Previously we have shown that a single subcarcinogenic dose of ionizing radiation followed by 60 wk of @entity864 ( @entity865 ) leads to the formation of @entity957 in Sencar @entity19 . Our previous results also indicate that @entity865 pretreatment prior to irradiation results in an overall increase in total @entity5 incidence, including both epidermal and @entity5 (D. R. Jaffe and G. T. Bowden, Radiat. Res., 106: 156-165, 1986). These studies have been expanded in @entity2659 @entity19 to further investigate the effect of the proliferative state of the skin prior to irradiation and the promotion duration after irradiation on @entity5 incidence. To examine the influence of the proliferative state of the skin, 17 nmol of @entity865 were applied to one-half of the @entity19 24 h prior to irradiation. The skin was irradiated using 4 MeV X-rays at a dose rate of 0.31 Gy/min. Animals received a single dose of X-rays at 0.5 or 11.25 Gy followed by twice weekly applications of @entity865 (8 nmol). The animals were then promoted for either 10 or 60 wk. All animals that were promoted with @entity865 for the same duration had a similar incidence of @entity1185 regardless of radiation or @entity865 pretreatment. Increasing the promotion duration did not significantly alter the incidence of @entity957 at either initiation dose. At the lower initiation dose only animals that were promoted for 60 wk developed @entity957 . @entity865 pretreatment at the higher dose resulted in a slight decrease in @entity5 incidence; however, this was not statistically significant. The incidence of @entity1491 was dose dependent and appeared to be independent of @entity865 promotion. These data support our earlier findings that radiation can act as a weak @entity957 and induce @entity1491 in @entity19 skin.

Ionizing radiation as an initiator: effects of proliferation and promotion time on @entity5 incidence in XXXX .

@entity19 :: ('10090', 'Species') :: ['mice', 'mouse'] @entity5 :: ('MESH:D009369', 'Disease') :: ['tumor', 'nonepidermal tumors'] @entity957 :: ('MESH:D002294', 'Disease') :: ['squamous cell carcinoma', 'initiator of squamous cell carcinomas', 'squamous cell carcinomas'] @entity1185 :: ('MESH:D010212', 'Disease') :: ['papillomas'] @entity2659 :: ('111334(Tax:10090)', 'Gene') :: ['CD-1'] @entity865 :: ('CHEBI:61432', 'Chemical') :: ['TPA'] @entity864 :: ('MESH:C554292|MESH:D013755', 'Chemical') :: ['12-O-tetradecanoylphorbol-13-acetate'] @entity1491 :: ('MESH:D002280', 'Disease') :: ['basal cell carcinomas']
@entity19 :: (10090,Species) :: ['mice']
