In Vitro Surfactant Structure-Toxicity Relationships: Implications for Surfactant Use in Sexually Transmitted Infection Prophylaxis and Contraception

Background The need for woman-controlled, cheap, safe, effective, easy-to-use and easy-to-store topical applications for prophylaxis against sexually transmitted infections (STIs) makes surfactant-containing formulations an interesting option that requires a more fundamental knowledge concerning surfactant toxicology and structure-activity relationships. Methodology/Principal Findings We report in vitro effects of surfactant concentration, exposure time and structure on the viability of mammalian cell types typically encountered in the vagina, namely, fully polarized and confluent epithelial cells, confluent but non-polarized epithelial-like cells, dendritic cells, and human sperm. Representatives of the different families of commercially available surfactants – nonionic (Triton X-100 and monolaurin), zwitterionic (DDPS), anionic (SDS), and cationic (CnTAB (n = 10 to 16), C12PB, and C12BZK) – were examined. Triton X-100, monolaurin, DDPS and SDS were toxic to all cell types at concentrations around their critical micelle concentration (CMC) suggesting a non-selective mode of action involving cell membrane destabilization and/or destruction. All cationic surfactants were toxic at concentrations far below their CMC and showed significant differences in their toxicity toward polarized as compared with non-polarized cells. Their toxicity was also dependent on the chemical nature of the polar head group. Our results suggest an intracellular locus of action for cationic surfactants and show that their structure-activity relationships could be profitably exploited for STI prophylaxis in vaginal gel formulations. The therapeutic indices comparing polarized epithelial cell toxicity to sperm toxicity for all surfactants examined, except C12PB and C12BZK, does not justify their use as contraceptive agents. C12PB and C12BZK are shown to have a narrow therapeutic index recommending caution in their use in contraceptive formulations. Conclusions/Significance Our results contribute to understanding the mechanisms involved in surfactant toxicity, have a predictive value with regard to their safety, and may be used to design more effective and less harmful surfactants for use in topical applications for STI prophylaxis.Foundation for Science and Technology of the Portuguese Ministry of Science and Higher Educatio

Laser treatment for pigmented lesions: a review

Just a few decades ago, before lasers were introduced into dermatologic practice, many cutaneous lesions were untreatable. Since the introduction of lasers in dermatology in the 1960s and its revolution by Anderson and Parrish in the 1980s based on the selective photothermolysis theory, lasers have become a main component of many dermatology practices. With the advent of these selective lasers and their constant technological advancements, many lesions can now be easily removed with a low incidence of complications, creating a high demand for laser surgery. Aims This paper will review current laser systems used for pigmented lesions. An English-language literature search and review through Medline from January 1994 to October 2004. Review of the latest techniques and lasers used in treating pigmentary disorders and possible future applications and treatment options. Laser technique and technology has greatly advanced producing more effacious treatment with minimal complications

Síndrome de Peutz-Jeghers: tratamento da lentiginose oral com laser Alexandrita Peutz-Jeghers Syndrome: treatment of oral lentiginosis with Alexandrite laser

Descreve-se o caso de uma paciente de 10 anos de idade, com síndrome de Peutz-Jeghers, que há oito anos apresentava manchas escuras nos lábios. As lesões da mucosa oral foram tratadas com laser de Alexandrita 755 nm, de pulso longo(3ms),com bons resultados estéticos.<br>We describe the case of a 10-year-old patient with Peutz-Jeghers Syndrome associated with brown melanin spots on the lips and onset 8 years previously. The oral lesions were treated using a long-pulse (3ms) Alexandrite 755 nm laser, with good results

Review Update on Topical Therapy for Psoriasis

© 2018, Springer Science+Business Media, LLC, part of Springer Nature. Purpose of Review: Studies show frequent usage but low adherence rates and poor satisfaction from topical therapy for psoriasis. These were attributed to low efficacy, inconvenience of application, and poor cosmetic quality for different body parts. Recent Findings: Multicenter surveys on patients suggest a two-way holistic approach, where patients convey what bothers them most and doctors explain how products address specific concerns. New rapid response targeted topical agents, in cosmetically acceptable preparations, applied less often, are undergoing efficacy and safety studies, ideally on large populations up to 1 year or more. Until available, this review addresses gaps in knowledge on how to maximize effects of emollients, used alone, with physiologic lipids, or as base for active topical therapy. Summary: Updates—on how psoriasis skin becomes itchy, red, dry, thick, and scaly from inflammation and barrier defects—explain clinical responses to the physical, chemical, and functional properties of psoriasis topical therapies