Long-term disposition of a novel lipophilic platinum complex SM-11355 in dog after intrahepatic arterial administration: highly sensitive detection of platinum and radioactivity

1. The disposition of SM-11355, an anticancer platinum complex for hepatocellular carcinoma, was investigated in dog by measuring platinum (Pt) and radioactivity levels following intrahepatic arterial administration of ¹⁴C-SM-11355 suspended in Lipiodol, an oily lymphographic agent. Plasma and excretion profiles were monitored in six animals, with tissue distribution studied after 1 day, 4 and 13 weeks (n = 2/time point). 2. SM-11355 was released very slowly into the systemic circulation from Lipiodol, resulting in very low levels of Pt compounds in plasma, urine, faeces and organs. Plasma levels of Pt and radioactivity declined with apparent half-lives of 5-7 weeks. Excretion continued even at 3 months after the administration with proportions excreted for Pt and radioactivity up to 30-60% in urine and 8-10% in faeces. 3. The Pt and radioactivity in the liver accounted for 80-100% of the dose at 1 day and for 20-50% at 13 weeks after the administration, predominately as intact SM-11355. The concentrations were highest in the left lobe of the liver, the administration site, but levels in the remainder of the liver were also markedly higher than those in plasma and other tissues. 4. The results strongly support the concept that SM-11355 targets the liver with highly selectivity and sustained release of Pt compounds.     

Enhanced production of low energy electrons by alpha particle impact

Radiation damage to living tissue stems not only from primary ionizing particles but to a substantial fraction from the dissociative attachment of secondary electrons with energies below the ionization threshold. We show that the emission yield of those low energy electrons increases dramatically in ion-atom collisions depending on whether or not the target atoms are isolated or embedded in an environment. Only when the atom that has been ionized and excited by the primary particle impact is in immediate proximity of another atom is a fragmentation route known as interatomic Coulombic decay (ICD) enabled. This leads to the emission of a low energy electron. Over the past decade ICD was explored in several experiments following photoionization. Most recent results show its observation even in water clusters. Here we show the quantitative role of ICD for the production of low energy electrons by ion impact, thus approaching a scenario closer to that of radiation damage by alpha particles: We choose ion energies on the maximum of the Bragg peak where energy is most efficiently deposited in tissue. We compare the electron production after colliding He(+) ions on isolated Ne atoms and on Ne dimers (Ne(2)). In the latter case the Ne atom impacted is surrounded by a most simple environment already opening ICD as a deexcitation channel. As a consequence, we find a dramatically enhanced low energy electron yield. The results suggest that ICD may have a significant influence on cell survival after exposure to ionizing radiation.     

旅客携带物放射性超标事件的应急处置

目的 探讨如何有效进行物品放射性超标事件的应急处置.方法 对2010年04月11日烟台空港查获一起旅客携带燃油添加剂进行放射性监测.结果 样品表面0.1m处周围剂量当量率为3.42 μSv/h,232Th比活度为26535.7 Bq/kg,超过限量的26.5倍[1].结论 应加强对航空口岸核与辐射监测工作,完善应急处置...     

Radon-222 and related activities in surface waters of the English Lake District

Activities of radon-222 in selected surface waters of the English Lake District have been determined. Very wide variations were observed. The activity present in lakes and streams depends on the nature of the bedrock or sediment, the presence of faulting, the degree of turbulence, and the supply of fresh water from tributaries and ground waters. Radium-226 and uranium-238 activities were found to be comparable but in no case was it found that radon-222 is significantly supported by dissolved radium-226.     

胰岛素微粒剂的体外释药、小鼠体内分布与绝对生物利用度

采用放射免疫分析方法测定了胰岛素微粒剂的体外释药性 .用放射性标记技术制备了12 5Ⅰ 胰岛素微粒制剂 ,且以微粒剂中12 5Ⅰ 胰岛素的放射性计数为指标 ,研究了12 5Ⅰ 胰岛素在小鼠体内的生物利用度与组织分布 .研究表明 :微粒剂在不同pH值的磷酸盐缓冲液中 ,释药规律接近一级动力学方程 :ln(Q∞ -Q) =bt +A ,相关系数为rpH 2 5=- 0 .9398、rpH 7 0 =- 0 .9933,但更好地符合自拟释药方程 :Q =Q∞ bt/(1+bt) ,相关系数为rpH 2 5=- 0 .995 2、rpH 7.0 =- 0 .996 9.小鼠口服绝对生物利用度为 11.5 1%± 4.41% .12 5Ⅰ 胰岛素在小鼠脏器的同位素强度分布依次为肝、肾、心、肺、脾 .     

肺细胞外基质水凝胶治疗大鼠 放射性肺损伤的实验研究

目的 探讨气管内注射肺细胞外基质（ECM）水凝胶对大鼠放射性肺损伤的疗效。方法 脱细 胞法制备肺ECM 水凝胶, 单次全肺20 Gy 照射复制放射性肺损伤模型。实验一：照射后30 min 将24 只大鼠 随机分为4 组,分别注射肺ECM 水凝胶0、300、500 及800μl,比较注射后30 min 的死亡率、动脉血氧分 压（PaO2）,免疫荧光染色观察水凝胶分布。实验二：将18 只大鼠分为对照组（正常大鼠）、照射组（照射+ 气管内注射生理盐水）及ECM 组（照射+ 气管内注射肺ECM 水凝胶）,注射时间为照射后30 min,剂量 500μl,照射7 d 后行肺病理学检查,ELISA 法检测血清中肿瘤坏死因子-α（TNF-α）、白细胞介素-6（IL-6） 水平。结果 气管内注射肺ECM 水凝胶300 或500μl 不会影响大鼠PaO2（P >0.05）,而800μl 则会影响大 鼠PaO2（P <0.05）,300、500 及800μl 组均能在肺泡表面观察到绿色荧光,其中800μl 分布最均匀;照射组 及ECM 组大鼠血清中TNF-α、IL-6 水平较对照组升高（P <0.05）,ECM 组大鼠血清中TNF-α、IL-6 水平 较照射组降低（P <0.05）。结论 肺ECM 水凝胶能减轻放射性肺损伤早期的炎症反应,可作为一种新的治疗策略。     

Natural and anthropogenic radioactivity levels and the associated radiation hazard in the soil of Oodalia Tea Estate in the hilly region of Fatickchari in Chittagong,Bangladesh

Radioactivity in the soil of a tea garden in the Fatickchari area in Chittagong, Bangladesh, was measured using a high-resolution HPGe detector. The soil samples were collected from depths of up to 20 cm beneath the soil surface. The activity concentrations of naturally occurring ²³⁸U and ²³²Th were observed to be in the range of 27 ± 7 to 53 ± 8 Bq kg⁻¹ and 36 ± 11 to 72 ± 11 Bq kg⁻¹, respectively. The activity concentration of ⁴⁰K ranged from 201 ± 78 to 672 ± 81 Bq kg⁻¹, and the highest activity of fallout ¹³⁷Cs observed was 10 ± 1 Bq kg⁻¹. The average activity concentration observed for ²³⁸U was 39 ± 8 Bq kg⁻¹, for ²³²Th was 57 ± 11 Bq kg⁻¹, for ⁴⁰K was 384 ± 79 Bq kg⁻¹ and for ¹³⁷Cs was 5 ± 0.5 Bq kg⁻¹. The radiological hazard parameters (representative level index, radium equivalent activity, outdoor and indoor dose rates, outdoor and indoor annual effective dose equivalents, and radiation hazard index) were calculated from the radioactivity in the soil.     

深圳特区土壤和建筑材料中的放射性水平

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.     

Natural radioactivity in lignite samples from open pit mines “Kolubara”, Serbia – risk assessment

Coal as fossil fuel mainly contains naturally occurring radionuclides from the uranium and thorium series and ⁴⁰K. Use of coal, primarily in industry, as a result has dispersion of radioactive material from coal in and through air and water. The aim of this study was to determine the activity concentrations of natural radionuclides in coal samples from open pit mines “Kolubara” and to evaluate its effect on population health. The results showed that all measured and calculated values were below the limits recommended in international legislation.     

On the calculation of activity concentrations and nuclide ratios from measurements of atmospheric radioactivity

Motivated by the need for consistent use of concepts central to the reporting of results from measurements of atmospheric radioactivity, we discuss some properties of the methods commonly used. Different expressions for decay correction of the activity concentration for parent–daughter decay pairs are presented, and it is suggested that this correction should be performed assuming parent–daughter ingrowth in the sample during the entire measurement process. We note that, as has already been suggested by others, activities rather than activity concentrations should be used when nuclide ratios are calculated. In addition, expressions that can be used to transform activity concentrations to activity ratios are presented. Finally we note that statistical uncertainties for nuclide ratios can be properly calculated using the exact solution to the problem of confidence intervals for a ratio of two jointly normally distributed variables, the so-called Fieller׳s theorem.