Subject(s)
Cell Transformation, Neoplastic , Fetus/drug effects , Maternal-Fetal Exchange , Pesticides/toxicity , Animals , Cells, Cultured , Cricetinae , Female , Mice , Mice, Nude , Neoplasm Transplantation , Neoplasms, Experimental/chemically induced , Neoplasms, Experimental/pathology , Nitroso Compounds/toxicity , Pregnancy , Transplantation, HeterologousABSTRACT
The transplacental host-mediated hamster cell culture system was used to test a variety of solvents and chemicals of unknown and known (positive and negative) activity for their ability to induce morphologic transformation of cells and growth in agar. Examination of approximately 13,000 colonies of cells from untreated animals yielded no transformants, thus demonstrating no spontaneous transformation in the system. Similar negative results were obtained after animals were treated with the solvents acetone, ethanol, dimethyl sulfoxide, dimethylformamide, and trioctanoin oil. Several known carcinogens, including benzo[a]pyrene, methylnitrosourethane, urethan, and diethylnitrosamine, were positive for transforming activity. Three pesticides, carbaryl, methomyl, and landrin, and their N-nitroso derivatives were tested. All the nitrosated forms had transforming activity, but only one of the pesticides, landrin, was positive. In all experiments conducted, results of the agar-growth test correlated well with tests for morphologic transformation. The transplacental hamster embryol cell culture system therefore detected transforming activity of N-nitroso compounds and some known carcinogens.
Subject(s)
Carcinogens , Cell Transformation, Neoplastic , Drug Evaluation, Preclinical/methods , Maternal-Fetal Exchange , Nitroso Compounds/toxicity , Agar , Animals , Cell Division , Cells, Cultured , Cricetinae , Embryo, Mammalian , Female , Pesticides/toxicity , PregnancyABSTRACT
The autogenous humoral immune response of mice to their endogenous leukemia virus (MuLV) has been examined with respect to the reactivities of natural antibodies to MuLV envelope antigens and virus-induced cells surface antigens. The natural reactivity of MuLV envelope antigens was evaluated by means of a radioimmune precipitation assay of intact and disrupted virus, as well as by virus neutralization tests. The specificity of natural antibody for MuLV envelope antigens was determined by immunoelectron microscopy and radioimmune precipitation. Antibody reactivity to virus-induced cell-surface antigens was evaluated by immunoelectron microscopy and a complement-dependent cytotoxicity test. The strains of mice seleced for study were C57BL/6, C3H/Anf, and the C57BL/6 X C3H/Anf F1 hybrid. Although there were quantitative differences in the antibody levels among these various strains, the naturally recognized antigenic determinants of the virus were consistent, i.e., gp68, gp-43, and p15. High levels of neutralizing antibody against the xenotropic BALB:virus-2 were detected in these various normal sera with the focus reduction assay; however, only marginal levels of neutralizing activity against Moloney leukemia virus were detected with the XC virus assay. No anticellular antibody could be detected in these normal sera with the complement-dependent cytotoxicity assay.
