1800 MHz射频电磁场对人乳腺癌细胞基因表达的影响

目的了解GSM 1800MHz射频电磁场对人乳腺癌细胞株MCF-7细胞基因表达谱的影响,筛选射频电磁场的可能反应基因,判断射频电磁场对细胞功能的影响。方法体外传代培养的MCF-7细胞分为2组,分别接受GSM 1800MHz射频电磁场辐照和假辐照24h,辐照组细胞受比吸收率为2．0W／kg或3．5W／kg的射频电磁场间断辐照（5min开、10min关）,辐照结束后,立即抽提细胞总RNA,用基因芯片进行全基因转录组水平分析,芯片实验数据采用MAS5．0软件和DMT3．0软件进行分析。采用定量逆转录-聚合酶链反应（RT-PCR）验证基因芯片分析筛选到的候选差异表达基因。结果MAS软件分析结果表明,MCF-7细胞受辐照后,有少量基因的表达水平发生变化。用DMT软件进行重复性和一致性分析后,在比吸收率为2．0W／kg的射频电磁场辐照组,未找到100％一致变化的差异基因;在比吸收率为3．5W／kg的射频电磁场辐照组,找到5个100％一致变化的候选差异基因,但定量RT—PCR结果未能验证基因芯片分析筛选到的差异基因。结论在本实验条件下,未能检测到GSM 1800MHz射频电磁场明显影响MCF-7细胞的基因表达谱,提示所用的射频电磁场辐照不影响本研究中所用的MCF-7细胞功能,或该MCF-7细胞对射频电磁场辐照反应性低。     

移动电话射频电磁场诱导膜受体聚簇及噪声磁场的干预

目的 研究GSM 1 800 MHz射频电磁场（以下简称“射频场”）对细胞膜表皮生长因子（EGF）受体聚簇的可能诱导作用及噪声磁场的干预.方法 将中国仓鼠肺成纤维细胞（CHL）分别用1 800 MHz射频场（包括217和50 Hz调制和非调制）、噪声磁场和射频场与噪声磁场叠加的复合场处理15 min,用EGF处理作为阳性对照,射频场的比吸收率（SAR）值取0.1、0.5、1.0、2.0和4.0W/kg.上述处理后的细胞经间接免疫荧光染色标记后,用激光共聚焦显微镜观察其细胞膜EGF受体的聚簇现象.结果 SAR值为0.5、1.0、2.0和4.0W/kg的调制射频场辐照CHL细胞15 min可诱导细胞膜EGF受体的聚簇,但当SAR值为0.1 W/kg时,细胞膜不出现EGF受体聚簇.而非调制射频场以及2μT噪声磁场不能诱导细胞膜EGF受体的聚簇,当2μT噪声磁场与射频场叠加后,可抑制射频场诱导的细胞膜EGF受体聚簇.结论 GSM1 800 MHz射频场能诱导细胞膜EGF受体的聚簇,波的调制在其中起主要作用;一定强度的噪声磁场可阻断GSM 1 800 MHz射频场诱导的细胞膜EGF受体聚簇.     

1800 MHz射频电磁场对人乳腺癌细胞蛋白质表达的影响

目的采用高通量的蛋白质组学技术研究人乳腺癌细胞株MCF-7细胞受GSM 1800MHz射频电磁场辐照后,其蛋白质表达谱的变化,以探索移动电话信号对细胞正常生理功能的可能影响。方法比吸收率为3．5W／kg时,采用不同时间（1、3、6、12和24h）和辐照模式（间断辐射和连续辐射）的GSM 1800MHz射频电磁场处理MCF-7细胞后,直接抽提蛋白质,然后进行双向凝胶电泳。凝胶经银染后,使用PDQuest软件分析假辐照组与电磁场辐照组间的差异表达蛋白质斑点。每个实验重复3次。结果凝胶上平均可检测到1100个蛋白斑点。3．5W／kg连续辐射6h未发现差异点,其他暴露情况下均可检测到不同数量的差异蛋白,以3．5W／kg间断辐射3h和连续辐照12h检测的差异蛋白点较多,分别为18个和7个。通过搜索SWISS-PROT蛋白数据库,对差异蛋白的类别和功能进行了初步推测,结果表明差异蛋白主要与生物分子的合成和调控、信号转导、DNA损伤修复等功能相关。结论GSM 1800MHz射频电磁场对MCF-7细胞蛋白质表达谱具有一定程度的影响,且依赖于暴露的强度、时间和模式,影响环节可能涉及多个生物学过程。     

DNA damage recognition proteins localize along heavy ion induced tracks in the cell nucleus

To identify the repair dynamics involved in high linear energy transfer (LET) radiation-induced DNA damage, phospho-H2AX (gammaH2AX) foci formation was analyzed after cellular exposure to iron ions (Fe-ions, 500 MeV u(-1), 200 KeV microm(-1)). The foci located at DNA damage sites were visualized using immunocytochemical methods. Since H2AX is phosphorylated at sites of radiation-induced double strand breaks (DSB), gammaH2AX foci were used to detect or illuminate tracks formed by DSB after exposure to various doses of ionizing radiation. Additional DSB-recognition proteins such as ATM phospho-serine 1981, DNA-PKcs phospho-threonine 2609, NBS1 phospho-serine 343 and CHK2 phospho-threonine 68 all co-localized with gammaH2AX at high LET radiation induced DSB. In addition, Fe-ion induced foci remained for longer times than X-radiation induced foci. These findings suggest that Fe-ion induced damage is repaired more slowly than X-radiation induced damage, possibly because Fe-ion induced damage or lesions are more complex or extensive. Antibodies for all these phosphorylated DNA DSB recognition proteins appear to be very effective for the detection and localization of DSB.     

Flow cytometric analysis of phosphorylated histone H2AX following exposure to ionizing radiation in human microvascular endothelial cells

We applied a flow cytometric method to quantify IR-induced histone H2AX phosphorylation at serine 139 (gammaH2AX) and compared those values to those obtained using a standard microscopy based foci counting method. After PFA fixation, methanol permeabilization was suitable for both FITC- or Alexa647-gammaH2AX. In contrast, Alexa647-gammaH2AX was not suitable for ethanol permeabilization. Antibody concentrations at 1-2 microg/ml yielded the highest gammaH2AX positive percentage for both antibodies. Without DAPI staining, gammaH2AX formation can be measured as a relative fold increase. Values determined by bivariant flow cytometric analysis and those obtained using microscopic foci formation exhibited a good quantitative correlation. Values obtained by both methods could vary according to the gating or threshold setting used. gammaH2AX positive cells increased as a function of radiation dose (2-16 Gy) followed by a dose-dependent decay. The free radical scavenger N-acetyl-L-cysteine (NAC), if administered at a concentration of 4 mM 30 min before IR, was effective in reducing IR-induced gammaH2AX formation in all phases of the cell cycle. We have developed a simplified and quantitative flow cytometry based method to measure IR-induced gammaH2AX in cells and demonstrated strong correlation to values obtained by a standard automated digital microscopic foci analysis along with NIH ImageJ custom macro software.     

900 MHz电磁辐射对人胚肺细胞DNA及p53基因蛋白表达的影响

目的 研究900 MHz电磁辐射对人胚肺细胞DNA及p53基因蛋白表达的影响.方法 用900 MHz电磁波辐照细胞.单细胞凝胶电泳实验分为1、2、5、8 mW/cm2 4个暴露组,并设阴性对照组(0mW/cm2)和阳性对照组(0.1 mmol/L重铬酸钾处理),每组2个平行样,暴露时间均为1 h,检测拖尾率和DNA迁移长度.Western Blot实验分为1、2、5、8 mW/cm2 4个暴露组,并设阴性对照组(0 mW/cm2)和阳性对照组(淋巴瘤细胞株Raji),暴露时间均为12 h,检测电磁辐射对p53基因蛋白表达的影响.结果 与阴性对照组(0 mW/cm2)比较,各暴露组的拖尾率和DNA迁移长度差异无统计学意义(P＞0.05).各暴露组和阴性对照组(0 mW/cm2)的细胞中p53蛋白表达为阴性,而阳性对照组检测到了p53蛋白的表达.结论 本实验未观察到900 MHz电磁辐射对人胚肺细胞DNA及p53基因蛋白表达有影响.     

No effects of 900 MHz and 1800 MHz electromagnetic field emitted from cellular phone on nocturnal serum melatonin levels in rats

In this study, the effects of exposure to a 900 MHz and 1800 MHz electromagnetic field (EMF) on serum nocturnal melatonin levels of adult male Sprague-Dawley rats were studied. Thirty rats were used in three independent groups, 10 of which were exposed to 900 MHz, 10 of which were exposed to 1800 MHz and 10 of which were sham-exposed (control). The exposures were performed 30 min/day, for five days/week for four weeks to 900 MHz or 1800 MHz EMF Control animals were kept under the same environmental conditions as the study groups except with no EMF exposure. The concentration of nocturnal melatonin in the rat serum was measured by using a radioimmunoassay method. There were no statistically significant differences in serum melatonin concentrations between the 900 MHz EMF group and the sham-exposed group (P > 0.05). The values at 12:00 pm were 39.11 +/- 6.5 pg/mL in the sham-exposed group and 34.97 +/- 5.1 pg/mL in the 900 MHz EMF-exposed group. Also, there were no statistically significant differences in serum melatonin concentrations between the sham-exposed group and the 1800 MHz EMF-exposed group (P > 0.05). The values at 12:00 pm were 39.11 +/- 6.5 pg/mL in the sham-exposed group and 37.96 +/- 7.4 pg/mL in the exposed group. These results indicate that mobile phones, emitting 900 and 1800 MHz EMF, have no effect on nocturnal serum melatonin levels in rats.     

移动电话微波辐射对二甲基苯蒽诱发大鼠乳腺癌的影响

目的研究900MHz GSM微波辐射对二甲基苯并蒽（DMBA）诱发的SD大鼠乳腺癌是否有促进作用。方法500只大鼠按体重分为5个实验组,并按35mg／kg体重1次性灌胃给予DMBA。其中,1组为不给予辐照的空白对照组,其余4组的900MHz GSM微波辐照剂量为双盲,比吸收率值分别为：O（假辐照）、0．44、1．33和4．00W／kg。微波辐照开始于给予DMBA后第2天,持续26周,每周辐照5次,每次持续4h,在辐照全部结束后第3至第7天中处死动物,进行病理学和肿瘤发生学研究。结果假辐照组大鼠乳腺癌的发生率为37％（37／100）;辐照剂量分别为0,44、1．33和4．00W／kg的各组大鼠乳腺癌发生率分别为25％（25／100）、34％（34／99）和38％（38／100）,与假辐照组比较,均差异无统计学意义。病理组织形态学观察可见,该模型的乳腺肿瘤有恶性与良性两类,恶性肿瘤有乳腺腺癌和鳞状细胞癌,良性肿瘤有腺瘤、纤维腺瘤和乳腺囊肿。有时几种病理形态可同时出现在1个个体中,其组织病理表现呈多样性。结论在本实验条件下,900MHz的GSM微波辐射对DMBA诱发大鼠乳腺癌的发生无促进作用。     

Molecular mechanism of the recruitment of NBS1/hMRE11/hRAD50 complex to DNA double-strand breaks: NBS1 binds to gamma-H2AX through FHA/BRCT domain

DNA double-strand breaks represent the most potentially serious damage to a genome, and hence, many repair proteins are recruited to DNA damage sites by as yet poorly characterized sensor mechanisms. We clarified that NBS1 physically interacts with gamma-H2AX to form nuclear foci at DNA damage sites. The fork-head associated (FHA) and the BRCA1 C-terminal domains (BRCT) of NBS1 are essential for this physical interaction and focus formation of NBS1 in response to DNA damage. The inhibition of this interaction by introduction of anti-gamma-H2AX antibody into cells abolishes NBS1 foci formation in response to DNA damage. Consequently, the FHA/BRCT domain is likely to have a crucial role for both binding to histone and for re-localization of the NBS1/hMRE11/hRAD50 complex to the vicinity of DNA damage. Moreover, the foci formation of DNA repair-related proteins containing BRCT domain, such as BRCA1, requires the interaction with gamma-H2AX in response to DNA damage. These findings indicate that the physical interaction between gamma-H2AX and DNA repair-related proteins is indispensable for the recruitment of these proteins. Further, it was recently reported that the NBS1/hMRE11/hRAD50 complex has a crucial role for both the recruitment of ATM to DNA damage sites and the subsequent activation of ATM. Therefore, both gamma-H2AX and the NBS1/hMRE11/hRAD50 complex might function for the initial recognition of DNA damage.     

移动电话射频电磁场对大鼠神经细胞微管结合蛋白2基因表达的影响

目的了解1．8 GHz移动电话射频电磁场(RF EMF)对大鼠神经细胞基因表达的影响,筛选射频电磁场反应基因。方法体外原代培养新生SD大鼠皮层和海马神经细胞至第13天,将细胞随机分为实验组(辐照组)和对照组(假辐照组)。实验组使用217 HZ调制的1．8 GHz射频电磁场,SAR为2 W/kg,间断辐照24 h(5 min开/10 min关)；对照组置于同样的波导腔中,但不输入射频信号,进行假辐照。辐照后即刻抽提两组细胞的总RNA,然后用Rat Neurobiology U34 array基因芯片进行基因转录水平分析,找到可能的RF EMF反应候选基因。利用核糖核酸酶保护分析(RPA)法对功能相对明确、表达丰度和表达相对比值较高的变化基因进行验证。结果在Rat Neurobiology U34 array 1 200个候选基因中,筛选出34个差异表达基因,从中确定上调基因微管结合蛋白2(microtubule associated protein 2,Map2)为候选基因,经RPA方法验证,差异有统计学意义(P＜0．05)。结论Map2作为神经细胞特有的骨架蛋白,它的表达和功能的调控对于神经细胞维持正常细胞骨架和功能十分重要。1．8 GHz射频辐照可以引起大鼠神经细胞Map2基因表达上调。     

900MHz微波电磁辐射对原代培养的大鼠脑皮质神经元能量代谢的影响

目的　研究 90 0MHz微波电磁辐射对原代培养的大鼠脑皮质神经元能量代谢的影响。方法　将大鼠脑皮质神经元暴露于 90 0MHz的连续性微波电磁辐射 (SAR =3 2 2mW g、PD =9mW cm2 ) ,每天暴露 2h ,连续 4d或 5d ,及一次性 1 2h暴露 ,以细胞色素氧化酶为观察指标 ,研究微波对神经元能量代谢的影响。结果　微波电磁辐射可使神经元细胞色素氧化酶活性降低。结论　神经元细胞色素氧化酶活性的改变并非“致热效应”所致 ;微波电磁辐射对神经元细胞色素氧化酶活性影响有蓄积毒性作用 ,其影响在一定程度上是可恢复的 ,并且与神经元接受微波辐射时细胞培养年龄关系不密切。     

Vitamin D Resists Cyclophosphamide-Induced Genomic and DNA Damage in CHL Cells In Vitro and in Mice In Vivo

Vitamin D as an adjuvant therapy for cancer patients is hoped to have a beneficial outcome based on its physiological activity, but clinical trials so far by addition of vitamin D show unremarkable curative improvement, mechanism for explain this phenomena is not well-understood. The aim of this study was to determine whether vitamin D resists cyclophosphamide (CP)-induced genomic and DNA damage. In CHL cells in vitro, 1α,25-(OH)₂D₃ at 10, 50, and 100?nM was found to alleviate the frequency of chromosomal aberration with an alleviation range of 40.7–44.0%. There was a dose-dependent decrease for a proportion of γ-H2AX foci positive cells in response to an increase in 1α,25-(OH)₂D₃ concentration. Two vitamin D₃ injections of 1,000, 5,000, or 10,000?IU suppressed CP-induced micronucleus formation in mice BMCs with an alleviation range of 36.7–44.5%, mitigated lymphocytes DNA damage reflected by lower tail DNA, tail length and olive tail moment parameter in comet assay. Vitamin D showed an antagonistic effect on CP-induced genomic and DNA damage. Our data suggest that vitamin D as an adjuvant combine antineoplastic drug with genotoxicity administer to tumor patients is contraindicant.     

手机模拟电磁信号对人眼晶状体上皮细胞DNA损伤及修复的影响

目的 检测手机微波辐照2 h后人眼晶状体上皮细胞（human lens epithelial cells,LECs）的DNA损伤及其修复情况.方法 LECs分为辐照组和假辐照组,置于sXc-1800细胞辐照（发射217 Hz脉冲调制的1.8 GHz微波）系统内连续波辐照2 h,辐照强度比吸收率（specific absorption rate,SAR）分别为0、1、2、3、4W/kg,辐照后0、30、60、120、240min分别进行彗星试验检测尾长和尾相,以判定细胞DNA的损伤及其修复情况.结果 1和2 W/kg辐照诱导的DNA损伤与假辐照组相比,在各个检测时段的差异均无统计学意义（P＞0.05）;辐照后即刻进行的检测发现,3和4W/kg组DNA损伤与假辐照组相比,差异有统计学意义（P＜0.01）,3 W/kg组的差异在修复30 min后仍然存在,修复60min后消失,而4 W/kg组的差异在各检测时段持续存在.结论 SAR≤3 W/kg的1.8 GHz手机微波辐照2 h对体外培养的人眼晶状体上皮细胞不产生或产生可修复DNA损伤,4 W/kg的辐照剂量可导致细胞DNA不可逆性损伤.     

微波电磁辐射对大鼠脑神经元细胞色素氧化酶活力影响

目的研究不同强度900MHz微波电磁辐射对原代培养的大鼠脑皮质神经元能量代谢的影响。方法将Wistar大鼠脑皮质神经元暴露于不同强度900MHz的连续性微波电磁辐射[比吸收率（SAR）分别为0．38、0．76、1．15、2．23及3．22mW／g]，每天2h，连续暴露4-6d，以细胞色素氧化酶（CCO）为指标，研究微波对神经元能量代谢的影响。结果3．22mW／g连续4d微波暴露组低于对照组（P〈0．01）。0．38、0．76、1．15、2．23、3．22mW／g连续6d暴露组神经元CCO活力低于对照组（P〈0．01）；微波强度相对较高的暴露组CCO活力低于微波强度相对较低的暴露组。结论0．38～3．22mW／g的900MHz微波电磁辐射暴露可使神经元细胞色素氧化酶活力降低。微波电磁辐射对神经元细胞色素氧化酶活力影响有蓄积毒性作用。     

900MHz微波电磁辐射对大鼠大脑皮质神经元神经递质受体γ-氨基丁酸蛋白表达的影响

目的研究900MHz微波电磁辐射对原代培养大鼠大脑皮质神经元神经递质γ-氨基丁酸(GABA)受体表达的影响。方法将大鼠大脑皮质神经元暴露于900MHz的连续性微波电磁辐射(SAR=1.15~3.22W/kg),进行每天2h、连续6d暴露及一次性12h暴露,以GABA受体蛋白表达为观察指标,研究微波对神经元的兴奋性影响。结果微波电磁辐射影响神经元GABA受体表达。结论微波电磁辐射对神经元兴奋性影响可能存在“窗口效应”。     

SAR and temperature distribution in the rat head model exposed to electromagnetic field radiation by 900 MHz dipole antenna

Rats are often used in the electromagnetic field (EMF) exposure experiments. In the study for the effect of 900 MHz EMF exposure on learning and memory in SD rats, the specific absorption rate (SAR) and the temperature rise in the rat head are numerically evaluated. The digital anatomical model of a SD rat is reconstructed with the MRI images. Numerical method as finite difference time domain has been applied to assess the SAR and the temperature rise during the exposure. Measurements and simulations are conducted to characterize the net radiated power of the dipole to provide a precise dosimetric result. The whole-body average SAR and the localized SAR averaging over 1, 0.5 and 0.05 g mass for different organs/tissues are given. It reveals that during the given exposure experiment setup, no significant temperature rise occurs. The reconstructed anatomical rat model could be used in the EMF simulation and the dosimetric result provides useful information for the biological effect studies.     

辐射对沉默ATRX的H460细胞增殖以及DNA损伤修复的影响

目的 探讨辐射对沉默ATRX的肺癌H460细胞增殖和DNA损伤修复的影响及二者的关系。方法 靶向ATRX的3个慢病毒载体转染293T细胞后,慢病毒感染H460细胞,获得ATRX低/无表达的细胞株shATRX1-H460、shATRX2-H460和shATRX3-H460,并以shControl-H460作为对照,利用Western blot检测沉默效率。分别以克隆形成实验检测细胞增殖,免疫荧光技术检测γH2AX和Rad51焦点数,同时以Western blot检测PARP1、γH2AX和Rad51蛋白的表达。结果 shControl-H460细胞中可见ATRX表达,而shATRX1-H460、shATRX2-H460和shATRX3-H460细胞中ATRX表达均出现不同程度的降低。克隆形成实验显示,shATRX2-H460和shATRX3-H460细胞的存活分数（survival fraction,SF）均较shControl-H460细胞降低。shControl-H460和shATRX3-H460细胞经4 Gy照射后1 h,γH2AX焦点最多,而3 h时Rad51焦点最多,而后均降低,与shControl-H460细胞比较,在1和6 h时shATRX3-H460细胞γH2AX焦点,以及1、3和6 h时Rad51焦点显著增加（P<0.05,P<0.001）。而且shATRX3-H460细胞中PARP1、γH2AX和Rad51蛋白在3和6 h时均较shControl-H460细胞表达增加。结论 成功地获得靶向沉默ATRX的细胞模型,辐射后细胞增殖能力降低,可能与DNA损伤修复能力降低有关。     

芥子气对大鼠骨髓细胞DNA损伤的研究

目的　研究芥子气 (MG)对大鼠骨髓细胞DNA的损伤作用。方法　雄性SD大鼠随机分为 6组 ,腹腔注射生理盐水 (NS)、丙二醇、MG(0 .2、0 .4、0 .8、1.6mg/kg体重 ) ,分别于染毒后 0、2 4、4 8、72h处死各组的 5只大鼠 ,用单细胞凝胶电泳法分析大鼠骨髓细胞DNA的损伤情况。结果　在染毒后 0h各组的大鼠骨髓细胞DNA损伤差异无显著性 (P >0 .0 5 ) ;丙二醇组的大鼠骨髓细胞DNA迁移率和迁移度在染毒后 2 4、4 8、72h分别为 15 .4 %± 0 .2 1%、16 .0 %± 0 .19%、15 .7%± 0 .2 3%和 (11.4±0 .2 )、(13.5± 0 .3)、(12 .8± 0 .2 ) μm ,明显高于在同时刻的NS组水平 ,差异有显著性 (P <0 .0 5 ) ;各MG组的大鼠骨髓细胞DNA迁移率和迁移度在染毒后 2 4、4 8、72h分别高于在同时刻的NS组和丙二醇组水平 ,差异有显著性 (P <0 .0 5 )。结论　MG对大鼠骨髓细胞DNA有损伤作用 ,随剂量的增大损伤有上升的趋势 ,损伤呈时间依赖性。     

铁路电力牵引工频电磁场现场职业卫生学调查

目的 探讨铁路电力牵引工频电磁场对职工健康的影响。方法 对铁路电力牵引接触网和变电所周围环境进行工频电场和磁场强度的测定,通过问卷对工人的症状和体征进行调查,同时采集静脉血,进行血液学分析、免疫球蛋白水平测定和外周血淋巴细胞DNA损伤分析。结果 铁路电力牵引接触网和变电所周围环境均存在不同强度的工频电场和磁场。接触组工人白细胞、淋巴细胞数目及IgA和IgG水平明显低于对照组,外周血淋巴细胞DNA损伤率则明显高于对照组。结论 铁路电力牵引工频电磁场可影响工人的免疫功能,可能与工频电磁场引起淋巴细胞DNA损伤、从而启动细胞凋亡有关。     

Microwaves from GSM mobile telephones affect 53BP1 and gamma-H2AX foci in human lymphocytes from hypersensitive and healthy persons

The data on biologic effects of nonthermal microwaves (MWs) from mobile telephones are diverse, and these effects are presently ignored by safety standards of the International Commission for Non-Ionizing Radiation Protection (ICNIRP). In the present study, we investigated effects of MWs of Global System for Mobile Communication (GSM) at different carrier frequencies on human lymphocytes from healthy persons and from persons reporting hypersensitivity to electromagnetic fields (EMFs). We measured the changes in chromatin conformation, which are indicative of stress response and genotoxic effects, by the method of anomalous viscosity time dependence, and we analyzed tumor suppressor p53-binding protein 1 (53BP1) and phosphorylated histone H2AX (gamma-H2AX), which have been shown to colocalize in distinct foci with DNA double-strand breaks (DSBs), using immunofluorescence confocal laser microscopy. We found that MWs from GSM mobile telephones affect chromatin conformation and 53BP1/gamma-H2AX foci similar to heat shock. For the first time, we report here that effects of MWs from mobile telephones on human lymphocytes are dependent on carrier frequency. On average, the same response was observed in lymphocytes from hypersensitive and healthy subjects.