Risk characterization involves hazard identification, determination of dose-response relationships, and exposure assessment. Improvement of the risk assessment process requires inclusion of the best available science. Recent findings in the area of dioxin toxicity have led to a major effort to reassess its risk. 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD), commonly referred to as "dioxin," is th...

Two mouse immunoglobulin G1 monoclonal antibodies that bind to the trichothecene mycotoxin T-2 were prepared. These antibodies, designated 12C12 and 15H6, had affinities for T-2 of 3.5 X 10(6) and 5.8 X 10(7) liters/mol, respectively. A competitive inhibition enzyme immunoassay that employed these antibodies had a sensitivity for T-2 of 50 ng per assay. Both antibodies bound to the metabolite H...

Effects of triphenyltin on mouse thymocytes were examined using fluorescent dyes to monitor membrane potential and intracellular Ca2+. Triphenyltin at 3 x 10(-7) M to 1 x 10(-6) M hyperpolarized thymocytes and depolarized them at 3 x 10(-6) M or more, associated with increasing intracellular Ca2+. Hyperpolarization was suppressed by quinine, but not by tetraethylammonium and 4-aminopyridine, su...

Recent research has pointed to the developing immune system as a remarkably sensitive toxicologic target for environmental chemicals and drugs. In fact, the perinatal period before and just after birth is replete with dynamic immune changes, many of which do not occur in adults. These include not only the basic maturation and distribution of immune cell types and selection against autoreactive ...

The immune response plays an important role in the pathophysiology of numerous diseases including asthma, autoimmunity and cancer. Application of biomarkers of immunotoxicity in epidemiology studies and human clinical trials can improve our understanding of the mechanisms that underlie the associations between environmental exposures and development of these immune-mediated diseases. Immunologi...

Per- and polyfluoroalkyl substances (PFAS) are a group of at least 4730 chemicals with clearly important surfactant properties. They used in coatings, paints, stain repellents, firefighting foams as well other industrial processes. Their high use recalcitrance to degradation coupled their lipophilicity bioaccumulation makes them persistent organic pollutants or forever chemicals. In turn, they ...