Comparative cytotoxicity of aflatoxin B1 and saxitoxin in cell cultures.

Human and animal cell cultures were evaluated for their susceptibility to two environmental toxins found as contaminants in human food supplies: aflatoxin B1, a hepatotoxin produced by the mold Aspergillus flavus, and saxitoxin, a paralytic neurotoxin produced by the marine dinoflagellate Gonyaulax catenella. Both toxins cause food poisoning in humans and other animals. The acute cytotoxicity of both toxins was measured and compared by inhibition of cell growth and by progressive cytopathogenicity resulting in cell destruction.

DDT and immunological responses. 3. Reduced anaphylaxis and mast cell population in rats fed DDT.

Previous work showed that anaphylaxis, mast cell population, and tissue histamine content are reduced in guinea pigs given DDT injections. This study was intended to determine whether dietary intake of DDT causes similar effects. Rats immunized with diphtheria toxoid and fed diets containing DDT at 20 and 200 ppm levels for 31 days did not show effects on their serum antitoxin titers, but the numbers of metachromatically stained, histamine-containing mast cells in mesenteries were reduced: in the 20 ppm group by 46% and in the 200 ppm group by 61%.

Protective action of 2,2-bis(parachlorophenyl). 1,1,1-trichloroethane against intoxication of cells by staphylococcal enterotoxin B.

Chlorinated hydrocarbon 2,2-bis(parachlorophenyl)-1,1,1-trichloroethane (DDT) and its derivative 2,2-bis(parachlorophenyl)-1,1-dichloroethane (o,p'-DDD) protected the cells of human embryonic intestine, Henle strain, against the cytotoxic effects induced by staphylococcal enterotoxin B (SEB). The hydrocarbons were incorporated in the culture medium, and the cytotoxicity of SEB was measured by cell destruction and by inhibition of cell growth during incubation for 48 hr. When DDT at nontoxic levels (4 to 25 mug/ml) was added to cultures, 24 or 4 hr prior to or 7 hr after the administration of toxin (100 mug/ml), the cells did not show the characteristic cytotoxicity.