[Polymorphic light eruption: prophylaxis using a topical combination of antioxidants and UVA protection formulations]. / Lucite estivale bénigne: prévention par un topique associant des filtres anti-UVA et des antioxydants.

BACKGROUND: In a recent randomized, double-blind, placebo-controlled clinical study, the efficacy of a combination consisting of 0.25% alpha-glucosyl-rutin, 1% vitamin E and a broad-spectrum, highly UVA-protective sunscreen (sun protector factor 15 - persistent pigmentation darkening 6) regarding prevention of polymorphous light eruption was well demonstrated. We evaluated this combination under real solar exposure conditions. PATIENTS AND METHODS: Patients with three previous typical polymorphous light eruptions (including one in the last year) were included in an open prospective multicenter study. The preparation was applied every two hours after the first summer exposure. No topical or systemic treatments presumed to be effective against polymorphous light eruption were given concomitantly. Evaluation was performed after the summer by a dermatologist. RESULTS: Two of the 54 patients dropped out of the study, one for an adverse effect (contact dermatitis). At the end of the study following application of the test preparation, no eruption was seen for 35 patients (67%), with minor eruption for 10 patients (19%) and an marked eruption for 7 patients (13%). Pruritus (present in all patients the year before) was not seen in 36 patients (69%), was considered bearable for 36 patients and unbearable for only 3 patients compared to 27 before inclusion. For the dermatologists, efficacy was excellent for 35 patients and good for 7 patients, giving global efficacy of around 80%, with inadequate results in 10% of cases (5 patients). Concerning protection against erythema, the test product reduced sunburn by 60% compared with the previous year. DISCUSSION: Because of the high clinical efficacy of the product noted after UVA challenge tests and verified by this clinical study under actual conditions of exposure, it may be proposed as a new prophylactic treatment for polymorphous light eruption.

Genetic and biochemical characterization of the alpha and beta components of a propionyl-CoA carboxylase complex of Streptomyces coelicolor A3(2).

Two genes, accA1 and accA2, with nearly identical nucleotide sequences were cloned from Streptomyces coelicolor A3(2). The deduced amino acid sequences of the product of these two genes showed high similarity to BcpA2 of Saccharopolyspora erythraea and other biotin-containing proteins from different organisms assumed to be the alpha subunit of a propionyl-CoA carboxylase. A gene, pccB, encoding the carboxyl transferase subunit of this enzyme complex was also characterized. Strains disrupted in accA1 did not show any change in acetyl- or propionyl-CoA carboxylase activity, whilst cell-free extracts of a pccB mutant strain contained a reduced level of propionyl-CoA carboxylase. No mutants in accA2 could be isolated, suggesting that the gene may be essential. Heterologous expression of accA1, accA2 and pccB in Escherichia col and in vitro reconstitution of enzyme activity confirmed that PccB is the beta subunit of a propionyl-CoA carboxylase and that either AccA1 or AccA2 could act as the alpha component of this enzyme complex. The fact that accA2 mutants appear to be inviable suggests that this gene encodes a biotinylated protein that might be shared with other carboxyl transferases essential for the growth of S. coelicolor.