首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 78 毫秒
1.
作者用低剂量γ射线预照射同源但辐射敏感性不同的小鼠乳癌细胞SR-1和SX-9,观察其对随后较大剂量照射所引起hprt基因突变的影响。结果,具有辐射抗性的SR-1细胞经5mGy或1cGy低剂量预照射后,能显著降低后3Gy照射诱发的hprt基因突变频率。而DNA双链断裂修复能力缺陷的电离辐射敏感细胞SX-9,经相同处理后,并不减轻随后的较大剂量照射所诱发的基因突变率。表明DNA双链断裂修复缺陷的细胞,  相似文献   

2.
低剂量辐射对细胞 DNA 修复兴奋效应   总被引:8,自引:0,他引:8       下载免费PDF全文
目的研究低剂量电离辐射对细胞DNA双链断裂修复及基因突变适应性的兴奋效应,并探测辐射诱导DNA结合蛋白。方法实验用小鼠SR-1细胞,60Coγ射线照射;用6-巯基鸟嘌呤筛选hprt基因突变克隆;脉冲电场凝胶电泳检测DNA双链断裂;Southwestern印迹杂交探测DNA结合蛋白。结果细胞受1cGy预照射后18小时、24小时显著降低3Gy照射诱发的hprt基因突变频率。预先受单次1cGy照射刺激,或每天照射一次,连续10天,显著增加3Gy照射细胞的DNA双链断裂修复效率。1cGy照射细胞后16小时提取的核蛋白中,探测到损伤DNA结合蛋白的诱导合成。结论低剂量辐射通过调节某些细胞辐射反应调控基因表达,诱导合成DNA修复反应蛋白,增强细胞DNA修复能力,减少基因突变的发生,提高细胞维持遗传稳定性机能。  相似文献   

3.
目的 研究电离辐射诱发人骨肉瘤肿瘤细胞DNA双链断裂与辐射损伤修复效应,观察辐射损伤、损伤修复效应敏感性之间的关系。方法 选用强制均匀电场电泳,分别测定经不同的剂量X射线照射和相同剂量照射后培养不同时间,人骨肉瘤Rho0和143.B肿瘤细胞株DNA双链断裂。结果 (1)X射线诱发人骨肉瘤瘤细胞的DNA双链辐射剂量呈线性正比关系;(2)培养后的人骨肉瘤肿瘤细胞对射诱发的DNA双链断裂具有一定修复能力  相似文献   

4.
低剂量X射线照射诱导G1期阻滞的适应性反应   总被引:9,自引:1,他引:8       下载免费PDF全文
目的观察低剂量X射线照射能否诱导G1期细胞阻滞。方法采用碘化丙啶(PI)荧光探针标记细胞,流式细胞术(FCM)检测并分析细胞周期。结果证实1.5GyX射线全身照射后12小时,小鼠胸腺细胞发生明显G1期阻滞。而0.075Gy低剂量预照射可明显减轻其后1.5Gy攻击剂量所致G1期阻滞。离体照射EL-4淋巴瘤细胞也得到类似结果。结论0.075GyX射线照射能诱导胸腺淋巴细胞及EL-4细胞G1期阻滞的适应性反应。  相似文献   

5.
研究了不同剂量γ线照射对小鼠SR-1细胞中ADPRT活性的影响。结果表明50Gy以上剂量照射对ADPRT的催化反应有明显的激活作用,并且随照射剂量的增加而提高。此外,细胞受0.01Gy低剂量照射之后一定时间,无论是再照射还是不照射50Gy大剂量,所测得的ADPRT活性都明显高于未受低剂量照射的细胞,表明低剂量辐射对细胞中ADPRT具有诱导作用。  相似文献   

6.
观察低剂量X射线照射能否诱导EL-4细胞凋亡及细胞周期的适应性反应。方法采用流式细胞术(FCM)检测细胞凋亡及细胞周期。结果单纯2GyX射线照射后12小时EL-4细胞凋亡显著增多,并伴有明显G1阻滞;0.075Gy预照射可明显减轻间隔6小时后2Gy攻击剂量照射所致的细胞凋亡和G1阻滞。结论0.075GyX射线离体照射可诱导EL-4细胞凋亡及G1阻滞的适应性反应  相似文献   

7.
目的:在低剂量照射条件下,合并化疗,以观察肿瘤细胞动力学变化。方法:应用0.05GyX射线对荷瘤鼠全身照射,结果:发现肿瘤细胞摄入^3H-TdR能力降低,G0/G1期细胞百分数增加,S期细胞百分数下降,G2期出现阻滞现象,且与对照组比较差异有显著性。低剂量辐射可增强丝裂霉素的化疗效果,导致肿瘤组织生长明显受抑。结论:上述结果证明:低剂量辐射可以抑制肿瘤细胞DNA合成,诱导肿瘤细胞动力学改变,间接证  相似文献   

8.
作者在研究低剂量辐射对全淋巴细胞刺激性效应的同时,用3种单克隆抗体分离出分化抗原簇+-4,分化抗原簇+-8和B细胞亚群,进一步探讨了低剂量辐射对3种亚群细胞的刺激作用。结果表明,Panning法分离的各亚群细胞的纯度及存活率均在90%以上;全淋巴细胞在0.1Gy剂量范围内有刺激作用,尤以0.1Gy剂量点效应最大;各亚群细胞在0.2Gy照射内均有刺激性效应的发生.分化抗原簇+-4和B细胞在0.1Gy剂量点效应最强,而分化抗原簇+-8在0.05Gy点效应最强;相同剂量,分化抗原簇+-4的刺激效应大于分化抗原簇+-8;0.5Gy照射则表现出明显的抑制作用.  相似文献   

9.
0.075Gy射线诱导EL—4细胞凋及细胞周期的适应性反应   总被引:1,自引:0,他引:1  
目的 观察低剂量X射线照射能否诱导EL-4细胞凋亡及细胞周期的适应性反应。方法 采用流式细胞术(FCM)检测细胞凋恨及细胞周期。结果 单纯2GyX射线照射后12小时EL-4细胞凋亡显著增多,并伴有明显G1阻滞;0.075Gy预照射可明显减轻间隔6小时后2Gy攻击剂量照射所致的细胞凋亡和G1阻滞。结论0.075Gy射线离照射可诱导EL-4细胞凋亡及G1阻滞的适应性反应。  相似文献   

10.
目的 探讨低剂量对致癌剂量辐射诱发小鼠胸腺淋巴瘤的影响及其免疫学机理。方法 采用4次1.75GyX射线全身照射C57BL/6J小鼠诱发胸腺淋巴瘤模型,观察不同剂量照后6个月小鼠胸腺淋巴瘤发生率,照后1个月脾脏NK细胞毒活性、IL-2和γ-IFN分泌活性、腹腔巨噬细胞吞洚功能及其TNF6分泌活性以及胸腺细胞分化的变化。结果 每次1.75Gy照射前6h、12h接受25mGy、75mGy全身照射均可降你  相似文献   

11.
One of the factors of the successful military career guidance Cadet schools students is preserving and promoting their health. Medical support of children and adolescents aged 10-17 years should include the full range of medical and preventive measures defined for this group. The state of providing outpatient care for pupils at the Cadet School in St. Petersburg was studied. These results show that full medical care in accordance with the standards can be based only on children's health clinics. It is important that the organization of medical support pupils cadet schools should be cooperate with civilian health care.  相似文献   

12.
带状疱疹是由水痘—带状疱疾病毒引起的皮肤科常见疾病。其主要的病理损害,一是受累神经的严重炎症性浸润,继而导致受侵犯神经节内神经细胞变性、坏死;二是皮肤的水泡。迅速抑制神经节和相应的感觉神经纤维的充血、水肿和坏死,防止粘连形成,达到迅速镇痛、改善皮损,缩短病程及防止后遗症的发生是治疗的关键。因而,尽早明确诊断,  相似文献   

13.
14.
15.
16.
ESR-spectrometry was used to investigate radiation-induced paramagnetic centers in enamel of mammals: carnivores (polar bear and fox), ungulates (reindeer, European bison, moose), and man. Values at half the microwave power saturation of the radiation signal, P1/2, evaluated at room temperature, was found to range from 16 to 26 mW for animals and man. A new approach to discrimination of the radiation induced signal from the total ESR spectrum of reindeer enamel is proposed. ‘Dose-response’ dependencies of enamel of different species mammals were measured within the dose range from 0.48 up to 10.08 Gy. Estimations of ‘radiosensitivity’ enamel of carnivores and ungulates showed good agreement with radiosensitivity enamel of man by ESR method.  相似文献   

17.
18.
The results of an international comparison of activity measurements of a solution of 55Fe organized by the BIPM in 2005 are reported and analysed. This exercise, which follows the procedures of the CIPM mutual recognition arrangement to update older comparisons, is a renewal of the comparison organized by the BIPM that took place in 1978. A EUROMET comparison was organized in 1996 specifically to compare activity measurements of a 55Fe solution by means of liquid-scintillation techniques. Results of these three comparisons are presented and discussed in this paper.

The radionuclide solution was provided by the NPL, which also distributed the samples to the participants. The activity of the ampoules was measured by 16 laboratories using 12 methods producing 25 results. Some general considerations on uncertainty assessments pertaining to the different techniques used are drawn. The outcome of four different estimators is compared from which the presence of at least one outlier can be confirmed. Further measurements should be made to try to reduce the discrepancy between the results. To date the outcome of the present comparison does not show an improvement to that of the 1996 comparison.  相似文献   


19.
A new method of non-surgical treatment of varicocele syndrome is described: it consists in sclerotherapy of spermatic vein by trans-femoral percutaneous catheterization with balloon-catheters. In 8 cases venous thrombosis has been induced by direct electric clotting. The techniques and a 6 months follow-up are discussed. It is pointed out that this procedure should be considered as the method of choice for tubular lesions and sub-fertility prophylaxis in young people and in childhood.  相似文献   

20.
目的探讨延迟性脾破裂误漏诊原因和预防措施.方法回顾性分析总结12例延迟性脾破裂中的诊断和误漏诊的经验与教训.结果本组延迟性脾破裂的误漏诊5例(41.66%).对多发伤与脾破裂并存可能认识不足,外伤史轻微或伤员隐瞒外伤史,缺乏腹痛-缓解-突然再腹痛的典型病史,缺乏“对冲性脾破裂”力学分析和整体化诊断思路等为其误漏诊的主要原因.结论详细的外伤史和全面系统检查,重视腹以外多发伤掩盖腹内脏器伤及延迟性脾破裂可能.确立外伤-腹内脏器伤-脾破裂整体化诊断思路.不间断地辅以B超检查脾形态学变化和腹内有无积液,腹腔穿刺确定有无血腹、X线胸腹部检查观察左侧胸肋角和膈肌运动情况、必要时CT检查以尽早发现脾包膜下血肿,降低延迟性脾破裂误漏诊率.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号