四种络合剂对241Am促排效果的比较

应用200只天鼠研究了²⁴¹Am内污染时四种络合剂(Ca-DTPA, Zn-DTPA,嗤胺酸钠盐和H-73-IO)钓促排效果.实验目的是为²⁴¹Am内污染治疗确定首先促排药物及制定最佳促排方案.实验结果表明:在四种结合剂中Ca-DTPA和Zn-DTPA促排效果为最佳,能使骨²⁴¹Am含量降低到对照组的10%,肝²⁴¹Am含量降低到对照组的5%左右.喹胺酸钠盐在降低骨、肝²⁴¹Am含量方面也有效(统计上与DTPA无显著差别),但能导致肾脏²⁴¹Am蓄积,甚至略高于对照组.H-73-10虽有-些效果,但远不及DTPA.     

喹胺酸和LICAM(C)对大鼠体内238Pu和241Am的促排效果比较

喹胺酸(Quinamic acid, QAA, 811)是一种异哇啉类络合剂, 对钍有较好的促排效果。本文主要研究大鼠静脉注入(iv)²³⁸Pu和²⁴¹Am各26kBq/kg后1小时, 经皮下注入(so)不同剂量.(1～30μmol/kg)QAA, 或静脉注入核素后立即灌胃(po)QAA(30μmol/kg)对²³⁸Pu、²⁴¹Am的促排疗效, 并与LICAM(C)相比较。实验观察到QAA对降低骨肝中²³⁸Pu、²⁴¹Am的蓄积量有较好的作用, QAA对²³⁸Pu的促排效果高于对²⁴¹Am.在剂量(1～30μgmol/kg)对肝、肾中²³⁸Pu和骨、肾中²⁴¹Am蓄积量的降低, QAA优于LICAM(C)；灌胃QAA(30μttmol/kg)伍用NaHCO₃(5mmol/kg的)疗效, 对骨、肝中²³⁸Pu蓄积量的降低, QAA和LICAM(C)二间无差异(P>0.05), 但对²³⁸Pu在肾中蓄积量和对²⁴¹Am在骨, 肾中蓄积量的降低, QAA明显优于LICAM(C)。     

放射自显影术评价促排和阻吸收放射性核素的效果研究

放射性桉素对机体的作用特性及其损伤效应的呈现,是与该核素在体内的蓄积特性、转移和排除程度密功相关联的。因此,本文研究了不同放射自显影术对加速排除和阻止吸收放射性桉素的效果评价如下,(1)宏观放射自显影评价喹胺酸和DTPA对¹⁶⁹Yb的促排作用,(2)宏现放射自显影评价稳定性Yb于¹⁶⁹Yb在骨中的减少沉积作用}(8)微观放射自显影评价噎胺酸和DTPA对¹⁶⁹Yb促排作用的机理探讨。     

镅-铍中子源事故及其处理

1982年4月我国南方某地误拾²⁴¹Am-Be中子源,经多人传递后被钻开,致使人身、场所大面积受到a污染.本协作组对污染情况作了较全面的调查、测量和初步评价,对事故进行了相应的处理.经估算受照人员x外照射剂量最高.胸部0.12Sv,手部0.32Sv;Y的²⁴¹Am内污染量最高,约3.3×10³Bq.对Y等4名受照人员进行了促排治疗,显著地增加了尿和粪中²⁴¹Am的排出.事故后1.5年进行的医学检查,除淋巴细胞染色体畸变率增高外,无归因于辐射作用的医学所见.     

苯酚氨羧酸类螯合剂对放射性核素加速排除效果的研究

动物实验表明取代苯酚、苯二酚等氨羧酸螯合剂对放射性核素¹⁴⁴Ce,²³⁴Th都有较好的促排效果。这类螯合剂的促排效果与结构有密切关系。本文对合成的27个螯合剂的构效关系研究初步表明:邻苯二酚化合物优于对,间苯二酚化合物。邻、间、对苯二酚审一个羟基代之以其它基因的化合物如邻取代苯酚化合物其效果下降,对、间代苯酚化合物效果有所提高,但不及邻苯二酚类效果好。     

离子交换法处理60Co污染的γ辐照装置源井水

目的 选择合适的离子交换树脂处理⁶⁰Co污染的贮源井水,使污染的贮源井水中放射性水平低于10 Bq/L,满足排放要求。 方法 通过亚硝酸钴钾共沉淀-β计数法测量水样中⁶⁰Co的活度,比较两种不同离子交换树脂处理⁶⁰Co污染模拟井水的效果,并选择净化效果较好的离子交换树脂处理⁶⁰Co污染的源井水。 结果 MBD-15-SC型混合离子交换树脂对模拟井水中⁶⁰Co净化效果明显高于ZGCNR50型强酸性阳离子交换树脂,大约为5.8倍;采用多次两级MBD-15-SC型混合离子交换树脂循环处理污染的源井水,可使水中⁶⁰Co放射性浓度从4.16×10⁵ Bq/L降至1.16 Bq/L。 结论 采用多次两级MBD-15-SC型混合离子交换树脂可有效处理⁶⁰Co污染的源井水,处理后的贮源井水符合排放要求。     

五种络合剂对促排钍的疗效评价

本文对有较好排钍效果的811、8102、8307-7603和DTPA等五种络合剂, 从量效关系, 时效关系和疗效强度等方面进行比较。结果表明, 从尿粪中²³⁴Th的排出量的增加和组织中²³⁴Th蓄积量的降低为指标, 以8102的疗效为最佳, 其次是811, 但811使肾²³⁴Th菩积量有增加。DTPA和7603在高剂量时才有较好的排²³⁴Th效果, 且7603以粪²³⁴Th形式排出为主, 其疗效与DTPA、8307基本相当。     

云南芒市地区野生食用蘑菇中137Cs、40K含量及所致居民剂量估算

目的 检测可食用野生蘑菇中人工放射性核素¹³⁷Cs和天然放射性核素⁴⁰K的含量及分布特点,计算野生蘑菇中放射性核素水平及其所致剂量。方法 采集了产自云南省芒市的18类33份可食用野生蘑菇样品,用实验室低本底高纯锗（HPGe）γ谱仪分析了其中放射性核素¹³⁷Cs、⁴⁰K的含量。结果 33份样品中,仅1份样品¹³⁷Cs的含量在探测限之下,其余32份样品中均可检测出¹³⁷Cs,比活度范围值为0.45~339.58 Bq/kg（干重）,平均值25.47 Bq/kg（干重）。所有样品均检测出天然放射性核素⁴⁰K,核素比活度最小值和最大值分别为453.4、1 882.6 Bq/kg（干重）,平均值为815.1 Bq/kg（干重）。当去除只有1个样品数的蘑菇种类后,毛钉菇、美味牛肝菌、白牛肝菌、锈盖粉孢牛肝菌、香菇、茶褐牛肝菌6个种类蘑菇间¹³⁷Cs含量差异有统计学意义（F=21.13,P<0.05）,而⁴⁰K含量差异无统计学意义。结论 6类不同蘑菇中¹³⁷Cs含量不同,其中毛钉菇、香菇中人工放射性核素¹³⁷Cs含量相对较高。但食入此类蘑菇对成人所致待积有效剂量极其微小,不会影响健康。     

125I-UdR壳聚糖纳米微粒对肝癌细胞的内照射生物学效应

目的 评估¹²⁵I-UdR壳聚糖载药纳米微粒(¹²⁵I-UdR-CS-DLN)对肝癌细胞的内照射生物学效应.方法 采用激光共聚焦显微镜观察¹²⁵I-UdR-CS-DLN在肝癌细胞HepG2和人正常肝组织细胞HL-7702内的聚积和分布;通过MTT实验、流式细胞仪和单细胞凝胶电泳技术,评价内照射细胞生物学效应;采用TUNEL染色法观察兔肝原位肿瘤细胞经¹²⁵I-UdR-CS-DLN靶向治疗后的细胞凋亡.结果 纳米微粒作用30 min后,其在HepG2细胞质内的聚积大于HL-7702;当¹²⁵I-UdR-CS-DLN浓度大于37 kBq/ml时,HepG2细胞在纳米微粒作用后24、48 h的存活率显著低于HL-7702细胞(t=-4.46~6.31,P<0.05),且细胞周期G₁期阻滞明显, G₂/M期细胞明显受损;¹²⁵I-UdR-CS-DLN造成细胞DNA双链断裂的程度明显高于¹²⁵I-UdR,HepG2细胞的DNA损伤后修复能力显著低于HL-7702(Olive尾矩:t=2.94,P<0.05;彗尾DNA%:t=10.64,P<0.01);兔肝原位癌模型经介入被动靶向治疗后的TUNEL染色结果表明,¹²⁵I-UdR-CS-DLN可使兔肝原位肿瘤细胞产生明显的凋亡,而相同剂量¹²⁵I-UdR作用后肿瘤并未出现明显的凋亡.结论 ¹²⁵I-UdR-CS-DLN进入肝癌细胞的能力明显强于¹²⁵I-UdR,引起的DNA辐射损伤效应更强,可明显加剧肝癌细胞的凋亡,阻止DNA损伤修复.     

56Fe17+、12C6+重离子束与60Co γ射线对人淋巴细胞染色体畸变、细胞周期

目的 比较⁵⁶Fe¹⁷⁺、¹²C⁶⁺重离子束与⁶⁰Co γ射线对人淋巴细胞染色体畸变、周期、凋亡的影响。方法 ⁵⁶Fe¹⁷⁺、¹²C⁶⁺重离子束和⁶⁰Co γ射线分别照射人淋巴细胞系Peng-EBV,吸收剂量均为0、0.5和2.0 Gy,⁵⁶Fe¹⁷⁺重离子束剂量率为0.26～0.55 Gy/min,¹²C⁶⁺重离子束剂量率为0.30～0.50 Gy/min,γ射线照射剂量率为0.75 Gy/min。研究不同射线对染色体细胞畸变率、“双+环”畸变率的影响。利用流式细胞仪检测细胞周期和细胞凋亡。结果 ¹²C⁶⁺、⁵⁶Fe¹⁷⁺重离子与⁶⁰Co γ射线照射后细胞畸变率与0 Gy相比,差异有统计学意义（χ²=12.08～322.97,P<0.05）。“双+环”畸变率与0 Gy相比,差异有统计学意义（χ²=4.06～205.37,P<0.05）。其中,¹²C⁶⁺重离子束诱导的细胞畸变率和“双+环”畸变率最高,其次是⁵⁶Fe¹⁷⁺重离子束,而且二者均高于⁶⁰Co γ射线。⁵⁶Fe¹⁷⁺、¹²C⁶⁺离子束与⁶⁰Co γ射线均能诱导人淋巴细胞发生明显的G₂期阻滞,差异有统计学意义（t=-80.9～0.17,P<0.05）,¹²C⁶⁺重离子、γ射线及⁵⁶Fe¹⁷⁺重离子诱导的G₂期阻滞程度依次降低。⁵⁶Fe¹⁷⁺、¹²C⁶⁺离子束与⁶⁰Co γ射线均能促进细胞凋亡,差异有统计学意义（t=-22.65～0.87,P<0.05）,¹²C⁶⁺重离子、γ射线及⁵⁶Fe¹⁷⁺重离子诱导的早期凋亡率依次降低。结论 ⁵⁶Fe¹⁷⁺、¹²C⁶⁺离子束与⁶⁰Co γ射线均能诱导人淋巴细胞发生明显的染色体畸变、G₂期阻滞及细胞凋亡。¹²C⁶⁺离子束诱导的染色体畸变、周期阻滞和凋亡程度最高。⁵⁶Fe¹⁷⁺、¹²C⁶⁺离子束与γ射线的生物学效应与LET相关。     

Determination of I in I-pharmaceuticals produced in THOR

¹³¹I is one of the most important radionuclides used in nuclear medicine. The accompanying isotope ¹²⁹I with insignificant activities in ¹³¹I-pharmaceuticals, produced in THOR, were determined in terms of ¹²⁹I/¹³¹I ratio by neutron activation analysis. The detection limit of ¹²⁹I can be lowered to order of 0.1 Bq, superior to conventional radiometric methods. The ¹²⁹I/¹³¹I ratios in the ¹³¹I-pharmaceuticals, were measured to be in the range from 3.9 to 8.3.     

Low level air radioactivity measurements in Prague,Czech Republic

Activity concentrations of radionuclides in the atmosphere have been monitored for over 21 years in the Czech Republic, at present at 10 sampling sites. Results of long-time observation of the radionuclides ¹³⁷Cs, ⁷Be, ²¹⁰Pb, ²²Na, ⁴⁰K, ²³⁸Pu, ^239,240Pu, ⁹⁰Sr, ⁸⁵Kr and ¹⁴C and statistical analysis of the data from the monitoring site in Prague are given in the paper. In 2007 mean activity concentrations of monitored radionuclides at Prague monitoring site in Bq/m³ were: ⁸⁵Kr, 1.6×10⁺⁰; ¹⁴C, 5.3×10⁻²; ¹³⁷Cs, 6.8×10⁻⁷; ⁷Be, 4.3×10⁻³; ²¹⁰Pb, 5.3×10⁻⁴; ⁴⁰K, 1.8×10⁻⁵; ²²Na, 3.5×10⁻⁷; ⁹⁰Sr, 5–7×10⁻⁸; ²³⁸Pu, 1–2×10⁻¹⁰ and ^239,240Pu, 1.7×10⁻⁹.     

核电站周边地表水中铀的同位素丰度分析

目的 掌握核电站周边地区地表水中铀同位素丰度比值基线数据.方法 采集江苏、山东、浙江省境内3个核电站周边地区供饮用的地表水,利用磷酸三丁酯(TBP)萃淋树脂分离富集铀,电感耦合等离子体质谱(ICP-MS)法分析样品中的234 U/238U与235 U/238U的丰度比.结果 地表水中234 U/238U丰度比范围为4.575×10-5 ～7.752×10-5,235 U/238U丰度比范围为7.273 ×10-3～7.639×10-3.结论 地表水中234U被不同程度地富集.     

Evaluation of triple quantum-filtered 23Na NMR spectroscopy in the in situ rat liver

Triple quantum (TQ)-filtered ²³Na NMR spectroscopy and the shift reagent, TmDOTP^5-, have been used to evaluate the contributions of intra- (Na_i⁺) and extracellular (Na_e⁺) sodium to the TQ-filtered signal in the rat liver, in situ. Na_e⁺ contributed significantly to the total TQ-filtered signal in live animals, and the intensity of this signal did not change postmortem. The TQ-filtered Na_i⁺ signal increased by approximately 380% over a period of 1 h postmortem, whereas the single quantum (SQ) Na_i⁺ increased by 90%. The constancy of the TQ-filtered Na_e⁺ signal indicates that changes in total TQ-filtered ²³Na signal intensity in liver (without a shift reagent) may accurately reflect changes in TQ-filtered Na_i⁺ signal intensity. The large percent increase in the TQ-filtered Na_i⁺ signal as compared to the SQ signal suggests that the fraction of Na_i⁺ interacting with macromolecules increases after death.     

Uptake of SPECT radiopharmaceuticals in neocortical brain cultures

The uptake, retention and uptake antagonism of ²⁰¹Tl-DDC, ²⁰¹Tl-Cl, ¹²³I-IMP, ^99mTc-HMPAO and ^99mTc-O ₄ ^– were compared in rat neocortex cultures. ²⁰¹Tl-DDC and ¹²³I-IMP revealed the highest uptake of radioactivity in the cultures. ⁹⁹mTc-HMPAO and ¹²³I-IMP showed the highest retention of radioactivity within the tissue in washout experiments. Blocking of bioelectric activity by tetrodotoxin did not significantly affect the uptake of the radiopharmaceuticals (RPHA). Inhibition of Na-K-ATPase by ouabain inhibited the uptake of ²⁰¹Tl-Cl (77%) and ²⁰¹Tl-DDC (27%). Imipramine showed a significantly stronger inhibitory effect on ¹²³I-IMP uptake in comparison with the effect on other RPHA. ^99mTc-O ₄ ^– was not concentrated within the cultured tissue. Under the in vitro conditions used in this study, the various RPHA were characterised by distinct differences in their interaction with cortical brain tissue.     

Samarium-153 chelate localization in malignant melanoma

¹⁵³Sm, a radiolanthanide of half life 46.27 h, has a gamma emission of 0.103 MeV which is well suited to imaging, it is also a moderate energy beta emitter and tumour localization of various ¹⁵³Sm chelates was evaluated in B16 murine melanoma to assess their endoradiotherapeutic potential. ¹⁵³Sm was prepared from enriched ¹⁵²Sm in the Australian Nuclear Science and Technology Organization reactor. ¹⁵³Sm chelates were prepared from ¹⁵³Smchloride and their chromatographic behaviour characterized. Tumour and organ uptake of ¹⁵³Sm-chloride, ¹⁵³Sm-citrate and the ¹⁵³Sm chelates, DTPA, HEDTA, HIDA, BZ, PBH, PIH and NTA were measured at 1, 6, 24 and 48 h after intravenous administration to C57 black mice bearing either melanotic or amelanotic B16 melanoma of mean size 0.75 cm³. Histopathological examination of the tumours at each passaging assured comparability of the degree of melanogenesis and the absence of necrosis. ¹⁵³Sm-chloride was immobile on chromatography and the rapid hepatic accumulation of both ¹⁵³Sm-chloride and ¹⁵³Sm-citrate was attributed to in vivo formation of a colloid. In contrast, ¹⁵³Sm-DTPA, moving at the solvent front on chromatography, showed no reticuloendothelial accumulation in vivo and was rapidly excreted by the kidneys without tumour uptake. The other ¹⁵³Sm chelates were of intermediate stability and all localized in both melanotic and amelanotic tumours, although to a significantly lesser degree than ⁶⁷Ga-citrate. The relatively high ¹⁵³Sm-HIDA activity in liver and ¹⁵³Sm-NTA activity in bone impaired tumour definition, but on imaging of all the ¹⁵³Sm chelates only ¹⁵³Sm-DTPA failed to demonstrate the B16 melanoma and the best tumour delineation was obtained using ¹⁵³Sm-HEDTA.     

Value of 111In-DOTA-lanreotide and 111In-DOTA-DPhe1-Tyr3-octreotide in differentiated thyroid cancer: results of in vitro binding studies and in vivo comparison with 18F-FDG PET

Purpose Radioiodine-negative thyroid cancer presents diagnostic and therapeutic difficulties, warranting the implementation of new imaging and treatment strategies. The purpose of this study was twofold. First, we investigated in vitro the binding characteristics of ¹¹¹In-DOTA-lanreotide (¹¹¹In-DOTA-LAN) and ¹¹¹In-DOTA-DPhe¹-Tyr³-octreotide (¹¹¹In-DOTA-TOC) to cells derived from differentiated thyroid cancer (DTC). Second, we evaluated the value of somatostatin receptor (SSTR) scintigraphy with these radioligands, as compared with ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography (PET), for the detection of tumour lesions in DTC patients.Methods Binding of ¹¹¹In-DOTA-LAN and ¹¹¹In-DOTA-TOC to cells isolated from surgically removed thyroid tissue was evaluated in vitro by performing saturation and displacement studies. Eighteen DTC patients with elevated thyroglobulin (12 radioiodine-negative, six radioiodine-positive) were investigated with ¹¹¹In-DOTA-LAN, ¹¹¹In-DOTA-TOC and ¹⁸F-FDG PET scans.Results Large numbers of SSTR binding sites for ¹¹¹In-DOTA-LAN and ¹¹¹In-DOTA-TOC were found on the cells investigated. Both SSTR radioligands exhibited a high binding affinity for these SSTR binding sites. ¹¹¹In-DOTA-LAN and ¹¹¹In-DOTA-TOC scintigraphy detected 37 and 33 lesions, respectively, in 17 (94%) patients each, whereas ¹⁸F-FDG PET revealed 30 lesions in 15 (83%) patients. Uptake of both SSTR radioligands was found in several radioiodine-negative sites. No striking differences in lesion imaging by ¹¹¹In-DOTA-LAN and ¹¹¹In-DOTA-TOC were found. In both radioiodine-negative and radioiodine-positive patients, more lesions were SSTR-positive/¹⁸F-FDG-negative than were ¹⁸F-FDG-positive/SSTR-negative.Conclusion Adding a SSTR scan with these radioligands to the diagnostic work-up increases the diagnostic capacity in DTC, and should be considered particularly in radioiodine-negative patients with elevated thyroglobulin levels.These studies were supported in part by the Austrian National Bank (Anniversary Foundation, Projects No. 7487 and 8185) and by a Foundation of the Mayor of the City of Vienna.     

Sulfite radicals in banded coral

We compare records of stable oxygen ratio (σ¹⁸O) and SO₃⁻/CO₂⁻ ratio in an 8 yr long modern coral skeleton from a small volcanic island in the Banda Islands, eastern Indonesia. The SO₃⁻/CO₂⁻ ratio in ESR signal intensity reflects the skeletal SO₃²⁻/CO₃²⁻ ratio, which is the degree of sulfite incorporation. The resulting σ¹⁸O and SO₃⁻/CO₂⁻ records correlate well for the most recent years of growth. We speculate that water mass effect and possibly sea surface temperature (SST) control the sulfite incorporation in the coral. The rainfall in Banda Islands and the SO₃⁻/CO₂⁻ record correlate negatively. This indicates that the source of sulfites in this coral is seawater and rainfall dilutes this sulfite loading to an inverse relationship between the SO₃⁻/CO₂⁻ and rainfall. A weaker negative correlation with SST exists which may represent an additional factor affecting SO₃⁻/CO₂⁻ ratios. We also analyzed ESR of a coral from Manado, Sulawesi Island which was affected by river discharge. The SO₃⁻/CO₂⁻ ratio of the coral is about twice as large as that of the Banda Islands in average, indicating there is additional sulfite source from terrestrial waters. The SO₃⁻/CO₂⁻ record also correlates negatively with rainfall. rainfall seems to dilute both the oceanic sulfite and the sulfite being delivered by Manado River.     

Radium-226 concentration in spring water sampled in high radon regions

Water ²²⁶Ra concentration in springs was measured in regions with high indoor radon: Ural, North Caucasus (Russia), Niska Banja (Serbia), Piestany (Slovakia), and Issyk-Kul (Kyrgyzstan). This paper presents the results for ²²⁶Ra concentration above 0.03 Bq l^–1. Radium in water could indicate indoor radon problem in the region and water investigation is useful at the initial stage of radon survey. Even low ²²⁶Ra concentration in water (0.1–0.6 Bq l^–1) caused high ²²⁶Ra activity in travertine (up to 1500 Bq kg^?1), which resulted in indoor radon concentration above 2000 Bq m^?3 (Niska Banja).     

Myocardial uptake of thallium-201 diethyldithiocarbamate (201TI-DDC) in cultured heart cells and in humans

We assessed the feasibility of SPECT imaging with ²⁰¹Tl-diethyldithiocarbamate (²⁰¹Tl-DDC), a new cerebral blood flow tracer with little redistribution, expecting to observe less extensive redistribution than with ²⁰¹Tl-chloride. Myocardial sections were obtained in three patients presenting with documented coronary artery disease and injected at peak exercise with 100 MBq ²⁰¹Tl-DDC. In two patients there was a clear redistribution phenomenon at four h after injection. In cultured myocardial cells of newborn rats, the uptake and washout of ²⁰¹Tl-chloride and ²⁰¹Tl-DDC were compared. The ²⁰¹Tl-DDC uptake was lower than ²⁰¹Tl-chloride (transmembrane gradients were respectively 89±10 and 4.1±0.2, mean±sem, n=14, P<0.001). After 2 h washout in a Tl free medium, the retention of ²⁰¹Tl-chloride in the cells was 4% vs 19% for ²⁰¹Tl-DDC. It is concluded that although myocardial imaging is feasible with ²⁰¹Tl-DDC, this agent redistributes significantly with time.