No previous report has demonstrated the relationship between Helicobacter pylori (HP) infection and gastric carcinogenesis in an experimental animal model. A total of 170 male Mongolian gerbils (MGs) were divided into nine groups (18 < or = n < or = 20 for each group). MGs of four groups were inoculated with HP before or after continuous N-methyl-N-nitrosourea (MNU) administration via the drink...

The Copenhagen rat is completely resistant to mammary cancer induction by N-methyl-N-nitrosourea (MNU) when the carcinogen is administered during sexual development, a period when other strains of rats are normally susceptible to mammary gland carcinogenesis. Here we administered 30 mg/kg MNU i.p. to two groups of neonatal (2-3-day-old) Copenhagen rats. One group (group B, 18 animals) received ...

Here, we use telomerase-deficient mice, Terc(-/-), to study the impact of telomerase abrogation in response to treatment with the alkylating agent N-Methyl-N-Nitrosourea (MNU), a potent carcinogen in the mouse. Wild-type mice treated with MNU developed lymphomas and carcinomas. In contrast, similarly treated G5 Terc(-/-) mice with critically short telomeres did not develop tumors and died of ac...

1. N[14C]-Methyl-N-nitrosourea, [14C]dimethylnitrosamine, [14C]dimethyl sulphate and [14C]methyl methanesulphonate were injected into rats, and nucleic acids were isolated from several organs after various time-intervals. Radioactivity was detected in DNA and RNA, partly in major base components and partly as the methylated base, 7-methylguanine. 2. No 7-methylguanine was detected in liver DNA ...

An alkaline elution assay previously used to detect single-strand breaks in DMA of cultured mammalian cells has been modified to allow the analysis of DMA damage in various organs of rats following exposure to chemical carcinogens. Prior to exposure, the DMA of neonatal animals was labeled with [3H]thymidine. DNA damage was assessed in liver, lung, thymus, brain, kidney, stomach, duodenum, colo...

nitrosourea (BCNTJ) is shown in Chart 1. The back ground for the development of the nitrosoureas has been recently reviewed by Schabel et al. (4). Initial interest in the group of compounds of which BCNU is a member was stimulated by the finding of the Cancer Chemotherapy National Service Center screening program that i-methyl i-nitroso-3-nitroguanidine (NSC-9369) had weak activity against i.p....