晶状体上皮细胞DNA损伤的SCGE测定法

目的 研究晶状体上皮细胞DNA的损伤.方法 应用单细胞凝胶电泳(SCGE)法测定氧化、辐射及细胞外高糖、高钙环境对晶状体上皮细胞DNA的损伤.结果 对照组中晶状体上皮细胞呈圆形无拖尾,表明其DNA未受损伤.各处理组细胞呈不同程度的典型彗星图像,头尾分明,与对照组相比差异具有显著性(P＜0.001).结论 以SCGE法测定出多种因素均可导致体外培养的晶状体上皮细胞DNA损伤,考虑其可能与白内障的形成有关.     

单细胞凝胶电泳在检测晶状体上皮细胞DNA氧化损伤中的应用

随着对晶状体上皮细胞氧化损伤的深入研究,多种方法被用来检测晶状体上皮细胞DNA的氧化损伤程度,近年来国内外所应用的单细胞凝胶电泳技术而得到了越来越普遍的重视,相关实验研究亦日渐增多,现就总结此项技术在检测晶状体上皮细胞DNA氧化损伤中的应用作一综述.     

微波辐射后晶状体上皮细胞与未辐射晶状体上皮细胞蛋白质组双向电泳图谱比较

[目的]比较正常晶状体上皮细胞与微波辐射后晶状体上皮细胞蛋白质组双向电泳图谱差异,从蛋白质组水平初步探索微波辐射对人眼晶状体的损伤。[方法]体外培养人晶状体上皮细胞株,随机分为实验组和对照组,实验组用SAR值为4.0 W/kg的1800 MHz制式微波辐照2 h,对照组同一辐射箱培养但不辐射。辐照后立即提取总蛋白质,固相pH梯度(IPG)等电聚焦双向凝胶电泳进行蛋白质分离,银染显色的凝胶通过GS-800扫描仪获取图像,使用PDQuest专业图像分析软件分析电泳图像。[结果]正常晶状体上皮细胞与微波辐射后晶状体上皮细胞分别检出897个和981个蛋白质斑点。对2张电泳图进行匹配后,发现有4个蛋白质点在辐射后细胞蛋白质组图谱中上调表达,3个蛋白质点下调表达。[结论]初步建立了人晶状体上皮细胞比较蛋白质组学的实验方法;差异蛋白质的发现为深入理解辐射性白内障发病机制提供了有益的线索。     

香烟烟雾对人支气管上皮细胞的氧化损伤研究

目的 探讨香烟烟雾对人支气管上皮细胞氧化损伤的影响,评价氧化损伤效应在香烟烟雾致肺癌中的作用.方法 体外培养人支气管上皮细胞(HBE),以DMSO作为吸收液采集香烟主流烟雾,MTT比色法测量香烟烟雾对HBE细胞的毒性,彗星实验和微核实验分别检测细胞DNA链断裂和细胞染色体损伤,同时使用荧光探针测定细胞内活性氧(ROS)的含量.结果 随着香烟烟雾浓度的增加,HBE细胞存活率逐渐下降;随着染毒时间的延长,香烟烟雾对HBE细胞的半数抑制浓度(IC50)逐渐降低,显示明显的剂量-效应和时间-效应关系.香烟烟雾可以诱导HBE细胞DNA链断裂,表现为细胞拖尾率增加,同时尾长、尾部DNA含量和Olive尾距均随香烟烟雾浓度增加而增大.香烟烟雾亦可诱导HBE细胞染色体损伤,当香烟烟雾浓度≥1支/L时,实验组微核率与对照组比差异均有统计学意义(P＜0.05).此外,HBE细胞ROS生成量与香烟烟雾浓度呈剂量-效应关系.结论 香烟烟雾可以直接诱导人支气管上皮细胞ROS增加,从而造成细胞毒性增加、染色体损伤和DNA链断裂,提示氧化损伤是香烟烟雾致肺癌的重要机制.     

二氧化硫衍生物对小鼠肝细胞DNA损伤的研究

目的研究SO2衍生物对小鼠肝细胞DNA的影响。方法运用单细胞凝胶电泳技术(又称彗星试验)对小鼠进行腹腔注射,三个染毒组SO2衍生物剂量为125,250,500mg/kg体重,对照组注射生理盐水,并测量SO2衍生物引起小鼠肝细胞DNA损伤的尾矩(OTM)。结果雄性小鼠肝细胞DNA的OTM值分别为0.95,4.99,9.83,15.50,雌性小鼠肝细胞DNA的OTM值分别为0.81,3.85,6.82,12.87,这提示SO2衍生物可引起小鼠肝细胞DNA损伤,且随SO2衍生物注射剂量的增加DNA损伤加重,并有明确的剂量效应关系(r=0.993～0.996,P<0.001)。另外SO2体内衍生物对雄性小鼠肝细胞DNA损伤比雌性小鼠严重。结论这些结果意味着SO2体内衍生物具有引起哺乳动物肝细胞DNA突变的潜在危险。     

工频磁场对人晶状体上皮细胞DNA双链断裂的影响

目的:采用γH2AX免疫荧光法观察工频磁场对人晶状体上皮细胞DNA双链断裂的影响.方法:将人晶状体上皮细胞暴露于0.4 mT、50 Hz工频磁场2 h、6 h、12 h、24 h、48 h,以0.1 μmol/L的DNA损伤剂4-硝基喹啉-1-氧化物作用1 h作为阳性对照,结束处理后进行γH2AX免疫荧光检测.计算细胞平均焦点数.将细胞平均焦点数及焦点阳性细胞率作为评价细胞DNA双链断裂程度的指标.结果:工频磁场暴露24 h的平均焦点数、γH2AX焦点阳性细胞率分别为(2.93±0.43)、(27.88±2.59)%,与假辐照组(1.77±0.37)、(19.38±2.70)%相比,差异具有显著性(P<0.05);工频磁场暴露48 h的平均焦点数、γH2AX焦点阳性细胞率分别为(3.14±0.35)、(31.00±3.44)%,与假辐照组相比,差异具有显著性(P<0.01);而工频磁场暴露2 h分别为(2.11±0.61)、(22.44±5.09)%,6 h分别为(2.18±0.47)、(22.59±3.08)%和12 h分别为(2.35±0.43)、(23.35±2.93)%,与假辐照组比较,差异没有显著性(P>0.05).结论:体外实验表明,0.4 mT工频磁场长时间辐照可以使人晶状体上皮细胞DNA双链断裂增加.     

氯化镉恶性转化16HBE细胞过程中DNA损伤的研究

目的 探讨氯化镉恶性转化人支气管上皮(16HBE)细胞中DNA断裂损伤情况,进一步揭示氯化镉的致癌机制.方法 采用单细胞凝胶电泳试验(彗星试验)检测氯化镉恶性转化人支气管上皮细胞中非转化16HBE细胞、氯化镉恶性转化第15代、第35代细胞及成瘤细胞的DNA链断裂情况.结果 与非转化16HBE对照细胞比较,氯化镉恶性转化16HBE第15代、第35代细胞和氯化镉诱发16HBE恶性转化细胞接种裸鼠成瘤细胞的DNA损伤率分别达22.00%、46.75.00%和49.00%,明显高于非转化16HBE细胞的4.75%损伤率(P＜0.001),三种细胞彗星尾长也显著大于非转化16HBE细胞(P＜0.001).结论 细胞DNA损伤可能是镉化物分子致癌的重要机制.     

氯化汞对离体小鼠骨髓细胞和睾丸生殖细胞DNA的损伤作用

目的:探讨氯化汞对小鼠骨髓细胞和生殖细胞DNA的损伤作用.方法:利用彗星试验(SCGE)技术检测0.01、0.1、1.0mmol/L氯化汞对离体小鼠骨髓细胞和睾丸细胞的DNA损伤.结果:0.01 mmol/L、0.1mmol/L、1.0 mmol/L氯化汞处理组骨髓细胞DNA损伤率分别为12.8%、57.2%和100%,与阴性对照组(5.5%)相比差异有显著性(P＜0.01);睾丸细胞DNA损伤率分别为26.7%、45.5%和98.0%;这与阴性对照组(6.0%)相比差异有显著性(P＜0.01).其相应的彗星细胞DNA迁移长度分别为:骨髓细胞(20.38±2.98)、(51.72±5.15)、(92.91±3.28);睾丸细胞(19.29±1.63)、(27.77±3.01)、(66.31±3.11);分别与阴性对照组[(12.32±0.61),(15.15±1.35)]相比差异有显著(P＜0.01).结论:氯化汞可引起DNA链损伤,且损伤随着氯化汞剂量增加而加重.     

体外培养下氢醌诱导淋巴细胞凋亡及对DNA损伤的影响

目的:研究氢醌对人淋巴细胞的细胞周期阻滞与凋亡、遗传毒性和氧化损伤作用。方法:离体培养淋巴细胞24 h后加S9液,设置氢醌低、中、高浓度(50,150,450μmol/L)组,另设空白对照组,经染毒处理后分别采用MTT比色法检测各组PBL相对存活率,FCM检测细胞周期和凋亡,DCFH-DA法检测ROS含量,FT-IR-ATR检测细胞损伤,SCGE检测DNA链断裂,微核实验检测染色体畸变。结果:氢醌能降低细胞存活度,诱导S+G2/M期周期阻滞,有明显促凋亡作用。细胞内ROS含量剂量依赖性增加,DNA/RNA的光谱区域(1 000～1 490 cm-1)峰型改变明显,高浓度氢醌(450μmol/L)诱导细胞DNA断裂与染色体畸变。结论:氢醌诱导人淋巴细胞结构和功能改变,与DNA氧化应激及DNA-蛋白质损伤有关。     

甲苯二异氰酸盐对人支气管上皮细胞通透性的影响

目的探讨甲苯二异氰酸盐(TDI)对正常人支气管上皮细胞(16HBE)活性氧(ROS)生成及通透性的影响。方法应用改良的Son氏等方法制备TDI-人血清白蛋白(TDI-HSA)。四唑盐(MTT)比色法检测不同浓度的TDI-HSA对正常人支气管上皮细胞株16HBE活力的影响。实验分4组:以未加任何处理因素的16HBE为对照组,20、60、100μg/ml的TDI-HSA处理16HBE 24 h,通过2’,7’-二氢二氯荧光黄双乙酸钠(DCFH-DA)细胞内ROS荧光染色,收集细胞后以流式细胞仪检测荧光强度。选择对ROS水平影响较大的100μg/ml的TDI-HSA处理16HBE 24 h。流式细胞仪定量检测抗氧化剂N-乙酰半胱氨酸(NAC)对TDI-HSA诱导ROS生成的影响,荧光显微镜观察照相。采用跨上皮电阻(TEER)法检测上皮单层细胞的通透性。结果 120μg/ml以下浓度的TDI-HSA对细胞活力无显著影响。ROS水平在对照组、20、60和100μg/ml组分别为:65.04±4.56,91.76±4.84,119.96±10.40,203.11±8.21。100μg/ml TDI-HSA组与对照组及20、60μg/ml组相比,16HBE的ROS水平显著升高(P<0.05)。对照组、100μg/ml TDI-HSA处理组、50 mmol/L NAC预处理组的细胞内ROS水平分别为:69.02±2.14,246.47±18.55,102.50±4.60;而TEER分别为:280.75±11.93,92.25±11.44,207.25±7.41。NAC可显著降低TDI-HSA诱导的ROS生成(P<0.05),改善氧化应激对单层细胞通透性的影响(P<0.05)。结论 TDI显著增加HBEROS的产生,其诱导的氧化应激部分参与支气管上皮细胞通透性的增加。这可能是TDI诱发哮喘的发病机制之一。     

Effect of Low Level Subchronic Microwave Radiation on Rat Brain

Objective The present study was designed to investigate the effects of subchronic low level microwave radiation(MWR) on cognitive function,heat shock protein 70(HSP70) level and DNA damage in brain of Fischer rats.Methods Experiments were performed on male Fischer rats exposed to microwave radiation for 90 days at three different frequencies: 900,1800,and 2450 MHz.Animals were divided into 4 groups: Group I: Sham exposed,Group II: animals exposed to microwave radiation at 900 MHz and specific absorption rate(SAR) 5.953 × 10-4 W/kg,Group III: animals exposed to 1800 MHz at SAR 5.835 × 10-4 W/kg and Group IV: animals exposed to 2450 MHz at SAR 6.672 × 10-4 W/kg.All the animals were tested for cognitive function using elevated plus maze and Morris water maze at the end of the exposure period and subsequently sacrificed to collect brain tissues.HSP70 levels were estimated by ELISA and DNA damage was assessed using alkaline comet assay.Results Microwave exposure at 900-2450 MHz with SAR values as mentioned above lead to decline in cognitive function,increase in HSP70 level and DNA damage in brain.Conclusion The results of the present study suggest that low level microwave exposure at frequencies 900,1800,and 2450 MHz may lead to hazardous effects on brain.     

Influence of electromagnetic fields and protective effect of CAPE on bone mineral density in rats

BACKGROUND: Most mobile phones emit electromagnetic radiation at 900 MHz or 1800 MHz. An electromagnetic field has some biological effects on the behavior of the cell population of bone. The aim of this work is to evaluate the effects of the radiation emitted by mobile phones on bone mineral density (BMD). The effects of caffeic acid phenethyl ester (CAPE) on the radiation-induced changes were also investigated. METHODS: In the study, 48 Sprague Dawley rats were used. Rats were divided into five groups as follows: control, irradiated with 900 MHz, irradiated with 900 MHz and treatment, irradiated with 1800 MHz, irradiated with 1800 MHz and treatment groups. The rats in the control group (first group) were left within the experimental setup during 30 min/day for 28 days without radiation exposure. Nine hundred-MHz radiation group was exposed to irradiate both second and third groups for 28 days (30 min/day); 1800-MHz radiation group was exposed to irradiate both fourth and fifth groups for 28 days (30 min/day). Third and fifth groups were also treated by CAPE for 28 days. Treatment groups received 10 microml/kg/day CAPE i.p. before the irradiation. Bone mineral densities were determined in all groups. RESULTS: BMD was found to be decreased in the irradiated groups and to be increased in the treatment groups. CONCLUSIONS: The changes were not significant (p >0.05).     

Effect of 935-MHz phone-simulating electromagnetic radiation on endometrial glandular cells during mouse embryo implantation

This study examined the impact of 935MHz phone-simulating electromagnetic radiation on embryo implantation of pregnant mice.Each 7-week-old Kunming (KM) female white mouse was set up with a KM male mouse in a single cage for mating overnight after induction of ovulation.In the first three days of pregnancy,the pregnant mice was exposed to electromagnetic radiation at low-intensity (150 μW/cm2,ranging from 130 to 200 μW/cm2,for 2-or 4-h exposure every day),mid-intensity (570 μW/cm2,ranging from 400 to 700 μW/cm2,for 2-or 4-h exposure every day) or high-intensity (1400 μW/cm2,ranging from 1200 to 1500 μW/cm2,for 2-or 4-h exposure every day),respectively.On the day 4 after gestation (known as the window of murine embryo implantation),the endometrium was collected and the suspension of endometrial glandular cells was made.Laser scanning microscopy was employed to detect the mitochondrial membrane potential and intracellular calcium ion concentration.In high-intensity,2-and 4-h groups,mitochondrial membrane potential of endometrial glandular cells was significantly lower than that in the normal control group (P<0.05).The calcium ion concentration was increased in low-intensity 2-h group but decreased in high-intensity 4-h group as compared with the normal control group (P<0.05).However,no significant difference was found in mitochondrial membrane potential of endometrial glandular cells between low-or mid-intensity groups and the normal control group,indicating stronger intensity of the electromagnetic radiation and longer length of the radiation are required to inflict a remarkable functional and structural damage to mitochondrial membrane.Our data demonstrated that electromagnetic radiation with a 935-MHz phone for 4 h conspicuously decreased mitochondrial membrane potential and lowered the calcium ion concentration of endometrial glandular cells.It is suggested that high-intensity electromagnetic radiation is very likely to induce the death of embryonic cells and decrease the chance of their implantati     

1800 MHz电磁波对大鼠心肌氧化应激的影响

目的 识别1 800 MHz电磁辐射对大鼠心肌组织氧化应激的影响.方法 采用0.5 mW/cm^2和1.0mW/cm^2功率密度的1 800 MHz电磁辐射连续暴露雄性SD大鼠21d,每天暴露12h,然后测定其心肌组织中的超氧化物歧化酶（SOD）、谷胱甘肽过氧化物酶（GSH-Px）和过氧化氢酶（CAT）活性.结果 0.5 mW/cm^2强度下暴露组心肌组织中SOD、GSH-Px和CAT活性低于虚拟暴露组,差异均有统计学意义（P＜0.05）;1.0 mW/cm^2强度下的暴露组和虚拟暴露组心肌组织中SOD、GSH-Px和CAT活性差异无统计学意义（P＞0.05）.结论 0.5mW/cm^2的功率密度的1 800 MHz电磁辐射致使大鼠心肌组织中SOD、CAT和GSH-Px的活性降低,产生氧化应激反应.     

Oxidative damage in the kidney induced by 900-MHz-emitted mobile phone: protection by melatonin

BACKGROUND: The mobile phones emitting 900-MHz electromagnetic radiation (EMR) may be mainly absorbed by kidneys because they are often carried in belts. Melatonin, the chief secretory product of the pineal gland, was recently found to be a potent free radical scavenger and antioxidant. The aim of this study was to examine 900-MHz mobile phone-induced oxidative stress that promotes production of reactive oxygen species (ROS) on renal tubular damage and the role of melatonin on kidney tissue against possible oxidative damage in rats. METHODS: The animals were randomly grouped as follows: 1) sham-operated control group and 2) study groups: i) 900-MHz EMR exposed (30 min/day for 10 days) group and ii) 900-MHz EMR exposed+melatonin (100 microg kg(-1) s.c. before the daily EMR exposure) treated group. Malondialdehyde (MDA), an index of lipid peroxidation), and urine N-acetyl-beta-d-glucosaminidase (NAG), a marker of renal tubular damage were used as markers of oxidative stress-induced renal impairment. Superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) activities were studied to evaluate the changes of antioxidant status. RESULTS: In the EMR-exposed group, while tissue MDA and urine NAG levels increased, SOD, CAT, and GSH-Px activities were reduced. Melatonin treatment reversed these effects as well. In this study, the increase in MDA levels of renal tissue and in urine NAG and also the decrease in renal SOD, CAT, GSH-Px activities demonstrated the role of oxidative mechanism induced by 900-MHz mobile phone exposure, and melatonin, via its free radical scavenging and antioxidant properties, ameliorated oxidative tissue injury in rat kidney. CONCLUSIONS: These results show that melatonin may exhibit a protective effect on mobile phone-induced renal impairment in rats.     

电磁辐射对小鼠神经系统超微结构影响的分析

目的 :探讨移动电话的电磁辐射对生物体的影响。方法 :用大众常用移动电话作为辐射源 ,工作频率为90 0MHz ,功率密度为 1190 μW cm2 ,在一定范围对小鼠辐射 2h d ,3 0d后把小鼠断颈处死 ,取出大脑皮层、海马和小脑进行电镜观察分析。结果 :电镜所见 ,处理组与对照组小鼠的神经系统的细胞超微结构未见明显异常。结论 :一定时间内 ,移动电话的电磁辐射 ,对小鼠神经系统的细胞超微结构并没有明显影响     

微波电磁辐射对小鼠卵母细胞钙离子浓度的影响

目的:探讨935 MHz微波电磁辐射对小鼠卵母细胞成熟过程中钙离子浓度的影响.方法:将7周龄昆明小鼠行腹腔注射促排卵药物,同时暴露于不同强度、不同时间的935 MHz微波连续辐射3d,应用激光扫描共聚焦显微镜下观察培养不同时间(0,2,4 h)的卵母细胞内钙离子浓度的变化.结果:1 400 μW/cm2,4 h/d组卵母细胞在培养0,2,4h与对照组相比钙离子浓度下降有显著性差异(P＜0.05),与1 400 μW/cm2,2 h/d组各培养时间段比较也均有显著性差异(P＜0.05),其余各组与对照组比较差异无显著性;在1 400 μW/cm2,4 h/d组内,培养0,2,4h分别观察时,4h观察组与0h、2h观察组比较有显著性差异(P＜0.05).结论:935 MHz微波电磁辐射可能通过增加小鼠卵母细胞钙离子释放来抑制小鼠卵母细胞成熟,并呈现出一定的剂量反应关系及累积效应.     

935 MHz微波电磁辐射对卵母细胞成熟的影响

目的:研究935 MHz微波电磁辐射对小鼠卵母细胞成熟的影响。方法:将促排卵小鼠暴露于不同强度、不同时间的935 MHz微波辐射,观察其对超排卵母细胞数以及不同时间间隔(0,8,24 h)生发泡破裂率、第一极体释放率及卵母细胞存活率的影响。结果:1 400μW/cm2,4 h/d组与对照组相比,第一极体释放率显著降低(0 h,P<0.01;8 h,P<0.01),卵母细胞存活率也明显下降(0 h,P<0.01;8 h,P<0.05;24 h,P<0.05);与1 400μW/cm2,2 h/d组比较,第一极体释放率均显著降低(0 h,P<0.01;8 h,P<0.01;24 h,P<0.05),卵母细胞存活率也均明显下降(P<0.01)。结论:935 MHz微波电磁辐射可抑制小鼠卵母细胞体内成熟,并具一定剂量反应关系及累积效应。