An investigation of the ratio of free to bound phenytoin in overdose cases was accomplished by three studies to answer these questions: 1. Will the free to bound ratio change with increasing total phenytoin concentration? 2. Will the free to bound ratio be altered with decreasing total protein concentration? 3. Do these results correlate with overdose cases? The results demonstrated that the ratio of free to bound phenytoin remains constant throughout the therapeutic range as long as a person has a normal total protein concentration. However, the free to bound ratio changes significantly when the total protein decreases by 25 per cent. This substantiates the importance of monitoring free and total phenytoin concentrations in hypoproteinemia.

Cigarette smoke condensates from all cigarettes tested were found to be potent inducers of AHH enzyme in cultured human lymphocytes and, with the exception of Kent Lights and Carlton CSC's, all were found to be toxic under the experiment conditions. Most of the AHH inducing activity was found in basic and neutral fractions of the lAl standard cigarettes. A radiometric assay of BP metabolites in cultured human lymphocytes was developed in which we were able to separate the primary metabolites and the secondary metabolites from the parent compound (BP) by neutral alumnia HPLC. The primary metabolites were further separated by a selective enzyme hydrolysis and/or reverse phase HPLC.

Male Fischer rats (n=43) were used in a diet-diet/ exercise design to investigate the apparent protein sparing effects of exercise. The animals were divided into five groups: INITIAL (baseline), SEDENTARY (control), DIET, DIET/EXERCISE, and EXERCISE. Carcasses were analyzed for body composition, the blood for plasma alanine concentration and the urine for urea nitrogen concentration. The results showed no significant differences between groups in urinary urea nitrogen, plasma alanine, body weight, or carcass weights. The EXERCISE group had a significant increase in percent protein and a significant decrease in percent fat and grams of fat when compared to all other groups (p <.05).

Mice were exposed to diesel exhaust for 9 months prior to evaluation for benzo(a)pyrene disposition. On the last day of exposure the mice were instilled intratracheally with tritiated-benzo(a)pyrene ([3H]BP). The mice were sacrificed at intervals of 2, 24, and 168 hours. Disappearance of radioactivity from lungs and liver was rapid and essentially linear with time. In lungs, liver, and testes; [3H]BP metabolites were found mainly as conjugates, a form readily excretable. Clearance of the hydrocarbon from liver and testes in exposed mice was not markedly different from that in nonexposed mice. However, mice exposed to diesel exhaust had delayed [3H]BP clearance from lungs, possibly due to [3H]BP adsorption to diesel smoke particles.