NPM基因在人淋巴母细胞中的差异表达与染色体不稳定性

目的：研究NPM基因与染色体不稳定性（CIN）、细胞增殖及p53的关系，为阐明恶性血液病发生的分子机制提供参考。方法：采用软琼脂克隆形成法、常规染色体分析和G显带法检测人淋巴母细胞TK6（wtp53）、WTK1（mtp53）和正常人淋巴细胞永生化细胞（HNILL）的细胞增殖、染色体数量变化和5号染色体质量排，并观察Olomoucine对其的影响；用Sanger测序法和Western Blot方法分别测定NPM第12外显子的DNA序列、NPM蛋白和磷酸化蛋白的表达。结果：WTK1细胞的克隆形成能力和多倍体率均显著高于TK6细胞，同时WTKI细胞的NPM蛋白和磷酸化蛋白表达亦明显高于TK6细胞，且它们均又显著高于HNILL细胞；3株细胞均未发现5号染色体的重排和NPM第12外显子编码区的突变。用Olomoucine抑制NPM蛋白磷酸化后WTK1细胞的多倍体率明显降低。结论：WTK1、TK6和HNILL细胞的增殖能力、CIN与NPM蛋白和磷酸化蛋白表达呈正相关，而且与p53状态密切相关。     

上海市大气中可吸入颗粒物PM_(10)对人体外周血淋巴细胞的毒性研究

采用ICP -MS分析了采自上海市桃浦工业区中PM10 的生理盐水提取液中 15种元素的含量 ,并通过对人离体血淋巴细胞的3 H -TDR掺入率、微核率和白细胞介素 2 (IL - 2 )的测试 ,研究了PM10 的遗传毒性和对免疫功能的影响。结果表明 :随着用于染毒的PM10 提取液浓度的增加 ,所诱发的淋巴细胞的微核率显著上升 ,而3 H -TDR掺入率则随PM10 浓度的增加而下降 ,两者均呈明显的剂量效应关系。同时 ,IL - 2水平在PM10 浓度增加到一定值后呈下降趋势。在离体血中加入一定量的PM10 提取液并经13 7Csγ射线照射 ,未观察到淋巴细胞的微核率和3 H -TDR掺入率有明显变化 ,说明两者无明显的协同加强效应。     

聚乙二醇诱发人淋巴细胞早熟凝集染色体的方法

人外周血淋巴细胞染色体畸变的检查,按常规方法至少需经48h培养。近年来由于细胞融合技术的发展,发现了早熟凝集染色体(Premature Condensation Chromosome,PCC)现象,对未进入分裂周期或处于间期的细胞也能进行染色体分析。本文介绍了用聚乙二醇(PEG)作为融合剂获得人淋巴细胞G_1-PCC的方法,还对影响细胞融合的各种因素进行了比较研究。     

慢性镉染毒及联合辐射对大鼠的基因毒性作用

目的 探讨慢性镉染毒及联合辐射对大鼠的基因毒性.方法 雄性SD大鼠分设空白对照组、0.1 mg CdCl2·kg-1·d-1低剂量镉染毒组、0.5 mg CdCl2·kg-1·d-1高剂量镉染毒组、单纯照射组、低剂量镉染毒+照射组和高剂量镉染毒+照射组.腹腔注射镉染毒连续8周,1次/d,然后给予2 Gy γ照射.于照射后第10天或受照即日后继续染镉4周,心脏取血,采用多核细胞法检测外周血淋巴细胞微核率和hprt基因突变率,同时检测外周血白细胞数量变化和血镉含量.结果 大鼠低剂量镉染毒8周和12周组未观察到外周血细胞损伤,而辐射诱导的微核率(F=26.74,P<0.01和F=14.13,P＜0.05)和hprt基因突变率(F=6.60,P＜0.05)显著降低;高剂量镉染毒8周和12周组与空白对照组比较,外周血白细胞数显著增高(F=8.74,P＜0.01和F=13.11,P=0.000),淋巴细胞微核率(F=26.74,P＜0.05和F=14.13,P=0.000)和hprt基因突变率(F=6.60,P＜0.05和F=12.83,P＜0.05)明显增加,而高剂量镉染毒+照射组的基因毒性又显著高于单纯高剂量镉染毒组或单纯照射组,表现出联合毒性效应.结论 慢性、低剂量镉染毒诱导外周血淋巴细胞对辐射产生适应性效应,血镉浓度增加到613～678 μg/L时能刺激白细胞显著增加并与辐射联合作用加重对淋巴细胞的基因毒性.

Abstract：

objective To investigate the effects of chronic cadmium exposure and cadmium exposure combined with γ-ray irradiation on the peripheral lymphocytes and their genotoxicity on hprt gene.Methods Ninety-six SD rats were randomly divided into 6 equal groups:①normal control group,②lowdose cadmium exposure group undergoing intraperitoneal injection of 0.1 mg CdCl2·kg-1·d-1 for 8 weeks,③high-dose cadmium exposure group undergoing intraperitoneal injection of 0.5 mg CdCl2·kg-1·d-1 for 8 weeks,④pure irradiation group exposed to whole-body γ-ray irradiation at the dose of 2 Gy for one time,⑤low-dose cadmium exposure combined with irradiation group undergoing intraperitoneal injection of 0.1 mg CdCl2·kg-1·d-1 for 8 weeks and then whole-body 2 Gy γ-ray irradiation,and ⑥high-dose cadmium exposure combined with whole-body 2 Gy γ-ray irradiation group undergoing intraperitoneal injection of 0.5 mg CdCl2·kg-1·d-1 for 8 weeks and then whole-body 2 Gy γ-ray irradiation.Ten days after the irradiation cardiac blood samples were collected from some of the rats to culture the peripheral lymphocytes to detect the micronucleus rate and hprt mutant frequency of lymphocytes bv multinucleated cell assay.The other rats underwent continuous Cd exposure for 4 weeks after γ-ray irradiation and then cardiac blood samples were collected to detect the micronucleus rate and hprt mutant frequencv of lymphocytes.Meanwhile,the amount of white blood cells(WBC)was counted and the blood cadmium concentration was measured by ICP-MS.Results The numbers of WBC in the peripheral blood at different time points of the high dose cadmium group were significantly higher than those of the normal control group(F=8.74.P<0.01 and F=13.11,P=0.000).The micronucleus rate at difierent time points of the pure irradiation group were significantly higher than those of the control group( F = 26. 74 ,P =0. 000 and F = 14. 13, P = 0. 000). The micronucleus rates of the high-dose cadmium group were significantly higher than those of the control group( F = 26. 74 ,P <0. 05 and F = 14. 13 ,P = 0. 000 ). The micronucleus rates of the low-dose cadmium + irradiation group were significantly lower than those of the pure irradiation group( F = 26. 74, P < 0. 01 and F = 14. 13, P < 0. 05 ). The micronucleus rates of the highdose cadmium + irradiation group were significantly higher than those of the pure irradiation group ( F =26.74,P =0. 000 and F = 14. 13 ,P =0. 000). The hprt mutation rates at different time points of the pure irradiation group were significantly higher than those of the normal control group( F = 6.60, P < 0. 01 and F = 12.83 ,P = 0. 001 ). The hprt mutation rates of the high-dose cadmium group were significantly higher than those of the control group ( F = 6. 60, P < 0. 05 and F = 12.83, P < 0.05 ), but not significantly different from those of the pure irradiation group. However, the hprt mutation rates of the high-dose cadmium + irradiation group were significantly higher than those of the pure irradiation ( F = 12. 83, P =0. 000) and high-dose cadmium group( F = 6.60,P < 0.05 and F = 12. 83, P < 0.05 ). The hprt mutation rates of the low-dose cadmium + irradiation group were significantly lower than those of the pure irradiation ( F = 6. 60, P < 0. 05 ) , but not significantly different from those of the control group. Conclusions Chronic exposure to low dose cadmium induces the adaptive response of lymphocytes to radiation. The cadmium in blood at the level of 613-678 μg/L induces leukocytosis and chronic exposure to high dose cadmium combined with irradiation leads to increased genotoxicity of lymphocytes.     

不纯泊松分布法在6 MV X射线局部照射剂量估算中的应用

目的从离体和活体两方面探索不纯泊松分布法估算6MV X射线局部受照射剂量和受照射份额的适用性。方法2、4Gy6MV X射线离体照射健康人外周血，受照射份额为20％、50％和80％模拟局部照射；选择2、3Gy6MV X射线局部放射治疗的肿瘤病人，观察首次放射治疗前、后24h外周血淋巴细胞染色体畸变，采用不纯泊松分布法，估算受照射剂量和份额。结果2Gv离体照射50％、80％份额和4Gy照射20％、50％、80％份额的淋巴细胞双着丝粒 环(dic r)畸变呈过分散分布，受照射剂量和份额估算值与实际值基本吻合。单次2Gy盆腔照射、受照射局部红骨髓比例大于20％或3Gy全颅照射放射治疗病人的外周血淋巴细胞dic r畸变呈过分散分布，估算的受照射份额与受照射局部红骨髓比例相接近，较大剂量3Gy放疗时估算的受照射剂量较为准确。患者局部放射治疗后与放射治疗前离体模拟的实验结果都显示较好的一致性。结论采用不纯泊松分布法可以比较准确的估算离体和活体局部受照射剂量和份额，适用于照射剂量较高和照射份额不是太小的低LET射线，受照射局部红骨髓占全身的比例可大致反映局部照射的份额。