I. F. H. Purchase

Learn More
Estimations of the incidence of hepatocellular carcinoma (HCC) for the period 1968-74 in the Province of Inhambane, Mozambique, have been calculated and together with rates observed in South Africa among mineworkers from the same Province indicate very high levels of incidence in certain districts of Inhambane. Exceptionally high incidence levels in(More)
Six short term tests for detecting carcinogenicity have been evaluated using 120 compounds, of which half were carcinogens and the rest non-carcinogens. The results obtained indicate that the Ames test and a "cell transformation" assay are both sufficiently sensitive to carcinogenicity, or the lack of it, in the compounds studied to enable them to be(More)
649 the book, effectively published in 1978, is at once 3 years out-of-date. I recently reviewred a multi-author symposium on the same topic. Dated 1976 and published early 1977: this contains more recent developments. In measuring tumour size, one sympathizes and agrees with the author's recommendation to accept classification by reference to the size of(More)
A number of tests have been described which are thought to be capable of identifying carcinogens without using the actual induction of cancer as an endpoint. This study compared the performance of 6 such tests on a selection of 120 organic chemicals. The tests studies were: (1) mutation of Salmonella typhimurium; (2) cell transformation; (3) degranulation(More)
The mutagenic activity of vinyl chloride (VC) and vinylidene dichloride (VDC) at three exposure levels was assessed in fertile male CD-1 mice with the dominant lethal test. Each compound was assessed in a separate study. Male mice were exposed by inhalation to VC at 3000, 10,000, and 30,000 ppm and to VDC at 10, 30, and 50 ppm for 6 hr/day for 5 days. By(More)
Groups of male and female beagle dogs were given daily doses of 400 mg of various mixtures of naphthylamines for up to 109 months. Survivors were killed at 128 months. A variety of pathological conditions was diagnosed, but the only effect related to treatment was the induction of bladder neoplasms. All dogs which received pure 2-naphthylamine developed(More)
Perera recently discussed the very real problems that accompany any attempt to classify rodent carcinogens into two groups--genotoxic or nongenotoxic. Not the least of these problems is that no agreed definition of these two terms exist. Nonetheless, the current carcinogen databases, for example, that of the U.S. National Toxicology Program (NTP), clearly(More)