An international validation study of the IL-2 Luc assay for evaluating the potential immunotoxic effects of chemicals on T cells and a proposal for reference data for immunotoxic chemicals

To evaluate the immunotoxic effects of xenobiotics, we have established the Multi-ImmunoTox assay, in which three stable reporter cell lines are used to evaluate the effects of chemicals on the IL-2, IFN-\u3b3, IL-1\u3b2 and IL-8 promoters. Here, we report the official validation study of the IL-2 luciferase assay (IL-2 Luc assay). In the Phase I study that evaluated five coded chemicals in three sets of experiments, the average within-laboratory reproducibility was 86.7%. In the Phase II study, 20 coded chemicals were evaluated at multiple laboratories. In the combined results of the Phase I and II studies, the between-laboratory reproducibility was 80.0%. These results suggested that the IL-2 Luc assay was reproducible both between and within laboratories. To determine the predictivity, we collected immunotoxicological information and constructed the reference data by classifying the chemical into immunotoxic compounds targeting T cells or others according to previously reported criteria. When compared with the reference data, the average predictivity of the Phase I and II studies was 75.0%, while that of additional 60 chemicals examined by the lead laboratory was 82.5%. Although the IL-2 Luc assay alone is not sufficient to predict immunotoxicity, it will be a useful tool when combined with other immune tests

Measurement of the spin and magnetic moment of 23Al

For the first time, we obtained the g factor for the ground state of 23Al by use of a -NMR measurement. 23Al has a small proton separation energy and is a potential proton-halo candidate. The obtained g factor, |g|=1.557±0.088, clearly shows the spin and parity, J=5/2+, for 23Al, which is the same as that of its mirror partner, 23Ne. The possible nuclear structure of 23Al is also discussed

Rate Constant and Antroxidant Property : OH Generation by UV-irradiation

The anti-oxidant property toward hydroxyl radicals was expressed by reaction rate constants for basic organic substances and some amino acids. The hydroxyl radicals were generated by UV-irradiation of hydrogen peroxide. The pH was controlled in the range 6.5 - 7.5 and the dependence on the concentration of anti-oxidant substances was examined

Rate Constant and Anti-oxidative Activity toward Hydroxyl Radicals; UV Irradiation

The anti-oxidative activity toward hydroxyl radicals was expressed by the reaction rate constant. Rate constants were presented for basic organic substances and reducing reagents. Hydroxyl radicals were generated by UV-irradiation of hydrogen peroxide. The pH was controlled through the reaction in the range 6.5-7.0. The dependence on the concentration of anti-oxidative substances was so small that the validity of the theoretical analysis was guaranteed