WorldWideScience

Sample records for human skin methods

  1. Automation Diagnosis of Skin Disease in Humans using Dempster-Shafer Method

    Science.gov (United States)

    Khairina, Dyna Marisa; Hatta, Heliza Rahmania; Rustam; Maharani, Septya

    2018-02-01

    Skin disease is an infectious disease that is common in people of all ages. Disorders of the skin often occur because there are factors, among others, are climate, environment, shelter, unhealthy living habits, allergies and others. Skin diseases in Indonesia are mostly caused by bacterial, fungal, parasitic, and allergies. The objective of the research is to diagnose skin diseases in humans by using the method of making decision tree then performing the search by forward chaining and calculating the probability value of Dempster-Shafer method. The results of research in the form of an automated system that can resemble an expert in diagnosing skin disease accurately and can help in overcoming the problem of skin diseases.

  2. Assessment of penetration of quantum dots through in vitro and in vivo human skin using the human skin equivalent model and the tape stripping method

    International Nuclear Information System (INIS)

    Jeong, Sang Hoon; Kim, Jae Hwan; Yi, Sang Min; Lee, Jung Pyo; Kim, Jin Ho; Sohn, Kyung Hee; Park, Kui Lea; Kim, Meyoung-Kon; Son, Sang Wook

    2010-01-01

    Quantum dots (QDs) are rapidly emerging as an important class of nanoparticles (NPs) with potential applications in medicine. However, little is known about penetration of QDs through human skin. This study investigated skin penetration of QDs in both in vivo and in vitro human skin. Using the tape stripping method, this study demonstrates for the first time that QDs can actually penetrate through the stratum corneum (SC) of human skin. Transmission electron microscope (TEM) and energy diverse X-ray (EDX) analysis showed accumulation of QDs in the SC of a human skin equivalent model (HSEM) after dermal exposure to QDs. These findings suggest possible transdermal absorption of QDs after dermal exposure over a relatively long period of time.

  3. A library based fitting method for visual reflectance spectroscopy of human skin

    International Nuclear Information System (INIS)

    Verkruysse, Wim; Zhang Rong; Choi, Bernard; Lucassen, Gerald; Svaasand, Lars O; Nelson, J Stuart

    2005-01-01

    The diffuse reflectance spectrum of human skin in the visible region (400-800 nm) contains information on the concentrations of chromophores such as melanin and haemoglobin. This information may be extracted by fitting the reflectance spectrum with an optical diffusion based analytical expression applied to a layered skin model. With the use of the analytical expression, it is assumed that light transport is dominated by scattering. For port wine stain (PWS) and highly pigmented human skin, however, this assumption may not be valid resulting in a potentially large error in visual reflectance spectroscopy (VRS). Monte Carlo based techniques can overcome this problem but are currently too computationally intensive to be combined with previously used fitting procedures. The fitting procedure presented herein is based on a library search which enables the use of accurate reflectance spectra based on forward Monte Carlo simulations or diffusion theory. This allows for accurate VRS to characterize chromophore concentrations in PWS and highly pigmented human skin. The method is demonstrated using both simulated and measured reflectance spectra. An additional advantage of the method is that the fitting procedure is very fast

  4. A library based fitting method for visual reflectance spectroscopy of human skin

    Energy Technology Data Exchange (ETDEWEB)

    Verkruysse, Wim [Beckman Laser Institute, University of California, Irvine, CA 92612 (United States); Zhang Rong [Beckman Laser Institute, University of California, Irvine, CA 92612 (United States); Choi, Bernard [Beckman Laser Institute, University of California, Irvine, CA 92612 (United States); Lucassen, Gerald [Personal Care Institute, Philips Research, Prof Holstlaan 4, Eindhoven (Netherlands); Svaasand, Lars O [Department of Physical Electronics Norwegian University of Science and Technology, N-7491 Trondheim (Norway); Nelson, J Stuart [Beckman Laser Institute, University of California, Irvine, CA 92612 (United States)

    2005-01-07

    The diffuse reflectance spectrum of human skin in the visible region (400-800 nm) contains information on the concentrations of chromophores such as melanin and haemoglobin. This information may be extracted by fitting the reflectance spectrum with an optical diffusion based analytical expression applied to a layered skin model. With the use of the analytical expression, it is assumed that light transport is dominated by scattering. For port wine stain (PWS) and highly pigmented human skin, however, this assumption may not be valid resulting in a potentially large error in visual reflectance spectroscopy (VRS). Monte Carlo based techniques can overcome this problem but are currently too computationally intensive to be combined with previously used fitting procedures. The fitting procedure presented herein is based on a library search which enables the use of accurate reflectance spectra based on forward Monte Carlo simulations or diffusion theory. This allows for accurate VRS to characterize chromophore concentrations in PWS and highly pigmented human skin. The method is demonstrated using both simulated and measured reflectance spectra. An additional advantage of the method is that the fitting procedure is very fast.

  5. A library based fitting method for visual reflectance spectroscopy of human skin

    Science.gov (United States)

    Verkruysse, Wim; Zhang, Rong; Choi, Bernard; Lucassen, Gerald; Svaasand, Lars O.; Nelson, J. Stuart

    2005-01-01

    The diffuse reflectance spectrum of human skin in the visible region (400-800 nm) contains information on the concentrations of chromophores such as melanin and haemoglobin. This information may be extracted by fitting the reflectance spectrum with an optical diffusion based analytical expression applied to a layered skin model. With the use of the analytical expression, it is assumed that light transport is dominated by scattering. For port wine stain (PWS) and highly pigmented human skin, however, this assumption may not be valid resulting in a potentially large error in visual reflectance spectroscopy (VRS). Monte Carlo based techniques can overcome this problem but are currently too computationally intensive to be combined with previously used fitting procedures. The fitting procedure presented herein is based on a library search which enables the use of accurate reflectance spectra based on forward Monte Carlo simulations or diffusion theory. This allows for accurate VRS to characterize chromophore concentrations in PWS and highly pigmented human skin. The method is demonstrated using both simulated and measured reflectance spectra. An additional advantage of the method is that the fitting procedure is very fast.

  6. Method of protecting human skin from actinic radiation

    International Nuclear Information System (INIS)

    Fusaro, R.M.

    1975-01-01

    Enhanced protection from sunlight is achieved by applying to human skin beforehand separate, time-spaced applications of (1) a carbonyl compound which is reactive with amino groups in human skin, for example dihydroxyacetone, and (2) a benzo- or naptho-quinone such as lawsone. Preferably several sequential applications of each active component in a separate carrier are made the evening before the first exposure, and protection is thereafter maintained by applying each component separately each evening

  7. Human skin volatiles: a review.

    Science.gov (United States)

    Dormont, Laurent; Bessière, Jean-Marie; Cohuet, Anna

    2013-05-01

    Odors emitted by human skin are of great interest to biologists in many fields; applications range from forensic studies to diagnostic tools, the design of perfumes and deodorants, and the ecology of blood-sucking insect vectors of human disease. Numerous studies have investigated the chemical composition of skin odors, and various sampling methods have been used for this purpose. The literature shows that the chemical profile of skin volatiles varies greatly among studies, and the use of different sampling procedures is probably responsible for some of these variations. To our knowledge, this is the first review focused on human skin volatile compounds. We detail the different sampling techniques, each with its own set of advantages and disadvantages, which have been used for the collection of skin odors from different parts of the human body. We present the main skin volatile compounds found in these studies, with particular emphasis on the most frequently studied body regions, axillae, hands, and feet. We propose future directions for promising experimental studies on odors from human skin, particularly in relation to the chemical ecology of blood-sucking insects.

  8. New methods for field collection of human skin volatiles and perspectives for their application in the chemical ecology of human-pathogen-vector interactions.

    Science.gov (United States)

    Dormont, Laurent; Bessière, Jean-Marie; McKey, Doyle; Cohuet, Anna

    2013-08-01

    Odours emitted by human skin are of great interest to biologists in many fields, with practical applications in forensics, health diagnostic tools and the ecology of blood-sucking insect vectors of human disease. Convenient methods are required for sampling human skin volatiles under field conditions. We experimentally compared four modern methods for sampling skin odours: solvent extraction, headspace solid-phase micro-extraction (SPME), and two new techniques not previously used for the study of mammal volatiles, contact SPME and dynamic headspace with a chromatoprobe design. These methods were tested and compared both on European subjects under laboratory conditions and on young African subjects under field conditions. All four methods permitted effective trapping of skin odours, including the major known human skin volatile compounds. In both laboratory and field experiments, contact SPME, in which the time of collection was restricted to 3 min, provided results very similar to those obtained with classical headspace SPME, a method that requires 45 min of collection. Chromatoprobe sampling also proved to be very sensitive, rapid and convenient for the collection of human-produced volatiles in natural settings. Both contact SPME and chromatoprobe design may considerably facilitate the study of human skin volatiles under field conditions, opening new possibilities for examining the olfactory cues mediating the host-seeking behaviour of mosquito vectors implicated in the transmission of major diseases.

  9. Development and validation of a simple method for the extraction of human skin melanocytes.

    Science.gov (United States)

    Wang, Yinjuan; Tissot, Marion; Rolin, Gwenaël; Muret, Patrice; Robin, Sophie; Berthon, Jean-Yves; He, Li; Humbert, Philippe; Viennet, Céline

    2018-03-21

    Primary melanocytes in culture are useful models for studying epidermal pigmentation and efficacy of melanogenic compounds, or developing advanced therapy medicinal products. Cell extraction is an inevitable and critical step in the establishment of cell cultures. Many enzymatic methods for extracting and growing cells derived from human skin, such as melanocytes, are described in literature. They are usually based on two enzymatic steps, Trypsin in combination with Dispase, in order to separate dermis from epidermis and subsequently to provide a suspension of epidermal cells. The objective of this work was to develop and validate an extraction method of human skin melanocytes being simple, effective and applicable to smaller skin samples, and avoiding animal reagents. TrypLE™ product was tested on very limited size of human skin, equivalent of multiple 3-mm punch biopsies, and was compared to Trypsin/Dispase enzymes. Functionality of extracted cells was evaluated by analysis of viability, morphology and melanin production. In comparison with Trypsin/Dispase incubation method, the main advantages of TrypLE™ incubation method were the easier of separation between dermis and epidermis and the higher population of melanocytes after extraction. Both protocols preserved morphological and biological characteristics of melanocytes. The minimum size of skin sample that allowed the extraction of functional cells was 6 × 3-mm punch biopsies (e.g., 42 mm 2 ) whatever the method used. In conclusion, this new procedure based on TrypLE™ incubation would be suitable for establishment of optimal primary melanocytes cultures for clinical applications and research.

  10. A dielectric method for measuring early and late reactions in irradiated human skin

    International Nuclear Information System (INIS)

    Nuutinen, J.; Lahtinen, T.; Turunen, M.; Alanen, E.; Tenhunen, M.; Usenius, T.; Kolle, R.

    1998-01-01

    Background and purpose: To measure the dielectric constant of irradiated human skin in order to test the feasibility of the dielectric measurements in the quantitation of acute and late radiation reactions. Materials and methods: The dielectric constant of irradiated breast skin was measured at an electromagnetic frequency of 300 MHz in 21 patients during postmastectomy radiotherapy. The measurements were performed with an open-ended coaxial line reflection method. The irradiation technique consisted of an anterior photon field to the lymph nodes and a matched electron field to the chest wall using conventional fractionation of five fractions/week to 50 Gy. Fourteen out of the 21 patients were remeasured 2 years later and the skin was palpated for subcutaneous fibrosis. Results: At 5 weeks the dielectric constant had decreased by 31 and 39% for the investigated skin sites of the photon and electron fields, respectively. There was a statistically significant inverse correlation between the mean dielectric constant and the clinical score of erythema. An unexpected finding was a decrease of the dielectric constant of the contralateral healthy skin during radiotherapy. Two years later a statistically significant positive correlation was found between the dielectric constant at the irradiated skin sites and the clinical score of subcutaneous fibrosis. Conclusions: Dielectric measurements non-invasively yield quantitative information concerning radiation-induced skin reactions. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

  11. Modelling glucose and water dynamics in human skin

    NARCIS (Netherlands)

    Groenendaal, W.; Schmidt, K.H.; Basum, von G.; Riel, van N.A.W.; Hilbers, P.A.J.

    2008-01-01

    Background: Glucose is heterogeneously distributed in the different physiological compartments in the human skin. Therefore, for the development of a noninvasive measurement method, both a good quantification of the different compartments of human skin and an understanding of glucose transport

  12. Multivariate Models for Prediction of Human Skin Sensitization Hazard

    Science.gov (United States)

    Strickland, Judy; Zang, Qingda; Paris, Michael; Lehmann, David M.; Allen, David; Choksi, Neepa; Matheson, Joanna; Jacobs, Abigail; Casey, Warren; Kleinstreuer, Nicole

    2016-01-01

    One of ICCVAM’s top priorities is the development and evaluation of non-animal approaches to identify potential skin sensitizers. The complexity of biological events necessary to produce skin sensitization suggests that no single alternative method will replace the currently accepted animal tests. ICCVAM is evaluating an integrated approach to testing and assessment based on the adverse outcome pathway for skin sensitization that uses machine learning approaches to predict human skin sensitization hazard. We combined data from three in chemico or in vitro assays—the direct peptide reactivity assay (DPRA), human cell line activation test (h-CLAT), and KeratinoSens™ assay—six physicochemical properties, and an in silico read-across prediction of skin sensitization hazard into 12 variable groups. The variable groups were evaluated using two machine learning approaches, logistic regression (LR) and support vector machine (SVM), to predict human skin sensitization hazard. Models were trained on 72 substances and tested on an external set of 24 substances. The six models (three LR and three SVM) with the highest accuracy (92%) used: (1) DPRA, h-CLAT, and read-across; (2) DPRA, h-CLAT, read-across, and KeratinoSens; or (3) DPRA, h-CLAT, read-across, KeratinoSens, and log P. The models performed better at predicting human skin sensitization hazard than the murine local lymph node assay (accuracy = 88%), any of the alternative methods alone (accuracy = 63–79%), or test batteries combining data from the individual methods (accuracy = 75%). These results suggest that computational methods are promising tools to effectively identify potential human skin sensitizers without animal testing. PMID:27480324

  13. Xenobiotic metabolism in human skin and 3D human skin reconstructs: A review

    NARCIS (Netherlands)

    Gibbs, S.; Sandt, J.J.M. van de; Merk, H.F.; Lockley, D.J.; Pendlington, R.U.; Pease, C.K.

    2007-01-01

    In this review, we discuss and compare studies of xenobiotic metabolism in both human skin and 3D human skin reconstructs. In comparison to the liver, the skin is a less studied organ in terms of characterising metabolic capability. While the skin forms the major protective barrier to environmental

  14. Skin Diseases: Cross-section of human skin

    Science.gov (United States)

    Skip Navigation Bar Home Current Issue Past Issues Skin Diseases Cross-section of human skin Past Issues / Fall 2008 Table of Contents For ... Logical Images, Inc. I n the areas of skin health and skin diseases, the NIH's National Institute ...

  15. Isolation of Human Skin Dendritic Cell Subsets.

    Science.gov (United States)

    Gunawan, Merry; Jardine, Laura; Haniffa, Muzlifah

    2016-01-01

    Dendritic cells (DCs) are specialized leukocytes with antigen-processing and antigen-presenting functions. DCs can be divided into distinct subsets by anatomical location, phenotype and function. In human, the two most accessible tissues to study leukocytes are peripheral blood and skin. DCs are rare in human peripheral blood (skin covering an average total surface area of 1.8 m(2) has approximately tenfold more DCs than the average 5 L of total blood volume (Wang et al., J Invest Dermatol 134:965-974, 2014). DCs migrate spontaneously from skin explants cultured ex vivo, which provide an easy method of cell isolation (Larsen et al., J Exp Med 172:1483-1493, 1990; Lenz et al., J Clin Invest 92:2587-2596, 1993; Nestle et al., J Immunol 151:6535-6545, 1993). These factors led to the extensive use of skin DCs as the "prototype" migratory DCs in human studies. In this chapter, we detail the protocols to isolate DCs and resident macrophages from human skin. We also provide a multiparameter flow cytometry gating strategy to identify human skin DCs and to distinguish them from macrophages.

  16. Volumetric Visualization of Human Skin

    Science.gov (United States)

    Kawai, Toshiyuki; Kurioka, Yoshihiro

    We propose a modeling and rendering technique of human skin, which can provide realistic color, gloss and translucency for various applications in computer graphics. Our method is based on volumetric representation of the structure inside of the skin. Our model consists of the stratum corneum and three layers of pigments. The stratum corneum has also layered structure in which the incident light is reflected, refracted and diffused. Each layer of pigment has carotene, melanin or hemoglobin. The density distributions of pigments which define the color of each layer can be supplied as one of the voxel values. Surface normals of upper-side voxels are fluctuated to produce bumps and lines on the skin. We apply ray tracing approach to this model to obtain the rendered image. Multiple scattering in the stratum corneum, reflective and absorptive spectrum of pigments are considered. We also consider Fresnel term to calculate the specular component for glossy surface of skin. Some examples of rendered images are shown, which can successfully visualize a human skin.

  17. Skin Sensitive Difference of Human Body Sections under Clothing--Multiple Analysis of Skin Surface Temperature Changes

    Institute of Scientific and Technical Information of China (English)

    李俊; 吴海燕; 张渭源

    2003-01-01

    A new researching method on clothing comfort perception is developed.By it the skin surface temperature changes and subjective psychological perception of human body sections stimulated by the same cold stimulation are studied.With the multiple comparison analysis method the changing laws of skin temperature of main human body sections is obtained.

  18. Immune Cell-Supplemented Human Skin Model for Studying Fungal Infections.

    Science.gov (United States)

    Kühbacher, Andreas; Sohn, Kai; Burger-Kentischer, Anke; Rupp, Steffen

    2017-01-01

    Human skin is a niche for various fungal species which either colonize the surface of this tissue as commensals or, primarily under conditions of immunosuppression, invade the skin and cause infection. Here we present a method for generation of a human in vitro skin model supplemented with immune cells of choice. This model represents a complex yet amenable tool to study molecular mechanisms of host-fungi interactions at human skin.

  19. DNA damage and repair in human skin in situ

    International Nuclear Information System (INIS)

    Sutherland, B.M.; Gange, R.W.; Freeman, S.E.; Sutherland, J.C.

    1987-01-01

    Understanding the molecular and cellular origins of sunlight-induced skin cancers in man requires knowledge of the damages inflicted on human skin during sunlight exposure, as well as the ability of cells in skin to repair or circumvent such damage. Although repair has been studied extensively in procaryotic and eucaryotic cells - including human cells in culture - there are important differences between repair by human skin cells in culture and human skin in situ: quantitative differences in rates of repair, as well as qualitative differences, including the presence or absence of repair mechanisms. Quantitation of DNA damage and repair in human skin required the development of new approaches for measuring damage at low levels in nanogram quantities of non-radioactive DNA. The method allows for analysis of multiple samples and the resulting data should be related to behavior of the DNA molecules by analytic expressions. Furthermore, it should be possible to assay a variety of lesions using the same methodology. The development of new analysis methods, new technology, and new biochemical probes for the study of DNA damage and repair are described. 28 refs., 4 figs

  20. DNA damage and repair in human skin in situ

    Energy Technology Data Exchange (ETDEWEB)

    Sutherland, B.M.; Gange, R.W.; Freeman, S.E.; Sutherland, J.C.

    1987-01-01

    Understanding the molecular and cellular origins of sunlight-induced skin cancers in man requires knowledge of the damages inflicted on human skin during sunlight exposure, as well as the ability of cells in skin to repair or circumvent such damage. Although repair has been studied extensively in procaryotic and eucaryotic cells - including human cells in culture - there are important differences between repair by human skin cells in culture and human skin in situ: quantitative differences in rates of repair, as well as qualitative differences, including the presence or absence of repair mechanisms. Quantitation of DNA damage and repair in human skin required the development of new approaches for measuring damage at low levels in nanogram quantities of non-radioactive DNA. The method allows for analysis of multiple samples and the resulting data should be related to behavior of the DNA molecules by analytic expressions. Furthermore, it should be possible to assay a variety of lesions using the same methodology. The development of new analysis methods, new technology, and new biochemical probes for the study of DNA damage and repair are described. 28 refs., 4 figs.

  1. Multivariate Models for Prediction of Human Skin Sensitization ...

    Science.gov (United States)

    One of the lnteragency Coordinating Committee on the Validation of Alternative Method's (ICCVAM) top priorities is the development and evaluation of non-animal approaches to identify potential skin sensitizers. The complexity of biological events necessary to produce skin sensitization suggests that no single alternative method will replace the currently accepted animal tests. ICCVAM is evaluating an integrated approach to testing and assessment based on the adverse outcome pathway for skin sensitization that uses machine learning approaches to predict human skin sensitization hazard. We combined data from three in chemico or in vitro assays - the direct peptide reactivity assay (DPRA), human cell line activation test (h-CLAT) and KeratinoSens TM assay - six physicochemical properties and an in silico read-across prediction of skin sensitization hazard into 12 variable groups. The variable groups were evaluated using two machine learning approaches , logistic regression and support vector machine, to predict human skin sensitization hazard. Models were trained on 72 substances and tested on an external set of 24 substances. The six models (three logistic regression and three support vector machine) with the highest accuracy (92%) used: (1) DPRA, h-CLAT and read-across; (2) DPRA, h-CLAT, read-across and KeratinoSens; or (3) DPRA, h-CLAT, read-across, KeratinoSens and log P. The models performed better at predicting human skin sensitization hazard than the murine

  2. In vivo study of the human skin by the method of laser-induced fluorescence spectroscopy

    International Nuclear Information System (INIS)

    Borisova, E.; Avramov, L.

    2000-01-01

    The goals of this study are to perform a preliminary evaluation of the diagnostic potential of noninvasive laser-induced auto-fluorescence spectroscopy (LIAFS) for human skin and optimize of detection and diagnosis of hollow organs and skin. In recent years, there has been growing interest in the use of laser-induced fluorescence to discriminate disease from normal surrounding tissue. The most fluorescence studies have used exogenous fluorophores of this discrimination. The laser-induced auto-fluorescence which is used for diagnosis of tissues in the human body avoids administration of any drugs. In this study a technique for optical biopsy of in vivo human skin is presented. The auto-fluorescence characterization of tissue relies on different spectral properties of tissues. It was demonstrated a differentiation between normal skin and skin with vitiligo. Two main endogenous fluorophores in the human skin account for most of the cellular auto-fluorescence for excitation wavelength 337 nm reduced from of nicotinamide adenine dinucleotide and collagen. The auto-fluorescence spectrum of human skin depend on main internal absorbers which are blood and melanin. In this study was described the effect caused by blood and melanin content on the shape of the auto-fluorescence spectrum of human skin. Human skin fluorescence spectrum might provide dermatologists with important information and such investigations are successfully used now in skin disease diagnostics, in investigation of the environmental factor impact or for evaluation of treatment efficiency. (authors)

  3. [Physiological features of skin ageing in human].

    Science.gov (United States)

    Tikhonova, I V; Tankanag, A V; Chemeris, N K

    2013-01-01

    The issue deals with the actual problem of gerontology, notably physiological features of human skin ageing. In the present review the authors have considered the kinds of ageing, central factors, affected on the ageing process (ultraviolet radiation and oxidation stress), as well as the research guidelines of the ageing changes in the skin structure and fuctions: study of mechanical properties, microcirculation, pH and skin thickness. The special attention has been payed to the methods of assessment of skin blood flow, and to results of investigations of age features of peripheral microhemodynamics. The laser Doppler flowmetry technique - one of the modern, noninvasive and extensively used methods for the assessmant of skin blood flow microcirculation system has been expanded in the review. The main results of the study of the ageing changes of skin blood perfusion using this method has been also presented.

  4. The Microbiota of the Human Skin.

    Science.gov (United States)

    Egert, Markus; Simmering, Rainer

    2016-01-01

    The aim of this chapter is to sum up important progress in the field of human skin microbiota research that was achieved over the last years.The human skin is one of the largest and most versatile organs of the human body. Owing to its function as a protective interface between the largely sterile interior of the human body and the highly microbially contaminated outer environment, it is densely colonized with a diverse and active microbiota. This skin microbiota is of high importance for human health and well-being. It is implicated in several severe skin diseases and plays a major role in wound infections. Many less severe, but negatively perceived cosmetic skin phenomena are linked with skin microbes, too. In addition, skin microorganisms, in particular on the human hands, are crucial for the field of hygiene research. Notably, apart from being only a potential source of disease and contamination, the skin microbiota also contributes to the protective functions of the human skin in many ways. Finally, the analysis of structure and function of the human skin microbiota is interesting from a basic, evolutionary perspective on human microbe interactions.Key questions in the field of skin microbiota research deal with (a) a deeper understanding of the structure (species inventory) and function (physiology) of the healthy human skin microbiota in space and time, (b) the distinction of resident and transient skin microbiota members, (c) the distinction of beneficial skin microorganisms from microorganisms or communities with an adverse or sickening effect on their hosts, (d) factors shaping the skin microbiota and its functional role in health and disease, (e) strategies to manipulate the skin microbiota for therapeutic reasons.

  5. Skin Sensitive Difference of Human Body Sections under Clothing-Smirnov Test of Skin Surface Temperatures' Dynamic Changing

    Institute of Scientific and Technical Information of China (English)

    LI Jun; WU Hai-yan; WANG Yun-yi

    2004-01-01

    Skin sensitive difference of human body sections under clothing is the theoretic foundation of thermal insulation clothing design.By a new method of researching on clothing comfort perception,the skin temperature live changing procedure of human body sections affected by the same cold stimulation is inspected.Furthermore with the Smirnov test the skin temperatures dynamic changing patterns of main human body sections are obtained.

  6. Elucidation of xenobiotic metabolism pathways in human skin and human skin models by proteomic profiling.

    Directory of Open Access Journals (Sweden)

    Sven van Eijl

    Full Text Available BACKGROUND: Human skin has the capacity to metabolise foreign chemicals (xenobiotics, but knowledge of the various enzymes involved is incomplete. A broad-based unbiased proteomics approach was used to describe the profile of xenobiotic metabolising enzymes present in human skin and hence indicate principal routes of metabolism of xenobiotic compounds. Several in vitro models of human skin have been developed for the purpose of safety assessment of chemicals. The suitability of these epidermal models for studies involving biotransformation was assessed by comparing their profiles of xenobiotic metabolising enzymes with those of human skin. METHODOLOGY/PRINCIPAL FINDINGS: Label-free proteomic analysis of whole human skin (10 donors was applied and analysed using custom-built PROTSIFT software. The results showed the presence of enzymes with a capacity for the metabolism of alcohols through dehydrogenation, aldehydes through dehydrogenation and oxidation, amines through oxidation, carbonyls through reduction, epoxides and carboxylesters through hydrolysis and, of many compounds, by conjugation to glutathione. Whereas protein levels of these enzymes in skin were mostly just 4-10 fold lower than those in liver and sufficient to support metabolism, the levels of cytochrome P450 enzymes were at least 300-fold lower indicating they play no significant role. Four epidermal models of human skin had profiles very similar to one another and these overlapped substantially with that of whole skin. CONCLUSIONS/SIGNIFICANCE: The proteomics profiling approach was successful in producing a comprehensive analysis of the biotransformation characteristics of whole human skin and various in vitro skin models. The results show that skin contains a range of defined enzymes capable of metabolising different classes of chemicals. The degree of similarity of the profiles of the in vitro models indicates their suitability for epidermal toxicity testing. Overall, these

  7. Water vapour loss measurements on human skin.

    NARCIS (Netherlands)

    Valk, Petrus Gerardus Maria van der

    1984-01-01

    In this thesis, the results of a series of investigations into the barrier function of human skin are presented. In these investigations, the barrier function was assessed by water vapour loss measurements of the skin using a method based on gradient estimation.... Zie: Summary and conclusions

  8. Low power cw-laser signatures on human skin

    International Nuclear Information System (INIS)

    Lihachev, A; Lesinsh, J; Jakovels, D; Spigulis, J

    2011-01-01

    Impact of cw laser radiation on autofluorescence features of human skin is studied. Two methods of autofluorescence detection are applied: the spectral method with the use of a fibreoptic probe and spectrometer for determining the autofluorescence recovery kinetics at a fixed skin area of ∼12 mm 2 , and the multispectral visualisation method with the use of a multispectral imaging camera for visualising long-term autofluorescence changes in a skin area of ∼4 cm 2 . The autofluorescence recovery kinetics after preliminary laser irradiation is determined. Skin autofluorescence images with visible long-term changes - 'signatures' of low power laser treatment are acquired. (application of lasers and laser-optical methods in life sciences)

  9. Materials used to simulate physical properties of human skin.

    Science.gov (United States)

    Dąbrowska, A K; Rotaru, G-M; Derler, S; Spano, F; Camenzind, M; Annaheim, S; Stämpfli, R; Schmid, M; Rossi, R M

    2016-02-01

    For many applications in research, material development and testing, physical skin models are preferable to the use of human skin, because more reliable and reproducible results can be obtained. This article gives an overview of materials applied to model physical properties of human skin to encourage multidisciplinary approaches for more realistic testing and improved understanding of skin-material interactions. The literature databases Web of Science, PubMed and Google Scholar were searched using the terms 'skin model', 'skin phantom', 'skin equivalent', 'synthetic skin', 'skin substitute', 'artificial skin', 'skin replica', and 'skin model substrate.' Articles addressing material developments or measurements that include the replication of skin properties or behaviour were analysed. It was found that the most common materials used to simulate skin are liquid suspensions, gelatinous substances, elastomers, epoxy resins, metals and textiles. Nano- and micro-fillers can be incorporated in the skin models to tune their physical properties. While numerous physical skin models have been reported, most developments are research field-specific and based on trial-and-error methods. As the complexity of advanced measurement techniques increases, new interdisciplinary approaches are needed in future to achieve refined models which realistically simulate multiple properties of human skin. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  10. Elastin hydrolysate derived from fish enhances proliferation of human skin fibroblasts and elastin synthesis in human skin fibroblasts and improves the skin conditions.

    Science.gov (United States)

    Shiratsuchi, Eri; Nakaba, Misako; Yamada, Michio

    2016-03-30

    Recent studies have shown that certain peptides significantly improve skin conditions, such as skin elasticity and the moisture content of the skin of healthy woman. This study aimed to investigate the effects of elastin hydrolysate on human skin. Proliferation and elastin synthesis were evaluated in human skin fibroblasts exposed to elastin hydrolysate and proryl-glycine (Pro-Gly), which is present in human blood after elastin hydrolysate ingestion. We also performed an ingestion test with elastin hydrolysate in humans and evaluated skin condition. Elastin hydrolysate and Pro-Gly enhanced the proliferation of fibroblasts and elastin synthesis. Maximal proliferation response was observed at 25 ng mL(-1) Pro-Gly. Ingestion of elastin hydrolysate improved skin condition, such as elasticity, number of wrinkles, and blood flow. Elasticity improved by 4% in the elastin hydrolysate group compared with 2% in the placebo group. Therefore, elastin hydrolysate activates human skin fibroblasts and has beneficial effects on skin conditions. © 2015 Society of Chemical Industry.

  11. Characterization of a Cryopreserved Split-Thickness Human Skin Allograft-TheraSkin.

    Science.gov (United States)

    Landsman, Adam; Rosines, Eran; Houck, Amanda; Murchison, Angela; Jones, Alyce; Qin, Xiaofei; Chen, Silvia; Landsman, Arnold R

    2016-09-01

    The purpose of this study was to examine the characteristics of a cryopreserved split-thickness skin allograft produced from donated human skin and compare it with fresh, unprocessed human split-thickness skin. Cutaneous wound healing is a complex and organized process, where the body re-establishes the integrity of the injured tissue. However, chronic wounds, such as diabetic or venous stasis ulcers, are difficult to manage and often require advanced biologics to facilitate healing. An ideal wound care product is able to directly influence wound healing by introducing biocompatible extracellular matrices, growth factors, and viable cells to the wound bed. TheraSkin (processed by LifeNet Health, Virginia Beach, Virginia, and distributed by Soluble Systems, Newport News, Virginia) is a minimally manipulated, cryopreserved split-thickness human skin allograft, which contains natural extracellular matrices, native growth factors, and viable cells. The authors characterized TheraSkin in terms of the collagen and growth factor composition using ELISA, percentage of apoptotic cells using TUNEL analysis, and cellular viability using alamarBlue assay (Thermo Fisher Scientific, Waltham, Massachusetts), and compared these characteristics with fresh, unprocessed human split-thickness skin. It was found that the amount of the type I and type III collagen, as well as the ratio of type I to type III collagen in TheraSkin, is equivalent to fresh unprocessed human split-thickness skin. Similar quantities of vascular endothelial growth factor, insulinlike growth factor 1, fibroblast growth factor 2, and transforming growth factor β1 were detected in TheraSkin and fresh human skin. The average percent of apoptotic cells was 34.3% and 3.1% for TheraSkin and fresh skin, respectively. Cellular viability was demonstrated in both TheraSkin and fresh skin.

  12. An in vitro human skin test for assessing sensitization potential.

    Science.gov (United States)

    Ahmed, S S; Wang, X N; Fielding, M; Kerry, A; Dickinson, I; Munuswamy, R; Kimber, I; Dickinson, A M

    2016-05-01

    Sensitization to chemicals resulting in an allergy is an important health issue. The current gold-standard method for identification and characterization of skin-sensitizing chemicals was the mouse local lymph node assay (LLNA). However, for a number of reasons there has been an increasing imperative to develop alternative approaches to hazard identification that do not require the use of animals. Here we describe a human in-vitro skin explant test for identification of sensitization hazards and the assessment of relative skin sensitizing potency. This method measures histological damage in human skin as a readout of the immune response induced by the test material. Using this approach we have measured responses to 44 chemicals including skin sensitizers, pre/pro-haptens, respiratory sensitizers, non-sensitizing chemicals (including skin-irritants) and previously misclassified compounds. Based on comparisons with the LLNA, the skin explant test gave 95% specificity, 95% sensitivity, 95% concordance with a correlation coefficient of 0.9. The same specificity and sensitivity were achieved for comparison of results with published human sensitization data with a correlation coefficient of 0.91. The test also successfully identified nickel sulphate as a human skin sensitizer, which was misclassified as negative in the LLNA. In addition, sensitizers and non-sensitizers identified as positive or negative by the skin explant test have induced high/low T cell proliferation and IFNγ production, respectively. Collectively, the data suggests the human in-vitro skin explant test could provide the basis for a novel approach for characterization of the sensitizing activity as a first step in the risk assessment process. Copyright © 2015 John Wiley & Sons, Ltd.

  13. Human reconstructed skin xenografts on mice to model skin physiology.

    Science.gov (United States)

    Salgado, Giorgiana; Ng, Yi Zhen; Koh, Li Fang; Goh, Christabelle S M; Common, John E

    Xenograft models to study skin physiology have been popular for scientific use since the 1970s, with various developments and improvements to the techniques over the decades. Xenograft models are particularly useful and sought after due to the lack of clinically relevant animal models in predicting drug effectiveness in humans. Such predictions could in turn boost the process of drug discovery, since novel drug compounds have an estimated 8% chance of FDA approval despite years of rigorous preclinical testing and evaluation, albeit mostly in non-human models. In the case of skin research, the mouse persists as the most popular animal model of choice, despite its well-known anatomical differences with human skin. Differences in skin biology are especially evident when trying to dissect more complex skin conditions, such as psoriasis and eczema, where interactions between the immune system, epidermis and the environment likely occur. While the use of animal models are still considered the gold standard for systemic toxicity studies under controlled environments, there are now alternative models that have been approved for certain applications. To overcome the biological limitations of the mouse model, research efforts have also focused on "humanizing" the mice model to better recapitulate human skin physiology. In this review, we outline the different approaches undertaken thus far to study skin biology using human tissue xenografts in mice and the technical challenges involved. We also describe more recent developments to generate humanized multi-tissue compartment mice that carry both a functioning human immune system and skin xenografts. Such composite animal models provide promising opportunities to study drugs, disease and differentiation with greater clinical relevance. Copyright © 2017 International Society of Differentiation. Published by Elsevier B.V. All rights reserved.

  14. Elevation of telomerase activity in chronic radiation ulcer of human skin

    International Nuclear Information System (INIS)

    Li Xiaoying; Zhao Po; Wang Dewen; Yang Zhixiang

    1997-01-01

    Objective: To investigate the levels of telomerase activity in chronic radiation ulcers of human skin and the possible relationship between the enzyme and cancer transformation. Method: Using nonisotopic telomere repeat amplification protocol (TRAP), detections were performed in 20 cases of chronic radiation ulcers of human skin, 5 cases of normal skin tissues and 5 cases of carcinoma. Results: The positive rates for telomerase activity were 30.0%(6/20), 0(0/5) and 100%(5/5) in chronic radiation ulcers of human skin, normal skin and carcinoma, respectively. The telomerase activity in radiation ulcer was weaker than in carcinoma. Conclusion: The telomerase activity assay might be used as a marker for predicting the prognosis and the effect of treatment in chronic radiation ulcer of human skin

  15. Human skin penetration of silver nanoparticles through intact and damaged skin

    International Nuclear Information System (INIS)

    Larese, Francesca Filon; D'Agostin, Flavia; Crosera, Matteo; Adami, Gianpiero; Renzi, Nadia; Bovenzi, Massimo; Maina, Giovanni

    2009-01-01

    There is a growing interest on nanoparticle safety for topical use. The benefits of nanoparticles have been shown in several scientific fields, but little is known about their potential to penetrate the skin. This study aims at evaluating in vitro skin penetration of silver nanoparticles. Experiments were performed using the Franz diffusion cell method with intact and damaged human skin. Physiological solution was used as receiving phase and 70 μg/cm 2 of silver nanoparticles coated with polyvinylpirrolidone dispersed in synthetic sweat were applied as donor phase to the outer surface of the skin for 24 h. The receptor fluid measurements were performed by electro thermal atomic absorption spectroscopy (ETAAS). Human skin penetration was also determined by using transmission electron microscope (TEM) to verify the location of silver nanoparticles in exposed membranes. Median silver concentrations of 0.46 ng cm -2 (range -2 (range 0.43-11.6) were found in the receiving solutions of cells where the nanoparticles solution was applied on intact skin (eight cells) and on damaged skin (eight cells), respectively. Twenty-four hours silver flux permeation in damaged skin was 0.62 ± 0.2 ng cm -2 with a lag time <1 h. Our experimental data showed that silver nanoparticles absorption through intact and damaged skin was very low but detectable, and that in case of damaged skin it was possible an increasing permeation of silver applied as nanoparticles. Moreover, silver nanoparticles could be detected in the stratum corneum and the outermost surface of the epidermis by electron microscopy. We demonstrated for the first time that silver applied as nanoparticles coated with polyvinylpirrolidone is able to permeate the damaged skin in an in vitro diffusion cell system

  16. Skin friction: a novel approach to measuring in vivo human skin

    OpenAIRE

    Veijgen, N.K.

    2013-01-01

    The human skin plays an important role in people’s lives. It is in constant interaction with the environment, clothing and consumer products. This thesis discusses one of the parameters in the interaction between the human skin in vivo and other materials: skin friction. The thesis is divided into three parts. The first part is an introduction to skin friction and to current knowledge on skin friction. The second part presents the RevoltST, the tribometer that was specially developed for skin...

  17. Preparation of Artificial Skin that Mimics Human Skin Surface and Mechanical Properties.

    Science.gov (United States)

    Shimizu, Rana; Nonomura, Yoshimune

    2018-01-01

    We have developed an artificial skin that mimics the morphological and mechanical properties of human skin. The artificial skin comprises a polyurethane block possessing a microscopically rough surface. We evaluated the tactile sensations when skin-care cream was applied to the artificial skin. Many subjects perceived smooth, moist, and soft feels during the application process. Cluster analysis showed that these characteristic tactile feels are similar to those when skin-care cream is applied to real human skin. Contact angle analysis showed that an oil droplet spread smoothly on the artificial skin surface, which occurred because there were many grooves several hundred micrometers in width on the skin surface. In addition, when the skin-care cream was applied, the change in frictional force during the dynamic friction process increased. These wetting and frictional properties are important factors controlling the similarity of artificial skin to real human skin.

  18. Evaluation of dermal-epidermal skin equivalents ('composite-skin') of human keratinocytes in a collagen-glycosaminoglycan matrix(Integra artificial skin).

    Science.gov (United States)

    Kremer, M; Lang, E; Berger, A C

    2000-09-01

    Integra artificial skin (Integra LifeSciences Corp., Plainsboro, NJ, USA) is a dermal template consisting of bovine collagen, chondroitin-6-sulphate and a silastic membrane manufactured as Integra. This product has gained widespread use in the clinical treatment of third degree burn wounds and full thickness skin defects of different aetiologies. The product was designed to significantly reduce the time needed to achieve final wound closure in the treatment of major burn wounds, to optimise the sparse autologous donor skin resources and to improve the durable mechanical quality of the skin substitute. The clinical procedure requires two stages. The first step creates a self neodermis, the second creates a self epidermis on the neodermis. However, it is desirable to cover major burn wounds early in a single step by a skin substitute consisting of a dermal equivalent seeded in vitro with autologous keratinocytes ('composite-skin') out of which a full thickness skin develops in vivo.The goal of this experimental study was to develop a method to integrate human keratinocytes in homogeneous distribution and depth into Integra Artificial Skin. The seeded cell-matrix composites were grafted onto athymic mice in order to evaluate their potential to reconstitute a human epidermis in vivo. We were able to demonstrate that the inoculated human keratinocytes reproducibly displayed a homogeneous pattern of distribution, adherence, proliferation and confluence. The cell-matrix composites grafted in this model exhibited good wound adherence, complete healing, minor wound contraction and had the potential to reconstitute an elastic, functional and durable human skin. Histologically we were able to show that the inoculated human keratinocytes in vivo colonised the matrix in a histomorphologically characteristic epidermal pattern (keratomorula, keratinocyte bubbling) and developed a persisting, stratified, keratinising epidermis which immunohistologically proved to be of human

  19. Diffusion of [2-14C]diazepam across hairless mouse skin and human skin

    International Nuclear Information System (INIS)

    Koch, R.L.; Palicharla, P.; Groves, M.J.

    1987-01-01

    The objectives of this study were to investigate the absorption of diazepam applied topically to the hairless mouse in vivo and to determine the diffusion of diazepam across isolated hairless mouse skin and human skin. [ 14 C]Diazepam was readily absorbed after topical administration to the intact hairless mouse, a total of 75.8% of the 14 C-label applied being recovered in urine and feces. Diazepam was found to diffuse across human and hairless mouse skin unchanged in experiments with twin-chambered diffusion cells. The variation in diffusion rate or the flux for both human and mouse tissues was greater among specimens than between duplicate or triplicate trials for a single specimen. Fluxes for mouse skin (stratum corneum, epidermis, and dermis) were greater than for human skin (stratum corneum and epidermis): 0.35-0.61 microgram/cm2/h for mouse skin vs 0.24-0.42 microgram/cm2/h for human skin. The permeability coefficients for mouse skin ranged from 1.4-2.4 X 10(-2)cm/h compared with 0.8-1.4 X 10(-2)cm/h for human skin. Although human stratum corneum is almost twice the thickness of that of the hairless mouse, the diffusion coefficients for human skin were 3-12 times greater (0.76-3.31 X 10(-6) cm2/h for human skin vs 0.12-0.27 X 10(-6) cm2/h for hairless mouse) because of a shorter lag time for diffusion across human skin. These differences between the diffusion coefficients and diffusion rates (or permeability coefficients) suggest that the presence of the dermis may present some barrier properties. In vitro the dermis may require complete saturation before the diazepam can be detected in the receiving chamber

  20. Human age and skin physiology shape diversity and abundance of Archaea on skin.

    Science.gov (United States)

    Moissl-Eichinger, Christine; Probst, Alexander J; Birarda, Giovanni; Auerbach, Anna; Koskinen, Kaisa; Wolf, Peter; Holman, Hoi-Ying N

    2017-06-22

    The human skin microbiome acts as an important barrier protecting our body from pathogens and other environmental influences. Recent investigations have provided evidence that Archaea are a constant but highly variable component of the human skin microbiome, yet factors that determine their abundance changes are unknown. Here, we tested the hypothesis that the abundance of archaea on human skin is influenced by human age and skin physiology by quantitative PCR of 51 different skin samples taken from human subjects of various age. Our results reveal that archaea are more abundant in human subjects either older than 60 years or younger than 12 years as compared to middle-aged human subjects. These results, together with results obtained from spectroscopy analysis, allowed us gain first insights into a potential link of lower sebum levels and lipid content and thus reduced skin moisture with an increase in archaeal signatures. Amplicon sequencing of selected samples revealed the prevalence of specific eury- and mainly thaumarchaeal taxa, represented by a core archaeome of the human skin.

  1. Skin friction: a novel approach to measuring in vivo human skin

    NARCIS (Netherlands)

    Veijgen, N.K.

    2013-01-01

    The human skin plays an important role in people’s lives. It is in constant interaction with the environment, clothing and consumer products. This thesis discusses one of the parameters in the interaction between the human skin in vivo and other materials: skin friction. The thesis is divided into

  2. Generation of human-induced pluripotent stem cells from burn patient-derived skin fibroblasts using a non-integrative method.

    Science.gov (United States)

    Fu, Shangfeng; Ding, Jianwu; Liu, Dewu; Huang, Heping; Li, Min; Liu, Yang; Tu, Longxiang; Liu, Deming

    2018-01-01

    Patient specific induced pluripotent stem cells (iPSCs) have been recognized as a possible source of cells for skin tissue engineering. They have the potential to greatly benefit patients with large areas of burned skin or skin defects. However, the integration virus-based reprogramming method is associated with a high risk of genetic mutation and mouse embryonic fibroblast feeder-cells may be a pollutant. In the present study, human skin fibroblasts (HSFs) were successfully harvested from patients with burns and patient-specific iPSCs were generated using a non-integration method with a feeder-free approach. The octamer-binding transcription factor 4 (OCT4), sex-determining region Y box 2 (SOX2) and NANOG transcription factors were delivered using Sendai virus vectors. iPSCs exhibited representative human embryonic stem cell-like morphology and proliferation characteristics. They also expressed pluripotent markers, including OCT4, NANOG, SOX2, TRA181, stage-specific embryonic antigen 4 and TRA-160, and exhibited a normal karyotype. Teratoma and embryoid body formation revealed that iPSCs were able to differentiate into cells of all three germ layers in vitro and in vivo. The results of the present study demonstrate that HSFs derived from patients with burns, may be reprogrammed into stem cells with pluripotency, which provides a basis for cell‑based skin tissue engineering in the future.

  3. Electroosmotic pore transport in human skin.

    Science.gov (United States)

    Uitto, Olivia D; White, Henry S

    2003-04-01

    To determine the pathways and origin of electroosmotic flow in human skin. Iontophoretic transport of acetaminophen in full thickness human cadaver skin was visualized and quantified by scanning electrochemical microscopy. Electroosmotic flow in the shunt pathways of full thickness skin was compared to flow in the pores of excised stratum corneum and a synthetic membrane pore. The penetration of rhodamine 6G into pore structures was investigated by laser scanning confocal microscopy. Electroosmotic transport is observed in shunt pathways in full thickness human skin (e.g., hair follicles and sweat glands), but not in pore openings of freestanding stratum corneum. Absolute values of the diffusive and iontophoretic pore fluxes of acetaminophen in full thickness human skin are also reported. Rhodamine 6G is observed to penetrate to significant depths (approximately 200 microm) along pore pathways. Iontophoresis in human cadaver skin induces localized electroosmotic flow along pore shunt paths. Electroosmotic forces arise from the passage of current through negatively charged mesoor nanoscale pores (e.g., gap functions) within cellular regions that define the pore structure beneath the stratum corneum.

  4. Quantitative evaluation methods of skin condition based on texture feature parameters

    Directory of Open Access Journals (Sweden)

    Hui Pang

    2017-03-01

    Full Text Available In order to quantitatively evaluate the improvement of the skin condition after using skin care products and beauty, a quantitative evaluation method for skin surface state and texture is presented, which is convenient, fast and non-destructive. Human skin images were collected by image sensors. Firstly, the median filter of the 3 × 3 window is used and then the location of the hairy pixels on the skin is accurately detected according to the gray mean value and color information. The bilinear interpolation is used to modify the gray value of the hairy pixels in order to eliminate the negative effect of noise and tiny hairs on the texture. After the above pretreatment, the gray level co-occurrence matrix (GLCM is calculated. On the basis of this, the four characteristic parameters, including the second moment, contrast, entropy and correlation, and their mean value are calculated at 45 ° intervals. The quantitative evaluation model of skin texture based on GLCM is established, which can calculate the comprehensive parameters of skin condition. Experiments show that using this method evaluates the skin condition, both based on biochemical indicators of skin evaluation methods in line, but also fully consistent with the human visual experience. This method overcomes the shortcomings of the biochemical evaluation method of skin damage and long waiting time, also the subjectivity and fuzziness of the visual evaluation, which achieves the non-destructive, rapid and quantitative evaluation of skin condition. It can be used for health assessment or classification of the skin condition, also can quantitatively evaluate the subtle improvement of skin condition after using skin care products or stage beauty.

  5. Quantitative evaluation methods of skin condition based on texture feature parameters.

    Science.gov (United States)

    Pang, Hui; Chen, Tianhua; Wang, Xiaoyi; Chang, Zhineng; Shao, Siqi; Zhao, Jing

    2017-03-01

    In order to quantitatively evaluate the improvement of the skin condition after using skin care products and beauty, a quantitative evaluation method for skin surface state and texture is presented, which is convenient, fast and non-destructive. Human skin images were collected by image sensors. Firstly, the median filter of the 3 × 3 window is used and then the location of the hairy pixels on the skin is accurately detected according to the gray mean value and color information. The bilinear interpolation is used to modify the gray value of the hairy pixels in order to eliminate the negative effect of noise and tiny hairs on the texture. After the above pretreatment, the gray level co-occurrence matrix (GLCM) is calculated. On the basis of this, the four characteristic parameters, including the second moment, contrast, entropy and correlation, and their mean value are calculated at 45 ° intervals. The quantitative evaluation model of skin texture based on GLCM is established, which can calculate the comprehensive parameters of skin condition. Experiments show that using this method evaluates the skin condition, both based on biochemical indicators of skin evaluation methods in line, but also fully consistent with the human visual experience. This method overcomes the shortcomings of the biochemical evaluation method of skin damage and long waiting time, also the subjectivity and fuzziness of the visual evaluation, which achieves the non-destructive, rapid and quantitative evaluation of skin condition. It can be used for health assessment or classification of the skin condition, also can quantitatively evaluate the subtle improvement of skin condition after using skin care products or stage beauty.

  6. In-vitro percutaneous absorption of losartan potassium in human skin and prediction of human skin permeability

    Directory of Open Access Journals (Sweden)

    Petkar K.C.

    2007-05-01

    Full Text Available This study describes the feasibility of transdermal controlled administration of Losartan potassium (LP across human cadaver skin. Study also defines the influence of capsaicin, sex and site of application on permeation characteristics and determined an appropriate animal model for human skin permeability. The permeation of LP of various formulations was studied using Keshary-Chein diffusion cell. Optimized controlled formulation (without capsaicin released 42.17% (±1.85 of LP in 12 hr whereas treatment formulation (with capsaicin 0.028 % w/v released 48.94% (±1.71 of LP with significant difference on null hypothesis. Influence of sex showed statistically significant difference for permeation of LP through male and female rats, as well as male and female mice across both the abdominal and dorsal sides of the skin (p<0.05. Similarly statistically significant differences were noted for permeation of LP across male and female mice abdomen-dorsal, but not for male rat abdomen-dorsal and female rat abdomen-dorsal. Furthermore, in-vitro permeation of LP across human skin was compared with the permeation across rat and mice skins. Male rat and male mice dorsal skin was found to have closer permeability characteristics to human than other skin membranes, but the Factor of Difference values were < 3 for all membranes which were used suggesting the membranes are good models for human skin permeability. In conclusion simple transdermal adhesive patches formulations incorporating high molecular weight of LP can deliver a dose in-vivo and proposed model skin membranes can be utilized for future pharmacokineic and toxicokinetic studies as well as metabolism studies of LP

  7. 3D imaging of cleared human skin biopsies using light-sheet microscopy: A new way to visualize in-depth skin structure.

    Science.gov (United States)

    Abadie, S; Jardet, C; Colombelli, J; Chaput, B; David, A; Grolleau, J-L; Bedos, P; Lobjois, V; Descargues, P; Rouquette, J

    2018-05-01

    Human skin is composed of the superimposition of tissue layers of various thicknesses and components. Histological staining of skin sections is the benchmark approach to analyse the organization and integrity of human skin biopsies; however, this approach does not allow 3D tissue visualization. Alternatively, confocal or two-photon microscopy is an effective approach to perform fluorescent-based 3D imaging. However, owing to light scattering, these methods display limited light penetration in depth. The objectives of this study were therefore to combine optical clearing and light-sheet fluorescence microscopy (LSFM) to perform in-depth optical sectioning of 5 mm-thick human skin biopsies and generate 3D images of entire human skin biopsies. A benzyl alcohol and benzyl benzoate solution was used to successfully optically clear entire formalin fixed human skin biopsies, making them transparent. In-depth optical sectioning was performed with LSFM on the basis of tissue-autofluorescence observations. 3D image analysis of optical sections generated with LSFM was performed by using the Amira ® software. This new approach allowed us to observe in situ the different layers and compartments of human skin, such as the stratum corneum, the dermis and epidermal appendages. With this approach, we easily performed 3D reconstruction to visualise an entire human skin biopsy. Finally, we demonstrated that this method is useful to visualise and quantify histological anomalies, such as epidermal hyperplasia. The combination of optical clearing and LSFM has new applications in dermatology and dermatological research by allowing 3D visualization and analysis of whole human skin biopsies. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  8. An ex vivo human skin model for studying skin barrier repair.

    Science.gov (United States)

    Danso, Mogbekeloluwa O; Berkers, Tineke; Mieremet, Arnout; Hausil, Farzia; Bouwstra, Joke A

    2015-01-01

    In the studies described in this study, we introduce a novel ex vivo human skin barrier repair model. To develop this, we removed the upper layer of the skin, the stratum corneum (SC) by a reproducible cyanoacrylate stripping technique. After stripping the explants, they were cultured in vitro to allow the regeneration of the SC. We selected two culture temperatures 32 °C and 37 °C and a period of either 4 or 8 days. After 8 days of culture, the explant generated SC at a similar thickness compared to native human SC. At 37 °C, the early and late epidermal differentiation programmes were executed comparably to native human skin with the exception of the barrier protein involucrin. At 32 °C, early differentiation was delayed, but the terminal differentiation proteins were expressed as in stripped explants cultured at 37 °C. Regarding the barrier properties, the SC lateral lipid organization was mainly hexagonal in the regenerated SC, whereas the lipids in native human SC adopt a more dense orthorhombic organization. In addition, the ceramide levels were higher in the cultured explants at 32 °C and 37 °C than in native human SC. In conclusion, we selected the stripped ex vivo skin model cultured at 37 °C as a candidate model to study skin barrier repair because epidermal and SC characteristics mimic more closely the native human skin than the ex vivo skin model cultured at 32 °C. Potentially, this model can be used for testing formulations for skin barrier repair. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  9. Generation of Genetically Modified Organotypic Skin Cultures Using Devitalized Human Dermis.

    Science.gov (United States)

    Li, Jingting; Sen, George L

    2015-12-14

    Organotypic cultures allow the reconstitution of a 3D environment critical for cell-cell contact and cell-matrix interactions which mimics the function and physiology of their in vivo tissue counterparts. This is exemplified by organotypic skin cultures which faithfully recapitulates the epidermal differentiation and stratification program. Primary human epidermal keratinocytes are genetically manipulable through retroviruses where genes can be easily overexpressed or knocked down. These genetically modified keratinocytes can then be used to regenerate human epidermis in organotypic skin cultures providing a powerful model to study genetic pathways impacting epidermal growth, differentiation, and disease progression. The protocols presented here describe methods to prepare devitalized human dermis as well as to genetically manipulate primary human keratinocytes in order to generate organotypic skin cultures. Regenerated human skin can be used in downstream applications such as gene expression profiling, immunostaining, and chromatin immunoprecipitations followed by high throughput sequencing. Thus, generation of these genetically modified organotypic skin cultures will allow the determination of genes that are critical for maintaining skin homeostasis.

  10. Targeted sequencing of clade-specific markers from skin microbiomes for forensic human identification.

    Science.gov (United States)

    Schmedes, Sarah E; Woerner, August E; Novroski, Nicole M M; Wendt, Frank R; King, Jonathan L; Stephens, Kathryn M; Budowle, Bruce

    2018-01-01

    The human skin microbiome is comprised of diverse communities of bacterial, eukaryotic, and viral taxa and contributes millions of additional genes to the repertoire of human genes, affecting human metabolism and immune response. Numerous genetic and environmental factors influence the microbiome composition and as such contribute to individual-specific microbial signatures which may be exploited for forensic applications. Previous studies have demonstrated the potential to associate skin microbial profiles collected from touched items to their individual owner, mainly using unsupervised methods from samples collected over short time intervals. Those studies utilize either targeted 16S rRNA or shotgun metagenomic sequencing to characterize skin microbiomes; however, these approaches have limited species and strain resolution and susceptibility to stochastic effects, respectively. Clade-specific markers from the skin microbiome, using supervised learning, can predict individual identity using skin microbiomes from their respective donors with high accuracy. In this study the hidSkinPlex is presented, a novel targeted sequencing method using skin microbiome markers developed for human identification. The hidSkinPlex (comprised of 286 bacterial (and phage) family-, genus-, species-, and subspecies-level markers), initially was evaluated on three bacterial control samples represented in the panel (i.e., Propionibacterium acnes, Propionibacterium granulosum, and Rothia dentocariosa) to assess the performance of the multiplex. The hidSkinPlex was further evaluated for prediction purposes. The hidSkinPlex markers were used to attribute skin microbiomes collected from eight individuals from three body sites (i.e., foot (Fb), hand (Hp) and manubrium (Mb)) to their host donor. Supervised learning, specifically regularized multinomial logistic regression and 1-nearest-neighbor classification were used to classify skin microbiomes to their hosts with up to 92% (Fb), 96% (Mb

  11. Speckle reduction in optical coherence tomography images of human skin by a spatial diversity method - art. no. 66270P

    DEFF Research Database (Denmark)

    Jørgensen, Thomas Martini; Thrane, Lars; Mogensen, M.

    2007-01-01

    the scheme with a mobile fiber-based time-domain real-time OCT system. Essential enhancement was obtained in image contrast when performing in vivo imaging of normal skin and lesions. Resulting images show improved delineation of structure in correspondence with the observed improvements in contrast...... system. Here, we consider a method that in principle can be fitted to most OCT systems without major modifications. Specifically, we address a spatial diversity technique for suppressing speckle noise in OCT images of human skin. The method is a variant of changing the position of the sample relative...

  12. RNA isolation for transcriptomics of human and mouse small skin biopsies

    Directory of Open Access Journals (Sweden)

    Breit Timo M

    2011-10-01

    Full Text Available Abstract Background Isolation of RNA from skin biopsies presents a challenge, due to the tough nature of skin tissue and a high presence of RNases. As we lacked the dedicated equipment, i.e. homogenizer or bead-beater, needed for the available RNA from skin isolation methods, we adapted and tested our zebrafish single-embryo RNA-isolation protocol for RNA isolation from skin punch biopsies. Findings We tested our new RNA-isolation protocol in two experiments: a large-scale study with 97 human skin samples, and a small study with 16 mouse skin samples. Human skin was sampled with 4.0 mm biopsy punches and for the mouse skin different punch diameter sizes were tested; 1.0, 1.5, 2.0, and 2.5 mm. The average RNA yield in human samples was 1.5 μg with an average RNA quality RIN value of 8.1. For the mouse biopsies, the average RNA yield was 2.4 μg with an average RIN value of 7.5. For 96% of the human biopsies and 100% of the mouse biopsies we obtained enough high-quality RNA. The RNA samples were successfully tested in a transcriptomics analysis using the Affymetrix and Roche NimbleGen platforms. Conclusions Using our new RNA-isolation protocol, we were able to consistently isolate high-quality RNA, which is apt for further transcriptomics analysis. Furthermore, this method is already useable on biopsy material obtained with a punch diameter as small as 1.5 mm.

  13. Reconstruction of living bilayer human skin equivalent utilizing human fibrin as a scaffold.

    Science.gov (United States)

    Mazlyzam, A L; Aminuddin, B S; Fuzina, N H; Norhayati, M M; Fauziah, O; Isa, M R; Saim, L; Ruszymah, B H I

    2007-05-01

    Our aim of this study was to develop a new methodology for constructing a bilayer human skin equivalent to create a more clinical compliance skin graft composite for the treatment of various skin defects. We utilized human plasma derived fibrin as the scaffold for the development of a living bilayer human skin equivalent: fibrin-fibroblast and fibrin-keratinocyte (B-FF/FK SE). Skin cells from six consented patients were culture-expanded to passage 1. For B-FF/FK SE formation, human fibroblasts were embedded in human fibrin matrix and subsequently another layer of human keratinocytes in human fibrin matrix was stacked on top. The B-FF/FK SE was then transplanted to athymic mice model for 4 weeks to evaluate its regeneration and clinical performance. The in vivo B-FF/FK SE has similar properties as native human skin by histological analysis and expression of basal Keratin 14 gene in the epidermal layer and Collagen type I gene in the dermal layer. Electron microscopy analysis of in vivo B-FF/FK SE showed well-formed and continuous epidermal-dermal junction. We have successfully developed a technique to engineer living bilayer human skin equivalent using human fibrin matrix. The utilization of culture-expanded human skin cells and fibrin matrix from human blood will allow a fully autologous human skin equivalent construction.

  14. Auto white balance method using a pigmentation separation technique for human skin color

    Science.gov (United States)

    Tanaka, Satomi; Kakinuma, Akihiro; Kamijo, Naohiro; Takahashi, Hiroshi; Tsumura, Norimichi

    2017-02-01

    The human visual system maintains the perception of colors of an object across various light sources. Similarly, current digital cameras feature an auto white balance function, which estimates the illuminant color and corrects the color of a photograph as if the photograph was taken under a certain light source. The main subject in a photograph is often a person's face, which could be used to estimate the illuminant color. However, such estimation is adversely affected by differences in facial colors among individuals. The present paper proposes an auto white balance algorithm based on a pigmentation separation method that separates the human skin color image into the components of melanin, hemoglobin and shading. Pigment densities have a uniform property within the same race that can be calculated from the components of melanin and hemoglobin in the face. We, thus, propose a method that uses the subject's facial color in an image and is unaffected by individual differences in facial color among Japanese people.

  15. The use of ex vivo human skin tissue for genotoxicity testing

    Energy Technology Data Exchange (ETDEWEB)

    Reus, Astrid A.; Usta, Mustafa [TNO Triskelion BV, Utrechtseweg 48, 3704 HE, Zeist (Netherlands); Krul, Cyrille A.M., E-mail: cyrille.krul@tno.nl [TNO, Utrechtseweg 48, 3704 HE Zeist (Netherlands)

    2012-06-01

    As a result of the chemical legislation concerning the registration, evaluation, authorization and restriction of chemicals (REACH), and the Seventh Amendment to the Cosmetics Directive, which prohibits animal testing in Europe for cosmetics, alternative methods for safety evaluation of chemicals are urgently needed. Current in vitro genotoxicity assays are not sufficiently predictive for the in vivo situation, resulting in an unacceptably high number of misleading positives. For many chemicals and ingredients of personal care products the skin is the first site of contact, but there are no in vitro genotoxicity assays available in the skin for additional evaluation of positive or equivocal responses observed in regulatory in vitro genotoxicity assays. In the present study ex vivo human skin tissue obtained from surgery was used for genotoxicity evaluation of chemicals by using the comet assay. Fresh ex vivo human skin tissue was cultured in an air–liquid interface and topically exposed to 20 chemicals, including true positive, misleading positive and true negative genotoxins. Based on the results obtained in the present study, the sensitivity, specificity and accuracy of the ex vivo skin comet assay to predict in vivo genotoxicity were 89%, 90% and 89%, respectively. Donor and experimental variability were mainly reflected in the magnitude of the response and not the difference between the presence and absence of a genotoxic response. The present study indicates that human skin obtained from surgery is a promising and robust model for safety evaluation of chemicals that are in direct contact with the skin. -- Highlights: ► We use human skin obtained from surgery for genotoxicity evaluation of chemicals. ► We use the comet assay as parameter for genotoxicity in ex vivo human skin. ► Sensitivity, specificity and accuracy to predict in vivo genotoxins are determined. ► Sensitivity, specificity and accuracy are 89%, 90% and 90%, respectively. ► The method

  16. The use of ex vivo human skin tissue for genotoxicity testing

    International Nuclear Information System (INIS)

    Reus, Astrid A.; Usta, Mustafa; Krul, Cyrille A.M.

    2012-01-01

    As a result of the chemical legislation concerning the registration, evaluation, authorization and restriction of chemicals (REACH), and the Seventh Amendment to the Cosmetics Directive, which prohibits animal testing in Europe for cosmetics, alternative methods for safety evaluation of chemicals are urgently needed. Current in vitro genotoxicity assays are not sufficiently predictive for the in vivo situation, resulting in an unacceptably high number of misleading positives. For many chemicals and ingredients of personal care products the skin is the first site of contact, but there are no in vitro genotoxicity assays available in the skin for additional evaluation of positive or equivocal responses observed in regulatory in vitro genotoxicity assays. In the present study ex vivo human skin tissue obtained from surgery was used for genotoxicity evaluation of chemicals by using the comet assay. Fresh ex vivo human skin tissue was cultured in an air–liquid interface and topically exposed to 20 chemicals, including true positive, misleading positive and true negative genotoxins. Based on the results obtained in the present study, the sensitivity, specificity and accuracy of the ex vivo skin comet assay to predict in vivo genotoxicity were 89%, 90% and 89%, respectively. Donor and experimental variability were mainly reflected in the magnitude of the response and not the difference between the presence and absence of a genotoxic response. The present study indicates that human skin obtained from surgery is a promising and robust model for safety evaluation of chemicals that are in direct contact with the skin. -- Highlights: ► We use human skin obtained from surgery for genotoxicity evaluation of chemicals. ► We use the comet assay as parameter for genotoxicity in ex vivo human skin. ► Sensitivity, specificity and accuracy to predict in vivo genotoxins are determined. ► Sensitivity, specificity and accuracy are 89%, 90% and 90%, respectively. ► The method

  17. In vivo transformation of human skin with human papillomavirus type 11 from condylomatot acuminata

    International Nuclear Information System (INIS)

    Kreider, J.W.; Howett, M.K.; Lill, N.L.; Bartlett, G.L.; Zaino, R.J.; Sedlacek, T.V.; Mortel, R.

    1986-01-01

    Human papillomaviruses (HPVs) have been implicated in the development of a number of human malignancies, but direct tests of their involvement have not been possible. The authors describe a system in which human skin from various skin from various sites was infected with HPV type 11 (HPV-11) extracted from vulvar condylomata and was grafted beneath the renal capsule of athymic mice. Most of the skin grafts so treated underwent morphological transformation, resulting in the development of condylomata identical to those which occur spontaneously in patients. Foreskins responded with the most vigorous proliferative response to HPV-11. The lesions produced the characteristic intranuclear group-specific antigen of papillomaviruses. Both dot blot and Southern blot analysis of DNA from the lesions revealed the presence of HPV-11 DNA in the transformed grafts. These results demonstrate the first laboratory system for the study of the interaction of human skin with an HPV. The method may be useful in understanding the mechanisms of HPV transformation and replication and is free of the ethical restraints which have impeded study. This system will allow the direct study of factors which permit neoplastic progression of HPV-induced cutaneous lesions in human tissues

  18. Illuminant color estimation based on pigmentation separation from human skin color

    Science.gov (United States)

    Tanaka, Satomi; Kakinuma, Akihiro; Kamijo, Naohiro; Takahashi, Hiroshi; Tsumura, Norimichi

    2015-03-01

    Human has the visual system called "color constancy" that maintains the perceptive colors of same object across various light sources. The effective method of color constancy algorithm was proposed to use the human facial color in a digital color image, however, this method has wrong estimation results by the difference of individual facial colors. In this paper, we present the novel color constancy algorithm based on skin color analysis. The skin color analysis is the method to separate the skin color into the components of melanin, hemoglobin and shading. We use the stationary property of Japanese facial color, and this property is calculated from the components of melanin and hemoglobin. As a result, we achieve to propose the method to use subject's facial color in image and not depend on the individual difference among Japanese facial color.

  19. Composition of human skin microbiota affects attractiveness to malaria mosquitoes.

    Directory of Open Access Journals (Sweden)

    Niels O Verhulst

    Full Text Available The African malaria mosquito Anopheles gambiae sensu stricto continues to play an important role in malaria transmission, which is aggravated by its high degree of anthropophily, making it among the foremost vectors of this disease. In the current study we set out to unravel the strong association between this mosquito species and human beings, as it is determined by odorant cues derived from the human skin. Microbial communities on the skin play key roles in the production of human body odour. We demonstrate that the composition of the skin microbiota affects the degree of attractiveness of human beings to this mosquito species. Bacterial plate counts and 16S rRNA sequencing revealed that individuals that are highly attractive to An. gambiae s.s. have a significantly higher abundance, but lower diversity of bacteria on their skin than individuals that are poorly attractive. Bacterial genera that are correlated with the relative degree of attractiveness to mosquitoes were identified. The discovery of the connection between skin microbial populations and attractiveness to mosquitoes may lead to the development of new mosquito attractants and personalized methods for protection against vectors of malaria and other infectious diseases.

  20. Characterisation of human skin models - stability, metabolic capacity and comparative investigations in percutaneous absorption

    OpenAIRE

    Schreiber, Sylvia

    2010-01-01

    In recent years, the demand for alternative test methods in safety assessment of cosmetics, risk assessment of chemicals, and testing of pharmaceuticals was increasingly included in the EU directives. Thereby, alternative test methods for the determination of percutaneous absorption should achieve a more reliable in vivo prediction of the response of human skin than animal skin. Even though freshly excised human skin is considered as a preferred test matrix its routine use is often difficult ...

  1. Oral Polypodium leucotomos extract decreases ultraviolet-induced damage of human skin

    NARCIS (Netherlands)

    Middelkamp-Hup, Maritza A.; Pathak, Madhu A.; Parrado, Concepcion; Goukassian, David; Rius-Díaz, Francisca; Mihm, Martín C.; Fitzpatrick, Thomas B.; González, Salvador

    2004-01-01

    BACKGROUND: UV radiation induces damage to human skin. Protection of skin by an oral photoprotective agent would have substantial benefits. Objective We investigated the photoprotective effect of oral administration of an extract of the natural antioxidant Polypodium leucotomos (PL). METHODS: A

  2. Design and fabrication of human skin by three-dimensional bioprinting.

    Science.gov (United States)

    Lee, Vivian; Singh, Gurtej; Trasatti, John P; Bjornsson, Chris; Xu, Xiawei; Tran, Thanh Nga; Yoo, Seung-Schik; Dai, Guohao; Karande, Pankaj

    2014-06-01

    Three-dimensional (3D) bioprinting, a flexible automated on-demand platform for the free-form fabrication of complex living architectures, is a novel approach for the design and engineering of human organs and tissues. Here, we demonstrate the potential of 3D bioprinting for tissue engineering using human skin as a prototypical example. Keratinocytes and fibroblasts were used as constituent cells to represent the epidermis and dermis, and collagen was used to represent the dermal matrix of the skin. Preliminary studies were conducted to optimize printing parameters for maximum cell viability as well as for the optimization of cell densities in the epidermis and dermis to mimic physiologically relevant attributes of human skin. Printed 3D constructs were cultured in submerged media conditions followed by exposure of the epidermal layer to the air-liquid interface to promote maturation and stratification. Histology and immunofluorescence characterization demonstrated that 3D printed skin tissue was morphologically and biologically representative of in vivo human skin tissue. In comparison with traditional methods for skin engineering, 3D bioprinting offers several advantages in terms of shape- and form retention, flexibility, reproducibility, and high culture throughput. It has a broad range of applications in transdermal and topical formulation discovery, dermal toxicity studies, and in designing autologous grafts for wound healing. The proof-of-concept studies presented here can be further extended for enhancing the complexity of the skin model via the incorporation of secondary and adnexal structures or the inclusion of diseased cells to serve as a model for studying the pathophysiology of skin diseases.

  3. A novel model of human skin pressure ulcers in mice.

    Directory of Open Access Journals (Sweden)

    Andrés A Maldonado

    Full Text Available INTRODUCTION: Pressure ulcers are a prevalent health problem in today's society. The shortage of suitable animal models limits our understanding and our ability to develop new therapies. This study aims to report on the development of a novel and reproducible human skin pressure ulcer model in mice. MATERIAL AND METHODS: Male non-obese, diabetic, severe combined immunodeficiency mice (n = 22 were engrafted with human skin. A full-thickness skin graft was placed onto 4×3 cm wounds created on the dorsal skin of the mice. Two groups with permanent grafts were studied after 60 days. The control group (n = 6 was focused on the process of engraftment. Evaluations were conducted with photographic assessment, histological analysis and fluorescence in situ hybridization (FISH techniques. The pressure ulcer group (n = 12 was created using a compression device. A pressure of 150 mmHg for 8 h, with a total of three cycles of compression-release was exerted. Evaluations were conducted with photographic assessment and histological analysis. RESULTS: Skin grafts in the control group took successfully, as shown by visual assessment, FISH techniques and histological analysis. Pressure ulcers in the second group showed full-thickness skin loss with damage and necrosis of all the epidermal and dermal layers (ulcer stage III in all cases. Complete repair occurred after 40 days. CONCLUSIONS: An inexpensive, reproducible human skin pressure ulcer model has been developed. This novel model will facilitate the development of new clinically relevant therapeutic strategies that can be tested directly on human skin.

  4. Black and white human skin differences

    DEFF Research Database (Denmark)

    Andersen, Klaus Ejner; Maibach, H I

    1979-01-01

    This review of black and white human skin differences emphasizes the alleged importance of factors other than the obvious, i.e., skin color. Physicochemical differences and differences in susceptibility to irritants and allergens suggest a more resistant black than white skin. Differences appear...

  5. 3D bioprinting of functional human skin: production and in vivo analysis.

    Science.gov (United States)

    Cubo, Nieves; Garcia, Marta; Del Cañizo, Juan F; Velasco, Diego; Jorcano, Jose L

    2016-12-05

    Significant progress has been made over the past 25 years in the development of in vitro-engineered substitutes that mimic human skin, either to be used as grafts for the replacement of lost skin, or for the establishment of in vitro human skin models. In this sense, laboratory-grown skin substitutes containing dermal and epidermal components offer a promising approach to skin engineering. In particular, a human plasma-based bilayered skin generated by our group, has been applied successfully to treat burns as well as traumatic and surgical wounds in a large number of patients in Spain. There are some aspects requiring improvements in the production process of this skin; for example, the relatively long time (three weeks) needed to produce the surface required to cover an extensive burn or a large wound, and the necessity to automatize and standardize a process currently performed manually. 3D bioprinting has emerged as a flexible tool in regenerative medicine and it provides a platform to address these challenges. In the present study, we have used this technique to print a human bilayered skin using bioinks containing human plasma as well as primary human fibroblasts and keratinocytes that were obtained from skin biopsies. We were able to generate 100 cm 2 , a standard P100 tissue culture plate, of printed skin in less than 35 min (including the 30 min required for fibrin gelation). We have analysed the structure and function of the printed skin using histological and immunohistochemical methods, both in 3D in vitro cultures and after long-term transplantation to immunodeficient mice. In both cases, the generated skin was very similar to human skin and, furthermore, it was indistinguishable from bilayered dermo-epidermal equivalents, handmade in our laboratories. These results demonstrate that 3D bioprinting is a suitable technology to generate bioengineered skin for therapeutical and industrial applications in an automatized manner.

  6. Xenobiotic-metabolizing enzymes in the skin of rat, mouse, pig, guinea pig, man, and in human skin models.

    Science.gov (United States)

    Oesch, F; Fabian, E; Guth, K; Landsiedel, R

    2014-12-01

    The exposure of the skin to medical drugs, skin care products, cosmetics, and other chemicals renders information on xenobiotic-metabolizing enzymes (XME) in the skin highly interesting. Since the use of freshly excised human skin for experimental investigations meets with ethical and practical limitations, information on XME in models comes in the focus including non-human mammalian species and in vitro skin models. This review attempts to summarize the information available in the open scientific literature on XME in the skin of human, rat, mouse, guinea pig, and pig as well as human primary skin cells, human cell lines, and reconstructed human skin models. The most salient outcome is that much more research on cutaneous XME is needed for solid metabolism-dependent efficacy and safety predictions, and the cutaneous metabolism comparisons have to be viewed with caution. Keeping this fully in mind at least with respect to some cutaneous XME, some models may tentatively be considered to approximate reasonable closeness to human skin. For dermal absorption and for skin irritation among many contributing XME, esterase activity is of special importance, which in pig skin, some human cell lines, and reconstructed skin models appears reasonably close to human skin. With respect to genotoxicity and sensitization, activating XME are not yet judgeable, but reactive metabolite-reducing XME in primary human keratinocytes and several reconstructed human skin models appear reasonably close to human skin. For a more detailed delineation and discussion of the severe limitations see the "Overview and Conclusions" section in the end of this review.

  7. In vitro methods for evaluating skin hydration under diapers and incontinence products.

    Science.gov (United States)

    Tate, M L; Wright, A S

    2017-11-01

    Excessive skin hydration from wearing wet undergarments, such as infant diapers and adult incontinence products, has been historically problematic. Skin damage occurs from wetness (urine) and limited product breathability. Evaporative water loss has been measured on adult arms (armband method) or infant torsos (on-baby method), after wearing a saline-insulted diaper product. The current study developed a reliable in vitro method of evaluating diaper and incontinence products for improvements in skin dryness. A simulated skin substrate was applied to a heated mechanical arm or baby torso. A disposable diaper or incontinence product was wrapped around the arm or baby torso, and loaded with saline. Hydration of the simulated skin was measured by evaporimetry and compared with clinical data from adult armband evaluations. The heated mechanical arm and baby torso accurately distinguished products for skin dryness. Eight diaper products were evaluated and compared to human test results. The torso in vitro and mechanical arm evaluations demonstrated strong correlations to human epidermal water loss evaluations, with repeatable results. Additionally, the bench test has been used for adult incontinence products, and it proved to differentiate those products as well as infant products. A rapid and reliable means of evaluation has been developed, and it is predictive of human subject testing. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  8. Development of human skin equivalents to unravel the impaired skin barrier in atopic dermatitis skin

    NARCIS (Netherlands)

    Eweje, M.O.

    2016-01-01

    The studies in this thesis describes the barrier defects in Atopic Dermatitis (AD) skin and various techniques to develop AD Human Skin Equivalents (HSEs) which can be used to better understand the role of several factors in the pathogenesis of AD skin. The results described show that Inflammation

  9. The Role of Carotenoids in Human Skin

    Directory of Open Access Journals (Sweden)

    Theognosia Vergou

    2011-12-01

    Full Text Available The human skin, as the boundary organ between the human body and the environment, is under the constant influence of free radicals (FR, both from the outside in and from the inside out. Carotenoids are known to be powerful antioxidant substances playing an essential role in the reactions of neutralization of FR (mainly reactive oxygen species ROS. Carotenoid molecules present in the tissue are capable of neutralizing several attacks of FR, especially ROS, and are then destroyed. Human skin contains carotenoids, such as α-, γ-, β-carotene, lutein, zeaxanthin, lycopene and their isomers, which serve the living cells as a protection against oxidation. Recent studies have reported the possibility to investigate carotenoids in human skin quickly and non-invasively by spectroscopic means. Results obtained from in-vivo studies on human skin have shown that carotenoids are vital components of the antioxidative protective system of the human skin and could serve as marker substances for the overall antioxidative status. Reflecting the nutritional and stress situation of volunteers, carotenoids must be administered by means of antioxidant-rich products, e.g., in the form of fruit and vegetables. Carotenoids are degraded by stress factors of any type, inter alia, sun radiation, contact with environmental hazards, illness, etc. The kinetics of the accumulation and degradation of carotenoids in the skin have been investigated.

  10. Automated epidermis segmentation in histopathological images of human skin stained with hematoxylin and eosin

    Science.gov (United States)

    Kłeczek, Paweł; Dyduch, Grzegorz; Jaworek-Korjakowska, Joanna; Tadeusiewicz, Ryszard

    2017-03-01

    Background: Epidermis area is an important observation area for the diagnosis of inflammatory skin diseases and skin cancers. Therefore, in order to develop a computer-aided diagnosis system, segmentation of the epidermis area is usually an essential, initial step. This study presents an automated and robust method for epidermis segmentation in whole slide histopathological images of human skin, stained with hematoxylin and eosin. Methods: The proposed method performs epidermis segmentation based on the information about shape and distribution of transparent regions in a slide image and information about distribution and concentration of hematoxylin and eosin stains. It utilizes domain-specific knowledge of morphometric and biochemical properties of skin tissue elements to segment the relevant histopathological structures in human skin. Results: Experimental results on 88 skin histopathological images from three different sources show that the proposed method segments the epidermis with a mean sensitivity of 87 %, a mean specificity of 95% and a mean precision of 57%. It is robust to inter- and intra-image variations in both staining and illumination, and makes no assumptions about the type of skin disorder. The proposed method provides a superior performance compared to the existing techniques.

  11. Permeation of chromium salts through human skin in vitro

    DEFF Research Database (Denmark)

    Gammelgaard, Bente; Fullerton, A; Avnstorp, C

    1992-01-01

    Chromium permeation studies were performed on full thickness human skin in diffusion cells. All samples were analysed for the total chromium content by graphite furnace Zeeman-corrected atomic absorption spectrometry. Some samples were analysed by an ion chromatographic method permitting...... the simultaneous determination of Cr(VI) and Cr(III) as well. The amounts of chromium found in all skin layers were significantly higher when potassium dichromate was applied to the skin compared with chromium chloride or chromium nitrate. Chromium could only be detected in the recipient phase after application...... of the dichromate solution. Chromium skin levels increased with increasing concentrations of applied chromium salts up to 0.034 M Cr. The amount of chromium in recipient phase and skin layers increased with increasing pH when the applied solution contained potassium dichromate. This was ascribed to a decreased skin...

  12. Neurogenic inflammation in human and rodent skin

    DEFF Research Database (Denmark)

    Schmelz, M; Petersen, Lars Jelstrup

    2001-01-01

    The combination of vasodilation and protein extravasation following activation of nociceptors has been termed "neurogenic inflammation." In contrast to rodents, no neurogenic protein extravasation can be elicited in healthy human skin. Dermal microdialysis has considerably increased our knowledge...... about neurogenic inflammation in human skin, including the involvement of mast cells.......The combination of vasodilation and protein extravasation following activation of nociceptors has been termed "neurogenic inflammation." In contrast to rodents, no neurogenic protein extravasation can be elicited in healthy human skin. Dermal microdialysis has considerably increased our knowledge...

  13. Characterization of SLC transporters in human skin

    Directory of Open Access Journals (Sweden)

    Marion Alriquet

    2015-03-01

    Full Text Available Most identified drug transporters belong to the ATP-binding Cassette (ABC and Solute Carrier (SLC families. Recent research indicates that some of these transporters play an important role in the absorption, distribution and excretion of drugs, and are involved in clinically relevant drug-drug interactions for systemic drugs. However, very little is known about the role of drug transporters in human skin in the disposition of topically applied drugs and their involvement in drug-drug interactions. The aim of this work was to compare the expression in human skin (vs human hepatocytes and kidney of SLC transporters included in the EMA guidance as the most likely clinical sources of drug interactions. The expression of SLC transporters in human tissues was analyzed by quantitative RT-PCR. Modulation of SLC47A1 and SLC47A2 (MATE1 and MATE2 expression was analyzed after treatment of human skin in organ-culture with rifampicin and UV irradiation. The expression of SLCO2B1 (OATPB, SLCO3A1 (OATPD, SLCO4A1 (OATPE, SLC47A1 and SLC47A2 (MATE1 and MATE2 was detected in human skin, OATPE and MATE1 being the most expressed. OATPE is about 70 times more expressed in human skin than in human hepatocytes. Moreover, the expression of SLC47A1 and SLC47A2 was down-regulated after treatment with rifampicin or after exposure to UV light. The present findings demonstrate that SLCO4A1 (OATPE and SLC47A1 (MATE1 are highly expressed in human skin and suggest the involvement of SLC transporters in the disposition of topically applied drugs.

  14. Three-Dimensional In Vitro Skin and Skin Cancer Models Based on Human Fibroblast-Derived Matrix.

    Science.gov (United States)

    Berning, Manuel; Prätzel-Wunder, Silke; Bickenbach, Jackie R; Boukamp, Petra

    2015-09-01

    Three-dimensional in vitro skin and skin cancer models help to dissect epidermal-dermal and tumor-stroma interactions. In the model presented here, normal human dermal fibroblasts isolated from adult skin self-assembled into dermal equivalents with their specific fibroblast-derived matrix (fdmDE) over 4 weeks. The fdmDE represented a complex human extracellular matrix that was stabilized by its own heterogeneous collagen fiber meshwork, largely resembling a human dermal in vivo architecture. Complemented with normal human epidermal keratinocytes, the skin equivalent (fdmSE) thereof favored the establishment of a well-stratified and differentiated epidermis and importantly allowed epidermal regeneration in vitro for at least 24 weeks. Moreover, the fdmDE could be used to study the features of cutaneous skin cancer. Complementing fdmDE with HaCaT cells in different stages of malignancy or tumor-derived cutaneous squamous cell carcinoma cell lines, the resulting skin cancer equivalents (fdmSCEs) recapitulated the respective degree of tumorigenicity. In addition, the fdmSCE invasion phenotypes correlated with their individual degree of tissue organization, disturbance in basement membrane organization, and presence of matrix metalloproteinases. Together, fdmDE-based models are well suited for long-term regeneration of normal human epidermis and, as they recapitulate tumor-specific growth, differentiation, and invasion profiles of cutaneous skin cancer cells, also provide an excellent human in vitro skin cancer model.

  15. The isolated perfused human skin flap model: A missing link in skin penetration studies?

    Science.gov (United States)

    Ternullo, Selenia; de Weerd, Louis; Flaten, Gøril Eide; Holsæter, Ann Mari; Škalko-Basnet, Nataša

    2017-01-01

    Development of effective (trans)dermal drug delivery systems requires reliable skin models to evaluate skin drug penetration. The isolated perfused human skin flap remains metabolically active tissue for up to 6h during in vitro perfusion. We introduce the isolated perfused human skin flap as a close-to-in vivo skin penetration model. To validate the model's ability to evaluate skin drug penetration the solutions of a hydrophilic (calcein) and a lipophilic (rhodamine) fluorescence marker were applied. The skin flaps were perfused with modified Krebs-Henseleit buffer (pH7.4). Infrared technology was used to monitor perfusion and to select a well-perfused skin area for administration of the markers. Flap perfusion and physiological parameters were maintained constant during the 6h experiments and the amount of markers in the perfusate was determined. Calcein was detected in the perfusate, whereas rhodamine was not detectable. Confocal images of skin cross-sections shoved that calcein was uniformly distributed through the skin, whereas rhodamine accumulated in the stratum corneum. For comparison, the penetration of both markers was evaluated on ex vivo human skin, pig skin and cellophane membrane. The proposed perfused flap model enabled us to distinguish between the penetrations of the two markers and could be a promising close-to-in vivo tool in skin penetration studies and optimization of formulations destined for skin administration. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Confocal laser scanning microscopy to estimate nanoparticles’ human skin penetration in vitro

    Science.gov (United States)

    Elmahdy, Akram; Cao, Yachao; Hui, Xiaoying; Maibach, Howard

    2017-01-01

    Objective With rapid development of nanotechnology, there is increasing interest in nanoparticle (NP) application and its safety and efficacy on human skin. In this study, we utilized confocal laser scanning microscopy to estimate NP skin penetration. Methods Three different-sized polystyrene NPs marked with red fluorescence were applied to human skin, and Calcium Green 5N was used as a counterstain. Dimethyl sulfoxide (DMSO) and ethanol were used as alternative vehicles for NPs. Tape stripping was utilized as a barrier-damaged skin model. Skin biopsies dosed with NPs were incubated at 4°C or 37°C for 24 hours and imaged using confocal laser scanning microscopy. Results NPs were localized in the stratum corneum (SC) and hair follicles without penetrating the epidermis/dermis. Barrier alteration with tape stripping and change in incubation temperature did not induce deeper penetration. DMSO enhanced NP SC penetration but ethanol did not. Conclusion Except with DMSO vehicle, these hydrolyzed polystyrene NPs did not penetrate intact or barrier-damaged human “viable” epidermis. For further clinical relevance, in vivo human skin studies and more sensitive analytic chemical methodology are suggested. PMID:29184403

  17. Quantitative Sasang Constitution Diagnosis Method for Distinguishing between Tae-eumin and Soeumin Types Based on Elasticity Measurements of the Skin of the Human Hand.

    Science.gov (United States)

    Song, Han Wook; Lee, Sungjun; Park, Yon Kyu; Woo, Sam Yong

    2009-09-01

    The usefulness of constitutional diagnoses based on skin measurements has been established in oriental medicine. However, it is very difficult to standardize traditional diagnosis methods. According to Sasang constitutional medicine, humans can be distinguished based on properties of the skin, including its texture, roughness, hardness and elasticity. The elasticity of the skin was previously used to distinguish between people with Tae-eumin (TE) and Soeumin (SE) constitutions. The present study designed a system that uses a compression method to measure the elasticity of hand skin and evaluated its measurement repeatability. The proposed system was used to compare the skin elasticity between SE and TE subjects, which produced a measurement repeatability error of <3%. The proposed system is suitable for use as a quantitative constitution diagnosis method for distinguishing between TE and SE subjects with an acceptable level of uncertainty.

  18. The skin immune system (SIS): distribution and immunophenotype of lymphocyte subpopulations in normal human skin

    NARCIS (Netherlands)

    Bos, J. D.; Zonneveld, I.; Das, P. K.; Krieg, S. R.; van der Loos, C. M.; Kapsenberg, M. L.

    1987-01-01

    The complexity of immune response-associated cells present in normal human skin was recently redefined as the skin immune system (SIS). In the present study, the exact immunophenotypes of lymphocyte subpopulations with their localizations in normal human skin were determined quantitatively. B cells

  19. Measurement of interstitial cetirizine concentrations in human skin

    DEFF Research Database (Denmark)

    Petersen, Lars Jelstrup; Church, M K; Rihoux, J P

    1999-01-01

    BACKGROUND: The purpose of the present study was to measure the concentrations of cetirizine in the extracellular water compartment in intact human skin and assess simultaneously inhibition of histamine-induced wheal and flare reactions. METHODS: Skin cetirizine levels were collected...... by the microdialysis technique and analyzed by high-pressure liquid chromatography with mass spectrometry detection. Skin levels in 20 subjects were compared to plasma levels for 4 h after a single oral dose of 10 or 20 mg of cetirizine. Skin prick tests were performed with histamine 100 mg/ml. RESULTS: Plasma...... cetirizine levels increased within 30 min to reach peak values of 315+/-10 and 786+/-45 ng/ml 90-120 min after administration of 10 and 20 mg of cetirizine. This was followed by a slow decline. In the skin, dialysate cetirizine levels (non-protein-bound fraction only) peaked at 1.6+/-0.1 and 2.4+/-0.3 ng...

  20. Formation of a protection film on the human skin by microparticles

    International Nuclear Information System (INIS)

    Lademann, J; Schanzer, S; Richter, H; Knorr, F; Sterry, W; Patzelt, A; Antoniou, C

    2008-01-01

    Laser scanning microscopy and tape stripping, in combination with optical methods, were used to analyze the distribution and penetration of a barrier cream into the horny layer (stratum corneum) of the human skin under in vivo conditions. The barrier cream contained microparticles of 10 – 100 μm loaded with antioxidant substances. The cream was designed for protection of the skin surface against the destructive action of free radicals, produced by systemically applied chemotherapeutic agents reaching the skin surface via the sweat. Both methods were able to demonstrate that the barrier cream was distributed homogeneously on the skin surface forming a protection film. A penetration into deeper parts of the stratum corneum (SC) was not observed

  1. A new method for skin color enhancement

    Science.gov (United States)

    Zeng, Huanzhao; Luo, Ronnier

    2012-01-01

    Skin tone is the most important color category in memory colors. Reproducing it pleasingly is an important factor in photographic color reproduction. Moving skin colors toward their preferred skin color center improves the skin color preference on photographic color reproduction. Two key factors to successfully enhance skin colors are: a method to detect original skin colors effectively even if they are shifted far away from the regular skin color region, and a method to morph skin colors toward a preferred skin color region properly without introducing artifacts. A method for skin color enhancement presented by the authors in the same conference last year applies a static skin color model for skin color detection, which may miss to detect skin colors that are far away from regular skin tones. In this paper, a new method using the combination of face detection and statistical skin color modeling is proposed to effectively detect skin pixels and to enhance skin colors more effectively.

  2. Screening Test for Shed Skin Cells by Measuring the Ratio of Human DNA to Staphylococcus epidermidis DNA.

    Science.gov (United States)

    Nakanishi, Hiroaki; Ohmori, Takeshi; Hara, Masaaki; Takahashi, Shirushi; Kurosu, Akira; Takada, Aya; Saito, Kazuyuki

    2016-05-01

    A novel screening method for shed skin cells by detecting Staphylococcus epidermidis (S. epidermidis), which is a resident bacterium on skin, was developed. Staphylococcus epidermidis was detected using real-time PCR. Staphylococcus epidermidis was detected in all 20 human skin surface samples. Although not present in blood and urine samples, S. epidermidis was detected in 6 of 20 saliva samples, and 5 of 18 semen samples. The ratio of human DNA to S. epidermidisDNA was significantly smaller in human skin surface samples than in saliva and semen samples in which S. epidermidis was detected. Therefore, although skin cells could not be identified by detecting only S. epidermidis, they could be distinguished by measuring the S. epidermidis to human DNA ratio. This method could be applied to casework touch samples, which suggests that it is useful for screening whether skin cells and human DNA are present on potential evidentiary touch samples. © 2016 American Academy of Forensic Sciences.

  3. Advanced haptic sensor for measuring human skin conditions

    Science.gov (United States)

    Tsuchimi, Daisuke; Okuyama, Takeshi; Tanaka, Mami

    2010-01-01

    This paper is concerned with the development of a tactile sensor using PVDF (Polyvinylidene Fluoride) film as a sensory receptor of the sensor to evaluate softness, smoothness, and stickiness of human skin. Tactile sense is the most important sense in the sensation receptor of the human body along with eyesight, and we can examine skin condition quickly using these sense. But, its subjectivity and ambiguity make it difficult to quantify skin conditions. Therefore, development of measurement device which can evaluate skin conditions easily and objectively is demanded by dermatologists, cosmetic industries, and so on. In this paper, an advanced haptic sensor system that can measure multiple information of skin condition in various parts of human body is developed. The applications of the sensor system to evaluate softness, smoothness, and stickiness of skin are investigated through two experiments.

  4. Quantitative Sasang Constitution Diagnosis Method for Distinguishing between Tae-eumin and Soeumin Types Based on Elasticity Measurements of the Skin of the Human Hand

    OpenAIRE

    Song, Han Wook; Lee, SungJun; Park, Yon Kyu; Woo, Sam Yong

    2009-01-01

    The usefulness of constitutional diagnoses based on skin measurements has been established in oriental medicine. However, it is very difficult to standardize traditional diagnosis methods. According to Sasang constitutional medicine, humans can be distinguished based on properties of the skin, including its texture, roughness, hardness and elasticity. The elasticity of the skin was previously used to distinguish between people with Tae-eumin (TE) and Soeumin (SE) constitutions. The present st...

  5. Noninvasive imaging of human skin hemodynamics using a digital red-green-blue camera

    Science.gov (United States)

    Nishidate, Izumi; Tanaka, Noriyuki; Kawase, Tatsuya; Maeda, Takaaki; Yuasa, Tomonori; Aizu, Yoshihisa; Yuasa, Tetsuya; Niizeki, Kyuichi

    2011-08-01

    In order to visualize human skin hemodynamics, we investigated a method that is specifically developed for the visualization of concentrations of oxygenated blood, deoxygenated blood, and melanin in skin tissue from digital RGB color images. Images of total blood concentration and oxygen saturation can also be reconstructed from the results of oxygenated and deoxygenated blood. Experiments using tissue-like agar gel phantoms demonstrated the ability of the developed method to quantitatively visualize the transition from an oxygenated blood to a deoxygenated blood in dermis. In vivo imaging of the chromophore concentrations and tissue oxygen saturation in the skin of the human hand are performed for 14 subjects during upper limb occlusion at 50 and 250 mm Hg. The response of the total blood concentration in the skin acquired by this method and forearm volume changes obtained from the conventional strain-gauge plethysmograph were comparable during the upper arm occlusion at pressures of both 50 and 250 mm Hg. The results presented in the present paper indicate the possibility of visualizing the hemodynamics of subsurface skin tissue.

  6. Phasor analysis of multiphoton spectral images distinguishes autofluorescence components of in vivo human skin

    NARCIS (Netherlands)

    Fereidouni, F.; Bader, A.N.; Colonna, A.; Gerritsen, H.C.

    2014-01-01

    Skin contains many autofluorescent components that can be studied using spectral imaging. We employed a spectral phasor method to analyse two photon excited auto-fluorescence and second harmonic generation images of in vivo human skin. This method allows segmentation of images based on spectral

  7. Human skin wetness perception: psychophysical and neurophysiological bases

    Science.gov (United States)

    Filingeri, Davide; Havenith, George

    2015-01-01

    The ability to perceive thermal changes in the surrounding environment is critical for survival. However, sensing temperature is not the only factor among the cutaneous sensations to contribute to thermoregulatory responses in humans. Sensing skin wetness (i.e. hygrosensation) is also critical both for behavioral and autonomic adaptations. Although much has been done to define the biophysical role of skin wetness in contributing to thermal homeostasis, little is known on the neurophysiological mechanisms underpinning the ability to sense skin wetness. Humans are not provided with skin humidity receptors (i.e., hygroreceptors) and psychophysical studies have identified potential sensory cues (i.e. thermal and mechanosensory) which could contribute to sensing wetness. Recently, a neurophysiological model of human wetness sensitivity has been developed. In helping clarifying the peripheral and central neural mechanisms involved in sensing skin wetness, this model has provided evidence for the existence of a specific human hygrosensation strategy, which is underpinned by perceptual learning via sensory experience. Remarkably, this strategy seems to be shared by other hygroreceptor-lacking animals. However, questions remain on whether these sensory mechanisms are underpinned by specific neuromolecular pathways in humans. Although the first study on human wetness perception dates back to more than 100 years, it is surprising that the neurophysiological bases of such an important sensory feature have only recently started to be unveiled. Hence, to provide an overview of the current knowledge on human hygrosensation, along with potential directions for future research, this review will examine the psychophysical and neurophysiological bases of human skin wetness perception. PMID:27227008

  8. In-Vivo Human Skin to Textiles Friction Measurements

    Science.gov (United States)

    Pfarr, Lukas; Zagar, Bernhard

    2017-10-01

    We report on a measurement system to determine highly reliable and accurate friction properties of textiles as needed for example as input to garment simulation software. Our investigations led to a set-up that allows to characterize not just textile to textile but also textile to in-vivo human skin tribological properties and thus to fundamental knowledge about genuine wearer interaction in garments. The method of test conveyed in this paper is measuring concurrently and in a highly time resolved manner the normal force as well as the resulting shear force caused by a friction subject intending to slide out of the static friction regime and into the dynamic regime on a test bench. Deeper analysis of various influences is enabled by extending the simple model following Coulomb's law for rigid body friction to include further essential parameters such as contact force, predominance in the yarn's orientation and also skin hydration. This easy-to-use system enables to measure reliably and reproducibly both static and dynamic friction for a variety of friction partners including human skin with all its variability there might be.

  9. Xenobiotica-metabolizing enzymes in the skin of rat, mouse, pig, guinea pig, man, and in human skin models.

    Science.gov (United States)

    Oesch, F; Fabian, E; Landsiedel, Robert

    2018-06-18

    Studies on the metabolic fate of medical drugs, skin care products, cosmetics and other chemicals intentionally or accidently applied to the human skin have become increasingly important in order to ascertain pharmacological effectiveness and to avoid toxicities. The use of freshly excised human skin for experimental investigations meets with ethical and practical limitations. Hence information on xenobiotic-metabolizing enzymes (XME) in the experimental systems available for pertinent studies compared with native human skin has become crucial. This review collects available information of which-taken with great caution because of the still very limited data-the most salient points are: in the skin of all animal species and skin-derived in vitro systems considered in this review cytochrome P450 (CYP)-dependent monooxygenase activities (largely responsible for initiating xenobiotica metabolism in the organ which provides most of the xenobiotica metabolism of the mammalian organism, the liver) are very low to undetectable. Quite likely other oxidative enzymes [e.g. flavin monooxygenase, COX (cooxidation by prostaglandin synthase)] will turn out to be much more important for the oxidative xenobiotic metabolism in the skin. Moreover, conjugating enzyme activities such as glutathione transferases and glucuronosyltransferases are much higher than the oxidative CYP activities. Since these conjugating enzymes are predominantly detoxifying, the skin appears to be predominantly protected against CYP-generated reactive metabolites. The following recommendations for the use of experimental animal species or human skin in vitro models may tentatively be derived from the information available to date: for dermal absorption and for skin irritation esterase activity is of special importance which in pig skin, some human cell lines and reconstructed skin models appears reasonably close to native human skin. With respect to genotoxicity and sensitization reactive

  10. Expression of telomerase reverse transcriptase in radiation-induced chronic human skin ulcer

    International Nuclear Information System (INIS)

    Zhao Po; Li Zhijun; Lu Yali; Zhong Mei; Gu Qingyang; Wang Dewen

    2001-01-01

    Objective: To investigate the expression of the catalytic subunit of telomerase, telomerase reverse transcriptase (TRT) and the possible relationship between the TRT and cancer transformation or poor healing in radiation-induced chronic ulcer of human skin. Methods: Rabbit antibody against human TRT and SP immunohistochemical method were used to detect TRT expression in 24 cases of formalin-fixed, paraffin-embed human skin chronic ulcer tissues induced by radiation, 5 cases of normal skin, 2 of burned skin, and 8 of carcinoma. Results: The positive rate for TRT was 58.3%(14/24) in chronic radiation ulcers, of which the strongly positive rate was 41.7%(10/24) and the weakly positive 16.7%(4/24), 0% in normal (0/5) and burned skin (0/2), and 100% in carcinoma (8/8). The strongly positive expression of TRT was observed almost always in the cytoplasm and nucleus of squamous epithelial cells of proliferative epidermis but the negative and partly weakly positive expression in the smooth muscles, endothelia of small blood vessels and capillaries, and fibroblasts. Chronic inflammtory cells, plasmacytes and lymphocytes also showed weakly positive for TRT. Conclusion: TRT expression could be involved in the malignant transformation of chronic radiation ulcer into squamous carcinoma, and in the poor healing caused by sclerosis of small blood vessels and lack of granulation tissue consisting of capillaries and fibroblasts

  11. Confocal laser scanning microscopy to estimate nanoparticles’ human skin penetration in vitro

    Directory of Open Access Journals (Sweden)

    Zou Y

    2017-10-01

    Full Text Available Ying Zou,1,2,* Anna Celli,2,3,* Hanjiang Zhu,2,* Akram Elmahdy,2 Yachao Cao,2 Xiaoying Hui,2 Howard Maibach2 1Skin & Cosmetic Research Department, Shanghai Skin Disease Hospital, Shanghai, People’s Republic of China; 2Department of Dermatology, School of Medicine, University of California San Francisco, San Francisco, CA, USA; 3San Francisco Veterans Medical Center, San Francisco, CA, USA *These authors contributed equally to this work Objective: With rapid development of nanotechnology, there is increasing interest in nanoparticle (NP application and its safety and efficacy on human skin. In this study, we utilized confocal laser scanning microscopy to estimate NP skin penetration.Methods: Three different-sized polystyrene NPs marked with red fluorescence were applied to human skin, and Calcium Green 5N was used as a counterstain. Dimethyl sulfoxide (DMSO and ethanol were used as alternative vehicles for NPs. Tape stripping was utilized as a barrier-damaged skin model. Skin biopsies dosed with NPs were incubated at 4°C or 37°C for 24 hours and imaged using confocal laser scanning microscopy.Results: NPs were localized in the stratum corneum (SC and hair follicles without penetrating the epidermis/dermis. Barrier alteration with tape stripping and change in incubation temperature did not induce deeper penetration. DMSO enhanced NP SC penetration but ethanol did not.Conclusion: Except with DMSO vehicle, these hydrolyzed polystyrene NPs did not penetrate intact or barrier-damaged human “viable” epidermis. For further clinical relevance, in vivo human skin studies and more sensitive analytic chemical methodology are suggested. Keywords: nanoparticles, skin penetration, stratum corneum, confocal laser scanning microscopy, tape stripping

  12. Direct 3D cell-printing of human skin with functional transwell system.

    Science.gov (United States)

    Kim, Byoung Soo; Lee, Jung-Seob; Gao, Ge; Cho, Dong-Woo

    2017-06-06

    Three-dimensional (3D) cell-printing has been emerging as a promising technology with which to build up human skin models by enabling rapid and versatile design. Despite the technological advances, challenges remain in the development of fully functional models that recapitulate complexities in the native tissue. Moreover, although several approaches have been explored for the development of biomimetic human skin models, the present skin models based on multistep fabrication methods using polydimethylsiloxane chips and commercial transwell inserts could be tackled by leveraging 3D cell-printing technology. In this paper, we present a new 3D cell-printing strategy for engineering a 3D human skin model with a functional transwell system in a single-step process. A hybrid 3D cell-printing system was developed, allowing for the use of extrusion and inkjet modules at the same time. We began by revealing the significance of each module in engineering human skin models; by using the extrusion-dispensing module, we engineered a collagen-based construct with polycaprolactone (PCL) mesh that prevented the contraction of collagen during tissue maturation; the inkjet-based dispensing module was used to uniformly distribute keratinocytes. Taking these features together, we engineered a human skin model with a functional transwell system; the transwell system and fibroblast-populated dermis were consecutively fabricated by using the extrusion modules. Following this process, keratinocytes were uniformly distributed onto the engineered dermis by the inkjet module. Our transwell system indicates a supportive 3D construct composed of PCL, enabling the maturation of a skin model without the aid of commercial transwell inserts. This skin model revealed favorable biological characteristics that included a stabilized fibroblast-stretched dermis and stratified epidermis layers after 14 days. It was also observed that a 50 times reduction in cost was achieved and 10 times less medium was

  13. Quality system and audit of human skin allografts

    International Nuclear Information System (INIS)

    Van Baare, J.

    1999-01-01

    Allograft skin has long been recognised as an important resource in the management of bum wounds. The important issue in skin banking is fust to guarantee safety of human cadaveric donor skin. Second, the quality of the allografts should be assured. The Euro Skin Bank, established in 1976, is located in The Netherlands. Not only in The Netherlands, but in many other (European) countries no specific regulation exists for tissue banking. With respect to skin banking in The Netherlands the Euro Skin Bank requested the government what regulations should be applied on their activities. It was stated in 1994 that human allografl skin should be regarded as a phan-naceutical drug, a magistral preparation. The Euro Skin Bank should therefore be subjected to the guidelines given for the Good Laboraton, Practices and Good Manufacturing Practices to process allogmft skin. Nevertheless, it was in the opinion of the Euro Skin Bank that regulating human tissue as a pharmaceutical drug was not sufficient e.g. no specific regulations for serologic testing of the tissue donor is given, which should be one of the most important issues in tissue banking. Recently the government has published new legislation for tissue banks in The Netherlands: on July I st, 1998, a new legislation was enforced concerning organ and tissue donation and on November I st, 1998, quality requirements for organ and tissue banks are published. The European Community discussed the possibility to bring all animal and human tissues under the Medical Device Directive (MDD). Soon it was proposed not to incorporate viable hw-nan tissue into the MDD. Last year all human tissue was excluded from the MDD. Lack of European regulations has been resulted in national laws, e.g. in The Netherlands, Germany and France. Possibly there might be a more significant role for the European Association of Tissue Banks in the near future for European legislation on tissue banking. In order to have a standard quality system wmch is

  14. Utilization of reconstructed cultured human skin models as an alternative skin for permeation studies of chemical compounds

    OpenAIRE

    Kano, Satoshi; 藤堂, 浩明; 杉江, 謙一; 藤本, 英哲; 中田, 圭一; 徳留, 嘉寛; 橋本, フミ惠; 杉林, 堅次

    2010-01-01

    Two reconstructed human skin models, EpiskinSM and EpiDermTM, have been approved as alternative membranes for skin corrosive/irritation experiments due to their close correlation with animal skin. Such reconstructed human skin models were evaluated as alternative membranes for skin permeation experiments. Seven drugs with different lipophilicities and almost the same molecular weight were used as test penetrants. Relationships were investigated between permeability coefficients (P values) of ...

  15. [The clinical use of cryopreserved human skin allografts for transplantation].

    Science.gov (United States)

    Martínez-Flores, Francisco; Chacón-Gómez, María; Madinaveitia-Villanueva, Juan Antonio; Barrera-Lopez, Araceli; Aguirre-Cruz, Lucinda; Querevalu-Murillo, Walter

    2015-01-01

    The biological recovery of human skin allografts is the gold standard for preservation in Skin Banks. However, there is no worldwide consensus about specific allocation criteria for preserved human skin allografts with living cells. A report is presented on the results of 5 years of experience of using human skin allografts in burned patient in the Skin and Tissue Bank at the "Instituto Nacional de Rehabilitacion" The human skin allografts were obtained from multi-organ donors. processed and preserved at -80 °C for 12 months. Allocation criteria were performed according to blood type match, clinical history, and burned body surface. Up to now, the Skin and Tissue Bank at 'Instituto Nacional de Rehabilitacion" has processed and recovered 125,000 cm(2) of human skin allografts. It has performed 34 surgical implants on 21 burned patients. The average of burn body surface was 59.2%. More than two-thirds (67.7%) of recipients of skin allografts were matched of the same to type blood of the donor, and 66.6% survived after 126 days hospital stay. It is proposed to consider recipient's blood group as allocation criteria to assign tissue; and use human skin allografts on patiens affected with burns over 30% of body surface (according the "rule of the 9"). Copyright © 2015 Academia Mexicana de Cirugía A.C. Published by Masson Doyma México S.A. All rights reserved.

  16. Evaluation of a Silicone Membrane as an Alternative to Human Skin for Determining Skin Permeation Parameters of Chemical Compounds.

    Science.gov (United States)

    Uchida, Takashi; Yakumaru, Masafumi; Nishioka, Keisuke; Higashi, Yoshihiro; Sano, Tomohiko; Todo, Hiroaki; Sugibayashi, Kenji

    2016-01-01

    We evaluated the effectiveness of a silicone membrane as an alternative to human skin using the skin permeation parameters of chemical compounds. An in vitro permeation study using 15 model compounds was conducted, and permeation parameters comprising permeability coefficient (P), diffusion parameter (DL(-2)), and partition parameter (KL) were calculated from each permeation profile. Significant correlations were obtained in log P, log DL(-2), and log KL values between the silicone membrane and human skin. DL(-2) values of model compounds, except flurbiprofen, in the silicone membrane were independent of the lipophilicity of the model compounds and were 100-fold higher than those in human skin. For antipyrine and caffeine, which are hydrophilic, KL values in the silicone membrane were 100-fold lower than those in human skin, and P values, calculated as the product of a DL(-2) and KL, were similar. For lipophilic compounds, such as n-butyl paraben and flurbiprofen, KL values for silicone were similar to or 10-fold higher than those in human skin, and P values for silicone were 100-fold higher than those in human skin. Furthermore, for amphiphilic compounds with log Ko/w values from 0.5 to 3.5, KL values in the silicone membrane were 10-fold lower than those in human skin, and P values for silicone were 10-fold higher than those in human skin. The silicone membrane was useful as a human skin alternative in an in vitro skin permeation study. However, depending on the lipophilicity of the model compounds, some parameters may be over- or underestimated.

  17. Simulation study of melanoma detection in human skin tissues by laser-generated surface acoustic waves.

    Science.gov (United States)

    Chen, Kun; Fu, Xing; Dorantes-Gonzalez, Dante J; Lu, Zimo; Li, Tingting; Li, Yanning; Wu, Sen; Hu, Xiaotang

    2014-01-01

    Air pollution has been correlated to an increasing number of cases of human skin diseases in recent years. However, the investigation of human skin tissues has received only limited attention, to the point that there are not yet satisfactory modern detection technologies to accurately, noninvasively, and rapidly diagnose human skin at epidermis and dermis levels. In order to detect and analyze severe skin diseases such as melanoma, a finite element method (FEM) simulation study of the application of the laser-generated surface acoustic wave (LSAW) technique is developed. A three-layer human skin model is built, where LSAW’s are generated and propagated, and their effects in the skin medium with melanoma are analyzed. Frequency domain analysis is used as a main tool to investigate such issues as minimum detectable size of melanoma, filtering spectra from noise and from computational irregularities, as well as on how the FEM model meshing size and computational capabilities influence the accuracy of the results. Based on the aforementioned aspects, the analysis of the signals under the scrutiny of the phase velocity dispersion curve is verified to be a reliable, a sensitive, and a promising approach for detecting and characterizing melanoma in human skin.

  18. Simulation study of melanoma detection in human skin tissues by laser-generated surface acoustic waves

    Science.gov (United States)

    Chen, Kun; Fu, Xing; Dorantes-Gonzalez, Dante J.; Lu, Zimo; Li, Tingting; Li, Yanning; Wu, Sen; Hu, Xiaotang

    2014-07-01

    Air pollution has been correlated to an increasing number of cases of human skin diseases in recent years. However, the investigation of human skin tissues has received only limited attention, to the point that there are not yet satisfactory modern detection technologies to accurately, noninvasively, and rapidly diagnose human skin at epidermis and dermis levels. In order to detect and analyze severe skin diseases such as melanoma, a finite element method (FEM) simulation study of the application of the laser-generated surface acoustic wave (LSAW) technique is developed. A three-layer human skin model is built, where LSAW's are generated and propagated, and their effects in the skin medium with melanoma are analyzed. Frequency domain analysis is used as a main tool to investigate such issues as minimum detectable size of melanoma, filtering spectra from noise and from computational irregularities, as well as on how the FEM model meshing size and computational capabilities influence the accuracy of the results. Based on the aforementioned aspects, the analysis of the signals under the scrutiny of the phase velocity dispersion curve is verified to be a reliable, a sensitive, and a promising approach for detecting and characterizing melanoma in human skin.

  19. Assessment of organ culture for the conservation of human skin allografts.

    Science.gov (United States)

    Hautier, A; Sabatier, F; Stellmann, P; Andrac, L; Nouaille De Gorce, Y; Dignat-George, F; Magalon, G

    2008-03-01

    Human skin allografts are used in the treatment of severe burns and their preservation is therefore critical for optimal clinical benefit. Current preservation methods, such as 4 degrees C storage or cryopreservation, cannot prevent the decrease of tissue viability. The aim of this study was to assess viability and function of skin allografts in a new skin organ culture model, allowing conservation parameters as close as possible to physiological conditions: 32 degrees C, air-liquid interface and physiological skin tension. Twelve skin samples, harvested from 6 living surgical donors, were conserved 35 days in two conditions: conservation at 4 degrees C and organ culture. Viability and function of skin samples were investigated at Day 0, 7, 14, 21, 28 and 35 using cell culture methods (trypan blue exclusion, Colony Forming Efficiency and Growth Rate), histopathological and histoenzymological studies (Ki67 immunostaining). In the two conditions, fibroblast and keratinocyte viability was progressively affected by storage, with a significant decrease observed after 35 days. No statistical difference could be observed between the two conditions. The two methods were also comparable regarding alterations of fibroblast and keratinocyte culture parameters, which were respectively significantly reduced at Day 7 and 21, compared to fresh skin. By contrast, histopathological and histoenzymological studies revealed a better preservation of skin architecture and proliferative potential at 4 degrees C, as compared to organ culture. These results indicate that skin organ culture does not provide significant advantages for skin allograft preservation. However, its potential use as an experimental model to study skin physiology and wound healing should be further evaluated.

  20. Skin and the non-human human

    DEFF Research Database (Denmark)

    Rösing, Lilian Munk

    2013-01-01

    The article puts forward an aesthetic and psychoanalytic analysis of Titian's painting, The Flaying of Marsyas, arguing that the painting is a reflection on the human subject as a being constituted by skin and by a core of non-humanity. The analysis is partly an answer to Melanie Hart's (2007) ar...... of the 'Muselmann', and Anton Ehrenzweig's psychoanalytic theory of artistic creation. Whereas Hart is focusing on form and colour, I also turn my attention towards the texture of the painting....

  1. In vitro dermal absorption of pyrethroid pesticides in human and rat skin

    International Nuclear Information System (INIS)

    Hughes, Michael F.; Edwards, Brenda C.

    2010-01-01

    Dermal exposure to pyrethroid pesticides can occur during manufacture and application. This study examined the in vitro dermal absorption of pyrethroids using rat and human skin. Dermatomed skin from adult male Long Evans rats or human cadavers was mounted in flow-through diffusion cells, and radiolabeled bifenthrin, deltamethrin or cis-permethrin was applied in acetone to the skin. Fractions of receptor fluid were collected every 4 h. At 24 h, the skins were washed with soap and water to remove unabsorbed chemical. The skin was then solubilized. Two additional experiments were performed after washing the skin; the first was tape-stripping the skin and the second was the collection of receptor fluid for an additional 24 h. Receptor fluid, skin washes, tape strips and skin were analyzed for radioactivity. For rat skin, the wash removed 53-71% of the dose and 26-43% remained in the skin. The cumulative percentage of the dose at 24 h in the receptor fluid ranged from 1 to 5%. For human skin, the wash removed 71-83% of the dose and 14-25% remained in the skin. The cumulative percentage of the dose at 24 h in the receptor fluid was 1-2%. Tape-stripping removed 50-56% and 79-95% of the dose in rat and human skin, respectively, after the wash. From 24-48 h, 1-3% and about 1% of the dose diffused into the receptor fluid of rat and human skin, respectively. The pyrethroids bifenthrin, deltamethrin and cis-permethrin penetrated rat and human skin following dermal application in vitro. However, a skin wash removed 50% or more of the dose from rat and human skin. Rat skin was more permeable to the pyrethroids than human skin. Of the dose in skin, 50% or more was removed by tape-stripping, suggesting that permeation of pyrethroids into viable tissue could be impeded. The percentage of the dose absorbed into the receptor fluid was considerably less than the dose in rat and human skin. Therefore, consideration of the skin type used and fractions analyzed are important when using

  2. Development of human skin equivalents mimicking skin aging : contrast between papillary and reticular fibroblasts as a lead

    NARCIS (Netherlands)

    Janson, D.

    2017-01-01

    This thesis describes the development of human skin equivalents that show characteristics of skin aging. The type of skin equivalent used was a fibroblast derived matrix equivalent, in which the dermal compartment is generated by fibroblasts and thus is fully of human origin. Two strategies are

  3. First genomic survey of human skin fungal diversity

    Science.gov (United States)

    Fungal infections of the skin affect 29 million people in the United States. In the first study of human fungal skin diversity, National Institutes of Health researchers sequenced the DNA of fungi that thrive at different skin sites of healthy adults to d

  4. Non-animal methods to predict skin sensitization (I): the Cosmetics Europe database.

    Science.gov (United States)

    Hoffmann, Sebastian; Kleinstreuer, Nicole; Alépée, Nathalie; Allen, David; Api, Anne Marie; Ashikaga, Takao; Clouet, Elodie; Cluzel, Magalie; Desprez, Bertrand; Gellatly, Nichola; Goebel, Carsten; Kern, Petra S; Klaric, Martina; Kühnl, Jochen; Lalko, Jon F; Martinozzi-Teissier, Silvia; Mewes, Karsten; Miyazawa, Masaaki; Parakhia, Rahul; van Vliet, Erwin; Zang, Qingda; Petersohn, Dirk

    2018-05-01

    Cosmetics Europe, the European Trade Association for the cosmetics and personal care industry, is conducting a multi-phase program to develop regulatory accepted, animal-free testing strategies enabling the cosmetics industry to conduct safety assessments. Based on a systematic evaluation of test methods for skin sensitization, five non-animal test methods (DPRA (Direct Peptide Reactivity Assay), KeratinoSens TM , h-CLAT (human cell line activation test), U-SENS TM , SENS-IS) were selected for inclusion in a comprehensive database of 128 substances. Existing data were compiled and completed with newly generated data, the latter amounting to one-third of all data. The database was complemented with human and local lymph node assay (LLNA) reference data, physicochemical properties and use categories, and thoroughly curated. Focused on the availability of human data, the substance selection resulted nevertheless resulted in a high diversity of chemistries in terms of physico-chemical property ranges and use categories. Predictivities of skin sensitization potential and potency, where applicable, were calculated for the LLNA as compared to human data and for the individual test methods compared to both human and LLNA reference data. In addition, various aspects of applicability of the test methods were analyzed. Due to its high level of curation, comprehensiveness, and completeness, we propose our database as a point of reference for the evaluation and development of testing strategies, as done for example in the associated work of Kleinstreuer et al. We encourage the community to use it to meet the challenge of conducting skin sensitization safety assessment without generating new animal data.

  5. Relating friction on the human skin to the hydration and temperature of the skin

    NARCIS (Netherlands)

    Veijgen, N.K.; Masen, Marc Arthur; van der Heide, Emile

    2013-01-01

    The human skin is constantly in interaction with materials and products. Therefore, skin friction is relevant to all people. In the literature, the frictional properties of the skin have been linked to a large variety of variables, like age, gender and hydration. The present study compares the data

  6. Quantitative relationship between the local lymph node assay and human skin sensitization assays.

    Science.gov (United States)

    Schneider, K; Akkan, Z

    2004-06-01

    The local lymph node assay (LLNA) is a new test method which allows for the quantitative assessment of sensitizing potency in the mouse. Here, we investigate the quantitative correlation between results from the LLNA and two human sensitization tests--specifically, human repeat insult patch tests (HRIPTs) and human maximization tests (HMTs). Data for 57 substances were evaluated, of which 46 showed skin sensitizing properties in human tests, whereas 11 yielded negative results in humans. For better comparability data from mouse and human tests were transformed to applied doses per skin area, which ranged over four orders of magnitude for the substances considered. Regression analysis for the 46 human sensitizing substances revealed a significant positive correlation between the LLNA and human tests. The correlation was better between LLNA and HRIPT data (n=23; r=0.77) than between LLNA and HMT data (n=38; r=0.65). The observed scattering of data points is related to various uncertainties, in part associated with insufficiencies of data from older HMT studies. Predominantly negative results in the LLNA for another 11 substances which showed no skin sensitizing activity in human maximization tests further corroborate the correspondence between LLNA and human tests. Based on this analysis, the LLNA can be considered a reliable basis for relative potency assessments for skin sensitizers. Proposals are made for the regulatory exploitation of the LLNA: four potency groups can be established, and assignment of substances to these groups according to the outcome of the LLNA can be used to characterize skin sensitizing potency in substance-specific assessments. Moreover, based on these potency groups, a more adequate consideration of sensitizing substances in preparations becomes possible. It is proposed to replace the current single concentration limit for skin sensitizers in preparations, which leads to an all or nothing classification of a preparation as sensitizing to

  7. Technical note: comparing von Luschan skin color tiles and modern spectrophotometry for measuring human skin pigmentation.

    Science.gov (United States)

    Swiatoniowski, Anna K; Quillen, Ellen E; Shriver, Mark D; Jablonski, Nina G

    2013-06-01

    Prior to the introduction of reflectance spectrophotometry into anthropological field research during the 1950s, human skin color was most commonly classified by visual skin color matching using the von Luschan tiles, a set of 36 standardized, opaque glass tiles arranged in a chromatic scale. Our goal was to establish a conversion formula between the tile-based color matching method and modern reflectance spectrophotometry to make historical and contemporary data comparable. Skin pigmentation measurements were taken on the forehead, inner upper arms, and backs of the hands using both the tiles and a spectrophotometer on 246 participants showing a broad range of skin pigmentation. From these data, a second-order polynomial conversion formula was derived by jackknife analysis to estimate melanin index (M-index) based on tile values. This conversion formula provides a means for comparing modern data to von Luschan tile measurements recorded in historical reports. This is particularly important for populations now extinct, extirpated, or admixed for which tile-based measures of skin pigmentation are the only data available. Copyright © 2013 Wiley Periodicals, Inc.

  8. Comparison of microRNA expression using different preservation methods of matched psoriatic skin samples

    DEFF Research Database (Denmark)

    Løvendorf, Marianne B; Zibert, John R; Hagedorn, Peter H

    2012-01-01

    MicroRNAs are non-coding RNA molecules modulating gene expression post-transcriptionally. Formalin-fixed, paraffin-embedding (FFPE) is a standard preservation method often used in clinical practices, but induces RNA degradation. Extracting high-quality RNA from human skin can be challenging as skin...

  9. Vasomotion in human skin before and after local heating recorded with laser Doppler flowmetry. A method for induction of vasomotion

    DEFF Research Database (Denmark)

    Kastrup, J; Bülow, J; Lassen, N A

    1989-01-01

    neurogenic origin. A method for induction of regular amplified alpha-oscillations was discovered and evaluated. When heating the skin locally to 42 degrees C the blood cell flux increased and the pre-heating alpha- and beta-oscillations disappeared. During the post-heating period, amplified regular rhythmic......Rhythmical variations in blood cell flux in human skin have been studied using laser Doppler flowmetry. The fluctuations in blood cell flux could be divided into two different categories named alpha- and beta-oscillations with a median frequency of 6.8 min-1 and 1.5 min-1, respectively...... alpha-oscillations appeared. At the end of the post-heating period beta-oscillations re-appeared....

  10. Surface topography and contact mechanics of dry and wet human skin

    Directory of Open Access Journals (Sweden)

    Alexander E. Kovalev

    2014-08-01

    Full Text Available The surface topography of the human wrist skin is studied by using optical and atomic force microscopy (AFM methods. By using these techniques the surface roughness power spectrum is obtained. The Persson contact mechanics theory is used to calculate the contact area for different magnifications, for the dry and wet skin. The measured friction coefficient between a glass ball and dry and wet skin can be explained assuming that a frictional shear stress σf ≈ 13 MPa and σf ≈ 5 MPa, respectively, act in the area of real contact during sliding. These frictional shear stresses are typical for sliding on surfaces of elastic bodies. The big increase in friction, which has been observed for glass sliding on wet skin as the skin dries up, can be explained as result of the increase in the contact area arising from the attraction of capillary bridges. Finally, we demonstrated that the real contact area can be properly defined only when a combination of both AFM and optical methods is used for power spectrum calculation.

  11. A novel method for visualising and quantifying through-plane skin layer deformations.

    Science.gov (United States)

    Gerhardt, L-C; Schmidt, J; Sanz-Herrera, J A; Baaijens, F P T; Ansari, T; Peters, G W M; Oomens, C W J

    2012-10-01

    Skin is a multilayer composite and exhibits highly non-linear, viscoelastic, anisotropic material properties. In many consumer product and medical applications (e.g. during shaving, needle insertion, patient re-positioning), large tissue displacements and deformations are involved; consequently large local strains in the skin tissue can occur. Here, we present a novel imaging-based method to study skin deformations and the mechanics of interacting skin layers of full-thickness skin. Shear experiments and real-time video recording were combined with digital image correlation and strain field analysis to visualise and quantify skin layer deformations during dynamic mechanical testing. A global shear strain of 10% was applied to airbrush-patterned porcine skin (thickness: 1.2-1.6mm) using a rotational rheometer. The recordings were analysed with ARAMIS image correlation software, and local skin displacement, strain and stiffness profiles through the skin layers determined. The results of this pilot study revealed inhomogeneous skin deformation, characterised by a gradual transition from a low (2.0-5.0%; epidermis) to high (10-22%; dermis) shear strain regime. Shear moduli ranged from 20 to 130kPa. The herein presented method will be used for more extended studies on viable human skin, and is considered a valuable foundation for further development of constitutive models which can be used in advanced finite element analyses of skin. Copyright © 2012 Elsevier Ltd. All rights reserved.

  12. Determination of the optical properties of melanin-pigmented human skin equivalents using terahertz time-domain spectroscopy

    Science.gov (United States)

    Lipscomb, Dawn; Echchgadda, Ibtissam; Peralta, Xomalin G.; Wilmink, Gerald J.

    2013-02-01

    Terahertz time-domain spectroscopy (THz-TDS) methods have been utilized in previous studies in order to characterize the optical properties of skin and its primary constituents (i.e., water, collagen, and keratin). However, similar experiments have not yet been performed to investigate whether melanocytes and the melanin pigment that they synthesize contribute to skin's optical properties. In this study, we used THz-TDS methods operating in transmission geometry to measure the optical properties of in vitro human skin equivalents with or without normal human melanocytes. Skin equivalents were cultured for three weeks to promote gradual melanogenesis, and THz time domain data were collected at various time intervals. Frequency-domain analysis techniques were performed to determine the index of refraction (n) and absorption coefficient (μa) for each skin sample over the frequency range of 0.1-2.0 THz. We found that for all samples as frequency increased, n decreased exponentially and the μa increased linearly. Additionally, we observed that skin samples with higher levels of melanin exhibited greater n and μa values than the non-pigmented samples. Our results indicate that melanocytes and the degree of melanin pigmentation contribute in an appreciable manner to the skin's optical properties. Future studies will be performed to examine whether these contributions are observed in human skin in vivo.

  13. Comparison of different skin preservation methods with gamma irradiation.

    Science.gov (United States)

    Guerrero, Linda; Camacho, Bernardo

    2017-06-01

    Allografts are in constant demand, not only for burn victims, but also for all open wounds as "biological dressings". Tissue quality and security are two of the major concerns of Tissue Banks. There are limited studies published. There has been extensive discussion on the subject of preservation methods for cadaver skin. Most literature available comes from clinical reports. In this research, the authors compared 85% glycerolized non irradiated skin allografts with three glycerolized irradiated skin allografts (using different glycerol concentrations 50%, 70% and 85%). The evaluation of allograft quality was done by measuring physical and biological properties of such prepared human tissue grafts. In the histological structure evaluation changes were minimal and did not alter the skin structure. The clinical function of their behavior as temporal dressings was tested. They proved to have similar capabilities for improving granulating tissue and contributing to wound beds closure (Hickerson et al. (1994) [1]). Copyright © 2017 Elsevier Ltd and ISBI. All rights reserved.

  14. Development of sampling method and chromatographic analysis of volatile organic compounds emitted from human skin.

    Science.gov (United States)

    Grabowska-Polanowska, Beata; Miarka, Przemysław; Skowron, Monika; Sułowicz, Joanna; Wojtyna, Katarzyna; Moskal, Karolina; Śliwka, Ireneusz

    2017-10-01

    The studies on volatile organic compounds emitted from skin are an interest for chemists, biologists and physicians due to their role in development of different scientific areas, including medical diagnostics, forensic medicine and the perfume design. This paper presents a proposal of two sampling methods applied to skin odor collection: the first one uses a bag of cellulose film, the second one, using cellulose sachets filled with active carbon. Volatile organic compounds were adsorbed on carbon sorbent, removed via thermal desorption and analyzed using gas chromatograph with mass spectrometer. The first sampling method allowed identification of more compounds (52) comparing to the second one (30). Quantitative analyses for acetone, butanal, pentanal and hexanal were done. The skin odor sampling method using a bag of cellulose film, allowed the identification of many more compounds when compared with the method using a sachet filled with active carbon.

  15. Non-invasive in vivo determination of the carotenoids beta-carotene and lycopene concentrations in the human skin using the Raman spectroscopic method

    International Nuclear Information System (INIS)

    Darvin, M E; Gersonde, I; Meinke, M; Sterry, W; Lademann, J

    2005-01-01

    Resonance Raman spectroscopy was used as a fast and non-invasive optical method of measuring the absolute concentrations of beta-carotene and lycopene in living human skin. Beta-carotene and lycopene have different absorption values at 488 and 514.5 nm and, consequently, the Raman lines for beta-carotene and lycopene have different scattering efficiencies at 488 and 514.5 nm excitations. These differences were used for the determination of the concentrations of beta-carotene and lycopene. Using multiline Ar + laser excitation, clearly distinguishable carotenoid Raman spectra can be obtained which are superimposed on a large fluorescence background. The Raman signals are characterized by two prominent Stokes lines at 1160 and 1525 cm -1 , which have nearly identical relative intensities. Both substances were detected simultaneously. The Raman spectra are obtained rapidly, i.e. within about 10 s, and the required laser light exposure level is well within safety standards. The disturbance of the measurements by non-homogeneous skin pigmentation was avoided by using a relatively large measuring area of 35 mm 2 . It was shown that beta-carotene and lycopene distribution in human skin strongly depends upon the skin region studied and drastically changed inter-individually. Skin beta-carotene and lycopene concentrations are lower in smokers than in non-smokers and higher in the vegetarian group

  16. Non-invasive in vivo determination of the carotenoids beta-carotene and lycopene concentrations in the human skin using the Raman spectroscopic method

    Energy Technology Data Exchange (ETDEWEB)

    Darvin, M E [Center of Experimental and Applied Cutaneous Physiology (CCP), Department of Dermatology, Charite University Hospital, Berlin (Germany); Gersonde, I [Institute of Medical Physics and Laser Medicine, Charite University Hospital, Berlin (Germany); Meinke, M [Institute of Medical Physics and Laser Medicine, Charite University Hospital, Berlin (Germany); Sterry, W [Center of Experimental and Applied Cutaneous Physiology (CCP), Department of Dermatology, Charite University Hospital, Berlin (Germany); Lademann, J [Center of Experimental and Applied Cutaneous Physiology (CCP), Department of Dermatology, Charite University Hospital, Berlin (Germany)

    2005-08-07

    Resonance Raman spectroscopy was used as a fast and non-invasive optical method of measuring the absolute concentrations of beta-carotene and lycopene in living human skin. Beta-carotene and lycopene have different absorption values at 488 and 514.5 nm and, consequently, the Raman lines for beta-carotene and lycopene have different scattering efficiencies at 488 and 514.5 nm excitations. These differences were used for the determination of the concentrations of beta-carotene and lycopene. Using multiline Ar{sup +} laser excitation, clearly distinguishable carotenoid Raman spectra can be obtained which are superimposed on a large fluorescence background. The Raman signals are characterized by two prominent Stokes lines at 1160 and 1525 cm{sup -1}, which have nearly identical relative intensities. Both substances were detected simultaneously. The Raman spectra are obtained rapidly, i.e. within about 10 s, and the required laser light exposure level is well within safety standards. The disturbance of the measurements by non-homogeneous skin pigmentation was avoided by using a relatively large measuring area of 35 mm{sup 2}. It was shown that beta-carotene and lycopene distribution in human skin strongly depends upon the skin region studied and drastically changed inter-individually. Skin beta-carotene and lycopene concentrations are lower in smokers than in non-smokers and higher in the vegetarian group.

  17. Exosomes derived from human umbilical cord blood mesenchymal stem cells stimulates rejuvenation of human skin.

    Science.gov (United States)

    Kim, Yoon-Jin; Yoo, Sae Mi; Park, Hwan Hee; Lim, Hye Jin; Kim, Yu-Lee; Lee, Seunghee; Seo, Kwang-Won; Kang, Kyung-Sun

    2017-11-18

    Human umbilical cord blood-derived mesenchymal stem cells (UCB-MSCs) play an important role in cutaneous wound healing, and recent studies suggested that MSC-derived exosomes activate several signaling pathways, which are conducive in wound healing and cell growth. In this study, we investigated the roles of exosomes that are derived from USC-CM (USC-CM Exos) in cutaneous collagen synthesis and permeation. We found that USC-CM has various growth factors associated with skin rejuvenation. Our in vitro results showed that USC-CM Exos integrate in Human Dermal Fibroblasts (HDFs) and consequently promote cell migration and collagen synthesis of HDFs. Moreover, we evaluated skin permeation of USC-CM Exos by using human skin tissues. Results showed that Exo-Green labeled USC-CM Exos approached the outermost layer of the epidermis after 3 h and gradually approached the epidermis after 18 h. Moreover, increased expressions of Collagen I and Elastin were found after 3 days of treatment on human skin. The results showed that USC-CM Exos is absorbed into human skin, it promotes Collagen I and Elastin synthesis in the skin, which are essential to skin rejuvenation and shows the potential of USC-CM integration with the cosmetics or therapeutics. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Use of Clotted Human Plasma and Aprotinin in Skin Tissue Engineering: A Novel Approach to Engineering Composite Skin on a Porous Scaffold.

    Science.gov (United States)

    Paul, Michelle; Kaur, Pritinder; Herson, Marisa; Cheshire, Perdita; Cleland, Heather; Akbarzadeh, Shiva

    2015-10-01

    Tissue-engineered composite skin is a promising therapy for the treatment of chronic and acute wounds, including burns. Providing the wound bed with a dermal scaffold populated by autologous dermal and epidermal cellular components can further entice host cell infiltration and vascularization to achieve permanent wound closure in a single stage. However, the high porosity and the lack of a supportive basement membrane in most commercially available dermal scaffolds hinders organized keratinocyte proliferation and stratification in vitro and may delay re-epithelization in vivo. The objective of this study was to develop a method to enable the in vitro production of a human skin equivalent (HSE) that included a porous scaffold and dermal and epidermal cells expanded ex vivo, with the potential to be used for definitive treatment of skin defects in a single procedure. A collagen-glycosaminoglycan dermal scaffold (Integra(®)) was populated with adult fibroblasts. A near-normal skin architecture was achieved by the addition of coagulated human plasma to the fibroblast-populated scaffold before seeding cultured keratinocytes. This resulted in reducing scaffold pore size and improving contact surfaces. Skin architecture and basement membrane formation was further improved by the addition of aprotinin (a serine protease inhibitor) to the culture media to inhibit premature clot digestion. Histological assessment of the novel HSE revealed expression of keratin 14 and keratin 10 similar to native skin, with a multilayered neoepidermis morphologically comparable to human skin. Furthermore, deposition of collagen IV and laminin-511 were detected by immunofluorescence, indicating the formation of a continuous basement membrane at the dermal-epidermal junction. The proposed method was efficient in producing an in vitro near native HSE using the chosen off-the-shelf porous scaffold (Integra). The same principles and promising outcomes should be applicable to other biodegradable

  19. Chemical ecology of interactions between human skin microbiota and mosquitoes

    NARCIS (Netherlands)

    Verhulst, N.O.; Takken, W.; Dicke, M.; Schraa, G.; Smallegange, R.C.

    2010-01-01

    Microbiota on the human skin plays a major role in body odour production. The human microbial and chemical signature displays a qualitative and quantitative correlation. Genes may influence the chemical signature by shaping the composition of the microbiota. Recent studies on human skin microbiota,

  20. Validation of Cyanoacrylate Method for Collection of Stratum Corneum in Human Skin for Lipid Analysis

    DEFF Research Database (Denmark)

    Jungersted, JM; Hellgren, Lars; Drachmann, Tue

    2010-01-01

    Background and Objective: Lipids in the stratum corneum (SC) are of major importance for the skin barrier function. Many different methods have been used for the collection of SC for the analysis of SC lipids. The objective of the present study was to validate the cyanoacrylate method for the col......Background and Objective: Lipids in the stratum corneum (SC) are of major importance for the skin barrier function. Many different methods have been used for the collection of SC for the analysis of SC lipids. The objective of the present study was to validate the cyanoacrylate method...

  1. Next generation human skin constructs as advanced tools for drug development.

    Science.gov (United States)

    Abaci, H E; Guo, Zongyou; Doucet, Yanne; Jacków, Joanna; Christiano, Angela

    2017-11-01

    Many diseases, as well as side effects of drugs, manifest themselves through skin symptoms. Skin is a complex tissue that hosts various specialized cell types and performs many roles including physical barrier, immune and sensory functions. Therefore, modeling skin in vitro presents technical challenges for tissue engineering. Since the first attempts at engineering human epidermis in 1970s, there has been a growing interest in generating full-thickness skin constructs mimicking physiological functions by incorporating various skin components, such as vasculature and melanocytes for pigmentation. Development of biomimetic in vitro human skin models with these physiological functions provides a new tool for drug discovery, disease modeling, regenerative medicine and basic research for skin biology. This goal, however, has long been delayed by the limited availability of different cell types, the challenges in establishing co-culture conditions, and the ability to recapitulate the 3D anatomy of the skin. Recent breakthroughs in induced pluripotent stem cell (iPSC) technology and microfabrication techniques such as 3D-printing have allowed for building more reliable and complex in vitro skin models for pharmaceutical screening. In this review, we focus on the current developments and prevailing challenges in generating skin constructs with vasculature, skin appendages such as hair follicles, pigmentation, immune response, innervation, and hypodermis. Furthermore, we discuss the promising advances that iPSC technology offers in order to generate in vitro models of genetic skin diseases, such as epidermolysis bullosa and psoriasis. We also discuss how future integration of the next generation human skin constructs onto microfluidic platforms along with other tissues could revolutionize the early stages of drug development by creating reliable evaluation of patient-specific effects of pharmaceutical agents. Impact statement Skin is a complex tissue that hosts various

  2. A multivariable model for predicting the frictional behaviour and hydration of the human skin.

    Science.gov (United States)

    Veijgen, N K; van der Heide, E; Masen, M A

    2013-08-01

    The frictional characteristics of skin-object interactions are important when handling objects, in the assessment of perception and comfort of products and materials and in the origins and prevention of skin injuries. In this study, based on statistical methods, a quantitative model is developed that describes the friction behaviour of human skin as a function of the subject characteristics, contact conditions, the properties of the counter material as well as environmental conditions. Although the frictional behaviour of human skin is a multivariable problem, in literature the variables that are associated with skin friction have been studied using univariable methods. In this work, multivariable models for the static and dynamic coefficients of friction as well as for the hydration of the skin are presented. A total of 634 skin-friction measurements were performed using a recently developed tribometer. Using a statistical analysis, previously defined potential influential variables were linked to the static and dynamic coefficient of friction and to the hydration of the skin, resulting in three predictive quantitative models that descibe the friction behaviour and the hydration of human skin respectively. Increased dynamic coefficients of friction were obtained from older subjects, on the index finger, with materials with a higher surface energy at higher room temperatures, whereas lower dynamic coefficients of friction were obtained at lower skin temperatures, on the temple with rougher contact materials. The static coefficient of friction increased with higher skin hydration, increasing age, on the index finger, with materials with a higher surface energy and at higher ambient temperatures. The hydration of the skin was associated with the skin temperature, anatomical location, presence of hair on the skin and the relative air humidity. Predictive models have been derived for the static and dynamic coefficient of friction using a multivariable approach. These

  3. QSAR models of human data can enrich or replace LLNA testing for human skin sensitization

    OpenAIRE

    Alves, Vinicius M.; Capuzzi, Stephen J.; Muratov, Eugene; Braga, Rodolpho C.; Thornton, Thomas; Fourches, Denis; Strickland, Judy; Kleinstreuer, Nicole; Andrade, Carolina H.; Tropsha, Alexander

    2016-01-01

    Skin sensitization is a major environmental and occupational health hazard. Although many chemicals have been evaluated in humans, there have been no efforts to model these data to date. We have compiled, curated, analyzed, and compared the available human and LLNA data. Using these data, we have developed reliable computational models and applied them for virtual screening of chemical libraries to identify putative skin sensitizers. The overall concordance between murine LLNA and human skin ...

  4. Non-animal methods to predict skin sensitization (II): an assessment of defined approaches *.

    Science.gov (United States)

    Kleinstreuer, Nicole C; Hoffmann, Sebastian; Alépée, Nathalie; Allen, David; Ashikaga, Takao; Casey, Warren; Clouet, Elodie; Cluzel, Magalie; Desprez, Bertrand; Gellatly, Nichola; Göbel, Carsten; Kern, Petra S; Klaric, Martina; Kühnl, Jochen; Martinozzi-Teissier, Silvia; Mewes, Karsten; Miyazawa, Masaaki; Strickland, Judy; van Vliet, Erwin; Zang, Qingda; Petersohn, Dirk

    2018-05-01

    Skin sensitization is a toxicity endpoint of widespread concern, for which the mechanistic understanding and concurrent necessity for non-animal testing approaches have evolved to a critical juncture, with many available options for predicting sensitization without using animals. Cosmetics Europe and the National Toxicology Program Interagency Center for the Evaluation of Alternative Toxicological Methods collaborated to analyze the performance of multiple non-animal data integration approaches for the skin sensitization safety assessment of cosmetics ingredients. The Cosmetics Europe Skin Tolerance Task Force (STTF) collected and generated data on 128 substances in multiple in vitro and in chemico skin sensitization assays selected based on a systematic assessment by the STTF. These assays, together with certain in silico predictions, are key components of various non-animal testing strategies that have been submitted to the Organization for Economic Cooperation and Development as case studies for skin sensitization. Curated murine local lymph node assay (LLNA) and human skin sensitization data were used to evaluate the performance of six defined approaches, comprising eight non-animal testing strategies, for both hazard and potency characterization. Defined approaches examined included consensus methods, artificial neural networks, support vector machine models, Bayesian networks, and decision trees, most of which were reproduced using open source software tools. Multiple non-animal testing strategies incorporating in vitro, in chemico, and in silico inputs demonstrated equivalent or superior performance to the LLNA when compared to both animal and human data for skin sensitization.

  5. The induction and repair of cyclobutane thymidine dimers in human skin

    International Nuclear Information System (INIS)

    Roza, L.; Erasmus Univ., Rotterdam; Vermeulen, W.; Schans, G.P. van der; Lohman, P.H.M.

    1987-01-01

    The most important detrimental effect of ultraviolet radiation (UV) on the living cell, so far known, is the induction of damage in the DNA. The major photoproducts induced in DNA by UV-C (200-280 nm) and UV-B (280-315 nm) are the cyclobutane-type pyrimidine dimers, which have been implicated in UV-induced mutagenesis and carcinogenesis. Dimer lesions in DNA of cells may be repaired in the dark by a multi-enzyme process (excision repair), or via a light dependent enzymatic reaction known as photoreactivation (phr) which is specific for pyrimidine dimers. Although phr has been found to occur in a wide range of organisms, studies on the presence of phr in mammalian cells have yielded conflicting results. To investigate repair of pyrimidine dimers in human skin cells irradiated in vivo, a specific and sensitive detection method was developed based on a monoclonal antibody directed against thymidine dimers. Application together with a fluorescent immunostaining permits the direct detection of thymidine dimers in human skin cells. The method is used in studies aimed at a better understanding of the role of these lesions in the process of carcinogenesis. A report is given on the isolation and characterization of the antibodies, and their application in a study on the induction of pyrimidine dimers in human skin and on photorepair in cultured cells. 10 refs.; 2 figs

  6. EPR detection of free radicals in UV-irradiated skin: mouse versus human

    International Nuclear Information System (INIS)

    Jurkiewicz, B.A.; Buettner, G.R.

    1996-01-01

    Ultraviolet radiation produces free radicals in Skh-1 mouse skin, contributing to photoaging and carcinogenesis. If a mouse model is a general indicator of free radical processes in human skin photobiology, then radical production observed in mouse and human skin should be directly comparative. In this work we show that UV radiation (λ > 300 nm, 14 μW/cm 2 UVB; 3.5 mW/cm 2 UVA) increases the ascorbate free radical (Asc) electron paramagnetic resonance (EPR) signal in both Skh-1 mouse skin (45%) and human facial skin biopsies (340%). Visible light (λ > 400 nm; 0.23 mW/cm 2 UVA) also increased the Ascsignal in human skin samples (45%) but did not increase baseline mouse Asc, indicating that human skin is more susceptible to free radical formation and that a chromophore for visible light may be present. Using EPR spin-trapping techniques, UV radiation produced spin adducts consistent with trapping lipid alkyl radicals in mouse skin (α-[4-pyridyl 1-oxide]-N-tert-butyl nitrone/alkyl radical adduct; a N = 15.56 G and a H 2.70 G) and lipid alkoxyl radicals in human skin (5,5-dimethylpyrroline -1-oxide/alkoxyl radical adduct; a N = 14.54 G and a H = 16.0 G). Topical application of the iron chelator Desferal to human skin significantly decreases these radicals (∼50%), indicating a role for iron in lipid peroxidation. (Author)

  7. The Nrf2-inducers tanshinone I and dihydrotanshinone protect human skin cells and reconstructed human skin against solar simulated UV☆

    Science.gov (United States)

    Tao, Shasha; Justiniano, Rebecca; Zhang, Donna D.; Wondrak, Georg T.

    2013-01-01

    Exposure to solar ultraviolet (UV) radiation is a causative factor in skin photocarcinogenesis and photoaging, and an urgent need exists for improved strategies for skin photoprotection. The redox-sensitive transcription factor Nrf2 (nuclear factor-E2-related factor 2), a master regulator of the cellular antioxidant defense against environmental electrophilic insult, has recently emerged as an important determinant of cutaneous damage from solar UV, and the concept of pharmacological activation of Nrf2 has attracted considerable attention as a novel approach to skin photoprotection. In this study, we examined feasibility of using tanshinones, a novel class of phenanthrenequinone-based cytoprotective Nrf2 inducers derived from the medicinal plant Salvia miltiorrhiza, for protection of cultured human skin cells and reconstructed human skin against solar simulated UV. Using a dual luciferase reporter assay in human Hs27 dermal fibroblasts pronounced transcriptional activation of Nrf2 by four major tanshinones [tanshinone I (T-I), dihydrotanshinone (DHT), tanshinone IIA (T-II-A) and cryptotanshinone (CT)] was detected. In fibroblasts, the more potent tanshinones T-I and DHT caused a significant increase in Nrf2 protein half-life via blockage of ubiquitination, ultimately resulting in upregulated expression of cytoprotective Nrf2 target genes (GCLC, NQO1) with the elevation of cellular glutathione levels. Similar tanshinone-induced changes were also observed in HaCaT keratinocytes. T-I and DHT pretreatment caused significant suppression of skin cell death induced by solar simulated UV and riboflavin-sensitized UVA. Moreover, feasibility of tanshinone-based cutaneous photoprotection was tested employing a human skin reconstruct exposed to solar simulated UV (80 mJ/cm2 UVB; 1.53 J/cm2 UVA). The occurrence of markers of epidermal solar insult (cleaved procaspase 3, pycnotic nuclei, eosinophilic cytoplasm, acellular cavities) was significantly attenuated in DHT

  8. The Nrf2-inducers tanshinone I and dihydrotanshinone protect human skin cells and reconstructed human skin against solar simulated UV.

    Science.gov (United States)

    Tao, Shasha; Justiniano, Rebecca; Zhang, Donna D; Wondrak, Georg T

    2013-01-01

    Exposure to solar ultraviolet (UV) radiation is a causative factor in skin photocarcinogenesis and photoaging, and an urgent need exists for improved strategies for skin photoprotection. The redox-sensitive transcription factor Nrf2 (nuclear factor-E2-related factor 2), a master regulator of the cellular antioxidant defense against environmental electrophilic insult, has recently emerged as an important determinant of cutaneous damage from solar UV, and the concept of pharmacological activation of Nrf2 has attracted considerable attention as a novel approach to skin photoprotection. In this study, we examined feasibility of using tanshinones, a novel class of phenanthrenequinone-based cytoprotective Nrf2 inducers derived from the medicinal plant Salvia miltiorrhiza, for protection of cultured human skin cells and reconstructed human skin against solar simulated UV. Using a dual luciferase reporter assay in human Hs27 dermal fibroblasts pronounced transcriptional activation of Nrf2 by four major tanshinones [tanshinone I (T-I), dihydrotanshinone (DHT), tanshinone IIA (T-II-A) and cryptotanshinone (CT)] was detected. In fibroblasts, the more potent tanshinones T-I and DHT caused a significant increase in Nrf2 protein half-life via blockage of ubiquitination, ultimately resulting in upregulated expression of cytoprotective Nrf2 target genes (GCLC, NQO1) with the elevation of cellular glutathione levels. Similar tanshinone-induced changes were also observed in HaCaT keratinocytes. T-I and DHT pretreatment caused significant suppression of skin cell death induced by solar simulated UV and riboflavin-sensitized UVA. Moreover, feasibility of tanshinone-based cutaneous photoprotection was tested employing a human skin reconstruct exposed to solar simulated UV (80 mJ/cm(2) UVB; 1.53 J/cm(2) UVA). The occurrence of markers of epidermal solar insult (cleaved procaspase 3, pycnotic nuclei, eosinophilic cytoplasm, acellular cavities) was significantly attenuated in DHT

  9. The Nrf2-inducers tanshinone I and dihydrotanshinone protect human skin cells and reconstructed human skin against solar simulated UV

    Directory of Open Access Journals (Sweden)

    Shasha Tao

    2013-01-01

    Full Text Available Exposure to solar ultraviolet (UV radiation is a causative factor in skin photocarcinogenesis and photoaging, and an urgent need exists for improved strategies for skin photoprotection. The redox-sensitive transcription factor Nrf2 (nuclear factor-E2-related factor 2, a master regulator of the cellular antioxidant defense against environmental electrophilic insult, has recently emerged as an important determinant of cutaneous damage from solar UV, and the concept of pharmacological activation of Nrf2 has attracted considerable attention as a novel approach to skin photoprotection. In this study, we examined feasibility of using tanshinones, a novel class of phenanthrenequinone-based cytoprotective Nrf2 inducers derived from the medicinal plant Salvia miltiorrhiza, for protection of cultured human skin cells and reconstructed human skin against solar simulated UV. Using a dual luciferase reporter assay in human Hs27 dermal fibroblasts pronounced transcriptional activation of Nrf2 by four major tanshinones [tanshinone I (T-I, dihydrotanshinone (DHT, tanshinone IIA (T-II-A and cryptotanshinone (CT] was detected. In fibroblasts, the more potent tanshinones T-I and DHT caused a significant increase in Nrf2 protein half-life via blockage of ubiquitination, ultimately resulting in upregulated expression of cytoprotective Nrf2 target genes (GCLC, NQO1 with the elevation of cellular glutathione levels. Similar tanshinone-induced changes were also observed in HaCaT keratinocytes. T-I and DHT pretreatment caused significant suppression of skin cell death induced by solar simulated UV and riboflavin-sensitized UVA. Moreover, feasibility of tanshinone-based cutaneous photoprotection was tested employing a human skin reconstruct exposed to solar simulated UV (80 mJ/cm2 UVB; 1.53 J/cm2 UVA. The occurrence of markers of epidermal solar insult (cleaved procaspase 3, pycnotic nuclei, eosinophilic cytoplasm, acellular cavities was significantly attenuated in DHT

  10. QSAR models of human data can enrich or replace LLNA testing for human skin sensitization

    Science.gov (United States)

    Alves, Vinicius M.; Capuzzi, Stephen J.; Muratov, Eugene; Braga, Rodolpho C.; Thornton, Thomas; Fourches, Denis; Strickland, Judy; Kleinstreuer, Nicole; Andrade, Carolina H.; Tropsha, Alexander

    2016-01-01

    Skin sensitization is a major environmental and occupational health hazard. Although many chemicals have been evaluated in humans, there have been no efforts to model these data to date. We have compiled, curated, analyzed, and compared the available human and LLNA data. Using these data, we have developed reliable computational models and applied them for virtual screening of chemical libraries to identify putative skin sensitizers. The overall concordance between murine LLNA and human skin sensitization responses for a set of 135 unique chemicals was low (R = 28-43%), although several chemical classes had high concordance. We have succeeded to develop predictive QSAR models of all available human data with the external correct classification rate of 71%. A consensus model integrating concordant QSAR predictions and LLNA results afforded a higher CCR of 82% but at the expense of the reduced external dataset coverage (52%). We used the developed QSAR models for virtual screening of CosIng database and identified 1061 putative skin sensitizers; for seventeen of these compounds, we found published evidence of their skin sensitization effects. Models reported herein provide more accurate alternative to LLNA testing for human skin sensitization assessment across diverse chemical data. In addition, they can also be used to guide the structural optimization of toxic compounds to reduce their skin sensitization potential. PMID:28630595

  11. An in vitro method for detecting chemical sensitization using human reconstructed skin models and its applicability to cosmetic, pharmaceutical, and medical device safety testing.

    Science.gov (United States)

    McKim, James M; Keller, Donald J; Gorski, Joel R

    2012-12-01

    Chemical sensitization is a serious condition caused by small reactive molecules and is characterized by a delayed type hypersensitivity known as allergic contact dermatitis (ACD). Contact with these molecules via dermal exposure represent a significant concern for chemical manufacturers. Recent legislation in the EU has created the need to develop non-animal alternative methods for many routine safety studies including sensitization. Although most of the alternative research has focused on pure chemicals that possess reasonable solubility properties, it is important for any successful in vitro method to have the ability to test compounds with low aqueous solubility. This is especially true for the medical device industry where device extracts must be prepared in both polar and non-polar vehicles in order to evaluate chemical sensitization. The aim of this research was to demonstrate the functionality and applicability of the human reconstituted skin models (MatTek Epiderm(®) and SkinEthic RHE) as a test system for the evaluation of chemical sensitization and its potential use for medical device testing. In addition, the development of the human 3D skin model should allow the in vitro sensitization assay to be used for finished product testing in the personal care, cosmetics, and pharmaceutical industries. This approach combines solubility, chemical reactivity, cytotoxicity, and activation of the Nrf2/ARE expression pathway to identify and categorize chemical sensitizers. Known chemical sensitizers representing extreme/strong-, moderate-, weak-, and non-sensitizing potency categories were first evaluated in the skin models at six exposure concentrations ranging from 0.1 to 2500 µM for 24 h. The expression of eight Nrf2/ARE, one AhR/XRE and two Nrf1/MRE controlled gene were measured by qRT-PCR. The fold-induction at each exposure concentration was combined with reactivity and cytotoxicity data to determine the sensitization potential. The results demonstrated that

  12. Enhancement of Human Cheek Skin Texture by Acacia Nilotica Bark ...

    African Journals Online (AJOL)

    HP

    Purpose: To evaluate the effect of a topical application of a cream formulation containing extract of. Acacia nilotica bark extract on human cheek skin texture. Methods: A cream containing 3 % concentrated extract of Acacia nilotica bark was developed by entrapping the extract in the internal aqueous phase of the cream ...

  13. Spectral Detection of Human Skin in VIS-SWIR Hyperspectral Imagery without Radiometric Calibration

    Science.gov (United States)

    2012-03-01

    6 Spectral reflectance of human skin at VIS-SWIR wavelengths. Skin with less melanin appears brighter because it has higher reflectance...6 illustrates the spectral reflectance of human skin with different melanin levels. One paper proposes a Normalized Difference Skin Index (NDSI), a...1.4% Melanin 12.6% Melanin 23.2% Melanin 34.3% Melanin 45% Melanin Figure 6. Spectral reflectance of human skin at VIS-SWIR wavelengths. Skin with less

  14. Three-dimensional multispectral optoacoustic mesoscopy reveals melanin and blood oxygenation in human skin in vivo.

    Science.gov (United States)

    Schwarz, Mathias; Buehler, Andreas; Aguirre, Juan; Ntziachristos, Vasilis

    2016-01-01

    Optical imaging plays a major role in disease detection in dermatology. However, current optical methods are limited by lack of three-dimensional detection of pathophysiological parameters within skin. It was recently shown that single-wavelength optoacoustic (photoacoustic) mesoscopy resolves skin morphology, i.e. melanin and blood vessels within epidermis and dermis. In this work we employed illumination at multiple wavelengths for enabling three-dimensional multispectral optoacoustic mesoscopy (MSOM) of natural chromophores in human skin in vivo operating at 15-125 MHz. We employ a per-pulse tunable laser to inherently co-register spectral datasets, and reveal previously undisclosed insights of melanin, and blood oxygenation in human skin. We further reveal broadband absorption spectra of specific skin compartments. We discuss the potential of MSOM for label-free visualization of physiological biomarkers in skin in vivo. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Chronic effects of UV on human skin

    International Nuclear Information System (INIS)

    Cesarini, J.P.

    1996-01-01

    Chronic exposures and acute accidents of the skin to UV has been recognized as an important risk for skin cancers in human. Attempts have been made with mathematical models to correlate the ambient UV dose and occupational irradiations with the risk of skin cancers. Development of accurate global measurements of solar irradiance and personal dosimetry is expected in the future in order to reduce the exposure of the general population, to precise the measures to be taken for indoor and outdoor workers. (author)

  16. Prediction of Human Pharmacokinetic Profile After Transdermal Drug Application Using Excised Human Skin.

    Science.gov (United States)

    Yamamoto, Syunsuke; Karashima, Masatoshi; Arai, Yuta; Tohyama, Kimio; Amano, Nobuyuki

    2017-09-01

    Although several mathematical models have been reported for the estimation of human plasma concentration profiles of drug substances after dermal application, the successful cases that can predict human pharmacokinetic profiles are limited. Therefore, the aim of this study is to investigate the prediction of human plasma concentrations after dermal application using in vitro permeation parameters obtained from excised human skin. The in vitro skin permeability of 7 marketed drug products was evaluated. The plasma concentration-time profiles of the drug substances in humans after their dermal application were simulated using compartment models and the clinical pharmacokinetic parameters. The transdermal process was simulated using the in vitro skin permeation rate and lag time assuming a zero-order absorption. These simulated plasma concentration profiles were compared with the clinical data. The result revealed that the steady-state plasma concentration of diclofenac and the maximum concentrations of nicotine, bisoprolol, rivastigmine, and lidocaine after topical application were within 2-fold of the clinical data. Furthermore, the simulated concentration profiles of bisoprolol, nicotine, and rivastigmine reproduced the decrease in absorption due to drug depletion from the formulation. In conclusion, this simple compartment model using in vitro human skin permeation parameters as zero-order absorption predicted the human plasma concentrations accurately. Copyright © 2017 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

  17. Chronological age affects the permeation of fentanyl through human skin in vitro

    DEFF Research Database (Denmark)

    Holmgaard, R; Benfeldt, E; Sorensen, J A

    2013-01-01

    AIM: To study the influence of chronological age on fentanyl permeation through human skin in vitro using static diffusion cells. Elderly individuals are known to be more sensitive to opioids and obtain higher plasma concentrations following dermal application of fentanyl compared to younger...... individuals. The influence of age - as an isolated pharmacokinetic term - on the absorption of fentanyl has not been previously studied. METHOD: Human skin from 30 female donors was mounted in static diffusion cells, and samples were collected during 48 h. Donors were divided into three age groups: ... and old age groups: 5,922 and 4,050 ng, respectively). Furthermore, the lag time and absorption rate were different between the three groups, with a significantly higher rate in the young participants versus the oldest participants. CONCLUSION: We demonstrate that fentanyl permeates the skin of young...

  18. Radio-sterilization and processing of frozen human skin

    International Nuclear Information System (INIS)

    Zarate S, Herman; Aguirre H, Paulina; Silva R, Samy; Hitschfeld G, Mario

    2006-01-01

    The Laboratory of Radio-sterilized Biological Tissues Processing (LPTR) belonging to the Chilean Commission of Nuclear Energy and the International Atomic Energy Agency have played a paramount role in our country, concerning the biological tissue processing, which can be radio-sterilized as human skin, pig skin, amniotic membrane, human bone and bovine bone. The frozen radio.-sterilized human skin processing began in 2001, by means of putting into practice the knowledge acquired in training courses through the IAEA and the experience transferred by experts who visited our laboratory. The human skin processing of dead donor can be divided into 6 stages: a) Profuse washing with physiological sterilized serum in to remove the microorganisms, chemical and pharmacological compounds; b) immersion in glycerol solution at 10% to better keep the stored tissues; c) packing, to avoid post manipulation of the sterilized tissue; d) microbiological controls which allow and guarantee a sterility assurance level of 10 6 ; e) radio-sterilization, technique that consists of exposing the grafts to electromagnetic gamma waves which eliminate the microorganisms of the tissue, f) and finally, dispatching and liberation of the frozen sterilized human skin for its clinical use in different centers that take care of burned people. The LPTR receives feedback from surgeons who have used these tissues in order to improve the processing stages based in an integral quality system ISO 9001.2000. The State Health System in our country counts on limited and scarce resources to implement synthetic substitutes that is why It is considered necessary to spread the use of these noble tissues which have sterility assurance and they are processed at low price

  19. Proof-of-concept: 3D bioprinting of pigmented human skin constructs.

    Science.gov (United States)

    Ng, Wei Long; Qi, Jovina Tan Zhi; Yeong, Wai Yee; Naing, May Win

    2018-01-23

    Three-dimensional (3D) pigmented human skin constructs have been fabricated using a 3D bioprinting approach. The 3D pigmented human skin constructs are obtained from using three different types of skin cells (keratinocytes, melanocytes and fibroblasts from three different skin donors) and they exhibit similar constitutive pigmentation (pale pigmentation) as the skin donors. A two-step drop-on-demand bioprinting strategy facilitates the deposition of cell droplets to emulate the epidermal melanin units (pre-defined patterning of keratinocytes and melanocytes at the desired positions) and manipulation of the microenvironment to fabricate 3D biomimetic hierarchical porous structures found in native skin tissue. The 3D bioprinted pigmented skin constructs are compared to the pigmented skin constructs fabricated by conventional a manual-casting approach; in-depth characterization of both the 3D pigmented skin constructs has indicated that the 3D bioprinted skin constructs have a higher degree of resemblance to native skin tissue in term of the presence of well-developed stratified epidermal layers and the presence of a continuous layer of basement membrane proteins as compared to the manually-cast samples. The 3D bioprinting approach facilitates the development of 3D in vitro pigmented human skin constructs for potential toxicology testing and fundamental cell biology research.

  20. Studies of the in vivo radiosensitivity of human skin fibroblasts

    International Nuclear Information System (INIS)

    Hill, Richard P.; Kaspler, Pavel; Griffin, Anthony M.; O'Sullivan, Brian; Catton, Charles; Alasti, Hamideh; Abbas, Ahmar; Heydarian, Moustafa; Ferguson, Peter; Wunder, Jay S.; Bell, Robert S.

    2007-01-01

    Background and purpose: To examine the radiosensitivity of skin cells obtained directly from the irradiated skin of patients undergoing fractionated radiation treatment prior to surgery for treatment of soft tissue sarcoma (STS) and to determine if there was a relationship with the development of wound healing complications associated with the surgery post-radiotherapy. Methods: Micronucleus (MN) formation was measured in cells (primarily dermal fibroblasts) obtained from human skin at their first division after being removed from STS patients during post-radiotherapy surgery (2-9 weeks after the end of the radiotherapy). At the time of radiotherapy (planned tumor dose - 50 Gy in 25 daily fractions) measurements were made of surface skin dose at predetermined marked sites. Skin from these sites was obtained at surgery and cell suspensions were prepared directly for the cytokinesis-blocked MN assay. Cultured strains of the fibroblasts were also established from skin nominally outside the edge of the radiation beam and DNA damage (MN formation) was examined following irradiation in vitro for comparison with the results from the in situ irradiations. Results: Extensive DNA damage (MN) was detectable in fibroblasts from human skin at extended periods after irradiation (2-9 weeks after the end of the 5-week fractionated radiotherapy). Analysis of skin receiving a range of doses demonstrated that the level of damage observed was dose dependent. There was no clear correlation between the level of damage observed after irradiation in situ and irradiation of cell strains in culture. Similarly, there was no correlation between the extent of MN formation following in situ irradiation and the propensity for the patient to develop wound healing complications post-surgery. Conclusions: Despite the presence of DNA damage in dermal fibroblasts weeks after the end of the radiation treatment, there was no relationship between this damage and wound healing complications following

  1. Analysis of human skin tissue by millimeter-wave reflectometry

    NARCIS (Netherlands)

    Smulders, P.F.M.

    2013-01-01

    Background/pupose: Millimeter-wave reflectometry is a potentially interesting technique to analyze the human skin in vivo in order to determine the water content locally in the skin. Purpose of this work is to investigate the possibility of skin-tissue differentiation. In addition, it addresses the

  2. Tribology of skin : review and analysis of experimental results for the friction coefficient of human skin

    NARCIS (Netherlands)

    Derler, S.; Gerhardt, L.C.

    2012-01-01

    In this review, we discuss the current knowledge on the tribology of human skin and present an analysis of the available experimental results for skin-friction coefficients. Starting with an overview on the factors influencing the friction behaviour of skin, we discuss the up-to-date existing

  3. Human skin in vitro permeation of bentazon and isoproturon formulations with or without protective clothing suit.

    Science.gov (United States)

    Berthet, Aurélie; Hopf, Nancy B; Miles, Alexandra; Spring, Philipp; Charrière, Nicole; Garrigou, Alain; Baldi, Isabelle; Vernez, David

    2014-01-01

    Skin exposures to chemicals may lead, through percutaneous permeation, to a significant increase in systemic circulation. Skin is the primary route of entry during some occupational activities, especially in agriculture. To reduce skin exposures, the use of personal protective equipment (PPE) is recommended. PPE efficiency is characterized as the time until products permeate through material (lag time, Tlag). Both skin and PPE permeations are assessed using similar in vitro methods; the diffusion cell system. Flow-through diffusion cells were used in this study to assess the permeation of two herbicides, bentazon and isoproturon, as well as four related commercial formulations (Basagran(®), Basamais(®), Arelon(®) and Matara(®)). Permeation was measured through fresh excised human skin, protective clothing suits (suits) (Microchem(®) 3000, AgriSafe Pro(®), Proshield(®) and Microgard(®) 2000 Plus Green), and a combination of skin and suits. Both herbicides, tested by itself or as an active ingredient in formulations, permeated readily through human skin and tested suits (Tlag < 2 h). High permeation coefficients were obtained regardless of formulations or tested membranes, except for Microchem(®) 3000. Short Tlag, were observed even when skin was covered with suits, except for Microchem(®) 3000. Kp values tended to decrease when suits covered the skin (except when Arelon(®) was applied to skin covered with AgriSafe Pro and Microgard(®) 2000), suggesting that Tlag alone is insufficient in characterizing suits. To better estimate human skin permeations, in vitro experiments should not only use human skin but also consider the intended use of the suit, i.e., the active ingredient concentrations and type of formulations, which significantly affect skin permeation.

  4. Thermal analysis of epidermal electronic devices integrated with human skin considering the effects of interfacial thermal resistance

    Science.gov (United States)

    Li, Yuhang; Zhang, Jianpeng; Xing, Yufeng; Song, Jizhou

    2018-05-01

    Epidermal electronic devices (EEDs) have similar mechanical properties as those of human skin such that they can be integrated with human skin for potential applications in monitoring of human vital signs for diagnostic, therapeutic or surgical functions. Thermal management is critical for EEDs in these applications since excessive heating may cause discomfort. Comprehensive analytical studies, finite element analysis and experiments are carried out to study the effects of interfacial thermal resistance between EEDs and human skin on thermal properties of the EED/skin system in this paper. The coupling between the Fourier heat transfer in EEDs and the bio-heat transfer in human skin is accounted in the analytical model based on the transfer matrix method to give accurate predictions on temperatures, which agree well with finite element analysis and experimental measurements. It is shown that the maximum temperature increase of the EED for the case of imperfect bonding between EED and skin is much higher than that of perfect bonding. These results may help the design of EEDs in bi-integrated applications and suggest a valuable route to evaluate the bonding condition between EEDs and biological tissues.

  5. Characterisation of mechanical behaviour of human skin in vivo

    NARCIS (Netherlands)

    Douven, L.F.A.; Meijer, R.; Oomens, C.W.J.

    2000-01-01

    Characterization of the biomechanical properties of human skin in vivo is studied both experimentally and by numerical modeling. These properties can be important in the evaluation of skin condition (e.g. aging) as well as skin disorders. In this study the authors focus on the static behavior of the

  6. Skin age testing criteria: characterization of human skin structures by 500 MHz MRI multiple contrast and image processing

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Rakesh, E-mail: rs05h@fsu.ed [Departments of Chemical Engineering and Biomedical Engineering, FAMU-FSU College of Engineering, Tallahassee, FL 32310 (United States)

    2010-07-21

    Ex vivo magnetic resonance microimaging (MRM) image characteristics are reported in human skin samples in different age groups. Human excised skin samples were imaged using a custom coil placed inside a 500 MHz NMR imager for high-resolution microimaging. Skin MRI images were processed for characterization of different skin structures. Contiguous cross-sectional T1-weighted 3D spin echo MRI, T2-weighted 3D spin echo MRI and proton density images were compared with skin histopathology and NMR peaks. In all skin specimens, epidermis and dermis thickening and hair follicle size were measured using MRM. Optimized parameters TE and TR and multicontrast enhancement generated better MRI visibility of different skin components. Within high MR signal regions near to the custom coil, MRI images with short echo time were comparable with digitized histological sections for skin structures of the epidermis, dermis and hair follicles in 6 (67%) of the nine specimens. Skin % tissue composition, measurement of the epidermis, dermis, sebaceous gland and hair follicle size, and skin NMR peaks were signatures of skin type. The image processing determined the dimensionality of skin tissue components and skin typing. The ex vivo MRI images and histopathology of the skin may be used to measure the skin structure and skin NMR peaks with image processing may be a tool for determining skin typing and skin composition.

  7. Skin age testing criteria: characterization of human skin structures by 500 MHz MRI multiple contrast and image processing

    International Nuclear Information System (INIS)

    Sharma, Rakesh

    2010-01-01

    Ex vivo magnetic resonance microimaging (MRM) image characteristics are reported in human skin samples in different age groups. Human excised skin samples were imaged using a custom coil placed inside a 500 MHz NMR imager for high-resolution microimaging. Skin MRI images were processed for characterization of different skin structures. Contiguous cross-sectional T1-weighted 3D spin echo MRI, T2-weighted 3D spin echo MRI and proton density images were compared with skin histopathology and NMR peaks. In all skin specimens, epidermis and dermis thickening and hair follicle size were measured using MRM. Optimized parameters TE and TR and multicontrast enhancement generated better MRI visibility of different skin components. Within high MR signal regions near to the custom coil, MRI images with short echo time were comparable with digitized histological sections for skin structures of the epidermis, dermis and hair follicles in 6 (67%) of the nine specimens. Skin % tissue composition, measurement of the epidermis, dermis, sebaceous gland and hair follicle size, and skin NMR peaks were signatures of skin type. The image processing determined the dimensionality of skin tissue components and skin typing. The ex vivo MRI images and histopathology of the skin may be used to measure the skin structure and skin NMR peaks with image processing may be a tool for determining skin typing and skin composition.

  8. Parameterization using Fourier series expansion of the diffuse reflectance of human skin to vary the concentration of the melanocytes

    Science.gov (United States)

    Narea, J. Freddy; Muñoz, Aarón A.; Castro, Jorge; Muñoz, Rafael A.; Villalba, Caroleny E.; Martinez, María. F.; Bravo, Kelly D.

    2013-11-01

    Human skin has been studied in numerous investigations, given the interest in knowing information about physiology, morphology and chemical composition. These parameters can be determined using non invasively optical techniques in vivo, such as the diffuse reflectance spectroscopy. The human skin color is determined by many factors, but primarily by the amount and distribution of the pigment melanin. The melanin is produced by the melanocytes in the basal layer of the epidermis. This research characterize the spectral response of the human skin using the coefficients of Fourier series expansion. Simulating the radiative transfer equation for the Monte Carlo method to vary the concentration of the melanocytes (fme) in a simplified model of human skin. It fits relating the Fourier series coefficient a0 with fme. Therefore it is possible to recover the skin biophysical parameter.

  9. Induction of Skin-Derived Precursor Cells from Human Induced Pluripotent Stem Cells.

    Science.gov (United States)

    Sugiyama-Nakagiri, Yoriko; Fujimura, Tsutomu; Moriwaki, Shigeru

    2016-01-01

    The generation of full thickness human skin from dissociated cells is an attractive approach not only for treating skin diseases, but also for treating many systemic disorders. However, it is currently not possible to obtain an unlimited number of skin dermal cells. The goal of this study was to develop a procedure to produce skin dermal stem cells from induced pluripotent stem cells (iPSCs). Skin-derived precursor cells (SKPs) were isolated as adult dermal precursors that could differentiate into both neural and mesodermal progenies and could reconstitute the dermis. Thus, we attempted to generate SKPs from iPSCs that could reconstitute the skin dermis. Human iPSCs were initially cultured with recombinant noggin and SB431542, an inhibitor of activin/nodal and TGFβ signaling, to induce neural crest progenitor cells. Those cells were then treated with SKP medium that included CHIR99021, a WNT signal activator. The induction efficacy from neural crest progenitor cells to SKPs was more than 97%. No other modifiers tested were able to induce those cells. Those human iPSC-derived SKPs (hiPSC-SKPs) showed a similar gene expression signature to SKPs isolated from human skin dermis. Human iPSC-SKPs differentiated into neural and mesodermal progenies, including adipocytes, skeletogenic cell types and Schwann cells. Moreover, they could be induced to follicular type keratinization when co-cultured with human epidermal keratinocytes. We here provide a new efficient protocol to create human skin dermal stem cells from hiPSCs that could contribute to the treatment of various skin disorders.

  10. First donation of human skin obtained from corpse

    International Nuclear Information System (INIS)

    Reyes F, M.L.; Luna Z, D.

    2007-01-01

    The first donation of human skin coming from a cadaverous donor was obtained in the State of Mexico. The skin was obtained of a 34 year-old multi organic donor, the extraction of the same was carried out in an operating theatre by medical personnel, supported by personal of the Radio sterilized Tissue Bank (BTR) of the ININ. The skin was transported to the BTR for it processing. (Author)

  11. Assessing human skin with diffuse reflectance spectroscopy and colorimetry

    Science.gov (United States)

    Seo, InSeok; Liu, Yang; Bargo, Paulo R.; Kollias, Nikiforos

    2012-02-01

    Colorimetry has been used as an objective measure of perceived skin color by human eye to document and score physiological responses of the skin from external insults. CIE color space values (L*, a* and b*) are the most commonly used parameters to correlate visually perceived color attributes such as L* for pigment, a* for erythema, and b* for sallowness of the skin. In this study, we investigated the relation of Lab color scale to the amount of major skin chromophores (oxy-, deoxyhemoglobin and melanin) calculated from diffuse reflectance spectroscopy. Thirty two healthy human subjects with ages from 20 to 70 years old, skin types I-VI, were recruited for the study. DRS and colorimetry measurements were taken from the left and right cheeks, and on the right upper inner arm. The melanin content calculated from 630-700 nm range of DRS measurements was shown to correlate with the lightness of skin (L*) for most skin types. For subjects with medium-to-light complexion, melanin measured at the blue part spectrum and hemoglobin interfered on the relation of lightness of the skin color to the melanin content. The sallowness of the skin that is quantified by the melanin contribution at the blue part spectrum of DRS was found to be related to b* scale. This study demonstrates the importance of documenting skin color by assessing individual skin chromophores with diffuse reflectance spectroscopy, in comparison to colorimetry assessment.

  12. Langerhans cell precursors acquire RANK/CD265 in prenatal human skin.

    Science.gov (United States)

    Schöppl, Alice; Botta, Albert; Prior, Marion; Akgün, Johnnie; Schuster, Christopher; Elbe-Bürger, Adelheid

    2015-01-01

    The skin is the first barrier against foreign pathogens and the prenatal formation of a strong network of various innate and adaptive cells is required to protect the newborn from perinatal infections. While many studies about the immune system in healthy and diseased adult human skin exist, our knowledge about the cutaneous prenatal/developing immune system and especially about the phenotype and function of antigen-presenting cells such as epidermal Langerhans cells (LCs) in human skin is still scarce. It has been shown previously that LCs in healthy adult human skin express receptor activator of NF-κB (RANK), an important molecule prolonging their survival. In this study, we investigated at which developmental stage LCs acquire this important molecule. Immunofluorescence double-labeling of cryostat sections revealed that LC precursors in prenatal human skin either do not yet [10-11 weeks of estimated gestational age (EGA)] or only faintly (13-15 weeks EGA) express RANK. LCs express RANK at levels comparable to adult LCs by the end of the second trimester. Comparable with adult skin, dermal antigen-presenting cells at no gestational age express this marker. These findings indicate that epidermal leukocytes gradually acquire RANK during gestation - a phenomenon previously observed also for other markers on LCs in prenatal human skin. Copyright © 2015 The Authors. Published by Elsevier GmbH.. All rights reserved.

  13. Hydrodynamic gene delivery in human skin using a hollow microneedle device.

    Science.gov (United States)

    Dul, M; Stefanidou, M; Porta, P; Serve, J; O'Mahony, C; Malissen, B; Henri, S; Levin, Y; Kochba, E; Wong, F S; Dayan, C; Coulman, S A; Birchall, J C

    2017-11-10

    Microneedle devices have been proposed as a minimally invasive delivery system for the intradermal administration of nucleic acids, both plasmid DNA (pDNA) and siRNA, to treat localised disease or provide vaccination. Different microneedle types and application methods have been investigated in the laboratory, but limited and irreproducible levels of gene expression have proven to be significant challenges to pre-clinical to clinical progression. This study is the first to explore the potential of a hollow microneedle device for the delivery and subsequent expression of pDNA in human skin. The regulatory approved MicronJet600® (MicronJet hereafter) device was used to deliver reporter plasmids (pCMVβ and pEGFP-N1) into viable excised human skin. Exogenous gene expression was subsequently detected at multiple locations that were distant from the injection site but within the confines of the bleb created by the intradermal bolus. The observed levels of gene expression in the tissue are at least comparable to that achieved by the most invasive microneedle application methods e.g. lateral application of a microneedle. Gene expression was predominantly located in the epidermis, although also evident in the papillary dermis. Optical coherence tomography permitted real time visualisation of the sub-surface skin architecture and, unlike a conventional intradermal injection, MicronJet administration of a 50μL bolus appears to create multiple superficial microdisruptions in the papillary dermis and epidermis. These were co-localised with expression of the pCMVβ reporter plasmid. We have therefore shown, for the first time, that a hollow microneedle device can facilitate efficient and reproducible gene expression of exogenous naked pDNA in human skin using volumes that are considered to be standard for intradermal administration, and postulate a hydrodynamic effect as the mechanism of gene delivery. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Effects of radiation on the skin blood volume pulse in humans

    Energy Technology Data Exchange (ETDEWEB)

    Zanelli, G D [Mount Vernon Hospital, Northwood (UK)

    1977-01-01

    Measurements have been made of the changes in skin blood volume pulse (BVP) in the irradiated skin of three patients (two female, one male) during and up to 250 days after radiotherapy for malignant disease. The instrumentation comprised a modified commercial finger photo-plethysmograph probe with associated electronics, and a survey of the literature revealed that the consensus of opinion seems to be that the recorded pulsations arise from small 'muscular' arteries and arterioles in the 40 to 300 ..mu..m size range. The results show that, as expected, normal, untreated skin shows sizeable variations in BVP. The BVP of irradiated skin became significantly greater than that of normal skin when a dose of 1000 to 1500 rad has been accumulated. The maximum amplitude of the BVP of the irradiated skin seemed to correlate well with the overall severity of the erythema, but increases in BVP preceded erythema flare-ups. In two patients, elevated BVP were recorded for irradiated areas even when most visual signs of erythema had disappeared. Mild cooling of irradiated and non-irradiated skin had differing effects in the BVP. The measurement of the BVP of irradiated skin is a simple, reliable and completely atraumatic method for investigating vascular damage to superficial tissues in humans.

  15. Combination of MALDI-MSI and cassette dosing for evaluation of drug distribution in human skin explant

    DEFF Research Database (Denmark)

    Sørensen, Isabella S; Janfelt, Christian; Nielsen, Mette Marie B

    2017-01-01

    Study of skin penetration and distribution of the drug compounds in the skin is a major challenge in the development of topical drug products for treatment of skin diseases. It is crucial to have fast and efficacious screening methods which can provide information concerning the skin penetration ...... that combination of MALDI-MSI and cassette dosing can be used as a medium throughput screening tool at an early stage in the drug discovery/development process. Graphical abstract Investigation of drug distribution in human skin explant by MALDI-MSI after cassette dosing....

  16. Vehicle effects on human stratum corneum absorption and skin penetration.

    Science.gov (United States)

    Zhang, Alissa; Jung, Eui-Chang; Zhu, Hanjiang; Zou, Ying; Hui, Xiaoying; Maibach, Howard

    2017-05-01

    This study evaluated the effects of three vehicles-ethanol (EtOH), isopropyl alcohol (IPA), and isopropyl myristate (IPM)-on stratum corneum (SC) absorption and diffusion of the [ 14 C]-model compounds benzoic acid and butenafine hydrochloride to better understand the transport pathways of chemicals passing through and resident in SC. Following application of topical formulations to human dermatomed skin for 30 min, penetration flux was observed for 24 h post dosing, using an in vitro flow-through skin diffusion system. Skin absorption and penetration was compared to the chemical-SC (intact, delipidized, or SC lipid film) binding levels. A significant vehicle effect was observed for chemical skin penetration and SC absorption. IPA resulted in the greatest levels of intact SC/SC lipid absorption, skin penetration, and total skin absorption/penetration of benzoic acid, followed by IPM and EtOH, respectively. For intact SC absorption and total skin absorption/penetration of butenafine, the vehicle that demonstrated the highest level of sorption/penetration was EtOH, followed by IPA and IPM, respectively. The percent doses of butenafine that were absorbed in SC lipid film and penetrated through skin in 24 h were greatest for IPA, followed by EtOH and IPM, respectively. The vehicle effect was consistent between intact SC absorption and total chemical skin absorption and penetration, as well as SC lipid absorption and chemical penetration through skin, suggesting intercellular transport as a main pathway of skin penetration for model chemicals. These results suggest the potential to predict vehicle effects on skin permeability with simple SC absorption assays. As decontamination was applied 30 min after chemical exposure, significant vehicle effects on chemical SC partitioning and percutaneous penetration also suggest that skin decontamination efficiency is vehicle dependent, and an effective decontamination method should act on chemical solutes in the lipid domain.

  17. Molecular cartography of the human skin surface in 3D

    Science.gov (United States)

    Bouslimani, Amina; Porto, Carla; Rath, Christopher M.; Wang, Mingxun; Guo, Yurong; Gonzalez, Antonio; Berg-Lyon, Donna; Ackermann, Gail; Moeller Christensen, Gitte Julie; Nakatsuji, Teruaki; Zhang, Lingjuan; Borkowski, Andrew W.; Meehan, Michael J.; Dorrestein, Kathleen; Gallo, Richard L.; Bandeira, Nuno; Knight, Rob; Alexandrov, Theodore; Dorrestein, Pieter C.

    2015-01-01

    The human skin is an organ with a surface area of 1.5–2 m2 that provides our interface with the environment. The molecular composition of this organ is derived from host cells, microbiota, and external molecules. The chemical makeup of the skin surface is largely undefined. Here we advance the technologies needed to explore the topographical distribution of skin molecules, using 3D mapping of mass spectrometry data and microbial 16S rRNA amplicon sequences. Our 3D maps reveal that the molecular composition of skin has diverse distributions and that the composition is defined not only by skin cells and microbes but also by our daily routines, including the application of hygiene products. The technological development of these maps lays a foundation for studying the spatial relationships of human skin with hygiene, the microbiota, and environment, with potential for developing predictive models of skin phenotypes tailored to individual health. PMID:25825778

  18. Collagen synthesis in human musculoskeletal tissues and skin

    DEFF Research Database (Denmark)

    Babraj, J A; Cuthbertson, D J R; Smith, K

    2005-01-01

    We have developed a direct method for the measurement of human musculoskeletal collagen synthesis on the basis of the incorporation of stable isotope-labeled proline or leucine into protein and have used it to measure the rate of synthesis of collagen in tendon, ligament, muscle, and skin....... In postabsorptive, healthy young men (28 +/- 6 yr) synthetic rates for tendon, ligament, muscle, and skin collagen were 0.046 +/- 0.005, 0.040 +/- 0.006, 0.016 +/- 0.002, and 0.037 +/- 0.003%/h, respectively (means +/- SD). In postabsorptive, healthy elderly men (70 +/- 6 yr) the rate of skeletal muscle collagen...... synthesis is greater than in the young (0.023 +/- 0.002%/h, P collagen are similar to those of mixed skeletal muscle protein in the postabsorptive state, whereas the rate for muscle collagen synthesis is much lower in both young and elderly men...

  19. Ultrathin conformal devices for precise and continuous thermal characterization of human skin

    Science.gov (United States)

    Webb, R. Chad; Bonifas, Andrew P.; Behnaz, Alex; Zhang, Yihui; Yu, Ki Jun; Cheng, Huanyu; Shi, Mingxing; Bian, Zuguang; Liu, Zhuangjian; Kim, Yun-Soung; Yeo, Woon-Hong; Park, Jae Suk; Song, Jizhou; Li, Yuhang; Huang, Yonggang; Gorbach, Alexander M.; Rogers, John A.

    2013-10-01

    Precision thermometry of the skin can, together with other measurements, provide clinically relevant information about cardiovascular health, cognitive state, malignancy and many other important aspects of human physiology. Here, we introduce an ultrathin, compliant skin-like sensor/actuator technology that can pliably laminate onto the epidermis to provide continuous, accurate thermal characterizations that are unavailable with other methods. Examples include non-invasive spatial mapping of skin temperature with millikelvin precision, and simultaneous quantitative assessment of tissue thermal conductivity. Such devices can also be implemented in ways that reveal the time-dynamic influence of blood flow and perfusion on these properties. Experimental and theoretical studies establish the underlying principles of operation, and define engineering guidelines for device design. Evaluation of subtle variations in skin temperature associated with mental activity, physical stimulation and vasoconstriction/dilation along with accurate determination of skin hydration through measurements of thermal conductivity represent some important operational examples.

  20. Impact of chemical peeling combined with negative pressure on human skin.

    Science.gov (United States)

    Kim, S J; Kang, I J; Shin, M K; Jeong, K H; Baek, J H; Koh, J S; Lee, S J

    2016-10-01

    In vivo changes in skin barrier function after chemical peeling with alpha hydroxyacids (AHAs) have been previously reported. However, the additional effects of physical treatment with chemical agents on skin barrier function have not been adequately studied. This study measured the degree of acute skin damage and the time required for skin barrier repair using non-invasive bioengineering methods in vivo with human skin to investigate the additional effect of a 4% AHA chemical jet accelerated at supersonic velocities. Thirteen female subjects (average age: 29.54 ± 4.86 years) participated in this study. The faces of the subjects were divided into half according to the block randomization design and were then assigned to receive AHA peeling alone or AHA peeling combined with pneumatic pressure on each side of the face. Transepidermal water loss (TEWL), skin colour and skin blood flow were evaluated at baseline and at 30 min, 2, 5 and 7 days after treatment. The TEWL and skin blood flow were significantly increased after 30 min in chemodermabrasion compared with chemical peeling alone (P peeling alone (P < 0.05). Chemodermabrasion can temporarily impair skin barriers, but it is estimated that it can enhance the skin barrier function after 7 days compared to the use of a chemical agent alone. In addition, chemodermabrasion has a more effective impact in the dermis and relatively preserves the skin barrier. © 2016 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

  1. A computer-based method for precise detection and calculation of affected skin areas

    DEFF Research Database (Denmark)

    Henriksen, Sille Mølvig; Nybing, Janus Damm; Bouert, Rasmus

    2016-01-01

    BACKGROUND: The aim of this study was to describe and validate a method to obtain reproducible and comparable results concerning extension of a specific skin area, unaffected by individual differences in body surface area. METHODS: A phantom simulating the human torso was equipped with three irre...

  2. Nutraceuticals for Skin Care: A Comprehensive Review of Human Clinical Studies.

    Science.gov (United States)

    Pérez-Sánchez, Almudena; Barrajón-Catalán, Enrique; Herranz-López, María; Micol, Vicente

    2018-03-24

    The skin is the body's largest organ, it participates in sensitivity and offers protection against microorganisms, chemicals and ultraviolet (UV) radiation. Consequently, the skin may suffer alterations such as photo-ageing, immune dysfunction and inflammation which may significantly affect human health. Nutraceuticals represent a promising strategy for preventing, delaying, or minimising premature ageing of the skin and also to alleviate certain skin disorders. Among them, bioactive peptides and oligosaccharides, plant polyphenols, carotenoids, vitamins and polyunsaturated fatty acids are the most widely used ingredients. Supplementation with these products has shown evidence of having an effect on the signs of ageing and protection against UV radiation ageing in several human trials. In this review, the most relevant human studies on skin nutraceuticals are evaluated and the statistical resolution, biological relevance of their results, and, the trial protocols are discussed. In conclusion, quality and rigorousness of the trials must be improved to build credible scientific evidence for skin nutraceuticals and to establish a cause-effect relationship between the ingredients the beneficial effects for the skin.

  3. Nutraceuticals for Skin Care: A Comprehensive Review of Human Clinical Studies

    Directory of Open Access Journals (Sweden)

    Almudena Pérez-Sánchez

    2018-03-01

    Full Text Available The skin is the body’s largest organ, it participates in sensitivity and offers protection against microorganisms, chemicals and ultraviolet (UV radiation. Consequently, the skin may suffer alterations such as photo-ageing, immune dysfunction and inflammation which may significantly affect human health. Nutraceuticals represent a promising strategy for preventing, delaying, or minimising premature ageing of the skin and also to alleviate certain skin disorders. Among them, bioactive peptides and oligosaccharides, plant polyphenols, carotenoids, vitamins and polyunsaturated fatty acids are the most widely used ingredients. Supplementation with these products has shown evidence of having an effect on the signs of ageing and protection against UV radiation ageing in several human trials. In this review, the most relevant human studies on skin nutraceuticals are evaluated and the statistical resolution, biological relevance of their results, and, the trial protocols are discussed. In conclusion, quality and rigorousness of the trials must be improved to build credible scientific evidence for skin nutraceuticals and to establish a cause-effect relationship between the ingredients the beneficial effects for the skin.

  4. Nutraceuticals for Skin Care: A Comprehensive Review of Human Clinical Studies

    Science.gov (United States)

    Pérez-Sánchez, Almudena; Micol, Vicente

    2018-01-01

    The skin is the body’s largest organ, it participates in sensitivity and offers protection against microorganisms, chemicals and ultraviolet (UV) radiation. Consequently, the skin may suffer alterations such as photo-ageing, immune dysfunction and inflammation which may significantly affect human health. Nutraceuticals represent a promising strategy for preventing, delaying, or minimising premature ageing of the skin and also to alleviate certain skin disorders. Among them, bioactive peptides and oligosaccharides, plant polyphenols, carotenoids, vitamins and polyunsaturated fatty acids are the most widely used ingredients. Supplementation with these products has shown evidence of having an effect on the signs of ageing and protection against UV radiation ageing in several human trials. In this review, the most relevant human studies on skin nutraceuticals are evaluated and the statistical resolution, biological relevance of their results, and, the trial protocols are discussed. In conclusion, quality and rigorousness of the trials must be improved to build credible scientific evidence for skin nutraceuticals and to establish a cause-effect relationship between the ingredients the beneficial effects for the skin. PMID:29587342

  5. Low Cost Skin Segmentation Scheme in Videos Using Two Alternative Methods for Dynamic Hand Gesture Detection Method

    Directory of Open Access Journals (Sweden)

    Eman Thabet

    2017-01-01

    Full Text Available Recent years have witnessed renewed interest in developing skin segmentation approaches. Skin feature segmentation has been widely employed in different aspects of computer vision applications including face detection and hand gestures recognition systems. This is mostly due to the attractive characteristics of skin colour and its effectiveness to object segmentation. On the contrary, there are certain challenges in using human skin colour as a feature to segment dynamic hand gesture, due to various illumination conditions, complicated environment, and computation time or real-time method. These challenges have led to the insufficiency of many of the skin color segmentation approaches. Therefore, to produce simple, effective, and cost efficient skin segmentation, this paper has proposed a skin segmentation scheme. This scheme includes two procedures for calculating generic threshold ranges in Cb-Cr colour space. The first procedure uses threshold values trained online from nose pixels of the face region. Meanwhile, the second procedure known as the offline training procedure uses thresholds trained out of skin samples and weighted equation. The experimental results showed that the proposed scheme achieved good performance in terms of efficiency and computation time.

  6. Demonstration of tyrosinase in the vitiligo skin of human beings by a sensitive fluorometric method as well as by 14C(U)-L-tyrosine incorporation into melanin

    International Nuclear Information System (INIS)

    Husain, I.; Vijayan, E.; Ramaiah, A.; Pasricha, J.S.; Madan, N.C.

    1982-01-01

    Tyrosinase activity (Monophenol, dihydroxyphenylalanine: oxygen oxidoreductase EC 1.14.18.1) in vitiligo and normal epidermal homogenates of skin from human beings was measured by estimating beta 3,4-dihydroxyphenylalanine (dopa) by a highly sensitive fluorometric method described in this paper. The tyrosine activity in the vitiligo skin was about 4 to 37% of corresponding normal skin. The activity of tyrosinase in normal human skin from different individuals and from different regions of the body was in the range of 4 to 140 picomoles of beta 3,4-dihydroxyphenylalanine formed per min/mg protein of epidermal homogenate. The enzyme from vitiligo and normal skin was severely inhibited by substance(s) of low molecular weight. The enzyme exhibits a lag of about 4 hr in the absence of added beta 3,4-dihydroxyphenylalanine and 1 hr in presence of 5 microM dopa. Tyrosinase from the normal and vitiligo skin was inhibited by excess concentration of tyrosine. The homogenates from vitiligo skin could synthesize melanin from C14(U)-L-Tyrosine. The rate of tyrosine incorporation into melanin by the epidermal homogenates is increased by 3,4-dihydroxyphenylalanine (dopa) disproportionate to its effect on tyrosinase activity. Based on the data presented in this paper it is concluded that melanocytes are present in the vitiligo skin. A tentative hypothesis is put forward to explain the lack of melanin synthesis by the vitiligo skin under in vivo conditions, although melanocytes are present

  7. A UV-Independent Topical Small-Molecule Approach for Melanin Production in Human Skin

    Directory of Open Access Journals (Sweden)

    Nisma Mujahid

    2017-06-01

    Full Text Available The presence of dark melanin (eumelanin within human epidermis represents one of the strongest predictors of low skin cancer risk. Topical rescue of eumelanin synthesis, previously achieved in “redhaired” Mc1r-deficient mice, demonstrated significant protection against UV damage. However, application of a topical strategy for human skin pigmentation has not been achieved, largely due to the greater barrier function of human epidermis. Salt-inducible kinase (SIK has been demonstrated to regulate MITF, the master regulator of pigment gene expression, through its effects on CRTC and CREB activity. Here, we describe the development of small-molecule SIK inhibitors that were optimized for human skin penetration, resulting in MITF upregulation and induction of melanogenesis. When topically applied, pigment production was induced in Mc1r-deficient mice and normal human skin. These findings demonstrate a realistic pathway toward UV-independent topical modulation of human skin pigmentation, potentially impacting UV protection and skin cancer risk.

  8. A UV-Independent Topical Small-Molecule Approach for Melanin Production in Human Skin.

    Science.gov (United States)

    Mujahid, Nisma; Liang, Yanke; Murakami, Ryo; Choi, Hwan Geun; Dobry, Allison S; Wang, Jinhua; Suita, Yusuke; Weng, Qing Yu; Allouche, Jennifer; Kemeny, Lajos V; Hermann, Andrea L; Roider, Elisabeth M; Gray, Nathanael S; Fisher, David E

    2017-06-13

    The presence of dark melanin (eumelanin) within human epidermis represents one of the strongest predictors of low skin cancer risk. Topical rescue of eumelanin synthesis, previously achieved in "redhaired" Mc1r-deficient mice, demonstrated significant protection against UV damage. However, application of a topical strategy for human skin pigmentation has not been achieved, largely due to the greater barrier function of human epidermis. Salt-inducible kinase (SIK) has been demonstrated to regulate MITF, the master regulator of pigment gene expression, through its effects on CRTC and CREB activity. Here, we describe the development of small-molecule SIK inhibitors that were optimized for human skin penetration, resulting in MITF upregulation and induction of melanogenesis. When topically applied, pigment production was induced in Mc1r-deficient mice and normal human skin. These findings demonstrate a realistic pathway toward UV-independent topical modulation of human skin pigmentation, potentially impacting UV protection and skin cancer risk. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  9. Refractive indices of human skin tissues at eight wavelengths and estimated dispersion relations between 300 and 1600 nm

    International Nuclear Information System (INIS)

    Ding Huafeng; Lu, Jun Q; Wooden, William A; Kragel, Peter J; Hu Xinhua

    2006-01-01

    The refractive index of human skin tissues is an important parameter in characterizing the optical response of the skin. We extended a previously developed method of coherent reflectance curve measurement to determine the in vitro values of the complex refractive indices of epidermal and dermal tissues from fresh human skin samples at eight wavelengths between 325 and 1557 nm. Based on these results, dispersion relations of the real refractive index have been obtained and compared in the same spectral region

  10. An in vitro model for detecting skin irritants: methyl green-pyronine staining of human skin explant cultures

    NARCIS (Netherlands)

    Jacobs, J. J. L.; Lehé, C.; Cammans, K. D. A.; Das, P. K.; Elliott, G. R.

    2002-01-01

    We evaluated the potential of human organotypic skin explant cultures (hOSECs) for screening skin irritants. Test chemicals were applied to the epidermis of the skin explants which were incubated for 4, 24 or 48 h in tissue culture medium. A decrease in epidermal RNA staining, visualised in frozen

  11. Global classification of human facial healthy skin using PLS discriminant analysis and clustering analysis.

    Science.gov (United States)

    Guinot, C; Latreille, J; Tenenhaus, M; Malvy, D J

    2001-04-01

    Today's classifications of healthy skin are predominantly based on a very limited number of skin characteristics, such as skin oiliness or susceptibility to sun exposure. The aim of the present analysis was to set up a global classification of healthy facial skin, using mathematical models. This classification is based on clinical, biophysical skin characteristics and self-reported information related to the skin, as well as the results of a theoretical skin classification assessed separately for the frontal and the malar zones of the face. In order to maximize the predictive power of the models with a minimum of variables, the Partial Least Square (PLS) discriminant analysis method was used. The resulting PLS components were subjected to clustering analyses to identify the plausible number of clusters and to group the individuals according to their proximities. Using this approach, four PLS components could be constructed and six clusters were found relevant. So, from the 36 hypothetical combinations of the theoretical skin types classification, we tended to a strengthened six classes proposal. Our data suggest that the association of the PLS discriminant analysis and the clustering methods leads to a valid and simple way to classify healthy human skin and represents a potentially useful tool for cosmetic and dermatological research.

  12. Pig and guinea pig skin as surrogates for human in vitro penetration studies: a quantitative review.

    Science.gov (United States)

    Barbero, Ana M; Frasch, H Frederick

    2009-02-01

    Both human and animal skin in vitro models are used to predict percutaneous penetration in humans. The objective of this review is a quantitative comparison of permeability and lag time measurements between human and animal skin, including an evaluation of the intra and inter species variability. We limit our focus to domestic pig and rodent guinea pig skin as surrogates for human skin, and consider only studies in which both animal and human penetration of a given chemical were measured jointly in the same lab. When the in vitro permeability of pig and human skin were compared, the Pearson product moment correlation coefficient (r) was 0.88 (Ppig and 35% for human, and an inter species average coefficient of variation of 37% for the set of studied compounds (n=41). The lag times of pig skin and human skin did not correlate (r=0.35, P=0.26). When the in vitro permeability of guinea pig and human skin were compared, r=0.96 (Pguinea pig and 24% for human, and an inter species coefficient of variation of permeability of 41% for the set of studied compounds (n=15). Lag times of guinea pig and human skin correlated (r=0.90, Ppig skin (n=50) and guinea pig skin (n=25). For pig skin, 80% of measurements fell within the range 0.3guinea pig skin, 65% fell within that range. Both pig and guinea pig are good models for human skin permeability and have less variability than the human skin model. The skin model of choice will depend on the final purpose of the study and the compound under investigation.

  13. Evaluation of the suitability of chromatographic systems to predict human skin permeation of neutral compounds.

    Science.gov (United States)

    Hidalgo-Rodríguez, Marta; Soriano-Meseguer, Sara; Fuguet, Elisabet; Ràfols, Clara; Rosés, Martí

    2013-12-18

    Several chromatographic systems (three systems of high-performance liquid chromatography and two micellar electrokinetic chromatography systems) besides the reference octanol-water partition system are evaluated by a systematic procedure previously proposed in order to know their ability to model human skin permeation. The precision achieved when skin-water permeability coefficients are correlated against chromatographic retention factors is predicted within the framework of the solvation parameter model. It consists in estimating the contribution of error due to the biological and chromatographic data, as well as the error coming from the dissimilarity between the human skin permeation and the chromatographic systems. Both predictions and experimental tests show that all correlations are greatly affected by the considerable uncertainty of the skin permeability data and the error associated to the dissimilarity between the systems. Correlations with much better predictive abilities are achieved when the volume of the solute is used as additional variable, which illustrates the main roles of both lipophilicity and size of the solute to penetrate through the skin. In this way, the considered systems are able to give precise estimations of human skin permeability coefficients. In particular, the HPLC systems with common C18 columns provide the best performances in emulating the permeation of neutral compounds from aqueous solution through the human skin. As a result, a methodology based on easy, fast, and economical HPLC measurements in a common C18 column has been developed. After a validation based on training and test sets, the method has been applied with good results to the estimation of skin permeation of several hormones and pesticides. Copyright © 2013 Elsevier B.V. All rights reserved.

  14. Near infrared laser penetration and absorption in human skin

    Science.gov (United States)

    Nasouri, Babak; Murphy, Thomas E.; Berberoglu, Halil

    2014-02-01

    For understanding the mechanisms of low level laser/light therapy (LLLT), accurate knowledge of light interaction with tissue is necessary. In this paper, we present a three dimensional, multi-layer Monte Carlo simulation tool for studying light penetration and absorption in human skin. The skin is modeled as a three-layer participating medium, namely epidermis, dermis, and subcutaneous, where its geometrical and optical properties are obtained from the literature. Both refraction and reflection are taken into account at the boundaries according to Snell's law and Fresnel relations. A forward Monte Carlo method was implemented and validated for accurately simulating light penetration and absorption in absorbing and anisotropically scattering media. Local profiles of light penetration and volumetric absorption densities were simulated for uniform as well as Gaussian profile beams with different spreads at 155 mW average power over the spectral range from 1000 nm to 1900 nm. The results show the effects of beam profiles and wavelength on the local fluence within each skin layer. Particularly, the results identify different wavelength bands for targeted deposition of power in different skin layers. Finally, we show that light penetration scales well with the transport optical thickness of skin. We expect that this tool along with the results presented will aid researchers resolve issues related to dose and targeted delivery of energy in tissues for LLLT.

  15. Comparison of skin decontamination efficacy of commercial decontamination products following exposure to VX on human skin.

    Science.gov (United States)

    Thors, L; Koch, M; Wigenstam, E; Koch, B; Hägglund, L; Bucht, A

    2017-08-01

    The decontamination efficacy of four commercially available skin decontamination products following exposure to the nerve agent VX was evaluated in vitro utilizing a diffusion cell and dermatomed human skin. The products included were Reactive Skin Decontamination Lotion (RSDL), the Swedish decontamination powder 104 (PS104), the absorbent Fuller's Earth and the aqueous solution alldecontMED. In addition, various decontamination procedures were assessed to further investigate important mechanisms involved in the specific products, e.g. decontamination removal from skin, physical removal by sponge swabbing and activation of degradation mechanisms. The efficacy of each decontamination product was evaluated 5 or 30 min after dermal application of VX (neat or diluted to 20% in water). The RSDL-lotion was superior in reducing the penetration of VX through human skin, both when exposed as neat agent and when diluted to 20% in water. Swabbing with the RSDL-sponge during 2 min revealed decreased efficacy compared to applying the RSDL-lotion directly on the skin for 30 min. Decontamination with Fuller's Earth and alldecontMED significantly reduced the penetration of neat concentration of VX through human skin. PS104-powder was insufficient for decontamination of VX at both time-points, independently of the skin contact time of PS104. The PS104-slurry (a mixture of PS104-powder and water), slightly improved the decontamination efficacy. Comparing the time-points for initiated decontamination revealed less penetrated VX for RSDL and Fuller's Earth when decontamination was initiated after 5 min compared to 30 min post-exposure, while alldecontMED displayed similar efficacy at both time-points. Decontamination by washing with water only resulted in a significant reduction of penetrated VX when washing was performed 5 min after exposure, but not when decontamination was delayed to 30 min post-exposure of neat VX. In conclusion, early initiated decontamination with the

  16. Tribological behaviour of skin equivalents and ex-vivo human skin against the material components of artificial turf in sliding

    NARCIS (Netherlands)

    Morales Hurtado, Marina; Peppelman, P.; Zeng, Xiangqiong; van Erp, P.E.J.; van der Heide, Emile

    2016-01-01

    This research aims to analyse the interaction of three artificial skin equivalents and human skin against the main material components of artificial turf. The tribological performance of Lorica, Silicone Skin L7350 and a recently developed Epidermal Skin Equivalent (ESE) were studied and compared to

  17. The source-skin distance measuring bridge: A method to avoid radiation teleangiectasia in the skin after interstitial therapy for breast cancer

    International Nuclear Information System (INIS)

    Van Limbergen, E.; Briot, E.; Drijkoningen, M.

    1990-01-01

    Inappropriate positioning of interstitial iridium 192 implants, used as booster dose in the breast conserving treatment of mammary cancer, may cause disturbing teleangiectasia of the breast skin, when high radiation doses are delivered on the dermal blood vessels. Based on the localization of the vascular plexuses in human breast skin, and on the dose distribution around different types of interstitial implants, a method is described to avoid overlap between the high dose area of the implant and the blood vessels in the skin. The latter are demonstrated to run within the first 5 mm under the epiderm. For source lengths varying from 5 to 8 cm, simple mathematical relations exist between the maximal security margin (MSM) and intersource distance (E) for single plane implants (MSM = 0.4 (E + 1)), double plane square implants (MSM = 0.4 E) and double plane triangular implants (MSM = 0.4 (E - 1)). We developed a device to measure precisely the distance between the radioactive wires and the overlying skin, along the whole source trajectory. Using this method, the occurrence of teleangiectasia in the breast skin after interstitial implants with Ir 192 may be significantly reduced

  18. A flexible skin piloerection monitoring sensor

    Science.gov (United States)

    Kim, Jaemin; Seo, Dae Geon; Cho, Young-Ho

    2014-06-01

    We have designed, fabricated, and tested a capacitive-type flexible micro sensor for measurement of the human skin piloerection arisen from sudden emotional and environmental change. The present skin piloerection monitoring methods are limited in objective and quantitative measurement by physical disturbance stimulation to the skin due to bulky size and heavy weight of measuring devices. The proposed flexible skin piloerection monitoring sensor is composed of 3 × 3 spiral coplanar capacitor array using conductive polymer for having high capacitive density and thin enough thickness to be attached to human skin. The performance of the skin piloerection monitoring sensor is characterized using the artificial bump, representing human skin goosebump; thus, resulting in the sensitivity of -0.00252%/μm and the nonlinearity of 25.9% for the artificial goosebump deformation in the range of 0-326 μm. We also verified successive human skin piloerection having 3.5 s duration on the subject's dorsal forearms, thus resulting in the capacitance change of -6.2 fF and -9.2 fF for the piloerection intensity of 145 μm and 194 μm, respectively. It is demonstrated experimentally that the proposed sensor is capable to measure the human skin piloerection objectively and quantitatively, thereby suggesting the quantitative evaluation method of the qualitative human emotional status for cognitive human-machine interfaces applications.

  19. Appreciating the image of God in all humanity: Towards a pastoral response to skin lightening as image enhancement to exit dark skin

    Directory of Open Access Journals (Sweden)

    Noah K. Tenai

    2016-05-01

    Full Text Available The practice of skin lightening is prevalent amongst dark-skinned people globally. Various current studies that map this practice and that seek motivations behind the practice are examined. It is observed that through shrewd marketing, dark-skinned people are offered a promise of a better quality of life, obtained by a lighter skin, through the use of skin lighteners. In spite of the severe health risks involved, the promise is ostensibly irresistible to some dark-skinned persons. A pastoral response is offered that affirms the full personhood and complete humanity of dark-skinned people as fully human and whole in their dark skins. Keywords: Skin lightening, Dark skin, Image of God

  20. Essential role of RAB27A in determining constitutive human skin color.

    Directory of Open Access Journals (Sweden)

    Yasuko Yoshida-Amano

    Full Text Available Human skin color is predominantly determined by melanin produced in melanosomes within melanocytes and subsequently distributed to keratinocytes. There are many studies that have proposed mechanisms underlying ethnic skin color variations, whereas the processes involved from melanin synthesis in melanocytes to the transfer of melanosomes to keratinocytes are common among humans. Apart from the activities in the melanogenic rate-limiting enzyme, tyrosinase, in melanocytes and the amounts and distribution patterns of melanosomes in keratinocytes, the abilities of the actin-associated factors in charge of melanosome transport within melanocytes also regulate pigmentation. Mutations in genes encoding melanosome transport-related molecules, such as MYO5A, RAB27A and SLAC-2A, have been reported to cause a human pigmentary disease known as Griscelli syndrome, which is associated with diluted skin and hair color. Thus we hypothesized that process might play a role in modulating skin color variations. To address that hypothesis, the correlations of expression of RAB27A and its specific effector, SLAC2-A, to melanogenic ability were evaluated in comparison with tyrosinase, using human melanocytes derived from 19 individuals of varying skin types. Following the finding of the highest correlation in RAB27A expression to the melanogenic ability, darkly-pigmented melanocytes with significantly higher RAB27A expression were found to transfer significantly more melanosomes to keratinocytes than lightly-pigmented melanocytes in co-culture and in human skin substitutes (HSSs in vivo, resulting in darker skin color in concert with the difference observed in African-descent and Caucasian skins. Additionally, RAB27A knockdown by a lentivirus-derived shRNA in melanocytes concomitantly demonstrated a significantly reduced number of transferred melanosomes to keratinocytes in co-culture and a significantly diminished epidermal melanin content skin color intensity (

  1. Immunohistochemical study of sensory nerve formations in human glabrous skin.

    Science.gov (United States)

    Haro, J J; Vega, J A; del Valle, M E; Calzada, B; Zaccheo, D; Malinovsky, L

    1991-01-01

    The sensory nerve formations (or corpuscles) of normal human glabrous skin from hand and fingers, obtained by punch biopsies, were studied by the streptavidin-biotin method using monoclonal antibodies directed against neurofilament protein (NFP), S-100 protein, glial fibrillary acidic protein (GFAP), cytokeratins, and vimentin. NFP immunoreactivity (IR) was observed in the central axons of most sensory formations, while S-100 protein IR was restricted to non-neuronal cells forming the so-called inner cells core or lamellar cells. Furthermore, vimentin IR was found in the same cells of Meissner's and glomerular corpuscles. None of the sensory nerve formations were stained for GFAP or keratin. The present results suggest that the main nature of the intermediate filaments of the non-neuronal cells of sensory nerve formations from human glabrous skin is represented by vimentin and not by GFAP. Thus, our findings suggest that lamellar and inner core cells of SNF are modified and specialized Schwann cells and not epithelial or perineurial derived cells.

  2. Confocal laser scanning microscopy to estimate nanoparticles' human skin penetration in vitro.

    Science.gov (United States)

    Zou, Ying; Celli, Anna; Zhu, Hanjiang; Elmahdy, Akram; Cao, Yachao; Hui, Xiaoying; Maibach, Howard

    2017-01-01

    With rapid development of nanotechnology, there is increasing interest in nanoparticle (NP) application and its safety and efficacy on human skin. In this study, we utilized confocal laser scanning microscopy to estimate NP skin penetration. Three different-sized polystyrene NPs marked with red fluorescence were applied to human skin, and Calcium Green 5N was used as a counterstain. Dimethyl sulfoxide (DMSO) and ethanol were used as alternative vehicles for NPs. Tape stripping was utilized as a barrier-damaged skin model. Skin biopsies dosed with NPs were incubated at 4°C or 37°C for 24 hours and imaged using confocal laser scanning microscopy. NPs were localized in the stratum corneum (SC) and hair follicles without penetrating the epidermis/dermis. Barrier alteration with tape stripping and change in incubation temperature did not induce deeper penetration. DMSO enhanced NP SC penetration but ethanol did not. Except with DMSO vehicle, these hydrolyzed polystyrene NPs did not penetrate intact or barrier-damaged human "viable" epidermis. For further clinical relevance, in vivo human skin studies and more sensitive analytic chemical methodology are suggested.

  3. Comparison of rat epidermal keratinocyte organotypic culture (ROC) with intact human skin

    DEFF Research Database (Denmark)

    Pappinen, Sari; Hermansson, Martin; Kuntsche, Judith

    2008-01-01

    study was to compare the stratum corneum lipid content of ROC with the corresponding material from human skin. The lipid composition was determined by thin-layer chromatography (TLC) and mass-spectrometry, and the thermal phase transitions of stratum corneum were studied by differential scanning...... calorimetry (DSC). All major lipid classes of the stratum corneum were present in ROC in a similar ratio as found in human stratum corneum. Compared to human skin, the level of non-hydroxyacid-sphingosine ceramide (NS) was increased in ROC, while alpha-hydroxyacid-phytosphingosine ceramide (AP) and non...... compared to human skin, in agreement with the results from DSC. ROC underwent a lipid lamellar order to disorder transition (T2) at a slightly lower temperature (68 degrees C) than human skin (74 degrees C). These differences in stratum corneum lipid composition and the thermal phase transitions may...

  4. Multiphoton spectroscopy of human skin in vivo

    Science.gov (United States)

    Breunig, Hans G.; Weinigel, Martin; König, Karsten

    2012-03-01

    In vivo multiphoton-intensity images and emission spectra of human skin are reported. Optical sections from different depths of the epidermis and dermis have been measured with near-infrared laser-pulse excitation. While the intensity images reveal information on the morphology, the spectra show emission characteristics of main endogenous skin fluorophores like keratin, NAD(P)H, melanin, elastin and collagen as well as of second harmonic generation induced by the excitation-light interaction with the dermal collagen network.

  5. Diffuse colonies of human skin fibroblasts in relation to cellular senescence and proliferation.

    Science.gov (United States)

    Zorin, Vadim; Zorina, Alla; Smetanina, Nadezhda; Kopnin, Pavel; Ozerov, Ivan V; Leonov, Sergey; Isaev, Artur; Klokov, Dmitry; Osipov, Andreyan N

    2017-05-16

    Development of personalized skin treatment in medicine and skin care may benefit from simple and accurate evaluation of the fraction of senescent skin fibroblasts that lost their proliferative capacity. We examined whether enriched analysis of colonies formed by primary human skin fibroblasts, a simple and widely available cellular assay, could reveal correlations with the fraction of senescent cells in heterogenic cell population. We measured fractions of senescence associated β-galactosidase (SA-βgal) positive cells in either mass cultures or colonies of various morphological types (dense, mixed and diffuse) formed by skin fibroblasts from 10 human donors. Although the donors were chosen to be within the same age group (33-54 years), the colony forming efficiency of their fibroblasts (ECO-f) and the percentage of dense, mixed and diffuse colonies varied greatly among the donors. We showed, for the first time, that the SA-βgal positive fraction was the largest in diffuse colonies, confirming that they originated from cells with the least proliferative capacity. The percentage of diffuse colonies was also found to correlate with the SA-βgal positive cells in mass culture. Using Ki67 as a cell proliferation marker, we further demonstrated a strong inverse correlation (r=-0.85, p=0.02) between the percentage of diffuse colonies and the fraction of Ki67+ cells. Moreover, a significant inverse correlation (r=-0.94, p=0.0001) between the percentage of diffuse colonies and ECO-f was found. Our data indicate that quantification of a fraction of diffuse colonies may provide a simple and useful method to evaluate the extent of cellular senescence in human skin fibroblasts.

  6. A Method for Quantification of Penetration of Nanoparticles through Skin Layers Using Near-Infrared Optical Imaging

    Directory of Open Access Journals (Sweden)

    Melinda Stees

    2015-07-01

    Full Text Available Our study presents a new method for tracking nanoparticle penetration through different layers of the skin using near-infrared dye-loaded nanoparticles (hydrodynamic diameter = 156 nm and optical imaging. The dye-loaded nanoparticles were mixed in a topical skin cream, applied to human cadaver skin and incubated either for three or 24 h post-application, skin tissue was clipped between glass slides prior to imaging for signal intensity across the skin thickness using an optical imaging system. The data show that nanoparticles penetrate through all the layers of the skin but there is almost an exponential decay in the signal intensity from epidermis to dermis. Depending upon the incubation time, about 55%–59% of the total signal was seen in the epidermis and the remaining through dermis and hypodermis. The advantage of the method is that it allows quantitative analysis of the extent of penetration of nanoparticles through different layers of the skin without interference of any background signal from skin tissue, and without requiring extensive tissue processing. Our method could potentially be used to study the effect of nanoparticle properties and/or the use of different formulation additives on penetration of nanoparticles through different skin layers.

  7. Human Skin Is the Largest Epithelial Surface for Interaction with Microbes.

    Science.gov (United States)

    Gallo, Richard L

    2017-06-01

    Human skin contains an abundant and diverse population of microbial organisms. Many of these microbes inhabit follicular structures of the skin. Furthermore, numerous studies have shown that the interaction of some members of the skin microbiome with host cells will result in changes in cell function. However, estimates of the potential for the microbiome to influence human health through skin have ignored the inner follicular surface, and therefore vastly underestimated the potential of the skin microbiome to have a systemic effect on the human body. By calculating the surface area of follicular and the interfollicular epithelial surface it is shown that skin provides a vast interface for interactions with the microbiome. Copyright © 2017 The Author. Published by Elsevier Inc. All rights reserved.

  8. Going skin deep: A direct comparison of penetration potential of lipid-based nanovesicles on the isolated perfused human skin flap model.

    Science.gov (United States)

    Ternullo, Selenia; de Weerd, Louis; Holsæter, Ann Mari; Flaten, Gøril Eide; Škalko-Basnet, Nataša

    2017-12-01

    Phospholipid-based nanocarriers are attractive drug carriers for improved local skin therapy. In the present study, the recently developed isolated perfused human skin flap (IPHSF) model was used to directly compare the skin penetration enhancing potential of the three commonly used nanocarriers, namely conventional liposomes (CLs), deformable liposomes (DLs) and solid lipid nanoparticles (SLNs). Two fluorescent markers, calcein (hydrophilic) or rhodamine (lipophilic), were incorporated individually in the three nanosystems. The nanocarrier size ranged between 200 and 300nm; the surface charge and entrapment efficiency for both markers were dependent on the lipid composition and the employed surfactant. Both carrier-associated markers could not penetrate the full thickness human skin, confirming their suitability for dermal drug delivery. CLs exhibited higher retention of both markers on the skin surface compared to DLs and SLNs, indicating a depo formation. DLs and SLNs enabled the deeper penetration of the two markers into the skin layers. In vitro and ex vivo skin penetration studies performed on the cellophane membrane and full thickness pig/human skin, respectively, confirmed the findings. In conclusion, efficient dermal drug delivery can be achieved by optimization of a lipid nanocarrier on the suitable skin-mimicking model to assure system's accumulation in the targeted skin layer. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Human Wharton's jelly mesenchymal stem cells promote skin wound healing through paracrine signaling.

    Science.gov (United States)

    Arno, Anna I; Amini-Nik, Saeid; Blit, Patrick H; Al-Shehab, Mohammed; Belo, Cassandra; Herer, Elaine; Tien, Col Homer; Jeschke, Marc G

    2014-02-24

    The prevalence of nonhealing wounds is predicted to increase due to the growing aging population. Despite the use of novel skin substitutes and wound dressings, poorly vascularized wound niches impair wound repair. Mesenchymal stem cells (MSCs) have been reported to provide paracrine signals to promote wound healing, but the effect of human Wharton's jelly-derived MSCs (WJ-MSCs) has not yet been described in human normal skin. Human WJ-MSCs and normal skin fibroblasts were isolated from donated umbilical cords and normal adult human skin. Fibroblasts were treated with WJ-MSC-conditioned medium (WJ-MSC-CM) or nonconditioned medium. Expression of genes involved in re-epithelialization (transforming growth factor-β2), neovascularization (hypoxia-inducible factor-1α) and fibroproliferation (plasminogen activator inhibitor-1) was upregulated in WJ-MSC-CM-treated fibroblasts (P≤0.05). WJ-MSC-CM enhanced normal skin fibroblast proliferation (P≤0.001) and migration (P≤0.05), and promoted wound healing in an excisional full-thickness skin murine model. Under our experimental conditions, WJ-MSCs enhanced skin wound healing in an in vivo mouse model.

  10. Deposition of contaminant aerosol on human skin

    DEFF Research Database (Denmark)

    Andersson, Kasper Grann; Roed, Jørn; Byrne, M.A.

    2006-01-01

    Over recent years, it has been established that deposition of various types of pollutant aerosols (e.g., radioactive) on human skin can have serious deleterious effects on health. However. only few investigations in the past have been devoted to measurement of deposition velocities on skin...... of particles of the potentially problematic sizes. An experimental programme has shown the deposition velocities on skin of particles in the ca. 0.5-5 mu m AMAD range to be high and generally associated with great variations. A series of investigations have been made to identify some of the factors that lead...... to this variation. Part of the variation was found to be caused by differences between individuals, whereas another part was found to be related to environmental factors, The identification of major influences on skin contaminant deposition is important in estimating health effects as well as in identifying means...

  11. Characterization of ionizing radiation effects on human skin allografts

    International Nuclear Information System (INIS)

    Bourroul, Selma Cecilia

    2004-01-01

    The skin has a fundamental role in the viability of the human body. In the cases of extensive wounds, allograft skin provides an alternative to cover temporarily the damaged areas. After donor screening and preservation in glycerol (above 85%), the skin can be stored in the Skin Banks. The glycerol at this concentration has a bacteriostatic effect after certain time of preservation. On the other hand, skin sterilization by ionizing radiation may reduces the quarantine period for transplantation in patients and its safety is considered excellent. The objectives of this work were to establish procedures using two sources of ionizing radiation for sterilization of human skin allograft, and to evaluate the skin after gamma and electron beam irradiation. The analysis of stress-strain intended to verify possible effects of the radiation on the structure of preserved grafts. Skin samples were submitted to doses of 25 kGy and 50 kGy in an irradiator of 60 Co and in an electron beam accelerator. Morphology and ultra-structure studies were also accomplished. The samples irradiated with a dose of 25 kGy seemed to maintain the bio mechanic characteristics. The gamma irradiated samples with a dose of 50 kGy and submitted to an electron beam at doses of 25 kGy and 50 kGy presented significant differences in the values of the elasticity modulus, in relation to the control. The analysis of the ultramicrographies revealed modifications in the structure and alterations in the pattern of collagen fibrils periodicity of the irradiated samples. (author)

  12. Effect of mixed-sulfonated aluminium phthalocyanine on human skin fibroblasts for photodynamic therapy

    CSIR Research Space (South Africa)

    Ndhundhuma, IM

    2008-08-01

    Full Text Available of the study was to evaluate the effect of mixed-sulfonated aluminium phthalocyanine (AlPcSmix) used as photosensitizers for PDT, determined by changes in cell morphology and cell viability of human skin fibroblasts (WS1). Methods. Cells incubated with 5, 10...

  13. Alternative methods for skin irritation testing: the current status : ECVAM skin irritation task force report 1

    NARCIS (Netherlands)

    Botham, P.A.; Earl, L.K.; Fentem, J.H.; Roguet, R.; Sandt, J.J.M.

    1998-01-01

    The ECVAM Skin Irritation Task Force was established in November 1996, primarily to prepare a report on the current status of the development and validation of alternative tests for skin irritation and corrosion and, in particular, to identify any appropriate non-animal tests for predicting human

  14. Fermentation of Propionibacterium acnes, a commensal bacterium in the human skin microbiome, as skin probiotics against methicillin-resistant Staphylococcus aureus.

    Directory of Open Access Journals (Sweden)

    Muya Shu

    Full Text Available Bacterial interference creates an ecological competition between commensal and pathogenic bacteria. Through fermentation of milk with gut-friendly bacteria, yogurt is an excellent aid to balance the bacteriological ecosystem in the human intestine. Here, we demonstrate that fermentation of glycerol with Propionibacterium acnes (P. acnes, a skin commensal bacterium, can function as a skin probiotic for in vitro and in vivo growth suppression of USA300, the most prevalent community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA. We also promote the notion that inappropriate use of antibiotics may eliminate the skin commensals, making it more difficult to fight pathogen infection. This study warrants further investigation to better understand the role of fermentation of skin commensals in infectious disease and the importance of the human skin microbiome in skin health.

  15. Cutaneous in vivo metabolism of topical lidocaine formulation in human skin

    DEFF Research Database (Denmark)

    Rolsted, K; Benfeldt, E; Kissmeyer, A-M

    2009-01-01

    Little is known about the metabolising capacity of the human skin in relation to topically applied drugs and formulations. We chose lidocaine as a model compound since the metabolic pathways are well known from studies concerning hepatic metabolism following systemic drug administration. However......, the enzymes involved are also expressed in the skin. Hence, the aim of the current study was to investigate the extent of the cutaneous in vivo metabolism of topically applied lidocaine in human volunteers. A dose of 5 mg/cm(2) of Xylocaine(R) (5% lidocaine) ointment was applied onto the buttock skin...... of the volunteers. After 2 h, residual formulation was removed, and two 4-mm punch biopsies were taken from each volunteer. The quantity of lidocaine extracted from the skin samples (epidermis + dermis) was 109 +/- 43 ng/mm(2) skin. One metabolite (monoethylglycine xylidide, MEGX) was detected in skin from 7...

  16. Reproducible pattern of microRNA in normal human skin

    DEFF Research Database (Denmark)

    Holst, Line; Kaczkowski, Bogumil; Gniadecki, Robert

    2010-01-01

    RNA expression pattern in normal human skin. Here we investigated miRNA expression profiles from skin biopsies of 8 healthy volunteers taken from sun protected and mildly photo damaged skin using the modified protocol for miRNA extraction. We were able to show a constant pattern of miRNA expression between......MicroRNAs (miRNAs) regulate cell growth, differentiation and apoptosis via specific targeting of messenger RNA (mRNA). Aberrant mRNA expression contributes to pathological processes such as carcinogenesis. To take advantage of miRNA profiling in skin disease it is essential to investigate mi...... different individuals. We did not find any significant differences in miRNA expression between sun protected and mildly photodamaged skin. These results may be valuable for future design of studies on miRNA expression in skin disease....

  17. Reproducible pattern of microRNA in normal human skin

    DEFF Research Database (Denmark)

    Holst, Line; Kaczkowski, Bogumil; Gniadecki, Robert

    2010-01-01

    RNA expression pattern in normal human skin. Here we investigated miRNA expression profiles from skin biopsies of 8 healthy volunteers taken from sun protected and mildly photo damaged skin using the modified protocol for miRNA extraction. We were able to show a constant pattern of miRNA expression between...... different individuals. We did not find any significant differences in miRNA expression between sun protected and mildly photodamaged skin. These results may be valuable for future design of studies on miRNA expression in skin disease.......MicroRNAs (miRNAs) regulate cell growth, differentiation and apoptosis via specific targeting of messenger RNA (mRNA). Aberrant mRNA expression contributes to pathological processes such as carcinogenesis. To take advantage of miRNA profiling in skin disease it is essential to investigate mi...

  18. Oxidative stress and CCN1 protein in human skin connective tissue aging

    Directory of Open Access Journals (Sweden)

    Zhaoping Qin

    2016-06-01

    Full Text Available Reactive oxygen species (ROS is an important pathogenic factor involved in human aging. Human skin is a primary target of oxidative stress from ROS generated from both extrinsic and intrinsic sources, like ultraviolet irradiation (UV and endogenous oxidative metabolism. Oxidative stress causes the alterations of collagen-rich extracellular matrix (ECM, the hallmark of skin connective tissue aging. Age-related alteration of dermal collagenous ECM impairs skin structural integrity and creates a tissue microenvironment that promotes age-related skin diseases, such as poor wound healing and skin cancer. Here, we review recent advances in our understanding of oxidative stress and CCN1 protein (first member of CCN family proteins, a critical mediator of oxidative stress-induced skin connective tissue aging.

  19. The moisturizing effects of glycolipid biosurfactants, mannosylerythritol lipids, on human skin.

    Science.gov (United States)

    Yamamoto, Shuhei; Morita, Tomotake; Fukuoka, Tokuma; Imura, Tomohiro; Yanagidani, Shusaku; Sogabe, Atsushi; Kitamoto, Dai; Kitagawa, Masaru

    2012-01-01

    Glycolipid biosurfactants, such as mannosylerythritol lipids (MELs), are produced by different yeasts belonging to the genus Pseudozyma and have been attracting much attention as new cosmetic ingredients owing to their unique liquid-crystal-forming and moisturizing properties. In this study, the effects of different MEL derivatives on the skin were evaluated in detail using a three-dimensional cultured human skin model and an in vivo human study. The skin cells were cultured and treated with sodium dodecyl sulfate (SDS), and the effects of different lipids on the SDS-damaged cells were evaluated on the basis of cell viability. Most MEL derivatives efficiently recovered the viability of the cells and showed high recovery rates (over 80%) comparable with that of natural ceramide. It is interesting that the recovery rate with MEL-A prepared from olive oil was significantly higher than that of MEL-A prepared from soybean oil. The water retention properties of MEL-B were further investigated on human forearm skin in a preliminary study. Compared with the control, the aqueous solution of MEL-B (5 wt%) was estimated to considerably increase the stratum corneum water content in the skin. Moreover, perspiration on the skin surface was clearly suppressed by treatment with the MEL-B solution. These results suggest that MELs are likely to exhibit a high moisturizing action, by assisting the barrier function of the skin. Accordingly, the yeast glycolipids have a strong potential as a new ingredient for skin care products.

  20. Optical coherence tomography applied to tests of skin care products in humans--a case study.

    Science.gov (United States)

    Vasquez-Pinto, L M C; Maldonado, E P; Raele, M P; Amaral, M M; de Freitas, A Z

    2015-02-01

    When evaluating skin care products for human skin, quantitative test methods need to be simple, precise and reliable. Optical coherence tomography (OCT), provides high-resolution sectional images of translucent materials to a depth of a few millimeters, a technique usually applied to medical measurements in ophthalmology and dermatology. This study aimed to demonstrate the application of OCT as the main technique for monitoring changes in skin topography during tests of a wrinkle-reduction product in humans. We used a commercial OCT apparatus to perform clinical examinations of skin roughness in treated and non-treated sites in the periorbital region of thirty human voluntaries who were using an anti-aging product commercially available: Natura Chronos® Flavonóides de Passiflora 45+ FPS15, from Natura Cosméticos, Brazil. Measurements were performed days 0, 7, 14 and 28 of treatment. Equipment and software allowed real-time recording of skin roughness parameters and wrinkle depths. The OCT measurements have allowed the monitoring of changes in skin roughness, which have shown reduction in treated sites around 10%. The obtained depth distributions also indicate reduction in the occurrence of wrinkles deeper than 170 μm. The verified results are consistent with those typically obtained after successful treatment with modern anti-aging products. By using the OCT technique, it was possible to quantify changes in skin roughness and in the distribution of depths of skin wrinkles, with adequate sensitivity. OCT imaging allows the direct visualization of the skin topography with resolution of micrometers, a reliable and interactive tool for clinical use. Therefore, for the first time, we demonstrated the use of OCT technique to verify the efficacy of cosmetic products in real time. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  1. The validity of wireless iButtons® and thermistors for human skin temperature measurement

    International Nuclear Information System (INIS)

    Smith, A D Harper; Walsh, N P; Crabtree, D R; Bilzon, J L J

    2010-01-01

    Skin temperature is a fundamental variable in human thermo-physiology, and yet skin temperature measurement remains impractical in most free-living, exercise and clinical settings, using currently available hard-wired methods. The purpose of this study was to compare wireless iButtons® and hard-wired thermistors for human skin temperature measurement. In the first of two investigations, iButtons® and thermistors monitored temperature in a controlled water bath (range: 10–40 °C) and were referenced against a certified, mercury thermometer. In the second investigation, eight healthy males completed three randomized trials (ambient temperature = 10 °C, 20 °C and 30 °C) while both devices recorded skin temperature at rest (in low and high wind velocities) and during cycle-ergometry exercise. The results are as follows; Investigation 1: both devices displayed very high validity correlation with the reference thermometer (r > 0.999). Prior to correction, the mean bias was +0.121 °C for iButtons® and +0.045 °C for thermistors. Upon calibration correction the mean bias for iButtons® and thermistors was not significantly different from zero bias. Interestingly, the typical error of the estimate of iButtons® (0.043 °C) was 1.5 times less than that of thermistors (0.062 °C), demonstrating iButtons'® lower random error. Investigation 2: the offset between iButton® and thermistor readings was generally consistent across conditions; however, thermistor responses gave readings that were always closer to ambient temperature than those given by iButtons®, suggesting potential thermistor drift towards environmental conditions. Mean temperature differences between iButtons® and thermistors during resting trials ranged from 0.261 °C to 1.356 °C. Mean temperature differences between iButtons® and thermistors during exercise were 0.989 °C (ambient temperature = 10 °C), 0.415 °C (ambient temperature = 20 °C) and 0.318 °C (ambient temperature = 30 °C). Observed

  2. Comparison of protocols for measuring cosmetic ingredient distribution in human and pig skin.

    Science.gov (United States)

    Gerstel, D; Jacques-Jamin, C; Schepky, A; Cubberley, R; Eilstein, J; Grégoire, S; Hewitt, N; Klaric, M; Rothe, H; Duplan, H

    2016-08-01

    The Cosmetics Europe Skin Bioavailability and Metabolism Task Force aims to improve the measurement and prediction of the bioavailability of topically-exposed compounds for risk assessment. Key parameters of the experimental design of the skin penetration studies were compared. Penetration studies with frozen human and pig skin were conducted in two laboratories, according to the SCCS and OECD 428 guidelines. The disposition in skin was measured 24h after finite topical doses of caffeine, resorcinol and 7-ethoxycoumarin. The bioavailability distribution in skin layers of cold and radiolabelled chemicals were comparable. Furthermore, the distribution of each chemical was comparable in human and pig skin. The protocol was reproducible across the two laboratories. There were small differences in the amount of chemical detected in the skin layers, which were attributed to differences in washing procedures and anatomical sites of the skin used. In conclusion, these studies support the use of pig skin as an alternative source of skin should the availability of human skin become a limiting factor. If radiolabelled chemicals are not available, cold chemicals can be used, provided that the influence of chemical stability, reactivity or metabolism on the experimental design and the relevance of the data obtained is considered. Copyright © 2016. Published by Elsevier Ltd.

  3. Skin graft influence in human tissue radiated in nude mice regeneration

    International Nuclear Information System (INIS)

    Miranda, Jurandir Tomaz de

    2016-01-01

    Over the last few years it has increased the interest in the human skin grafts radio sterilized for application mainly in extensive and deep burns. Because these grafts quickly grip and present antigenic lower potential, compared with other treatments used. The purpose of this study was to evaluate the histoarchitecture of human skin grafts irradiated with doses 25 kGy, 50 kGy and non-irradiated during the repair tissue process in nude mice submitted by skin grafting in the dorsal region. Three groups of animals received irradiated human skin grafts (25 kGy and 50 kGy) and non-irradiated and were euthanized on the 3 rd , 7 th and 21 th day after the surgery. Indeed, routine histologic procedures, tissue samples were stained with hematoxylin and eosin (HE) for quantification of keratinocytes, fibroblasts, immune cells and blood vessels and immunofluorescence (IF) was performed to determine the expression human collagen type I and collagen type I and III mouse. Therefore, quantification of both the cells and the collagen types was performed by image analysis using Image-Pro Plus 6.0 software. Histologic results demonstrated at a dose of 25 kGy that human skin irradiation when grafted influences the increase in the number of cells in wound site over time and it provides better dispersion of these cells. In addition, on the 21 st day, three groups of animals with human skin graft were embedded part of the graft in the healing process. On the other hand, the group not irradiated showed greater incorporation of the graft (43 %), but less production of collagen type III mouse (22 %). Since the groups irradiated skin graft showed lower graft incorporation (6 and 15%), but with greater production of collagen type III mice (35 % and 28 % to 25 kGy and 50 kGy, respectively). In conclusion, this study presented that the group irradiated to 25 kGy and it has a higher cell proliferation and vessel formation, and better remodeling of the healing area. (author)

  4. Experimental metagenomics and ribosomal profiling of the human skin microbiome.

    Science.gov (United States)

    Ferretti, Pamela; Farina, Stefania; Cristofolini, Mario; Girolomoni, Giampiero; Tett, Adrian; Segata, Nicola

    2017-03-01

    The skin is the largest organ in the human body, and it is populated by a large diversity of microbes, most of which are co-evolved with the host and live in symbiotic harmony. There is increasing evidence that the skin microbiome plays a crucial role in the defense against pathogens, immune system training and homoeostasis, and microbiome perturbations have been associated with pathological skin conditions. Studying the skin resident microbial community is thus essential to better understand the microbiome-host crosstalk and to associate its specific configurations with cutaneous diseases. Several community profiling approaches have proved successful in unravelling the composition of the skin microbiome and overcome the limitations of cultivation-based assays, but these tools remain largely inaccessible to the clinical and medical dermatology communities. The study of the skin microbiome is also characterized by specific technical challenges, such as the low amount of microbial biomass and the extensive human DNA contamination. Here, we review the available community profiling approaches to study the skin microbiome, specifically focusing on the practical experimental and analytical tools necessary to generate and analyse skin microbiome data. We describe all the steps from the initial samples collection to the final data interpretation, with the goal of enabling clinicians and researchers who are not familiar with the microbiome field to perform skin profiling experiments. © 2016 The Authors. Experimental Dermatology Published by John Wiley & Sons Ltd.

  5. Friction of Human Skin against Different Fabrics for Medical Use

    Directory of Open Access Journals (Sweden)

    Luís Vilhena

    2016-03-01

    Full Text Available Knowledge of the tribology of human skin is essential to improve and optimize surfaces and materials in contact with the skin. Besides that, friction between the human skin and textiles is a critical factor in the formation of skin injuries, which are caused if the loads and shear forces are high enough and/or over long periods of time. This factor is of particular importance in bedridden patients, since they are not moving about or are confined to wheelchairs. Decubitus ulcers are one of the most frequently-reported iatrogenic injuries in developed countries. The risk of developing decubitus ulcers can be predicted by using the “Braden Scale for Predicting Pressure Ulcer Risk” that was developed in 1987 and contains six areas of risk (cognitive-perceptual, immobility, inactivity, moisture, nutrition, friction/shear, although there are limitations to the use of such tools. The coefficient of friction of textiles against skin is mainly influenced by: the nature of the textile, skin moisture content and ambient humidity. This study will investigate how skin friction (different anatomical regions varies, rubbing against different types of contacting materials (i.e., fabrics for medical use under different contact conditions and their relationship in the formation and prevention of decubitus ulcers.

  6. Effect of Different Skin Penetration Promoters in Halobetasol Propionate Permeation and Retention in Human Skin

    Directory of Open Access Journals (Sweden)

    Paulina Carvajal-Vidal

    2017-11-01

    Full Text Available Halobetasol propionate (HB is a potent synthetic corticosteroid used against inflammatory skin diseases, such as dermatitis, eczema, and psoriasis, among others. The aim of this study is to define how the presence of different skin penetration enhancers (nonane, menthone, limonene, azone, carene, decanol, linoleic acid and cetiol affects the penetration and retention in skin of HB. To determine drug penetration through skin, 5% of each promoter was used in an ex vivo system with human skin on Franz cells. The results showed that the highest permeation occurs in the presence of menthone, followed by nonane. Permeation parameters were determined. The in vivo test was assessed, and the formulation containing HB-menthone presented better anti-inflammatory efficacy. These results are useful to generate a specific treatment according to each patient’s needs, and the inflammatory characteristics of the disease.

  7. Relevance of sunscreen application method, visible light and sunlight intensity to free-radical protection: A study of ex vivo human skin.

    Science.gov (United States)

    Haywood, Rachel

    2006-01-01

    With the continued rise in skin cancers worldwide there is a need for effective skin protection against sunlight damage. It was shown previously that sunscreens, which claimed UVA protection (SPF 20+), provided limited protection against UV-induced ascorbate radicals in human skin. Here the results of an electron spin resonance (ESR) investigation to irradiate ex vivo human skin with solar-simulated light are reported. The ascorbate radical signal in the majority of skin samples was directly proportional to the irradiance over relevant sunlight intensities (0.9-2.9 mW cm(-2)). Radical production (substratum-corneum) by UV (wavelengths 400 nm) was approximately 67% and 33% respectively. Ascorbate radicals were in steady state concentration at low irradiance (approximately 1 mW cm(-2) equivalent to UK sunlight), but at higher irradiance (approximately 3 mW cm(-2)) decreased with time, suggesting ascorbate depletion. Radical protection by a four star-rated sunscreen (with UVA protection) was optimal when applied as a thin film (40-60% at 2 mg cm(-2)) but less so when rubbed into the skin (37% at 4 mg cm(-2) and no significant protection at 2 mg cm(-2)), possibly due to cream filling crevices, which reduced film thickness. This study validates ESR determinations of the ascorbate radical for quantitative protection measurements. Visible light contribution to radical production, and loss of protection when sunscreen is rubbed into skin, has implications for sunscreen design and use for the prevention of free-radical damage.

  8. Minimally-invasive Sampling of Interleukin-1α and Interleukin-1 Receptor Antagonist from the Skin: A Systematic Review of In vivo Studies in Humans.

    Science.gov (United States)

    Falcone, Denise; Spee, Pieter; van de Kerkhof, Peter C M; van Erp, Piet E J

    2017-10-02

    Interleukin-1α (IL-1α) and its receptor antagonist IL-1RA play a pivotal role in skin homeostasis and disease. Although the use of biopsies to sample these cytokines from human skin is widely employed in dermatological practice, knowledge about less invasive, in vivo sampling methods is scarce. The aim of this study was to provide an overview of such methods by systematically reviewing studies in Medline, EMBASE, Web of Science and Cochrane Library using combinations of the terms "IL-1α", IL-1RA", "skin", "human", including all possible synonyms. Quality was assessed using the STrengthening the Reporting of OBservational studies in Epidemiology (STROBE) checklist. The search, performed on 14 October 2016, revealed 10 different sampling methods, with varying degrees of invasiveness and wide application spectrum, including assessment of both normal and diseased skin, from several body sites. The possibility to sample quantifiable amounts of cytokines from human skin with no or minimal discomfort holds promise for linking clinical outcomes to molecular profiles of skin inflammation.

  9. Pheno- and genotyping of Staphylococcus epidermidis isolated from bovine milk and human skin

    DEFF Research Database (Denmark)

    Thorberg, B. M.; Kuhn, I.; Aarestrup, Frank Møller

    2006-01-01

    showed one pattern, which was identical to the most common pattern found in the milk isolates. Isolates from herd 2 showed three to four patterns, two of these being identical to skin isolates from the milker. As dairy cows are not a natural host for S. epidermidis the results suggest a human source...... (PFGE) and 122 by ribotyping. PFGE showed single patterns in the human strains with one exception; one strain was categorised as the same clone as four of the milk strains. PFGE divided 73 of the milk strains into 62 different patterns. The PFGE method had high discriminatory power and shows that many...... different S. epidermidis types exist in milk samples. Antibiotic resistance patterns matched the SmaI profiles closely in the two herds, but poorly in the routinely collected milk samples. Isolates from herd I showed one to five patterns, depending on the typing method used. Isolates from the milker's skin...

  10. Predicting chemically-induced skin reactions. Part II: QSAR models of skin permeability and the relationships between skin permeability and skin sensitization

    Science.gov (United States)

    Alves, Vinicius M.; Muratov, Eugene; Fourches, Denis; Strickland, Judy; Kleinstreuer, Nicole; Andrade, Carolina H.; Tropsha, Alexander

    2015-01-01

    Skin permeability is widely considered to be mechanistically implicated in chemically-induced skin sensitization. Although many chemicals have been identified as skin sensitizers, there have been very few reports analyzing the relationships between molecular structure and skin permeability of sensitizers and non-sensitizers. The goals of this study were to: (i) compile, curate, and integrate the largest publicly available dataset of chemicals studied for their skin permeability; (ii) develop and rigorously validate QSAR models to predict skin permeability; and (iii) explore the complex relationships between skin sensitization and skin permeability. Based on the largest publicly available dataset compiled in this study, we found no overall correlation between skin permeability and skin sensitization. In addition, cross-species correlation coefficient between human and rodent permeability data was found to be as low as R2=0.44. Human skin permeability models based on the random forest method have been developed and validated using OECD-compliant QSAR modeling workflow. Their external accuracy was high (Q2ext = 0.73 for 63% of external compounds inside the applicability domain). The extended analysis using both experimentally-measured and QSAR-imputed data still confirmed the absence of any overall concordance between skin permeability and skin sensitization. This observation suggests that chemical modifications that affect skin permeability should not be presumed a priori to modulate the sensitization potential of chemicals. The models reported herein as well as those developed in the companion paper on skin sensitization suggest that it may be possible to rationally design compounds with the desired high skin permeability but low sensitization potential. PMID:25560673

  11. Human Epidermal Langerhans Cells Maintain Immune Homeostasis in Skin by Activating Skin Resident Regulatory T Cells

    Science.gov (United States)

    Seneschal, Julien; Clark, Rachael A.; Gehad, Ahmed; Baecher-Allan, Clare M.; Kupper, Thomas S.

    2013-01-01

    Recent discoveries indicate that the skin of a normal individual contains 10-20 billion resident memory T cells ( which include various T helper, T cytotoxic, and T regulatory subsets, that are poised to respond to environmental antigens. Using only autologous human tissues, we report that both in vitro and in vivo, resting epidermal Langerhan cells (LC) selectively and specifically induced the activation and proliferation of skin resident regulatory T cells (Treg), a minor subset of skin resident memory T cells. In the presence of foreign pathogen, however, the same LC activated and induced proliferation of effector memory T (Tem) cells and limited Treg cells activation. These underappreciated properties of LC: namely maintenance of tolerance in normal skin, and activation of protective skin resident memory T cells upon infectious challenge, help clarify the role of LC in skin. PMID:22560445

  12. Micro-patterned graphene-based sensing skins for human physiological monitoring

    Science.gov (United States)

    Wang, Long; Loh, Kenneth J.; Chiang, Wei-Hung; Manna, Kausik

    2018-03-01

    Ultrathin, flexible, conformal, and skin-like electronic transducers are emerging as promising candidates for noninvasive and nonintrusive human health monitoring. In this work, a wearable sensing membrane is developed by patterning a graphene-based solution onto ultrathin medical tape, which can then be attached to the skin for monitoring human physiological parameters and physical activity. Here, the sensor is validated for monitoring finger bending/movements and for recognizing hand motion patterns, thereby demonstrating its future potential for evaluating athletic performance, physical therapy, and designing next-generation human-machine interfaces. Furthermore, this study also quantifies the sensor’s ability to monitor eye blinking and radial pulse in real-time, which can find broader applications for the healthcare sector. Overall, the printed graphene-based sensing skin is highly conformable, flexible, lightweight, nonintrusive, mechanically robust, and is characterized by high strain sensitivity.

  13. Effect of fluocinolone acetonide cream on human skin blood flow

    International Nuclear Information System (INIS)

    Chimoskey, J.E.; Holloway, A. Jr.; Flanagan, W.J.

    1975-01-01

    Blood flow rate was measured in the forearm skin of human subjects exposed to ultraviolet irradiation. Blood flow was determined by the 133 Xe disappearance technique 18 hr after ultraviolet (UV) irradiation with a Westinghouse RS sunlamp held 10 inches from the skin for 10 min. Ultraviolet irradiation caused skin blood flow to increase. Application of fluocinolone acetonide cream, 0.025 percent, 4 times in the 16 hr following UV irradiation had no effect on either control skin blood flow or the UV-induced hyperemia

  14. Insertion Testing of Polyethylene Glycol Microneedle Array into Cultured Human Skin with Biaxial Tension

    Science.gov (United States)

    Takano, Naoki; Tachikawa, Hiroto; Miyano, Takaya; Nishiyabu, Kazuaki

    Aiming at the practical use of polyethylene glycol (PEG) microneedles for transdermal drug delivery system (DDS), a testing apparatus for their insertion into cultured human skin has been developed. To simulate the variety of conditions of human skin, biaxial tension can be applied to the cultured human skin. An adopted testing scheme to apply and control the biaxial tension is similar to the deep-draw forming technique. An attention was also paid to the short-time setup of small, thin and wet cultured skin. One dimensional array with four needles was inserted and influence of tension was discussed. It was found that tension, deflection of skin during insertion and original curvature of skin are the important parameters for microneedles array design.

  15. Isolation, identification, and pathological effects of beach sand bacterial extract on human skin keratinocytes in vitro

    Directory of Open Access Journals (Sweden)

    Fazli Subhan

    2018-01-01

    Full Text Available Background Beaches are recreational spots for people. However, beach sand contains harmful microbes that affect human health, and there are no established methods for either sampling and identifying beach-borne pathogens or managing the quality of beach sand. Method This study was conducted with the aim of improving human safety at beaches and augmenting the quality of the beach experience. Beach sand was used as a resource to isolate bacteria due to its distinctive features and the biodiversity of the beach sand biota. A selected bacterial isolate termed FSRS was identified as Pseudomonas stutzeri using 16S rRNA sequencing and phylogenetic analysis, and the sequence was deposited in the NCBI GenBank database under the accession number MF599548. The isolated P. stutzeri bacterium was cultured in Luria–Bertani growth medium, and a crude extract was prepared using ethyl acetate to examine the potential pathogenic effect of P. stutzeri on human skin. A human skin keratinocyte cell line (HaCaT was used to assess cell adhesion, cell viability, and cell proliferation using a morphological analysis and a WST-1 assay. Result The crude P. stutzeri extract inhibited cell adhesion and decreased cell viability in HaCaT cells. We concluded that the crude extract of P. stutzeri FSRS had a strong pathological effect on human skin cells. Discussion Beach visitors frequently get skin infections, but the exact cause of the infections is yet to be determined. The beach sand bacterium P. stutzeri may, therefore, be responsible for some of the dermatological problems experienced by people visiting the beach.

  16. CON4EI: SkinEthic™ Human Corneal Epithelium Eye Irritation Test (SkinEthic™ HCE EIT) for hazard identification and labelling of eye irritating chemicals.

    Science.gov (United States)

    Van Rompay, A R; Alépée, N; Nardelli, L; Hollanders, K; Leblanc, V; Drzewiecka, A; Gruszka, K; Guest, R; Kandarova, H; Willoughby, J A; Verstraelen, S; Adriaens, E

    2018-06-01

    Assessment of ocular irritancy is an international regulatory requirement and a necessary step in the safety evaluation of industrial and consumer products. Although a number of in vitro ocular irritation assays exist, none are capable of fully categorizing chemicals as a stand-alone assay. Therefore, the CEFIC-LRI-AIMT6-VITO CON4EI (CONsortium for in vitro Eye Irritation testing strategy) project was developed with the goal of assessing the reliability of eight in vitro/alternative test methods as well as establishing an optimal tiered-testing strategy. One of the in vitro assays selected was the validated SkinEthic™ Human Corneal Epithelium Eye Irritation Test method (SkinEthic™ HCE EIT). The SkinEthic™ HCE EIT has already demonstrated its capacity to correctly identify chemicals (both substances and mixtures) not requiring classification and labelling for eye irritation or serious eye damage (No Category). The goal of this study was to evaluate the performance of the SkinEthic™ HCE EIT test method in terms of the important in vivo drivers of classification. For the performance with respect to the drivers all in vivo Cat 1 and No Cat chemicals were 100% correctly identified. For Cat 2 chemicals the liquids and the solids had a sensitivity of 100% and 85.7%, respectively. For the SkinEthic™ HCE EIT test method, 100% concordance in predictions (No Cat versus No prediction can be made) between the two participating laboratories was obtained. The accuracy of the SkinEthic™ HCE EIT was 97.5% with 100% sensitivity and 96.9% specificity. The SkinEthic™ HCE EIT confirms its excellent results of the validation studies. Copyright © 2017. Published by Elsevier Ltd.

  17. Use of 125I-labeled human serum albumin for quantitation of microvascular permeability in rat skin: reevaluation of an old method for studies on substances with an enhancing effect on microvascular permeability

    International Nuclear Information System (INIS)

    Gerdin, B.

    1981-01-01

    A method of determining the leakage of 125I-labeled human serum albumin in the plasma into a standardized area of rat skin to study the effects of intracutaneous application of vasoactive substances on microvascular permeability, was reevaluated. The effect is expressed as a quotient (Q) between the amount of labeled albumin in the test area and that in an area injected with buffer. This calculation is simple and as reliable as more complicated expressions of activity. Within a limited dose range, linear/log dose-response curves can be obtained after application of histamine or bradykinin. Locally injected 125I-labeled human serum albumin is eliminated very slowly from rat skin and determination of the amount of radiolabeled albumin in skin after an intravenous injection therefore represents leakage from the vascular compartments. The potentialities and advantages of this method in pharmacological studies are stressed

  18. Underprediction of human skin erythema at low doses per fraction by the linear quadratic model

    International Nuclear Information System (INIS)

    Hamilton, Christopher S.; Denham, James W.; O'Brien, Maree; Ostwald, Patricia; Kron, Tomas; Wright, Suzanne; Doerr, Wolfgang

    1996-01-01

    Background and purpose. The erythematous response of human skin to radiotherapy has proven useful for testing the predictions of the linear quadratic (LQ) model in terms of fractionation sensitivity and repair half time. No formal investigation of the response of human skin to doses less than 2 Gy per fraction has occurred. This study aims to test the validity of the LQ model for human skin at doses ranging from 0.4 to 5.2 Gy per fraction. Materials and methods. Complete erythema reaction profiles were obtained using reflectance spectrophotometry in two patient populations: 65 patients treated palliatively with 5, 10, 12 and 20 daily treatment fractions (varying thicknesses of bolus, various body sites) and 52 patients undergoing prostatic irradiation for localised carcinoma of the prostate (no bolus, 30-32 fractions). Results and conclusions. Gender, age, site and prior sun exposure influence pre- and post-treatment erythema values independently of dose administered. Out-of-field effects were also noted. The linear quadratic model significantly underpredicted peak erythema values at doses less than 1.5 Gy per fraction. This suggests that either the conventional linear quadratic model does not apply for low doses per fraction in human skin or that erythema is not exclusively initiated by radiation damage to the basal layer. The data are potentially explained by an induced repair model

  19. Thyrotropin-releasing hormone (TRH promotes wound re-epithelialisation in frog and human skin.

    Directory of Open Access Journals (Sweden)

    Natalia T Meier

    Full Text Available There remains a critical need for new therapeutics that promote wound healing in patients suffering from chronic skin wounds. This is, in part, due to a shortage of simple, physiologically and clinically relevant test systems for investigating candidate agents. The skin of amphibians possesses a remarkable regenerative capacity, which remains insufficiently explored for clinical purposes. Combining comparative biology with a translational medicine approach, we report the development and application of a simple ex vivo frog (Xenopus tropicalis skin organ culture system that permits exploration of the effects of amphibian skin-derived agents on re-epithelialisation in both frog and human skin. Using this amphibian model, we identify thyrotropin-releasing hormone (TRH as a novel stimulant of epidermal regeneration. Moving to a complementary human ex vivo wounded skin assay, we demonstrate that the effects of TRH are conserved across the amphibian-mammalian divide: TRH stimulates wound closure and formation of neo-epidermis in organ-cultured human skin, accompanied by increased keratinocyte proliferation and wound healing-associated differentiation (cytokeratin 6 expression. Thus, TRH represents a novel, clinically relevant neuroendocrine wound repair promoter that deserves further exploration. These complementary frog and human skin ex vivo assays encourage a comparative biology approach in future wound healing research so as to facilitate the rapid identification and preclinical testing of novel, evolutionarily conserved, and clinically relevant wound healing promoters.

  20. Thyrotropin-Releasing Hormone (TRH) Promotes Wound Re-Epithelialisation in Frog and Human Skin

    Science.gov (United States)

    Zhang, Guo-You; Emelianov, Vladimir; Paredes, Roberto; Debus, Sebastian; Augustin, Matthias; Funk, Wolfgang; Amaya, Enrique; Kloepper, Jennifer E.; Hardman, Matthew J.; Paus, Ralf

    2013-01-01

    There remains a critical need for new therapeutics that promote wound healing in patients suffering from chronic skin wounds. This is, in part, due to a shortage of simple, physiologically and clinically relevant test systems for investigating candidate agents. The skin of amphibians possesses a remarkable regenerative capacity, which remains insufficiently explored for clinical purposes. Combining comparative biology with a translational medicine approach, we report the development and application of a simple ex vivo frog (Xenopus tropicalis) skin organ culture system that permits exploration of the effects of amphibian skin-derived agents on re-epithelialisation in both frog and human skin. Using this amphibian model, we identify thyrotropin-releasing hormone (TRH) as a novel stimulant of epidermal regeneration. Moving to a complementary human ex vivo wounded skin assay, we demonstrate that the effects of TRH are conserved across the amphibian-mammalian divide: TRH stimulates wound closure and formation of neo-epidermis in organ-cultured human skin, accompanied by increased keratinocyte proliferation and wound healing-associated differentiation (cytokeratin 6 expression). Thus, TRH represents a novel, clinically relevant neuroendocrine wound repair promoter that deserves further exploration. These complementary frog and human skin ex vivo assays encourage a comparative biology approach in future wound healing research so as to facilitate the rapid identification and preclinical testing of novel, evolutionarily conserved, and clinically relevant wound healing promoters. PMID:24023889

  1. Ultrastructural age-related changes in the sensory corpuscles of the human genital skin.

    Science.gov (United States)

    Tammaro, A; Parisella, F R; Cavallotti, C; Persechino, S; Cavallotti, C

    2013-01-01

    In human genital skin the majority of superficial sensory corpuscles is represented by glomerular corpuscles. These corpuscles show an own morphology. Our aim is to compare the ultra-structure of superficial sensory corpuscles in the penis skin of younger and older subjects. In this report the ultra-structure of the sensitive corpuscle in the penis skin of the younger and older subjects was compared, showing that the genital skin of the older humans contains more simple complexes than the younger ones. Our findings support the view that the age-related changes that can be observed in human glomerular genital corpuscles are consistent with an increase of the simple complexes and a strong decrease of the poly-lamellar one in the older people. These findings demonstrate that human genital corpuscles underwent age-related changes. Moreover our morphological findings can be correlated in relation to the clinical evolution of the sensitivity in the genital skin.

  2. Detecting electroporation by assessing the time constants in the exponential response of human skin to voltage controlled impulse electrical stimulation.

    Science.gov (United States)

    Bîrlea, Sinziana I; Corley, Gavin J; Bîrlea, Nicolae M; Breen, Paul P; Quondamatteo, Fabio; OLaighin, Gearóid

    2009-01-01

    We propose a new method for extracting the electrical properties of human skin based on the time constant analysis of its exponential response to impulse stimulation. As a result of this analysis an adjacent finding has arisen. We have found that stratum corneum electroporation can be detected using this analysis method. We have observed that a one time-constant model is appropriate for describing the electrical properties of human skin at low amplitude applied voltages (30V). Higher voltage amplitudes (>30V) have been proven to create pores in the skin's stratum corneum which offer a new, lower resistance, pathway for the passage of current through the skin. Our data shows that when pores are formed in the stratum corneum they can be detected, in-vivo, due to the fact that a second time constant describes current flow through them.

  3. Solar ultraviolet irradiation induces decorin degradation in human skin likely via neutrophil elastase.

    Science.gov (United States)

    Li, Yong; Xia, Wei; Liu, Ying; Remmer, Henriette A; Voorhees, John; Fisher, Gary J

    2013-01-01

    Exposure of human skin to solar ultraviolet (UV) irradiation induces matrix metalloproteinase-1 (MMP-1) activity, which degrades type I collagen fibrils. Type I collagen is the most abundant protein in skin and constitutes the majority of skin connective tissue (dermis). Degradation of collagen fibrils impairs the structure and function of skin that characterize skin aging. Decorin is the predominant proteoglycan in human dermis. In model systems, decorin binds to and protects type I collagen fibrils from proteolytic degradation by enzymes such as MMP-1. Little is known regarding alterations of decorin in response to UV irradiation. We found that solar-simulated UV irradiation of human skin in vivo stimulated substantial decorin degradation, with kinetics similar to infiltration of polymorphonuclear (PMN) cells. Proteases that were released from isolated PMN cells degraded decorin in vitro. A highly selective inhibitor of neutrophil elastase blocked decorin breakdown by proteases released from PMN cells. Furthermore, purified neutrophil elastase cleaved decorin in vitro and generated fragments with similar molecular weights as those resulting from protease activity released from PMN cells, and as observed in UV-irradiated human skin. Cleavage of decorin by neutrophil elastase significantly augmented fragmentation of type I collagen fibrils by MMP-1. Taken together, these data indicate that PMN cell proteases, especially neutrophil elastase, degrade decorin, and this degradation renders collagen fibrils more susceptible to MMP-1 cleavage. These data identify decorin degradation and neutrophil elastase as potential therapeutic targets for mitigating sun exposure-induced collagen fibril degradation in human skin.

  4. Human Skin 3D Bioprinting Using Scaffold-Free Approach.

    Science.gov (United States)

    Pourchet, Léa J; Thepot, Amélie; Albouy, Marion; Courtial, Edwin J; Boher, Aurélie; Blum, Loïc J; Marquette, Christophe A

    2017-02-01

    Organ in vitro synthesis is one of the last bottlenecks between tissue engineering and transplantation of synthetic organs. Bioprinting has proven its capacity to produce 3D objects composed of living cells but highly organized tissues such as full thickness skin (dermis + epidermis) are rarely attained. The focus of the present study is to demonstrate the capability of a newly developed ink formulation and the use of an open source printer, for the production of a really complete skin model. Proofs are given through immunostaining and electronic microscopy that the bioprinted skin presents all characteristics of human skin, both at the molecular and macromolecular level. Finally, the printability of large skin objects is demonstrated with the printing of an adult-size ear. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Predicting chemically-induced skin reactions. Part II: QSAR models of skin permeability and the relationships between skin permeability and skin sensitization

    Energy Technology Data Exchange (ETDEWEB)

    Alves, Vinicius M. [Laboratory of Molecular Modeling and Design, Faculty of Pharmacy, Federal University of Goiás, Goiânia, GO 74605-220 (Brazil); Laboratory for Molecular Modeling, Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC 27599 (United States); Muratov, Eugene [Laboratory for Molecular Modeling, Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC 27599 (United States); Laboratory of Theoretical Chemistry, A.V. Bogatsky Physical–Chemical Institute NAS of Ukraine, Odessa 65080 (Ukraine); Fourches, Denis [Laboratory for Molecular Modeling, Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC 27599 (United States); Strickland, Judy; Kleinstreuer, Nicole [ILS/Contractor supporting the NTP Interagency Center for the Evaluation of Alternative Toxicological Methods (NICEATM), P.O. Box 13501, Research Triangle Park, NC 27709 (United States); Andrade, Carolina H. [Laboratory of Molecular Modeling and Design, Faculty of Pharmacy, Federal University of Goiás, Goiânia, GO 74605-220 (Brazil); Tropsha, Alexander, E-mail: alex_tropsha@unc.edu [Laboratory for Molecular Modeling, Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC 27599 (United States)

    2015-04-15

    Skin permeability is widely considered to be mechanistically implicated in chemically-induced skin sensitization. Although many chemicals have been identified as skin sensitizers, there have been very few reports analyzing the relationships between molecular structure and skin permeability of sensitizers and non-sensitizers. The goals of this study were to: (i) compile, curate, and integrate the largest publicly available dataset of chemicals studied for their skin permeability; (ii) develop and rigorously validate QSAR models to predict skin permeability; and (iii) explore the complex relationships between skin sensitization and skin permeability. Based on the largest publicly available dataset compiled in this study, we found no overall correlation between skin permeability and skin sensitization. In addition, cross-species correlation coefficient between human and rodent permeability data was found to be as low as R{sup 2} = 0.44. Human skin permeability models based on the random forest method have been developed and validated using OECD-compliant QSAR modeling workflow. Their external accuracy was high (Q{sup 2}{sub ext} = 0.73 for 63% of external compounds inside the applicability domain). The extended analysis using both experimentally-measured and QSAR-imputed data still confirmed the absence of any overall concordance between skin permeability and skin sensitization. This observation suggests that chemical modifications that affect skin permeability should not be presumed a priori to modulate the sensitization potential of chemicals. The models reported herein as well as those developed in the companion paper on skin sensitization suggest that it may be possible to rationally design compounds with the desired high skin permeability but low sensitization potential. - Highlights: • It was compiled the largest publicly-available skin permeability dataset. • Predictive QSAR models were developed for skin permeability. • No concordance between skin

  6. Predicting chemically-induced skin reactions. Part II: QSAR models of skin permeability and the relationships between skin permeability and skin sensitization

    International Nuclear Information System (INIS)

    Alves, Vinicius M.; Muratov, Eugene; Fourches, Denis; Strickland, Judy; Kleinstreuer, Nicole; Andrade, Carolina H.; Tropsha, Alexander

    2015-01-01

    Skin permeability is widely considered to be mechanistically implicated in chemically-induced skin sensitization. Although many chemicals have been identified as skin sensitizers, there have been very few reports analyzing the relationships between molecular structure and skin permeability of sensitizers and non-sensitizers. The goals of this study were to: (i) compile, curate, and integrate the largest publicly available dataset of chemicals studied for their skin permeability; (ii) develop and rigorously validate QSAR models to predict skin permeability; and (iii) explore the complex relationships between skin sensitization and skin permeability. Based on the largest publicly available dataset compiled in this study, we found no overall correlation between skin permeability and skin sensitization. In addition, cross-species correlation coefficient between human and rodent permeability data was found to be as low as R 2 = 0.44. Human skin permeability models based on the random forest method have been developed and validated using OECD-compliant QSAR modeling workflow. Their external accuracy was high (Q 2 ext = 0.73 for 63% of external compounds inside the applicability domain). The extended analysis using both experimentally-measured and QSAR-imputed data still confirmed the absence of any overall concordance between skin permeability and skin sensitization. This observation suggests that chemical modifications that affect skin permeability should not be presumed a priori to modulate the sensitization potential of chemicals. The models reported herein as well as those developed in the companion paper on skin sensitization suggest that it may be possible to rationally design compounds with the desired high skin permeability but low sensitization potential. - Highlights: • It was compiled the largest publicly-available skin permeability dataset. • Predictive QSAR models were developed for skin permeability. • No concordance between skin sensitization and

  7. Application of a non-invasive method to study the moisturizing effect of formulations containing vitamins A or E or ceramide on human skin.

    Science.gov (United States)

    Leonardi, Gislaine Ricci; Gaspar, Lorena Rigo; Maia Campos, Patrícia M B G

    2002-01-01

    Moisturizers containing vitamins A and E as well as ceramides are believed to improve the skin condition by increasing the water content of the stratum corneum. The aim of this research was to evaluate, through the capacitance method (a non-invasive method), the moisturizing effect of an O/W emulsion (non-ionic self-emulsifying base) containing vitamin A palmitate, vitamin E acetate, and ceramide III on human skin. The studies were carried out on a group of 40 healthy Caucasian female test subjects between 30 and 45 years of age, using the Corneometer CM 825 PC. Skin measurements were taken from the volunteers at 7 and 30 days after daily use (twice a day) of the tested products. The presence of vitamins A and E or ceramide III did not cause an improvement in the hydration of the stratum corneum, which means that none of those compounds strengthens the hydration effectiveness of the base formulations used, at least at the doses tested. The interpretation of electrical measurement regarding skin moisture should be made with caution; thus the results observed in this study show the importance of using different approaches (or methodologies) to verify the performance of the formulas tested. We conclude that, at the low doses typically used in cosmetic formulations, vitamins A and E and ceramide III are not likely to contribute to the hydrating effects of the base moisturizing formulation when assessed by capacitance.

  8. Colony size distributions according to in vitro aging in human skin fibroblasts

    International Nuclear Information System (INIS)

    Kim, Jun Sang; Kim, Jae Sung; Cho, Moon June; Park, Jeong Kyu; Paik, Tae Hyun

    1999-01-01

    To investigate the percentage of colonies with 16 or more cells distribution of human skin fibroblast according to in vitro aging, and to evaluate the relationship between percentage of colonies with 16 or more cells and in vivo donor age in human skin fibroblast culture. C1, C2, C3a, and C3b human skin fibroblast samples from three breast cancer patients were used as subjects. The C1, C2, and C3a donor were 44, 54, and 55 years old, respectively. C3a and C3b cells were isolated from the same person. Single cell suspension of skin fibroblasts was prepared with primary explant technique. One hundred cells are plated into 100ml tissue culture flask and cultured for two weeks. The colony size was defined as colonies with 16 or more cells. The cultured cell was stained with crystal violet, and number of cells in each colony was determined with stereo microscope at x 10 magnification. Passage number of C1, C2, C3a and C3b skin fibroblast were 12th, 17th, and 14th, respectively. Percentage of colonies with 16 or more cells of skin fibroblast samples decreased with increasing in vitro passage number. In contrast, cumulative population doublings of skin fibroblast sample increased with increasing in vitro passage number. Percentage of colonies with 16 or more cells also decreased with increasing population doublings in human skin fibroblast culture. There was strong correlation with percentage of colonised with 16 or more cells and population doublings in C3a skin fibroblast sample. At the same point of population doublings, the percentage of colonies with 16 or more cells of the young C1 donor was higher level than the old C3a donor. The population doublings increased with increasing in vitro passage number but percentage of colonies with 16 or more cells decreased. The results of this study imply that percentage of colonies with 16 or more cells is useful as a indicator of in vitro human skin fibroblast aging and may estimate the in vivo donor age

  9. A mechanics approach to the study of pressure sensitive adhesives and human skin for transdermal drug delivery applications

    Science.gov (United States)

    Taub, Marc Barry

    Transdermal drug delivery is an alternative approach to the systemic delivery of pharmaceuticals where drugs are administered through the skin and absorbed percutaneously. This method of delivery offers several advantages over more traditional routes; most notably, the avoidance of the fast-pass metabolism of the liver and gut, the ability to offer controlled release rates, and the possibility for novel devices. Pressure sensitive adhesives (PSAs) are used to bond transdermal drug delivery devices to the skin because of their good initial and long-term adhesion, clean removability, and skin and drug compatibility. However, an understanding of the mechanics of adhesion to the dermal layer, together with quantitative and reproducible test methods for measuring adhesion, have been lacking. This study utilizes a mechanics-based approach to quantify the interfacial adhesion of PSAs bonded to selected substrates, including human dermal tissue. The delamination of PSA layers is associated with cavitation in the PSA followed by the formation of an extensive cohesive zone behind the debond tip. A quantitative metrology was developed to assess the adhesion and delamination of PSAs, such that it could be possible to easily distinguish between the adhesive characteristics of different PSA compositions and to provide a quantitative basis from which the reliability of adhesive layers bonded to substrates could be studied. A mechanics-based model was also developed to predict debonding in terms of the relevant energy dissipation mechanisms active during this process. As failure of transdermal devices may occur cohesively within the PSA layer, adhesively at the interface between the PSA and the skin, or cohesively between the corneocytes that comprise the outermost layer of the skin, it was also necessary to explore the mechanical and fracture properties of human skin. The out-of-plane delamination of corneocytes was studied by determining the strain energy release rate during

  10. Spatially Resolved Two-Color Diffusion Measurements in Human Skin Applied to Transdermal Liposome Penetration

    DEFF Research Database (Denmark)

    Brewer, Jonathan; Bloksgaard, Maria; Kubiak, Jakub

    2013-01-01

    A multiphoton excitation-based fluorescence fluctuation spectroscopy method, Raster image correlation spectroscopy (RICS), was used to measure the local diffusion coefficients of distinct model fluorescent substances in excised human skin. In combination with structural information obtained by mu......; doi:10.1038/jid.2012.461....

  11. Percutaneous penetration of 2-phenoxyethanol through rat and human skin.

    Science.gov (United States)

    Roper, C S; Howes, D; Blain, P G; Williams, F M

    1997-01-01

    2-Phenoxyethanol applied in methanol was absorbed (64 +/- 4.4% at 24 hr) through unoccluded rat skin in vitro in the static diffusion cell with ethanol/water as receptor fluid. By comparison (43 +/- 3.7% in 24 hr) was absorbed in the flow-through diffusion system with tissue culture medium as receptor fluid. 2-Phenoxyethanol applied in methanol was absorbed (59.3 +/- 7.0% at 6 hr) through unoccluded human skin in vitro in the flow-through diffusion cell with tissue culture medium. With both unoccluded cells, 2-phenoxyethanol was lost by evaporation but occlusion of the static cell reduced evaporation and increased total absorption to 98.8 +/- 7.0%. Skin, post mitochondrial fraction, metabolized phenoxyethanol to phenoxyacetic acid at 5% of the rate for liver. Metabolism was inhibited by 1 mM pyrazole, suggesting involvement of alcohol dehydrogenase. However, first-pass metabolism of phenoxyethanol to phenoxyacetic acid was not detected during percutaneous penetration through viable rat skin in the flow-through system. First-pass metabolism in the skin does not therefore have an influence on systemic availability of dermally absorbed phenoxyethanol. These measures of phenoxyethanol absorption through rat and human skin in vitro agree well with those obtained previously in vivo.

  12. The Protective Role of Melanin Against UV Damage in Human Skin

    OpenAIRE

    Brenner, Michaela; Hearing, Vincent J.

    2008-01-01

    Human skin is repeatedly exposed to ultraviolet radiation (UVR) that influences the function and survival of many cell types and is regarded as the main causative factor in the induction of skin cancer. It has been traditionally believed that skin pigmentation is the most important photoprotective factor, since melanin, besides functioning as a broadband UV absorbent, has antioxidant and radical scavenging properties. Besides, many epidemiological studies have shown a lower incidence for skin...

  13. Tribology of human skin and mechanical skin equivalents in contact with textiles

    NARCIS (Netherlands)

    Derler, S.; Schrade, G.U.; Gerhardt, L.C.

    2007-01-01

    The friction of untreated human skin (finger) against a reference textile was investigated with 12 subjects using a force plate. In touch experiments, in which the subjects assessed the surface roughness of the textile at normal loads of 1.5 ± 0.7 N, the average friction coefficients ranged from

  14. Assessment of skin barrier function and biochemical changes of ex vivo human skin in response to physical and chemical barrier disruption.

    Science.gov (United States)

    Döge, Nadine; Avetisyan, Araks; Hadam, Sabrina; Pfannes, Eva Katharina Barbosa; Rancan, Fiorenza; Blume-Peytavi, Ulrike; Vogt, Annika

    2017-07-01

    Topical dermatotherapy is intended to be used on diseased skin. Novel drug delivery systems even address differences between intact and diseased skin underlining the need for pre-clinical assessment of different states of barrier disruption. Herein, we studied how short-term incubation in culture media compared to incubation in humidified chambers affects human skin barrier function and viability. On both models we assessed different types and intensities of physical and chemical barrier disruption methods with regard to structural integrity, biophysical parameters and cytokine levels. Tissue degeneration and proliferative activity limited the use of tissue cultures to 48h. Viability is better preserved in cultured tissue. Tape-stripping (50×TS) and 4h sodium lauryl sulfate (SLS) pre-treatment were identified as highly reproducible and effective procedures for barrier disruption. Transepidermal water loss (TEWL) values reproducibly increased with the intensity of disruption while sebum content and skin surface pH were of limited value. Interleukin (IL)-6/8 and various chemokines and proteases were increased in tape-stripped skin which was more pronounced in SLS-treated skin tissue extracts. Thus, albeit limited to 48h, cultured full-thickness skin maintained several barrier characteristics and responded to different intensities of barrier disruption. Potentially, these models can be used to assess pre-clinically the efficacy and penetration of anti-inflammatory compounds. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. The effect of skin thermistor fixation method on weighted mean skin temperature

    International Nuclear Information System (INIS)

    Tyler, Christopher James

    2011-01-01

    The purpose of this study was to investigate the effect of three different skin thermistor attachment methods on weighted mean skin temperature (WMT sk ) at three different ambient temperatures (∼24 °C (TEMP); ∼30 °C (WARM); ∼35 °C (HOT)) compared to uncovered thermistors. Eleven, non-acclimated, volunteers completed three 5 min bouts of submaximal cycling (∼70 W mechanical work)—one at each environmental condition in sequential order (TEMP, WARM, HOT). One thermistor was fixed to the sternal notch whilst four skin thermistors were spaced at 3 cm intervals on each of the sites on the limbs as per the formula of Ramanathan (1964 J. Appl. Physiol. 19 531–3). Each thermistor was either held against the skin uncovered (UC) or attached with surgical acrylic film dressing (T); surgical acrylic film dressing and hypoallergenic surgical tape (TT) or surgical acrylic film dressing, hypoallergenic surgical tape and surgical bandage (TTC). The WMT sk calculated was significantly lower in UC compared to T, TT and TTC (p < 0.001, d = 0.46), in T compared to TT and TTC (p < 0.001, d = 0.33) and in TT compared to TTC (p < 0.001; d = 0.25). The mean differences (across the three temperatures) were + 0.27 ±0.34 °C, + 0.52 ± 0.35 °C and + 0.82 ± 0.34 °C for T, TT and TTC, respectively. The results demonstrate that the method of skin thermistor attachment can result in the significant over-estimation of weighted mean skin temperature

  16. Influence of epidermal hydration on the friction of human skin against textiles

    OpenAIRE

    Gerhardt, L.-C; Strässle, V; Lenz, A; Spencer, N.D; Derler, S

    2008-01-01

    Friction and shear forces, as well as moisture between the human skin and textiles are critical factors in the formation of skin injuries such as blisters, abrasions and decubitus. This study investigated how epidermal hydration affects the friction between skin and textiles.

  17. Comparison of in vivo and ex vivo laser scanning microscopy and multiphoton tomography application for human and porcine skin imaging

    Energy Technology Data Exchange (ETDEWEB)

    Darvin, M E; Richter, H; Zhu, Y J; Meinke, M C; Knorr, F; Lademann, J [Center of Experimental and Applied Cutaneous Physiology, Department of Dermatology, Venerology and Allergology, Charité - Universitätsmedizin Berlin (Germany); Gonchukov, S A [National Research Nuclear University ' ' MEPhI' ' (Russian Federation); Koenig, K [JenLab GmbH, Schillerstr. 1, 07745 Jena (Germany)

    2014-07-31

    Two state-of-the-art microscopic optical methods, namely, confocal laser scanning microscopy in the fluorescence and reflectance regimes and multiphoton tomography in the autofluorescence and second harmonic generation regimes, are compared for porcine skin ex vivo and healthy human skin in vivo. All skin layers such as stratum corneum (SC), stratum spinosum (SS), stratum basale (SB), papillary dermis (PD) and reticular dermis (RD) as well as transition zones between these skin layers are measured noninvasively at a high resolution, using the above mentioned microscopic methods. In the case of confocal laser scanning microscopy (CLSM), measurements in the fluorescence regime were performed by using a fluorescent dye whose topical application on the surface is well suited for the investigation of superficial SC and characterisation of the skin barrier function. For investigations of deeply located skin layers, such as SS, SB and PD, the fluorescent dye must be injected into the skin, which markedly limits fluorescence measurements using CLSM. In the case of reflection CLSM measurements, the obtained results can be compared to the results of multiphoton tomography (MPT) for all skin layers excluding RD. CLSM cannot distinguish between dermal collagen and elastin measuring their superposition in the RD. By using MPT, it is possible to analyse the collagen and elastin structures separately, which is important for the investigation of anti-aging processes. The resolution of MPT is superior to CLSM. The advantages and limitations of both methods are discussed and the differences and similarities between human and porcine skin are highlighted. (laser biophotonics)

  18. Comparison of in vivo and ex vivo laser scanning microscopy and multiphoton tomography application for human and porcine skin imaging

    Science.gov (United States)

    Darvin, M. E.; Richter, H.; Zhu, Y. J.; Meinke, M. C.; Knorr, F.; Gonchukov, S. A.; Koenig, K.; Lademann, J.

    2014-07-01

    Two state-of-the-art microscopic optical methods, namely, confocal laser scanning microscopy in the fluorescence and reflectance regimes and multiphoton tomography in the autofluorescence and second harmonic generation regimes, are compared for porcine skin ex vivo and healthy human skin in vivo. All skin layers such as stratum corneum (SC), stratum spinosum (SS), stratum basale (SB), papillary dermis (PD) and reticular dermis (RD) as well as transition zones between these skin layers are measured noninvasively at a high resolution, using the above mentioned microscopic methods. In the case of confocal laser scanning microscopy (CLSM), measurements in the fluorescence regime were performed by using a fluorescent dye whose topical application on the surface is well suited for the investigation of superficial SC and characterisation of the skin barrier function. For investigations of deeply located skin layers, such as SS, SB and PD, the fluorescent dye must be injected into the skin, which markedly limits fluorescence measurements using CLSM. In the case of reflection CLSM measurements, the obtained results can be compared to the results of multiphoton tomography (MPT) for all skin layers excluding RD. CLSM cannot distinguish between dermal collagen and elastin measuring their superposition in the RD. By using MPT, it is possible to analyse the collagen and elastin structures separately, which is important for the investigation of anti-aging processes. The resolution of MPT is superior to CLSM. The advantages and limitations of both methods are discussed and the differences and similarities between human and porcine skin are highlighted.

  19. Comparison of in vivo and ex vivo laser scanning microscopy and multiphoton tomography application for human and porcine skin imaging

    International Nuclear Information System (INIS)

    Darvin, M E; Richter, H; Zhu, Y J; Meinke, M C; Knorr, F; Lademann, J; Gonchukov, S A; Koenig, K

    2014-01-01

    Two state-of-the-art microscopic optical methods, namely, confocal laser scanning microscopy in the fluorescence and reflectance regimes and multiphoton tomography in the autofluorescence and second harmonic generation regimes, are compared for porcine skin ex vivo and healthy human skin in vivo. All skin layers such as stratum corneum (SC), stratum spinosum (SS), stratum basale (SB), papillary dermis (PD) and reticular dermis (RD) as well as transition zones between these skin layers are measured noninvasively at a high resolution, using the above mentioned microscopic methods. In the case of confocal laser scanning microscopy (CLSM), measurements in the fluorescence regime were performed by using a fluorescent dye whose topical application on the surface is well suited for the investigation of superficial SC and characterisation of the skin barrier function. For investigations of deeply located skin layers, such as SS, SB and PD, the fluorescent dye must be injected into the skin, which markedly limits fluorescence measurements using CLSM. In the case of reflection CLSM measurements, the obtained results can be compared to the results of multiphoton tomography (MPT) for all skin layers excluding RD. CLSM cannot distinguish between dermal collagen and elastin measuring their superposition in the RD. By using MPT, it is possible to analyse the collagen and elastin structures separately, which is important for the investigation of anti-aging processes. The resolution of MPT is superior to CLSM. The advantages and limitations of both methods are discussed and the differences and similarities between human and porcine skin are highlighted. (laser biophotonics)

  20. A methodology for extracting the electrical properties of human skin

    International Nuclear Information System (INIS)

    Birgersson, Ulrik; Nicander, Ingrid; Ollmar, Stig; Birgersson, Erik

    2013-01-01

    A methodology to determine dielectrical properties of human skin is presented and analyzed. In short, it is based on a mathematical model that considers the local transport of charge in the various layers of the skin, which is coupled with impedance measurements of both stripped and intact skin, an automated code generator, and an optimization algorithm. New resistivity and permittivity values for the stratum corneum soaked with physiological saline solution for 1 min and the viable skin beneath are obtained and expressed as easily accessible functions. The methodology can be extended to account for different electrode designs as well as more physical phenomena that are relevant to electrical impedance measurements of skin and their interpretation. (paper)

  1. Hydrolysis of a series of parabens by skin microsomes and cytosol from human and minipigs and in whole skin in short-term culture

    International Nuclear Information System (INIS)

    Jewell, Christopher; Prusakiewicz, Jeffery J.; Ackermann, Chrisita; Payne, N. Ann; Fate, Gwendolyn; Voorman, Richard; Williams, Faith M.

    2007-01-01

    Parabens are esters of 4-hydroxybenzoic acid and used as anti-microbial agents in a wide variety of toiletries, cosmetics and pharmaceuticals. It is of interest to understand the dermal absorption and hydrolysis of parabens, and to evaluate their disposition after dermal exposure and their potential to illicit localised toxicity. The use of minipig as a surrogate model for human dermal metabolism and toxicity studies, justifies the comparison of paraben metabolism in human and minipig skin. Parabens are hydrolysed by carboxylesterases to 4-hydroxybenzoic acid. The effects of the carboxylesterase inhibitors paraoxon and bis-nitrophenylphosphate provided evidence of the involvement of dermal carboxylesterases in paraben hydrolysis. Loperamide, a specific inhibitor of human carboxylesterase-2 inhibited butyl- and benzylparaben hydrolysis in human skin but not methylparaben or ethylparaben. These results show that butyl- and benzylparaben are more selective substrates for human carboxylesterase-2 in skin than the other parabens examined. Parabens applied to the surface of human or minipig skin were absorbed to a similar amount and metabolised to 4-hydroxybenzoic acid during dermal absorption. These results demonstrate that the minipig is a suitable model for man for assessing dermal absorption and hydrolysis of parabens, although the carboxylesterase profile in skin differs between human and minipig

  2. Variables influencing the frictional behaviour of in vivo human skin

    NARCIS (Netherlands)

    Veijgen, N.K.; Masen, Marc Arthur; van der Heide, Emile

    2013-01-01

    In the past decades, skin friction research has focused on determining which variables are important to affect the frictional behaviour of in vivo human skin. Until now, there is still limited knowledge on these variables. This study has used a large dataset to identify the effect of variables on

  3. Influence of epidermal hydration on the friction of human skin against textile

    NARCIS (Netherlands)

    Gerhardt, L.C.; Strässle, V.; Lenz, A.; Spencer, N.D.; Derler, S.

    2008-01-01

    Friction and shear forces, as well as moisture between the human skin and textiles are critical factors in the formation of skin injuries such as blisters, abrasions and decubitus. This study investigated how epidermal hydration affects the friction between skin and textiles. The friction between

  4. Comparison of the effect of fatty alcohols on the permeation of melatonin between porcine and human skin.

    Science.gov (United States)

    Andega, S; Kanikkannan, N; Singh, M

    2001-11-09

    Melatonin (MT) is a hormone secreted by the pineal gland that plays an important role in the regulation of the circadian sleep-wake cycle. It would be advantageous to administer MT using a transdermal delivery system for the treatment of sleep disorders such as delayed sleep syndrome, jet lag in travelers, cosmonauts and shift workers. The porcine skin has been found to have similar morphological and functional characteristics as human skin. The elastic fibres in the dermis, enzyme pattern of the epidermis, epidermal tissue turnover time, keratinous proteins and thickness of epidermis of porcine skin are similar to human skin. However, the fat deposition and vascularisation of the cutaneous glands of porcine skin are different from human skin. In addition, porcine skin has been found to have a close permeability character to human skin. However, the comparative effect of chemical penetration enhancers on the permeation of drugs between porcine and human skin has not been reported. The purpose of this study was to compare the effect of fatty alcohols on the permeability of porcine and human skin using MT as a model compound. The effect of saturated fatty alcohols (octanol, nonanol, decanol, undecanol, lauryl alcohol, tridecanol, myristyl alcohol) and unsaturated fatty alcohols (oleyl alcohol, linoleyl alcohol, linolenyl alcohol) at 5% concentration was tested across dermatomed porcine and human skin. Our studies showed a parabolic relationship between the carbon chain length of saturated fatty alcohols and permeation enhancement of MT with both porcine and human skin. Maximum permeation of MT was observed when fatty alcohol carbon chain length was 10. In general, as the level of unsaturation increased from one to two double bonds, there was an increase in the permeation of MT both in porcine and human skin. However, a decrease in the permeation was observed with three double bonds. Regression analysis using the steady state flux data showed a significant positive

  5. Testing Human Skin and Respiratory Sensitizers—What Is Good Enough?

    Directory of Open Access Journals (Sweden)

    Anki Malmborg

    2017-01-01

    Full Text Available Alternative methods for accurate in vitro assessment of skin and respiratory sensitizers are urgently needed. Sensitization is a complex biological process that cannot be evaluated accurately using single events or biomarkers, since the information content is too restricted in these measurements. On the contrary, if the tremendous information content harbored in DNA/mRNA could be mined, most complex biological processes could be elucidated. Genomic technologies available today, including transcriptional profiling and next generation sequencing, have the power to decipher sensitization, when used in the right context. Thus, a genomic test platform has been developed, denoted the Genomic Allergen Rapid Detection (GARD assay. Due to the high informational content of the GARD test, accurate predictions of both the skin and respiratory sensitizing capacity of chemicals, have been demonstrated. Based on a matured dendritic cell line, acting as a human-like reporter system, information about potency has also been acquired. Consequently, multiparametric diagnostic technologies are disruptive test principles that can change the way in which the next generation of alternative methods are designed.

  6. Black tattoos entail substantial uptake of genotoxicpolycyclic aromatic hydrocarbons (PAH) in human skin and regional lymph nodes.

    Science.gov (United States)

    Lehner, Karin; Santarelli, Francesco; Vasold, Rudolf; Penning, Randolph; Sidoroff, Alexis; König, Burkhard; Landthaler, Michael; Bäumler, Wolfgang

    2014-01-01

    Hundreds of millions of people worldwide have tattoos, which predominantly contain black inks consisting of soot products like Carbon Black or polycyclic aromatic hydrocarbons (PAH). We recently found up to 200 μg/g of PAH in commercial black inks. After skin tattooing, a substantial part of the ink and PAH should be transported to other anatomical sites like the regional lymph nodes. To allow a first estimation of health risk, we aimed to extract and quantify the amount of PAH in black tattooed skin and the regional lymph nodes of pre-existing tattoos. Firstly, we established an extraction method by using HPLC-DAD technology that enables the quantification of PAH concentrations in human tissue. After that, 16 specimens of human tattooed skin and corresponding regional lymph nodes were included in the study. All skin specimen and lymph nodes appeared deep black. The specimens were digested and tested for 20 different PAH at the same time.PAH were found in twelve of the 16 tattooed skin specimens and in eleven regional lymph nodes. The PAH concentration ranged from 0.1-0.6 μg/cm2 in the tattooed skin and 0.1-11.8 μg/g in the lymph nodes. Two major conclusions can be drawn from the present results. Firstly, PAH in black inks stay partially in skin or can be found in the regional lymph nodes. Secondly, the major part of tattooed PAH had disappeared from skin or might be found in other organs than skin and lymph nodes. Thus, beside inhalation and ingestion, tattooing has proven to be an additional, direct and effective route of PAH uptake into the human body.

  7. Black tattoos entail substantial uptake of genotoxicpolycyclic aromatic hydrocarbons (PAH in human skin and regional lymph nodes.

    Directory of Open Access Journals (Sweden)

    Karin Lehner

    Full Text Available Hundreds of millions of people worldwide have tattoos, which predominantly contain black inks consisting of soot products like Carbon Black or polycyclic aromatic hydrocarbons (PAH. We recently found up to 200 μg/g of PAH in commercial black inks. After skin tattooing, a substantial part of the ink and PAH should be transported to other anatomical sites like the regional lymph nodes. To allow a first estimation of health risk, we aimed to extract and quantify the amount of PAH in black tattooed skin and the regional lymph nodes of pre-existing tattoos. Firstly, we established an extraction method by using HPLC-DAD technology that enables the quantification of PAH concentrations in human tissue. After that, 16 specimens of human tattooed skin and corresponding regional lymph nodes were included in the study. All skin specimen and lymph nodes appeared deep black. The specimens were digested and tested for 20 different PAH at the same time.PAH were found in twelve of the 16 tattooed skin specimens and in eleven regional lymph nodes. The PAH concentration ranged from 0.1-0.6 μg/cm2 in the tattooed skin and 0.1-11.8 μg/g in the lymph nodes. Two major conclusions can be drawn from the present results. Firstly, PAH in black inks stay partially in skin or can be found in the regional lymph nodes. Secondly, the major part of tattooed PAH had disappeared from skin or might be found in other organs than skin and lymph nodes. Thus, beside inhalation and ingestion, tattooing has proven to be an additional, direct and effective route of PAH uptake into the human body.

  8. Inter-individual and inter-cell type variation in residual DNA damage after in vivo irradiation of human skin

    International Nuclear Information System (INIS)

    Chua, Melvin Lee Kiang; Somaiah, Navita; Bourne, Sara; Daley, Frances; A'Hern, Roger; Nuta, Otilia; Davies, Sue; Herskind, Carsten; Pearson, Ann; Warrington, Jim; Helyer, Sarah; Owen, Roger; Yarnold, John; Rothkamm, Kai

    2011-01-01

    Purpose: The aim of this study was to compare inter-individual and inter-cell type variation in DNA double-strand break (DSB) repair following in vivo irradiation of human skin. Materials and methods: Duplicate 4 mm core biopsies of irradiated and unirradiated skin were collected from 35 patients 24 h after 4 Gy exposure using 6 MeV electrons. Residual DSB were quantified by scoring 53BP1 foci in dermal fibroblasts, endothelial cells, superficial keratinocytes and basal epidermal cells. Results: Coefficients of inter-individual variation for levels of residual foci 24 h after in vivo irradiation of skin were 39.9% in dermal fibroblasts, 44.3% in endothelial cells, 32.9% in superficial keratinocytes and 46.4% in basal epidermal cells (p < 0.001, ANOVA). In contrast, the coefficient of inter-cell type variation for residual foci levels was only 11.3% in human skin between the different epidermal and dermal cells (p = 0.034, ANOVA). Foci levels between the different skin cell types were correlated (Pearson's R = 0.855-0.955, p < 0.001). Conclusions: Patient-specific factors appear to be more important than cell type-specific factors in determining residual foci levels following in vivo irradiation of human skin.

  9. Degradation and protection of DNAzymes on human skin.

    Science.gov (United States)

    Marquardt, Kay; Eicher, Anna-Carola; Dobler, Dorota; Höfer, Frank; Schmidts, Thomas; Schäfer, Jens; Renz, Harald; Runkel, Frank

    2016-10-01

    DNAzymes are catalytic nucleic acid based molecules that have become a new class of active pharmaceutical ingredients (API). Until now, five DNAzymes have entered clinical trials. Two of them were tested for topical application, whereby dermally applied DNAzymes had been prone to enzymatic degradation. To protect the DNAzymes the enzymatic activity of human skin has to be examined. Therefore, the enzymatic activity of human skin was qualitatively and quantitatively analyzed. Activity similar to that of DNase II could be identified and the specific activity was determined to be 0.59Units/mg. These results were used to develop an in vitro degradation assay to screen different kinds of protective systems on human skin. The chosen protective systems consisted of biodegradable chitosans or polyethylenimine, which forms polyplexes when combined with DNAzymes. The polyplexes were characterized in terms of particle size, zeta potential, stability and degree of complexation. The screening revealed that the protective efficiency of the polyplexes depended on the polycation and the charge ratio (ξ). At a critical ξ ratio between 1.0 and 4.1 and at a maximal zeta potential, sufficient protection of the DNAzyme was achieved. The results of this study will be helpful for the development of a protective dermal drug delivery systems using polyplexes. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. In vitro permeation of palladium powders through intact and damaged human skin.

    Science.gov (United States)

    Crosera, Matteo; Mauro, Marcella; Bovenzi, Massimo; Adami, Gianpiero; Baracchini, Elena; Maina, Giovanni; Larese Filon, Francesca

    2018-05-01

    The use of palladium (Pd) has grown in the last decades, commonly used in automotive catalytic converters, jewellery and dental restorations sectors. Both general and working population can be exposed to this metal, which may act as skin sensitizer. This study investigated in vitro palladium powders permeation through excised intact and damaged human skin using the Franz diffusion cell method and the effect of rapid skin decontamination using sodium laureth-sulphate. 1 mL of a 10 min sonicated suspension made of 2.5 g of Pd powder in 50 mL synthetic sweat at pH 4.5 and room temperature was applied to the outer surface of the skin membranes for 24 h. Pd permeation, assessed by ICP-MS, was higher when damaged skin was used (p = 0.03). Final flux permeation values and lag times were 0.02 ± 0.01 μg cm -2  h -1 and 6.00 ± 3.95 h for intact, and 0.10 ± 0.02 μg cm -2  h -1 and 2.05 ± 1.49 h for damaged skin samples, respectively. Damaged skin protocol enhances Pd skin penetration inside dermal layer (p = 0.04), thus making the metal available for systemic uptake. Pd penetration (p = 0.02) and permeation (p = 0.012) through intact skin decreased significantly when a cleaning procedure was applied. This study demonstrates that after skin exposure to Pd powders a small permeation of the metal happen both through intact and damaged skin and that an early decontamination with a common cleanser can significantly decrease the final amount of metal available forsystemic uptake. Copyright © 2018 Elsevier B.V. All rights reserved.

  11. Variables influencing the frictional behaviour of in vivo human skin

    NARCIS (Netherlands)

    Veijgen, N.K.; Masen, M.A.; Heide, E. van der

    2013-01-01

    In the past decades, skin friction research has focused on determining which variables are important to affect the frictional behaviour of in vivo human skin. Until now, there is still limited knowledge on these variables.This study has used a large dataset to identify the effect of variables on the

  12. Protection against UVB-induced oxidative stress in human skin cells and skin models by methionine sulfoxide reductase A.

    Science.gov (United States)

    Pelle, Edward; Maes, Daniel; Huang, Xi; Frenkel, Krystyna; Pernodet, Nadine; Yarosh, Daniel B; Zhang, Qi

    2012-01-01

    Environmental trauma to human skin can lead to oxidative damage of proteins and affect their activity and structure. When methionine becomes oxidized to its sulfoxide form, methionine sulfoxide reductase A (MSRA) reduces it back to methionine. We report here the increase in MSRA in normal human epidermal keratinocytes (NHEK) after ultraviolet B (UVB) radiation, as well as the reduction in hydrogen peroxide levels in NHEK pre-treated with MSRA after exposure. Further, when NHEK were pre-treated with a non-cytotoxic pentapeptide containing methionine sulfoxide (metSO), MSRA expression increased by 18.2%. Additionally, when the media of skin models were supplemented with the metSO pentapeptide and then exposed to UVB, a 31.1% reduction in sunburn cells was evident. We conclude that the presence of MSRA or an externally applied peptide reduces oxidative damage in NHEK and skin models and that MSRA contributes to the protection of proteins against UVB-induced damage in skin.

  13. Estimation of tetrabromobisphenol A (TBBPA) percutaneous uptake in humans using the parallelogram method

    International Nuclear Information System (INIS)

    Knudsen, Gabriel A.; Hughes, Michael F.; McIntosh, Katelyn L.; Sanders, J. Michael; Birnbaum, Linda S.

    2015-01-01

    Tetrabromobisphenol A (TBBPA) is currently the world's highest production volume brominated flame retardant. Humans are frequently exposed to TBBPA by the dermal route. In the present study, a parallelogram approach was used to make predictions of internal dose in exposed humans. Human and rat skin samples received 100 nmol of TBBPA/cm 2 skin and absorption and penetrance were determined using a flow-through in vitro system. TBBPA-derived [ 14 C]-radioactivity was determined at 6 h intervals in the media and at 24 h post-dosing in the skin. The human skin and media contained an average of 3.4% and 0.2% of the total dose at the terminal time point, respectively, while the rat skin and media contained 9.3% and 3.5%, respectively. In the intact rat, 14% of a dermally-administered dose of ~ 100 nmol/cm 2 remained in the skin at the dosing site, with an additional 8% reaching systemic circulation by 24 h post-dosing. Relative absorption and penetrance were less (10% total) at 24 h following dermal administration of a ten-fold higher dose (~ 1000 nmol/cm 2 ) to rats. However, by 72 h, 70% of this dose was either absorbed into the dosing-site skin or had reached systemic circulation. It is clear from these results that TBBPA can be absorbed by the skin and dermal contact with TBBPA may represent a small but important route of exposure. Together, these in vitro data in human and rat skin and in vivo data from rats may be used to predict TBBPA absorption in humans following dermal exposure. Based on this parallelogram calculation, up to 6% of dermally applied TBBPA may be bioavailable to humans exposed to TBBPA. - Highlights: • Tetrabromobisphenol A is the brominated flame retardant with highest global production volumes. • Humans are frequently exposed to TBBPA by the dermal route, especially via contaminated dust. • Human and rat skin data were integrated using a parallelogram method to predict human absorption. • TBBPA was dermally absorbed and skin contact

  14. Estimation of tetrabromobisphenol A (TBBPA) percutaneous uptake in humans using the parallelogram method

    Energy Technology Data Exchange (ETDEWEB)

    Knudsen, Gabriel A., E-mail: gabriel.knudsen@nih.gov [NCI at NIEHS, 111 T W Alexander Dr., Research Triangle Park, NC (United States); Hughes, Michael F. [Integrated Systems Toxicology Division, National Health and Environmental Effects Research Laboratory, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711 (United States); McIntosh, Katelyn L.; Sanders, J. Michael; Birnbaum, Linda S. [NCI at NIEHS, 111 T W Alexander Dr., Research Triangle Park, NC (United States)

    2015-12-01

    Tetrabromobisphenol A (TBBPA) is currently the world's highest production volume brominated flame retardant. Humans are frequently exposed to TBBPA by the dermal route. In the present study, a parallelogram approach was used to make predictions of internal dose in exposed humans. Human and rat skin samples received 100 nmol of TBBPA/cm{sup 2} skin and absorption and penetrance were determined using a flow-through in vitro system. TBBPA-derived [{sup 14}C]-radioactivity was determined at 6 h intervals in the media and at 24 h post-dosing in the skin. The human skin and media contained an average of 3.4% and 0.2% of the total dose at the terminal time point, respectively, while the rat skin and media contained 9.3% and 3.5%, respectively. In the intact rat, 14% of a dermally-administered dose of ~ 100 nmol/cm{sup 2} remained in the skin at the dosing site, with an additional 8% reaching systemic circulation by 24 h post-dosing. Relative absorption and penetrance were less (10% total) at 24 h following dermal administration of a ten-fold higher dose (~ 1000 nmol/cm{sup 2}) to rats. However, by 72 h, 70% of this dose was either absorbed into the dosing-site skin or had reached systemic circulation. It is clear from these results that TBBPA can be absorbed by the skin and dermal contact with TBBPA may represent a small but important route of exposure. Together, these in vitro data in human and rat skin and in vivo data from rats may be used to predict TBBPA absorption in humans following dermal exposure. Based on this parallelogram calculation, up to 6% of dermally applied TBBPA may be bioavailable to humans exposed to TBBPA. - Highlights: • Tetrabromobisphenol A is the brominated flame retardant with highest global production volumes. • Humans are frequently exposed to TBBPA by the dermal route, especially via contaminated dust. • Human and rat skin data were integrated using a parallelogram method to predict human absorption. • TBBPA was dermally absorbed

  15. Fathers' experiences with the skin-to-skin method in NICU

    DEFF Research Database (Denmark)

    Helth, Theresa Dall; Jarden, Mary

    2013-01-01

    -depth, semi-structured interviews with five fathers of premature infants in the NICU, Copenhagen University Hospital, Hvidovre Hospital, Denmark. Findings: Three themes emerged: 1) “The competent parenthood”. 2) The paternal role and the division of roles between the parents. 3) Balance between working life......Abstract Aim: To explore how fathers of premature infants experience and potentially benefit from using the skin-to-skin (STS) method during their infants’ admission to the neonatal intensive care unit (NICU). Methods, participants and setting: Hermeneutic phenomenological qualitative study. In...... and time spent with the infant. Conclusion: STS enhances the fathers’ ability to play a caring role in their infant’s life. Fathers consider themselves less important, as compared to the mother in relation to their infant. STS enhances an understanding of their own role as a father. Health professionals...

  16. Permeability of commercial solvents through living human skin

    DEFF Research Database (Denmark)

    Ursin, C; Hansen, C M; Van Dyk, J W

    1995-01-01

    A procedure has been developed for measuring the steady state rate of permeation of commercial solvents through living human skin. To get the most consistent results, it was necessary with some solvents to normalize the solvent permeation rate of a given skin sample with its [3H]water permeation...... rate. For other solvents this was not necessary, so the un-normalized data were used. High [3H]water permeation rate also was used as a criterion for "defective" skin samples that gave erroneous permeability rates, especially for solvents having slow permeability. The linearity of the steady state data...... of DMSO and octyl acetate were measured. No octyl acetate was detected and the permeability of DMSO was proportional to its mole fraction in the mixture. The effect of two hours of solvent exposure on the viability of skin (based on DNA synthesis) was measured and found to be very dependent on the solvent....

  17. Modified methods for growing 3-D skin equivalents: an update.

    Science.gov (United States)

    Lamb, Rebecca; Ambler, Carrie A

    2014-01-01

    Artificial epidermis can be reconstituted in vitro by seeding primary epidermal cells (keratinocytes) onto a supportive substrate and then growing the developing skin equivalent at the air-liquid interface. In vitro skin models are widely used to study skin biology and for industrial drug and cosmetic testing. Here, we describe updated methods for growing 3-dimensional skin equivalents using de-vitalized, de-epidermalized dermis (DED) substrates including methods for DED substrate preparation, cell seeding, growth conditions, and fixation procedures.

  18. Validation of radiosterilization dose of human skin dressings for burnt treatment: preliminary study

    International Nuclear Information System (INIS)

    Castro, E.

    2008-01-01

    Full text: Due to the need for better materials to treat burnt patients, the Peruvian Institute of Nuclear Energy (IPEN) and the Rosa Guerzoni Chambergo Tissue Bank are collaborating for developing human skin dressings. Skin was procured from living donors, who surgically were performed a dermolipectomy. Exclusion criteria, stated by the Peruvian Organization for Transplant and Donation were observed. Glycerolized human skin dressings were processed at the tissue bank and sent to IPEN, where the gamma irradiation sterilizing dose was determined. The purpose of this work is to validate the radiation sterilization dose delivered to human skin dressings using the IAEA Code of Practice for the Radiation Sterilization of Tissue Allografts: Requirements for Validation and Routine Control. A batch of human skin dressings was tested. Average values of bioburden present in ten samples was 30 UFC/item, obtaining a sub-sterilization dose of 4 kGy. Irradiations were performed in the GammacellExcel 220. Sterility tests performed fulfilled the requirements established by the Code, achieving a validated dose value of 19.7 kGy. This preliminary study, that should be repeated in two other batches of processed human skin, allows to diminish 25 kGy the sterilizing dose to the stated above dose value, in a frame of a quality assurance system that also comprises the processes held at tissue banks previous irradiation. It also permit the availability of these materials in Peruvian hospitals. (Author)

  19. Ultrastructural changes in human skin after exposure to a pulsed laser

    Energy Technology Data Exchange (ETDEWEB)

    Nakagawa, H.; Tan, O.T.; Parrish, J.A.

    1985-05-01

    Selective vascular injury following irradiation using a pulsed laser source at 577 nm was examined using ultrastructural methods in the skin of 3 fair-skinned healthy human volunteers. This vascular-specific damage was confined to the papillary dermis. Red blood cells were altered in several ways. As well as an increase in the electron density, configurational distortion modified the normal biconcave forms to ameboid structures. The most interesting finding was the appearance within these altered cells of well-defined circular/oval electron-lucent areas of 800 A diameter, possibly representing a heat-fixed record of steam formation within the red blood cell. In addition, considerable degenerative changes were evident in endothelial cells and pericytes, while mast cells, neutrophils, histiocytes, and fibroblasts as well as collagen bundles immediately surrounding most laser-damaged blood vessels appeared normal.

  20. Protective Effects of Soy Oligopeptides in Ultraviolet B-Induced Acute Photodamage of Human Skin

    Directory of Open Access Journals (Sweden)

    Bing-rong Zhou

    2016-01-01

    Full Text Available Aim. We explored the effects of soy oligopeptides (SOP in ultraviolet B- (UVB- induced acute photodamage of human skin in vivo and foreskin ex vivo. Methods. We irradiated the forearm with 1.5 minimal erythemal dose (MED of UVB for 3 consecutive days, establishing acute photodamage of skin, and topically applied SOP. Erythema index (EI, melanin index, stratum corneum hydration, and transepidermal water loss were measured by using Multiprobe Adapter 9 device. We irradiated foreskin ex vivo with the same dose of UVB (180 mJ/cm2 for 3 consecutive days and topically applied SOP. Sunburn cells were detected by using hematoxylin and eosin staining. Apoptotic cells were detected by using terminal deoxynucleotidyl transferase dUTP nick end labeling assay. Cyclobutane pyrimidine dimers (CPDs, p53 protein, Bax protein, and Bcl-2 protein were detected by using immunohistochemical staining. Results. Compared with UVB group, UVB-irradiated skin with topically applied SOP showed significantly decreased EI. Compared with UVB group, topical SOP significantly increased Bcl-2 protein expression and decreased CPDs-positive cells, sunburn cells, apoptotic cells, p53 protein expression, and Bax protein expressions in the epidermis of UVB-irradiated foreskin. Conclusion. Our study demonstrated that topical SOP can protect human skin against UVB-induced photodamage.

  1. A novel approach to measuring the frictional behaviour of human skin in vivo

    NARCIS (Netherlands)

    Veijgen, N.K.; Masen, Marc Arthur; van der Heide, Emile

    2012-01-01

    Friction involving human skin plays a key role in human life. The availability of a portable tribometer improves the accessibility to large number of both subjects and anatomical sites. This is the first mobile device suitable to measure skin friction with a controlled and variable normal load

  2. Detection of hypercholesterolemia using hyperspectral imaging of human skin

    Science.gov (United States)

    Milanic, Matija; Bjorgan, Asgeir; Larsson, Marcus; Strömberg, Tomas; Randeberg, Lise L.

    2015-07-01

    Hypercholesterolemia is characterized by high blood levels of cholesterol and is associated with increased risk of atherosclerosis and cardiovascular disease. Xanthelasma is a subcutaneous lesion appearing in the skin around the eyes. Xanthelasma is related to hypercholesterolemia. Identifying micro-xanthelasma can thereforeprovide a mean for early detection of hypercholesterolemia and prevent onset and progress of disease. The goal of this study was to investigate spectral and spatial characteristics of hypercholesterolemia in facial skin. Optical techniques like hyperspectral imaging (HSI) might be a suitable tool for such characterization as it simultaneously provides high resolution spatial and spectral information. In this study a 3D Monte Carlo model of lipid inclusions in human skin was developed to create hyperspectral images in the spectral range 400-1090 nm. Four lesions with diameters 0.12-1.0 mm were simulated for three different skin types. The simulations were analyzed using three algorithms: the Tissue Indices (TI), the two layer Diffusion Approximation (DA), and the Minimum Noise Fraction transform (MNF). The simulated lesions were detected by all methods, but the best performance was obtained by the MNF algorithm. The results were verified using data from 11 volunteers with known cholesterol levels. The face of the volunteers was imaged by a LCTF system (400- 720 nm), and the images were analyzed using the previously mentioned algorithms. The identified features were then compared to the known cholesterol levels of the subjects. Significant correlation was obtained for the MNF algorithm only. This study demonstrates that HSI can be a promising, rapid modality for detection of hypercholesterolemia.

  3. Black Tattoos Entail Substantial Uptake of Genotoxicpolycyclic Aromatic Hydrocarbons (PAH) in Human Skin and Regional Lymph Nodes

    Science.gov (United States)

    Lehner, Karin; Santarelli, Francesco; Vasold, Rudolf; Penning, Randolph; Sidoroff, Alexis; König, Burkhard; Landthaler, Michael; Bäumler, Wolfgang

    2014-01-01

    Hundreds of millions of people worldwide have tattoos, which predominantly contain black inks consisting of soot products like Carbon Black or polycyclic aromatic hydrocarbons (PAH). We recently found up to 200 μg/g of PAH in commercial black inks. After skin tattooing, a substantial part of the ink and PAH should be transported to other anatomical sites like the regional lymph nodes. To allow a first estimation of health risk, we aimed to extract and quantify the amount of PAH in black tattooed skin and the regional lymph nodes of pre-existing tattoos. Firstly, we established an extraction method by using HPLC – DAD technology that enables the quantification of PAH concentrations in human tissue. After that, 16 specimens of human tattooed skin and corresponding regional lymph nodes were included in the study. All skin specimen and lymph nodes appeared deep black. The specimens were digested and tested for 20 different PAH at the same time.PAH were found in twelve of the 16 tattooed skin specimens and in eleven regional lymph nodes. The PAH concentration ranged from 0.1–0.6 μg/cm2 in the tattooed skin and 0.1–11.8 μg/g in the lymph nodes. Two major conclusions can be drawn from the present results. Firstly, PAH in black inks stay partially in skin or can be found in the regional lymph nodes. Secondly, the major part of tattooed PAH had disappeared from skin or might be found in other organs than skin and lymph nodes. Thus, beside inhalation and ingestion, tattooing has proven to be an additional, direct and effective route of PAH uptake into the human body. PMID:24670978

  4. Nicotinic acid receptor abnormalities in human skin cancer: implications for a role in epidermal differentiation.

    Directory of Open Access Journals (Sweden)

    Yira Bermudez

    Full Text Available Chronic UV skin exposure leads to epidermal differentiation defects in humans that can be largely restored by pharmacological doses of nicotinic acid. Nicotinic acid has been identified as a ligand for the human G-protein-coupled receptors GPR109A and GPR109B that signal through G(i-mediated inhibition of adenylyl cyclase. We have examined the expression, cellular distribution, and functionality of GPR109A/B in human skin and skin derived epidermal cells.Nicotinic acid increases epidermal differentiation in photodamaged human skin as judged by the terminal differentiation markers caspase 14 and filaggrin. Both GPR109A and GPR109B genes are transcribed in human skin and in epidermal keratinocytes, but expression in dermal fibroblasts is below limits of detection. Receptor transcripts are greatly over-expressed in squamous cell cancers. Receptor protein in normal skin is prominent from the basal through granular layers of the epidermis, with cellular localization more dispersive in the basal layer but predominantly localized at the plasma membrane in more differentiated epidermal layers. In normal human primary and immortalized keratinocytes, nicotinic acid receptors show plasma membrane localization and functional G(i-mediated signaling. In contrast, in a squamous cell carcinoma derived cell line, receptor protein shows a more diffuse cellular localization and the receptors are nearly non-functional.The results of these studies justify future genetic and pharmacological intervention studies to define possible specific role(s of nicotinic acid receptors in human skin homeostasis.

  5. Microneedle Enhanced Delivery of Cosmeceutically Relevant Peptides in Human Skin

    Science.gov (United States)

    Mohammed, Yousuf H.; Yamada, Miko; Lin, Lynlee L.; Grice, Jeffrey E.; Roberts, Michael S.; Raphael, Anthony P.; Benson, Heather A. E.; Prow, Tarl W.

    2014-01-01

    Peptides and proteins play an important role in skin health and well-being. They are also found to contribute to skin aging and melanogenesis. Microneedles have been shown to substantially enhance skin penetration and may offer an effective means of peptide delivery enhancement. The aim of this investigation was to assess the influence of microneedles on the skin penetration of peptides using fluorescence imaging to determine skin distribution. In particular the effect of peptide chain length (3, 4, 5 amino acid chain length) on passive and MN facilitated skin penetration was investigated. Confocal laser scanning microscopy was used to image fluorescence intensity and the area of penetration of fluorescently tagged peptides. Penetration studies were conducted on excised full thickness human skin in Franz type diffusion cells for 1 and 24 hours. A 2 to 22 fold signal improvement in microneedle enhanced delivery of melanostatin, rigin and pal-KTTKS was observed. To our knowledge this is the first description of microneedle enhanced skin permeation studies on these peptides. PMID:25033398

  6. Microneedle enhanced delivery of cosmeceutically relevant peptides in human skin.

    Directory of Open Access Journals (Sweden)

    Yousuf H Mohammed

    Full Text Available Peptides and proteins play an important role in skin health and well-being. They are also found to contribute to skin aging and melanogenesis. Microneedles have been shown to substantially enhance skin penetration and may offer an effective means of peptide delivery enhancement. The aim of this investigation was to assess the influence of microneedles on the skin penetration of peptides using fluorescence imaging to determine skin distribution. In particular the effect of peptide chain length (3, 4, 5 amino acid chain length on passive and MN facilitated skin penetration was investigated. Confocal laser scanning microscopy was used to image fluorescence intensity and the area of penetration of fluorescently tagged peptides. Penetration studies were conducted on excised full thickness human skin in Franz type diffusion cells for 1 and 24 hours. A 2 to 22 fold signal improvement in microneedle enhanced delivery of melanostatin, rigin and pal-KTTKS was observed. To our knowledge this is the first description of microneedle enhanced skin permeation studies on these peptides.

  7. Resonance Raman Spectroscopic Evaluation of Skin Carotenoids as a Biomarker of Carotenoid Status for Human Studies

    Science.gov (United States)

    Mayne, Susan T.; Cartmel, Brenda; Scarmo, Stephanie; Jahns, Lisa; Ermakov, Igor V.; Gellermann, Werner

    2013-01-01

    Resonance Raman Spectroscopy (RRS) is a non-invasive method that has been developed to assess carotenoid status in human tissues including human skin in vivo. Skin carotenoid status has been suggested as a promising biomarker for human studies. This manuscript describes research done relevant to the development of this biomarker, including its reproducibility, validity, feasibility for use in field settings, and factors that affect the biomarker such as diet, smoking, and adiposity. Recent studies have evaluated the response of the biomarker to controlled carotenoid interventions, both supplement-based and dietary [e.g., provision of a high-carotenoid fruit and vegetable (F/V)-enriched diet], demonstrating consistent response to intervention. The totality of evidence supports the use of skin carotenoid status as an objective biomarker of F/V intake, although in the cross-sectional setting, diet explains only some of the variation in this biomarker. However, this limitation is also a strength in that skin carotenoids may effectively serve as an integrated biomarker of health, with higher status reflecting greater F/V intake, lack of smoking, and lack of adiposity. Thus, this biomarker holds promise as both a health biomarker and an objective indicator of F/V intake, supporting its further development and utilization for medical and public health purposes. PMID:23823930

  8. Analogs of human genetic skin disease in domesticated animals

    Directory of Open Access Journals (Sweden)

    Justin Finch, MD

    2017-09-01

    The genetic skin diseases we will review are pigmentary mosaicism, piebaldism, albinism, Griscelli syndrome, ectodermal dysplasias, Waardenburg syndrome, and mucinosis in both humans and domesticated animals.

  9. INFLUENCE OF LASER BEAM PROFILE ON LIGHT SCATTERING BY HUMAN SKIN DURING PHOTOMETRY BY ELLIPSOIDAL REFLECTORS

    Directory of Open Access Journals (Sweden)

    M. A. Bezuglyi

    2018-01-01

    Full Text Available The correct accounting of laser emitter parameters for improvement of diagnostic authenticity of methods of optical biomedical diagnostic is important problem for applied biophotonic tasks. The purpose of the current research is estimation of influence of energy distribution profile in transversal section of laser beam on light scattering by human skin layers at photometry by ellipsoidal reflectors.Biomedical photometer with ellipsoidal reflectors for investigation of biological tissue specimens in transmitted and reflected light uses laser probing radiation with infinitely thin, Gauss-type and uniform cross-section profile. Distribution of beams with denoted profiles, which consist of 20 million photons with wavelength 632.8 nm, was modeled by using of Monte-Carlo simulation in human skin layers (corneous layer, epidermis, derma and adipose tissue of various anatomic thickness and with ellipsoidal reflectors with focal parameter equal to 16.875 mm and eccentricity of 0.66.The modeling results represent that illuminance distribution in zones of photometric imaging is significantly influenced by the laser beam cross-section profile for various thickness of corneous layer and epidermis in transmitted and reflected light, and also derma in reflected light. Illuminance distribution for adipose tissue in reflected and transmitted light, and also derma in transmitted light, practically do not depend of laser beam profile for anatomic thicknesses, which are appropriate for human skin on various sections of body.There are represented results of modified Monte-Carlo simulation method for biomedical photometer with ellipsoidal reflectors during biometry of human skin layers. For highly scattered corneous layer and epidermis the illumination of middle and external rings of photometric images changes depending from the laser beam profile for more than 50 % in transmitted and 30 % in reflected light. For weakly scattering skin layers (derma and adipose layer

  10. Bioactive reagents used in mesotherapy for skin rejuvenation in vivo induce diverse physiological processes in human skin fibroblasts in vitro- a pilot study.

    Science.gov (United States)

    Jäger, Claudia; Brenner, Christiane; Habicht, Jüri; Wallich, Reinhard

    2012-01-01

    The promise of mesotherapy is maintenance and/or recovery of a youthful skin with a firm, bright and moisturized texture. Currently applied medications employ microinjections of hyaluronic acid, vitamins, minerals and amino acids into the superficial layer of the skin. However, the molecular and cellular processes underlying mesotherapy are still elusive. Here we analysed the effect of five distinct medication formulas on pivotal parameters involved in skin ageing, that is collagen expression, cell proliferation and morphological changes using normal human skin fibroblast cultures in vitro. Whereas in the presence of hyaluronic acid, NCTF135(®) and NCTF135HA(®) , cell proliferation was comparable to control cultures; however, with higher expression of collagen type-1, matrix metalloproteinase-1 and tissue inhibitor of matrix metalloproteinase-1, addition of Soluvit(®) N and Meso-BK led to apoptosis and/or necrosis of human fibroblasts. The data indicate that bioactive reagents currently applied for skin rejuvenation elicit strikingly divergent physiological processes in human skin fibroblast in vitro. © 2011 John Wiley & Sons A/S.

  11. Comparison of structure and organization of cutaneous lipids in a reconstructed skin model and human skin: spectroscopic imaging and chromatographic profiling.

    Science.gov (United States)

    Tfayli, Ali; Bonnier, Franck; Farhane, Zeineb; Libong, Danielle; Byrne, Hugh J; Baillet-Guffroy, Arlette

    2014-06-01

    The use of animals for scientific research is increasingly restricted by legislation, increasing the demand for human skin models. These constructs present comparable bulk lipid content to human skin. However, their permeability is significantly higher, limiting their applicability as models of barrier function, although the molecular origins of this reduced barrier function remain unclear. This study analyses the stratum corneum (SC) of one such commercially available reconstructed skin model (RSM) compared with human SC by spectroscopic imaging and chromatographic profiling. Total lipid composition was compared by chromatographic analysis (HPLC). Raman spectroscopy was used to evaluate the conformational order, lateral packing and distribution of lipids in the surface and skin/RSM sections. Although HPLC indicates that all SC lipid classes are present, significant differences are observed in ceramide profiles. Raman imaging demonstrated that the RSM lipids are distributed in a non-continuous matrix, providing a better understanding of the limited barrier function. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  12. Age-associated decrease in GDNF and its cognate receptor GFRα-1 protein expression in human skin.

    Science.gov (United States)

    Adly, Mohamed A; Assaf, Hanan A; Hussein, Mahmoud Rezk Abdelwahed

    2016-06-01

    Glial cell line-derived neurotrophic factor (GDNF) and its cognate receptor (GFRα-1) are expressed in normal human skin. They are involved in murine hair follicle morphogenesis and cycling control. We hypothesize that 'GDNF and GFRα-1 protein expression in human skin undergoes age-associated alterations. To test our hypothesis, the expression of these proteins was examined in human skin specimens obtained from 30 healthy individuals representing three age groups: children (5-18 years), adults (19-60 years) and the elderly (61-81 years). Immunofluorescent and light microscopic immunohistologic analyses were performed using tyramide signal amplification and avidin-biotin complex staining methods respectively. GDNF mRNA expression was examined by RT-PCR analysis. GDNF mRNA and protein as well as GFRα-1 protein expressions were detected in normal human skin. We found significantly reduced epidermal expression of these proteins with ageing. In the epidermis, the expression was strong in the skin of children and declined gradually with ageing, being moderate in adults and weak in the elderly. In children and adults, the expression of both GDNF and GFRα-1 proteins was strongest in the stratum basale and decreased gradually towards the surface layers where it was completely absent in the stratum corneum. In the elderly, GDNF and GFRα-1 protein expression was confined to the stratum basale. In the dermis, both GDNF and GFRα-1 proteins had strong expressions in the fibroblasts, sweat glands, sebaceous glands, hair follicles and blood vessels regardless of the age. Thus there is a decrease in epidermal GDNF and GFRα-1 protein expression in normal human skin with ageing. Our findings suggest that the consequences of this is that GFRα-1-mediated signalling is altered during the ageing process. The clinical and therapeutic ramifications of these observations mandate further investigations. © 2016 The Authors. International Journal of Experimental Pathology © 2016

  13. Palladium nanoparticles exposure: Evaluation of permeation through damaged and intact human skin.

    Science.gov (United States)

    Larese Filon, Francesca; Crosera, Matteo; Mauro, Marcella; Baracchini, Elena; Bovenzi, Massimo; Montini, Tiziano; Fornasiero, Paolo; Adami, Gianpiero

    2016-07-01

    The intensified use of palladium nanoparticles (PdNPs) in many chemical reactions, jewellery, electronic devices, in car catalytic converters and in biomedical applications lead to a significant increase in palladium exposure. Pd can cause allergic contact dermatitis when in contact with the skin. However, there is still a lack of toxicological data related to nano-structured palladium and information on human cutaneous absorption. In fact, PdNPs, can be absorbed through the skin in higher amounts than bulk Pd because NPs can release more ions. In our study, we evaluated the absorption of PdNPs, with a size of 10.7 ± 2.8 nm, using intact and damaged human skin in Franz cells. 0.60 mg cm(-2) of PdNPs were applied on skin surface for 24 h. Pd concentrations in the receiving solutions at the end of experiments were 0.098 ± 0.067 μg cm(-2) and 1.06 ± 0.44 μg cm(-2) in intact skin and damaged skin, respectively. Pd flux permeation after 24 h was 0.005 ± 0.003 μg cm(-2) h(-1) and 0.057 ± 0.030 μg cm(-2) h(-1) and lag time 4.8 ± 1.7 and 4.2 ± 3.6 h, for intact and damaged skin respectively. This study indicates that Pd can penetrate human skin. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Characterization of the early local immune response to Ixodes ricinus tick bites in human skin.

    Science.gov (United States)

    Glatz, Martin; Means, Terry; Haas, Josef; Steere, Allen C; Müllegger, Robert R

    2017-03-01

    Little is known about the immunomodulation by tick saliva during a natural tick bite in human skin, the site of the tick-host interaction. We examined the expression of chemokines, cytokines and leucocyte markers on the mRNA levels and histopathologic changes in human skin biopsies of tick bites (n=37) compared to unaffected skin (n=9). Early tick-bite skin lesions (skin. With longer tick attachment (>24 hours), the numbers of innate immune cells and mediators (not significantly) declined, whereas the numbers of lymphocytes (not significantly) increased. Natural tick bites by Ixodes ricinus ticks initially elicit a strong local innate immune response in human skin. Beyond 24 hours of tick attachment, this response usually becomes less, perhaps because of immunomodulation by tick saliva. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  15. Skin Blood Perfusion and Oxygenation Colour Affect Perceived Human Health

    Science.gov (United States)

    Stephen, Ian D.; Coetzee, Vinet; Law Smith, Miriam; Perrett, David I.

    2009-01-01

    Skin blood perfusion and oxygenation depends upon cardiovascular, hormonal and circulatory health in humans and provides socio-sexual signals of underlying physiology, dominance and reproductive status in some primates. We allowed participants to manipulate colour calibrated facial photographs along empirically-measured oxygenated and deoxygenated blood colour axes both separately and simultaneously, to optimise healthy appearance. Participants increased skin blood colour, particularly oxygenated, above basal levels to optimise healthy appearance. We show, therefore, that skin blood perfusion and oxygenation influence perceived health in a way that may be important to mate choice. PMID:19337378

  16. The safety of donor skin preserved with glycerol - Evaluating the Euro Skin Bank preservation procedures of human donor skin against the prEN 12442 standard

    NARCIS (Netherlands)

    Geertsma RE; Wassenaar C; LGM

    2000-01-01

    The procedures for preservation of human donor skin with glycerol, as applied by the Euro Skin Bank (ESB), were evaluated against the prEN 12442 standard: animal tissues and their derivatives used in the manufacture of medical devices. The focus chosen for this review is on risks related to the

  17. Recovery of latent fingerprints and DNA on human skin.

    Science.gov (United States)

    Färber, Doris; Seul, Andrea; Weisser, Hans-Joachim; Bohnert, Michael

    2010-11-01

    The project "Latent Fingerprints and DNA on Human Skin" was the first systematic research in Europe dealing with detection of fingerprints and DNA left by offenders on the skin of corpses. One thousand samples gave results that allow general statements on the materials and methods used. The tests were carried out according to a uniform trial structure. Fingerprints were deposited by natural donors on corpses. The latent fingerprints were treated with magnetic powder or black fingerprint powder. Afterward, they were lifted with silicone casting material (Isomark(®)) or gelatine foil. All lifts were swabbed to recover DNA. It was possible to visualize comparable and identifiable fingerprints on the skin of corpses (16%). In the same categories, magnetic powder (18.4%) yielded better results than black fingerprint powder (13.6%). The number of comparable and identifiable fingerprints decreased on the lifts (12.7%). Isomark(®) (14.9%) was the better lifting material in comparison with gelatine foil (10.1%). In one-third of the samples, DNA could be extracted from the powdered and lifted latents. Black fingerprint powder delivered the better result with a rate of 2.2% for full DNA profiles and profiles useful for exclusion in comparison with 1.8% for the magnetic powder traces. Isomark(®) (3.1%) yielded better results than gelatine foil (0.6%). © 2010 American Academy of Forensic Sciences.

  18. New analysis methods for skin fine-structure via optical image and development of 3D skin Cycloscan(™).

    Science.gov (United States)

    Han, J Y; Nam, G W; Lee, H K; Kim, M J; Kim, E J

    2015-11-01

    This study was conducted to develop methods for measuring skin fine-structure via optical image and apparatus for photographing to analyze efficacy of anti-aging. We developed an apparatus named 3D Skin CycloScan(™) to evaluate the efficacy of cosmetics by imagification of skin fine-structure such as wrinkles, pores, and skin texture. The semi-sphere shaped device has 12 different sequential flashing light sources captures optical image simultaneously in one second to exclude the influence of the subject's movement. The normal map that is extracted through shape from shading method is composed of face contour and skin fine-structure parts. When the low-frequency component which is the result of the Gaussian Filter application is eliminated, we can get only skin fine-structure. In this normal map, it is possible to extract two-dimensional vector map called direction map and we can regulate the intensity of the image of wrinkles, pores, and skin texture after filtering the direction map. We performed a clinical study to apply this new apparatus and methods to evaluate an anti-aging efficacy of cosmetics visually and validate with other conventional methods. After using anti-aging cream including 2% adenosine for 8 weeks, the total amount of fine wrinkle around eye area detected via 3D Skin CycloScan(™) was reduced by 12.1%. Also, wrinkles on crow's feet measured by PRIMOS COMPACT(®) (GFMesstechnik GmbH, Germany) reduced 11.7%. According to an aspect of the present study, by changing the direction of the lights toward to subject's skin, we can obtain the information about the fine structures present on the skin such as wrinkles, pores, or skin texture and represent it as an image. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  19. Adaptive skin detection based on online training

    Science.gov (United States)

    Zhang, Ming; Tang, Liang; Zhou, Jie; Rong, Gang

    2007-11-01

    Skin is a widely used cue for porn image classification. Most conventional methods are off-line training schemes. They usually use a fixed boundary to segment skin regions in the images and are effective only in restricted conditions: e.g. good lightness and unique human race. This paper presents an adaptive online training scheme for skin detection which can handle these tough cases. In our approach, skin detection is considered as a classification problem on Gaussian mixture model. For each image, human face is detected and the face color is used to establish a primary estimation of skin color distribution. Then an adaptive online training algorithm is used to find the real boundary between skin color and background color in current image. Experimental results on 450 images showed that the proposed method is more robust in general situations than the conventional ones.

  20. Advanced tools for in vivo skin analysis.

    Science.gov (United States)

    Cal, Krzysztof; Zakowiecki, Daniel; Stefanowska, Justyna

    2010-05-01

    A thorough examination of the skin is essential for accurate disease diagnostics, evaluation of the effectiveness of topically applied drugs and the assessment of the results of dermatologic surgeries such as skin grafts. Knowledge of skin parameters is also important in the cosmetics industry, where the effects of skin care products are evaluated. Due to significant progress in the electronics and computer industries, sophisticated analytic devices are increasingly available for day-to-day diagnostics. The aim of this article is to review several advanced methods for in vivo skin analysis in humans: magnetic resonance imaging, electron paramagnetic resonance, laser Doppler flowmetry and time domain reflectometry. The molecular bases of these techniques are presented, and several interesting applications in the field are discussed. Methods for in vivo assessment of the biomechanical properties of human skin are also reviewed.

  1. Dermal absorption behavior of fluorescent molecules in nanoparticles on human and porcine skin models.

    Science.gov (United States)

    Debotton, Nir; Badihi, Amit; Robinpour, Mano; Enk, Claes D; Benita, Simon

    2017-05-30

    The percutaneous passage of poorly skin absorbed molecules can be improved using nanocarriers, particularly biodegradable polymeric nanospheres (NSs) or nanocapsules (NCs). However, penetration of the encapsulated molecules may be affected by other factors than the nanocarrier properties. To gain insight information on the skin absorption of two fluorescent cargos, DiIC 18 (5) and coumarin-6 were incorporated in NSs or NCs and topically applied on various human and porcine skin samples. 3D imaging techniques suggest that NSs and NCs enhanced deep dermal penetration of both probes similarly, when applied on excised human skin irrespective of the nature of the cargo. However, when ex vivo pig skin was utilized, the cutaneous absorption of DiIC 18 (5) was more pronounced by means of PLGA NCs than NSs. In contrast, PLGA NSs noticeably improved the porcine skin penetration of coumarin-6, as compared to the NCs. Furthermore, the porcine skin results were reproducible when triplicated whereas from various human skin samples, as expected, the results were not sufficiently reproducible and large deviations were observed. The overall findings from this comprehensive comparison emphasize the potential of PLGA NCs or NSs to promote cutaneous bioavailability of encapsulated drugs, exhibiting different physicochemical properties but depending on the nature of the skin. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. A Role for Human Skin Mast Cells in Dengue Virus Infection and Systemic Spread.

    Science.gov (United States)

    Troupin, Andrea; Shirley, Devon; Londono-Renteria, Berlin; Watson, Alan M; McHale, Cody; Hall, Alex; Hartstone-Rose, Adam; Klimstra, William B; Gomez, Gregorio; Colpitts, Tonya M

    2016-12-01

    Dengue virus (DENV) is a mosquito-borne flavivirus that causes serious global human disease and mortality. Skin immune cells are an important component of initial DENV infection and systemic spread. Here, we show that mast cells are a target of DENV in human skin and that DENV infection of skin mast cells induces degranulation and alters cytokine and growth factor expression profiles. Importantly, to our knowledge, we also demonstrate for the first time that DENV localizes within secretory granules in infected skin mast cells. In addition, DENV within extracellular granules was infectious in vitro and in vivo, trafficking through lymph to draining lymph nodes in mice. We demonstrate an important role for human skin mast cells in DENV infection and identify a novel mechanism for systemic spread of DENV infection from the initial peripheral mosquito injection site. Copyright © 2016 by The American Association of Immunologists, Inc.

  3. Microdialysis of the interstitial water space in human skin in vivo

    DEFF Research Database (Denmark)

    Petersen, L J; Kristensen, J K; Bülow, J

    1992-01-01

    The purpose of this study was to evaluate the usefulness of a microdialysis technique for measurement of substances in the interstitial water space in intact human skin. Glucose was selected to validate the method. The cutaneous glucose concentration was measured by microdialysis and compared...... to that in venous blood. Single dialysis fibers (length 20 mm, 2,000 Da molecular weight cutoff) were glued to nylon tubings and inserted in forearm skin by means of a fine needle. Dialysis fibers were inserted in duplicate. Seven subjects were investigated after an overnight fast. Intradermal position...... of the dialysis probes was established by C-mode ultrasound scanning. The implantation trauma lasted 90-135 min as measured by laser Doppler flowmetry. Each dialysis fiber was calibrated in vivo by perfusing it with four to five different glucose concentrations. The perfusion rate was 3 microliters...

  4. Genetic deletion of amphiregulin restores the normal skin phenotype in a mouse model of the human skin disease tylosis

    Directory of Open Access Journals (Sweden)

    Vishnu Hosur

    2017-08-01

    Full Text Available In humans, gain-of-function (GOF mutations in RHBDF2 cause the skin disease tylosis. We generated a mouse model of human tylosis and show that GOF mutations in RHBDF2 cause tylosis by enhancing the amount of amphiregulin (AREG secretion. Furthermore, we show that genetic disruption of AREG ameliorates skin pathology in mice carrying the human tylosis disease mutation. Collectively, our data suggest that RHBDF2 plays a critical role in regulating EGFR signaling and its downstream events, including development of tylosis, by facilitating enhanced secretion of AREG. Thus, targeting AREG could have therapeutic benefit in the treatment of tylosis.

  5. Mechanical response of human female breast skin under uniaxial stretching.

    Science.gov (United States)

    Kumaraswamy, N; Khatam, Hamed; Reece, Gregory P; Fingeret, Michelle C; Markey, Mia K; Ravi-Chandar, Krishnaswamy

    2017-10-01

    Skin is a complex material covering the entire surface of the human body. Studying the mechanical properties of skin to calibrate a constitutive model is of great importance to many applications such as plastic or cosmetic surgery and treatment of skin-based diseases like decubitus ulcers. The main objective of the present study was to identify and calibrate an appropriate material constitutive model for skin and establish certain universal properties that are independent of patient-specific variability. We performed uniaxial tests performed on breast skin specimens freshly harvested during mastectomy. Two different constitutive models - one phenomenological and another microstructurally inspired - were used to interpret the mechanical responses observed in the experiments. Remarkably, we found that the model parameters that characterize dependence on previous maximum stretch (or preconditioning) exhibited specimen-independent universal behavior. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Melanin Transfer in Human 3D Skin Equivalents Generated Exclusively from Induced Pluripotent Stem Cells.

    Science.gov (United States)

    Gledhill, Karl; Guo, Zongyou; Umegaki-Arao, Noriko; Higgins, Claire A; Itoh, Munenari; Christiano, Angela M

    2015-01-01

    The current utility of 3D skin equivalents is limited by the fact that existing models fail to recapitulate the cellular complexity of human skin. They often contain few cell types and no appendages, in part because many cells found in the skin are difficult to isolate from intact tissue and cannot be expanded in culture. Induced pluripotent stem cells (iPSCs) present an avenue by which we can overcome this issue due to their ability to be differentiated into multiple cell types in the body and their unlimited growth potential. We previously reported generation of the first human 3D skin equivalents from iPSC-derived fibroblasts and iPSC-derived keratinocytes, demonstrating that iPSCs can provide a foundation for modeling a complex human organ such as skin. Here, we have increased the complexity of this model by including additional iPSC-derived melanocytes. Epidermal melanocytes, which are largely responsible for skin pigmentation, represent the second most numerous cell type found in normal human epidermis and as such represent a logical next addition. We report efficient melanin production from iPSC-derived melanocytes and transfer within an entirely iPSC-derived epidermal-melanin unit and generation of the first functional human 3D skin equivalents made from iPSC-derived fibroblasts, keratinocytes and melanocytes.

  7. Melanin Transfer in Human 3D Skin Equivalents Generated Exclusively from Induced Pluripotent Stem Cells.

    Directory of Open Access Journals (Sweden)

    Karl Gledhill

    Full Text Available The current utility of 3D skin equivalents is limited by the fact that existing models fail to recapitulate the cellular complexity of human skin. They often contain few cell types and no appendages, in part because many cells found in the skin are difficult to isolate from intact tissue and cannot be expanded in culture. Induced pluripotent stem cells (iPSCs present an avenue by which we can overcome this issue due to their ability to be differentiated into multiple cell types in the body and their unlimited growth potential. We previously reported generation of the first human 3D skin equivalents from iPSC-derived fibroblasts and iPSC-derived keratinocytes, demonstrating that iPSCs can provide a foundation for modeling a complex human organ such as skin. Here, we have increased the complexity of this model by including additional iPSC-derived melanocytes. Epidermal melanocytes, which are largely responsible for skin pigmentation, represent the second most numerous cell type found in normal human epidermis and as such represent a logical next addition. We report efficient melanin production from iPSC-derived melanocytes and transfer within an entirely iPSC-derived epidermal-melanin unit and generation of the first functional human 3D skin equivalents made from iPSC-derived fibroblasts, keratinocytes and melanocytes.

  8. Climate change, ozone depletion and the impact on ultraviolet exposure of human skin

    International Nuclear Information System (INIS)

    Diffey, Brian

    2004-01-01

    For 30 years there has been concern that anthropogenic damage to the Earth's stratospheric ozone layer will lead to an increase of solar ultraviolet (UV) radiation reaching the Earth's surface, with a consequent adverse impact on human health, especially to the skin. More recently, there has been an increased awareness of the interactions between ozone depletion and climate change (global warming), which could also impact on human exposure to terrestrial UV. The most serious effect of changing UV exposure of human skin is the potential rise in incidence of skin cancers. Risk estimates of this disease associated with ozone depletion suggest that an additional peak incidence of 5000 cases of skin cancer per year in the UK would occur around the mid-part of this century. Climate change, which is predicted to lead to an increased frequency of extreme temperature events and high summer temperatures, will become more frequent in the UK. This could impact on human UV exposure by encouraging people to spend more time in the sun. Whilst future social trends remain uncertain, it is likely that over this century behaviour associated with climate change, rather than ozone depletion, will be the largest determinant of sun exposure, and consequent impact on skin cancer, of the UK population. (topical review)

  9. Flexible Nanosomes (SECosomes) Enable Efficient siRNA Delivery in Cultured Primary Skin Cells and in the Viable Epidermis of Ex Vivo Human Skin

    NARCIS (Netherlands)

    Geusens, Barbara; Van Gele, Mireille; Braat, Sien; De Smedt, Stefaan C.; Stuart, Marc C. A.; Prow, Tarl W.; Sanchez, Washington; Roberts, Michael S.; Sanders, Niek N.; Lambert, Jo

    2010-01-01

    The extent to which nanoscale-engineered systems cross intact human skin and can exert pharmacological effects in viable epidermis is controversial. This research seeks to develop a new lipid-based nanosome that enables the effective delivery of siRNA into human skin. The major finding is that an

  10. Photoprotection by pistachio bioactives in a 3-dimensional human skin equivalent tissue model.

    Science.gov (United States)

    Chen, C-Y Oliver; Smith, Avi; Liu, Yuntao; Du, Peng; Blumberg, Jeffrey B; Garlick, Jonathan

    2017-09-01

    Reactive oxygen species (ROS) generated during ultraviolet (UV) light exposure can induce skin damage and aging. Antioxidants can provide protection against oxidative injury to skin via "quenching" ROS. Using a validated 3-dimensional (3D) human skin equivalent (HSE) tissue model that closely mimics human skin, we examined whether pistachio antioxidants could protect HSE against UVA-induced damage. Lutein and γ-tocopherol are the predominant lipophilic antioxidants in pistachios; treatment with these compounds prior to UVA exposure protected against morphological changes to the epithelial and connective tissue compartments of HSE. Pistachio antioxidants preserved overall skin thickness and organization, as well as fibroblast morphology, in HSE exposed to UVA irradiation. However, this protection was not substantiated by the analysis of the proliferation of keratinocytes and apoptosis of fibroblasts. Additional studies are warranted to elucidate the basis of these discordant results and extend research into the potential role of pistachio bioactives promoting skin health.

  11. Latitudinal Clines of the Human Vitamin D Receptor and Skin Color Genes

    Directory of Open Access Journals (Sweden)

    Dov Tiosano

    2016-05-01

    Full Text Available The well-documented latitudinal clines of genes affecting human skin color presumably arise from the need for protection from intense ultraviolet radiation (UVR vs. the need to use UVR for vitamin D synthesis. Sampling 751 subjects from a broad range of latitudes and skin colors, we investigated possible multilocus correlated adaptation of skin color genes with the vitamin D receptor gene (VDR, using a vector correlation metric and network method called BlocBuster. We discovered two multilocus networks involving VDR promoter and skin color genes that display strong latitudinal clines as multilocus networks, even though many of their single gene components do not. Considered one by one, the VDR components of these networks show diverse patterns: no cline, a weak declining latitudinal cline outside of Africa, and a strong in- vs. out-of-Africa frequency pattern. We confirmed these results with independent data from HapMap. Standard linkage disequilibrium analyses did not detect these networks. We applied BlocBuster across the entire genome, showing that our networks are significant outliers for interchromosomal disequilibrium that overlap with environmental variation relevant to the genes’ functions. These results suggest that these multilocus correlations most likely arose from a combination of parallel selective responses to a common environmental variable and coadaptation, given the known Mendelian epistasis among VDR and the skin color genes.

  12. Ultrasonic evaluation of local human skin anisotropy

    Czech Academy of Sciences Publication Activity Database

    Tokar, Daniel; Převorovský, Zdeněk; Hradilová, Jana

    2014-01-01

    Roč. 19, č. 12 (2014) ISSN 1435-4934. [European Conference on Non-Destructive Testing (ECNDT 2014) /11./. Praha, 06.10.2014-10.10.2014] Institutional support: RVO:61388998 Keywords : anisotropy * ultrasonic testing * human skin in-vivo * fabric-fiber composite * signal processing Subject RIV: BI - Acoustics http://www.ndt.net/events/ECNDT2014/app/content/Paper/324_Tokar.pdf

  13. A role for human mitochondrial complex II in the production of reactive oxygen species in human skin

    Directory of Open Access Journals (Sweden)

    Alasdair Anderson

    2014-01-01

    Full Text Available The mitochondrial respiratory chain is a major generator of cellular oxidative stress, thought to be an underlying cause of the carcinogenic and ageing process in many tissues including skin. Previous studies of the relative contributions of the respiratory chain (RC complexes I, II and III towards production of reactive oxygen species (ROS have focussed on rat tissues and certainly not on human skin which is surprising as this tissue is regularly exposed to UVA in sunlight, a potent generator of cellular oxidative stress. In a novel approach we have used an array of established specific metabolic inhibitors and DHR123 fluorescence to study the relative roles of the mitochondrial RC complexes in cellular ROS production in 2 types of human skin cells. These include additional enhancement of ROS production by exposure to physiological levels of UVA. The effects within epidermal and dermal derived skin cells are compared to other tissue cell types as well as those harbouring a compromised mitochondrial status (Rho-zero A549. The results show that the complex II inhibitor, TTFA, was the only RC inhibitor to significantly increase UVA-induced ROS production in both skin cell types (P<0.05 suggesting that the role of human skin complex II in terms of influencing ROS production is more important than previously thought particularly in comparison to liver cells. Interestingly, two-fold greater maximal activity of complex II enzyme was observed in both skin cell types compared to liver (P<0.001. The activities of RC enzymes appear to decrease with increasing age and telomere length is correlated with ageing. Our study showed that the level of maximal complex II activity was higher in the MRC5/hTERT (human lung fibroblasts transfected with telomerase cells than the corresponding wild type cells (P=0.0012 which can be considered (in terms of telomerase activity as models of younger and older cells respectively.

  14. Differentiation of involved and uninvolved psoriatic skin from healthy skin using noninvasive visual, colorimeter and evaporimeter methods.

    Science.gov (United States)

    Pershing, L K; Bakhtian, S; Wright, E D; Rallis, T M

    1995-08-01

    Uninvolved skin of psoriasis may not be entirely normal. The object was to characterize healthy, uninvolved psoriatic skin and lesional skin by biophysical methods. Involved and uninvolved psoriatic and age-gender matched healthy skin was measured objectively with a colorimeter and evaporimeter and subjectively with visual assessment in 14 subjects. Visual assessment of erythema (E), scaling (S) and induration (I) as well as the target lesion score at the involved psoriatic skin sites were significantly elevated (puninvolved psoriatic skin >healthy skin (pcolorimeter L* and a* scale values at uninvolved psoriatic skin sites were lower and higher (pcolorimeter description (L*× b*)/a* significantly differentiated healthy skin from both involved and uninvolved psoriatic skin. These collective data highlight that even visually appearing uninvolved psoriatic skin is compromised compared with healthy skin. These objective, noninvasive but differential capabilities of the colorimeter and evaporimeter will aid in the mechanistic quantification of new psoriatic drug therapies and in conjuction with biochemical studies, add to understanding of the multifactorial pathogenesis of psoriasis.

  15. Percutaneous absorption and skin decontamination of PCBs: In vitro studies with human skin and in vivo studies in the rhesus monkey

    International Nuclear Information System (INIS)

    Wester, R.C.; Maibach, H.I.; Bucks, D.A.; McMaster, J.; Mobayen, M.; Sarason, R.; Moore, A.

    1990-01-01

    Knowledge of the entry of polychlorinated biphenyls through the skin into the body and subsequent disposition aids estimation of potential for human health hazard. [14C]Aroclor 1242 and [14C]Aroclor 1254 were separately administered intravenously and topically to rhesus monkeys. Following iv administration, 30-d excretion was 39.4 +/- 5.9% urine and 16.1 +/- 0.8% feces (total 55.5 +/- 5.1%) for Aroclor 1242, and 7.0 +/- 2.2% urine and 19.7 +/- 5.8% feces (total 26.7 +/- 7.5%) for Aroclor 1254. Mineral oil and trichlorobenzene are common PCB cosolvents in transformers. Skin absorption of Aroclor 1242 was 20.4 +/- 8.5% formulated in mineral oil and 18.0 +/- 3.8% in trichlorobenzene (p greater than .05). Absorption of Aroclor 1254 was 20.8 +/- 8.3% in mineral oil and 14.6 +/- 3.6% in trichlorobenzene (p greater than .05). PCBs are thus absorbed through skin, and excretion from the body is slow. Vehicle (trichlorobenzene or mineral oil) did not affect percutaneous absorption. In vitro skin absorption in human cadaver skin did not correlate with in vivo findings. This was due to lack of PCB partition from skin into the water receptor fluid, even with addition of 6% Oleth 20 (Volpo 20) solubilizer. Skin decontamination of PCBs showed soap and water to be as effective as or better than the solvent ethanol, mineral oil, and trichlorobenzene in removing PCBs from skin. There is a dynamic time lapse for PCBs between initial skin contact and skin absorption (irreversible removal). Thus initially most PCBs could be removed from skin, but this ability decreased with time to the point where at 24 h only about 25% of the initial PCB skin dose could be recovered with skin washing

  16. UV decreases the synthesis of free fatty acids and triglycerides in the epidermis of human skin in vivo, contributing to development of skin photoaging.

    Science.gov (United States)

    Kim, Eun Ju; Jin, Xing-Ji; Kim, Yeon Kyung; Oh, In Kyung; Kim, Ji Eun; Park, Chi-Hyun; Chung, Jin Ho

    2010-01-01

    Although fatty acids are known to be important in various skin functions, their roles on photoaging in human skin are poorly understood. We investigated the alteration of lipid metabolism in the epidermis by photoaging and acute UV irradiation in human skin. UV irradiated young volunteers (21-33 years, n=6) and elderly volunteers (70-75 years, n=7) skin samples were obtained by punch biopsy. Then the epidermis was separated from dermis and lipid metabolism was investigated. We observed that the amounts of free fatty acids (FFA) and triglycerides (TG) in the epidermis of photoaged or acutely UV irradiated human skin were significantly decreased. The expressions of genes related to lipid synthesis, including acetyl-CoA carboxylase (ACC), fatty acid synthase (FAS), stearoyl-CoA desaturase (SCD), sterol regulatory element binding proteins (SREBPs), and peroxisome proliferator-activated receptors (PPARgamma) were also markedly decreased. To elucidate the significance of these changes of epidermal lipids in human skin, we investigated the effects of TG or various inhibitors for the enzymes involved in TG synthesis on the expression of matrix metalloproteinase-1 (MMP-1) in cultured human epidermal keratinocytes. We demonstrated that triolein (TG) reduced basal and UV-induced MMP-1 mRNA expression. In addition, each inhibitor for various lipid synthesis enzymes, such as TOFA (ACC inhibitor), cerulenin (FAS inhibitor) and trans-10, cis-12-CLA (SCD inhibitor), increased the MMP-1 expression significantly in a dose-dependent manner. We also demonstrated that triolein could inhibit cerulenin-induced MMP-1 expression. Furthermore, topical application of triolein (10%) significantly prevented UV-induced MMP-13, COX-2, and IL-1beta expression in hairless mice. Our results suggest that TG and FFA may play important roles in photoaging of human skin. Copyright 2009 Japanese Society for Investigative Dermatology. Published by Elsevier Ireland Ltd. All rights reserved.

  17. The effects of mucopolysaccharide polysulphate on hydration and elasticity of human skin.

    Science.gov (United States)

    Wanitphakdeedecha, Rungsima; Eimpunth, Sasima; Manuskiatti, Woraphong

    2011-01-01

    Background. Mucopolysaccharide polysulphate (MPS) has been used in medicine as an anti-inflammatory and antithrombotic agent for over 50 years. Its chemical structure permits considerable hydrogen bonding with adjacent water molecules, which effectively leads to hydration of the surrounding tissue. In addition, it stimulates endogenous hyaluronate synthesis, resulting in an increase in water-binding capacity and viscoelasticity of the skin. Objective. To study the efficacy of 0.1% MPS on hydration and elasticity of human skin. Methods. The first part of this study was a randomized double blind placebo-controlled study which included 60 female volunteers aged 30-45 years with dry skin, defined by Corneometer CM 825. The volunteers were treated with either 0.1% MPS or vehicle control. All subjects were asked to apply 1 g of cream to their face twice daily for a total period of 4 weeks. Skin hydration and elasticity were measured at baseline and week 4 with Corneometer CM 825 and cutometer MPA 580, respectively, at forehead and both cheeks. The second part of this study focused on the efficacy of 0.1% MPS on skin hydration after single application. 20 female volunteers aged 30-45 years with dry skin, defined by Corneometer CM 825, were recruited to the study. All subjects were asked to apply 2 g of 0.1% MPS cream on entirely randomly selected forearm. Skin hydration at the middle of both forearms was measured at baseline, immediately after application, and every 1 hour after application for a period of 10 hours. Results. 57 subjects (28 in vehicle control group, 29 in MPS) completed treatment protocol. The baseline skin hydration of both groups was not significantly different (P = 0.47). Hower, there was a statistically significant difference in skin hydration at 4 weeks between MPS and placebo group (P = 0.01). Skin elasticity was significantly improved at week 4 in both groups (vehicle-control, P skin elasticity between MPS and vehicle-control group

  18. Lipidomic analysis of epidermal lipids: a tool to predict progression of inflammatory skin disease in humans.

    Science.gov (United States)

    Li, Shan; Ganguli-Indra, Gitali; Indra, Arup K

    2016-05-01

    Lipidomics is the large-scale profiling and characterization of lipid species in a biological system using mass spectrometry. The skin barrier is mainly comprised of corneocytes and a lipid-enriched extracellular matrix. The major skin lipids are ceramides, cholesterol and free fatty acids (FFA). Lipid compositions are altered in inflammatory skin disorders with disrupted skin barrier such as atopic dermatitis (AD). Here we discuss some of the recent applications of lipidomics in human skin biology and in inflammatory skin diseases such as AD, psoriasis and Netherton syndrome. We also review applications of lipidomics in human skin equivalent and in pre-clinical animal models of skin diseases to gain insight into the pathogenesis of the skin disease. Expert commentary: Skin lipidomics analysis could be a fast, reliable and noninvasive tool to characterize the skin lipid profile and to monitor the progression of inflammatory skin diseases such as AD.

  19. The human skin/chick chorioallantoic membrane model accurately predicts the potency of cosmetic allergens.

    Science.gov (United States)

    Slodownik, Dan; Grinberg, Igor; Spira, Ram M; Skornik, Yehuda; Goldstein, Ronald S

    2009-04-01

    The current standard method for predicting contact allergenicity is the murine local lymph node assay (LLNA). Public objection to the use of animals in testing of cosmetics makes the development of a system that does not use sentient animals highly desirable. The chorioallantoic membrane (CAM) of the chick egg has been extensively used for the growth of normal and transformed mammalian tissues. The CAM is not innervated, and embryos are sacrificed before the development of pain perception. The aim of this study was to determine whether the sensitization phase of contact dermatitis to known cosmetic allergens can be quantified using CAM-engrafted human skin and how these results compare with published EC3 data obtained with the LLNA. We studied six common molecules used in allergen testing and quantified migration of epidermal Langerhans cells (LC) as a measure of their allergic potency. All agents with known allergic potential induced statistically significant migration of LC. The data obtained correlated well with published data for these allergens generated using the LLNA test. The human-skin CAM model therefore has great potential as an inexpensive, non-radioactive, in vivo alternative to the LLNA, which does not require the use of sentient animals. In addition, this system has the advantage of testing the allergic response of human, rather than animal skin.

  20. In situ depletion of CD4(+) T cells in human skin by Zanolimumab

    DEFF Research Database (Denmark)

    Villadsen, L.S.; Skov, L.; Dam, T.N.

    2007-01-01

    CD4(+) T cells, in activated or malignant form, are involved in a number of diseases including inflammatory skin diseases such as psoriasis, and T cell lymphomas such as the majority of cutaneous T cell lymphomas (CTCL). Targeting CD4 with an antibody that inhibits and/or eliminates disease......-driving T cells in situ may therefore be a useful approach in the treatment of inflammatory and malignant skin diseases. Depletion of CD4(+) T cells in intact inflamed human skin tissue by Zanolimumab, a fully human therapeutic monoclonal antibody (IgG1, kappa) against CD4, was studied in a human psoriasis......(+), but not CD8(+) CD3(+) T cells. The capacity of Zanolimumab to deplete the CD4(+) T cells in the skin may be of importance in diseases where CD4(+) T cells play a central role. Indeed, in a phase II clinical trial Zanolimumab has shown a dose-dependent clinical response in patients with CTCL and the antibody...

  1. Cultured skin microbiota attracts malaria mosquitoes

    Directory of Open Access Journals (Sweden)

    Takken Willem

    2009-12-01

    Full Text Available Abstract Background Host-seeking of the African malaria mosquito, Anopheles gambiae sensu stricto, is guided by human odours. The precise nature of the odours, and the composition of attractive blends of volatiles, remains largely unknown. Skin microbiota plays an important role in the production of human body odours. It is hypothesized that host attractiveness and selection of An. gambiae is affected by the species composition, density, and metabolic activity of the skin microbiota. A study is presented in which the production and constituency of volatile organic compounds (VOCs by human skin microbiota is examined and the behavioural responses of An. gambiae to VOCs from skin microbiota are investigated. Methods Blood agar plates incubated with skin microbiota from human feet or with a reference strain of Staphylococcus epidermidis were tested for their attractiveness to An. gambiae in olfactometer bioassays and indoor trapping experiments. Entrained air collected from blood agar plates incubated with natural skin microbiota or with S. epidermidis were analysed using GC-MS. A synthetic blend of the compounds identified was tested for its attractiveness to An. gambiae. Behavioural data were analysed by a χ2-test and GLM. GC-MS results were analysed by fitting an exponential regression line to test the effect of the concentration of bacteria. Results More An. gambiae were caught with blood agar plates incubated with skin bacteria than with sterile blood agar plates, with a significant effect of incubation time and dilution of the skin microbiota. When bacteria from the feet of four other volunteers were tested, similar effects were found. Fourteen putative attractants were found in the headspace of the skin bacteria. A synthetic blend of 10 of these was attractive to An. gambiae. Conclusions The discovery that volatiles produced by human skin microorganisms in vitro mediate An. gambiae host-seeking behaviour creates new opportunities for the

  2. Diclofenac enables unprecedented week-long microneedle-enhanced delivery of a skin impermeable medication in humans

    Science.gov (United States)

    Brogden, Nicole K.; Banks, Stan L.; Crofford, Leslie J.; Stinchcomb, Audra L.

    2013-01-01

    Microneedles applied to the skin create micropores, allowing transdermal drug delivery of skin-impermeable compounds. The first human study with this technique demonstrated delivery of naltrexone (an opioid antagonist) for two to three days. Rapid micropore closure, however, blunts the delivery window. Application of diclofenac (an anti-inflammatory) allows seven days of naltrexone delivery in animals. Purpose the purpose of the current work was to demonstrate delivery of naltrexone for seven days following one microneedle treatment in humans. Methods Human subjects were treated with microneedles, diclofenac (or placebo), and naltrexone. Impedance measurements were used as a surrogate marker to measure micropore formation, and plasma naltrexone concentrations were measured for seven days post-microneedle application. Results Impedance dropped significantly from baseline to post-microneedle treatment, confirming micropore formation. Naltrexone was detected for seven days in Group 1 (diclofenac + naltrexone, n = 6), vs. 72 hours in Group 2 (placebo + naltrexone, n = 2). At study completion, a significant difference in impedance was observed between intact and microneedle-treated skin in Group 1 (confirming the presence of micropores). Conclusion This is the first study demonstrating week-long drug delivery after one microneedle application, which would increase patient compliance and allow delivery of therapies for chronic diseases. PMID:23761054

  3. Development and validation of a high-performance liquid chromatographic method for the determination of cyproterone acetate in human skin.

    Science.gov (United States)

    Henry de Hassonville, Sandrine; Chiap, Patrice; Liégeois, Jean-François; Evrard, Brigitte; Delattre, Luc; Crommen, Jacques; Piel, Géraldine; Hubert, Philippe

    2004-09-21

    In the framework of a preliminary study on the transdermal penetration of cyproterone acetate (CPA), a simple and rapid procedure involving an extraction step coupled to a HPLC-UV determination has been developed for the separation and quantification of CPA in the two main skin layers-epidermis and dermis-after local application. The separation of epidermis and dermis layers was carefully carried out by means of a sharp spatula after skin immersion in heated water at 65 degrees C. The two skin layers were then treated separately according to the same process: (1) sample homogenization by vibration after freezing with liquid nitrogen in a Mikro-Dismembrator; (2) CPA extraction with methanol after addition of the internal standard (betamethasone dipropionate); (3) centrifugation; (4) evaporation of a supernatant aliquot; (5) dissolution of the dry residue in methanol and addition of water; (6) centrifugation; (7) injection of a supernatant aliquot into the HPLC system. The separation was achieved on octadecylsilica stationary phase using a mobile phase consisting in a mixture of acetonitrile and water (40:60 (v/v)). The method was then validated using a new approach based on accuracy profiles over a CPA concentration range from 33 to 667 ng/ml for each skin layer. Finally, the method was successfully applied to the determination of CPA to several skin samples after topical application of different gel formulations containing CPA.

  4. A novel method for real-time skin impedance measurement during radiofrequency skin tightening treatments.

    Science.gov (United States)

    Harth, Yoram; Lischinsky, Daniel

    2011-03-01

    The thermal effects of monopolar and bipolar radiofrequency (RF) have been proven to be beneficial in skin tightening. Nevertheless, these effects were frequently partial or unpredictable because of the uncontrolled nature of monopolar or unipolar RF and the superficial nature of energy flow for bipolar or tripolar configurations. One of the hypotheses for lack or predictability of efficacy of the first-generation RF therapy skin tightening systems is lack of adaptation of delivered power to differences in individual skin impedance. A novel multisource phase-controlled system was used (1 MHz, power range 0-65 W) for treatment and real-time skin impedance measurements in 24 patients (EndyMed PRO™; EndyMed, Cesarea, Israel). This system allows continuous real-time measurement of skin impedance delivering constant energy to the patient skin independent of changes in its impedance. More than 6000 unique skin impedance measurements on 22 patients showed an average session impedance range was 215-584 Ohm with an average of 369 Ohm (standard deviation of 49 Ohm). Analyzing individual pulses (total of 600 readings) showed a significant decrease in impedance during the pulse. These findings validate the expected differences in skin impedance between individual patients and in the same patients during the treatment pulse. Clinical study on 30 patients with facial skin aging using the device has shown high predictability of efficacy (86.7% of patients had good results or better at 3 months' follow-up [decrease of 2 or more grades in Fitzpatrick's wrinkle scale]). The real-time customization of energy according to skin impedance allows a significantly more accurate and safe method of nonablative skin tightening with more consistent and predictable results. © 2011 Wiley Periodicals, Inc.

  5. Approach to quantify human dermal skin aging using multiphoton laser scanning microscopy

    Science.gov (United States)

    Puschmann, Stefan; Rahn, Christian-Dennis; Wenck, Horst; Gallinat, Stefan; Fischer, Frank

    2012-03-01

    Extracellular skin structures in human skin are impaired during intrinsic and extrinsic aging. Assessment of these dermal changes is conducted by subjective clinical evaluation and histological and molecular analysis. We aimed to develop a new parameter for the noninvasive quantitative determination of dermal skin alterations utilizing the high-resolution three-dimensional multiphoton laser scanning microscopy (MPLSM) technique. To quantify structural differences between chronically sun-exposed and sun-protected human skin, the respective collagen-specific second harmonic generation and the elastin-specific autofluorescence signals were recorded in young and elderly volunteers using the MPLSM technique. After image processing, the elastin-to-collagen ratio (ELCOR) was calculated. Results show that the ELCOR parameter of volar forearm skin significantly increases with age. For elderly volunteers, the ELCOR value calculated for the chronically sun-exposed temple area is significantly augmented compared to the sun-protected upper arm area. Based on the MPLSM technology, we introduce the ELCOR parameter as a new means to quantify accurately age-associated alterations in the extracellular matrix.

  6. Permeability of commercial solvents through living human skin

    DEFF Research Database (Denmark)

    Ursin, C; Hansen, C M; Van Dyk, J W

    1995-01-01

    A procedure has been developed for measuring the steady state rate of permeation of commercial solvents through living human skin. To get the most consistent results, it was necessary with some solvents to normalize the solvent permeation rate of a given skin sample with its [3H]water permeation...... rate. For other solvents this was not necessary, so the un-normalized data were used. High [3H]water permeation rate also was used as a criterion for "defective" skin samples that gave erroneous permeability rates, especially for solvents having slow permeability. The linearity of the steady state data...... was characterized by calculation of the "percent error of the slope." The following permeability rates (g/m2h) of single solvents were measured: dimethyl sulfoxide (DMSO), 176; N-methyl-2-pyrrolidone, 171; dimethyl acetamide, 107; methyl ethyl ketone, 53; methylene chloride, 24; [3H]water, 14.8; ethanol, 11...

  7. Multivariate Models for Prediction of Human Skin Sensitization Hazard.

    Science.gov (United States)

    One of the lnteragency Coordinating Committee on the Validation of Alternative Method's (ICCVAM) top priorities is the development and evaluation of non-animal approaches to identify potential skin sensitizers. The complexity of biological events necessary to produce skin sensiti...

  8. Thermal Response of In Vivo Human Skin to Fractional Radiofrequency Microneedle Device

    Directory of Open Access Journals (Sweden)

    Woraphong Manuskiatti

    2016-01-01

    Full Text Available Background. Fractional radiofrequency microneedle system (FRMS is a novel fractional skin resurfacing system. Data on thermal response to this fractional resurfacing technique is limited. Objectives. To investigate histologic response of in vivo human skin to varying energy settings and pulse stacking of a FRMS in dark-skinned subjects. Methods. Two female volunteers who were scheduled for abdominoplasty received treatment with a FRMS with varying energy settings at 6 time periods including 3 months, 1 month, 1 week, 3 days, 1 day, and the time immediately before abdominoplasty. Biopsy specimens were analyzed using hematoxylin and eosin (H&E, Verhoeff-Van Gieson (VVG, colloidal iron, and Fontana-Masson stain. Immunohistochemical study was performed by using Heat Shock Protein 70 (HSP70 antibody and collagen III monoclonal antibody. Results. The average depth of radiofrequency thermal zone (RFTZ ranged from 100 to 300 μm, correlating with energy levels. Columns of cell necrosis and collagen denaturation followed by inflammatory response were initially demonstrated, with subsequent increasing of mucin at 1 and 3 months after treatment. Immunohistochemical study showed positive stain with HSP70. Conclusion. A single treatment with a FRMS using appropriate energy setting induces neocollagenesis. This wound healing response may serve as a mean to improve the appearance of photodamaged skin and atrophic scars.

  9. Signatures of human skin in the millimetre wave band (80-100) GHz

    Science.gov (United States)

    Owda, Amani Y.; Rezgui, Nacer-Ddine; Salmon, Neil A.

    2017-10-01

    With the performance of millimeter wave security screening imagers improving (reduced speckle, greater sensitivity, and better spatial resolution) attention is turning to identification of anomalies which appear on the human body. Key to this identification is the understanding of how the emissive and reflective properties vary over the human body and between different categories of people, defined by age and gender for example. As the interaction of millimetre waves with the human body is only a fraction of a millimetre into the skin, precise measurement of the emission and reflection of this radiation will allow comparisons with the norm for that region of the body and person category. On an automated basis at security screening portals, this will increase detection probabilities and reduce false alarm rates, ensuring high throughputs at entrances to future airport departure lounges and transport networks. A technique to measure the human skin emissivity in vivo over the frequency band 80 GHz to 100 GHz is described. The emissivities of the skin of a sample of 60 healthy participants (36 males and 24 females) measured using a 90 GHz calibrated radiometer was found to range from 0.17+/-0.002 to 0.68+/-0.002. The radiometric measurements were made at four locations on the arm, namely: palm of hand, back of hand, dorsal surface of the forearm, and volar side of the forearm, where the water content and the skin thickness are known to be different. These measurements show significant variation in emissivity from person to person and, more importantly, significant variation at different locations on the arms of individuals. Males were found to have an emissivity 0.03 higher than those of females. The emissivity of the back of the hand, where the skin is thinner and the blood vessels are closer to the skin surface, was found to be lower by 0.0681 than the emissivity of the palm of the hand, where the skin is thicker. The measurements also show that the emissivity of the

  10. Nanotribological characterization of human hair and skin using atomic force microscopy

    International Nuclear Information System (INIS)

    LaTorre, Carmen; Bhushan, Bharat

    2005-01-01

    Healthy hair and skin is highly desired. Characterization of their morphological, frictional, and adhesive properties (tribological properties) is essential to enhance understanding of hair and skin and to advance the science. Literature on the tribological characterization of hair and skin is scarce to date. The paper presents nanotribological data and analysis on hair (Caucasian, Asian, and African hair at virgin, chemo-mechanically damaged, and treated conditions) and synthetic hair and skin, as well as roughness data of human skin replica. Roughness statistics are presented to characterize the vertical and spatial surface parameters. Average coefficient of friction values were determined for each ethnicity and hair type, and are discussed. The directionality dependence of friction is also discussed. Magnitude and spatial distribution of adhesive force are used to estimate thickness and distribution of the conditioner film

  11. Age-related changes in expression and function of Toll-like receptors in human skin

    Science.gov (United States)

    Iram, Nousheen; Mildner, Michael; Prior, Marion; Petzelbauer, Peter; Fiala, Christian; Hacker, Stefan; Schöppl, Alice; Tschachler, Erwin; Elbe-Bürger, Adelheid

    2012-01-01

    Toll-like receptors (TLRs) initiate innate immune responses and direct subsequent adaptive immunity. They play a major role in cutaneous host defense against micro-organisms and in the pathophysiology of several inflammatory skin diseases. To understand the role of TLRs in the acquisition of immunological competence, we conducted a comprehensive study to evaluate TLR expression and function in the developing human skin before and after birth and compared it with adults. We found that prenatal skin already expresses the same spectrum of TLRs as adult skin. Strikingly, many TLRs were significantly higher expressed in prenatal (TLRs 1-5) and infant and child (TLRs 1 and 3) skin than in adult skin. Surprisingly, neither dendritic cell precursors in prenatal skin nor epidermal Langerhans cells and dermal dendritic cells in adult skin expressed TLRs 3 and 6, whereas the staining pattern and intensity of both TLRs in fetal basal keratinocytes was almost comparable to those of adults. Stimulation of primary human keratinocytes from fetal, neonatal and adult donors with selected TLR agonists revealed that the synthetic TLR3 ligand poly (I:C) specifically, mimicking viral double-stranded RNA, induced a significantly enhanced secretion of CXCL8/IL8, CXCL10/IP-10 and TNFα in fetal and neonatal keratinocytes compared with adult keratinocytes. This study demonstrates quantitative age-specific modifications in TLR expression and innate skin immune reactivity in response to TLR activation. Thus, antiviral innate immunity already in prenatal skin may contribute to protect the developing human body from viral infections in utero in a scenario where the adaptive immune system is not yet fully functional. PMID:23034637

  12. Discrimination of skin sensitizers from non-sensitizers by interleukin-1α and interleukin-6 production on cultured human keratinocytes.

    Science.gov (United States)

    Jung, Daun; Che, Jeong-Hwan; Lim, Kyung-Min; Chun, Young-Jin; Heo, Yong; Seok, Seung Hyeok

    2016-09-01

    In vitro testing methods for classifying sensitizers could be valuable alternatives to in vivo sensitization testing using animal models, such as the murine local lymph node assay (LLNA) and the guinea pig maximization test (GMT), but there remains a need for in vitro methods that are more accurate and simpler to distinguish skin sensitizers from non-sensitizers. Thus, the aim of our study was to establish an in vitro assay as a screening tool for detecting skin sensitizers using the human keratinocyte cell line, HaCaT. HaCaT cells were exposed to 16 relevant skin sensitizers and 6 skin non-sensitizers. The highest dose used was the dose causing 75% cell viability (CV75) that we determined by an MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay. The levels of extracellular production of interleukin-1α (IL-1α) and IL-6 were measured. The sensitivity of IL-1α was 63%, specificity was 83% and accuracy was 68%. In the case of IL-6, sensitivity: 69%, specificity: 83% and accuracy: 73%. Thus, this study suggests that measuring extracellular production of pro-inflammatory cytokines IL-1α and IL-6 by human HaCaT cells may potentially classify skin sensitizers from non-sensitizers. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

  13. Robust Lentiviral Gene Delivery But Limited Transduction Capacity of Commonly Used Adeno-Associated Viral Serotypes in Xenotransplanted Human Skin.

    Science.gov (United States)

    Jakobsen, Maria; Askou, Anne Louise; Stenderup, Karin; Rosada, Cecilia; Dagnæs-Hansen, Frederik; Jensen, Thomas G; Corydon, Thomas J; Mikkelsen, Jacob Giehm; Aagaard, Lars

    2015-08-01

    Skin is an easily accessible organ, and therapeutic gene transfer to skin remains an attractive alternative for the treatment of skin diseases. Although we have previously documented potent lentiviral gene delivery to human skin, vectors based on adeno-associated virus (AAV) rank among the most promising gene delivery tools for in vivo purposes. Thus, we compared the potential usefulness of various serotypes of recombinant AAV vectors and lentiviral vectors for gene transfer to human skin in a xenotransplanted mouse model. Vector constructs encoding firefly luciferase were packaged in AAV capsids of serotype 1, 2, 5, 6, 8, and 9 and separately administered by intradermal injection in human skin transplants. For all serotypes, live bioimaging demonstrated low levels of transgene expression in the human skin graft, and firefly luciferase expression was observed primarily in neighboring tissue outside of the graft. In contrast, gene delivery by intradermally injected lentiviral vectors was efficient and led to extensive and persistent firefly luciferase expression within the human skin graft only. The study demonstrates the limited capacity of single-stranded AAV vectors of six commonly used serotypes for gene delivery to human skin in vivo.

  14. Evaluation of 3D-human skin equivalents for assessment of human dermal absorption of some brominated flame retardants.

    Science.gov (United States)

    Abdallah, Mohamed Abou-Elwafa; Pawar, Gopal; Harrad, Stuart

    2015-11-01

    Ethical and technical difficulties inherent to studies in human tissues are impeding assessment of the dermal bioavailability of brominated flame retardants (BFRs). This is further complicated by increasing restrictions on the use of animals in toxicity testing, and the uncertainties associated with extrapolating data from animal studies to humans due to inter-species variations. To overcome these difficulties, we evaluate 3D-human skin equivalents (3D-HSE) as a novel in vitro alternative to human and animal testing for assessment of dermal absorption of BFRs. The percutaneous penetration of hexabromocyclododecanes (HBCD) and tetrabromobisphenol-A (TBBP-A) through two commercially available 3D-HSE models was studied and compared to data obtained for human ex vivo skin according to a standard protocol. No statistically significant differences were observed between the results obtained using 3D-HSE and human ex vivo skin at two exposure levels. The absorbed dose was low (less than 7%) and was significantly correlated with log Kow of the tested BFR. Permeability coefficient values showed increasing dermal resistance to the penetration of γ-HBCD>β-HBCD>α-HBCD>TBBPA. The estimated long lag times (>30 min) suggests that frequent hand washing may reduce human exposure to HBCDs and TBBPA via dermal contact. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Association of common genetic variants with human skin color variation in Indian populations.

    Science.gov (United States)

    Sarkar, Anujit; Nandineni, Madhusudan R

    2018-01-01

    Human skin color is one of the most conspicuously variable physical traits that has attracted the attention of physical anthropologists, social scientists and human geneticists. Although several studies have established the underlying genes and their variants affecting human skin color, they were mostly confined to Europeans and Africans and similar studies in Indian populations have been scanty. Studying the association between candidate genetic variants and skin color will help to validate previous findings and to better understand the molecular mechanism of skin color variation. In this study, 22 candidate SNPs from 12 genes were tested for association with skin color in 299 unrelated samples sourced from nine geographical locations in India. Our study establishes the association of 9 SNPs with the phenotype in Indian populations and could explain ∼31% of the variance in skin color. Haplotype analysis of chromosome 15 revealed a significant association of alleles G, A and C of SNPs rs1426654, rs11070627, and rs12913316, respectively, to the phenotype, and accounted for 17% of the variance. Latitude of the sampling location was also a significant factor, contributing to ∼19% of the variation observed in the samples. These observations support the findings that rs1426654 and rs4775730 located in SLC24A5, and rs11070627 and rs12913316 located in MYEF2 and CTXN2 genes respectively, are major contributors toward skin pigmentation and would aid in further unraveling the genotype-phenotype association in Indian populations. These findings can be utilized in forensic DNA applications for criminal investigations. © 2017 Wiley Periodicals, Inc.

  16. Migration of human antigen-presenting cells in a human skin graft onto nude mice model after contact sensitization

    NARCIS (Netherlands)

    Hoefakker, S.; Balk, H.P.; Boersma, W.J.A.; Joost, T. van; Notten, W.R.F.; Claassen, E.

    1995-01-01

    Fluorescent contact chemical allergens provoke sensitization after application on both syngeneic and allogeneic skin grafts in mice. We attempted to determine whether the functional activity in a contact sensitization response of human skin graft was affected at the level of antigen uptake and

  17. Skin contamination - prevention and decontaminating

    International Nuclear Information System (INIS)

    Henning, K.

    2001-01-01

    A detailed examination is made of the structure of human skin. Measures were drawn up to prevent skin contamination in nuclear installations as well as contaminated skin was decontaminated from the personnel. By systematically applying these measures a significant level of success was achieved in preventing contamination in nuclear installations. Cases where more far-reaching chemical methods had to be used were kept to a minimum. (R.P.)

  18. In vivo confirmation of hydration-induced changes in human-skin thickness, roughness and interaction with the environment.

    Science.gov (United States)

    Dąbrowska, Agnieszka K; Adlhart, Christian; Spano, Fabrizio; Rotaru, Gelu-Marius; Derler, Siegfried; Zhai, Lina; Spencer, Nicholas D; Rossi, René M

    2016-09-15

    The skin properties, structure, and performance can be influenced by many internal and external factors, such as age, gender, lifestyle, skin diseases, and a hydration level that can vary in relation to the environment. The aim of this work was to demonstrate the multifaceted influence of water on human skin through a combination of in vivo confocal Raman spectroscopy and images of volar-forearm skin captured with the laser scanning confocal microscopy. By means of this pilot study, the authors have both qualitatively and quantitatively studied the influence of changing the depth-dependent hydration level of the stratum corneum (SC) on the real contact area, surface roughness, and the dimensions of the primary lines and presented a new method for characterizing the contact area for different states of the skin. The hydration level of the skin and the thickness of the SC increased significantly due to uptake of moisture derived from liquid water or, to a much lesser extent, from humidity present in the environment. Hydrated skin was smoother and exhibited higher real contact area values. The highest rates of water uptake were observed for the upper few micrometers of skin and for short exposure times.

  19. Porphyrin metabolisms in human skin commensal Propionibacterium acnes bacteria: potential application to monitor human radiation risk.

    Science.gov (United States)

    Shu, M; Kuo, S; Wang, Y; Jiang, Y; Liu, Y-T; Gallo, R L; Huang, C-M

    2013-01-01

    Propionibacterium acnes (P. acnes), a Gram-positive anaerobic bacterium, is a commensal organism in human skin. Like human cells, the bacteria produce porphyrins, which exhibit fluorescence properties and make bacteria visible with a Wood's lamp. In this review, we compare the porphyrin biosynthesis in humans and P. acnes. Also, since P. acnes living on the surface of skin receive the same radiation exposure as humans, we envision that the changes in porphyrin profiles (the absorption spectra and/or metabolism) of P. acnes by radiation may mirror the response of human cells to radiation. The porphyrin profiles of P. acnes may be a more accurate reflection of radiation risk to the patient than other biodosimeters/biomarkers such as gene up-/down-regulation, which may be non-specific due to patient related factors such as autoimmune diseases. Lastly, we discuss the challenges and possible solutions for using the P. acnes response to predict the radiation risk.

  20. Expression of intercellular adhesion molecule-1 in UVA-irradiated human skin cells in vitro and in vivo

    International Nuclear Information System (INIS)

    Treina, G.; Scaletta, C.; Frenk, E.; Applegate, L.A.; Fourtanier, A.; Seite, S.

    1996-01-01

    Ultraviolet A (UVA) radiation represents an important oxidative stress to human skin and certain forms of oxidative stress have been shown to modulate intercellular adhesion molecule-1 (ICAM-1) expression. ICAM-1 has been shown to play an important part in many immune reactions and the perturbations of this molecule by ultraviolet radiation could have implications in many inflammatory responses. An enhancement immunohistochemical method with avidin/biotin was used for analysing the early effects of UVA radiation on human cell cultures and human skin (340-400 nm). Both in vitro and in vivo data show that ICAM-1 staining in epidermal keratinocytes, which was expressed constitutively, decreased in a UVA dose-dependent manner. The decrease was most noted at 3-6 h following UVA radiation with some ICAM-1 staining returning by 48 h post-UVA. ICAM-1 positive staining in the dermis was specific for vascular structures and was increased 24 h after UVA radiation. Cultured dermal fibroblasts exhibited ICAM-1 staining which increased slightly within 6-48 h post-UVA radiation. As epidermal ICAM-1 expression is depleted following UVA radiation and dermal expression increases due to an increase in the vascular structures, ICAM-1 provides a valuable marker following UVA radiation in human skin that can be readily measured in situ. (author)

  1. In vivo study of human skin using pulsed terahertz radiation

    Energy Technology Data Exchange (ETDEWEB)

    Pickwell, E [Semiconductor Physics Group, Cavendish Laboratory, Cambridge University, Madingley Road, Cambridge CB3 0HE (United Kingdom); Cole, B E [TeraView Ltd, Unit 302/4 Cambridge Science Park, Cambridge CB4 0WG (United Kingdom); Fitzgerald, A J [TeraView Ltd, Unit 302/4 Cambridge Science Park, Cambridge CB4 0WG (United Kingdom); Pepper, M [Semiconductor Physics Group, Cavendish Laboratory, Cambridge University, Madingley Road, Cambridge CB3 0HE (United Kingdom); Wallace, V P [TeraView Ltd, Unit 302/4 Cambridge Science Park, Cambridge CB4 0WG (United Kingdom)

    2004-05-07

    Studies in terahertz (THz) imaging have revealed a significant difference between skin cancer (basal cell carcinoma) and healthy tissue. Since water has strong absorptions at THz frequencies and tumours tend to have different water content from normal tissue, a likely contrast mechanism is variation in water content. Thus, we have previously devised a finite difference time-domain (FDTD) model which is able to closely simulate the interaction of THz radiation with water. In this work we investigate the interaction of THz radiation with normal human skin on the forearm and palm of the hand in vivo. We conduct the first ever systematic in vivo study of the response of THz radiation to normal skin. We take in vivo reflection measurements of normal skin on the forearm and palm of the hand of 20 volunteers. We compare individual examples of THz responses with the mean response for the areas of skin under investigation. Using the in vivo data, we demonstrate that the FDTD model can be applied to biological tissue. In particular, we successfully simulate the interaction of THz radiation with the volar forearm. Understanding the interaction of THz radiation with normal skin will form a step towards developing improved imaging algorithms for diagnostic detection of skin cancer and other tissue disorders using THz radiation.

  2. In vivo study of human skin using pulsed terahertz radiation

    International Nuclear Information System (INIS)

    Pickwell, E; Cole, B E; Fitzgerald, A J; Pepper, M; Wallace, V P

    2004-01-01

    Studies in terahertz (THz) imaging have revealed a significant difference between skin cancer (basal cell carcinoma) and healthy tissue. Since water has strong absorptions at THz frequencies and tumours tend to have different water content from normal tissue, a likely contrast mechanism is variation in water content. Thus, we have previously devised a finite difference time-domain (FDTD) model which is able to closely simulate the interaction of THz radiation with water. In this work we investigate the interaction of THz radiation with normal human skin on the forearm and palm of the hand in vivo. We conduct the first ever systematic in vivo study of the response of THz radiation to normal skin. We take in vivo reflection measurements of normal skin on the forearm and palm of the hand of 20 volunteers. We compare individual examples of THz responses with the mean response for the areas of skin under investigation. Using the in vivo data, we demonstrate that the FDTD model can be applied to biological tissue. In particular, we successfully simulate the interaction of THz radiation with the volar forearm. Understanding the interaction of THz radiation with normal skin will form a step towards developing improved imaging algorithms for diagnostic detection of skin cancer and other tissue disorders using THz radiation

  3. Structural and biophysical characteristics of human skin in maintaining proper epidermal barrier function

    Directory of Open Access Journals (Sweden)

    Magdalena Boer

    2016-02-01

    Full Text Available The complex structure of human skin and its physicochemical properties turn it into an efficient outermost defence line against exogenous factors, and help maintain homeostasis of the human body. This role is played by the epidermal barrier with its major part – stratum corneum. The condition of the epidermal barrier depends on individual and environmental factors. The most important biophysical parameters characterizing the status of this barrier are the skin pH, epidermal hydration, transepidermal water loss and sebum excretion. The knowledge of biophysical skin processes may be useful for the implementation of prophylactic actions whose aim is to restore the barrier function.

  4. UV irradiation-induced methionine oxidation in human skin keratins: Mass spectrometry-based non-invasive proteomic analysis.

    Science.gov (United States)

    Lee, Seon Hwa; Matsushima, Keita; Miyamoto, Kohei; Oe, Tomoyuki

    2016-02-05

    Ultraviolet (UV) radiation is the major environmental factor that causes oxidative skin damage. Keratins are the main constituents of human skin and have been identified as oxidative target proteins. We have recently developed a mass spectrometry (MS)-based non-invasive proteomic methodology to screen oxidative modifications in human skin keratins. Using this methodology, UV effects on methionine (Met) oxidation in human skin keratins were investigated. The initial screening revealed that Met(259), Met(262), and Met(296) in K1 keratin were the most susceptible oxidation sites upon UVA (or UVB) irradiation of human tape-stripped skin. Subsequent liquid chromatography/electrospray ionization-MS and tandem MS analyses confirmed amino acid sequences and oxidation sites of tryptic peptides D(290)VDGAYMTK(298) (P1) and N(258)MQDMVEDYR(267) (P2). The relative oxidation levels of P1 and P2 increased in a time-dependent manner upon UVA irradiation. Butylated hydroxytoluene was the most effective antioxidant for artifactual oxidation of Met residues. The relative oxidation levels of P1 and P2 after UVA irradiation for 48 h corresponded to treatment with 100mM hydrogen peroxide for 15 min. In addition, Met(259) was oxidized by only UVA irradiation. The Met sites identified in conjunction with the current proteomic methodology can be used to evaluate skin damage under various conditions of oxidative stress. We demonstrated that the relative Met oxidation levels in keratins directly reflected UV-induced damages to human tape-stripped skin. Human skin proteins isolated by tape stripping were analyzed by MS-based non-invasive proteomic methodology. Met(259), Met(262), and Met(296) in K1 keratin were the most susceptible oxidation sites upon UV irradiation. Met(259) was oxidized by only UVA irradiation. Quantitative LC/ESI-SRM/MS analyses confirmed a time-dependent increase in the relative oxidation of target peptides (P1 and P2) containing these Met residues, upon UVA irradiation

  5. Transfection of Primary Human Skin Fibroblasts for Peroxisomal Studies

    NARCIS (Netherlands)

    Koster, Janet; Waterham, Hans R.

    2017-01-01

    Functional studies with primary human skin fibroblasts from patients with a peroxisomal disorder often require efficient transfection with plasmids to correct the genetic defect or to express heterologous reporter proteins. Here, we describe a protocol we commonly use for efficient nonviral

  6. Effectiveness of hand washing on the removal of iron oxide nanoparticles from human skin ex vivo.

    Science.gov (United States)

    Lewinski, Nastassja A; Berthet, Aurélie; Maurizi, Lionel; Eisenbeis, Antoine; Hopf, Nancy B

    2017-08-01

    In this study, the effectiveness of washing with soap and water in removing nanoparticles from exposed skin was investigated. Dry, nanoscale hematite (α-Fe 2 O 3 ) or maghemite (γ-Fe 2 O 3 ) powder, with primary particle diameters between 20-30 nm, were applied to two samples each of fresh and frozen ex vivo human skin in two independent experiments. The permeation of nanoparticles through skin, and the removal of nanoparticles after washing with soap and water were investigated. Bare iron oxide nanoparticles remained primarily on the surface of the skin, without penetrating beyond the stratum corneum. Skin exposed to iron oxide nanoparticles for 1 and 20 hr resulted in removal of 85% and 90%, respectively, of the original dose after washing. In the event of dermal exposure to chemicals, removal is essential to avoid potential local irritation or permeation across skin. Although manufactured at an industrial scale and used extensively in laboratory experiments, limited data are available on the removal of engineered nanoparticles after skin contact. Our finding raises questions about the potential consequences of nanoparticles remaining on the skin and whether alternative washing methods should be proposed. Further studies on skin decontamination beyond use of soap and water are needed to improve the understanding of the potential health consequences of dermal exposure to nanoparticles.

  7. Preliminary observations on differences in the Raman spectra of cancerous and noncancerous cells and connective tissue of human skin

    Science.gov (United States)

    Short, Michael A.; Lui, Harvey; McLean, David I.; Zeng, Haishan; Alajlan, Abdulmajeed; Chen, Michael X.

    2005-04-01

    A less invasive method of reliably detecting skin cancers is required. Raman spectroscopy is just one of several spectroscopic methods that look promising, but are not yet sufficiently reliable. More information is needed on how and why the Raman spectra of cancerous skin tissue is different from its normal counterpart. We have used confocal micro-Raman spectroscopy with a spatial resolution of about a micron to obtain spectra of unstained thin sections of human skin. We found that there were clear differences in the Raman spectra between cancerous and non-cancerous tissue both in cells and in the connective tissue. The DNA contribution to the spectra was generally stronger in malignant cells than normal ones. In regions of the dermis far away from the tumor one obtains the usual collagen spectra of normal skin, but adjacent to the tumor the spectra no longer appeared to be those of native collagen.

  8. Airborne polycyclic aromatic hydrocarbons trigger human skin cells aging through aryl hydrocarbon receptor.

    Science.gov (United States)

    Qiao, Yuan; Li, Qiang; Du, Hong-Yang; Wang, Qiao-Wei; Huang, Ye; Liu, Wei

    2017-07-01

    Accumulating evidence suggests that polycyclic aromatic hydrocarbons (PAH) which adsorbed on the surface of ambient air particulate matters (PM), are the major toxic compound to cause cardiovascular and respiratory diseases, even cancer. However, its detrimental effects on human skin cell remain unclear. Here, we demonstrated that SRM1649b, a reference urban dust material of PAH, triggers human skin cells aging through cell cycle arrest, cell growth inhibition and apoptosis. Principally, SRM1649b facilitated Aryl hydrocarbon receptor (AhR) translocated into nucleus, subsequently activated ERK/MAPK signaling pathway, and upregulated aging-related genes expression. Most important, we found that AhR antagonist efficiently revert the aging of skin cells. Thus our novel findings firstly revealed the mechanism of skin aging under PAH contamination and provided potential strategy for clinical application. Copyright © 2017. Published by Elsevier Inc.

  9. Inhibition of ultraviolet irradiation response of human skin by topical phlogostatic compounds

    International Nuclear Information System (INIS)

    Weirich, E.G.; Lutz, U.C.

    1977-01-01

    By adaption of the model of UV dermatitis in human skin a test procedure has been developed which facilitates realistic assessment of topical contra-inflammatory activity of steroidal as well as non-steroidal compounds. Sixt typical skin drug agents were tested according to their reaction inhibition effect. (orig./MG) [de

  10. Optimization of PIXE-sensitivity for detection of Ti in thin human skin sections

    International Nuclear Information System (INIS)

    Pallon, Jan; Garmer, Mats; Auzelyte, Vaida; Elfman, Mikael; Kristiansson, Per; Malmqvist, Klas; Nilsson, Christer; Shariff, Asad; Wegden, Marie

    2005-01-01

    Modern sunscreens contain particles like TiO 2 having sizes of 25-70 nm and acting as a reflecting substance. For cosmetic reasons the particle size is minimized. Questions have been raised to what degree these nano particles penetrate the skin barrier, and how they do affect the human. The EU funded project 'Quality of skin as a barrier to ultra-fine particles' - NANODERM has started with the purpose to evaluate the possible risks of TiO 2 penetration into vital skin layers. The purpose of the work presented here was to find the optimal conditions for micro-PIXE analysis of Ti in thin skin sections. In the skin region where Ti is expected to be found, the naturally occurring major elements phosphorus, chlorine, sulphur and potassium have steep gradients and thus influence the X-ray background in a non-predictable manner. Based on experimental studies of Ti-exposed human skin sections using proton energies ranging from 1.8-2.55 MeV, the corresponding PIXE detection limits for Ti were calculated. The energy that was found to be the most favourable, 1.9 MeV, was then selected for future studies

  11. The Human Skin Microbiome Associates with the Outcome of and Is Influenced by Bacterial Infection

    OpenAIRE

    van Rensburg, Julia J.; Lin, Huaiying; Gao, Xiang; Toh, Evelyn; Fortney, Kate R.; Ellinger, Sheila; Zwickl, Beth; Janowicz, Diane M.; Katz, Barry P.; Nelson, David E.; Dong, Qunfeng; Spinola, Stanley M.

    2015-01-01

    ABSTRACT The influence of the skin microbiota on host susceptibility to infectious agents is largely unexplored. The skin harbors diverse bacterial species that may promote or antagonize the growth of an invading pathogen. We developed a human infection model for Haemophilus ducreyi in which human volunteers are inoculated on the upper arm. After inoculation, papules form and either spontaneously resolve or progress to pustules. To examine the role of the skin microbiota in the outcome of H. ...

  12. Response of Human Skin Equivalents to Sarcoptes scabiei

    Science.gov (United States)

    MORGAN, MARJORIE S.; ARLIAN, LARRY G.

    2010-01-01

    Studies have shown that molecules in an extract made from bodies of the ectoparasitic mite, Sarcoptes scabiei De Geer, modulate cytokine secretion from cultured human keratinocytes and fibroblasts. In vivo, in the parasitized skin, these cells interact with each other by contact and cytokine mediators and with the matrix in which they reside. Therefore, these cell types may function differently together than they do separately. In this study, we used a human skin equivalent (HSE) model to investigate the influence of cellular interactions between keratinocytes and fibroblasts when the cells were exposed to active/burrowing scabies mites, mite products, and mite extracts. The HSE consisted of an epidermis of stratified stratum corneum, living keratinocytes, and basal cells above a dermis of fibroblasts in a collagen matrix. HSEs were inoculated on the surface or in the culture medium, and their cytokine secretions on the skin surface and into the culture medium were determined by enzyme-linked immunosorbent assay. Active mites on the surface of the HSE induced secretion of cutaneous T cell-attracting chemokine, thymic stromal lymphopoietin, interleukin (IL)-1α, IL-1β, IL-1 receptor antagonist (IL-1ra), IL-6, IL-8, monocyte chemoattractant protein-1, granulocyte/macrophage colony-stimulating factor, and macrophage colony-stimulating factor. The main difference between HSEs and monocultured cells was that the HSEs produced the proinflammatory cytokines IL-1α and IL-1β and their competitive inhibitor IL-1ra, whereas very little of these mediators was previously found for cultured keratinocytes and fibroblasts. It is not clear how the balance between these cytokines influences the overall host response. However, IL-1ra may contribute to the depression of an early cutaneous inflammatory response to scabies in humans. These contrasting results illustrate that cell interactions are important in the host’s response to burrowing scabies mites. PMID:20939384

  13. Quantitative detection of caffeine in human skin by confocal Raman spectroscopy--A systematic in vitro validation study.

    Science.gov (United States)

    Franzen, Lutz; Anderski, Juliane; Windbergs, Maike

    2015-09-01

    For rational development and evaluation of dermal drug delivery, the knowledge of rate and extent of substance penetration into the human skin is essential. However, current analytical procedures are destructive, labor intense and lack a defined spatial resolution. In this context, confocal Raman microscopy bares the potential to overcome current limitations in drug depth profiling. Confocal Raman microscopy already proved its suitability for the acquisition of qualitative penetration profiles, but a comprehensive investigation regarding its suitability for quantitative measurements inside the human skin is still missing. In this work, we present a systematic validation study to deploy confocal Raman microscopy for quantitative drug depth profiling in human skin. After we validated our Raman microscopic setup, we successfully established an experimental procedure that allows correlating the Raman signal of a model drug with its controlled concentration in human skin. To overcome current drawbacks in drug depth profiling, we evaluated different modes of peak correlation for quantitative Raman measurements and offer a suitable operating procedure for quantitative drug depth profiling in human skin. In conclusion, we successfully demonstrate the potential of confocal Raman microscopy for quantitative drug depth profiling in human skin as valuable alternative to destructive state-of-the-art techniques. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. Infusion pressure and pain during microneedle injection into skin of human subjects

    Science.gov (United States)

    Gupta, Jyoti; Park, Sohyun; Bondy, Brian; Felner, Eric I.; Prausnitz, Mark R.

    2011-01-01

    Infusion into skin using hollow microneedles offers an attractive alternative to hypodermic needle injections. However, the fluid mechanics and pain associated with injection into skin using a microneedle have not been studied in detail before. Here, we report on the effect of microneedle insertion depth into skin, partial needle retraction, fluid infusion flow rate and the co-administration of hyaluronidase on infusion pressure during microneedle-based saline infusion, as well as on associated pain in human subjects. Infusion of up to a few hundred microliters of fluid required pressures of a few hundred mmHg, caused little to no pain, and showed weak dependence on infusion parameters. Infusion of larger volumes up to 1 mL required pressures up to a few thousand mmHg, but still usually caused little pain. In general, injection of larger volumes of fluid required larger pressures and application of larger pressures cause more pain, although other experimental parameters also played a significant role. Among the intradermal microneedle groups, microneedle length had little effect; microneedle retraction lowered infusion pressure but increased pain; lower flow rate reduced infusion pressure and kept pain low; and use of hyaluronidase also lowered infusion pressure and kept pain low. We conclude that microneedles offer a simple method to infuse fluid into the skin that can be carried out with little to no pain. PMID:21684001

  15. Photoreactivation and other ultraviolet/visible light effects on DNA in human skin

    International Nuclear Information System (INIS)

    Sutherland, B.M.; Blackett, A.D.; Feng, N.I.; Freeman, S.E.; Ogut, E.S.; Gange, R.W.; Sutherland, J.C.

    1985-01-01

    Wavelengths of light present in sunlight, sunlamps, and fluorescent and incandescent lamps induce changes in human skin DNA in a multiplicity of reactions. UVB and UVA exposures can induce damage in DNA as well as can the inducement of tanning to protect against such damage. Longer wavelength ultraviolet radiation can mediate enzymatic (or perhaps nonenzymatic) reversal of dimers. None of the action spectra, kinetics, or other characteristics of such reactions are known. Elucidation of their properties will provide essential information to allow evaluation of the interaction of light with human skin DNA

  16. Influence of probe pressure on diffuse reflectance spectra of human skin measured in vivo

    Science.gov (United States)

    Popov, Alexey P.; Bykov, Alexander V.; Meglinski, Igor V.

    2017-11-01

    Mechanical pressure superficially applied on the human skin surface by a fiber-optic probe influences the spatial distribution of blood within the cutaneous tissues. Upon gradual load of weight on the probe, a stepwise increase in the skin reflectance spectra is observed. The decrease in the load follows the similar inverse staircase-like tendency. The observed stepwise reflectance spectra changes are due to, respectively, sequential extrusion of blood from the topical cutaneous vascular beds and their filling afterward. The obtained results are confirmed by Monte Carlo modeling. This implies that pressure-induced influence during the human skin diffuse reflectance spectra measurements in vivo should be taken into consideration, in particular, in the rapidly developing area of wearable gadgets for real-time monitoring of various human body parameters.

  17. Skin sensitisation: the Colipa strategy for developing and evaluating non-animal test methods for risk assessment.

    Science.gov (United States)

    Maxwell, Gavin; Aeby, Pierre; Ashikaga, Takao; Bessou-Touya, Sandrine; Diembeck, Walter; Gerberick, Frank; Kern, Petra; Marrec-Fairley, Monique; Ovigne, Jean-Marc; Sakaguchi, Hitoshi; Schroeder, Klaus; Tailhardat, Magali; Teissier, Silvia; Winkler, Petra

    2011-01-01

    Allergic contact dermatitis is a delayed-type hypersensitivity reaction induced by small reactive chemicals (haptens). Currently, the sensitising potential and potency of new chemicals is usually characterised using data generated via animal studies, such as the local lymph node assay (LLNA). There are, however, increasing public and political concerns regarding the use of animals for the testing of new chemicals. Consequently, the development of in vitro, in chemico or in silico models for predicting the sensitising potential and/or potency of new chemicals is receiving widespread interest. The Colipa Skin Tolerance task force currently collaborates with and/or funds several academic research groups to expand our understanding of the molecular and cellular events occurring during the acquisition of skin sensitisation. Knowledge gained from this research is being used to support the development and evaluation of novel alternative approaches for the identification and characterisation of skin sensitizing chemicals. At present three non-animal test methods (Direct Peptide Reactivity Assay (DPRA), Myeloid U937 Skin Sensitisation Test (MUSST) and human Cell Line Activation Test (hCLAT)) have been evaluated in Colipa interlaboratory ring trials for their potential to predict skin sensitisation potential and were recently submitted to ECVAM for formal pre-validation. Data from all three test methods will now be used to support the study and development of testing strategy approaches for skin sensitiser potency prediction. This publication represents the current viewpoint of the cosmetics industry on the feasibility of replacing the need for animal test data for informing skin sensitisation risk assessment decisions.

  18. Pred-Skin: A Fast and Reliable Web Application to Assess Skin Sensitization Effect of Chemicals.

    Science.gov (United States)

    Braga, Rodolpho C; Alves, Vinicius M; Muratov, Eugene N; Strickland, Judy; Kleinstreuer, Nicole; Trospsha, Alexander; Andrade, Carolina Horta

    2017-05-22

    Chemically induced skin sensitization is a complex immunological disease with a profound impact on quality of life and working ability. Despite some progress in developing alternative methods for assessing the skin sensitization potential of chemical substances, there is no in vitro test that correlates well with human data. Computational QSAR models provide a rapid screening approach and contribute valuable information for the assessment of chemical toxicity. We describe the development of a freely accessible web-based and mobile application for the identification of potential skin sensitizers. The application is based on previously developed binary QSAR models of skin sensitization potential from human (109 compounds) and murine local lymph node assay (LLNA, 515 compounds) data with good external correct classification rate (0.70-0.81 and 0.72-0.84, respectively). We also included a multiclass skin sensitization potency model based on LLNA data (accuracy ranging between 0.73 and 0.76). When a user evaluates a compound in the web app, the outputs are (i) binary predictions of human and murine skin sensitization potential; (ii) multiclass prediction of murine skin sensitization; and (iii) probability maps illustrating the predicted contribution of chemical fragments. The app is the first tool available that incorporates quantitative structure-activity relationship (QSAR) models based on human data as well as multiclass models for LLNA. The Pred-Skin web app version 1.0 is freely available for the web, iOS, and Android (in development) at the LabMol web portal ( http://labmol.com.br/predskin/ ), in the Apple Store, and on Google Play, respectively. We will continuously update the app as new skin sensitization data and respective models become available.

  19. The use of nanoencapsulation to decrease human skin irritation caused by capsaicinoids

    Directory of Open Access Journals (Sweden)

    Contri RV

    2014-02-01

    Full Text Available Renata V Contri,1 Luiza A Frank,2 Moacir Kaiser,1 Adriana R Pohlmann,1,3 Silvia S Guterres1,2 1Programa de Pós-Graduação em Ciências Farmacêuticas, 2Faculdade de Farmácia, 3Instituto de Química, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil Abstract: Capsaicin, a topical analgesic used in the treatment of chronic pain, has irritant properties that frequently interrupt its use. In this work, the effect of nanoencapsulation of the main capsaicinoids (capsaicin and dihydrocapsaicin on skin irritation was tested in humans. Skin tolerance of a novel vehicle composed of chitosan hydrogel containing nonloaded nanocapsules (CH-NC was also evaluated. The chitosan hydrogel containing nanoencapsulated capsaicinoids (CH-NC-CP did not cause skin irritation, as measured by an erythema probe and on a visual scale, while a formulation containing free capsaicinoids (chitosan gel with hydroalcoholic solution [CH-ET-CP] and a commercially available capsaicinoids formulation caused skin irritation. Thirty-one percent of volunteers reported slight irritation one hour after application of CH-NC-CP, while moderate (46% [CH-ET-CP] and 23% [commercial product] and severe (8% [CH-ET-CP] and 69% [commercial product] irritation were described for the formulations containing free capsaicinoids. When CH-NC was applied to the skin, erythema was not observed and only 8% of volunteers felt slight irritation, which demonstrates the utility of the novel vehicle. A complementary in vitro skin permeation study showed that permeation of capsaicinoids through an epidermal human membrane was reduced but not prevented by nanoencapsulation. Keywords: chitosan, nanocapsules, capsaicinoids, skin irritation, skin permeation

  20. Resident CD141 (BDCA3)+ dendritic cells in human skin produce IL-10 and induce regulatory T cells that suppress skin inflammation.

    Science.gov (United States)

    Chu, Chung-Ching; Ali, Niwa; Karagiannis, Panagiotis; Di Meglio, Paola; Skowera, Ania; Napolitano, Luca; Barinaga, Guillermo; Grys, Katarzyna; Sharif-Paghaleh, Ehsan; Karagiannis, Sophia N; Peakman, Mark; Lombardi, Giovanna; Nestle, Frank O

    2012-05-07

    Human skin immune homeostasis, and its regulation by specialized subsets of tissue-residing immune sentinels, is poorly understood. In this study, we identify an immunoregulatory tissue-resident dendritic cell (DC) in the dermis of human skin that is characterized by surface expression of CD141, CD14, and constitutive IL-10 secretion (CD141(+) DDCs). CD141(+) DDCs possess lymph node migratory capacity, induce T cell hyporesponsiveness, cross-present self-antigens to autoreactive T cells, and induce potent regulatory T cells that inhibit skin inflammation. Vitamin D(3) (VitD3) promotes certain phenotypic and functional properties of tissue-resident CD141(+) DDCs from human blood DCs. These CD141(+) DDC-like cells can be generated in vitro and, once transferred in vivo, have the capacity to inhibit xeno-graft versus host disease and tumor alloimmunity. These findings suggest that CD141(+) DDCs play an essential role in the maintenance of skin homeostasis and in the regulation of both systemic and tumor alloimmunity. Finally, VitD3-induced CD141(+) DDC-like cells have potential clinical use for their capacity to induce immune tolerance.

  1. Human skin condition and its associations with nutrient concentrations in serum and diet

    NARCIS (Netherlands)

    Boelsma, E.; Vijver, L.P.L. van de; Goldbohm, R.A.; Klöpping-Ketelaars, I.A.A.; Hendriks, H.F.J.; Roza, L.

    2003-01-01

    Background: Nutritional factors exert promising actions on the skin, but only scant information is available on the modulating effects of physiologic concentrations of nutrients on the skin condition of humans. Objective: The objective was to evaluate whether nutrient concentrations in serum and

  2. Chemical applicability domain of the local lymph node assay (LLNA) for skin sensitisation potency. Part 4. Quantitative correlation of LLNA potency with human potency.

    Science.gov (United States)

    Roberts, David W; Api, Anne Marie

    2018-07-01

    Prediction of skin sensitisation potential and potency by non-animal methods is the target of many active research programmes. Although the aim is to predict sensitisation potential and potency in humans, data from the murine local lymph node assay (LLNA) constitute much the largest source of quantitative data on in vivo skin sensitisation. The LLNA has been the preferred in vivo method for identification of skin sensitising chemicals and as such is potentially valuable as a benchmark for assessment of non-animal approaches. However, in common with all predictive test methods, the LLNA is subject to false positives and false negatives with an overall level of accuracy said variously to be approximately 80% or 90%. It is also necessary to consider the extent to which, for true positives, LLNA potency correlates with human potency. In this paper LLNA potency and human potency are compared so as to express quantitatively the correlation between them, and reasons for non-agreement between LLNA and human potency are analysed. This leads to a better definition of the applicability domain of the LLNA, within which LLNA data can be used confidently to predict human potency and as a benchmark to assess the performance of non-animal approaches. Copyright © 2018. Published by Elsevier Inc.

  3. Multiple spatially resolved reflection spectroscopy for in vivo determination of carotenoids in human skin and blood

    Science.gov (United States)

    Darvin, Maxim E.; Magnussen, Björn; Lademann, Juergen; Köcher, Wolfgang

    2016-09-01

    Non-invasive measurement of carotenoid antioxidants in human skin is one of the important tasks to investigate the skin physiology in vivo. Resonance Raman spectroscopy and reflection spectroscopy are the most frequently used non-invasive techniques in dermatology and skin physiology. In the present study, an improved method based on multiple spatially resolved reflection spectroscopy (MSRRS) was introduced. The results obtained were compared with those obtained using the ‘gold standard’ resonance Raman spectroscopy method and showed strong correlations for the total carotenoid concentration (R  =  0.83) as well as for lycopene (R  =  0.80). The measurement stability was confirmed to be better than 10% within the total temperature range from 5 °C to  +  30 °C and pressure contact between the skin and the MSRRS sensor from 800 Pa to 18 000 Pa. In addition, blood samples taken from the subjects were analyzed for carotenoid concentrations. The MSRRS sensor was calibrated on the blood carotenoid concentrations resulting in being able to predict with a correlation of R  =  0.79. On the basis of blood carotenoids it could be demonstrated that the MSRRS cutaneous measurements are not influenced by Fitzpatrick skin types I-VI. The MSRRS sensor is commercially available under the brand name biozoom.

  4. Collagen cross-linking in sun-exposed and unexposed sites of aged human skin

    Science.gov (United States)

    Yamauchi, M.; Prisayanh, P.; Haque, Z.; Woodley, D. T.

    1991-01-01

    A recently described nonreducible, acid-heat stable compound, histidinohydroxylysinonorleucine (HHL), is a collagen cross-link isolated from mature skin tissue. Its abundance is related to chronologic aging of skin. The present communication describes the quantity of HHL from aged human skin of the same individuals in sun-exposed (wrist) and unexposed (buttock) sites. Punch biopsies were obtained from these sites from nine people of age 60 or older. HHL contents (moles/mole of collagen) at these sites were for wrist 0.13 +/- 0.07 and for buttock 0.69 +/- 0.17 (mean +/- SD, p less than 0.001). In addition, it was found that acute irradiation of the cross-linked peptides with UVA (up to 250 J/cm2) and UVB (up to 1 J/cm2) had no effect on HHL structure. The same treatment significantly degraded another nonreducible, stable collagen cross-link, pyridinoline. The results suggest that chronic sunlight exposure may be associated with an impediment to normal maturation of human dermal collagen resulting in tenuous amount of HHL. Thus, the process of photoaging in dermal collagen is different from that of chronologic aging in human skin.

  5. The use of non-invasive instruments in characterizing human facial and abdominal skin.

    Science.gov (United States)

    Bailey, Steven H; Oni, Georgette; Brown, Spencer A; Kashefi, Natalie; Cheriyan, Salim; Maxted, Michael; Stewart, Collin; Jones, Caroline; Maluso, Patrick; Kenkel, Ashley M; Kenkel, Matthew M; Hoopman, John; Barton, Fritz; Kenkel, Jeffrey M

    2012-02-01

    The skin is highly variable. This variation, although helpful for function, causes inconsistencies when assessed using subjective scales. The purpose of this study is to measure differences in skin on the face and abdomen using non-invasive, objective devices as a method to eliminate subjective error and help reduce intra- and inter-observer variability in clinical analysis. Eighty-eight subjects between the ages of 18 and 61 were enrolled in this study. These subjects varied in age, ethnicity, and Fitzpatrick score. Facial analysis was performed by clinical evaluation and utilizing non-invasive objective devices which included the DermaScan C 20 MHz HFUS (Cyberderm, Broomall, PA), Tru Vu (Johnson and Johnson), BTC 2000 (SRLI Technologies, Nashville, TN), Derma Unit SSC3 (CK Electronic, Köln, Germany), and the Chromometer. Non-invasive devices were shown to be consistent and accurate through repeated measurement at each of the anatomical points with error rates of less than 5%. Chromometer measurements were able to categorize patients into Fitzpatrick level. DermaScan measurements demonstrated decreasing skin thicknesses associated with increasing age, smoking, and female gender. Derma Unit SSC 3 showed gender and sun exposure related differences in sebum concentration, pH, and moisture content. The Derma Unit SSC 3 sebum concentration also showed correlation with Tru Vu readings for clogged pores and bacterial activity. The skin assessment scales that are in use today are often prone to variability and inaccuracy due to their subjectivity. Use of the described objective non-invasive facial analysis method provides an accurate, objective analysis of human skin which can be used to measure changes pre- and post-operatively, or even screen patients prior to procedure to identify non-responders or those prone to adverse events. Utilization of these devices introduces a foundation on which a strong evidence-based approach to aesthetic medicine can be built. Copyright

  6. Novel Inhibitory Effect of N-(2-Hydroxycyclohexylvaliolamine on Melanin Production in a Human Skin Model

    Directory of Open Access Journals (Sweden)

    Bum-Ho Bin

    2014-07-01

    Full Text Available Hyper-pigmentation causes skin darkness and medical disorders, such as post-inflammatory melanoderma and melasma. Therefore, the development of anti-melanogenic agents is important for treating these conditions and for cosmetic production. In our previous paper, we demonstrated that the anti-diabetic drug voglibose, a valiolamine derivative, is a potent anti-melanogenic agent. In addition, we proposed an alternative screening strategy to identify valiolamine derivatives with high skin permeability that act as anti-melanogenic agents when applied topically. In this study, we synthesized several valiolamine derivatives with enhanced lipophilicity and examined their inhibitory effects in a human skin model. N-(2-hydroxycyclohexylvaliolamine (HV possesses a stronger inhibitory effect on melanin production than voglibose in a human skin model, suggesting that HV is a more potent anti-melanogenic agent for the skin.

  7. Under Persistent Assault: Understanding the Factors that Deteriorate Human Skin and Clinical Efficacy of Topical Antioxidants in Treating Aging Skin

    Directory of Open Access Journals (Sweden)

    Patricia K. Farris

    2015-11-01

    Full Text Available Recent studies contend that the skin is subject to far more damage than just ultraviolet (UV light, with infrared radiation and pollution now clearly demonstrated to degrade cutaneous tissue. While consumers continue to strive for new ways to augment the aesthetic appeal and improve the health of their skin, awareness regarding environmental insults and effective ways to protect the skin remains low. New advances in dermatologic science have exponentially increased the available information on the underlying mechanism of cutaneous damage and potential of topical antioxidants to treat aging skin. Combining antioxidants that can work through multiple pathways holds great potential for a cumulative and synergistic way to treat aging skin. Our goal is to provide a comprehensive review on environmental factors that damage human skin, discuss scientifically proven benefits of topical antioxidants, understand challenges of formulating and administering topical antioxidants, evaluate novel mechanisms of antioxidant activity, and suggest practical ways of integrating topical antioxidants with aesthetic procedures to complement clinical outcomes.

  8. [Objective non-contact method of study of the color of the human skin integument by use of a photoelectric colorimeter].

    Science.gov (United States)

    Gruzdeva, N I; Zherebtsov, L D; Vasilevskiĭ, V K; Vremzen, S A

    1975-04-01

    The authors describe a method of determination of the colour of the skin in man based on the use of contactless photoelectric colorimeter made especially for this purpose. The mean normal values of the indices of the skin colour of the anterior and the posterior surface of the arm in 45 men and 35 women of the Europeoid race under normal conditions are presented.

  9. Molecular basis of retinol anti-ageing properties in naturally aged human skin in vivo.

    Science.gov (United States)

    Shao, Y; He, T; Fisher, G J; Voorhees, J J; Quan, T

    2017-02-01

    Retinoic acid has been shown to improve the aged-appearing skin. However, less is known about the anti-ageing effects of retinol (ROL, vitamin A), a precursor of retinoic acid, in aged human skin in vivo. This study aimed to investigate the molecular basis of ROL anti-ageing properties in naturally aged human skin in vivo. Sun-protected buttock skin (76 ± 6 years old, n = 12) was topically treated with 0.4% ROL and its vehicle for 7 days. The effects of topical ROL on skin epidermis and dermis were evaluated by immunohistochemistry, in situ hybridization, Northern analysis, real-time RT-PCR and Western analysis. Collagen fibrils nanoscale structure and surface topology were analysed by atomic force microscopy. Topical ROL shows remarkable anti-ageing effects through three major types of skin cells: epidermal keratinocytes, dermal endothelial cells and fibroblasts. Topical ROL significantly increased epidermal thickness by stimulating keratinocytes proliferation and upregulation of c-Jun transcription factor. In addition to epidermal changes, topical ROL significantly improved dermal extracellular matrix (ECM) microenvironment; increasing dermal vascularity by stimulating endothelial cells proliferation and ECM production (type I collagen, fibronectin and elastin) by activating dermal fibroblasts. Topical ROL also stimulates TGF-β/CTGF pathway, the major regulator of ECM homeostasis, and thus enriched the deposition of ECM in aged human skin in vivo. 0.4% topical ROL achieved similar results as seen with topical retinoic acid, the biologically active form of ROL, without causing noticeable signs of retinoid side effects. 0.4% topical ROL shows remarkable anti-ageing effects through improvement of the homeostasis of epidermis and dermis by stimulating the proliferation of keratinocytes and endothelial cells, and activating dermal fibroblasts. These data provide evidence that 0.4% topical ROL is a promising and safe treatment to improve the naturally aged human skin

  10. Method of making self-cleaning skin-like prosthetic polymer surfaces

    Science.gov (United States)

    Simpson, John T.; Ivanov, Ilia N.; Shibata, Jason

    2017-06-06

    An external covering and method of making an external covering for hiding the internal endoskeleton of a mechanical (e.g., prosthetic) device that exhibits skin-like qualities is provided. The external covering generally comprises an internal bulk layer in contact with the endoskeleton of the prosthetic device and an external skin layer disposed about the internal bulk layer. The external skin layer is comprised of a polymer composite with carbon nanotubes embedded therein. The outer surface of the skin layer has multiple cone-shaped projections that provide the external skin layer with superhydrophobicity. The carbon nanotubes are preferably vertically aligned between the inner surface and outer surface of the external skin layer in order to provide the skin layer with the ability to transmit heat. Superhydrophobic powders may optionally be used as part of the polymer composite or applied as a coating to the surface of the skin layer to enhance superhydrophobicity.

  11. Dynamics of glycerine and water transport across human skin from binary mixtures.

    Science.gov (United States)

    Ventura, S A; Kasting, G B

    2017-04-01

    Skin transport properties of glycerine and water from binary mixtures contacting human skin were determined to better understand the mechanism of skin moisturization by aqueous glycerine formulations. Steady-state permeation for 3 H 2 O and 14 C-glycerine across split-thickness human skin in vitro and desorption dynamics of the same permeants in isolated human stratum corneum (HSC) were experimentally determined under near equilibrium conditions. These data were compared to a priori values developed in the context of a thermodynamic model for binary mixtures of glycerine and water and a previously determined water sorption isotherm for HSC. This allowed the estimation of diffusion and partition coefficients for each permeant in the HSC, as well as HSC thickness, as a function of composition of the contacting solution. These data may be used to estimate water retention and associated HSC swelling related to the absorption and slow release of glycerine from the skin. It took 6+ days for glycerine to completely desorb from HSC immersed in glycerine/water binary solutions. Desorption of both 3 H 2 O and 14 C-glycerine from HSC was slower in pure water than from binary mixtures, a result that is largely explained by the greater swelling of HSC in water. Parametric relationships were developed for water and glycerine intradiffusivities in HSC as functions of HSC water content, and a mutual diffusion coefficient was estimated by analogy with glycerine/water binary solutions. The intradiffusivity of 14 C-glycerine in HSC as inferred from sorption/desorption experiments was shown to be approximately 10-fold less than that inferred from permeation experiments, whereas the corresponding values for 3 H 2 O were comparable. These studies confirm that glycerine enters HSC in substantial quantities and has a long residence time therein. The coupling between bulk water and glycerine transport projected from binary solution data suggests the net effect of glycerine is to slow water

  12. Modeling and simulation of heat distribution in human skin caused by laser irradiation

    NARCIS (Netherlands)

    Luan, Y.; Dams, S.D.

    2009-01-01

    Study of light-based skin rejuvenation needs prospective insights of mechanism of laser tissue interaction. A well-built model plays a key role in predicting temperature distribution in human skin exposed to laser irradiation. Therefore, it not only provides guidance for in vitro experiment, but

  13. Response of Human Skin to Aesthetic Scarification

    Science.gov (United States)

    Gabriel, Vincent A.; McClellan, Elizabeth A.; Scheuermann, Richard H.

    2014-01-01

    This study was undertaken to investigate changes in RNA expression in previously healthy adult human skin following thermal injury induced by contact with hot metal that was undertaken as part of aesthetic scarification, a body modification practice. Subjects were recruited to have pre-injury skin and serial wound biopsies performed. 4 mm punch biopsies were taken prior to branding and 1 hour, 1 week, and 1, 2 and 3 months post injury. RNA was extracted and quality assured prior to the use of a whole-genome based bead array platform to describe expression changes in the samples using the pre-injury skin as a comparator. Analysis of the array data was performed using k-means clustering and a hypergeometric probability distribution without replacement and corrections for multiple comparisons were done. Confirmatory q-PCR was performed. Using a k of 10, several clusters of genes were shown to co-cluster together based on Gene Ontology classification with probabilities unlikely to occur by chance alone. OF particular interest were clusters relating to cell cycle, proteinaceous extracellular matrix and keratinization. Given the consistent expression changes at one week following injury in the cell cycle cluster, there is an opportunity to intervene early following burn injury to influence scar development. PMID:24582755

  14. Systematic evaluation of non-animal test methods for skin sensitisation safety assessment.

    Science.gov (United States)

    Reisinger, Kerstin; Hoffmann, Sebastian; Alépée, Nathalie; Ashikaga, Takao; Barroso, Joao; Elcombe, Cliff; Gellatly, Nicola; Galbiati, Valentina; Gibbs, Susan; Groux, Hervé; Hibatallah, Jalila; Keller, Donald; Kern, Petra; Klaric, Martina; Kolle, Susanne; Kuehnl, Jochen; Lambrechts, Nathalie; Lindstedt, Malin; Millet, Marion; Martinozzi-Teissier, Silvia; Natsch, Andreas; Petersohn, Dirk; Pike, Ian; Sakaguchi, Hitoshi; Schepky, Andreas; Tailhardat, Magalie; Templier, Marie; van Vliet, Erwin; Maxwell, Gavin

    2015-02-01

    The need for non-animal data to assess skin sensitisation properties of substances, especially cosmetics ingredients, has spawned the development of many in vitro methods. As it is widely believed that no single method can provide a solution, the Cosmetics Europe Skin Tolerance Task Force has defined a three-phase framework for the development of a non-animal testing strategy for skin sensitization potency prediction. The results of the first phase – systematic evaluation of 16 test methods – are presented here. This evaluation involved generation of data on a common set of ten substances in all methods and systematic collation of information including the level of standardisation, existing test data,potential for throughput, transferability and accessibility in cooperation with the test method developers.A workshop was held with the test method developers to review the outcome of this evaluation and to discuss the results. The evaluation informed the prioritisation of test methods for the next phase of the non-animal testing strategy development framework. Ultimately, the testing strategy – combined with bioavailability and skin metabolism data and exposure consideration – is envisaged to allow establishment of a data integration approach for skin sensitisation safety assessment of cosmetic ingredients.

  15. Chondroitin-6-sulfate-containing proteoglycan: a new component of human skin dermoepidermal junction

    DEFF Research Database (Denmark)

    Fine, J D; Couchman, J R

    1988-01-01

    chondroitin sulfate proteoglycan is present in adult, neonatal, and/or fetal skin, and if present, its ultrastructural localization. Indirect immunofluorescence was performed on human adult, neonatal, and fetal skin. To detect the antigen, specimens were pretreated with chondroitinase ABC; absence of enzyme...... treatment served as negative control. Chondroitin sulfate proteoglycan was detectable in linear homogeneous array along the dermoepidermal junction and within vascular (and when present, adnexal) basement membranes in both adult and neonatal skin. In fetal skin, basement membrane staining was noted as early...... as 54 gestational days. Indirect immunoelectron microscopy and NaCl-split skin studies were performed to ultrastructurally localize the antigen; immune deposits were detectable within the lamina densa in chondroitinase-treated skin. These findings demonstrate that chondroitin sulfate proteoglycan...

  16. Humanized Mouse Model of Skin Inflammation Is Characterized by Disturbed Keratinocyte Differentiation and Influx of IL-17A Producing T Cells

    Science.gov (United States)

    de Oliveira, Vivian L.; Keijsers, Romy R. M. C.; van de Kerkhof, Peter C. M.; Seyger, Marieke M. B.; Fasse, Esther; Svensson, Lars; Latta, Markus; Norsgaard, Hanne; Labuda, Tord; Hupkens, Pieter; van Erp, Piet E. J.; Joosten, Irma; Koenen, Hans J. P. M.

    2012-01-01

    Humanized mouse models offer a challenging possibility to study human cell function in vivo. In the huPBL-SCID-huSkin allograft model human skin is transplanted onto immunodeficient mice and allowed to heal. Thereafter allogeneic human peripheral blood mononuclear cells are infused intra peritoneally to induce T cell mediated inflammation and microvessel destruction of the human skin. This model has great potential for in vivo study of human immune cells in (skin) inflammatory processes and for preclinical screening of systemically administered immunomodulating agents. Here we studied the inflammatory skin response of human keratinocytes and human T cells and the concomitant systemic human T cell response. As new findings in the inflamed human skin of the huPBL-SCID-huSkin model we here identified: 1. Parameters of dermal pathology that enable precise quantification of the local skin inflammatory response exemplified by acanthosis, increased expression of human β-defensin-2, Elafin, K16, Ki67 and reduced expression of K10 by microscopy and immunohistochemistry. 2. Induction of human cytokines and chemokines using quantitative real-time PCR. 3. Influx of inflammation associated IL-17A-producing human CD4+ and CD8+ T cells as well as immunoregulatory CD4+Foxp3+ cells using immunohistochemistry and -fluorescence, suggesting that active immune regulation is taking place locally in the inflamed skin. 4. Systemic responses that revealed activated and proliferating human CD4+ and CD8+ T cells that acquired homing marker expression of CD62L and CLA. Finally, we demonstrated the value of the newly identified parameters by showing significant changes upon systemic treatment with the T cell inhibitory agents cyclosporine-A and rapamycin. In summary, here we equipped the huPBL-SCID-huSkin humanized mouse model with relevant tools not only to quantify the inflammatory dermal response, but also to monitor the peripheral immune status. This combined approach will gain our

  17. Superresolution and Fluorescence Dynamics Evidence Reveal That Intact Liposomes Do Not Cross the Human Skin Barrier

    DEFF Research Database (Denmark)

    Dreier, Jes; Sørensen, Jens A; Brewer, Jonathan R

    2016-01-01

    In this study we use the combination of super resolution optical microscopy and raster image correlation spectroscopy (RICS) to study the mechanism of action of liposomes as transdermal drug delivery systems in human skin. Two different compositions of liposomes were applied to newly excised human...... skin, a POPC liposome and a more flexible liposome containing the surfactant sodium cholate. Stimulated emission depletion microscopy (STED) images of intact skin and cryo-sections of skin treated with labeled liposomes were recorded displaying an optical resolution low enough to resolve the 100 nm...... liposomes in the skin. The images revealed that virtually none of the liposomes remained intact beneath the skin surface. RICS two color cross correlation diffusion measurements of double labeled liposomes confirmed these observations. Our results suggest that the liposomes do not act as carriers...

  18. Protective influence of hyaluronic acid on focal adhesion kinase activity in human skin fibroblasts exposed to ethanol.

    Science.gov (United States)

    Donejko, Magdalena; Rysiak, Edyta; Galicka, Elżbieta; Terlikowski, Robert; Głażewska, Edyta Katarzyna; Przylipiak, Andrzej

    2017-01-01

    The aim of this study was to evaluate the effect of ethanol and hyaluronic acid (HA) on cell survival and apoptosis in cultured human skin fibroblasts. Regarding the mechanism of ethanol action on human skin fibroblasts, we investigated cell viability and apoptosis, expression of focal adhesion kinase (FAK), and the influence of HA on those processes. Studies were conducted in confluent human skin fibroblast cultures that were treated with 25 mM, 50 mM, and 100 mM ethanol or with ethanol and 500 µg/mL HA. Cell viability was examined using methyl thiazolyl tetrazolium (MTT) assay and NC-300 Nucleo-Counter. Imaging of the cells using a fluorescence microscope Pathway 855 was performed to measure FAK expression. Depending on the dosage, ethanol decreased cell viability and activated the process of apoptosis in human skin fibroblasts. HA prevented the negative influence of ethanol on cell viability and prevented apoptosis. The analysis of fluorescence imaging using BD Pathway 855 High-Content Bioimager showed the inhibition of FAK migration to the cell nucleus, depending on the increasing concentration of ethanol. This study proves that downregulation of signaling pathway of FAK is involved in ethanol-induced apoptosis in human skin fibroblasts. The work also indicates a protective influence of HA on FAK activity in human skin fibroblasts exposed to ethanol.

  19. Analyzing reflectance spectra of human skin in legal medicine

    Science.gov (United States)

    Belenki, Liudmila; Sterzik, Vera; Schulz, Katharina; Bohnert, Michael

    2013-01-01

    Our current research in the framework of an interdisciplinary project focuses on modelling the dynamics of the hemoglobin reoxygenation process in post-mortem human skin by reflectance spectrometry. The observations of reoxygenation of hemoglobin in livores after postmortem exposure to a cold environment relate the reoxygenation to the commonly known phenomenon that the color impression of livores changes from livid to pink under low ambient temperatures. We analyze the spectra with respect to a physical model describing the optical properties of human skin, discuss the dynamics of the reoxygenation, and propose a phenomenological model for reoxygenation. For additional characterization of the reflectance spectra, the curvature of the local minimum and maximum in the investigated spectral range is considered. There is a strong correlation between the curvature of specra at a wavelength of 560 nm and the concentration of O2-Hb. The analysis is carried out via C programs, as well as MySQL database queries in Java EE, JDBC, Matlab, and Python.

  20. Ultraviolet Radiation Induced Apoptosis in Human Skin In Vivo

    Energy Technology Data Exchange (ETDEWEB)

    Sheehan, J.M.; Young, A.R

    2000-07-01

    Sunburn cells, having many characteristics of apoptotic cells, appear in human skin after exposure to UVB. Time-courses and dose responses for solar simulated radiation (SSR)-induced sunburn cells in human volunteers of skin type II have been determined. For the time-course, two groups of volunteers were exposed to two minimal erythema doses (MED) of SSR. Punch biopsies were obtained from Group 1 immediately, 3, 6, 12, 18 and 24 h after SSR exposure and Group 2 were biopsied immediately, 18, 24, 36, 48 and 72 h after exposure. For the dose-response (Group 3), biopsies were taken 24 h after SSR exposure to 0, 0.25, 0.5, 1, 2 and 3 MED. Sections were stained with H and E and also using TUNEL and analysed by light microscopy. Results show a dose-dependent appearance of SBC after SSR exposure. The time point for maximum SBC counts with both H and E staining and TUNEL staining lie between 24 and 36 h. (author)

  1. Ultraviolet Radiation Induced Apoptosis in Human Skin In Vivo

    International Nuclear Information System (INIS)

    Sheehan, J.M.; Young, A.R.

    2000-01-01

    Sunburn cells, having many characteristics of apoptotic cells, appear in human skin after exposure to UVB. Time-courses and dose responses for solar simulated radiation (SSR)-induced sunburn cells in human volunteers of skin type II have been determined. For the time-course, two groups of volunteers were exposed to two minimal erythema doses (MED) of SSR. Punch biopsies were obtained from Group 1 immediately, 3, 6, 12, 18 and 24 h after SSR exposure and Group 2 were biopsied immediately, 18, 24, 36, 48 and 72 h after exposure. For the dose-response (Group 3), biopsies were taken 24 h after SSR exposure to 0, 0.25, 0.5, 1, 2 and 3 MED. Sections were stained with H and E and also using TUNEL and analysed by light microscopy. Results show a dose-dependent appearance of SBC after SSR exposure. The time point for maximum SBC counts with both H and E staining and TUNEL staining lie between 24 and 36 h. (author)

  2. Skin-mimetic chromatography for prediction of human percutaneous absorption of biologically active compounds occurring in medicinal plant extracts.

    Science.gov (United States)

    Stepnik, Katarzyna; Malinowska, Irena

    2017-04-01

    The main aim of this study was to predict quantitatively human percutaneous absorption of chosen compounds commonly occurring in plants which can be used as medicinal extracts in the drug and beauty industries. The most important human percutaneous descriptors, i.e. logK p (logarithm of the water/skin partition coefficient) and logJ max (logarithm of the maximum flux of solutes penetrating the skin), of fatty acids and polyphenols were determined using both in vitro and in silico methods. For in vitro determination of human percutaneous absorption, micellar liquid chromatography based on hexadecyltrimethylammonium bromide, sodium dodecyl sulfate and polyoxyethylene (23) lauryl ether (Brij35) was used. Human percutaneous absorption was characterized by entirely new QSAR/QRAR models based on retention, lipophilic, steric and electronic data as well as on the linear free energy relationship parameters. Many different correlations between human skin absorption and different physicochemical parameters were performed, e.g. the in silico estimated logK p value was correlated with the retention parameter logk w (logarithm of the retention factor extrapolated to pure water) from the systems imitating a cutaneous environment (R 2  = 0.92). Moreover, the influence of lipophilicity on percutaneous absorption was examined. The obtained correlation was excellent (R 2  = 0.95). Copyright © 2016 John Wiley & Sons, Ltd.

  3. Impact of Humidity on In Vitro Human Skin Permeation Experiments for Predicting In Vivo Permeability.

    Science.gov (United States)

    Ishida, Masahiro; Takeuchi, Hiroyuki; Endo, Hiromi; Yamaguchi, Jun-Ichi

    2015-12-01

    In vitro skin permeation studies have been commonly conducted to predict in vivo permeability for the development of transdermal therapeutic systems (TTSs). We clarified the impact of humidity on in vitro human skin permeation of two TTSs having different breathability and then elucidated the predictability of in vivo permeability based on in vitro experimental data. Nicotinell(®) TTS(®) 20 and Frandol(®) tape 40mg were used as model TTSs in this study. The in vitro human skin permeation experiments were conducted under humidity levels similar to those used in clinical trials (approximately 50%) as well as under higher humidity levels (approximately 95%). The skin permeability values of drugs at 95% humidity were higher than those at 50% humidity. The time profiles of the human plasma concentrations after TTS application fitted well with the clinical data when predicted based on the in vitro permeation parameters at 50% humidity. On the other hand, those profiles predicted based on the parameters at 95% humidity were overestimated. The impact of humidity was higher for the more breathable TTS; Frandol(®) tape 40mg. These results show that in vitro human skin permeation experiments should be investigated under realistic clinical humidity levels especially for breathable TTSs. © 2015 Wiley Periodicals, Inc. and the American Pharmacists Association.

  4. Human Skin Barrier Structure and Function Analyzed by Cryo-EM and Molecular Dynamics Simulation.

    Science.gov (United States)

    Lundborg, Magnus; Narangifard, Ali; Wennberg, Christian L; Lindahl, Erik; Daneholt, Bertil; Norlén, Lars

    2018-04-24

    In the present study we have analyzed the molecular structure and function of the human skin's permeability barrier using molecular dynamics simulation validated against cryo-electron microscopy data from near native skin. The skin's barrier capacity is located to an intercellular lipid structure embedding the cells of the superficial most layer of skin - the stratum corneum. According to the splayed bilayer model (Iwai et al., 2012) the lipid structure is organized as stacked bilayers of ceramides in a splayed chain conformation with cholesterol associated with the ceramide sphingoid moiety and free fatty acids associated with the ceramide fatty acid moiety. However, knowledge about the lipid structure's detailed molecular organization, and the roles of its different lipid constituents, remains circumstantial. Starting from a molecular dynamics model based on the splayed bilayer model, we have, by stepwise structural and compositional modifications, arrived at a thermodynamically stable molecular dynamics model expressing simulated electron microscopy patterns matching original cryo-electron microscopy patterns from skin extremely closely. Strikingly, the closer the individual molecular dynamics models' lipid composition was to that reported in human stratum corneum, the better was the match between the models' simulated electron microscopy patterns and the original cryo-electron microscopy patterns. Moreover, the closest-matching model's calculated water permeability and thermotropic behaviour were found compatible with that of human skin. The new model may facilitate more advanced physics-based skin permeability predictions of drugs and toxicants. The proposed procedure for molecular dynamics based analysis of cellular cryo-electron microscopy data might be applied to other biomolecular systems. Copyright © 2018. Published by Elsevier Inc.

  5. Chromium content in human skin after in vitro application of ordinary cement and ferrous-sulphate-reduced cement

    DEFF Research Database (Denmark)

    Fullerton, A; Gammelgaard, Bente; Avnstorp, C

    1993-01-01

    The amount of chromium found in human skin after in vitro application of cement suspensions on full-thickness human skin in diffusion cells was investigated. Cement suspensions made from ordinary Portland cement or Portland cement with the chromate reduced with added ferrous sulphate were used....... The cement suspensions were either applied on the skin surface under occlusion for 48 h or applied repeatedly every 24 h for 96 h. No statistically significant difference in chromium content of skin layers between skin exposed to ordinary Portland cement, skin exposed to cement with added ferrous sulphate...... and unexposed skin was observed, despite a more permeable skin barrier at the alkaline pH of the cement suspensions, i.e., pH 12.5. Increased chromium levels in epidermis and dermis were seen when ordinary Portland cement was applied as a suspension with added sodium sulphate (20%) on the skin surface for 96 h...

  6. In vivo THz imaging of human skin: Accounting for occlusion effects.

    Science.gov (United States)

    Sun, Qiushuo; Parrott, Edward P J; He, Yuezhi; Pickwell-MacPherson, Emma

    2018-02-01

    In vivo terahertz (THz) imaging of human skin needs to be done in reflection geometry due to the high attenuation of THz light by water in the skin. To aid the measurement procedure, there is typically an imaging window onto which the patient places the area of interest. The window enables better pulse alignment and helps keep the patient correctly positioned during the measurement. In this paper, we demonstrate how the occlusion caused by the skin contact with the imaging window during the measurement affects the THz response. By studying both rapid point measurements and imaging over an area of a human volar forearm, we find that even 5 seconds of occlusion affects the THz response. As the occlusion time increases, the skin surface water content increases, resulting in the reduction of the amplitude of the reflected THz pulse, especially in the first 3 minutes. Furthermore, it was found that the refractive index of the volar forearm increased by 10% to 15% after 20 minutes of occlusion. In this work, we examine and propose a model for the occlusion effects due to the quartz window with a view to compensating for its influence. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Non-occlusive topical exposure of human skin in vitro as model for cytotoxicity testing of irritant compounds.

    Science.gov (United States)

    Lönnqvist, Susanna; Briheim, Kristina; Kratz, Gunnar

    2016-02-01

    Testing of irritant compounds has traditionally been performed on animals and human volunteers. Animal testing should always be restricted and for skin irritancy mice and rabbits hold poor predictive value for irritant potential in humans. Irritant testing on human volunteers is restricted by the duration subjects can be exposed, and by the subjectivity of interpreting the visual signs of skin irritation. We propose an irritant testing system using viable human full thickness skin with the loss of cell viability in the exposed skin area as end point measurement. Skin was exposed to sodium dodecyl sulfate (SDS) at 20% concentration by non-occluded topical exposure to establish a positive control response and subsequent test compounds were statistically compared with the 20% SDS response. Cell viability and metabolism were measured with 3-(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. The model presents correlation between increased concentration of SDS and decreased viability of cells in the exposed skin area (R(2) = 0.76). We propose the model to be used for cytotoxicity testing of irritant compounds. With fully intact barrier function, the model comprises all cells present in the skin with quantifiable end point measurement.

  8. Vascular effects of leukotriene D4 in human skin

    DEFF Research Database (Denmark)

    Bisgaard, H

    1987-01-01

    Leukotriene D4 (LTD4) increased the blood flow rate in human skin, equipotent to histamine in the dose range of 3.1-200 pmol. The vasodilatation lasted for up to 60 min, and no late reactions occurred. Indomethacin did not affect the LTD4-induced blood flow rate. H1 and H2 antagonists reduced...... as a mediator of the axon reflex, and show that LTD4 causes a direct vasodilatory effect that is not mediated via histamine or cyclooxygenase products. The laser-Doppler flowmeter was applied for dynamic studies of the vasopressor response in the skin during a Valsalva maneuver, and the relative changes...

  9. Simulation study and guidelines to generate Laser-induced Surface Acoustic Waves for human skin feature detection

    Science.gov (United States)

    Li, Tingting; Fu, Xing; Chen, Kun; Dorantes-Gonzalez, Dante J.; Li, Yanning; Wu, Sen; Hu, Xiaotang

    2015-12-01

    Despite the seriously increasing number of people contracting skin cancer every year, limited attention has been given to the investigation of human skin tissues. To this regard, Laser-induced Surface Acoustic Wave (LSAW) technology, with its accurate, non-invasive and rapid testing characteristics, has recently shown promising results in biological and biomedical tissues. In order to improve the measurement accuracy and efficiency of detecting important features in highly opaque and soft surfaces such as human skin, this paper identifies the most important parameters of a pulse laser source, as well as provides practical guidelines to recommended proper ranges to generate Surface Acoustic Waves (SAWs) for characterization purposes. Considering that melanoma is a serious type of skin cancer, we conducted a finite element simulation-based research on the generation and propagation of surface waves in human skin containing a melanoma-like feature, determine best pulse laser parameter ranges of variation, simulation mesh size and time step, working bandwidth, and minimal size of detectable melanoma.

  10. An External Wire Frame Fixation Method of Skin Grafting for Burn Reconstruction.

    Science.gov (United States)

    Yoshino, Yukiko; Ueda, Hyakuzoh; Ono, Simpei; Ogawa, Rei

    2017-06-28

    The skin graft is a prevalent reconstructive method for burn injuries. We have been applying external wire frame fixation methods in combination with skin grafts since 1986 and have experienced better outcomes in percentage of successful graft take. The overall purpose of this method was to further secure skin graft adherence to wound beds in hard to stabilize areas. There are also location-specific benefits to this technique such as eliminating the need of tarsorrhaphy in periorbital area, allowing immediate food intake after surgery in perioral area, and performing less invasive fixing methods in digits, and so on. The purpose of this study was to clarify its benefits and applicable locations. We reviewed 22 postburn patients with skin graft reconstructions using the external wire frame method at our institution from December 2012 through September 2016. Details of the surgical technique and individual reports are also discussed. Of the 22 cases, 15 (68%) were split-thickness skin grafts and 7 (32%) were full-thickness skin grafts. Five cases (23%) involved periorbital reconstruction, 5 (23%) involved perioral reconstruction, 2 (9%) involved lower limb reconstruction, and 10 (45%) involved digital reconstruction. Complete (100%) survival of the skin graft was attained in all cases. No signs of complication were observed. With 30 years of experiences all combined, we have summarized fail-proof recommendations to a successful graft survival with an emphasis on the locations of its application.

  11. Human skin kinetics of cyclic depsipeptide mycotoxins

    OpenAIRE

    Taevernier, Lien; Veryser, Lieselotte; ROCHE, NATHALIE; De Spiegeleer, Bart

    2014-01-01

    Cyclic depsipeptides (CDPs) are an emerging group of naturally occurring bioactive peptides, some of which are already developed as pharmaceutical drugs, e.g. valinomycin. They are produced by bacteria, marine organisms and fungi [1]. Some CDPs are secondary fungal metabolites, which can be very toxic to humans and animals, and are therefore called mycotoxins. Currently, dermal exposure data of CDP mycotoxins is scarce and fragmentary with a lack of understanding about the local skin and syst...

  12. Modified skin window technique for the extended characterisation of acute inflammation in humans

    Science.gov (United States)

    Marks, D. J. B.; Radulovic, M.; McCartney, S.; Bloom, S.; Segal, A. W.

    2009-01-01

    Objective To modify the skin window technique for extended analysis of acute inflammatory responses in humans, and demonstrate its applicability for investigating disease. Subjects 15 healthy subjects and 5 Crohn’s patients. Treatment Skin windows, created by dermal abrasion, were overlaid for various durations with filter papers saturated in saline, 100 ng/ml muramyl dipeptide (MDP) or 10 μg/ml interleukin-8 (IL-8). Methods Exuded leukocytes were analyzed by microscopy, immunoblot, DNA-bound transcription factor arrays and RT-PCR. Inflammatory mediators were quantified by ELISA. Results Infiltrating leukocytes were predominantly neutrophils. Numerous secreted mediators were detectable. MDP and IL-8 enhanced responses. Many signalling proteins were phosphorylated with differential patterns in Crohn’s patients, notably PKC α/β hyperphosphorylation (11.3 ± 3.1 vs 1.2 ± 0.9 units, P immunomodulators. PMID:17522815

  13. The Impact of Environmental and Endogenous Damage on Somatic Mutation Load in Human Skin Fibroblasts.

    Directory of Open Access Journals (Sweden)

    Natalie Saini

    2016-10-01

    Full Text Available Accumulation of somatic changes, due to environmental and endogenous lesions, in the human genome is associated with aging and cancer. Understanding the impacts of these processes on mutagenesis is fundamental to understanding the etiology, and improving the prognosis and prevention of cancers and other genetic diseases. Previous methods relying on either the generation of induced pluripotent stem cells, or sequencing of single-cell genomes were inherently error-prone and did not allow independent validation of the mutations. In the current study we eliminated these potential sources of error by high coverage genome sequencing of single-cell derived clonal fibroblast lineages, obtained after minimal propagation in culture, prepared from skin biopsies of two healthy adult humans. We report here accurate measurement of genome-wide magnitude and spectra of mutations accrued in skin fibroblasts of healthy adult humans. We found that every cell contains at least one chromosomal rearrangement and 600–13,000 base substitutions. The spectra and correlation of base substitutions with epigenomic features resemble many cancers. Moreover, because biopsies were taken from body parts differing by sun exposure, we can delineate the precise contributions of environmental and endogenous factors to the accrual of genetic changes within the same individual. We show here that UV-induced and endogenous DNA damage can have a comparable impact on the somatic mutation loads in skin fibroblasts. Trial Registration: ClinicalTrials.gov NCT01087307.

  14. Comparison of the incidence and time patterns of radiation-induced skin cancer in humans and rats

    International Nuclear Information System (INIS)

    Albert, R.E.; Burns, F.J.; Shore, R.

    1978-01-01

    Cancer induction in rat skin and human skin are compared following exposure to X-rays. The human data were obtained by follow-up of 2213 children irradiated between 1940 and 1959 for tinea capitis (ringworm) of the scalp. The scalp was irradiated at one session using five fields of 100 kVp X-rays. The scalp dose ranged from 500-800 rads. The rats were irradiated on their dorsal skin with a 1100-rad dose of 30 kVp X-rays. The tumours were predominantly basal cell carcinomas in both species. The proportion of people with tumours as a function of elapsed time since exposure was consistent with a power function with an exponent of 5.4, and had reached 3% or 0.08 tumours per person in most recent survey (35 years after exposure). Of the 64 tumours observed in human skin, a substantial proportion was on the directly irradiated skin just outside the hair-covered regions of the scalp. So far there are no tumours among the 530 irradiated nonwhites in the study when about eight cases would be expected in a comparable group of irradiated whites. Only four skin tumours have been observed in 1396 control patients. The temporal curve of radiation-induced tumours for human skin could be approximately superimposed on that for rats by contracting the time scale by a factor of 37.1. The temporal response of the two species is approximately proportional to their median life spans. (author)

  15. Targeting of human interleukin-12B by small hairpin RNAs in xenografted psoriatic skin

    Directory of Open Access Journals (Sweden)

    Jakobsen Maria

    2011-02-01

    Full Text Available Abstract Background Psoriasis is a chronic inflammatory skin disorder that shows as erythematous and scaly lesions. The pathogenesis of psoriasis is driven by a dysregulation of the immune system which leads to an altered cytokine production. Proinflammatory cytokines that are up-regulated in psoriasis include tumor necrosis factor alpha (TNFα, interleukin-12 (IL-12, and IL-23 for which monoclonal antibodies have already been approved for clinical use. We have previously documented the therapeutic applicability of targeting TNFα mRNA for RNA interference-mediated down-regulation by anti-TNFα small hairpin RNAs (shRNAs delivered by lentiviral vectors to xenografted psoriatic skin. The present report aims at targeting mRNA encoding the shared p40 subunit (IL-12B of IL-12 and IL-23 by cellular transduction with lentiviral vectors encoding anti-IL12B shRNAs. Methods Effective anti-IL12B shRNAs are identified among a panel of shRNAs by potency measurements in cultured cells. The efficiency and persistency of lentiviral gene delivery to xenografted human skin are investigated by bioluminescence analysis of skin treated with lentiviral vectors encoding the luciferase gene. shRNA-expressing lentiviral vectors are intradermally injected in xenografted psoriatic skin and the effects of the treatment evaluated by clinical psoriasis scoring, by measurements of epidermal thickness, and IL-12B mRNA levels. Results Potent and persistent transgene expression following a single intradermal injection of lentiviral vectors in xenografted human skin is reported. Stable IL-12B mRNA knockdown and reduced epidermal thickness are achieved three weeks after treatment of xenografted psoriatic skin with lentivirus-encoded anti-IL12B shRNAs. These findings mimick the results obtained with anti-TNFα shRNAs but, in contrast to anti-TNFα treatment, anti-IL12B shRNAs do not ameliorate the psoriatic phenotype as evaluated by semi-quantitative clinical scoring and by

  16. Raman spectroscopy of human skin: looking for a quantitative algorithm to reliably estimate human age

    Science.gov (United States)

    Pezzotti, Giuseppe; Boffelli, Marco; Miyamori, Daisuke; Uemura, Takeshi; Marunaka, Yoshinori; Zhu, Wenliang; Ikegaya, Hiroshi

    2015-06-01

    The possibility of examining soft tissues by Raman spectroscopy is challenged in an attempt to probe human age for the changes in biochemical composition of skin that accompany aging. We present a proof-of-concept report for explicating the biophysical links between vibrational characteristics and the specific compositional and chemical changes associated with aging. The actual existence of such links is then phenomenologically proved. In an attempt to foster the basics for a quantitative use of Raman spectroscopy in assessing aging from human skin samples, a precise spectral deconvolution is performed as a function of donors' ages on five cadaveric samples, which emphasizes the physical significance and the morphological modifications of the Raman bands. The outputs suggest the presence of spectral markers for age identification from skin samples. Some of them appeared as authentic "biological clocks" for the apparent exactness with which they are related to age. Our spectroscopic approach yields clear compositional information of protein folding and crystallization of lipid structures, which can lead to a precise identification of age from infants to adults. Once statistically validated, these parameters might be used to link vibrational aspects at the molecular scale for practical forensic purposes.

  17. Melanin-concentrating hormone and its receptor are expressed and functional in human skin.

    Science.gov (United States)

    Hoogduijn, Martin J; Ancans, Janis; Suzuki, Itaru; Estdale, Siân; Thody, Anthony J

    2002-08-23

    In this study, we have demonstrated the presence of melanin-concentrating hormone (MCH) and melanin-concentrating hormone receptor (MCHR1) transcripts in human skin. Sequence analysis confirmed that the transcripts of both genes were identical to those previously found in human brain. In culture, endothelial cells showed pro-MCH expression whereas no signal was found in keratinocytes, melanocytes, and fibroblasts. MCHR1 expression was restricted to melanocytes and melanoma cells. Stimulation of cultured human melanocytes with MCH reduced the alpha-MSH-induced increase in cAMP production. Furthermore, the melanogenic actions of alpha-MSH were inhibited by MCH. We propose that the MCH/MCHR1 signalling system is present in human skin and may have a role with the melanocortins in regulating the melanocyte.

  18. In Vitro Desensitization of Human Skin Mast Cells

    Science.gov (United States)

    Zhao, Wei; Gomez, Gregorio; Macey, Matthew; Kepley, Christopher L.

    2013-01-01

    Desensitization is a clinical procedure whereby incremental doses of a drug are administered over several hours to a sensitive patient until a therapeutic dose and clinical tolerance are achieved. Clinical tolerance may occur in part by attenuating the mast cell response. In the present study, primary human skin mast cells were used to establish and characterize an in vitro model of desensitization. Mast cells in culture were armed with allergen-specific (4-hydroxy-3-nitro-phenylacety and Der p2) and non-specific IgE antibodies, and then desensitized by incremental exposures to 4-hydroxy-3-nitrophenylacety-BSA. This desensitization procedure abrogated the subsequent degranulation response to the desensitizing allergen, to an unrelated allergen, and to IgG anti-FcεRI, but not to C5a, substance P, compound 48/80, and calcium ionophore. Desensitized cells regained their FcεRI-dependent degranulation capability by 24–48 h after free allergen had been removed. Therefore, sensitized human skin mast cells are reversibly desensitized in vitro by exposure to incremental doses of that allergen, which also cross-desensitizes them to an unrelated allergen. PMID:22009002

  19. Generation of electrical power under human skin by subdermal solar cell arrays for implantable bioelectronic devices.

    Science.gov (United States)

    Song, Kwangsun; Han, Jung Hyun; Yang, Hyung Chae; Nam, Kwang Il; Lee, Jongho

    2017-06-15

    Medical electronic implants can significantly improve people's health and quality of life. These implants are typically powered by batteries, which usually have a finite lifetime and therefore must be replaced periodically using surgical procedures. Recently, subdermal solar cells that can generate electricity by absorbing light transmitted through skin have been proposed as a sustainable electricity source to power medical electronic implants in bodies. However, the results to date have been obtained with animal models. To apply the technology to human beings, electrical performance should be characterized using human skin covering the subdermal solar cells. In this paper, we present electrical performance results (up to 9.05mW/cm 2 ) of the implantable solar cell array under 59 human skin samples isolated from 10 cadavers. The results indicate that the power densities depend on the thickness and tone of the human skin, e.g., higher power was generated under thinner and brighter skin. The generated power density is high enough to operate currently available medical electronic implants such as pacemakers that require tens of microwatt. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Reflectance spectrometry of normal and bruised human skins: experiments and modeling

    International Nuclear Information System (INIS)

    Kim, Oleg; Alber, Mark; McMurdy, John; Lines, Collin; Crawford, Gregory; Duffy, Susan

    2012-01-01

    A stochastic photon transport model in multilayer skin tissue combined with reflectance spectroscopy measurements is used to study normal and bruised skins. The model is shown to provide a very good approximation to both normal and bruised real skin tissues by comparing experimental and simulated reflectance spectra. The sensitivity analysis of the skin reflectance spectrum to variations of skin layer thicknesses, blood oxygenation parameter and concentrations of main chromophores is performed to optimize model parameters. The reflectance spectrum of a developed bruise in a healthy adult is simulated, and the concentrations of bilirubin, blood volume fraction and blood oxygenation parameter are determined for different times as the bruise progresses. It is shown that bilirubin and blood volume fraction reach their peak values at 80 and 55 h after contusion, respectively, and the oxygenation parameter is lower than its normal value during 80 h after contusion occurred. The obtained time correlations of chromophore concentrations in developing contusions are shown to be consistent with previous studies. The developed model uses a detailed seven-layer skin approximation for contusion and allows one to obtain more biologically relevant results than those obtained with previous models using one- to three-layer skin approximations. A combination of modeling with spectroscopy measurements provides a new tool for detailed biomedical studies of human skin tissue and for age determination of contusions. (paper)

  1. Dynamic in vivo mapping of model moisturiser ingress into human skin by GARfield MRI.

    Science.gov (United States)

    Ciampi, Elisabetta; van Ginkel, Michael; McDonald, Peter J; Pitts, Simon; Bonnist, Eleanor Y M; Singleton, Scott; Williamson, Ann-Marie

    2011-02-01

    We describe the development of in vivo one-dimensional MRI (profiling) using a GARField (Gradient At Right angles to Field) magnet for the characterisation of side-of-hand human skin. For the first time and in vivo, we report measurements of the NMR longitudinal and transverse relaxation parameters and self-diffusivity of the upper layers of human skin with a nominal spatial resolution better than 10 µm. The results are correlated with in vivo confocal Raman spectroscopy measurements of water concentration and natural moisturiser factors, and discussed in terms of known skin biology and microstructure of the stratum corneum and viable epidermis. The application of model moisturiser solutions to the skin is followed and their dynamics of ingress are characterised using the MRI methodology developed. Selected hydrophilic and lipophilic formulations are studied. The results are corroborated by standard in vivo measurements of transepidermal water loss and hydration status. A further insight into moisturisation mechanisms is gained. The effect of two different penetration enhancers on a commonly used skin care oil is also discussed, and different timescales of oil penetration into the skin are reported depending on the type of enhancer. Copyright © 2010 John Wiley & Sons, Ltd.

  2. Skin absorption through atopic dermatitis skin

    DEFF Research Database (Denmark)

    Halling-Overgaard, A-S; Kezic, S; Jakasa, I

    2017-01-01

    Patients with atopic dermatitis have skin barrier impairment in both lesional and non-lesional skin. They are typically exposed to emollients daily and topical anti-inflammatory medicaments intermittently, hereby increasing the risk of developing contact allergy and systemic exposed to chemicals...... ingredients found in these topical preparations. We systematically searched for studies that investigated skin absorption of various penetrants, including medicaments, in atopic dermatitis patients, but also animals with experimentally induced dermatitis. We identified 40 articles, i.e. 11 human studies...... examining model penetrants, 26 human studies examining atopic dermatitis drugs and 3 animal studies. We conclude that atopic dermatitis patients have nearly two-fold increased skin absorption when compared to healthy controls. There is a need for well-designed epidemiological and dermato...

  3. Assessing the impacts of lifetime sun exposure on skin damage and skin aging using a non-invasive method

    International Nuclear Information System (INIS)

    Kimlin, Michael G.; Guo, Yuming

    2012-01-01

    Background: Ultraviolet radiation exposure during an individuals' lifetime is a known risk factor for the development of skin cancer. However, less evidence is available on assessing the relationship between lifetime sun exposure and skin damage and skin aging. Objectives: This study aims to assess the relationship between lifetime sun exposure and skin damage and skin aging using a non-invasive measure of exposure. Methods: We recruited 180 participants (73 males, 107 females) aged 18–83 years. Digital imaging of skin hyperpigmentation (skin damage) and skin wrinkling (skin aging) on the facial region was measured. Lifetime sun exposure (presented as hours) was calculated from the participants' age multiplied by the estimated annual time outdoors for each year of life. We analyzed the effects of lifetime sun exposure on skin damage and skin aging. We adjust for the influence of age, sex, occupation, history of skin cancer, eye color, hair color, and skin color. Results: There were non-linear relationships between lifetime sun exposure and skin damage and skin aging. Younger participant's skin is much more sensitive to sun exposure than those who were over 50 years of age. As such, there were negative interactions between lifetime sun exposure and age. Age had linear effects on skin damage and skin aging. Conclusion: The data presented showed that self reported lifetime sun exposure was positively associated with skin damage and skin aging, in particular, the younger people. Future health promotion for sun exposure needs to pay attention to this group for skin cancer prevention messaging. - Highlights: ► This is the first study finding the non-linear relationship between lifetime sun exposure and skin damage and skin aging. ► This study finds there is negative interaction between lifetime sun exposure and age for skin damage and aging. ► This study suggests that future health promotion for sun exposure needs to pay attention to youth group for skin cancer

  4. Assessing the impacts of lifetime sun exposure on skin damage and skin aging using a non-invasive method

    Energy Technology Data Exchange (ETDEWEB)

    Kimlin, Michael G., E-mail: m.kimlin@qut.edu.au; Guo, Yuming, E-mail: guoyuming@yahoo.cn

    2012-05-15

    Background: Ultraviolet radiation exposure during an individuals' lifetime is a known risk factor for the development of skin cancer. However, less evidence is available on assessing the relationship between lifetime sun exposure and skin damage and skin aging. Objectives: This study aims to assess the relationship between lifetime sun exposure and skin damage and skin aging using a non-invasive measure of exposure. Methods: We recruited 180 participants (73 males, 107 females) aged 18-83 years. Digital imaging of skin hyperpigmentation (skin damage) and skin wrinkling (skin aging) on the facial region was measured. Lifetime sun exposure (presented as hours) was calculated from the participants' age multiplied by the estimated annual time outdoors for each year of life. We analyzed the effects of lifetime sun exposure on skin damage and skin aging. We adjust for the influence of age, sex, occupation, history of skin cancer, eye color, hair color, and skin color. Results: There were non-linear relationships between lifetime sun exposure and skin damage and skin aging. Younger participant's skin is much more sensitive to sun exposure than those who were over 50 years of age. As such, there were negative interactions between lifetime sun exposure and age. Age had linear effects on skin damage and skin aging. Conclusion: The data presented showed that self reported lifetime sun exposure was positively associated with skin damage and skin aging, in particular, the younger people. Future health promotion for sun exposure needs to pay attention to this group for skin cancer prevention messaging. - Highlights: Black-Right-Pointing-Pointer This is the first study finding the non-linear relationship between lifetime sun exposure and skin damage and skin aging. Black-Right-Pointing-Pointer This study finds there is negative interaction between lifetime sun exposure and age for skin damage and aging. Black-Right-Pointing-Pointer This study suggests that future

  5. Contrasting effects of ultraviolet-A and ultraviolet B exposure on induction of contact sensitivity in human skin

    DEFF Research Database (Denmark)

    Skov, Lone; Hansen, Henrik; Barker, J. N.

    1997-01-01

    Ultraviolet-B (UVB), in addition to direct effects on DNA, induces immunological changes in the skin that predispose to the development of skin cancer. Whether ultraviolet-A (UVA) induces similar changes is unknown. This effect can be investigated in humans in vivo using epicutaneous antigens...... as a model of tumour antigens. Volunteers (n = 46) were randomly assigned to received no sensitization, sensitization with the allergen diphenylcyclopropenone (DPCP) on non-UV-exposed normal skin, or sensitization with DPCP on skin exposed to three minimal erythema doses (MED) of either UVA or UVB radiation...... the immunization rate compared with sensitization on non-irradiated skin (P UVA radiation did not result in a decreased immunization rate compared with non-irradiated skin. These results indicate that in humans erythemagenic...

  6. Bee venom processes human skin lipids for presentation by CD1a.

    Science.gov (United States)

    Bourgeois, Elvire A; Subramaniam, Sumithra; Cheng, Tan-Yun; De Jong, Annemieke; Layre, Emilie; Ly, Dalam; Salimi, Maryam; Legaspi, Annaliza; Modlin, Robert L; Salio, Mariolina; Cerundolo, Vincenzo; Moody, D Branch; Ogg, Graham

    2015-02-09

    Venoms frequently co-opt host immune responses, so study of their mode of action can provide insight into novel inflammatory pathways. Using bee and wasp venom responses as a model system, we investigated whether venoms contain CD1-presented antigens. Here, we show that venoms activate human T cells via CD1a proteins. Whereas CD1 proteins typically present lipids, chromatographic separation of venoms unexpectedly showed that stimulatory factors partition into protein-containing fractions. This finding was explained by demonstrating that bee venom-derived phospholipase A2 (PLA2) activates T cells through generation of small neoantigens, such as free fatty acids and lysophospholipids, from common phosphodiacylglycerides. Patient studies showed that injected PLA2 generates lysophospholipids within human skin in vivo, and polyclonal T cell responses are dependent on CD1a protein and PLA2. These findings support a previously unknown skin immune response based on T cell recognition of CD1a proteins and lipid neoantigen generated in vivo by phospholipases. The findings have implications for skin barrier sensing by T cells and mechanisms underlying phospholipase-dependent inflammatory skin disease. © 2015 Bourgeois et al.

  7. Cloud-based Monte Carlo modelling of BSSRDF for the rendering of human skin appearance (Conference Presentation)

    Science.gov (United States)

    Doronin, Alexander; Rushmeier, Holly E.; Meglinski, Igor; Bykov, Alexander V.

    2016-03-01

    We present a new Monte Carlo based approach for the modelling of Bidirectional Scattering-Surface Reflectance Distribution Function (BSSRDF) for accurate rendering of human skin appearance. The variations of both skin tissues structure and the major chromophores are taken into account correspondingly to the different ethnic and age groups. The computational solution utilizes HTML5, accelerated by the graphics processing units (GPUs), and therefore is convenient for the practical use at the most of modern computer-based devices and operating systems. The results of imitation of human skin reflectance spectra, corresponding skin colours and examples of 3D faces rendering are presented and compared with the results of phantom studies.

  8. Application of optical non-invasive methods in skin physiology

    Science.gov (United States)

    Lademann, J.; Patzelt, A.; Darvin, M.; Richter, H.; Antoniou, C.; Sterry, W.; Koch, S.

    2008-05-01

    In the present paper the application of optical non-invasive methods in dermatology and cosmetology is discussed. Laser scanning microscopy (LSM) and optical coherent tomography (OCT) are the most promising methods for this application. Using these methods, the analysis of different skin parameters like dryness and oiliness of the skin, the barrier function and the structure of furrows and wrinkles are discussed. Additionally the homogeneity of distribution of topically applied creams, as well as their penetration into the skin were investigated. It is shown that these methods are highly valuable in dermatology for diagnostic and therapy control and for basic research, for instance in the field of structure analysis of hair follicles and sweat glands. The vertical images of the tissue produced by OCT can be easily compared with histological sections. Unfortunately, the resolution of the OCT technique is not high enough to carry out measurements on a cellular level, as is possible by LSM. LSM has the advantage that it can be used for the investigation of penetration and storage processes of topically applied substances, if these substances have fluorescent properties or if they are fluorescent-labelled.

  9. Application of optical non-invasive methods in skin physiology

    International Nuclear Information System (INIS)

    Lademann, J; Patzelt, A; Darvin, M; Richter, H; Sterry, W; Antoniou, C; Koch, S

    2008-01-01

    In the present paper the application of optical non-invasive methods in dermatology and cosmetology is discussed. Laser scanning microscopy (LSM) and optical coherent tomography (OCT) are the most promising methods for this application. Using these methods, the analysis of different skin parameters like dryness and oiliness of the skin, the barrier function and the structure of furrows and wrinkles are discussed. Additionally the homogeneity of distribution of topically applied creams, as well as their penetration into the skin were investigated. It is shown that these methods are highly valuable in dermatology for diagnostic and therapy control and for basic research, for instance in the field of structure analysis of hair follicles and sweat glands. The vertical images of the tissue produced by OCT can be easily compared with histological sections. Unfortunately, the resolution of the OCT technique is not high enough to carry out measurements on a cellular level, as is possible by LSM. LSM has the advantage that it can be used for the investigation of penetration and storage processes of topically applied substances, if these substances have fluorescent properties or if they are fluorescent-labelled

  10. Histamine is not released in acute thermal injury in human skin in vivo: a microdialysis study

    DEFF Research Database (Denmark)

    Petersen, Lars Jelstrup; Pedersen, Juri Lindy; Skov, Per Stahl

    2009-01-01

    BACKGROUND: Animal models have shown histamine to be released from the skin during the acute phase of a burn injury. The role of histamine during the early phase of thermal injuries in humans remains unclear. PURPOSE: The objectives of this trial were to study histamine release in human skin during...

  11. A comparison of scaffold-free and scaffold-based reconstructed human skin models as alternatives to animal use.

    Science.gov (United States)

    Kinikoglu, Beste

    2017-12-01

    Tissue engineered full-thickness human skin substitutes have various applications in the clinic and in the laboratory, such as in the treatment of burns or deep skin defects, and as reconstructed human skin models in the safety testing of drugs and cosmetics and in the fundamental study of skin biology and pathology. So far, different approaches have been proposed for the generation of reconstructed skin, each with its own advantages and disadvantages. Here, the classic tissue engineering approach, based on cell-seeded polymeric scaffolds, is compared with the less-studied cell self-assembly approach, where the cells are coaxed to synthesise their own extracellular matrix (ECM). The resulting full-thickness human skin substitutes were analysed by means of histological and immunohistochemical analyses. It was found that both the scaffold-free and the scaffold-based skin equivalents successfully mimicked the functionality and morphology of native skin, with complete epidermal differentiation (as determined by the expression of filaggrin), the presence of a continuous basement membrane expressing collagen VII, and new ECM deposition by dermal fibroblasts. On the other hand, the scaffold-free model had a thicker epidermis and a significantly higher number of Ki67-positive proliferative cells, indicating a higher capacity for self-renewal, as compared to the scaffold-based model. 2017 FRAME.

  12. Endothelial network formed with human dermal microvascular endothelial cells in autologous multicellular skin substitutes.

    Science.gov (United States)

    Ponec, Maria; El Ghalbzouri, Abdoelwaheb; Dijkman, Remco; Kempenaar, Johanna; van der Pluijm, Gabri; Koolwijk, Pieter

    2004-01-01

    A human skin equivalent from a single skin biopsy harboring keratinocytes and melanocytes in the epidermal compartment, and fibroblasts and microvascular dermal endothelial cells in the dermal compartment was developed. The results of the study revealed that the nature of the extracellular matrix of the dermal compartments plays an important role in establishment of endothelial network in vitro. With rat-tail type I collagen matrices only lateral but not vertical expansion of endothelial networks was observed. In contrast, the presence of extracellular matrix of entirely human origin facilitated proper spatial organization of the endothelial network. Namely, when human dermal fibroblasts and microvascular endothelial cells were seeded on the bottom of an inert filter and subsequently epidermal cells were seeded on top of it, fibroblasts produced extracellular matrix throughout which numerous branched tubes were spreading three-dimensionally. Fibroblasts also facilitated the formation of basement membrane at the epidermal/matrix interface. Under all culture conditions, fully differentiated epidermis was formed with numerous melanocytes present in the basal epidermal cell layer. The results of the competitive RT-PCR revealed that both keratinocytes and fibroblasts expressed VEGF-A, -B, -C, aFGF and bFGF mRNA, whereas fibroblasts also expressed VEGF-D mRNA. At protein level, keratinocytes produced 10 times higher amounts of VEGF-A than fibroblasts did. The generation of multicellular skin equivalent from a single human skin biopsy will stimulate further developments for its application in the treatment of full-thickness skin defects. The potential development of biodegradable, biocompatible material suitable for these purposes is a great challenge for future research.

  13. Smartphone confocal microscopy for imaging cellular structures in human skin in vivo.

    Science.gov (United States)

    Freeman, Esther E; Semeere, Aggrey; Osman, Hany; Peterson, Gary; Rajadhyaksha, Milind; González, Salvador; Martin, Jeffery N; Anderson, R Rox; Tearney, Guillermo J; Kang, Dongkyun

    2018-04-01

    We report development of a low-cost smartphone confocal microscope and its first demonstration of in vivo human skin imaging. The smartphone confocal microscope uses a slit aperture and diffraction grating to conduct two-dimensional confocal imaging without using any beam scanning devices. Lateral and axial resolutions of the smartphone confocal microscope were measured as 2 and 5 µm, respectively. In vivo confocal images of human skin revealed characteristic cellular structures, including spinous and basal keratinocytes and papillary dermis. Results suggest that the smartphone confocal microscope has a potential to examine cellular details in vivo and may help disease diagnosis in resource-poor settings, where conducting standard histopathologic analysis is challenging.

  14. Diffuse Reflectance Spectroscopy of Human Skin Using a Commercial Fiber Optic Spectrometer

    International Nuclear Information System (INIS)

    Atencio, J. A. Delgado; Rodriguez, M. Cunill; Montiel, S. Vazquez y; Castro, Jorge; Rodriguez, A. Cornejo; Gutierrez, J. L.; Martinez, F.; Gutierrez, B.; Orozco, E.

    2008-01-01

    Diffuse reflectance spectroscopy is a reliable and easy to implement technique in human tissue characterization. In this work we evaluate the performance of the commercial USB4000 miniature fiber optic spectrometer in the in-vivo measurement of the diffuse reflectance spectra of different healthy skin sites and lesions in a population of 54 volunteers. Results show, that this spectrometer reproduces well the typical signatures of skin spectra over the 400-1000 nm region. Remarkable spectral differences exist between lesions and normal surrounding skin. A diffusion-based model was used to simulate reflectance spectra collected by the optical probe of the system

  15. In vitro activation of the neuro-transduction mechanism in sensitive organotypic human skin model.

    Science.gov (United States)

    Martorina, Francesca; Casale, Costantino; Urciuolo, Francesco; Netti, Paolo A; Imparato, Giorgia

    2017-01-01

    Recent advances in tissue engineering have encouraged researchers to endeavor the production of fully functional three-dimensional (3D) thick human tissues in vitro. Here, we report the fabrication of a fully innervated human skin tissue in vitro that recapitulates and replicates skin sensory function. Previous attempts to innervate in vitro 3D skin models did not demonstrate an effective functionality of the nerve network. In our approach, we initially engineer functional human skin tissue based on fibroblast-generated dermis and differentiated epidermis; then, we promote rat dorsal root ganglion (DRG) neurons axon ingrowth in the de-novo developed tissue. Neurofilaments network infiltrates the entire native dermis extracellular matrix (ECM), as demonstrated by immunofluorescence and second harmonic generation (SHG) imaging. To prove sensing functionality of the tissue, we use topical applications of capsaicin, an agonist of transient receptor protein-vanilloid 1 (TRPV1) channel, and quantify calcium currents resulting from variations of Ca ++ concentration in DRG neurons innervating our model. Calcium currents generation demonstrates functional cross-talking between dermis and epidermis compartments. Moreover, through a computational fluid dynamic (CFD) analysis, we set fluid dynamic conditions for a non-planar skin equivalent growth, as proof of potential application in creating skin grafts tailored on-demand for in vivo wound shape. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Pistacia lentiscus fruit oil reduces oxidative stress in human skin explants caused by hydrogen peroxide.

    Science.gov (United States)

    Ben Khedir, S; Moalla, D; Jardak, N; Mzid, M; Sahnoun, Z; Rebai, T

    2016-10-01

    We investigated the efficacy of Pistacia lentiscus fruit oil (PLFO) for protecting human skin from damage due to oxidative stress. PLFO contains natural antioxidants including polyphenols, sterols and tocopherols. We compared the antioxidant potential of PLFO with extra virgin olive oil (EVOO). Explants of healthy adult human skin were grown in culture with either PLFO or EVOO before adding hydrogen peroxide (H 2 O 2 ). We also used cultured skin explants to investigate the effects of PLFO on lipid oxidation and depletion of endogenous antioxidant defense enzymes including glutathione peroxidase (GPx), superoxide dismutase (SOD) and catalase (CAT) one day after 2 h exposure to H 2 O 2 . We found that PLFO scavenged radicals and protected skin against oxidative injury. PLFO exhibited greater antioxidant and free radical scavenging activity than EVOO. Skin explants treated with PLFO inhibited H 2 O 2 induced MDA formation by inhibition of lipid oxidation. In addition, the oil inhibited H 2 O 2 induced depletion of antioxidant defense enzymes including GPx, SOD and CAT. We found that treatment with PLFO repaired skin damage owing to its antioxidant properties.

  17. Wavelength dependence of pyrimidine dimer formation in DNA of human skin irradiated in situ with ultraviolet light

    International Nuclear Information System (INIS)

    Freeman, S.E.; Hacham, H.; Gange, R.W.; Maytum, D.J.; Sutherland, J.C.; Sutherland, B.M.

    1989-01-01

    The UV components of sunlight are believed to be a major cause of human skin caner, and DNA is though to be the principal molecular target. Alterations of the intensity and wavelength distribution of solar UV radiation reaching the surface of the earth, for example by depletion of stratospheric ozone, will change the effectiveness of solar radiation in damaging DNA in human skin. Evaluation of the magnitude of such effects requires knowledge of the altered sunlight spectrum and of the action spectrum for damaging DNA in human skin. The authors have determined an action spectrum for the frequency of pyrimidine dimer formation induced in the DNA of human skin per unit dose of UV incident on the skin surface. The peak of this action spectrum is near 300 nm and decreases rapidly at both longer and shorter wavelengths. The decrease in the action spectrum for wavelengths <300 nm is attributed to the absorption of the upper layers of the skin. Convolution of the dimer action spectrum with the solar spectra corresponding to a solar angle of 40 degree under current levels of stratospheric ozone and those for 50% ozone depletion, indicate about a 2.5-fold increase in dimer formation. If the action spectrum for DNA damage that results in skin cancer resembles that for dimer induction in skin, these results suggest that a 50% decrease in stratospheric ozone would increase the incidence of nonmelanoma skin cancers among white males in Seattle, Washington, by 7.5- to 8-fold, to a higher incidence than is presently seen in the corresponding population of Albuquerque, New Mexico

  18. Full-thickness human skin explants for testing the toxicity of topically applied chemicals

    International Nuclear Information System (INIS)

    Nakamura, M.; Rikimaru, T.; Yano, T.; Moore, K.G.; Pula, P.J.; Schofield, B.H.; Dannenberg, A.M. Jr.

    1990-01-01

    This report describes a model organ-culture system for testing the toxicity of chemical substances that are topically applied to human skin. In this system, the viable keratinocytes in the full-thickness skin explants are protected by the same keratinized layer as skin remaining on the donor, and toxicity can be assessed microscopically and/or biochemically. The human skin specimens were discards from a variety of surgical procedures. They were cut into full-thickness 1.0-cm2 explants, and briefly exposed to the military vesicant sulfur mustard (SM), which was used as a model toxicant. The explants were then organ cultured in small Petri dishes for 24 h at 36 degrees C. In the 0.03-1.0% dosage range, a straight-line dose-response relationship occurred between the concentration of SM applied and the number of paranuclear vacuoles seen histologically in the epidermis. Within the same SM dosage range, there was also a proportional decrease in 14C-leucine incorporation by the explants. Thus, the number of paranuclear vacuoles reflected decreases in protein synthesis by the injured epidermal cells. The epidermis of full-thickness untreated (control) human skin explants usually remained viable for 7 d when stored at 4 degrees C in culture medium. During storage, a relatively small number of paranuclear vacuoles developed within the epidermis, but the explants were still quite satisfactory for testing SM toxicity. Incubation (for 4 or 24 h at 36 degrees C) of such control skin explants reduced (often by 50%) the small number of paranuclear vacuoles produced during 4-7 d of storage. This reduction was probably caused by autolysis of many of the vacuolated cells. Two types of paranuclear vacuoles could be identified by both light and electron microscopy: a storage type and a toxicant type. The storage type seemed to be caused by autolysis of cell components

  19. Full-thickness human skin explants for testing the toxicity of topically applied chemicals

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, M.; Rikimaru, T.; Yano, T.; Moore, K.G.; Pula, P.J.; Schofield, B.H.; Dannenberg, A.M. Jr. (Johns Hopkins Univ., Baltimore, MD (USA))

    1990-09-01

    This report describes a model organ-culture system for testing the toxicity of chemical substances that are topically applied to human skin. In this system, the viable keratinocytes in the full-thickness skin explants are protected by the same keratinized layer as skin remaining on the donor, and toxicity can be assessed microscopically and/or biochemically. The human skin specimens were discards from a variety of surgical procedures. They were cut into full-thickness 1.0-cm2 explants, and briefly exposed to the military vesicant sulfur mustard (SM), which was used as a model toxicant. The explants were then organ cultured in small Petri dishes for 24 h at 36 degrees C. In the 0.03-1.0% dosage range, a straight-line dose-response relationship occurred between the concentration of SM applied and the number of paranuclear vacuoles seen histologically in the epidermis. Within the same SM dosage range, there was also a proportional decrease in 14C-leucine incorporation by the explants. Thus, the number of paranuclear vacuoles reflected decreases in protein synthesis by the injured epidermal cells. The epidermis of full-thickness untreated (control) human skin explants usually remained viable for 7 d when stored at 4 degrees C in culture medium. During storage, a relatively small number of paranuclear vacuoles developed within the epidermis, but the explants were still quite satisfactory for testing SM toxicity. Incubation (for 4 or 24 h at 36{degrees}C) of such control skin explants reduced (often by 50%) the small number of paranuclear vacuoles produced during 4-7 d of storage. This reduction was probably caused by autolysis of many of the vacuolated cells. Two types of paranuclear vacuoles could be identified by both light and electron microscopy: a storage type and a toxicant type. The storage type seemed to be caused by autolysis of cell components.

  20. Ultra-pure soft water ameliorates atopic skin disease by preventing metallic soap deposition in NC/Tnd mice and reduces skin dryness in humans.

    Science.gov (United States)

    Tanaka, Akane; Matsuda, Akira; Jung, Kyungsook; Jang, Hyosun; Ahn, Ginnae; Ishizaka, Saori; Amagai, Yosuke; Oida, Kumiko; Arkwright, Peter D; Matsuda, Hiroshi

    2015-09-01

    Mineral ions in tap water react with fatty acids in soap, leading to the formation of insoluble precipitate (metallic soap) on skin during washing. We hypothesised that metallic soap might negatively alter skin conditions. Application of metallic soap onto the skin of NC/Tnd mice with allergic dermatitis further induced inflammation with elevation of plasma immunoglobulin E and proinflammatory cytokine expression. Pruritus and dryness were ameliorated when the back of mice was washed with soap in Ca2+- and Mg2+-free ultra-pure soft water (UPSW). Washing in UPSW, but not tap water, also protected the skin of healthy volunteers from the soap deposition. Furthermore, 4 weeks of showering with UPSW reduced dryness and pruritus of human subjects with dry skin. Washing with UPSW may be therapeutically beneficial in patients with skin troubles.

  1. Effect of flexing and massage on in vivo human skin penetration and toxicity of zinc oxide nanoparticles.

    Science.gov (United States)

    Leite-Silva, Vânia R; Liu, David C; Sanchez, Washington Y; Studier, Hauke; Mohammed, Yousuf H; Holmes, Amy; Becker, Wolfgang; Grice, Jeffrey E; Benson, Heather Ae; Roberts, Michael S

    2016-05-01

    We assessed the effects of flexing and massage on human skin penetration and toxicity of topically applied coated and uncoated zinc oxide nanoparticles (˜75 nm) in vivo. Noninvasive multiphoton tomography with fluorescence lifetime imaging was used to evaluate the penetration of nanoparticles through the skin barrier and cellular apoptosis in the viable epidermis. All nanoparticles applied to skin with flexing and massage were retained in the stratum corneum or skin furrows. No significant penetration into the viable epidermis was seen and no cellular toxicity was detected. Exposure of normal in vivo human skin to these nanoparticles under common in-use conditions of flexing or massage is not associated with significant adverse events.

  2. Topical stabilized retinol treatment induces the expression of HAS genes and HA production in human skin in vitro and in vivo.

    Science.gov (United States)

    Li, Wen-Hwa; Wong, Heng-Kuan; Serrano, José; Randhawa, Manpreet; Kaur, Simarna; Southall, Michael D; Parsa, Ramine

    2017-05-01

    Skin Aging manifests primarily with wrinkles, dyspigmentations, texture changes, and loss of elasticity. During the skin aging process, there is a loss of moisture and elasticity in skin resulting in loss of firmness finally leading to skin sagging. The key molecule involved in skin moisture is hyaluronic acid (HA), which has a significant water-binding capacity. HA levels in skin decline with age resulting in decrease in skin moisture, which may contribute to loss of firmness. Clinical trials have shown that topically applied ROL effectively reduces wrinkles and helps retain youthful appearance. In the current study, ROL was shown to induce HA production and stimulates the gene expression of all three forms of hyaluronic acid synthases (HAS) in normal human epidermal keratinocytes monolayer cultures. Moreover, in human skin equivalent tissues and in human skin explants, topical treatment of tissues with a stabilized-ROL formulation significantly induced the gene expression of HAS mRNA concomitant with an increased HA production. Finally, in a vehicle-controlled human clinical study, histochemical analysis confirmed increased HA accumulation in the epidermis in ROL-treated human skin as compared to vehicle. These results show that ROL increases skin expression of HA, a significant contributing factor responsible for wrinkle formation and skin moisture, which decrease during aging. Taken together with the activity to increase collagen, elastin, and cell proliferation, these studies establish that retinol provides multi-functional activity for photodamaged skin.

  3. Degradation of type IV collagen by neoplastic human skin fibroblasts

    International Nuclear Information System (INIS)

    Sheela, S.; Barrett, J.C.

    1985-01-01

    An assay for the degradation of type IV (basement membrane) collagen was developed as a biochemical marker for neoplastic cells from chemically transformed human skin fibroblasts. Type IV collagen was isolated from basement membrane of Syrian hamster lung and type I collagen was isolated from rat tails; the collagens were radioactively labelled by reductive alkylation. The abilities of normal (KD) and chemically transformed (Hut-11A) human skin fibroblasts to degrade the collagens were studied. A cell-associated assay was performed by growing either normal or transformed cells in the presence of radioactively labelled type IV collagen and measuring the released soluble peptides in the medium. This assay also demonstrated that KD cells failed to synthesize an activity capable of degrading type IV collagen whereas Hut-11A cells degraded type IV collagen in a linear manner for up to 4 h. Human serum at very low concentrations, EDTA and L-cysteine inhibited the enzyme activity, whereas protease inhibitors like phenylmethyl sulfonyl fluoride, N-ethyl maleimide or soybean trypsin inhibitor did not inhibit the enzyme from Hut-11A cells. These results suggest that the ability to degrade specifically type IV collagen may be an important marker for neoplastic human fibroblasts and supports a role for this collagenase in tumor cell invasion

  4. Qualitative and semi quantitative analysis in the healing area of athymic nude mice skin engrafted with human skin sterilized with gamma radiation

    International Nuclear Information System (INIS)

    Miranda, Jurandir Tomaz de; Bringel, Fabiana; Alves, Nelson Mendes; Antebi, Uri; Funari, Ana Paula; Mathor, Monica B.

    2015-01-01

    In recent decades there has been a great interest in the radio-sterilized grafts for human skin grafts. This tissue is taken from a cadaver or multi-organ donor and samples are processed and stored in glycerol at concentrations above 85%. Although this procedure is carried out under aseptic conditions, after the final packaging one can sterilize the tissues with ionizing radiation in order to increase the safety level of sterility. The purpose of this study was to evaluate the behavior of the healing repair process that occurs between the graft and the skin of athymic NUDE mice. The samples of human skin treated with glycerol were divided into three groups: the control group 1 (non-irradiated), irradiated group 2 at 25 kGy and irradiated group 3, at 50 kGy. These tissues were grafted onto athymic NUDE mice which were sacrificed after 3, 7 and 21 days. After the sacrifice, part of the back fur of the animals containing human skin graft was removed with hematoxylin and eosin (H/E). The histological sections were analyzed for the integrity of tissue, presence and location of keratinocytes, fibroblasts, defense cells and blood vessels. Thus it was examined whether over time the graft was incorporated into the body or if there was a process of healing by secondary intention. (author)

  5. Qualitative and semi quantitative analysis in the healing area of athymic nude mice skin engrafted with human skin sterilized with gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Miranda, Jurandir Tomaz de; Bringel, Fabiana; Alves, Nelson Mendes; Antebi, Uri; Funari, Ana Paula; Mathor, Monica B., E-mail: tomaz_ju@hotmail.com [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2015-07-01

    In recent decades there has been a great interest in the radio-sterilized grafts for human skin grafts. This tissue is taken from a cadaver or multi-organ donor and samples are processed and stored in glycerol at concentrations above 85%. Although this procedure is carried out under aseptic conditions, after the final packaging one can sterilize the tissues with ionizing radiation in order to increase the safety level of sterility. The purpose of this study was to evaluate the behavior of the healing repair process that occurs between the graft and the skin of athymic NUDE mice. The samples of human skin treated with glycerol were divided into three groups: the control group 1 (non-irradiated), irradiated group 2 at 25 kGy and irradiated group 3, at 50 kGy. These tissues were grafted onto athymic NUDE mice which were sacrificed after 3, 7 and 21 days. After the sacrifice, part of the back fur of the animals containing human skin graft was removed with hematoxylin and eosin (H/E). The histological sections were analyzed for the integrity of tissue, presence and location of keratinocytes, fibroblasts, defense cells and blood vessels. Thus it was examined whether over time the graft was incorporated into the body or if there was a process of healing by secondary intention. (author)

  6. Effects of Thermal Resistance on One-Dimensional Thermal Analysis of the Epidermal Flexible Electronic Devices Integrated with Human Skin

    Science.gov (United States)

    Li, He; Cui, Yun

    2017-12-01

    Nowadays, flexible electronic devices are increasingly used in direct contact with human skin to monitor the real-time health of human body. Based on the Fourier heat conduction equation and Pennes bio-heat transfer equation, this paper deduces the analytical solutions of one - dimensional heat transfer for flexible electronic devices integrated with human skin under the condition of a constant power. The influence of contact thermal resistance between devices and skin is considered as well. The corresponding finite element model is established to verify the correctness of analytical solutions. The results show that the finite element analysis agrees well with the analytical solution. With bigger thermal resistance, temperature increase of skin surface will decrease. This result can provide guidance for the design of flexible electronic devices to reduce the negative impact that exceeding temperature leave on human skin.

  7. Applying tattoo dye as a third-harmonic generation contrast agent for in vivo optical virtual biopsy of human skin

    Science.gov (United States)

    Tsai, Ming-Rung; Lin, Chen-Yu; Liao, Yi-Hua; Sun, Chi-Kuang

    2013-02-01

    Third-harmonic generation (THG) microscopy has been reported to provide intrinsic contrast in elastic fibers, cytoplasmic membrane, nucleus, actin filaments, lipid bodies, hemoglobin, and melanin in human skin. For advanced molecular imaging, exogenous contrast agents are developed for a higher structural or molecular specificity. We demonstrate the potential of the commonly adopted tattoo dye as a THG contrast agent for in vivo optical biopsy of human skin. Spectroscopy and microscopy experiments were performed on cultured cells with tattoo dyes, in tattooed mouse skin, and in tattooed human skin to demonstrate the THG enhancement effect. Compared with other absorbing dyes or nanoparticles used as exogenous THG contrast agents, tattoo dyes are widely adopted in human skin so that future clinical biocompatibility evaluation is relatively achievable. Combined with the demonstrated THG enhancement effect, tattoo dyes show their promise for future clinical imaging applications.

  8. Proteome Analysis of Human Sebaceous Follicle Infundibula Extracted from Healthy and Acne-Affected Skin

    Science.gov (United States)

    Bek-Thomsen, Malene; Lomholt, Hans B.; Scavenius, Carsten; Enghild, Jan J.; Brüggemann, Holger

    2014-01-01

    Acne vulgaris is a very common disease of the pilosebaceous unit of the human skin. The pathological processes of acne are not fully understood. To gain further insight sebaceous follicular casts were extracted from 18 healthy and 20 acne-affected individuals by cyanoacrylate-gel biopsies and further processed for mass spectrometry analysis, aiming at a proteomic analysis of the sebaceous follicular casts. Human as well as bacterial proteins were identified. Human proteins enriched in acne and normal samples were detected, respectively. Normal follicular casts are enriched in proteins such as prohibitins and peroxiredoxins which are involved in the protection from various stresses, including reactive oxygen species. By contrast, follicular casts extracted from acne-affected skin contained proteins involved in inflammation, wound healing and tissue remodeling. Among the most distinguishing proteins were myeloperoxidase, lactotransferrin, neutrophil elastase inhibitor and surprisingly, vimentin. The most significant biological process among all acne-enriched proteins was ‘response to a bacterium’. Identified bacterial proteins were exclusively from Propionibacterium acnes. The most abundant P. acnes proteins were surface-exposed dermatan sulphate adhesins, CAMP factors, and a so far uncharacterized lipase in follicular casts extracted from normal as well as acne-affected skin. This is a first proteomic study that identified human proteins together with proteins of the skin microbiota in sebaceous follicular casts. PMID:25238151

  9. Amnion s and radio-sterilized porcine skin use as potential matrices for the development of human skin substitutes

    International Nuclear Information System (INIS)

    Martinez P, M. E.; Reyes F, M. L.; Reboyo B, D.; Velasquillo M, M. C.; Sanchez S, R.; Brena M, A. M.; Ibarra P, J. C.

    2014-10-01

    The injuries by burns constitute a primordial problem of public health; they cause a high mortality index, severe physical and psychological disability, etc. The autologous skin transplant is the replacement therapy recommended for its treatment, but in patients that present a high percentage of burnt skin; this is not possible to carry out. Another strategy is the transplant of donated skin; however, due to the little donation that exists in our country is not very feasible to apply this treatment. A challenge of the tissues engineering is to develop biological skin substitutes, based on cells and amnion s, favoring the cutaneous regeneration and quick repair of injuries, diminishing this way the hospitalization expenses. At present skin substitutes that can equal to the same skin do not exist. On the other hand, the mesenchymal stromal cells (Msc) represent an alternative to achieve this objective; since has been demonstrated that the Msc participate in the tissue repair by means of inhibition of pro-inflammatory cytokines and differentiation to dermal fibroblasts and keratinocytes. To apply the Msc in cutaneous injuries a support material is required that to allow transplanting these cells to a lesion or burn. The radio-sterilized human amnion and the radio-sterilized porcine skin, processed by the Radio-Sterilized Tissues Bank of the Instituto Nacional de Investigaciones Nucleares (ININ), are biomaterials that are used as temporary cutaneous coverings. We suppose that these two matrices will be appropriate for the growth and maintenance in cultivation of the Msc, to generate two biological skin substitutes, in collaboration with the Biotechnology Laboratory of the Instituto Nacional de Rehabilitacion. (Author)

  10. Estimating physiological skin parameters from hyperspectral signatures

    Science.gov (United States)

    Vyas, Saurabh; Banerjee, Amit; Burlina, Philippe

    2013-05-01

    We describe an approach for estimating human skin parameters, such as melanosome concentration, collagen concentration, oxygen saturation, and blood volume, using hyperspectral radiometric measurements (signatures) obtained from in vivo skin. We use a computational model based on Kubelka-Munk theory and the Fresnel equations. This model forward maps the skin parameters to a corresponding multiband reflectance spectra. Machine-learning-based regression is used to generate the inverse map, and hence estimate skin parameters from hyperspectral signatures. We test our methods using synthetic and in vivo skin signatures obtained in the visible through the short wave infrared domains from 24 patients of both genders and Caucasian, Asian, and African American ethnicities. Performance validation shows promising results: good agreement with the ground truth and well-established physiological precepts. These methods have potential use in the characterization of skin abnormalities and in minimally-invasive prescreening of malignant skin cancers.

  11. An effective dose assessment technique with NORM added consumer products using skin-point source on computational human phantom

    International Nuclear Information System (INIS)

    Yoo, Do Hyeon; Shin, Wook-Geun; Lee, Hyun Cheol; Choi, Hyun Joon; Testa, Mauro; Lee, Jae Kook; Yeom, Yeon Soo; Kim, Chan Hyeong; Min, Chul Hee

    2016-01-01

    The aim of this study is to develop the assessment technique of the effective dose by calculating the organ equivalent dose with a Monte Carlo (MC) simulation and a computational human phantom for the naturally occurring radioactive material (NORM) added consumer products. In this study, we suggests the method determining the MC source term based on the skin-point source enabling the convenient and conservative modeling of the various type of the products. To validate the skin-point source method, the organ equivalent doses were compared with that by the product modeling source of the realistic shape for the pillow, waist supporter, sleeping mattress etc. Our results show that according to the source location, the organ equivalent doses were observed as the similar tendency for both source determining methods, however, it was observed that the annual effective dose with the skin-point source was conservative than that with the modeling source with the maximum 3.3 times higher dose. With the assumption of the gamma energy of 1 MeV and product activity of 1 Bq g"−"1, the annual effective doses of the pillow, waist supporter and sleeping mattress with skin-point source was 3.09E-16 Sv Bq"−"1 year"−"1, 1.45E-15 Sv Bq"−"1 year"−"1, and 2,82E-16 Sv Bq"−"1 year"−"1, respectively, while the product modeling source showed 9.22E-17 Sv Bq"−"1 year"−"1, 9.29E-16 Sv Bq"−"1 year"−"1, and 8.83E-17 Sv Bq"−"1 year"−"1, respectively. In conclusion, it was demonstrated in this study that the skin-point source method could be employed to efficiently evaluate the annual effective dose due to the usage of the NORM added consumer products. - Highlights: • We evaluate the exposure dose from the usage of NORM added consumer products. • We suggest the method determining the MC source term based on the skin-point source. • To validate the skin-point source, the organ equivalent doses were compared with that the modeling source. • The skin-point source could

  12. Detection of human papillomavirus in nonmelanoma skin cancer lesions and healthy perilesional skin in kidney transplant recipients and immunocompetent patients.

    Science.gov (United States)

    Bernat-García, J; Morales Suárez-Varela, M; Vilata-Corell, J J; Marquina-Vila, A

    2014-04-01

    The influence of human papillomavirus (HPV) on the development of nonmelanoma skin cancer (NMSC) is a topic of debate. HPV types from the beta genus (HPV-β) have been most frequently associated with the development of skin cancer. To analyze the prevalence and range of HPV types in NMSC lesions and healthy perilesional skin in immunodepressed and immunocompetent patients and to evaluate the influence of various clinical factors on the prevalence of HPV in skin cancer. Nested polymerase chain reaction and sequencing were used to detect HPV in 120 NMSC samples obtained by biopsy from 30 kidney transplant recipients and 30 immunocompetent patients. In all cases, a sample was taken from the tumor site and the surrounding healthy skin. Potential confounders were assessed and the data analyzed by multivariate logistic regression. HPV DNA was detected in 44 (73.3%) of the 60 samples from immunodepressed patients and in 32 (53.3%) of the 60 samples from immunocompetent patients (adjusted odds ratio, 3.4; 95% CI, 1.2-9.6). In both groups of patients, HPV was more common in healthy perilesional skin than in lesional skin. HPV-β was the most common type isolated. We found a wide range of HPV types (mostly HPV-β) in the skin of kidney transplant recipients and immunocompetent patients with skin cancer. Copyright © 2013 Elsevier España, S.L. and AEDV. All rights reserved.

  13. A pathological study on overexpression of c-fos and Rb proteins in human radiation skin ulcer

    International Nuclear Information System (INIS)

    Du Yuejiao; Wang Dewen; Gao Yabing

    1996-01-01

    We performed an immunohistochemical study on human radiation skin ulcer by using antibodies against c-fos and Rb proteins and antigen-repairing method with a microwave oven. We found that the positive rates of overexpression of c-fos and Rb proteins were 84.0% and 100%, respectively. The overexpression of c-fos protein was mainly observed in cell nuclei of squamous epithelial cells, fibroblasts, endothelial cells, and leiomyocytes in media and fibrocytes in adventitia of arterioles. The location of the Rb protein overexpression was mostly similar to that of c-fos protein. The overexpression of c-fos and Rb proteins may be related to cancer transformation and poor healing of radiation-induced skin ulcers

  14. Shelf-life evaluation of bilayered human skin equivalent, MyDerm™.

    Directory of Open Access Journals (Sweden)

    Wan Tai Seet

    Full Text Available Skin plays an important role in defense against infection and other harmful biological agents. Due to its fragile structure, skin can be easily damaged by heat, chemicals, traumatic injuries and diseases. An autologous bilayered human skin equivalent, MyDerm™, was engineered to provide a living skin substitute to treat critical skin loss. However, one of the disadvantages of living skin substitute is its short shelf-life, hence limiting its distribution worldwide. The aim of this study was to evaluate the shelf-life of MyDerm™ through assessment of cell morphology, cell viability, population doubling time and functional gene expression levels before transplantation. Skin samples were digested with 0.6% Collagenase Type I followed by epithelial cells dissociation with TrypLE Select. Dermal fibroblasts and keratinocytes were culture-expanded to obtain sufficient cells for MyDerm™ construction. MyDerm™ was constructed with plasma-fibrin as temporary biomaterial and evaluated at 0, 24, 48 and 72 hours after storage at 4°C for its shelf-life determination. The morphology of skin cells derived from MyDerm™ remained unchanged across storage times. Cells harvested from MyDerm™ after storage appeared in good viability (90.5%±2.7% to 94.9%±1.6% and had short population doubling time (58.4±8.7 to 76.9±19 hours. The modest drop in cell viability and increased in population doubling time at longer storage duration did not demonstrate a significant difference. Gene expression for CK10, CK14 and COL III were also comparable between different storage times. In conclusion, MyDerm™ can be stored in basal medium at 4°C for at least 72 hours before transplantation without compromising its functionality.

  15. Shelf-life evaluation of bilayered human skin equivalent, MyDerm™.

    Science.gov (United States)

    Seet, Wan Tai; Manira, Maarof; Maarof, Manira; Khairul Anuar, Khairoji; Chua, Kien-Hui; Ahmad Irfan, Abdul Wahab; Ng, Min Hwei; Aminuddin, Bin Saim; Ruszymah, Bt Hj Idrus

    2012-01-01

    Skin plays an important role in defense against infection and other harmful biological agents. Due to its fragile structure, skin can be easily damaged by heat, chemicals, traumatic injuries and diseases. An autologous bilayered human skin equivalent, MyDerm™, was engineered to provide a living skin substitute to treat critical skin loss. However, one of the disadvantages of living skin substitute is its short shelf-life, hence limiting its distribution worldwide. The aim of this study was to evaluate the shelf-life of MyDerm™ through assessment of cell morphology, cell viability, population doubling time and functional gene expression levels before transplantation. Skin samples were digested with 0.6% Collagenase Type I followed by epithelial cells dissociation with TrypLE Select. Dermal fibroblasts and keratinocytes were culture-expanded to obtain sufficient cells for MyDerm™ construction. MyDerm™ was constructed with plasma-fibrin as temporary biomaterial and evaluated at 0, 24, 48 and 72 hours after storage at 4°C for its shelf-life determination. The morphology of skin cells derived from MyDerm™ remained unchanged across storage times. Cells harvested from MyDerm™ after storage appeared in good viability (90.5%±2.7% to 94.9%±1.6%) and had short population doubling time (58.4±8.7 to 76.9±19 hours). The modest drop in cell viability and increased in population doubling time at longer storage duration did not demonstrate a significant difference. Gene expression for CK10, CK14 and COL III were also comparable between different storage times. In conclusion, MyDerm™ can be stored in basal medium at 4°C for at least 72 hours before transplantation without compromising its functionality.

  16. Sarcoptes scabiei mites modulate gene expression in human skin equivalents.

    Directory of Open Access Journals (Sweden)

    Marjorie S Morgan

    Full Text Available The ectoparasitic mite, Sarcoptes scabiei that burrows in the epidermis of mammalian skin has a long co-evolution with its hosts. Phenotypic studies show that the mites have the ability to modulate cytokine secretion and expression of cell adhesion molecules in cells of the skin and other cells of the innate and adaptive immune systems that may assist the mites to survive in the skin. The purpose of this study was to identify genes in keratinocytes and fibroblasts in human skin equivalents (HSEs that changed expression in response to the burrowing of live scabies mites. Overall, of the more than 25,800 genes measured, 189 genes were up-regulated >2-fold in response to scabies mite burrowing while 152 genes were down-regulated to the same degree. HSEs differentially expressed large numbers of genes that were related to host protective responses including those involved in immune response, defense response, cytokine activity, taxis, response to other organisms, and cell adhesion. Genes for the expression of interleukin-1α (IL-1α precursor, IL-1β, granulocyte/macrophage-colony stimulating factor (GM-CSF precursor, and G-CSF precursor were up-regulated 2.8- to 7.4-fold, paralleling cytokine secretion profiles. A large number of genes involved in epithelium development and keratinization were also differentially expressed in response to live scabies mites. Thus, these skin cells are directly responding as expected in an inflammatory response to products of the mites and the disruption of the skin's protective barrier caused by burrowing. This suggests that in vivo the interplay among these skin cells and other cell types, including Langerhans cells, dendritic cells, lymphocytes and endothelial cells, is responsible for depressing the host's protective response allowing these mites to survive in the skin.

  17. Further development of LLNA:DAE method as stand-alone skin-sensitization testing method and applied for evaluation of relative skin-sensitizing potency between chemicals.

    Science.gov (United States)

    Yamashita, Kunihiko; Shinoda, Shinsuke; Hagiwara, Saori; Itagaki, Hiroshi

    2015-04-01

    To date, there has been no well-established local lymph node assay (LLNA) that includes an elicitation phase. Therefore, we developed a modified local lymph node assay with an elicitation phase (LLNA:DAE) to discriminate true skin sensitizers from chemicals that gave borderline positive results and previously reported this assay. To develop the LLNA:DAE method as a useful stand-alone testing method, we investigated the complete procedure for the LLNA:DAE method using hexyl cinnamic aldehyde (HCA), isoeugenol, and 2,4-dinitrochlorobenzene (DNCB) as test compounds. We defined the LLNA:DAE procedure as follows: in the dose-finding test, four concentrations of chemical applied to dorsum of the right ear on days 1, 2, and 3 and dorsum of both ears on day 10. Ear thickness and skin irritation score were measured on days 1, 3, 5, 10, and 12. Local lymph nodes were excised and weighed on day 12. The test dose for the primary LLNA:DAE study was selected as the dose that gave the highest left ear lymph node weight in the dose-finding study, or the lowest dose that produced a left ear lymph node of over 4 mg. This procedure was validated using nine different chemicals. Furthermore, qualitative relationship was observed between the degree of elicitation response in the left ear lymph node and the skin sensitizing potency of 32 chemicals tested in this study and the previous study. These results indicated that LLNA:DAE method was as first LLNA method that was able to evaluate the skin sensitizing potential and potency in elicitation response.

  18. Extraction of high-quality epidermal RNA after ammonium thiocyanate-induced dermo-epidermal separation of 4 mm human skin biopsies

    DEFF Research Database (Denmark)

    Clemmensen, Anders; Thomassen, Mads; Clemmensen, Ole

    2009-01-01

    To obtain a separation of the epidermal and dermal compartments to examine compartment specific biological mechanisms in the skin, we incubated 4 mm human skin punch biopsies in ammonium thiocyanate. We wanted to test (i) the histological quality of the dermo-epidermal separation obtained...... by different incubation times; (ii) the amount and quality of extractable epidermal RNA and (iii) its impact on sample RNA expression profiles assessed by large-scale gene expression microarray analysis in both normal and inflamed skin. At 30-min incubation, the split between dermis and epidermis...... and almost completely separated from the dermis of 4 mm skin biopsies by 30 min incubation in 3.8% ammonium thiocyanate combined with curettage of the dermal surface, producing high-quality RNA suitable for transcriptional analysis. Our refined method of dermo-epidermal separation will undoubtedly prove...

  19. Artificial skin and patient simulator comprising the artificial skin

    NARCIS (Netherlands)

    2011-01-01

    The invention relates to an artificial skin (10, 12, 14), and relates to a patient simulator (100) comprising the artificial skin. The artificial skin is a layered structure comprising a translucent cover layer (20) configured for imitating human or animal skin, and comprising a light emitting layer

  20. Human skin is protected by four functionally and phenotypically discrete populations of resident and recirculating memory T cells

    Science.gov (United States)

    Watanabe, Rei; Gehad, Ahmed; Yang, Chao; Campbell, Laura; Teague, Jessica E.; Schlapbach, Christoph; Elco, Christopher; Huang, Victor; Matos, Tiago R.; Kupper, Thomas S.; Clark, Rachael A.

    2015-01-01

    The skin of an adult human contains approximately 20 billion memory T cells. Epithelial barrier tissues are infiltrated by a combination of resident and recirculating T cells in mice but the relative proportions and functional activities of resident versus recirculating T cells have not been evaluated in human skin. We discriminated resident from recirculating T cells in human engrafted mice and lymphoma patients using alemtuzumab, a medication that depletes recirculating T cells from skin, and then analyzed these T cell populations in healthy human skin. All non-recirculating resident memory T cells (TRM) expressed CD69, but the majority were CD4+, CD103− and located in the dermis, in contrast to studies in mice. Both CD4+ and CD8+ CD103+ TRM were enriched in the epidermis, had potent effector functions and had a limited proliferative capacity compared to CD103− TRM. TRM of both types had more potent effector functions than recirculating T cells. Induction of CD103 on human T cells was enhanced by keratinocyte contact, depended on TGFβ and was independent of T cell keratinocyte adhesive interactions. We observed two distinct populations of recirculating T cells, CCR7+/L-selectin+ central memory T cells (TCM) and CCR7+/L-selectin− T cells, which we term migratory memory T cells (TMM). Circulating skin-tropic TMM were intermediate in cytokine production between TCM and effector memory T cells. In patients with cutaneous T cell lymphoma, malignant TCM and TMM induced distinct inflammatory skin lesions and TMM were depleted more slowly from skin after alemtuzumab, suggesting TMM may recirculate more slowly. In summary, human skin is protected by four functionally distinct populations of T cells, two resident and two recirculating, with differing territories of migration and distinct functional activities. PMID:25787765

  1. Body Site Is a More Determinant Factor than Human Population Diversity in the Healthy Skin Microbiome.

    Directory of Open Access Journals (Sweden)

    Guillermo I Perez Perez

    Full Text Available We studied skin microbiota present in three skin sites (forearm, axilla, scalp in men from six ethnic groups living in New York City.Samples were obtained at baseline and after four days following use of neutral soap and stopping regular hygiene products, including shampoos and deodorants. DNA was extracted using the MoBio Power Lyzer kit and 16S rRNA gene sequences determined on the IIlumina MiSeq platform, using QIIME for analysis.Our analysis confirmed skin swabbing as a useful method for sampling different areas of the skin because DNA concentrations and number of sequences obtained across subject libraries were similar. We confirmed that skin location was the main factor determining the composition of bacterial communities. Alpha diversity, expressed as number of species observed, was greater in arm than on scalp or axilla in all studied groups. We observed an unexpected increase in α-diversity on arm, with similar tendency on scalp, in the South Asian group after subjects stopped using their regular shampoos and deodorants. Significant differences at phylum and genus levels were observed between subjects of the different ethnic origins at all skin sites.We conclude that ethnicity and particular soap and shampoo practices are secondary factors compared to the ecological zone of the human body in determining cutaneous microbiota composition.

  2. Protoporphyrin IX formation and photobleaching in different layers of normal human skin

    DEFF Research Database (Denmark)

    Togsverd-Bo, Katrine; Idorn, Luise W; Philipsen, Peter A

    2012-01-01

    human skin was tape-stripped and incubated with 20% methylaminolevulinate (MAL) or 20% hexylaminolevulinate (HAL) for 3 h. Fluorescence microscopy quantified PpIX accumulation in epidermis, superficial, mid and deep dermis, down to 2 mm. PpIX photobleaching by light-emitting diode (LED, 632 nm, 18......Topical photodynamic therapy (PDT) is used for various skin disorders, and selective targeting of specific skin structures is desirable. The objective was to assess accumulation of PpIX fluorescence and photobleaching within skin layers using different photosensitizers and light sources. Normal...... and 37 J/cm(2)), intense pulsed light (IPL, 500-650 nm, 36 and 72 J/cm(2)) and long-pulsed dye laser (LPDL, 595 nm, 7.5 and 15 J/cm(2)) was measured using fluorescence photography and microscopy. We found higher PpIX fluorescence intensities in epidermis and superficial dermis in HAL-incubated skin than...

  3. Systematic evaluation of non-animal test methods for skin sensitisation safety assessment

    NARCIS (Netherlands)

    Reisinger, K.; Hoffmann, S.; Alépée, N.; Ashikaga, T.; Barroso, J.; Elcombe, C.; Gellatly, N.; Galbiati, V.; Gibbs, S.; Groux, H.; Hibatallah, J.; Keller, D.; Kern, P.; Klaric, M.; Kolle, S.; Kuehnl, J.; Lambrechts, N.; Lindstedt, M.; Millet, M.; Martinozzi-Teissier, S.; Natsch, A.; Petersohn, D.; Pike, I.; Sakaguchi, H.; Schepky, A.; Tailhardat, M.; Templier, M.; van Vliet, E; Maxwell, G.

    2015-01-01

    The need for non-animal data to assess skin sensitisation properties of substances, especially cosmetics ingredients, has spawned the development of many in vitro methods. As it is widely believed that no single method can provide a solution, the Cosmetics Europe Skin Tolerance Task Force has

  4. Experimental study on tissue phantoms to understand the effect of injury and suturing on human skin mechanical properties.

    Science.gov (United States)

    Chanda, Arnab; Unnikrishnan, Vinu; Flynn, Zachary; Lackey, Kim

    2017-01-01

    Skin injuries are the most common type of injuries occurring in day-to-day life. A skin injury usually manifests itself in the form of a wound or a cut. While a shallow wound may heal by itself within a short time, deep wounds require surgical interventions such as suturing for timely healing. To date, suturing practices are based on a surgeon's experience and may vary widely from one situation to another. Understanding the mechanics of wound closure and suturing of the skin is crucial to improve clinical suturing practices and also to plan automated robotic surgeries. In the literature, phenomenological two-dimensional computational skin models have been developed to study the mechanics of wound closure. Additionally, the effect of skin pre-stress (due to the natural tension of the skin) on wound closure mechanics has been studied. However, in most of these analyses, idealistic two-dimensional skin geometries, materials and loads have been assumed, which are far from reality, and would clearly generate inaccurate quantitative results. In this work, for the first time, a biofidelic human skin tissue phantom was developed using a two-part silicone material. A wound was created on the phantom material and sutures were placed to close the wound. Uniaxial mechanical tests were carried out on the phantom specimens to study the effect of varying wound size, quantity, suture and pre-stress on the mechanical behavior of human skin. Also, the average mechanical behavior of the human skin surrogate was characterized using hyperelastic material models, in the presence of a wound and sutures. To date, such a robust experimental study on the effect of injury and sutures on human skin mechanics has not been attempted. The results of this novel investigation will provide important guidelines for surgical planning and validation of results from computational models in the future.

  5. Effects of radiation on the skin

    International Nuclear Information System (INIS)

    Hopewell, J.W.

    1985-01-01

    The effects of X-irradiation on pig skin are described, comparing and contrasting the effects seen in human and rodent skin. It is concluded that, anatomically, pig skin is the best animal model for human skin. The applications of the 'pig skin model' to investigations of the problems of radiation therapy and radiological protection of human skin are discussed. (U.K.)

  6. [Studies on the novel association of human herpesvirus-7 with skin diseases].

    Science.gov (United States)

    Vág, Tibor; Sonkoly, Enikó; Kemény, Béla; Kárpáti, Sarolta; Horváth, Attila; Ongrádi, József

    2003-08-17

    Human herpesvirus 7 in pityriasis rosea, this and other viruses in papular-purpuric gloves-and-socks syndrome have been implicated, but their primary or recurrent infections are still in question. In one available blood sample, therefore, IgM, IgG and its high avidity fraction characteristic for recurrent infections were quantitated by indirect immunofluorescence. Peripheral lymphocytes were subjected to nested polymerase chain reaction to detect viral DNA, or cocultivated with several cell cultures. One third of 33 pityriasis rosea patients had elevated IgM, another third had elevated IgG without high avidity molecules to human herpesvirus 7 suggesting primary infection. Thirty percent of controls, more than half of the patients had virtual DNA in their lymphocytes, but only one in 5 skin biopsy specimens were PCR positive. All three co-cultivation attempts yielded viruses extremely rapidly, verified by electron microscopy, polymerase chain reaction and monoclonal antibodies as human herpesvirus 7. These are the first isolates in the geographical regions of Hungary. These data suggest that pityriasis rosea is the consequence of a primary human herpesvirus 7 infection in seronegative adults, and only occasionally is due to virus reactivation. One patient with gloves-and-socks syndrome had an acute, another patient had a persistent coinfection with human herpesvirus 7 and parvovirus B19, two others had a primary herpesvirus 7 infection. Interestingly, this disease might be elicited by both viruses individually or in synergism. Neither human herpesvirus 7 nor parvovirus B19 infect skin cells, but both can be detected in the infiltrating lymphocytes of skin eruptions, in which they induce an altered mediator production, that might be responsible for the general and local symptoms.

  7. The Human Skin Microbiome Associates with the Outcome of and Is Influenced by Bacterial Infection.

    Science.gov (United States)

    van Rensburg, Julia J; Lin, Huaiying; Gao, Xiang; Toh, Evelyn; Fortney, Kate R; Ellinger, Sheila; Zwickl, Beth; Janowicz, Diane M; Katz, Barry P; Nelson, David E; Dong, Qunfeng; Spinola, Stanley M

    2015-09-15

    The influence of the skin microbiota on host susceptibility to infectious agents is largely unexplored. The skin harbors diverse bacterial species that may promote or antagonize the growth of an invading pathogen. We developed a human infection model for Haemophilus ducreyi in which human volunteers are inoculated on the upper arm. After inoculation, papules form and either spontaneously resolve or progress to pustules. To examine the role of the skin microbiota in the outcome of H. ducreyi infection, we analyzed the microbiomes of four dose-matched pairs of "resolvers" and "pustule formers" whose inoculation sites were swabbed at multiple time points. Bacteria present on the skin were identified by amplification and pyrosequencing of 16S rRNA genes. Nonmetric multidimensional scaling (NMDS) using Bray-Curtis dissimilarity between the preinfection microbiomes of infected sites showed that sites from the same volunteer clustered together and that pustule formers segregated from resolvers (P = 0.001, permutational multivariate analysis of variance [PERMANOVA]), suggesting that the preinfection microbiomes were associated with outcome. NMDS using Bray-Curtis dissimilarity of the endpoint samples showed that the pustule sites clustered together and were significantly different than the resolved sites (P = 0.001, PERMANOVA), suggesting that the microbiomes at the endpoint differed between the two groups. In addition to H. ducreyi, pustule-forming sites had a greater abundance of Proteobacteria, Bacteroidetes, Micrococcus, Corynebacterium, Paracoccus, and Staphylococcus species, whereas resolved sites had higher levels of Actinobacteria and Propionibacterium species. These results suggest that at baseline, resolvers and pustule formers have distinct skin bacterial communities which change in response to infection and the resultant immune response. Human skin is home to a diverse community of microorganisms, collectively known as the skin microbiome. Some resident

  8. Inhibition of hydrogen peroxide induced injuring on human skin fibroblast by Ulva prolifera polysaccharide.

    Science.gov (United States)

    Cai, Chuner; Guo, Ziye; Yang, Yayun; Geng, Zhonglei; Tang, Langlang; Zhao, Minglin; Qiu, Yuyan; Chen, Yifan; He, Peimin

    2016-10-01

    Ulva prolifera can protect human skin fibroblast from being injured by hydrogen peroxide. This work studied the composition of Ulva prolifera polysaccharide and identified its physicochemical properties. The results showed that the cell proliferation of 0.5mg/mL crude polysaccharide was 154.4% of that in negative control group. Moreover, ROS detection indices, including DCFH-DA, GSH-PX, MDA and CAT, indicated that crude polysaccharide could improve cellular ability to scavenge free radical and decrease the injury on human skin fibroblast by hydrogen peroxide. In purified polysaccharide, the activity of fraction P1-1 was the highest, with 174.6% of that in negative control group. The average molecular weight of P1-1 was 137kD with 18.0% of sulfate content. This work showed the inhibition of hydrogen peroxide induced injuries on human skin fibroblast by Ulva prolifera polysaccharide, which may further evaluate the application of U. prolifera on cosmetics. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. Millimeter-wave emissivity as a metric for the non-contact diagnosis of human skin conditions.

    Science.gov (United States)

    Owda, Amani Yousef; Salmon, Neil; Harmer, Stuart William; Shylo, Sergiy; Bowring, Nicholas John; Rezgui, Nacer Ddine; Shah, Mamta

    2017-10-01

    A half-space electromagnetic model of human skin over the band 30-300 GHz was constructed and used to model radiometric emissivity. The model showed that the radiometric emissivity rose from 0.4 to 0.8 over this band, with emission being localized to a layer approximately one millimeter deep in the skin. Simulations of skin with differing water contents associated with psoriasis, eczema, malignancy, and thermal burn wounds indicated radiometry could be used as a non-contact technique to detect and monitor these conditions. The skin emissivity of a sample of 30 healthy volunteers, measured using a 95 GHz radiometer, was found to range from 0.2 to 0.7, and the experimental measurement uncertainty was ±0.002. Men on average were found to have an emissivity 0.046 higher than those of women, a measurement consistent with men having thicker skin than women. The regions of outer wrist and dorsal forearm, where skin is thicker, had emissivities 0.06-0.08 higher than the inner wrist and volar forearms where skin is generally thinner. Recommendations are made to develop a more sophisticated model of the skin and to collect larger data sets to obtain a deeper understanding of the signatures of human skin in the millimeter wave band. Bioelectromagnetics. 38:559-569, 2017. © 2017 The Authors. Bioelectromagnetics published by Wiley Periodicals, Inc. © 2017 The Authors. Bioelectromagnetics Published by Wiley Periodicals, Inc.

  10. Antimelanogenic Efficacy of Melasolv (3,4,5-Trimethoxycinnamate Thymol Ester) in Melanocytes and Three-Dimensional Human Skin Equivalent.

    Science.gov (United States)

    Lee, John Hwan; Lee, Eun-Soo; Bae, Il-Hong; Hwang, Jeong-Ah; Kim, Se-Hwa; Kim, Dae-Yong; Park, Nok-Hyun; Rho, Ho Sik; Kim, Yong Jin; Oh, Seong-Geun; Lee, Chang Seok

    2017-01-01

    Excessive melanogenesis often causes unaesthetic hyperpigmentation. In a previous report, our group introduced a newly synthesized depigmentary agent, Melasolv™ (3,4,5-trimethoxycinnamate thymol ester). In this study, we demonstrated the significant whitening efficacy of Melasolv using various melanocytes and human skin equivalents as in vitro experimental systems. The depigmentary effect of Melasolv was tested in melan-a cells (immortalized normal murine melanocytes), α-melanocyte-stimulating hormone (α-MSH)-stimulated B16 murine melanoma cells, primary normal human melanocytes (NHMs), and human skin equivalent (MelanoDerm). The whitening efficacy of Melasolv was further demonstrated by photography, time-lapse microscopy, Fontana-Masson (F&M) staining, and 2-photon microscopy. Melasolv significantly inhibited melanogenesis in the melan-a and α-MSH-stimulated B16 cells. In human systems, Melasolv also clearly showed a whitening effect in NHMs and human skin equivalent, reflecting a decrease in melanin content. F&M staining and 2-photon microscopy revealed that Melasolv suppressed melanin transfer into multiple epidermal layers from melanocytes as well as melanin synthesis in human skin equivalent. Our study showed that Melasolv clearly exerts a whitening effect on various melanocytes and human skin equivalent. These results suggest the possibility that Melasolv can be used as a depigmentary agent to treat pigmentary disorders as well as an active ingredient in cosmetics to increase whitening efficacy. © 2017 S. Karger AG, Basel.

  11. The importance of optical methods for non-invasive measurements in the skin care industry

    Science.gov (United States)

    Stamatas, Georgios N.

    2010-02-01

    Pharmaceutical and cosmetic industries are concerned with treating skin disease, as well as maintaining and promoting skin health. They are dealing with a unique tissue that defines our body in space. As such, skin provides not only the natural boundary with the environment inhibiting body dehydration as well as penetration of exogenous aggressors to the body, it is also ideally situated for optical measurements. A plurality of spectroscopic and imaging methods is being used to understand skin physiology and pathology and document the effects of topically applied products on the skin. The obvious advantage of such methods over traditional biopsy techniques is the ability to measure the cutaneous tissue in vivo and non-invasively. In this work, we will review such applications of various spectroscopy and imaging methods in skin research that is of interest the cosmetic and pharmaceutical industry. Examples will be given on the importance of optical techniques in acquiring new insights about acne pathogenesis and infant skin development.

  12. Radiation sterilization of skin allograft

    International Nuclear Information System (INIS)

    Kairiyama, E.; Horak, C.; Spinosa, M.; Pachado, J.; Schwint, O.

    2009-01-01

    In the treatment of burns or accidental loss of skin, cadaveric skin allografts provide an alternative to temporarily cover a wounded area. The skin bank facility is indispensable for burn care. The first human skin bank was established in Argentina in 1989; later, 3 more banks were established. A careful donor selection is carried out according to the national regulation in order to prevent transmissible diseases. As cadaveric human skin is naturally highly contaminated, a final sterilization is necessary to reach a sterility assurance level (SAL) of 10 -6 . The sterilization dose for 106 batches of processed human skin was determined on the basis of the Code of Practice for the Radiation Sterilization of Tissue Allografts: Requirements for Validation and Routine Control (2004) and ISO 11137-2 (2006). They ranged from 17.6 to 33.4 kGy for bioburdens of >10-162.700 CFU/100 cm 2 . The presence of Gram negative bacteria was checked for each produced batch. From the analysis of the experimental results, it was observed that the bioburden range was very wide and consequently the estimated sterilization doses too. If this is the case, the determination of a tissue-specific dose per production batch is necessary to achieve a specified requirement of SAL. Otherwise if the dose of 25 kGy is preselected, a standardized method for substantiation of this dose should be done to confirm the radiation sterilization process.

  13. Radiation sterilization of skin allograft

    Science.gov (United States)

    Kairiyama, E.; Horak, C.; Spinosa, M.; Pachado, J.; Schwint, O.

    2009-07-01

    In the treatment of burns or accidental loss of skin, cadaveric skin allografts provide an alternative to temporarily cover a wounded area. The skin bank facility is indispensable for burn care. The first human skin bank was established in Argentina in 1989; later, 3 more banks were established. A careful donor selection is carried out according to the national regulation in order to prevent transmissible diseases. As cadaveric human skin is naturally highly contaminated, a final sterilization is necessary to reach a sterility assurance level (SAL) of 10 -6. The sterilization dose for 106 batches of processed human skin was determined on the basis of the Code of Practice for the Radiation Sterilization of Tissue Allografts: Requirements for Validation and Routine Control (2004) and ISO 11137-2 (2006). They ranged from 17.6 to 33.4 kGy for bioburdens of >10-162.700 CFU/100 cm 2. The presence of Gram negative bacteria was checked for each produced batch. From the analysis of the experimental results, it was observed that the bioburden range was very wide and consequently the estimated sterilization doses too. If this is the case, the determination of a tissue-specific dose per production batch is necessary to achieve a specified requirement of SAL. Otherwise if the dose of 25 kGy is preselected, a standardized method for substantiation of this dose should be done to confirm the radiation sterilization process.

  14. How Does Chronic Cigarette Smoke Exposure Affect Human Skin? A Global Proteomics Study in Primary Human Keratinocytes.

    Science.gov (United States)

    Rajagopalan, Pavithra; Nanjappa, Vishalakshi; Raja, Remya; Jain, Ankit P; Mangalaparthi, Kiran K; Sathe, Gajanan J; Babu, Niraj; Patel, Krishna; Cavusoglu, Nükhet; Soeur, Jeremie; Pandey, Akhilesh; Roy, Nita; Breton, Lionel; Chatterjee, Aditi; Misra, Namita; Gowda, Harsha

    2016-11-01

    Cigarette smoking has been associated with multiple negative effects on human skin. Long-term physiological effects of cigarette smoke are through chronic and not acute exposure. Molecular alterations due to chronic exposure to cigarette smoke remain unclear. Primary human skin keratinocytes chronically exposed to cigarette smoke condensate (CSC) showed a decreased wound-healing capacity with an increased expression of NRF2 and MMP9. Using quantitative proteomics, we identified 4728 proteins, of which 105 proteins were overexpressed (≥2-fold) and 41 proteins were downregulated (≤2-fold) in primary skin keratinocytes chronically exposed to CSC. We observed an alteration in the expression of several proteins involved in maintenance of epithelial barrier integrity, including keratin 80 (5.3 fold, p value 2.5 × 10 -7 ), cystatin A (3.6-fold, p value 3.2 × 10 -3 ), and periplakin (2.4-fold, p value 1.2 × 10 -8 ). Increased expression of proteins associated with skin hydration, including caspase 14 (2.2-fold, p value 4.7 × 10 -2 ) and filaggrin (3.6-fold, p value 5.4 × 10 -7 ), was also observed. In addition, we report differential expression of several proteins, including adipogenesis regulatory factor (2.5-fold, p value 1.3 × 10 -3 ) and histone H1.0 (2.5-fold, p value 6.3 × 10 -3 ) that have not been reported earlier. Bioinformatics analyses demonstrated that proteins differentially expressed in response to CSC are largely related to oxidative stress, maintenance of skin integrity, and anti-inflammatory responses. Importantly, treatment with vitamin E, a widely used antioxidant, could partially rescue adverse effects of CSC exposure in primary skin keratinocytes. The utility of antioxidant-based new dermatological formulations in delaying or preventing skin aging and oxidative damages caused by chronic cigarette smoke exposure warrants further clinical investigations and multi-omics research.

  15. Steroid synthesis by primary human keratinocytes; implications for skin disease

    Energy Technology Data Exchange (ETDEWEB)

    Hannen, Rosalind F., E-mail: r.f.hannen@qmul.ac.uk [Centre for Cutaneous Research, Institute of Cell and Molecular Science, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London E1 2AT (United Kingdom); Michael, Anthony E. [Centre for Developmental and Endocrine Signalling, Academic Section of Obstetrics and Gynaecology, Division of Clinical Developmental Sciences, 3rd Floor, Lanesborough Wing, St. George' s, University of London, Cranmer Terrace, Tooting, London SW17 0RE (United Kingdom); Jaulim, Adil [Centre for Cutaneous Research, Institute of Cell and Molecular Science, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London E1 2AT (United Kingdom); Bhogal, Ranjit [Life Science, Unilever R and D Colworth House, Sharnbrook, Bedfordshire MK44 1LQ (United Kingdom); Burrin, Jacky M. [Centre for Endocrinology, William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London EC1M 6BQ (United Kingdom); Philpott, Michael P. [Centre for Cutaneous Research, Institute of Cell and Molecular Science, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London E1 2AT (United Kingdom)

    2011-01-07

    Research highlights: {yields} Primary keratinocytes express the steroid enzymes required for cortisol synthesis. {yields} Normal primary human keratinocytes can synthesise cortisol. {yields} Steroidogenic regulators, StAR and MLN64, are expressed in normal epidermis. {yields} StAR expression is down regulated in eczema and psoriatic epidermis. -- Abstract: Cortisol-based therapy is one of the most potent anti-inflammatory treatments available for skin conditions including psoriasis and atopic dermatitis. Previous studies have investigated the steroidogenic capabilities of keratinocytes, though none have demonstrated that these skin cells, which form up to 90% of the epidermis are able to synthesise cortisol. Here we demonstrate that primary human keratinocytes (PHK) express all the elements required for cortisol steroidogenesis and metabolise pregnenolone through each intermediate steroid to cortisol. We show that normal epidermis and cultured PHK express each of the enzymes (CYP11A1, CYP17A1, 3{beta}HSD1, CYP21 and CYP11B1) that are required for cortisol synthesis. These enzymes were shown to be metabolically active for cortisol synthesis since radiometric conversion assays traced the metabolism of [7-{sup 3}H]-pregnenolone through each steroid intermediate to [7-{sup 3}H]-cortisol in cultured PHK. Trilostane (a 3{beta}HSD1 inhibitor) and ketoconazole (a CYP17A1 inhibitor) blocked the metabolism of both pregnenolone and progesterone. Finally, we show that normal skin expresses two cholesterol transporters, steroidogenic acute regulatory protein (StAR), regarded as the rate-determining protein for steroid synthesis, and metastatic lymph node 64 (MLN64) whose function has been linked to cholesterol transport in steroidogenesis. The expression of StAR and MLN64 was aberrant in two skin disorders, psoriasis and atopic dermatitis, that are commonly treated with cortisol, suggesting dysregulation of epidermal steroid synthesis in these patients. Collectively these data

  16. Steroid synthesis by primary human keratinocytes; implications for skin disease

    International Nuclear Information System (INIS)

    Hannen, Rosalind F.; Michael, Anthony E.; Jaulim, Adil; Bhogal, Ranjit; Burrin, Jacky M.; Philpott, Michael P.

    2011-01-01

    Research highlights: → Primary keratinocytes express the steroid enzymes required for cortisol synthesis. → Normal primary human keratinocytes can synthesise cortisol. → Steroidogenic regulators, StAR and MLN64, are expressed in normal epidermis. → StAR expression is down regulated in eczema and psoriatic epidermis. -- Abstract: Cortisol-based therapy is one of the most potent anti-inflammatory treatments available for skin conditions including psoriasis and atopic dermatitis. Previous studies have investigated the steroidogenic capabilities of keratinocytes, though none have demonstrated that these skin cells, which form up to 90% of the epidermis are able to synthesise cortisol. Here we demonstrate that primary human keratinocytes (PHK) express all the elements required for cortisol steroidogenesis and metabolise pregnenolone through each intermediate steroid to cortisol. We show that normal epidermis and cultured PHK express each of the enzymes (CYP11A1, CYP17A1, 3βHSD1, CYP21 and CYP11B1) that are required for cortisol synthesis. These enzymes were shown to be metabolically active for cortisol synthesis since radiometric conversion assays traced the metabolism of [7- 3 H]-pregnenolone through each steroid intermediate to [7- 3 H]-cortisol in cultured PHK. Trilostane (a 3βHSD1 inhibitor) and ketoconazole (a CYP17A1 inhibitor) blocked the metabolism of both pregnenolone and progesterone. Finally, we show that normal skin expresses two cholesterol transporters, steroidogenic acute regulatory protein (StAR), regarded as the rate-determining protein for steroid synthesis, and metastatic lymph node 64 (MLN64) whose function has been linked to cholesterol transport in steroidogenesis. The expression of StAR and MLN64 was aberrant in two skin disorders, psoriasis and atopic dermatitis, that are commonly treated with cortisol, suggesting dysregulation of epidermal steroid synthesis in these patients. Collectively these data show that PHK are capable of extra

  17. Training of skin decontamination and its results

    International Nuclear Information System (INIS)

    Yasunaka, Hideo; Wadachi, Yoshiki.

    1976-01-01

    In the nuclear power and radioisotope handling facilities, one of the most important problems is a radioactive contamination on skin. Hand skin contamination occurs very often in the operation area and such surface contamination must be removed as soon as possible to prevent an internal contamination. From 1967 to 1975, training courses for skin decontamination had been held with total 536 of trainee based on the radiation protection manual at the Oarai Research Establishment of JAERI. In the training courses, fresh pig skin samples used instead of human skin were contaminated with 137 Cs, 131 I, 85 Sr, 60 Co, 144 Ce, 88 Y, 239 Pu, fission products and activated metal corrosion particles, respectively. These samples were washed practically by each trainee with the skin decontamination method recommended in the manual. Results obtained in the training showed that such training itself is a significant work and this skin decontamination method is an excellent first aid. (auth.)

  18. Human cell transformation in the study of sunlight-induced cancers in the skin of man

    International Nuclear Information System (INIS)

    Sutherland, B.M.; Bennett, P.V.

    1988-01-01

    Human cell transformation provides a powerful approach to understanding - at the cellular and molecular levels - induction of cancers in the skin of man. A principal approach to this problem is the direct transformation of human skin cells by exposure to ultraviolet and/or near-UV radiation. The frequency of human cells transformed to anchorage independence increases with radiation exposure; the relative transforming efficiencies of different wavelengths implies that direct absorption by nucleic acids is a primary initial event. Partial reversal of potential transforming lesions by photoreactivation suggests that pyrimidine dimers, as well as other lesions, are important in UV transformation of human cells. Human cells can also be transformed by transfection with cloned oncogenes, or with DNAs from tumors or tumor cell lines. Cells treated by the transfection procedure (but without DNA) or cells transfected with DNAs from normal mammalian cells or tissues show only background levels of transformation. Human cells can be transformed to anchorage-independent growth by DNAs ineffective in transformation of NIH 3T3 cells (including most human skin cancers), permitting the analysis of oncogenic molecular changes even in tumor DNAs difficult or impossible to analyze in rodent cell systems. 29 refs.; 4 figs.; 1 table

  19. First Insights into the Diverse Human Archaeome: Specific Detection of Archaea in the Gastrointestinal Tract, Lung, and Nose and on Skin

    Directory of Open Access Journals (Sweden)

    Kaisa Koskinen

    2017-11-01

    Full Text Available Human-associated archaea remain understudied in the field of microbiome research, although in particular methanogenic archaea were found to be regular commensals of the human gut, where they represent keystone species in metabolic processes. Knowledge on the abundance and diversity of human-associated archaea is extremely limited, and little is known about their function(s, their overall role in human health, or their association with parts of the human body other than the gastrointestinal tract and oral cavity. Currently, methodological issues impede the full assessment of the human archaeome, as bacteria-targeting protocols are unsuitable for characterization of the full spectrum of Archaea. The goal of this study was to establish conservative protocols based on specifically archaea-targeting, PCR-based methods to retrieve first insights into the archaeomes of the human gastrointestinal tract, lung, nose, and skin. Detection of Archaea was highly dependent on primer selection and the sequence processing pipeline used. Our results enabled us to retrieve a novel picture of the human archaeome, as we found for the first time Methanobacterium and Woesearchaeota (DPANN superphylum to be associated with the human gastrointestinal tract and the human lung, respectively. Similar to bacteria, human-associated archaeal communities were found to group biogeographically, forming (i the thaumarchaeal skin landscape, (ii the (methanoeuryarchaeal gastrointestinal tract, (iii a mixed skin-gastrointestinal tract landscape for the nose, and (iv a woesearchaeal lung landscape. On the basis of the protocols we used, we were able to detect unexpectedly high diversity of archaea associated with different body parts.

  20. Skin exposure to isocyanates: reasons for concern.

    Science.gov (United States)

    Bello, Dhimiter; Herrick, Christina A; Smith, Thomas J; Woskie, Susan R; Streicher, Robert P; Cullen, Mark R; Liu, Youcheng; Redlich, Carrie A

    2007-03-01

    Isocyanates (di- and poly-), important chemicals used worldwide to produce polyurethane products, are a leading cause of occupational asthma. Respiratory exposures have been reduced through improved hygiene controls and the use of less-volatile isocyanates. Yet isocyanate asthma continues to occur, not uncommonly in settings with minimal inhalation exposure but opportunity for skin exposure. In this review we evaluate the potential role of skin exposure in the development of isocyanate asthma. We reviewed the published animal and human literature on isocyanate skin-exposure methods, workplace skin exposure, skin absorption, and the role of skin exposure in isocyanate sensitization and asthma. We selected relevant articles from computerized searches on Medline, U.S. Environmental Protection Agency, Occupational Safety and Health Administration, National Institute for Occupational Safety and Health, and Google databases using the keywords "isocyanate," "asthma," "skin," "sensitization," and other synonymous terms, and our own extensive collection of isocyanate publications. Isocyanate production and use continues to increase as the polyurethane industry expands. There is substantial opportunity for isocyanate skin exposure in many work settings, but such exposure is challenging to quantify and continues to be underappreciated. Isocyanate skin exposure can occur at work, even with the use of personal protective equipment, and may also occur with consumer use of certain isocyanate products. In animals, isocyanate skin exposure is an efficient route to induce sensitization, with subsequent inhalation challenge resulting in asthma-like responses. Several lines of evidence support a similar role for human isocyanate skin exposure, namely, that such exposure occurs and can contribute to the development of isocyanate asthma in certain settings, presumably by inducing systemic sensitization. Integrated animal and human research is needed to better understand the role of skin

  1. Q-switched ruby laser irradiation of normal human skin. Histologic and ultrastructural findings.

    Science.gov (United States)

    Hruza, G J; Dover, J S; Flotte, T J; Goetschkes, M; Watanabe, S; Anderson, R R

    1991-12-01

    The Q-switched ruby laser is used for treatment of tatoos. The effects of Q-switched ruby laser pulses on sun-exposed and sun-protected human skin, as well as senile lentigines, were investigated with clinical observation, light microscopy, and transmission electron microscopy. A pinpricklike sensation occurred at radiant exposures as low as 0.2 J/cm2. Immediate erythema, delayed edema, and immediate whitening occurred with increasing radiant exposure. The threshold for immediate whitening varied inversely with skin pigmentation, ranging from a mean of 1.4 J/cm2 in lentigines to 3.1 J/cm2 in sun-protected skin. Transmission electron microscopy showed immediate alteration of mature melanosomes and nuclei within keratinocytes and melanocytes, but stage I and II melanosomes were unaffected. Histologically, immediate injury was confined to the epidermis. There was minimal inflammatory response 1 day after exposure. After 1 week, subthreshold exposures induced hyperpigmentation, with epidermal hyperplasia and increased melanin staining noted histologically. At higher radiant exposures, hypopigmentation occurred with desquamation of a pigmented scale/crust. All sites returned to normal skin color and texture without scarring within 3 to 6 months. These observations suggest that the human skin response to selective photothermolysis of pigmented cells is similar to that reported in animal models, including low radiant exposure stimulation of melanogenesis and high radiant exposure lethal injury to pigmented epidermal cells.

  2. Superresolution and Fluorescence Dynamics Evidence Reveal That Intact Liposomes Do Not Cross the Human Skin Barrier.

    Directory of Open Access Journals (Sweden)

    Jes Dreier

    Full Text Available In this study we use the combination of super resolution optical microscopy and raster image correlation spectroscopy (RICS to study the mechanism of action of liposomes as transdermal drug delivery systems in human skin. Two different compositions of liposomes were applied to newly excised human skin, a POPC liposome and a more flexible liposome containing the surfactant sodium cholate. Stimulated emission depletion microscopy (STED images of intact skin and cryo-sections of skin treated with labeled liposomes were recorded displaying an optical resolution low enough to resolve the 100 nm liposomes in the skin. The images revealed that virtually none of the liposomes remained intact beneath the skin surface. RICS two color cross correlation diffusion measurements of double labeled liposomes confirmed these observations. Our results suggest that the liposomes do not act as carriers that transport their cargo directly through the skin barrier, but mainly burst and fuse with the outer lipid layers of the stratum corneum. It was also found that the flexible liposomes showed a greater delivery of the fluorophore into the stratum corneum, indicating that they functioned as chemical permeability enhancers.

  3. [The advantages in using cyanoacrylate glue over skin staples as a method of skin graft fixation in the pediatric burns population].

    Science.gov (United States)

    Curings, P; Vincent, P-L; Viard, R; Gir, P; Comparin, J-P; Voulliaume, D

    2017-11-23

    Local postoperative care and burn wound management can present with a certain degree of difficulty in the pediatric population. While the use of skin staples as a method of skin graft fixation is a well-known, rapid and simple method, their removal can be painful and may necessitate some sedation or even general anesthesia. We studied in this article the advantages and economic value of using the cyanoacrylate glue as a fixation method for skin grafts. A comparative study was carried out from 2012 to 2016. Hundred and eighteen infants with burns up to 5% of total body surface area were included in the study. Seventy-two infants had split thickness skin grafts fixed with skin staples. Forty-six infants had split thickness skin grafts fixed with cyanoacrylate glue. We compared the quality of graft, the sedation used during the first postoperative dressing, the length of hospital stay, the amount of glue used and the presence of complications. There is a difference between the two groups studied in terms of age and total burn surface area. The rate of graft take was 100% in both groups. The first postoperative dressing was carried out without the use of powerful analgesia in the cyanoacrylate group, while it was necessary to use general anesthesia in 64% of the skin staples group. The average length of stay in hospital after skin grafting was 4.9 days for the cyanoacrylate glue versus 6.5 days in the skin staples group. No complications were noted in the 2 groups. The use of cyanoacrylate glue allows rapid fixation of skin grafts and avoid general anesthesia for postoperative cares. Subsequently the length of hospital stay is reduced within 25%. The medico-economic value of glue protocol is highly significant compared to skin staples, while having similar good results and without significant problems. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  4. Supraclavicular skin temperature as a measure of 18F-FDG uptake by BAT in human subjects.

    Science.gov (United States)

    Boon, Mariëtte R; Bakker, Leontine E H; van der Linden, Rianne A D; Pereira Arias-Bouda, Lenka; Smit, Frits; Verberne, Hein J; van Marken Lichtenbelt, Wouter D; Jazet, Ingrid M; Rensen, Patrick C N

    2014-01-01

    Brown adipose tissue (BAT) has emerged as a novel player in energy homeostasis in humans and is considered a potential new target for combating obesity and related diseases. The current 'gold standard' for quantification of BAT volume and activity is cold-induced 18F-FDG uptake in BAT. However, use of this technique is limited by cost and radiation exposure. Given the fact that BAT is a thermogenic tissue, mainly located in the supraclavicular region, the aim of the current study was to investigate whether cold-induced supraclavicular skin temperature and core body temperature may be alternative markers of BAT activation in humans. BAT volume and activity were measured in 24 healthy lean adolescent males (mean age 24.1±0.8 years), using cold-induced 18F-FDG uptake with PET-CT. Core body temperature was measured continuously in the small intestine with use of an ingestible telemetric capsule and skin temperature was measured by eighteen wireless iButtons attached to the skin following ISO-defined locations. Proximal and distal (hand/feet) skin temperatures markedly decreased upon cold exposure, while supraclavicular skin temperature significantly increased (35.2±0.1 vs. 35.5±0.1°C, p = 0.001). Furthermore, cold-induced supraclavicular skin temperature positively correlated with both total (R2 = 0.28, P = 0.010) and clavicular BAT volume (R2 = 0.20, P = 0.030) and clavicular SUVmax (R2 = 0.27, P = 0.010), while core body temperature did not. Supraclavicular skin temperature as measured by iButtons may have predictive value for BAT detection in adult humans. This is highly desirable considering the increasing interest in pharmacological interventions to stimulate BAT in human subjects. NTR 2473.

  5. Permeation of platinum and rhodium nanoparticles through intact and damaged human skin

    International Nuclear Information System (INIS)

    Mauro, Marcella; Crosera, Matteo; Bianco, Carlotta; Adami, Gianpiero; Montini, Tiziano; Fornasiero, Paolo; Jaganjac, Morana; Bovenzi, Massimo; Filon, Francesca Larese

    2015-01-01

    The aim of the study was to evaluate percutaneous penetration of platinum and rhodium nanoparticles (PtNPs: 5.8 ± 0.9 nm, RhNPs: 5.3 ± 1.9 nm) through human skin. Salts compounds of these metals are sensitizers and some also carcinogenic agents. In vitro permeation experiments were performed using Franz diffusion cells with intact and damaged skin. PtNPs and RhNPs, stabilized with polyvinylpyrrolidone, were synthesized by reduction of Na 2 PtC l6 and RhCl 3 ·3H 2 O respectively. Suspensions with a concentration of 2.0 g/L of PtNPs and RhNPs were dispersed separately in synthetic sweat at pH 4.5 and applied as donor phases to the outer surface of the skin for 24 h. Measurements of the content of the metals in the receiving solution and in the skin were performed subsequently. Rhodium skin permeation was demonstrated through damaged skin, with a permeation flux of 0.04 ± 0.04 μg cm −2  h −1 and a lag time of 7.9 ± 1.1 h, while no traces of platinum were found in receiving solutions. Platinum and rhodium skin-analysis showed significantly higher concentrations of the metals in damaged skin. Rh and Pt applied as NPs can penetrate the skin barrier and Rh can be found in receiving solutions. These experiments pointed out the need for skin contamination prevention, since even a minor injury to the skin barrier can significantly increase penetration

  6. Permeation of platinum and rhodium nanoparticles through intact and damaged human skin

    Energy Technology Data Exchange (ETDEWEB)

    Mauro, Marcella [University of Trieste, Clinical Unit of Occupational Medicine, Department of Medical Sciences (Italy); Crosera, Matteo; Bianco, Carlotta; Adami, Gianpiero; Montini, Tiziano; Fornasiero, Paolo [University of Trieste, Department of Chemical and Pharmaceutical Sciences (Italy); Jaganjac, Morana [Rudjer Boskovic Institute, Laboratory for Oxidative Stress, Department of Molecular Medicine (Croatia); Bovenzi, Massimo; Filon, Francesca Larese, E-mail: larese@units.it [University of Trieste, Clinical Unit of Occupational Medicine, Department of Medical Sciences (Italy)

    2015-06-15

    The aim of the study was to evaluate percutaneous penetration of platinum and rhodium nanoparticles (PtNPs: 5.8 ± 0.9 nm, RhNPs: 5.3 ± 1.9 nm) through human skin. Salts compounds of these metals are sensitizers and some also carcinogenic agents. In vitro permeation experiments were performed using Franz diffusion cells with intact and damaged skin. PtNPs and RhNPs, stabilized with polyvinylpyrrolidone, were synthesized by reduction of Na{sub 2}PtC{sub l6} and RhCl{sub 3}·3H{sub 2}O respectively. Suspensions with a concentration of 2.0 g/L of PtNPs and RhNPs were dispersed separately in synthetic sweat at pH 4.5 and applied as donor phases to the outer surface of the skin for 24 h. Measurements of the content of the metals in the receiving solution and in the skin were performed subsequently. Rhodium skin permeation was demonstrated through damaged skin, with a permeation flux of 0.04 ± 0.04 μg cm{sup −2} h{sup −1} and a lag time of 7.9 ± 1.1 h, while no traces of platinum were found in receiving solutions. Platinum and rhodium skin-analysis showed significantly higher concentrations of the metals in damaged skin. Rh and Pt applied as NPs can penetrate the skin barrier and Rh can be found in receiving solutions. These experiments pointed out the need for skin contamination prevention, since even a minor injury to the skin barrier can significantly increase penetration.

  7. Using a portable terahertz spectrometer to measure the optical properties of in vivo human skin

    Science.gov (United States)

    Echchgadda, Ibtissam; Grundt, Jessica A.; Tarango, Melissa; Ibey, Bennett L.; Tongue, Thomas; Liang, Min; Xin, Hao; Wilmink, Gerald J.

    2013-12-01

    Terahertz (THz) time-domain spectroscopy systems permit the measurement of a tissue's hydration level. This feature makes THz spectrometers excellent tools for the noninvasive assessment of skin; however, current systems are large, heavy and not ideal for clinical settings. We previously demonstrated that a portable, compact THz spectrometer permitted measurement of porcine skin optical properties that were comparable to those collected with conventional systems. In order to move toward human use of this system, the goal for this study was to measure the absorption coefficient (μa) and index of refraction (n) of human subjects in vivo. Spectra were collected from 0.1 to 2 THz, and measurements were made from skin at three sites: the palm, ventral and dorsal forearm. Additionally, we used a multiprobe adapter system to measure each subject's skin hydration levels, transepidermal water loss, and melanin concentration. Our results suggest that the measured optical properties varied considerably for skin tissues that exhibited dissimilar hydration levels. These data provide a framework for using compact THz spectrometers for clinical applications.

  8. Reconstruction of segmented human voxel phantoms for skin dosimetry

    International Nuclear Information System (INIS)

    Antunes, Paula C.G.; Siqueira, Paulo de Tarso D.; Yoriyaz, Helio; Fonseca, Gabriel P.; Reis, Gabriela; Furnari, Laura

    2009-01-01