Download or read book Carcinogenesis Abstracts, 1979, Vol. 17 written by Department of Pathology and Laboratory Medicine George P Studzinski and published by Forgotten Books. This book was released on 2018-01-09 with total page 1002 pages. Available in PDF, EPUB and Kindle. Book excerpt: Excerpt from Carcinogenesis Abstracts, 1979, Vol. 17: A Monthly Publication Sponsored by the National Cancer Institute Design considerations in in vivo carcinogen testing and obsta cles to properly carrying out such tests are reviewed. In the approach used by the National Cancer Institute to identify chemical carcinogens, two Species Of animals of both sexes are exposed to the test chemical using the highest doses the animals can tolerate. After 2 yr, survivors are killed and the tumors produced compared with Spontaneously occurring tumors in controls. The purity of the chemical and the nature and amount of any impurities must be known. The chances of detecting carcinogenicity are greatly enhanced when test ing is conducted in several species of animals. The outcome may also be altered by the route of exposure and dosage. In many studies, the results are difficult to evaluate, especially in the case Of benign tumors. It is necessary to distinguish between truly benign tumors and those lesions that are premalignant or potentially malignant; the distinction is not always possible. These tests only attempt to divide chemicals into carcinogens and noncarcinogens. Considerably more te search related to risk assessment is necessary to provide a basis for regulatory action. (2 refs) About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.