35 research outputs found
Recommended from our members
Radiation toxicology
Extensive studies on both human and experimental animal populations have provided information that allow radiation protection standards to be set with greater confidence than for most if not all other carcinogenic agents. Furthermore, both international and national advisory bodies are continually updating the risk estimates and the standards as new information is available. However, it is clear that models are needed that take into account the multistage nature of carcinogenesis. Studies in both ionizing and ultraviolet radiation carcinogenesis are more valuable to the general problem of elucidating the mechanisms involved in cancer than is indicated by the amount of work or support for this field of research
Recommended from our members
Radiation toxicology
The extensive studies on both human and experimental animal populations have provided information that allows radiation protection standards to be set with greater confidence than for most if not all other carcinogenic agents. Furthermore, both international and national advisory bodies are continually updating the risk estimates and the standards as new information is available. However, it is clear that we need models that take into account the multistage nature of carcinogenesis. Studies in both ionizing and ultraviolet radiation carcinogenesis are more valuable to the general problem of elucidating the mechanisms involved in cancer than is indicated by the amount of work or support for this field of research
Recommended from our members
Radiation induction of cancer of the skin
The induction of epidermal tumors was studied using exposures to 25 kV x-rays with or without subsequent exposures to 12-0-tetradeconyl phorbol-13 acetate (TPA) or ultraviolet radiation (uvr) 280-400 nm. Fractionation regimens and total exposure up to 4000R produced no squamous cell carcinomas. When these regimes were followed by TPA an incidence of about 80% was obtained, and incidence of 60% when uvr exposures followed the x-irradiation. A dose-dependent increase in fibrosarcomas was found when x-irradiation was followed by 24 weeks of topical treatment with TPA. These results support the contention that uvr can enhance the expression of cells initiated by x-rays. The experimental evidence is compared with the data from the tinea capitis patients treated with x-rays. In C3HF/He male mice exposed to 50, 100, 150 and 200 rads /sup 137/Cs gamma rays the induction rate for fibrosarcomas was 2.9 x 10/sup -4/ per cGy/per mouse. This result compares with 2.5 x 10/sup -6/ transformations per surviving cell per cGy with 10T1/2 cells that are fibroblasts derived from C3H mice. 16 refs., 1 fig., 1 tab