RADIOIMMUNOTOXICOLOGICAL EFFECT OF ENRICHED URANIUM ON CENTRAL AND PERIPHERAL IMMUNE CELLS AND THE PROTECTIVE ACTION OF IL—1 AND IL—2

Accumulation of enriched 235U-UO2F2 in the body had injurious effects on the immune function of central and peripheral immune cells.After an intravenous injection of ^235U-UO2F2,the spontaneous ^3H-TdR incorporation in thymocytes and bone marrow cells decreased.with the thymocytes damaged more markedly.The proliferation ability of spleen T and B lymphocytes were both inhibited,with B lymphocytes inhibited more severely.In spleen B lymphocytes the IL-1 production and IL-2 consumption were diminshed.The inhibition of spleen B lymphocyte proliferation by ^235U-UO2F2 was partially restored by adding exogenous IL-1 or IL-2 to the cultured lymphocytes obtained from ^235U injected mice.     

INDUCTION OF MUTAGENIC EFFECT IN SOMATIC AND GERM CELLS BY ENRICHED URANIUM

Enriched uranium(UO2F2) accumulated in organism could cause chromosome aberrations in somatic cells, its rates on bone marrow cells were elevated when the dose of 235UO2F2 was increased. Among the types of induced aberrations, chromatid breakage was predominant, accompanied with a few chromosome breakage and translocation. At the same time mitosis index of metaphase cells was depressed. Chromatid delation and chromatid exchange were induced in peripheral blood lymphocytes. The important type of aberrations in spermatogonia was break. For primary spermatocytes the most significant aberration was multivalents which resulted either from chromatid interchanges or reciprocal translocations. 235UO2F2 could result in DNA breakage in germ cells. The sensitivity of germ cells at various stages to 235UO2F2. was different. At 12d after exposure the amount of sperm DNA eluted reached the peak. When the treating time was fixed, elution of sperm DNA from treated animals increased with the increasing doses. 235UO2F2. could also result in sperm abnormalities. Especially at 13 to 36 d after treatment the rates of sperm abnormalities were significantly elevated.     

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.     

THE EFFECT OF SOME MEDICAL TREATMENTS ON THE RED BLOOD CELLS IN THE PATIENTS WITH THALASSEMIA

The Mossbauer spectroscopy and circular dichroism measurements have been used to investigate the effect of some medical treatments on the red blood cells (RBCs) of the patients with HbH disease and β-thalassemia major, respectively. The results indicate that both splenectomy and treatment with myleran are effective to alleviate the symptoms of anemia for some patients, but both of them are different in the effect on the RBCs of the patients. On the basis of the results, a hypothesis on the course of denaturation in hemoglobin of the patients is proposed.     

EFFECT OF SOLVENT ON THE MAGNETIC INTERACTIONS BETWEEN Fe_3O_4 PARTICLES AND SURFACTANTS

Mossbauer spectra for 5 nm Fe3O4 particles coated with different surfactants (the polar end groups as -COONa and -SO3Na) were measured and show a significant influence on superparamagnetic relaxation with and without the solvent. Some phenomena were explained by the superparamagnetism and the surfactant hydrophilicity.     

THE INHIBITION EFFECT OF ~(211)At-Te COLLOID AND Na~(211) At INJECTIONS ON MURINE EHRLICH ASCITES TUMOR CELLS

Na211 At and 211 At-Te colloid injections are prepared. It has been demonstrated that the 211 At-Te colloid is stable in vivo and vitro, and can be applied in the study of biology and medicine. In the report, the model of Murine Ehrlich Ascites Cells cultured in vivo and vitro is elected for a series of experiments. It has been proved that Na 211At and 211At-Te colloid injections possess an inhibition effect on tumor cells. The inhibition effect was expressed in surviving of the mice and inhibiting growth of tumor as well as the changes of enzyme activity. Meanwhile, it was also noticed that Na 211 At and 211 At-Te colloid injections of various dose inhibited the absorb of pyrimidine nucleosides in Murine Ehrlich Ascites Cells. And the effect isn't reversible. It is closely related to the dose administratered and 50% inhibition rate needs about 1.48×105 Bq/ml culture.     

PROGRESS ON NUCLEAR DATA CALCULATION AND NUCLEAR THEORY RESEARCH AT THE THEORY GROUP OF CNDC

In last year,the theory group of CNDC has been mainly working on the fields of nuclear data calculations,theoretical evaluation method,nuclear mod-el parameters,computer codes and the nuclear reaction theory research des-cribed briefly as follows:     

CONCLUSION OF INTERNATIONAL SYMPOSIUM ON NUCLEAR ENERGY AND THE ENVIRONMENT AT BEIJIN ON 14～18 OCT.1996

ＣＯＮＣＬＵＳＩＯＮＯＦＩＮＴＥＲＮＡＴＩＯＮＡＬＳＹＭＰＯＳＩＵＭＯＮＮＵＣＬＥＡＲＥＮＥＲＧＹＡＮＤＴＨＥＥＮＶＩＲＯＮＭＥＮＴＡＴＢＥＩＪＩＮＯＮ１４～１８ＯＣＴ．１９９６Ｂ．Ｇ．Ｂｅｎｎｅｔ（ＵＮＳＣＥＡＲ）Ｗｅｈａｖｅｃｏｍｅｔｏｔｈｅｅｎ...     

INVESTIGATION OF THE SOLID- SOLID SURFACE ADSORPTION OF Eu_2O_3 ON AMORPHOUS Al_2O_3

Solid-solid surface adsorption of Eu2O3 on amorphous Al2O3 have been investigated by Mossbauer spectroscopy, X- ray diffraction analysis and laser Raman spectra (LRS). No X-ray diffraction peak of crystalline Eu2O3 can be found for all samples studied. The LRS show that two peaks at 998 and 1051 cm-1 assigned to two-dimensional surface europium-oxygen species appear at Eu2O3 content of 18.7 wt%. The peak at 1068 cm-1 due to the surface species and another peak at 342cm-1 due to crystalline Eu2O3 content start to appear for the sample with an Eu2O3 content of 36.5 wt%. The dispersity of Eu2O3 on the surface of amorphous Al2O3 were compared with that of α-Al2O3,η-Al2O3 and SiO2 gel. The results of these studies indicate that the structure of Eu2O3 dispersed onto the support surface depend on the structure of support and that there is an inductive effect of support on the structure of the Eu2O3.     

精脒含量对浓缩铀诱发PCI2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,同时细胞内游离精眯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。     

rIL—1和rIL—2对浓缩铀UO2F2的防护作用

本文介绍用3H-TdR 掺入示踪技术,探讨了外源性白细胞介素-1(rIL-1)和外源性白细胞介素-2(rIL-2)对浓缩铀 UO_2F_2损伤小鼠脾脏 B 淋巴细胞的防护作用。经 BALB/c 小白鼠尾静脉注入20mg/kg 体重的浓缩铀 UO_2F_2 48 h 后,无菌取脾,制成单细胞悬液加入细菌脂多糖(LPS)、rIL-1或 rIL-2常规培养,以淋巴细胞 DNA 中~3H-TdR 掺入量的变化来衡量 B 淋巴细胞的增殖能力。结果表明,浓缩铀 UO_2F_2能明显抑制小鼠脾脏 B 淋巴细胞 DNA 的合成,使 B 淋巴细胞增殖受到明显抑制;rIL-1和 rIL-2可使受浓缩铀 UO_2F_2损伤的小鼠脾脏 B 淋巴细胞的增殖抑制部分逆转,最大增殖率分别为67%和51%;二者合并使用时可使增殖率增至83%。     

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。     

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。     

^235U诱发细胞凋亡及IL—2和IL—6的防护作用

本文采用ＤＮＡ琼脂糖凝胶电泳研究了＾２３５Ｕ诱发的免疫细胞（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）凋亡,探讨了细胞因子ＩＬ－２和ＩＬ－６的防护作用。结果表明,经＾２３５Ｕ照射达６ｈ以上的各组Ｍｏｌｔ－４和Ａｎａ－１细胞,均可观察到呈现凋亡细胞特征的阶梯状条带形成;而预先使用细胞因子ＩＬ－２和ＩＬ－６,对＾２３５Ｕ诱发的免疫细胞ＤＮＡ链断裂有显著的防护作用。     

淋巴因子相应靶细胞的小剂量辐射效应

观察了单次小剂量Ｘ射线全身照射后Ｃ５７ＢＬ／６小鼠胸腺细胞ＩＬ－１反应性和脾细胞ＩＬ－２反应性的变化，发现在１００ｍＧｙ以内的小剂量照射后，整个胸腺和脾脏的细胞数趋于增多，胸腺细胞对ＩＬ－１的反应性和脾细胞对ＩＬ－２的反应性趋于增强，体外照ＩＬ－２细胞亦出现同样的反应趋势，但统计学处理与对照组比较均地明显差异。     

浓缩铀内污染对小鼠脾淋巴细胞DNA损伤修复的作用

研究了不同水平浓缩铀(235UO2F2)对淋巴细胞DNA损伤修复的作用及其机理.应用紫外线诱导的非程序DNA合成 (UDS) 检测,观察浓缩铀(235UO2F2)内污染对小鼠脾淋巴细胞DNA损伤修复的影响.结果表明, 浓缩铀摄入量为0.1-20μg/kg 体重时, 脾淋巴细胞紫外线诱导的UDS显著高于对照组 (p<0.05或p<0.01); 浓缩铀内污染12d时, 脾淋巴细胞未经紫外线照射的UDS显著增加 (p<0.05或p<0.01); PHA组脾淋巴细胞紫外线诱导的UDS显著低于未加PHA组.在一定剂量范围内,低剂量浓缩铀内污染对淋巴细胞DNA损伤修复功能具有明显的刺激作用,并且该剂量范围明显大于外照射;浓缩铀内污染对淋巴细胞DNA具有持续的损伤作用,继而诱发细胞DNA修复功能的增强;PHA刺激但未增殖的脾淋巴细胞DNA损伤修复功能明显减低.     

加速效应在阳离子交换法分离铀同位素中的应用

本文研究了丁二酸、Ca~+的加速效应在(O_2)_~(2+)-苹果酸-Na~+排代体系分离铀同位素中的作用。对(O_2)_~(2+)-苹果酸-丁二酸-Ca~(2+) (NH_4~+)排代体系的色谱特征、铀同位素的单级分离因子ε和斜率系数δ及它们的温度系数进行研究测定并和(O_2)~(2+)-苹果酸-Na~+排代体系作了对比后,肯定了丁二酸和Ca~(2+)对(UO_2)~(2+)传质的加速效应δ使值增加63％,或ε×δ值增加37％;还明确了(O_2)_2~(2+)-苹果酸-丁二酸-Ca~(2+)(NH_4~+)体系的铀区pH是可调控的,因而具有选择最佳分离条件的优点。