Histidine-rich protein from newborn rat epidermis has been further characterized. Polyacrylamide gel electrophoresis in 8 M urea demonstrated dissociation of the protein, a possible oligomeric series, and one major band with two minor bands of the, pH 5.0 precipitate. Amino acid analysis correlated well with previous analyses (except for lower levels of histidine), while the amino acids of high content increased with purification. Sedimentation coefficients and molecular weights determined by ultracentribfugation of all monomers and the residual tissue in histidine-rich protein were in agreement with estimates from gel filtration chromatography. Lower values were obtained for keratohyalin granule proteins. Isoelectric focusing indicated diisoelectric properties of the protein. A molecular model of deamidation is presented in an attempt to explain this property.

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.

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.

Balb/c normal mice were used to study the effects of gold sodium thiomalate (GST) on intact, nonadherent, and adherent mononuclear spleen cells. The three populations were tested for the following aspects: in vitro effects of GST on the mitogen-triggered DNA synthesis; intracellular levels of cyclic AMP; and chemotaxis ability. These studies showed that GST inhibited the proliferative responses of all three populations as the concentration of GST increased. Cyclic AMP levels in the nonadherent population increased as the GST concentration increased. GST had a biphasic effect on the adherent population. At concentrations of 5 and 10 jag/ml, GST suppressed the cyclic AMP levels, and at concentration of 50 pg/ml it enhanced the cyclic AMP levels. GST had no effect on the cyclic AMP levels in the intact mononuclear spleen cells. GST appeared to have an inhibitory effect on the chemotaxis ability of all three populations of spleen cells.

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.

In CBA/NJ mice, splenic natural killer (NK) cell activity varies with stages of estrous. Susceptibility of ICR mice to intravaginal inoculation of herpes simplex virus type 2 (HSV-2) decreases with age. Susceptibility of female ICR and CBA/NJ mice to HSV-2 inoculated intravaginally and intraperitoneally was examined during the estrous cycle. In cycling ICR mice, greatest susceptibility to intravaginal inoculation was observed during diestrous and the least during metestrous. CBA/NJ mice were most susceptible to intravaginal inoculation of HSV-2 during diestrous. ICR mice were ovariectomized to mimic diestrous and found to be highly susceptible to intravaginal inoculation at all virus doses. No difference in susceptibility among phases of the estrous cycle was seen following intraperitoneal inoculation.