Medvedovsky C, Worgul B V
Eye Radiation and Environmental Research Laboratory, Columbia University, New York, New York 10032.
Radiat Res. 1991 Oct;128(1 Suppl):S103-10.
Few in vivo systems have received the investigative attention or have provided the grist for our understanding of basic radiobiological principles as have the lens and the cataract. From Roentgen's time the lens has been recognized as a "biological dosimeter" for gauging radiation response. Its advantages range from its in vivo status to its qualification as an integrated tissue. From the time of the Hiroshima/Nagasaki experience, there has been some urgency in attempting to understand the breadth of neutron-radiation effects on humans. The major obstacle has been our understanding of the doses which were received by the individuals who express the damage. The majority of the work has been derived from experimental animals and findings related to photons: X and gamma rays. Cataractogenesis provides insights in terms of not only ocular radiopathy but also the basic mechanisms of the action of radiation. Often referred to as the "classic" nonstochastic radiation effect, it is becoming increasingly clear that the suggestion of a threshold reflects the limitations imposed on expression by the life span. Thus the primary damage which appears to be a somatic mutation is fully stochastic. This being the case, it is not surprising that, as is the case for simpler systems, the RBEs for cataracts following neutron exposure are significantly higher than for X rays, and that there is evidence for an inverse dose-rate effect in their production. This presentation focuses on these data and on the merits of the lens for the assessment of neutron effects on humans, the existing data for known dose levels in the human population, and the confounding issues associated with extrapolation from experimental work. Data from Western sources as well as those from the USSR are presented.
很少有体内系统能像晶状体和白内障那样受到如此多的研究关注，或者为我们理解基本的放射生物学原理提供丰富的素材。从伦琴时代起，晶状体就被公认为是衡量辐射反应的“生物剂量计”。它的优点包括其在体内的状态以及作为一个整合组织的特性。自广岛/长崎事件以来，人们迫切希望了解中子辐射对人类的影响范围。主要障碍在于我们对那些表现出损伤的个体所接受剂量的了解。大多数研究工作都源于实验动物以及与光子（X射线和γ射线）相关的研究结果。白内障的形成不仅为眼部放射性病变提供了见解，也为辐射作用的基本机制提供了启示。它常被称为“经典”的非随机辐射效应，越来越明显的是，阈值的存在反映了寿命对损伤表现的限制。因此，看似体细胞突变的原发性损伤实际上是完全随机的。在这种情况下，与简单系统一样，中子照射后白内障的相对生物效应（RBE）明显高于X射线，并且有证据表明其产生存在剂量率反比效应，这并不奇怪。本报告重点关注这些数据，以及晶状体在评估中子对人类影响方面的优势、人群中已知剂量水平的现有数据，以及与从实验工作进行外推相关的混杂问题。报告中呈现了来自西方以及苏联的相关数据。
