ABSTRACT
The aim of the study was the comparison of photo-activity of three types of titanium dioxide (TiO2) micro-dispersions intended for use as UV filters for cosmetic sunscreen products. The dispersions were also investigated with regard to their influence on the stability of photo-protective systems in cosmetic emulsions, their skin penetration/absorption and their photo-toxicity for humans and skin bacterial flora. All the tested micro-dispersions of rutile TiO2 type (agglomerates with diameter 120-150 nm), with primary particle size lower than 100 nm, demonstrated no phototoxic effect and insignificant antimicrobial behaviour. On the other hand, TiO2 with insufficient deactivation of photo-activity had significant negative impact on the stability of other organic UV filters and therefore on the stability of declared UV protective factors (SPF, UVA-PF). The study demonstrated that the level of deactivation of TiO2 is one of the highly important factors for evaluation of UV filters used as sunscreens.
Subject(s)
Anti-Bacterial Agents , Nanoparticles , Sunscreening Agents , Titanium , 3T3 Cells , Animals , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/radiation effects , Ascorbic Acid/chemistry , Azo Compounds/chemistry , Benzenesulfonates/chemistry , Chemistry, Pharmaceutical , Coloring Agents/chemistry , Escherichia coli/drug effects , Female , In Vitro Techniques , Mice , Myristates/chemistry , Nanoparticles/chemistry , Nanoparticles/radiation effects , Particle Size , Skin/metabolism , Skin Absorption , Staphylococcus epidermidis/drug effects , Sunscreening Agents/chemistry , Sunscreening Agents/pharmacology , Sunscreening Agents/radiation effects , Swine , Titanium/chemistry , Titanium/pharmacology , Titanium/radiation effects , Ultraviolet Rays , Water/chemistryABSTRACT
The authors describe a newly identified beta0-thalassaemic mutation found in two subjects from two generations of a Slovak family. The beta0-thalassaemic allele developed by insertion of one nucleotide (+G, CD 7/8) into the first exon of the beta-globin gene. The mutation causes a shift of the open globin reading frame which leads to the development of a terminal codon in codon 22. The thalassaemic allele is associated with the mediterranean haplotype IX. The mutation has in both heterozygotes the phenotype of beta0-thalassaemia minor with a slightly elevated level of HbF.
Subject(s)
Frameshift Mutation , Globins/genetics , beta-Thalassemia/genetics , Alleles , Codon, Terminator/genetics , Exons/genetics , Female , Haplotypes , Heterozygote , Humans , Male , Middle Aged , Pedigree , Phenotype , Sequence Analysis, DNAABSTRACT
In 29 Czech and Slovak families with the most frequent and newly identified beta-thalassaemic alleles and with some structural haemoglobin variants (Hb E, Hb Haná, Hb Santa Ana) haplotypes of the beta-globin locus of alleles with these mutations were identified. In most instances haplotypes I and V were involved which were found in 57% of the patients. The bond of the most common beta-thalassaemic mutation: IVS-I-1, IVS-I-110, CD 39 (C-T), IVS-II-745, IVS-I-6 with alleles with the same haplotypes as in the mediterranean region suggests a mediterranean origin of these mutations. In Hb Santa Ana a hitherto not described haplotype was identified (-(+)-(-)-(+3), indicating a de novo origin of the mutation. Also in newly identified beta-thalassaemic mutations in CD 7/8 (+G), in CD 38/39 (-C) and in HbE and Hb Haná de novo development is probable.
