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Sample records for human skin in-vivo

  1. In vivo friction properties of human skin.

    PubMed

    Zhang, M; Mak, A F

    1999-08-01

    In vivo frictional properties of human skin and five materials, namely aluminium, nylon, silicone, cotton sock, Pelite, were investigated. Normal and untreated skin over six anatomic regions of ten normal subjects were measured under a controlled environment. The average coefficient of friction for all measurements is 0.46+/-0.15 (p<0.05). Among all measured sites, the palm of the hand has the highest coefficient of friction (0.62+/-0.22). For all the materials tested, silicone has the highest coefficient of friction (0.61+/-0.21), while nylon has the lowest friction (0.37+/-0.09). PMID:10493141

  2. Spectral reflectance of human skin in vivo.

    PubMed

    Andersen, P H; Bjerring, P

    1990-02-01

    A newly developed skin reflectance spectrophotometer was evaluated for measurements of both melanin pigmentation and erythema. Physiological changes in blood flow and blood content in normal humans were induced by compression with an arm cuff during recording of skin reflectance spectra. Reflectance spectra of UV-induced erythema were also recorded and compared with laser-Doppler flow measurements. Spectral reflectance measurements were found to be highly sensitive in determining minimal erythema, which was not clinically detectable. The measurements of erythema using reflectance spectroscopy and UV irradiation were very highly correlated (r = 0.996). It was possible to calculate the in vivo absorbance of oxygenized haemoglobin. The melanin pigmentation following UV irradiation was quantified by reflectance spectroscopy and correlates highly with the dose of UV irradiation (r = 0.995). Furthermore, regional variations in skin melanin and haemoglobin were analysed for fair Caucasian skin. PMID:2196543

  3. OCT monitoring of cosmetic creams in human skin in vivo

    NASA Astrophysics Data System (ADS)

    Han, Seung Hee; Yoon, Chang Han; Conroy, Leigh; Vitkin, I. Alex

    2012-02-01

    Optical coherence tomography (OCT) is a tool currently used for noninvasive diagnosis of human disease as well as for monitoring treatment during or after therapy. In this study, OCT was used to examine penetration and accumulation of cosmetic creams on human hand skin. The samples varied in collagen content with one formulation containing soluble collagen as its primary active ingredient. Collagen is a major connective tissue protein that is essential in maintaining health vitality and strength of many organs. The penetration and localization of collagen in cosmetic creams is thought to be the main determinant of the efficacy of new collagen synthesis. Detection and quantification of collagen in cosmetic creams applied to skin may thus help predict the eventual efficacy of the product in skin collagen regeneration. We hypothesize that the topically applied collagen may be detectable by OCT through its modulation of skin scattering properties. To test this hypothesis, we used a FDML swept-source optical coherence tomography (SS-OCT) system. A particular location on the skin of two male adult volunteers was used to investigate 4 different cosmetic creams. The duration of OCT monitoring of cosmetic penetration into skin ranged from 5 minutes to 2 hours following topical application. The results showed that OCT can discriminate between a cream with collagen and other collagen-free formulations. Thus it seems feasible that OCT intensity can monitor the in vivo effects of topical application of collagen contained in cosmetic formulations.

  4. In vivo optical coherence tomography of human skin microstructure

    NASA Astrophysics Data System (ADS)

    Sergeev, Alexander M.; Gelikonov, Valentin M.; Gelikonov, Grigory V.; Feldchtein, Felix I.; Pravdenko, Kirill I.; Shabanov, Dmitry V.; Gladkova, Natalia D.; Pochinko, Vitaly; Zhegalov, V.; Dmitriev, G.; Vazina, I.; Petrova, Galina P.; Nikulin, Nikolai K.

    1994-12-01

    A compact effective optical coherence tomography (OCT) system is presented. It contains approximately equals 0.3 mW superluminescent diode with spectral width 30 nm FWHM (providing approximately equals 15 micrometers longitudinal resolution) and fiber interferometer with integrated longitudinal scanning. The dynamic range 60 dB allows to observe structure of human skin in vivo up to 1.5 mm in depth. A comparison of obtained tomographs with data of histologic analysis of the same samples of the skin have been carried out to identify the observed structures and determine their optical properties. This technique allows one to perform noncontact, noninvasive diagnostic of early stages of different pathological state of the skin, to measure the burn depth and to observe the process of the recovery. Unlike scanning confocal microscopy, OCT is more suitable for an endoscopic investigation of the mucous membranes of hollow organs. Possible diagnostic applications include dermatology, gastroenterology, gynecology, urology, oncology, othorinolaryngology, transplantology. The most promising features are the potential possibility of differential diagnosis of precancer and various types of cancer, estimation of the invasion depth, differential diagnosis of inflammation and dystrophic processes, control of radical operative treatment.

  5. In vivo multiscale photoacoustic microscopy of human skin

    NASA Astrophysics Data System (ADS)

    Favazza, Christopher P.; Hu, Song; Huang, Victor; Jassim, Omar; Cornelius, Lynn A.; Wang, Lihong V.

    2011-03-01

    Scalability is a key feature of photoacoustic microscopy (PAM). Reports have shown that PAM systems can be designed to possess sub-micron resolution at shallow depths or penetrate centimeters deep at the expense of resolution while the number of resolved pixels in the depth direction remains high. This capability to readily tune the imaging parameters while maintaining the same inherent contrast could be extremely useful for a variety of biomedical applications. Human skin, with its layered vascular structure whose dimensions scale with depth, provides an ideal imaging target to illustrate this advantage. Here, we present results from in vivo human skin imaging experiments using two different PAM systems, an approach which enables better characterization of the cutaneous microvasculature throughout the imaging depth. Specifically, we show images from several distinct areas of skin: the palm and the forearm. For each region, the same area was imaged with both an optical-resolution PAM (OR-PAM) and an acoustic-resolution PAM (AR-PAM), and the subsequent images were combined into composite images. The OR-PAM provides less than 5 μm lateral resolution, capable of imaging the smallest capillary vessels, while the AR-PAM enables imaging at depths of several millimeters. Several structures are identifiable in the ORPAM images which cannot be differentiated in AR-PAM images, namely thin epidermal and stratum corneum layers, undulations in the dermal papillae, and capillary loops. However, the AR-PAM provides images of larger vessels, deeper than the OR-PAM can penetrate. These results demonstrate how PAM's scalability can be utilized to more fully characterize cutaneous vasculature, potentially impacting the assessment of numerous cardiovascular related and cutaneous diseases.

  6. In vivo non-invasive multiphoton tomography of human skin

    NASA Astrophysics Data System (ADS)

    König, Karsten; Riemann, Iris; Ehlers, Alexander; Le Harzic, Ronan

    2005-10-01

    High resolution non-invasive 3D imaging devices are required to detect pathogenic microorganisms such as Anthrax spores, bacteria, viruses, fungi and chemical agents entering biological tissues such as the epidermis. Due to the low light penetration depth and the biodamage potential, ultraviolet light sources can not be employed to realize intratissue imaging of bio- and chemohazards. We report on the novel near infrared laser technology multiphoton tomography and the high resolution 4D imaging tool DermaInspect for non-invasive detection of intratissue agents and their influence on cellular metabolism based on multiphoton autofluorescence imaging (MAI) and second harmonic generation (SHG). Femtosecond laser pulses in the spectral range of 750 nm to 850 nm have been used to image in vivo human skin with subcellular spatial and picosecond temporal resolution. The non-linear induced autofluorescence of both, skin tissues and microorganisms, originates mainly from naturally endogenous fluorophores/protein structures like NAD(P)H, flavins, keratin, collagen, elastin, porphyrins and melanin. Bacteria emit in the blue/green spectral range due to NAD(P)H and flavoproteins and, in certain cases, in the red spectral range due to the biosynthesis of Zn-porphyrins, coproporphyrin and protoporphyrin. Collagen and exogenous non-centrosymmetric molecules can be detected by SHG signals. The system DermaInspect consists of a wavelength-tunable compact 80/90 MHz Ti:sapphire laser, a scan module with galvo scan mirrors, piezo-driven objective, fast photon detector and time-resolved single photon counting unit. It can be used to perform optical sectioning and 3D autofluorescence lifetime imaging (τ-mapping) with 1 μm spatial resolution and 270 ps temporal resolution. The parameter fluorescence lifetime depends on the type of fluorophore and its microenvironment and can be used to distinguish bio- and chemohazards from cellular background and to gain information for pathogen

  7. Spectral characteristics of two-photon autofluorescence and second harmonic generation from human skin in vivo

    NASA Astrophysics Data System (ADS)

    Breunig, Hans G.; König, Karsten

    2011-03-01

    We performed multiphoton imaging of human skin and recorded in combination the complete spectral content of the signals in vivo. The spectra represent the integration of multiphoton signals over the investigated regions of the epidermis and dermis. They are used to study depth-resolved in vivo emission characteristics of main endogenous skin fluorophores like keratin, NAD(P)H, collagen and elastin. The identification of the specific fluorophores is supported by analysis of additional in vivo fluorescence lifetime imaging. Furthermore, as a potential application of spectrally selective imaging the possibility to investigate the penetration of nanoparticles from sunscreen lotion into skin in vivo is discussed.

  8. In vivo time-resolved autofluorescence measurements on human skin

    NASA Astrophysics Data System (ADS)

    Katika, Kamal M.; Pilon, Laurent; Dipple, Katrina; Levin, Seymour; Blackwell, Jennifer; Berberoglu, Halil

    2006-02-01

    In this paper we present preliminary results obtained from fluorescence lifetime measurements on human skin using time-correlated single photon counting (TCSPC) techniques. Human skin was exposed to light from a pulsed LED of 700 ps pulse width at a wavelength of 375 nm and fluorescence decays were recorded at four different emission wavelengths (442, 460, 478 and 496 nm) using a photomultiplier tube (PMT) coupled to a monochromator. Measurements were carried out on the left and right palms of subjects recruited for the study after obtaining consent using a UCLA IRB approved consent form. The subjects recruited consisted of 18 males and 17 females with different skin complexions and ages ranging from 10 to 70 years. In addition, a set of experiments were also performed on various locations including the palm, the arm and the cheek of a Caucasian subject. The fluorescence decays thus obtained were fit to a three-exponential decay model in all cases and were approximately 0.4, 2.7 and 9.4 ns, respectively. The variations in these lifetimes with location, gender, skin complexion and age are studied. It is speculated that the shorter lifetimes correspond to free and bound NADH while the longer lifetime is due to AGE crosslinks.

  9. Biophysical study of porcine ear skin in vitro and its comparison to human skin in vivo.

    PubMed

    Sekkat, N; Kalia, Y N; Guy, R H

    2002-11-01

    The goal of this work was to establish, using biophysical characterization, that porcine ear skin in vitro is a valid model for its human counterpart. Specifically, stratum corneum (SC) barrier function was evaluated during its progressive removal by adhesive tape-stripping using the techniques of transepidermal water loss (TEWL) and impedance spectroscopy. TEWL increased slowly at first and then more rapidly with the degree of SC impairment. In contrast, low-frequency skin impedance declined exponentially as a function of progressive SC removal. The methods provide complementary and correlated information about SC barrier function. Biophysical parameters, including the diffusivity and permeability coefficient of water across the SC, and the thickness of the barrier were determined from the TEWL data using Fick's first law of diffusion. Furthermore, an ionic partition coefficient-mobility product was estimated from the skin impedance measurements. Comparison of the results with those previously reported for human skin in vivo strongly supports the validity of the porcine membrane as an in vitro model. PMID:12379922

  10. Laser system for optical biopsy and in-vivo study of the human skin

    NASA Astrophysics Data System (ADS)

    Borisova, Ekaterina G.; Avramov, Lachezar A.

    2001-04-01

    The aim of this study was to perform a preliminary evaluation of the diagnostic potential of noninvasive laser-induced autofluorescence spectroscopy (LIAFS) for human skin in vivo. The autofluorescence characterization of tissue relies on different spectral properties of tissue. It was demonstrated a differentiation between normal skin and skin with vitaligo. In our experimental investigation of the autofluorescence spectrum of human skin in vivo a nitrogen laser with excitation wavelength 337 nm was used. Two fluorescence bands were observed at 440 and 490 nm, these were attributed to reduced nicotinamide adenine dinucleotide (NADH) and collagen. The intensity of the NADH emission band was markedly reduced in the skin with vitaligo compared with the normal skin, which could indicate different redox conditions in skin with vitaligo. The autofluorescence spectrum of human skin depends on the main internal absorbers, which are blood and melanin. In this study was described the effect caused by melanin content on the shape of the autofluorescence 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. The goal of this work is optimization of detection and diagnosis of hollow organs and skin.

  11. Contribution to the Determination of In Vivo Mechanical Characteristics of Human Skin by Indentation Test

    PubMed Central

    Zahouani, Hassan

    2013-01-01

    This paper proposes a triphasic model of intact skin in vivo based on a general phenomenological thermohydromechanical and physicochemical (THMPC) approach of heterogeneous media. The skin is seen here as a deforming stratified medium composed of four layers and made out of different fluid-saturated materials which contain also an ionic component. All the layers are treated as linear, isotropic materials described by their own behaviour law. The numerical simulations of in vivo indentation test performed on human skin are given. The numerical results correlate reasonably well with the typical observations of indented human skin. The discussion shows the versatility of this approach to obtain a better understanding on the mechanical behaviour of human skin layers separately. PMID:24324525

  12. In vivo optical elastography: stress and strain imaging of human skin lesions

    NASA Astrophysics Data System (ADS)

    Es'haghian, Shaghayegh; Gong, Peijun; Kennedy, Kelsey M.; Wijesinghe, Philip; Sampson, David D.; McLaughlin, Robert A.; Kennedy, Brendan F.

    2015-03-01

    Probing the mechanical properties of skin at high resolution could aid in the assessment of skin pathologies by, for example, detecting the extent of cancerous skin lesions and assessing pathology in burn scars. Here, we present two elastography techniques based on optical coherence tomography (OCT) to probe the local mechanical properties of skin. The first technique, optical palpation, is a high-resolution tactile imaging technique, which uses a complaint silicone layer positioned on the tissue surface to measure spatially-resolved stress imparted by compressive loading. We assess the performance of optical palpation, using a handheld imaging probe on a skin-mimicking phantom, and demonstrate its use on human skin. The second technique is a strain imaging technique, phase-sensitive compression OCE that maps depth-resolved mechanical variations within skin. We show preliminary results of in vivo phase-sensitive compression OCE on a human skin lesion.

  13. In vivo confocal Raman spectroscopy study of the vitamin A derivative perfusion through human skin

    NASA Astrophysics Data System (ADS)

    dos Santos, Laurita; Téllez Soto, Claudio A.; Favero, Priscila P.; Martin, Airton A.

    2016-03-01

    In vivo confocal Raman spectroscopy is a powerful non-invasive technique able to analyse the skin constituents. This technique was applied to transdermal perfusion studies of the vitamin A derivative in human skin. The composition of the stratum corneum (lipid bilayer) is decisive for the affinity and transport of the vitamin through skin. The vitamin A is significantly absorbed by human skin when applied with water in oil emulsion or hydro-alcoholic gel. The purpose of this study is to elucidate the behaviour of vitamin A derivative into human skin without the presence of enhancers. The results showed that the intensity band of the derivative (around 1600 cm-1), which represents the -C=O vibrational mode, was detected in different stratum corneum depths (up to 20 μm). This Raman peak of vitamin A derivative has non-coincident band with the Raman spectra of the skin epidermis, demonstrating that compound penetrated in forearm skin.

  14. Dynamic in vivo mapping of model moisturiser ingress into human skin by GARfield MRI.

    PubMed

    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. PMID:20842757

  15. OCT-based label-free in vivo lymphangiography within human skin and areola

    PubMed Central

    Baran, Utku; Qin, Wan; Qi, Xiaoli; Kalkan, Goknur; Wang, Ruikang K.

    2016-01-01

    Due to the limitations of current imaging techniques, visualization of lymphatic capillaries within tissue in vivo has been challenging. Here, we present a label-free high resolution optical coherence tomography (OCT) based lymphangiography (OLAG) within human skin in vivo. OLAG enables rapid (~seconds) mapping of lymphatic networks, along with blood vessel networks, over 8 mm x 8 mm of human skin and 5 mm x 5 mm of human areola. Moreover, lymphatic system’s response to inflammation within human skin is monitored throughout an acne lesion development over 7 days. The demonstrated results promise OLAG as a revolutionary tool in the clinical research and treatment of patients with pathologic conditions such as cancer, diabetes, and autoimmune diseases. PMID:26892830

  16. OCT-based label-free in vivo lymphangiography within human skin and areola

    NASA Astrophysics Data System (ADS)

    Baran, Utku; Qin, Wan; Qi, Xiaoli; Kalkan, Goknur; Wang, Ruikang K.

    2016-02-01

    Due to the limitations of current imaging techniques, visualization of lymphatic capillaries within tissue in vivo has been challenging. Here, we present a label-free high resolution optical coherence tomography (OCT) based lymphangiography (OLAG) within human skin in vivo. OLAG enables rapid (~seconds) mapping of lymphatic networks, along with blood vessel networks, over 8 mm x 8 mm of human skin and 5 mm x 5 mm of human areola. Moreover, lymphatic system’s response to inflammation within human skin is monitored throughout an acne lesion development over 7 days. The demonstrated results promise OLAG as a revolutionary tool in the clinical research and treatment of patients with pathologic conditions such as cancer, diabetes, and autoimmune diseases.

  17. OCT-based label-free in vivo lymphangiography within human skin and areola.

    PubMed

    Baran, Utku; Qin, Wan; Qi, Xiaoli; Kalkan, Goknur; Wang, Ruikang K

    2016-01-01

    Due to the limitations of current imaging techniques, visualization of lymphatic capillaries within tissue in vivo has been challenging. Here, we present a label-free high resolution optical coherence tomography (OCT) based lymphangiography (OLAG) within human skin in vivo. OLAG enables rapid (~seconds) mapping of lymphatic networks, along with blood vessel networks, over 8 mm x 8 mm of human skin and 5 mm x 5 mm of human areola. Moreover, lymphatic system's response to inflammation within human skin is monitored throughout an acne lesion development over 7 days. The demonstrated results promise OLAG as a revolutionary tool in the clinical research and treatment of patients with pathologic conditions such as cancer, diabetes, and autoimmune diseases. PMID:26892830

  18. Application of the front detection photopiroelectric configuration to the study of in vivo human skin

    NASA Astrophysics Data System (ADS)

    Gutierrez-Juarez, G.; Pichardo-Molina, J. L.; Rocha-Osornio, L. N.; Huerta-Franco, R.; Ivanov, R.; Huerta-Franco, B.; Cordova-Fraga, T.; Vargas-Luna, M.

    2005-06-01

    We report a novel method for measurements in vivo of the penetration of topically applied substances by inverse photopyroelectric configuration. This configuration was used to obtain the thermal effusivity, as a function of time, of in vivo human skin with ointments. This thermal magnitude was employed to characterize the penetration on the anterior-face of the volunteers forearm. This thermal effusivity was fitted with an exponential function in order to obtain a parameter (characteristic time) for the penetration. The substances used were a sunscreen and Vick Vaporub ointment. We found that the sunscreen have a characteristic time bigger that the Vick Vaporub ointment. The feasibility of skin hydration studies are discussed.

  19. Biomechanical Properties of In Vivo Human Skin From Dynamic Optical Coherence Elastography

    PubMed Central

    Liang, Xing

    2013-01-01

    Dynamic optical coherence elastography is used to determine in vivo skin biomechanical properties based on mechanical surface wave propagation. Quantitative Young’s moduli are measured on human skin from different sites, orientations, and frequencies. Skin thicknesses, including measurements from different layers, are also measured simultaneously. Experimental results show significant differences among measurements from different skin sites, between directions parallel and orthogonal to Langer’s lines, and under different skin hydration states. Results also suggest surface waves with different driving frequencies represent skin biomechanical properties from different layers in depth. With features such as micrometer-scale resolution, noninvasive imaging, and real-time processing from the optical coherence tomography technology, this optical measurement technique has great potential for measuring skin biomechanical properties in dermatology. PMID:19822464

  20. In vivo analysis of human skin anisotropy by polarization-sensitive optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Sakai, Shingo; Yamanari, Masahiro; Lim, Yiheng; Makita, Shuichi; Nakagawa, Noriaki; Yasuno, Yoshiaki

    2011-03-01

    Skin anisotropy is an important issue for plastic surgeons and cosmetics science. Cleavage lines, such as Langer's lines and relaxed skin tension lines (RSTLs), have been proposed as keys to understanding skin anisotropy. Collagen, a dominant dermal structural protein, forms a fibrous structure believed to play an important role in skin anisotropy. There have been few reports, however, on the relationship between the orientation of collagen fiber and the direction of the cleavage line. Collagen fiber has birefringence, a property analyzable in skin in three dimensions by high-speed polarization-sensitive optical coherence tomography (PS-OCT). Here we used PS-OCT for an in vivo analysis of anisotropic changes in the dermal birefringence of mechanically deformed human skin. The dermal birefringence of the forehead increased significantly when the skin was shrunk perpendicular to the RSTL and increased significantly when the skin was shrunk parallel to the RSTL. En-face images of dermal birefringence revealed that both shrinking perpendicular to and stretching in parallel to the RSTL promoted the formation of a macro rope-like collagen structure. Moreover, the birefringent change under shrinking conditions perpendicular to the RSTL showed negative correlation to Ra, a skin roughness parameter. These results suggest that PS-OCT enables the in vivo evaluation of skin anisotropy.

  1. In vivo multimodality video microscopy of human skin in the vertical plane (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Wu, Zhenguo; Tian, Yunxian; Zhao, Jianhua; Lui, Harvey; McLean, David I.; Zeng, Haishan

    2016-02-01

    Reflectance confocal microscopy (RCM) and multiphoton microscopy (MPM) are non-invasive methods of acquiring morphological images of the skin in vivo. Most research in this area focuses on instruments that are configured for two-dimensional imaging in a horizontal plane parallel to the skin surface. In contrast, conventional histopathologic evaluation of the skin is based on vertical tissue sections that show microscopic features and their interrelationships according to their depth within the skin. The ability to similarly depict the skin in the vertical plane during in vivo microscopic imaging poses several significant challenges with respect to imaging speed, resolution and extractable information. Aiming to address above challenges, we developed a laser scanning multimodal microscopy system which combines RCM and MPM, and has the ability to do fast xz scanning to achieve high resolution vertical "optical sectioning" of in vivo human skin at video rates. RCM and MPM images are obtained simultaneously and co-registered thereby providing complementary morphological information. To validate the performance of this system vertical section RCM and MPM microscopic images of normal human skin in vivo were obtained at half video rates (15 frames/s). Using our system it is possible to discern the following structures: all layers of the epidermis including the stratum lucidum, the dermal-epidermal junction, and the papillary dermis. Blood flow is also visible as evidenced by blood cell movement within vessels. The effective imaging depth is about 200 micrometers. This system provides a means of interrogating human skin noninvasively at an orientation analogous to conventional histological sectioning.

  2. Excision repair of UV-induced pyrimidine dimers in human skin in vivo

    SciTech Connect

    D'Ambrosio, S.M.; Slazinski, L.; Whetstone, J.W.; Lowney, E.

    1981-09-01

    The induction and loss of pyrimidine dimers in human skin in vivo was determined using UV endonuclease, alkaline sucrose sedimentations, and the fluorescent detection of nonradiolabeled DNA. The number of dimers induced following exposure of the skin to radiation emitted from a Burdick UV-800 sunlamp was quantitated by reacting the extracted DNA with Micrococcus luteus endonuclease specific for pyrimidine dimers. Exposure to 15 and 30 seconds of radiation emitted from this lamp produced the formation of 12.8 and 23.6 dimers per 10(8) daltons DNA, respectively. Approximately 50% of the dimers induced were lost 58 min after irradiation. Only a small percentage (less than 10) remained 24 hr postirradiation. These data partially characterize the process by which pyrimidine dimers are excised from human skin DNA in vivo.

  3. Impact of Humidity on In Vitro Human Skin Permeation Experiments for Predicting In Vivo Permeability.

    PubMed

    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. PMID:26461468

  4. Photoprotective and anti-skin-aging effects of eicosapentaenoic acid in human skin in vivo.

    PubMed

    Kim, Hyeon Ho; Cho, Soyun; Lee, Serah; Kim, Kyu Han; Cho, Kwang Hyun; Eun, Hee Chul; Chung, Jin Ho

    2006-05-01

    Skin aging can be attributed to photoaging (extrinsic) and chronological (intrinsic) aging. Photoaging and intrinsic aging are induced by damage to human skin attributable to repeated exposure to ultraviolet (UV) irradiation and to the passage of time, respectively. In our previous report, eicosapentaenoic acid (EPA) was found to inhibit UV-induced matrix metalloproteinase-1 (MMP-1) expression in human dermal fibroblasts. Therefore, we investigated the effects of EPA on UV-induced skin damage and intrinsic aging by applying EPA topically to young and aged human skin, respectively. By immunohistochemical analysis and Western blotting, we found that topical application of EPA reduced UV-induced epidermal thickening and inhibited collagen decrease induced by UV light. It was also found that EPA attenuated UV-induced MMP-1 and MMP-9 expression by inhibiting UV-induced c-Jun phosphorylation, which is closely related to UV-induced activator protein-1 activation, and by inhibiting JNK and p38 activation. EPA also inhibited UV-induced cyclooxygenase-2 (COX-2) expression without altering COX-1 expression. Moreover, it was found that EPA increased collagen and elastic fibers (tropoelastin and fibrillin-1) expression by increasing transformin growth factor-beta expression in aged human skin. Together, these results demonstrate that topical EPA has potential as an anti-skin-aging agent. PMID:16467281

  5. Skin Concentrations of Topically Applied Substances in Reconstructed Human Epidermis (RHE) Compared with Human Skin Using in vivo Confocal Raman Microscopy.

    PubMed

    Fleischli, Franziska D; Morf, Fabienne; Adlhart, Christian

    2015-01-01

    Detailed knowledge about the skin concentration of topically applied substances is important to understand their local pharmacological activity. In particular since in vitro models of reconstructed human epidermis are increasingly used as models for diseased skin. In general, diffusion cell experiments are performed to determine the diffusion flux of test substances through either skin models or excised skin both from humans and animals. Local concentrations of the test substances within the skin are then calculated applying diffusion laws and suitable boundary conditions. In this study we used a direct approach to reveal the local concentrations of test substances within skin using confocal Raman microscopy. This non-invasive method can also be applied in vivo and therefore we directly compared in vivo concentrations with those obtained from commercially available reconstructed human epidermis (RHE). Hydrophilic and lipophilic test substances with log Pow from -0.07 to 5.91 were topically applied on human skin in vivo and RHE from SkinEthic was used as the commercial skin model. Local concentration profiles in the stratum corneum (SC) showed substantial differences between the RHE model and the in vivo situation. Differences between RHE models and human skin in vivo were also observed in their molecular composition, in particular in terms of their water profile, lipid content and the presence of natural moisturizing factor (NMF). Confocal Raman is shown to be a powerful non-invasive method for qualitative and quantitative comparative studies between RHE models and human skin in vivo. This method can also be applied to validate RHE models for future use in clinical studies. PMID:26507219

  6. In vivo measurement of mid-infrared light scattering from human skin

    PubMed Central

    Michel, Anna P. M.; Liakat, Sabbir; Bors, Kevin; Gmachl, Claire F.

    2013-01-01

    Two mid-infrared light sources, a broadband source from a Fourier Transform Infrared Spectrometer (FTIR) and a pulsed Quantum Cascade (QC) Laser, are used to measure angle-resolved backscattering in vivo from human skin across a broad spectral range. Scattering profiles measured using the FTIR suggest limited penetration of the light into the skin, with most of the light interacting with the stratum corneum layer of the epidermis. Scattering profiles from the QC laser show modulation patterns with angle suggesting interaction with scattering centers in the skin. The scattering is attributed to interaction of the laser light with components such as collagen fibers and capillaries in the dermis layer of the skin. PMID:23577287

  7. In vivo Raman spectroscopy of biochemical changes in human skin by cosmetic application

    NASA Astrophysics Data System (ADS)

    Tosato, Maira Gaspar; dos Santos, Edson Pereira; Alves, Rani de Souza; Raniero, Leandro; Menezes, Priscila Fernanda C.; Kruger, Odivânia; Praes, Carlos Eduardo O.; Martin, Airton Abrahão

    2010-02-01

    The skin aging process is mainly accelerated by external agents such as sunlight, air humidity and surfactants action. Changes in protein structures and hydration during the aging process are responsible for skin morphological variations. In this work the human skin was investigated by in vivo Raman spectroscopy before and after the topical applications of a cosmetic on 17 healthy volunteers (age 60 to 75). In vivo Raman spectra of the skin were obtained with a Spectrometer SpectraPro- 2500i (Pi-Acton), CCD detector and a 785 nm laser excitation source, collected at the beginning of experiment without cream (T0), after 30 (T30) and 60 (T60) days using the product. The primary changes occurred in the following spectral regions: 935 cm-1 (νCC), 1060 cm-1 (lipids), 1174 to 1201 cm-1 (tryptofan, phenylalanine and tyrosine), 1302 cm-1 (phospholipids), 1520 to 1580 cm-1 (C=C) and 1650 cm-1 (amide I). These findings indicate that skin positive effects were enhanced by a continuous cream application.

  8. Volumetric cutaneous microangiography of human skin in vivo by VCSEL swept-source optical coherence tomography

    PubMed Central

    Choi, Woo June; Wang, Ruikang K.

    2015-01-01

    Three-dimensional (3D) assessment of cutaneous microcirculation in human skin is essential in the identification of disease states in skin or other organs. Few 3D imaging techniques have revealed the skin micro-vasculatures non-invasively and with sufficient imaging depth. Here, we demonstrate volumetric cutaneous microangiography of the human skin in vivo that utilizes a 1.3 µm high-speed swept-source optical coherence tomography (SS-OCT). The swept source is based on a MEMS tunable vertical cavity surface emission laser (VCSEL) that is advantageous in terms of long coherence length over 50 mm and 100 nm spectral bandwidth that enables the visualization of microstructures within a few mm from the skin surface. We show that skin microvasculature can be delineated in 3D SS-OCT images using ultrahigh-sensitive optical microangiography (UHS-OMAG) with a correlation mapping mask, providing a contrast enhanced blood perfusion map with capillary flow sensitivity. 3D microangiograms of a healthy human finger are shown with distinct cutaneous vessel architectures from different dermal layers and even within hypodermis. These findings suggest that the OCT microangiography could be a beneficial biomedical assay to assess cutaneous vascular functions in clinic. PMID:25635163

  9. Using a portable terahertz spectrometer to measure the optical properties of in vivo human skin

    NASA Astrophysics Data System (ADS)

    Echchgadda, Ibtissam; Grundt, Jessica E.; Tarango, Melissa; Ibey, Bennett L.; Tongue, Thomas; Liang, Min; Xin, Hao; Wilmink, Gerald J.

    2013-02-01

    Terahertz time-domain spectroscopy (THz-TDS) systems are capable of detecting small differences in water concentration levels in biological tissues. This feature makes THz devices excellent tools for the noninvasive assessment of skin; however, most conventional systems prove too cumbersome for limited-space environments. 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 collect the optical properties, specifically the absorption coefficient (μa) and index of refraction (n), of human subjects in vivo. Spectra were collected from 0.1-2 THz, and measurements were made on the palm, ventral (inner) and dorsal (outer) forearm. Prior to each THz measurement, we used a multiprobe adapter system to measure each subject's skin hydration levels, transepidermal waterloss (TEWL), skin color, and degree of melanin pigmentation. Our results suggest that the measured optical properties were wide-ranging, and varied considerably for skin tissues with different hydration and melanin levels. These data provide a novel framework for accurate human tissue measurements using THz spectrometers in limited-space environments.

  10. In vivo quantification of human dermal skin aging using SHG and autofluorescence

    NASA Astrophysics Data System (ADS)

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

    2012-03-01

    There are visible changes during skin aging. In the extracellular matrix these changes referred to as intrinsic aging (skin areas not exposed to sunlight) and extrinsic aging can be measured using various methods, such as subjective clinical evaluation, histology and molecular analysis. In this study we developed a new parameter for the non-invasive quantitative determination of dermal skin aging utilizing a five-dimensional intravital tomography (5D-IVT). This device, also known as 5D - multi-photon laser scanning microscopy, is a powerful tool to investigate (photo)aging-associated alterations in vivo. Structural alterations in the dermis of extrinsically aged (chronically sun-exposed) and intrinsically aged (sun-protected) human skin were recorded utilizing the collagen-specific second harmonic generation (SHG) signal and the elastin-specific autofluorescence (AF) signal. Recording took place in young and elderly volunteers. The resulting images were processed in order to gain the elastin percentage and the collagen percentage per image. Then, the elastin - to - collagen ratio (ELCOR) was calculated. With respect to volar forearm skin, the ELCOR significantly increased with age. In elderly volunteers, the ELCOR value calculated for the chronically sun-exposed temple area was significantly augmented compared with the sun-protected upper arm area. Based on 5D-IVT we introduce the ELCOR as a new means to quantify age-associated alterations in the extracellular matrix of in vivo human skin. This novel parameter is compared to the currently used "SHG to AF aging index" of the dermis (SAAID).

  11. Photoaging is associated with protein oxidation in human skin in vivo.

    PubMed

    Sander, Christina S; Chang, Hong; Salzmann, Susann; Müller, Cornelia S L; Ekanayake-Mudiyanselage, Swarna; Elsner, Peter; Thiele, Jens J

    2002-04-01

    There is increasing evidence for the generation of reactive oxygen species in skin upon ultraviolet exposure, but little is known about their pathophysiologic relevance in human skin in vivo. We hypothesized that chronic and acute photodamage is mediated by depleted antioxidant enzyme expression and increased oxidative protein modifications. Biopsies from patients with histologically confirmed solar elastosis, from non-ultraviolet-exposed sites of age-matched controls, and from young subjects were analyzed. To evaluate the influence of acute ultraviolet exposures, buttock skin of 12 healthy subjects was irradiated repetitively on 10 d with a solar simulator and compared intraindividually to non-ultraviolet-treated contralateral sites. The antioxidant enzymes catalase, copper-zinc superoxide dismutase, and manganese superoxide dismutase were investigated by immunohistochemistry. Protein carbonyls were analyzed by immunohistochemical and immunoblotting techniques in human skin and in cell models. Whereas overall expression of antioxidant enzymes was very high in the epidermis, low baseline levels were found in the dermis. In photoaged skin, a significant depletion of antioxidant enzyme expression was observed within the stratum corneum and in the epidermis. Importantly, an accumulation of oxidatively modified proteins was found specifically within the upper dermis of photoaged skin. Upon acute ultraviolet exposure of healthy subjects, depleted catalase expression and increased protein oxidation were detected. Exposures of keratinocytes and fibroblasts to ultraviolet B, ultraviolet A, and H2O2 led to dose-dependent protein oxidation and thus confirmed in vivo results. In conclusion, the correlation between photodamage and protein oxidation was demonstrated for the first time, which hence may be a relevant pathophysiologic factor in photoaging. PMID:11918707

  12. In Vivo Multiphoton Microscopy for Investigating Biomechanical Properties of Human Skin

    PubMed Central

    Liang, Xing; Graf, Benedikt W.; Boppart, Stephen A.

    2012-01-01

    The biomechanical properties of living cells depend on their molecular building blocks, and are important for maintaining structure and function in cells, the extracellular matrix, and tissues. These biomechanical properties and forces also shape and modify the cellular and extracellular structures under stress. While many studies have investigated the biomechanics of single cells or small populations of cells in culture, or the properties of organs and tissues, few studies have investigated the biomechanics of complex cell populations in vivo. With the use of advanced multiphoton microscopy to visualize in vivo cell populations in human skin, the biomechanical properties are investigated in a depth-dependent manner in the stratum corneum and epidermis using quasi-static mechanical deformations. A 2D elastic registration algorithm was used to analyze the images before and after deformation to determine displacements in different skin layers. In this feasibility study, the images and results from one human subject demonstrate the potential of the technique for revealing differences in elastic properties between the stratum corneum and the rest of the epidermis. This interrogational imaging methodology has the potential to enable a wide range of investigations for understanding how the biomechanical properties of in vivo cell populations influence function in health and disease. PMID:22468160

  13. Human growth factor and cytokine skin cream for facial skin rejuvenation as assessed by 3D in vivo optical skin imaging.

    PubMed

    Gold, Michael H; Goldman, Mitchel P; Biron, Julie

    2007-10-01

    Growth factors, in addition to their crucial role in cutaneous wound healing, are also beneficial for skin rejuvenation. Due to their multifunctional activities such as promoting skin cell proliferation and stimulating collagen formation, growth factors may participate in skin rejuvenation at various levels. The present placebo-controlled study aimed to further investigate the antiaging effects of a novel skin cream containing a mixture of human growth factors and cytokines, which was obtained through a biotechnology process using cultured human fetal fibroblasts. Aside from clinical assessment of skin wrinkles, the skin surface topography was analyzed by 3D in vivo optical skin imaging using the Phaseshift Rapid in vivo Measurement of Skin (PRIMOS) device. This device allows fast, contact-free, and direct measurement of the skin surface topography in vivo at high resolution. This technique is quantitative and more reliable than a visual assessment of wrinkles using a scoring system, which is subjective and strongly dependent on investigator and assessment conditions. Using the PRIMOS device, which is also regarded as a more accurate method than the commonly used silicon replica technique, skin surface roughness was shown to significantly decrease between 10% and 18% depending on the roughness parameter after 2 months of twice-daily application of the human growth factor and cytokine cream. This was compared to treatment with the placebo formulation resulting in an approximate 10% decrease of 2 roughness parameters, whereas the remaining parameters remained unchanged. We found that topical application of growth factors and cytokines are beneficial in reducing signs of skin aging. PMID:17966179

  14. In vivo optical interferometric imaging of human skin utilizing monochromatic light source.

    PubMed

    Osawa, Kentaro; Minemura, Hiroyuki; Anzai, Yumiko; Tomita, Daisuke; Shimanaka, Tetsuya; Suzuki, Tomokazu; Iida, Hiroki; Matsuura, Naoya; Katagiri, Chika; Yamashita, Toyonobu; Hara, Yusuke; Watanabe, Koichi

    2016-07-01

    We have demonstrated tomographic imaging of in vivo human skin with an optical interferometric imaging technique using a monochromatic light source. The axial resolution of this method is determined by the center wavelength and the NA of the objective and is irrelevant to the bandwidth of the light source in contrast to optical coherence tomography. Our imaging system is constructed with low-priced and small-sized compact disk optical pickup components, a laser diode, a high NA objective, and a voice coil actuator. In spite of its low cost and small size, our imaging system can visualize the structure of human skin as clearly as a commercial reflectance confocal microscope. PMID:27409189

  15. Detection of advanced glycation end products (AGEs) on human skin by in vivo confocal Raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Martin, A. A.; Pereira, L.; Ali, S. M.; Pizzol, C. D.; Tellez, C. A.; Favero, P. P.; Santos, L.; da Silva, V. V.; Praes, C. E. O.

    2016-03-01

    The aging process involves the reduction in the production of the major components of skin tissue. During intrinsic aging and photoaging processes, in dermis of human skin, fibroblasts become senescent and have decreased activity, which produce low levels of collagen. Moreover, there is accumulation of advanced glycation end products (AGEs). AGEs have incidence in the progression of age-related diseases, principally in diabetes mellitus and in Alzheimer's diseases. AGEs causes intracellular damage and/or apoptosis leading to an increase of the free radicals, generating a crosslink with skin proteins and oxidative stress. The aim of this study is to detect AGEs markers on human skin by in vivo Confocal Raman spectroscopy. Spectra were obtained by using a Rivers Diagnostic System, 785 nm laser excitation and a CCD detector from the skin surface down to 120 μm depth. We analyzed the confocal Raman spectra of the skin dermis of 30 women volunteers divided into 3 groups: 10 volunteers with diabetes mellitus type II, 65-80 years old (DEW); 10 young healthy women, 20-33 years old (HYW); and 10 elderly healthy women, 65-80 years old (HEW). Pentosidine and glucosepane were the principally identified AGEs in the hydroxyproline and proline Raman spectral region (1000-800 cm-1), in the 1.260-1.320 cm-1 region assignable to alpha-helical amide III modes, and in the Amide I region. Pentosidine and glucosepane calculated vibrational spectra were performed through Density Functional Theory using the B3LYP functional with 3-21G basis set. Difference between the Raman spectra of diabetic elderly women and healthy young women, and between healthy elderly women and healthy young women were also obtained with the purpose of identifying AGEs Raman bands markers. AGEs peaks and collagen changes have been identified and used to quantify the glycation process in human skin.

  16. New developments in two-photon analysis of human skin in vivo

    NASA Astrophysics Data System (ADS)

    Riemann, I.; Schwarz, M.; Stracke, F.; Ehlers, A.; Dimitrow, E.; Kaatz, M.; König, K.; Le Harzic, R.

    2009-02-01

    Two-photon imaging of human skin using ultra short laser pulses can be used to obtain information about the state of cells and tissues by means of their natural autofluorescence. Using this method, it is possible to determine whether the normal cell pattern is disturbed or the autofluorescence is influenced by internal or external stimuli. Two-photon fluorescence lifetime imaging (FLIM) can further enhance this providing information about physiological processes, fluorophores (like NAD(P)H, collagen, keratin, elastin, flavins, melanin,...) and external applied probes inside cells and tissue parts. For example the part of the cells metabolism and energy level can be determined by analyzing the NADH regarding its free / bound state and its oxidized / reduced state. The combination of two-photon imaging with FLIM may lead to a better understanding and diagnosis of skin reactions and disorders. We also present some results of in vivo simultaneous collagen and elastin measurements in skin dermis. Changes of dermal collagen and elastin content are characteristic for skin aging as well as for pathological skin conditions.

  17. Multiple spatially resolved reflection spectroscopy for in vivo determination of carotenoids in human skin and blood

    NASA Astrophysics Data System (ADS)

    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.

  18. Quantitative determination of percutaneous absorption of radiolabeled drugs in vitro and in vivo by human skin.

    PubMed

    Schaefer, H; Stüttgen, G; Zesch, A; Schalla, W; Gazith, J

    1978-01-01

    We have measured concentrations of about 30 drugs in the living layers of the skin under conditions which provide data which are applicable in therapeutic treatment. Since the skin is a thin organ and small amounts of drug represent high target concentrations, it is necessary to select a sensitive quantitative method; observation of the kinetics of absorption using radiolabeled drugs is the method of choice. Because of possible hazards--and legal and ethical problems--absorption studies in human skin are commonly performed in vitro. Related in vivo investigations demonstrate the relevance and the limitations of the in vitro experiments. The main hindrance against penetration of drugs is by the horny layer. The barrier-function of this layer--if it is undisturbed--may be described by a multilayer model. The reciprocal function, the reservoir function, is important for the efficiency of topical treatment; it also plays a role in determining the unique pharmacokinetics of drug absorption in the skin and percutaneous resorption. If the horny layer is injured, i.e. in diseased skin, both the barrier and the reservoir functions are disturbed. In consequence, drug concentrations in the skin--and percutaneous resorption--may be greatly enhanced, and topically applied drugs may enter preferentially into diseased areas. The form of application, such as ointment, solution, etc. influences the penetration kinetics in such a specific manner that a specific vehicle for a specific drug should always be postulated. The frequently discussed hazards of side effects due to percutaneous resorption of drugs like corticosteroids are a function of the treated area rather than of its penetration capacity. Thus the indication for local or oral treatment of severe dermatoses should be considered in terms of the affected area. The relatively frequent side effects in the skin itself which originate from unnecessarily high drug concentrations and long term treatment must also be taken into

  19. Area tracking in topographical in-vivo measurement series of human skin by displacement vector fields

    NASA Astrophysics Data System (ADS)

    Hopermann, Hermann; Lunderstaedt, Reinhart A.

    2000-12-01

    In the first part of the presented paper a new measurement system for fast three-dimensional in vivo measurement of the microtopography of human skin is proposed. It is based on the principle of active image triangulation. A Digital Micromirror Device (DMDTM) is used for projecting sinusoidal intensity distributions on the surface of human skin. By using temporal phase shift algorithms the three-dimensional topography is reconstructed from two-dimensional images. Displacement vector fields represent a promising approach for detecting deformation and other lateral changes in the surface of human skin. In the second part of the presented paper a method based on local template matching and smooth interpolation algorithms for determining a displacement vector field is proposed. Aiming at a minimal expenditure of numerical calculation, a stepwise algorithm was developed for this purpose. The deformatory component of the calculated vector field is separated by minimizing a suitable functional, which is also presented in the paper. In investigations of measurement series the proposed method proves to be very efficient. The calculated displacement vector fields connect corresponding areas in two subsequent measurements. Distortions caused by mechanical deformation or other influences can be detected and visualized by the separated deformatory components of the vector fields.

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

    PubMed Central

    Manuskiatti, Woraphong; Pattanaprichakul, Penvadee; Inthasotti, Siriluk; Sitthinamsuwan, Panitta; Hanamornroongruang, Suchanan; Wanitphakdeedecha, Rungsima; Chu-ongsakol, Sorawuth

    2016-01-01

    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. PMID:27247943

  1. Volumetric cutaneous microangiography of human skin in vivo by VCSEL swept-source optical coherence tomography

    SciTech Connect

    Woo June Choi; Wang, R K

    2014-08-31

    We demonstrate volumetric cutaneous microangiography of the human skin in vivo that utilises 1.3-μm high-speed sweptsource optical coherence tomography (SS-OCT). The swept source is based on a micro-electro-mechanical (MEMS)-tunable vertical cavity surface emission laser (VCSEL) that is advantageous in terms of long coherence length over 50 mm and 100 nm spectral bandwidth, which enables the visualisation of microstructures within a few mm from the skin surface. We show that the skin microvasculature can be delineated in 3D SS-OCT images using ultrahigh-sensitive optical microangiography (UHS-OMAG) with a correlation mapping mask, providing a contrast enhanced blood perfusion map with capillary flow sensitivity. 3D microangiograms of a healthy human finger are shown with distinct cutaneous vessel architectures from different dermal layers and even within hypodermis. These findings suggest that the OCT microangiography could be a beneficial biomedical assay to assess cutaneous vascular functions in clinic. (laser biophotonics)

  2. Volumetric cutaneous microangiography of human skin in vivo by VCSEL swept-source optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Choi, Woo June; Wang, R. K.

    2014-08-01

    We demonstrate volumetric cutaneous microangiography of the human skin in vivo that utilises 1.3-μm high-speed sweptsource optical coherence tomography (SS-OCT). The swept source is based on a micro-electro-mechanical (MEMS)-tunable vertical cavity surface emission laser (VCSEL) that is advantageous in terms of long coherence length over 50 mm and 100 nm spectral bandwidth, which enables the visualisation of microstructures within a few mm from the skin surface. We show that the skin microvasculature can be delineated in 3D SS-OCT images using ultrahigh-sensitive optical microangiography (UHS-OMAG) with a correlation mapping mask, providing a contrast enhanced blood perfusion map with capillary flow sensitivity. 3D microangiograms of a healthy human finger are shown with distinct cutaneous vessel architectures from different dermal layers and even within hypodermis. These findings suggest that the OCT microangiography could be a beneficial biomedical assay to assess cutaneous vascular functions in clinic.

  3. 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

    SciTech Connect

    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

    2010-04-09

    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.

  4. In vivo human skin penetration of (-)-epigallocatechin-3-gallate from topical formulations.

    PubMed

    Scalia, Santo; Trotta, Valentina; Bianchi, Anna

    2014-06-01

    The aim of the study was to examine the effect of topical vehicles on the in vivo human stratum corneum penetration of the antioxidant and skin photoprotective agent (-)-epigallocatechin-3-gallate (EGCG). Model oil-in-water (o/w) emulsion and gel formulations containing 1 % (m/m) EGCG were prepared and subjected to photodegradation studies in order to select excipients that minimize the light instability of EGCG. The optimized emulsion and gel were applied to human volunteers and the EGCG percutaneous permeation was evaluated in vivo by the tape- -stripping technique. No significant differences in the percentage of the applied EGCG dose diffused into the stratum corneum were observed between the o/w emulsion (36.1 ± 7.5 %) and gel (35.5 ± 8.1 %) preparations. However, the amount of EGCG permeated into the deeper region of human stratum corneum was significantly larger for the o/w emulsion compared to the gel. Therefore, the emulsion represents a suitable vehicle for topical delivery of EGCG. PMID:24914725

  5. Electrically Activated Primary Human Fibroblasts Improve In Vitro and In Vivo Skin Regeneration.

    PubMed

    Rouabhia, Mahmoud; Park, Hyun Jin; Zhang, Ze

    2016-08-01

    Electrical stimulation (ES) changes cellular behaviors and thus constitutes a potential strategy to promote wound healing. However, well-controlled in vitro findings have yet to be translated to in vivo trials. This study was to demonstrate the feasibility and advantages of transplanting electrically activated cells (E-Cells) to help wound healing. Primary human skin fibroblasts were activated through well defined ES and cultured with keratinocytes to generate engineered human skin (EHS), which were transplanted to nu/nu mice. The electrically activated EHS grafts were analyzed at 20 and 30 days post-grafting, showing faster wound closure, thick epidermis, vasculature, and functional basement membrane containing laminin and type IV collagen that were totally produced by the implanted human cells. Because a variety of cells can be electrically activated, E-Cells may become a new cell source and the transplantation of E-Cells may represent a new strategy in wound healing and tissue engineering. J. Cell. Physiol. 231: 1814-1821, 2016. © 2015 Wiley Periodicals, Inc. PMID:26661681

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

    SciTech Connect

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

    1986-08-01

    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.

  7. High-resolution multiphoton tomography of human skin in vivo and in vitro

    NASA Astrophysics Data System (ADS)

    Riemann, Iris; Dimitrov, Enrico; Fischer, Peter; Reif, Annette; Kaatz, Martin; Elsner, Peter; Konig, Karsten

    2004-09-01

    The novel compact femtosecond NIR (near infrared) laser imaging system DermaInspect was used to perform for the first time in vivo high resolution non-invasive 4D tomography of human skin based on multiphoton autofluorescence imaging and second harmonic generation (SHG). Using fast galvoscan mirrors, a time correlated single photon counting (TCSPC) module and femtosecond 80 MHz laser pulses in the spectral range of 750 nm-850 nm human skin was analyzed with subcellular spatial resolution (3D) and 250 ps temporal resolution (4D). The non-linear induced autofluorescence originates from naturally endogenous fluorophores and protein structures like NAD(P)H, flavins, phorphyrins, melanin, elastin and collagen. Collagenous structures were detected using SHG. Tissues of patients with dermatological disorders like nevi and melanoma have been investigated with a clear visualization of cells and intratissue structures. Further characterization of those components was performed by the fluorescence lifetime imaging (FLIM) and the determination of two photon excitation spectra. This method of non invasive high resolution optical biopsy provides a painless diagnostic tool for dermatological applications.

  8. Removing noises caused by motion artefacts in microcirculation maps of human skin in vivo.

    PubMed

    Chen, C; Shi, W; Gao, W

    2015-12-01

    This paper presents a zero-padding and cross-correlation technique-based correlation mapping optical coherence tomography (ZPCC-cmOCT) to reconstruct microcirculation maps of human skin in vivo, which can remove the background decorrelation noise caused by motion artefacts. In conventional correlation mapping optical coherence tomography method, the correlation degree of static tissue may be lowered by the motion artefacts due to cardiac and respiratory motion, resulting in background decorrelation noise in microcirculation maps. In zero-padding and cross-correlation technique-based correlation mapping optical coherence tomography method, structural images are first obtained by performing Fourier transform on zero-padded interference fringes, and then cross-correlation-based image registration is utilized to align local areas in two adjacent structural images. Finally, correlation mapping optical coherence tomography method is performed to generate microcirculation maps. Both phantom experiments and in vivo experiments were implemented and the results demonstrate that the proposed method is capable of providing microcirculation maps with the background decorrelation noise removed. PMID:26356237

  9. In vivo stepwise multi-photon activation fluorescence imaging of melanin in human skin

    NASA Astrophysics Data System (ADS)

    Lai, Zhenhua; Gu, Zetong; Abbas, Saleh; Lowe, Jared; Sierra, Heidy; Rajadhyaksha, Milind; DiMarzio, Charles

    2014-03-01

    The stepwise multi-photon activated fluorescence (SMPAF) of melanin is a low cost and reliable method of detecting melanin because the activation and excitation can be a continuous-wave (CW) mode near infrared (NIR) laser. Our previous work has demonstrated the melanin SMPAF images in sepia melanin, mouse hair, and mouse skin. In this study, we show the feasibility of using SMPAF to detect melanin in vivo. in vivo melanin SMPAF images of normal skin and benign nevus are demonstrated. SMPAF images add specificity for melanin detection than MPFM images and CRM images. Melanin SMPAF is a promising technology to enable early detection of melanoma for dermatologists.

  10. In vivo chemical investigation of human skin using a confocal Raman fiber optic microprobe.

    PubMed

    Chrit, L; Hadjur, C; Morel, S; Sockalingum, G; Lebourdon, G; Leroy, F; Manfait, M

    2005-01-01

    To evaluate the potential of a new in vivo confocal Raman microprobe, we undertake a pilot study in human skin. A fiber optic probe is operated with a 633-nm laser and trials are conducted in healthy volunteers. We examine changes in molecular composition and structure of the stratum corneum, from different volunteers, from different anatomical sites and skin layers. Main spectral variations are detected in the following regions: 800 to 900 cm(-1) (amino acids); 1200 to 1290 cm(-1) (proteins); and 1030 to 1130 cm(-1), 1300 to 1450 cm(-1), and 2800 to 2900 cm(-1) (lipids). Curve fitting of the amide 1 region performs in detail protein secondary structural variations of the amide 1 band. Protein conformation is also found to vary depending on the anatomical site and volunteer. Similar analysis of the 730- to 1170-cm(-1) spectral window reveals a different organization of lamellar lipids: gel for forearm and palm, and liquid-crystalline phase for fingertips. All these variations result from changes in the stratum corneum components such as natural moisturizing factor (NMF), lipids (namely ceramides), and water. Hierarchical clustering classification is also performed to sort out Raman data obtained from different subjects. Further improvement of the confocal probe would be to adapt a 360-deg configuration enabling access to other anatomical sites. PMID:16178641

  11. In-vitro and in-vivo study of dye diffusion into the human skin and hair follicles

    NASA Astrophysics Data System (ADS)

    Genina, Elina A.; Bashkatov, Alexey N.; Sinichkin, Yurii P.; Kochubey, Vyacheslav I.; Lakodina, Nina A.; Perpelitzina, Olga A.; Altshuler, Gregory B.; Tuchin, Valery V.

    2000-11-01

    We present experimental results on in vitro and in vivo investigation of dye diffusion into the human skin and hair follicles. It was shown that dyeing as a method of enhancement of the absorption coefficient of hair follicle tissue components can be used for selective photodestruction of hair follicle and surrounding tissues. Strength and depth of hair follicle dyeing inside the skin were determined for various dyes.

  12. In Vivo Assessment of Acute UVB Responses in Normal and Xeroderma Pigmentosum (XP-C) Skin-Humanized Mouse Models

    PubMed Central

    García, Marta; Llames, Sara; García, Eva; Meana, Alvaro; Cuadrado, Natividad; Recasens, Mar; Puig, Susana; Nagore, Eduardo; Illera, Nuria; Jorcano, José Luis; Del Rio, Marcela; Larcher, Fernando

    2010-01-01

    In vivo studies of UVB effects on human skin are precluded by ethical and technical arguments on volunteers and inconceivable in cancer-prone patients such as those affected with Xeroderma Pigmentosum (XP). Establishing reliable models to address mechanistic and therapeutic matters thus remains a challenge. Here we have used the skin-humanized mouse system that circumvents most current model constraints. We assessed the UVB radiation effects including the sequential changes after acute exposure with respect to timing, dosage, and the relationship between dose and degree-sort of epidermal alteration. On Caucasian-derived regenerated skins, UVB irradiation (800 J/m2) induced DNA damage (cyclobutane pyrimidine dimers) and p53 expression in exposed keratinocytes. Epidermal disorganization was observed at higher doses. In contrast, in African descent–derived regenerated skins, physiological hyperpigmentation prevented tissue alterations and DNA photolesions. The acute UVB effects seen in Caucasian-derived engrafted skins were also blocked by a physical sunscreen, demonstrating the suitability of the system for photoprotection studies. We also report the establishment of a photosensitive model through the transplantation of XP-C patient cells as part of a bioengineered skin. The inability of XP-C engrafted skin to remove DNA damaged cells was confirmed in vivo. Both the normal and XP-C versions of the skin-humanized mice proved proficient models to assess UVB-mediated DNA repair responses and provide a strong platform to test novel therapeutic strategies. PMID:20558577

  13. Weight-bearing-induced changes in the microtopography and structural stiffness of human skin in vivo following immobility periods.

    PubMed

    Dobos, Gabor; Gefen, Amit; Blume-Peytavi, Ulrike; Kottner, Jan

    2015-01-01

    Pressure ulcers (PUs) are injuries to the skin and underlying tissues, caused by sustained deformations and occur frequently in aged patients. Skin microtopography and stiffness affect the interaction of skin with contact surfaces contributing to PU development. We simulated immobility in 20 healthy females (mean age 69.9 years). Skin microtopography and stiffness were measured at the PU predilection sites before and after loading. Skin roughness decreased at the heels by 18.1% after 90 minutes (p = 0.022), but remained unchanged at the sacrum and the upper back. Structural elasticity and elastic deformations increased at all skin areas; changes over time were significant at the sacrum (p = 0.005) and the heel, (p = 0.002). The residual skin deformation increased at all skin areas after loading significantly at the sacrum (32.0%, p = 0.013) and upper back (20.6%, p = 0.007). The structural "biological" elasticity of the skin decreased significantly at the upper back after loading, but remained unchanged at the heels. All skin changes recovered after unloading. Results indicate that prolonged loading causes structural skin changes in humans in vivo in PU predilection sites. The pathogenesis of PUs is different at the heels, the sacral and upper back skin. PMID:25682694

  14. In vivo imaging of microvascular changes in inflammatory human skin induced by tape stripping and mosquito saliva using optical microangiography

    NASA Astrophysics Data System (ADS)

    Baran, Utku; Choi, Woo J.; Wang, Ruikang K.

    2015-03-01

    Tape stripping on human skin induces mechanical disruptions of the epidermal barrier that lead to minor skin inflammation which leads to temporary changes in microvasculature. On the other hand, when mosquitoes probe the skin for blood feeding, they inject saliva in dermal tissue. Mosquito saliva is known to exert various biological activities, such as dermal mast cell degranulation, leading to fluid extravasation and neutrophil influx. This inflammatory response remain longer than the tape stripping caused inflammation. In this study, we demonstrate the capabilities of swept-source optical coherence tomography (OCT) in detecting in vivo microvascular response of inflammatory human skin. Optical microangiography (OMAG), noninvasive volumetric microvasculature in vivo imaging method, has been used to track the vascular responses after tape stripping and mosquito bite. Vessel density has been quantified and used to correlate with the degree of skin irritation. The proved capability of OMAG technique in visualizing the microvasculature network under inflamed skin condition can play an important role in clinical trials of treatment and diagnosis of inflammatory skin disorders as well as studying mosquito bite's perception by the immune system and its role in parasite transmission.

  15. Analysis of the in vivo confocal Raman spectral variability in human skin

    NASA Astrophysics Data System (ADS)

    Mogilevych, Borys; dos Santos, Laurita; Rangel, Joao L.; Grancianinov, Karen J. S.; Sousa, Mariane P.; Martin, Airton A.

    2015-06-01

    Biochemical composition of the skin changes in each layer and, therefore, the skin spectral profile vary with the depth. In this work, in vivo Confocal Raman spectroscopy studies were performed at different skin regions and depth profile (from the surface down to 10 μm) of the stratum corneum, to verify the variability and reproducibility of the intra- and interindividual Raman data. The Raman spectra were collected from seven healthy female study participants using a confocal Raman system from Rivers Diagnostic, with 785 nm excitation line and a CCD detector. Measurements were performed in the volar forearm region, at three different points at different depth, with the step of 2 μm. For each depth point, three spectra were acquired. Data analysis included the descriptive statistics (mean, standard deviation and residual) and Pearson's correlation coefficient calculation. Our results show that inter-individual variability is higher than intraindividual variability, and variability inside the SC is higher than on the skin surface. In all these cases we obtained r values, higher than 0.94, which correspond to high correlation between Raman spectra. It reinforces the possibility of the data reproducibility and direct comparison of in vivo results obtained with different study participants of the same age group and phototype.

  16. Ethosomes for skin delivery of ammonium glycyrrhizinate: in vitro percutaneous permeation through human skin and in vivo anti-inflammatory activity on human volunteers.

    PubMed

    Paolino, Donatella; Lucania, Giuseppe; Mardente, Domenico; Alhaique, Franco; Fresta, Massimo

    2005-08-18

    The aim of this work was the evaluation of various ethosomal suspensions made up of water, phospholipids and ethanol at various concentrations for their potential application in dermal administration of ammonium glycyrrhizinate, a useful drug for the treatment of various inflammatory-based skin diseases. Physicochemical characterization of ethosomes was carried out by photon correlation spectroscopy and freeze fracture electron microscopy. The percutaneous permeation of ammonium glycyrrhizinate/ethosomes was evaluated in vitro through human stratum corneum and epidermis membranes by using Franz's cells and compared with the permeation profiles of drug solutions either in water or in a water-ethanol mixture. Reflectance spectrophotometry was used as a non-invasive technique to evaluate the carrier toxicity, the drug permeation and the anti-inflammatory activity of ammonium glycyrrhizinate in a model of skin erythema in vivo on human volunteers. Ethosomal suspensions had mean sizes ranging from 350 nm to 100 nm as a function of ethanol and lecithin quantities, i.e., high amounts of ethanol and a low lecithin concentration provided ethosome suspensions with a mean size of approximately 100 nm and a narrow size distribution. In vitro and in vivo experiments were carried out by using an ethosome formulation made up of ethanol 45% (v/v) and lecithin 2% (w/v). The ethosome suspension showed a very good skin tolerability in human volunteers, also when applied for a long period (48 h). Ethosomes elicited an increase of the in vitro percutaneous permeation of both methylnicotinate and ammonium glycyrrhizinate. Ethosomes were able to significantly enhance the anti-inflammatory activity of ammonium glycyrrhizinate compared to the ethanolic or aqueous solutions of this drug. Some in vivo experiments also showed the ability of ethosome to ensure a skin accumulation and a sustained release of the ammonium glycyrrhizinate. PMID:15935505

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

    NASA Astrophysics Data System (ADS)

    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.

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

    SciTech Connect

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

    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)

  19. Spectral analysis of photo-induced delayed luminescence from human skin in vivo

    NASA Astrophysics Data System (ADS)

    Musumeci, Francesco; Lanzanò, Luca; Privitera, Simona; Tudisco, Salvatore; Scordino, Agata

    2007-07-01

    The UVA induced Delayed Luminescence (DL), has been measured in vivo in the forearm skin of some healthy volunteers of different sex and age during several periods of the year. An innovative instrument able to detect, in single photon counting mode, the spectrum and the time trend of the DL emission has been used. The measured differences in the time trends of the spectral components may be related to the sex and the age. The potential development of a new analysis technique based on this phenomenon is discussed.

  20. Fluorescence dynamics of human epidermis (ex vivo) and skin (in vivo)

    NASA Astrophysics Data System (ADS)

    Salomatina, Elena V.; Pravdin, Alexander B.

    2003-10-01

    The temporal behavior of autofluorescence of human skin and epidermis under continuous UV-irradiation has been studied. Fluorescence spectra and kinetic curves of fluorescence intensity have been obtained. The fluorescence intensity recovery after dark period also has been examined. The vitiligo skin and epidermis were used for comparing their spectra with reflectance and fluorescence spectra of healthy skin. The epidermal samples were prepared using surface epidermis stripping technique. It has been concluded that fluorophores being undergone the UVA photobleaching are actually present in epidermal layer, and immediate pigment darkening does contribute, no less than a half of magnitude, to the autofluorescence decrease under continuous UVA irradiation.

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

    SciTech Connect

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

    1990-12-01

    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.

  2. Hazards and benefits of in-vivo Raman spectroscopy of human skin

    NASA Astrophysics Data System (ADS)

    Carter, Elizabeth A.; Williams, Adrian C.; Barry, Brian W.; Edwards, Howell G.

    1999-04-01

    The resurgence of Raman spectroscopy, in the late 1980's has led to an increase in the use of the technique for the analysis of biological tissues. Consequently, Raman spectroscopy is now regarded to be a well-established non- invasive, non-destructive technique, which is used to obtain good quality spectra from biological tissues with minimal fluorescence. What is presently of interest to our group is to develop further and establish the technique for in vivo investigations of healthy and diseased skin. This presentation discusses some potentially valuable clinical applications of the technique, and also highlights some of the experimental difficulties that were encountered when examining patients who were receiving treatment for psoriasis.

  3. In vivo evaluation of Fe in human skin employing X-Ray Fluorescence Methodology (XRF)

    NASA Astrophysics Data System (ADS)

    Estevam, M.; Appoloni, C. R.

    2007-02-01

    Recent technological improvements allow the method of in vivo XRF to provide useful sensibility for diagnostics or monitoring in biomedical applications. In cases of hereditary sanguine disorders as the β-thalassaemia or a genetic disorder like Haemochromatosis, there is a high concentration of elements as Fe, Zn and Cu in the skin and internal organs, due to the treatment of those abnormalities or due to the own dysfunction caused by the disease. The levels of Fe related to the patient bearers of the β-thalassaemia are determined, at the moment, measuring a protein in the sanguine current, called ferritin. The monitoring of the protein is ineffective in several situations, such as when the patient suffers any disturbance of health. Nowadays, the main forms of measuring the levels of those metals through hepatic storage are the biopsy of the liver, that is invasive and potentially dangerous, presenting a rate of mortality of 0.1%, and by means of magnetic susceptibilities that employs a quantum superconductor, which is highly expensive and there are only three main world centers with this equipment This work investigates the use of a Si PIN-diode detector and a 238Pu source (13 and 17keV; 13%; 95.2mCi; 86y) for the measurement of Fe skin levels compatible with those associated to the disease β-thalassaemia. XRF spectra were analyzed using a set of AXIL-WinQXAS programs elaborated and disseminated by the IAEA. The determination coefficient of the calibration model (sensitivity curve) was 0.97. Measurements on skin phantoms containing concentrations of Fe in the range from 10 to 150 parts per million (ppm), indicate that we are able to detect Fe at levels of the order of 15ppm, using monitoring periods of 50 seconds and skin entrance dose less than 10 mSv, The literature reports skin Fe levels from 15.0 to 60.0 ppm in normal persons and from 70 to 150 ppm in thalassaemics patients. So, the employed methodology allows the measurement of the skin Fe concentration.

  4. In vivo evaluation of Fe in human skin employing X-Ray Fluorescence Methodology (XRF)

    SciTech Connect

    Estevam, M.; Appoloni, C. R.

    2007-02-12

    Recent technological improvements allow the method of in vivo XRF to provide useful sensibility for diagnostics or monitoring in biomedical applications. In cases of hereditary sanguine disorders as the {beta}-thalassaemia or a genetic disorder like Haemochromatosis, there is a high concentration of elements as Fe, Zn and Cu in the skin and internal organs, due to the treatment of those abnormalities or due to the own dysfunction caused by the disease. The levels of Fe related to the patient bearers of the {beta}-thalassaemia are determined, at the moment, measuring a protein in the sanguine current, called ferritin. The monitoring of the protein is ineffective in several situations, such as when the patient suffers any disturbance of health. Nowadays, the main forms of measuring the levels of those metals through hepatic storage are the biopsy of the liver, that is invasive and potentially dangerous, presenting a rate of mortality of 0.1%, and by means of magnetic susceptibilities that employs a quantum superconductor, which is highly expensive and there are only three main world centers with this equipment This work investigates the use of a Si PIN-diode detector and a 238Pu source (13 and 17keV; 13%; 95.2mCi; 86y) for the measurement of Fe skin levels compatible with those associated to the disease {beta}-thalassaemia. XRF spectra were analyzed using a set of AXIL-WinQXAS programs elaborated and disseminated by the IAEA. The determination coefficient of the calibration model (sensitivity curve) was 0.97. Measurements on skin phantoms containing concentrations of Fe in the range from 10 to 150 parts per million (ppm), indicate that we are able to detect Fe at levels of the order of 15ppm, using monitoring periods of 50 seconds and skin entrance dose less than 10 mSv, The literature reports skin Fe levels from 15.0 to 60.0 ppm in normal persons and from 70 to 150 ppm in thalassaemics patients. So, the employed methodology allows the measurement of the skin Fe

  5. Thermal transport characteristics of human skin measured in vivo using ultrathin conformal arrays of thermal sensors and actuators.

    PubMed

    Webb, R Chad; Pielak, Rafal M; Bastien, Philippe; Ayers, Joshua; Niittynen, Juha; Kurniawan, Jonas; Manco, Megan; Lin, Athena; Cho, Nam Heon; Malyrchuk, Viktor; Balooch, Guive; Rogers, John A

    2015-01-01

    Measurements of the thermal transport properties of the skin can reveal changes in physical and chemical states of relevance to dermatological health, skin structure and activity, thermoregulation and other aspects of human physiology. Existing methods for in vivo evaluations demand complex systems for laser heating and infrared thermography, or they require rigid, invasive probes; neither can apply to arbitrary regions of the body, offers modes for rapid spatial mapping, or enables continuous monitoring outside of laboratory settings. Here we describe human clinical studies using mechanically soft arrays of thermal actuators and sensors that laminate onto the skin to provide rapid, quantitative in vivo determination of both the thermal conductivity and thermal diffusivity, in a completely non-invasive manner. Comprehensive analysis of measurements on six different body locations of each of twenty-five human subjects reveal systematic variations and directional anisotropies in the characteristics, with correlations to the thicknesses of the epidermis (EP) and stratum corneum (SC) determined by optical coherence tomography, and to the water content assessed by electrical impedance based measurements. Multivariate statistical analysis establishes four distinct locations across the body that exhibit different physical properties: heel, cheek, palm, and wrist/volar forearm/dorsal forearm. The data also demonstrate that thermal transport correlates negatively with SC and EP thickness and positively with water content, with a strength of correlation that varies from region to region, e.g., stronger in the palmar than in the follicular regions. PMID:25658947

  6. Thermal Transport Characteristics of Human Skin Measured In Vivo Using Ultrathin Conformal Arrays of Thermal Sensors and Actuators

    PubMed Central

    Webb, R. Chad; Pielak, Rafal M.; Bastien, Philippe; Ayers, Joshua; Niittynen, Juha; Kurniawan, Jonas; Manco, Megan; Lin, Athena; Cho, Nam Heon; Malyrchuk, Viktor; Balooch, Guive; Rogers, John A.

    2015-01-01

    Measurements of the thermal transport properties of the skin can reveal changes in physical and chemical states of relevance to dermatological health, skin structure and activity, thermoregulation and other aspects of human physiology. Existing methods for in vivo evaluations demand complex systems for laser heating and infrared thermography, or they require rigid, invasive probes; neither can apply to arbitrary regions of the body, offers modes for rapid spatial mapping, or enables continuous monitoring outside of laboratory settings. Here we describe human clinical studies using mechanically soft arrays of thermal actuators and sensors that laminate onto the skin to provide rapid, quantitative in vivo determination of both the thermal conductivity and thermal diffusivity, in a completely non-invasive manner. Comprehensive analysis of measurements on six different body locations of each of twenty-five human subjects reveal systematic variations and directional anisotropies in the characteristics, with correlations to the thicknesses of the epidermis (EP) and stratum corneum (SC) determined by optical coherence tomography, and to the water content assessed by electrical impedance based measurements. Multivariate statistical analysis establishes four distinct locations across the body that exhibit different physical properties: heel, cheek, palm, and wrist/volar forearm/dorsal forearm. The data also demonstrate that thermal transport correlates negatively with SC and EP thickness and positively with water content, with a strength of correlation that varies from region to region, e.g., stronger in the palmar than in the follicular regions. PMID:25658947

  7. In vivo reflectance-mode confocal microscopy assessments: impact of overweight on human skin microcirculation and histomorphology

    NASA Astrophysics Data System (ADS)

    Altintas, Ahmet A.; Aust, Matthias C.; Krämer, Robert; Vogt, Peter M.; Altintas, Mehmet A.

    2016-03-01

    Reflectance-mode confocal microscopy (RCM) enables in vivo assessment of the human skin. Impact of overweight on both human skin microcirculation and histomorphology has not been investigated in vivo. The purpose of this study is to evaluate both microcirculation and histomorphology in vivo in overweight. In 10 normotensive overweight nondiabetic individuals (OW-group, BMI 29.1±2.7 kg/m2) and 10 age- and sex-matched healthy lean controls (CO-group, BMI 20.4±1.9 kg/m2) the following parameters were evaluated using RCM: dermal blood cell flow (DBCF), density of dermal capillaries (DDC), epidermal thickness (ET), and epidermal cell size (ECS). DBCF was counted at 63.11±4.14 cells/min in OW-group and at 51.06±3.84 cells/min in CO-group (P<0.05). DDC was reduced in OW-group (4.91±0.39 capillaries/mm2) compared to the controls (6.02±0.64 capillaries/mm2, P<0.05). Histometric evaluation of ET reveals thickening in OW-group compared to the CO-group (54.79±4.25 μm versus 44.03±3.11 μm, P<0.05). ECS differed significantly (P<0.05) in OW-group (821.3±42.02 μm2) compared to the controls (772.6±34.79 μm2). Inverse correlation of dermal capillary density and overweight point to reduced total tissue perfusion while positive related blood cell flow reveals vasodilatation. Increase of both ET and cell size indicates remodeling of cutaneous histomorphology, maybe as an early stage of adiposity-related skin condition.

  8. Motion correction of in vivo three-dimensional optical coherence tomography of human skin using a fiducial marker

    PubMed Central

    Liew, Yih Miin; McLaughlin, Robert A.; Wood, Fiona M.; Sampson, David D.

    2012-01-01

    This paper presents a novel method based on a fiducial marker for correction of motion artifacts in 3D, in vivo, optical coherence tomography (OCT) scans of human skin and skin scars. The efficacy of this method was compared against a standard cross-correlation intensity-based registration method. With a fiducial marker adhered to the skin, OCT scans were acquired using two imaging protocols: direct imaging from air into tissue; and imaging through ultrasound gel into tissue, which minimized the refractive index mismatch at the tissue surface. The registration methods were assessed with data from both imaging protocols and showed reduced distortion of skin features due to motion. The fiducial-based method was found to be more accurate and robust, with an average RMS error below 20 µm and success rate above 90%. In contrast, the intensity-based method had an average RMS error ranging from 36 to 45 µm, and a success rate from 50% to 86%. The intensity-based algorithm was found to be particularly confounded by corrugations in the skin. By contrast, tissue features did not affect the fiducial-based method, as the motion correction was based on delineation of the flat fiducial marker. The average computation time for the fiducial-based algorithm was approximately 21 times less than for the intensity-based algorithm. PMID:22876343

  9. Accurate measurement of blood vessel depth in port wine stained human skin in vivo using pulsed photothermal radiometry.

    PubMed

    Li, Bincheng; Majaron, Boris; Viator, John A; Milner, Thomas E; Chen, Zhongping; Zhao, Yonghua; Ren, Hongwu; Nelson, J Stuart

    2004-01-01

    We report on application of pulsed photothermal radiometry (PPTR) to determine the depth of port wine stain (PWS) blood vessels in human skin. When blood vessels are deep in the PWS skin (>100 microm), conventional PPTR depth profiling can be used to determine PWS depth with sufficient accuracy. When blood vessels are close or partially overlap the epidermal melanin layer, a modified PPTR technique using two-wavelength (585 and 600 nm) excitation is a superior method to determine PWS depth. A direct difference approach in which PWS depth is determined from a weighted difference of temperature profiles reconstructed independently from two-wavelength excitation is demonstrated to be appropriate for a wider range of PWS patients with various blood volume fractions, blood vessel sizes, and depth distribution. The most superficial PWS depths determined in vivo by PPTR are in good agreement with those measured using optical Doppler tomography (ODT). PMID:15447017

  10. Assessment of laser-induced acceleration effects in optical clearing of in vivo human skin by optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Zhan, Zhigang; Wei, Huajiang; Jin, Ying

    2015-02-01

    Laser irradiation is considered to be a promising innovative technology which has been developed in an attempt to increase transdermal drug delivery. In this study, a near-infrared CW diode laser (785 nm) was applied to increase permeability of glycerol solutions in human skin in vivo and improve the optical clearing efficacy. Results show that for both 15%v/v and 30%v/v glycerol, the permeability coefficient increased significantly if the detected area of the skin tissue was treated with laser irradiation before optical clearing agents (OCAs) were applied. This study based on optical coherence tomography imaging technique and optical clearing effect finds laser irradiation a new approach for enhancing the penetration of OCAs and accelerating the rate of transdermal drug delivery.

  11. In vivo studies of sterol and squalene secretion by human skin.

    PubMed

    Nikkari, T; Schreibman, P H; Ahrens, E H

    1974-11-01

    This work was aimed at studying the quantity and composition of sterols and squalene secreted by the human skin. Lipids secreted by the entire skin were recovered by Soxhlet extraction of the clothing worn by a patient for 24 hr with a chloroform-methanol azeotrope and by extracting the water of a shower taken by the patient at the end of the 24-hr period. Squalene and sterols were quantified by gas-liquid chromatography. Plant sterols were separated from total sterols by thin-layer chromatography. Free and esterified cholesterol were separated by digitonin precipitation. In eight adults, seven of them with hyperlipoproteinemia, the total skin secretion of cholesterol ranged from 59 to 108 mg/day, with a mean of 88 +/- 17 (SD) mg/day. There was no difference in cholesterol secretion between the normocholesterolemic individual and the hypercholesterolemic ones, nor were there any differences according to type of hyperlipoproteinemia. Free cholesterol amounted to 54 +/- 5% of the total cholesterol. The secretion of squalene ranged from 125 to 475 mg/day in five patients. The secretion of both squalene and cholesterol was quite constant for any individual on a given diet. Cholesterol constituted 95.6 +/- 0.5% of the digitonin-precipitable total body surface sterols of eight patients, and lathosterol, the next largest fraction, 3.4 +/- 0.4%. Total plant sterols formed only 0.65 +/- 0.38% and beta-sitosterol 0.35 +/- 0.23% of the skin surface sterols in six patients whose dietary beta-sitosterol intake ranged from 230 to 3400 mg/day. PMID:4430879

  12. U. V. -induced DNA damage and its repair in human skin in vivo studied by sensitive immunohistochemical methods

    SciTech Connect

    Eggset, G.; Volden, G.; Krokan, H.

    1983-01-01

    Antibodies specific for u.v.-induced DNA damage were raised in rabbits, and used to study damage and repair of nuclear DNA in nude mouse and human skin in vivo by immuno-fluorescence and immunoperoxidase techniques. Purification of the antibodies by affinity chromatography strongly reduced unspecific background staining. In situ denaturation of nuclear DNA with 70 mM NaOH in 70% ethanol increased the sensitivity of the assay approximately 10-fold. Absorption experiments indicated that the specificity of the antibodies was primarily directed against pyrimidine dimers in single stranded DNA. Immunofluorescence and immunoperoxidase staining were essentially equally sensitive and positive responses using these techniques were already apparent in epidermal cell nuclei after 0.5 minimal erythemal dose (MED) of u.v. light. At higher doses, such as 2 MED, the staining was strong in all the epidermal layers and could also be observed in dermis. Even so, removal of antibody binding sites was well under way at 4-5 h post-irradiation and essentially complete after 24 h. Visible light increased the rate of repair, indicating the involvement of a photoreactivation enzyme in human skin in vivo.

  13. In vivo multiphoton NADH fluorescence reveals depth-dependent keratinocyte metabolism in human skin.

    PubMed

    Balu, Mihaela; Mazhar, Amaan; Hayakawa, Carole K; Mittal, Richa; Krasieva, Tatiana B; König, Karsten; Venugopalan, Vasan; Tromberg, Bruce J

    2013-01-01

    We employ a clinical multiphoton microscope to monitor in vivo and noninvasively the changes in reduced nicotinamide adenine dinucleotide (NADH) fluorescence of human epidermal cells during arterial occlusion. We correlate these results with measurements of tissue oxy- and deoxyhemoglobin concentration during oxygen deprivation using spatial frequency domain imaging. During arterial occlusion, a decrease in oxyhemoglobin corresponds to an increase in NADH fluorescence in the basal epidermal cells, implying a reduction in basal cell oxidative phosphorylation. The ischemia-induced oxygen deprivation is associated with a strong increase in NADH fluorescence of keratinocytes in layers close to the stratum basale, whereas keratinocytes from epidermal layers closer to the skin surface are not affected. Spatial frequency domain imaging optical property measurements, combined with a multilayer Monte Carlo-based radiative transport model of multiphoton microscopy signal collection in skin, establish that localized tissue optical property changes during occlusion do not impact the observed NADH signal increase. This outcome supports the hypothesis that the vascular contribution to the basal layer oxygen supply is significant and these cells engage in oxidative metabolism. Keratinocytes in the more superficial stratum granulosum are either supplied by atmospheric oxygen or are functionally anaerobic. Based on combined hemodynamic and two-photon excited fluorescence data, the oxygen consumption rate in the stratum basale is estimated to be ∼0.035 μmoles/10(6) cells/h. PMID:23332078

  14. In vivo measurement of human skin absorption of topically applied substances by a photoacoustic technique.

    PubMed

    Gutiérrez-Juárez, G; Vargas-Luna, M; Córdova, T; Varela, J B; Bernal-Alvarado, J J; Sosa, M

    2002-08-01

    A photoacoustic technique is used for studying topically applied substance absorption in human skin. The proposed method utilizes a double-chamber PA cell. The absorption determination was obtained through the measurement of the thermal effusivity of the binary system substance-skin. The theoretical model assumes that the effective thermal effusivity of the binary system corresponds to that of a two-phase system. Experimental applications of the method employed different substances of topical application in different parts of the body of a volunteer. The method is demonstrated to be an easily used non-invasive technique for dermatology research. The relative concentrations as a function of time of substances such as ketoconazol and sunscreen were determined by fitting a sigmoidal function to the data, while an exponential function corresponds to the best fit for the set of data for nitrofurazona, vaseline and vaporub. The time constants associated with the rates of absorption, were found to vary in the range between 10 and 58 min, depending on the substance and the part of the body. PMID:12214760

  15. Molecular events underlying maggot extract promoted rat in vivo and human in vitro skin wound healing.

    PubMed

    Li, Pei-Nan; Li, Hong; Zhong, Li-Xia; Sun, Yuan; Yu, Li-Jun; Wu, Mo-Li; Zhang, Lin-Lin; Kong, Qing-You; Wang, Shou-Yu; Lv, De-Cheng

    2015-01-01

    Maggot extracts promote wound healing, but their bioactive part(s) and molecular effects on the regenerating tissues/cells remain largely unclear. These issues are addressed here by treating rat skin wounds, human keratinocyte line/HaCat and fibroblasts with maggot secretion/excretion, and the extracts of maggots without and with secretion/excretion. The wound closure rates, cell proliferation activities, and statuses of wound healing-related signaling pathways (STAT3, Notch1, Wnt2, NF-κB, and TGF-beta/Smad3) and their downstream gene expression (c-Myc, cyclin D1, and VEGF) are evaluated by multiple approaches. The results reveal that the maggot extracts, especially the one from the maggots without secretion/excretion, show the best wound healing-promoting effects in terms of quicker wound closure rates and more rapid growth of keratinocytes and fibroblasts. Of the five signaling pathways checked, the ones mediated by TGF-beta/Smad3, and STAT3 are activated in the untreated wounds and become further enhanced by the maggot extracts, accompanied with c-Myc, VEGF, and cyclin D1 up-regulation. Our results thus show (1) that both body extract and secretion/excretion of maggots contain favorable wound healing elements and (2) that the enhancement of TGF-beta/Smad3 and STAT3 signaling activities may be the main molecular effects of maggot extracts on the wound tissues. PMID:25469773

  16. An unsupervised machine learning method for delineating stratum corneum in reflectance confocal microscopy stacks of human skin in vivo

    NASA Astrophysics Data System (ADS)

    Bozkurt, Alican; Kose, Kivanc; Fox, Christi A.; Dy, Jennifer; Brooks, Dana H.; Rajadhyaksha, Milind

    2016-02-01

    Study of the stratum corneum (SC) in human skin is important for research in barrier structure and function, drug delivery, and water permeability of skin. The optical sectioning and high resolution of reflectance confocal microscopy (RCM) allows visual examination of SC non-invasively. Here, we present an unsupervised segmentation algorithm that can automatically delineate thickness of the SC in RCM images of human skin in-vivo. We mimic clinicians visual process by applying complex wavelet transform over non-overlapping local regions of size 16 x 16 μm called tiles, and analyze the textural changes in between consecutive tiles in axial (depth) direction. We use dual-tree complex wavelet transform to represent textural structures in each tile. This transform is almost shift-invariant, and directionally selective, which makes it highly efficient in texture representation. Using DT-CWT, we decompose each tile into 6 directional sub-bands with orientations in +/-15, 45, and 75 degrees and a low-pass band, which is the decimated version of the input. We apply 3 scales of decomposition by recursively transforming the low-pass bands and obtain 18 bands of different directionality at different scales. We then calculate mean and variance of each band resulting in a feature vector of 36 entries. Feature vectors obtained for each stack of tiles in axial direction are then clustered using spectral clustering in order to detect the textural changes in depth direction. Testing on a set of 15 RCM stacks produced a mean error of 5.45+/-1.32 μm, compared to the "ground truth" segmentation provided by a clinical expert reader.

  17. Diamine oxidase-gold ultrastructural localization of histamine in human skin biopsies containing mast cells stimulated to degranulate in vivo by exposure to recombinant human stem cell factor.

    PubMed

    Dvorak, A M; Costa, J J; Morgan, E S; Monahan-Earley, R A; Galli, S J

    1997-10-15

    Stem cell factor (SCF) has a major role in hematopoiesis and in the regulation of mast cell development and function. For example, recombinant human SCF (rhSCF) can induce the development of human mast cells from precursor cells in vitro, stimulate mediator release from human skin mast cells in vitro, and promote both the development and functional activation of human skin mast cells in vivo. In the present study, we used a new ultrastructural enzyme-affinity method, employing diamine oxidase (DAO)-conjugated gold particles (DAO-gold), to detect histamine in skin biopsies obtained from patients with breast carcinomas who were receiving daily subcutaneous (SC) injections of rhSCF in a phase I study of this cytokine. We examined control biopsies obtained at sites remote from rhSCF injection as well as biopsies of rhSCF-injected skin that were obtained within 2 hours and 30 minutes of the SC injection of rhSCF at that site. The rhSCF-injected sites (which clinically exhibited a wheal-and-flare response), but not the control sites, contained mast cells undergoing regulated secretion by granule extrusion. The DAO-gold-affinity method detected histamine in electron-dense granules of mast cells in control and injected skin biopsies; however, the altered matrix of membrane-free, extruded mast cell granules was largely unreactive with DAO-gold. Notably, DAO-gold bound strongly to fibrin deposits and collagen fibers that were adjacent to degranulated mast cells. These findings represent the first morphologic evidence of histamine secretion by classical granule exocytosis in human mast cells in vivo. PMID:9376568

  18. Percutaneous absorption of PCBs from soil: In vivo rhesus monkey, in vitro human skin, and binding to powdered human stratum corneum

    SciTech Connect

    Wester, R.C.; Maibach, H.I.; Sedik, L.; Melendres, J.; Wade, M. )

    1993-07-01

    Polychlorinated biphenyls (PCBs) are ubiquitous and persistent environmental pollutants. The major resident site for these PCBs is the soil, and human skin is frequently in contact with soil. Our objective was to determine the percutaneous absorption of the PCBs Aroclor 1242 and Aroclor 1254 from soil. PCB-contaminated soil was prepared at levels of 44 ppm Aroclor 1242 and 23 ppm Aroclor 1254. PCB concentrations on skin were 1.75 micrograms/cm2 for Aroclor 1242 and 0.91 microgram/cm2 for Aroclor 1254. In vivo percutaneous absorption in the rhesus monkey was determined by urinary and fecal [14C]-PCB excretion for a 5-wk period following topical dosing. Absorption of Aroclor 1242 was determined in vitro with human skin for comparative purposes. In vivo in the rhesus monkey the percutaneous absorption of Aroclor 1242 was 13.8 +/- 2.7 (SD)% of the dose and the absorption of Aroclor 1254 was 14.1 +/- 1.0%. These absorption amounts are similar to the absorption of Aroclor 1242 and 1254 from other vehicles (mineral oil, trichlorobenzene, acetone). With in vitro percutaneous absorption through human skin, most of the Aroclor 1242 and Aroclor 1254 resided in the skin and the amounts were dependent upon dosing vehicle (water > mineral oil > soil). Both PCBs readily partitioned from water into soil and human powdered stratum corneum. By difference the partitioning favored both PCBs going from soil into stratum corneum. These data emphasize the role of soil in percutaneous absorption and provide information for appropriate risk assessment.

  19. Skin2--an in vitro human skin model: the correlation between in vivo and in vitro testing of surfactants.

    PubMed

    Demetrulias, J; Donnelly, T; Morhenn, V; Jessee, B; Hainsworth, S; Casterton, P; Bernhofer, L; Martin, K; Decker, D

    1998-02-01

    The availability of an in vitro test system to replace animal testing of potential irritants is becoming more and more urgent especially in Europe as a consequence of the European Community Cosmetics Directive. To evaluate the ability of Advanced Tissue Sciences' (ATS) ZK1301 skin model to predict the skin irritation potential of surfactants, we performed a pilot validation study utilizing four different laboratories. The in vitro protocol was designed as a quantitative pre-screen for the clinical patch studies. Sixteen substances, representing various surfactant categories and ranges of irritation potential, were tested. The 3-[4,5-Dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay was used to quantitate viability in vitro. We documented the viability of tissues exposed to unknown substances for specific periods. The in vitro results were calculated as percent distilled water controls (DWC). The time required to reduce the viability of each tissue to 50% of the distilled water controls (T50) was compared to mean erythema and edema scores from the clinical studies by Pearson's correlation. The individual laboratories demonstrated coefficients of 0.72. The results indicated that the 30 min percent untreated control values best predicted the 24 h clinical patch scores. No statistically significant interlab variability was found. Only one false negative was seen when non/mild and moderate/severe irritant categories were assigned according to the in vitro scores. These results demonstrate that the skin2 in vitro test system may serve as a good screening method prior to clinical patch studies. PMID:9517918

  20. In vivo analysis of tissue by Raman microprobe: examination of human skin lesions and esophagus Barrett's mucosa on an animal model

    NASA Astrophysics Data System (ADS)

    Tfayli, Ali; Piot, Olivier; Derancourt, Sylvie; Cadiot, Guillaume; Diebold, Marie D.; Bernard, Philippe; Manfait, Michel

    2006-02-01

    In the last few years, Raman spectroscopy has been increasingly used for the characterization of normal and pathological tissues. A new Raman system, constituted of optic fibers bundle coupled to an axial Raman spectrometer (Horiba Jobin Yvon SAS), was developed for in vivo investigations. Here, we present in vivo analysis on two tissues: human skin and esophagus mucosa on a rat model. The skin is a directly accessible organ, representing a high diversity of lesions and cancers. Including malignant melanoma, basal cell carcinoma and the squamous cell carcinoma, skin cancer is the cancer with the highest incidence worldwide. Several Raman investigations were performed to discriminate and classify different types of skin lesions, on thin sections of biopsies. Here, we try to characterize in vivo the different types of skin cancers in order to be able to detect them in their early stages of development and to define precisely the exeresis limits. Barrett's mucosa was also studied by in vivo examination of rat's esophagus. Barrett's mucosa, induced by gastro-esophageal reflux, is a pretumoral state that has to be carefully monitored due to its high risk of evolution in adenocarcinoma. A better knowledge of the histological transformation of esophagus epithelium in a Barrett's type will lead to a more efficient detection of the pathology for its early diagnosis. To study these changes, an animal model (rats developing Barrett's mucosa after duodenum - esophagus anastomosis) was used. Potential of vibrational spectroscopy for Barrett's mucosa identification is assessed on this model.

  1. Gaussian-function-based deconvolution method to determine the penetration ability of petrolatum oil into in vivo human skin using confocal Raman microscopy

    NASA Astrophysics Data System (ADS)

    Choe, Chun-Sik; Lademann, Jürgen; Darvin, Maxim E.

    2014-10-01

    Human skin pre-treated with petrolatum was analyzed in vivo using confocal Raman microscopy in order to determine the penetration depth of the oil into the skin. The broad Raman peak (2820-3030 cm-1) measured in vivo on human skin in the high wavenumber region exhibits two prominent main Raman peaks at 2880 cm-1 and 2935 cm-1 that originated from cutaneous lipids and keratin and two main peak shoulders at 2850 cm-1 and 2980 cm-1 that originated from lipids and keratin, respectively. Topical application of petrolatum oil onto the skin gives rise to an increase of the intensity of the broad lipid-keratin Raman peak (2820-3030 cm-1). Herewith, not only the intensity of the lipid part but also of the keratin part is increased, making the normalization to keratin and the determination of the petrolatum penetration profile erroneous. To solve this problem, the Gaussian-function-based deconvolution method is introduced in analyzing the Raman spectrum of the lipid-keratin peak and the least square method is applied for analyzing the petrolatum penetration profile. Results obtained in vivo show that the petrolatum oil does not penetrate deeper than 10 µm into intact human skin.

  2. In vivo quantification of propylene glycol, glucose and glycerol diffusion in human skin with optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Guo, X.; Guo, Z. Y.; Wei, H. J.; Yang, H. Q.; He, Y. H.; Xie, S. S.; Wu, G. Y.; Zhong, H. Q.; Li, L. Q.; Zhao, Q. L.

    2010-09-01

    The purpose of study is to quantify and compare diffusion of propylene glycol, glucose, glycerol in the human skin in vivo noninvasively. Optical coherence tomography (OCT) was utilized in the functional imaging of optical cleaning agents for monitoring and quantifying the permeability coefficients (PCs) of them. Our experiments showed that the permeability coefficient of 40% propylene glycol from different subjects was averaged and found to be (2.52 ± 0.02) × 10-6 cm/s, the permeability coefficient of 40% glucose was (1.94 ± 0.05) × 10-6 cm/s, and the permeability coefficient of 40% glycerol was (1.82 ± 0.04) × 10-6 cm/s. The results indicated that the diffusion of propylene glycol solutions was faster than that of glucose solution, and the diffusion of glucose solutions was faster than that of glycerol solutions. The dependence of the permeability on the different hyperosmotic analytes could potentially be used in various basic science and clinical fields, such as optical clearing of tissues and cells as well as in clinical pharmacology.

  3. Intravital multiphoton tomography as a novel tool for non-invasive in vivo analysis of human skin affected with atopic dermatitis

    NASA Astrophysics Data System (ADS)

    Huck, Volker; Gorzelanny, Christian; Thomas, Kai; Niemeyer, Verena; Luger, Thomas A.; König, Karsten; Schneider, Stefan W.

    2010-02-01

    Atopic Dermatitis (AD) is an inflammatory disease of human skin. Its pathogenesis is still unknown; however, dysfunctions of the epidermal barrier and the immune response are regarded as key factors for the development of AD. In our study we applied intravital multiphoton tomography (5D-IVT), equipped with a spectral-FLIM module for in-vivo and ex-vivo analysis of human skin affected with AD. In addition to the morphologic skin analysis, FLIM technology gain access to the metabolic status of the epidermal cells referring to the NADH specific fluorescence lifetime. We evaluated a characteristic 5D-IVT skin pattern of AD in comparison to histological sections and detected a correlation with the disease activity measured by SCORAD. FLIM analysis revealed a shift of the mean fluorescence lifetime (taum) of NADH, indicating an altered metabolic activity. Within an ex-vivo approach we have investigated cryo-sections of human skin with or without barrier defects. Spectral-FLIM allows the detection of autofluorescent signals that reflect the pathophysiological conditions of the defect skin barrier. In our study the taum value was shown to be different between healthy and affected skin. Application of the 5D-IVT allows non-invasive in-vivo imaging of human skin with a penetration depth of 150 μm. We could show that affected skin could be distinguished from healthy skin by morphological criteria, by FLIM and by spectral-FLIM. Further studies will evaluate the application of the 5D-IVT technology as a diagnostic tool and to monitor the therapeutic efficacy.

  4. Full-pupil versus divided-pupil confocal line-scanners for reflectance imaging of human skin in vivo

    NASA Astrophysics Data System (ADS)

    Gareau, Dan; Abeytunge, Sanjeewa; Rajadhyaksha, Milind

    2007-02-01

    A full-pupil confocal line-scanning microscope is under development for imaging human skin in vivo in reflectance. The new design potentially offers an alternative to current point- and line-scanners that may simplify the optics, electronics and mechanics, and lead to simpler and smaller confocal microscopes. With a combination of a cylindrical lens and an objective lens, the line-scanner creates a focused line of laser light in the object plane within tissue. An oscillating galvanometric mirror scans the focused line transverse to its axis. The backscattered light from the tissue is de-scanned and focused onto a linear CMOS detector array. Preliminary measurements of the axial line-spread function, with a 30x, 0.9-NA water immersion objective lens and illumination wavelength of 633 nm, determined the optical sectioning to be 10 μm. The new design is simple, requiring only eight optical components. However, the disadvantage is non-confocality in one dimension that results in 20% weaker sectioning than with a point-scanner, and reduced contrast in scattering tissue. The images of standard reflective targets such as a mirror and grating as well as dermis-like scattering target such as paper offer a preliminary glimpse into the performance of the line-scanner. A similar alternative design is the divided-pupil (theta) line-scanner, which provides 50% weaker sectioning than with a point scanner, but better contrast and less speckle due to the theta configuration. Such line scanners may prove useful for routine imaging of humans in clinical settings.

  5. Mechanical characterisation of in vivo human skin using a 3D force-sensitive micro-robot and finite element analysis.

    PubMed

    Flynn, Cormac; Taberner, Andrew; Nielsen, Poul

    2011-02-01

    The complex mechanical properties of skin have been the subject of much study in recent years. Several experimental methods developed to measure the mechanical properties of skin in vivo, such as suction or torsion, are unable to measure skin's anisotropic characteristics. An experiment characterising the mechanical properties of in vivo human skin using a novel force-sensitive micro-robot is presented. The micro-robot applied in-plane deformations to the anterior forearm and the posterior upper arm. The behaviour of the skin in each area is highly nonlinear, anisotropic, and viscoelastic. The response of the upper arm skin is very dependent on the orientation of the arm. A finite element model consisting of an Ogden strain energy function and quasi-linear viscoelasticity was developed to simulate the experiments. An orthogonal initial stress field, representing the in vivo skin tension, was used as an additional model parameter. The model simulated the experiments accurately with an error-of-fit of 17.5% for the anterior lower forearm area, 6.5% for the anterior upper forearm and 9.3% for the posterior upper arm. The maximum in vivo tension in each area determined by the model was 6.2 Nm(-1) in the anterior lower forearm, 11.4 Nm(-1) in anterior upper forearm and 5.6 Nm(-1) in the posterior upper arm. The results also show that a finite element model with a neo-Hookean strain energy function cannot simulate the experiments with the same accuracy. PMID:20429025

  6. Non-invasive in-vivo Raman spectroscopic measurement of the dynamics of the antioxidant substance lycopene in the human skin after a dietary supplementation

    NASA Astrophysics Data System (ADS)

    Darvin, M. E.; Gersonde, I.; Albrecht, H.; Sterry, W.; Lademann, J.

    2007-05-01

    A non-invasive optical method based on resonance Raman spectroscopy was used for the in vivo detection of the concentration of the carotenoid antioxidant substance lycopene in the human skin. The physiological variation of the level of lycopene in the skin during a 6 month period was measured daily in 7 volunteers. It was shown that all volunteers had a different individual level of lycopene in the skin, depending on the lifestyle of volunteers. It was shown that the supplementation of the foodstuffs containing lycopene, such as tomato products and some fruits, increases the level of lycopene in the skin. The increase in the lycopene level can be usually observed on the next day after the supplementation. The present results demonstrate that a diet rich in products containing a high amount of carotenoids, such as lycopene, can be an efficient strategy to increase the carotenoid level of the skin.

  7. Measurements of the thermal coefficient of optical attenuation at different depth regions of in vivo human skins using optical coherence tomography: a pilot study

    PubMed Central

    Su, Ya; Yao, X. Steve; Li, Zhihong; Meng, Zhuo; Liu, Tiegen; Wang, Longzhi

    2015-01-01

    We present detailed measurement results of optical attenuation’s thermal coefficients (referenced to the temperature of the skin surface) in different depth regions of in vivo human forearm skins using optical coherence tomography (OCT). We first design a temperature control module with an integrated optical probe to precisely control the surface temperature of a section of human skin. We propose a method of using the correlation map to identify regions in the skin having strong correlations with the surface temperature of the skin and find that the attenuation coefficient in these regions closely follows the variation of the surface temperature without any hysteresis. We observe a negative thermal coefficient of attenuation in the epidermis. While in dermis, the slope signs of the thermal coefficient of attenuation are different at different depth regions for a particular subject, however, the depth regions with a positive (or negative) slope are different in different subjects. We further find that the magnitude of the thermal coefficient of attenuation coefficient is greater in epidermis than in dermis. We believe the knowledge of such thermal properties of skins is important for several noninvasive diagnostic applications, such as OCT glucose monitoring, and the method demonstrated in this paper is effective in studying the optical and biological properties in different regions of skin. PMID:25780740

  8. Recovery of Aging-Related Size Increase of Skin Epithelial Cells: In vivo Mouse and In vitro Human Study

    PubMed Central

    Sokolov, Igor; Guz, Natali V.; Iyer, Swaminathan; Hewitt, Amy; Sokolov, Nina A.; Erlichman, Joseph S.; Woodworth, Craig D.

    2015-01-01

    The size increase of skin epithelial cells during aging is well-known. Here we demonstrate that treatment of aging cells with cytochalasin B substantially decreases cell size. This decrease was demonstrated on a mouse model and on human skin cells in vitro. Six nude mice were treated by topical application of cytochalasin B on skin of the dorsal left midsection for 140 days (the right side served as control for placebo treatment). An average decrease in cell size of 56±16% resulted. A reduction of cell size was also observed on primary human skin epithelial cells of different in vitro age (passages from 1 to 8). A cell strain obtained from a pool of 6 human subjects was treated with cytochalasin B in vitro for 12 hours. We observed a decrease in cell size that became statistically significant and reached 20–40% for cells of older passage (6–8 passages) whereas no substantial change was observed for younger cells. These results may be important for understanding the aging processes, and for cosmetic treatment of aging skin. PMID:25807526

  9. Intravital multiphoton tomography as an appropriate tool for non-invasive in vivo analysis of human skin affected with atopic dermatitis

    NASA Astrophysics Data System (ADS)

    Huck, Volker; Gorzelanny, Christian; Thomas, Kai; Mess, Christian; Dimitrova, Valentina; Schwarz, Martin; Riemann, Iris; Niemeyer, Verena; Luger, Thomas A.; König, Karsten; Schneider, Stefan W.

    2011-03-01

    Increasing incidence of inflammatory skin diseases such as Atopic Dermatitis (AD) has been noted in the past years. According to recent estimations around 15% of newborn subjects are affected with a disease severity that requires medical treatment. Although its pathogenesis is multifactorial, recent reports indicate that an impaired physical skin barrier predispose for the development of AD. The major part of this barrier is formed by the stratum corneum (SC) wherein corneocytes are embedded in a complex matrix of proteins and lipids. Its components were synthesized in the stratum granulosum (SG) and secreted via lamellar bodies at the SC/SG interface. Within a clinical in vivo study we focused on the skin metabolism at the SC/SG interface in AD affected patients in comparison to healthy subjects. Measurement of fluorescence life-time of NADH provides access to the metabolic state of skin. Due to the application of a 5D intravital tomographic skin analysis we facilitate the non-invasive investigation of human epidermis in the longitudinal course of AD therapy. We could ascertain by blinded analysis of 40 skin areas of 20 patients in a three month follow-up that the metabolic status at the SC/SG interface was altered in AD compromised skin even in non-lesional, apparent healthy skin regions. This illustrates an impaired skin barrier formation even at non-affected skin of AD subjects appearing promotive for the development of acute skin inflammation. Therefore, our findings allow a deeper understanding of the individual disease development and the improved management of the therapeutic intervention in clinical application.

  10. Responsive corneosurfametry following in vivo skin preconditioning.

    PubMed

    Uhoda, E; Goffin, V; Pierard, G E

    2003-12-01

    Skin is subjected to many environmental threats, some of which altering the structure and function of the stratum corneum. Among them, surfactants are recognized factors that may influence irritant contact dermatitis. The present study was conducted to compare the variations in skin capacitance and corneosurfametry (CSM) reactivity before and after skin exposure to repeated subclinical injuries by 2 hand dishwashing liquids. A forearm immersion test was performed on 30 healthy volunteers. 2 daily soak sessions were performed for 5 days. At inclusion and the day following the last soak session, skin capacitance was measured and cyanoacrylate skin-surface strippings were harvested. The latter specimens were used for the ex vivo microwave CSM. Both types of assessments clearly differentiated the 2 hand dishwashing liquids. The forearm immersion test allowed the discriminant sensitivity of CSM to increase. Intact skin capacitance did not predict CSM data. By contrast, a significant correlation was found between the post-test conductance and the corresponding CSM data. In conclusion, a forearm immersion test under realistic conditions can discriminate the irritation potential between surfactant-based products by measuring skin conductance and performing CSM. In vivo skin preconditioning by surfactants increases CSM sensitivity to the same surfactants. PMID:15025702

  11. In-vivo fluorescence dosimetry of aminolevulinate-based protoporphyrin IX (PpIX) accumulation in human nonmelanoma skin cancers and precancers

    NASA Astrophysics Data System (ADS)

    Warren, Christine B.; Lohser, Sara; Chang, Sung; Bailin, Philip A.; Maytin, Edward V.

    2009-06-01

    PDT is clinically useful for precancers (actinic keratoses; AK) of the skin, but the optimal duration for 5-ALA application is still controversial. For basal cell carcinoma (BCC) and squamous cell carcinoma (SCC), cure rates remain inferior to surgical excision. Lack of knowledge about regional levels of PpIX levels within target tissues clearly contribute to these suboptimal results. To investigate PpIX levels achievable in human skin neoplasias in-vivo, a clinical study to monitor PpIX accumulation in vivo was performed. PpIX-fluorescence in patients undergoing ALA-PDT for facial AK was monitored via real-time in-vivo fluorescence dosimetry, with measurements q20 min following application of 5-ALA (Levulan Kerastick). PpIX accumulation followed linear kinetics in nearly all cases. The slopes varied widely, and did not correlate with clinical outcome in all patients. Some patients with a low accumulation of PpIX fluorescence had a good response to therapy, whereas others with high PpIX accumulation required repeat treatment (although not necessarily of the same lesion). PpIX accumulation rates did correlate to a certain degree with the overall amount of erythema. We conclude that unknown factors besides PpIX levels must be critical for the response to treatment. To assess the relationship between PpIX levels in various skin cancers, patients undergoing routine Mohs surgery for BCC or SCC were measured by in-vivo dosimetry at 2 h after 5-ALA application. Overall, a progressive increase in PpIX signal during malignant progression was observed, in the following rank order: Normal skin < AK < SCC ~ BCC.

  12. In vivo multiphoton imaging of human skin: assessment of topical corticosteroid-induced epidermis atrophy and depigmentation

    NASA Astrophysics Data System (ADS)

    Ait El Madani, Hassan; Tancrède-Bohin, Emmanuelle; Bensussan, Armand; Colonna, Anne; Dupuy, Alain; Bagot, Martine; Pena, Ana-Maria

    2012-02-01

    Multiphoton microscopy has emerged in the past decade as a promising tool for noninvasive skin imaging. Our aim was to evaluate the potential of multiphoton microscopy to detect topical corticosteroids side effects within the epidermis and to provide new insights into their dynamics. Healthy volunteers were topically treated with clobetasol propionate on a small region of their forearms under overnight occlusion for three weeks. The treated region of each patient was investigated at D0, D7, D15, D22 (end of the treatment), and D60. Our study shows that multiphoton microscopy allows for the detection of corticoid-induced epidermis modifications: thinning of stratum corneum compactum and epidermis, decrease of keratinocytes size, and changes in their morphology from D7 to D22. We also show that multiphoton microscopy enables in vivo three-dimensional (3-D) quantitative assessment of melanin content. We observe that melanin density decreases during treatment and almost completely disappears at D22. Moreover, these alterations are reversible as they are no longer present at D60. Our study demonstrates that multiphoton microscopy is a convenient and powerful tool for noninvasive 3-D dynamical studies of skin integrity and pigmentation.

  13. Assessment of dermal toxicity of nanosilica using cultured keratinocytes, a human skin equivalent model and an in vivo model.

    PubMed

    Park, Yoon-Hee; Kim, Ji Na; Jeong, Sang Hoon; Choi, Jae Eun; Lee, Seung-Ho; Choi, Byeong Hyeok; Lee, Jung Pyo; Sohn, Kyung Hee; Park, Kui Lea; Kim, Meyoung-Kon; Son, Sang Wook

    2010-01-12

    Assessments of skin irritation potentials are important aspects of the development of nanotechnology. Nanosilica is currently being widely used for commercial purposes, but little literature is available on its skin toxicity and irritation potential. This study was designed to determine whether nanosilica has the potential to cause acute cutaneous toxicity, using cultured HaCaT keratinocytes (CHK), a human skin equivalent model (HSEM), and invivo model. Nanosilica was characterized by scanning electron microscopy. We evaluated the cytotoxic effects of nanosilica on CHKs and the HSEM. In addition, we also investigated whether two commercially available nanosilicas with different sizes (7 and 10-20 nm) have different effects. To confirm invitro results, we evaluated the irritation potentials of nanosilicas on rabbit skin. Nanosilicas reduced the cell viabilities of CHKs in a dose-dependent manner. However, the HSEM revealed no irritation at 500 microg/ml of nanosilica. Furthermore, this result concurred with Draize skin irritation test findings. The present study data indicate that nanosilica does not cause acute cutaneous irritation. Furthermore, this study shows that the HSEM used provides more useful screening data than the conventional cell culture model on the relative toxicities of NPs. PMID:19850098

  14. Skin metabolism of aminophenols: Human keratinocytes as a suitable in vitro model to qualitatively predict the dermal transformation of 4-amino-2-hydroxytoluene in vivo

    SciTech Connect

    Goebel, C. Hewitt, N.J.; Kunze, G.; Wenker, M.; Hein, D.W.; Beck, H.; Skare, J.

    2009-02-15

    4-Amino-2-hydroxytolune (AHT) is an aromatic amine ingredient in oxidative hair colouring products. As skin contact occurs during hair dyeing, characterisation of dermal metabolism is important for the safety assessment of this chemical class. We have compared the metabolism of AHT in the human keratinocyte cell line HaCaT with that observed ex-vivo in human skin and in vivo (topical application versus oral (p.o.) and intravenous (i.v.) route). Three major metabolites of AHT were excreted, i.e. N-acetyl-AHT, AHT-sulfate and AHT-glucuronide. When 12.5 mg/kg AHT was applied topically, the relative amounts of each metabolite were altered such that N-acetyl-AHT product was the major metabolite (66% of the dose in comparison with 37% and 32% of the same applied dose after i.v. and p.o. administration, respectively). N-acetylated products were the only metabolites detected in HaCaT cells and ex-vivo whole human skin discs for AHT and p-aminophenol (PAP), an aromatic amine known to undergo N-acetylation in vivo. Since N-acetyltransferase 1 (NAT1) is the responsible enzyme, kinetics of AHT was further compared to the standard NAT1 substrate p-aminobenzoic acid (PABA) in the HaCaT model revealing similar values for K{sub m} and V{sub max}. In conclusion NAT1 dependent dermal N-acetylation of AHT represents a 'first-pass' metabolism effect in the skin prior to entering the systemic circulation. Since the HaCaT cell model represents a suitable in vitro assay for addressing the qualitative contribution of the skin to the metabolism of topically-applied aromatic amines it may contribute to a reduction in animal testing.

  15. Deficiency of dermcidin-derived antimicrobial peptides in sweat of patients with atopic dermatitis correlates with an impaired innate defense of human skin in vivo.

    PubMed

    Rieg, Siegbert; Steffen, Heiko; Seeber, Silke; Humeny, Andreas; Kalbacher, Hubert; Dietz, Klaus; Garbe, Claus; Schittek, Birgit

    2005-06-15

    Antimicrobial peptides are an integral part of the epithelial innate defense system. Dermcidin (DCD) is a recently discovered antimicrobial peptide with a broad spectrum of activity. It is constitutively expressed in human eccrine sweat glands and secreted into sweat. Patients with atopic dermatitis (AD) have recurrent bacterial or viral skin infections and pronounced colonization with Staphylococcus aureus. We hypothesized that patients with AD have a reduced amount of DCD peptides in sweat contributing to the compromised constitutive innate skin defense. Therefore, we performed semiquantitative and quantitative analyses of DCD peptides in sweat of AD patients and healthy subjects using surface-enhanced laser desorption ionization time-of-flight mass spectrometry and ELISA. The data indicate that the amount of several DCD-derived peptides in sweat of patients with AD is significantly reduced. Furthermore, compared with atopic patients without previous infectious complications, AD patients with a history of bacterial and viral skin infections were found to have significantly less DCD-1 and DCD-1L in their sweat. To analyze whether the reduced amount of DCD in sweat of AD patients correlates with a decreased innate defense, we determined the antimicrobial activity of sweat in vivo. We showed that in healthy subjects, sweating leads to a reduction of viable bacteria on the skin surface, but this does not occur in patients with AD. These data indicate that reduced expression of DCD in sweat of patients with AD may contribute to the high susceptibility of these patients to skin infections and altered skin colonization. PMID:15944307

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

    PubMed

    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. PMID:22151394

  17. Evaluating the Photoprotective Effects of Ochre on Human Skin by In Vivo SPF Assessment: Implications for Human Evolution, Adaptation and Dispersal.

    PubMed

    Rifkin, Riaan F; Dayet, Laure; Queffelec, Alain; Summers, Beverley; Lategan, Marlize; d'Errico, Francesco

    2015-01-01

    Archaeological indicators of cognitively modern behaviour become increasingly prevalent during the African Middle Stone Age (MSA). Although the exploitation of ochre is viewed as a key feature of the emergence of modern human behaviour, the uses to which ochre and ochre-based mixtures were put remain ambiguous. Here we present the results of an experimental study exploring the efficacy of ochre as a topical photoprotective compound. This is achieved through the in vivo calculation of the sun protection factor (SPF) values of ochre samples obtained from Ovahimba women (Kunene Region, Northern Namibia) and the Palaeozoic Bokkeveld Group deposits of the Cape Supergroup (Western Cape Province, South Africa). We employ visible spectroscopy, energy-dispersive X-ray fluorescence (ED-XRF), X-ray diffraction (XRD) and granulometric analyses to characterise ochre samples. The capacity of ochre to inhibit the susceptibility of humans to the harmful effects of exposure to ultraviolet radiation (UVR) is confirmed and the mechanisms implicated in the efficacy of ochre as a sunscreen identified. It is posited that the habitual application of ochre may have represented a crucial innovation for MSA humans by limiting the adverse effects of ultraviolet exposure. This may have facilitated the colonisation of geographic regions largely unfavourable to the constitutive skin colour of newly arriving populations. PMID:26353012

  18. Evaluating the Photoprotective Effects of Ochre on Human Skin by In Vivo SPF Assessment: Implications for Human Evolution, Adaptation and Dispersal

    PubMed Central

    Rifkin, Riaan F.; Dayet, Laure; Queffelec, Alain; Summers, Beverley; Lategan, Marlize; d’Errico, Francesco

    2015-01-01

    Archaeological indicators of cognitively modern behaviour become increasingly prevalent during the African Middle Stone Age (MSA). Although the exploitation of ochre is viewed as a key feature of the emergence of modern human behaviour, the uses to which ochre and ochre-based mixtures were put remain ambiguous. Here we present the results of an experimental study exploring the efficacy of ochre as a topical photoprotective compound. This is achieved through the in vivo calculation of the sun protection factor (SPF) values of ochre samples obtained from Ovahimba women (Kunene Region, Northern Namibia) and the Palaeozoic Bokkeveld Group deposits of the Cape Supergroup (Western Cape Province, South Africa). We employ visible spectroscopy, energy-dispersive X-ray fluorescence (ED-XRF), X-ray diffraction (XRD) and granulometric analyses to characterise ochre samples. The capacity of ochre to inhibit the susceptibility of humans to the harmful effects of exposure to ultraviolet radiation (UVR) is confirmed and the mechanisms implicated in the efficacy of ochre as a sunscreen identified. It is posited that the habitual application of ochre may have represented a crucial innovation for MSA humans by limiting the adverse effects of ultraviolet exposure. This may have facilitated the colonisation of geographic regions largely unfavourable to the constitutive skin colour of newly arriving populations. PMID:26353012

  19. Increased epidermal cell proliferation in normal human skin in vivo following local administration of interferon-gamma.

    PubMed Central

    Barker, J. N.; Goodlad, J. R.; Ross, E. L.; Yu, C. C.; Groves, R. W.; MacDonald, D. M.

    1993-01-01

    Recombinant human interferon-gamma was administered intradermally (10 micrograms in 0.1 ml) to healthy adult human volunteers from day 1 to day 3, and epidermal cell proliferation was measured on whole skin biopsies at day 6. Three independent parameters were assessed, namely, a) epidermal keratin-16 expression, b) keratinocyte proliferating cell nuclear antigen expression, and c) keratinocyte silver nucleolar organizer region counts. Significantly increased scores for each parameter were observed after interferon-gamma injection (P < 0.01 in each case) compared to site-matched controls. Keratin-16 expression was confined to suprabasal epidermis, whereas proliferating cell nuclear antigen and silver nucleolar organizer region counts were particularly elevated in the basal epidermis. Taken together with previous findings, these studies indicate both proinflammatory and growth regulatory roles for interferon-gamma in human skin. These data are likely to be of particular importance to pathophysiological mechanisms of psoriasis and related cutaneous inflammatory diseases. Images Figure 1 Figure 2 Figure 3 PMID:7682760

  20. Reduction of image artifacts in three-dimensional optical coherence tomography of skin in vivo.

    PubMed

    Liew, Yih Miin; McLaughlin, Robert A; Wood, Fiona M; Sampson, David D

    2011-11-01

    This paper presents results of in vivo studies on the effect of refractive index-matching media on image artifacts in optical coherence tomography (OCT) images of human skin. These artifacts present as streaks of artificially low backscatter and displacement or distortion of features. They are primarily caused by refraction and scattering of the OCT light beam at the skin surface. The impact of the application of glycerol and ultrasound gel is assessed on both novel skin-mimicking phantoms and in vivo human skin, including assessment of the epidermal thickening caused by the media. Based on our findings, recommendations are given for optimal OCT imaging of skin in vivo. PMID:22112123

  1. In vitro and in vivo percutaneous absorption of organoleads, lead salts, and inorganic lead in guinea pig and human autopsy skin

    SciTech Connect

    Bress, W.C.

    1984-01-01

    Using diffusion tubes, the degree of penetration of tetrabutyl lead, lead napthanate, lead nuolate, lead acetate and lead oxide through guinea pig skin and human skin from autopsy was measured. Tetrabutyl lead demonstrated the greatest absorption in both the guinea pig and man. Lead nuolate, lead napthanate and lead acetate followed in descending order with the human tissue. The same leads, applied to guinea pig skin, followed a similar pattern of absorption in most cases. There were no measureable amounts of lead oxide absorbed in either species. Tetrabutyl lead, lead nuolate, lead napthanate, lead acetate and lead oxide were applied to the shaved backs of guinea pigs at 300mg/kg, under an occluded wrapping, daily, for seven days. Tissue concentrations of lead were highest when tetrabutyl lead was applied. The application of lead nuolate caused higher concentrations of lead in liver and kidney, than the corresponding applicaiton of lead napthanate. Lead acetate was poorly absorbed. No absorption was evidenced in the case of the lead oxide application. Light microscopic examination of integument, treated with tetrabutyl lead, revealed marked inflammation within the dermis. Inflammation was less marked in the integument of animals treated with lead napthanate and lead nuolate. Staining with sodium rhodizonate proved unsuccessful, but treatment of tissues exposed to lead nuolate and lead napthanate with ammonium sulfide showed evidence of lead on the stratum corneum and hair shafts. Correlation between the in vitro and in vivo data, as well as the comparison of human and guinea pig results, are discussed.

  2. Impact of refractive index mismatches on coherent anti-Stokes Raman scattering and multiphoton autofluorescence tomography of human skin in vivo.

    PubMed

    Weinigel, M; Breunig, H G; Darvin, M E; Klemp, M; Röwert-Huber, J; Lademann, J; König, K

    2015-09-01

    Optical non-linear multimodal tomography is a powerful diagnostic imaging tool to analyse human skin based on its autofluorescence and second-harmonic generation signals. Recently, the field of clinical non-linear imaging has been extended by adding coherent anti-Stokes Raman scattering (CARS)-a further optical sectioning method for the detection of non-fluorescent molecules. However, the heterogeneity of refractive indices of different substances in complex tissues like human skin can have a strong influence on CARS image formation and requires careful clinical interpretation of the detected signals. Interestingly, very regular patterns are present in the CARS images, which have no correspondence to the morphology revealed by autofluorescence at the same depth. The purpose of this paper is to clarify this phenomenon and to sensitize users for possible artefacts. A further part of this paper is the detailed comparison of CARS and autofluorescence images of healthy human skin in vivo covering the complete epidermis and part of the upper dermis by employing the flexible medical non-linear tomograph MPTflex CARS. PMID:26305454

  3. 5D-intravital tomography as a novel tool for non-invasive in-vivo analysis of human skin

    NASA Astrophysics Data System (ADS)

    König, Karsten; Weinigel, Martin; Breunig, Hans G.; Gregory, Axel; Fischer, Peter; Kellner-Höfer, Marcel; Bückle, Rainer; Schwarz, Martin; Riemann, Iris; Stracke, Frank; Huck, Volker; Gorzelanny, Christian; Schneider, Stefan W.

    2010-02-01

    Some years ago, CE-marked clinical multiphoton systems for 3D imaging of human skin with subcellular resolution have been launched. These tomographs provide optical biopsies with submicron resolution based on two-photon excited autofluorescence (NAD(P)H, flavoproteins, keratin, elastin, melanin, porphyrins) and second harmonic generation by collagen. The 3D tomograph was now transferred into a 5D imaging system by the additional detection of the emission spectrum and the fluorescence lifetime based on spatially and spectrally resolved time-resolved single photon counting. The novel 5D intravital tomograph (5D-IVT) was employed for the early detection of atopic dermatitis and the analysis of treatment effects.

  4. Dose-survival relationship for epithelial cells of human skin after multifraction irradiation: evaluation by a quantitative method in vivo

    SciTech Connect

    Arcangeli, G.; Mauro, F.; Nervi, C.; Withers, H.R.

    1980-07-01

    The dose-survival relationship for normal epithelial cells after single and fractionated radiation exposures has been established by Withers for the mouse, but it is not available for humans according to a strict criterion for survival of single cell reproductive integrity. In an attempt to obtain such a quantitative estimation, 2 patients requiring radical radiation therapy to the chest wall were treated according to particular Multiple Daily Fractionation (MDF) protocols: i) 250 + 150 + 150 rad/day, 4 hr interval, 5 days/week; and ii) 150 + 150 + 150 + 150 rad/day, 3.5 hr interval, 5 days/week. In both cases, different strips of skin received different total doses: 6300, 6850, and 7150 rad, and 6300, 6750, and 7200 rad, respectively. In case (i), moist desquamation appeared and thereafter repopulating colonies of epithelium could be recognized and counted. Using these counts a survival curve having a D/sub o/ value of 490 +- 150 rad was estimated according to the formula proposed by Withers. In case (ii), no moist desquamation was reached at the doses delivered. The difference observed may imply that the initial region of the survival curve deviates appreciably from exponential between doses of 150 and 250 rad. If such is the case, a /sub 1/D/sub o/ value of 490 rad may represent an underestimate. These results are discussed from the point of view of both the shape of the survival curve and the effectiveness of nonconventional fractionation courses.

  5. In vitro and in vivo comparison of dermal irritancy of jet fuel exposure using EpiDerm (EPI-200) cultured human skin and hairless rats.

    PubMed

    Chatterjee, Abhijit; Babu, R Jayachandra; Klausner, M; Singh, Mandip

    2006-12-01

    The purpose of this study was to evaluate an in vitro EpiDerm human skin model (EPI-200) to study the irritation potential of jet fuels (JP-8 and JP-8+100). Parallel in vivo studies on hairless rats on the dermal irritancy of jet fuels were also conducted. Cytokines are an important part of an irritation and inflammatory cascade, which are expressed in upon dermal exposures of irritant chemicals even when there are no obvious visible marks of irritation on the skin. We have chosen two primary cytokines (IL-1alpha and TNF-1alpha) as markers of irritation response of jet fuels. Initially, the EPI-200 was treated with different quantities of JP-8 and JP-8+100 to determine quantities which did not cause significant cytotoxicity, as monitored using the MTT assay and paraffin embedded histological cross-sections. Volumes of 2.5-50 microl/tissue (approximately 4.0-78 microl/cm2) of JP-8 and JP-8+100 showed a dose dependent loss of tissue viability and morphological alterations of the tissue. At a quantity of 1.25 microl/tissue (approximately 2.0 microl/cm2), no significant change in tissue viability or morphology was observed for exposure time extending to 48 h. Nonetheless, this dose induced significant increase in IL-1alpha and TNF-alpha release versus non-treated controls after 24 and 48 h. In addition, IL-1alpha release for JP-8+100 was significantly higher than that observed for JP-8, but TNF-alpha release after 48 h exposure to these two jet fuels was the same. These findings parallel in vivo studies on hairless rats, which indicated higher irritation levels due to JP-8+100 versus JP-8. In vivo, transepidermal water loss (TEWL) and IL-1alpha expression levels followed the order JP-8+100 > JP-8 > control. Further, in vivo TNF-alpha levels for JP-8 and JP-8+100 were also elevated but not significantly different from one another. In aggregate, these findings indicate that EPI-200 tissue model can be utilized as an alternative to the use of animals in evaluating dermal

  6. A modified algorithm for continuous wave near infrared spectroscopy applied to in-vivo animal experiments and on human skin

    NASA Astrophysics Data System (ADS)

    Klaessens, John H. G. M.; Hopman, Jeroen C. W.; Liem, K. Djien; de Roode, Rowland; Verdaasdonk, Rudolf M.; Thijssen, Johan M.

    2008-02-01

    Continuous wave Near Infrared Spectroscopy is a well known non invasive technique for measuring changes in tissue oxygenation. Absorption changes (ΔO2Hb and ΔHHb) are calculated from the light attenuations using the modified Lambert Beer equation. Generally, the concentration changes are calculated relative to the concentration at a starting point in time (delta time method). It is also possible, under certain assumptions, to calculate the concentrations by subtracting the equations at different wavelengths (delta wavelength method). We derived a new algorithm and will show the possibilities and limitations. In the delta wavelength method, the assumption is that the oxygen independent attenuation term will be eliminated from the formula even if its value changes in time, we verified the results with the classical delta time method using extinction coefficients from different literature sources for the wavelengths 767nm, 850nm and 905nm. The different methods of calculating concentration changes were applied to the data collected from animal experiments. The animals (lambs) were in a stable normoxic condition; stepwise they were made hypoxic and thereafter they returned to normoxic condition. The two algorithms were also applied for measuring two dimensional blood oxygen saturation changes in human skin tissue. The different oxygen saturation levels were induced by alterations in the respiration and by temporary arm clamping. The new delta wavelength method yielded in a steady state measurement the same changes in oxy and deoxy hemoglobin as the classical delta time method. The advantage of the new method is the independence of eventual variation of the oxygen independent attenuations in time.

  7. Confocal imaging of benign and malignant proliferative skin lesions in vivo

    NASA Astrophysics Data System (ADS)

    Gonzalez, Salvador; Rajadhyaksha, Milind M.; Anderson, R. Rox

    1999-06-01

    Near-infrared confocal reflectance microscopy (CM) provides non- invasive real-time images of thin en-face tissue sections with high resolution and contrast. Imaging of cells, nuclei, other organelles, microvessels, and hair follicles has been possible at resolution comparable to standard histology, to a maximum depth of 250-300 μm in human skin in vivo. We have characterized psoriasis as a prototype of benign proliferative skin conditions, and non-pigmented skin malignancies in vivo based on their unstained, native histologic features using CM. Our data shows that reflectance CM may potentially diagnose and morphometrically evaluate proliferative skin lesions in vivo.

  8. Kinetics of carotenoid distribution in human skin in vivo after exogenous stress: disinfectant and wIRA-induced carotenoid depletion recovers from outside to inside

    NASA Astrophysics Data System (ADS)

    Fluhr, Joachim W.; Caspers, Peter; van der Pol, J. Andre; Richter, Heike; Sterry, Wolfram; Lademann, Juergen; Darvin, Maxim E.

    2011-03-01

    The human organism has developed a protection system against the destructive effect of free radicals. The aim of the present study was to investigate the extent of exogenous stress factors such as disinfectant and IR-A radiation on the skin, and their influence on the kinetics of carotenoids distribution during the recovery process. Ten healthy volunteers were assessed with resonance spectroscopy using an Argon-laser at 488 nm to excite the carotenoids in vivo. Additionally, Raman-confocal-micro-spectroscopy measurements were performed using a model 3510 Skin Composition Analyzer with spatially resolved measurements down to 30 μm. The measurements were performed at a baseline of 20, 40, 60, and 120 min after an external stressor consisting either of water-filtered infrared A (wIRA) with 150 mW/cm2 or 1 ml/cm2 of an alcoholic disinfectant. Both Raman methods were capable to detect the infrared-induced depletion of carotenoids. Only Raman-microspectroscopy could reveal the carotenoids decrease after topical disinfectant application. The carotenoid-depletion started at the surface. After 60 min, recovery starts at the surface while deeper parts were still depleted. The disinfectant- and wIRA-induced carotenoid depletion in the epidermis recovers from outside to inside and probably delivered by sweat and sebaceous glands. We could show that the Raman microscopic spectroscopy is suited to analyze the carotenoid kinetic of stress effects and recovery.

  9. Feasibility of measuring arsenic and selenium in human skin using in vivo x-ray fluorescence (XRF)--a comparison of methods.

    PubMed

    Shehab, H; Desouza, E D; O'Meara, J; Pejović-Milić, A; Chettle, D R; Fleming, D E B; McNeill, F E

    2016-01-01

    In recent years, in vivo measurement systems of arsenic in skin by K-shell x-ray fluorescence (XRF) have been developed, including one which was applied in a pilot study of human subjects. Improved tube-based approaches suggest the method can be further exploited for in vivo studies. Recently, it has been suggested that selenium deficiency is correlated with arsenic toxicity. A non-invasive measurement of both elements could therefore be of potential interest. The main aim of this current study was to evaluate and compare the performance of an upgraded portable XRF system and an advanced version of the benchtop XRF system for both selenium and arsenic. This evaluation was performed in terms of arsenic and selenium Kα detection limits for a 4W gold anode Olympus InnovX Delta portable analyzer (40 kVp) in polyester resin skin-mimicking phantoms. Unlike the polychromatic source earlier reported in the literature, the benchtop tube-based technique involves monochromatic excitation (25 W silver anode, manufactured by x-ray optics, XOS) and a higher throughput detector type. Use of a single exciting energy allows for a lower in vivo dose delivered and superior signal-noise ratio. For the portable XRF method, arsenic and selenium minimum detection limits (MDLs) of 0.59  ±  0.03 ppm and 0.75  ±  0.02 ppm respectively were found for 1 min measurement times. The MDLs for arsenic and selenium using the benchtop system were found to be 0.35  ±  0.01 ppm and 0.670  ±  0.004 ppm respectively for 30 min measurement times. In terms of a figure of merit (FOM), allowing for dose as well as MDL, the benchtop system was found to be superior for arsenic and the two systems were equivalent, within error, for selenium. We shall discuss the performance and possible improvements of each system, their ease of use and potential for field application. PMID:26683849

  10. The effect of formulation on the penetration of coated and uncoated zinc oxide nanoparticles into the viable epidermis of human skin in vivo.

    PubMed

    Leite-Silva, Vânia R; Le Lamer, Marina; Sanchez, Washington Y; Liu, David C; Sanchez, Washington H; Morrow, Isabel; Martin, Darren; Silva, Heron D T; Prow, Tarl W; Grice, Jeffrey E; Roberts, Michael S

    2013-06-01

    The use of nanoparticulate zinc oxide (ZnO-NP) in sunscreens and other cosmetic products has raised public health concerns. The two key issues are the extent of exposure to ZnO-NP and the likely hazard after the application of ZnO-NP in sunscreen and cosmetic products to humans in vivo. Our aims were to assess exposure by the extent of ZnO-NP penetration into the viable epidermis and hazard by changes in the viable epidermal redox state for a number of topical products. Of particular interest is the role of the particle coating, formulation used, and the presence of any enhancers. Multiphoton tomography with fluorescence lifetime imaging microscopy (MPT-FLIM) was used to simultaneously observe ZnO-NP penetration and potential metabolic changes within the viable epidermis of human volunteers after topical application of various ZnO-NP products. Coated and uncoated ZnO-NP remained in the superficial layers of the SC and in the skin furrows. We observed limited penetration of coated ZnO-NP dispersed in a water-in-oil emulsion formulation, which was predominantly localized adjacent to the skin furrow. However, the presence of ZnO-NP in the viable epidermis did not alter the metabolic state or morphology of the cells. In summary, our data suggest that some limited penetration of coated and uncoated ZnO-NP may occur into viable stratum granulosum epidermis adjacent to furrows, but that the extent is not sufficient to affect the redox state of those viable cells. PMID:23454052

  11. Skin thickness effects on in vivo LXRF

    SciTech Connect

    Preiss, I.L.; Washington, W. II

    1995-12-31

    The analysis of lead concentration in bone utilizing LXRF can be adversely effected by overlying issue. A quantitative measure of the attenuation of the 10.5 keV Pb L a x-ray signal by skin and skin equivalent plastic has been conducted. Concentration ranges in plaster of Paris and goat bone from 7 to 90 ppm with attenuators of Lucite{reg_sign} and pig skin were examined. It is concluded that no quantitative or semi quantitative analysis can be achieved if overlying sue thickness exceeds 3 mm for Ph concentrations of less than 30 porn Ph in bone.

  12. Percutaneous absorption of nicotinic acid, phenol, benzoic acid and triclopyr butoxyethyl ester through rat and human skin in vitro: further validation of an in vitro model by comparison with in vivo data.

    PubMed

    Hotchkiss, S A; Hewitt, P; Caldwell, J; Chen, W L; Rowe, R R

    1992-10-01

    The in vitro percutaneous absorption of three model compounds, nicotinic acid, phenol and benzoic acid, and the herbicide triclopyr butoxyethyl ester (triclopyr BEE) has been investigated in flow-through diffusion cells using skin from male Fischer 344 rats and humans. After the application of the four chemicals to the epidermal surface of unoccluded full-thickness rat skin, the absorption of each compound across the skin and into the receptor fluid at 72 hr reached 3.7 +/- 0.3, 5.7 +/- 0.6, 26.7 +/- 3.7 and 48.3 +/- 1.2% (mean +/- SD, n = 2-7) of the applied dose for triclopyr BEE, nicotinic acid, phenol and benzoic acid, respectively. After the application of the four chemicals to the epidermal surface of unoccluded full-thickness human skin, the absorption of each compound across the skin and into the receptor fluid at 72 hr was significantly (P < 0.05) less than through rat skin, reaching 0.7 +/- 0.1, 0.7 +/- 0.2, 18.8 +/- 1.3 and 37.8 +/- 6.9% (mean +/- SD, n = 2-7) of the applied dose for triclopyr BEE, nicotinic acid, phenol and benzoic acid, respectively. Occlusion of the skin surface with teflon caps often significantly (P < 0.05) enhanced the percutaneous absorption of the model compounds, although this effect was not uniform, varying with the compound under study and the skin (rat or human) used. When rat skin was occluded with teflon caps, the extent of absorption at 72 hr reached 8.6 +/- 0.8, 36.2 +/- 1.7 and 51.8 +/- 3.3% (mean +/- SD, n = 3-4) for nicotinic acid, phenol and benzoic acid, respectively. Corresponding values for human skin occluded with teflon caps were 3.3 +/- 1.6, 47.1 +/- 0.5 and 65.5 +/- 7.1% (mean +/- SD, n = 3-4). The experiments on the absorption of each model compound through rat and human skin were repeated and there was generally good agreement between the results from the two sets of experiments. The in vitro data reported compare favourably with data obtained by other workers using both in vitro and in vivo methodologies

  13. Reconstructing in-vivo reflectance spectrum of pigmented skin lesion by Monte Carlo simulation

    NASA Astrophysics Data System (ADS)

    Wang, Shuang; He, Qingli; Zhao, Jianhua; Lui, Harvey; Zeng, Haishan

    2011-11-01

    In dermatology applications, diffuse reflectance spectroscopy has been extensively investigated as a promising tool for the noninvasive method to distinguish melanoma from benign pigmented skin lesion (nevus), which is concentrated with the skin chromophores like melanin and hemoglobin. We carried out a theoretical study to examine melanin distribution in human skin tissue and establish a practical optical model for further pigmented skin investigation. The theoretical simulation was using junctional nevus as an example. A multiple layer skin optical model was developed on established anatomy structures of skin, the published optical parameters of different skin layers, blood and melanin. Monte Carlo simulation was used to model the interaction between excitation light and skin tissue and rebuild the diffuse reflectance process from skin tissue. A testified methodology was adopted to determine melanin contents in human skin based on in vivo diffuse reflectance spectra. The rebuild diffuse reflectance spectra were investigated by adding melanin into different layers of the theoretical model. One of in vivo reflectance spectra from Junctional nevi and their surrounding normal skin was studied by compare the ratio between nevus and normal skin tissue in both the experimental and simulated diffuse reflectance spectra. The simulation result showed a good agreement with our clinical measurements, which indicated that our research method, including the spectral ratio method, skin optical model and modifying the melanin content in the model, could be applied in further theoretical simulation of pigmented skin lesions.

  14. Reconstructing in-vivo reflectance spectrum of pigmented skin lesion by Monte Carlo simulation

    NASA Astrophysics Data System (ADS)

    Wang, Shuang; He, Qingli; Zhao, Jianhua; Lui, Harvey; Zeng, Haishan

    2012-03-01

    In dermatology applications, diffuse reflectance spectroscopy has been extensively investigated as a promising tool for the noninvasive method to distinguish melanoma from benign pigmented skin lesion (nevus), which is concentrated with the skin chromophores like melanin and hemoglobin. We carried out a theoretical study to examine melanin distribution in human skin tissue and establish a practical optical model for further pigmented skin investigation. The theoretical simulation was using junctional nevus as an example. A multiple layer skin optical model was developed on established anatomy structures of skin, the published optical parameters of different skin layers, blood and melanin. Monte Carlo simulation was used to model the interaction between excitation light and skin tissue and rebuild the diffuse reflectance process from skin tissue. A testified methodology was adopted to determine melanin contents in human skin based on in vivo diffuse reflectance spectra. The rebuild diffuse reflectance spectra were investigated by adding melanin into different layers of the theoretical model. One of in vivo reflectance spectra from Junctional nevi and their surrounding normal skin was studied by compare the ratio between nevus and normal skin tissue in both the experimental and simulated diffuse reflectance spectra. The simulation result showed a good agreement with our clinical measurements, which indicated that our research method, including the spectral ratio method, skin optical model and modifying the melanin content in the model, could be applied in further theoretical simulation of pigmented skin lesions.

  15. In vivo multiphoton tomography of skin cancer

    NASA Astrophysics Data System (ADS)

    König, Karsten; Riemann, Iris; Ehlers, Alexander; Buckle, Rainer; Dimitrow, Enrico; Kaatz, Martin; Fluhr, Joachim; Elsner, Peter

    2006-02-01

    The multiphoton tomograph DermaInspect was used to perform first clinical studies on the early non-invasive detection of skin cancer based on non-invasive optical sectioning of skin by two-photon autofluorescence and second harmonic generation. In particular, deep-tissue pigmented lesions -nevi- have been imaged with intracellular resolution using near infrared (NIR) femtosecond laser radiation. So far, more than 250 patients have been investigated. Cancerous tissues showed significant morphological differences compared to normal skin layers. In the case of malignant melanoma, the occurrence of luminescent melanocytes has been detected. Multiphoton tomography will become a novel non-invasive method to obtain high-resolution 3D optical biopsies for early cancer detection, treatment control, and in situ drug screening.

  16. In vivo observation of age-related structural changes of dermal collagen in human facial skin using collagen-sensitive second harmonic generation microscope equipped with 1250-nm mode-locked Cr:Forsterite laser

    NASA Astrophysics Data System (ADS)

    Yasui, Takeshi; Yonetsu, Makoto; Tanaka, Ryosuke; Tanaka, Yuji; Fukushima, Shu-ichiro; Yamashita, Toyonobu; Ogura, Yuki; Hirao, Tetsuji; Murota, Hiroyuki; Araki, Tsutomu

    2013-03-01

    In vivo visualization of human skin aging is demonstrated using a Cr:Forsterite (Cr:F) laser-based, collagen-sensitive second harmonic generation (SHG) microscope. The deep penetration into human skin, as well as the specific sensitivity to collagen molecules, achieved by this microscope enables us to clearly visualize age-related structural changes of collagen fiber in the reticular dermis. Here we investigated intrinsic aging and/or photoaging in the male facial skin. Young subjects show dense distributions of thin collagen fibers, whereas elderly subjects show coarse distributions of thick collagen fibers. Furthermore, a comparison of SHG images between young and elderly subjects with and without a recent life history of excessive sun exposure show that a combination of photoaging with intrinsic aging significantly accelerates skin aging. We also perform image analysis based on two-dimensional Fourier transformation of the SHG images and extracted an aging parameter for human skin. The in vivo collagen-sensitive SHG microscope will be a powerful tool in fields such as cosmeceutical sciences and anti-aging dermatology.

  17. In vivo observation of age-related structural changes of dermal collagen in human facial skin using collagen-sensitive second harmonic generation microscope equipped with 1250-nm mode-locked Cr:Forsterite laser.

    PubMed

    Yasui, Takeshi; Yonetsu, Makoto; Tanaka, Ryosuke; Tanaka, Yuji; Fukushima, Shu-ichiro; Yamashita, Toyonobu; Ogura, Yuki; Hirao, Tetsuji; Murota, Hiroyuki; Araki, Tsutomu

    2013-03-01

    In vivo visualization of human skin aging is demonstrated using a Cr:Forsterite (Cr:F) laser-based, collagen-sensitive second harmonic generation (SHG) microscope. The deep penetration into human skin, as well as the specific sensitivity to collagen molecules, achieved by this microscope enables us to clearly visualize age-related structural changes of collagen fiber in the reticular dermis. Here we investigated intrinsic aging and/or photoaging in the male facial skin. Young subjects show dense distributions of thin collagen fibers, whereas elderly subjects show coarse distributions of thick collagen fibers. Furthermore, a comparison of SHG images between young and elderly subjects with and without a recent life history of excessive sun exposure show that a combination of photoaging with intrinsic aging significantly accelerates skin aging. We also perform image analysis based on two-dimensional Fourier transformation of the SHG images and extracted an aging parameter for human skin. The in vivo collagen-sensitive SHG microscope will be a powerful tool in fields such as cosmeceutical sciences and anti-aging dermatology. PMID:23212157

  18. Laser Doppler imager (LDI) scanner and intradermal injection for in vivo pharmacology in human skin microcirculation: responses to acetylcholine, endothelin-1 and their repeatability

    PubMed Central

    Saez, Anabelle M Opazo; Mosel, Frank; Nürnberger, Jens; Rushentsova, U; Gössl, Mario; Mitchell, Anna; Schäfers, Rafael F; Philipp, Thomas; Wenzel, René R

    2005-01-01

    a significant correlation between responses measured in the same site, in the same individual on two different days by the same observer (ACh, r = 0.94, P < 0.0001; ET-1, r = 0.90, P < 0.0006), and between responses measured by two different observers (ACh, r = 0.94, P < 0.0001; ET-1, r = 0.91, P < 0.0003). Conclusion We have shown that interday and intraobserver responses to intradermal injections of ET-1 and ACh, assessed using the DIT in combination with an LDI scanner, exhibited good reproducibility and may be a useful tool for studying the skin microcirculation in vivo. PMID:15842548

  19. Mechanism and biological relevance of blue-light (420-453 nm)-induced nonenzymatic nitric oxide generation from photolabile nitric oxide derivates in human skin in vitro and in vivo.

    PubMed

    Opländer, Christian; Deck, Annika; Volkmar, Christine M; Kirsch, Michael; Liebmann, Jörg; Born, Matthias; van Abeelen, Frank; van Faassen, Ernst E; Kröncke, Klaus-Dietrich; Windolf, Joachim; Suschek, Christoph V

    2013-12-01

    Human skin contains photolabile nitric oxide (NO) derivates such as nitrite and S-nitrosothiols, which upon UVA radiation decompose under high-output NO formation and exert NO-specific biological responses such as increased local blood flow or reduced blood pressure. To avoid the injurious effects of UVA radiation, we here investigated the mechanism and biological relevance of blue-light (420-453 nm)-induced nonenzymatic NO generation from photolabile nitric oxide derivates in human skin in vitro and in vivo. As quantified by chemiluminescence detection (CLD), at physiological pH blue light at 420 or 453 nm induced a significant NO formation from S-nitrosoalbumin and also from aqueous nitrite solutions by a to-date not entirely identified Cu(1+)-dependent mechanism. As detected by electron paramagnetic resonance spectrometry in vitro with human skin specimens, blue light irradiation significantly increased the intradermal levels of free NO. As detected by CLD in vivo in healthy volunteers, irradiation of human skin with blue light induced a significant emanation of NO from the irradiated skin area as well as a significant translocation of NO from the skin surface into the underlying tissue. In parallel, blue light irradiation caused a rapid and significant rise in local cutaneous blood flow as detected noninvasively by using micro-light-guide spectrophotometry. Irradiation of human skin with moderate doses of blue light caused a significant increase in enzyme-independent cutaneous NO formation as well as NO-dependent local biological responses, i.e., increased blood flow. The effects were attributed to blue-light-induced release of NO from cutaneous photolabile NO derivates. Thus, in contrast to UVA, blue-light-induced NO generation might be therapeutically used in the treatment of systemic and local hemodynamic disorders that are based on impaired physiological NO production or bioavailability. PMID:24121056

  20. Terahertz spectroscopy of pigmentary skin nevi in vivo

    NASA Astrophysics Data System (ADS)

    Zaitsev, K. I.; Chernomyrdin, N. V.; Kudrin, K. G.; Reshetov, I. V.; Yurchenko, S. O.

    2015-09-01

    Pigmentary skin nevi are studied in vivo using terahertz pulsed spectroscopy. Dielectric parameters of healthy skin and dysplastic and nondysplastic nevi are reconstructed and analyzed. The fact that complex permittivities of the samples substantially differ in the terahertz spectral range can be used for early noninvasive diagnostics of dysplastic nevi, which are precursors of melanoma (the most dangerous skin cancer). A method is proposed to identify various dysplastic and nondysplastic nevi using the analysis of terahertz dielectric characteristics. It is demonstrated that terahertz pulsed spectroscopy is promising for early noninvasive diagnostics of dysplastic nevi and melanomas of the skin.

  1. In vivo skin penetration of salicylic compounds in hairless rats.

    PubMed

    Simonsen, Lene; Petersen, Mads B; Groth, Lotte

    2002-10-01

    The in vivo skin penetration of four salicylic compounds was investigated using a hairless rat model, which allowed for non-occluded, finite dose application, and free mobility of the rats throughout the test period. The model compounds were applied in equimolal concentrations of 0.4 mmol/g dimethyl isosorbide. At certain times (0.5-24 h) the rats were killed, and the amount of test compound on the skin surface, in the stratum corneum, and in the deeper viable skin layers was determined. Significant different skin concentrations were found with the following ranking: [(14)C]diethylamine salicylate>[(14)C]salicylic acid>[(14)C]salicylamide>[(14)C]butyl salicylate. In addition, the in vivo percutaneous rate of absorption was in the following order: [(14)C]butyl salicylate>[(14)C]salicylic acid> or =[(14)C]salicylamide>[(14)C]diethylamine salicylate. [(14)C]Butyl salicylate was rapidly absorbed and completely depleted from the surface 3 h post application. In comparison with [(14)C]salicylic acid, the ionic [(14)C]diethylamine salicylate had larger surface depots and penetrated the skin at a lower rate. The relatively hydrophilic [(14)C]salicylamide also had larger surface depots but much lower skin levels. For comparison, the in vitro permeation of the formulations was studied through freshly excised hairless rat skin using Franz diffusions cells, and an agreement between the techniques was found. PMID:12356424

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

    NASA Astrophysics Data System (ADS)

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

    2005-08-01

    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 mm2. 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.

  3. Increased in vivo skin penetration of quantum dots with UVR and in vitro quantum dot cytotoxicity

    NASA Astrophysics Data System (ADS)

    Mortensen, Luke; Zheng, Hong; Faulknor, Renea; De Benedetto, Anna; Beck, Lisa; DeLouise, Lisa A.

    2009-02-01

    The growing presence of quantum dots (QD) in a variety of biological, medical, and electronics applications means an increased risk of human exposure in manufacturing, research, and consumer use. However, very few studies have investigated the susceptibility of skin to penetration of QD - the most common exposure route- and the results of those that exist are conflicting. This suggests that a technique allowing determination of skin barrier status and prediction of skin permeability to QD would be of crucial interest as recent findings have provided evidence of in vitro cytotoxicity and long-term in vivo retention in the body for most QD surface chemistries. Our research focuses on barrier status of the skin (intact and with ultraviolet radiation induced barrier defect) and its impact on QD skin penetration. These model studies are particularly relevant to the common application condition of NP containing sunscreen and SPF cosmetics to UV exposed skin. Herein we present our initial efforts to develop an in vivo model of nanoparticle skin penetration using the SKH-1 hairless mouse with transepidermal water loss (TEWL) to evaluate skin barrier status and determine its ability to predict QD penetration. Our results show that ultraviolet radiation increases both TEWL and skin penetration of QD. Additionally, we demonstrate cytotoxic potential of QD to skin cells using a metastatic melanoma cell line. Our research suggests future work in specific targeting of nanoparticles, to prevent or enhance penetration. This knowledge will be used to develop powerful therapeutic agents, decreased penetration cosmetic nanoparticles, and precise skin cancer imaging modalities.

  4. Combined Raman spectroscopy and autofluoresence imaging method for in vivo skin tumor diagnosis

    NASA Astrophysics Data System (ADS)

    Zakharov, V. P.; Bratchenko, I. A.; Myakinin, O. O.; Artemyev, D. N.; Khristoforova, Y. A.; Kozlov, S. V.; Moryatov, A. A.

    2014-09-01

    The fluorescence and Raman spectroscopy (RS) combined method of in vivo detection of malignant human skin cancer was demonstrated. The fluorescence analysis was used for detection of abnormalities during fast scanning of large tissue areas. In suspected cases of malignancy the Raman spectrum analysis of biological tissue was performed to determine the type of neoplasm. A special RS phase method was proposed for in vivo identification of skin tumor. Quadratic Discriminant Analysis was used for tumor type classification on phase planes. It was shown that the application of phase method provides a diagnosis of malignant melanoma with a sensitivity of 89% and a specificity of 87%.

  5. Investigation of in-vivo skin autofluorescence lifetimes under long-term cw optical excitation

    SciTech Connect

    Lihachev, A; Ferulova, I; Vasiljeva, K; Spigulis, J

    2014-08-31

    The main results obtained during the last five years in the field of laser-excited in-vivo human skin photobleaching effects are presented. The main achievements and results obtained, as well as methods and experimental devices are briefly described. In addition, the impact of long-term 405-nm cw low-power laser excitation on the skin autofluorescence lifetime is experimentally investigated. (laser biophotonics)

  6. In vivo activation of human immunodeficiency virus type 1 long terminal repeat by UV type A (UV-A) light plus psoralen and UV-B light in the skin of transgenic mice.

    PubMed Central

    Morrey, J D; Bourn, S M; Bunch, T D; Jackson, M K; Sidwell, R W; Barrows, L R; Daynes, R A; Rosen, C A

    1991-01-01

    UV irradiation has been shown to activate the human immunodeficiency virus type 1 (HIV-1) long terminal repeat (LTR) in cell culture; however, only limited studies have been described in vivo. UV light has been categorized as UV-A (400 to 315 nm), -B (315 to 280 nm), or -C (less than 280 nm); the longer wavelengths are less harmful but more penetrative. Highly penetrative UV-A radiation constitutes the vast majority of UV sunlight reaching the earth's surface but is normally harmless. UV-B irradiation is more harmful but less prevalent than UV-A. In this report, the HIV-1 LTR-luciferase gene in the skin of transgenic mice was markedly activated when exposed to UV-B irradiation. The LTR in the skin of transgenic mice pretreated topically with a photosensitizing agent (psoralen) was also activated to similar levels when exposed to UV-A light. A 2-h exposure to sunlight activated the LTR in skin treated with psoralen, whereas the LTR in skin not treated with psoralen was activated after 7 h of sunlight exposure. The HIV-1 LTR-beta-galactosidase reporter gene was preferentially activated by UV-B irradiation in a small population of epidermal cells. The transgenic mouse models carrying HIV-1 LTR-luciferase and LTR-beta-galactosidase reporter genes have been used to demonstrate the in vivo UV-induced activation of the LTR and might be used to evaluate other environmental factors or pharmacologic substances that might potentially activate the HIV-1 LTR in vivo. Images PMID:1908029

  7. In vivo spectroscopy of healthy skin and pathology in terahertz frequency range

    NASA Astrophysics Data System (ADS)

    Zaytsev, Kirill I.; Kudrin, Konstantin G.; Reshetov, Igor V.; Gavdush, Arseniy A.; Chernomyrdin, Nikita V.; Karasik, Valeriy E.; Yurchenko, Stanislav O.

    2015-01-01

    Biomedical applications of terahertz (THz) technology and, in particular, THz pulsed spectroscopy have attracted considerable interest in the scientific community. A lot of papers have been dedicated to studying the ability for human disease diagnosis, including the diagnosis of human skin cancers. In this paper we have studied the THz material parameters and THz dielectric properties of human skin and pathology in vivo, and THz pulsed spectroscopy has been utilized for this purpose. We have found a contrast between material parameters of basal cell carcinoma and healthy skin, and we have also compared the THz material parameters of dysplastic and non-dysplastic pigmentary nevi in order to study the ability for early melanoma diagnosis. Significant differences between the THz material parameters of healthy skin and pathology have been detected, thus, THz pulsed spectroscopy promises to be become an effective tool for non-invasive diagnosis of skin neoplasms.

  8. A Guide to Studying Human Hair Follicle Cycling In Vivo.

    PubMed

    Oh, Ji Won; Kloepper, Jennifer; Langan, Ewan A; Kim, Yongsoo; Yeo, Joongyeub; Kim, Min Ji; Hsi, Tsai-Ching; Rose, Christian; Yoon, Ghil Suk; Lee, Seok-Jong; Seykora, John; Kim, Jung Chul; Sung, Young Kwan; Kim, Moonkyu; Paus, Ralf; Plikus, Maksim V

    2016-01-01

    Hair follicles (HFs) undergo lifelong cyclical transformations, progressing through stages of rapid growth (anagen), regression (catagen), and relative "quiescence" (telogen). Given that HF cycling abnormalities underlie many human hair growth disorders, the accurate classification of individual cycle stages within skin biopsies is clinically important and essential for hair research. For preclinical human hair research purposes, human scalp skin can be xenografted onto immunocompromised mice to study human HF cycling and manipulate long-lasting anagen in vivo. Although available for mice, a comprehensive guide on how to recognize different human hair cycle stages in vivo is lacking. In this article, we present such a guide, which uses objective, well-defined, and reproducible criteria, and integrates simple morphological indicators with advanced, (immuno)-histochemical markers. This guide also characterizes human HF cycling in xenografts and highlights the utility of this model for in vivo hair research. Detailed schematic drawings and representative micrographs provide examples of how best to identify human HF stages, even in suboptimally sectioned tissue, and practical recommendations are given for designing human-on-mouse hair cycle experiments. Thus, this guide seeks to offer a benchmark for human hair cycle stage classification, for both hair research experts and newcomers to the field. PMID:26763421

  9. A guide to studying human hair follicle cycling in vivo

    PubMed Central

    Oh, Ji Won; Kloepper, Jennifer; Langan, Ewan A.; Kim, Yongsoo; Yeo, Joongyeub; Kim, Min Ji; Hsi, Tsai-Ching; Rose, Christian; Yoon, Ghil Suk; Lee, Seok-Jong; Seykora, John; Kim, Jung Chul; Sung, Young Kwan

    2015-01-01

    Hair follicles (HFs) undergo life-long cyclical transformations, progressing through stages of rapid growth (anagen), regression (catagen), and relative “quiescence” (telogen). Since HF cycling abnormalities underlie many human hair growth disorders, the accurate classification of individual cycle stages within skin biopsies is clinically important and essential for hair research. For preclinical human hair research purposes, human scalp skin can be xenografted onto immunocompromised mice to study human HF cycling and manipulate long-lasting anagen in vivo. While available for mice, a comprehensive guide on how to recognize different human hair cycle stages in vivo is lacking. Here, we present such a guide, which uses objective, well-defined, and reproducible criteria and integrates simple morphological indicators with advanced, (immuno)-histochemical markers. This guide also characterizes human HF cycling in xenografts and highlights the utility of this model for in vivo hair research. Detailed schematic drawings and representative micrographs provide examples of how best to identify human HF stages, even in sub-optimally sectioned tissue, and practical recommendations are given for designing human-on-mouse hair cycle experiments. Thus, this guide seeks to offer a benchmark for human hair cycle stage classification, for both hair research experts and newcomers to the field. PMID:26763421

  10. Hydrogel patches for transdermal drug delivery; in-vivo water exchange and skin compatibility.

    PubMed

    Boddé, H E; Van Aalten, E A; Junginger, H E

    1989-03-01

    Hydrogel patches based on water swellable polyacrylates have been developed for long-term transdermal drug delivery. Two properties, relevant to the performance of hydrogel patches in-vivo have been investigated in humans over five days. These were: (i) the kinetics of water exchange between the skin and the patches; (ii) the skin compatibility of the patches. It was found that initially there was a gradually increasing uptake of water from the skin by the patches, but after about 20 h the water exchange followed a regular fluctuating pattern, peaking once a day and once a night. The skin compatibility of the patches was satisfactory, in that no redness or pustulation was noticed throughout the five days. This was most likely due to the capability of the patches to exchange water with the skin. PMID:2568439

  11. In vivo terahertz imaging of rat skin burns

    NASA Astrophysics Data System (ADS)

    Tewari, Priyamvada; Kealey, Colin P.; Bennett, David B.; Bajwa, Neha; Barnett, Kelli S.; Singh, Rahul S.; Culjat, Martin O.; Stojadinovic, Alexander; Grundfest, Warren S.; Taylor, Zachary D.

    2012-04-01

    A reflective, pulsed terahertz (THz) imaging system was used to acquire high-resolution (d10-90/ λ~1.925) images of deep, partial thickness burns in a live rat. The rat's abdomen was burned with a brass brand heated to ~220°C and pressed against the skin with contact pressure for ~10 sec. The burn injury was imaged beneath a Mylar window every 15 to 30 min for up to 7 h. Initial images display an increase in local water concentration of the burned skin as evidenced by a marked increase in THz reflectivity, and this likely correlates to the post-injury inflammatory response. After ~1 h the area of increased reflectivity consolidated to the region of skin that had direct contact with the brand. Additionally, a low reflecting ring of tissue could be observed surrounding the highly reflective burned tissue. We hypothesize that these regions of increased and decreased reflectivity correlate to the zones of coagulation and stasis that are the classic foundation of burn wound histopathology. While further investigations are necessary to confirm this hypothesis, if true, it likely represents the first in vivo THz images of these pathologic zones and may represent a significant step forward in clinical application of THz technology.

  12. In vivo optical investigation of short term skin water contact and moisturizer application using NIR spectroscopy.

    PubMed

    Qassem, M; Kyriacou, P A

    2013-01-01

    Nowadays, a number of noninvasive methods and instruments are available to inspect the biophysical properties and effects of various applicants on human skin, providing quantitative measurements and more details regarding the interactions between skin and various products. Such methods include Near Infrared Spectroscopy (NIRS), a technique which over the years, has gained quite a reputation in being able to accurately determine moisture levels and water contents due to its sensitivity to hydrogen bonding. This paper reports preliminary results of an in vivo study carried out on the skin of a small number of human participants, investigating the optical response of human skin after direct short-term contact with water followed by application of a moisturizer, using a highly advanced spectrophotometer in the region of 900-2100 nm, and equipped with a reflectance fibre optic probe. Results obtained here certainly raise some questions regarding the optical characteristics of different skin types and the influence of frequent moisturizer use, as well as the varying response between different water bands in the NIR region. Future work will focus on gaining more knowledge about these, in order to further improve optical skin measurements, and hopefully support the design and development of a portable and/or miniaturized optical device that could provide reliable, accurate and fast skin hydration readings in real time. PMID:24110207

  13. Effect of barrier perturbation on cutaneous salicylic acid penetration in human skin: in vivo pharmacokinetics using microdialysis and non-invasive quantification of barrier function.

    PubMed

    Benfeldt, E; Serup, J; Menné, T

    1999-04-01

    We have used microdialysis in the dermis for assessing penetration kinetics of salicylic acid (SA) in healthy volunteers (n = 18), following application on the volar aspect of the left forearm. Penetration was monitored at four locations: in normal (unmodified) skin and in skin with perturbed barrier function from (i) repeated tape stripping (ii) irritant dermatitis from 1 or 2% sodium lauryl sulphate (SLS) for 24 h and (iii) delipidization by acetone. The order of the treatments was randomized according to a latin square design. Epidermal barrier function and skin irritation were assessed in each location using evaporimetry and colorimetry. Transepidermal water loss (TEWL) values confirmed that both mild (acetone), moderate (1% SLS) and severe barrier damage (tape stripping and 2% SLS) had occurred. Microdialysis sampling with two parallel probes in the dermis was performed in each of the four treatment areas for every subject. SA (5% in ethanol) was applied in a chamber glued to the skin overlying the microdialysis probes and sampling was continued for 4 h. SA was detectable in all samples and measurable in all samples from penetration through perturbed skin. Comparing the SA penetration in barrier-perturbed skin with the penetration in unmodified skin in the same subject, the mean SA penetration increase was 2.2-fold in acetone-treated skin (P = 0.012), 46-fold in mild dermatitis and 146- and 157-fold in severe dermatitis and tape stripped skin, respectively (P < 0.001). The penetration of SA significantly correlated with the measurements of barrier perturbation by TEWL (P = 0.01) and erythema (P = 0.02) for each individual. Microdialysis sampling of SA penetration was more sensitive than non-invasive measuring techniques in detecting significant barrier perturbation in acetone-treated skin. A positive dose-response relationship for the percutaneous penetration of SA in response to increasing SLS pretreatment concentrations and thus the degree of irritant

  14. Archaea on human skin.

    PubMed

    Probst, Alexander J; Auerbach, Anna K; Moissl-Eichinger, Christine

    2013-01-01

    The recent era of exploring the human microbiome has provided valuable information on microbial inhabitants, beneficials and pathogens. Screening efforts based on DNA sequencing identified thousands of bacterial lineages associated with human skin but provided only incomplete and crude information on Archaea. Here, we report for the first time the quantification and visualization of Archaea from human skin. Based on 16 S rRNA gene copies Archaea comprised up to 4.2% of the prokaryotic skin microbiome. Most of the gene signatures analyzed belonged to the Thaumarchaeota, a group of Archaea we also found in hospitals and clean room facilities. The metabolic potential for ammonia oxidation of the skin-associated Archaea was supported by the successful detection of thaumarchaeal amoA genes in human skin samples. However, the activity and possible interaction with human epithelial cells of these associated Archaea remains an open question. Nevertheless, in this study we provide evidence that Archaea are part of the human skin microbiome and discuss their potential for ammonia turnover on human skin. PMID:23776475

  15. In vivo percutaneous absorption and skin decontamination of alachlor in rhesus monkey.

    PubMed

    Wester, R C; Melendres, J; Maibach, H I

    1992-05-01

    The objectives of this study were to determine the percutaneous absorption of alachlor relative to formulation dilution with water, and to determine the ability of soap and water, and of water only, to remove alachlor from skin, relative to time. Alachlor is a preemergence herbicide. The in vivo percutaneous absorption of alachlor in rhesus monkeys was 17.3 +/- 3.3, 15.3 +/- 3.9, and 21.4 +/- 14.2% for 24-h skin exposure to Lasso formulation diluted 1:20, 1:40, and 1:80, respectively. In vivo, there was no support for increased alachlor skin absorption with water dilution, as previously reported for in vitro absorption. The average in vivo absorption of 18% applied dose over 24 h (0.75%/h) was similar to the maximum in vitro rate of 0.8%/h using human skin and human plasma as receptor fluid. Dose accountability in vivo was 80.6-95.2%. [14C]Alachlor in Lasso diluted 1:20 with water was placed on rhesus monkeys at concentrations of 23 micrograms/10 microliters/cm2. Skin decontamination at 0 h with soap and water (50% Ivory liquid 1:1 v/v with water) removed 73 +/- 15.8% (n = 4) of the applied dose with the first wash; this increased to a total of 82.3 +/- 14.8% with two additional washes. Decontamination after 1 h removed 87.5 +/- 12.4% with three successive washes. After 3 h decontamination ability decreased, and after 24 h only 51.9 +/- 12.2% could be recovered with three successive washes. Using water only, at 0 h 36.6 +/- 12.3% alachlor was removed with the first wash and the total increased to 56.0 +/- 14.0% with two additional washes. At 24 h the total amount decreased to 28.7 +/- 12.2% for three successive washes. Alachlor as Lasso in field-use rate (11 micrograms/cm2) and undiluted (217 and 300 micrograms/cm2) proportions were left on rhesus monkey skin for 12 h and decontaminated with soap and water (10% Ivory liquid v/v with water). Continual successive washes (6-8 in sequence) recovered 80-90% of the skin-applied alachlor. These results suggest that simple

  16. Sodium lauryl sulphate alters the mRNA expression of lipid-metabolizing enzymes and PPAR signalling in normal human skin in vivo.

    PubMed

    Törmä, Hans; Berne, Berit

    2009-12-01

    Detergents irritate skin and affect skin barrier homeostasis. In this study, healthy skin was exposed to 1% sodium lauryl sulphate (SLS) in water for 24 h. Biopsies were taken 6 h to 8 days post exposure. Lipid patterns were stained in situ and real-time polymerase chain reaction (PCR) was used to examine mRNA expression of enzymes synthesizing barrier lipids, peroxisome proliferator-activated receptors (PPAR) and lipoxygenases. The lipid pattern was disorganized from 6 h to 3 days after SLS exposure. Concomitant changes in mRNA expression included: (i) reduction, followed by induction, of ceramide-generating beta-glucocerebrosidase, (ii) increase on day 1 of two other enzymes for ceramide biosynthesis and (iii) persistent reduction of acetyl-CoA carboxylase-B, a key enzyme in fatty acid synthesis. Surprisingly, the rate-limiting enzyme in cholesterol synthesis, HMG-CoA reductase, was unaltered. Among putative regulators of barrier lipids synthesis, PPARalpha and PPARgamma exhibited reduced mRNA expression, while PPARbeta/delta and LXRbeta were unaltered. Epidermal lipoxygenase-3, which may generate PPARalpha agonists, exhibited reduced expression. In conclusion, SLS induces reorganization of lipids in the stratum corneum, which play a role in detergents' destruction of the barrier. The changes in mRNA expression of enzymes involved in synthesizing barrier lipids are probably important for the restoration of the barrier. PMID:19366370

  17. In vivo enhancement of sensory perception recovery in a tissue-engineered skin enriched with laminin.

    PubMed

    Caissie, René; Gingras, Marie; Champigny, Marie-France; Berthod, François

    2006-05-01

    The use of autologous reconstructed skin appears to be a promising treatment for the permanent coverage of deep and extensive burns. However, the capability of reconstructed skin transplanted on wounds to promote recovery of sensory perception is a major concern. Our aim was to assess the effect of laminin on cutaneous nerve regeneration. We prepared collagen-chitosan sponges enriched with 0, 1, 10 or 50 microg of laminin/sponge to produce tissue-engineered reconstructed skins by culture of human fibroblasts and keratinocytes, then grafted on the back of athymic mice for 120 days. Immunohistochemical studies demonstrated that there were 7 times more neurofilament 150 kD-positive nerve fibers migrating in the graft in the samples enriched with 10 microg laminin/sponge, compared to reconstructed skin without laminin, 120 days after graft. A significant improvement in the current perception threshold of the Abeta and Adelta nerve fibers was measured using a Neurometer in all grafts enriched with laminin. In addition, the type C nerve fibers reached an identical current perception threshold than mouse skin, in all reconstructed skins enriched or not with laminin. We conclude that the use of a tissue-engineered autologous skin graft enriched with laminin has the potential to efficiently optimize cutaneous sensory nerve regeneration in vivo. PMID:16448695

  18. Optical properties of neonatal skin measured in vivo as a function of age and skin pigmentation

    NASA Astrophysics Data System (ADS)

    Bosschaart, Nienke; Mentink, Rosaline; Kok, Joke H.; van Leeuwen, Ton G.; Aalders, Maurice C. G.

    2011-09-01

    Knowledge of the optical properties of neonatal skin is invaluable when developing new, or improving existing optical techniques for use at the neonatal intensive care. In this article, we present in vivo measurements of the absorption μa and reduced scattering coefficient μs' of neonatal skin between 450 and 600 nm and assess the influence of age and skin pigmentation on the optical properties. The optical properties were measured using a spatially resolved, steady state diffuse reflectance spectroscopy setup, combined with a modified spatially resolved diffusion model. The method was validated on phantoms with known values for the absorption and reduced scattering coefficient. Values of μa and μs' were obtained from the skin at four different body locations (forehead, sternum, hand, and foot) of 60 neonates with varying gestational age, postnatal age, and skin pigmentation. We found that μa ranged from 0.02 to 1.25 mm-1 and μs' was in the range of 1 to 2.8 mm-1 (5th to 95th percentile of the patient population), independent of body location. In contrast to previous studies, no to very weak correlation was observed between the optical properties and gestational maturity, but a strong dependency of the absorption coefficient on postnatal age was found for dark skinned patients.

  19. Glucocorticoids enhance the in vivo migratory response of human monocytes.

    PubMed

    Yeager, Mark P; Pioli, Patricia A; Collins, Jane; Barr, Fiona; Metzler, Sara; Sites, Brian D; Guyre, Paul M

    2016-05-01

    Glucocorticoids (GCs) are best known for their potent anti-inflammatory effects. However, an emerging model for glucocorticoid (GC) regulation of in vivo inflammation also includes a delayed, preparatory effect that manifests as enhanced inflammation following exposure to an inflammatory stimulus. When GCs are transiently elevated in vivo following exposure to a stressful event, this model proposes that a subsequent period of increased inflammatory responsiveness is adaptive because it enhances resistance to a subsequent stressor. In the present study, we examined the migratory response of human monocytes/macrophages following transient in vivo exposure to stress-associated concentrations of cortisol. Participants were administered cortisol for 6h to elevate in vivo cortisol levels to approximate those observed during major systemic stress. Monocytes in peripheral blood and macrophages in sterile inflammatory tissue (skin blisters) were studied before and after exposure to cortisol or placebo. We found that exposure to cortisol induced transient upregulation of monocyte mRNA for CCR2, the receptor for monocyte chemotactic protein-1 (MCP-1/CCL2) as well as for the chemokine receptor CX3CR1. At the same time, mRNA for the transcription factor IκBα was decreased. Monocyte surface expression of CCR2 but not CX3CR1 increased in the first 24h after cortisol exposure. Transient exposure to cortisol also led to an increased number of macrophages and neutrophils in fluid derived from a sterile inflammatory site in vivo. These findings suggest that the delayed, pro-inflammatory effects of cortisol on the human inflammatory responses may include enhanced localization of effector cells at sites of in vivo inflammation. PMID:26790757

  20. In vivo assessment of the structure of skin microcirculation by reflectance confocal-laser-scanning microscopy

    NASA Astrophysics Data System (ADS)

    Sugata, Keiichi; Osanai, Osamu; Kawada, Hiromitsu

    2012-02-01

    One of the major roles of the skin microcirculation is to supply oxygen and nutrition to the surrounding tissue. Regardless of the close relationship between the microcirculation and the surrounding tissue, there are few non-invasive methods that can evaluate both the microcirculation and its surrounding tissue at the same site. We visualized microcapillary plexus structures in human skin using in vivo reflectance confocal-laser-scanning microscopy (CLSM), Vivascope 3000® (Lucid Inc., USA) and Image J software (National Institutes of Health, USA) for video image processing. CLSM is a non-invasive technique that can visualize the internal structure of the skin at the cellular level. In addition to internal morphological information such as the extracellular matrix, our method reveals capillary structures up to the depth of the subpapillary plexus at the same site without the need for additional optical systems. Video images at specific depths of the inner forearm skin were recorded. By creating frame-to-frame difference images from the video images using off-line video image processing, we obtained images that emphasize the brightness depending on changes of intensity coming from the movement of blood cells. Merging images from different depths of the skin elucidates the 3-dimensional fine line-structure of the microcirculation. Overall our results show the feasibility of a non-invasive, high-resolution imaging technique to characterize the skin microcirculation and the surrounding tissue.

  1. In vivo biophysical characterization of skin physiological differences in races.

    PubMed

    Berardesca, E; de Rigal, J; Leveque, J L; Maibach, H I

    1991-01-01

    The role of race in modulating skin responses has been investigated. Several parameters (skin thickness, transepidermal water loss, water content of the stratum corneum and skin biomechanics) have been measured using noninvasive tools in whites, Hispanics and blacks to assess whether the melanin content could induce changes in skin biophysical properties. Marked differences between races appear in stratum corneum water content and in skin extensibility, recovery and elastic modulus. Measurements done in different sun-exposed sites highlight the effects of solar irradiation on the skin and the role of melanin in preventing skin damage. The study shows that racial differences in skin physiology exist and are mainly related to the protective role of melanin present in races with darker skin. Moreover, differences in skin hydration are not fully explained according to the site and presence of hair. PMID:2050240

  2. In vitro fabrication of engineered human skin.

    PubMed

    Margulis, Alexander; Zhang, Weitian; Garlick, Jonathan A

    2005-01-01

    In vitro fabrication of human epidermal tissues that mimic the biochemical and morphologic properties of human skin, known as skin-equivalent (organotypic) cultures, has opened new avenues in the study of skin biology. In this chapter, methods for the generation of these tissues from their component parts are described. Conditions for culture of human keratinocytes and fibroblasts that allow optimal growth in skin equivalent cultures are delineated. These cell types are then sequentially combined so that keratinocytes are grown at an air-liquid interface on a contracted collagen gel containing dermal fibroblasts. The methods described enable the generation of human epidermal tissues that show in vivo-like tissue architecture and phenotype. PMID:15502170

  3. Exploring Valrubicin's Effect on Propionibacterium Acnes-Induced Skin Inflammation in Vitro and in Vivo

    PubMed Central

    Rottboell, Louise; de Foenss, Sarah; Thomsen, Kenneth; Christiansen, Helle; Andersen, Stine M.; Dam, Tomas N.; Rosada, Cecilia

    2015-01-01

    Acne is a common skin disease involving colonization with Propionibacterium acnes (P. acnes), hyperproliferation of the follicular epithelium and inflammatory events. Valrubicin is a second-generation anthracycline, non-toxic upon contact, and available in a topical formulation. Valrubicin’s predecessor doxorubicin possesses antibacterial effects and previously we demonstrated that valrubicin inhibits keratinocyte proliferation and skin inflammation suggesting beneficial topical treatment of acne with valrubicin. This study aims to investigate valrubicin’s possible use in acne treatment by testing valrubicin’s antibacterial effects against P. acnes and P. acnes-induced skin inflammation in vitro and in vivo. Valrubicin was demonstrated not to possess antibacterial effects against P. acnes. Additionally, valrubicin was demonstrated not to reduce mRNA and protein expression levels of the inflammatory markers interleukin (IL)-1β, IL-8, and tumor necrosis factor (TNF)-α in vitro in human keratinocytes co-cultured with P. acnes. Moreover, in vivo, valrubicin, applied both topically and intra-dermally, was not able to reduce signs of inflammation in mouse ears intra-dermally injected with P. acnes. Taken together, this study does not support beneficial antibacterial and anti inflammatory effects of topical valrubicin treatment of acne. PMID:26734122

  4. In vivo monitoring of external pressure induced hemodynamics in skin tissue using optical coherence tomography angiography

    NASA Astrophysics Data System (ADS)

    Choi, Woo June; Wang, Hequn; Wang, Ruikang K.

    2015-03-01

    Characterization of the relationship between external pressure and blood flow is important in the examination of pressure-induced disturbance in tissue microcirculation. Optical coherence tomography (OCT) angiography is a promising imaging technique, capable of providing the noninvasive extraction of functional vessels within the skin tissue with capillary-scale resolution. Here, we present a feasibility study of OCT angiography to monitor effect of external pressures on blood perfusion in human skin tissue in vivo. Graded external pressure is loaded normal to the surface of the nailfold tissue of a healthy human. The incremental loading is applied step by step and then followed by an immediate release. Concurrent OCT imaging of the nailfold is performed during the pre/post loading. Blood perfusion images including baseline (at pre-loading) and corresponding tissue strain maps are calculated from 3D OCT dataset obtained at the different applied pressures, allowing visualization of capillary perfusion events at stressed nailfold tissue. The results indicate that the perfusion progressively decreases with the constant increase of tissue strain. Reactive hyperemia is occurred right after the removal of the pressure corresponding to quick drop of the increased strain. The perfusion is returned to the baseline level after a few minutes. These findings suggest that OCT microangiography may have great potential for quantitatively assessing tissue microcirculation in the locally pressed tissue in vivo.

  5. Optical clearing of skin under action of glycerol: Ex vivo and in vivo investigations

    NASA Astrophysics Data System (ADS)

    Genina, E. A.; Bashkatov, A. N.; Sinichkin, Yu. P.; Tuchin, V. V.

    2010-08-01

    The behavior of optical parameters of the skin of a laboratory rat under the action of an aqueous solution of glycerol is studied ex vivo and in vivo. It is found that the collimated transmission coefficient of ex vivo skin samples increases by a factor of 20-40-fold depending on the wavelength in the studied spectral range, and the diffuse reflection coefficient of skin in vivo decreases on the average by 16%. The results presented can be useful for many methods of laser therapy and optical diagnostics of skin diseases and localization of subcutaneous neoplasms.

  6. Memristance in human skin

    NASA Astrophysics Data System (ADS)

    Martinsen, Ø. G.; Grimnes, S.; Lütken, C. A.; Johnsen, G. K.

    2010-04-01

    The memristor is basically a resistor with memory, so that the resistance is dependent on the net amount of charge having passed through the device. It is the regarded the fourth fundamental component, in addition to the resistor, capacitor and inductor, that can be deduced from the four basic circuit variables; current, voltage, charge and magnetic flux. We show that memristors can be used for modelling electrical properties of human skin. In particular is electro-osmosis in human sweat ducts of memristive nature.

  7. High altitude impairs in vivo immunity in humans.

    PubMed

    Oliver, Samuel J; Macdonald, Jamie H; Harper Smith, Adam D; Lawley, Justin S; Gallagher, Carla A; Di Felice, Umberto; Walsh, Neil P

    2013-06-01

    The aim was to assess the effect of high altitude on the development of new immune memory (induction) using a contact sensitization model of in vivo immunity. We hypothesized that high-altitude exposure would impair induction of the in vivo immune response to a novel antigen, diphenylcyclopropenone (DPCP). DPCP was applied (sensitization) to the lower back of 27 rested controls at sea level and to ten rested mountaineers 28 hours after passive ascent to 3777 m. After sensitization, mountaineers avoided strenuous exercise for a further 24 hours, after which they completed alpine activities for 11-18 days. Exactly 4 weeks after sensitization, the strength of immune memory induction was quantified in rested mountaineers and controls at sea level, by measuring the response to a low, dose-series DPCP challenge, read at 48 hours as skin measures of edema (skinfold thickness) and redness (erythema). Compared with control responses, skinfold thickness and erythema were reduced in the mountaineers (skinfold thickness,-52%, p=0.01, d=0.86; erythema, -36%, p=0.02, d=0.77). These changes in skinfold thickness and erythema were related to arterial oxygen saturation (r=0.7, p=0.04), but not cortisol (r<0.1, p>0.79), at sensitization. In conclusion, this is the first study to show, using a contact sensitization model of in vivo immunity, that high altitude exposure impairs the development of new immunity in humans. PMID:23795734

  8. In vivo skin dose measurement in breast conformal radiotherapy

    PubMed Central

    Soleymanifard, Shokouhozaman; Noghreiyan, Atefeh Vejdani; Ghorbani, Mahdi; Jamali, Farideh; Davenport, David

    2016-01-01

    Aim of the study Accurate skin dose assessment is necessary during breast radiotherapy to assure that the skin dose is below the tolerance level and is sufficient to prevent tumour recurrence. The aim of the current study is to measure the skin dose and to evaluate the geometrical/anatomical parameters that affect it. Material and methods Forty patients were simulated by TIGRT treatment planning system and treated with two tangential fields of 6 MV photon beam. Wedge filters were used to homogenise dose distribution for 11 patients. Skin dose was measured by thermoluminescent dosimeters (TLD-100) and the effects of beam incident angle, thickness of irradiated region, and beam entry separation on the skin dose were analysed. Results Average skin dose in treatment course of 50 Gy to the clinical target volume (CTV) was 36.65 Gy. The corresponding dose values for patients who were treated with and without wedge filter were 35.65 and 37.20 Gy, respectively. It was determined that the beam angle affected the average skin dose while the thickness of the irradiated region and the beam entry separation did not affect dose. Since the skin dose measured in this study was lower than the amount required to prevent tumour recurrence, application of bolus material in part of the treatment course is suggested for post-mastectomy advanced breast radiotherapy. It is more important when wedge filters are applied to homogenize dose distribution. PMID:27358592

  9. In vivo measurements of skin barrier: comparison of different methods and advantages of laser scanning microscopy

    NASA Astrophysics Data System (ADS)

    Patzelt, A.; Sterry, W.; Lademann, J.

    2010-12-01

    A major function of the skin is to provide a protective barrier at the interface between external environment and the organism. For skin barrier measurement, a multiplicity of methods is available. As standard methods, the determination of the transepidermal water loss (TEWL) as well as the measurement of the stratum corneum hydration, are widely accepted, although they offer some obvious disadvantages such as increased interference liability. Recently, new optical and spectroscopic methods have been introduced to investigate skin barrier properties in vivo. Especially, laser scanning microscopy has been shown to represent an excellent tool to study skin barrier integrity in many areas of relevance such as cosmetology, occupation, diseased skin, and wound healing.

  10. The optics of human skin

    SciTech Connect

    Anderson, R.R.; Parrish, J.A.

    1981-07-01

    An integrated review of the transfer of optical radiation into human skin is presented, aimed at developing useful models for photomedicine. The component chromophores of epidermis and stratum corneum in general determine the attenuation of radiation in these layers, moreso than does optical scattering. Epidermal thickness and melanization are important factors for UV wavelengths less than 300 nm, whereas the attenuation of UVA (320-400 nm) and visible radiation is primarily via melanin. The selective penetration of all optical wavelengths into psoriatic skin can be maximized by application of clear lipophilic liquids, which decrease regular reflectance by a refractive-index matching mechanism. Sensitivity to wavelengths less than 320 nm can be enhanced by prolonged aqueous bathing, which extracts urocanic acid and other diffusible epidermal chromophores. Optical properties of the dermis are modelled using the Kubelka-Munk approach, and calculations of scattering and absorption coefficients are presented. This simple approach allows estimates of the penetration of radiation in vivo using noninvasive measurements of cutaneous spectral remittance (diffuse reflectance). Although the blood chromophores Hb, HbO/sup 2/, and bilirubin determine dermal absorption of wavelengths longer than 320 nm, scattering by collagen fibers largely determines the depths to which these wavelengths penetrate the dermis, and profoundly modifies skin colors. An optical ''window'' exists between 600 and 1300 nm, which offers the possibility of treating large tissue volumes with certain long-wavelength photosensitizers. Moreover, whenever photosensitized action spectra extend across the near UV and/or visible spectrum, judicious choice of wavelengths allows some selection of the tissue layers directly affected.

  11. Ranking of aqueous surfactant-humectant systems based on an analysis of in vitro and in vivo skin barrier perturbation measurements.

    PubMed

    Ghosh, Saswata; Hornby, Sidney; Grove, Gary; Zerwick, Charles; Appa, Yohini; Blankschtein, Daniel

    2007-01-01

    We propose that skin electrical current measurements can be used in vitro to effectively rank aqueous solutions containing surfactants and humectants (the enhancer) contacting the skin, relative to a PBS aqueous solution (the control) contacting the skin, based on their ability to perturb the skin aqueous pores. Specifically, we develop an in vitro ranking metric using the increase in the skin electrical current induced by an enhancer relative to the control. Aqueous contacting solutions containing (i) surfactants [SDS (sodium dodecyl sulfate)] and C(12)E(6) [dodecyl hexa (ethylene oxide)], (ii) humectants (glycerol and propylene glycol), and (iii) a control (PBS) were studied. Utilizing the new in vitro ranking metric, these aqueous contacting solutions were ranked as follows (from the mildest to the harshest): glycerol < propylene glycol < PBS < C(12)E(6) < SDS. In order to further develop this ranking methodology, which can potentially lead to the reduction, or elimination, of costly and time-consuming procedures, such as human and animal testing and trial-and-error screening in vivo, it was important to correlate the findings of the in vitro ranking metric with direct in vivo skin barrier measurements. For this purpose, in vivo soap chamber measurements, including transepidermal water loss, visual skin dryness, and chromameter erythema measurements, were carried out on human volunteers using the aqueous surfactant-humectant solutions described above. The results of these in vivo measurements were found to be consistent with the ranking results obtained using the in vitro ranking metric. To further explore the validity of our model and to verify the skin barrier mitigating effect of glycerol, in vivo soap chamber measurements were carried out for aqueous SDS solutions containing 10 wt% added glycerol. These in vivo measurements support our recent in vitro finding that glycerol reduces the average radius and the pore number density of the skin aqueous pores, such

  12. In Vivo Imaging of Human Neuroinflammation.

    PubMed

    Albrecht, Daniel S; Granziera, Cristina; Hooker, Jacob M; Loggia, Marco L

    2016-04-20

    Neuroinflammation is implicated in the pathophysiology of a growing number of human disorders, including multiple sclerosis, chronic pain, traumatic brain injury, and amyotrophic lateral sclerosis. As a result, interest in the development of novel methods to investigate neuroinflammatory processes, for the purpose of diagnosis, development of new therapies, and treatment monitoring, has surged over the past 15 years. Neuroimaging offers a wide array of non- or minimally invasive techniques to characterize neuroinflammatory processes. The intent of this Review is to provide brief descriptions of currently available neuroimaging methods to image neuroinflammation in the human central nervous system (CNS) in vivo. Specifically, because of the relatively widespread accessibility of equipment for nuclear imaging (positron emission tomography [PET]; single photon emission computed tomography [SPECT]) and magnetic resonance imaging (MRI), we will focus on strategies utilizing these technologies. We first provide a working definition of "neuroinflammation" and then discuss available neuroimaging methods to study human neuroinflammatory processes. Specifically, we will focus on neuroimaging methods that target (1) the activation of CNS immunocompetent cells (e.g. imaging of glial activation with TSPO tracer [(11)C]PBR28), (2) compromised BBB (e.g. identification of MS lesions with gadolinium-enhanced MRI), (3) CNS-infiltration of circulating immune cells (e.g. tracking monocyte infiltration into brain parenchyma with iron oxide nanoparticles and MRI), and (4) pathological consequences of neuroinflammation (e.g. imaging apoptosis with [(99m)Tc]Annexin V or iron accumulation with T2* relaxometry). This Review provides an overview of state-of-the-art techniques for imaging human neuroinflammation which have potential to impact patient care in the foreseeable future. PMID:26985861

  13. Oncogenic Radiation Abscopal Effects In Vivo: Interrogating Mouse Skin

    SciTech Connect

    Mancuso, Mariateresa; Leonardi, Simona; Giardullo, Paola; Pasquali, Emanuela; Tanori, Mirella; De Stefano, Ilaria; Casciati, Arianna; Naus, Christian C.; Pazzaglia, Simonetta; Saran, Anna

    2013-08-01

    Purpose: To investigate the tissue dependence in transmission of abscopal radiation signals and their oncogenic consequences in a radiosensitive mouse model and to explore the involvement of gap junction intercellular communication (GJIC) in mediating radiation tumorigenesis in off-target mouse skin. Methods and Materials: Patched1 heterozygous (Ptch1{sup +/−}) mice were irradiated at postnatal day 2 (P2) with 10 Gy of x-rays. Individual lead cylinders were used to protect the anterior two-thirds of the body, whereas the hindmost part was directly exposed to radiation. To test the role of GJICs and their major constituent connexin43 (Cx43), crosses between Ptch1{sup +/−} and Cx43{sup +/−} mice were similarly irradiated. These mouse groups were monitored for their lifetime, and skin basal cell carcinomas (BCCs) were counted and recorded. Early responses to DNA damage - Double Strand Breaks (DSBs) and apoptosis - were also evaluated in shielded and directly irradiated skin areas. Results: We report abscopal tumor induction in the shielded skin of Ptch1{sup +/−} mice after partial-body irradiation. Endpoints were induction of early nodular BCC-like tumors and macroscopic infiltrative BCCs. Abscopal tumorigenesis was significantly modulated by Cx43 status, namely, Cx43 reduction was associated with decreased levels of DNA damage and oncogenesis in out-of-field skin, suggesting a key role of GJIC in transmission of oncogenic radiation signals to unhit skin. Conclusions: Our results further characterize the nature of abscopal responses and the implications they have on pathologic processes in different tissues, including their possible underlying mechanistic bases.

  14. In vivo confocal Raman microspectroscopy of the skin: noninvasive determination of molecular concentration profiles.

    PubMed

    Caspers, P J; Lucassen, G W; Carter, E A; Bruining, H A; Puppels, G J

    2001-03-01

    Confocal Raman spectroscopy is introduced as a noninvasive in vivo optical method to measure molecular concentration profiles in the skin. It is shown how it can be applied to determine the water concentration in the stratum corneum as a function of distance to the skin surface, with a depth resolution of 5 microm. The resulting in vivo concentration profiles are in qualitative and quantitative agreement with published data, obtained by in vitro X-ray microanalysis of skin samples. Semi-quantitative concentration profiles were determined for the major constituents of natural moisturizing factor (serine, glycine, pyrrolidone-5-carboxylic acid, arginine, ornithine, citrulline, alanine, histidine, urocanic acid) and for the sweat constituents lactate and urea. A detailed description is given of the signal analysis methodology that enables the extraction of this information from the skin Raman spectra. No other noninvasive in vivo method exists that enables an analysis of skin molecular composition as a function of distance to the skin surface with similar detail and spatial resolution. Therefore, it may be expected that in vivo confocal Raman spectroscopy will find many applications in basic and applied dermatologic research. PMID:11231318

  15. Comparison of human and porcine skin for characterization of sunscreens

    NASA Astrophysics Data System (ADS)

    Weigmann, Hans-Jürgen; Schanzer, Sabine; Patzelt, Alexa; Bahaban, Virginie; Durat, Fabienne; Sterry, Wolfram; Lademann, Jürgen

    2009-03-01

    The universal sun protection factor (USPF) characterizing sunscreen efficacy based on spectroscopically determined data, which were obtained using the tape stripping procedure. The USPF takes into account the complete ultraviolet (UV) spectral range in contrast to the classical sun protection factor (SPF). Until now, the USPF determination has been evaluated only in human skin. However, investigating new filters not yet licensed excludes in vivo investigation on human skin but requires the utilization of a suitable skin model. The penetration behavior and the protection efficacy of 10 commercial sunscreens characterized by USPF were investigated, comparing human and porcine skin. The penetration behavior found for typical UV filter substances is nearly identical for both skin types. The comparison of the USPF obtained for human and porcine skin results in a linear relation between both USPF values with a correlation factor R2=0.98. The results demonstrate the possibility for the use of porcine skin to determine the protection efficacy of sunscreens.

  16. Study of the vitamins A, E and C esters penetration into the skin by confocal Raman spectroscopy in vivo

    NASA Astrophysics Data System (ADS)

    Mogilevych, Borys; Isensee, Debora; Rangel, Joao L.; Dal Pizzol, Carine; Martinello, Valeska C. A.; Dieamant, Gustavo C.; Martin, Airton A.

    2015-06-01

    Vitamins A, E and C play important role in skin homeostasis and protection. Hence, they are extensively used in many cosmetic and cosmeceutic products. However, their molecules are unstable, and do not easily penetrate into the skin, which drastically decreases its efficiency in topical formulations. Liposoluble derivative of the vitamin A - retinyl palmitate, vitamin E - tocopheryl acetate, and vitamin C - tetraisopalmitoyl ascorbic acid, are more stable, and are frequently used as an active ingredient in cosmetic products. Moreover, increased hydrophobicity of these molecules could lead to a higher skin penetration. The aim of this work is to track and compare the absorption of the liposoluble derivatives of the vitamins and their encapsulated form, into the healthy human skin in vivo. We used Confocal Raman Spectroscopy (CRS) that is proven to be helpful in label-free non-destructive investigation of the biochemical composition and molecular conformational analysis of the biological samples. The measurements were performed in the volar forearm of the 10 healthy volunteers. Skin was treated with both products, and Raman spectra were obtained after 15 min, 3 hours, and 6 hours after applying the formulation. 3510 Skin Composition Analyzer (River Diagnostics, The Netherlands) with 785 nm laser excitation was used to acquire information in the fingerprint region. Significant difference in permeation of the products was observed. Whereas only free form of retinyl palmitate penetrate the skin within first 15 minutes, all three vitamin derivatives were present under the skin surface in case of nanoparticulated form.

  17. In vivo gene silencing following non-invasive siRNA delivery into the skin using a novel topical formulation.

    PubMed

    Hegde, Vikas; Hickerson, Robyn P; Nainamalai, Sitheswaran; Campbell, Paul A; Smith, Frances J D; McLean, W H Irwin; Pedrioli, Deena M Leslie

    2014-12-28

    Therapeutics based on short interfering RNAs (siRNAs), which act by inhibiting the expression of target transcripts, represent a novel class of potent and highly specific next-generation treatments for human skin diseases. Unfortunately, the intrinsic barrier properties of the skin combined with the large size and negative charge of siRNAs make epidermal delivery of these macromolecules quite challenging. To help evaluate the in vivo activity of these therapeutics and refine delivery strategies we generated an innovative reporter mouse model that predominantly expresses firefly luciferase (luc2p) in the paw epidermis--the region of murine epidermis that most closely models the tissue architecture of human skin. Combining this animal model with state-of-the-art live animal imaging techniques, we have developed a real-time in vivo analysis work-flow that has allowed us to compare and contrast the efficacies of a wide range nucleic acid-based gene silencing reagents in the skin of live animals. While inhibition was achieved with all of the reagents tested, only the commercially available "self-delivery" modified Accell-siRNAs (Dharmacon) produced potent and sustained in vivo gene silencing. Together, these findings highlight just how informative reliable reporter mouse models can be when assessing novel therapeutics in vivo. Using this work-flow, we developed a novel clinically-relevant topical formulation that facilitates non-invasive epidermal delivery of unmodified and "self-delivery" siRNAs. Remarkably, a sustained >40% luc2p inhibition was observed after two 1-hour treatments with Accell-siRNAs in our topical formulation. Importantly, our ability to successfully deliver siRNA molecules topically brings these novel RNAi-based therapeutics one-step closer to clinical use. PMID:25449884

  18. The effects of heat on skin barrier function and in vivo dermal absorption.

    PubMed

    Oliveira, Gabriela; Leverett, Jesse C; Emamzadeh, Mandana; Lane, Majella E

    2014-04-10

    Enhanced delivery of ingredients across the stratum corneum (SC) is of great interest for improving the efficacy of topically applied formulations. Various methods for improving dermal penetration have been reported including galvanic devices and micro-needles. From a safety perspective it is important that such approaches do not compromise SC barrier function. This study investigates the influence of topically applied heat in vivo on the dermal uptake and penetration of a model active, allantoin from gel and lotion formulations. A custom designed device was used to deliver 42°C for 30s daily to human subjects after application of two formulations containing allantoin. The results were compared with sites treated with formulations containing no active and no heat, and a control site. In addition to penetration of allantoin, the integrity of the SC was monitored using trans-epidermal water loss (TEWL) measurements. The results showed that just 30s of 42°C topically applied heat was enough to cause significantly more penetration of allantoin from the lotion formulation compared with no application of heat. TEWL data indicated that the integrity of the skin was not compromised by the treatment. However, the application of heat did not promote enhanced penetration of the active from the gel formulation. Vehicle composition is therefore an important factor when considering thermal enhancement strategies for targeting actives to the skin. PMID:24445121

  19. In vitro Percutaneous Absorption of Niacinamide and Phytosterols and in vivo Evaluation of their Effect on Skin Barrier Recovery.

    PubMed

    Offerta, Alessia; Bonina, Francesco; Gasparri, Franco; Zanardi, Andrea; Micicche, Lucia; Puglia, Carmelo

    2016-01-01

    In this study, we evaluated different strategies to optimize the percutaneous absorption of niacinamide (NA) and soy phytosterols (FITO) by making use of solid lipid nanoparticles (SLN) and penetration enhancers, such as the hydrogenated lecithin. The evaluation of the skin permeation of NA and FITO has been effected in vitro using excised human skin (i.e., stratum corneum-epidermis or SCE). Furthermore, we evaluated the in vivo effect that NA and FITO has on skin barrier recovery after the topical application; using the extent of methyl nicotinate (MN)-induced erythema in damaged skin as a parameter to determine the rate of stratum corneum recovery. Results pointed out the importance of these strategies as valid tools for NA and FITO topical delivery. In fact, soy lecithin based formulations were able to increase the percutaneous absorption of the two active ingredients, while SLN guaranteed an interesting delayed and sustained release of FITO. In vivo evaluation showed clearly that the formulation containing both the actives (NA and FITO) is able to recover about 95% of skin barrier integrity eight days after tape stripping. This effect is probably due to the "synergistic effect" of NA and FITO. PMID:26201345

  20. Enhanced in vitro and in vivo skin deposition of apigenin delivered using ethosomes.

    PubMed

    Shen, Li-Na; Zhang, Yong-Tai; Wang, Qin; Xu, Ling; Feng, Nian-Ping

    2014-01-01

    The aim of this study was to develop and evaluate a novel topical delivery system for apigenin by using ethosomes. An optimal apigenin-loaded ethosome formulation was identified by means of uniform design experiments. Skin deposition and transdermal flux of apigenin loaded in ethosomes, liposomes, and deformable liposomes were compared in vitro and in vivo. The efficiency of apigenin encapsulation increased with an increase in the amount of phospholipids in ethosome formulations. Moreover, skin deposition and transdermal flux of apigenin improved with an increase in the levels of phospholipids (Lipoid S 75) and short-chain alcohols (propylene glycol and ethanol), but decreased with an increase in the ratio of propylene glycol to ethanol. Profiles of skin deposition versus time for ethosomes varied markedly between in vivo and in vitro studies compared with those of liposomes or deformable liposomes. Optimized ethosomes showed superior skin targeting both in vitro and in vivo. Moreover, they had the strongest effect on reduction of cyclooxygenase-2 levels in mouse skin inflammation induced by ultraviolet B (UVB) light. Therefore, apigenin-loaded ethosomes represent a promising therapeutic approach for the treatment of UVB-induced skin inflammation. PMID:24269286

  1. Improvement of in vivo rat skin optical clearing with chemical penetration enhancers

    NASA Astrophysics Data System (ADS)

    Wang, Jing; Zhou, Xue; Duan, Shu; Chen, Zhongwei; Zhu, Dan

    2011-03-01

    Optical method plays an important role in clinical diagnosis and treatment, but suffers from limited penetration depth of light in turbid tissue. The optical clearing technique can improve the light delivery significantly through immersion of tissues into Optical Clearing Agents (OCAs). However, the barrier function of stratum corneum makes it difficult for optical clearing of skin by topical application of OCAs. Addition of penetration enhancers to OCAs can improve the skin clearing efficacy, but most investigations were performed on in vitro skin. Here, to evaluate the efficacy of this method on in vivo skin, direct observation and measurement of diffuse reflectance spectra were performed after topical application of different mixtures. One OCA, PEG-400, and three penetration enhancers (PEs), Thiazone, Azone and Propylene Glycol (PG), were used. The results indicated that the addition of penetration enhancers could improve the optical clearing efficacy of rat skin in vivo significantly, the dermal blood vessels could be observed directly with PEs. Among the three penetration enhancers, Thiazone induced the largest enhancement of clearing efficacy, and the enhancement induced by PG is the least. This study is very helpful for in vivo application of OCAs to enhance skin optical clearing non- invasively.

  2. Polarization speckle imaging as a potential technique for in vivo skin cancer detection

    NASA Astrophysics Data System (ADS)

    Tchvialeva, Lioudmila; Dhadwal, Gurbir; Lui, Harvey; Kalia, Sunil; Zeng, Haishan; McLean, David I.; Lee, Tim K.

    2013-06-01

    Skin cancer is the most common cancer in the Western world. In order to accurately detect the disease, especially malignant melanoma-the most fatal form of skin cancer-at an early stage when the prognosis is excellent, there is an urgent need to develop noninvasive early detection methods. We believe that polarization speckle patterns, defined as a spatial distribution of depolarization ratio of traditional speckle patterns, can be an important tool for skin cancer detection. To demonstrate our technique, we conduct a large in vivo clinical study of 214 skin lesions, and show that statistical moments of the polarization speckle pattern could differentiate different types of skin lesions, including three common types of skin cancers, malignant melanoma, squamous cell carcinoma, basal cell carcinoma, and two benign lesions, melanocytic nevus and seborrheic keratoses. In particular, the fourth order moment achieves better or similar sensitivity and specificity than many well-known and accepted optical techniques used to differentiate melanoma and seborrheic keratosis.

  3. Determination of in vivo skin moisture level by near-infrared reflectance spectroscopy

    NASA Astrophysics Data System (ADS)

    Saknite, Inga; Spigulis, Janis

    2015-03-01

    Near-infrared spectroscopy has a potential for noninvasive determination of skin moisture level due to high water absorption. In this study, diffuse reflectance spectra of in vivo skin were acquired in the spectral range of 900 nm to 1700 nm by using near-infrared spectrometer, optical fiber and halogen bulb light source. Absorption changes after applying skin moisturizers were analyzed over time at different body sites. Results show difference in absorption when comparing dry and normal skin. Comparison of absorption changes over time after applying moisturizer at different body sites is analyzed and discussed. Some patterns of how skin reacts to different skin moisturizers are shown, although no clear pattern can be seen due to signal noise.

  4. In vitro and in vivo percutaneous absorption of retinol from cosmetic formulations: Significance of the skin reservoir and prediction of systemic absorption

    SciTech Connect

    Yourick, Jeffrey J. Jung, Connie T.; Bronaugh, Robert L.

    2008-08-15

    The percutaneous absorption of retinol (Vitamin A) from cosmetic formulations was studied to predict systemic absorption and to understand the significance of the skin reservoir in in vitro absorption studies. Viable skin from fuzzy rat or human subjects was assembled in flow-through diffusion cells for in vitro absorption studies. In vivo absorption studies using fuzzy rats were performed in glass metabolism cages for collection of urine, feces, and body content. Retinol (0.3%) formulations (hydroalcoholic gel and oil-in-water emulsion) containing {sup 3}H-retinol were applied and absorption was measured at 24 or 72 h. All percentages reported are % of applied dose. In vitro studies using human skin and the gel and emulsion vehicles found 0.3 and 1.3% retinol, respectively, in receptor fluid at 24 h. Levels of absorption in the receptor fluid increased over 72 h with the gel and emulsion vehicles. Using the gel vehicle, in vitro rat skin studies found 23% in skin and 6% in receptor fluid at 24 h, while 72-h studies found 18% in skin and 13% in receptor fluid. Thus, significant amounts of retinol remained in rat skin at 24 h and decreased over 72 h, with proportional increases in receptor fluid. In vivo rat studies with the gel found 4% systemic absorption of retinol after 24 h and systemic absorption did not increase at 72 h. Retinol remaining in rat skin after in vivo application was 18% and 13% of the applied dermal dose after 24 and 72 h, respectively. Similar observations were made with the oil-in water emulsion vehicle in the rat. Retinol formed a reservoir in rat skin both in vivo and in vitro. Little additional retinol was bioavailable after 24 h. Comparison of these in vitro and in vivo results for absorption through rat skin indicates that the 24-h in vitro receptor fluid value accurately estimated 24-h in vivo systemic absorption. Therefore, the best single estimate of retinol systemic absorption from in vitro human skin studies is the 24-h receptor

  5. Measurement of diffusion of fluorescent compounds and autofluorescence in skin in vivo using a confocal instrument

    NASA Astrophysics Data System (ADS)

    Buttenschoen, K. K.; Sutton, E. E.; Daly, D.; Girkin, J. M.

    2016-02-01

    Using compact and affordable instrumentation based upon fluorescent confocal imaging we have tracked the movement of autofluorescent compounds through skin in near real time with high temporal and spatial resolution and sensitivity. The ability to measure the diffusion of compounds through skin with such resolution plays an important role for applications such as monitoring the penetration of pharmaceuticals applied to skin and assessing the integrity of the skin barrier. Several measurement methods exist, but they suffer from a number of problems such as being slow, expensive, non-portable and lacking sensitivity. To address these issues, we adapted a technique that we previously developed for tracking fluorescent compounds in the eye to measure the autofluorescence and the diffusion of externally applied fluorescent compounds in skin in vivo. Results are presented that show the change in autofluorescence of the volar forearm over the course of a week. We furthermore demonstrate the ability of the instrument to measure the diffusion speed and depth of externally applied fluorescent compounds both in healthy skin and after the skin barrier function has been perturbed. The instrument is currently being developed further for increased sensitivity and multi-wavelength excitation. We believe that the presented instrument is suitable for a large number of applications in fields such as assessment of damage to the skin barrier, development of topical and systemic medication and tracking the diffusion of fluorescent compounds through skin constructs as well as monitoring effects of skin products and general consumer products which may come into contact with the skin.

  6. Diagnostic opto-electronic system for measuring physical and biological characteristics of the skin in vivo

    NASA Astrophysics Data System (ADS)

    Makara, Ivanna V.; Kozhukhar, Oleksander T.; Komada, Pawel; Dussembayeva, Shynar

    2015-12-01

    Actuality development of optoelectronic rapid diagnostic system for measuring physical and biological characteristics of the skin in vivo with radiation of electromagnetic radiation in the optical range to obtain objective information on the spatial distribution of biochemical and morphological and anatomical components are different for state standards and pathology.

  7. Enhanced optical clearing of skin in vivo and optical coherence tomography in-depth imaging

    NASA Astrophysics Data System (ADS)

    Wen, Xiang; Jacques, Steven L.; Tuchin, Valery V.; Zhu, Dan

    2012-06-01

    The strong optical scattering of skin tissue makes it very difficult for optical coherence tomography (OCT) to achieve deep imaging in skin. Significant optical clearing of in vivo rat skin sites was achieved within 15 min by topical application of an optical clearing agent PEG-400, a chemical enhancer (thiazone or propanediol), and physical massage. Only when all three components were applied together could a 15 min treatment achieve a three fold increase in the OCT reflectance from a 300 μm depth and 31% enhancement in image depth Zthreshold.

  8. Establishment of a Transgenic Zebrafish Line for Superficial Skin Ablation and Functional Validation of Apoptosis Modulators In Vivo

    PubMed Central

    Chen, Chi-Fang; Chu, Che-Yu; Chen, Te-Hao; Lee, Shyh-Jye; Shen, Chia-Ning; Hsiao, Chung-Der

    2011-01-01

    Background Zebrafish skin is composed of enveloping and basal layers which form a first-line defense system against pathogens. Zebrafish epidermis contains ionocytes and mucous cells that aid secretion of acid/ions or mucous through skin. Previous studies demonstrated that fish skin is extremely sensitive to external stimuli. However, little is known about the molecular mechanisms that modulate skin cell apoptosis in zebrafish. Methodology/Principal Findings This study aimed to create a platform to conduct conditional skin ablation and determine if it is possible to attenuate apoptotic stimuli by overexpressing potential apoptosis modulating genes in the skin of live animals. A transgenic zebrafish line of Tg(krt4:NTR-hKikGR)cy17 (killer line), which can conditionally trigger apoptosis in superficial skin cells, was first established. When the killer line was incubated with the prodrug metrodinazole, the superficial skin displayed extensive apoptosis as judged by detection of massive TUNEL- and active caspase 3-positive signals. Great reductions in NTR-hKikGR+ fluorescent signals accompanied epidermal cell apoptosis. This indicated that NTR-hKikGR+ signal fluorescence can be utilized to evaluate apoptotic events in vivo. After removal of metrodinazole, the skin integrity progressively recovered and NTR-hKikGR+ fluorescent signals gradually restored. In contrast, either crossing the killer line with testing lines or transiently injecting the killer line with testing vectors that expressed human constitutive active Akt1, mouse constitutive active Stat3, or HPV16 E6 element displayed apoptosis-resistant phenotypes to cytotoxic metrodinazole as judged by the loss of reduction in NTR-hKikGR+ fluorescent signaling. Conclusion/Significance The killer/testing line binary system established in the current study demonstrates a nitroreductase/metrodinazole system that can be utilized to conditionally perform skin ablation in a real-time manner, and provides a valuable tool to

  9. Relevance of in vivo models in melanoma skin cancer

    SciTech Connect

    Setlow, R.B.

    1995-12-31

    A discussion of possible wavelength dependence of induction of cutaneous malignant melanoma (CMM) is provided. Strengths and weaknesses of various experimental approaches to better understanding of the prevalence of CMM in different human populations including latitude effects are compared. Further the advantages and limitations of the use of the laboratory opossum (Monodelphis domestic), transgenic mice containing SV40 ongogene sequences under tyrosinase promoter control, and a backcross hybrid fish of the genus Xenophorus are contrasted.

  10. In vivo measurement of skin microrelief using photometric stereo in the presence of interreflections.

    PubMed

    Sohaib, Ali; Farooq, Abdul R; Atkinson, Gary A; Smith, Lyndon N; Smith, Melvyn L; Warr, Robert

    2013-03-01

    This paper proposes and describes an implementation of a photometric stereo-based technique for in vivo assessment of three-dimensional (3D) skin topography in the presence of interreflections. The proposed method illuminates skin with red, green, and blue colored lights and uses the resulting variation in surface gradients to mitigate the effects of interreflections. Experiments were carried out on Caucasian, Asian, and African American subjects to demonstrate the accuracy of our method and to validate the measurements produced by our system. Our method produced significant improvement in 3D surface reconstruction for all Caucasian, Asian, and African American skin types. The results also illustrate the differences in recovered skin topography due to the nondiffuse bidirectional reflectance distribution function (BRDF) for each color illumination used, which also concur with the existing multispectral BRDF data available for skin. PMID:23456103

  11. Genome Wide Evaluation of Normal Human Tissue in Response to Controlled, In vivo Low-Dose Low LET Ionizing Radiation Exposure: Pathways and Mechanisms Final Report, September 2013

    SciTech Connect

    Rocke, David M.

    2013-09-09

    During course of this project, we have worked in several areas relevant to low-dose ionizing radiation. Using gene expression to measure biological response, we have examined the response of human skin exposed in-vivo to radation, human skin exposed ex-vivo to radiation, and a human-skin model exposed to radiation. We have learned a great deal about the biological response of human skin to low-dose ionizing radiation.

  12. 3D in vivo optical skin imaging for intense pulsed light and fractional ablative resurfacing of photodamaged skin.

    PubMed

    Clementoni, Matteo Tretti; Lavagno, Rosalia; Catenacci, Maximilian; Kantor, Roman; Mariotto, Guido; Shvets, Igor

    2011-11-01

    The authors present a 3D in vivo imaging system used to assess the effectiveness of IPL and fractional laser treatments of photodamaged skin. Preoperative and postoperative images of patients treated with these procedures are analyzed and demonstrate the superior ability of this 3D technology to reveal decrease in vascularity and improvement in melanin distribution and calculate the degree of individual deep wrinkles before and after treatment. PMID:22004864

  13. Advances in the in Vivo Raman Spectroscopy of Malignant Skin Tumors Using Portable Instrumentation

    PubMed Central

    Kourkoumelis, Nikolaos; Balatsoukas, Ioannis; Moulia, Violetta; Elka, Aspasia; Gaitanis, Georgios; Bassukas, Ioannis D.

    2015-01-01

    Raman spectroscopy has emerged as a promising tool for real-time clinical diagnosis of malignant skin tumors offering a number of potential advantages: it is non-intrusive, it requires no sample preparation, and it features high chemical specificity with minimal water interference. However, in vivo tissue evaluation and accurate histopathological classification remain a challenging task for the successful transition from laboratory prototypes to clinical devices. In the literature, there are numerous reports on the applications of Raman spectroscopy to biomedical research and cancer diagnostics. Nevertheless, cases where real-time, portable instrumentations have been employed for the in vivo evaluation of skin lesions are scarce, despite their advantages in use as medical devices in the clinical setting. This paper reviews the advances in real-time Raman spectroscopy for the in vivo characterization of common skin lesions. The translational momentum of Raman spectroscopy towards the clinical practice is revealed by (i) assembling the technical specifications of portable systems and (ii) analyzing the spectral characteristics of in vivo measurements. PMID:26132563

  14. High resolution in-vivo imaging of skin with full field optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Dalimier, E.; Bruhat, Alexis; Grieve, K.; Harms, F.; Martins, F.; Boccara, C.

    2014-03-01

    Full-field OCT (FFOCT) has the ability to provide en-face images with a very good axial sectioning as well as a very high transverse resolution (about 1 microns in all directions). Therefore it offers the possibility to visualize biological tissues with very high resolution both on the axial native view, and on vertical reconstructed sections. Here we investigated the potential dermatological applications of in-vivo skin imaging with FFOCT. A commercial FFOCT device was adapted for the in-vivo acquisition of stacks of images on the arm, hand and finger. Several subjects of different benign and pathological skin conditions were tested. The images allowed measurement of the stratum corneum and epidermis thicknesses, measurement of the stratum corneum refractive index, size measurement and count of the keratinocytes, visualization of the dermal-epidermal junction, and visualization of the melanin granules and of the melanocytes. Skins with different pigmentations could be discriminated and skin pathologies such as eczema could be identified. The very high resolution offered by FFOCT both on axial native images and vertical reconstructed sections allows for the visualization and measurement of a set of parameters useful for cosmetology and dermatology. In particular, FFOCT is a potential tool for the understanding and monitoring of skin hydration and pigmentation, as well as skin inflammation.

  15. Optical characterization of murine model's in-vivo skin using Mueller matrix polarimetric imaging

    NASA Astrophysics Data System (ADS)

    Mora-Núñez, Azael; Martinez-Ponce, Geminiano; Garcia-Torales, Guillermo

    2015-12-01

    Mueller matrix polarimetric imaging (MMPI) provides a complete characterization of an anisotropic optical medium. Subsequent single value decomposition allows image interpretation in terms of basic optical anisotropies, such as depolarization, diattenuation, and retardance. In this work, healthy in-vivo skin at different anatomical locations of a biological model (Rattus norvegicus) was imaged by the MMPI technique using 532nm coherent illumination. The body parts under study were back, abdomen, tail, and calvaria. Because skin components are randomly distributed and skin thickness depends on its location, polarization measures arise from the average over a single detection element (pixel) and on the number of free optical paths, respectively. Optical anisotropies over the imaged skin indicates, mainly, the presence of components related to the physiology of the explored region. In addition, a MMPI-based comparison between a tumor on the back of one test subject and proximal healthy skin was made. The results show that the single values of optical anisotropies can be helpful in distinguishing different areas of in-vivo skin and also lesions.

  16. Freeze-drying as a preserving preparation technique for in vitro testing of human skin.

    PubMed

    Franzen, Lutz; Vidlářová, Lucie; Kostka, Karl-Heinz; Schaefer, Ulrich F; Windbergs, Maike

    2013-01-01

    In vitro testing of drugs with excised human skin is a valuable prerequisite for clinical studies. However, the analysis of excised human skin presents several obstacles. Ongoing drug diffusion, microbial growth and changes in hydration state influence the results of drug penetration studies. In this work, we evaluate freeze-drying as a preserving preparation method for skin samples to overcome these obstacles. We analyse excised human skin before and after freeze-drying and compare these results with human skin in vivo. Based on comprehensive thermal and spectroscopic analysis, we demonstrate comparability to in vivo conditions and exclude significant changes within the skin samples due to freeze-drying. Furthermore, we show that freeze-drying after skin incubation with drugs prevents growth of drug crystals on the skin surface due to drying effects. In conclusion, we introduce freeze-drying as a preserving preparation technique for in vitro testing of human skin. PMID:23278895

  17. Evaluation of Paeonol Skin-Target Delivery from Its Microsponge Formulation: In Vitro Skin Permeation and In Vivo Microdialysis

    PubMed Central

    Liu, Li; Jiang, Xiao; Zhang, Bin; Liu, Zhi-Gang; Li, Xue-Ling; Weng, Li-Dong; Zuo, Ting; Liu, Qiang

    2013-01-01

    The aim of the present study was to design a novel topical skin-target drug-delivery system, the paeonol microsponge, and to investigate its drug-release patterns in dosage form, both in vitro and in vivo. Paeonol microsponges were prepared using the quasi-emulsion solvent-diffusion method. In vitro release studies were carried out using Franz diffusion cells, while in vivo studies were investigated by microdialysis after the paeonol microsponges were incorporated into a cream base. In vitro release studies showed that the drug delivered via microsponges increased the paeonol permeation rate. Ex vivo drug-deposition studies showed that the microsponge formulation improved drug residence in skin. In addition, in vivo microdialysis showed that the values for the area under the concentration versus time curve (AUC) for the paeonol microsponge cream was much higher than that of paeonol cream without microsponges. Maximum time (Tmax) was 220 min for paeonol microsponge cream and 480 min for paeonol cream, while the half-life (t1/2) of paeonol microsponge cream (935.1 min) was almost twice that of paeonol cream (548.6 min) in the skin (n = 3). Meanwhile, in the plasma, the AUC value for paeonol microsponge cream was half that of the paeonol cream. Based on these results, paeonol-loaded microsponge formulations could be a better alternative for treating skin disease, as the formulation increases drug bioavailability by lengthening the time of drug residence in the skin and should reduce side-effects because of the lower levels of paeonol moving into the circulation. PMID:24278204

  18. Remote Skin Tissue Diagnostics In Vivo By Fiber Optic Evanescent Wave Fourier Transform Infrared (FEW-FTIR) Spectroscopy

    NASA Astrophysics Data System (ADS)

    Kolyakov, Sergei; Afanasyeva, Natalia; Bruch, Reinhard; Afanasyeva, Natalia

    1998-05-01

    The new method of fiber optical evanescent wave Fourier transform infrared (FEW-FTIR) spectroscopy has been applied to the diagnostics of normal skin tissue, as well as precancerous and cancerous conditions. The FEW-FTIR technique is nondestructive and sensitive to changes of vibrational spectra in the IR region, without heating and damaging human and animal skin tissue. Therefore this method and technique is an ideal diagnostic tool for tumor and cancer characterization at an early stage of development on a molecular level. The application of fiber optic technology in the middle infrared (MIR) region is relatively inexpensive and can be adapted easily to any commercially available tabletop FTIR spectrometers. This method of diagnostics is fast (several seconds), and can be applied to many fields. Noninvasive medical diagnostics of skin cancer and other skin diseases in vivo, ex vivo, and in vitro allow for the development of convenient, remote clinical applications in dermatology and related fields. The spectral variations from normal to pathological skin tissue and environmental influence on skin have been measured.

  19. Fluorescence lifetime imaging of human skin and hair

    NASA Astrophysics Data System (ADS)

    Ehlers, A.; Riemann, I.; Anhut, T.; Kaatz, M.; Elsner, P.; König, K.

    2006-02-01

    Multiphoton imaging has developed into an important technique for in-vivo research in life sciences. With the laser System DermaInspect (JenLab, Germany) laser radiation from a Ti:Sapphire laser is used to generate multiphotonabsorption deep in the human skin in vivo. The resulting autofluorescence radiation arises from endogenous fluorophores such as NAD(P)H, flavines, collagen, elastin, porphyrins und melanin. Second harmonic generation (SHG) was used to detect collagen structures in the dermal layer. Femtosecond laser multiphoton imaging offers the possibility of high resolution optical tomography of human skin as well as fluorescence lifetime imaging (FLIM) with picosecond time resolution. In this work a photon detector with ultrashort rise time of less than 30ps was applied to FLIM measurements of human skin and hair with different pigmentation. Fluorescence lifetime images of different human hair types will be discussed.

  20. Diffusion of (2-/sup 14/C)diazepam across hairless mouse skin and human skin

    SciTech Connect

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

    1987-05-01

    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. (/sup 14/C)Diazepam was readily absorbed after topical administration to the intact hairless mouse, a total of 75.8% of the /sup 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.

  1. In-vivo data on the influence of tobacco smoke and UV light on murine skin.

    PubMed

    Pavlou, P; Rallis, M; Deliconstantinos, G; Papaioannou, G; Grando, S A

    2009-01-01

    Inhaled tobacco smoke comes in direct contact with few organs such as mouth, lungs, and stomach. Cigarette smoke (CS) in lungs has been extensively studied. However, limited data exist on its effect on skin, and there are no long-term experimental studies suggesting toxic effects on skin. Even though it is generally accepted that CS is among the main factors of skin aging, the number of experimental studies showing this aging effect is limited. We hereby studied the effect of long-term exposure to CS on the skin of hairless mice in combination with or without ultraviolet (UV) light. In addition, we investigated potential skin protection by a potent antioxidant namely procyanidine-rich French maritime pine bark extract (PBE) pycnogenol. Male and female hairless SKH-2 mice were exposed for 10 months to tobacco smoke and/or UV light in vivo, and their effects on skin were investigated. Some biophysical parameters such as development of erythema, transepidermal water loss (TEWL), and skin elasticity were measured. The results show that UV and CS may be acting synergistically, as shown by the enhanced TEWL, erythema values, epitheliomas, and squamous cell carcinomas (SCCs) observed, whereas PBE seems to protect skin against SCC. PMID:19651792

  2. In Vivo Two-Photon Microscopy of Single Nerve Endings in Skin

    PubMed Central

    Yuryev, Mikhail; Molotkov, Dmitry

    2014-01-01

    Nerve endings in skin are involved in physiological processes such as sensing1 as well as in pathological processes such as neuropathic pain2. Their close-to-surface positioning facilitates microscopic imaging of skin nerve endings in living intact animal. Using multiphoton microscopy, it is possible to obtain fine images overcoming the problem of strong light scattering of the skin tissue. Reporter transgenic mice that express EYFP under the control of Thy-1 promoter in neurons (including periphery sensory neurons) are well suited for the longitudinal studies of individual nerve endings over extended periods of time up to several months or even life-long. Furthermore, using the same femtosecond laser as for the imaging, it is possible to produce highly selective lesions of nerve fibers for the studies of the nerve fiber restructuring. Here, we present a simple and reliable protocol for longitudinal multiphoton in vivo imaging and laser-based microsurgery on mouse skin nerve endings. PMID:25178088

  3. In Vitro and In Vivo Germ Line Potential of Stem Cells Derived from Newborn Mouse Skin

    PubMed Central

    Dyce, Paul W.; Liu, Jinghe; Tayade, Chandrakant; Kidder, Gerald M.; Betts, Dean H.; Li, Julang

    2011-01-01

    We previously reported that fetal porcine skin-derived stem cells were capable of differentiation into oocyte-like cells (OLCs). Here we report that newborn mice skin-derived stem cells are also capable of differentiating into early OLCs. Using stem cells from mice that are transgenic for Oct4 germline distal enhancer-GFP, germ cells resulting from their differentiation are expected to be GFP+. After differentiation, some GFP+ OLCs reached 40–45 µM and expressed oocyte markers. Flow cytometric analysis revealed that ∼0.3% of the freshly isolated skin cells were GFP+. The GFP-positive cells increased to ∼7% after differentiation, suggesting that the GFP+ cells could be of in vivo origin, but are more likely induced upon being cultured in vitro. To study the in vivo germ cell potential of skin-derived cells, they were aggregated with newborn ovarian cells, and transplanted under the kidney capsule of ovariectomized mice. GFP+ oocytes were identified within a subpopulation of follicles in the resulting growth. Our finding that early oocytes can be differentiated from mice skin-derived cells in defined medium may offer a new in vitro model to study germ cell formation and oogenesis. PMID:21629667

  4. In-vivo dynamic characterization of microneedle skin penetration using optical coherence tomography.

    PubMed

    Enfield, Joey; O'Connell, Marie-Louise; Lawlor, Kate; Jonathan, Enock; O'Mahony, Conor; Leahy, Martin

    2010-01-01

    The use of microneedles as a method of circumventing the barrier properties of the stratum corneum is receiving much attention. Although skin disruption technologies and subsequent transdermal diffusion rates are being extensively studied, no accurate data on depth and closure kinetics of microneedle-induced skin pores are available, primarily due to the cumbersome techniques currently required for skin analysis. We report on the first use of optical coherence tomography technology to image microneedle penetration in real time and in vivo. We show that optical coherence tomography (OCT) can be used to painlessly measure stratum corneum and epidermis thickness, as well as microneedle penetration depth after microneedle insertion. Since OCT is a real-time, in-vivo, nondestructive technique, we also analyze skin healing characteristics and present quantitative data on micropore closure rate. Two locations (the volar forearm and dorsal aspect of the fingertip) have been assessed as suitable candidates for microneedle administration. The results illustrate the applicability of OCT analysis as a tool for microneedle-related skin characterization. PMID:20799803

  5. In-vivo dynamic characterization of microneedle skin penetration using optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Enfield, Joey; O'Connell, Marie-Louise; Lawlor, Kate; Jonathan, Enock; O'Mahony, Conor; Leahy, Martin

    2010-07-01

    The use of microneedles as a method of circumventing the barrier properties of the stratum corneum is receiving much attention. Although skin disruption technologies and subsequent transdermal diffusion rates are being extensively studied, no accurate data on depth and closure kinetics of microneedle-induced skin pores are available, primarily due to the cumbersome techniques currently required for skin analysis. We report on the first use of optical coherence tomography technology to image microneedle penetration in real time and in vivo. We show that optical coherence tomography (OCT) can be used to painlessly measure stratum corneum and epidermis thickness, as well as microneedle penetration depth after microneedle insertion. Since OCT is a real-time, in-vivo, nondestructive technique, we also analyze skin healing characteristics and present quantitative data on micropore closure rate. Two locations (the volar forearm and dorsal aspect of the fingertip) have been assessed as suitable candidates for microneedle administration. The results illustrate the applicability of OCT analysis as a tool for microneedle-related skin characterization.

  6. Skin Diseases: Cross-section of human skin

    MedlinePlus

    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 ...

  7. In vivo terahertz spectroscopy of pigmentary skin nevi: Pilot study of non-invasive early diagnosis of dysplasia

    NASA Astrophysics Data System (ADS)

    Zaytsev, Kirill I.; Kudrin, Konstantin G.; Karasik, Valeriy E.; Reshetov, Igor V.; Yurchenko, Stanislav O.

    2015-02-01

    In vivo terahertz (THz) spectroscopy of pigmentary skin nevi is performed. The in vivo THz dielectric characteristics of healthy skin and dysplastic and non-dysplastic skin nevi are reconstructed and analyzed. The dielectric permittivity curves of these samples in the THz range exhibit significant differences that could allow non-invasive early diagnosis of dysplastic nevi, which are melanoma precursors. An approach for differentiating dysplastic and non-dysplastic skin nevi using the THz dielectric permittivity is proposed. The results demonstrate that THz pulsed spectroscopy is potentially an effective tool for non-invasive early diagnosis of dysplastic nevi and melanomas of the skin.

  8. Epilobium angustifolium extract demonstrates multiple effects on dermal fibroblasts in vitro and skin photo-protection in vivo.

    PubMed

    Ruszová, Ema; Cheel, José; Pávek, Stanislav; Moravcová, Martina; Hermannová, Martina; Matějková, Ilona; Spilková, Jiřina; Velebný, Vladimír; Kubala, Lukáš

    2013-09-01

    Stress-induced fibroblast senescence is thought to contribute to skin aging. Ultraviolet light (UV) radiation is the most potent environmental risk factor in these processes. An Epilobium angustifolium (EA) extract was evaluated for its capacity to reverse the senescent response of normal human dermal fibroblasts (NHDF) in vitro and to exhibit skin photo-protection in vivo. The HPLC-UV-MS analysis of the EA preparation identified three major polyphenol groups: tannins (oenothein B), phenolic acids (gallic and chlorogenic acids) and flavonoids. EA extract increased the cell viability of senescent NHDF induced by serum deprivation. It diminished connective tissue growth factor and fibronectin gene expressions in senescent NHDF. Down-regulation of the UV-induced release of both matrix metalloproteinase-1 and -3 and the tissue inhibitor of matrix metalloproteinases-1 and -2, and also down-regulation of the gene expression of hyaluronidase 2 were observed in repeatedly UV-irradiated NHDF after EA extract treatment. Interestingly, EA extract diminished the down-regulation of sirtuin 1 dampened by UV-irradiation. The application of EA extract using a sub-irritating dose protected skin against UV-induced erythema formation in vivo. In summary, EA extract diminished stress-induced effects on NHDF, particularly on connective tissue growth factor, fibronectin and matrix metalloproteinases. These results collectively suggest that EA extract may possess anti-aging properties and that the EA polyphenols might account for these benefits. PMID:23817638

  9. Determination of the thickness and structure of the skin barrier by in vivo laser scanning microscopy

    NASA Astrophysics Data System (ADS)

    Lademann, J.; Richter, H.; Astner, S.; Patzelt, A.; Knorr, F.; Sterry, W.; Antoniou, Ch

    2008-04-01

    Normal skin barrier function is an essential aspect of skin homeostasis and regeneration. Dynamic inflammatory, proliferative and neoplastic skin processes such as wound healing, psoriasis and contact dermatitis are associated with a significant disruption of the skin barrier. In recent years, there has been increasing interest in evaluating cosmetic and pharmacologic products for their ability to restore these protective properties. The gold standard for characterization of barrier function has been the measurement of the transepidermal water loss, however the disadvantage of this method is its interference with several endogenous and exogenous factors such as hydration, perspiration and topically applied substances. This study was aimed to test the clinical applicability of a fluorescence confocal laser scanning microscope (LSM) for a systematic morphologic analysis of the structure, integrity and thickness of the stratum corneum in 10 otherwise healthy volunteers. The influence of skin treatment with commercial moisturizing cream on skin barrier function was evaluated in serial non-invasive examinations. Our findings showed that in vivo LSM may represent a simple and efficient method for the characterization of skin barrier properties, such as the thickness and hydration of the stratum corneum.

  10. Remote skin tissue diagnostics in vivo by fiber optic evanescent wave Fourier transform infrared (FEW-FTIR) spectroscopy

    NASA Astrophysics Data System (ADS)

    Afanasyeva, Natalia I.; Kolyakov, Sergei F.; Butvina, Leonid N.

    1998-04-01

    The new method of fiber-optical evanescent wave Fourier transform IR (FEW-FTIR) spectroscopy has been applied to the diagnostics of normal tissue, as well as precancerous and cancerous conditions. The FEW-FTIR technique is nondestructive and sensitive to changes of vibrational spectra in the IR region, without heating and damaging human and animal skin tissue. Therefore this method and technique is an ideal diagnostic tool for tumor and cancer characterization at an early stage of development on a molecular level. The application of fiber optic technology in the middle IR region is relatively inexpensive and can be adapted easily to any commercially available tabletop FTIR spectrometers. This method of diagnostics is fast, remote, and can be applied to many fields Noninvasive medical diagnostics of skin cancer and other skin diseases in vivo, ex vivo, and in vitro allow for the development convenient, remote clinical applications in dermatology and related fields. The spectral variations from normal to pathological skin tissue and environmental influence on skin have been measured and assigned in the regions of 850-4000 cm-1. The lipid structure changes are discussed. We are able to develop the spectral histopathology as a fast and informative tool of analysis.

  11. Genetic identification of C-fibers that detect massage-like stroking of hairy skin in vivo

    PubMed Central

    Vrontou, Sophia; Wong, Allan M.; Rau, Kristofer K.; Koerber, H. Richard; Anderson, David J.

    2012-01-01

    Stroking of the skin produces pleasant sensations that can occur during social interactions with conspecifics, such as grooming1. Despite numerous physiological studies (reviewed in ref. 2), molecularly defined sensory neurons that detect pleasant stroking of hairy skin3,4 in vivo have not been reported. Previously, we identified a rare population of unmyelinated sensory neurons that express the G protein-coupled receptor (GPCR) MrgprB45,6. These neurons exclusively innervate hairy skin with large terminal arborizations7 that resemble the receptive fields of C-tactile (CT) afferents in humans8. Unlike other molecularly defined mechanosensory C-fiber subtypes9,10, MrgprB4+ neurons could not be detectably activated by sensory stimulation of the skin ex vivo. Therefore, we developed a preparation for calcium imaging in their spinal projections during stimulation of the periphery in intact animals. MrgprB4+ neurons were activated by massage-like stroking of hairy skin, but not by noxious punctate mechanical stimulation. By contrast, a different population of C-fibers expressing MrgprD11 was activated by pinching but not by stroking, consistent with previous physiological and behavioral data10,12. Pharmacogenetic activation of MrgprB4- expressing neurons in freely behaving animals promoted conditioned place preference13, suggesting that such activation is positively reinforcing and/or anxiolytic. These data open the way to understanding the function of MrgprB4 neurons during natural behaviors, and provide a general approach to functionally characterizing genetically identified subsets of somatosensory neurons in vivo. PMID:23364746

  12. Microencapsulation of a cyclodextrin complex of the UV filter, butyl methoxydibenzoylmethane: in vivo skin penetration studies.

    PubMed

    Scalia, Santo; Coppi, Gilberto; Iannuccelli, Valentina

    2011-01-25

    Lipid microparticles loaded with the complex between hydroxypropyl-β-cyclodextrin (HP-β-CD) and the sunscreen agent, butyl methoxydibenzoylmethane (BMDBM) were evaluated for their effect on the UV filter percutaneous penetration. The microparticles were prepared by the melt emulsification technique using tristearin as lipidic material and hydrogenate phosphatidylcholine as the surfactant. Human skin penetration was investigated in vivo by the tape stripping technique, a minimal invasive procedure based on the progressive removal of the upper cutaneous layers (stratum corneum) with adhesive tape strips. The amount of sunscreen fixed to each strip was determined by HPLC after solvent extraction. The recovery of the UV filter from spiked adhesive tapes was >94.4% and the precision of the method was better than 7.6% relative standard deviation. Non-encapsulated BMDBM, its complex with HP-β-CD, the lipid microparticles loaded with the sunscreen alone or the BMDBM/HP-β-CD complex were introduced into oil-in-water emulsions and applied to human volunteers. Compared to the cream with the non-encapsulated sunscreen agent (percentage of the applied dose penetrated, 9.7%±2.5), the amount of BMDBM diffusing into the stratum corneum was increased by the formulations containing the BMDBM/HP-β-CD complex (17.1%±3.2 of the applied dose) or the microparticles loaded with BMDBM only (15.1%±2.7 of the applied dose). On the contrary, a significant decrease in the level of UV filter penetrated into the stratum corneum was achieved by the cream containing the microencapsulated BMDBM/HP-β-CD complex (percentage of the applied dose penetrated, 6.0%±1.5). The reduced BMDBM percutaneous penetration attained by the latter system should enhance the UV filter efficacy and limit potential toxicological risks. PMID:20934293

  13. In vivo skin chromophore mapping using a multimode imaging dermoscope (SkinSpec)

    NASA Astrophysics Data System (ADS)

    MacKinnon, Nicholas; Vasefi, Fartash; Gussakovsky, Eugene; Bearman, Gregory; Chave, Robert; Farkas, Daniel L.

    2013-02-01

    We introduce a multimode dermoscope (SkinSpectTM) we developed for early detection of melanoma by combining fluorescence, polarization and hyperspectral imaging. Acquired reflection image datacubes were input to a wavelength-dependent linear model to extract the relative contributions of skin chromophores at every pixel. The oxy-hemoglobin, deoxy hemoglobin, melanin concentrations, and hemoglobin oxygen saturation by the single step linear least square fitting and Kubelka-Munk tissue model using cross polarization data cubes were presented. The comprehensive data obtained by SkinSpect can be utilized to improve the accuracy of skin chromophore decomposition algorithm with less computation cost. As an example in this work, the deoxy-hemoglobin over-estimation error in highly pigmented lesion due to melanin and deoxy hemoglobin spectral cross talk were analyzed and corrected using two-step linear least square fitting procedure at different wavelength ranges. The proposed method also tested in skin with underlying vein area for validating the proof of concept.

  14. Histological study of subcutaneous fat at NIR laser treatment of the rat skin in vivo

    NASA Astrophysics Data System (ADS)

    Yanina, I. Y.; Svenskaya, Yu. I.; Navolokin, N. A.; Matveeva, O. V.; Bucharskaya, A. B.; Maslyakova, G. N.; Gorin, D. A.; Sukhorukov, G. B.; Tuchin, V. V.

    2015-07-01

    The goal of this work is to quantify impact of in vivo photochemical treatment using indocyanine green (ICG) or encapsulated ICG and NIR laser irradiation through skin of rat with obesity by the follow up tissue sampling and histochemistry. After 1 hour elapsed since 1-min light exposure samples of rat skin with subcutaneous tissue of thickness of 1.5-2.5 mm were taken by surgery from rats within marked 4-zones of the skin site. For hematoxylin-eosin histological examination of excised tissue samples, fixation was carried out by 10%-formaldehyde solution. For ICG and encapsulated ICG subcutaneous injection and subsequent 1-min diode laser irradiation with power density of 8 W/cm2, different necrotic regions with lipolysis of subcutaneous fat were observed. The obtained data can be used for safe layer-by-layer laser treatment of obesity and cellulite.

  15. Defining human mesenchymal stem cell efficacy in vivo.

    PubMed

    Bonfield, Tracey L; Nolan Koloze, Mary T; Lennon, Donald P; Caplan, Arnold I

    2010-01-01

    Allogeneic human mesenchymal stem cells (hMSCs) can suppress graft versus host disease (GvHD) and have profound anti-inflammatory and regenerative capacity in stroke, infarct, spinal cord injury, meniscus regeneration, tendinitis, acute renal failure, and heart disease in human and animal models of disease. There is significant clinical hMSC variability in efficacy and the ultimate response in vivo. The challenge in hMSC based therapy is defining the efficacy of hMSC in vivo. Models which may provide insight into hMSC bioactivity in vivo would provide a means to distinguish hMSCs for clinical utility. hMSC function has been described as both regenerative and trophic through the production of bioactive factors. The regenerative component involves the multi-potentiality of hMSC progenitor differentiation. The secreted factors generated by the hMSCs are milieu and injury specific providing unique niches for responses in vivo. These bioactive factors are anti-scarring, angiogenic, anti-apoptotic as well as regenerative. Further, from an immunological standpoint, hMSC's can avoid host immune response, providing xenographic applications. To study the in vivo immuno-regulatory effectiveness of hMSCs, we used the ovalbumin challenge model of acute asthma. This is a quick 3 week in vivo pulmonary inflammation model with readily accessible ways of measuring effectiveness of hMSCs. Our data show that there is a direct correlation between the traditional ceramic cube score to hMSCs attenuation of cellular recruitment due to ovalbumin challenge. The results from these studies verify the in vivo immuno-modulator effectiveness of hMSCs and support the potential use of the ovalbumin model as an in vivo model of hMSC potency and efficacy. Our data also support future directions toward exploring hMSCs as an alternative therapeutic for the treatment of airway inflammation associated with asthma. PMID:20974000

  16. Resonance Raman spectroscopic evaluation of skin carotenoids as a biomarker of carotenoid status for human studies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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, as assessed by RRS, has been suggested as a promising biomarker for use in human studies. This manuscript describes...

  17. Molecular mechanisms and in vivo mouse models of skin aging associated with dermal matrix alterations.

    PubMed

    Hwang, Kyung-A; Yi, Bo-Rim; Choi, Kyung-Chul

    2011-03-01

    Skin is the most superficial body organ and plays an important role in protecting the body from environmental damage and in forming social relations. With the increase of the aging population in our society, dermatological and cosmetic concerns of skin aging are rapidly increasing. Skin aging is a complex process combined with intrinsic and extrinsic factors. Intrinsic or chronological skin aging results from the passage of time and is influenced by genetic factors. Extrinsic skin aging is mainly determined by UV irradiation, also called photoaging. These two types of aging processes are superimposed on sun-exposed skin, and have a common feature of causing dermal matrix alterations that mostly contribute to the formation of wrinkles, laxity, and fragility of aged skin. The dermal matrix contains extracellular matrix proteins such as collagen, elastin, and proteoglycans that confer the strength and resiliency of skin. Skin aging associated with dermal matrix alterations and atrophy can be caused by cellular senescence of dermal cells like fibroblasts, and decreased synthesis and accelerated degradation of dermal matrix components, especially collagen fibers. Both intrinsic aging and photoaging exert influence during each step of dermal matrix alteration via different mechanisms. Mouse models of skin aging have been extensively developed to elucidate intrinsic aging and photoaging processes, to validate in vitro biochemical data, and to test the effects of pharmacological tools for retarding skin aging because they have the advantages of being genetically similar to humans and are easily available. PMID:21826153

  18. In-vivo differentiation of photo-aged epidermis skin by texture-based classification

    NASA Astrophysics Data System (ADS)

    Zhang, Xiaoman; Weng, Cuncheng; Yu, Biying; Li, Hui

    2014-11-01

    Two sets of in vivo female cheek skin epidermis images were analyzed through gray level co-occurrence matrix (GLCM) and fast fourier transform (FFT). One set was derived from women in their 20s and the other from women more than 60 years of age. GLCM was used to evaluate the texture features of the regions of interest within the cheek epidermis, and texture classification was subsequently performed. During texture classification, 25 images (320×240 pixels) in each age set were randomly selected. Three texture features, i.e., energy, contrast, and correlation, were obtained from the skin images and analyzed at four orientations (0°, 45°,90°, and 135°), accompanied by different distances between two pixels. The textures of the different aging skins were characterized by FFT, which provides the dermatoglyph orientation index. The differences in the textures between the young and old skin samples can be well described by the FFT dermatoglyph orientation index. The texture features varied among the different aging skins, which provide a versatile platform for differentiating the statuses of aging skins.

  19. The human parental brain: In vivo neuroimaging

    PubMed Central

    Swain, James E.

    2015-01-01

    Interacting parenting thoughts and behaviors, supported by key brain circuits, critically shape human infants’ current and future behavior. Indeed, the parent–infant relationship provides infants with their first social environment, forming templates for what they can expect from others, how to interact with them and ultimately how they go on to themselves to be parents. This review concentrates on magnetic resonance imaging experiments of the human parent brain, which link brain physiology with parental thoughts and behaviors. After reviewing brain imaging techniques, certain social cognitive and affective concepts are reviewed, including empathy and trust—likely critical to parenting. Following that is a thorough study-by-study review of the state-of-the-art with respect to human neuroimaging studies of the parental brain—from parent brain responses to salient infant stimuli, including emotionally charged baby cries and brief visual stimuli to the latest structural brain studies. Taken together, this research suggests that networks of highly conserved hypothalamic–midbrain–limbic–paralimbic–cortical circuits act in concert to support parental brain responses to infants, including circuits for limbic emotion response and regulation. Thus, a model is presented in which infant stimuli activate sensory analysis brain regions, affect corticolimbic limbic circuits that regulate emotional response, motivation and reward related to their infant, ultimately organizing parenting impulses, thoughts and emotions into coordinated behaviors as a map for future studies. Finally, future directions towards integrated understanding of the brain basis of human parenting are outlined with profound implications for understanding and contributing to long term parent and infant mental health. PMID:21036196

  20. Human Skin Aryl Hydrocarbon Hydroxylase

    PubMed Central

    Bickers, David R.; Kappas, Attallah

    1978-01-01

    Coal tar products, which are widely used in treating dermatologic disease, contain numerous polycyclic aromatic hydrocarbons, including 3,4-benzo[a]pyrene (BP). BP is among the most potent environmental chemical carcinogens and is known to evoke tumors in the skin of experimental animals and perhaps also of man. In this study the effect of cutaneous application of coal tar solution (U. S. Pharmacopeia) on aryl hydrocarbon hydroxylase (AHH) activity in the skin of patients usually treated with this drug was investigated. AHH, a cytochrome P-450 dependent carcinogen-metabolizing enzyme appears to play an important role in the activation of polycyclic hydrocarbons into reactive moieties that can bind to DNA and that may directly induce cancer. Application of coal tar solution to human skin caused a two to five-fold induction of cutaneous AHH in nine subjects. In further studies, the incubation of human skin with coal tar solution in vitro also caused variable induction of cutaneous AHH. Maximum responses in both systems occurred after 24 h and enzyme activity in vitro was time- and tissue- and substrate-concentration dependent. Studies in experimental animals showed that topical application of coal tar solution caused induction of AHH in skin and, after percutaneous absorption, in liver as well. Assay of several defined constituents of coal tar for AHH induction showed that BP was the most potent inducer of AHH tested. These studies indicate that topical application of coal tar solution in doses ordinarily used in treating dermatologic disease causes induction of AHH in human skin and suggest that such induced enzymatic activity could relate to carcinogenic responses to this agent in skin or, after percutaneous absorption, in other tissues as well. PMID:711851

  1. Imaging immune response of skin mast cells in vivo with two-photon microscopy

    NASA Astrophysics Data System (ADS)

    Li, Chunqiang; Pastila, Riikka K.; Lin, Charles P.

    2012-02-01

    Intravital multiphoton microscopy has provided insightful information of the dynamic process of immune cells in vivo. However, the use of exogenous labeling agents limits its applications. There is no method to perform functional imaging of mast cells, a population of innate tissue-resident immune cells. Mast cells are widely recognized as the effector cells in allergy. Recently their roles as immunoregulatory cells in certain innate and adaptive immune responses are being actively investigated. Here we report in vivo mouse skin mast cells imaging with two-photon microscopy using endogenous tryptophan as the fluorophore. We studied the following processes. 1) Mast cells degranulation, the first step in the mast cell activation process in which the granules are released into peripheral tissue to trigger downstream reactions. 2) Mast cell reconstitution, a procedure commonly used to study mast cells functioning by comparing the data from wild type mice, mast cell-deficient mice, and mast-cell deficient mice reconstituted with bone marrow-derived mast cells (BMMCs). Imaging the BMMCs engraftment in tissue reveals the mast cells development and the efficiency of BMMCs reconstitution. We observed the reconstitution process for 6 weeks in the ear skin of mast cell-deficient Kit wsh/ w-sh mice by two-photon imaging. Our finding is the first instance of imaging mast cells in vivo with endogenous contrast.

  2. Quantitative analysis of intrinsic skin aging in dermal papillae by in vivo harmonic generation microscopy

    PubMed Central

    Liao, Yi-Hua; Kuo, Wei-Cheng; Chou, Sin-Yo; Tsai, Cheng-Shiun; Lin, Guan-Liang; Tsai, Ming-Rung; Shih, Yuan-Ta; Lee, Gwo-Giun; Sun, Chi-Kuang

    2014-01-01

    Chronological skin aging is associated with flattening of the dermal-epidermal junction (DEJ), but to date no quantitative analysis focusing on the aging changes in the dermal papillae (DP) has been performed. The aim of the study is to determine the architectural changes and the collagen density related to chronological aging in the dermal papilla zone (DPZ) by in vivo harmonic generation microscopy (HGM) with a sub-femtoliter spatial resolution. We recruited 48 Asian subjects and obtained in vivo images on the sun-protected volar forearm. Six parameters were defined to quantify 3D morphological changes of the DPZ, which we analyzed both manually and computationally to study their correlation with age. The depth of DPZ, the average height of isolated DP, and the 3D interdigitation index decreased with age, while DP number density, DP volume, and the collagen density in DP remained constant over time. In vivo high-resolution HGM technology has uncovered chronological aging-related variations in DP, and sheds light on real-time quantitative skin fragility assessment and disease diagnostics based on collagen density and morphology. PMID:25401037

  3. In vivo interstitial glucose characterization and monitoring in the skin by ATR-FTIR spectroscopy

    NASA Astrophysics Data System (ADS)

    Skrebova Eikje, Natalja

    2011-03-01

    Successful development of real-time non-invasive glucose monitoring would represent a major advancement not only in the treatment and management of patients with diabetes mellitus and carbohydrate metabolism disorders, but also for understanding in those biochemical, metabolic and (patho-)physiological processes of glucose at the molecular level in vivo. Here, ATR-FTIR spectroscopy technique has been challenged not only for in vivo measurement of interstitial glucose levels, but also for their non-invasive molecular qualitative and quantitative comparative characterization in the skin tissue. The results, based on calculated mean values of determined 5 glucose-specific peaks in the glucose-related 1000-1160 cm-1 region, showed intra- and inter-subject differences in interstitial glucose activity levels with their changes at different times and doses of OGTT, while raising questions about the relationships between interstitial and blood glucose levels. In conclusion, the introduction of ATR-FTIR spectroscopy technique has opened up an access to the interstitial fluid space in the skin tissue for interstitial glucose characterization and monitoring in vivo. Though interstitial versus blood glucose monitoring has different characteristics, it can be argued that accurate and precise measurements of interstitial glucose levels may be more important clinically.

  4. Penetration of quantum dot particles through human skin.

    PubMed

    Gratieri, Taís; Schaefer, Ulrich F; Jing, Lihong; Gao, Mingyuan; Kostka, K-H; Lopez, Renata F V; Schneider, Marc

    2010-10-01

    The skin is a large and accessible area of the body, offering the possibility to be used as an alternative route for drug delivery. In the last few years strong progress has been made on the developing of nanoparticulate systems for specific applications. The interaction of such small particles with human skin and their possible penetration attracted some interest from toxicological as well as from drug delivery perspectives. As size is assumed to play a key role, the aim of the present work was to investigate the penetration profile of very small model particles (approximately 4 nm) into excised human skin under conditions chosen to mimic the in vivo situation. Possible application procedures such as massaging the formulation (5 to 10 minutes) were analyzed by non-invasive multiphoton- and confocal laser scanning microscopy (MPM, CLSM). Furthermore, the application on damaged skin was taken into account by deliberately removing parts of the stratum corneum. Although it was clearly observed that the mechanical actions affected the distribution pattern of the QDs on the skin surface, there was no evidence of penetration into the skin in all cases tested. QDs could be found in deeper layers only after massaging of damaged skin for 10 min. Taking these data into account, obtained on the gold standard human skin, the potential applications of nanoparticulate systems to act as carrier delivering drugs into intact skin might be limited and are only of interest for partly damaged skin. PMID:21329051

  5. Characterization of a new MOSFET detector configuration for in vivo skin dosimetry

    SciTech Connect

    Scalchi, Paolo; Francescon, Paolo; Rajaguru, Priyadarshini

    2005-06-15

    The dose released to the patient skin during a radiotherapy treatment is important when the skin is an organ at risk, or on the contrary, is included in the target volume. Since most treatment planning programs do not predict dose within several millimeters of the body surface, it is important to have a method to verify the skin dose for the patient who is undergoing radiotherapy. A special type of metal oxide semiconductors field-effect transistors (MOSFET) was developed to perform in vivo skin dosimetry for radiotherapy treatments. Water-equivalent depth (WED), both manufacturing and sensor reproducibility, dependence on both field size and angulation of the sensor were investigated using 6 MV photon beams. Patient skin dosimetries were performed during 6 MV total body irradiations (TBI). The resulting WEDs ranged from 0.04 and 0.15 mm (0.09 mm on average). The reproducibility of the sensor response, for doses of 50 cGy, was within {+-}2% (maximum deviation) and improves with increasing sensitivity or dose level. As to the manufacturing reproducibility, it was found to be {+-}0.055 mm. No WED dependence on the field size was verified, but possible variations of this quantity with the field size could be hidden by the assessment uncertainty. The angular dependence, for both phantom-surface and in-air setups, when referred to the mean response, is within {+-}27% until 80 deg. rotations. The results of the performed patient skin dosimetries showed that, normally, our TBI setup was suitable to give skin the prescribed dose, but, for some cases, interventions were necessary: as a consequence the TBI setup was corrected. The water-equivalent depth is, on average, less than the thinnest thermoluminescent dosimeters (TLD). In addition, when compared with TLDs, the skin MOSFETs have significant advantages, like immediate both readout and reuse, as well as the permanent storage of dose. These sensors are also waterproof. The in vivo dosimetries performed prove the

  6. In vivo comparative documentation of skin hydration by confocal Raman microscopy, SkinSensor, Skicon, and NovaMeter

    NASA Astrophysics Data System (ADS)

    Zhang, Guojin; Papillon, Aline; Ruvolo, Eduardo, Jr.; Bargo, Paulo R.; Kollias, Nikiforos

    2010-02-01

    The stratum corneum provides a vital physical barrier that protects against external insults and excessive internal water loss. Water activity is thought as a key factor to maintain proper skin barrier integrity via regulating enzyme activities and lipid phase behavior. Consequently, maintenance of an optimal hydration level in SC becomes an important clinical and cosmetic concern. The objective methods to assess SC hydration are based on either electrical or optical measurements. Electrical techniques used in the current study include high frequency conductance (Skicon), impedance (Nova DPM) and DC I-V curve (Skinsensor). Confocal Raman Microscopy was utilized to document water profile versus depth, and this technique is based on inelastic scattering of monochromatic light from different chemical species of skin. Water patches were applied on the 14 subjects' forearm for 20 minutes and 1.5 hrs. Skin hydration levels for individuals were documented by utilizing the mentioned above instruments in vivo. Results show that patterns of water profiles upon the hydration are significantly different among the individuals and these differences may be related to skin barrier function integrity. The intrinsic water content and water absorption upon the hydration were summed corresponding to different depths (3 μm and 15 μm) from the data obtained by confocal Raman microscopy. These results were correlated to the readings from electrical approaches. Superficial (3 μm) but not deeper layer (15 μm) water contents correlated well with the readings from SkinSensor. Neither depth measurements correlate well with the Skicon. There is strong correlation between the data acquired with Skicon and SkinSensor.

  7. In-vivo monitoring rat skin wound healing using nonlinear optical microscopy

    NASA Astrophysics Data System (ADS)

    Chen, Jing; Guo, Chungen; Zhang, Fan; Xu, Yahao; Zhu, Xiaoqin; Xiong, Shuyuan; Chen, Jianxin

    2014-11-01

    Nonlinear optical microscopy (NLOM) was employed for imaging and evaluating the wound healing process on rat skin in vivo. From the high-resolution nonlinear optical images, the morphology and distribution of specific biological markers in cutaneous wound healing such as fibrin clot, collagens, blood capillaries, and hairs were clearly observed at 1, 5 and 14 days post injury. We found that the disordered collagen in the fibrin clot at day 1 was replaced by regenerative collagen at day 5. By day 14, the thick collagen with well-network appeared at the original margin of the wound. These findings suggested that NLOM is ideal for noninvasively monitoring the progress of wound healing in vivo.

  8. Three-dimensional imaging of skin melanoma in vivo by dual-wavelength photoacoustic microscopy.

    PubMed

    Oh, Jung-Taek; Li, Meng-Lin; Zhang, Hao F; Maslov, Konstantin; Stoica, George; Wang, Lihong V

    2006-01-01

    Dual-wavelength reflection-mode photoacoustic microscopy is used to noninvasively obtain three-dimensional (3-D) images of subcutaneous melanomas and their surrounding vasculature in nude mice in vivo. The absorption coefficients of blood and melanin-pigmented melanomas vary greatly relative to each other at these two optical wavelengths (764 and 584 nm). Using high-resolution and high-contrast photoacoustic imaging in vivo with a near-infrared (764-nm) light source, the 3-D melanin distribution inside the skin is imaged, and the maximum thickness of the melanoma (approximately 0.5 mm) is measured. The vascular system surrounding the melanoma is also imaged with visible light (584 nm) and the tumor-feeding vessels found. This technique can potentially be used for melanoma diagnosis, prognosis, and treatment planning. PMID:16822081

  9. DNA methylation dynamics during in vivo differentiation of blood and skin stem cells

    PubMed Central

    Bock, Christoph; Beerman, Isabel; Lien, Wen-Hui; Smith, Zachary D.; Gu, Hongcang; Boyle, Patrick; Gnirke, Andreas; Fuchs, Elaine; Rossi, Derrick J.; Meissner, Alexander

    2012-01-01

    DNA methylation is a mechanism of epigenetic regulation that is common to all vertebrates. Functional studies underscore its relevance for tissue homeostasis, but the global dynamics of DNA methylation during in vivo differentiation remain underexplored. Here we report high-resolution DNA methylation maps of adult stem cell differentiation in mouse, focusing on 19 purified cell populations of the blood and skin lineages. DNA methylation changes were locus-specific and relatively modest in magnitude. They frequently overlapped with lineage-associated transcription factors and their binding sites, suggesting that DNA methylation may protect cells from aberrant transcription factor activation. DNA methylation and gene expression provided complementary information, and combining the two enabled us to infer the cellular differentiation hierarchy of the blood lineage directly from genomic data. In summary, these results demonstrate that in vivo differentiation of adult stem cells is associated with small but informative changes in the genomic distribution of DNA methylation. PMID:22841485

  10. Optical coherence tomography monitoring of enhanced skin optical clearing in rats in vivo.

    PubMed

    Genina, Elina A; Bashkatov, Alexey N; Kolesnikova, Ekaterina A; Basko, Marina V; Terentyuk, Georgy S; Tuchin, Valery V

    2014-02-01

    A comparative study of physical, chemical, and combined enhancement of transdermal transport of optical clearing agents (OCAs) is presented. As a physical enhancer of diffusivity, ultrasound (US) with a frequency 1 MHz and a power 1.1 W in the continuous mode was used, and dimethyl sulfoxide (DMSO) was used as a chemical enhancer. OCA (glycerol and polyethylene glycol-400 in equal proportion) was topically applied to the rat skin in vivo as alone or as together with the enhancers. Monitoring of skin optical clearing was implemented using an optical coherence tomography. The results have shown that the attenuation coefficient of intact skin dermis after the application of US-DMSO-OCA, US-OCA (both for 4 min), and DMSO-OCA (for 20 min) combinations decreased approximately by 31%, 19%, and 5%, respectively, while OCA alone did not induce a noticeable clearing effect for 20 min. Control skin sites with removed epidermis were used for modeling the upper limit of dermis optical clearing, i.e., maximal degree of optical clearing, by using the studied enhancers. They demonstrated that the attenuation coefficient decreases by 32%, 30%, 17%, and 16% at the action of US-DMSO-OCA, US-OCA, DMSO-OCA, and OCA, respectively. It can be concluded that US-DMSO-OCA combination only allowed reaching the upper limit of skin optical clearing. PMID:24105426

  11. Handheld confocal Raman microspectrometer for in-vivo skin cancer measurement

    NASA Astrophysics Data System (ADS)

    Lieber, Chad A.; Ellis, Darrel L.; Billheimer, D. D.; Mahadevan-Jansen, Anita

    2004-07-01

    Several studies have demonstrated Raman spectroscopy to be capable of tissue diagnosis with accuracy rivaling that of histopathologic analysis. This technique obtains biochemical-specific information noninvasively, and can eliminate the pain, time, and cost associated with biopsy and pathological analysis. Furthermore, when used in a confocal arrangement, Raman spectra can be obtained from localized regions of the tissue. Skin cancers are an ideal candidate for this emerging technology, due to their obvious accessibility and presentation at specific depths. However, most commercially available confocal Raman microspectrometers are large, rigid systems ill-suited for clinical application. We developed a bench-top confocal Raman microspectrometer using a portable external-cavity diode laser excitation source. This system was used to study several skin lesions in vitro. Results show the depth-resolved Raman spectra can diagnose in vitro skin lesions with 96% sensitivity, 88% specificity, and 86% pathological classification accuracy. Based on the success of this study, a portable Raman system with a handheld confocal microscope was developed for clinical application. Preliminary in vivo data show several distinct spectral differences between skin pathologies. Diagnostic algorithms are planned for this continuing study to assess the capability of Raman spectroscopy for clinical skin cancer diagnosis.

  12. In-vivo fluorescence detection and imaging of porphyrin-producing bacteria in the human skin and in the oral cavity for diagnosis of acne vulgaris, caries, and squamous cell carcinoma

    NASA Astrophysics Data System (ADS)

    Koenig, Karsten; Schneckenburger, Herbert; Hemmer, Joerg; Tromberg, Bruce J.; Steiner, Rudolf W.

    1994-05-01

    Certain bacteria are able to synthesize metal-free fluorescent porphyrins and can therefore be detected by sensitive autofluorescence measurements in the red spectral region. The porphyrin-producing bacterium Propionibacterium acnes, which is involved in the pathogenesis of acne vulgaris, was localized in human skin. Spectrally resolved fluorescence images of bacteria distribution in the face were obtained by a slow-scan CCD camera combined with a tunable liquid crystal filter. The structured autofluorescence of dental caries and dental plaque in the red is caused by oral bacteria, like Bacteroides or Actinomyces odontolyticus. `Caries images' were created by time-gated imaging in the ns-region after ultrashort laser excitation. Time-gated measurements allow the suppression of backscattered light and non-porphyrin autofluorescence. Biopsies of oral squamous cell carcinoma exhibited red autofluorescence in necrotic regions and high concentrations of the porphyrin-producing bacterium Pseudomonas aerigunosa. These studies suggest that the temporal and spectral characteristics of bacterial autofluorescence can be used in the diagnosis and treatment of a variety of diseases.

  13. In vivo determination of optical properties and fluorophore characteristics of non-melanoma skin cancer

    NASA Astrophysics Data System (ADS)

    Rajaram, Narasimhan; Kovacic, Dianne; Migden, Michael F.; Reichenberg, Jason S.; Nguyen, Tri H.; Tunnell, James W.

    2009-02-01

    Diffuse optical spectroscopy (DOS) and laser-induced fluorescence (LIF) techniques have widely been used as noninvasive tools for early cancer detection in several organs including the cervix, oral cavity and gastrointestinal tract. Using a combined DOS/LIF approach, one can simultaneously measure the morphology and biochemical composition of tissue and use these features to diagnose malignancy. We report for the first time to our knowledge both the optical properties and native fluorophore characteristics of non-melanoma skin cancer in the UV-visible range. We collected in vivo diffuse reflectance and intrinsic fluorescence measurements from 44 skin lesions on 37 patients. The skin sites were further categorized into three groups of non-melanoma skin cancer according to histopathology: 1) pre-cancerous actinic keratosis 2) malignant squamous cell carcinoma (SCC) and 3) basal cell carcinoma (BCC). We used a custom-built probe-based clinical system that collects both white light reflectance and laser-induced fluorescence in the wavelength range of 350-700 nm. We extracted the blood volume fraction, oxygen saturation, blood vessel size, tissue microarchitecture and melanin content from diffuse reflectance measurements. In addition, we determined the native fluorophore contributions of NADH, collagen and FAD from laser-induced fluorescence for all groups. The scattering from tissue decreased with progression from clinically normal to precancerous actinic keratosis to malignant SCC. A similar trend was observed for clinically normal skin and malignant BCC. Statistically significant differences were observed in the collagen contributions, which were lower in malignant SCC and BCC as compared to normal skin. Our data demonstrates that the mean optical properties and fluorophore contributions of normal, benign and malignant nonmelanoma cancers are significantly different from each other and can potentially be used as biomarkers for the early detection of skin cancer.

  14. Solvent effects in permeation assessed in vivo by skin surface biopsy

    PubMed Central

    Rosado, Catarina; Rodrigues, Luis Monteiro

    2003-01-01

    Background Transdermal drug delivery has become an important means of drug administration. It presents numerous advantages but it is still limited by the small number of drugs with a suitable profile. The use of solvents that affect the skin barrier function is one of the classic strategies of penetration enhancement. Some of these solvents have well characterised actions on the stratum corneum, but the majority are still selected using empirical criteria. The objective of this work was to conduct a systematic study on the ability to affect skin permeation of solvents commonly used in transdermal formulations. An innovative methodology in this area was employed, consisting of the combination of skin surface biopsy with colorimetry. Methods The study compared in vivo differences in the permeation of a hydrophilic (methylene blue) and a lipophilic (Sudan III) dye, after treatment of the skin with different vehicles. Consecutive skin surface biopsies of each site were taken and the cumulative amounts of the dyes in the stripped stratum corneum were measured by reflectance colourimetry. Results Results indicate that the amount of methylene blue present in the stratum corneum varied significantly with different skin pre-treatments. Some solvents provided a 1.5 fold penetration enhancement but others decreased by almost half the permeation of the dye. The permeation of Sudan III was less significantly affected by solvent pre-treatment. Conclusions This study has only superficially explored the potential of the combination of skin surface biopsy and colourimetry, but the encouraging results obtained confirm that the methodology can be extended to the study of more complex formulations. PMID:14680512

  15. In Vivo Activity of a Novel Polymeric Guanidine in Experimental Skin Infection with Methicillin-Resistant Staphylococcus aureus▿

    PubMed Central

    Kratzer, Christina; Tobudic, Selma; Macfelda, Karin; Graninger, Wolfgang; Georgopoulos, Apostolos

    2007-01-01

    The in vivo efficacy of the novel polymeric guanidine AKACID Plus was evaluated in a guinea pig model of experimental skin infection with methicillin-resistant Staphylococcus aureus (MRSA). Topical application of AKACID Plus at concentrations of ≥0.5% was as effective as mupirocin 2% cream in the treatment of superficial skin infection with MRSA. PMID:17620381

  16. Analysis of the structure of human telomerase RNA in vivo

    PubMed Central

    Antal, Mária; Boros, Éva; Solymosy, Ferenc; Kiss, Tamás

    2002-01-01

    Telomerase is a ribonucleoprotein reverse transcriptase that synthesises telomeric DNA. The RNA component of telomerase acts as a template for telomere synthesis and binds the reverse transcriptase. In this study, we have performed in vivo and in vitro structural analyses of human telomerase RNA (hTR). In vivo mapping experiments showed that the 5′-terminal template domain of hTR folds into a long hairpin structure, in which the template sequence occupies a readily accessible position. Intriguingly, neither in vivo nor in vitro mapping of hTR confirmed formation of a stable ‘pseudoknot’ helix, suggesting that this functionally essential long range interaction is formed only temporarily. In vitro control mappings demonstrated that the 5′-terminal template domain of hTR cannot fold correctly in the absence of cellular protein factors. The 3′-terminal domain of hTR, both in vivo and in vitro, folds into the previously predicted box H/ACA snoRNA-like ‘hairpin–hinge–hairpin–tail’ structure. Finally, comparison of the in vivo and in vitro modification patterns of hTR revealed several regions that might be directly involved in binding of telomerase reverse transcriptase or other telomerase proteins. PMID:11842102

  17. Infrared neural stimulation of human spinal nerve roots in vivo

    PubMed Central

    Cayce, Jonathan M.; Wells, Jonathon D.; Malphrus, Jonathan D.; Kao, Chris; Thomsen, Sharon; Tulipan, Noel B.; Konrad, Peter E.; Jansen, E. Duco; Mahadevan-Jansen, Anita

    2015-01-01

    Abstract. Infrared neural stimulation (INS) is a neurostimulation modality that uses pulsed infrared light to evoke artifact-free, spatially precise neural activity with a noncontact interface; however, the technique has not been demonstrated in humans. The objective of this study is to demonstrate the safety and efficacy of INS in humans in vivo. The feasibility of INS in humans was assessed in patients (n=7) undergoing selective dorsal root rhizotomy, where hyperactive dorsal roots, identified for transection, were stimulated in vivo with INS on two to three sites per nerve with electromyogram recordings acquired throughout the stimulation. The stimulated dorsal root was removed and histology was performed to determine thermal damage thresholds of INS. Threshold activation of human dorsal rootlets occurred in 63% of nerves for radiant exposures between 0.53 and 1.23  J/cm2. In all cases, only one or two monitored muscle groups were activated from INS stimulation of a hyperactive spinal root identified by electrical stimulation. Thermal damage was first noted at 1.09  J/cm2 and a 2∶1 safety ratio was identified. These findings demonstrate the success of INS as a fresh approach for activating human nerves in vivo and providing the necessary safety data needed to pursue clinically driven therapeutic and diagnostic applications of INS in humans. PMID:26157986

  18. Clinical study of noninvasive in vivo melanoma and nonmelanoma skin cancers using multimodal spectral diagnosis

    PubMed Central

    Lim, Liang; Nichols, Brandon; Migden, Michael R.; Rajaram, Narasimhan; Reichenberg, Jason S.; Markey, Mia K.; Ross, Merrick I.; Tunnell, James W.

    2014-01-01

    Abstract. The goal of this study was to determine the diagnostic capability of a multimodal spectral diagnosis (SD) for in vivo noninvasive disease diagnosis of melanoma and nonmelanoma skin cancers. We acquired reflectance, fluorescence, and Raman spectra from 137 lesions in 76 patients using custom-built optical fiber-based clinical systems. Biopsies of lesions were classified using standard histopathology as malignant melanoma (MM), nonmelanoma pigmented lesion (PL), basal cell carcinoma (BCC), actinic keratosis (AK), and squamous cell carcinoma (SCC). Spectral data were analyzed using principal component analysis. Using multiple diagnostically relevant principal components, we built leave-one-out logistic regression classifiers. Classification results were compared with histopathology of the lesion. Sensitivity/specificity for classifying MM versus PL (12 versus 17 lesions) was 100%/100%, for SCC and BCC versus AK (57 versus 14 lesions) was 95%/71%, and for AK and SCC and BCC versus normal skin (71 versus 71 lesions) was 90%/85%. The best classification for nonmelanoma skin cancers required multiple modalities; however, the best melanoma classification occurred with Raman spectroscopy alone. The high diagnostic accuracy for classifying both melanoma and nonmelanoma skin cancer lesions demonstrates the potential for SD as a clinical diagnostic device. PMID:25375350

  19. Clinical study of noninvasive in vivo melanoma and nonmelanoma skin cancers using multimodal spectral diagnosis

    NASA Astrophysics Data System (ADS)

    Lim, Liang; Nichols, Brandon; Migden, Michael R.; Rajaram, Narasimhan; Reichenberg, Jason S.; Markey, Mia K.; Ross, Merrick I.; Tunnell, James W.

    2014-11-01

    The goal of this study was to determine the diagnostic capability of a multimodal spectral diagnosis (SD) for in vivo noninvasive disease diagnosis of melanoma and nonmelanoma skin cancers. We acquired reflectance, fluorescence, and Raman spectra from 137 lesions in 76 patients using custom-built optical fiber-based clinical systems. Biopsies of lesions were classified using standard histopathology as malignant melanoma (MM), nonmelanoma pigmented lesion (PL), basal cell carcinoma (BCC), actinic keratosis (AK), and squamous cell carcinoma (SCC). Spectral data were analyzed using principal component analysis. Using multiple diagnostically relevant principal components, we built leave-one-out logistic regression classifiers. Classification results were compared with histopathology of the lesion. Sensitivity/specificity for classifying MM versus PL (12 versus 17 lesions) was 100%;/100%;, for SCC and BCC versus AK (57 versus 14 lesions) was 95%;/71%, and for AK and SCC and BCC versus normal skin (71 versus 71 lesions) was 90%/85%. The best classification for nonmelanoma skin cancers required multiple modalities; however, the best melanoma classification occurred with Raman spectroscopy alone. The high diagnostic accuracy for classifying both melanoma and nonmelanoma skin cancer lesions demonstrates the potential for SD as a clinical diagnostic device.

  20. Glabridin nanosuspension for enhanced skin penetration: formulation optimization, in vitro and in vivo evaluation.

    PubMed

    Wang, W P; Hul, J; Sui, H; Zhao, Y S; Feng, J; Liu, C

    2016-05-01

    Glabridin, a polyphenolic flavonoid from licorice, has inspired great interest for its antioxidant, anti-inflammatory and skin-lightening activities. However, low water solubility and poor stability of glabridin impedes its topical application in cosmetic products and therapies of dermal diseases. The purpose of this study was to develop a nanosuspension formulation of glabridin to improve its skin permeation. Glabridin nanosuspensions were prepared using anti-solvent precipitation-homogenization method, and Box-Behnken design was adopted to investigate the effects of crucial formulation variables on particle size and to optimize the nanosuspension formulation. The optimal formulation consisted of 0.25% glabridin, 0.47% Poloxamer 188 and 0.11% Polyvinylpyrrolidone K30, and the obtained nanosuspension showed an average particle size of 149.2 nm with a polydispersity index of 0.254. Furthermore, the nanosuspension exhibited significantly enhanced drug permeation flux of glabridin through rat skin with no lag phase both in vitro and in vivo, compared to the coarse suspension and physical mixture. The glabridin nanosuspension showed no significant particle aggregates and a drug loss of 5.46% after storage for 3 months at room temperature. With its enhanced skin penetration, the nanosuspension might be a more preferable formulation for topical administration of poorly soluble glabridin. PMID:27348968

  1. Sexual hormones in human skin.

    PubMed

    Zouboulis, C C; Chen, W-C; Thornton, M J; Qin, K; Rosenfield, R

    2007-02-01

    The skin locally synthesizes significant amounts of sexual hormones with intracrine or paracrine actions. The local level of each sexual steroid depends upon the expression of each of the androgen- and estrogen-synthesizing enzymes in each cell type, with sebaceous glands and sweat glands being the major contributors. Sebocytes express very little of the key enzyme, cytochrome P450c17, necessary for synthesis of the androgenic prohormones dehydroepiandrosterone and androstenedione, however, these prohormones can be converted by sebocytes and sweat glands, and probably also by dermal papilla cells, into more potent androgens like testosterone and dihydrotestosterone. Five major enzymes are involved in the activation and deactivation of androgens in skin. Androgens affect several functions of human skin, such as sebaceous gland growth and differentiation, hair growth, epidermal barrier homeostasis and wound healing. Their effects are mediated by binding to the nuclear androgen receptor. Changes of isoenzyme and/or androgen receptor levels may have important implications in the development of hyperandrogenism and the associated skin diseases such as acne, seborrhoea, hirsutism and androgenetic alopecia. On the other hand, estrogens have been implicated in skin aging, pigmentation, hair growth, sebum production and skin cancer. Estrogens exert their actions through intracellular receptors or via cell surface receptors, which activate specific second messenger signaling pathways. Recent studies suggest specific site-related distribution of ERalpha and ERbeta in human skin. In contrast, progestins play no role in the pathogenesis of skin disorders. However, they play a major role in the treatment of hirsutism and acne vulgaris, where they are prescribed as components of estrogen-progestin combination pills and as anti-androgens. These combinations enhance gonadotropin suppression of ovarian androgen production. Estrogen-progestin treatment can reduce the need for shaving

  2. Polarization-Sensitive Hyperspectral Imaging in vivo: A Multimode Dermoscope for Skin Analysis

    NASA Astrophysics Data System (ADS)

    Vasefi, Fartash; MacKinnon, Nicholas; Saager, Rolf B.; Durkin, Anthony J.; Chave, Robert; Lindsley, Erik H.; Farkas, Daniel L.

    2014-05-01

    Attempts to understand the changes in the structure and physiology of human skin abnormalities by non-invasive optical imaging are aided by spectroscopic methods that quantify, at the molecular level, variations in tissue oxygenation and melanin distribution. However, current commercial and research systems to map hemoglobin and melanin do not correlate well with pathology for pigmented lesions or darker skin. We developed a multimode dermoscope that combines polarization and hyperspectral imaging with an efficient analytical model to map the distribution of specific skin bio-molecules. This corrects for the melanin-hemoglobin misestimation common to other systems, without resorting to complex and computationally intensive tissue optical models. For this system's proof of concept, human skin measurements on melanocytic nevus, vitiligo, and venous occlusion conditions were performed in volunteers. The resulting molecular distribution maps matched physiological and anatomical expectations, confirming a technologic approach that can be applied to next generation dermoscopes and having biological plausibility that is likely to appeal to dermatologists.

  3. In vivo skin absorption dynamics of topically applied pharmaceuticals monitored by fiber-optic diffuse reflectance spectroscopy

    NASA Astrophysics Data System (ADS)

    Kim, Ki-Hong; Jheon, Sanghoon; Kim, Jong-Ki

    2007-03-01

    A simple non-invasive ultra-violet/visible (UV/vis) diffusive reflectance spectroscopy combined with fiber-optics was investigated to elicit the dynamics of skin penetration in vivo of a pharmaceutical, aminolevulinic acid polyethylene glycol cream (5-ALA-PEG cream). Temporal data of the reflectance, R( λ), were measured from a bare skin region and from a skin region treated with 5-ALA cream. The difference in apparent optical density [(ΔAOD) = Δ log[1/ R( λ)

  4. The Microbiota of the Human Skin.

    PubMed

    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, PMID:27161351

  5. Multi-spectral mapping of in vivo skin hemoglobin and melanin

    NASA Astrophysics Data System (ADS)

    Jakovels, Dainis; Spigulis, Janis; Saknite, Inga

    2010-04-01

    The multi-spectral imaging technique has been used for distant mapping of in-vivo skin chromophores by analyzing spectral data at each reflected image pixel and constructing 2-D maps of the relative concentrations of oxy-/deoxyhemoglobin and melanin. Instead of using a broad visible-NIR spectral range, this study focuses on narrowed spectral band 500-700 nm, so speeding-up the signal processing procedure. Regression analysis confirmed that superposition of three Gaussians is optimal analytic approximation for the oxy-hemoglobin absorption tabular spectrum in this spectral band, while superposition of two Gaussians fits well for deoxy-hemoglobin absorption and exponential function - for melanin absorption. The proposed approach was clinically tested for three types of in-vivo skin provocations - ultraviolet irradiance, chemical reaction with vinegar essence and finger arterial occlusion. Spectral range 500-700 nm provided better sensitivity to oxy-hemoglobin changes and higher response stability to melanin than two reduced ranges 500-600 nm and 530-620 nm.

  6. Modulation of host CD59 expression by varicella-zoster virus in human xenografts in vivo.

    PubMed

    Wang, Wei; Wang, Xin; Yang, Lianwei; Fu, Wenkun; Pan, Dequan; Liu, Jian; Ye, Jianghui; Zhao, Qinjian; Zhu, Hua; Cheng, Tong; Xia, Ningshao

    2016-04-01

    Varicella-zoster virus (VZV) is the causative agent of both chickenpox (varicella) and shingles (zoster). VZV survives host defenses, even with an intact immune system, and disseminates in the host before causing disease. To date, several diverse immunomodulatory strategies used by VZV to undermine host immunity have been identified; however, few studies have addressed the complement evasion strategies used by this virus. Here, we show that expression of CD59, which is a key member of host regulators of complement activation (RCA), is significantly upregulated in response to VZV infection in human T cells and dorsal root ganglia (DRG) but not in human skin xenografts in SCID-hu mice in vivo. This is the first report demonstrating that VZV infection upregulates host CD59 expression in a tissue-specific manner in vivo, which may aid VZV in complement evasion and pathogenesis. PMID:26891237

  7. Growth and invasion of human melanomas in human skin grafted to immunodeficient mice.

    PubMed Central

    Juhasz, I.; Albelda, S. M.; Elder, D. E.; Murphy, G. F.; Adachi, K.; Herlyn, D.; Valyi-Nagy, I. T.; Herlyn, M.

    1993-01-01

    An orthotopic model of human melanoma was developed in which malignant cells were injected into human skin grafted to nude and SCID mice. Melanoma cells proliferated and invaded the human skin grafts with characteristic patterns. Three of six melanomas grew as multiple nodules and infiltered the grafts without major architectural changes in the dermis, whereas the others invaded the dermis along collagen fibers with prominent endothelial vessels. By contrast, melanoma cells inoculated into mouse skin grew as diffusely expanding nodules that did not invade the murine dermis. In human skin grafts, human melanoma cells were angiogenic for human blood vessels, and murine vessels were only found at the periphery of grafts. Tumor cells invaded the human vessels, and four out of seven cell lines metastasized to lungs, suggesting that this model is useful to determine in vivo the interactions between normal and malignant human cells. Images Figure 1 Figure 2 Figure 3 Figure 4 PMID:8342600

  8. In Vitro and In Vivo Studies on Protective Action of N-Phenethyl Caffeamide against Photodamage of Skin

    PubMed Central

    Kuo, Yueh-Hsiung; Chen, Chien-Wen; Chu, Yin; Lin, Ping; Chiang, Hsiu-Mei

    2015-01-01

    In our previous study, N-phenethyl caffeamide (K36) was proved to act as an antioxidant and an antiphotoaging agent by inhibiting type I procollagen degradation and stimulating collagen synthesis in human skin fibroblasts. In the present study, in vitro and in vivo experiments were conducted to investigate the mechanism of action and the antiinflammatory and antiphotoaging activity of K36. K36 reduced UVB-induced cyclooxygenase-2 (COX-2) and inducible nitric oxide synthases (iNOS) expression by regulating IκB and p-IκB expression. K36 also inhibited the nuclear translocation of NF-κB. Furthermore, the inhibition of mitogen-activated protein (MAP) kinases by K36 was attributed to the downregulation of COX-2. Topically applying K36 led to efficient antiwrinkle formation and reduced UVB-induced erythema and thickness of epidermis in hairless mice. In addition, K36 penetrated into the skin of hairless mice. Our findings show that K36 has significant beneficial effects on antioxidant, antiinflammatory, and antiphotoaging activity and suggest that K36 can be developed as an antiaging agent for cosmetic and skin care products. PMID:26367260

  9. Characterization of a MOSkin detector for in vivo skin dose measurements during interventional radiology procedures

    SciTech Connect

    Safari, M. J.; Wong, J. H. D.; Ng, K. H.; Jong, W. L.; Cutajar, D. L.; Rosenfeld, A. B.

    2015-05-15

    Purpose: The MOSkin is a MOSFET detector designed especially for skin dose measurements. This detector has been characterized for various factors affecting its response for megavoltage photon beams and has been used for patient dose measurements during radiotherapy procedures. However, the characteristics of this detector in kilovoltage photon beams and low dose ranges have not been studied. The purpose of this study was to characterize the MOSkin detector to determine its suitability for in vivo entrance skin dose measurements during interventional radiology procedures. Methods: The calibration and reproducibility of the MOSkin detector and its dependency on different radiation beam qualities were carried out using RQR standard radiation qualities in free-in-air geometry. Studies of the other characterization parameters, such as the dose linearity and dependency on exposure angle, field size, frame rate, depth-dose, and source-to-surface distance (SSD), were carried out using a solid water phantom under a clinical x-ray unit. Results: The MOSkin detector showed good reproducibility (94%) and dose linearity (99%) for the dose range of 2 to 213 cGy. The sensitivity did not significantly change with the variation of SSD (±1%), field size (±1%), frame rate (±3%), or beam energy (±5%). The detector angular dependence was within ±5% over 360° and the dose recorded by the MOSkin detector in different depths of a solid water phantom was in good agreement with the Markus parallel plate ionization chamber to within ±3%. Conclusions: The MOSkin detector proved to be reliable when exposed to different field sizes, SSDs, depths in solid water, dose rates, frame rates, and radiation incident angles within a clinical x-ray beam. The MOSkin detector with water equivalent depth equal to 0.07 mm is a suitable detector for in vivo skin dosimetry during interventional radiology procedures.

  10. Engineering the Human Thymic Microenvironment to Support Thymopoiesis in Vivo

    PubMed Central

    Chung, Brile; Montel-Hagen, Amélie; Ge, Shundi; Blumberg, Garrett; Kim, Kenneth; Klein, Sam; Zhu, Yuhua; Parekh, Chintan; Balamurugan, Arumugam; Yang, Otto O.; Crooks, Gay M.

    2014-01-01

    A system that allows manipulation of the human thymic microenvironment is needed both to elucidate the extrinsic mechanisms that control human thymopoiesis, and to develop potential cell therapies for thymic insufficiency. In this report, we developed an implantable thymic microenvironment composed of two human thymic stroma populations critical for thymopoiesis; thymic epithelial cells (TECs) and thymic mesenchyme (TM). TECs and TM from postnatal human thymi were cultured in specific conditions, allowing cell expansion and manipulation of gene expression, prior to re-aggregation into a functional thymic unit. Human CD34+ hematopoietic stem and progenitor cells (HSPC) differentiated into T cells in the aggregates in vitro and in vivo following inguinal implantation of aggregates in immune deficient mice. Cord blood HSPC previously engrafted into murine bone marrow, migrated to implants and differentiated into human T cells with a broad T cell receptor repertoire. Furthermore, lentiviral-mediated expression of vascular endothelial growth factor in TM enhanced implant size and function, and significantly increased thymocyte production. These results demonstrate an in vivo system for the generation of T cells from human HSPC, and represent the first model to allow manipulation of gene expression and cell composition in the microenvironment of the human thymus. PMID:24801626

  11. Measuring skin aging using optical coherence tomography in vivo: a validation study

    NASA Astrophysics Data System (ADS)

    Trojahn, Carina; Dobos, Gabor; Richter, Claudia; Blume-Peytavi, Ulrike; Kottner, Jan

    2015-04-01

    Dermal and epidermal structures in human skin change during intrinsic and extrinsic aging. Epidermal thickness is one of the most often reported parameters for the assessment of skin aging in cross-sectional images captured by optical coherence tomography (OCT). We aimed to identify further parameters for the noninvasive measurement of skin aging of sun-exposed and sun-protected areas utilizing OCT. Based on a literature review, seven parameters were inductively developed. Three independent raters assessed these parameters using four-point scales on images of female subjects of two age groups. All items could be detected and quantified in our sample. Interrater agreement ranged between 25.0% and 83.3%. The item scores "stratum corneum reflectivity," "upper dermal reflectivity," and "dermoepidermal contrast" showed significant differences between age groups on the volar and dorsal forearm indicating that they were best able to measure changes during skin aging. "Surface unevenness" was associated with the skin roughness parameters, Rz and Rmax, on the inner upper arm and volar forearm supporting the criterion validity of this parameter on sun-protected skin areas. Based on the interrater agreement and the ability to differentiate between age groups, these four parameters are being considered as the best candidates for measuring skin aging in OCT images.

  12. DeoxyArbutin: a novel reversible tyrosinase inhibitor with effective in vivo skin lightening potency.

    PubMed

    Boissy, Raymond E; Visscher, Marty; DeLong, Mitchell A

    2005-08-01

    Modulation of melanogenesis in the melanocytes can be achieved using chemicals that share structural homologies with the substrate tyrosine and as thus competitively inhibit the catalytic function of tyrosinase. We have developed a new tyrosinase inhibitor, deoxyArbutin (dA), based on this premise. DeoxyArbutin demonstrates effective inhibition of mushroom tyrosinase in vitro with a Ki that is 10-fold lower that hydroquinone (HQ) and 350-fold lower than arbutin. In a hairless, pigmented guinea pig model, dA demonstrated rapid and sustained skin lightening that was completely reversible within 8 weeks after halt in topical application. In contrast, HQ induced a short but unsustained skin lightening effect whereas kojic acid and arbutin exhibit no skin lightening effect. Results from a panel of safety tests supported the overall establishment of dA as an actionable molecule. In a human clinical trial, topical treatment of dA for 12 weeks resulted in a significant or slight reduction in overall skin lightness and improvement of solar lentigines in a population of light skin or dark skin individuals, respectively. These data demonstrate that dA has potential tyrosinase inhibitory activity that can result in skin lightening and may be used to ameliorate hyperpigmentary lesions. PMID:16026582

  13. Epidermal melanin absorption in human skin

    NASA Astrophysics Data System (ADS)

    Norvang Nilsen, Lill T.; Fiskerstrand, Elisanne J.; Nelson, J. Stuart; Berns, Michael W.; Svaasand, Lars O.

    1996-01-01

    The principle of laser induced selective photothermolysis is to induced thermal damage to specific targets in such a manner that the temperature of the surrounding tissue is maintained below the threshold for thermal damage. The selectivity is obtained by selection of a proper wavelength and pulse duration. The technique is presently being used in the clinic for removal of port-wine stains. The presence of melanin in the epidermal layer can represent a limitation to the selectivity. Melanin absorption drops off significantly with increasing wavelength, but is significant in the entire wavelength region where the blood absorption is high. Treatment of port-wine stain in patients with high skin pigmentation may therefore give overheating of the epidermis, resulting in epidermal necrosis. Melanosomal heating is dependent on the energy and duration of the laser pulse. The heating mechanism for time scales less than typically 1 microsecond(s) corresponds to a transient local heating of the individual melanosomes. For larger time scales, heat diffusion out of the melanosomes become of increased importance, and the temperature distribution will reach a local steady state condition after typically 10 microsecond(s) . For even longer pulse duration, heat diffusing from neighboring melanosomes becomes important, and the temperature rise in a time scale from 100 - 500 microsecond(s) is dominated by this mechanism. The epidermal heating during the typical 450 microsecond(s) pulse used for therapy is thus dependent on the average epidermal melanin content rather than on the absorption coefficient of the individual melanosomes. This study will present in vivo measurements of the epidermal melanin absorption of human skin when exposed to short laser pulses (< 0.1 microsecond(s) ) from a Q-switched ruby laser and with long laser pulses (approximately 500 microsecond(s) ) from a free-running ruby laser or a long pulse length flashlamp pumped dye laser. The epidermal melanin

  14. Influence of IR radiation on the carotenoid content in human skin

    NASA Astrophysics Data System (ADS)

    Darvin, M. E.; Zastrov, L.; Gonchukov, S. A.; Lademann, J.

    2009-12-01

    It is shown that the infrared irradiation decreases the content of β-carotene and lycopene carotenoids in human skin. A decrease in the content of β-carotene and lycopene may indicate that the IR radiation, as well as the UV radiation, is capable of forming free radicals in human skin. The investigations were performed in vivo using the technique of resonance Raman scattering developed by us for the noninvasive determination of antioxidant potential in skin.

  15. Lymphedematous skin and subcutis: in vivo high resolution magnetic resonance imaging evaluation.

    PubMed

    Idy-Peretti, I; Bittoun, J; Alliot, F A; Richard, S B; Querleux, B G; Cluzan, R V

    1998-05-01

    Physico-chemical and morphologic parameters of skin layers and subcutaneous tissue in lymphedematous limb were studied in vivo using magnetic resonance imaging. High resolution images were obtained with a depth resolution of about 70 microm, using a specific surface gradient coil specially designed for skin imaging and connected to a standard whole-body imager at 1.5 T. Twenty-one patients with unilateral lower extremity lymphedema (11 primary and 10 secondary) were examined. Skin thickness, relaxation times, and relative proton density were calculated in lymphedematous limbs and in contralateral extremities. In diseased limbs, the average skin thickness (2.17 mm) was significantly larger (p = 1.5 x 10(-4)) than that of contralateral limb (1.14 mm). Major cutaneous alterations due to lymphedema took place in dermis. In lymphedematous dermis, the significant increase of relaxation time values could be due to a shift in the equilibrium of water inside this tissue in relation to the interactions between macromolecules and water molecules. In lymphedematous epidermis our results showed an increase in the number of free water protons. Information about water and fat distribution in lymphedema was also obtained using chemical shift weighted images. Our results demonstrated a water retention diffusely spread over the entire dermis, and an important fluid retention located in the interlobular spacing and beside the superficial fascia. Inside the subcutis, the mean thickness of the superficial fat lobules was increased more than that of the deep fat lobules. From all the various measurements we could not distinguish primary from secondary lymphedema. PMID:9579546

  16. [Experimental models of human skin aging].

    PubMed

    Nikolakis, G; Zoschke, C; Makrantonaki, E; Hausmann, C; Schäfer-Korting, M; Zouboulis, C C

    2016-02-01

    The skin is a representative model for the study of human aging. Despite the high regenerative capacity of the skin, skin physiology changes over the course of life. Medical and cosmetic research is trying to prevent aging, to slow, to stop, or to reverse it. Effects of age-related DNA damage and of changing skin structure on pharmacological parameters are largely unknown. This review article summarizes the state of scientific knowledge in the field of experimental models of human skin aging and shows approaches to improve organotypic skin models, to develop predictive models of aging, and improve aging research. PMID:26743051

  17. Handheld Diffuse Reflectance Spectral Imaging (DRSi) for in-vivo characterization of skin

    PubMed Central

    Bish, Sheldon F.; Sharma, Manu; Wang, Youmin; Triesault, Nicholas J.; Reichenberg, Jason S.; Zhang, John X.J.; Tunnell, James W.

    2014-01-01

    Diffuse reflectance spectroscopy provides a noninvasive means to measure optical and physiological properties of tissues. To expand on these measurements, we have developed a handheld diffuse reflectance spectral imaging (DRSi) system capable of acquiring wide field hyperspectral images of tissue. The image acquisition time was approximately 50 seconds for a 50x50 pixel image. A transport model was used to fit each spectra for reduced scattering coefficient, hemoglobin concentration and melanin concentration resulting in optical property maps. The system was validated across biologically relevant levels of reduced scattering (5.14% error) and absorption (8.34% error) using tissue simulating phantoms. DRSi optical property maps of a pigmented skin lesion were acquired in vivo. These trends in optical properties were consistent with previous observations using point probe devices. PMID:24575350

  18. Review of the results of the in vivo dosimetry during total skin electron beam therapy

    PubMed Central

    Guidi, Gabriele; Gottardi, Giovanni; Ceroni, Paola; Costi, Tiziana

    2013-01-01

    This work reviews results of in vivo dosimetry (IVD) for total skin electron beam (TSEB) therapy, focusing on new methods, data emerged within 2012. All quoted data are based on a careful review of the literature reporting IVD results for patients treated by means of TSEB therapy. Many of the reviewed papers refer mainly to now old studies and/or old guidelines and recommendations (by IAEA, AAPM and EORTC), because (due to intrinsic rareness of TSEB-treated pathologies) only a limited number of works and reports with a large set of numerical data and proper statistical analysis is up-to-day available in scientific literature. Nonetheless, a general summary of the results obtained by the now numerous IVD techniques available is reported; innovative devices and methods, together with areas of possible further and possibly multicenter investigations for TSEB therapies are highlighted. PMID:24936333

  19. Studies in human skin epithelial cell carcinogenesis

    SciTech Connect

    Lehman, T.A.

    1987-01-01

    Metabolism and DNA adduct formation of benzo(a)pyrene (BP) by human epidermal keratinocytes pretreated with inhibitors or inducer of cytochrame P450 was studied. To study DNA adduct analysis, cultures were pretreated as described above, and then treated with non-radiolabeled BP. DNA was prepared from these cultures, digested to the nucleotide level, and /sup 32/P-postlabeled for adduct analysis. Cultures pretreated with BHA, 7,8-BF or disulfiralm formed significantly fewer BPDE I-dB adducts than non-pretreated cultures, while cultures pretreated with MeBHA formed more BPDE-I-dG adducts. MeBHA increased BP activation and adduct formation inhuman keratinocyte in cultures by inducing a specific isoenzyme of cytochrome P450 which preferentially increases the oxidative metabolism of BP to 7,8 diol BP and 7,8 diol BP to BPDE I. To approximate an in vivo human system, metabolism of BPDE I by human skin xenografts treated with cell cycles modulators was studied. When treated with BPDE I, specific carcinogen-DNA adducts were formed. Separation and identification of these adducts by the /sup 32/P-postlabeling technique indicated that the 7R- and 7S-BPDE I-dG adducts were the major adducts.

  20. Three-dimensional confocal fluorescence microscopic visualization of the living human skin

    NASA Astrophysics Data System (ADS)

    Masters, Barry R.

    1995-04-01

    Three-dimensional confocal visualization of living human skin is a new development in the noninvasive imaging of normal and pathological tissue. I have investigated the autofluorescence of in vivo human skin with a laser scanning confocal microscope. An argon ion laser (488 nm) was used for excitation of the natural fluorescence of skin and a 515 nm cut off filter was used to separate the fluorescence from the excitation light. I found that normal skin has a very high autofluorescence. The laser scanning confocal microscope was used to obtain a stack of serial sections through the skin. A stack of optical sections through the hair follicle was reconstructed as well as the three-dimensional reconstruction of the pores of sweat glands. The ability to obtain two and three-dimensional visualizations of in vivo human skin may provide a new tool for noninvasive diagnostics in dermatology.

  1. Persistent DNA Damage after High Dose In Vivo Gamma Exposure of Minipig Skin

    PubMed Central

    Ahmed, Emad A.; Agay, Diane; Schrock, Gerrit; Drouet, Michel; Meineke, Viktor; Scherthan, Harry

    2012-01-01

    Background Exposure to high doses of ionizing radiation (IR) can lead to localized radiation injury of the skin and exposed cells suffer dsDNA breaks that may elicit cell death or stochastic changes. Little is known about the DNA damage response after high-dose exposure of the skin. Here, we investigate the cellular and DNA damage response in acutely irradiated minipig skin. Methods and Findings IR-induced DNA damage, repair and cellular survival were studied in 15 cm2 of minipig skin exposed in vivo to ∼50 Co-60 γ rays. Skin biopsies of control and 4 h up to 96 days post exposure were investigated for radiation-induced foci (RIF) formation using γ-H2AX, 53BP1, and active ATM-p immunofluorescence. High-dose IR induced massive γ-H2AX phosphorylation and high 53BP1 RIF numbers 4 h, 20 h after IR. As time progressed RIF numbers dropped to a low of <1% of keratinocytes at 28–70 days. The latter contained large RIFs that included ATM-p, indicating the accumulation of complex DNA damage. At 96 days most of the cells with RIFs had disappeared. The frequency of active-caspase-3-positive apoptotic cells was 17-fold increased 3 days after IR and remained >3-fold elevated at all subsequent time points. Replicating basal cells (Ki67+) were reduced 3 days post IR followed by increased proliferation and recovery of epidermal cellularity after 28 days. Conclusions Acute high dose irradiation of minipig epidermis impaired stem cell replication and induced elevated apoptosis from 3 days onward. DNA repair cleared the high numbers of DBSs in skin cells, while RIFs that persisted in <1% cells marked complex and potentially lethal DNA damage up to several weeks after exposure. An elevated frequency of keratinocytes with persistent RIFs may thus serve as indicator of previous acute radiation exposure, which may be useful in the follow up of nuclear or radiological accident scenarios. PMID:22761813

  2. Antiphotoaging Effect of Conditioned Medium of Dedifferentiated Adipocytes on Skin In Vivo and In Vitro: A Mechanistic Study

    PubMed Central

    Xu, Yang; Zhang, Jia-an; Xu, Yan; Guo, Shi-lei; Wang, Shen; Wu, Di; Wang, Ying

    2015-01-01

    Photoaging of skin occurs partially due to decreased synthesis and increased degradation of dermal collagen. Antiphotoaging therapy aims to counteract these effects. This study aimed to investigate whether secretory factors from dedifferentiated adipocytes (DAs) could alleviate photoaging in human dermal fibroblasts (HDFs) and in mice and to clarify the underlying mechanism. DAs were acquired and verified based on cellular biomarkers and multilineage differentiation potential. The concentrations of several cytokines in conditioned medium from DAs (DA-CM) were determined. In vivo pathological changes, collagen types I and III, and matrix metalloproteinase (MMP)-1 and -3 were evaluated following the injection of 10-fold concentrated DA-CM into photoaged mice. In vitro, the effect of DA-CM on stress-induced premature senescence in HDFs was investigated by 5-ethynyl-2′-deoxyuridine (EdU) staining and β-galactosidase staining. The influence of DA-CM and transforming growth factor-β1 (TGF-β1) on the secretion of collagen types I and III, MMP-1, and MMP-3 in HDFs was evaluated by ELISA. In vivo, we found that subcutaneously injected 10-fold concentrated DA-CM increased the expression of collagen types I and III. In vitro, DA-CM clearly mitigated the decreased cell proliferation and delayed the senescence status in HDFs induced by ultraviolet B (UVB). HDFs treated with DA-CM exhibited higher collagen types I and III secretion and significantly lower MMP-1 and MMP-3 secretion. The TGF-β1-neutralizing antibody could partially reduce the recovery effect. Our results suggest that DAs may be useful for aging skin and their effects are mainly due to secreted factors, especially TGF-β1, which stimulate collagen synthesis and alleviate collagen degradation in HDFs. PMID:25517994

  3. Antiphotoaging effect of conditioned medium of dedifferentiated adipocytes on skin in vivo and in vitro: a mechanistic study.

    PubMed

    Xu, Yang; Zhang, Jia-an; Xu, Yan; Guo, Shi-lei; Wang, Shen; Wu, Di; Wang, Ying; Luo, Dan; Zhou, Bing-rong

    2015-05-01

    Photoaging of skin occurs partially due to decreased synthesis and increased degradation of dermal collagen. Antiphotoaging therapy aims to counteract these effects. This study aimed to investigate whether secretory factors from dedifferentiated adipocytes (DAs) could alleviate photoaging in human dermal fibroblasts (HDFs) and in mice and to clarify the underlying mechanism. DAs were acquired and verified based on cellular biomarkers and multilineage differentiation potential. The concentrations of several cytokines in conditioned medium from DAs (DA-CM) were determined. In vivo pathological changes, collagen types I and III, and matrix metalloproteinase (MMP)-1 and -3 were evaluated following the injection of 10-fold concentrated DA-CM into photoaged mice. In vitro, the effect of DA-CM on stress-induced premature senescence in HDFs was investigated by 5-ethynyl-2'-deoxyuridine (EdU) staining and β-galactosidase staining. The influence of DA-CM and transforming growth factor-β1 (TGF-β1) on the secretion of collagen types I and III, MMP-1, and MMP-3 in HDFs was evaluated by ELISA. In vivo, we found that subcutaneously injected 10-fold concentrated DA-CM increased the expression of collagen types I and III. In vitro, DA-CM clearly mitigated the decreased cell proliferation and delayed the senescence status in HDFs induced by ultraviolet B (UVB). HDFs treated with DA-CM exhibited higher collagen types I and III secretion and significantly lower MMP-1 and MMP-3 secretion. The TGF-β1-neutralizing antibody could partially reduce the recovery effect. Our results suggest that DAs may be useful for aging skin and their effects are mainly due to secreted factors, especially TGF-β1, which stimulate collagen synthesis and alleviate collagen degradation in HDFs. PMID:25517994

  4. Triparanol suppresses human tumor growth in vitro and in vivo

    SciTech Connect

    Bi, Xinyu; Han, Xingpeng; Zhang, Fang; He, Miao; Zhang, Yi; Zhi, Xiu-Yi; Zhao, Hong

    2012-08-31

    Highlights: Black-Right-Pointing-Pointer Demonstrate Triparanol can block proliferation in multiple cancer cells. Black-Right-Pointing-Pointer Demonstrate Triparanol can induce apoptosis in multiple cancer cells. Black-Right-Pointing-Pointer Proved Triparanol can inhibit Hedgehog signaling in multiple cancer cells. Black-Right-Pointing-Pointer Demonstrated Triparanol can impede tumor growth in vivo in mouse xenograft model. -- Abstract: Despite the improved contemporary multidisciplinary regimens treating cancer, majority of cancer patients still suffer from adverse effects and relapse, therefore posing a significant challenge to uncover more efficacious molecular therapeutics targeting signaling pathways central to tumorigenesis. Here, our study have demonstrated that Triparanol, a cholesterol synthesis inhibitor, can block proliferation and induce apoptosis in multiple human cancer cells including lung, breast, liver, pancreatic, prostate cancer and melanoma cells, and growth inhibition can be rescued by exogenous addition of cholesterol. Remarkably, we have proved Triparanol can significantly repress Hedgehog pathway signaling in these human cancer cells. Furthermore, study in a mouse xenograft model of human lung cancer has validated that Triparanol can impede tumor growth in vivo. We have therefore uncovered Triparanol as potential new cancer therapeutic in treating multiple types of human cancers with deregulated Hedgehog signaling.

  5. Functional Consequences of Mitochondrial DNA Deletions in Human Skin Fibroblasts

    PubMed Central

    Majora, Marc; Wittkampf, Tanja; Schuermann, Bianca; Schneider, Maren; Franke, Susanne; Grether-Beck, Susanne; Wilichowski, Ekkehard; Bernerd, Françoise; Schroeder, Peter; Krutmann, Jean

    2009-01-01

    Deletions within the mitochondrial DNA (mtDNA) are thought to contribute to extrinsic skin aging. To study the translation of mtDNA deletions into functional and structural changes in the skin, we seeded human skin fibroblasts into collagen gels to generate dermal equivalents. These cells were either derived from Kearns-Sayre syndrome (KSS) patients, who constitutively carry large amounts of the UV-inducible mitochondrial common deletion, or normal human volunteers. We found that KSS fibroblasts, in comparison with normal human fibroblasts, contracted the gels faster and more strongly, an effect that was dependent on reactive oxygen species. Gene expression and Western blot analysis revealed significant upregulation of lysyl oxidase (LOX) in KSS fibroblasts. Treatment with the specific LOX inhibitor β-aminopropionitrile decreased the contraction difference between KSS and normal human fibroblast equivalents. Also, addition of the antioxidant N-tert-butyl-α-phenylnitrone reduced the contraction difference by inhibiting collagen gel contraction in KSS fibroblasts, and both β-aminopropionitrile and N-tert-butyl-α-phenylnitrone diminished LOX activity. These data suggest a causal relationship between mtDNA deletions, reactive oxygen species production, and increased LOX activity that leads to increased contraction of collagen gels. Accordingly, increased LOX expression was also observed in vivo in photoaged human and mouse skin. Therefore, mtDNA deletions in human fibroblasts may lead to functional and structural alterations of the skin. PMID:19661442

  6. In vivo imaging of human burn injuries with polarization-sensitive optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Kim, Ki Hean; Pierce, Mark C.; Maguluri, Gopi; Park, B. Hyle; Yoon, Sang June; Lydon, Martha; Sheridan, Robert; de Boer, Johannes F.

    2012-06-01

    The accurate determination of burn depth is critical in the clinical management of burn wounds. Polarization-sensitive optical coherence tomography (PS-OCT) has been proposed as a potentially non-invasive method for determining burn depth by measuring thermally induced changes in the structure and birefringence of skin, and has been investigated in pre-clinical burn studies with animal models and ex vivo human skin. In this study, we applied PS-OCT to the in-vivo imaging of two pediatric burn patients. Deep and superficial burned skins along with contralateral controls were imaged in 3D. The imaging size was 8 mm×6 mm×2 mm in width, length, and depth in the air respectively, and the imaging time was approximately 6 s per volume. Superficially burned skins exhibited the same layered structure as the contralateral controls, but more visible vasculature and reduced birefringence compared to the contralateral controls. In contrast, a deeply burned skin showed loss of the layered structure, almost absent vasculature, and smaller birefringence compared to superficial burns. This study suggested the vasculature and birefringence as parameters for characterizing burn wounds.

  7. In vivo photoacoustic microscopy of human cutaneous microvasculature and a nevus

    NASA Astrophysics Data System (ADS)

    Favazza, Christopher P.; Jassim, Omar; Cornelius, Lynn A.; Wang, Lihong V.

    2011-01-01

    In several human volunteers, photoacoustic microscopy (PAM) has been utilized for noninvasive cutaneous imaging of the skin microvasculature and a melanocytic nevus. Microvascular networks in both acral and nonacral skin were imaged, and multiple features within the skin have been identified, including the stratum corneum, epidermal-dermal junction, and subpapillary vascular plexus. Several vascular and structural differences between acral and nonacral skin were also observed in the photoacoustic images. In addition, a nevus was photoacoustically imaged, excised, and histologically analyzed. The photoacoustic images allowed for in vivo measurement of tumor thickness, depth, and microvasculature-values confirmed by histologic examination. The presented images demonstrate the potential of PAM to aid in the study and evaluation of cutaneous microcirculation and analysis of pigmented lesions. Through its ability to three-dimensionally image the structure and function of the microvasculature and pigmented lesions, PAM can have a clinical impact in diagnosis and assessment of systemic diseases that affect the microvasculature such as diabetes and cardiovascular disease, cutaneous malignancies such as melanoma, and potentially other skin disorders.

  8. In vivo imaging reveals a pioneer wave of monocyte recruitment into mouse skin wounds.

    PubMed

    Rodero, Mathieu P; Licata, Fabrice; Poupel, Lucie; Hamon, Pauline; Khosrotehrani, Kiarash; Combadiere, Christophe; Boissonnas, Alexandre

    2014-01-01

    The cells of the mononuclear phagocyte system are essential for the correct healing of adult skin wounds, but their specific functions remain ill-defined. The absence of granulation tissue immediately after skin injury makes it challenging to study the role of mononuclear phagocytes at the initiation of this inflammatory stage. To study their recruitment and migratory behavior within the wound bed, we developed a new model for real-time in vivo imaging of the wound, using transgenic mice that express green and cyan fluorescent proteins and specifically target monocytes. Within hours after the scalp injury, monocytes invaded the wound bed. The complete abrogation of this infiltration in monocyte-deficient CCR2(-/-) mice argues for the involvement of classical monocytes in this process. Monocyte infiltration unexpectedly occurred as early as neutrophil recruitment did and resulted from active release from the bloodstream toward the matrix through microhemorrhages rather than transendothelial migration. Monocytes randomly scouted around the wound bed, progressively slowed down, and stopped. Our approach identified and characterized a rapid and earlier than expected wave of monocyte infiltration and provides a novel framework for investigating the role of these cells during early stages of wound healing. PMID:25272047

  9. Video-Mosaicing of Reflectance Confocal Images For Rapid Examination of Large Areas of Skin In Vivo

    PubMed Central

    Kose, Kivanc; Cordova, Miguel; Duffy, Megan; Flores, Eileen S.; Brooks, Dana H.; Rajadhyaksha, Milind

    2015-01-01

    Background With reflectance confocal microscopy (RCM) imaging, skin cancers can be diagnosed in vivo and margins detected to guide treatment. Since the field of view of an RCM image is much smaller than the typical size of lesions, mosaicing approaches have been developed to display larger areas of skin. However, the current paradigm for RCM mosaicing in vivo is limited both in speed and to pre-selected rectangular-shaped small areas. Another approach, called “video-mosaicing,” enables higher speeds and real-time operator-selected areas of any size and shape, and will be more useful for RCM examination of skin in vivo. Objectives To demonstrate the feasibility and clinical potential of video-mosaicing of RCM images to rapidly display large areas of skin in vivo. Methods Thirteen videos of benign lesions, melanocytic cancers and residual basal cell carcinoma margins were collected on volunteer subjects with a handheld RCM scanner. The images from each video were processed and stitched into mosaics to display the entire area that was imaged. Results Acquisition of RCM videos covering 5.0–16.0 mm2 was performed in 20–60 seconds. The video-mosaics were visually determined to be of high quality for resolution, contrast and seamless contiguity, and the appearance of cellular-level and morphologic detail. Conclusion Video-mosaicing confocal microscopy, with real-time operator-choice of the shape and size of the area to be imaged, will enable rapid examination of large areas of skin in vivo. This approach may further advance noninvasive detection of skin cancer and, eventually, facilitate wider adoption of RCM imaging in the clinic. PMID:24720744

  10. Polarization-Sensitive Hyperspectral Imaging in vivo: A Multimode Dermoscope for Skin Analysis

    PubMed Central

    Vasefi, Fartash; MacKinnon, Nicholas; Saager, Rolf B.; Durkin, Anthony J.; Chave, Robert; Lindsley, Erik H.; Farkas, Daniel L.

    2014-01-01

    Attempts to understand the changes in the structure and physiology of human skin abnormalities by non-invasive optical imaging are aided by spectroscopic methods that quantify, at the molecular level, variations in tissue oxygenation and melanin distribution. However, current commercial and research systems to map hemoglobin and melanin do not correlate well with pathology for pigmented lesions or darker skin. We developed a multimode dermoscope that combines polarization and hyperspectral imaging with an efficient analytical model to map the distribution of specific skin bio-molecules. This corrects for the melanin-hemoglobin misestimation common to other systems, without resorting to complex and computationally intensive tissue optical models. For this system's proof of concept, human skin measurements on melanocytic nevus, vitiligo, and venous occlusion conditions were performed in volunteers. The resulting molecular distribution maps matched physiological and anatomical expectations, confirming a technologic approach that can be applied to next generation dermoscopes and having biological plausibility that is likely to appeal to dermatologists. PMID:24815987