RADIATION TRANSFORMATION AND ITS MODULATION BY CHEMICALS

证据确凿地表明，人类可以通过以下方式诱发癌症 辐射或化学物质(包括用于治疗的物质 癌症)。然而，人们对这两种因素的综合影响知之甚少。 探员们。一般人可能会长期暴露在剂量下。 在他们的一生中或多或少。尽管剂量可以预期为 很小，这样的旷日持久通常会涉及到同时代的 暴露在两个或两个以上的特工面前。因此，除了 单一制剂对公众健康危害预测的不确定性 当涉及有效低剂量率下的低剂量时， 代理人的组合甚至更不确定，因为潜在的 交互效果。 这项研究的目的是启动一项系统的研究 长期暴露的综合效应(即多分馏或 低剂量率照射)对肿瘤转化的诱导作用 培养中的哺乳动物细胞。最初的C3H小鼠品系，命名为 10T-1/2，因为辐射的数据量很大 暴露，或化学暴露，已经存在。随着工作的进展， 其他动物细胞以及人类细胞将被用来建立 概括地说。 这项研究最初的出发点是确定 不同类别化学品的成员(例如，直接和间接 作用诱变剂和致癌物、促进剂、抗启动剂等)和 辐射(电离和非电离辐射)独立起作用，或 以交互方式。除了这样的测量外，还将增加对 确定任何交互作用的性质，修复的贡献 (或错误修复)过程，以及细胞表面受体的可能作用 在调制反应方面。 这些研究也与癌症治疗有关。随着治疗变得 更有效，寿命延长，导致第二次死亡的风险 肿瘤将不得不面对。第二种肿瘤的诱发已经是 在某些情况下，有很好的记录。这项工作可能会导致以下战略 将此类风险降至最低。

The evidence is unequivocal that cancer can be induced in people by radiation or by chemicals (including those used in the treatment of cancer). However, little is known about the combined effects of these two agents. People at large can be expected to be exposed to doses protracted more or less over their lifetimes. Although the doses can be expected to be small, such protractions in general will involve contemporaneous exposures to two or more agents. Therefore, in addition to the uncertainties in predicting hazards to public health from a single agent when low doses at effectively low dose rates are involved, the risks due to combinations of agents are even more uncertain because of the potential for interactive effects. The purpose of this research is to initiate a systematic study of the combined effects of protracted exposure (i.e., multifractionation or low-dose-rate rate exposure) on the induction of neoplastic transformation of mammalian cells in culture. Initially the C3H mouse line, designated 10T-1/2, will be used since a significant amount of data for radiation exposure, or for chemical exposure, already exist. As the work progresses, other animal cells, as well as human cells, will be used to establish generalizations. The initial departure of the research will be to determine whether or not members of different classes of chemicals (e.g., directly and indirectly acting mutagens and carcinogens, promoters, antipromoters, etc.) and radiation (ionizing and nonionizing radiation) act independently, or interactively. To such measurements will be added mechanistic studies to determine the nature of any interactive effects, the contribution of repair (or misrepair) processes, and the possible role of cell-surface receptors in modulating responses. These studies are also relevant to cancer treatment. As therapy becomes more effective and lifespans are extended, the risks of inducing second tumors will have to be faced. The induction of second tumors is already well documented in some instances. This work may lead to strategies to minimize such risks.