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Sample records for absorption skin

  1. Percutaneous absorption in diseased skin: an overview.

    Chiang, Audris; Tudela, Emilie; Maibach, Howard I

    2012-08-01

    The stratum corneum's (SC) functions include protection from external hazardous environments, prevention of water loss and regulation of body temperature. While intact skin absorption studies are abundant, studies on compromised skin permeability are less common, although products are often used to treat affected skin. We reviewed literature on percutaneous absorption through abnormal skin models. Tape stripping is used to disrupt water barrier function. Studies demonstrated that physicochemical properties influence the stripping effect: water-soluble drugs are more affected. Abrasion did not affect absorption as much. Freezing is commonly used to preserve skin. It does not seem to modify water absorption, but still increases the penetration of compounds. Comparatively, heating the skin consistently increased percutaneous absorption. Removing SC lipids may increase percutaneous absorption of drugs. Many organic solvents are employed to delipidize. Delipidization with chloroform-methanol increased hydrophilic compound permeability, but not lipophilic. Acetone pre-treatment enhanced hydrophilic compound penetration. More data is needed to determine influence on highly lipophilic compound penetration. Sodium lauryl sulfate (SLS) induces irritant dermatitis and is frequently used as a model. Studies revealed that SLS increases hydrophilic compound absorption, but not lipophilic. However, skin irritation with other chemicals increases lipophilic penetration as much as hydrophilic. Animal studies show that UV exposure increases percutaneous absorption whereas human studies do not. Human studies show increased penetration in psoriatic and atopic dermatitis skin. The data summarized here begin to characterize flux alteration associated with damaged skin. Understanding the degree of alteration requires interpretation of involved conditions and the enlarging of our database to a more complete physicochemical spectrum. PMID:22912973

  2. Near infrared laser penetration and absorption in human skin

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

    2014-02-01

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

  3. Povidone iodine skin absorption: an ex-vivo study.

    Nesvadbova, Martina; Crosera, Matteo; Maina, Giovanni; Larese Filon, Francesca

    2015-06-15

    Povidone iodine is a water-soluble complex used to disinfect the skin surface and it exerts prolonged germicidal action against a broad spectrum of germs. Indeed, it is often applied on burned skin, large wounds, deep tissues or mucosa. Notably some surgical hand-scrub solutions, which are considered safe antiseptics, contain large amounts of iodine that can be absorbed by skin. The aim of present study was to study the skin absorption of iodine after the application on the skin of povidone-iodine solution, used by health care workers during surgical procedure. We use Franz diffusion static cells with human skin. After 24h from the beginning of our measurement the iodine concentration in the receiving compartment was 11.59±6.3μg/cm(2). The medium flux calculated was 0.73±0.33μg/cm(2)/h with a lag time of 8.9±1.5h. These in vitro results confirmed that povidone iodine could pass through the skin in a relevant amount that can explain the clinical findings in burned or surgically treated patients. In professional use the repetitive contact with povidone iodine, also as soap, can cause iodine skin permeation that must be considered when the washing procedures are repeated more than 20 times a day. PMID:25858112

  4. A high absorption coefficient DL-MPP imitating owl skin

    Guo, Lijun; Zhao, Zhan; Kong, Deyi; Wu, Shaohua; Du, Lidong; Fang, Zhen

    2012-11-01

    This paper proposes a high absorption coefficient micro-perforated panel (MPP) imitating owl skin structure for acoustic noise reduction. Compared to the traditional micro-perforated panel, this device has two unique characteristics-simulating the owl skin structure, its radius of perforated apertures even can be as small as 55μ, and its material is silicon and fabricated by micro-electrical mechanical system (MEMS) technology; So that its absorption coefficients of acoustic noise for normal incidence sound wave whose frequencies arrange from 1.5 kHz to 6.0 kHz are all above 0.8 which is the owl's hunts sensitivity frequency band. Double leaf MPP fabricated by MEMS technology is an absolutely bionic success in functional-imitation.

  5. Absorption of some glycol ethers through human skin in vitro.

    Dugard, P H; M. Walker; Mawdsley, S J; Scott, R.C.

    1984-01-01

    To assist evaluation of the hazards of skin contact with selected undiluted glycol ethers, their absorption across isolated human abdominal epidermis was measured in vitro. Epidermal membranes were set up in glass diffusion cells and, following an initial determination of permeability to tritiated water, excess undiluted glycol ether was applied to the outer surface for 8 hr. The appearance of glycol ether in an aqueous "receptor" phase bathing the underside of the epidermis was quantified by...

  6. Absorption of vitamin A ointment to the skin

    14C-Vitamin A palmitate prepared as hydrophilic ointments of 3 kinds of concentrations (1 mg/g, 5 mg/g and 10 mg/g) was applied to the skin in rabbits, and the absorption to the skin was studied. 1. The concentration of radioactivity in the skin showed peak levels 1 hour after the dermal application of ointments with all concentrations, and hereafter it progressively decreased. As for the concentration of radioactivity in the skin due to the differences of concentrations of vitamin A palmitate, there was difference between the ointment of 1 mg/g and that of 5 mg/g in proportion to differences of concentrations, while there was no significant difference between the ointment of 5 mg/g and that of 10 mg/g as compared with differences of concentrations. 2. The urinary excretion of radioactivity was measured on the group which received the dermal application of vitamin A palmitate of 5 mg/g. The excretion of radioactivity of 0.06% was observed in the urine for 12 hours often the application. (Ichikawa, K.)

  7. Stratum corneum damage and ex vivo porcine skin water absorption - a pilot study

    Duch Lynggaard, C; Bang Knudsen, D; Jemec, G B E

    2009-01-01

    A simple ex vivo screening technique would be of interest for mass screening of substances for potential barrier disruptive qualities. Ex vivo water absorption as a marker of skin barrier integrity was studied on pig ear skin. Skin water absorption was quantified by weighing and weight changes were...

  8. Fate of chemicals in skin after dermal application: does the in vitro skin reservoir affect the estimate of systemic absorption?

    Recent international guidelines for the conduct of in vitro skin absorption studies put forward different approaches for addressing the status of chemicals remaining in the stratum corneum and epidermis/dermis at the end of a study. The present study investigated the fate of three chemicals [dihydroxyacetone (DHA), 7-(2H-naphtho[1,2-d]triazol-2-yl)-3-phenylcoumarin (7NTPC), and disperse blue 1 (DB1)] in an in vitro absorption study. In these studies, human and fuzzy rat skin penetration and absorption were determined over 24 or 72 h in flow-through diffusion cells. Skin penetration of these chemicals resulted in relatively low receptor fluid levels but high skin levels. For DHA, penetration studies found approximately 22% of the applied dose remaining in the skin (in both the stratum corneum and viable tissue) as a reservoir after 24 h. Little of the DHA that penetrates into skin is actually available to become systemically absorbed. 7NTPC remaining in the skin after 24 h was approximately 14.7% of the applied dose absorbed. Confocal laser cytometry studies with 7NTPC showed that it is present across skin in mainly the epidermis and dermis with intense fluorescence around hair. For DB1, penetration studies found approximately 10% (ethanol vehicle) and 3% (formulation vehicle) of the applied dose localized in mainly the stratum corneum after 24 h. An extended absorption study (72 h) revealed that little additional DB1 was absorbed into the receptor fluid. Skin levels should not be considered as absorbed material for DHA or DB1, while 7NTPC requires further investigation. These studies illustrate the importance of determining the fate of chemicals remaining in skin, which could significantly affect the estimates of systemically available material to be used in exposure estimates. We recommend that a more conclusive means to determine the fate of skin levels is to perform an extended study as conducted for DB1

  9. CHIRAL MULTIPHOTON ABSORPTION AND INVERSE SKIN EFFECT IN WLAN SYSTEMS

    Héctor Torres Silva

    2005-12-01

    Full Text Available A model formed by chiral bioplasma with a set of macromolecules of DNA, which represents the human head inner structure, makes possible to analyze its behavior, when it is radiated by a microwave electromagnetic field from cellular phones and WLAN's at frequencies of 2.4 and 5.2 GHz is presented. The finite difference time domain, FDTD, numeric technique is used under multiphoton regime deduced from Maxwell equations. The numerical results of the Specific Absorption Rate, SAR, show the SAR behavior in function of input power and the chirality factor. The main conclusions of our work are: a the microwave absorption from cellular phones or WLAN's is enhanced, compared with classical models, when values of the normalized chiral factor are of order of one which appear under multiphoton regime ; b a phenomena like an “inverse skin effect” in 5.2 GHz, with respect to a 2.4 GHz source, was observed. c In the metamaterial region we show that the absorption rate always is positive.Un modelo formado por bioplasma quiral con un conjunto de macromoléculas de ADN, que representa la estructura interna de la cabeza humana, hace posible analizar su comportamiento, cuando es irradiada por campos electromagnéticos de microondas de teléfonos celulares o sistemas WLAN a frecuencias de 2.4 y 5.2 GHz. El método de diferencias finitas en el dominio del tiempo, FDTD, en régimen de multifotones deducido de las ecuaciones de Maxwell es usado. Los resultados numéricos de la taza de absorción específica SAR, muestran el comportamiento de la SAR en función de la potencia de entrada y del factor quiral. Las principales conclusiones de nuestro trabajo son: a la absorción de microondas es aumentada comparada con modelos clásicos, cuando valores del factor quiral normalizado son del orden de la unidad, que aparecen bajo régimen multifotónico; b Un fenómeno de efecto pelicular inverso en 5.2 GHz con respecto a una fuente de 2.4 GHz fue observado; c En la regi

  10. Erbium:YAG laser resurfacing increases skin permeability and the risk of excessive absorption of antibiotics and sunscreens: the influence of skin recovery on drug absorption.

    Lee, Woan-Ruoh; Shen, Shing-Chuan; Al-Suwayeh, Saleh A; Li, Yi-Ching; Fang, Jia-You

    2012-06-01

    While laser skin resurfacing is expected to result in reduced barrier function and increased risk of drug absorption, the extent of the increment has not yet been systematically investigated. We aimed to establish the skin permeation profiles of tetracycline and sunscreens after exposure to the erbium:yttrium-aluminum-garnet (Er:YAG) laser during postoperative periods. Physiological and histopathological examinations were carried out for 5 days after laser treatment on nude mice. Percutaneous absorption of the permeants was determined by an in vitro Franz cell. Ablation depths varied in reaching the stratum corneum (10 μm, 2.5 J/cm²) to approach the epidermis (25 μm, 6.25 J/cm²) and upper dermis (40 μm, 10 J/cm²). Reepithelialization evaluated by transepidermal water loss was complete within 2-4 days and depended on the ablation depth. Epidermal hyperplasia was observed in the 40-μm-treated group. The laser was sufficient to disrupt the skin barrier and allow the transport of the permeants into and across the skin. The laser fluence was found to play an important role in modulating skin absorption. A 25-μm ablation depth increased tetracycline flux 84-fold. A much smaller enhancement (3.3-fold) was detected for tetracycline accumulation within the skin. The laser with different fluences produced enhancement of oxybenzone skin deposition of 3.4-6.4-fold relative to the untreated group. No penetration across the skin was shown regardless of whether titanium dioxide was applied to intact or laser-treated skin. However, laser resurfacing increased the skin deposition of titanium dioxide from 46 to 109-188 ng/g. Tetracycline absorption had recovered to the level of intact skin after 5 days, while more time was required for oxybenzone absorption. The in vivo skin accumulation and plasma concentration revealed that the laser could increase tetracycline absorption 2-3-fold. The experimental results indicated that clinicians should be cautious when determining the

  11. Absorption of human skin and its detecting platform in the process of laser cosmetology

    Zhang, Yong-Lin; Ouyang, Li; Wang, Yang

    2000-10-01

    Because of the melanin, hemoglobin and water molecules, etc. contained, light absorption of human skin tissue changes with wavelength of light. This is the principle used in laser cosmetology for treating pigment diseases and vascular lesion diseases as well as skin decoration such as body tattooing, eyebrow tattooing, etc. The parameters of treatment used in laser cosmetology principally come from the research of the skin tissue optical characteristics of whites, and it is not suitable for the Oriental. The absorption spectrum of yellow race alive skin has been researched. The detecting platform for use in the measuring of vivi-tissue absorption spectrum has been developed which using opto-electronic nondestructive testing and virtual instrument techniques. The degree of pathological changes of skin can be detected by this platform also, thus the shortcoming of dosage selection in laser clinical treatments which have been decided only by naked eye observation and past experience of doctors can be solved.

  12. Skin aging modulates percutaneous drug absorption: the impact of ultraviolet irradiation and ovariectomy

    Hung, Chi-Feng; Chen, Wei-Yu; Aljuffali, Ibrahim A.; Lin, Yin-Ku; Shih, Hui-Chi; Fang, Jia-you

    2015-01-01

    Ultraviolet (UV) exposure and menopause are known as the inducers of damage to the skin structure. The combination of these two factors accelerates the skin aging process. In this study, we aimed to evaluate the influence of UV and ovariectomy (OVX) on the permeation of drugs through the skin. The role of tight junctions (TJs) and adherens junctions (AJs) in the cutaneous absorption of extremely lipophilic permeants and macromolecules was explored. The OVX nude mouse underwent bilateral ovary...

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

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

  14. Topically applied mesoridazine exhibits the strongest cutaneous analgesia and minimized skin disruption among tricyclic antidepressants: The skin absorption assessment.

    Liu, Kuo-Sheng; Chen, Yu-Wen; Aljuffali, Ibrahim A; Chang, Chia-Wen; Wang, Jhi-Joung; Fang, Jia-You

    2016-08-01

    Tricyclic antidepressants (TCAs) are found to have an analgesic action for relieving cutaneous pain associated with neuropathies. The aim of this study was to assess cutaneous absorption and analgesia of topically applied TCAs. Percutaneous delivery was investigated using nude mouse and pig skin models at both infinite and saturated doses. We evaluated the cutaneous analgesia in nude mice using the pinprick scores. Among five antidepressants tested in the in vitro experiment, mesoridazine, promazine and doxepin showed a superior total absorption percentage. The drug with the lowest total absorption percentage was found to be fluphenazine (dose or at saturated solubility. The follicular pathway was important for mesoridazine and promazine delivery. Mesoridazine showed stronger skin analgesia than the other TCAs although the in vivo skin absorption of mesoridazine (0.34nmol/mg) was less than that of promazine (0.80nmol/mg) and doxepin (0.74nmol/mg). Mesoridazine had a prolonged duration of pain relief (165min) compared to promazine (83min) and doxepin (17min). The skin irritation test demonstrated an evident barrier function deterioration and cutaneous erythema by promazine and doxepin treatment, whereas mesoridazine caused no obvious adverse effect by topical application for up to 7days. PMID:27260201

  15. Skin aging modulates percutaneous drug absorption: the impact of ultraviolet irradiation and ovariectomy.

    Hung, Chi-Feng; Chen, Wei-Yu; Aljuffali, Ibrahim A; Lin, Yin-Ku; Shih, Hui-Chi; Fang, Jia-You

    2015-01-01

    Ultraviolet (UV) exposure and menopause are known as the inducers of damage to the skin structure. The combination of these two factors accelerates the skin aging process. In this study, we aimed to evaluate the influence of UV and ovariectomy (OVX) on the permeation of drugs through the skin. The role of tight junctions (TJs) and adherens junctions (AJs) in the cutaneous absorption of extremely lipophilic permeants and macromolecules was explored. The OVX nude mouse underwent bilateral ovary removal. Both UVA and UVB were employed to irradiate the skin. The physiological and biochemical changes of the skin structure were examined with focus on transepidermal water loss (TEWL), skin color, immunohistochemistry, and mRNA levels of proteins. UVB and OVX increased TEWL, resulting in stratum corneum (SC) integrity disruption and dehydration. A hyperproliferative epidermis was produced by UVB. UVA caused a pale skin color tone due to keratinocyte apoptosis in the epidermis. E-cadherin and β-catenin showed a significant loss by both UVA and UVB. OVX downregulated the expression of filaggrin and involucrin. A further reduction was observed when UV and OVX were combined. The in vitro cutaneous absorption demonstrated that UV increased the skin permeation of tretinoin by about twofold. However, skin accumulation and flux of estradiol were not modified by photoaging. OVX basically revealed a negligible effect on altering the permeation of small permeants. OVX increased tretinoin uptake by the appendages from 1.36 to 3.52 μg/cm(2). A synergistic effect on tretinoin follicular uptake enhancement was observed for combined UV and OVX. However, the intervention of OVX to photoaged skin resulted in less macromolecule (dextran, molecular weight = 4 kDa) accumulation in the skin reservoir because of retarded partitioning into dry skin. The in vivo percutaneous absorption of lipophilic dye examined by confocal microscopy had indicated that the SC was still important to

  16. CHIRAL MULTIPHOTON ABSORPTION AND INVERSE SKIN EFFECT IN WLAN SYSTEMS

    Héctor Torres Silva; Mario Zamorano Lucero

    2005-01-01

    A model formed by chiral bioplasma with a set of macromolecules of DNA, which represents the human head inner structure, makes possible to analyze its behavior, when it is radiated by a microwave electromagnetic field from cellular phones and WLAN's at frequencies of 2.4 and 5.2 GHz is presented. The finite difference time domain, FDTD, numeric technique is used under multiphoton regime deduced from Maxwell equations. The numerical results of the Specific Absorption Rate, SAR, show the SAR be...

  17. Influence of different layers of skin on the percutaneous absorption of drugs with different lipophilicity

    LI Guo-feng; Kamiyama Fumio; LIU Li-jie; Yamamoto Akira; CHEN Jian-hai

    2002-01-01

    Objectives: To evaluate the barrier function of different skin layers in the process of percutaneous drug absorption. Methods: In vitro permeability via intact or stripped skin of 6 drugs (5-fluorouracil, theophylline, hydroquinone, barbital, isosorbide dinitrate and ketoprofen) with a wide span of lipophilicity were investigated in the patch dosage forms. Results: Characteristic parabolic relations was observed between the permeability (Kp, cm/h) of the drugs with different lipophilicity and their LogPc via either intact or stripped skin. However, due to the absence of the stratum corneum, increased Kp ratio for the tested drugs was proportional to their solubility in water other than their LogKp. When isopropyl myristate was used as absorption promoter of the drugs, the parabolic relationship no longer existed. For the intact skin, increase of Kp ratio of the drugs was enhanced resulting from IPM as drug's LogPc decreased. On the other hand, in the case of stripped skin, this enhancement was positively related to the solubility of the drugs in IPM. Conclusion: These data and methods present a novel approach to describe percutaneous drug absorption via damaged or diseased skin.

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

    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 3H-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 fluid

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

    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

  20. Photoacoustic study of percutaneous absorption of Carbopol and transdermic gels for topic use in skin

    Rossi, R. C. P.; de Paiva, R. F.; da Silva, M. D.; Barja, P. R.

    2008-01-01

    Topical medicine application has been used to treat a good number of pathological processes. Its efficacy is associated to an efficient penetration of the drug in the internal skin layers, promoting systemic effects and excluding the possibility of drug degradation by the digestive tract and hepatic elimination. This work analyzes the penetration kinetics of two soluble bases employed as vehicles for topic application: superficial gel (Carbopol 940) and transdermic (transdermal) gel. Analysis was performed with the photoacoustic technique, based upon the absorption of modulated light by a sample with subsequent conversion of the absorbed energy in heat, generating acoustic waves in the air layer adjacent to the sample. Each of the two vehicles was evaluated through in vivo (human skin) and in vitro application. Measurements in vitro employed samples of VitroSkin (synthetic material with properties similar to those of real skin, employed in the pharmaceutical industry research). Results show that the permeation was faster for the transdermal gel, both for in vivo and in vitro measurements, indicating that in vitro measurements may be utilized in qualitative, comparative permeation studies.

  1. Percutaneous absorption of selected hydrophilic compounds - an in vitro study on hairless mouse skin

    The objective of this study was to assess 1. the relationship between hydrophobicity and percutaneous absorption; and 2. the validity of the view that the skin can be diffusionally characterized as a simple lipoidal barrier. In the course of the permeability studies, a very slow but gradually accelerating permeation of the hydrophylic compounds was noted, a phenomenon that became very noticeable when the permeation profile was observed over longer periods e.g. 100 hours instead of the conventional 6-12 hours. The initial objective had to be expanded to search for the cause of the increasing permeability of these compounds. With urea reproduceable results were obtained in the preliminary study and therefore urea was chosen for this study. The percutaneous absorption studies of urea, thiourea, glycerol and glucose were executed by means of an in vitro method. The method included the use of a diffusion cell system where the skin was clamped between two diffusion cells. The ether-water partition coefficients of the hydrophylic compounds were determined by a simple radiotracer procedure. The radio-labelled compound was equilibrated between the ether and water phases and the sample taken from the phases were analysed by means of scintillation counting. The ether-water partition coefficients of hydrocortisone and its 21-n-alkyl esters were determined by means of a HPLC method. The significance of this study may be summarized as: 1. it showed errors of interpretation in previous work on the percutaneous absorption of hydrophilic compounds; 2. it confirmed the incompatibility of a simple lipid membrane mechanism with the behaviour of skin; and 3. it formed a basis for the systematic solution of the mechanism of increasing permeability as a function of time phenomenon, encountered with the studied hydrophilic compounds

  2. In vitro predictions of skin absorption of caffeine, testosterone, and benzoic acid: A multi-centre comparison study

    Sandt, J.J.M. van de; Burgsteden, J.A. van; Cage, S.; Carmichael, P.L.; Dick, I.; Kenyon, S.; Korinth, G.; Larese, F.; Limasset, J.C.; Maas, W.J.M.; Montomoli, L.; Nielsen, J.B.; Payan, J.-P.; Robinson, E.; Sartorelli, P.; Schaller, K.H.; Wilkinson, S.C.; Williams, F.M.

    2004-01-01

    To obtain better insight into the robustness of in vitro percutaneous absorption methodology, the intra- and inter-laboratory variation in this type of study was investigated in 10 European laboratories. To this purpose, the in vitro absorption of three compounds through human skin (9 laboratories)

  3. The risk of hydroquinone and sunscreen over-absorption via photodamaged skin is not greater in senescent skin as compared to young skin: nude mouse as an animal model.

    Hung, Chi-Feng; Chen, Wei-Yu; Aljuffali, Ibrahim A; Shih, Hui-Chi; Fang, Jia-You

    2014-08-25

    Intrinsic aging and photoaging modify skin structure and components, which subsequently change percutaneous absorption of topically applied permeants. The purpose of this study was to systematically evaluate drug/sunscreen permeation via young and senescent skin irradiated by ultraviolet (UV) light. Both young and senescent nude mice were subjected to UVA (10 J/cm(2)) and/or UVB radiation (175 mJ/cm(2)). Physiological parameters, immunohistology, and immunoblotting were employed to examine the aged skin. Hydroquinone and sunscreen permeation was determined by in vitro Franz cell. In vivo skin absorption was documented using a hydrophilic dye, rhodamine 123 (log P=-0.4), as a permeant. UVA exposure induced cyclooxygenase (COX)-2 and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) upregulation. Epidermal tight junction (TJ) were degraded by UVA. UVB increased transepidermal water loss (TEWL) from 13 to 24 g/m(2)/h. Hyperplasia and inflammation, but not loss of TJ, were also observed in UVB-treated skin. UVA+UVB- and UVA-irradiated skin demonstrated similar changes in histology and biomarkers. UVA+UVB or UVA exposure increased hydroquinone flux five-fold. A negligible alteration of hydroquinone permeation was shown with UVB exposure. Hydroquinone exhibited a lower penetration through senescent skin than young skin. Both UVA and UVB produced enhancement of oxybenzone flux and skin uptake. However, the amount of increase was less than that of hydroquinone delivery. Photoaging did not augment skin absorption of sunscreens with higher lipophilicity, including avobenzone and ZnO. Exposure to UVA generally increased follicular entrance of these permeants, which showed two- to three-fold greater follicular uptake compared to the untreated group. Photoaging had less impact on drug/sunscreen absorption with more lipophilic permeants. Percutaneous absorption did not increase in skin subjected to both intrinsic and extrinsic aging. PMID:24858384

  4. Occupational dermal exposure to nanoparticles and nano-enabled products: Part I-Factors affecting skin absorption.

    Larese Filon, Francesca; Bello, Dhimiter; Cherrie, John W; Sleeuwenhoek, Anne; Spaan, Suzanne; Brouwer, Derk H

    2016-08-01

    The paper reviews and critically assesses the evidence on the relevance of various skin uptake pathways for engineered nanoparticles, nano-objects, their agglomerates and aggregates (NOAA). It focuses especially in occupational settings, in the context of nanotoxicology, risk assessment, occupational medicine, medical/epidemiological surveillance efforts, and the development of relevant exposure assessment strategies. Skin uptake of nanoparticles is presented in the context of local and systemic health effects, especially contact dermatitis, skin barrier integrity, physico-chemical properties of NOAA, and predisposing risk factors, such as stratum corneum disruption due to occupational co-exposure to chemicals, and the presence of occupational skin diseases. Attention should be given to: (1) Metal NOAA, since the potential release of ions may induce local skin effects (e.g. irritation and contact dermatitis) and absorption of toxic or sensitizing metals; (2) NOAA with metal catalytic residue, since potential release of ions may also induce local skin effects and absorption of toxic metals; (3) rigid NOAA smaller than 45nm that can penetrate and permeate the skin; (4) non rigid or flexible NOAA, where due to their flexibility liposomes and micelles can penetrate and permeate the intact skin; (5) impaired skin condition of exposed workers. Furthermore, we outline possible situations where health surveillance could be appropriate where there is NOAA occupational skin exposures, e.g. when working with nanoparticles made of sensitizer metals, NOAA containing sensitizer impurities, and/or in occupations with a high prevalence of disrupted skin barrier integrity. The paper furthermore recommends a stepwise approach to evaluate risk related to NOAA to be applied in occupational exposure and risk assessment, and discusses implications related to health surveillance, labelling, and risk communication. PMID:27289581

  5. Simulation study of the thermal and the thermoelastic effects induced by pulsed laser absorption in human skin

    Kim, Jae-Young; Jang, Kyungmin; Yang, Seung-Jin; Baek, Jun-Hyeok; Park, Jong-Rak; Yeom, Dong-Il; Kim, Ji-Sun; Kim, Hyung-Sik; Jun, Jae-Hoon; Chung, Soon-Cheol

    2016-04-01

    We studied the thermal and the mechanical effects induced by pulsed laser absorption in human skin by numerically solving the heat-transfer and the thermoelastic wave equations. The simulation of the heat-transfer equation yielded the spatiotemporal distribution of the temperature increase in the skin, which was then used in the driving term of the thermoelastic wave equation. We compared our simulation results for the temperature increase and the skin displacements with the measured and numerical results, respectively. For the comparison, we used a recent report by Jun et al. [Sci. Rep. 5, 11016 (2015)], who measured in vivo skin temperature and performed numerical simulation of the thermoelastic wave equation using a simple assumption about the temporal evolution of the temperature distribution, and found their results to be in good agreement with our results. In addition, we obtained solutions for the stresses in the human skin and analyzed their dynamic behaviors in detail.

  6. Tensile and Water Absorption Properties of Biodegradable Composites Derived from Cassava Skin/ Polyvinyl Alcohol with Glycerol as Plasticizer

    Natural organic and abundant resources biopolymers received more attention due to their low cost, availability and degradability after usage. Cassava skin was used as natural fillers to the polyvinyl alcohol (PVA). Cassava skin/ poly vinyl alcohol blends were compounded using melt extrusion twin screw extruder and test samples were prepared using the compression method. Various ratios of cassava skin and glycerol were investigated to identify suitable composition based on the water absorption and tensile properties. The water absorption of the cassava skins/ PVA samples increased at higher composition of cassava skin due to their hydrophilic properties but decrease with glycerol content. The strength of the cassava skins/ PVA samples increased with the higher composition of cassava skin up to 70 wt % while gradually decreased with the increasing composition of glycerol. The Young modulus increased with glycerol content but decreased with fibre loading up to 70 wt %. Elongation at break decreased with fibre loading and glycerol up to 70 wt % and 30 phr, respectively. (author)

  7. The isolated perfused bovine udder as an in vitro model of percutaneous drug absorption. Skin viability and percutaneous absorption of dexamethasone, benzoyl peroxide, and etofenamate.

    Kietzmann, M; Löscher, W; Arens, D; Maass, P; Lubach, D

    1993-10-01

    Using udders from slaughtered cows as a new in vitro model of percutaneous drug absorption, the tissue viability and the percutaneous absorption of dexamethasone, benzoyl peroxide, and etofenamate were studied. The organ was perfused with gassed tyrode solution for up to 6 hr. As shown by measurement of glucose consumption, lactate production, lactate dehydrogenase activity, and pH in the perfusate, the tissue was viable over a 6-hr period. This was confirmed by a histological examination. Determination of the udder skin-fold thickness demonstrated that no edema developed within the perfusion period. A maximum skin penetration of dexamethasone was found after administration of dexamethasone dissolved in acetone with dimethyl sulfoxide, followed by ointment with salicylic acid, ointment without salicylic acid, and acetone solution. Experiments with benzoyl peroxide and etofenamate demonstrated that the perfused udder skin was capable of metabolizing drugs in vitro. In conclusion, the isolated perfused bovine udder is a new in vitro model, which maintains bovine udder skin with an isolated vasculature in a viable state. Using this in vitro model, we note it is possible to compare the dermal penetration, metabolism, and absorption of substances after topical administration of different drug formulations. PMID:8298184

  8. Relationship between concentration and exposed area on absorption and excretion of T-2 mycotoxin through rabbit skin

    T-2 mycotoxin is a severe skin irritant that can be lethal via the dermal route. A non-occlusive barrier model was developed to study the effects of concentration and size of the exposed area on the absorption rate of toxin in rabbit skin. The skin was shaved and, twenty-four hours later, varying concentrations of both [4H]-labeled and unlabeled T0 toxin in DMSO were painted on the surface. A barrier, consisting of a mesh-jacketed, half-inch foam pad with a hole in the center, was applied to the skin. In order to assess absorption, lethality and excretion were used as endpoints, and dosage, area, and concentration (μ g/cm2) were varied. At doses of 5, 10, and 15 mg/kg of T-2 toxin in DMSO applied to a 200 cm2 area, lethality was 0 of 2, 6 of 11, and 6 of 6 rabbits, respectively. This suggests a direct dose-response relationship. However, at a dose of 10 mg/kg applied in a 100 cm2 area, there were no deaths in 4 rabbits. This indicates a lower rate of absorption at this higher concentration. The percentage of [3H]-toxin excreted was higher at lower doses of T-2 toxin and reduced at higher concentrations. The authors conclude that area, dose, and concentration of applied toxin can influence the amount of T-2 toxin that is absorbed through the skin

  9. Skin dose rate conversion factors after contamination with radiopharmaceuticals: influence of contamination area, epidermal thickness and percutaneous absorption.

    Covens, P; Berus, D; Caveliers, V; Struelens, L; Vanhavere, F; Verellen, D

    2013-06-01

    Skin contamination with radiopharmaceuticals can occur during biomedical research and daily nuclear medicine practice as a result of accidental spills, after contact with bodily fluids of patients or by inattentively touching contaminated materials. Skin dose assessment should be carried out by repeated quantification to map the course of the contamination together with the use of appropriate skin dose rate conversion factors. Contamination is generally characterised by local spots on the palmar surface of the hand and complete decontamination is difficult as a result of percutaneous absorption. This specific issue requires special consideration as to the skin dose rate conversion factors as a measure for the absorbed dose rate to the basal layer of the epidermis. In this work we used Monte Carlo simulations to study the influence of the contamination area, the epidermal thickness and the percutaneous absorption on the absorbed skin dose rate conversion factors for a set of 39 medical radionuclides. The results show that the absorbed dose to the basal layer of the epidermis can differ by up to two orders of magnitude from the operational quantity Hp(0.07) when using an appropriate epidermal thickness in combination with the effect of percutaneous absorption. PMID:23519114

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

    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

  11. Modelling millimetre wave propagation and absorption in a high resolution skin model: the effect of sweat glands

    The aim of this work was to investigate the potential effect of sweat gland ducts (SGD) on specific absorption rate (SAR) and temperature distributions during mm-wave irradiation. High resolution electromagnetic and bio-heat transfer models of human skin with SGD were developed using a commercially available simulation software package (SEMCAD X(TM)). The skin model consisted of a 30 μm stratum corneum, 350 μm epidermis and papillary dermis (EPD) and 1000 μm dermis. Five SGD of 60 μm radius and 300 μm height were embedded linearly with 370 μm separation. A WR-10 waveguide positioned 20 μm from the skin surface and delivering 94 GHz electromagnetic radiation was included in the model. Saline conductivity was assigned inside SGD. SAR and temperatures were computed with and without SGD. Despite their small scale, SAR was significantly higher within SGD than in the EPD without SGD. Without SGD, SAR and temperature maxima were in the dermis near EPD. With SGD, SAR maximum was inside SGD while temperature maximum moved to the EPD/stratum-corneum junction. Since the EPD participates actively in perception, the effect of SGD should be taken into account in nociceptive studies involving mm-waves. This research represents a significant step towards higher spatial resolution numerical modelling of the skin and shows that microstructures can play a significant role in mm-wave absorption and induced temperature distributions.

  12. P-Glycoprotein (Abcb1) is involved in absorptive drug transport in skin

    Ito, Katsuaki; Nguyen, Hai Thien; Kato, Yukio; Wakayama, Tomohiko; Kubo, Yoshiyuki; Iseki, Shoichi; Tsuji, Akira

    2008-01-01

    The purpose of the present study was to investigate the role of P-glycoprotein (P-gp) in drug disposition in skin. The distribution of P-gp substrates (rhodamine 123 and itraconazole) to the skin after administration from the epidermal side was lower in P-gp gene knockout (mdr1a/1b-/-) mice than that in wild-type mice. Coadministration of propranolol, a P-gp inhibitor, decreased the distribution of itraconazole to the skin in wild-type mice, but not in mdr1a/1b-/- mice. These results suggest ...

  13. P-Glycoprotein (Abcb1) is involved in absorptive drug transport in skin

    Ito, Katsuaki; Nguyen, Hai Thien; Kato, Yukio; Wakayama, Tomohiko; Kubo, Yoshiyuki; Iseki, Shoichi; Tsuji, Akira

    2008-01-01

    The purpose of the present study was to investigate the role of P-glycoprotein (P-gp) in drug disposition in skin. The distribution of P-gp substrates (rhodamine 123 and itraconazole) to the skin after administration from the epidermal side was lower in P-gp gene knockout (mdr1a/1b-/- ) mice than that in wild-type mice. Coadministration of propranolol, a P-gp inhibitor, decreased the distribution of itraconazole to the skin in wild-type mice, but not in mdr1a/1b-/- mice. These results suggest...

  14. Characteristics of anomalous skin effect and evolution of power absorption regions in a cylindrical radio frequency inductively coupled plasma

    Ding, Z. F., E-mail: zfding@dlut.edu.cn [Key Laboratory of Materials Modification by Laser, Ion, and Electron Beams, Ministry of Education, School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116023 (China); Sun, B. [Key Laboratory of Materials Modification by Laser, Ion, and Electron Beams, Ministry of Education, School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116023 (China); Xi' an Aerospace Propulsion Institute, China Aerospace Science and Technology Corporation, Xi' an 710100 (China); Huo, W. G. [Key Laboratory of Materials Modification by Laser, Ion, and Electron Beams, Ministry of Education, School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116023 (China); School of Physics and Electronic Technology, Liaoning Normal University, Dalian 116029 (China)

    2015-06-15

    In a low-pressure radio-frequency (13.56 MHz), inductively coupled argon plasma generated by a normal cylindrical rf coil, electric field, current density, and absorbed power density is calculated from magnetic field measured with a phase-resolved magnetic probe. The anomalous skin effect (ASE) for the cylindrical rf coil is compared to those previously reported for the planar and re-entrant cylindrical rf coils. Physical reasons for our observed characteristics of ASE are presented. With the increasing discharge power, the size and the number of negative and positive power absorption regions evolve into several distinct patterns. For the low discharge power (at 156.9 W), there is one area of positive and one area of negative power absorption in the radial direction. For the medium discharge power (279 W–683.5 W), there are two areas of negative and two areas of positive power absorption. For the even higher discharge power (above 803.5 W), the number of areas is the same as that of the medium discharge power, but the size of the inner positive and negative power absorption areas is approximately doubled and halved, respectively, while the outer positive and negative power absorption areas slightly shrinks. The evolution of positive and negative power absorption regions is explained as a result of electron thermal diffusion and the energy conversion between rf current and electric field. The spatial decays of electric field and current density are also elucidated by linking them with the positive and negative power absorption pattern.

  15. Characteristics of anomalous skin effect and evolution of power absorption regions in a cylindrical radio frequency inductively coupled plasma

    In a low-pressure radio-frequency (13.56 MHz), inductively coupled argon plasma generated by a normal cylindrical rf coil, electric field, current density, and absorbed power density is calculated from magnetic field measured with a phase-resolved magnetic probe. The anomalous skin effect (ASE) for the cylindrical rf coil is compared to those previously reported for the planar and re-entrant cylindrical rf coils. Physical reasons for our observed characteristics of ASE are presented. With the increasing discharge power, the size and the number of negative and positive power absorption regions evolve into several distinct patterns. For the low discharge power (at 156.9 W), there is one area of positive and one area of negative power absorption in the radial direction. For the medium discharge power (279 W–683.5 W), there are two areas of negative and two areas of positive power absorption. For the even higher discharge power (above 803.5 W), the number of areas is the same as that of the medium discharge power, but the size of the inner positive and negative power absorption areas is approximately doubled and halved, respectively, while the outer positive and negative power absorption areas slightly shrinks. The evolution of positive and negative power absorption regions is explained as a result of electron thermal diffusion and the energy conversion between rf current and electric field. The spatial decays of electric field and current density are also elucidated by linking them with the positive and negative power absorption pattern

  16. Extrapolation of systemic bioavailability assessing skin absorption and epidermal and hepatic metabolism of aromatic amine hair dyes in vitro.

    Manwaring, John; Rothe, Helga; Obringer, Cindy; Foltz, David J; Baker, Timothy R; Troutman, John A; Hewitt, Nicola J; Goebel, Carsten

    2015-09-01

    Approaches to assess the role of absorption, metabolism and excretion of cosmetic ingredients that are based on the integration of different in vitro data are important for their safety assessment, specifically as it offers an opportunity to refine that safety assessment. In order to estimate systemic exposure (AUC) to aromatic amine hair dyes following typical product application conditions, skin penetration and epidermal and systemic metabolic conversion of the parent compound was assessed in human skin explants and human keratinocyte (HaCaT) and hepatocyte cultures. To estimate the amount of the aromatic amine that can reach the general circulation unchanged after passage through the skin the following toxicokinetically relevant parameters were applied: a) Michaelis-Menten kinetics to quantify the epidermal metabolism; b) the estimated keratinocyte cell abundance in the viable epidermis; c) the skin penetration rate; d) the calculated Mean Residence Time in the viable epidermis; e) the viable epidermis thickness and f) the skin permeability coefficient. In a next step, in vitro hepatocyte Km and Vmax values and whole liver mass and cell abundance were used to calculate the scaled intrinsic clearance, which was combined with liver blood flow and fraction of compound unbound in the blood to give hepatic clearance. The systemic exposure in the general circulation (AUC) was extrapolated using internal dose and hepatic clearance, and Cmax was extrapolated (conservative overestimation) using internal dose and volume of distribution, indicating that appropriate toxicokinetic information can be generated based solely on in vitro data. For the hair dye, p-phenylenediamine, these data were found to be in the same order of magnitude as those published for human volunteers. PMID:26028483

  17. Extrapolation of systemic bioavailability assessing skin absorption and epidermal and hepatic metabolism of aromatic amine hair dyes in vitro

    Approaches to assess the role of absorption, metabolism and excretion of cosmetic ingredients that are based on the integration of different in vitro data are important for their safety assessment, specifically as it offers an opportunity to refine that safety assessment. In order to estimate systemic exposure (AUC) to aromatic amine hair dyes following typical product application conditions, skin penetration and epidermal and systemic metabolic conversion of the parent compound was assessed in human skin explants and human keratinocyte (HaCaT) and hepatocyte cultures. To estimate the amount of the aromatic amine that can reach the general circulation unchanged after passage through the skin the following toxicokinetically relevant parameters were applied: a) Michaelis–Menten kinetics to quantify the epidermal metabolism; b) the estimated keratinocyte cell abundance in the viable epidermis; c) the skin penetration rate; d) the calculated Mean Residence Time in the viable epidermis; e) the viable epidermis thickness and f) the skin permeability coefficient. In a next step, in vitro hepatocyte Km and Vmax values and whole liver mass and cell abundance were used to calculate the scaled intrinsic clearance, which was combined with liver blood flow and fraction of compound unbound in the blood to give hepatic clearance. The systemic exposure in the general circulation (AUC) was extrapolated using internal dose and hepatic clearance, and Cmax was extrapolated (conservative overestimation) using internal dose and volume of distribution, indicating that appropriate toxicokinetic information can be generated based solely on in vitro data. For the hair dye, p-phenylenediamine, these data were found to be in the same order of magnitude as those published for human volunteers. - Highlights: • An entirely in silico/in vitro approach to predict in vivo exposure to dermally applied hair dyes • Skin penetration and epidermal conversion assessed in human skin explants and Ha

  18. Extrapolation of systemic bioavailability assessing skin absorption and epidermal and hepatic metabolism of aromatic amine hair dyes in vitro

    Manwaring, John, E-mail: manwaring.jd@pg.com [Procter & Gamble Inc., Mason Business Center, Mason, OH 45040 (United States); Rothe, Helga [Procter & Gamble Service GmbH, Sulzbacher Str. 40, 65823 Schwalbach am Taunus (Germany); Obringer, Cindy; Foltz, David J.; Baker, Timothy R.; Troutman, John A. [Procter & Gamble Inc., Mason Business Center, Mason, OH 45040 (United States); Hewitt, Nicola J. [SWS, Erzhausen (Germany); Goebel, Carsten [Procter & Gamble Service GmbH, Sulzbacher Str. 40, 65823 Schwalbach am Taunus (Germany)

    2015-09-01

    Approaches to assess the role of absorption, metabolism and excretion of cosmetic ingredients that are based on the integration of different in vitro data are important for their safety assessment, specifically as it offers an opportunity to refine that safety assessment. In order to estimate systemic exposure (AUC) to aromatic amine hair dyes following typical product application conditions, skin penetration and epidermal and systemic metabolic conversion of the parent compound was assessed in human skin explants and human keratinocyte (HaCaT) and hepatocyte cultures. To estimate the amount of the aromatic amine that can reach the general circulation unchanged after passage through the skin the following toxicokinetically relevant parameters were applied: a) Michaelis–Menten kinetics to quantify the epidermal metabolism; b) the estimated keratinocyte cell abundance in the viable epidermis; c) the skin penetration rate; d) the calculated Mean Residence Time in the viable epidermis; e) the viable epidermis thickness and f) the skin permeability coefficient. In a next step, in vitro hepatocyte K{sub m} and V{sub max} values and whole liver mass and cell abundance were used to calculate the scaled intrinsic clearance, which was combined with liver blood flow and fraction of compound unbound in the blood to give hepatic clearance. The systemic exposure in the general circulation (AUC) was extrapolated using internal dose and hepatic clearance, and C{sub max} was extrapolated (conservative overestimation) using internal dose and volume of distribution, indicating that appropriate toxicokinetic information can be generated based solely on in vitro data. For the hair dye, p-phenylenediamine, these data were found to be in the same order of magnitude as those published for human volunteers. - Highlights: • An entirely in silico/in vitro approach to predict in vivo exposure to dermally applied hair dyes • Skin penetration and epidermal conversion assessed in human

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

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

    2015-11-01

    Ethical and technical difficulties inherent to studies in human tissues are impeding assessment of the dermal bioavailability of brominated flame retardants (BFRs). This is further complicated by increasing restrictions on the use of animals in toxicity testing, and the uncertainties associated with extrapolating data from animal studies to humans due to inter-species variations. To overcome these difficulties, we evaluate 3D-human skin equivalents (3D-HSE) as a novel in vitro alternative to human and animal testing for assessment of dermal absorption of BFRs. The percutaneous penetration of hexabromocyclododecanes (HBCD) and tetrabromobisphenol-A (TBBP-A) through two commercially available 3D-HSE models was studied and compared to data obtained for human ex vivo skin according to a standard protocol. No statistically significant differences were observed between the results obtained using 3D-HSE and human ex vivo skin at two exposure levels. The absorbed dose was low (less than 7%) and was significantly correlated with log Kow of the tested BFR. Permeability coefficient values showed increasing dermal resistance to the penetration of γ-HBCD>β-HBCD>α-HBCD>TBBPA. The estimated long lag times (>30 min) suggests that frequent hand washing may reduce human exposure to HBCDs and TBBPA via dermal contact. PMID:26232142

  20. The efficiency of laser radiation absorption by hemoglobin and oxyhemoglobin in the skin blood vessels

    The results of the investigation of the efficiency of light absorption by oxyhemoglobin (HbO2) and deoxyhemoglobin (Hb) in cutaneous blood vessels in dependence on the radiation wavelength and the optical properties of the tissue is presented. Using the Kubelka - Munk optical model of the tissue the spectral dependence of the efficiency of laser interaction both on HbO2 and Hb of blood vessels at different depths of the tissue layer are calculated. The obtained results show that for blood vessels located in tissue up to a depth of 2500 μm the efficiency of laser radiation absorption follows the shape of the Q -absorption bands of HbO2 and Hb

  1. Absorption and metabolism of triclosan after application to the skin of B6C3F1 mice.

    Fang, Jia-Long; Vanlandingham, Michelle; Gamboa da Costa, Gonçalo; Beland, Frederick A

    2016-05-01

    Triclosan is used as an antimicrobial agent in personal care products, household items, medical devices, and clinical settings. Humans can receive lifelong exposures to triclosan; however, data on the toxicity and carcinogenicity after topical application are lacking. This study determined the absorption, distribution, metabolism, and excretion of triclosan after application to the skin of B6C3F1 mice. [(14) C(U)]triclosan (10 or 100 mg triclosan/kg body weight) was administered topically to mice in two separate experiments: a vehicle selection experiment using propylene glycol, ethanol, and a generic cosmetic cream, and a toxicokinetic experiment. Mice were killed up to 72 h after triclosan administration, and excreta and tissues were analyzed for radioactivity. Ethanol had the best properties of the vehicles evaluated. Maximum absorption was obtained at approximately 12 h after dosing. Radioactivity appeared in the excreta and in all tissues examined, with the highest levels in the gall bladder and the lowest levels in the brain. Triclosan was metabolized to triclosan sulfate, triclosan glucuronide, 2,4-dichlorophenol, and hydroxytriclosan. The metabolite profile was tissue-dependent and the predominant route of excretion was fecal. The AUC0-∞ and the Cmax of plasma and liver in females were greater than those in males. Slightly lower absorption was observed in mice with Elizabethan collars. © 2014 Wiley Periodicals, Inc. Environ Toxicol 31: 609-623, 2016. PMID:25410937

  2. A new Monte Carlo code for absorption simulation of laser-skin tissue interaction

    Afshan Shirkavand; Saeed Sarkar; Marjaneh Hejazi; Leila Ataie-Fashtami; Mohammad Reza Alinaghizadeh

    2007-01-01

    In laser clinical applications, the process of photon absorption and thermal energy diffusion in the target tissue and its surrounding tissue during laser irradiation are crucial. Such information allows the selection of proper operating parameters such as laser power, and exposure time for optimal therapeutic. The Monte Carlo method is a useful tool for studying laser-tissue interaction and simulation of energy absorption in tissue during laser irradiation. We use the principles of this technique and write a new code with MATLAB 6.5, and then validate it against Monte Carlo multi layer (MCML) code. The new code is proved to be with good accuracy. It can be used to calculate the total power bsorbed in the region of interest. This can be combined for heat modelling with other computerized programs.

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

    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

  4. Noninvasive determination of absorption coefficient and reduced scattering coefficient of human skin tissues in vivo with oblique-incidence reflectometry

    Ping Sun; Yu Wang; Xiaoli Mo; Jinghui Xie

    2008-01-01

    A spatial distribution of diffuse reflectance produced by obliquely incident light is not centered about the point of light entry. The value of shift in the center of diffuse reflectance is directly related to the absorption coefficient μa and the effective attenuation coefficient μeff. μa and the reduced scattering coefficient μ's of human skin tissues in vivo are measured by oblique-incidence reflectometry based on the two-source diffuse theory model. For ten Chinese volunteers aged 15-63 years, μa and μ's are noninvasively determined to be 0.029 - 0.075 and 0.52 - 0.97 mm-1, respectively.

  5. Human systemic exposure to a [14C]-para-phenylenediamine- containing oxidative hair dye and correlation with in vitro percutaneous absorption in human or pig skin

    Hueber-Becker, F.; Nohynek, G.J.; Meuling, W.J.A.; Benech-Kieffer, F.; Toutain, H.

    2004-01-01

    We investigated the absorption of a commercial [14C]-PPD- containing oxidative dark-shade hair dye in human volunteers as well as in vitro using human or pig ear skin. The hair of eight male volunteers was cut to a standard length, dyed, washed, dried, clipped and collected. Hair, washing water, mat

  6. Absorption of ethanol, acetone, benzene and 1,2-dichloroethane through human skin in vitro: a test of diffusion model predictions

    The overall goal of this research was to further develop and improve an existing skin diffusion model by experimentally confirming the predicted absorption rates of topically-applied volatile organic compounds (VOCs) based on their physicochemical properties, the skin surface temperature, and the wind velocity. In vitro human skin permeation of two hydrophilic solvents (acetone and ethanol) and two lipophilic solvents (benzene and 1,2-dichloroethane) was studied in Franz cells placed in a fume hood. Four doses of each 14C-radiolabed compound were tested — 5, 10, 20, and 40 μL cm−2, corresponding to specific doses ranging in mass from 5.0 to 63 mg cm−2. The maximum percentage of radiolabel absorbed into the receptor solutions for all test conditions was 0.3%. Although the absolute absorption of each solvent increased with dose, percentage absorption decreased. This decrease was consistent with the concept of a stratum corneum deposition region, which traps small amounts of solvent in the upper skin layers, decreasing the evaporation rate. The diffusion model satisfactorily described the cumulative absorption of ethanol; however, values for the other VOCs were underpredicted in a manner related to their ability to disrupt or solubilize skin lipids. In order to more closely describe the permeation data, significant increases in the stratum corneum/water partition coefficients, Ksc, and modest changes to the diffusion coefficients, Dsc, were required. The analysis provided strong evidence for both skin swelling and barrier disruption by VOCs, even by the minute amounts absorbed under these in vitro test conditions. - Highlights: • Human skin absorption of small doses of VOCs was measured in vitro in a fume hood. • The VOCs tested were ethanol, acetone, benzene and 1,2-dichloroethane. • Fraction of dose absorbed for all compounds at all doses tested was less than 0.3%. • The more aggressive VOCs absorbed at higher levels than diffusion model predictions

  7. Efficacy of skin wash on dermal absorption: an in vitro study on four model compounds of varying solubility

    Nielsen, Jesper Bo

    2010-01-01

    PURPOSE: Following dermal exposure to chemicals causing systemic toxicity, the general advice to avoid further systemic exposure is to wash the skin. The present study uses four model compounds (benzoic acid, glyphosat, caffeine, malathion) with varying size and solubility to substantiate this...... advice and quantify the effect of skin wash following 6 h dermal exposure on subsequent extent of skin penetration and deposition within the skin compartment. METHOD: Percutaneous penetration through human skin is studied in an in vitro model with static diffusion cells. RESULTS: The study demonstrates...... that percutaneous penetration continues after end of exposure due to the reservoir present in the skin. However, penetration rate will decrease significantly, and it is evident that simple hand-wash after end of exposure not only reduces the amount of residue present in the upper skin compartment but...

  8. Percutaneous Absorption of Salicylic Acid after Administration of Trolamine Salicylate Cream in Rats with Transcutol® and Eucalyptus Oil Pre-Treated Skin

    Paniz Sajjadi

    2013-08-01

    Full Text Available Purpose: This study was conducted to assess the effect of skin pre-treatment with Transcutol® and eucalyptus oil on systemic absorption of topical trolamine salicylate in rat. Methods: Pharmacokinetic parameters of salicylic acid following administration of trolamine salicylate on rat skin pre-treated with either Transcutol® or eucalyptus oil were determined using both non-compartmental and non-linear mixed effect modeling approaches and compared with those of control group. Results: Median (% of interquartile range/median of salicylic acid AUC0-8hr (ng/mL/hr values in Transcutol® or eucalyptus oil treated rats were 2522(139% and 58976(141%, respectively as compared to the 3023(327% of the control group. Skin pre-treatment with eucalyptus oil could significantly decrease extravascular volume of distribution (V/F and elimination rate constant (k of salicylic acid. Conclusion: Unlike Transcutol®, eucalyptus oil lead to enhanced transdermal absorption of trolamine salicylate through rat skin.

  9. Prediction of formulation effects on dermal absorption of topically applied ectoparasiticides dosed in vitro on canine and porcine skin using a mixture-adjusted quantitative structure permeability relationship.

    Riviere, J E; Brooks, J D; Collard, W T; Deng, J; de Rose, G; Mahabir, S P; Merritt, D A; Marchiondo, A A

    2014-10-01

    Topical application of ectoparasiticides for flea and tick control is a major focus for product development in animal health. The objective of this work was to develop a quantitative structure permeability relationship (QSPeR) model sensitive to formulation effects for predicting absorption and skin deposition of five topically applied drugs administered in six vehicle combinations to porcine and canine skin in vitro. Saturated solutions (20 μL) of (14) C-labeled demiditraz, fipronil, permethrin, imidacloprid, or sisapronil were administered in single or binary (50:50 v/v) combinations of water, ethanol, and transcutol (6 formulations, n = 4-5 replicates per treatment) nonoccluded to 0.64 cm(2) disks of dermatomed pig or dog skin mounted in flow-through diffusion cells. Perfusate flux over 24 h and skin deposition at termination were determined. Permeability (logKp), absorption, and penetration endpoints were modeled using a four-term Abrahams and Martin (hydrogen-bond donor acidity and basicity, dipolarity/polarizability, and excess molar refractivity) linear free energy QSPeR equation with a mixture factor added to compensate for formulation ingredient interactions. Goodness of fit was judged by r(2) , cross-validation coefficient, coefficients (q(2) s), and Williams Plot to visualize the applicability domain. Formulation composition was the primary determinant of permeation. Compounds generally penetrated dog skin better than porcine skin. The vast majority of permeated penetrant was deposited within the dosed skin relative to transdermal flux, an attribute for ectoparasiticides. The best QSPeR logKp model for pig skin permeation (r(2) = 0.86, q(2) s = 0.85) included log octanol/water partition coefficient as the mixture factor, while for dogs (r(2) = 0.91, q(2) s = 0.90), it was log water solubility. These studies clearly showed that the permeation of topical ectoparasiticides could be well predicted using QSPeR models that account for both the physical

  10. Percutaneous absorption of steroids: determination of in vitro permeability and tissue reservoir characteristics in human skin layers.

    Magnusson, B M; Cross, S E; Winckle, G; Roberts, M S

    2006-01-01

    The skin localization of steroids following topical application is largely unknown. We determined the distribution of five steroids in human skin using excised epidermal, dermal, and full-thickness membranes in vitro. There was no significant difference in steroid maximum flux through epidermal and full-thickness membranes, other than significantly lower fluxes for the most polar steroid, aldosterone. Hydrocortisone had the highest dermal diffusivity and dermal penetration, and the accumulation of hydrocortisone and corticosterone was higher than that of the other steroids. Slower penetration and higher accumulation in the viable epidermis of progesterone in full-thickness skin were consistent with dermal penetration limitation effects associated with high lipophilicity. PMID:16931901

  11. Two-dimensional transport analysis of transdermal drug absorption with a non-perfect sink boundary condition at the skin-capillary interface.

    Simon, Laurent; Ospina, Juan

    2013-07-01

    A transient percutaneous drug absorption model was solved in two dimensions. Clearance of the topically-applied pharmaceutical occured at the skin-capillary boundary. Timolol penetration profiles in the dermal tissue were produced revealing concentration gradients in the directions normal and parallel to the skin surface. Ninety-eight percent of the steady-state flux was reached after 85 h or four time constants. The analytical solution procedure agreed with published results. As the clearance rate increased relative to diffusion, the delivery rate and amount of drug absorbed into the bloodstream increased while the time to reach the equilibrium flux decreased. Researchers can apply the closed-form expressions to simulate the process, estimate key parameters and design devices that meet specific performance requirements. PMID:23624255

  12. Skin absorption and human exposure estimation of three widely discussed UV filters in sunscreens--In vitro study mimicking real-life consumer habits.

    Klimová, Z; Hojerová, J; Beránková, M

    2015-09-01

    Due to health concerns about safety, three UV-filters (Benzophenone-3, BP3, 10%; Ethylhexyl Methoxycinnamate, EHMC, 10%; Butyl Methoxydibenzoylmethane, BMDBM; 5%) were examined in vitro for absorption on full-thickness pig-ear skin, mimicking human in-use conditions. Kinetic profiles confirmed the rapid permeation of BP3; after the first hour of skin (frozen-stored) exposure to 2 mg/cm(2) (W/O sunscreen; recommended but unrealistic amount), about 0.5% of the applied dose passed into the receptor fluid. The absorption rate of filters was higher from W/O than from O/W emulsions. The fresh/frozen-stored skin permeability coefficient (0.83-0.54) for each UV filter was taken into account. Systemic Exposure Dosage of BP3, EHMC, BMDBM for humans as a consequence of (i) whole-body and (ii) face treatment with 0.5 mg/cm(2) of W/O sunscreen for 6-h skin exposure followed by washing and subsequent 18-h permeation (a realistic scenario) were estimated to be (i) 4744, 1032 and 1036 μg/kg-bw/day, and (ii) 153, 33 and 34 μg/kg-bw/day, respectively. From Margin of Safety for BP3, EHMC and BMDBM (i) 42, 485 and 192 as well as (ii) 1307; 15,151 and 5882, respectively, only the value of 42 (<100) for BP3 indicated a possible health risk. Escalation of a phobia towards all organic UV filters is undesirable. PMID:26151237

  13. 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.

    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 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. The in vitro: in vivo correlation supports the use of the flow-through diffusion cell system as a model for the prediction of percutaneous absorption

  14. Anti-HepG-2 Cell Properties of Rare Earth Tungstosilicic Polyoxometalates Containing 5-Fluorouracil%The Study of Absorption Efficiency and Restoring Effects of Collagen and Ascorbic Acid on Aged Skin by Fluorescence and Reflection Spectroscopy

    LIU Xia; WANG Shuai-shuai; FENG Chang-gen

    2012-01-01

    Collagen is one of the main structural proteins in human dermis. The lack and atrophy of collagen induces the appearance of wrinkles and beginning of aging. L-ascorbic acid has significant effects on skin-whitening and anti-oxidation, which helps keep skin beautiful and healthy, respectively. With auto-fluorescence, the amount of collagen is in proportion to the strength of its fluorescence spectrum. Therefore, a new method is proposed to determine the content of collagen and the health of skin through the analysis of fluorescence and reflection spectra. Compared with conventional chemical analysis, this method needs less time, and is much more noninvasive. Solutions of different concentration of external collagen and L-ascorbic acid were applied on healthy, spotted and wrinkled skin in this study. By the time dependence of fluorescence and reflection spectra, the effects of skin absorption and restoration of collagen and L-ascorbic acid were derived, respectively. The experiment shows that the collagen or L-ascorbic acid solution of adequate concentration is best for skin absorption. Admixed with suitable concentration of L-ascorbic acid, the collagen solution was well absorbed and results in effect of smoothing wrinkles; the effect of L-ascorbic acid to clear up the spots was also demonstrated. By scientific explorations shown above, the restoration effects of cosmetic materials were validated, and people's confusion and myth about skincare products were avoided. Consequently, this study helps advance cosmetic industry.

  15. Skin graft

    Skin transplant; Skin autografting; FTSG; STSG; Split thickness skin graft; Full thickness skin graft ... site. Most people who are having a skin graft have a split-thickness skin graft. This takes ...

  16. Skin Diseases: Skin Health and Skin Diseases

    ... threatening skin cancer. The "ABCD's" of what to watch for with the moles on your skin: Asymmetry : ... skin cancer has been increasing. Exposure to the sun is a major factor. In 2006, over 30 ...

  17. Aging Skin

    ... email address Submit Home > Healthy Aging > Wellness Healthy Aging Aging skin More information on aging skin When it ... treated early. Return to top More information on Aging skin Read more from womenshealth.gov Varicose Veins ...

  18. Skin Conditions

    Your skin is your body's largest organ. It covers and protects your body. Your skin Holds body fluids in, preventing dehydration Keeps harmful ... it Anything that irritates, clogs, or inflames your skin can cause symptoms such as redness, swelling, burning, ...

  19. [The stabilizing effect of enterosgel on the structural bases of membrane digestion and absorption in the small intestine in severe thermal skin burns].

    Pasechka, N V

    1996-01-01

    Enterosgel effect on morphofunctional indices of the small intestine has been ascertained in experiments on animals, histochemical, electron-microscopic and morphometric methods being used. Enterosorbent in the dose of 0.3 g/kg body weight was injected orally to the guinea-pigs for 14 days. The results of the investigations prove the severe burn traumas to result in sufficient structural changes in the small intestine wall which causes impairment of membranous digestion processes and absorption of nutrients. It is to be noted that the developing burn disease results in the increase of changes severity and reaches the highest values at the stage of septicotoxemia. The enterosorbent assessed positively affects morphofunctional values of the small intestine. The enterosorbent does not enhance conventional development of the pathologic process but considerably decreases its manifestation. The enterosgel promotes the improvement of membranous digestion and absorption in the small intestine, increasing alkaline phosphatase action and rising the number of endocellular vesicles in epitheliocytes having brush margins. PMID:9044818

  20. Study of surfactant-skin interactions by skin impedance measurements.

    Lu, Guojin; Moore, David J

    2012-02-01

    The stratum corneum (SC) plays a very critical physiological role as skin barrier in regulating water loss through the skin and protects the body from a wide range of physical and chemical exogenous insults. Surfactant-containing formulations can induce skin damage and irritation owing to surfactant absorption and penetration. It is generally accepted that reduction in skin barrier properties occurs only after surfactants have penetrated/permeated into the skin barrier. To mitigate the harshness of surfactant-based cleansing products, penetration/permeation of surfactants should be reduced. Skin impedance measurements have been taken in vitro on porcine skin using vertical Franz diffusion cells to investigate the impact of surfactants, temperature and pH on skin barrier integrity. These skin impedance results demonstrate excellent correlation with other published methods for assessing skin damage and irritation from different surfactant chemistry, concentration, pH, time of exposure and temperature. This study demonstrates that skin impedance can be utilized as a routine approach to screen surfactant-containing formulations for their propensity to compromise the skin barrier and hence likely lead to skin irritation. PMID:21923733

  1. Percutaneous absorption from soil.

    Andersen, Rosa Marie; Coman, Garrett; Blickenstaff, Nicholas R; Maibach, Howard I

    2014-01-01

    Abstract Some natural sites, as a result of contaminants emitted into the air and subsequently deposited in soil or accidental industrial release, have high levels of organic and non-organic chemicals in soil. In occupational and recreation settings, these could be potential sources of percutaneous exposure to humans. When investigating percutaneous absorption from soil - in vitro or vivo - soil load, particle size, layering, soil "age" time, along with the methods of performing the experiment and analyzing the results must be taken into consideration. Skin absorption from soil is generally reduced compared with uptake from water/acetone. However, the absorption of some compounds, e.g., pentachlorophenol, chlorodane and PCB 1254, are similar. Lipophilic compounds like dichlorodiphenyltrichloroethane, benzo[A]pyrene, and metals have the tendency to form reservoirs in skin. Thus, one should take caution in interpreting results directly from in vitro studies for risk assessment; in vivo validations are often required for the most relevant risk assessment. PMID:25205703

  2. SKIN CANCER

    Made Putri Hendaria

    2013-03-01

    Full Text Available Skin is an organ which protect the human body from the environment. It was build by milion cells. According to the changes in human lifestyle which tends to unhealthy life, increasing ultraviolet radiation, toxins, and genetics makes the cells who build the skin do the abnormal growth being cancer cells. Classification of skin cancer is according the most common three types, they are Basal Cell Carcinoma, Squamous Cell Carcinoma, and Malignant Melanoma. More than 3,5 milion skin cancer cases was happened in United States, which makes it become the most common cancer type in that country. Skin cancer diagnosis is build from anamnesis, physic examination about skin eufloressence, using dermoscopy, and histopatologic examination as the gold standar. Therapy for skin cancer is classified to surgery and non surgery therapy and its prognostic is depend to the types of the skin cancer itself.

  3. Skin Aging

    ... too. Sunlight is a major cause of skin aging. You can protect yourself by staying out of ... person has smoked. Many products claim to revitalize aging skin or reduce wrinkles, but the Food and ...

  4. Skin turgor

    ... up during a check. This can indicate severe dehydration that needs quick treatment. You have reduced skin turgor and are unable ... Urinalysis Intravenous fluids may be needed for severe ... treat other conditions that affect skin turgor and elasticity.

  5. Sagging Skin

    ... turkey neck,” this occurs as skin loses its elasticity and in cases where individuals have lost a ... technique or procedure is appropriate for my skin type? Did the doctor show me before-and-after ...

  6. Skin Dictionary

    ... resources Meet our partners Español Donate Diseases and treatments Acne and rosacea Bumps and growths Color problems Contagious skin diseases Cosmetic treatments Dry / sweaty skin Eczema / dermatitis Hair and scalp ...

  7. Skin Biopsy

    ... skin condition cannot be diagnosed by the patient's history and what the physician finds on examination alone. Confirming a clinical diagnosis may also be necessary prior to starting therapy. Skin biopsy types are as follows: Shave biopsies Punch biopsies ...

  8. Skin Cancer

    Skin cancer is the most common form of cancer in the United States. The two most common types ... face, neck, hands, and arms. Another type of skin cancer, melanoma, is more dangerous but less common. Anyone ...

  9. Skin Graft

    Ruka Shimizu; Kazuo Kishi

    2012-01-01

    Skin graft is one of the most indispensable techniques in plastic surgery and dermatology. Skin grafts are used in a variety of clinical situations, such as traumatic wounds, defects after oncologic resection, burn reconstruction, scar contracture release, congenital skin deficiencies, hair restoration, vitiligo, and nipple-areola reconstruction. Skin grafts are generally avoided in the management of more complex wounds. Conditions with deep spaces and exposed bones normally require the use o...

  10. SKIN CANCER

    Made Putri Hendaria; AAGN Asmarajaya; Sri Maliawan

    2013-01-01

    Skin is an organ which protect the human body from the environment. It was build by milion cells. According to the changes in human lifestyle which tends to unhealthy life, increasing ultraviolet radiation, toxins, and genetics makes the cells who build the skin do the abnormal growth being cancer cells. Classification of skin cancer is according the most common three types, they are Basal Cell Carcinoma, Squamous Cell Carcinoma, and Malignant Melanoma. More than 3,5 milion skin cancer cases ...

  11. Frog skin epithelium: electrolyte transport and chytridiomycosis

    Campbell, Craig R.; Voyles, Jamie; Cook, David I.; Dinudom, Anuwat

    2011-01-01

    One unique physiological characteristic of frogs is that their main route for intake of water is across the skin. In these animals, the skin acts in concert with the kidney and urinary bladder to maintain electrolyte homeostasis. Water absorption across the skin is driven by the osmotic gradient that develops as a consequence of solute transport. Our recent study demonstrated that chytridiomycosis, an infection of amphibian skin by the fungal pathogen, Batrachochytrium dendrobatidis, inhibits...

  12. Skin graft

    ... caused a large amount of skin loss Burns Cosmetic reasons or reconstructive surgeries where there has been skin damage or skin ... anesthesia are: Reactions to medicines Problems with breathing Risks for this surgery are: Bleeding Chronic pain (rarely) Infection Loss of ...

  13. Skin Aging

    Your skin changes as you age. You might notice wrinkles, age spots and dryness. Your skin also becomes thinner and loses fat, making it ... heal, too. Sunlight is a major cause of skin aging. You can protect yourself by staying out ...

  14. OCT系统中皮肤组织对光的漫反射和光能量吸收研究%Light Diffuse Reflection and Photon Energy Absorption of Skin in OCT System

    许世军; 贾潇

    2013-01-01

    According to the properties of light transmission in highly scattering medium ,radial diffuse reflection intensity of R(r) and longitudinal energy absorption intensity of A (z ) in the skin tissue are discussed .Stochastic motions of a bunch of photons in the highly scattering multi-layered skin were calculated and analyzed with Monte Carlo simulation based on the Matlab software .A series of R(r) and A (z) were obtained when the three typical kinds of parameters had different values by successively changing the parameters of the muscle layer .The calculation results show that ,with the rest of the parameters unchanged the larger the absorption coefficient μs is ,the greater the gradient of energy decay and the initial value of the A(z) in the muscle layer are and the smaller the R(r) is ,with the scattering coefficient μs increasing ,the initial value of A (z ) and the gradient of energy decay in the muscle layer become stronger ,and gradients of R(r) with different μs are almost the same .The greater the anisotropy factor g in the muscle layer is ,the smaller the initial value of A(z) is ,which means that the absorption of photons hardly happens ,and the smaller R(r) is .The influences of the three types of optical parameters on R(r) are similar and weak ,and every curve of R(r) presents similar and high gradient in the range with the radius being 0 .05 cm .%针对光在高散射介质中的传播特性,研究了皮肤组织中径向漫反射强度 R(r)和纵向能量吸收强度 A(z).利用Matlab对高散射随机皮肤组织中光子的随机运行进行蒙特卡罗模拟计算,依次改变肌肉层参数,得到三类典型参数在不同取值时的 R(r)与 A(z).模拟结果表明,在其余参数不变,当吸收系数μα越大时,肌肉层中的能量衰减梯度越大,能量吸收强度的初值也越大,同时漫反射强度越小;当散射系数μs 越大时,能量吸收强度的初值越大,衰减梯度也越

  15. Curious Skin

    Angel, G.

    2010-01-01

    Some of Henry Wellcome’s collection of tattoos on human skin will be on display in our forthcoming Skin exhibition. But how did the Parisian doctor from whom they were acquired come by his macabre collection of tattoos in the first place, and what did they mean to those whose skin they were on? It’s Gemma Angel‘s job to find out…

  16. Assessment of human skin decontamination from radioactive contamination

    A suitable and practicable means for assessing skin decontamination and percutaneous adsorption of radioactive skin contaminants is developed by comparing the streams of beta-particles and gamma-quanta characterizing the penetration and distribution of radioactive skin contaminants. The principal requirements which a preparation for human skin decontaminants should meet are: effectiveness of the preparation, minimal percutaneous absorption, broad activity spectrum on compounds and radionuclides, preservation of integrity of the treated skin and a simple method of use of the decontaminant. (author)

  17. Skin Cancer in Skin of Color

    Bradford, Porcia T.

    2009-01-01

    Skin cancers in skin of color often present atypically or with advanced stage in comparison to Caucasian patients. Health care providers must maintain a high index of suspicion when examining skin lesions in skin of color.

  18. Electrophysiological evidence for an ATP-gated ion channel in the principal cells of the frog skin epithelium

    Brodin, Birger; Nielsen, Robert

    P2X receptor, Na+ absorption, Short circuit current, Cell potential, Microelectrodes, Frog skin, Cytosolic Ca2+......P2X receptor, Na+ absorption, Short circuit current, Cell potential, Microelectrodes, Frog skin, Cytosolic Ca2+...

  19. Skin abscess

    ... infection (often staphylococcus) A minor wound or injury Boils Folliculitis (infection in a hair follicle) A skin ... Elsevier Churchill Livingstone; 2009:chap 90. Read More Boils Endocarditis Folliculitis MRSA Osteomyelitis Update Date 11/12/ ...

  20. Skin Pigment

    ... This Article Medical Dictionary Also of Interest (Quiz) Vitiligo (Video) Hives Additional Content Medical News Overview of ... Version Pigment Disorders Overview of Skin Pigment Albinism Vitiligo Hyperpigmentation Melasma Melanin is the brown pigment that ...

  1. Skin color - patchy

    Patchy skin color is areas where the skin color is irregular. Mottling or mottled skin refers to blood vessel changes in ... in the skin cells that gives skin its color Growth of bacteria or other organisms on the ...

  2. Skin Cancer Screening

    ... Genetics of Skin Cancer Skin Cancer Screening Research Skin Cancer Screening (PDQ®)–Patient Version What is screening? Go ... These are called diagnostic tests . General Information About Skin Cancer Key Points Skin cancer is a disease in ...

  3. Skin Health and Skin Diseases

    ... watch for with the moles on your skin: Asymmetry : the shape of one half does not match ... Number 4 Pages 22 - 25 MedlinePlus | Subscribe | Magazine Information | Contact Us | Viewers & Players Friends of the National ...

  4. Absorption studies

    Absorption studies were once quite popular but hardly anyone does them these days. It is easier to estimate the blood level of the nutrient directly by radioimmunoassay (RIA). However, the information obtained by estimating the blood levels of the nutrients is not the same that can be obtained from the absorption studies. Absorption studies are primarily done to find out whether some of the essential nutrients are absorbed from the gut or not and if they are absorbed, to determine how much is being absorbed. In the advanced countries, these tests were mostly done to detect pernicious anaemia where vitamin B12 is not absorbed because of the lack of the intrinsic factor in the stomach. In the tropical countries, ''malabsorption syndrome'' is quire common. In this condition, several nutrients like fat, folic acid and vitamin B12 are not absorbed. It is possible to study absorption of these nutrients by radioisotopic absorption studies

  5. Lead and the skin

    Allen, B.R.; Moore, M.R.; Hunter, J.A.A.

    1975-01-01

    The increasing use of lead will continue to give rise to problems of toxicity. Protective measures have resulted in florid lead poisoning becoming rare. Attention has recently turned to the possibility of prolonged exposure to low doses of lead causing morbidity in the absence of the classical clinical features of poisoning. Lead is absorbed mostly through the lungs and gastrointestinal tract. Some is also absorbed through the skin but with inorganic compounds the amount is small. Shortly after the most widely used compound, tetraethyl lead, was first manufactured, cases of toxicity began to occur. Manufacture was forbidden until plant design produced greater safety. Significant absorption can occur through the skin. The hazard to those handling leaded gasoline in a normal manner is probably small, mainly because 95 percent of a dose applied to the open skin surface evaporates. Hair has been used as a biopsy material to assess lead exposure. The biological effects of lead poisoning are discussed, including the synergistic effects of lead and agents provoking porphyria.

  6. Skin Care and Aging

    ... page please turn Javascript on. Skin Care and Aging How Aging Affects Skin Your skin changes with age. It ... if they bother you. See additional resources on aging skin, including information on treatment options, specific conditions, ...

  7. Skin Care and Aging

    ... Home » Skin Care and Aging Heath and Aging Skin Care and Aging Dry Skin and Itching Bruises Wrinkles Age Spots ... doctor. For More Information About Skin Care and Aging American Academy of Dermatology 1-866-503-7546 ( ...

  8. Allergy testing - skin

    Patch tests - allergy; Scratch tests - allergy; Skin tests - allergy; RAST test ... There are three common methods of allergy skin testing. The skin prick test involves: Placing a small amount of substances that may be causing your symptoms on the skin, ...

  9. Skin Pigmentation Disorders

    Pigmentation means coloring. Skin pigmentation disorders affect the color of your skin. Your skin gets its color from a pigment called melanin. Special cells in the skin make melanin. When these cells become damaged or ...

  10. Skin aging:

    Puizina-Ivić, Neira

    2008-01-01

    There are two main processes that induce skin aging: intrinsic and extrinsic. A stochastic process that implies random cell damage as a result of mutations during metabolic processes due to the production of free radicals is also implicated. Extrinsic aging is caused by environmental factors such as sun exposure, air pollution, smoking, alcohol abuse, and poor nutrition. Intrinsicaging reflects the genetic background and depends on time. Various expressions of intrinsic aging include smooth, ...

  11. Skin Substitutes

    Zavan, Barbara; Vindigni, Vincenzo; Cortivo, Roberta; Abatangelo, Giovanni

    2010-01-01

    The many studies conducted so far reveal that Tissue Engineering of the skin is only at the beginning of its use in human applications. Burns patients were the first targets for such tissue substitutes, then chronic diseases, such as venous ulcers, have followed. The more experience is gained from the surgeon, the more feedback for the basic scientist to improve the product and to broaden clinical indications. Nowadays, progress in cell culture and biomedical material technologies have added ...

  12. Cutaneous skin tag

    Skin tag; Acrochordon; Fibroepithelial polyp ... have diabetes. They are thought to occur from skin rubbing against skin. ... The tag sticks out of the skin and may have a short, narrow stalk connecting it to the surface of the skin. Some skin tags are as long as ...

  13. Meloxicam transdermal delivery: effect of eutectic point on the rate and extent of skin permeation

    Soliman Mohammadi-Samani

    2014-02-01

    Conclusion: This study set out to determine that thymol plays as a skin permeation enhancer and increases the meloxicam skin absorption and this enhancement is significant at the eutectic point of drug-enhancer mixture.

  14. Skin to skin care:heat balance.

    Karlsson, H.

    1996-01-01

    Skin to skin care has been practised in primitive and high technology cultures for body temperature preservation in neonates. Regional skin temperature and heat flow was measured in moderately hypothermic term neonates to quantitate the heat transfer occurring during one hour of skin to skin care. Nine healthy newborns with a mean rectal temperature of 36.3 degrees C were placed skin to skin on their mothers' chests. The mean (SD) rectal temperature increased by 0.7 (0.4) degrees C to 37.0 de...

  15. Anyone Can Get Skin Cancer

    ... Cancer Skin Cancer Screening Research Anyone Can Get Skin Cancer Order the free Anyone Can Get Skin Cancer ... true that only people with light skin get skin cancer? No. Anyone can get skin cancer. It's more ...

  16. 两种盐酸特比萘芬乳膏经离体小型猪皮渗透吸收的比较研究%The Comparative Studies on Percutaneous Absorption for Two Kind of Terbinafine Hydrochloride Cream by in vitro Tibet Minipig's Skin

    罗荣; 周临; 陈卫

    2013-01-01

    目的 比较研究两家企业生产的盐酸特比萘芬乳膏对离体小型猪皮的透皮吸收性能.方法 采用改良的Franz扩散池,离体小型猪皮片涂药后不同时间采样,用高效液相色谱法测定接收液和皮片中盐酸特比萘芬的浓度.结果 盐酸特比萘芬乳膏透皮释放量很低,在80%乙醇生理盐水释放液中,某企业生产的乳膏产品和中美天津史克制药有限公司生产的乳膏产品在48h时累积透皮渗透量分别为55.23 mg/cm2和63.33 mg/cm2,48 h的累积透过率分别为:1.09%、1.19%.结论 两家企业生产的乳膏产品在相同渗透介质下,对于离体小型猪皮的透皮无显著性差别,二者透皮情况相当.盐酸特比萘芬乳膏主成分大部分滞留在皮肤上,只有极少数透过皮肤屏障,有利于其发挥局部治疗作用.%Objective To study the percutaneous absorption of terbinafine hydrochloride cream through in vitro Tibet minipig's skins, and compare the penetration absorption of domestic certain enterprise product with GlaxoSmithKline china product. Methods Using the modified Franz diffusion cell, samples were collected at different time after the drug was applied. The concentration of terbinafine hydrochloride in the samples was measured by HPLC. Results The penetration release quantities of terbinafine hydrochloride across Tibet minipig skins in 80% ethanol saline solution in 48h were very low, only 63.33 mg · cm2 for GlaxoSmithKline China product, and 55.23 mg · cm2 for certain enterprise product, and the percolation rate were 1.19% and 1.09%, respectively. Conclusion The percutaneous absorption of terbinafine hydrochloride cream was very low between two products without significant difference. The penetration absorbency through Tibet minipig skins of certain enterprise cream is similar to GlaxoSmithKline china product. The most of the main components of terbinafine hydrochloride cream remain in the surface of the skins, only a few through the

  17. Skin color - patchy

    ... page: //medlineplus.gov/ency/article/003224.htm Skin color - patchy To use the sharing features on this page, please enable JavaScript. Patchy skin color is areas where the skin color is irregular. ...

  18. Skin Cancer Foundation

    ... Fundraising Event | About Us | Store The Skin Cancer Foundation The Skin Cancer Foundation is the only international organization devoted solely to ... About Us Contact Us © 2016 The Skin Cancer Foundation | 149 Madison Avenue Suite 901 New York, NY ...

  19. Learning about Skin Cancer

    ... Why Deadly Skin Cancers Spread 2000 News Release Learning About Skin Cancer What are the most common ... skin surface. When a melanoma becomes thick and deep, the disease often spreads to other parts of ...

  20. Skin care and incontinence

    Incontinence - skin care ... or bowels (called incontinence) are at risk of skin problems around the buttocks, hips, genitals, and the ... rectum (perineum). Excess moisture in these areas makes skin problems such as redness, peeling, irritation, and yeast ...

  1. Transdermic absorption of Melagenina II

    The transdermic absorption of Melagenina II (MII) was evaluated. MII was a labelled with 125I by the yodogen method and purified by column chromatography with Sephadex LH-20 in ethanol: water (7:3). In vitro absorption of (125I) - MII thought human skin was carried out in Keshary-Chien modified diffusion cells. Tape stripping method was applied after 24 hours to evaluate the accumulated activity in dermis and epidermis. In vivo assays were performed in Sprague Dawley rats to analyze absorption of MII until 24 hours after a single application and for five days a low penetrability of the drug while in vivo there were not found blood levels significantly greater than zero , nevertheless and important amount of radioactivity was found in feces and urine. The activity was concentrated mainly in the application site in both models

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

    There is a growing interest on nanoparticle safety for topical use. The benefits of nanoparticles have been shown in several scientific fields, but little is known about their potential to penetrate the skin. This study aims at evaluating in vitro skin penetration of silver nanoparticles. Experiments were performed using the Franz diffusion cell method with intact and damaged human skin. Physiological solution was used as receiving phase and 70 μg/cm2 of silver nanoparticles coated with polyvinylpirrolidone dispersed in synthetic sweat were applied as donor phase to the outer surface of the skin for 24 h. The receptor fluid measurements were performed by electro thermal atomic absorption spectroscopy (ETAAS). Human skin penetration was also determined by using transmission electron microscope (TEM) to verify the location of silver nanoparticles in exposed membranes. Median silver concentrations of 0.46 ng cm-2 (range -2 (range 0.43-11.6) were found in the receiving solutions of cells where the nanoparticles solution was applied on intact skin (eight cells) and on damaged skin (eight cells), respectively. Twenty-four hours silver flux permeation in damaged skin was 0.62 ± 0.2 ng cm-2 with a lag time <1 h. Our experimental data showed that silver nanoparticles absorption through intact and damaged skin was very low but detectable, and that in case of damaged skin it was possible an increasing permeation of silver applied as nanoparticles. Moreover, silver nanoparticles could be detected in the stratum corneum and the outermost surface of the epidermis by electron microscopy. We demonstrated for the first time that silver applied as nanoparticles coated with polyvinylpirrolidone is able to permeate the damaged skin in an in vitro diffusion cell system

  3. Expression of human solute carrier family transporters in skin: possible contributor to drug-induced skin disorders

    Ryoichi Fujiwara; Saya Takenaka; Mitsuhiro Hashimoto; Tomoya Narawa; Tomoo Itoh

    2014-01-01

    Solute carrier (SLC) transporters play important roles in absorption and disposition of drugs in cells; however, the expression pattern of human SLC transporters in the skin has not been determined. In the present study, the expression patterns of 28 human SLC transporters were determined in the human skin. Most of the SLC transporter family members were either highly or moderately expressed in the liver, while their expression was limited in the skin and small intestine. Treatment of human k...

  4. Stiff skin syndrome.

    Geng, S; Lei, X; Toyohara, J P; Zhan, P; Wang, J; Tan, S

    2006-07-01

    Stiff skin syndrome is a rare disorder characterized by pronounced skin induration, mild hypertrichosis and limited joint mobility, predominantly on the buttocks and thighs. Many heterogeneous cases have been reported under the name of stiff skin syndrome. We present a case of stiff skin syndrome from China, the diagnosis based on the patient's typical clinical and histopathological features. PMID:16836505

  5. Skin Cancer Prevention

    ... the lower part of the epidermis. They make melanin , the pigment that gives skin its natural color. When skin is exposed to the sun, melanocytes make more pigment, causing the skin to tan, or darken. The dermis contains blood and lymph vessels , hair follicles , and glands . Enlarge Anatomy of the skin, ...

  6. Dry Skin (Xerosis)

    ... resources Meet our partners Español Donate Diseases and treatments Acne and rosacea Bumps and growths Color problems Contagious skin diseases ... Dry skin public SPOT Skin Cancer™ Diseases and treatments Acne and rosacea Bumps and growths Color problems Contagious skin diseases ...

  7. Estrogens and aging skin

    Thornton, M. Julie

    2013-01-01

    Estrogen deficiency following menopause results in atrophic skin changes and acceleration of skin aging. Estrogens significantly modulate skin physiology, targeting keratinocytes, fibroblasts, melanocytes, hair follicles and sebaceous glands, and improve angiogenesis, wound healing and immune responses. Estrogen insufficiency decreases defense against oxidative stress; skin becomes thinner with less collagen, decreased elasticity, increased wrinkling, increased dryness and reduced vascularity...

  8. Risks of Skin Cancer Screening

    ... Genetics of Skin Cancer Skin Cancer Screening Research Skin Cancer Screening (PDQ®)–Patient Version What is screening? Go ... These are called diagnostic tests . General Information About Skin Cancer Key Points Skin cancer is a disease in ...

  9. Effect of microplasma irradiation on skin barrier function

    Shimizu, Kazuo; Tran, An N.; Blajan, Marius

    2016-07-01

    In this paper, we introduce the feasibility of atmospheric-pressure argon microplasma irradiation (AAMI) to promote percutaneous absorption. A hairless Yucatan micropig skin was used for this ex vivo study. After AAMI, the disturbance in the stratum corneum (SC) lipids was observed using attenuated total reflectance-Fourier transform infrared spectroscopy. Also, an increase in transepidermal water loss and no physical damage on pig skins were confirmed by microscopic observation. These results of AAMI were compared with those of a plasma jet irradiation (PJI) and a tape stripping test (TST) leading to the conclusion that AAMI reduces the barrier function of the skin and could also enhance the transdermal absorption of drugs.

  10. A diffusion-diffusion model for percutaneous drug absorption.

    Kubota, K; Ishizaki, T

    1986-08-01

    Several theories describing percutaneous drug absorption have been proposed, incorporating the mathematical solutions of differential equations describing percutaneous drug absorption processes where the vehicle and skin are regarded as simple diffusion membranes. By a solution derived from Laplace transforms, the mean residence time MRT and the variance of the residence time VRT in the vehicle are expressed as simple elementary functions of the following five pharmacokinetic parameters characterizing the percutaneous drug absorption: kd, which is defined as the normalized diffusion coefficient of the skin, kc, which is defined as the normalized skin-capillary boundary clearance, the apparent length of diffusion of the skin 1d, the effective length of the vehicle lv, and the diffusion coefficient of the vehicle Dv. All five parameters can be obtained by the methods proposed here. Results of numerical computation indicate that: concentration-distance curves in the vehicle and skin approximate two curves which are simply expressed using trigonometric functions when sufficient time elapses after an ointment application; the most suitable condition for the assumption that the concentration of a drug in the uppermost epidermis can be considered unchanged is the case where the partition coefficient between vehicle and skin is small, and the constancy of drug concentration is even more valid when the effective length of the vehicle is large; and the amount of a drug in the vehicle or skin and the flow rate of the drug from vehicle into skin or from skin into blood becomes linear on a semilogarithmic scale, and the slopes of those lines are small when Dv is small, when the partition coefficient between vehicle and skin is small, when lv is large, or when kc is small. A simple simulation method is also proposed using a biexponential for the concentration-time curve for the skin near the skin-capillary boundary, that is, the flow rate-time curve for drug passing from skin

  11. 17种生物碱类药物体外经皮渗透行为的实验研究%To Study in Vitro Percutaneous Absorption of 17 Alkaloidal Drugs with Mouse Skin

    许景峰

    2001-01-01

    目的研究生物碱类药物经皮吸收系数与药物油/水分配系数的关系。方法采用Ficks扩散装置测定17种生物碱类药物在小鼠皮的透皮速率,并与含2%促渗剂氮酮比较。结果生物碱类药物的经皮渗透系数(kp)与药物油/水分配系数(logk)的关系式为:logkp=7.35×10-2-3.079×10-2logk-8.11(logk)2;logkp(2%Azo)=8.32×10-2-2.68×10-2logk-5.27(logk)2;结论 17种药物的油/水分配系数平均最佳值为2.83,含2%氮酮后的其平均最佳值为3.17。%Aim To study the relationship between permeability coefficient and oil/water partition coefficient of 17 alkaloidal drugs.Methods The percutaneous absorption speed of 17 alkaloidal drugs were studied in mouse with improved Fick's diffusing device.Results The relationship between permeability coefficient (kp) and oil/water partition coefficient (logk) of 17 alkaloidal drugs or drugs containing 2% Azone can be described as following equations.logkp=7.35×10-2-3.079×10-2logk-8.11(logk)2;logkp(2%Azo)=8.32×10-2-2.68×10-2logk-5.27(logk)2,respectively.Conclusion ko/w and ko/w(2%Azo) was 2.83 and 3.17 respectively.

  12. An improved model for studies on transdermal drug absorption in-vivo in rats

    Vollmer, U.; Muller, B.W.; Wilffert, B.; Peters, Thies

    1993-01-01

    In rats, transdermal drug absorption can be studied under physiological conditions cannulating the peripheral skin vein, draining the area of the skin which is used for drug application, and collecting the blood. This method leads to decreased blood volume, which causes a reduction in skin blood flo

  13. An improved model for studies on transdermal drug absorption invivo in rats

    VOLLMER, U; MULLER, BW; WILFFERT, B; Peters, Thies

    1993-01-01

    In rats, transdermal drug absorption can be studied under physiological conditions by cannulating the peripheral skin vein, draining the area of the skin which is used for drug application, and collecting the blood. This method leads to decreased blood volume, which causes a reduction in skin blood

  14. Skin cancer and solar UV radiation.

    de Gruijl, F R

    1999-12-01

    Ultraviolet (UV) radiation in sunlight is the most prominent and ubiquitous physical carcinogen in our natural environment. It is highly genotoxic but does not penetrate the body any deeper than the skin. Like all organisms regularly exposed to sunlight, the human skin is extremely well adapted to continuous UV stress. Well-pigmented skin is clearly better protected than white Caucasian skin. The sun-seeking habits of white Caucasians in developed countries are likely to have contributed strongly to the increase in skin cancer observed over the last century. Skin cancer is by far the most common type of cancer in the U.S.A. and Australia, which appears to be the result of an 'unnatural displacement' of people with sun-sensitive skin to sub-tropical regions. Although campaigns have been successful in informing people about the risks of sun exposure, general attitudes and behaviour do not yet appear to have changed to the extent that trends in skin cancer morbidity and the corresponding burden on public healthcare will be reversed. The relationship between skin cancer and regular sun exposure was suspected by physicians in the late 19th century, and subsequently substantiated in animal experiments in the early part of the 20th century. UV radiation was found to be highly genotoxic, and DNA repair proved to be crucial in fending off detrimental effects such as mutagenesis and cell death. In fact, around 1940 it was shown that the wavelength dependence of mutagenicity paralleled the UV absorption by DNA. In the 1970s research on UV carcinogenesis received a new impetus from the arising concern about a possible future depletion of the stratospheric ozone layer: the resulting increases in ambient UV loads were expected to raise skin cancer incidences. Epidemiological studies in the last decades of the 20th century have greatly refined our knowledge on the aetiology of skin cancers. Analyses of gene mutations in skin carcinomas have identified UV radiation as the cause

  15. Effects of solvent on percutaneous absorption of nonvolatile lipophilic solute.

    Intarakumhaeng, Rattikorn; Li, S Kevin

    2014-12-10

    Understanding the effects of solvents upon percutaneous absorption can improve drug delivery across skin and allow better risk assessment of toxic compound exposure. The objective of the present study was to examine the effects of solvents upon the deposition of a moderately lipophilic solute at a low dose in the stratum corneum (SC) that could influence skin absorption of the solute after topical application. Skin permeation experiments were performed using Franz diffusion cells and human epidermal membrane (HEM). Radiolabeled corticosterone ((3)H-CS) was the model permeant. The solvents used had different evaporation and skin penetration properties that were expected to impact skin deposition of CS and its absorption across skin. The results show no correlation between the rate of absorption of the permeant and the rate of solvent evaporation/penetration with ethanol, hexane, isopropanol, and butanol as the solvent; all of these solvents have fast evaporation rates (complete evaporation in water, propylene glycol, and polyethylene glycol 400, that a relationship between permeant absorption and the rate of solvent evaporation was observed. PMID:25261711

  16. Percutaneous absorption of triclocarban in rat and man.

    Howes, D; Black, J G

    1976-06-01

    The route and rate of excretion by rats of the germicide (1 4 C) Triclocarban formerly called trichlorocarbanilide, given by parenteral injection has been investigated. Blood levels based on radioactivity and by chemical determination after parenteral injection have been compared with those obtained after topical application of (1 4 C) Triclocarban in soaps and in dimethylformamide (DMF) through occluded rat skin has been studied. Other soaps and a hand cleanser containing (1 4 C) Triclocarban have been applied to rat skin without occlusion and the effects of duration of contact, concentration and the use of a solubilizer have been investigated. In humans, absorption of Triclocarban through skin after bathing daily for 28 days has been investigated by chemical analysis of blood and urine. The data show that elimination by the rat is rapid and complete principally via the faeces. Blood levels after parenteral injection are low and comparison of the radioactivity and chemical determinations suggest rapid metabolism of the Triclocarban. After application to the skin, blood levels based on 1 4 C are very low. Absorption of (1 4 C) Triclocarban through occluded rat skin was greater from DMF than from soaps. With non-occluded rat skin, absorption from soaps was less and was dependent on concentration but independent of duration of contact. The use of a solubilizer did not increase absorption through skin. No measurable Triclocarban (less than 25 ppb) was present in blood and urine samples of volunteers during or shortly after a 28-day intensive bathing regimen. PMID:941165

  17. Allergic Skin Conditions

    ... can trigger eczema, especially in young children. Skin staph infections can cause flare-ups in children as well. ... oral corticosteroids are also prescribed. If a skin staph infection is suspected to be a trigger for an ...

  18. Examine Your Skin

    Full Text Available ... Suggestions Examine Your Skin Newly Diagnosed? Understanding Your Pathology Biopsy: The First Step Sentinel Node Biopsy Melanoma ... Suggestions Examine Your Skin Newly Diagnosed? Understanding Your Pathology Biopsy: The First Step Sentinel Node Biopsy Melanoma ...

  19. Squamous cell skin cancer

    ... earliest form of squamous cell cancer is called Bowen disease (or squamous cell carcinoma in situ). This type ... cancer; Squamous cell carcinoma of the skin Images Bowen's disease on the hand Keratoacanthoma Keratoacanthoma Skin cancer, squamous ...

  20. Skin lesion KOH exam

    ... KOH exam is a test to diagnose a fungal infection of the skin . How the Test is Performed ... Performed This test is done to diagnose a fungal infection of the skin. Normal Results No fungus is ...

  1. Healthy Skin Matters

    ... your health, talk to your doctor or a physical therapist to find out what kinds of activities are ... the treatment of diseases of the skin. Follicle (FALL-lick-el). The opening in the skin where ...

  2. Examine Your Skin

    ... Support Donate Share Facebook Twitter Newsletter Examine Your Skin Watch the video below and in only two minutes, you can learn to examine your skin. A special thanks to Dr. Martin Weinstock, MD, ...

  3. Aging changes in skin

    ... pigments seem to provide some protection against sun-induced skin damage. Blue-eyed, fair-skinned people show ... 80. Women gradually produce less oil beginning after menopause. This can make it harder to keep the ...

  4. Dry Skin Relief

    ... resources Meet our partners Español Donate Diseases and treatments Acne and rosacea Bumps and growths Color problems Contagious skin diseases Cosmetic treatments Dry / sweaty skin Eczema / dermatitis Hair and scalp ...

  5. CSD skin test

    ... this page: //medlineplus.gov/ency/article/003385.htm CSD skin test To use the sharing features on this page, please enable JavaScript. The cat scratch disease (CSD) skin test was once used to help ...

  6. Stages of Skin Cancer

    ... cells than in normal cells. For skin cancer, laser light is shined onto the skin and the drug becomes active and kills the cancer cells. Photodynamic therapy causes little damage to healthy tissue. Biologic therapy ...

  7. Skin Cancer Treatment

    ... cells than in normal cells. For skin cancer, laser light is shined onto the skin and the drug becomes active and kills the cancer cells. Photodynamic therapy causes little damage to healthy tissue. Biologic therapy ...

  8. Skin Cancer Trends

    ... Search The CDC Cancel Submit Search The CDC Skin Cancer Note: Javascript is disabled or is not supported ... Cervical Colorectal (Colon) Lung Ovarian Prostate Cancer Home Skin Cancer Trends Language: English Español (Spanish) Recommend on Facebook ...

  9. Examine Your Skin

    Full Text Available ... Support Donate Share Facebook Twitter Newsletter Examine Your Skin Watch the video below and in only two minutes, you can learn to examine your skin. A special thanks to Dr. Martin Weinstock, MD, ...

  10. Artificial Skin in Robotics

    Strohmayr, Michael

    2012-01-01

    Artificial Skin - A comprehensive interface for system-environment interaction - This thesis investigates a multifunctional artificial skin as touch sensitive whole-body cover for robotic systems. To further the evolution from tactile sensors to an implementable artificial skin a general concept for the design process is derived. A standard test procedure is proposed to evaluate the performance. The artificial skin contributes to a safe and intuitive physical human robot interaction.

  11. Metabolism of skin-absorbed resveratrol into its glucuronized form in mouse skin.

    Itsuo Murakami

    Full Text Available Resveratrol (RESV is a plant polyphenol, which is thought to have beneficial metabolic effects in laboratory animals as well as in humans. Following oral administration, RESV is immediately catabolized, resulting in low bioavailability. This study compared RESV metabolites and their tissue distribution after oral uptake and skin absorption. Metabolomic analysis of various mouse tissues revealed that RESV can be absorbed and metabolized through skin. We detected sulfated and glucuronidated RESV metabolites, as well as dihydroresveratrol. These metabolites are thought to have lower pharmacological activity than RESV. Similar quantities of most RESV metabolites were observed 4 h after oral or skin administration, except that glucuronidated RESV metabolites were more abundant in skin after topical RESV application than after oral administration. This result is consistent with our finding of glucuronidated RESV metabolites in cultured skin cells. RESV applied to mouse ears significantly suppressed inflammation in the TPA inflammation model. The skin absorption route could be a complementary, potent way to achieve therapeutic effects with RESV.

  12. Microbiome and skin diseases

    Zeeuwen, P.L.; Kleerebezem, M.; Timmerman, H.M.; Schalkwijk, J.

    2013-01-01

    Purpose of review: This article reviews recent findings on the skin microbiome. It provides an update on the current understanding of the role of microbiota in healthy skin and in inflammatory and allergic skin diseases. Recent findings: Advances in computing and high-throughput sequencing technolog

  13. Microbiome and skin diseases

    Zeeuwen, P.L.J.M.; Kleerebezem, M.; Timmerman, H.M.; Schalkwijk, J.

    2013-01-01

    PURPOSE OF REVIEW: This article reviews recent findings on the skin microbiome. It provides an update on the current understanding of the role of microbiota in healthy skin and in inflammatory and allergic skin diseases. RECENT FINDINGS: Advances in computing and high-throughput sequencing technolog

  14. Artificial skin. Jinko hifu

    Kifune, K. (Unitika Ltd., Osaka (Japan))

    1993-06-15

    In order to restore the human skin wounds, the transplantation is only one measure. The transplantation can take only when own skin is used, and there is no successful example by using other person's skin. When the own skin is not sufficient due to the too vast damage, the artificial skin, which can be regenerated as it is, is required. The artificial skin is said to be the most difficult organ among the artificial organs, even though its function is quite simple. Although there are the pig skin, the collagen membrane and the synthetic materials such as the polyurethane and so forth, as the materials similar to the artificial skin, they cover the wounds just until the cuticle is formed. Recently there is a cultivated skin. Firstly the normal skin with a size of the stamp is cut off, and then the cuticle cells are taken to pieces and cultivated, and consequently it is possible to increase the area by several 10 times. In addition, there is also a trial to make the artificial skin synthetically. Its upper layer is composed of the silicon, and the lower layer is the collagen membrane with a sponge structure. The silicon, membrane can be said to be an ideal artificial skin, because it detaches naturally. The chitin, which has recently appeared as the wound protection material, is also the promising material. 3 figs.

  15. Friction induced skin tags.

    Allegue, Francisco; Fachal, Carmen; Pérez-Pérez, Lidia

    2008-01-01

    Skin tags are common benign neoplasm located predominantly in intertriginous skin. Generally of cosmetic concern, they can be easily treated with cryotherapy, electrodessication or snip-excision. Despite their high incidence data about their etiopathogenesis are scarce in the medical literature. We describe a patient who developed multiple skin tags arranged in a linear fashion suggesting an etiopathogenic role for friction. PMID:18627719

  16. Skin self-exam

    Skin cancer - self-exam; Melanoma - self-exam; Basal cell cancer - self-exam; Squamous cell - self-exam; Skin mole - self-exam ... do not agree on whether or not skin self-exams should be performed. So there is no ...

  17. What Is Melanoma Skin Cancer?

    ... statistics for melanoma skin cancer What is melanoma skin cancer? Cancer starts when cells in the body begin ... causing the skin to tan or darken. Melanoma skin cancers Melanoma is a cancer that begins in the ...

  18. Sensitive skin: An overview

    Arun C Inamadar

    2013-01-01

    Full Text Available Sensitive skin is less tolerant to frequent and prolonged use of cosmetics and toiletries. It is self-diagnosed and typically unaccompanied by any obvious physical signs of irritation. With the change in lifestyle and also with increased opportunity to use many new brands of cosmetics and toiletries, there has been an increase in females complaining of unique sensation in their facial skin. Sensitive skin presents as smarting, burning, stinging, itching, and/or tight sensation in their facial skin. The condition is found in more than 50% of women and 40% of men, creating a sizable demand for products designed to minimize skin sensitivity. Good numbers of invasive and non-invasive tests are designed to evaluate and predict the sensitive skin. Management includes guidelines for selecting suitable cosmetics and toiletries in sensitive skin individuals.

  19. Pursuing prosthetic electronic skin.

    Chortos, Alex; Liu, Jia; Bao, Zhenan

    2016-09-01

    Skin plays an important role in mediating our interactions with the world. Recreating the properties of skin using electronic devices could have profound implications for prosthetics and medicine. The pursuit of artificial skin has inspired innovations in materials to imitate skin's unique characteristics, including mechanical durability and stretchability, biodegradability, and the ability to measure a diversity of complex sensations over large areas. New materials and fabrication strategies are being developed to make mechanically compliant and multifunctional skin-like electronics, and improve brain/machine interfaces that enable transmission of the skin's signals into the body. This Review will cover materials and devices designed for mimicking the skin's ability to sense and generate biomimetic signals. PMID:27376685

  20. Percutaneous absorption of an insect repellent p-menthane-3,8-DIOL: a model for human dermal absorption.

    Reifenrath, William G; Olson, James J; Vedula, Usha; Osimitz, Thomas G

    2009-01-01

    p-Menthane-3,8-diol(38DIOL) was recently introduced as a natural topical insect repellent in the commercial product "OFF! Botanicals" lotion. The objective of this study was to provide an estimate of the potential for 38DIOL systemic absorption in humans. Carbon-14-labeled 38DIOL formulated in the lotion and in an ethanol solution was applied to excised pig skin in an in vitro flow-through test system predictive of skin absorption in humans. Twenty-four hours after application, radiolabel recovered from the dermis and receptor fluid was summed to determine percent absorption. At a dose of approximately 80 microg/cm(2) of 38DIOL in the lotion, a value of 3.5 +/- 0.8% of applied dose was obtained with pig skin. The corresponding value for 38DIOL in ethanol (90 microg/cm(2)) was not significantly different (3.0 +/- 1.2%). Most of the applied dose of 38DIOL was found to evaporate from pig skin (77 +/- 8% for the lotion and 87 +/- 1% for ethanol solution), thus limiting percutaneous absorption values. For reference purposes, the pig skin absorptions of piperonyl butoxide (PBO) at 100 microg/cm(2) in isopropanol, N,N-diethyl-m-toluamide (DEET) at 500 microg/cm(2) in ethanol, and neat isododecane at 650 microg/cm(2) (in order of increasing volatility) were 15 +/- 6%, 23 +/- 3%, and 0.09 +/- 0.05% of applied dose respectively. Isododecane was lost almost exclusively from the skin surface by evaporation. For additional reference, absorptions of PBO, DEET, and 38DIOL were found to be higher with excised rat skin. PMID:19557607

  1. Skin mirrors human aging.

    Nikolakis, Georgios; Makrantonaki, Evgenia; Zouboulis, Christos C

    2013-12-01

    Abstract Aged skin exhibits disturbed lipid barrier, angiogenesis, production of sweat, immune functions, and calcitriol synthesis as well as the tendency towards development of certain benign or malignant diseases. These complex biological processes comprise endogenous and exogenous factors. Ethnicity also markedly influences the phenotype of skin aging. The theories of cellular senescence, telomere shortening and decreased proliferative capacity, mitochondrial DNA single mutations, the inflammation theory, and the free radical theory try to explain the biological background of the global aging process, which is mirrored in the skin. The development of advanced glycation end-products and the declining hormonal levels are major factors influencing intrinsic aging. Chronic photodamage of the skin is the prime factor leading to extrinsic skin aging. The deterioration of important skin functions, due to intrinsic and extrinsic aging, leads to clinical manifestations, which mirror several internal age-associated diseases such as diabetes, arterial hypertension and malignancies. PMID:25436743

  2. Skin tribology: Science friction?

    Heide, van der, M.; X. Zeng; Masen, M.A.

    2013-01-01

    The application of tribological knowledge is not just restricted to optimizing mechanical and chemical engineering problems. In fact, effective solutions to friction and wear related questions can be found in our everyday life. An important part is related to skin tribology, as the human skin is frequently one of the interacting surfaces in relative motion. People seem to solve these problems related to skin friction based upon a trial-and-error strategy and based upon on our sense for touch....

  3. Sensitive skin: An overview

    Inamadar, Arun C.; Aparna Palit

    2013-01-01

    Sensitive skin is less tolerant to frequent and prolonged use of cosmetics and toiletries. It is self-diagnosed and typically unaccompanied by any obvious physical signs of irritation. With the change in lifestyle and also with increased opportunity to use many new brands of cosmetics and toiletries, there has been an increase in females complaining of unique sensation in their facial skin. Sensitive skin presents as smarting, burning, stinging, itching, and/or tight sensation in their facial...

  4. Archaea on human skin

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

    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 mi...

  5. Neuromodulators for Aging Skin

    ... Skin Rejuvenation Soft-tissue Fillers Combination: Soft-tissue Fillers and Neuromodulators Neuromodulators – wrinkle-relaxing injections of botulinum toxin commercially known as Botox, Dysport ...

  6. Skin Images Segmentation

    Ali E. Zaart

    2010-01-01

    Full Text Available Problem statement: Image segmentation is a fundamental step in many applications of image processing. Skin cancer has been the most common of all new cancers detected each year. At early stage detection of skin cancer, simple and economic treatment can cure it mostly. An accurate segmentation of skin images can help the diagnosis to define well the region of the cancer. The principal approach of segmentation is based on thresholding (classification that is lied to the problem of the thresholds estimation. Approach: The objective of this study is to develop a method to segment the skin images based on a mixture of Beta distributions. We assume that the data in skin images can be modeled by a mixture of Beta distributions. We used an unsupervised learning technique with Beta distribution to estimate the statistical parameters of the data in skin image and then estimate the thresholds for segmentation. Results: The proposed method of skin images segmentation was implemented and tested on different skin images. We obtained very good results in comparing with the same techniques with Gamma distribution. Conclusion: The experiment showed that the proposed method obtained very good results but it requires more testing on different types of skin images.

  7. Immunohistochemistry of porcine skin.

    Wollina, U; Berger, U; Mahrle, G

    1991-01-01

    The present paper reports immunohistological findings in porcine skin, which were obtained by use of mono- and polyclonal antihuman antibodies and either alkaline phosphatase anti-alkaline phosphatase (APAAP) or peroxidase (POX) technique. Epidermal staining was observed with antibodies to keratins (K 8.12, RSKE 60), filaggrin, and calmodulin (ACAM). Staining of connective tissue and vessels was achieved using antibodies to vimentin (V9(1)), collagen type IV, and fibronectin. In general, these antibodies gave a staining pattern similar to that of normal human skin. The similarities of immunoreactivity to poly- and monoclonal antihuman antibodies in porcine and human skin render porcine skin a reliable model in biomedical research. PMID:1710864

  8. An elastic second skin

    Yu, Betty; Kang, Soo-Young; Akthakul, Ariya; Ramadurai, Nithin; Pilkenton, Morgan; Patel, Alpesh; Nashat, Amir; Anderson, Daniel G.; Sakamoto, Fernanda H.; Gilchrest, Barbara A.; Anderson, R. Rox; Langer, Robert

    2016-08-01

    We report the synthesis and application of an elastic, wearable crosslinked polymer layer (XPL) that mimics the properties of normal, youthful skin. XPL is made of a tunable polysiloxane-based material that can be engineered with specific elasticity, contractility, adhesion, tensile strength and occlusivity. XPL can be topically applied, rapidly curing at the skin interface without the need for heat- or light-mediated activation. In a pilot human study, we examined the performance of a prototype XPL that has a tensile modulus matching normal skin responses at low strain (skin barrier function, pharmaceutical delivery and wound dressings.

  9. Effect of Terpenes on the Skin Permeation of Ketoprofen through Shed Snake Skin

    Hilal Bilek; Nanthida Wonglertnirant; Tanasait Ngawhirunpat; Praneet Opanasopit; Mont Kumpugdee -Vollrath

    2009-01-01

    The objective of this work was to investigate the effect of hydrocarbon (α-pinene and limonene) and oxygen containing monoterpenes (carvone and terpineole) at 5%w/v in hydroalcoholic mixtures (50% ethanol) on the permeation of ketoprofen across shed snake skin of Python molurus bivittatus. The amount of KP retained in the skin after 8 h of diffusion was determined. It was found that the percutaneous absorption of ketoprofen was enhanced in the presence of the enhancers. The rank order of enha...

  10. Assessing the Impact of Mechanical Damage on Full-Thickness Porcine and Human Skin Using an In Vitro Approach

    Hinda Dabboue; Nicolas Builles; Éric Frouin; Dan Scott; Jeanne Ramos; Gilberte Marti-Mestres

    2015-01-01

    For most xenobiotics, the rates of percutaneous absorption are limited by diffusion through the horny layer of skin. However, percutaneous absorption of chemicals may seriously increase when the skin is damaged. The aim of this work was to develop an in vitro representative model of mechanically damaged skins. The epidermal barrier was examined following exposure to a razor, a rotating brush, and a microneedle system in comparison to tape-stripping which acted as a reference. Excised full-thi...

  11. EFFECT OF CHAMOMILE OIL AS A PERCUTANEOUS ABSORPTION ENHANCER

    Ali Heyam Saad

    2013-09-01

    Full Text Available The aim of this study was to investigate the ability of Chamomile oil as absorption enhancers for cutaneously administered Silver Sulfadiazine by comparing it with a penetration enhancer Dimethyl Sulfoxide. Silver sulfadiazine is used in burn infection. Gel was selected as the vehicle for Silver Rat’ skin samples were placed in a continuous flow diffusion cell, with Silver Sulfadiazine gel on top. Receptor fluid samples were analyzed using high-performance liquid chromatography. The quantity of gel remaining on the skin surface after completion of each test was weighed and the amount of drug in the skin was analyzed. Addition of chamomile oil or Dimethyl Sulfoxide to the gel increased the percutaneous absorption of the drug. 5 % Chamomile oil was found to be the most efficient absorption enhancer in this comparison.

  12. Shark skin: function in locomotion.

    Wainwright, S A; Vosburgh, F; Hebrank, J H

    1978-11-17

    Hydrostatic pressure under the skin of sharks varies with swimming speed. Stress in the skin varies with the internal pressure, and the skin stress controls skin stiffness. Locomotory muscles attach to the skin which is thus a whole-body exotendon whose mechanical advantage in transmitting muscular contraction is greater than that of the endoskeleton. PMID:17807247

  13. Examine Your Skin

    Full Text Available ... Your Skin Watch the video below and in only two minutes, you can learn to examine your skin. A special thanks to Dr. Martin Weinstock, MD, PhD, Professor of Dermatology, Brown University, for permission to use this video. UPDATED: February ...

  14. Deformable skinning on bones

    Larsen, Bent Dalgaard; Petersen, Kim Steen; Jakobsen, Bjarke

    2001-01-01

    Applying skin to a model is a relatively simple task to implement. Nonetheless it seems that no good resource exists that describes both the concepts and math necessary to understand and implement skinning. The intention of this article is an attempt to give a thoroughly description of the theore...

  15. Skin Diseases: Skin and Sun—Not a good mix

    Skip Navigation Bar Home Current Issue Past Issues Skin Diseases Skin and Sun —Not a good mix Past Issues / ... of this page please turn Javascript on. Good skin care begins with sun safety. Whether it is ...

  16. Bionanomaterials for skin regeneration

    Leonida, Mihaela D

    2016-01-01

    This book gives a concise overview of bionanomaterials with applications for skin regeneration. The advantages and challenges of nanoscale materials are covered in detail, giving a basic view of the skin structure and conditions that require transdermal or topical applications. Medical applications, such as wound healing, care for burns, skin disease, and cosmetic care, such as aging of the skin and photodamage, and how they benefit from bionanomaterials, are described in detail. A final chapter is devoted to the ethical and social issues related to the use of bionanomaterials for skin regeneration. This is an ideal book for researchers in materials science, medical scientists specialized in dermatology, and cosmetic chemists working in formulations. It can also serve as a reference for nanotechnologists, dermatologists, microbiologists, engineers, and polymer chemists, as well as students studying in these fields.

  17. Effect of Photofrin on skin reflection of basal cell nevus syndrome patients

    Grossweiner, Leonard I.; Jones, Linda R.; Koehler, Irmgard K.; Bilgin, Mehmet D.

    1996-04-01

    Skin reflection spectra were measured before and 24 hours after administration of Photofrin (Reg. TM) to basal cell nevus syndrome (BCNS) patients. The drug reduced the reflectivity of uninvolved BCNS skin and increased the reflectivity of basal cell cancers. Photofrin (Reg. TM) absorption in normal rat skin and uninvolved BCNS skin was resolved by the diffusion approximation. Optical constants calculated with a two-layer skin model indicate that the drug increased light scattering in tumor tissues. The possible use of reflection spectra for PDT light dosimetry is discussed.

  18. Sun Safety: Save Your Skin

    Full Text Available ... brown hair been treated for skin cancer a family member who's had skin cancer If you take ... Day” offers simple steps that you and your family can take to prevent sun-related skin cancer, ...

  19. Infrared spectroscopic measurement of skin hydration and sebum levels and comparison to corneometer and sebumeter

    Ezerskaia, Anna; Pereira, S. F.; Urbach, H. P.; Varghese, Babu

    2016-05-01

    Skin health characterized by a system of water and lipids in Stratum Corneum provide protection from harmful external elements and prevent trans-epidermal water loss. Skin hydration (moisture) and sebum (skin surface lipids) are considered to be important factors in skin health; a right balance between these components is an indication of skin health and plays a central role in protecting and preserving skin integrity. In this manuscript we present an infrared spectroscopic method for simultaneous and quantitative measurement of skin hydration and sebum levels utilizing differential detection with three wavelengths 1720, 1750, and 1770 nm, corresponding to the lipid vibrational bands that lie "in between" the prominent water absorption bands. The skin sebum and hydration values on the forehead under natural conditions and its variations to external stimuli were measured using our experimental set-up. The experimental results obtained with the optical set-up show good correlation with the results obtained with the commercially available instruments Corneometer and Sebumeter.

  20. Skin and Psyche : Diversionary Symbiosis

    Sharma, YK; Sudarsanan, S.; Bhatnagar, A

    2005-01-01

    A significant proportion of patients with skin diseases have associated psychosocial factors. Not only does psychopathology manifest on the skin in absence of any real skin disease, primary skin disorders can also be exacerbated by emotional stress adversely influencing the homeostasis of immunological and inflammatory processes in deeper layers of the skin. Furthermore, many patients develop emotional problems as a result of having disfiguring skin diseases. In addition, some patients having...

  1. Skin Picking Disorder

    Pinar Cetinay Aydin

    2014-08-01

    Full Text Available Skin picking disorder is not a dermatological disorder and it is a table characterized with picking skin excessively and repetitively, leading to damage in skin tissue. Unlike normal picking behaviour, psychogenic skin picking is repetitive and it can lead to severe damage in the skin and even complications which constitute vital danger. While some patients define frequent but short lasting picking attacks, others define rarer attacks which last a few hours. Skin picking disorder, which is not included in the classification systems up to DSM-5 as a separate diagnosis category, is included as an independent diagnosis in Obsessive Compulsive Disorder and Associated Disorders category in DSM-5. In case reports, open label studies and double blind studies selective serotonin reuptake inhibitors are shown to be effective in the treatment of skin picking disorder. Mostly, cognitive-behaviourial techniques are used and have been proven to be useful in psychotherapy. Habit reversal is one of the behaviourial techniques which are frequently applied, give positive results in which well-being state can be maintained. [Psikiyatride Guncel Yaklasimlar - Current Approaches in Psychiatry 2014; 6(4.000: 401-428

  2. Archaea on human skin.

    Alexander J Probst

    Full Text Available 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.

  3. Occupational skin cancers

    Gawkrodger, D.J. [Royal Hallamshire Hospital, Sheffield (United Kingdom). Dept. of Dermatology

    2004-10-01

    Skin cancer due to occupation is more common than is generally recognized, although it is difficult to obtain an accurate estimate of its prevalence. Over the past two centuries, occupational skin cancers have particularly been due to industrial exposure of men (it seems more so than women) to chemical carcinogens such as polycyclic hydrocarbons (e.g. from coal tar products) or to arsenic. Industrial processes have improved in most Western countries to limit this type of exposure, but those with outdoor occupations are still exposed to solar ultraviolet irradiation without this being widely recognized as an industrial hazard. Ionizing radiation such as X-rays can also cause skin cancer. Occupational skin cancers often resemble skin tumours found in non-occupational subjects, e.g. basal cell carcinoma, squamous cell carcinoma and malignant melanoma, but some pre-malignant lesions can be more specific and point to an occupational origin, e.g. tar keratoses or arsenical keratoses. An uncommon but well-recognized cause of occupational skin cancer is that which results from scar formation following an industrial burn. In the future it will be necessary to focus on preventative measures, e.g. for outdoor workers, the need to cover up in the sun and use sun protective creams and a campaign for earlier recognition of skin cancers, which are usually curable if treated in their early stages.

  4. D-xylose absorption

    ... this page: //medlineplus.gov/ency/article/003606.htm D-xylose absorption To use the sharing features on this page, please enable JavaScript. D-xylose absorption is a laboratory test to determine ...

  5. D-xylose absorption

    D-xylose absorption is a laboratory test to determine how well the intestines absorb a simple sugar (D-xylose). The test ... test is primarily used to determine if nutrient absorption problems are due to a disease of the ...

  6. Nutrition and magnesium absorption.

    Brink, E.J.

    1992-01-01

    The influence of various nutrients present in dairy products and soybean-based products on absorption of magnesium has been investigated. The studies demonstrate that soybean protein versus casein lowers apparent magnesium absorption in rats through its phytate component. However, true magnesium absorption was neither affected by soybean protein in the diet nor by supplemental phytate. The inhibitory influence of soybean protein and phytate on apparent magnesium absorption was found to be cau...

  7. Four energy levels device for skin punching

    Savastru, D.; Ristici, Esofina; Mustata, Marina; Miclos, S.; Rusu, M. I.; Radu, C.; Savu, V.

    2007-03-01

    Generally, the beam distribution in the tissue in interaction with a pulsed laser is defined by optical properties (effective scattering and absorption coefficient). In 2900 nm range, the effective scattering coefficient is much smaller than the absorption coefficient. An Er:YAG skin puncher is presented. Thermal action of a laser beam can be described as one of three types: hyperthermia, coagulation and volatilization, depending on the degree and the duration of tissue heating. We are interested in the volatilization process that means a loss of material. The various constituents of the tissue disappear in smoke at above 100 0C in a relatively short time of around one tenth of a second. At the edges of the volatilization zone there is a region of coagulation necrosis. In presented case of an Er:YAG laser operating in a free generation mode, the mechanical effects can result from explosive vaporization. When the exposure time of the laser is lower than the characteristic time of the thermal diffusion in the tissue, it produces a thermal containment with an accumulation of heat without diffusion and an explosive vaporization of the target. The Er:YAG laser device has the pulse length of about 160 microseconds and four emitted energy levels. This device is used to punch the skin for blood sampling for different kinds of analysis. The front panel of the device has four keys to select the desired energy according to the skin type.

  8. Skin disorders at sea.

    Lucas, Ray; Boniface, Keith; Hite, Michael

    2010-01-01

    The purpose of this study is to characterize the types of skin disorders occurring at sea requiring acute treatment. The case logs of a tele-medicine service for US flagged ships at sea were reviewed from March 1, 2006 until March 1, 2009. Of 1844 total cases, 10% (n = 183) were for skin disorders. Sixty-eight percent (n = 125) were infections, 14% (n = 25) were inflammatory, 7% (n = 13) were environmental, and 11% (n = 20) were non-specific rashes. Cutaneous abscesses and cellulitis (n = 84) were the most common acute skin disorders encountered. In some cases (n = 81), still digital photographs aided in the diagnosis. PMID:20496321

  9. Interactions of skin thickness and physicochemical properties of test compounds in percutaneous penetration studies

    Wilkinson, S.C.; Maas, W.J.M.; Nielsen, J.B.; Greaves, L.C.; Sandt, J.J.M. van de; Williams, F.M.

    2006-01-01

    Objectives: To determine the effect of skin thickness on the percutaneous penetration and distribution of test compounds with varying physicochemical properties using in vitro systems. Studies were carried out in accordance with OECD guidelines on skin absorption tests. Methods: Percutaneous penetra

  10. Skin Allergy Quiz

    ... Training Grants & Awards Program Directors Practice Resources ASTHMA IQ Consultation and Referral Guidelines Practice Financial Survey Practice ... Your local allergist can do a skin prick test or blood test to find out if you ...

  11. Laser Skin Renewal

    ... rashes clinical tools newsletter | contact Share | Skin Renewal, Laser A A A BEFORE: This patient wanted the appearance of his acne scars minimized by laser treatment. Procedure Overview Photorejuvenation, simply put, is the ...

  12. Skin or nail culture

    Mucosal culture; Culture - skin; Culture - mucosal; Nail culture; Culture - fingernail; Fingernail culture ... There, it is placed in a special dish (culture). It is then watched to see if bacteria, ...

  13. Examine Your Skin

    Full Text Available ... Centers Online Resources The Melanoma Book Clinical Trials Patient Access Grant: Apply Download a Skin Self-Exam Card Download a Patient Navigation Card Events, Webinars & Videos Events, Webinars & Videos ...

  14. Dry Skin (Xerosis)

    ... skin may have cracks that resemble a dry lake bed. Inflammation of the areas may lead to ... free creams or ointments Preparations containing alpha-hydroxy acids such as glycolic acid or lactic acid Creams ...

  15. Aging changes in skin

    ... developing heat stroke increases. Growths such as skin tags , warts , rough patches (keratoses), and other blemishes are ... to the principles of the Health on the Net Foundation (www.hon.ch). The information provided herein ...

  16. Layers of the Skin

    ... Review Abstracting, Coding, & Staging ICD-O Site Codes Morphology & Grade Extent of Disease Evaluation Physical Exam Lab ... the majority of the structure of the skin, hair, and nails. The squamous cell layer is the ...

  17. Necrotizing Skin Infections

    ... and Treatment Medical Dictionary Also of Interest (Quiz) Vitiligo (Video) Hives Additional Content Medical News Necrotizing Skin ... Professional Version Also of Interest Test your knowledge Vitiligo is a loss of melanocytes (cells that produce ...

  18. Fungal Skin Infections

    ... Skin Infections Medical Dictionary Also of Interest (Quiz) Vitiligo (Video) Hives Additional Content Medical News Overview of ... Professional Version Also of Interest Test your knowledge Vitiligo is a loss of melanocytes (cells that produce ...

  19. Spiritual and religious aspects of skin and skin disorders

    Shenefelt PD

    2014-08-01

    Full Text Available Philip D Shenefelt,1 Debrah A Shenefelt2 1Dermatology and Cutaneous Surgery, University of South Florida, Tampa, 2Congregation Or Ahavah, Lutz, FL, USA Abstract: Skin and skin disorders have had spiritual aspects since ancient times. Skin, hair, and nails are visible to self and others, and touchable by self and others. The skin is a major sensory organ. Skin also expresses emotions detectable by others through pallor, coldness, "goose bumps", redness, warmth, or sweating. Spiritual and religious significances of skin are revealed through how much of the skin has been and continues to be covered with what types of coverings, scalp and beard hair cutting, shaving and styling, skin, nail, and hair coloring and decorating, tattooing, and intentional scarring of skin. Persons with visible skin disorders have often been stigmatized or even treated as outcasts. Shamans and other spiritual and religious healers have brought about healing of skin disorders through spiritual means. Spiritual and religious interactions with various skin disorders such as psoriasis, leprosy, and vitiligo are discussed. Religious aspects of skin and skin diseases are evaluated for several major religions, with a special focus on Judaism, both conventional and kabbalistic. Keywords: skin, skin disorders, spiritual, religious

  20. Cure of skin cancer. Surgical cure of skin cancer

    In this chapter authors studied the cure of skin cancer in particular the surgical cure of skin cancer. They noted that surgical cure of skin cancer is remain one of the primary and most important methods in treatment of skin cancer

  1. Skin Diseases: Cross-section of human skin

    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 ...

  2. Probing skin interaction with hydrogen peroxide using diffuse reflectance spectroscopy

    Zonios, George; Dimou, Aikaterini; Galaris, Dimitrios

    2008-01-01

    Hydrogen peroxide is an important oxidizing agent in biological systems. In dermatology, it is frequently used as topical antiseptic, it has a haemostatic function, it can cause skin blanching, and it can facilitate skin tanning. In this work, we investigated skin interaction with hydrogen peroxide, non-invasively, using diffuse reflectance spectroscopy. We observed transient changes in the oxyhaemoglobin and deoxyhaemoglobin concentrations as a result of topical application of dilute H2O2 solutions to the skin, with changes in deoxyhaemoglobin concentration being more pronounced. Furthermore, we did not observe any appreciable changes in melanin absorption properties as well as in the skin scattering properties. We also found no evidence for production of oxidized haemoglobin forms. Our observations are consistent with an at least partial decomposition of hydrogen peroxide within the stratum corneum and epidermis, with the resulting oxygen and/or remaining hydrogen peroxide inducing vasoconstriction to dermal blood vessels and increasing haemoglobin oxygen saturation. An assessment of the effects of topical application of hydrogen peroxide to the skin may serve as the basis for the development of non-invasive techniques to measure skin antioxidant capacity and also may shed light onto skin related disorders such as vitiligo.

  3. Probing skin interaction with hydrogen peroxide using diffuse reflectance spectroscopy

    Hydrogen peroxide is an important oxidizing agent in biological systems. In dermatology, it is frequently used as topical antiseptic, it has a haemostatic function, it can cause skin blanching, and it can facilitate skin tanning. In this work, we investigated skin interaction with hydrogen peroxide, non-invasively, using diffuse reflectance spectroscopy. We observed transient changes in the oxyhaemoglobin and deoxyhaemoglobin concentrations as a result of topical application of dilute H2O2 solutions to the skin, with changes in deoxyhaemoglobin concentration being more pronounced. Furthermore, we did not observe any appreciable changes in melanin absorption properties as well as in the skin scattering properties. We also found no evidence for production of oxidized haemoglobin forms. Our observations are consistent with an at least partial decomposition of hydrogen peroxide within the stratum corneum and epidermis, with the resulting oxygen and/or remaining hydrogen peroxide inducing vasoconstriction to dermal blood vessels and increasing haemoglobin oxygen saturation. An assessment of the effects of topical application of hydrogen peroxide to the skin may serve as the basis for the development of non-invasive techniques to measure skin antioxidant capacity and also may shed light onto skin related disorders such as vitiligo

  4. Probing skin interaction with hydrogen peroxide using diffuse reflectance spectroscopy

    Zonios, George [Department of Materials Science and Engineering, University of Ioannina, 45110 Ioannina (Greece); Dimou, Aikaterini [Department of Materials Science and Engineering, University of Ioannina, 45110 Ioannina (Greece); Galaris, Dimitrios [Laboratory of Biological Chemistry, School of Medicine, University of Ioannina, 45110 Ioannina (Greece)

    2008-01-07

    Hydrogen peroxide is an important oxidizing agent in biological systems. In dermatology, it is frequently used as topical antiseptic, it has a haemostatic function, it can cause skin blanching, and it can facilitate skin tanning. In this work, we investigated skin interaction with hydrogen peroxide, non-invasively, using diffuse reflectance spectroscopy. We observed transient changes in the oxyhaemoglobin and deoxyhaemoglobin concentrations as a result of topical application of dilute H{sub 2}O{sub 2} solutions to the skin, with changes in deoxyhaemoglobin concentration being more pronounced. Furthermore, we did not observe any appreciable changes in melanin absorption properties as well as in the skin scattering properties. We also found no evidence for production of oxidized haemoglobin forms. Our observations are consistent with an at least partial decomposition of hydrogen peroxide within the stratum corneum and epidermis, with the resulting oxygen and/or remaining hydrogen peroxide inducing vasoconstriction to dermal blood vessels and increasing haemoglobin oxygen saturation. An assessment of the effects of topical application of hydrogen peroxide to the skin may serve as the basis for the development of non-invasive techniques to measure skin antioxidant capacity and also may shed light onto skin related disorders such as vitiligo.

  5. Designing pliable structural Skins

    Tamke, Martin; Peters, Brady; Nielsen, Stig Anton; Andersen, Niels Jakubiak; Campbell, Reese; Stasiuk, David

    2013-01-01

    Structural stability can be formed through structured or seemingly unstructured approaches to fold, plead or crumble paper. This paper reports on two projects that showcase how computational design approaches can help to widen the understanding and use of structural skins.......Structural stability can be formed through structured or seemingly unstructured approaches to fold, plead or crumble paper. This paper reports on two projects that showcase how computational design approaches can help to widen the understanding and use of structural skins....

  6. Human Skin Fungal Diversity

    Findley, Keisha; OH, JULIA; Yang, Joy; Conlan, Sean; Deming, Clayton; Meyer, Jennifer A.; Schoenfeld, Deborah; Nomicos, Effie; Park, Morgan; ,; Kong, Heidi H.; Segre, Julia A

    2013-01-01

    Traditional culture-based methods have incompletely defined the etiology of common recalcitrant human fungal skin diseases including athlete’s foot and toenail infections. Skin protects humans from invasion by pathogenic microorganisms, while providing a home for diverse commensal microbiota 1 . Bacterial genomic sequence data have generated novel hypotheses about species and community structures underlying human disorders 2,3,4 . However, microbial diversity is not limited to bacteria; micro...

  7. Nicotinamide and the skin.

    Chen, Andrew C; Damian, Diona L

    2014-08-01

    Nicotinamide, an amide form of vitamin B3, boosts cellular energy and regulates poly-ADP-ribose-polymerase 1, an enzyme with important roles in DNA repair and the expression of inflammatory cytokines. Nicotinamide shows promise for the treatment of a wide range of dermatological conditions, including autoimmune blistering disorders, acne, rosacea, ageing skin and atopic dermatitis. In particular, recent studies have also shown it to be a potential agent for reducing actinic keratoses and preventing skin cancers. PMID:24635573

  8. Mantoux Tuberculin Skin Test

    2006-11-22

    Learn how to evaluate people for latent TB infection with the Mantoux tuberculin skin test. This podcast includes sections on administering and reading the Mantoux tuberculin skin test, the standard method for detecting latent TB infection since the 1930s.  Created: 11/22/2006 by National Center for HIV, STD and TB Prevention (NCHHSTP).   Date Released: 12/12/2006.

  9. Calcium absorption and achlorhydria

    Defective absorption of calcium has been thought to exist in patients with achlorhydria. The author compared absorption of calcium in its carbonate form with that in a pH-adjusted citrate form in a group of 11 fasting patients with achlorhydria and in 9 fasting normal subjects. Fractional calcium absorption was measured by a modified double-isotope procedure with 0.25 g of calcium used as the carrier. Mean calcium absorption (+/- S.D.) in the patients with achlorhydria was 0.452 +/- 0.125 for citrate and 0.042 +/- 0.021 for carbonate (P less than 0.0001). Fractional calcium absorption in the normal subjects was 0.243 +/- 0.049 for citrate and 0.225 +/- 0.108 for carbonate (not significant). Absorption of calcium from carbonate in patients with achlorhydria was significantly lower than in the normal subjects and was lower than absorption from citrate in either group; absorption from citrate in those with achlorhydria was significantly higher than in the normal subjects, as well as higher than absorption from carbonate in either group. Administration of calcium carbonate as part of a normal breakfast resulted in completely normal absorption in the achlorhydric subjects. These results indicate that calcium absorption from carbonate is impaired in achlorhydria under fasting conditions. Since achlorhydria is common in older persons, calcium carbonate may not be the ideal dietary supplement

  10. DOSHIC PHYSIOLOGY OF SKIN

    Shivprasad Chiplunkar

    2013-06-01

    Full Text Available The balance of dosha  represents the healthy state and imbalance will cause various diseases. In normalcy doshas will be performing their own functions and individual doshas will be having their own specific sites. By telling the various sthana of each dosha, different function that is taken up by individual dosha in different sites has been highlighted.By mentioning ‘sparshanendriyam’ as one of the sthana of vata dosha the sensory functions of skin to vata dosha has been emphasised. By mentioning ‘sparshanam’ as one of the sthana of pittadosha, the function of colouring/pigmentation of skin, which is majorly carried out  by melanocytes by secreting melanin pigment has been highlighted. Meda is one among the sthanas of kapha dosha; this can be considered as the adipose tissue of skin/below skin. Since sweda is mala of meda it can be also considered as the secretions from the eccrine glands.With respect to skin, sensory functions, both tactile and thermal is carried out by vata dosha more specifically vyana vata, pigmentation to the skin carried out by meloncytes by secreting melanin, it is nothing but function of pitta dosha more specifically brajaka pitta with the help of udana vata and finally production of sweat in sweat glands is the function of kapha. So there is the need for further study and research regarding the sthanas of all three doshas in different structures/organs in the body and its physiology.

  11. Ultraflexible organic photonic skin

    Yokota, Tomoyuki; Zalar, Peter; Kaltenbrunner, Martin; Jinno, Hiroaki; Matsuhisa, Naoji; Kitanosako, Hiroki; Tachibana, Yutaro; Yukita, Wakako; Koizumi, Mari; Someya, Takao

    2016-01-01

    Thin-film electronics intimately laminated onto the skin imperceptibly equip the human body with electronic components for health-monitoring and information technologies. When electronic devices are worn, the mechanical flexibility and/or stretchability of thin-film devices helps to minimize the stress and discomfort associated with wear because of their conformability and softness. For industrial applications, it is important to fabricate wearable devices using processing methods that maximize throughput and minimize cost. We demonstrate ultraflexible and conformable three-color, highly efficient polymer light-emitting diodes (PLEDs) and organic photodetectors (OPDs) to realize optoelectronic skins (oe-skins) that introduce multiple electronic functionalities such as sensing and displays on the surface of human skin. The total thickness of the devices, including the substrate and encapsulation layer, is only 3 μm, which is one order of magnitude thinner than the epidermal layer of human skin. By integrating green and red PLEDs with OPDs, we fabricate an ultraflexible reflective pulse oximeter. The device unobtrusively measures the oxygen concentration of blood when laminated on a finger. On-skin seven-segment digital displays and color indicators can visualize data directly on the body. PMID:27152354

  12. Spiritual and religious aspects of skin and skin disorders

    Shenefelt, Philip

    2014-01-01

    Philip D Shenefelt,1 Debrah A Shenefelt2 1Dermatology and Cutaneous Surgery, University of South Florida, Tampa, 2Congregation Or Ahavah, Lutz, FL, USA Abstract: Skin and skin disorders have had spiritual aspects since ancient times. Skin, hair, and nails are visible to self and others, and touchable by self and others. The skin is a major sensory organ. Skin also expresses emotions detectable by others through pallor, coldness, "goose bumps", redness, warmth, or sweating. ...

  13. Spiritual and religious aspects of skin and skin disorders

    Shenefelt PD; Shenefelt DA

    2014-01-01

    Philip D Shenefelt,1 Debrah A Shenefelt2 1Dermatology and Cutaneous Surgery, University of South Florida, Tampa, 2Congregation Or Ahavah, Lutz, FL, USA Abstract: Skin and skin disorders have had spiritual aspects since ancient times. Skin, hair, and nails are visible to self and others, and touchable by self and others. The skin is a major sensory organ. Skin also expresses emotions detectable by others through pallor, coldness, "goose bumps", redness, warmth, or sweating. Spiritua...

  14. Skin aging and oxidative stress

    Sayeeda Ahsanuddin

    2016-05-01

    Full Text Available Skin aging occurs through two main pathways, intrinsic and extrinsic. These pathways have significant interaction in contributing to the aging phenotype, which includes skin laxity, wrinkling, pigmentation irregularities, and the appearance of neoplastic skin lesions. Here, we review the critical role that oxidative stress plays in skin aging, including its effects on signaling pathways involved in skin matrix formation and degradation, proteasome activity, as well as DNA structure. Furthermore, we discuss the recent literature surrounding the prevention and treatment of skin aging. Although current research is suggestive of the role of antioxidants in anti-aging skin therapies, further research is much needed to explore its role in humans.

  15. Variability of calcium absorption

    Variability in calcium absorption was estimated in three groups of normal subjects in whom Ca absorption was measured by standard isotopic-tracer methods at interstudy intervals ranging from 1 to 4 mo. Fifty absorption tests were performed in 22 subjects. Each was done in the morning after an overnight fast with an identical standard breakfast containing a Ca load of approximately 250 mg. Individual fractional absorption values were normalized to permit pooling of the data. The coefficient of variation (CVs) for absorption for the three groups ranged from 10.57 to 12.79% with the size of the CV increasing with interstudy duration. One other published study presenting replicate absorption values was analyzed in a similar fashion and was found to have a CV of absorption of 9.78%. From these data we estimate that when the standard double-isotope method is used to measure Ca absorption there is approximately 10% variability around any given absorption value within an individual human subject and that roughly two-thirds of this represents real biological variability in absorption

  16. Monte Carlo Method in optical diagnostics of skin and skin tissues

    Meglinski, Igor V.

    2003-12-01

    A novel Monte Carlo (MC) technique for photon migration through 3D media with the spatially varying optical properties is presented. The employed MC technique combines the statistical weighting variance reduction and real photon paths tracing schemes. The overview of the results of applications of the developed MC technique in optical/near-infrared reflectance spectroscopy, confocal microscopy, fluorescence spectroscopy, OCT, Doppler flowmetry and Diffusing Wave Spectroscopy (DWS) are presented. In frame of the model skin represents as a complex inhomogeneous multi-layered medium, where the spatial distribution of blood and chromophores are variable within the depth. Taking into account variability of cells structure we represent the interfaces of skin layers as a quasi-random periodic wavy surfaces. The rough boundaries between the layers of different refractive indices play a significant role in the distribution of photons within the medium. The absorption properties of skin tissues in visible and NIR spectral region are estimated by taking into account the anatomical structure of skin as determined from histology, including the spatial distribution of blood vessels, water and melanin content. Model takes into account spatial distribution of fluorophores following the collagen fibers packing, whereas in epidermis and stratum corneum the distribution of fluorophores assumed to be homogeneous. Reasonable estimations for skin blood oxygen saturation and haematocrit are also included. The model is validated against analytic solution of the photon diffusion equation for semi-infinite homogeneous highly scattering medium. The results demonstrate that matching of the refractive index of the medium significantly improves the contrast and spatial resolution of the spatial photon sensitivity profile. It is also demonstrated that when model supplied with reasonable physical and structural parameters of biological tissues the results of skin reflectance spectra simulation

  17. Skin aging and oxidative stress

    Sayeeda Ahsanuddin; Minh Lam; Baron, Elma D.

    2016-01-01

    Skin aging occurs through two main pathways, intrinsic and extrinsic. These pathways have significant interaction in contributing to the aging phenotype, which includes skin laxity, wrinkling, pigmentation irregularities, and the appearance of neoplastic skin lesions. Here, we review the critical role that oxidative stress plays in skin aging, including its effects on signaling pathways involved in skin matrix formation and degradation, proteasome activity, as well as DNA structure. Furthermo...

  18. Evaluation of skin colouring properties of curcuma longa extract

    J Arct

    2014-01-01

    Full Text Available The aim of this study was to evaluate the skin colouring properties of curcuma extract in cosmetic formulations. Objective measurements of the skin colour changes were done by Chromameter using the CIE LFNx01aFNx01bFNx01 colour space parameters. These measurements were correlated with the results of the sensory analysis. The observations showed permanent, visible and statistically significant changing of bFNx01 component after one application of emulsions containing 12% and 25% of turmeric extract. The change of skin color remained also after removing the emulsion. Sensory analysis indicated that the tested emulsions with curcuma extract have a significant impact on skin smoothness, spreadability, cosmetic absorption and pillow effect.

  19. Spiritual and religious aspects of skin and skin disorders.

    Shenefelt, Philip D; Shenefelt, Debrah A

    2014-01-01

    Skin and skin disorders have had spiritual aspects since ancient times. Skin, hair, and nails are visible to self and others, and touchable by self and others. The skin is a major sensory organ. Skin also expresses emotions detectable by others through pallor, coldness, "goose bumps", redness, warmth, or sweating. Spiritual and religious significances of skin are revealed through how much of the skin has been and continues to be covered with what types of coverings, scalp and beard hair cutting, shaving and styling, skin, nail, and hair coloring and decorating, tattooing, and intentional scarring of skin. Persons with visible skin disorders have often been stigmatized or even treated as outcasts. Shamans and other spiritual and religious healers have brought about healing of skin disorders through spiritual means. Spiritual and religious interactions with various skin disorders such as psoriasis, leprosy, and vitiligo are discussed. Religious aspects of skin and skin diseases are evaluated for several major religions, with a special focus on Judaism, both conventional and kabbalistic. PMID:25120377

  20. Spiritual and religious aspects of skin and skin disorders

    Shenefelt, Philip D; Shenefelt, Debrah A

    2014-01-01

    Skin and skin disorders have had spiritual aspects since ancient times. Skin, hair, and nails are visible to self and others, and touchable by self and others. The skin is a major sensory organ. Skin also expresses emotions detectable by others through pallor, coldness, “goose bumps”, redness, warmth, or sweating. Spiritual and religious significances of skin are revealed through how much of the skin has been and continues to be covered with what types of coverings, scalp and beard hair cutting, shaving and styling, skin, nail, and hair coloring and decorating, tattooing, and intentional scarring of skin. Persons with visible skin disorders have often been stigmatized or even treated as outcasts. Shamans and other spiritual and religious healers have brought about healing of skin disorders through spiritual means. Spiritual and religious interactions with various skin disorders such as psoriasis, leprosy, and vitiligo are discussed. Religious aspects of skin and skin diseases are evaluated for several major religions, with a special focus on Judaism, both conventional and kabbalistic. PMID:25120377

  1. Extreme skin depth waveguides

    Jahani, Saman

    2014-01-01

    Recently, we introduced a paradigm shift in light confinement strategy and introduced a class of extreme skin depth (e-skid) photonic structures (S. Jahani and Z. Jacob, "Transparent sub-diffraction optics: nanoscale light confinement without metal," Optica 1, 96-100 (2014)). Here, we analytically establish that figures of merit related to light confinement in dielectric waveguides are fundamentally tied to the skin depth of waves in the cladding. We contrast the propagation characteristics of the fundamental mode of e-skid waveguides and conventional waveguides to show that the decay constant in the cladding is dramatically larger in e-skid waveguides, which is the origin of sub-diffraction confinement. Finally, we propose an approach to verify the reduced skin depth in experiment using the decrease in the Goos-H\\"anchen phase shift.

  2. Environment and the skin

    The skin is an important organ of defense adaptation and a portal of entry for xenobiotics. It is vulnerable to physical, chemical, and biologic agents and capable of expressing responses to these agents in a variety of pathologic patterns. These patterns are characterized by morphologic and functional features which are elicited by careful examination and test procedures. Cutaneous cancer may result from exposure to nonionizing as well as ionizing radiation, to specific identifiable chemical hazards, and may be enhanced by trauma. Cutaneous hazards of chemical sources are largely found in the workplace and among consumer products, including drugs and toilet goods. Environmental skin diseases and injuries are preventable. Prior to use assessment for safety and for possible risks from exposure to an agent, product, or process is of primary importance in the prevention and control of environmental skin disease and injury

  3. Double-Skin Facade

    Kalyanova, Olena

    Double-Skin Facades (DSF) are gaining popularity that, in fact, appears to be independent from sturdy critics of the concept in the past years. DSF buildings are being built in Europe and worldwide, DSF concept is being taught at schools of architecture and fully glazed office buildings are being...... to perform the simulations. To fill in the gap of lacking experimental data a range of measurements was carried out in an outdoor, double-skin façade full-scale test facility ‘The Cube'. As a result, three complete sets of experimental data were composed. These are available for external air curtain...... IEA Annex 34/43, subtask E "Double-Skin Facade". The results of empirical validation are discussed in this work. Discussion and analysis of experimental results is carried out. It has lead to hypothesis of recirculation flow phenomenon in the DSF cavity. Finally, a suggestion of a new numerical model...

  4. Thyroid and skin

    Dogra Alka

    2006-01-01

    Full Text Available The association of thyroid disorders with skin manifestations is complex. Both hypothryoidism and hyperthyroidism are known to cause these changes. In order to study this association of skin changes in relation to hypothyroidism, a study was carried out in the outpatients department of Dermatology of Dayanand Medical College and Hospital, Ludhiana, over a period of 3 months from Jan-March 2005. Thirty two patients were enrolled in the study and parameters were noted regarding history, general symptoms, cutaneous signs and associated diseases. We found gain in weight (71.85% and lethargy (65.62% to be the most common complaints. On cutaneous examination, dry, coarse texture of the skin (56%, pigmentary disorders (37.5% and telogen effluvium (40.62% were the most common findings. Other associated disorders were vitiligo, melasma, pemphigus, alopecia areata, xanthelasma palpebrarum, etc.

  5. Smoking and skin disease

    Thomsen, S F; Sørensen, L T

    2010-01-01

    Tobacco smoking is a serious and preventable health hazard that can cause or exacerbate a number of diseases and shorten life expectancy, but the role of smoking as an etiologic factor in the development of skin disease is largely unknown. Although epidemiological evidence is sparse, findings...... suggest that tobacco smoking is a contributing factor in systemic lupus erythematosus, psoriasis, palmoplantar pustulosis, cutaneous squamous cell carcinoma, hidradenitis suppurativa, and genital warts. In contrast, smoking may confer some protective effects and mitigate other skin diseases, notably...... pemphigus vulgaris, pyoderma gangrenosum, aphthous ulcers, and Behçet's disease. Various degenerative dermatologic conditions are also impacted by smoking, such as skin wrinkling and dysregulated wound healing, which can result in post-surgical complications and delayed or even arrested healing of chronic...

  6. Epidermal skin grafting.

    Herskovitz, Ingrid; Hughes, Olivia B; Macquhae, Flor; Rakosi, Adele; Kirsner, Robert

    2016-09-01

    Autologous skin grafts, such as full- and split-thickness, have long been part of the reconstructive ladder as an option to close skin defects. Although they are effective in providing coverage, they require the need for a trained surgeon, use of anaesthesia and operating room and creation of a wound at the donor site. These drawbacks can be overcome with the use of epidermal skin grafts (ESGs), which can be harvested without the use of anaesthesia in an office setting and with minimal to no scarring at the donor site. ESGs consist only of the epidermal layer and have emerged as an appealing alternative to other autologous grafts for the treatment of acute and chronic wounds. In this article, we provide an overview of epidermal grafting and its role in wound management. PMID:27547964

  7. Intelligent skin: Real virtual

    Bühlmann, Vera

    2006-01-01

    What will it feel like to live in a city, where houses court each other in springtime? The 'intelligent-skin' project investigates the potential of media-façades in terms of corporate communication: what does it mean to build houses out of bricks of mediality? What does it imply to say that communication literally takes place? The virtualization of housing through large sized media skins will introduce medial milieus into our urban spheres to come – they might seize to function as add-ons...

  8. [Skin and hand disinfection].

    Mathis, U

    1991-04-01

    In modern medicine, hygiene has become an issue of ever increasing importance. Disinfection of hands is crucial, since hands are the main vector of bacteria. Successful disinfection depends not only on the appropriate choice of an active agent, but equally so on proper techniques and skin care. The spectre and the time profile of activity as well as the skin-protecting properties of the chosen disinfectant must be known. Basic knowledge of disinfection is necessary for a rational interpretation of the information given in the glossy printed material of advertisement. PMID:1858061

  9. Novel biodegradable porous scaffold applied to skin regeneration.

    Hui-Min Wang

    Full Text Available Skin wound healing is an important lifesaving issue for massive lesions. A novel porous scaffold with collagen, hyaluronic acid and gelatin was developed for skin wound repair. The swelling ratio of this developed scaffold was assayed by water absorption capacity and showed a value of over 20 g water/g dried scaffold. The scaffold was then degraded in time- and dose-dependent manners by three enzymes: lysozyme, hyaluronidase and collagenase I. The average pore diameter of the scaffold was 132.5±8.4 µm measured from SEM images. With human skin cells growing for 7 days, the SEM images showed surface fractures on the scaffold due to enzymatic digestion, indicating the biodegradable properties of this scaffold. To simulate skin distribution, the human epidermal keratinocytes, melanocytes and dermal fibroblasts were seeded on the porous scaffold and the cross-section immunofluorescent staining demonstrated normal human skin layer distributions. The collagen amount was also quantified after skin cells seeding and presented an amount 50% higher than those seeded on culture wells. The in vivo histological results showed that the scaffold ameliorated wound healing, including decreasing neutrophil infiltrates and thickening newly generated skin compared to the group without treatments.

  10. In vivo study of human skin using pulsed terahertz radiation

    Pickwell, E [Semiconductor Physics Group, Cavendish Laboratory, Cambridge University, Madingley Road, Cambridge CB3 0HE (United Kingdom); Cole, B E [TeraView Ltd, Unit 302/4 Cambridge Science Park, Cambridge CB4 0WG (United Kingdom); Fitzgerald, A J [TeraView Ltd, Unit 302/4 Cambridge Science Park, Cambridge CB4 0WG (United Kingdom); Pepper, M [Semiconductor Physics Group, Cavendish Laboratory, Cambridge University, Madingley Road, Cambridge CB3 0HE (United Kingdom); Wallace, V P [TeraView Ltd, Unit 302/4 Cambridge Science Park, Cambridge CB4 0WG (United Kingdom)

    2004-05-07

    Studies in terahertz (THz) imaging have revealed a significant difference between skin cancer (basal cell carcinoma) and healthy tissue. Since water has strong absorptions at THz frequencies and tumours tend to have different water content from normal tissue, a likely contrast mechanism is variation in water content. Thus, we have previously devised a finite difference time-domain (FDTD) model which is able to closely simulate the interaction of THz radiation with water. In this work we investigate the interaction of THz radiation with normal human skin on the forearm and palm of the hand in vivo. We conduct the first ever systematic in vivo study of the response of THz radiation to normal skin. We take in vivo reflection measurements of normal skin on the forearm and palm of the hand of 20 volunteers. We compare individual examples of THz responses with the mean response for the areas of skin under investigation. Using the in vivo data, we demonstrate that the FDTD model can be applied to biological tissue. In particular, we successfully simulate the interaction of THz radiation with the volar forearm. Understanding the interaction of THz radiation with normal skin will form a step towards developing improved imaging algorithms for diagnostic detection of skin cancer and other tissue disorders using THz radiation.

  11. Nutrition and magnesium absorption.

    Brink, E.J.

    1992-01-01

    The influence of various nutrients present in dairy products and soybean-based products on absorption of magnesium has been investigated. The studies demonstrate that soybean protein versus casein lowers apparent magnesium absorption in rats through its phytate component. However, true magnesium abs

  12. Zeeman atomic absorption spectroscopy

    A new method of background correction in atomic absorption spectroscopy has recently been introduced, based on the Zeeman splitting of spectral lines in a magnetic field. A theoretical analysis of the background correction capability observed in such instruments is presented. A Zeeman atomic absorption spectrometer utilizing a 50 Hz sine wave modulated magnetic field is described. (Auth.)

  13. About Skin-to-Skin Care (Kangaroo Care)

    ... Prenatal Baby Bathing & Skin Care Breastfeeding Crying & Colic Diapers & Clothing Feeding & Nutrition Preemie Sleep Teething & Tooth Care Toddler Preschool Gradeschool Teen Young Adult Healthy Children > Ages & Stages > Baby > Preemie > About Skin- ...

  14. Petawatt laser absorption bounded

    Levy, Matthew C; Tabak, Max; Libby, Stephen B; Baring, Matthew G

    2014-01-01

    The interaction of petawatt ($10^{15}\\ \\mathrm{W}$) lasers with solid matter forms the basis for advanced scientific applications such as table-top particle accelerators, ultrafast imaging systems and laser fusion. Key metrics for these applications relate to absorption, yet conditions in this regime are so nonlinear that it is often impossible to know the fraction of absorbed light $f$, and even the range of $f$ is unknown. Here using a relativistic Rankine-Hugoniot-like analysis, we show for the first time that $f$ exhibits a theoretical maximum and minimum. These bounds constrain nonlinear absorption mechanisms across the petawatt regime, forbidding high absorption values at low laser power and low absorption values at high laser power. For applications needing to circumvent the absorption bounds, these results will accelerate a shift from solid targets, towards structured and multilayer targets, and lead the development of new materials.

  15. Light and skin disease

    Because of the depletion of ozone in the stratosphere due to chlorofluorocarbons, the screening effect of this ozone layer on ultraviolet radiation (especially the so-called UV-B component) is reduced. This paper describes the impact of increased UV radiation on the human skin. Because of the 'ozone-hole', a distinct increase in the rate of skin cancer is to be expected which will affect all living beings but most of all man - an indirect consequence of the climate development. What makes the increased intensity of UV-B radiation so harmful is the fact that light-induced skin damage accumulates for the period of the life-time of the individual and cannot be reversed. A further thinning of stratospheric ozone would let through, in addition, the more short-waved ('harder') UV-C radiation. The latter, though clinically not significant currently, would then account for a further increase in the rate of malignant skin disease world-wide. (orig.)

  16. PPD skin test

    ... have been infected with the bacteria that cause TB. You may need treatment to lower the risk of the disease coming back (reactivation of the disease). A positive skin test does not mean that a person has active TB. More tests must be done to check whether ...

  17. Skin Conditions during Pregnancy

    ... line that runs from the navel to the pubic hair • Stretch marks •Acne • Spider veins • Varicose veins • Changes ... Nigra: A line running from the navel to pubic hair that darkens during pregnancy. Melasma: A common skin ...

  18. Preventing Skin Cancer

    2016-05-18

    A man and a woman talk about how they’ve learned to protect their skin from the sun over the years. .  Created: 5/18/2016 by National Center for Chronic Disease Prevention and Health Promotion (NCCDPHP).   Date Released: 5/18/2016.

  19. Slicing, skinning, and grafting

    Dumas, David; Kent IV, Richard P.

    2007-01-01

    We prove that a Bers slice is never algebraic, meaning that its Zariski closure in the character variety has strictly larger dimension. A corollary is that skinning maps are never constant. The proof uses grafting and the theory of complex projective structures.

  20. Skin peeling syndrome

    Sharma Rajeev; Kumar Ashok

    1994-01-01

    We are reporting a case of skin peeling syndrome, a rare disorder in which sudden generalized exfoliation of the stratum corneum occurs. Histopathologically, there was well formed subcorneal pustule filled with polymorphs and nuclear dust, considering this to be a varient of subcorneal pustular dermatosis, we have put the patient on Dapsone.

  1. Skin painting studies

    In order to estimate eventual risks to human health as a consequence of incidental and prolonged skin contact, it is necessary to obtain some information on the potential of coal-derived liquids to elicit skin cancer. In addition, it also must be established whether prolonged dermal exposure will produce signs of toxicity not only on the skin but to internal organs. During the past 2 years, they completed a life-long skin painting study with mice designed to answer some of these questions. The following materials were tested: Raw H-coal blend, containing 5700 ppm N; H-coal blend after low hydrotreatment (2650 ppm N); H-coal blend after high hydrotreatment (0.2 ppm N); H-coal home heating oil, a devolatilized version of the high-hydrotreatment H-coal blend; and an H-coal reformed naphtha. Two petroleum-derived references samples were used: Petroleum No. 2 fuel oil and high catalytically cracked naphtha. Benzo(a)pyrene was used as reference substance. Experimental animals were male and female C3H mice

  2. Researches on skin decontamination

    Living 4∼6 week-aged San Yuan white pigs (Suzhou, China) were used in skin decontamination experiments. Following a standard procedure, SM series of decontamination agents were used for decontamination of liquid nuclides. The results of immediate decontamination were as follows: K(decontamination efficiency) = 97.7% (decontamination factor DF = 43.5) for 131I; K>99% (DF>100) for 90Sr/90Y, MFP and U + TRU; K = 99.9% (DF 1000) for 137Cs. In 3 h-delayed decontamination, DF = 27∼67 (K 96.3%∼98.5) for the nuclides mentioned above. When the initiatory MFP contamination increased from 20 to 300 s-1·cm-2, the value of DF by immediate decontamination increased from 20 to 173 with the remaining activity not higher than 10 Bq·cm-2, and no additional decontamination was needed. For radioactive ash contamination of skin, DF 57∼1000 (K = 98.2%∼99.9%) in 4 h-delayed decontamination. SM series of decontamination agents are neutral liquid or cream without any irritative effect on skin. They are effective and easy to use in skin decontamination. (5 refs., 4 figs., 3 tabs.)

  3. Chemokines and skin diseases.

    Sugaya, Makoto

    2015-04-01

    Chemokines are small molecules that induce chemotaxis and activation of certain subsets of leukocytes. The expression patterns of chemokines and chemokine receptors are specific to certain organs and cells. Therefore, chemokines are important to elucidate the mechanism of organ-specific human diseases. CCL17 expressed by Langerhans cells, blood endothelial cells, and fibroblasts plays a key role in attracting Th2 cells and tumor cells of adult T-cell leukemia/lymphoma and mycosis fungoides/Sézary syndrome into the skin, developing various Th2-type inflammatory skin diseases as well as cutaneous lymphoma. CCL11 and CCL26 expressed by skin-resident cells, such as fibroblasts, blood endothelial cells, and keratinocytes, induce infiltration of CCR3-expressing cells such as Th2 cells and eosinophils. CCL11 may also serve as an autocrine as well as a paracrine in anaplastic large cell lymphoma. CX3CL1 expressed on blood endothelial cells leads to infiltration of CX3CR1(+) immune cells, such as mast cells, neutrophils, and macrophages, playing important roles in wound healing, tumor immunity, and vasculitis. Biologics targeting chemokines and their receptors are promising strategies for various skin diseases that are resistant to the current therapy. PMID:25182982

  4. Skin prick test in patients with chronic allergic skin disorders

    Pooja Bains; Alka Dogra

    2015-01-01

    Background: Chronic allergic skin disorders are the inflammatory and proliferative conditions in which both genetic and environmental factors play important roles. Chronic idiopathic urticaria (CIU) and atopic dermatitis (AD) are among the most common chronic allergic skin disorders. These can be provoked by various food and aeroallergens. Skin prick tests (SPTs) represent the cheapest and most effective method to diagnose type I hypersensitivity. Positive skin tests with a history suggestive...

  5. Cytokines and the Skin Barrier

    Jens Malte Baron

    2013-03-01

    Full Text Available The skin is the largest organ of the human body and builds a barrier to protect us from the harmful environment and also from unregulated loss of water. Keratinocytes form the skin barrier by undergoing a highly complex differentiation process that involves changing their morphology and structural integrity, a process referred to as cornification. Alterations in the epidermal cornification process affect the formation of the skin barrier. Typically, this results in a disturbed barrier, which allows the entry of substances into the skin that are immunologically reactive. This contributes to and promotes inflammatory processes in the skin but also affects other organs. In many common skin diseases, including atopic dermatitis and psoriasis, a defect in the formation of the skin barrier is observed. In these diseases the cytokine composition within the skin is different compared to normal human skin. This is the result of resident skin cells that produce cytokines, but also because additional immune cells are recruited. Many of the cytokines found in defective skin are able to influence various processes of differentiation and cornification. Here we summarize the current knowledge on cytokines and their functions in healthy skin and their contributions to inflammatory skin diseases.

  6. Sun Safety: Save Your Skin

    Full Text Available ... that exposure to the sun can cause skin cancer. Harmful rays from the sun—and from sunlamps ... enjoying the outdoors, the National Council on Skin Cancer Prevention (NCSCP) has designated May 25, 2012 as “ ...

  7. Sun Safety: Save Your Skin

    Full Text Available ... all types of skin damage caused by sunlight water resistance—sunscreen that stays on your skin longer, even if it gets wet. Reapply water-resistant sunscreens as instructed on the label back ...

  8. Sun Safety: Save Your Skin

    Full Text Available ... have pale skin blond, red, or light brown hair been treated for skin cancer a family member ... the sun. If you don't have much hair, apply sunscreen to the top of your head, ...

  9. SKIN DETECTION OF ANIMATION CHARACTERS

    Kazi Tanvir Ahmed Siddiqui

    2015-02-01

    Full Text Available The increasing popularity of animes makes it vulnerable to unwanted usages like copyright violations and pornography. That’s why, we need to develop a method to detect and recognize animation characters. Skin detection is one of the most important steps in this way. Though there are some methods to detect human skin color, but those methods do not work properly for anime characters. Anime skin varies greatly from human skin in color, texture, tone and in different kinds of lighting. They also vary greatly among themselves. Moreover, many other things (for example leather, shirt, hair etc., which are not skin, can have color similar to skin. In this paper, we have proposed three methods that can identify an anime character’s skin more successfully as compared with Kovac, Swift, Saleh and Osman methods, which are primarily designed for human skin detection. Our methods are based on RGB values and their comparative relations.

  10. Skin - abnormally dark or light

    ... ency/article/003242.htm Skin - abnormally dark or light To use the sharing features on this page, ... the hands. The bronze color can range from light to dark (in fair-skinned people) with the ...

  11. Radiation Therapy for Skin Cancer

    ... skin cells called melanocytes that produce skin color ( melanin ). Radiation therapy is used mostly for melanomas that ... in addition to surgery, chemotherapy or biologic therapy. Hair Epidermis Dermis Subcutaneous Hair Follicle Vein Artery © ASTRO ...

  12. Sun Safety: Save Your Skin

    Full Text Available ... For Consumers Consumer Updates Sun Safety: Save Your Skin! Share Tweet Linkedin Pin it More sharing options ... show that exposure to the sun can cause skin cancer. Harmful rays from the sun—and from ...

  13. Tips for Relieving Dry Skin

    ... resources Meet our partners Español Donate Diseases and treatments Acne and rosacea Bumps and growths Color problems Contagious skin diseases Cosmetic treatments Dry / sweaty skin Eczema / dermatitis Hair and scalp ...

  14. Sun Safety: Save Your Skin

    Full Text Available ... against all types of skin damage caused by sunlight water resistance—sunscreen that stays on your skin ... go out. back to top Protect the Eyes Sunlight reflecting off snow, sand, or water further increases ...

  15. Skin lesion removal-aftercare

    ... aftercare; Nevi - removal aftercare; Scissor excision aftercare; Skin tag removal aftercare; Mole removal aftercare; Skin cancer removal ... to the principles of the Health on the Net Foundation (www.hon.ch). The information provided herein ...

  16. Aspergillus antigen skin test (image)

    The aspergillus antigen skin test determines whether or not a person has been exposed to the mold aspergillus. It is performed by injecting an aspergillus antigen under the skin with a needle. After 48 ...

  17. Drugs Approved for Skin Cancer

    ... Ask about Your Treatment Research Drugs Approved for Skin Cancer This page lists cancer drugs approved by the Food and Drug Administration (FDA) for skin cancer, including drugs for basal cell carcinoma and melanoma. ...

  18. How to improve skin notation. Position paper from a workshop

    Sartorelli, Pietro; Ahlers, Heinz W; Alanko, Kristiina;

    2007-01-01

    The ICOH Scientific Committee on Occupational and Environmental Dermatoses organized an International Workshop on "Dermal risk assessment at workplace" with the aim of focussing on the different ways of approaching the concept of skin notation (S) for chemicals. The Workshop participants presented...... their ideas on several aspects of S such as the problems related to the absorption through the compromised skin, the different approaches to S and models that can be used as alternatives to S. Participants agreed to produce a position paper with the goal of exploring the actions needed to improve the S...

  19. Ozone layer, ultraviolet radiation and skin cancer

    If the ozone layer is reduced, the fluence rate of carcinogenic UV-light from the sun will increase at the surface of the earth. Calculations based on the assuption that the carcionogenic process starts by absorption of UV-light in DNA in cells in the basal layer of the skin, indicate that a 1% reduction in the ozone level leads to a 4-5% increase in the incidence of non-melanoma skin cancer, i.e. the amplification factor is 4-5. However, light at wavelenghts above 310 nm, which is poorly absorbed by DNA as well as by ozone, seems to be carcinogenic. The amplification factor in South Norway is estimated to be about 2 or slightly less. The amplification factor decreases with increasing distance from the equator. The estimation is based on the action spectrum for mutation of cells in the basal layer of the skin, a spectrum similar to the action spectrum for carcinogenesis in mice, and to that for erythema in humans. The fluence rate of carcionogenic UV-light is probably more dependent on other climatic and environmental factors than on the ozone level. Thus, it was recently reported that the integrated yearly UVB dose measured several places in USA showed a decreasing tendency with time in the period 1974-1985

  20. Coumarin derivatives, but not coumarin itself, cause skin irritation via topical delivery.

    Pan, Tai-Long; Wang, Pei-Wen; Aljuffali, Ibrahim A; Leu, Yann-Lii; Hung, Yi-Yun; Fang, Jia-You

    2014-04-21

    Coumarin and its derivatives are widely employed as a fragrance in cosmetics and skin care products. The skin absorption level and possible disruption to the skin by topical application of coumarins were evaluated in this study. Percutaneous absorption of osthole, daphnoretin, coumarin, byakangelicin, and 7-hydroxycoumarin was assessed in vitro and in vivo. Skin physiology measurements and immunoblotting were utilized as methodologies for validating toxicity. The relationship between structures and permeation/toxicity of coumarins was elucidated. Both equimolar concentration and saturated solubility in 30% ethanol were used as the applied dose. Osthole with the most lipophilic characteristic demonstrated the greatest skin accumulation, followed by coumarin and 7-hydroxycoumarin. Coumarin was the permeant with the highest flux across the skin. The trend of in vivo deposition was consistent with that of the in vitro profiles. Skin uptake of osthole was 8-fold higher than that of coumarin. Hair follicles played a significant role as a pathway for transport of coumarin according to the examination of follicular accumulation. Osthole and 7-hydroxycoumarin slightly, but significantly, enhanced transepidermal water loss after a consecutive 5-day administration. The immunoblotting profiling verified the role of proliferation in skin damage induced by osthole, byakangelicin, and 7-hydroxycoumarin. The proliferation-related proteins examined in this work included glucose-regulated proteins, cytokeratin, and C-myc. Daphnoretin and coumarin showed a negligible alteration on protein biomarkers. The experimental results suggested that skin irritation caused by coumarins was mainly derived from the analogs but not from coumarin itself. PMID:24561300

  1. Quasar Absorption Studies

    Mushotzky, Richard (Technical Monitor); Elvis, Martin

    2004-01-01

    The aim of the proposal is to investigate the absorption properties of a sample of inter-mediate redshift quasars. The main goals of the project are: Measure the redshift and the column density of the X-ray absorbers; test the correlation between absorption and redshift suggested by ROSAT and ASCA data; constrain the absorber ionization status and metallicity; constrain the absorber dust content and composition through the comparison between the amount of X-ray absorption and optical dust extinction. Unanticipated low energy cut-offs where discovered in ROSAT spectra of quasars and confirmed by ASCA, BeppoSAX and Chandra. In most cases it was not possible to constrain adequately the redshift of the absorber from the X-ray data alone. Two possibilities remain open: a) absorption at the quasar redshift; and b) intervening absorption. The evidences in favour of intrinsic absorption are all indirect. Sensitive XMM observations can discriminate between these different scenarios. If the absorption is at the quasar redshift we can study whether the quasar environment evolves with the Cosmic time.

  2. Tissue Engineered Human Skin Equivalents

    Zheng Zhang; Michniak-Kohn, Bozena B.

    2012-01-01

    Human skin not only serves as an important barrier against the penetration of exogenous substances into the body, but also provides a potential avenue for the transport of functional active drugs/reagents/ingredients into the skin (topical delivery) and/or the body (transdermal delivery). In the past three decades, research and development in human skin equivalents have advanced in parallel with those in tissue engineering and regenerative medicine. The human skin equivalents are used commerc...

  3. A REVIEW ON SKIN CANCER

    S. Ramya Silpa; Chidvila V

    2013-01-01

    Skin cancer can be of 2 types mainly. They are malignant melanoma and non-malignant melanoma. Skin cancer mainly occurs due to exposure of sunlight. Ozone depletion and chemical exposures are other factors involved in precipitating skin cancer. Mutations of p53 gene are involved in UV- induced carcinogenesis. P53 gene acts vital in development of SCC. So, prevention of skin cancer is the main criteria. Regular application of sunscreens could be one of the primary prevention. The purpose of pr...

  4. Microbial Skin Inhabitants: Friends Forever.

    Dorrestein, Pieter C; Gallo, Richard L; Knight, Rob

    2016-05-01

    To gain insight into the stability of the microbial communities that inhabit our skin, Oh et al., in a tour-de-force effort, map the human skin metagenomes over time. Remarkably, their data indicate that the individual, not the environment, primarily drives the composition of skin microbial communities. PMID:27153488

  5. Skin Cancers of the Feet

    ... skin of the lower legs and feet. Skin cancers affecting the feet may have a very different appearance from those arising on the rest of the body. For this reason, a podiatrist's knowledge and clinical training is of ... and malignant skin tumors. Learn the ABCDs of melanoma. If you notice ...

  6. Skin Pedagogies and Abject Bodies

    Kenway, Jane; Bullen, Elizabeth

    2011-01-01

    How does the beauty industry "narrate the skin"? What does it teach women from different cultural groups about the female body? How does skin function as a site where female subjection and abjection are produced and reproduced? In this paper we examine the skin industry pointing to its extreme commodification of the female body and to the…

  7. What is the discrepancy between drug permeation into/across intact and diseased skins? Atopic dermatitis as a model.

    Fang, Yi-Ping; Yang, Sien-Hung; Lee, Chih-Hung; Aljuffali, Ibrahim A; Kao, Hsiao-Ching; Fang, Jia-You

    2016-01-30

    The discrepancy in drug absorption between healthy and diseased skins is an issue that needs to be elucidated. The present study attempted to explore the percutaneous absorption of drugs via lesional skin by using atopic dermatitis (AD) as a model. Tape-stripping and ovalbumin (OVA) sensitization induced AD-like skin. The lesions were evaluated by physiological parameters, histology, cytokines, and differentiation proteins. The permeants of tacrolimus, 8-methoxypsoralen, methotrexate, and dextran were used to examine in vitro and in vivo cutaneous permeation. Transepidermal water loss (TEWL) increased from 5.2 to 27.4 g/m(2)/h by OVA treatment. AD-like lesions were characterized by hyperplasia, skin redness, desquamation, and infiltration of inflammatory cells. Repeated OVA challenge produced a T-helper 2 (Th2) hypersensitivity accompanied by downregulation of filaggrin, involucrin, and integrin β. Tacrolimus, the most lipophilic permeant, revealed an increase of cutaneous deposition by 2.7-fold in AD-like skin compared to intact skin. The transdermal flux of methotrexate and dextran, the hydrophilic permeants, across AD-like skin increased about 18 times compared to the control skin. Surprisingly, AD-like skin showed less skin deposition of 8-methoxypsoralen than intact skin. This may be because the deficient lipids in the atopic-affected stratum corneum (SC) diminished drug partitioning into the superficial skin layer. The fluorescence and confocal microscopic images demonstrated a broad and deep passage of small-molecular and macromolecular dyes into AD-like skin. The results obtained from this report were advantageous for showing how the lesional skin influenced percutaneous absorption. PMID:26657274

  8. The influence of water mixtures on the dermal absorption of glycol ethers

    Glycol ethers are solvents widely used alone and as mixtures in industrial and household products. Some glycol ethers have been shown to have a range of toxic effects in humans following absorption and metabolism to their aldehyde and acid metabolites. This study assessed the influence of water mixtures on the dermal absorption of butoxyethanol and ethoxyethanol in vitro through human skin. Butoxyethanol penetrated human skin up to sixfold more rapidly from aqueous solution (50%, 450 mg/ml) than from the neat solvent. Similarly penetration of ethoxyethanol was increased threefold in the presence of water (50%, 697 mg/ml). There was a corresponding increase in apparent permeability coefficient as the glycol ether concentration in water decreased. The maximum penetration rate of water also increased in the presence of both glycol ethers. Absorption through a synthetic membrane obeyed Fick's Law and absorption through rat skin showed a similar profile to human skin but with a lesser effect. The mechanisms for this phenomenon involves disruption of the stratum corneum lipid bilayer by desiccation by neat glycol ether micelles, hydration with water mixtures and the physicochemical properties of the glycol ether-water mixtures. Full elucidation of the profile of absorption of glycol ethers from mixtures is required for risk assessment of dermal exposure. This work supports the view that risk assessments for dermal contact scenarios should ideally be based on absorption data obtained for the relevant formulation or mixture and exposure scenario and that absorption derived from permeability coefficients may be inappropriate for water-miscible solvents

  9. [Cutaneous absorption of chemicals].

    Schröder, J

    1986-09-01

    Chemicals have become indispensible for the maintenance of health in animals and man. The route of administration of each medicament is decided by factors such as site of desired action, chemistry of the active ingredient, age and species of the patient, and frequency of administration (or desired duration of activity). In situations where the oral and hypodermic routes, which are used most frequently, are inadequate or unsatisfactory, dermal application can provide a valuable alternative method to achieve systemic activity. Examples of formulations currently available for dermal application contain diverse chemicals and are intended for a variety of purposes, such as crufomate against cattle grubs, fenthion against cattle lice, levamisole against gastrointestinal nematodes, nitroglycerine for angina pectoris, and scopolamine for motion sickness. The skin acts as a barrier to penetration by chemicals and micro-organisms by virtue of its morphology and chemical composition. Chemicals which do penetrate, do not necessarily pass through the appendages (hair follicles and gland ducts), but mostly penetrate through the interjacent epidermis, either through the cells, or via the intracellular spaces. These spaces have recently been shown by electron microscopy to be filled by an amorphous substance which exudes on the skin surface in convex ridges. This substance has a lipid nature, but is not hydrophobic as is often accepted. For a chemical to be able to penetrate the skin, it must be partially water and lipid soluble, polar, and weakly ionizing. A variety of factors can possibly affect the permeability of skin for a chemical. These include species differences in morphology (skin thickness, tightness of intercellular junctions, density of hair follicles and other appendages), biochemistry, and physiology; seasonal and climatic variations; and differences between breeds and genders. Species differences in skin permeability are largely unpredictable and inconsistent. An

  10. Clinical skin imaging using color spatial frequency domain imaging (Conference Presentation)

    Yang, Bin; Lesicko, John; Moy, Austin J.; Reichenberg, Jason; Tunnell, James W.

    2016-02-01

    Skin diseases are typically associated with underlying biochemical and structural changes compared with normal tissues, which alter the optical properties of the skin lesions, such as tissue absorption and scattering. Although widely used in dermatology clinics, conventional dermatoscopes don't have the ability to selectively image tissue absorption and scattering, which may limit its diagnostic power. Here we report a novel clinical skin imaging technique called color spatial frequency domain imaging (cSFDI) which enhances contrast by rendering color spatial frequency domain (SFD) image at high spatial frequency. Moreover, by tuning spatial frequency, we can obtain both absorption weighted and scattering weighted images. We developed a handheld imaging system specifically for clinical skin imaging. The flexible configuration of the system allows for better access to skin lesions in hard-to-reach regions. A total of 48 lesions from 31 patients were imaged under 470nm, 530nm and 655nm illumination at a spatial frequency of 0.6mm^(-1). The SFD reflectance images at 470nm, 530nm and 655nm were assigned to blue (B), green (G) and red (R) channels to render a color SFD image. Our results indicated that color SFD images at f=0.6mm-1 revealed properties that were not seen in standard color images. Structural features were enhanced and absorption features were reduced, which helped to identify the sources of the contrast. This imaging technique provides additional insights into skin lesions and may better assist clinical diagnosis.