The prechronic studies will determine what exposure regimen maximizes the probability of vector infection following intraperitoneal injection with a LacZ containing vector constructed from the Maloney Murine Leukemia Virus. These studies will also evaluate methods of monitoring for the presence of vector-derived DNA in selected tissues. For the prechronic studies, both neonate and weanling F344 rats and B6C3Fl mice will be used. The chronic study will evaluate the carcinogenic potential associated with random insertion of a retroviral vector into cellular DNA of organs and tissues of F344 rats and B6C3Fl mice. Based on results of the prechronic studies, the chronic study will involve either neonates or weanlings and will include the treatment regimen determined to be most effective.
