238 research outputs found
Carotenoids - Effective Radical Scavengers for Healthy and Beautiful Skin
Free radicals are involved in various diseases and skin aging. To reduce and prevent this risk, our body produces antioxidants that can neutralize free radicals. However, some antioxidants need to be taken up with food, so a balanced and varied diet is essential for human health and beauty, along with sufficient exercise. Vegetables, especially curly kale, show very good antioxidative capacity due to the presence of carotenoids. As the recommended daily intake of vegetables is usually not consumed, dietary supplements are a good possibility to ingest carotenoids in a controlled and natural way. The positive effect of carotenoid-based dietary supplements on the skin has already been shown in several studies on healthy volunteers. Innovative non-invasive measuring methods have shown that oil extracts from vegetables significantly reduce not only free radicals in the skin but also the age-related breakdown of collagen and have a positive effect on skin parameters such as wrinkle volume. Thus, a balanced mixture of different natural carotenoids contributes to maintaining health and beauty
The INO80 Complex Removes H2A.Z to Promote Presynaptic Filament Formation during Homologous Recombination
The INO80 complex (INO80-C) is an evolutionarily conserved nucleosome remodeler that acts in transcription, replication, and genome stability. It is required for resistance against genotoxic agents and is involved in the repair of DNA double-strand breaks (DSBs) by homologous recombination (HR). However, the causes of the HR defect in INO80-C mutant cells are controversial. Here, we unite previous findings using a system to study HR with high spatial resolution in budding yeast. We find that INO80-C has at least two distinct functions during HR-DNA end resection and presynaptic filament formation. Importantly, the second function is linked to the histone variant H2A.Z. In the absence of H2A.Z, presynaptic filament formation and HR are restored in INO80-C-deficient mutants, suggesting that presynaptic filament formation is the crucial INO80-C function during HR
Noninvasive Determination of Epidermal and Stratum Corneum Thickness in vivo Using Two-Photon Microscopy and Optical Coherence Tomography: Impact of Body Area, Age, and Gender
Background: High-resolution images of the epidermis are important to understand the transdermal penetration and changes in epidermal components. Both ex vivo and in vivo technologies are available to picture the epidermal thickness (ET). So far, the illustration of the stratum corneum (SC) has not been possible without artifacts. Objective: Precision in vivo measurement of the ET and SC, duly considering the impact of location on the body, age, and gender. Methods: In this pilot study on 20 skin-healthy subjects aged 18-66 years, the ET was imaged by two-photon microscopy (2PM) and optical coherence tomography (OCT), and the SC by using 2PM at five different body sites. Results: On solar-exposed body areas, both the epidermis and SC are thicker compared to solar-protected areas (p < 0.05), the epidermis at the gluteal region being the thickest (p < 0.05). The ET decreases with age (p < 0.05). Males show a thicker epidermis than females (p < 0.05). Conclusion: 2PM provides a noninvasive method for imaging the epidermis and especially the SC in vivo and is optimally suited for the application of histological criteria
Tattoo Pigments Are Localized Intracellularly in the Epidermis and Dermis of Fresh and Old Tattoos: In vivo Study Using Two-Photon Excited Fluorescence Lifetime Imaging
Background: The knowledge about the location and kinetics of tattoo pigments in human skin after application and during the recovery is restricted due to the limitation of in vivo methods for visualizing pigments. Here, the localization and distribution of tattoo ink pigments in freshly and old tattooed human skin during the regeneration of the epidermis and dermis were investigated in vivo.Methods: Two-photon excited fluorescence lifetime imaging (TPE-FLIM) was used to identify tattoo ink pigments in human skin in vivo down to the reticular dermis. One subject with a freshly applied tattoo and 10 subjects with tattoos applied over 3 years ago were investigated in the epidermal and dermal layers in vivo. One histological slide of tattooed skin was used to localize skin-resident tattoo pigment using light microscopy. Results: The carbon black particles deposited around the incision have still been visible 84 days after tattoo application, showing delayed recovery of the epidermis. The TPE-FLIM parameters of carbon black tattoo ink pigments were found to be different to all skin components except for melanin. Distinction from melanin in the skin was based on higher fluorescence intensity and agglomerate size. Using TPE-FLIM in vivo tattoo pigment was found in 75% of tattoos applied up to 9 years ago in the epidermis within keratinocytes, dendritic cells and basal cells and in the dermis within the macrophages, mast cells and fibroblasts. Loading of highly fluorescent carbon black particles enables in vivo imaging of dendritic cells in the epidermis and fibroblasts in the dermis, which cannot be visualized in native conditions. The collagen I structures showed a higher directionality similar to scar tissue resulting in a greater firmness and decreased elasticity of the tattooed skin. Conclusions: Here we show the kinetics and location of carbon black tattoo ink pigment immediately after application for the first time in vivo in human skin. Carbon black particles are located exclusively intracellularly in the skin of fresh and old tattoos. They are found within macrophages, mast cells and fibroblasts in the dermis and within keratinocytes, dendritic cells and basal cells in the continuously renewed epidermis even in 9-year-old tattoos in skin showing no inflammation
Influences of Orally Taken Carotenoid-Rich Curly Kale Extract on Collagen I/Elastin Index of the Skin
Two differently designed, spatially resolved reflectance spectroscopy-based
scanners and two-photon tomography were used for noninvasive in vivo
determination of cutaneous carotenoids, and collagen I/elastin aging index of
dermis, respectively, in the skin of 29 healthy female volunteers between 40
and 56 years of age. The volunteers received a supplement in the form of a
carotenoid-rich natural curly kale extract containing 1650 µg of carotenoids
in total (three capsules of 550 µg), once a day. Measurements were taken
before, after 5 months and after 10 months of daily supplementation. The
results showed significantly increased values for the cutaneous carotenoids
and the collagen I/elastin aging index of dermis 5 and 10 months after the
beginning of the study. The obtained results show that a natural carotenoid-
rich extract could prevent the aging-related collagen I degradation in the
dermis and improve the extracellular matrix
Electrohydrodynamic spray applicator for homogenous application and reduced overspray of sunscreen
Background: The recommended amount of sunscreen by hand application (2 mg/cm(2)) is in reality not achieved, which decreases the homogeneity and thereby the effective sun protection factor (SPF).
Materials and Methods: The homogeneity of sunscreen applied by a newly developed spray applicator using an electrostatically charged aerosol, for which a hand rubbing of the formulation is not necessary, is evaluated. In vivo experiments were performed on the volar forearms of human volunteers using the spray applicator compared to the standardized hand application according to ISO 24444.
Results: The distribution homogeneity was assessed qualitatively using in vivo laser scanning microscopy and quantitatively by absorption spectroscopy after tape stripping and by the standard deviation of multiple spatially displaced reflectance measurements for non-invasive SPF determination below the minimal erythemal dose, which showed a significantly higher homogeneity by 20.9% after spray application compared to hand application.
Conclusion: Non-invasive SPF determination of multiple spatially displaced reflectance measurements was proven to be a suitable method for the non-invasive determination of the sunscreen distribution homogeneity. Electrostatically charged spray application increased the sunscreen distribution homogeneity on the skin and can reduce the amount of overspray
Comparison of Transepidermal Water Loss and Laser Scanning Microscopy Measurements to Assess Their Value in the Characterization of Cutaneous Barrier Defects
The exact qualitative and quantitative analysis of wound healing processes is a decisive prerequisite for optimizing wound care and for therapy control. Transepidermal water loss (TEWL) measurements are considered to be the standard procedure for assessing the progress of epidermal wound healing. The damage to the stratum corneum correlates with an increased loss of water through the skin barrier. This method is highly susceptible to failure by environmental factors, in particular by temperature and moisture. This study was aimed at comparing TEWL measurements and in vivo laser scanning microscopy (LSM) for the characterization of the epidermal wound healing process. LSM is a high-resolution in vivo method permitting to analyze the kinetics and dynamics of wound healing at a cellular level. While the TEWL values for the individual volunteers showed a wide scattering, LSM permitted the wound healing process to be clearly characterized at the cellular level. However, a comparison between the two methods was very difficult, because the results provided by LSM were images and not numerical. Therefore, a scoring system was set up which evaluates the stages of wound healing. Thus, the healing process could be numerically described. This method is independent of any environmental factors. Providing morphologically qualitative and numerically quantitative analyses of the wound healing process and being far less vulnerable to failure, LSM is advantageous over TEWL
Laser Scanning Microscopic Investigations of the Decontamination of Soot Nanoparticles from the Skin
Background/Aims: Airborne pollutants, such as nano-sized soot particles, are increasingly being released into the environment as a result of growing population densities and industrialization. They can absorb organic and metal compounds with potential biological activity, such as polycyclic aromatic hydrocarbons and airborne pollen allergens. Local and systemic toxicities may be induced in the skin if the particulates release their harmful components upon dermal contact. Methods: In the present study, skin pretreatments with serum and/or shield as barrier formulations prior to exposure and washing with a cleanser subsequent to exposure were evaluated as a protection and decontamination strategy using laser scanning microscopy. Results: The results indicate that while the application of serum and a cleanser was insufficient for decontamination, the pretreatment with shield prior to nanoparticle exposure followed by washing led to the removal of a considerable amount of the carbon black particles. The combined application of serum and shield before the administration of carbon black particles and subsequent washing led to their elimination from the skin samples. Conclusion: The application of barrier-enhancing formulations in combination with a cleanser may reduce the penetration of harmful airborne particulates by preventing their adhesion to the skin and facilitating their removal by subsequent washing with the cleanser
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