Bioavailability of TNT residues in composts of TNT-contaminated soil.

Composting is being explored as a means to remediate 2,4,6-trinitrotoluene (TNT) contaminated soils. This process appears to modify TNT and to bind it to organic matter. The health hazards associated with dusts generated from such materials cannot be predicted without knowing if the association between TNT residues and compost particulate is stable in biological systems.

Comparative binding and toxicity of saxitoxin and saxitoxinol in mice and in cultured cells.

The binding characteristics of saxitoxin (STX), a known voltage-gated sodium channel blocker, and its analog saxitoxinol (STXOL), were studied in neuroblastoma, peritoneal macrophage, hepatocytes and PC-12 cell lines. 3H-STXOL bound to the cell-surface sites which appear to be the same as those occupied by 3H-STX and which can, therefore, be identified as STX receptors. The relative agreement of respective Kd obtained by saturation, competition, association and dissociation kinetics for STX and STXOL suggest the absence of any artifact in binding measurements.

Oxidation of saxitoxin: detection and biological activity of its reaction products.

We characterized the oxidation products of saxitoxin by high-performance liquid chromatography and thin-layer chromatography. We observed several changes in the saxitoxin and neosaxitoxin chromatographic profile, as well as changes in the biological activities of the saxitoxin oxidized product. Toxins were heated in the presence of oxidizing agent, and at least five oxidation products were detected.

Protection of mice from inhaled ricin by vaccination with ricin or by passive treatment with heterologous antibody.

Mice were vaccinated subcutaneously with 25 micrograms kg-1 of ricin in the presence of Freund's complete adjuvant or Ribi adjuvant, followed by a boost 14 days later with 50 micrograms kg-1 ricin in Freund's incomplete adjuvant or Ribi adjuvant, respectively. Three subsequent boosts at 28-day intervals with 25 micrograms kg-1 ricin yielded high anti-ricin antibody titres as determined by ELISA. Vaccinated animals were exposed to an aerosolized LD99 dose of ricin.

Protection against microcystin-LR-induced hepatotoxicity by Silymarin: biochemistry, histopathology, and lethality.

Microcystin-LR, a cyclic heptapeptide synthesized by the blue-green algae, Microcystis aeruginosa, is a potent hepatotoxin. Pathological examination of livers from mice and rats that received microcystin-LR revealed severe, peracute, diffuse, centrilobular hepatocellular necrosis, and hemorrhage. These changes were correlated with increased serum activities of sorbitol dehydrogenase, alanine aminotransferase, and lactate dehydrogenase.