The aim of our studies was to analyze carcinogen dose effects on the development of "carcinogen-altered" preneoplastic epithelial cell populations in rat tracheas following ex posure to 7,12-dimethylbenz(a)anthracene. As described pre viously (Cancer Res., 39: 4003-4010, 1979), cells appear in the trachéalepithelium upon exposure to carcinogen which are distinguishable from the majority of the...

My colleague Professor John Cherrie once said that we know more about the number of birds breeding in British meadows each year (see http://jncc.defra. gov.uk/pdf/BBSreport12_web.pdf) than the number of workers exposed to carcinogens in the workplace. It is clearly important to monitor bird populations, but I would consider it of at least equal importance to know what hazardous agents workers a...

Chlorophyllin (CHL) is a potent antimutagen in vitro, an effective anti-carcinogen in several animal models, and significantly reduced urinary biomarkers of aflatoxin B(1) (AFB(1)) exposure in a human population. Here we report an expanded analysis of CHL chemoprevention using the potent environmental hydrocarbon dibenzo[a,l]pyrene (DBP). A dose-dose matrix design employed over 12 000 rainbow t...

The effect of four dose levels of piroxicam administered during different stages of colon tumor development was studied in male F344 rats to obtain a data base on the efficacy of piroxicam as an inhibitor of colon carcinogenesis. Piroxicam was added at levels of 25, 50, 75, and 150 ppm to the NIH-07 open-formula diet and fed to male F344 rats starting 1, 13, and 23 wk after the carcinogen admin...

Formaldehyde is a well known nasal carcinogen in rodents, but so far there has been no convincing evidence that workers occupationally exposed to formaldehyde have an increased risk of nasal cancer. In this study three cases of malignant melanoma of the nasal mucosa in persons occupationally exposed to formaldehyde for a long time are presented. The occurrence of such a rare tumour in patients ...

The increased susceptibility of epidermal cells to a carcinogen following a single prior treatment with croton oil and its correla tion with increaced DNA synthesis following croton oil was con firmed. The effect of croton oil on DNA synthesis was local rather than systemic, just as Pound found its effect on increased susceptibility to a carcinogento belocalratherthan systemic. The effect of pr...

An environmental problem is in a serious situation. In order to suppress and advance discharge, the measure which grasps quantity of substance impact affects various kinds environment advanced. The PRTR system was enacted grasp discharge transfers industry. unification evaluation category, technique evaluating influence using an are proposed. Moreover, this study has grasped it as tendency by s...