RESPIRATORY CARCINOGENESIS BY CHEMICAL AND PHYSICAL FACTORS

黄曲霉毒素诱导呼吸道癌变机制的研究 化学和物理因素，单独或在各种组合中，是 在适当的动物模型中追求。两个最近成立的叙利亚人 金黄仓鼠群体(近交系15：16/EHS：CR和近交系叙利亚/CR：RGH)是 用于气管内滴注吸附在颗粒物上的致癌物 携带者单独或组合，全身治疗与局部治疗，以及 致癌物质和辅因子的联合治疗。F-344大鼠也是 用于研究二氧化硅致癌机理和致癌机理 纤维化。呼吸道上皮组织反应的特征是 组织学、超微结构、组织化学和生化方法 通过他们对器官和细胞培养条件的研究。 二乙基亚硝胺诱发金黄地鼠呼吸道癌 发现当给予致癌物时效果要好得多 从出生一天开始，而不是在4或8周时，但诱导 气管乳头状瘤不受此年龄因素的影响。 联合暴露方案已经被用来研究 N-甲基硝基-尿素、苯并[a]芘(BP)、3-甲基吲哚和 二甲基亚砜。关于物理因素的作用的研究仍在继续， 涉及微创、生理盐水和微粒物质的方案。 比较研究了BP在仓鼠气管、支气管和肺组织中的代谢。 BP单次或多次滴注三氧化二铁后的肺 粒子。致癌的靶点(气管和支气管) 表现出最高的新陈代谢和DNA结合水平。 二氧化硅诱导的肺上皮细胞增生性损伤研究 它们与肉芽肿细胞反应的致病关系 活性氧和炎症细胞介质的作用。

Studies on the mechanisms of respiratory tract carcinoma induction by chemical and physical factors, alone or in various combinations, are pursued in the appropriate animal models. Two recently established Syrian golden hamster colonies (inbred 15:16/EHS:CR and outbred Syrian/CR:RGH) are used for intratracheal instillation of carcinogens adsorbed on particulate carriers alone or in combinations, systemic versus topical treatments,a nd combined treatments with carcinogens and cofactors. F-344 rats are also used for studies on mechanisms of silica-indued carcinogenesis and fibrogenesis. Respiratory epithelial tissue responses are characterized by histological, ultrastructural, histochemical and biochemical methods, and by their study in organ and cell culture conditions. Induction of respiratory tract carcinomas by diethylnitrosamine in hamster was found to be much more effective when the carcinogen was administered starting at one day of age than at 4 or 8 weeks, but the induction of tracheal papillomas is not affected by this age factor. Combined exposure protocols have been used to study the effects of N-methylnitro-sourea, benzo[a]pyrene (BP), 3-methylindole and dimethylsulfoxide. Studies on the role of physical factors are continuing, with protocols involving microtrauma, saline and particulate materials. Metabolism of BP was comparatively studies in hamster trachea, bronchi and lung after single or repeated instillation of BP with ferric oxide particles. The target sites for carcinogenesis (trachea and bronchi) showed the highest level of metabolism and of DNA binding. Silica-induced pulmonary epithelial proliferative lesions are studied for their pathogenetic relationship to granulomatous cell reactions, to the role fo reactive oxygen and cellular mediators of inflammation.