Photosensitized Membrane Permeabilization Requires Contact-Dependent Reactions between Photosensitizer and Lipids.

Although the general mechanisms of lipid oxidation are known, the chemical steps through which photosensitizers and light permeabilize lipid membranes are still poorly understood. Herein we characterized the products of lipid photooxidation and their effects on lipid bilayers, also giving insight into their formation pathways. Our experimental system was designed to allow two phenothiazinium-based photosensitizers (methylene blue, MB, and DO15) to deliver the same amount of singlet oxygen molecules per second to 1-palmitoyl-2-oleoyl- sn-glycero-3-phosphocholine liposome membranes, but with a substantial difference in terms of the extent of direct physical contact with lipid double bonds; that is, DO15 has a 27-times higher colocalization with ω-9 lipid double bonds than MB.

Early childhood caries and its relationship with perinatal, socioeconomic and nutritional risks: a cross-sectional study.

Background: Socioeconomic, perinatal and other life cycle events can be important determinants of the health status of the individual and populations. This study aimed to assess the prevalence of early childhood caries (ECC), perinatal factors (gestational age, teenage pregnancy and birth weight), family income and nutritional risk in children.

Methods: A cross-sectional study in which 320 children were examined according to the criteria established by the World Health Organization.