2 450 MHz微波辐射对大鼠海马长时程增强和脑组织脂褐素的影响

目的 探讨微波对学习记忆影响的作用机制。方法 对海马诱发电位的长时程增强(LTP)和脑脂褐素含量进行研究，用2450MHz微波理疗机为照射源，以大鼠为实验对象，分别采用在体海马诱发电位法和分光光度法。结果 10～25mW／cm^2强度范围内的连续微波，可以对弱条件刺激和强条件刺激引发的LTP的群峰电位(PS)峰值产生抑制作用，并存在强度一效应关系，在25mW／cm^2时脂褐素含量显著高于对照组和10mW／cm^2组(P＜0．05)。结论 10～25mW／cm^2强度范围内的2450MHz连续微波可以通过抑制海马LTP的生成和脑脂褐素含量增加，造成学习记忆损害。     

高功率微波辐射后大鼠海马组织中突触后致密物-95及cAMP反应元件结合蛋白的变化

目的 观察高功率微波(HPM)辐射后大鼠海马组织中突触后致密物(PSD)-95及cAMP反应元件结合蛋白(CREB)的变化。方法 采用10、30和100 mW/cm² HPM照射75只Wistar雄性大鼠,于辐射后6 h、1、7、14和28 d活杀取海马组织,采用免疫组化、凝胶阻滞实验和图像分析等技术,观察海马神经元中PSD-95及CREB的变化。结果 HPM辐射后大鼠海马神经元胞浆中PSD-95的表达有不同程度的增加;10 mW/cm²组辐射后6 h, PSD-95表达增加,于辐射后1 d达高峰,28 d基本恢复正常;100 mW/cm²组辐射后6 h, PSD-95表达增加,MOD于1 d达高峰,IOD于7 d达高峰,28 d基本恢复至正常水平;30 mW/cm²组于辐射后3 d内,海马组织CREB与DNA的结合能力进行性降低。结论 HPM辐射后大鼠海马PSD-95表达增加,CREB与DNA结合能力减弱,参与了HPM辐射后海马组织损伤及海马神经元突触可塑性改变的病理生理过程。     

S波段微波长期间歇照射对大鼠内分泌功能的影响

目的 研究S波段微波长期间歇照射对大鼠内分泌功能的影响.方法 二级Wistar 大鼠雌雄各半,随机分为假照射(对照)和照射组,分别给予4、10和20 mW/cm2照射,每次照射6min,每周固定2次照射,共照射12周.分别在照射的4、8和12周和停止照射后4周分批活杀,分离血清进行12项内分泌指标检测.结果 S波段微波长期间歇照射后,大鼠血清内分泌有部分指标出现变化.其中雌性大鼠随着照射时间延长,T3水平先降低后上升,10 mW/cm2组在照射8和12周、4及20 mW/cm2组在照射12周均明显升高(t=-2.586、-2.642、-5.075、-4.365,P＜0.05).FT3变化趋势与T3类似,照射4周时4及10 mW/cm2组雌性大鼠FT3水平明显低于对照组(t=2.275、2.510,P＜0.05),随后升高;照射12周3个照射组均明显高于对照组(t=-2.636,-2.851、-5.240,P＜0.05).TSH在照射4周时降低,其中10 mW/cm2组与对照组相比降低显著(t=2.300,P＜0.05),然后升高;20 mW/cm2组在照射8和12周时与对照组相比增高显著(t=-2.838、-3.651,P＜0.05).雄性大鼠皮质醇(COR)及促肾上腺皮质激素(ACTH)呈波动性变化,其中COR的4、10和20 mW/cm2组在照射8周时与对照组相比增高显著(t=-2.772、-2.234、-2.505,P＜0.05):20 mW/cm2组在照射12周时与对照组相比降低显著(t=3.067,P＜0.05).雌性大鼠E2在照射4周时略低于对照组,随后升高,10 mW/cm2组在照射8周时、3个照射组在照射12周时与对照组相比增高显著(t=-2.322、-3.179、-2.655、-4.716,P＜0.05);停止照射后4周回复,其中4 mW/cm2组E2水平明显低于对照组(t=2.250,P＜0.05).雄性大鼠T水平呈先升后降的趋势,10 mW/cm2组在照射8周时与对照组相比增高显著(t=-2.435,P＜0.05).上述指标在停止照射后均有一定程度恢复.结论 S波段微波长期间歇照射可引起大鼠的内分泌功能性损伤.

Abstract：

Objective To observe the effect of S-band micro-wave long-term intermittent irradiation on endocrine function in rats.Methods A total of 192 rats (male and female) were randomly divided into the sham-irradiation (normal control) groups and the irradiation groups.The irradiation groups were exposed with micro-wave at 3 dosages of 4,10 and 20 mW/cm2 for 6 min twice a week for 12 weeks,while no administration was given to control group.The endocrine parameters in blood serum were examined by radioimmunoassay at 4,8,12 week during irradiation and 4 week post-irradiation.Results After the irradiation of S-band microwave,parts of the endocrine parameters changed.T3 in famale rats decreased at first and then increased,especially in 10 mW/cm2 group at 8 and 12 week,20 mW/cm2 group at 4 and 12week(t =-2.586,-2.642,-5.075,-4.365,P <0.05).FT3 in famale rats had the similar trend asT3,significantly lower in 4 and 10 mW/cm2 groups than that in the control group at 4 week (t = 2.275,2.510,P <0.05),then increased,especially in three irradiation groups at 12 week (t =-2.636,-2.851,-5.240,P < 0.05).TSH decreased at 4 week,especially in 10 mW/cm2 group (t = 2.300,P < 0.05) ; and then increased in the irradiation groups at 20 mW/cm2 at 8 and 12 week (t =-2.838,-3.651,P <0.05).COR and ACTH in male rats showed changes in volatility,in which the 4,10 and 20 mW/cm2 groups at 8 week increased significantly (t =-2.772,-2.234,-2.505,P < 0.05),while 20 mW/cm2 group at 12 week decreased significantly (t=3.067,P < 0.05).E2 in female rats was slightly lower in irradiation groups at 4 week than the control group,then increased,especially in 10 mW/cm2 group at 8 week,three irradiation groups at 12 week (t =-2.322,-3.179,-2.655,-4.716,P < 0.05),and returned to the normal at 4 week post-irradiation,significantly lower in 4 mW/cm2 group than that in the control group (t = 2.250,P < 0.05).T in male rats increased first and then decreased,especially in 10 mW/cm2 group at 8 week(t =-2.435,P < 0.05).After exposure the above indexes restored to some extent.Conclusions The long-term intermittent irradiation of S-band microwave can cause adverse effects on the endocrine function of rats.     

Repeated exposure to low‐level extremely low frequency‐modulated microwaves affects baseline and scopolamine‐modified electroencephalograms in freely moving rats

Purpose: To compare in the electroencephalogram of rats the effects of scopolamine (an acetylcholine receptor antagonist) alone and after repeated exposure to low‐level microwaves modulated at extremely low frequency.

Materials and methods: Averaged frequency spectra (0.5–30?Hz) of the electroencephalogram were studied in freely moving rats with carbon electrodes implanted into the somatosensory cortex. The rats were repeatedly (3 days, 30?min?day^?1) exposed to low‐intensity (?0.3?mW?cm^?2) microwaves (915?MHz, 20‐ms pulse duration), amplitude modulated (square‐wave) at extremely low frequency (4?Hz).

Results: The exposure to extremely low frequency microwaves alone significantly enhanced the fast electroencephalographic rhythms (18–30?Hz). This effect was observed neither in subsequent sham‐exposure experiment nor in radiation‐naïve animals. In the microwave‐exposed rats, scopolamine (0.1?mg?kg^?1, subcutaneously) did not cause a slowing in the electroencephalogram that was shown in non‐exposed rats. A similarity between the scopolamine‐induced electroencephalogram effect in the microwave‐exposed rats and that of physostigmine (enhancing the acetylcholine level in the brain) in radiation‐naïve animals was noted. This paradoxical phenomenon stimulates new experimentation for understanding its mechanism(s).

Conclusions: The data obtained provide additional evidence that repeated low‐level exposure to extremely low frequency microwaves can modify an activity of cholinergic system in the brain.     

Influence of electromagnetic fields on reproductive system of male rats

Abstract

Purpose: Reports of declining male fertility have renewed interest in the role of environmental and occupational exposures in the etiology of human infertility. The aim of the present work was to investigate the effect of 10 GHz exposure on the male Wistar rat's reproductive system and to find out the possible causative factors.

Materials and methods: The study was divided into sham-exposed and exposed groups. Seventy day-old rats were exposed to 10 GHz microwave radiation for 2 h per day for 45 days at power density 0.21 mW/cm² and specific absorption rate (SAR) of 0.014 W/kg. After the end of the experiment, blood samples were collected for the estimation of in vivo chromosomal aberration damage and micronucleus test. Spermatozoa were taken out for estimation of Caspase-3, comet assay, testosterone and electron microscopy and compared with sham-exposed.

Results: The study of scanning electron microscopic revealed shrinkage of the lumen of the seminiferous tubules. Apoptotic bodies were found in exposed group. A flow cytometry examination showed formation of micronuclei body in lymphocytes of exposed group. Comet assay confirmed DNA (deoxyribonucleic acid) strand break. Testosterone level was found significantly decreased with the shrinkage of testicular size.

Conclusions: 10 GHz field has an injurious effect on fertility potential of male-exposed animals.     

安多霖对微波辐射致大鼠脑损伤的预防作用研究

目的 探讨安多霖对微波辐射致大鼠脑损伤的预防作用.方法 140只二级雄性Wiser大鼠随机分为5组:健康对照组、辐射对照组、低浓度(0.75 g·kg～·d-1)预防组、中浓度(1.5 g·kg～·d-1)预防组及高浓度(3 g·kg～·d-1)预防组.预防组每日1次灌胃给予安多霖溶液,连续给药工2周.给药结束后采用30 mW/cm.微波辐射大鼠15 min.于处理后6 h、7 d和14 d,采用Morris水迷宫检测大鼠学习和记忆能力,高效液相色谱检测海马氨基酸类神经递质含量,光镜和电镜观察海马组织学和超微结构变化.结果 微波辐射后7 d内,大鼠学习和记忆能力下降(F=0.000～0.043,P<0.05);微波辐射后6 h,4种氨基酸类神经递质含量均降低,其中谷氨酸、甘氨酸及γ-氨基丁酸降低明显(F=0.000～0.007,P<0.01);微波辐射后6 h、7 d,海马组织水肿,神经元变性;神经元线粒体肿胀、空化,内质网扩张,突触间隙模糊,血管周间隙增宽.低浓度预防组上述变化与辐射对照组相似.中浓度和高浓度预防组微波辐射后7 d内,大鼠学习和记忆能力损伤不明显,两者与辐射对照组相比,差异有统计学意义(F=0.015～0.028,P<0.05);微波辐射后6 h,4种氮基酸类神经递质含量均无明显下降,其中谷氨酸含量接近正常,两者与辐射对照组比,差异有统计学意义(F=0.000-0.042,P<0.05);微波辐射后6 h、7 d,海马组织无明显损伤.结论 30 mW/cm.微波辐射可引起大鼠学习和记忆能力下降、海马氨基酸类神经递质代谢紊乱及海马组织学和超微结构损伤;1.5和3 g·kg-1·d-1安多霖对微波辐射致大鼠脑损伤有预防作用.1.5 g·kg-1·d-1安多霖为预防微波辐射致大鼠脑损伤的有效剂量.

Abstract：

Objective To study the prevention effects of AduoLa Fuzhenglin(ADL)Oll the brain injury induced by microwave radiation in rats.Methods A total of 140 male Wismr rats were divided randomly into 5 groups,including control group,microwave exposed group,low dosage(0.75 g·kg-1·d-1)group.middle dosage(1.5 g·kg-1·d-1)group and high dosage(3 g·kg-1·d-1)group.Rats in three ADL groups were lavaged with ADL per day for 2 weeks before radiation.After administration,rats were exposed to microwave at 30 mW/cm2 for 15 min.The abilities of learning and memory were detected by Morris water maze,and the contents of amino acids neurotransmitter of hippocampus were detected by HPLC, then the histology and uhrastrncture of hippocampus were observed with light and electron microscope at 6 h,7 and 14 d after exposure.Results The abilities of learning and memory were declined(F=0.000-0.043,P<0.05)from 6 h to 7 d after exposure,and the contents of four kinds of amino acid neurotransmitter in hippocampus were decreased,of which GLU,GLY and GABA were decreased significantly(F=0.000-0.007,P<0.01)at 6h after exposure,then tissue edema,neuronal degeneration,neuron mitoehondria swelling and cavitation,endocytoplasmie rotieulum broaden,synaptic cleft blurred,and perivascular space widen were found in the hippocampus at 6 h and 7 d after exposure.The changes in low dosage group were similar to those of the radiation group.However,in middle and high dosage groups,the abilities of learning and memory were normal to some extent with the significant differences compared to the radiation group from 6 h to 7 d after exposure(F=0.015-0.028.P<0.05).The contents of four kinds of amino acid neurotransmitter were not decreased,especially GLU contents close tO normal level.There were significant differences between middle and high dosage groups and radiation group at 6 h after exposure(F=0.000-0.042,P<0.05).Moreover,no obvious injury in the hippocampus was observed in middle and high dosage groups at 6 h and 7 d after exposure.Conclusions Exposure to 30 mW/cm2 microwave radiation could decrease the abilities of learning and memory,induce amino acid neurotransmitter turbulence,and injure the histology and uhrastructure of hippocampus.ADL at the dosages of 1.5 and 3 g·kg-1·d-1 would have preventive effects on the injury induced by microwave exposure.The concentration of 1.5 g·kg-1 ·d-1 of ADL might be the effective dosage to prevent the brain damage after microwave exposure.     

不同强度微波辐射对小鼠脑组织钙、镁ATP酶活性的影响

目的　探讨微波对机体中枢神经系统作用的机理。　方法　用 2 45 0 MHz连续波微波理疗机为辐射源 ,以昆明小鼠为对象 ,观察在 1m W/ cm2、5 m W/ cm2和 10 m W/ cm2三种照射强度下 ,小鼠脑皮层、海马及丘脑细胞膜 Ca2 、Mg2 - ATP酶活性的变化情况 ,用组织化学方法测定其活性。　结果　 1m W/ cm2时 ,皮层、海马及丘脑 Ca2 、Mg2 - ATP酶活性均比对照组高 (P<0 .0 5 ) ,5 m W/ cm2 时 ,酶活性与对照组差别均无显著性的意义 ,10 m W/ cm2 时 ,皮层、海马酶活性比对照组显著降低 ,而丘脑则无明显变化。　结论　 2 45 0 MHz微波照射小鼠时 ,脑组织细胞膜上 Ca2 、Mg2 -ATP酶活性随照射强度不同而有不同变化。受高强度照射时 ,参与学习记忆功能的皮层、海马先于参与体温调节功能的丘脑受到影响     

Repeated exposure to low-level extremely low frequency-modulated microwaves affects cortex-hypothalamus interplay in freely moving rats: EEG study

Purpose:?To compare the effects of repeated exposure to extremely low frequency-modulated microwaves (ELF-MW) on cortical and hypothalamic electroencephalograms (EEG).

Materials and methods:?In 10 freely moving rats with carbon electrodes implanted into the cortex and dorsomedial hypothalamus, averaged frequency spectra (0.5–30?Hz) of the EEG were studied for five consecutive days either under sham exposures (five rats) or under mixed sham/MW-exposures (five rats). The rats were exposed to ELF-MW (915 MHz, 20-ms pulse duration, ～0.3 mW/cm², 4?Hz) intermittently (1-min ‘On’, 1-min ‘Off’) for 10?min (specific absorption rate, SAR, ～0.7 mW/g on average) several times per day, with 10-min pre- and post-exposure periods.

Results:?In baseline EEG, the activities of 3.2–6.0?Hz and 17.8–30.5?Hz dominated in the cortex and of 6.0–17.8?Hz in the hypothalamus. This cortical-hypothalamic imbalance was relatively stable at sham-exposures and insensitive to ELF-MW in all frequency ranges but one. ELF-MW increased the beta₂ (17.8–30.5?Hz) level in the hypothalamus to a greater extent than in the cortex, causing significant diminishing of the initial EEG bias between them. Moreover, a cumulative phenomenon under repeated exposures to ELF-MW was revealed.

Conclusions:?These results are in line with evidence that repeated low-level exposure to ELF-MW affects brain functioning and provide an additional approach when analysing underlying mechanisms.     

安多霖对高功率微波辐射大鼠生精细胞凋亡的影响及机制研究

目的 探讨安多霖对微波辐射的防护作用及作用机制。方法 选用SPF级雄性SD大鼠,随机分为3个给药组,剂量分别为3、6、9 g/kg,另设辐射模型组和健康对照组,每组20~21只。给药组大鼠连续灌胃安多霖20 d ,停药后,给药组和辐射模型组动物行一次平均功率密度为100 mW/cm²高功率微波全身辐照10min,健康对照组不辐照。动物分别于辐照后24、48 h和5 d 取睾丸组织,制作睾丸石蜡切片,采用原位末端标记术(TUNEL)检测睾丸生精细胞凋亡,免疫组化法检测细胞凋亡相关蛋白Bax和Bcl-2。结果 微波辐射后24、48 h和5 d,与健康对照组相比,辐射组睾丸生精细胞的凋亡数明显升高(t=-41.89、-11.29、-62.24,P<0.05),Bcl-2/Bax比值明显降低(t=8.49、4.36、4.47,P<0.05);而与辐射组相比,低、中和高剂量给药组的凋亡细胞数显著降低(F=5.25、9.79、15.35, P<0.05), Bcl-2/Bax比值明显升高(F=20.17、11.75、11.98, P<0.05)。结论 高功率微波辐射可诱导大鼠生精细胞凋亡增加,安多霖对细胞凋亡有明显抑制作用。安多霖抑制大鼠睾丸生精细胞凋亡的机制可能与其能够上调Bcl-2及下调Bax蛋白的表达,改变了Bcl-2/Bax的比值有关。     

Mutagenic response of 2.45 GHz radiation exposure on rat brain

Purpose:?To investigate the effect of 2.45?GHz microwave radiation on rat brain of male wistar strain.

Material and methods:?Male rats of wistar strain (35 days old with 130?±?10?g body weight) were selected for this study. Animals were divided into two groups: Sham exposed and experimental. Animals were exposed for 2?h a day for 35 days to 2.45?GHz frequency at 0.34?mW/cm² power density. The whole body specific absorption rate (SAR) was estimated to be 0.11?W/Kg. Exposure took place in a ventilated Plexiglas cage and kept in anechoic chamber in a far field configuration from the horn antenna. After the completion of exposure period, rats were sacrificed and the whole brain tissue was dissected and used for study of double strand DNA (Deoxyribonucleic acid) breaks by micro gel electrophoresis and the statistical analysis was carried out using comet assay (IV-2 version software). Thereafter, antioxidant enzymes and histone kinase estimation was also performed.

Results:?A significant increase was observed in comet head (P?<?0.002), tail length (P?<?0.0002) and in tail movement (P?<?0.0001) in exposed brain cells. An analysis of antioxidant enzymes glutathione peroxidase (P?<?0.005), and superoxide dismutase (P?<?0.006) showed a decrease while an increase in catalase (P?<?0.006) was observed. A significant decrease (P?<?0.023) in histone kinase was also recorded in the exposed group as compared to the control (sham-exposed) ones. One-way analysis of variance (ANOVA) method was adopted for statistical analysis.

Conclusion:?The study concludes that the chronic exposure to these radiations may cause significant damage to brain, which may be an indication of possible tumour promotion (Behari and Paulraj ).     

Juliana Littbrand-Denekamp (1943-2000)

Purpose: The aim of this study was to evaluate the effect of microwaves modulated at different frequencies on human electroencephalographic (EEG) rhythms.

Materials and methods: Thirteen healthy volunteers were exposed to microwaves (450 MHz) pulse-modulated at frequencies of 7, 14 and 21 Hz. The field power density at the scalp was 0.16 mW/cm². Our experimental protocol consisted of two five-cycle (1 min on and 1 min off) series of exposures at fixed modulation frequencies. A relative change in the EEG power with and without exposure was used as a quantitative measure. EEG frequencies recorded in the theta (4 – 6.8 Hz), alpha (8 – 13 Hz), beta1 (15 – 20 Hz), and beta2 (22 – 38 Hz) bands were analyzed.

Results: Modulated microwaves caused an increase in the average EEG alpha (17%) and beta (7%) power but the theta rhythm remained unaffected. Increases in the EEG alpha and beta power were statistically significant during the first half-period of the exposure interval (30 s) at the modulation frequencies of 14 and 21 Hz. Differences were found in individual sensitivity to exposure. Increases in the EEG beta power appeared statistically significant in the case of four subjects.

Conclusions: Our findings suggest that the effect of the 450 MHz microwave radiation modulated at 7, 14 and 21 Hz varies depending on the modulation frequency. The microwave exposure modulated at 14 and 21 Hz enhanced the EEG power in the alpha and beta frequency bands, whereas no enhancement occurred during exposure to the modulation frequency of 7 Hz.     

Thermal Effects of 2·45 GHz Microwaves on Survival and Viability of Chinese Hamster V-79 Cells

Summary

The possible existence of thermal effects specific to microwaves at 2·45 GHz and not found with classical heating in a waterbath was studied by measuring cell survival (colony-forming ability) and cell viability (the ability to exclude trypan blue) in Chinese hamster V79 cells. The microwaves were employed at high power densities (125 to 175 mW/cm²) corresponding to specific absorption rates ranging between 62 and 87 mW/g.

When matching the rises in temperature, the effects of microwave-induced hyperthermia at 125 mW/cm² on cell survival were comparable to those of classical heating. However, they were statistically significantly different when using power densities of 150 and 175 mW/cm². The response obtained in terms of cell viability appeared to be comparable. The conclusions are also valid when taking into account a correction factor for energy losses during microwave treatment.

The apparent specific effect of microwaves appears to be associated with exposures at high power densities involving short treatment times and rapid rises in temperature.     

微波辐射对小鼠联合型学习记忆功能及海马组织结构的影响

目的 探讨微波辐射对联合型学习记忆功能及海马组织结构的影响。方法 将小鼠按随机数表法分为假辐射组和微波辐射组,各27只。采用2.856 GHz、8 mW/cm²微波辐射C57BL/6N小鼠15 min,建立微波辐射动物模型。采用Morris水迷宫和穿梭箱行为学实验,研究微波辐射对小鼠空间学习记忆和联合型学习记忆功能的影响。观察海马组织病理学变化,研究微波辐射后海马组织超微结构改变。结果 Morris水迷宫结果表明,微波辐射后小鼠反向空间探索实验跨越平台次数减少,由(3.60±0.79)次降至(2.55±0.47)次(t = 2.21,P= 0.046);穿梭箱实验结果表明,辐射后小鼠平均主动逃避率显著下降(t = 2.70,P<0.05),平均主动潜伏期和总电击时间显著延长(t = -3.09、-3.02,P < 0.05)。辐射后8 d,海马CA3和DG区部分神经元核固缩,海马CA3区神经元凋亡、突触间隙模糊、胶质细胞肿胀、血管周隙增宽。结论 微波辐射可引起小鼠空间参考记忆能力及联合型学习记忆能力下降,海马组织形态学病理改变是其功能障碍的结构基础。     

Thermal Aspects of Biological Effects of Microwaves in Saccharomyces Cerevisiae

Summary

The formation of zygotes between two haploid strains of yeast (Saccharomyces cerevisiae) was determined under treatment with microwaves of 9·4 and 17 GHz at power levels up to 50 and 60 mW/cm² and a specific absorption rate below 24 mW/g, or with conventional heating. Microwave treatments at 9·4 GHz or 17 GHz at a power density of 10 mW/cm² produced an increase in zygote formation equivalent to that produced by conventional heating in an incubator, i.e. equivalent to a rise in temperature of 0·5 or 1°C. At higher power densities zygote formation was slightly increased by microwaves at 17 GHz as compared to microwaves at 9·4 GHz probably due to the higher absorption of microwaves at 17 GHz by intracellular water molecules. Under these conditions, microwaves had no effect on cell survival or the induction of cytoplasmic ‘petite’ mutations.     

不同条件微波辐射致大鼠学习和记忆能力及脑组织结构改变的影响研究

目的探讨微波单次和累积辐射对大鼠学习和记忆能力以及脑组织结构的影响。方法对80只二级SD大鼠采用单次和累积辐射,单次辐射平均功率密度分别为2 mW/cm2和11 mW/cm2,累积辐射组每天辐射,平均功率密度为4.68μW/cm2,连续辐射30 d。采用Morris水迷宫观察大鼠学习与记忆能力的改变,于辐射后1,7,14,30,60 d采用光镜和电镜观察大鼠脑组织学和超微结构的改变。结果 （1）单次辐射后,与正常对照组相比,各辐射组大鼠逃避潜伏期均在辐射后有不同程度延长。2 mW/cm2组辐射后1 d和2 d,大鼠逃避潜伏期差异有显著性,11 mW/cm2组辐射后1 d和3 d,逃避潜伏期有显著性差异。累积辐射后大鼠逃避潜伏期无显著性差异。（2）11 mW/cm2组辐射后7~14 d,大鼠海马和大脑皮质神经元皱缩,核固缩,线粒体肿胀,局部空化,内质网扩张,突触间隙不清、囊泡减少,血管内皮连接增宽;累积辐射后14 d,大鼠海马及大脑皮质神经元固缩,线粒体肿胀空化,内质网扩张,突触间隙不清。结论 2和11 mW/cm2微波单次辐射可使大鼠学习和记忆能力下降,大鼠脑组织结构损伤;4.68μW/cm230 d微波累积辐射可引起大鼠脑组织结构损伤。     

高功率微波辐射对大鼠血脑屏障的影响

目的：研究高功率微波辐射对大鼠血脑屏障结构和功能的影响。方法：以10、30和100mW／cm^2高功率微波源辐射66只二级雄性Wistar大鼠。于辐射后6h、1d、3d和7d灌注2％亚铁氰化钾和4．2％硫酸铁后取材，通过HE染色、组织化学、免疫组化和图像分析等技术，研究毛细血管形态、血脑屏障通透性及GFAP改变。结果：10mW／cm^2组大鼠血脑屏障无明显改变。30和100mW／cm^2组辐射后1～3d血管间隙增宽，组织水肿，指示剂通透性增加。上述改变于辐射后3d达高峰，7d基本恢复。皮质血管较海马血管改变明显，100mW／cm^2组重于30mW／cm^2组。30和100mW／cm^2组大鼠皮质和海马组织中GFAP表达增强，3d达高峰，7d仍高于假辐射组。结论：一定剂量高功率微波辐射可损伤大鼠血脑屏障结构和功能。     

In vitro photodynamic inactivation of Candida spp. by different doses of low power laser light

This study evaluated the efficacy of PDT in photoinactivation of Candida species using methylene blue (MB) and irradiation with a diode laser (660 nm, 40 mW). Suspensions of Candida species were obtained containing 10⁶ cfu/ml, transferred to 96-holes plates and exposed to 03 doses of laser light (60 J/cm², 120 J/cm², 180 J/cm²) in the presence of MB. Additional suspensions were treated with only the MB, the laser light or with 0.85% saline (control groups). After the treatments, 1 μl aliquot of the suspensions was plated in duplicate on SDA. The plates were incubated at 37 °C for 24–48 h and after this period there was the counting of colonies (cfu/ml). The three evaluated doses determined meaningful inactivation of Candida spp. (p < 0.05). The 180 J/cm² dose was the most effective, inactivating 78% of cfu/ml. At a dose of 180 J/cm²C. albicans was the most susceptible specie. PDT has demonstrated effectiveness in the inactivation of Candida spp.     

Exposure of tumor-bearing mice to extremely high-frequency electromagnetic radiation modifies the composition of fatty acids in thymocytes and tumor tissue

Abstract

Purpose: To test the participation of fatty acids (FA) in antitumor effects of extremely high-frequency electromagnetic radiation (EHF EMR), the changes in the FA composition in the thymus, liver, blood plasma, muscle tissue, and tumor tissue in mice with Ehrlich solid carcinoma exposed to EHF EMR were studied.

Materials and methods: Normal and tumor-bearing mice were exposed to EHF EMR with effective parameters (42.2 GHz, 0.1 mW/cm², 20 min daily during five consecutive days beginning the first day after the inoculation of tumor cells). Fatty acid composition of various organs and tissues of mice were determined using a gas chromatography.

Results: It was shown that the exposure of normal mice to EHF EMR or tumor growth significantly increased the content of monounsaturated FA (MUFA) and decreased the content of polyunsaturated FA (PUFA) in all tissues examined. Exposure of tumor-bearing mice to EHF EMR led to the recovery of FA composition in thymocytes to the state that is typical for normal animals. In other tissues of tumor-bearing mice, the exposure to EHF EMR did not induce considerable changes that would be significantly distinguished between disturbances caused by EHF EMR exposure or tumor growth separately. In tumor tissue which is characterized by elevated level of MUFA, the exposure to EHF EMR significantly decreased the summary content of MUFA and increased the summary content of PUFA.

Conclusions: The recovery of the FA composition in thymocytes and the modification of the FA composition in the tumor under the influence of EHF EMR on tumor-bearing animals may have crucial importance for elucidating the mechanisms of antitumor effects of the electromagnetic radiation.     

Parametric mechanism of excitation of the electroencephalographic rhythms by modulated microwave radiation

Abstract

Purpose: The aim of this study was to evaluate the mechanism of parametric excitation of the electroencephalographic (EEG) rhythms by modulated microwave radiation.

Materials and methods: The model of parametric excitation based on polarization of water molecules was proposed and experimental results compared to the model. The experiments were carried out on 28 human volunteers. The 450 MHz microwave radiation modulated at 7, 14, 21, 40 and 70 Hz frequencies was applied at the field power density 0.16 mW/cm². The resting EEG was recorded in 8 channels and EEG power at selected frequencies was analyzed. A relative change in the EEG power during 10 cycles with and without radiation was used as a quantitative measure.

Results: Microwave radiation caused an increase in the average EEG power in all selected EEG frequency bands. Increase in the EEG power was statistically significant only at the EEG frequency f₀ to modulation frequency F ratios f₀ /F = 0.25, 0.5 and 0.75.

Conclusions: Results of the experimental study are in accordance with the proposed model of parametric excitation of the brain neural oscillations and demonstrate that modulated microwave radiation causes excitation of the brain EEG rhythms at the frequencies predicted by the non-linear model.     

An investigation of the effects of TETRA RF fields on intracellular calcium in neurones and cardiac myocytes

Purpose:?This study aimed to determine whether Terrestrial Trunked Radio (TETRA) fields can affect intracellular calcium signalling in excitable cells.

Materials and methods:?Intracellular calcium concentration ([Ca^{2 +} ]_i) was measured in cultured rat cerebellar granule cells and cardiac myocytes during exposure to TETRA fields (380.8875 MHz pulse modulated at 17.6 Hz, 25% duty cycle). [Ca^{2 +} ]_i was measured as fura-PE3, fluo-3 or fluo-4 fluorescence by digital image analysis.

Results:?Granule cells exposed at specific absorption rates (SARs) of 5, 10, 20, 50 or 400 mW · kg^?1 showed no significant changes in resting [Ca^{2 +} ]_i. Increases in [Ca^{2 +} ]_i in response to potassium-induced depolarization were significantly different from sham controls in TETRA-exposed cells, but the majority of the difference was attributable to initial biological variation between cell cultures. No difference was found between fura-PE3 (UV excitation) and fluo-3 (visible light excitation) measurements in these cells. Exposure to TETRA (50 or 400 mW · kg^?1) had no significant effect on either the rate or amplitude of spontaneous Ca^{2 +} transients in cardiac myocytes. The cells showed normal responses to salbutamol (50 μM) and acetylcholine (10 μM).

Conclusions:?Overall, these results showed no evidence of any consistent or biologically relevant effect of TETRA fields on [Ca^{2 +} ]_i in granule cells and cardiac myocytes at any of the SAR tested.