Induction of glutathione transferase activity in wheat and pea seedlings by cadmium.

The effect of the heavy metal cadmium on the glutathione transferase (GT) activity was studied in the shoots and roots of wheat and pea seedlings. The exposure to cadmium led to the reduction of plant growth rates and to a marked induction of GT activity in both plants. In wheat the induction was stronger in the roots than in the shoots at low cadmium concentrations (40-160 microM), but at 640 microM cadmium the effect was more pronounced in the shoots (4.

Two-site sandwich enzyme immunoassay with monoclonal antibodies to human alpha-fetoprotein.

Monoclonal antibodies reacting with different antigenic determinants on the alpha-fetoprotein (AFP) molecule were used to develop a simplified 'sandwich' ELISA (enzyme-linked immunospecific assay) in which one monoclonal antibody was immobilized and another labeled with an enzyme. Due to their different specificities the antibody attached to the solid phase and the one conjugated to the enzyme did not compete for binding to AFP making it possible to complete the two antigen-antibody reactions required in a single, short incubation. The rapidity, simplicity and excellent sensitivity of this assay combined with the exquisite specificity associated with the use of two monoclonal antibodies make us believe that assays based on this principle will be useful in the quantitation of substances of medical and biological importance.

Backstimulation by blastogenic factor in the primed LD typing test: possible role in anomalous responses.

The anomalous false-positive results often found in the primed lymphocyte typing (PLT) test seem to be partially due to the release of blastogenic factor (BF) from the stimulating cell, resulting in back stimulation of the primed lymphocyte. These anomalous responses can be greatly reduced by treating the stimulator cell with high doses of irradiation or with puromycin.