨膜迁移量显著上升,而[f=32 Hz]且[EP=53 Vm]、[f=60 Hz]且[EP=53 Vm]、[f=16 Hz]且[EP=26 Vm]以及[f=16 Hz]且[EP=87 Vm]的电磁暴露未使钙离子跨膜迁移量显著上升。 结论:不同频率和电场强度组合的ELF电磁暴露均会引起钙离子跨膜迁移量产生变化且呈现出明显差异,这可为ELF电磁环境下生物学应用提供实验依据;注重细胞膜离子通道物理、生物特性基础上探讨ELF电磁暴露对钙离子跨膜迁移影响的机理。     

Prenatal exposure to an extremely low frequency-low intensity rotating magnetic field and increases in thyroid and testicle weight in rats

Extremely low frequency (ELF) electromagnetic fields and waves (.1–40 Hz) Which occur daily in the environment, are associated with lightning discharges, atmospheric lability, solar eruptions, and geomagnetic micropulsations. In 3 experiments, adult rats that had been exposed to a .5–3 or 3–15 gauss ELF (.5 Hz) rotating magnetic field (RMF) during various periods of gestation, had significantly heavier thyroid and testicle weights than controls. The difference in these measures was a function of the field intensity and duration of exposure. Rats exposed prenatally to a sham-RMF (no magnets) did not differ from controls in the above measures. No significant differences were found between the thymus weights, adrenal weights, blood sugar, or circulating blood eosinophil levels of RMF-exposed and control rats. The implications of the thyroid and testicle changes are discussed in terms of the physiological and physicochemical effects of ELF electromagnetic phenomena.     

Effects of sino-aortic denervation on spectral characteristics of blood pressure and pulse interval variability: a wide-band approach

Sino-aortic denervation (SAD) is employed in cats to evaluate the baroreflex influence on blood pressure (BP) and pulse interval (PI) spectral components from 0·00008 to 0·9 Hz as assessed by FFT wide-band spectra and their 1/f modelling; and the linear coupling between BP and PI and between systolic and diastolic BP as assessed by coherence analysis. Specific procedures have been developed to obtain an effective smoothing of spectra and coherence functions. SAD induced an increase in BP powers from 0·03 to 0·0006 Hz and a power reduction of most of the remaining BP components; a reduction of PI powers at all frequencies; marked deviations of BP spectra from the 1/f trend; a reduction of the coherence between BP and PI from 0·12 to 0·5 Hz and a coherence enhancement at lower frequencies. These findings indicate that the arterial baroreflex modulates both fast and slow spectral components of BP and PI; homogeneously enhances PI fluctuations at all frequencies; produces differentiated effects on BP fluctuations along the frequency axis; and at low frequencies exerts the buffering action on BP through strategies which reduce the BP-PI linear link.     

Extremely Low Frequency Magnetic Fields Do Not Induce DNA Damage in Human Lens Epithelial Cells In Vitro

Non‐ionizing radiations, e.g., radiofrequency electromagnetic fields, could induce DNA damage and oxidative stress in human lens epithelial cells (LECs) which can be early events in cataractogenesis. Extremely low frequency magnetic fields (ELF MF) as another common form of man‐made electromagnetic fields has been considered as suspected human carcinogen by International Agency for Research on Cancer (IARC) and become a focus that people play more and more attentions to. This study aimed to determine whether ELF MF can induce DNA damage in cultured human LECs at a relatively low intensity. Human LECs were exposed or sham‐exposed to a 50 Hz ELF MF which produced by a well‐designed exposure system at the intensity of 0.4 mT. DNA damage in human LECs was examined by the phosphorylated form of histone variant H2AX (γH2AX) foci formation assay and further explored with western blot, flow cytometry, and alkaline comet assay. Immunofluorescence analysis showed that 0.4 mT ELF MF did not significantly increase γH2AX foci formation in human LECs after 2, 6, 12, 24, or 48 hr exposure. No significant differences had been detected in γH2AX expression level between the ELF MF‐ and sham‐exposure groups, while no obvious chromosomal DNA fragmentation was detected by alkaline comet assay after ELF MF exposure. The results indicate an absence of genotoxicity in ELF MF‐exposed human epithelial cells and do not support the hypothesis that environmental ELF MF might be causally led to genomic instability via chromosomal damage response processes. Neither short nor long term continuous exposure to 50 Hz ELF MF at 0.4 mT could induce DNA damage in human lens epithelial cells in vitro. Anat Rec, 299:688–697, 2016. © 2016 Wiley Periodicals, Inc.     

Effects of extremely low-frequency electromagnetic fields on morphine-induced conditioned place preferences in rats

In the present study, we examined the effects of extremely low-frequency (ELF) electromagnetic fields on morphine-induced conditioned place preferences in rats. During the conditioning phase (12 days), three groups of rats were placed in a sensory cue-defined environment paired with morphine (10mg/kg, i.p.) following exposure to either 20 Hz (1.80 mT) or 50 Hz (2.20 mT) or sham electromagnetic fields for 60 min/day, respectively, and were placed in another sensory cue-defined environment paired with physiological saline (1 ml/kg, i.p.) without exposure to electromagnetic fields. After finishing 12 days of conditioning, preference tests for the morphine-paired place were performed during a 10-day withdrawal period. The exposure to electromagnetic fields substantially potentiated morphine-induced place preferences in rodents, suggesting that ELF electromagnetic fields can increase the propensity for morphine-induced conditioned behaviors.     

脉冲电磁场防治骨质疏松的动物实验装置研制及实验观察

目的根据脉冲电磁场治疗骨质疏松的原理，设计用于动物实验的脉冲电磁场治疗装置．并用该装置观察在脉冲电磁场作用下实验动物力学特性和骨组织形态的变化。方法设计了强度为11MT．频率12Hz／8Hz自动跳变的脉冲电磁场发生装置和专用的动物实验装置，并将磁场作用于去势大鼠的骨质疏松模型。结果实验装置运行时．对各参数检测表明，实验装置满足设计的要求：经脉冲电磁场装置治疗的大鼠骨形态和力学特性与未经治疗的模型组都有明显改善。结论实验装置满足设计要求，脉冲电磁场可以改善骨的形态和骨骼的力学特性。     

生物活性肽调节胰岛素分泌的信号转导机制

Mastoparan(MAS) and α-latrotoxin(α-LTX) are two kinds of insulinotropic peptides obtained from insect toxins which can interact with islet β-cells and induce insulin secretion. The signal mechanism of these insulinotropic peptides regulating insulin-releasing attracts notable attention and has been elucidated more and more details. MAS mainly acts on the molecular components of exocytosis at a late stage. Insulin secretion induced by MAS is obviously dependent on GTP, which subsequently activates G-protein located on insulin secretion granules(ISG), or activates the Rho subfamily of small G proteins to evoke exocytosis and sensitize fusion machinery. The MAS stimulated insulin-releasing activity can be augmented by nutrients. However, its effect is not Ca2+ dependent. There are two regulatory pathway triggered by α-LTX: one way is pore formation caused through plasma membrane, another way is the transmembrane signal transduction evoked by cytosolic second messengers. Tetrameri complexs assembled at high concentration of α-LTX toxin or in the presence of extracellular Ca2+, can insert α-LTX into plasma membrane to form Ca2+ permeable channels and trigger Ca2+-dependent secretion. By binding to transmembrane receptors and activating phospholipase C, α-LTX induces the generation of second messenger DAG and IP3. IP3 triggers Ca2+ influx and subsequently activates CaMK pathway, however, DAG also activates PKC pathway to increase insulin release.     

Sleep EEG alterations: effects of pulsed magnetic fields versus pulse‐modulated radio frequency electromagnetic fields

Studies have repeatedly shown that electroencephalographic power during sleep is enhanced in the spindle frequency range following radio frequency electromagnetic field exposures pulse‐modulated with fundamental frequency components of 2, 8, 14 or 217 Hz and combinations of these. However, signals used in previous studies also had significant harmonic components above 20 Hz. The current study aimed: (i) to determine if modulation components above 20 Hz, in combination with radio frequency, are necessary to alter the electroencephalogram; and (ii) to test the demodulation hypothesis, if the same effects occur after magnetic field exposure with the same pulse sequence used in the pulse‐modulated radio frequency exposure. In a randomized double‐blind crossover design, 25 young healthy men were exposed at weekly intervals to three different conditions for 30 min before sleep. Cognitive tasks were also performed during exposure. The conditions were a 2‐Hz pulse‐modulated radio frequency field, a 2‐Hz pulsed magnetic field, and sham. Radio frequency exposure increased electroencephalogram power in the spindle frequency range. Furthermore, delta and theta activity (non‐rapid eye movement sleep), and alpha and delta activity (rapid eye movement sleep) were affected following both exposure conditions. No effect on sleep architecture and no clear impact of exposure on cognition was observed. These results demonstrate that both pulse‐modulated radio frequency and pulsed magnetic fields affect brain physiology, and the presence of significant frequency components above 20 Hz are not fundamental for these effects to occur. Because responses were not identical for all exposures, the study does not support the hypothesis that effects of radio frequency exposure are based on demodulation of the signal only.