Characterization of ozone effect on human hair

Ozone is a toxic, oxidizing agent formed in nature by lightning or UV radiation. In the modern world, exposure to ozone rises due to outdoor environmental pollution as well as various indoor appliances and consumer products, including those marketed for air “purifying” purposes. The effect of ozone on human hair is not well studied consequently, we provide a brief study in this poster. Virgin, 6% and 9% bleached hair was exposed to ozone in a chamber for 1, 3 and 6 hours. Hair oxidation by the ozone revealed different behavior to oxidation as a result of liquid (bleach) or radiation (UV, IR). We observed changes of the hair both inside and outside the fiber. We observed significant increase in hair roughness (dry combing force) as well as properties characterizing alpha-helix and matrix interaction (as observed by denaturation temperatures and post-yield tensile properties). The highest changes in properties were observed with virgin hair. The insult mechanisms of ozone action will be discussed

Quantification and visulization of taurine delivery and penetration into skin

Taurine is used in many personal care products to help deliver skin repair and anti-irritation benefits. Enhancing the deposition and penetration of taurine in skin is likely to boost the performance of these products. In this study, we demonstrated the deposition of taurine onto skin surfaces through a serum formulation, as well as enhanced penetration of taurine into deeper skin layers, aided by permeation enhancers such as glycerin and dimethyl isosorbide. We used a tape stripping method to collect samples from porcine skin and, coupled with HPLC analysis, to quantify the deposition and penetration of taurine. Serum formulations containing different levels of the permeation enhancers were tested. Glycerin and dimethyl isosorbide were found particularly effective and showed a dose-response manner to enhance the taurine penetration. We also employed two spectroscopic techniques, ATR-FTIR and confocal Raman to visualize the taurine distribution in the skin. The hyperspectral images of both IR and Raman clearly demonstrated the increased penetration of taurine into the deeper layers of the skin, beyond stratum corneum and into the epidermis, through the use of these permeation enhancers. These observations are consistent with the results from the tape stripping-HPLC analyses

Bisphosphonate Treatment Modifies Canine Bone Mineral and Matrix Properties and their Heterogeneity

Bone loss and alterations in bone quality are major causes leading to bone fragility in postmenopausal women. Although bisphosphonates are well known to reduce bone turnover and prevent bone loss in postmenopausal osteoporosis, their effects on other bone properties are not fully characterized. Changes in bone mineral and matrix properties may contribute to the anti-fracture efficacy observed with bisphosphonate treatments. The aim of this work was to analyze the effect of a 1-year treatment with either alendronate or risedronate, at low and high doses, on spatially resolved bone material and compositional properties that could contribute to the fracture efficacy of these agents. Distal tibias from 30 normal beagles that had been treated daily for 1 year with oral doses of vehicle (Veh), alendronate (Aln) at 0.2 or 1 mg/kg, and risedronate (Ris) at 0.1 or 0.5 mg/kg were analyzed by Fourier Transform Infrared imaging (FTIRI) to assess the changes in both mineral and matrix properties in discrete bone areas. The widths at half maximum of the pixel histograms for each FTIRI parameter were used to assess the heterogeneity of the bone tissue. Aln and Ris increased the mineral content and the collagen maturity mainly in cancellous bone and at the endocortical surface. Significant differences were observed in the mineral content and in the hydroxyapatite crystallinity distribution in bone tissue, which can contribute to reduced ductility and micro-crack accumulation. No significant differences were observed between low and high dose nor between Aln and Ris treatments. These results show that pharmacologic suppression of bone turnover increases the mineral and matrix bone tissue maturity in normal cancellous and endocortical bone areas where bone turnover is higher. These positive effects for decreased fracture risk are also associated with a loss of bone heterogeneity that could be one factor contributing to increased bone tissue brittleness and micro-crack accumulation

Etude structure fonction de sites métalliques protéiques par spectroscopie infrarouge différentielle

AIX-MARSEILLE2-BU Sci.Luminy (130552106) / SudocSudocFranceF

Formate binding near the redox-active TyrosineD in Photosystem II: consequences on the properties of TyrD

International audienc

Bisphosphonate Treatment Modifies Canine Bone Mineral and Matrix Properties and their Heterogeneity

Bone loss and alterations in bone quality are major causes leading to bone fragility in postmenopausal women. Although bisphosphonates are well known to reduce bone turnover and prevent bone loss in postmenopausal osteoporosis, their effects on other bone properties are not fully characterized. Changes in bone mineral and matrix properties may contribute to the anti-fracture efficacy observed with bisphosphonate treatments. The aim of this work was to analyze the effect of a 1-year treatment with either alendronate or risedronate, at low and high doses, on spatially resolved bone material and compositional properties that could contribute to the fracture efficacy of these agents. Distal tibias from 30 normal beagles that had been treated daily for 1 year with oral doses of vehicle (Veh), alendronate (Aln) at 0.2 or 1 mg/kg, and risedronate (Ris) at 0.1 or 0.5 mg/kg were analyzed by Fourier Transform Infrared imaging (FTIRI) to assess the changes in both mineral and matrix properties in discrete bone areas. The widths at half maximum of the pixel histograms for each FTIRI parameter were used to assess the heterogeneity of the bone tissue. Aln and Ris increased the mineral content and the collagen maturity mainly in cancellous bone and at the endocortical surface. Significant differences were observed in the mineral content and in the hydroxyapatite crystallinity distribution in bone tissue, which can contribute to reduced ductility and micro-crack accumulation. No significant differences were observed between low and high dose nor between Aln and Ris treatments. These results show that pharmacologic suppression of bone turnover increases the mineral and matrix bone tissue maturity in normal cancellous and endocortical bone areas where bone turnover is higher. These positive effects for decreased fracture risk are also associated with a loss of bone heterogeneity that could be one factor contributing to increased bone tissue brittleness and micro-crack accumulation

Structural Consequences of Binding of UO 2 2+ to Apotransferrin: Can This Protein Account for Entry of Uranium into Human Cells?

International audienc

Regulation of hematopoietic stem and progenitor cell mobilization by cholesterol efflux pathways

Intact cholesterol homeostasis helps to maintain hematopoietic stem and multipotential progenitor cell (HSPC) quiescence. Mice with defects in cholesterol efflux pathways due to deficiencies of the ATP binding cassette transporters ABCA1 and ABCG1 displayed a dramatic increase in HSPC mobilization and extramedullary hematopoiesis. Increased extramedullary hematopoiesis was associated with elevated serum levels of G-CSF due to generation of IL-23 by splenic macrophages and dendritic cells. This favored hematopoietic lineage decisions toward granulocytes rather than macrophages in the bone marrow leading to impaired support for osteoblasts and decreased Cxcl12/SDF-1 production by mesenchymal progenitors. Greater HSPC mobilization and extramedullary hematopoiesis were reversed by raising HDL levels in Abca1(-/-)Abcg1(-/-) and Apoe(-/-) mice or in a mouse model of myeloproliferative neoplasm mediated by Flt3-ITD mutation. Our data identify a role of cholesterol efflux pathways in the control of HSPC mobilization. This may translate into therapeutic strategies for atherosclerosis and hematologic malignancies