Eric Longstaff

Learn 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)
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)
There is widespread dietary exposure to capsaicin in the form of chili peppers, while capsaicin's analgesic qualities have led to increased use of a topical herbal remedy in various impure forms. Most recently, injection of pure capsaicin has been proposed as a means of relieving a variety of debilitating diseases, in which case tissues would receive(More)
A malignant invasive fibrosarcoma in hamsters and a malignant mammary carcinoma in mice were each challenged with the broad spectrum proteinase inhibitor aprotinin (Trasylol). In both tumour systems, significant anti-tumour effects of aprotinin were observed. Variations in the site and dosage of aprotinin application were made in an attempt to improve the(More)
The inhibitory effect of the protease inhibitor aprotinin (Trasylol) on the invasion of mouse kidney explants by polyoma virus transformed BHK21 cells was investigated using a mixed cell/organ culture technique. The extent of invasion was monitored by following the changes in LDH isoenzyme pattern in the explants and by histological assessment. The kidney(More)
The ingestion of carbon and benzpyrene particles in vitro by rat peritoneal macrophages, baby hamster kidney fibroblasts (BHK-21) and mouse L-cells has been shown to be significantly stimulated by the inclusion of histone or polylysine in the culture medium. Parallel studies using methylated bovine albumin did not significantly stimulate carbon or(More)
Two short-term in vitro tests for mutagenicity (Salmonella reverse mutation and BHK21 cell transformation) were conducted on a series of fluorocarbons. Some of these materials (FC22, FC31, FC142b, FC143, and FC143a) were found to be positive in one or both of the tests and could therefore be considered as being potentially carcinogenic to animals. Such(More)
4-N-Pyrrolidinylazobenzene (4N) is a close structural analog of the rodent liver carcinogen 4-dimethylaminoazobenzene (DAB). This structural similarity led us to evaluate it for genotoxic activity in vitro. We observed activity for 4N and DAB in the BHK cell transformation assay and subsequently in the Salmonella mutation assay of Ames. By a curious chance,(More)