RESUMO
Ichthyosis vulgaris is the most common of the inherited ichthyoses, with a semi-autosomal dominance. Approximately 37-50% of people affected have associated atopic eczema and a similar proportion have atopic relatives. In this case report, we present a 15-year-old female with a history of atopic eczema who clinically presented with asymptomatic, brown, scaly patches on the extensor surfaces of the lower limbs and flexural surfaces of the upper limbs, sparing the flexural creases on all limbs. She also had neck, abdominal, and mild truncal involvement. A clinical diagnosis of ichthyosis vulgaris was made and the differential diagnoses of X-linked recessive ichthyosis, pityriasis rubra pilaris, and xerotic dermatitis were entertained. While waiting for the histological report, she was maintained on 5% glycerine in aqueous cream for daily moisturizing with alternating nightly applications of 10% glycolic acid lotion and a 5% salicylic acid mixture. The diagnosis of ichthyosis vulgaris was confirmed by histopathological findings of hyperkeratosis and an absent granular layer. She then received a 70% glycolic acid in-office chemical peel on the abdomen to test for the cosmetic outcome. The glycolic acid peel was approximately 90% efficacious in reducing the hyperkeratinization and is recommended as an adjunctive biannual maintenance regime in combination with other topical therapies such as daily emollients, topical alpha/beta hydroxy, and/or urea compounds.
RESUMO
The enzymatic, asymmetric reduction of imines is catalyzed by imine reductases (IREDs), members of the short-chain dehydrogenase/reductase (SDR) family, and ß-hydroxy acid dehydrogenase (ßHAD) variants. Systematic evaluation of the structures and substrate-binding sites of the three enzyme families has revealed four common principles for imine reduction: structurally conserved cofactor-binding domains; tyrosine, aspartate, or glutamate as proton donor; at least four characteristic flanking residues that adapt the donor's pKa and polarize the substrate; and a negative electrostatic potential in the substrate-binding site to stabilize the transition state. As additional catalytically relevant positions, we propose alternative proton donors in IREDs and ßHADs as well as proton relays in IREDs, ßHADs, and SDRs. The functional role of flanking residues was experimentally confirmed by alanine scanning of the imine-reducing SDR from Zephyranthes treatiae. Mutating the "gatekeeping" phenylalanine at standard position 200 resulted in a tenfold increase in imine-reducing activity.
Assuntos
Iminas/metabolismo , Oxirredutases/metabolismo , Iminas/química , Oxirredutases/químicaRESUMO
BACKGROUND: Several studies demonstrated that high concentration salicylic acid (beta hydroxy acid, BHA) peels were beneficial for acne, post inflammatory hyperpigmentation, melasma, oily skin, enlarged pores and surface roughness. OBJECTIVE: We have focused on the facial skin in acne patients after several BHA peels. METHODS: Thirty patients with acne vulgaris were included in this study. The peels were performed at 2 week intervals and sixteen patients completed a series of five peels. Stratum corneum hydration, skin surface lipid, skin pH, transepidermal water loss(TEWL) were measured at each visit and 2 weeks later after the last peel. RESULTS: The stratum corneum hydration, skin surface lipid, skin pH, TEWL did not show a statistically significant difference between the value of pretreatment and after five peels CONCLUSION: The results of this study suggest that BHA peels can be used to treat acne patients without disruption of normal skin function.