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.

French mesothelioma register: critical appraisal of the registered data.

The French mesothelioma register has three objectives. The first, collection of morbidity data could not be achieved since the data collected are not exhaustive. The second, the collection of histological material for establishing diagnostic criteria, has provided interesting data; and the third, etiological research, may constitute the basis for well-defined studies.

[French mesothelioma register 1965-1978 (author's transl)].

A mesothelioma register was initiated in France in 1975 to record pathologists, cases diagnosed since 1965. These cases have been accepted as definite mesothelioma after histological reexamination by the mesothelioma panel. Histories of asbestos exposure have been recorded using a standardized questionnaire.

Pleural effusion: laboratory tests in 300 cases.

The cause of pleural effusion was studied in 300 consecutive patients by clinical examination and laboratory tests. The three most common causes were found to be cancer 117 cases (metastatic 65, bronchogenic 34, mesothelioma 10, lymphoma 7, other 1); tuberculous infection 53; and bacterial infection 38. The cause was not found in 62 patients.