应用细胞周期阻断法分析初诊白血病患者骨髓及外周血微核率

目的：对初诊白血病患者骨髓及外周血进行微核分析。方法：应用细胞周期阻断法对54例初诊白血病患者骨髓及外周血与30例健康人外周血淋巴细胞进行微核检测。结果：54例初诊白血病患者骨髓及外周血淋巴细胞微核率（MNR）和微核细胞率（MCR）,与30例健康人外周血相比,P〈0.01。同一患者骨髓与外周血淋巴细胞MNR和MCR相比,P〉0.05。急性淋巴细胞白血病（ALL）、急性髓细胞白血病（AML）与慢性粒细胞白血病（CML）患者骨髓及外周血淋巴细胞MNR和MCR相比,P〈0.05。结论：白血病患者发病初期即存在染色体不稳定现象,不同类型白血病患者微核检测结果间有差异,推测与白血病的发病机制密切相关。     

外周血淋巴细胞微核率与放射治疗敏感性的关系

外周血淋巴细胞微核率与放射治疗敏感性的关系王捷，何玲，郎锦义，陈念永，王冀川，陈裕永，卢铀，王静波外周血淋巴细胞微核（ＰｂＬｓＭＮ）测定已被广泛应用于放射防护生物剂量监测领域，但与放疗敏感性的关系，研究较少，本文将进行这方面的探讨。１材料与方法１．１...     

140例X射线受检者照射量与外周血淋巴细胞微核的观察

１４０例Ｘ射线受检者照射量与外周血淋巴细胞微核的观察王禄忠，任风英，杨海华，孙丽敏为了观条医疗照射对照射人一群的影响，作者对１４０例钡餐Ｘ射线受检者的照射量与外周血淋巴细胞微核作了观察．用ＬＩＦ（Ｍｇ，Ｐ／ｕ）热释光剂量元件进行测量，微核采用甲基纤维...     

介入放射学照射剂量对患者淋巴细胞微核的影响

医疗照射是人工电离辐射主要来源。介入放射是医疗照射的重要组成部分。介入放射学是否造成患者遗传物质的损伤，目前这方面报道还较少，因此我们用人淋巴细胞微核为指标（ＣＢ法），检测介入放射学患者照射前后的双核微核变化，以判别患者的淋巴细胞遗传物质的损伤情况。...     

狗全身照射后淋巴细胞微核蜕减规律的探讨

狗全身照射后淋巴细胞微核蜕减规律的探讨蒋本荣，张海鹰，姚波淋巴细胞微核ＯＩ入）检测在核辐射事故受照者剂量估算中的重要性日益受到重视。国内一些学者相继以常规法及ＣＢ法建立了ＭＮ的剂量效应刻度曲线，用于临床，取得可喜的结果。由于射线诱发的ＭＮ主要源于染色...     

γ线对小鼠细胞遗传学的影响及重组人超氧化物歧化酶的抗放射作用(论著)

目的：研究γ射线对小鼠遗传学的影响及重组人超氧化物歧化酶（rhSOD）的抗放作用。方法：实验用甲基纤维素缩集法计算淋巴细胞微核率和活体秋水仙素法进行骨髓细胞染色体畸变率分析。结果：（1）4．0Gyγ线能明显增加小鼠淋巴细胞微核细胞率、微核率和骨髓染色体畸变率。（2）rhSOD可减轻射线所致小鼠淋巴细胞微核细胞率、微核率及骨髓细胞染色体畸变率，尤以照射前后给药为佳。结论：rhSOD对小鼠细胞遗传学辐射损伤有明显保护作用。     

某氡温泉周边居民外周血淋巴细胞微核的变化

目的 观察氡温泉周边居民外周血淋巴细胞微核率,为氡温泉对健康是否有影响提供依据。 方法 采用简单随机抽样法抽取某地氡温泉周边居民42人;同时简单随机抽取生活习惯相似,但未接触过氡温泉的居民44人。采用胞质分裂阻断微核法检测两组居民外周血淋巴细胞微核。 结果 氡温泉组的微核率（u=8.26,P＜0.01）和微核细胞率（χ2=47.76,P＜0.01）均值显著高于对照组。氡温泉组微核率和微核细胞率随着年龄的增加而增加,且差异具有统计学意义（χ2=44.034、27.739,P＜0.01）。氡温泉组女性的微核率（u=7.98,P＜0.01）和微核细胞率（χ2=37.123,P＜0.01）均高于男性且差异具有统计学意义。控制年龄、性别、吸烟和饮酒等混杂因素后,氡暴露与微核率呈高度正相关（χ2=57.68,P＜0.01）。 结论 高氡温泉能够引起居民外周血淋巴细胞微核率增加。     

游泳训练对小鼠脾脏淋巴细胞亚群的影响

小鼠经1-3周游泳训练后,脾脏中单个核细胞数量减少,T淋巴细胞比例下降,B淋巴细胞比例增加,CD_2~+T细胞比例减少以及C_4~+/CD_3~+比值增加。表明运动训练会改变脾脏淋巴细胞亚群的分布,从而影响机体免疫状态。     

快中子照射离体血建立淋巴细胞微核的剂量效应曲线

十年来，国内外学者们用ＣＢ微核法研究了各种辐射类型诱发微核的剂量效应关系和影响因素，并建立了多条剂量效应曲线［１～４］。国内学者已报道多例用ＣＢ法估算生物剂量的结果［５～７］。本研究目的是用快中子照射离体血建立淋巴细胞微核的剂量效应曲线，以备用于中子...     

357例放射工作人员外周血淋巴细胞微核分析

对淋巴细胞微核率的观察，不仅能早期发现辐射效应，而且还能对受照个体进行生物剂量估算。随着电离辐射装置的改进及辐射防护措施的加强，放射工作人员受照剂量逐年降低。为探讨低剂量电离辐射对放射工作人员细胞遗传学的影响，笔者于2003年11—12月对濮阳市放射工作人员进行了外周血淋巴细胞微核分析，结果报道如下。     

Micronuclei in cytokinesis-blocked lymphocytes of cancer patients following fractionated partial-body radiotherapy

We applied the cytokinesis-block micronucleus assay to measure chromosome damage in lymphocytes of 11 cancer patients undergoing fractionated partial-body irradiation. Measurements performed before, during and after cessation of radiotherapy showed a dose-related increase in micronucleus frequency in each of the patients studied. When the results for micronucleus frequency (Y) were plotted against the estimated equivalent whole-body dose (X) the dose-response relationship obtained was Y = 75.8X + 49.5 (r = 0.783, P less than 0.0001). A general decline in MN frequency was observed during the post-treatment period down to 57 per cent (+/- 10) after 12 months but there was considerable variation between individuals. The advantages and disadvantages of the application of the cytokinesis-block micronucleus assay as a biological dosimeter for lymphocytes irradiated in vivo are discussed.     

Heritability of chromosomal radiosensitivity in breast cancer patients: a pilot study with the lymphocyte micronucleus assay

Of breast cancer patients, 30% are sensitive in a lymphocyte assay of radiation-induced chromosome damage (micronucleus induction) compared with 10% of healthy controls. Twenty-two first-degree relatives of 11 sensitive patients had an average micronucleus yield significantly higher than that of 68 controls. This suggests that radiosensitivity in this assay may be an inherited characteristic associated with predisposition to breast cancer.     

Heritability of chromosomal radiosensitivity in breast cancer patients: a pilot study with the lymphocyte micronucleus assay

Of breast cancer patients, 30% are sensitive in a lymphocyte assay of radiation-induced chromosome damage (micronucleus induction) compared with 10% of healthy controls. Twenty-two first-degree relatives of 11 sensitive patients had an average micronucleus yield significantly higher than that of 68 controls. This suggests that radiosensitivity in this assay may be an inherited characteristic associated with predisposition to breast cancer.     

Role of mitochondrial DNA in radiation exposure

PURPOSE: To evaluate the role of mitochondrial DNA (mtDNA) following exposure to ionizing irradiation. MATERIALS AND METHODS: We examined two human osteosarcoma cell lines either lacking mtDNA (143B.rho(0)206; rho0 cells) or having normal mtDNA (143B.TK-; rho+ cells). Cell survival curves were generated by using colony formation and micronucleus assay. The delay in population doubling time after irradiation was evaluated with dye exclusion tests. RESULTS: No significant difference was seen between rho+ and rho0 cell lines in colony formation assay. In micronucleus assay, rho0 cells showed a significantly lower rate of micronucleus formation. The ratios of binucleated cells with micronuclei were 0.49 for rho+ cells and 0.25 for rho0 cells (p=0.005). In the dye exclusion test, rho0 cells revealed a delay of about 1.6 times in population doubling time compared with the control after 5 Gy of irradiation, similar to the 1.7 times of rho+ cells. CONCLUSION: In the human osteosarcoma cell line 143B.TK-, mtDNA does not influence clonogenic survival and delay of population doubling time after irradiation. However, the difference in micronucleus formation shows that mtDNA influences DNA damage after radiation exposure.     

胞浆分裂阻滞微核法对山东"10·21"辐射事故病人受照射剂量的估算

目的 对山东"10·21"辐射事故中2例严重受照射者进行淋巴细胞微核(MN)检测,并估算受照射剂量.方法 用胞浆分裂阻滞微核(CBMN)法对2例患者(A和B)的外周血和骨髓样本分别进行MN检测.结果 2例患者的外周血培养均未见双核淋巴细胞.患者A的骨髓培养所获双核细胞极少,依据双核淋巴细胞多少粗估剂量＞20Gy.患者B的骨髓MN率为2.42个/细胞,剂量估计为8.7(8.0～9.4)Gy,与用染色体畸变分析、物理方法及ESR法所估算剂量接近,与临床表现基本一致.结论 MN法简便快速,结果准确,是除染色体畸变分析之外又一种可靠的生物剂量计.     

Hepatocyte response to continuous low dose-rate radiation in radioimmunotherapy assessed by micronucleus assay.

The response of hepatocytes to low dose-rate irradiation was examined in mice following the injection of radiolabelled monoclonal antibody. Mice were injected intravenously with an 131I-labelled monoclonal antibody 196-14 which recognizes CA125 antigen, and the effect of continuous low dose-rate irradiation on hepatocytes was assessed using the micronucleus assay. The frequency of micronuclei increased in a dose-dependent fashion, but it was lower than the frequency induced by conventional external X-rays which was determined immediately after the irradiation. A linear quadratic model (micronucleus frequency = aD+bD2+c) showed that the value of b decreased with low dose-rate irradiation from the radiolabelled antibody. It is concluded that the micronucleus assay is useful for the evaluation of the response of hepatocytes to irradiation in radioimmunotherapy.     

Inter-individual differences in radiation response shown by an in vitro micronucleus assay: effects of 3-aminobenzamide on X-ray treatment.

Among the methods of biological dosimetry of ionizing radiation, we propose the cytokinesis-block micronucleus assay for the measurement of the individual dose absorbed. The dose-response curve was determined for in vitro-irradiated lymphocytes from 25 individuals. The dose-response relationship, fitted by the linear-quadratic function, was F(MN) = 0.015 (+/- 0.0016) + 0.043 (+/- 0.0075).D + 0.083 (+/- 0.0045).D2. Our results are compared with those of other authors. 3-aminobenzamide (3AB) combined with X-rays were used to evaluate the micronucleus dose-response relationship in blood from 14 individuals. While it is known that 3AB inhibits poly(ADP-ribose) polymerase activity in vitro, we demonstrate that it also increases the X-ray-induced micronucleus yields. The resulting dose-response relationship varies from subject to subject. The possibility of using this approach to identify the individual radiosensitivity level is discussed.     

Micronuclei in Cytokinesis-blocked Lymphocytes of Cancer Patients Following Fractionated Partial-body Radiotherapy

Summary

We applied the cytokinesis-block micronucleus assay to measure chromosome damage in lymphocytes of 11 cancer patients undergoing fractionated partial-body irradiation. Measurements performed before, during and after cessation of radiotherapy showed a dose-related increase in micronucleus frequency in each of the patients studied. When the results for micronucleus frequency (Y) were plotted against the estimated equivalent whole-body dose (X) the dose-response relationship obtained was Y = 75·8X + 49·5 (r = 0·783, P < 0·0001). A general decline in MN frequency was observed during the post-treatment period down to 57 per cent (± 10) after 12 months but there was considerable variation between individuals. The advantages and disadvantages of the application of the cytokinesis-block micronucleus assay as a biological dosemeter for lymphocytes irradiated in vivo are discussed.     

Influence of Magnolol on the bystander effect induced by alpha-particle irradiation

In this work, the influence of Magnolol on the bystander effect in alpha-particle irradiated Chinese hamster ovary (CHO) cells was examined. The bystander effect was studied through medium transfer experiments. Cytokinesis-block micronucleus (CBMN) assay was performed to quantify the chromosome damage induced by alpha-particle irradiation. Our results showed that the alpha-particle induced micronuclei (MN) frequencies were suppressed with the presence of Magnolol.     

Micronucleus assay prediction and application optimized by cytochalasin B-induced binucleated tumor cells.

Improvement in the predictive assertion of the micronucleus assay was achieved by treating human malignant melanoma cells (Mewo) with cytochalasin B (CB), generating binucleated cells (BNC) representing cells after a single karyokinesis. Optimal cell binucleation was determined by testing several cytochalasin B concentrations and different incubation times. On average, 56% binucleated cells were found after incubation with 2 to 3 micrograms/ml cytochalasin B for 48 h. Cells with at least one micronucleus (Mn) were defined as fraction of cells with micronuclei and describes the degree of damaged cells. We found in binucleated cells 2.2 fold the fraction of cells with micronuclei than in mononucleated cells (MNC), as expected assuming that an induced micronucleus is associated with only one single daughter cell after mitosis. The mean of micronuclei per binucleated cells, however, was enhanced about 2.9 fold in relation to that of micronuclei per mononucleated cells and is related to the nuclear damage per cell. The application of cytochalasin B did not enhance the fraction of damaged cells although the degree of the injury per cell is intensified. A micronuclei promoting or inhibiting effect of the experimental design due to changes in cell proliferation was excluded by cytofluorometric investigations of DNA content and synthesis after cytochalasin B application. A comparison of the modified with the conventional micronucleus assay shows the superiority of the former.