BACKGROUND The major potential site of acid nitrosation is the proximal stomach, an anatomical site prone to a rising incidence of metaplasia and adenocarcinoma. Nitrite, a pre-carcinogen present in saliva, can be converted to nitrosating species and N-nitroso compounds by acidification at low gastric pH in the presence of thiocyanate. AIMS To assess the effect of lipid and ascorbic acid on t...

In studies in this and other laboratories, induction of hepatocardinoma by several different chemical carcinogens was enhanced in rats fed diets deficient in lipotropes (choline, methionine, folic acid), amino acids, and niacin, and high in fat. In some cases, specific supplementation with lipotropes blocked carcinogenesis. In studies reported here, specific supplementation of a marginally defi...

./V-acetoxy-acetylaminofluorene; but no increase was demon strated when cells were treated with ./V-nitrosodiethylamine, yV-nitrosodimethylamine, or 2-acetylaminofluorene. The frequency of viral transformation increased linearly with chemical concentration until a maximum level was reached; however, higher concentrations decreased the trans formation frequency relative to that observed with low...

./V-acetoxy-acetylaminofluorene; but no increase was demon strated when cells were treated with ./V-nitrosodiethylamine, yV-nitrosodimethylamine, or 2-acetylaminofluorene. The frequency of viral transformation increased linearly with chemical concentration until a maximum level was reached; however, higher concentrations decreased the trans formation frequency relative to that observed with low...

of hepatic aflatoxIn Bi and N-nitrosodiethylamine in infected males and 20-40% in infected females (Kirby et al., 1994). Immunohistochemical analysis of aflatoxIn Bi-DNA adducts in parasitized animaIs indicated that the greatest numbers of adducts occurred in the regions of highest CYP2A activity. Studies with a related liver fluke, Fasciola hepatica, also showed enhanced cyochrome P450-related...

N-nitrosamines, which are classified as carcinogens by IARC and US EPA, can be easily found in various foods. They are reaction products between nitrogen oxide and secondary amines, but can also be generated during fermentation. Ever since the 1960s, when nitrite, used as a preservative in processed meats, was suspected to generate N-nitrosamines, the usage of the food additive has been debated...

Metanil yellow (MY) and malachite green (MG) are textile dyes, which, despite the ban occurs unsrupulously as food colouring agents. Accordingly they constitute a serious public health hazard and are of sufficient environmental concern. We have earlier reported that both MY and MG have tumor enhancing effects on the development of hepatic preneoplastic lesions induced by N-nitrosodiethylamine i...

Hepatomas were induced in monkeys by the administration of jV-nitrosodiethylamine. An a-fetoprotein, not normally found in adult monkeys, was present in the serum of the majority of the animals with the liver tumor. Frequently, the test for serum a-fetoprotein was positive prior to any histolÃ3gica!evidence of a cancer. With tRNA from Escherichia coli K12W6 or from normal adult monkey liver or ...