Mesothelioma in rats following intrapleural injection of chrysotile and phosphorylated chrysotile (chrysophosphate).

Pathological effects of asbestos are probably dependent on the size and surface properties of the fibers. Surface-modified chrysotile fibers were injected into the pleural cavity of rats to investigate the potency of the fiber to induce mesothelioma. Chrysotile fibers were modified by a phosphorylation process, resulting in the presence of phosphorus at the fiber surface.

Toxicity of an attapulgite sample studied in vivo and in vitro.

Conflicting data are found in the literature concerning the carcinogenic potency of attapulgite. We tested the carcinogenic potency of French attapulgite in rats, and compared it with 2 chrysotile samples: Rhodesian UICC (Ch A) and short Canadian fibres (Ch C). The mean length of the fibres was 0.

Occurrence and morphology of tumors induced in nude mice transplanted with chrysotile-transformed rat pleural mesothelial cells.

Rat pleural mesothelial cells treated in vitro with chrysotile fibers have been successfully transplanted into nude mice. Three cultures (1 untreated, 2 treated) were injected at passage 75; a fourth culture was obtained from a mesothelioma induced in rat by chrysotile fibers. Overall, tumors grew in each series, but the delay between cell injection and tumor formation was 22 wk with untreated cells whereas only 1 or 2 wk were needed with treated cells, and 1 wk with cells from in vivo-induced mesothelioma.

Pleural carcinogenic potency of mineral fibers (asbestos, attapulgite) and their cytotoxicity on cultured cells.

The carcinogenicity of several samples of mineral fibers was tested following injection of 20 mg in the pleural cavity of noninbred Sprague-Dawley rats. Three samples of chrysotile asbestos (mean length: 3.2, 2.