EFFECTS OF LOW ENERGY ELECTRONS FROM AUGER PROCESSES

螺旋钻过程中低能电子的影响

• 批准号: 3170759
• 负责人: DANDAMUDI V RAO
• 金额: $ 16.04万
• 依托单位: UNIV OF MED/DENT OF NJ-NJ MEDICAL SCHOOL
• 依托单位国家: 美国
• 财政年份: 1982
• 资助国家: 美国
• 起止时间: 1982-05-01 至 1991-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3170759
• 关键词: autoradiography; cis platinum compound; laboratory mouse; radiation dosage; radiation hazard; radiation sensitivity; radiobiology; radionuclide imaging /scanning; spermatogenesis

Several radionuclides decaying by electron capture (EC) and internal conversion (IC) are widely used for imaging in Nuclear Medicine. Such radionuclides also emit numerous low and very low energy Auger electrons, and may cause extensive damage in biological systems, similar to the case of 125I. It is proposed to study the radiotoxicity of several commonly used radionuclides in vivo in experimental mice. Spermatogenesis will be used as a model to observe any excessive damage caused by the low energy electrons from the incorporated radionuclides. Comparison with the effects of beta-decaying radionuclides of the same element give the relative biological effectiveness (RBE) of the incorporated EC and IC radionuclides. Such information may be useful to estimate better a realistic radiation dose to the germ cells in the gonads of the patient from the clinical procedures. The observed RBE values may be considerably higher than l if highly localized energy deposition by the low energy electrons plays an important role. Completed studies give RBE of about 3.5 for 20lT lambda relative to 204T lambda. To understand the RBE values, autoradiographic and other studies will be conducted to determine the distribution of the radionuclides; theoretical Auger and Coster-Kronig electron spectra will be calculated; and appropriate dosimetric models will be developed. The low energy Auger electrons also offer new possibilities not yet explored. Using radiolabeled DNA-seeking chemotherapeutic agents such as cis-platimum, it is proposed to investigate in mouse tumor models possible enhancement of therapeutic efficacy with reduced chemotoxicity of the drug.

几种放射性核素通过电子捕获（EC）和内部衰变 转换（IC）广泛用于核医学成像。 这样的 放射性核素还发射大量低能和极低能俄歇电子， 并可能对生物系统造成广泛的损害，类似于案例 125I。 建议研究几种常见物质的放射毒性 在实验小鼠体内使用放射性核素。 精子发生将是 用作模型来观察低能量造成的过度损坏 来自掺入的放射性核素的电子。 效果对比 相同元素的β衰变放射性核素的相对值 合并的 EC 和 IC 的生物有效性 (RBE) 放射性核素。 这些信息可能有助于更好地估计 对患者性腺生殖细胞的真实辐射剂量 从临床程序来看。 观察到的 RBE 值可能相当大 如果低能量高度局部化的能量沉积则高于 l 电子起着重要作用。 已完成的研究得出 RBE 约为 3.5 20lT lambda 相对于 204T lambda。 要了解 RBE 值， 将进行放射自显影和其他研究以确定 放射性核素的分布；理论俄歇和科斯特-克罗尼格 将计算电子谱；适当的剂量测定模型将 得到开发。 低能俄歇电子也提供了尚未出现的新可能性 探索过。 使用放射性标记的 DNA 寻找化疗药物，例如 顺铂，建议在小鼠肿瘤模型中进行研究 提高治疗效果并降低药物的化学毒性。