精脒含量对浓缩铀诱发PC12细胞凋亡的影响

研究PC12细胞内精脒含量在浓缩铀诱导细胞凋亡中的作用。在PC12细胞中加入浓缩铀DMEM/F12工作液，计算PC12细胞的内照射吸收剂量，运用丹磺酰氯薄层分析技术测定细胞内游离精脒含量。结果表明，随着浓缩铀内照射时间的延长，细胞增殖活性迅速下降，DNA链断裂明显增多，放射性核素迅速渗入细胞核中，AO/EB染色可见凋亡细胞，同时细胞内游离精脒随内照射时程的延长而显著减少。表明浓缩铀可致PC12细胞的凋亡，细胞内游离精脒的含量可能与细胞活性有一定作用。     

精脒含量对浓缩铀诱发PC12细胞凋亡的影响

研究PC12细胞内精脒含量在浓缩铀诱导细胞凋亡中的作用。在PC12细胞中加入浓缩铀DMEM／F12工作液，计算PC12细胞的内照射吸收剂量，运用丹磺酰氯薄层分析技术测定细胞内游离精脒含量。结果表明，随着浓缩铀内照射时间的延长，细胞增知性迅速下降，DNA链断裂明显增多，放射性核素迅速渗入细胞核中，AO／EB梁色可见凋亡细胞，同时细胞内游离精脒随内照射时程的延长而显著减少。表明浓缩铀可致PC12细胞的凋亡，细胞内游离精脒的含量可能与细胞活性有一定作用。     

浓缩铀诱发免疫细胞凋亡的形态观察及IL-2和IL-6的防护作用

对浓缩铀２３５Ｕ内照射人淋巴细胞白血病细胞株Ｍｏｌｔ４细胞和巨噬细胞株Ａｎａ１细胞诱发的细胞凋亡及细胞因子的防护作用进行了研究。实验中估算了２３５Ｕ在不同阶段培养细胞中的辐射累积吸收剂量。通过荧光显微镜形态观察，发现免疫细胞在受２３５Ｕ辐照后，可诱发明显的以核断裂和核固缩为特征的细胞凋亡。微观放射自显影研究显示，２３５Ｕ可迅速被免疫细胞吞噬，在细胞内以吞噬小泡的形式均匀地弥散于胞浆和胞核内。研究发现，ＩＬ２和ＩＬ６这两个细胞因子对由２３５Ｕ诱发的免疫细胞ＤＮＡ链断裂具有显著的防护作用。研究结果对于临床上寻找提高内照射放射治疗病例的免疫功能措施，具有一定的价值。     

浓缩铀对新生大鼠发育脑损伤的影响

首先建立了脑辐射损伤的动物模型,运用放射自显影示踪技术表明,新生大鼠脑内注射浓缩铀后,放射性核素行径主要定位于细胞核中,在细胞浆和细胞间隙中亦有呈现。多方位地研究了 α辐射体浓缩铀脑内照射对 Wistar 纯品系新生大鼠体格生长及神经行为的影响。结果表明新生大鼠脑内照射浓缩铀后可导致生长延迟及神经行为异常。运用放射免疫技术检测了浓缩铀脑内照射后,大鼠的小脑、皮质、海马、间脑中神经元特异性烯醇化酶 (NSE)、白细胞介素-1β (IL-1β)、超氧化物歧化酶 (SOD)、内皮素 (ET) 的含量变化。从生物化学角度表明,α 辐射体浓缩铀在新生大鼠中对发育脑损伤的作用特征具有神经细胞的敏感性,易脆性和代偿性。     

浓缩铀诱发免疫细胞凋亡的形态观察及IL—2和IL—6的 …

对浓缩铀＾２３５Ｕ内照射人淋巴细胞白血病细胞株Ｍｏｌｔ－４细胞和巨噬细胞株Ａｎａ－１细胞诱发的细胞凋亡及细胞因子的防护作用进行了研究。实验中估算了＾２３５Ｕ在不同阶段培养细胞中的辐射累积吸收剂量。通过荧光显微镜形态观察，发现免疫细胞在受＾２３５Ｕ辐照后，可诱发明显的以核断裂和核固缩为特征的细胞凋亡。     

荧光显微镜及放射自显影观察^147Pm内照射诱发免疫细胞凋亡

对荧光涂料＾１４７Ｐｍ内照射人淋巴细胞血病细胞株Ｍｏｌｔ－４巨噬细胞株ＡＮＡ－１细胞诱发细胞凋亡进行了研究。估算了＾１４７Ｐｍ在不同阶段培养细胞中的辐射累积吸收剂量。通过荧光显微镜的形态观察，发现免疫细胞Ｍｏｌｔ－４和ＡＮＡ－１细胞在受和＾１４７Ｐｍ内照射作用后，可诱发明显的核断裂和核固缩，以及凋亡小体形成为特征的细胞凋亡。微观放射自显影研究表明，＾１４７Ｐｍ可通过免疫细胞膜，在细胞内呈亲膜性积聚     

N-乙酰半胱氨酸对HT22细胞辐射诱导氧化应激及增殖和凋亡的影响

为探讨N-乙酰-L-半胱氨酸(N-acetylcysteine, NAC)对辐射相关氧化应激和海马神经元HT22细胞的增殖及凋亡的影响。首先选用不同剂量(0、2、4、6、8、10、12 Gy)的X射线分别照射HT22细胞,筛选出最佳照射剂量(10 Gy),然后进行实验分组:空白对照(Control)组,单纯照射(RT)组,照射+NAC(RT+NAC)组,照射后继续培养24 h后,CCK-8法检测细胞增殖、AnnexinV/PI双标记流式细胞术检测细胞凋亡情况;DCFH-DA荧光探针检测细胞内活性氧(reactive oxygen species, ROS)水平以评估细胞内氧化应激程度,比色法测定细胞内谷胱甘肽(glutathione, GSH)、丙二醛(malondialdehyde, MDA)含量、超氧化物歧化酶(superoxide dismutase, SOD)活性,Western blot检测Cleaved caspase-3、Bax、Bcl-2蛋白表达变化。结果表明,(1)2 Gy的照射对细胞增殖的影响不明显,当辐射剂量大于2 Gy时,随着辐射剂量的增高,HT22细胞增殖率明显降低(p<0.05);辐射剂量达10 Gy时,细胞增殖抑制率接近50%,因此将10 Gy作为实验最佳辐射剂量。(2)给予10 Gy X射线照射前给予NAC预处理可明显增加HT22细胞的增殖率(p＜0.01)。(3)给予10 Gy X射线照射可明显增加细胞内ROS、MDA含量(p＜0.01),减少细胞内GSH含量和SOD的活力(p＜0.01),促进凋亡蛋白Bax、Cleaved-caspase-3的表达(p＜0.01),细胞凋亡率显著增加(p＜0.01);NAC可减少照射后细胞内ROS和MDA含量(p＜0.01),提高GSH水平及SOD活性(p＜0.01),显著减少凋亡蛋白的表达和细胞凋亡。以上结果表明NAC可抑制辐射相关氧化应激,减少辐射对HT22细胞增殖抑制,减少细胞凋亡。     

美国Y-12工厂雇员16年的体检结果

【英国《保健物理》1979年6月报道】橡树岭Y-12工厂是联合碳化物公司为美国能源部经营的大型工厂。该厂大量处理浓缩铀和贫铀,经常有2000多雇员受到铀的内照射。十六年来,一直分析尿中铀含量以估     

荧光显微镜及微观放射自显影对~(153)Sm-EDTMP诱发骨瘤细胞凋亡研究

研究了~(153)Sm-EDTMP内照射治疗时对骨瘤细胞诱发的细胞凋亡过程。通过荧光显微镜观察,发现当骨瘤细胞受~(153)Sm-EDTMP内照射作用时,可诱发明显的核断裂和核固缩,以及凋亡小体形成为特征的细胞凋亡发生。微观放射自显影研究表明,~(153)Sm-EDTMP可掺入通过骨瘤细胞膜,在细胞内呈亲膜性积聚,也可被骨瘤细胞吞噬,在细胞质及细胞核内以吞噬     

单次或多次摄入浓缩铀(UO_2F_2)后的体内蓄积对血淋巴细胞的畸变效应

研究发现,当浓缩铀UO_2F_2单次或多次为机体摄入后,都观察到在体内蓄积最高的器官是肾脏,其次是骨骼,再则为肝脏,而在其余器官组织中含量甚微。实验观察表明,无论机体是单次或多次摄入浓缩铀,其在体内呈现的选择性蓄积特性与天然铀是一致的。 浓缩铀UO_2F_2在体内的蓄积动态是,在肾脏和肝脏中迅速出现蓄积高峰,并随观察时间的延长而逐渐降低。至于在骨骼中则随着观察时间的增长而持续升高。浓缩铀UO_2F_2诱发的血淋巴细胞畸变效应,可随摄入体内的剂量增大而血细胞畸变率亦增高。且可在一个细胞中观察到有两个畸变发生,同时细胞分裂指数亦受到明显抑制。     

用41Ca-AMS法测定谷氨酸毒性对PC12细胞外钙内流的影响

本工作用41Ca示踪PC12细胞,以CaF2作为最终测量样品,用加速器质谱计(全称AMS)测量41Ca.从谷氨酸毒性对PC12细胞的时间效应,MK-801对PC12细胞受体门控钙通道(全称ROC)阻断效应两方面进行分析,以激光扫描共聚焦显微镜的检测结果作为参照,结果表明41Ca的加速器质谱(AMS)测量方法能有效地检测到在不同情况下谷氨酸引起PC12细胞中外钙内流的情况.综合两种方法推测在谷氨酸引起的钙超载中,NMDAR介导的外钙内流起了重要作用.     

ABSTRACTS OF JAPANESE ARTICLES

Radiation damage to 30v/0 TBP/kerosene was investigated to determine changes in the extraction behavior of uranium and thorium with the solvent irradiated up to 10⁸ R in nitrate system and similarly in the stripping behavior with 0.01 N nitric acid.

The effect on uranium and thorium was discernible only with irradiations reaching 10⁸ R.

Changes in the behavior of fission products present in company with uranium or thorium were found to be the similar to the case where they existed free of uranium or thorium. At irradiations below 10⁷ R, uranium and thorium manifested loading effect, but it disappeared when irradiation reached 10⁸R.

Calculation of one stage decontamination factors of fission products from uranium and thorium confirmed deterioration of the power of separation with irradiation, and the degree of deterioration was determined quantitatively. The decontamination factor for ⁹⁵Zr-⁹⁵Nb was decreased to 1/2,000 by irradiation to 10⁸ R, while the same dosage of irradiation had little effect for ¹⁰⁶Ru-¹⁰⁶Rh.

Physical properties such as density, viscosity, emulsification tendency and phase separation time were also observed to be effected by irradiation to 10⁸ R.     

Chromatin and DNA chain fragmentation studies on apoptosis in immune cells induced by ^235U and radioprotection of IL—2 or IL—6

The apoptosis in human acute lymphoblastic leukemia cell line Molt-4 cell and macrophage cell line Ana-1 cell are studied after internal irradiation with enriched uranium 235U.The cumulative absorption dose of ^235U in cultural cells through different periods are estimated.The fluorescence microscopic observations indicate that Molt-4 and Ana-1 immune cells internally irradiated by ^235U displayed significant chromatin fragmentation and marked pyknosis in immune cells nuclei.as well as DNA chain fragmentation and apoptotic bodies formation.It should be noted that DNA chain fragmentation induced by ^235U may be inhibited statistically by IL-2(interleukin-2)or IL-6 treatment.     

STUDY ON THE ACCUMULATION OF ENRICHED URANIUM UO_2F_2 IN SUBCELLULAR LEVEL BY ELECTRON MICROSCOPIC AUTORADIOGRAPHY

In this paper we try to study the retentive peculiarity of soluble enriched uranium UO2F2 in subcellular level by electron microscopic autoradiography. The early dynamic accumulation of radioactivity in the body showed that enriched uranium UO2F2 was chiefly localized in kidney, especially accumulated in epicyte of kidney near- convoluted tubule. In liver cells, enriched uranium UO2F2 at first deposited in the nucleus and the cytoplasm, then accumulated in mitochondria selectively and lysosome as well. The electron microscopic autoradiographic study showed that the dynamic retention of radioactivity of enriched uranium UO2F2 in skeleton rose steadily throughout the exposure. Enriched uranium UO2F2 chiefly deposited in nucleus and mitochondria of the osteoblast as well as osteoclast.     

Neutronic analysis for core conversion (HEU–LEU) of Pakistan research reactor-2 (PARR-2)

Neutronic analyses for the core conversion of Pakistan research reactor-2 (PARR-2) from high enriched uranium (HEU) fuel to low enriched uranium (LEU) fuel has been performed. Neutronic model has been verified for 90.2% enriched HEU fuel (UAl₄–Al). For core conversion, UO₂ fuel was chosen as an appropriate fuel option because of higher uranium density. Clad has been changed from aluminum to zircalloy-4. Uranium enrichment of 12.6% has been optimized based on the design basis criterion of excess reactivity 4 mk in miniature neutron source reactor (MNSR). Lattice calculations for cross-section generation have been performed utilizing WIMS while core modeling was carried out employing three dimensions option of CITATION. Calculated neutronic parameters were compared for HEU and LEU fuels. Comparison shows that to get same thermal neutron flux at inner irradiation sites, reactor power has to be increased from 30 to 33 kW for LEU fuel. Reactivity coefficients calculations show that doppler and void coefficient values of LEU fuel are higher while moderator coefficient of HEU fuel is higher. It is concluded that from neutronic point of view LEU fuel UO₂ of 12.6% enrichment with zircalloy-4 clad is suitable to replace the existing HEU fuel provided that dimensions of fuel pin and total number of fuel pins are kept same as for HEU fuel.     

电离辐射对小鼠小肠和结肠细胞凋亡的影响

观察不同剂量ｒ射线照射对小鼠小肠和结肠细胞凋亡水平的影响。６０Ｃｏｒ射线全 身照射 ＢＡＬＢ／ｃ 小鼠;剂量分别为 １、 ６、 １２Ｇｙ,于照射后 ２４ｈ内分批取材,常规石蜡包埋, ＨＥ染色, Ｏｌｙｍｐｕｓ显微镜下观察辐射诱导小肠和结肠细胞凋亡的情况。结果表明：正常小鼠小 肠细胞有自发的凋亡现象,平均每个隐窝的凋亡细胞数为０．０３８±０．０５９个,结肠在正常情况下没 有细胞凋亡发生;不同剂量ｒ射线照射后小肠隐窝细胞凋亡数目明显增加（ｐ ＜０．０５）,其中 １Ｇｙ 照射组凋亡峰在照射后 １２ｈ明显, ６Ｇｙ和 １２Ｇｙ组分别在照射后 ２４ｈ和 ６ｈ凋亡细胞最多。结 肠未见或偶见凋亡细胞;各照射剂量组及照射后不同时间（照射后 ６、 １２、 ２４ｈ）组小肠隐窝细 胞凋亡数较相应结肠组显著增加（ｐ＜０．０５）。说明在电离辐射的情况下,小肠较结肠能更有效的 清除辐射损伤的细胞,而后者在体内的蓄积可能与以后的肿瘤发生有关。     

CANDU-6型反应堆中引入稍加浓铀的研究

为了比较稍加浓铀（SEU）与天然铀燃料的优劣，寻找最优的稍加浓铀富集度水平，本文利用WIMS-AECL和ORIGEN程序研究不同富集度的CANDU-6堆燃料在燃料循环成本、天然铀消耗量、高放废物积累等方面的表现。结果显示，采用稍加浓铀可节约20%以上的天然铀，乏燃料量减少30%以上，燃料循环成本降低50%以上；1.3%是最优的富集度水平。      

Improvement of plutonium proliferation resistance by doping minor actinides

This paper focuses on improving the proliferation resistance of plutonium resulting from uranium-based fuel irradiation. Intrinsic properties of plutonium isotopes with even mass numbers (²³⁸Pu, ²⁴⁰Pu and ²⁴²Pu) — in terms of their intense decay heat and high spontaneous fission neutron rates — were used as a measure to improve the proliferation resistance of plutonium itself. The present study explores MA addition effect into LEU (5%²³⁵U) and HEU (20%²³⁵U) with regard to plutonium proliferation resistance characteristics. Consideration goes beyond critical condition to examine the potential of subcritical system in enhancing the plutonium proliferation properties. Results show that even the doping level of 1% of Np, TrPu or all MA elements into low enriched uranium improves the proliferation-resistant properties of plutonium. A potential for further improvement is achieved by higher doping of minor actinides into high enriched uranium irradiated in a subcritical mode.     

电离辐射诱导HeLaS_3细胞凋亡时程变化的影响

采用PI和Hoechst33342双染、流式细胞术 (FCM)和图像分析术 (ICM)检测了不同剂量电离辐射对HeLaS3 细胞凋亡的影响。结果表明 ,HeLaS3 细胞在分别受到 0 .5 - 4 .0GyX射线照射后 8h ,其细胞凋亡呈增高趋势 ,但无统计学意义。照射后 12h ,细胞凋亡显著增加 (p <0 .0 1) ,并达峰值。随后 ,细胞凋亡率迅速下降 ,4 8h ,又有所回升。且流式细胞术与图像分析术所得结果数据相近 ,趋势一致。     

三种非活性微生物对铀的吸附行为及其受γ辐照的动力学影响

以非活性酿酒酵母菌、耐辐射奇球菌、大肠杆菌为研究对象,利用电感耦合等离子体质谱仪(ICP-MS)、红外光谱(FTIR)等测试手段,研究溶液初始pH值、U(Ⅵ)初始浓度等因素对三种非活性微生物吸附U(Ⅵ)的影响,并探讨了不同强度γ辐照下三种非活性微生物对U(Ⅵ)的吸附动力学过程。结果显示:三种非活性微生物均能有效去除水体中的U(Ⅵ),并且是一个快速反应过程。溶液pH=5.0时吸附效果最佳。同等实验条件下,三种非活性微生物吸附U(Ⅵ)达到吸附平衡的顺序为酿酒酵母菌耐辐射奇球菌大肠杆菌。三种非活性微生物细胞通过细胞表面的羟基、氨基、羧基、羰基及磷酸基团的配位作用来吸附铀。γ射线辐照后,三种非活性微生物对U(Ⅵ)的吸附率明显低于未受辐照时的吸附率,原因可能是辐照因素改变了菌体表面的活性位点。实验用非活性微生物与U(Ⅵ)作用的激烈程度是细菌真菌。