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Photoelectron (PE) spectra of ethylene and vinylene carbonates and thiocarbonates as well as of methylene trithiocarbonate and some open-chain derivatives are reported.

A single application of 17 nmol of 12-O-tetradecanoyl phorbol-13-acetate (TPA) to mouse skin caused a marked (200- to 400-fold) induction of ornithine decarboxylase (EC 4.1.1.17, L-ornithine carboxy-lyase) activity in mouse epidermal and epidermal-dermal preparations. No change in the basal level of 3':5'-cyclic AMP occurred in epidermal-dermal preparations within 30 min of TPA application. Intraperitoneal injection of the beta-agonist isoproterenol resulted in a dose-dependent accumulation of 3':5'-cyclic AMP occurred in epidermal-dermal preparations within 30 min of TPA application. Intraperitoneal injection of the beta-agonist isoproterenol resulted in a dose-dependent accumulation of 3':5'-cyclic AMP 10 min after injection, but caused no induction of ornithine decarboxylase. When isoproterenol was injected 10 min prior to an application of either 1.7 or 17 nmol of TPA, the magnitude of the ornithine decarboxylase induction was the same as induction with TPA alone. Topical application of 17 nmol of TPA caused no increase in the level of 3':5'-cyclic GMP present in the mouse epidermal-dermal preparations 2-20 min after application. Intraperitoneal injection of 1.75 mumol of dibutyryl 3':5'-cyclic GMP and/or butyryl derivatives of cyclic GMP caused a 6-fold increase in the level of cyclic GMP and/or butyryl derivatives of cyclic GMP in epidermal-dermal preparations within 5 min of injection, and the level remained elevated for at least 20-30 min. This dose of dibutyryl 3':5'-cyclic GMP was incapable of inducing ornithine decarboxylase. Injection of dibutyryl 3':5'-cyclic GMP 5 min before application of 1.7 nmol of TPA or 30 min before application of 17 nmol of TPA did not alter the magnitude of the ornithine decarboxylase induction produced by TPA alone. These results suggest that early increases in the total intracellular levels of either 3':5'-cyclic AMP or 3':5'-cyclic GMP are not part of the mechanism by which TPA induces ornithine decarboxylase in the epidermis.

1. Ten subjects with acute intermittent porphyria from three different families, and 92 relatives, were investigated for their erythrocyte uroporphyrinogen I synthase (EC 4.3.1.8) activities by the spectrofluorimetric method described and for their urinary concentrations of d-aminolaevulinic acid and porphobilinogen. 2. The mean uroporphyrinogen I synthase activity in 41 healthy women and 41 healthy men showed a significant (P < 0·001) sex difference. 3. A reduction of about 32% of the enzyme activity was observed in the porphyric subjects as compared with values in healthy normal subjects and the values from the porphyric subjects overlapped those of the reference subjects. 4. With the values from the normal subjects in each family used as reference, however, the enzyme activity in normal subjects was twice that in affected subjects. Thus by using an internal family reference uroporphyrinogen I synthase values became more reliable in disclosing latent cases of the disorder. Furthermore, these measurements were shown to have a stronger discriminative power than urinary d-aminolaevulinic acid and porphobilinogen determinations.