Sunscreens have been shown to protect against UVR-induced DNA damage in human skin under laboratory conditions. We presently extended these observations to real-life conditions in volunteers after their ordinary exposure habits during summer holidays. Volunteers were randomly assigned to a control group and an educated group supplied with a SPF ≥50 sunscreen and receiving instructions for use.
View Article and Find Full Text PDFJ Eur Acad Dermatol Venereol
October 2023
Background: Overexposure to sunlight can have many harmful biological effects on the skin, leading to skin cancer and photoaging. As ultraviolet (UV) radiation has been identified as a cause of DNA damage and oxidative stress in the skin, the photoprotection provided by sunscreens is evaluated through their ability to filter UV light, using the sun protection factor (SPF). However, recent data have shown that high-energy visible (HEV) light can also cause biological skin damage.
View Article and Find Full Text PDFBackground: The sun protection factor (SPF) of sunscreens is evaluated using standardized protocols based on the application of 2 mg/cm of product. However, the amount of product applied by sunscreen users in real life is likely to be much lower.
Objectives: To evaluate a new multispectral imaging approach for determining the actual quantity of sunscreen applied by users and to assess the benefits of an application guide for the use of an SPF 50+ sunscreen.
Background: Homeostasis in the differentiation programme of sebaceous stem cells has been identified as a key step in comedogenesis and should be a target for acne-prone skin care.
Objective: To report on a multicentre, year-long/real-life use study of a patented natural product containing proven to modulate molecular actors in the initial steps of comedogenesis.
Methods: An open-label multicentric international study, with a 12 month follow-up, included 54 teenage and young adult subjects with mild to moderate facial acne.
UV-induced formation of photoproducts in DNA is a major initiating event of skin cancer. Consequently, many analytical tools have been developed for their quantification in DNA. In the present work, we extended our previous liquid chromatography-mass spectrometry method to the quantification of the short DNA fragments containing photoproducts that are released from cells by the repair machinery.
View Article and Find Full Text PDFBackground: Atopic dermatitis (AD) is a chronic inflammatory skin disease leading to substantial quality of life impairment with heterogeneous treatment responses. People with AD would benefit from personalised treatment strategies, whose design requires predicting how AD severity evolves for each individual.
Objective: This study aims to develop a computational framework for personalised prediction of AD severity dynamics.
In adipocytes and sebocytes, lipid droplet proteins control the storage of lipids in organized droplets and their release on demand. The contribution of lipid droplet proteins to the pathogenesis of acne is plausible because they control the levels of comedogenic free fatty acids. The expression of two lipid droplet proteins, CIDEA and PLIN2, was analyzed in the skin of patients with acne by immunohistochemistry and western blotting.
View Article and Find Full Text PDFCorrection for 'Confocal Raman microspectroscopy for skin characterization: a comparative study between human skin and pig skin' by Sana Tfaili et al., Analyst, 2012, 137, 3673-3682, DOI: .
View Article and Find Full Text PDFBackground: Although acne vulgaris has a multifactorial aetiology, comedogenesis and bacteria colonization of the pilosebaceous unit are known to play a major role in the onset of inflammatory acne lesions. However, many aspects remain poorly understood such as where and when is the early stage of the Propionibacterium acnes colonization in follicular unit? Our research aimed at providing a precise analysis of microcomedone's structure to better understand the interplay between Propionibacterium acnes and follicular units, and therefore, the role of its interplay in the formation of acne lesions.
Methods: Microcomedones were sampled using cyanoacrylate skin surface stripping (CSSS).
Solar lentigo, benign lesions which mostly appear on chronically, sun-exposed surfaces, are associated with ageing. Patients are increasingly requesting a more uniform skin texture, especially for hands. Treatment options include dermoabrasion, intense pulsed light, cryotherapy, peelings, and laser therapy.
View Article and Find Full Text PDFWe propose a novel joint segmentation and characterization algorithm for the assessment of skin aging using 50 MHz high-frequency ultrasound images. The proposed segmentation method allows a fine determination of the envelope signal's statistics in the dermis as a function of depth. The sequence of statistical estimates obtained is then combined into a single aging score.
View Article and Find Full Text PDFBackground: Skin aging is a complex biological process mixing intrinsic and extrinsic factors, such as sun exposure. At the molecular level, skin aging affects in particular the extracellular matrix proteins.
Materials And Methods: Using Raman imaging, which is a nondestructive approach appropriate for studying biological samples, we analyzed how aging modifies the matrix proteins of the papillary and reticular dermis.
The use of multiphoton imaging has become a standard technique to visualize the dermis fibers as it requires no specific staining. The density and organization of collagen and elastin are common markers of skin intrinsic aging and photoaging; thus, there is a need of grading this skin aging with quantitative indicators able to provide a robust evaluation of the dermis fibers' state. We propose a systematic analysis of multiphoton images of skin biopsies taken on the buttock and the forearm of patients of different ages.
View Article and Find Full Text PDFThe cyclobutane pyrimidine dimer (CPD) is a potentially mutagenic DNA photolesion that is the basis of most skin cancers. There are no data on DNA protection by sunscreens under typical conditions of use. The study aim was to determine such protection, in phototypes I/II, with representative sunscreen-user application.
View Article and Find Full Text PDFSkin Res Technol
August 2018
Background/purpose: The aim of this study was to measure lentigines' pigmentation over a long period of time and evaluate if summer over-pigmentation can be avoided by the use a SPF30 day skin cream.
Methods: Seventeen healthy female volunteers aged 50 and over and presenting lentigines participated in the study from spring to summer. Throughout the study, all subjects applied a SPF30 daily skin cream to only one hand.
Detecting skin lentigo in reflectance confocal microscopy images is an important and challenging problem. This imaging modality has not yet been widely investigated for this problem and there are a few automatic processing techniques. They are mostly based on machine learning approaches and rely on numerous classical image features that lead to high computational costs given the very large resolution of these images.
View Article and Find Full Text PDFJ Photochem Photobiol B
February 2018
The formation of DNA photoproducts caused by solar UVR exposure needs to be investigated in-vivo and in particular in order to assess sunscreens' level of protection against solar genotoxicity. The study's purposes were: i) to evaluate if the roof of suction blisters is an appropriate sampling method for measuring photoproducts, and ii) to measure in-vivo sunscreen protection against cyclobutane pyrimidine dimers. Skin areas on the interior forearms of eight healthy volunteers were exposed in-vivo to 2 MED of simulated solar radiation (SSR) and to 15 MED on a sunscreen protected area.
View Article and Find Full Text PDFAtopic dermatitis (AD) is a chronic and multifactorial inflammatory skin disease involving various dendritic cells such as epidermal Langerhans cells (LC) and inflammatory dendritic epidermal cells (IDECs). Most of the clinical studies was performed on isolated cells, and thus, it would be useful to characterize directly on the human epidermal tissue the first cellular events occurred during the AD. The suction blister method was used to obtain whole epidermis samples and interstitial cutaneous fluids.
View Article and Find Full Text PDFRecently, it has been shown that epidermal sheets taken from suction blisters are very appropriate skin samples for Multi-Photon (MP) microscopy. However, we observed that image quality was much better when the sample was visualized through the basale side. Thus, the epidermis orientation needs to be controlled before MP imaging.
View Article and Find Full Text PDFChronic exposure to ultraviolet (UV) radiation causes oxidative stress, which is involved in photoaging and actinic elastosis. UV and reactive oxygen species generate lipid peroxidation products, including the α, β-unsaturated carbonyl compounds such as acrolein or 4-hydroxynonenal (4-HNE). These aldehydes can modify proteins of the extracellular matrix, but their role in the pathogenesis of photoaging is not clarified.
View Article and Find Full Text PDFBackground And Objective: To assess an objective method evaluating the effects of a retinaldehyde-based cream (RA-cream) on solar lentigines; 29 women randomly applied RA-cream on lentigines of one hand and a control cream on the other, once daily for 3 months.
Methods: A specific method enabling a reliable visualisation of the lesions was proposed, using high-magnification colour-calibrated camera imaging. Assessment was performed using clinical evaluation by Physician Global Assessment score and image analysis.
Elastin is a long-lived protein and a key component of connective tissues. The tissular elastin content decreases during chronological aging, and the mechanisms underlying its slow repair are not known. Lipid oxidation products that accumulate in aged tissues may generate protein dysfunction.
View Article and Find Full Text PDFBrain tumors can have different shapes or locations, making their identification very challenging. In functional MRI, it is not unusual that patients have only one anatomical image due to time and financial constraints. Here, we provide a modified automatic lesion identification (ALI) procedure which enables brain tumor identification from single MR images.
View Article and Find Full Text PDF