不同辐射体核素诱发体细胞和生殖细胞畸变产额比较研究

目的 对β辐射体核素^147Pm和主要为γ辐射体核素^134Cs诱发体细胞和生殖细胞的畸变产额，进行比较研究。方法 不同辐射体核素诱发的畸变产额变化，通过骨髓细胞和精原细胞染色体畸变测定。比较机体内污染不同核素在同一放射性活度的作用不同阶段，诱发的畸变产额。结果 研究发现，^147Pm和^134Cs诱发骨髓细胞和精原细胞的畸变类型均以染色单体型畸变为主，但畸变产额在骨髓细胞受辐照作用不同阶段，都显著高于精原细胞：如β核素^147Pm诱发骨髓细胞的畸变产额要比精原细胞高出2．8—5．6倍；而γ核素^134Cs诱发的畸变产额，要高1．2—2．6倍。结论 不同辐射体核素^147Pm和^134Cs内污染机体时，其诱发体细胞的畸变产额，都显著高于诱发生殖细胞的畸变产额．     

睾丸中滞留的不同辐射体核素诱发生殖毒性比较研究

探讨了α辐射体浓缩铀（２３５Ｕ）、β辐射体（１４７Ｐｍ）和γ辐射体（１３４Ｃｓ）在睾丸的滞留特性，诱发生殖细胞精子畸形和精原细胞染色体畸变效应比较研究、，拟合了不同辐射体核素在睾丸中的滞留分数方程，观察到其半滞留期以２３５Ｕ为最长，１４７Ｐｍ次之，１３４Ｃｓ最短，其值分别为１９７天，７６天，５天。研究还给出了三种辐射体核素在每厘戈瑞累积吸收剂量水平诱发精子畸形的生殖毒性比较值α：β：γ为２８：３：１；而诱发精原细胞染色体畸变的生殖毒性比较值为２９：４：１。     

苯和射线对培养中人体淋巴细胞的复合细胞遗传学效应

关于作业环境中的苯能够诱发外周血淋巴细胞和骨髓细胞的染色体畸变已屡有报导。已经有了一些关于诱发骨髓细胞或外周血淋巴细胞染色体变异的实验研究。在放射性事故受照者和广岛,长琦原爆幸存者中也发现了类似的染色体变异。环境中各种突变诱发剂(mutagenica-     

氚化合物致体外培养人淋巴细胞染色体畸变的比较及与剂量的关系

本研究选用了6种氚化合物比较氚诱发的体外培养人淋巴细胞染色体畸变的剂量·效应关系。以加氚活度表示剂量一效应关系时,氚化台物致染色体畸变的效率顺序依次为,³H～TdR>³H—UdR>³H—lysine>H—thymine>³H—leucine>HTO,这主要与各种化合物掺入细胞或细胞核内的量有关。若以估算的吸收剂量代替加氚活度,则各化合物致畸变的差别大大缩小。6种氚化合物致染色体畸变的氚活度(或吸收剂量一效应关系均符合线性一平方的数学模式:Y=A+BX+CX²。各不同化合物诱发的染色单体型及染色体型畸变产额率不尽相同,与它们代谢上差异有关.     

放射性核素内照射诱发大鼠外周血淋巴细胞HPRT基因 …

阐明放射性素核内照射诱发外周血淋巴细胞ＨＰＲＴ基因位点突变的剂量效应关系,并与染色体畸变剂量效应关系进行比较。方法给动物尾静脉注射放射性核素,注射量为０．５ｍｇ／１００ｇ体重。剂量效应关系组动物注射活度为３．６４＊１０＾５Ｂｑ／ｍｌ,于注射后１、３、６和９ｄ心脏穿刺取血。     

低剂量134Cs内照射对中枢免疫器官免疫反应的兴奋效应研究

作者探讨了机体受低剂量裂变产物１３４Ｃｓ内照射时的体内滞留对中枢免疫器官骨髓和胸腺免疫细胞的刺激增生作用．１３４Ｃｓ的体内滞留过程包括快、慢两个不同的滞留半减期，其中快组份的Ｔ１＝０．０７天，慢组份的Ｔ２＝１６．３８天．实验结果表明：当机体摄入低剂量１３４Ｃｓ０．１８５和０．７４ｋＢｑ·ｇ－１时，即此时的全身累积吸收剂量为０．９１ｃＧｙ和４．５６ｃＧｙ作用下，发现骨髓细胞和胸腺细胞的３Ｈ－ＴｄＲ掺入率呈显著增升，表明其ＤＮＡ合成能力的增高，呈现出１３４Ｃｓ内照射对中枢免疫器官骨髓和胸腺免疫反应增强的兴奋效应．     

~（60）Co、~（59）Fe、~（51）Cr、~（85）Sr在不同年龄大鼠体

研究核动力堆排放废液中常见核素６０ＣＯ、５９Ｆｅ、５１Ｃｒ、８５Ｓｒ在两种年龄大鼠体内的分布、剂量及细胞遗传效应。方法予动物一次静注或口服放射性核素，定期进行全身及器官放射性测量和染色体畸变分析。结果８５Ｓｒ主要聚集于骨骼；５９Ｆｅ、５１Ｃｒ全身广泛分布，但以肝、骨髓、红细胞含量最高；６０Ｃｏ主要分布于肝、肾、肺和皮毛。８５Ｓｒ、５９Ｆｅ、６０Ｃｏ在本实验条件下都能诱发骨髓和血淋巴细胞染色体畸变。结论四种核素在动物体内分布有年龄差异，摄入同量放射性核素，幼年鼠较成年鼠受到较大的辐射剂量。     

催醒安与丝裂霉素C对小白鼠骨髓细胞染色体的影响

催醒安,结构式为: 目前已用于治疗青光眼,有关它对细胞染色体的作用文献未查及。丝裂霉素C(Mitomycin C,简称MC),结构式为: 它是一种抗肿瘤剂,文献报告它可致小鼠骨髓和精原细胞染色体畸变,本文用作阳性对照物。本工作研究了催醒安与丝裂霉素C给药后对小鼠骨髓细胞染色体畸变的影响。     

电离辐射诱发小鼠生殖细胞染色体畸变率的比较

利用小剂量(0～1.0Gy)的X线照射昆明种小白鼠,对雄性各类型生殖细胞,同一指标不同阶段照射以及雌、雄生殖细胞染色体畸变率进行了比较.结果表明,雄性生殖细胞中以次级精母细胞染色体畸变率最高,剂量效应曲线的斜率约是精原细胞的3.6倍;初级精母细胞的10倍.当以D-MI和MI期雄性生殖细胞为终点,观察不同阶段受照射时的染色体畸变,表现为初级精母细胞的终变期最敏感,从终变期至前期表现为染色体畸变率逐渐下降.照射后21天至120天的结果为分化型精原细胞和精原干细胞受照射所诱发的染色体畸变率,无明显差异.比较雌、雄生殖细胞MI染色体畸变率,以后者的畸变率高,平均畸变率为前者的4.4倍,曲线斜率约为6倍.     

电离辐射诱发哺乳动物生殖细胞染色体畸变

由于核能的广泛应用，辐射诱发生殖细胞染色体畸变的效应已成为辐射遗传学研究的重要课题，各种不同的电离辐射均可诱发生殖细胞内作为遗传基因载体的染色体畸变，两性生殖细胞的畸变可分为结构畸变和数量畸变两大类，且具有很多常见类型。     

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。     

阳江高本底辐射地区家庭成员外周血淋巴细胞非稳定性染色体畸变的剂量效应关系初探

用改良的技术方法研究高本底辐射诱发染色体畸变剂量效应关系。方法２８名受检者选自高本底和对照地区１０个家庭中的祖、父、子三代。个体累积剂量分别为２５．２～２４４．８和５．４～５１．７ｍＧｙ。分离淋巴细胞培养法制备染色体标本。每例分析２０００～３０００细胞。结果高本底地区家庭成员非稳定性染色体畸变率随年龄增长而增高（Ｙ＝０．６３２３＋０．０４６３Ｘ，ｒ＝０．８７５０）；并且其中年组和老年组平均畸变率显著高于对照组（２．５６ｖｓ．１．２５，Ｐ＜０．０５和３．６０ｖｓ．１．２２，Ｐ＜０．００１）。在对照地区未见到染色体畸变率与年龄增长相关。高本底地区个体畸变率和累积剂量间呈明显的直线相关（Ｙ＝０．７４４１＋０．０１５４Ｄ，ｒ＝０．８６）。结论高本底持续照射诱发的人体内非稳定性染色体畸变可随受照射时间的延长而持续升高，但当累积剂量降至约５０ｍＧｙ时，用目前方法进行定量分析是有困难的。     

脐带血造血干细胞的“质”“量”研究

目的 对脐带血造血干细胞移植的“质”“量”作出评估，使其更广泛有效地应用于临床。 方法 利用免疫磁珠分离法、ＦＡＣＳ分析与分选、体外液体培养，铺展贴壁等方法对脐带血ＣＤ３４＾＋造血干、粗细胞及其的数量、体外增殖分化性能、生长因子扩增效应，植入成人骨髓基质效率等进行研究，数据经ｔ检验。结果 脐带血有核细胞、ＣＦＣｓ、ＣＤ３４＾＋细胞及其亚群等的绝对数量明显低于常规骨髓移植所需的细胞数量，但脐带血ＣＤ     

Chromosome aberrations determined by sFISH and G-banding in lymphocytes from workers with internal deposits of plutonium

Purpose: To examine the influence of α-particle radiation exposure from internally deposited plutonium on chromosome aberration frequencies in peripheral blood lymphocytes of workers from the Sellafield nuclear facility, UK. Materials and methods: Chromosome aberration data from historical single colour fluorescence in situ hybridization (sFISH) and Giemsa banding (G-banding) analyses, together with more recent sFISH results, were assessed using common aberration analysis criteria and revised radiation dosimetry. The combined sFISH group comprised 29 men with a mean internal red bone marrow dose of 21.0 mGy and a mean external γ-ray dose of 541 mGy. The G-banding group comprised 23 men with a mean internal red bone marrow dose of 23.0 mGy and a mean external γ-ray dose of 315 mGy. Results: Observed translocation frequencies corresponded to expectations based on age and external γ-ray dose with no need to postulate a contribution from α-particle irradiation of the red bone marrow by internally deposited plutonium. Frequencies of stable cells with complex aberrations, including insertions, were similar to those in a group of controls and a group of workers with external radiation exposure only, who were studied concurrently. In a similar comparison there is some suggestion of an increase in cells with unstable complex aberrations and this may reflect recent direct exposure to circulating lymphocytes. Conclusions: Reference to in vitro dose response data for the induction of stable aberrant cells by α-particle irradiation indicates that the low red bone marrow α-particle radiation doses received by the Sellafield workers would not result in a discernible increase in translocations, thus supporting the in vivo findings. Therefore, the greater risk from occupational radiation exposure of the bone marrow resulting in viable chromosomally aberrant cells comes from, in general, much larger γ-ray exposure in comparison to α-particle exposure from plutonium.     

骨髓细胞经酸性成纤维细胞生长因子孵育后程序移植的实验研究

目的　充分利用酸性成纤维细胞生长因子（ａＦＧＦ） 促进造血重建的作用,以进一步完善程序移植新方法。方法　以昆明种小鼠急性放射病为模型,进行了骨髓细胞（ＢＭＣ） 经自牛脑中制备的ａＦＧＦ孵育后程序移植对造血重建、急性移植物抗宿生病（ＧＶＨＤ） 的研究。结果　ａＦＧＦ 孵育后程序移植ＢＭＣ４ ×１０６ ,存活率达４０％ ,比单纯一次移植ＢＭＣ１ ×１０７ 组高（３０％ ）,但不如单纯骨髓程序移植ＢＭＣ４ ×１０６ 组（６０％ ）;另一方面,外周血白细胞、骨髓有核细胞计数、ＣＦＵＥ、ＣＦＵＧＭ、ＣＦＵＳ比一次骨髓移植１×１０７ 组和单纯骨髓程序移植ＢＭＣ４ ×１０６ 回升快,而ＣＦＵＦ回升无差别;ＧＶＨＤ较一次骨髓移植１ ×１０７ 组轻,较骨髓程序移植４ ×１０６ 重。结论　引起ＧＶＨＤ 的主要原因是异基因Ｔ淋巴细胞,通过ａＦＧＦ孵育后程序移植可以更充分地发挥其促进造血重建的作用,而减轻ＧＶＨＤ。     

Postirradiation Protection of Chromosomes by Linoleate

Summary

Physiological concentrations of linoleate reduce the frequency of micronuclei and chromosome aberrations in mouse bone marrow cells in vivo and of micronuclei in human lymphocytes in vitro when adminstered one hour after exposure of the cells to gamma rays.     

Induction of Cytogenetic Adaptive Response of Somatic and Germ Cells in Vivo and in Vitro by Low-dose X-irradiation

Summary

The cytogenetic adaptive response induced by low-level radiation was studied using human and rabbit lymphocytes in vitro and bone marrow cells and germ cells in vivo. The inductive dose of X-rays was 10 mGy for the in vitro studies at a dose rate of 10 mGy/min, and 2, 10, 50, 75 and 100 mGy for the in vivo studies at a dose rate of 50 mGy/min. The challenging dose was 1·5 Gy X-rays for the in vitro experiments and 0·65 or 0·75 Gy for the in vivo experiments at a dose rate of 0·44 Gy/min. The results reported here, in addition to those that have appeared in the literature, show the following characteristics documented for the first time: (1) 10 mGy could induce the adaptive response in human as well as rabbit lymphocytes irradiated not only in G₁, S and G₂ phases, but also in the G₀ state; (2) although the induced adaptive response could only last three cell cycles, it could be revived when the inductive dose was repeated after the third cell cycle; (3) the adaptive response could be induced by low-dose X-rays in somatic cells, both in vitro (lymphocytes) and in vivo (bone marrow cells), and also in germ cells (spermatocytes); (4) the magnitude of the adaptive response induced by whole-body irradiation was found to be dose-dependent–the lower the inductive dose the more the reduction of the frequency of chromatid aberrations following the challenging dose.     

Cytogenetic Effects of Microwave Irradiation on Male Germ Cells of the Mouse

Summary

Hybrid male mice were exposed to 2·45 GHz microwaves for 30 min/day, 6 days a week for two consecutive weeks at power densities of 1·0, 100 or 400 W m^?2, with sham-exposed controls. Rectal temperatures before and after exposure were measured on days 1, 6 and 12. Measurements made on day 1 were treated with caution because of heterogeneity in rectal temperatures taken before exposure between the groups of mice given different treatments. On days 6 and 12, rectal temperatures rose by approximately 1°C in mice sham exposed, or exposed to 1 W m^?2 or 100 W m^?2. Only in the group of mice exposed to 400 W m^?2 was the mean rise in rectal temperature during exposure (about 3°C) significantly increased above the sham value. In groups killed 2–3 days after treatment (mainly meiotic exposure) frequencies of chromosome aberrations in spermatocytes showed no significant heterogeneity although the highest frequency of 1·5 per cent was at the highest (400 W m^?2 power density. Another group killed 30 days after 100 W m^?2 exposures (spermatogonial sampling) showed no significant increase over controls in chromosome aberration frequency. There was a small but significant increase in sperm count with increasing power density in mice killed 12–13 days after exposure, but a non-significant one in those exposed as spermatogonia (killed 41 days later). Thus effects were markedly less severe than those reported previously by Manikowska-Czerska et al. (1985) with a very similar radiation regime and were probably caused by the temperature enhancement.     

射频辐射对哺乳动物体细胞遗传学效应的Meta分析

目的 探讨射频辐射对哺乳动物体细胞的遗传学影响。方法 采用Meta分析方法,对国内外1991—2009年关于哺乳动物体细胞遗传学损伤与射频辐射暴露关系的研究文献共计46篇进行综合定量分析。结果 射频辐射暴露后,辐射组与对照组彗尾尾长的加权均数差(WMD)及95%CI为1.03(0.74, 1.31),尾距为0.10 (0.04, 0.16);和对照组比较,2000 MHz以下的射频辐射组染色体畸变RR及95%CI为1.21(0.68,2.13),大于2000 MHz组为1.76(1.05,2.97);射频辐射与微核发生的合并RR及95%CI为1.39(1.18,1.64);射频辐射组与对照组SCE发生数目的WMD及95%CI为0.40(-0.33,1.14)。结论 射频辐射暴露一定程度上会加重哺乳动物体细胞DNA损伤,增加微核发生率;2000 MHz以上的射频辐射可能会引起染色体畸变率的上升,低于2000 MHz的射频辐射对染色体畸变发生无显著影响;射频辐射暴露对哺乳动物体细胞姐妹染色单体交换的发生无显著影响。     

低剂量电离辐射对职业暴露人群染色体畸变率和微核细胞率影响的Meta分析

目的 用Meta分析的方法综合定量分析电离辐射对职业暴露人群染色体畸变率和微核细胞率的影响。方法 全面检索国内外中英文相关文献,按预先设定的纳入排除标准进行严格筛选后,最终纳入21篇文献,总研究细胞数1 970 626个。用Stata 12.0进行Meta分析,异质性检验用Q检验和I²统计量,发表偏倚用漏斗图法、Begg秩相关法和Egger线性回归法3种方法识别。结果 放射工作人员发生染色体型畸变、双着丝粒体+环状染色体畸变、易位、微核细胞的危险性要高于非放射工作人员,其比值比及95%的可信区间分别为3.03 （2.59,3.56）、4.12 （2.99,5.67）、2.73 （1.67,4.46）、1.70 （1.40,2.06）。结论 长期暴露在低剂量电离辐射下会显著增加外周血淋巴细胞染色体畸变率和微核细胞率,应加强放射工作人员的辐射防护。