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研究了人肝癌细胞SMMC-7721在低剂量γ射线照射下超敏感性和增强的辐射抗性响应。选用对数生长期细胞接受0—6 Gy不同剂量的^60Coγ射线的照射。利用流式细胞仪对细胞进行分选计数,并用克隆形成法检测细胞存活率。发现SMMC-7721细胞存在低剂量辐射超敏感性和增强的辐射抗性响应,即在0—0.3Gy之间细胞表现出单位剂量杀伤增强现象,在0.3—1Gy细胞表现一定的辐射抗性,在1Gy以上,细胞的存活符合线性平方模型。  相似文献   
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探讨12C6+ 离子束辐射对用带有绿色荧光蛋白基因的缺陷性腺病毒(AdCMV GFP)转染小鼠黑色素瘤细胞(B16细胞系)的影响。 采用不同剂量的12C6+ 重离子束辐射经AdCMV GFP 转染的B16细胞, 利用流式细胞仪检测腺病毒的转染率。 结果表明, 12C6+重离子束辐射能提高腺病毒对B16细胞的转染率, 且具有量效关系。 此外, 先转染后辐射法比起先辐射后转染法能更显著地提高转染率。The effect of 12C6+ beam irradiation on AdCMV GFP (a replication deficient recombinant adenoviral vector containing CMV promoter and green fluorescent protein) gene transfection efficiency for murine melanoma cell B16 has been investigated. B16 cells infected with AdCMV GFP were irradiated by different doses of 12C6+ beam. The transfection efficiency was assessed by flow cytometry (FCM). Results show that 12C6+ beam irradiation can improve tansfection efficiency of AdCMV GFP on murine melanoma cell B16 in a dose dependent manner. In addition, the tansfection efficiency in pre tranfection plus irradiation group is higher than that in pre irradiation plus tranfection group at the same dose irradiation dose.  相似文献   
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为了评估低剂量X射线连续辐射对BALB/c小鼠健康机体免疫系统的影响, 实验采用X射线全身连续照射BALB/c小鼠, 照射第一天剂量为0.07 Gy, 剂量率0.2 Gy/min, 之后每天照射0.08 Gy, 共照射12 d, 累积剂量1.03 Gy, 照射后24和48 h取血、胸腺和脾脏。 流式细胞仪检测免疫细胞周期和凋亡的变化, 胸腺和脾脏指数用重量法获取。 实验结果表明, 小鼠胸腺细胞的周期在照射后24 h被阻滞在G2/M期; 外周血淋巴和胸腺细胞周期48 h被阻滞在 G0/G1期, 细胞凋亡比例在照射后两个时间点都显著增加; 脾脏淋巴细胞周期24 h被阻滞在 G0/G1期, 48 h被阻滞在 S期, 细胞凋亡比例在24和48 h显著减少; 脾脏指数在照射后48 h显著减少。 故低剂量X射线连续全身照射BALB/c小鼠可激活免疫细胞不同的周期监测点, 引起免疫细胞凋亡比例发生变化, 造成一定的辐射损伤, 且这种影响随着免疫器官的不同而不同。 For estimating the effect of low doses X ray continual irradiation to immunity system of mouse, BALB/c mice were continually irradiated to 1.03 Gy by X rays at a dose rate of 0.2 Gy/min in 13 d. At 24 or 48 h after irradiation, the immunocyte cycle and apoptosis were determined by flow cytometry, and the thymus and spleen weights were measured too. The results showed that the cycle of thymocyte were arrested in G2/M at 24 h, the number of peripheral blood lymphocytes and thymocytes in G0/G1 phase at 48 h was up and the percentage of apoptosis had a significance increase in both of time points; the cycle of spleen lymphocytes was delayed in G0/G1 at 24 h, in S phase at 48 h, the apoptosis had a significance decrase at 24 and 48 h; spleen index declined significantly at 48 h. The results suggested that low doses continual X ray whole body irradiation could activate different cell cycle checkpoints, and result in some changes of apoptosis and some damages to immunocytes. The continual X ray irradiation affects the organs differently, it might provide experiment basis for radioprotection.  相似文献   
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肿瘤治疗的重离子束物理性质研究   总被引:2,自引:0,他引:2  
重离子在肿瘤治疗方面的优势主要是由于其优越的物理性质,因此,研究其与生物体相互作用也就成为肿瘤治疗中的基本课题,介绍一些研究结果来解决人们关心的问题.The advance of tumor therapy with heavy ions beam is due to the physics quality of heavy ions.So,the investigation of heavy ions action with biological materials will be a basic task. In the paper, the investigated results show a picture to resolve some problems which attract people's attention.  相似文献   
5.
利用超分次技术进行肿瘤治疗的探讨   总被引:1,自引:0,他引:1  
以人类肝癌细胞SMMC-7721和正常肝细胞L02为研究对象,以这两种细胞0.3Gy时超敏感性的存活数据为基础,从理论上探讨了γ射线照射时,用超分次技术治疗肝癌的可能性。经过计算发现:如果目标肿瘤和周围的正常组织超敏感性的存活差异提高到3%,即可利用超分次技术对肿瘤进行治疗。应用超分次进行分次照射时,照射的结果与分次的间隔时间有关。对这一现象的机理进行了一定的探讨,发现时间间隔与细胞G2期的长短可能存在一定的相关性。Based on the survival data of human hepatoma SMMC-7721 and normal liver L02 cells irradiated with γ-rays at 0.3 Gy and 2 Gy, the possibility of uhra-fractionated radiotherapy is discussed in this paper. According to calculations, it is found that if the difference in cell survival between target tumor and adjacent normal tissue is up to 3%, radiotherapy using HRS would be realized through uhra-fractionation. Furthermore, the low-dose response is time-dependent. After analyzing this phenomenon, it was pointed that there would be a correlation between fractionation interval and the duration of cell G2 phase.  相似文献   
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P53及其相关蛋白对X射线照射肝癌细胞周期的调节   总被引:1,自引:0,他引:1  
X射线照射人肝癌细胞HepG2, 照射后细胞存活随照射剂量增大明显下降。 流式细胞术分析, 不同剂量组照射后24 h均发生G2期阻滞。 照射后不同时间组的细胞周期分布也有不同, 照射后12 h, 有显著的S期延迟。 Western Blot 显示照射后24 h P53, MDM2, P21蛋白表达上升, 并有时间效应: P53在照射后24 h之内始终维持较高表达, MDM2和P21分别在照射后6和12 h的表达最高。 X射线照射通过影响P53及其相关蛋白的表达影响细胞周期。 HepG2 cells were irradiated with X ray at the doses of 0, 1.0, 2.0, 4.0 or 8.0 Gy and separately maintained in DMEM at 37 ℃ for 0, 6, 12 or 24 h. Colony forming assay showed that cell survival decreased with the irradiation dose increasing. Cell cycle was detected by FACS, the arrest of S phase was found after 12 h irradiation and arrest of G2 phase took place at 24 h after all irradiation doses, which suggested that cell cycle distribution was different in groups gathered after different maintaining time. The results of Western blotting showed that the expression of P53, MDM2 and P21 increased more after irradiation than the control. The expression of P53 remained high at 24 h after irradiation, while the levels of MDM2 or P21 arrived at the highest at 6 h or 12 h after irradiation respectively. The expressions of P21 after irradiation were in corresponding with the cell cycle distribution in the groups of different maintaining time. In conclusion, irradiation change the distribution of cell cycle by effecting the expression of P53 and its related proteins.  相似文献   
7.
离子束次级辐射对春麦的诱变效应   总被引:4,自引:3,他引:1  
利用中能重离子束辐照生物靶材料时产生的中子、γ射线和次级碎片等次级辐射对春麦种子进行辐照 ,然后通过田间试验和实验室的分析测定 ,得到了 M1代植株的变化 . (1 )在生物学性状中 ,穗粒数、小穗数、千粒重、穗粒重、小穗密度和有效分蘖数变异率较大 ;(2 )除 SOD活性外 ,POD活性、CAT活性、MDA含量和蛋白质含量的变异率也较大 ;(3 )休眠种子和萌发种子辐照M1代在生物学性状的变化上存在很大的差异 ;(4)两个春麦材料的辐射敏感性差异明显 .由此表明 ,兰州重离子加速器辐照终端在进行生物学实验时产生的次级辐射是可能利用的诱变源. Secondary radiation such as neutrons, high energy light particees, γ rays is produced when ion beams with medium energy irradiate biological materials. Spring wheat was placed in radiobiological experiment area(irradiation terminal L2) to expose to the secondary radiation. The variation of M1 generation of the wheat seeds was obtained through test in the fields and measuremeat in laboratery: (1) There were very high variation rates in grain number, number of small...  相似文献   
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选取对数生长期人肺癌细胞A549接受0—6.0 Gy 碳离子照射, 用克隆形成法检测细胞的存活率; 并于照射后12和24 h收集细胞, 用流式细胞术检测细胞周期各时相的细胞百分比, 观察不同剂量碳离子辐照对A549细胞周期进程的影响。 结果显示: 0—6.0 Gy 碳离子照射后细胞存活率显著下降; 照射后12 h细胞发生G0/G1期阻滞, 而照射后24 h, 1.0 Gy 照射组细胞在G0/G1期阻滞, 2.0—6.0 Gy 照射组细胞在G2/M期阻滞。 上述结果表明, 在A549细胞接受碳离子照射后的12 和24 h内, 1.0 Gy 照射可持续激活细胞G1期检查点, 而2.0—6.0 Gy 碳离子照射后其细胞周期进程是随时间变化的。 To investigate the effects of cell cycle progression of A549 cell induced by 12C6+ ion irradiation at different doses, the survival fractions of the A549 cells were determined by colony forming assay; cell cycles were analyzed by FACS at 12 h or 24 h after irradiation. The results showed that the percentage of survival in the A549 cells decreased with irradiation doses. Compared with control group, the percentage of the cells in G0/G1 phase significantly increased at 12 h after irradiation with different doses of 12C6+ ions. However, at 24 h after irradiation the percentage of the cells in G0/G1 phase significantly increased with 1.0 Gy 12C6+ ions, while the cells showed increasing percentage in G2/M phase with 2.0, 4.0 or 6.0 Gy 12C6+ ions. The results suggested that G1 cell cycle checkpoint was activated in 12—24 h after irradiation with 1.0 Gy 12C6+ ions, but after irradiation with 2.0—6.0 Gy 12C6+ ions, the cell cycle progression of the A549 cells changed with time.  相似文献   
9.
12C6+离子辐照小鼠Lewis肿瘤的研究   总被引:4,自引:3,他引:1  
研究了HIRFL提供的12C6+离子辐照C57BL/6J小鼠右后腿移植的Lewis肿瘤的生长延迟和碳离子辐照对Lewis肿瘤小鼠寿命的延长.结果表明,碳离子照射的小鼠肿瘤生长体积明显地小于对照的体积.在剂量相同、分次数辐照越多时,肿瘤生长就越缓慢,肿瘤抑制就越高.在辐照分次数相同时,不同剂量对受照肿瘤生长体积未产生差异.在4Gy×3,8Gy×3和12Gy×2组3种辐照剂量下,小鼠寿命的P值小于0.05;可知小鼠的寿命延长具有统计学意义. Growth delay of the transplantable Lewis tumors growing in right hind legs of C(57) BL/6J mice and life prolongation of the mice with Lewis tumors were investigated after()~(12)C~(6+) ion radiation at HIRFL. The results show that growth volumes of the mouse tumors following carbon radiation are distinctly less than control during 21 days; the more fractions of radiation with same doses, the slower growth of tumors and the higher inhibition of tumors; different doses with the same fractions of radiation ...  相似文献   
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