底泥重金属镉对鳙鱼血细胞微核率的影响

目的 研究河流底泥重金属镉污染对鳙鱼血细胞微核率的影响。方法 在含不同浓度Cd^2 底泥环境下饲养鳙鱼，并分别于实验的15、25、35、45、55、65、75和85d，每次每组随机取4尾鱼，取其血细胞涂片、染色．测定其微核细胞率。结果 底泥Cd^2 含量与水体中Cd^2 浓度正相关；随水体中Cd^2 浓度升高，鳙鱼血细胞的微核细胞率也升高，表现出明显的量效关系。结论 河流底泥重金属镉污染对细胞遗传物质有损伤作用。     

甲醛对小鼠精子毒作用和微核作用的研究

目的 :观察甲醛对雄性小鼠的生殖毒性和致突变作用。方法 :用不同剂量 (5 0 mg· kg- 1、10 0 mg· kg- 1、15 0 mg· kg- 1、2 0 0 m g· kg- 1 )的甲醛溶液经腹腔染毒 ICR小鼠 ,2 4 h后用颈椎脱臼法处死 ,观察甲醛对小鼠精子形态的影响及对骨髓嗜多染红细胞的致微核作用。结果 :各剂量组精子畸形率和致微核作用均随浓度的增大而升高 ,呈现剂量反应关系。结论 :甲醛对小鼠有生殖毒性并具有一定的致突变作用。     

流式细胞仪筛选环磷酰胺诱导骨髓嗜多染红细胞微核的技术方法

目的利用单一荧光试剂吖啶橙(acridine orange,AO)和简单的单激光流式细胞仪(FCM)计数骨髓嗜多染红细胞的微核率,达到了解化合物诱导微核作用的目的。方法分别以环磷酰胺(CP)处理雄性KM小鼠和SD大鼠,采用AO荧光染色和单激光流式细胞仪检测小鼠和大鼠骨髓含微核的嗜多染红细胞(MNPCE)及含微核的成熟红细胞(MNNCE)的微核率,并对结果进行比较分析。结果随着CP浓度的增高,骨髓中MNPCE和MNNCE也相应增多,呈良好的量效关系。实验结果同时和手工计数比较,没有显著差异。结论 AO_FCM自动化检测方法完全适用于小鼠和大鼠骨髓MNPCE及MNNCE微核率的检测。     

基于负二项分布的确切推断在微核试验数据分析中的模拟研究

目的通过模拟研究对几种可用于小样本微核数据统计分析的方法进行讨论,为小样本微核数据的分析提供科学依据。方法用R软件进行编程模拟来估计不同参数下不同分析方法的Ⅰ类错误和检验功效。结果 Poisson精确概率法、Fisher精确概率法、负二项精确概率法、t检验及其变换、确切概率秩和检验的检验功效和Ⅰ型错误各不相同,其检验功效随δ和动物数n的增大而增大。其中Poisson精确概率法、Fisher精确概率法、负二项精确概率法的检验功效较高,但总体来自于负二项分布时,Poisson精确概率法、Fisher精确概率法的Ⅰ型错误较大,而负二项精确概率法Ⅰ型错误较小。结论在小样本微核数据分析中负二项精确概率法具有检验功效较高且犯Ⅰ型错误概率小的优越性。     

创新性实验在本科生实验课程中的应用

目的：探索医学细胞生物学创新性实验方法及培养学生的创新思维和动手能力。方法：在实验课程中,学生用10个X射线剂量照射小鼠,检测小鼠嗜多染细胞和外周血红细胞的微核率,通过查阅文献、骨髓提取、制片、实验记录与报告书写等步骤完成相应的研究工作。结果：学生掌握了文献查阅及综述撰写、小鼠嗜多染细胞和外周血红细胞的微核的测定方法、评价X射线的剂量与效应的关系、分析嗜多染细胞与红细胞微核率差异的意义及正确书写实验报告。结论：把创新性实验应用于实验课堂教学,提高了学生学习兴趣和参与科学研究的积极性,锻炼了学生的独立动手能力,提高了实验教学质量。     

Nuclear abnormalities in cells from nasal epithelium: a promising assay to evaluate DNA damage related to air pollution in infants

ObjectivesThis study intends to provide a quick, easy, and inexpensive way to assess nuclear abnormalities such as micronuclei and bud frequencies; binucleated, karyorrhectic, karyolytic, pycnotic, and condensed chromatin cells in nasal scrapings of infants, which are particularly important for conducting genotoxic studies related to the inhaled atmosphere in pediatric populations.MethodsNasal swab samples were collected from 40 infants under 12 months of age using a small cytobrush. 2,000 cells from each infant sample were analyzed and classified according to the frequency of nuclear abnormalities.ResultsRates of nuclear abnormalities found agree with values reported in other studies of neonates and children. This study found 0.13% of cells with micronuclei; 1.20% karyorrhexis; 0.03% pyknosis; 10.85% karyolysis; 1.11% condensed chromatin; 0.54 binucleated cells; and 0.02% nuclear bud. Differences were not observed between genders or environmental passive smoking, nor was any age correlation found.ConclusionThe assay proposed here is suitable for assessing the frequency of nuclear abnormalities from nasal cells in infants.     

铬酸盐低水平长期职业接触与劳动者早期健康效应

目的: 从肺功能、免疫毒性及遗传损伤方面综合探讨铬酸盐长期低水平职业接触对劳动者健康的影响,以期发现潜在的早期健康效应标志物。方法: 以内蒙古某职业卫生环境监测下长期符合国家标准的电镀企业22名铬酸盐接触工人和44名非铬酸盐接触工人为研究对象,问卷调查收集工人基本情况、吸烟饮酒史、疾病史等信息;分别采用便携式肺功能仪、电感耦合等离子体质谱法和胞滞分裂阻滞微核试验测定铬酸盐接触工人肺功能、全血铬(whole blood Cr, WB-Cr)和外周血淋巴细胞微核率(micronuclei frequency, MNF);采用流式微球阵列法检测两组工人血清细胞因子IL-1β、IL-6、IL-8、IL-10、IL-12P70和TNFα含量,分析铬酸盐接触对上述生物内暴露、肺功能、免疫应答、遗传损伤各指标的影响及不同损伤效应间的相关性。结果: (1)铬酸盐接触工人平均工龄为31年,WB-Cr浓度为1.11~4.19 μg/L,按中位数1.72 μg/L将铬酸盐接触者分为高暴露组和低暴露组,高暴露组平均WB-Cr水平(2.17 μg/L)高于低暴露组(1.58 μg/L)和健康人群参考值(1.74 μg/L, P<0.05);(2)肺功能检测发现10名(45.45%)铬酸盐接触工人出现单个或多个肺功能指标异常情况,其中大气道损伤指标呼气流量峰值(peak expiratory flow,PEF)与小气道损伤指标每分钟最大通气量(maximum ventilation volume,MVV)和FEF25%~75%分别与WB-Cr呈负相关(r=-0.53,P<0.05; r=-0.52, P<0.05; r=-0.44,P<0.05);(3)铬酸盐接触工人血清IL-1β,IL-6,IL-8和TNFα均高于对照人群(P<0.05), 且TNFα与WB-Cr间存在正相关,各细胞因子之间两两正相关(P<0.05);(4)铬酸盐接触工人淋巴细胞MNF平均为1.341%, 高于一般人群参考值0.436%(P<0.01),Poisson多元回归结果显示高暴露工人MNF高于低暴露工人,OR(95%CI)值为1.323(1.049,1.669);(5)多元线性回归结果显示肺功能指标用力呼气中段流量 (forced expiratory flow rate 25%~75%,FEF25%~75%)随TNFα升高而降低(P<0.05),未发现其他细胞因子、MNF、肺功能指标之间存在有统计学意义的相关性。结论: 长期低水平铬酸盐职业接触引起劳动者肺功能下降、免疫炎症反应、遗传损伤的发生,其中局部或全身炎症反应与肺功能下降有关。肺功能指标PEF、FEF25%~75%、MVV,血清细胞因子IL-1β、IL-6、IL-8、TNFα水平和外周血淋巴细胞微核率可能作为铬酸盐暴露的早期健康效应标志物。     

医用生物玻璃和磷灰石材料对小鼠骨髓细胞微核率的影响

采用啮齿类动物微核试验对医用生物玻璃材料和磷灰石材料的浸提液进行诱变性检测，结果显示，每一材料浸提液的浸提原液，１／５和１／１０倍浸提液３个剂量组诱导的多染红细胞微核率与溶剂对照组比较，无显著性差异，Ｐ〉０．０５，表明各剂量线的浸提液无诱发小鼠骨髓细胞微核增加作用。     

In vitro genotoxic effects of the insecticide deltamethrin in human peripheral blood leukocytes: DNA damage (‘comet’ assay) in relation to the induction of sister-chromatid exchanges and micronuclei

Deltamethrin, a synthetic dibromo-pyrethroid insecticide, is extensively used in agriculture, forestry and in household products because of its high activity against a broad spectrum of insect pests (both adults and larvae), its low animal toxicity and its lack of persistence in the environment. Data on the genotoxicity and carcinogenicity of deltamethrin are rather controversial, depending on the genetic system or the assay used. The aim of this study was to further evaluate the potential genotoxic activity of deltamethrin. The in vitro genotoxicity of deltamethrin has been evaluated by assessing the ability of the insecticide to damage DNA (as evaluated using the single-cell microgel-electrophoresis or ‘comet’ assay) or induce sister-chromatid exchanges (SCE) and micronuclei (MN) in human peripheral blood leukocytes. All treatments were conducted with and without the presence of an external bioactivation source (±S9mix). The results indicate that deltamethrin, in the presence of metabolic activation (+S9mix), is able to induce DNA damage (double- and single-strand breaks, alkali-labile sites and open excision repair sites) as revealed by the increasing tail moment values observed with increasing doses. The frequency of SCE and MN were not statistically increased in deltamethrin-treated cells as compared to controls, both with and without S9mix. However, lower deltamethrin doses were tested, as compared to ‘comet’ assay, because of cytotoxicity.