外周血淋巴细胞复合染色体畸变作为高LETα粒子照射的潜在生物标志

目的 :测定高传能线密度 (L ET) α粒子照射后诱导外周血淋巴细胞复合染色体畸变和传递至二次、三次分裂细胞的份额。研究复合染色体畸变作为既往照射的生物标志的可用性。方法 :将 4名自愿供血者外周血中分离的淋巴细胞在RPMl 16 40培养基中培养。用 2 3 8Pu源的高 L ETα粒子(12 1ke V;0 .5 Gy)或低 L ET X射线 (2 5 0 k V;3Gy)照射培养细胞。收获照射后一次、二次和三次分裂细胞 ,用荧光原位杂交 (FISH)和二脒苯基吲哚 (DAPI) / Hoechst332 5 8多色染色技术分析各次分裂细胞的染色体畸变。用 1、2和 5号全染色体探针和着丝粒…     

M-FISH技术检测辐射诱导染色体易位和双着丝粒畸变

目的　探讨用多色荧光原位杂交 (M FISH)技术检测的易位和双着丝粒染色体畸变的差异。方法　用 1,2 ,3,7,8,9,14和 15号染色体端粒和着丝粒特异性探针的M FISH方法 ,分析6 0 Coγ射线离体照射的脐带血淋巴细胞染色体易位和双着丝粒畸变。结果　 (1)用M FISH方法分析6 0 Coγ射线诱导的易位和双着丝粒染色体畸变的剂量 效应曲线 ,均符合线性二次剂量效应模式 ;易位与双着丝粒的比值在大多数剂量水平不等于 1。 (2 )细胞中无非稳定性畸变的完全相互易位的比例随着吸收剂量的增加而降低。 (3)对大多数被标记染色体 ,3 0 0Gyγ射线照射诱发的染色体畸变观察值与理论值无差别 ;9号染色体畸变 (易位和双着丝粒 )观察值显著高于理论值 (P <0 0 5或P <0 0 1) ,15号染色体易位观察值显著低于理论值 (P <0 0 1)。结论　电离辐射诱导的染色体易位率不等于双着丝粒畸变率 ;对于大多数染色体 ,辐射诱发染色体易位率和双着丝粒畸变率符合随机性规律。     

南京“5.7” 192Ir源放射事故患者的生物剂量估算

目的 用3种方法估算南京"5.7" ¹⁹²Ir源放射事故患者的生物剂量,为核与辐射事故受照者的临床救治提供剂量资料。方法 受照后第5天采集患者外周血,分别进行外周血淋巴细胞染色体"双着丝粒+环"("dic+r")畸变分析、胞质分裂阻滞微核(CBMN)分析、核质桥(NPB +FHC)分析,并估算生物剂量。用双着丝粒畸变在细胞间的泊松分布情况检验照射的均匀性。结果3种方法估算的该患者受到的一次全身等效剂量分别为"dic+r"畸变分析1.51 Gy (95% CI 1.40~1.61),CBMN 分析1.47 Gy (95% CI 1.36~1.60),NPB+FHC分析1.30 Gy(95% CI 1.00~1.60)。泊松分布检验结果显示,该患者"dic+r"畸变偏离泊松分布,受到了不均匀照射。结论 外周血淋巴细胞染色体"dic+r"畸变分析、CBMN分析、NPB+FHC分析均是有效的生物剂量估算手段,对本例急性局部不均匀照射患者估算的一次全身等效剂量与临床诊断结果相符。     

用FISH分析人淋巴细胞染色体畸变对~(60)Coγ射线的剂量反应及对生物剂量的可用性

目的:研究用荧光原位杂交(FISH)法分析人淋巴细胞染色体畸变对γ射线的剂量反应关系,并考虑如何应用于剂量重建。方法:采自31岁健康男子的抗凝全血,在37℃用60Coγ射线照射,剂量为0.25～4Gy(剂量率为0.5Gy·min-1)。富集的淋巴细胞在Eagle′s最低必需培养基(MEM)加10%胎牛血清的培养液中培养48h,获得中期细胞,固定后在-20℃保存供彩涂染色。用FISH法彩涂2、3、5号染色体和所有着丝粒,记录稳定性染色体畸变和复染染色体的非稳定性畸变。结果:彩涂的和全基因组的双着丝粒相对数符合刻度基因组当量的Lucas假说。全基因组双着丝粒(dic)的…     

不同剂量60Co γ 射线部分照射人离体血对染色体畸变形成的影响

目的 分析不同剂量60Co γ射线部分照射人离体血对淋巴细胞染色体畸变形成的影响.方法 用0～8 Gy(剂量率为0.35 Gy/min)60Coγ射线在37 ℃条件下照射3份离体健康人外周血标本,以0.5∶1的比例与同一供血者的未受照血混合,120 min后进行培养、制片,显微镜下分析染色体畸变(双着丝粒+着丝粒环)的变化,借此进行剂量估算.结果 各组的双着丝粒体+着丝粒环和总畸变,以及断片和单体断裂均随着剂量的增加而增加.用双着丝粒+着丝粒环进行的剂量估算,0.5～2 Gy组大于照射剂量的1/3,4～8 Gy组均接近照射剂量的1/3.结论 染色体畸变可以作为估算非均匀照射的生物学指标之一.

Abstract：

Objective To investigate the effects of 60Co γ-ray partial radiation on chromosome aberration in human peripheral blood in vitro.Methods The samples of heparinized peripheral whole blood from 3 healthy persons were exposed to 60Co γ-rays at the doses between 0 and 8 Gy with the dose rate of 0.35 Gy/min at the temperature of 37 ℃ ,and then mixed with the unirradiated blood samples of the Microscopy was used to observe the chromosome aberration double ( centromere + centromere) and the biological dose was estimated thereby.ResultsThe amounts of double centromere + centromere were increased along with the dose of irradiation in all groups.The estimated biological dose was higher than the 1/3 of the irradiation dose when the dose was between 0.5 to 2 Gy,and was close to the 1/3 of the irradiation dose when the dose was between 4 to 8 Gy.Conclusion Chromosome aberration can be used as a biomarker in estimation of uneven irradiation.     

南京^192Ir放射事故患者照后第4年细胞遗传学随访

目的用5种细胞遗传学方法对南京192Ir源放射事故患者进行照后第4年随访,筛选回顾性剂量估算指标,为探明电离辐射远后效应提供依据。方法采集事故患者外周血,进行非稳定性染色体畸变(双着丝粒+着丝粒环)、微核和核质桥分析,应用荧光原位杂交技术及G显带方法检测染色体易位,并估算生物剂量。结果荧光原位杂交技术及G显带方法检测染色体易位估算的剂量分别为1.45和1.21 Gy,与事故后短期内估算的生物剂量相近;非稳定性染色体畸变、微核、核质桥估算的剂量分别为0.56、0.45、0.41 Gy,低于事故后短期内估算的生物剂量,其修正系数与时间的变化规律符合幂函数模型。结论荧光原位杂交技术及G显带方法检测染色体易位估算方法,适用于回顾性剂量估算,应用非稳定性染色体畸变进行回顾性剂量估算需用修正系数进行校正。     

南京“5.7” 192Ir放射事故患者三种生物剂量估算指标的衰变规律探讨

目的 观察南京"5.7" ¹⁹²Ir放射事故患者受照后不同采血时间对生物剂量估算的影响,探讨3种生物剂量估算指标在体内的自然衰减规律。方法 事故后5、40和280 d,采集患者的外周血,分别进行外周血淋巴细胞染色体"双着丝粒+环"("dic+r")畸变分析、胞质分裂阻滞微核(CBMN)分析、核质桥+融合+马蹄形+环(NPB +FHC)分析。观察受照后不同时间染色体"dic+r"畸变、微核、NPB +FHC衰变情况及对生物剂量估算结果的影响。结果 与事故后5 d的估算剂量相比,在40和280 d,染色体"dic+r"畸变分析估算的剂量分别下降34%和49%, CBMN的估算结果分别下降48%和79%,NPB +FHC的估算结果分别下降48%和75%。结论 本例事故患者受照后3种生物剂量估算指标在体内呈进行性下降,染色体"dic+r"/细胞的半衰期为40 d,3个指标在40 d时剂量估算结果与5 d时比较,相对偏差 > 20%。     

介入诊疗对心血管病患者外周淋巴细胞DNA的损伤

目的探讨心血管病介入诊疗中的X线电离辐射对心血管病患者DNA损伤的影响。方法收治接受心血管病介入诊疗患者244例,按介入术式不同分为四组:经皮冠状动脉造影术组87例,经皮冠状动脉介入术组72例,射频消融术组48例,起搏器植入术组37例。分别于术前、术后2 h、24 h抽取患者外周血,检测外周血淋巴细胞染色体微核。同时记录患者手术全程辐射的累积皮肤表面入射剂量(CD)、面积剂量乘积(DAP)、透视时间(FT)等,观察各种介入诊疗中患者接受的辐射损伤程度和差异。结果经皮冠状动脉支架置入术组CD和DAP值显著高于其他三组,而其他三组间CD和DAP值差异无统计学意义(P>0.05)。患者术后2 h染色体微核率为16.3‰±4.2‰,P<0.05),术后24 h为17.5‰±5.1‰,,明显高于术前水平(13.8‰±4.7‰,P<0.05)。结论不同介入术中,患者接受的辐射剂量不同,但介入诊疗中的电离辐射都可能会造成患者的DNA损伤。     

染色体畸变率估算32P的辐射剂量

目的 应用G显带的染色体双着丝粒畸变率评估32p的辐射剂量.方法 应用4 MV的X射线对离体人血液进行0.5 Gy、1 Gy、2 Gy和4 Gy的照射,建立染色体双着丝粒畸变率和X射线的辐射剂量的剂量-效应曲线.将74 kBq的32p胶体加入淋巴细胞的培养液后72 h,进行G显带染色体分析,通过X射线的辐射剂量和染色体双着丝粒畸变率的剂量-效应曲线来评估32p的辐射剂量.结果 4 MV的X射线的辐射剂量和染色体的双着丝粒畸变率呈线性正相关,剂量-效应曲线为y=24.05x- 13.34 (R2=0.975).74 kBq的32P胶体产生的染色体双着丝粒畸变率为18％,即74 kBq的32p胶体在5 ml淋巴细胞培养液中72 h约产生1.3 Gy的辐射剂量.结论 应用染色体畸变率可以有效地评估放射性核素的内照射剂量.     

包钢选矿厂含钍粉尘作业工人外周血淋巴细胞适应性反应的研究

目的 探索低剂量天然放射性钍是否诱导出职业人员的外周血淋巴细胞适应性反应。方法 选择包钢选矿厂含钍粉尘作业工人(暴露组)和对照人员各20例,采集外周静脉血,分析染色体畸变。同时,对采集的外周血用⁶⁰Coγ射线离体照射2.0Gy,分析非稳定性染色体畸变或用单细胞凝胶电泳分析DNA链断裂水平。结果 照射前两组的双着丝粒畸变暴露组较高,照射2.0Gy⁶⁰Coγ射线后观察到的双着丝粒畸变暴露组低于对照组,但两组间差异无统计学意义(U=0.0026、0.0084,P>0.05),三着丝粒畸变在两组间差异具有统计学意义(U=3.1622, 0.001<P<0.002);两组间的"彗星"尾长差异有统计学意义(t=25,P<0.001)。结论 低剂量天然放射性钍诱导出职业人员的外周血淋巴细胞染色体畸变和DNA损伤的适应性反应。     

《中华放射医学与防护杂志》创办者之一姚家祥(1922—2021)

《中华放射医学与防护杂志》的创办者之一、中国疾控中心辐射安全所姚家祥研究员因病医治无效,于2021年12月23日上午7点40分逝世,享年100岁。     

高本底辐射诱发居民外周血淋巴细胞染色体畸变的剂量效应关系

目的通过人群调查探讨高本底辐射诱发居民染色体畸变的剂量效应关系,为建立环境小剂量辐射剂量效应模型和评估群体剂量提供参考。方法３９名调查对象选自高本底和对照地区１３个家庭中的祖、父、子三代成员。个体累积剂量分别为２３９～２６１３和５２～２９８ｍＧｙ。分离淋巴细胞培养法制备染色体标本,总计观察细胞数约１０００００。结果①在高本底组每一家庭中均观察到个体染色体畸变率随年龄增加而升高,其趋势在户间差异无显著性。②高本底组不同年龄个体染色体畸变率与年龄和累积剂量密切相关,可拟合为线性一次式：Ｙａｇｅ＝００４４８Ｘ＋０４９１３（Ｒ２＝０７８１４）;Ｙｄｏｓｅ＝００１５６Ｘ＋０５７１５（Ｒ２＝０７０６１）;③对照组个体间畸变率差异不显著,其平均畸变率接近正常人群自发畸变率。结论高本底持续照射诱发的人体内双着丝点加环畸变随受照时间的延长而持续升高。双加环畸变分析可作为小剂量持续照射的可信赖的生物剂量仪,但存在一个应用上的累积剂量阈值,其值约为５０ｍＧｙ。     

Dose estimation by chromosome aberration analysis and micronucleus assays in victims accidentally exposed to 60Co radiation

The objective of this study was to assess the radiation exposure levels in victims of a ⁶⁰Co radiation accident using chromosome aberration analysis and the micronucleus assay. Peripheral blood samples were collected from three victims exposed to ⁶⁰Co 10 days after the accident and were used for the chromosome aberration and micronucleus assays. After in vitro culture of the lymphocytes, the frequencies of dicentric chromosomes and rings (dic+r) and the numbers of cytokinesis blocking micronuclei (CBMN) in the first mitotic division were determined and used to estimate radiation dosimetry. The Poisson distribution of the frequency of dic+r in lymphocytes was used to assess the uniformity of the exposure to ⁶⁰Co radiation. Based on the frequency of dic+r in lymphocytes, estimates of radiation exposure of the three victims were 5.61 Gy (A), 2.48 Gy (B) and 2.68 Gy (C). The values were estimated based on the frequencies of CBMN, which were 5.45 Gy (A), 2.78 Gy (B) and 2.84 Gy (C). The estimated radiation dosimetry demonstrated a critical role in estimating the radiation dose and facilitating an accurate clinical diagnosis. Furthermore, the frequencies of dir+r in victims A and B deviated significantly from a normal Poisson distribution. Chromosome aberration analysis offers a reliable means for estimating biological exposure to radiation. In the present study, the micronucleus assay demonstrated a high correlation with the chromosome aberration analysis in determining the radiation dosimetry 10 days after radiation exposure.As early as the mid-1960s, ionising radiation was known to be capable of inducing chromosome aberrations in the metaphase of human peripheral lymphocytes [1, 2]. Since then, the chromosome aberration assay has been widely used as a sensitive biomarker for dose reconstruction following radiation exposure [3–6]. In particular, the analysis of dicentric chromosomes and rings (dic+r), two aberrations exemplifying inter- and intrachromosomal exchanges, respectively, has been generally considered to be the standard means for estimating biodosimetry based on its well-established dose–response relationship with radiation exposure and its low baseline levels in the general population [7, 8]. However, the utility of the chromosome aberration assay relies heavily on the expertise and experience of individual investigators. As an alternative method for determining radiation biodosimetry, the cytokinesis blocking micronucleus (CBMN) assay is easy to perform and less time-consuming, but its drawbacks include large individual variations in baseline values in the general population [7] and a markedly lower sensitivity when used for estimating low dose exposure compared with the chromosome aberration assay. Therefore, the micronucleus assay is widely used as a supplement to the chromosome aberration analysis [9]. In the present study, we made a comparative estimate of the radiation exposure in three victims of a ⁶⁰Co radiation accident that occurred in 1999 using dose–response curves of γ-ray-induced chromosome aberration and micronuclei, which were previously established in our laboratory. The results provide evidence of the utility of both methods in estimating biological doses of radiation exposure in humans.     

放射工作人员染色体畸变研究现状

长期暴露于低剂量电离辐射会对放射工作人员的辐射敏感组织器官造成损伤。目前,常用于评价慢性低剂量电离辐射所致辐射损伤的主要细胞遗传学指标是外周血淋巴细胞染色体畸变。本文对国内外放射工作人员暴露于低剂量电离辐射所致细胞遗传学效应的调查和研究进行综述,了解目前放射工作人员外周血淋巴细胞染色体畸变检测的现状及存在的问题,为国内开展放射工作人员染色体畸变检测与评价提供参考。     

60Coγ射线超大剂量照射离体人外周血染色体畸变的剂量-效应研究

目的 探讨超大剂量γ射线离体照射后人外周血淋巴细胞染色体畸变的量效关系,建立双+环(dic+r)大剂量-效应曲线。方法 外周静脉血样采自3名健康男性,经 ⁶⁰Co γ线(0~50 Gy,剂量率2.35Gy/min)照射。采用即刻加秋水仙素的微量全血法,分别培养52、72及96h。计数有丝分裂指数(MI)、双着丝粒体(dic)和环(r)畸变数,拟合dic+r剂量-效应曲线,对2例受大剂量照射的事故患者进行剂量估算。结果 MI随照射剂量的增加而逐渐减少。每细胞dic+r频率随照射剂量增加而增加直到23Gy(5Gy之后增加幅度较前变小),＞23Gy后趋于饱和。对所获数据进行回归分析,拟合dic+r大剂量-效应曲线(5~23Gy):每细胞dic+r频率y=-1.608(±0.300)+0.830 (±0.051)D-0.013(±0.002) D² (R²=0.998)。用拟合曲线对2例受照患者剂量的估算结果与用物理方法和电子自旋共振(ESR)法估算的剂量及临床表现基本一致。结论 本研究建立的dic+r大剂量-效应曲线, 可估计的上限剂量达23Gy,有可能提高常规染色体畸变分析用作生物剂量计的实用价值。     

Enhanced yield of chromosome aberrations after CT examinations in paediatric patients

Purpose: To determine whether computed tomography (CT) could enhance the chromosome aberration yields in paediatric patients.

Material and methods: Blood samples were taken before and after CT scans from 10 children for whom the medical justifications for CT examinations were accidental injuries and not diseases as investigated in earlier studies. Chromosome analysis was carried out in lymphocytes by fluorescence plus Giemsa (FPG) staining exclusively in metaphases of the first cell cycle in vitro.

Results: The mean blood dose of the 10 children was about 12.9 mGy which was determined by a newly developed dose estimation. Based on more than 20,000 analyzed cells it was found that after CT examination the frequencies of dicentrics (dic) and excess acentric fragments (ace) in lymphocytes were significantly increased. By subdividing the children into two age groups, those with an age from 0.4 years to 9 years and from 10 – 15 years, it became obvious that the observed increase in chromosome aberrations was mainly contributed by the younger age group. In this group the frequency of dicentrics was significantly increased whereas in the older group the observed increase was not significant.

Conclusion: Our results demonstrate that CT examinations enhance the dicentrics yields in peripheral lymphocytes of children aged up to 15 years. Since in particular significantly increased dicentric yields could be observed in children with an age from 0.4 – 9 years, it can be assumed that children younger than 10 years may be more radiation sensitive than older subjects.     

天然高本底辐射对人群外周血淋巴细胞染色体畸变率影响的Meta分析

目的 用Meta分析方法综合评估长期天然高本底辐照对人群外周血染色体畸变率的影响. 方法 检索国内外相关中英文数据库文献,并按照事先定义的纳入和排除标准,剔除不符合要求的文献,对纳入文献采用Meta分析方法进行综合定量分析,对9篇有染色体畸变率的研究进行综合分析,其中,2篇为单独报道易位率,2篇为单独报道非稳定性畸变率,综合报道的5篇.高本底辐射组研究总人数17 777人,对照组总人数10 386人.用Stata 12.0进行分析,Q检验和I²检验反映异质性的大小,发表偏倚用漏斗图法、Begg秩相关和Egger线性回归法识别. 结果 长期居住于天然高本底辐射地区的居民外周血染色体易位率和非稳定性畸变(双着丝粒+环状染色体、断片)率高于对照地区,其OR和95%CI分别为:1.57(1.10,2.24)和2.04(1.32,3.14);对易位率影响的研究中,男性、女性、成人和中国地区的OR和95%CI分别为1.24(1.09,1.42)、1.37(1.17,1.60)、1.17(1.05,1.30)、1.38(1.25,1.51),异质性检验I²分别为0.00、0.00、69.50%和0.00;对非稳定性畸变率影响的研究中,女性、成人、儿童、伊朗和中国地区的OR和95%CI分别为3.78(2.40,5.97)、2.60(2.25,3.00)、1.03(0.85,1.24)、3.19(2.46,4.13)和1.64(1.33,2.02),异质性检验I²分别为:0.00、69.60%、0.00、21.60%和0.00;高本底辐射、性别和年龄是上述异质性的来源. 结论 长期暴露于天然高本底辐射会增加外周血淋巴细胞染色体易位率和非稳定性畸变率,应综合分析其对高本底辐射暴露人群产生的健康风险,为建立防护措施和出台相关政策提供科学依据.