Effect of human skin grafts on whole-body heat loss during exercise heat stress: a case report.

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Ganio, Matthew S; Gagnon, Daniel; Stapleton, Jill; Crandall, Craig G; Kenny, Glen P

2013-01-01

When exposed to heat stress, increases in cutaneous blood flow and sweating in well-healed grafted skin are severely attenuated, which could impair whole-body heat loss if skin grafts cover a large portion of total body surface area (TBSA). It is unknown to what extent whole-body heat loss is impaired when skin grafts cover a significant (eg, >50%) proportion of TBSA. The authors examined whole-body heat exchange during and after 60 min of cycling exercise in the heat (35°C; 25% relative humidity), at a fixed rate of metabolic heat production (~400 W) in a woman (age, 36 years; mass, 78.2 kg) with well-healed (17+ years) skin grafts covering 75% of TBSA. Her responses were compared with two noninjured control subjects. Whole-body evaporative and dry heat exchange were measured by direct calorimetry. While exercising in the same ambient conditions and at the same rate of heat production, relative evaporative heat loss of nongrafted skin in the grafted subject (ie, evaporative heat loss per m) was nearly twice that of the control subjects. However, total rate of evaporative heat loss reached only 59% of the amount required for heat balance in the skin-grafted subject compared with 92 ± 3% in controls. Thus, the increase in core temperature was 2-fold greater for the grafted (1.22°C) vs control (0.61 ± 0.19°C) individuals. This case study demonstrates that a large area of grafted skin greatly diminishes maximum evaporative heat loss during exercise in the heat, making a compensable environment for control subjects uncompensable for skin-grafted individuals.

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

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

2018-01-01

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

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

NARCIS (Netherlands)

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

2007-01-01

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

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

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

2017-10-01

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

Skin Diseases: Cross-section of human skin

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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 ...

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

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Gallo, Richard L

2017-06-01

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

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

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

2018-03-24

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

Composition of human skin microbiota affects attractiveness to malaria mosquitoes.

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Niels O Verhulst

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

Russell bodies in a skin biopsy: a case report

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Verheij Joanne

2009-11-01

Full Text Available Abstract Introduction The presence of eosinophilic bodies in a skin biopsy can be found in a variety of situations and this may present a challenge to the pathologist. The differential diagnosis of these eosinophilic structures include microorganisms such as histoplasmosis or cryptococcosis, fungi, Michaelis-Gutmann bodies, deposits of amyloid or immunoglobulins, colloid bodies or elastic bodies. Case presentation During a routine examination of a skin biopsy with actinic keratosis taken from the cheek of a 61-year-old man, clusters of eosinophilic bodies were seen within an inflammatory infiltrate in the dermis, both intracytoplasmic and extracellular. Using additional immunohistochemical staining, these structures were identified as polyclonal Russell bodies. Conclusion The differential diagnosis of intracytoplasmic eosinophilic structures in a skin biopsy includes Russell bodies, an uncommon finding that may be associated with chronic inflammatory conditions.

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

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Sven van Eijl

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

Influence of mechanical stimulation on human dermal fibroblasts derived from different body sites.

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Kuang, Ruixia; Wang, Zhiguo; Xu, Quanchen; Liu, Su; Zhang, Weidong

2015-01-01

Mechanical stimulation is highly associated with pathogenesis of human hypertrophic scar. Although much work has focused on the influence of mechanical stress on fibroblast populations from various tissues and organs in the human body, their effects on cultured dermal fibroblasts by the area of the body have not been as well studied. In this study, cultures of skin fibroblasts from two different body sites were subjected to cyclic mechanical stimulation with a 10% stretching amplitude at a frequency of 0.1 Hz for 24, 36 and 48 hours, respectively, and thereafter harvested for experimental assays. Fibroblasts from scapular upper back skin, subjected to mechanical loads for 36 and 48 hours, respectively, were observed to proliferate at a higher rate and reach confluent more rapidly during in vitro culturing, had higher expression levels of mRNA and protein production of integrin β1, p130Cas and TGF β1 versus those from medial side of upper arm. These data indicate that skin fibroblasts, with regard to originated body sites studied in the experiments, display a diversity of mechanotransduction properties and biochemical reactions in response to applied mechanical stress, which contributes to the increased susceptibility to hypertrophic scars formation at certain areas of human body characterized by higher skin and muscle tension.

The effect of stress on core and peripheral body temperature in humans.

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Vinkers, Christiaan H; Penning, Renske; Hellhammer, Juliane; Verster, Joris C; Klaessens, John H G M; Olivier, Berend; Kalkman, Cor J

2013-09-01

Even though there are indications that stress influences body temperature in humans, no study has systematically investigated the effects of stress on core and peripheral body temperature. The present study therefore aimed to investigate the effects of acute psychosocial stress on body temperature using different readout measurements. In two independent studies, male and female participants were exposed to a standardized laboratory stress task (the Trier Social Stress Test, TSST) or a non-stressful control task. Core temperature (intestinal and temporal artery) and peripheral temperature (facial and body skin temperature) were measured. Compared to the control condition, stress exposure decreased intestinal temperature but did not affect temporal artery temperature. Stress exposure resulted in changes in skin temperature that followed a gradient-like pattern, with decreases at distal skin locations such as the fingertip and finger base and unchanged skin temperature at proximal regions such as the infra-clavicular area. Stress-induced effects on facial temperature displayed a sex-specific pattern, with decreased nasal skin temperature in females and increased cheek temperature in males. In conclusion, the amplitude and direction of stress-induced temperature changes depend on the site of temperature measurement in humans. This precludes a direct translation of the preclinical stress-induced hyperthermia paradigm, in which core temperature uniformly rises in response to stress to the human situation. Nevertheless, the effects of stress result in consistent temperature changes. Therefore, the present study supports the inclusion of body temperature as a physiological readout parameter of stress in future studies.

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

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Shiratsuchi, Eri; Nakaba, Misako; Yamada, Michio

2016-03-30

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

Human reconstructed skin xenografts on mice to model skin physiology.

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

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

A bacteriophages journey through the human body.

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Barr, Jeremy J

2017-09-01

The human body is colonized by a diverse collective of microorganisms, including bacteria, fungi, protozoa and viruses. The smallest entity of this microbial conglomerate are the bacterial viruses. Bacteriophages, or phages for short, exert significant selective pressure on their bacterial hosts, undoubtedly influencing the human microbiome and its impact on our health and well-being. Phages colonize all niches of the body, including the skin, oral cavity, lungs, gut, and urinary tract. As such our bodies are frequently and continuously exposed to diverse collections of phages. Despite the prevalence of phages throughout our bodies, the extent of their interactions with human cells, organs, and immune system is still largely unknown. Phages physically interact with our mucosal surfaces, are capable of bypassing epithelial cell layers, disseminate throughout the body and may manipulate our immune system. Here, I establish the novel concept of an "intra-body phageome," which encompasses the collection of phages residing within the classically "sterile" regions of the body. This review will take a phage-centric view of the microbiota, human body, and immune system with the ultimate goal of inspiring a greater appreciation for both the indirect and direct interactions between bacteriophages and their mammalian hosts. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

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

OpenAIRE

Veijgen, N.K.

2013-01-01

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

In-Vivo Human Skin to Textiles Friction Measurements

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Pfarr, Lukas; Zagar, Bernhard

2017-10-01

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

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

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Shimizu, Rana; Nonomura, Yoshimune

2018-01-01

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

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

International Nuclear Information System (INIS)

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

1990-01-01

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

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

International Nuclear Information System (INIS)

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

1987-01-01

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

Mechanical response of human female breast skin under uniaxial stretching.

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

2017-10-01

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

Prediction of human core body temperature using non-invasive measurement methods.

Science.gov (United States)

Niedermann, Reto; Wyss, Eva; Annaheim, Simon; Psikuta, Agnes; Davey, Sarah; Rossi, René Michel

2014-01-01

The measurement of core body temperature is an efficient method for monitoring heat stress amongst workers in hot conditions. However, invasive measurement of core body temperature (e.g. rectal, intestinal, oesophageal temperature) is impractical for such applications. Therefore, the aim of this study was to define relevant non-invasive measures to predict core body temperature under various conditions. We conducted two human subject studies with different experimental protocols, different environmental temperatures (10 °C, 30 °C) and different subjects. In both studies the same non-invasive measurement methods (skin temperature, skin heat flux, heart rate) were applied. A principle component analysis was conducted to extract independent factors, which were then used in a linear regression model. We identified six parameters (three skin temperatures, two skin heat fluxes and heart rate), which were included for the calculation of two factors. The predictive value of these factors for core body temperature was evaluated by a multiple regression analysis. The calculated root mean square deviation (rmsd) was in the range from 0.28 °C to 0.34 °C for all environmental conditions. These errors are similar to previous models using non-invasive measures to predict core body temperature. The results from this study illustrate that multiple physiological parameters (e.g. skin temperature and skin heat fluxes) are needed to predict core body temperature. In addition, the physiological measurements chosen in this study and the algorithm defined in this work are potentially applicable as real-time core body temperature monitoring to assess health risk in broad range of working conditions.

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

NARCIS (Netherlands)

Veijgen, N.K.

2013-01-01

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

Structural and biophysical characteristics of human skin in maintaining proper epidermal barrier function

Directory of Open Access Journals (Sweden)

Magdalena Boer

2016-02-01

Full Text Available The complex structure of human skin and its physicochemical properties turn it into an efficient outermost defence line against exogenous factors, and help maintain homeostasis of the human body. This role is played by the epidermal barrier with its major part – stratum corneum. The condition of the epidermal barrier depends on individual and environmental factors. The most important biophysical parameters characterizing the status of this barrier are the skin pH, epidermal hydration, transepidermal water loss and sebum excretion. The knowledge of biophysical skin processes may be useful for the implementation of prophylactic actions whose aim is to restore the barrier function.

Electroosmotic pore transport in human skin.

Science.gov (United States)

Uitto, Olivia D; White, Henry S

2003-04-01

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

Experimental metagenomics and ribosomal profiling of the human skin microbiome.

Science.gov (United States)

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

2017-03-01

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

Characterization of ionizing radiation effects on human skin allografts

International Nuclear Information System (INIS)

Bourroul, Selma Cecilia

2004-01-01

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

Methodological assessment of skin and limb blood flows in the human forearm during thermal and baroreceptor provocations

OpenAIRE

Brothers, R. Matthew; Wingo, Jonathan E.; Hubing, Kimberly A.; Crandall, Craig G.

2010-01-01

Skin blood flow responses in the human forearm, assessed by three commonly used technologies—single-point laser-Doppler flowmetry, integrated laser-Doppler flowmetry, and laser-Doppler imaging—were compared in eight subjects during normothermic baseline, acute skin-surface cooling, and whole body heat stress (Δ internal temperature = 1.0 ± 0.2°C; P < 0.001). In addition, while normothermic and heat stressed, subjects were exposed to 30-mmHg lower-body negative pressure (LBNP). Skin blood flow...

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

International Nuclear Information System (INIS)

Borisova, E.; Avramov, L.

2000-01-01

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

Core body temperature, skin temperature, and interface pressure. Relationship to skin integrity in nursing home residents.

Science.gov (United States)

Knox, D M

1999-06-01

To ascertain the effects of 1-, 1 1/2-, and 2-hour turning intervals on nursing home residents' skin over the sacrum and trochanters. (1) the higher the core body temperature, the higher the skin surface temperature; (2) the 2-hour turning interval would have significantly higher skin surface temperature; (3) there would be no relationship between skin surface temperature and interface pressure; and (4) the sacrum would have the lowest skin surface temperature. Modified Latin-square. For-profit nursing home. Convenience sample of 26 residents who scored bedridden. First Temp measured core temperature; a disposable thermistor temperature probe, skin temperature; and a digital interface pressure evaluator, the interface pressure. Negative correlation (r = -.33, P = .003) occurred between core body temperature and skin surface temperature. Skin surface temperature rose at the end of the 2-hour turning interval but was not significant (F = (2.68) = .73, P = .49). Weak negative relationship (r = -12, P = .29) occurred between skin surface temperature and interface pressure, and sacral skin surface temperature was significantly lower for the left trochanter only (F = (8.68) = 7.05, P = .002). Although hypotheses were not supported, more research is needed to understand how time in position and multiple chronic illnesses interact to affect skin pressure tolerance.

Supraclavicular skin temperature as a measure of 18F-FDG uptake by BAT in human subjects.

Science.gov (United States)

Boon, Mariëtte R; Bakker, Leontine E H; van der Linden, Rianne A D; Pereira Arias-Bouda, Lenka; Smit, Frits; Verberne, Hein J; van Marken Lichtenbelt, Wouter D; Jazet, Ingrid M; Rensen, Patrick C N

2014-01-01

Brown adipose tissue (BAT) has emerged as a novel player in energy homeostasis in humans and is considered a potential new target for combating obesity and related diseases. The current 'gold standard' for quantification of BAT volume and activity is cold-induced 18F-FDG uptake in BAT. However, use of this technique is limited by cost and radiation exposure. Given the fact that BAT is a thermogenic tissue, mainly located in the supraclavicular region, the aim of the current study was to investigate whether cold-induced supraclavicular skin temperature and core body temperature may be alternative markers of BAT activation in humans. BAT volume and activity were measured in 24 healthy lean adolescent males (mean age 24.1±0.8 years), using cold-induced 18F-FDG uptake with PET-CT. Core body temperature was measured continuously in the small intestine with use of an ingestible telemetric capsule and skin temperature was measured by eighteen wireless iButtons attached to the skin following ISO-defined locations. Proximal and distal (hand/feet) skin temperatures markedly decreased upon cold exposure, while supraclavicular skin temperature significantly increased (35.2±0.1 vs. 35.5±0.1°C, p = 0.001). Furthermore, cold-induced supraclavicular skin temperature positively correlated with both total (R2 = 0.28, P = 0.010) and clavicular BAT volume (R2 = 0.20, P = 0.030) and clavicular SUVmax (R2 = 0.27, P = 0.010), while core body temperature did not. Supraclavicular skin temperature as measured by iButtons may have predictive value for BAT detection in adult humans. This is highly desirable considering the increasing interest in pharmacological interventions to stimulate BAT in human subjects. NTR 2473.

NIH Human Microbiome Project defines normal bacterial makeup of the body

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Microbes inhabit just about every part of the human body, living on the skin, in the gut, and up the nose. Sometimes they cause sickness, but most of the time, microorganisms live in harmony with their human hosts, providing vital functions essential for

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

Directory of Open Access Journals (Sweden)

Petkar K.C.

2007-05-01

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

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

Science.gov (United States)

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

2015-01-01

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

About possibility of temperature trace observing on the human skin using commercially available IR camera

Science.gov (United States)

Trofimov, Vyacheslav A.; Trofimov, Vladislav V.; Shestakov, Ivan L.; Blednov, Roman G.

2016-09-01

One of urgent security problems is a detection of objects placed inside the human body. Obviously, for safety reasons one cannot use X-rays for such object detection widely and often. Three years ago, we have demonstrated principal possibility to see a temperature trace, induced by food eating or water drinking, on the human body skin by using a passive THz camera. However, this camera is very expensive. Therefore, for practice it will be very convenient if one can use the IR camera for this purpose. In contrast to passive THz camera using, the IR camera does not allow to see the object under clothing, if an image, produced by this camera, is used directly. Of course, this is a big disadvantage for a security problem solution based on the IR camera using. To overcome this disadvantage we develop novel approach for computer processing of IR camera images. It allows us to increase a temperature resolution of IR camera as well as increasing of human year effective susceptibility. As a consequence of this, a possibility for seeing of a human body temperature changing through clothing appears. We analyze IR images of a person, which drinks water and eats chocolate. We follow a temperature trace on human body skin, caused by changing of temperature inside the human body. Some experiments were made with measurements of a body temperature covered by T-shirt. Shown results are very important for the detection of forbidden objects, cancelled inside the human body, by using non-destructive control without using X-rays.

Gigapixel photography for skin cancer surveillance: a novel alternative to total-body photography.

Science.gov (United States)

Mikailov, Anar; Blechman, Adam

2013-11-01

There is substantial evidence supporting the use of cutaneous imaging in combination with standard total-body skin examinations for early detection and treatment of melanoma. In the last 2 decades, total-body photography (TBP) has been widely used in combination with standard total-body skin examinations for active skin cancer surveillance with proven clinical utility; however, the groundbreaking image detail provided by gigapixel photography (GP) could improve dermatologists' ability to monitor suspicious lesions and therefore could serve a critical role in supplementing traditional total-body skin examinations for skin cancer surveillance. Although it has been successfully implemented in other fields, future studies are required to determine the effectiveness of GP in dermatology.

Is there just one lesion? The need for whole body skin examination in patients presenting with non-melanocytic skin cancer.

Science.gov (United States)

Terrill, Patricia Jane; Fairbanks, Sian; Bailey, Michael

2009-10-01

In patients presenting with non-melanoma skin cancer (NMSC) the frequency of concurrently presenting tumours is poorly documented. Whole body skin examination is recommended but in a recent survey of Australian General Practitioners and skin cancer clinics doctors it was infrequently performed. The aim of this study was to examine the incidence of concurrent skin cancer at initial presentation and therefore to examine the need for whole body skin examination for NMSC presentations. One hundred consecutive patients with a referral diagnosis indicative of NMSC were examined. Data was analysed as to the referring doctor's diagnosis, whole body skin examination findings and histology of excised lesions. Epidemiological data was obtained by patient questionnaire. One hundred patients, 41 males and 59 females, with a mean age of 70 years (range 39-91 years) underwent whole body skin examination. Sixty-seven per cent of patients were found to have additional lesions requiring treatment, 46% sin cancers (30 patients basal cell carcinomas, five squamous cell carcinomas, seven basal and squamous cell carcinomas, two lentigo maligna, two adenexal tumours) and 21% solar keratoses. Thirty-four of the additional lesions detected were in areas covered by clothing. Sixty-eight patients had a past history of skin cancer excision. In the Australian patient population, the need for whole body skin examination is essential to avoid missing concurrent lesions. Ongoing surveillance is also essential as these patients have a high risk of developing future NMSC.

Simultaneous and multi-point measurement of ammonia emanating from human skin surface for the estimation of whole body dermal emission rate.

Science.gov (United States)

Furukawa, Shota; Sekine, Yoshika; Kimura, Keita; Umezawa, Kazuo; Asai, Satomi; Miyachi, Hayato

2017-05-15

Ammonia is one of the members of odor gases and a possible source of odor in indoor environment. However, little has been known on the actual emission rate of ammonia from the human skin surface. Then, this study aimed to estimate the whole-body dermal emission rate of ammonia by simultaneous and multi-point measurement of emission fluxes of ammonia employing a passive flux sampler - ion chromatography system. Firstly, the emission fluxes of ammonia were non-invasively measured for ten volunteers at 13 sampling positions set in 13 anatomical regions classified by Kurazumi et al. The measured emission fluxes were then converted to partial emission rates using the surface body areas estimated by weights and heights of volunteers and partial rates of 13 body regions. Subsequent summation of the partial emission rates provided the whole body dermal emission rate of ammonia. The results ranged from 2.9 to 12mgh -1 with an average of 5.9±3.2mgh -1 per person for the ten healthy young volunteers. The values were much greater than those from human breath, and thus the dermal emission of ammonia was found more significant odor source than the breath exhalation in indoor environment. Copyright © 2017 Elsevier B.V. All rights reserved.

Considerations for the measurement of core, skin and mean body temperatures.

Science.gov (United States)

Taylor, Nigel A S; Tipton, Michael J; Kenny, Glen P

2014-12-01

Despite previous reviews and commentaries, significant misconceptions remain concerning deep-body (core) and skin temperature measurement in humans. Therefore, the authors have assembled the pertinent Laws of Thermodynamics and other first principles that govern physical and physiological heat exchanges. The resulting review is aimed at providing theoretical and empirical justifications for collecting and interpreting these data. The primary emphasis is upon deep-body temperatures, with discussions of intramuscular, subcutaneous, transcutaneous and skin temperatures included. These are all turnover indices resulting from variations in local metabolism, tissue conduction and blood flow. Consequently, inter-site differences and similarities may have no mechanistic relationship unless those sites have similar metabolic rates, are in close proximity and are perfused by the same blood vessels. Therefore, it is proposed that a gold standard deep-body temperature does not exist. Instead, the validity of each measurement must be evaluated relative to one's research objectives, whilst satisfying equilibration and positioning requirements. When using thermometric computations of heat storage, the establishment of steady-state conditions is essential, but for clinically relevant states, targeted temperature monitoring becomes paramount. However, when investigating temperature regulation, the response characteristics of each temperature measurement must match the forcing function applied during experimentation. Thus, during dynamic phases, deep-body temperatures must be measured from sites that track temperature changes in the central blood volume. Copyright © 2014 Elsevier Ltd. All rights reserved.

Influence of probe pressure on diffuse reflectance spectra of human skin measured in vivo

Science.gov (United States)

Popov, Alexey P.; Bykov, Alexander V.; Meglinski, Igor V.

2017-11-01

Mechanical pressure superficially applied on the human skin surface by a fiber-optic probe influences the spatial distribution of blood within the cutaneous tissues. Upon gradual load of weight on the probe, a stepwise increase in the skin reflectance spectra is observed. The decrease in the load follows the similar inverse staircase-like tendency. The observed stepwise reflectance spectra changes are due to, respectively, sequential extrusion of blood from the topical cutaneous vascular beds and their filling afterward. The obtained results are confirmed by Monte Carlo modeling. This implies that pressure-induced influence during the human skin diffuse reflectance spectra measurements in vivo should be taken into consideration, in particular, in the rapidly developing area of wearable gadgets for real-time monitoring of various human body parameters.

Realtime Reconstruction of an Animating Human Body from a Single Depth Camera.

Science.gov (United States)

Chen, Yin; Cheng, Zhi-Quan; Lai, Chao; Martin, Ralph R; Dang, Gang

2016-08-01

We present a method for realtime reconstruction of an animating human body,which produces a sequence of deforming meshes representing a given performance captured by a single commodity depth camera. We achieve realtime single-view mesh completion by enhancing the parameterized SCAPE model.Our method, which we call Realtime SCAPE, performs full-body reconstruction without the use of markers.In Realtime SCAPE, estimations of body shape parameters and pose parameters, needed for reconstruction, are decoupled. Intrinsic body shape is first precomputed for a given subject, by determining shape parameters with the aid of a body shape database. Subsequently, per-frame pose parameter estimation is performed by means of linear blending skinning (LBS); the problem is decomposed into separately finding skinning weights and transformations. The skinning weights are also determined offline from the body shape database,reducing online reconstruction to simply finding the transformations in LBS. Doing so is formulated as a linear variational problem;carefully designed constraints are used to impose temporal coherence and alleviate artifacts. Experiments demonstrate that our method can produce full-body mesh sequences with high fidelity.

Modeling skin blood flow: a neuro-physiological approach

NARCIS (Netherlands)

Kingma, B.R.M.; Saris, W.H.M.; Frijns, A.J.H.; Steenhoven, van A.A.; Marken Lichtenbelt, van W.D.

2010-01-01

In humans skin blood flow (SBF) plays a major role in body heat loss. Therefore the accuracy of models ofhuman thermoregulation depends for a great deal on their ability to predict skin blood flow. Most SBFmodelsuse body temperatures directly for calculation of skin perfusion. However, humans do not

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

Science.gov (United States)

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

2007-05-01

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

Total Body Photography as an Aid to Skin Self-examination: A Patient's Perspective.

Science.gov (United States)

Secker, Lisanne J; Bergman, Wilma; Kukutsch, Nicole A

2016-02-01

Skin self-examination can help patients who are at high risk for developing melanoma to become more involved in their own surveillance and treatment. This study examined the use of total body photography as an aid to skin self-examination from the patients' perspective. A total of 179 individuals at high risk for developing melanoma who had undergone total body photography (60.5% response rate) completed a self-reported questionnaire assessing the frequency of skin self-examination, perceived usefulness of total body photography, and a variety of potential demographic, clinical and psychological factors. Only approximately half of the participants indicated skin self-examination as useful and 78.9% preferred clinical skin examination by a specialist. Finding total body photography useful was associated with having received instructions on how to perform skin self-examination, the use of a (hand)mirror, and confidence to detect changing moles. These findings allow us to develop strategies to further improve patients' self-screening behaviours.

Characterising the variations in ethnic skin colours: a new calibrated data base for human skin.

Science.gov (United States)

Xiao, K; Yates, J M; Zardawi, F; Sueeprasan, S; Liao, N; Gill, L; Li, C; Wuerger, S

2017-02-01

Accurate skin colour measurements are important for numerous medical applications including the diagnosis and treatment of cutaneous disorders and the provision of maxillofacial soft tissue prostheses. In this study, we obtained accurate skin colour measurements from four different ethnic groups (Caucasian, Chinese, Kurdish, Thai) and at four different body locations (Forehead, cheek, inner arm, back of hand) with a view of establishing a new skin colour database for medical and cosmetic applications. Skin colours are measured using a spectrophotometer and converted to a device-independent standard colour appearance space (CIELAB) where skin colour is expressed as values along the three dimensions: Lightness L*, Redness a* and Yellowness b*. Skin colour differences and variation are then evaluated as a function of ethnicity and body location. We report three main results: (1) When plotted in a standard colour appearance space (CIELAB), skin colour distributions for the four ethnic groups overlap significantly, although there are systematic mean differences. Between ethnicities, the most significant skin colour differences occur along the yellowness dimension, with Thai skin exhibiting the highest yellowness (b*) value and Caucasian skin the lowest value. Facial redness (a*) is invariant across the four ethnic groups. (2) Between different body locations, there are significant variations in redness (a*), with the forehead showing the highest redness value and the inner arm the lowest. (3) The colour gamut is smallest in the Chinese sample and largest in the Caucasian sample, with the Chinese gamut lying entirely the Caucasian gamut. Similarly, the largest variability in skin tones is found in the Caucasian group, and the smallest in the Chinese group. Broadly speaking, skin colour variation can be explained by two main factors: individual differences in lightness and yellowness are mostly due to ethnicity, whereas differences in redness are primarily due to

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

Science.gov (United States)

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

2015-01-01

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

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

Directory of Open Access Journals (Sweden)

Karl Gledhill

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

Isolation of Human Skin Dendritic Cell Subsets.

Science.gov (United States)

Gunawan, Merry; Jardine, Laura; Haniffa, Muzlifah

2016-01-01

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

Body composition in Pan paniscus compared with Homo sapiens has implications for changes during human evolution.

Science.gov (United States)

Zihlman, Adrienne L; Bolter, Debra R

2015-06-16

The human body has been shaped by natural selection during the past 4-5 million years. Fossils preserve bones and teeth but lack muscle, skin, fat, and organs. To understand the evolution of the human form, information about both soft and hard tissues of our ancestors is needed. Our closest living relatives of the genus Pan provide the best comparative model to those ancestors. Here, we present data on the body composition of 13 bonobos (Pan paniscus) measured during anatomical dissections and compare the data with Homo sapiens. These comparative data suggest that both females and males (i) increased body fat, (ii) decreased relative muscle mass, (iii) redistributed muscle mass to lower limbs, and (iv) decreased relative mass of skin during human evolution. Comparison of soft tissues between Pan and Homo provides new insights into the function and evolution of body composition.

Black and white human skin differences

DEFF Research Database (Denmark)

Andersen, Klaus Ejner; Maibach, H I

1979-01-01

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

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

Science.gov (United States)

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

2014-12-01

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

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

NARCIS (Netherlands)

Eweje, M.O.

2016-01-01

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

Volumetric Visualization of Human Skin

Science.gov (United States)

Kawai, Toshiyuki; Kurioka, Yoshihiro

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

Effects of whole-body and partial-body x irradiation upon epidermal mitotic activity during wound healing in mouse skin

International Nuclear Information System (INIS)

Kobayashi, K.

1977-01-01

Mitotic activity of normal (unwounded) and wounded skin was measured in the control (nonirradiated) and whole-body or partial-body x-irradiated mouse. Higher mitotic activity in the anterior than in the posterior region of the body was found in both the normal and the wounded skin of the control mouse. Whole-body irradiation (500 R) depressed completely the mitotic activity of normal skin 2 to 4 days after irradiation. In spite of this depression in mitotic activity, a surgical incision made 1 to 3 days after irradiation could induce a burst of proliferation after an inhibition of an initial mitosis increase. When the animals were partially irradiated with 500 R 3 days before wounding, it was shown that mitosis at 24 hr after wounding was inhibited markedly by the local effect of irradiation and that mitosis also could be inhibited diversely by the abscopal effect of irradiation. Because of a close similarity of sequential mitotic patterns between whole-body-irradiated and flapped-skin-only-irradiated groups (direct irradiation), the effect of irradiation upon mitosis was considered to be primarily local. Some discussions were made concerning the possible reasons which made a difference in mitotic patterns between the head-only-irradiated group, the irradiated group including the head and other parts of the body except for the skin flap

Effects of Thermal Resistance on One-Dimensional Thermal Analysis of the Epidermal Flexible Electronic Devices Integrated with Human Skin

Science.gov (United States)

Li, He; Cui, Yun

2017-12-01

Nowadays, flexible electronic devices are increasingly used in direct contact with human skin to monitor the real-time health of human body. Based on the Fourier heat conduction equation and Pennes bio-heat transfer equation, this paper deduces the analytical solutions of one - dimensional heat transfer for flexible electronic devices integrated with human skin under the condition of a constant power. The influence of contact thermal resistance between devices and skin is considered as well. The corresponding finite element model is established to verify the correctness of analytical solutions. The results show that the finite element analysis agrees well with the analytical solution. With bigger thermal resistance, temperature increase of skin surface will decrease. This result can provide guidance for the design of flexible electronic devices to reduce the negative impact that exceeding temperature leave on human skin.

Applying tattoo dye as a third-harmonic generation contrast agent for in vivo optical virtual biopsy of human skin

Science.gov (United States)

Tsai, Ming-Rung; Lin, Chen-Yu; Liao, Yi-Hua; Sun, Chi-Kuang

2013-02-01

Third-harmonic generation (THG) microscopy has been reported to provide intrinsic contrast in elastic fibers, cytoplasmic membrane, nucleus, actin filaments, lipid bodies, hemoglobin, and melanin in human skin. For advanced molecular imaging, exogenous contrast agents are developed for a higher structural or molecular specificity. We demonstrate the potential of the commonly adopted tattoo dye as a THG contrast agent for in vivo optical biopsy of human skin. Spectroscopy and microscopy experiments were performed on cultured cells with tattoo dyes, in tattooed mouse skin, and in tattooed human skin to demonstrate the THG enhancement effect. Compared with other absorbing dyes or nanoparticles used as exogenous THG contrast agents, tattoo dyes are widely adopted in human skin so that future clinical biocompatibility evaluation is relatively achievable. Combined with the demonstrated THG enhancement effect, tattoo dyes show their promise for future clinical imaging applications.

Neurogenic inflammation in human and rodent skin

DEFF Research Database (Denmark)

Schmelz, M; Petersen, Lars Jelstrup

2001-01-01

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

Characterization of SLC transporters in human skin

Directory of Open Access Journals (Sweden)

Marion Alriquet

2015-03-01

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

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

Science.gov (United States)

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

2015-09-01

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

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

Science.gov (United States)

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

2017-01-01

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

Response of Human Skin to Aesthetic Scarification

Science.gov (United States)

Gabriel, Vincent A.; McClellan, Elizabeth A.; Scheuermann, Richard H.

2014-01-01

This study was undertaken to investigate changes in RNA expression in previously healthy adult human skin following thermal injury induced by contact with hot metal that was undertaken as part of aesthetic scarification, a body modification practice. Subjects were recruited to have pre-injury skin and serial wound biopsies performed. 4 mm punch biopsies were taken prior to branding and 1 hour, 1 week, and 1, 2 and 3 months post injury. RNA was extracted and quality assured prior to the use of a whole-genome based bead array platform to describe expression changes in the samples using the pre-injury skin as a comparator. Analysis of the array data was performed using k-means clustering and a hypergeometric probability distribution without replacement and corrections for multiple comparisons were done. Confirmatory q-PCR was performed. Using a k of 10, several clusters of genes were shown to co-cluster together based on Gene Ontology classification with probabilities unlikely to occur by chance alone. OF particular interest were clusters relating to cell cycle, proteinaceous extracellular matrix and keratinization. Given the consistent expression changes at one week following injury in the cell cycle cluster, there is an opportunity to intervene early following burn injury to influence scar development. PMID:24582755

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

NARCIS (Netherlands)

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

1987-01-01

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

Surface topography and contact mechanics of dry and wet human skin

Directory of Open Access Journals (Sweden)

Alexander E. Kovalev

2014-08-01

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

Generation of electrical power under human skin by subdermal solar cell arrays for implantable bioelectronic devices.

Science.gov (United States)

Song, Kwangsun; Han, Jung Hyun; Yang, Hyung Chae; Nam, Kwang Il; Lee, Jongho

2017-06-15

Medical electronic implants can significantly improve people's health and quality of life. These implants are typically powered by batteries, which usually have a finite lifetime and therefore must be replaced periodically using surgical procedures. Recently, subdermal solar cells that can generate electricity by absorbing light transmitted through skin have been proposed as a sustainable electricity source to power medical electronic implants in bodies. However, the results to date have been obtained with animal models. To apply the technology to human beings, electrical performance should be characterized using human skin covering the subdermal solar cells. In this paper, we present electrical performance results (up to 9.05mW/cm 2 ) of the implantable solar cell array under 59 human skin samples isolated from 10 cadavers. The results indicate that the power densities depend on the thickness and tone of the human skin, e.g., higher power was generated under thinner and brighter skin. The generated power density is high enough to operate currently available medical electronic implants such as pacemakers that require tens of microwatt. Copyright © 2016 Elsevier B.V. All rights reserved.

Total body photography for skin cancer screening.

Science.gov (United States)

Dengel, Lynn T; Petroni, Gina R; Judge, Joshua; Chen, David; Acton, Scott T; Schroen, Anneke T; Slingluff, Craig L

2015-11-01

Total body photography may aid in melanoma screening but is not widely applied due to time and cost. We hypothesized that a near-simultaneous automated skin photo-acquisition system would be acceptable to patients and could rapidly obtain total body images that enable visualization of pigmented skin lesions. From February to May 2009, a study of 20 volunteers was performed at the University of Virginia to test a prototype 16-camera imaging booth built by the research team and to guide development of special purpose software. For each participant, images were obtained before and after marking 10 lesions (five "easy" and five "difficult"), and images were evaluated to estimate visualization rates. Imaging logistical challenges were scored by the operator, and participant opinion was assessed by questionnaire. Average time for image capture was three minutes (range 2-5). All 55 "easy" lesions were visualized (sensitivity 100%, 90% CI 95-100%), and 54/55 "difficult" lesions were visualized (sensitivity 98%, 90% CI 92-100%). Operators and patients graded the imaging process favorably, with challenges identified regarding lighting and positioning. Rapid-acquisition automated skin photography is feasible with a low-cost system, with excellent lesion visualization and participant acceptance. These data provide a basis for employing this method in clinical melanoma screening. © 2014 The International Society of Dermatology.

Harmful effects of mobile phone waves on blood tissues of the human body

OpenAIRE

Kumar, Vijay; Ahmad, Mushtaq; Sharma, A. K.

2013-01-01

  Abstract. Penetration of electromagnetic waves emitted by mobile phones into human skin and blood was studied. The transmitted waves from these mobile phones were exposed to the human body and were penetrated into the body where field was reduced exponentially with depth. As the reduction in field was due to absorption of power, specific absorption rate was calculated and compared with permissible limit given by International Commission on Non-ionizing Radiation Protection (ICNIRP) and Worl...

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

Science.gov (United States)

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

2012-01-01

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

Materials used to simulate physical properties of human skin.

Science.gov (United States)

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

2016-02-01

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

Heat balance model for a human body in the form of wet bulb globe temperature indices.

Science.gov (United States)

Sakoi, Tomonori; Mochida, Tohru; Kurazumi, Yoshihito; Kuwabara, Kohei; Horiba, Yosuke; Sawada, Shin-Ichi

2018-01-01

The purpose of this study is to expand the empirically derived wet bulb globe temperature (WBGT) index to a rational thermal index based on the heat balance for a human body. We derive the heat balance model in the same form as the WBGT for a human engaged in moderate intensity work with a metabolic heat production of 174W/m 2 while wearing typical vapor-permeable clothing under shady and sunny conditions. Two important relationships are revealed based on this derivation: (1) the natural wet bulb and black globe temperature coefficients in the WBGT coincide with the heat balance equation for a human body with a fixed skin wettedness of approximately 0.45 at a fixed skin temperature; and (2) the WBGT can be interpreted as the environmental potential to increase skin temperature rather than the heat storage rate of a human body. We propose an adjustment factor calculation method that supports the application of WBGT for humans dressed in various clothing types and working under various air velocity conditions. Concurrently, we note difficulties in adjusting the WBGT by using a single factor for humans wearing vapor-impermeable protective clothing. The WBGT for shady conditions does not need adjustment depending on the positive radiant field (i.e., when a radiant heat source exists), whereas that for the sunny condition requires adjustments because it underestimates heat stress, which may result in insufficient human protection measures. Copyright © 2017 Elsevier Ltd. All rights reserved.

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

Science.gov (United States)

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

2000-09-01

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

2-Nonenal newly found in human body odor tends to increase with aging.

Science.gov (United States)

Haze, S; Gozu, Y; Nakamura, S; Kohno, Y; Sawano, K; Ohta, H; Yamazaki, K

2001-04-01

Human body odor consists of various kinds of odor components. Here, we have investigated the changes in body odor associated with aging. The body odor of subjects between the ages of 26 and 75 was analyzed by headspace gas chromatography/mass spectrometry. 2-Nonenal, an unsaturated aldehyde with an unpleasant greasy and grassy odor, was detected only in older subjects (40 y or older). Furthermore, analysis of skin surface lipids revealed that omega7 unsaturated fatty acids and lipid peroxides also increased with aging and that there were positive correlations between the amount of 2-nonenal in body odor and the amount of omega7 unsaturated fatty acids or lipid peroxides in skin surface lipids. 2-Nonenal was generated only when omega7 unsaturated fatty acids were degraded by degradation tests in which some main components of skin surface lipids were oxidatively decomposed using lipid peroxides as initiator of an oxidative chain reaction. The results indicate that 2-nonenal is generated by the oxidative degradation of omega7 unsaturated fatty acids, and suggest that 2-nonenal may be involved in the age-related change of body odor.

Human skin penetration of silver nanoparticles through intact and damaged skin

International Nuclear Information System (INIS)

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

2009-01-01

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

Human skin wetness perception: psychophysical and neurophysiological bases

Science.gov (United States)

Filingeri, Davide; Havenith, George

2015-01-01

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

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

Science.gov (United States)

Oesch, F; Fabian, E; Landsiedel, Robert

2018-06-18

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

Oral sapropterin augments reflex vasoconstriction in aged human skin through noradrenergic mechanisms.

Science.gov (United States)

Stanhewicz, Anna E; Alexander, Lacy M; Kenney, W Larry

2013-10-01

Reflex vasoconstriction is attenuated in aged skin due to a functional loss of adrenergic vasoconstriction. Bioavailability of tetrahydrobiopterin (BH4), an essential cofactor for catecholamine synthesis, is reduced with aging. Locally administered BH4 increases vasoconstriction through adrenergic mechanisms in aged human skin. We hypothesized that oral sapropterin (Kuvan, a pharmaceutical BH4) would augment vasoconstriction elicited by whole-body cooling and tyramine perfusion in aged skin. Ten healthy subjects (age 75 ± 2 yr) ingested sapropterin (10 mg/kg) or placebo in a randomized, double-blind crossover design. Venous blood samples were collected prior to, and 3 h following ingestion. Three intradermal microdialysis fibers were placed in the forearm skin for local delivery of 1) lactated Ringer, 2) 5 mM BH4, and 3) 5 mM yohimbine + 1 mM propranolol (Y+P; to inhibit adrenergic vasoconstriction). Red cell flux was measured at each site by laser-Doppler flowmetry (LDF) as reflex vasoconstriction was induced by lowering and then clamping whole-body skin temperature (Tsk) using a water-perfused suit. Following whole-body cooling, subjects were rewarmed and 1 mM tyramine was perfused at each site to elicit endogenous norepinephrine release from the perivascular nerve terminal. Cutaneous vascular conductance was calculated as CVC = LDF/mean arterial pressure and expressed as change from baseline (ΔCVC). Plasma BH4 was elevated 3 h after ingestion of sapropterin (43.8 ± 3 vs. 19.1 ± 2 pmol/ml; P effect on reflex vasoconstriction at the BH4-perfused or Y+P-perfused sites. Sapropterin increased pharmacologically induced vasoconstriction at the Ringer site (-0.19 ± 0.03 vs. -0.08 ± 0.02 ΔCVC; P = 0.01). There was no difference in pharmacologically induced vasoconstriction between treatments at the BH4-perfused site (-0.16 ± 0.04 vs. -0.14 ± 0.03 ΔCVC; P = 0.60) or the Y+P-perfused site (-0.05 ± 0.02 vs.-0.06 ± 0.02 ΔCVC; P = 0.79). Sapropterin increases

Response of Human Skin Equivalents to Sarcoptes scabiei

Science.gov (United States)

MORGAN, MARJORIE S.; ARLIAN, LARRY G.

2010-01-01

Studies have shown that molecules in an extract made from bodies of the ectoparasitic mite, Sarcoptes scabiei De Geer, modulate cytokine secretion from cultured human keratinocytes and fibroblasts. In vivo, in the parasitized skin, these cells interact with each other by contact and cytokine mediators and with the matrix in which they reside. Therefore, these cell types may function differently together than they do separately. In this study, we used a human skin equivalent (HSE) model to investigate the influence of cellular interactions between keratinocytes and fibroblasts when the cells were exposed to active/burrowing scabies mites, mite products, and mite extracts. The HSE consisted of an epidermis of stratified stratum corneum, living keratinocytes, and basal cells above a dermis of fibroblasts in a collagen matrix. HSEs were inoculated on the surface or in the culture medium, and their cytokine secretions on the skin surface and into the culture medium were determined by enzyme-linked immunosorbent assay. Active mites on the surface of the HSE induced secretion of cutaneous T cell-attracting chemokine, thymic stromal lymphopoietin, interleukin (IL)-1α, IL-1β, IL-1 receptor antagonist (IL-1ra), IL-6, IL-8, monocyte chemoattractant protein-1, granulocyte/macrophage colony-stimulating factor, and macrophage colony-stimulating factor. The main difference between HSEs and monocultured cells was that the HSEs produced the proinflammatory cytokines IL-1α and IL-1β and their competitive inhibitor IL-1ra, whereas very little of these mediators was previously found for cultured keratinocytes and fibroblasts. It is not clear how the balance between these cytokines influences the overall host response. However, IL-1ra may contribute to the depression of an early cutaneous inflammatory response to scabies in humans. These contrasting results illustrate that cell interactions are important in the host’s response to burrowing scabies mites. PMID:20939384

Multivariate Models for Prediction of Human Skin Sensitization ...

Science.gov (United States)

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

Modelling glucose and water dynamics in human skin

NARCIS (Netherlands)

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

2008-01-01

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

Self-powered implantable electronic-skin for in situ analysis of urea/uric-acid in body fluids and the potential applications in real-time kidney-disease diagnosis.

Science.gov (United States)

Yang, Wenyan; Han, Wuxiao; Gao, Huiling; Zhang, Linlin; Wang, Shuai; Xing, Lili; Zhang, Yan; Xue, Xinyu

2018-01-25

As the concentration of different biomarkers in human body fluids are an important parameter of chronic disease, wearable biosensors for in situ analysis of body fluids with high sensitivity, real-time detection, flexibility and biocompatibility have significant potential therapeutic applications. In this paper, a flexible self-powered implantable electronic-skin (e-skin) for in situ body fluids analysis (urea/uric-acid) as a real-time kidney-disease diagnoser has been proposed based on the piezo-enzymatic-reaction coupling process of ZnO nanowire arrays. It can convert the mechanical energy of body movements into a piezoelectric impulse, and the outputting piezoelectric signal contains the urea/uric-acid concentration information in body fluids. This piezoelectric-biosensing process does not need an external electricity supply or battery. The e-skin was implanted under the abdominal skin of a mouse and provided in situ analysis of the kidney-disease parameters. These results provide a new approach for developing a self-powered in situ body fluids-analysis technique for chronic-disease diagnosis.

Full body illusion is associated with widespread skin temperature reduction

Directory of Open Access Journals (Sweden)

Roy eSalomon

2013-07-01

Full Text Available A central feature of our consciousness is the experience of the self as a unified entity residing in a physical body, termed bodily self-consciousness. This phenomenon includes aspects such as the sense of owning a body (also known as body ownership and has been suggested to arise from the integration of sensory and motor signals from the body. Several studies have shown that temporally synchronous tactile stimulation of the real body and visual stimulation of a fake or virtual body can induce changes in bodily self-consciousness, typically resulting in a sense of illusory ownership over the fake body. The present study assessed the effect of anatomical congruency of visuo-tactile stimulation on bodily self-consciousness. A virtual body was presented and temporally synchronous visuo-tactile stroking was applied simultaneously the participants’ body and to the virtual body. We manipulated the anatomical locations of the visuo-tactile stroking (i.e. on the back, on the leg, resulting in congruent stroking (stroking was felt and seen on the back or the leg or incongruent stroking (i.e. stroking was felt on the leg and seen on the back. We measured self-identification with the virtual body and self-location as well as skin temperature. Illusory self-identification with the avatar as well as changes in self-localization were experienced in the congruent stroking conditions. Participants showed a decrease in skin temperature across several body locations during congruent stimulation. These data establish that the full-body illusion alters bodily self-consciousness and instigates widespread physiological changes in the participant’s body.

Variation of Biophysical Parameters of the Skin with Age, Gender, and Body Region

Science.gov (United States)

Firooz, Alireza; Sadr, Bardia; Babakoohi, Shahab; Sarraf-Yazdy, Maryam; Fanian, Ferial; Kazerouni-Timsar, Ali; Nassiri-Kashani, Mansour; Naghizadeh, Mohammad Mehdi; Dowlati, Yahya

2012-01-01

Background. Understanding the physiological, chemical, and biophysical characteristics of the skin helps us to arrange a proper approach to the management of skin diseases. Objective. The aim of this study was to measure 6 biophysical characteristics of normal skin (sebum content, hydration, transepidermal water loss (TEWL), erythema index, melanin index, and elasticity) in a normal population and assess the effect of sex, age, and body location on them. Methods. Fifty healthy volunteers in 5 age groups (5 males and females in each) were enrolled in this study. A multifunctional skin physiology monitor (Courage & Khazaka electronic GmbH, Germany) was used to measure skin sebum content, hydration, TEWL, erythema index, melanin index, and elasticity in 8 different locations of the body. Results. There were significant differences between the hydration, melanin index, and elasticity of different age groups. Regarding the locations, forehead had the highest melanin index, where as palm had the lowest value. The mean values of erythema index and melanin index and TEWL were significantly higher in males and anatomic location was a significant independent factor for all of 6 measured parameters. Conclusion. Several biophysical properties of the skin vary among different gender, age groups, and body locations. PMID:22536139

Qualitative and semi quantitative analysis in the healing area of athymic nude mice skin engrafted with human skin sterilized with gamma radiation

International Nuclear Information System (INIS)

Miranda, Jurandir Tomaz de; Bringel, Fabiana; Alves, Nelson Mendes; Antebi, Uri; Funari, Ana Paula; Mathor, Monica B.

2015-01-01

In recent decades there has been a great interest in the radio-sterilized grafts for human skin grafts. This tissue is taken from a cadaver or multi-organ donor and samples are processed and stored in glycerol at concentrations above 85%. Although this procedure is carried out under aseptic conditions, after the final packaging one can sterilize the tissues with ionizing radiation in order to increase the safety level of sterility. The purpose of this study was to evaluate the behavior of the healing repair process that occurs between the graft and the skin of athymic NUDE mice. The samples of human skin treated with glycerol were divided into three groups: the control group 1 (non-irradiated), irradiated group 2 at 25 kGy and irradiated group 3, at 50 kGy. These tissues were grafted onto athymic NUDE mice which were sacrificed after 3, 7 and 21 days. After the sacrifice, part of the back fur of the animals containing human skin graft was removed with hematoxylin and eosin (H/E). The histological sections were analyzed for the integrity of tissue, presence and location of keratinocytes, fibroblasts, defense cells and blood vessels. Thus it was examined whether over time the graft was incorporated into the body or if there was a process of healing by secondary intention. (author)

Qualitative and semi quantitative analysis in the healing area of athymic nude mice skin engrafted with human skin sterilized with gamma radiation

Energy Technology Data Exchange (ETDEWEB)

Miranda, Jurandir Tomaz de; Bringel, Fabiana; Alves, Nelson Mendes; Antebi, Uri; Funari, Ana Paula; Mathor, Monica B., E-mail: tomaz_ju@hotmail.com [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

2015-07-01

In recent decades there has been a great interest in the radio-sterilized grafts for human skin grafts. This tissue is taken from a cadaver or multi-organ donor and samples are processed and stored in glycerol at concentrations above 85%. Although this procedure is carried out under aseptic conditions, after the final packaging one can sterilize the tissues with ionizing radiation in order to increase the safety level of sterility. The purpose of this study was to evaluate the behavior of the healing repair process that occurs between the graft and the skin of athymic NUDE mice. The samples of human skin treated with glycerol were divided into three groups: the control group 1 (non-irradiated), irradiated group 2 at 25 kGy and irradiated group 3, at 50 kGy. These tissues were grafted onto athymic NUDE mice which were sacrificed after 3, 7 and 21 days. After the sacrifice, part of the back fur of the animals containing human skin graft was removed with hematoxylin and eosin (H/E). The histological sections were analyzed for the integrity of tissue, presence and location of keratinocytes, fibroblasts, defense cells and blood vessels. Thus it was examined whether over time the graft was incorporated into the body or if there was a process of healing by secondary intention. (author)

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

Science.gov (United States)

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

2017-01-01

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

Quality system and audit of human skin allografts

International Nuclear Information System (INIS)

Van Baare, J.

1999-01-01

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

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

OpenAIRE

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

2010-01-01

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

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

Science.gov (United States)

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

2016-01-01

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

Total-body photography in skin cancer screening: the clinical utility of standardized imaging.

Science.gov (United States)

Rosenberg, Alexandra; Meyerle, Jon H

2017-05-01

Early detection of skin cancer is essential to reducing morbidity and mortality from both melanoma and nonmelanoma skin cancers. Total-body skin examinations (TBSEs) may improve early detection of malignant melanomas (MMs) but are controversial due to the poor quality of data available to establish a mortality benefit from skin cancer screening. Total-body photography (TBP) promises to provide a way forward by lowering the costs of dermatologic screening while simultaneously leveraging technology to increase patient access to dermatologic care. Standardized TBP also offers the ability for dermatologists to work synergistically with modern computer technology involving algorithms capable of analyzing high-quality images to flag concerning lesions that may require closer evaluation. On a population level, inexpensive TBP has the potential to increase access to skin cancer screening and it has several specific applications in a military population. The utility of standardized TBP is reviewed in the context of skin cancer screening and teledermatology.

DNA damage and repair in human skin in situ

International Nuclear Information System (INIS)

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

1987-01-01

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

DNA damage and repair in human skin in situ

Energy Technology Data Exchange (ETDEWEB)

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

1987-01-01

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

Realistic Modeling and Animation of Human Body Based on Scanned Data

Institute of Scientific and Technical Information of China (English)

Yong-You Ma; Hui Zhang; Shou-Wei Jiang

2004-01-01

In this paper we propose a novel method for building animation model of real human body from surface scanned data.The human model is represented by a triangular mesh and described as a layered geometric model.The model consists of two layers: the control skeleton generating body animation from motion capture data,and the simplified surface model providing an efficient representation of the skin surface shape.The skeleton is generated automatically from surface scanned data using the feature extraction,and thena point-to-line mapping is used to map the surface model onto the underlying skeleton.The resulting model enables real-time and smooth animation by manipulation of the skeleton while maintaining the surface detail.Compared with earlier approach,the principal advantages of our approach are the automated generation of body control skeletons from the scanned data for real-time animation,and the automatic mapping and animation of the captured human surface shape.The human model constructed in this work can be used for applications of ergonomic design,garment CAD,real-time simulating humans in virtual reality environment and so on.

Nuclear microprobe investigation of the penetration of ultrafine zinc oxide into human skin affected by atopic dermatitis

Science.gov (United States)

Szikszai, Z.; Kertész, Zs.; Bodnár, E.; Borbíró, I.; Angyal, A.; Csedreki, L.; Furu, E.; Szoboszlai, Z.; Kiss, Á. Z.; Hunyadi, J.

2011-10-01

Skin penetration is one of the potential routes for nanoparticles to gain access into the human body. Ultrafine metal oxides, such as titanium dioxide and zinc oxide are widely used in cosmetic and health products like sunscreens. These oxides are potent UV filters and the particle size smaller than 200 nm makes the product more transparent compared to formulations containing coarser particles. The present study continues the work carried out in the frame of the NANODERM: “Quality of skin as a barrier to ultrafine particles” European project and complements our previous investigations on human skin with compromised barrier function. Atopic dermatitis (a type of eczema) is an inflammatory, chronically relapsing, non-contagious skin disease. It is very common in children but may occur at any age. The exact cause of atopic dermatitis is unknown, but is likely due to a combination of impaired barrier function together with a malfunction in the body's immune system. In this study, skin samples were obtained from two patients suffering from atopic dermatitis. Our results indicate that the ultrafine zinc oxide particles, in a hydrophobic basis gel with an application time of 2 days or 2 weeks, have penetrated deeply into the stratum corneum in these patients. On the other hand, penetration into the stratum spinosum was not observed even in the case of the longer application time.

Modeling and characterization of different channels based on human body communication.

Science.gov (United States)

Jingzhen Li; Zedong Nie; Yuhang Liu; Lei Wang

2017-07-01

Human body communication (HBC), which uses the human body as a transmission medium for electrical signals, provides a prospective communication solution for body sensor networks (BSNs). In this paper, an inhomogeneous model which includes the tissue layers of skin, fat, and muscle is proposed to study the propagation characteristics of different HBC channels. Specifically, the HBC channels, namely, the on-body to on-body (OB-OB)channel, on-body to in-body (OB-IB) channel, in-body to on-body (IB-OB) channel, and in-body to in-body (IB-IB)channel, are studied over different frequencies (from 1MHz to 100MHz) through numerical simulations with finite-difference time-domain (FDTD) method. The results show that the gain of OB-IB channel and IB-OB channel is almost the same. The gain of IB-IB channel is greater than other channels in the frequency range 1MHz to 70MHz. In addition, the gain of all channels is associated with the channel length and communication frequency. The simulations are verified by experimental measurements in a porcine tissue sample. The results show that the simulations are in agreement with the measurements.

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

International Nuclear Information System (INIS)

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

2010-01-01

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

Skin exposure to aliphatic polyisocyanates in the auto body repair and refinishing industry: II. A quantitative assessment.

Science.gov (United States)

Bello, Dhimiter; Redlich, Carrie A; Stowe, Meredith H; Sparer, Judy; Woskie, Susan R; Streicher, Robert P; Hosgood, H Dean; Liu, Youcheng

2008-03-01

Skin exposure to isocyanates, in addition to respiratory exposures, may contribute to sensitization and asthma. Quantitative skin exposure data are scarce and quantitative methods limited. As part of the Survey of Painters and Repairers of Autobodies by Yale study, a method to sample and quantify human isocyanate skin exposure was developed (based on NIOSH 5525 method) and used to evaluate aliphatic isocyanate skin exposure in 81 auto body shop painters and body technicians. Wipe samples were collected from unprotected skin and from under PPE (gloves, clothing and respirator) using a polypropylene glycol-impregnated wipe. Hexamethylene diisocyanate (HDI), its polyisocyanates [HDI-derived polyisocyanates (pHDI)], isophorone diisocyanate (IPDI) and its polyisocyanates and IPDI-derived polyisocyanates (pIPDI) were quantified separately and also expressed as the total free isocyanate groups (total NCO). For unprotected skin areas, 49 samples were collected for spray painting, 13 for mixing, 27 for paint-related tasks (e.g. sanding and compounding) and 53 for non-paint-related tasks. Forty-three samples were also collected under PPE. The geometric mean (GM) [geometric standard deviation (GSD)] total NCO concentrations (ng NCO cm(-2)) for unprotected skin (hands, face and forearms) was 1.9 (10.9) and range 0.0-64.4. pHDI species were the major contributor to the total NCO content. Levels were very variable, with the highest concentrations measured for clear coating and paint mixing tasks. Isocyanate skin exposure was also commonly detected under PPE, with 92% of samples above the limit of detection. Levels were very variable with the overall GM (GSD) total NCO (ng NCO cm(-2)) under PPE 1.0 (5.2) and range (0.0-47.0) and similar under the different PPE (glove, respirator and clothing). The highest concentrations were detected for mixing and spraying tasks, 6.9 (5.3) and 1.0 (5.2), respectively. Levels under PPE were generally lower than unpaired samples obtained with no

Skin and the non-human human

DEFF Research Database (Denmark)

Rösing, Lilian Munk

2013-01-01

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

The choice of sensitive skin layer responsible for aftereffects of daily irradiation of the skin

International Nuclear Information System (INIS)

Keirim-Markus, I.B.

1992-01-01

The choice of sensitive human skin layer manifesting in delayed period after daily irradiation of the human skin (stochastic and determined effects) was evaluated. It was established that delayed aftereffects of daily radiation of the skin manifested as epidem damages. This layer of papilla derma of 10-15 mg/cm 2 thick situated at the great part of body surface, 15 mg/cm 2 on dorsal side of hands and 40 mg/cm 2 on palms and pillows of the fingers. Sensitive layer of skin dosimeter for a control of daily irradiation of people must have the same geometry

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

International Nuclear Information System (INIS)

Hughes, Michael F.; Edwards, Brenda C.

2010-01-01

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

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

NARCIS (Netherlands)

Janson, D.

2017-01-01

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

Safety issues associated with the use of nanoparticles in human body.

Science.gov (United States)

Sufian, Mian Muhammad; Khattak, Jabar Zaman Khan; Yousaf, Shahzad; Rana, Muhammad Suleman

2017-09-01

Nanotechnology has transformed the world by the introduction of a distinctive class of materials and products in a wide array of fields. It has contributed to the production of innovative materials and devices. Having unique advantages and domestic along with industrial applications, however, has raised the issue of safety for consumers, producers and environment. Having a comparative smaller dimension and other exclusive properties, nanoparticles have the ability to harm human body by interacting through various mechanisms. Here, we endeavoured to review and discuss the characteristics of nanoparticles relevant to their toxicity, conceivable exposure routes of nanoparticles to human body like skin contact, inhalation, and ingestion, and the basic approaches which can aid to control human exposures to toxic nanoparticles have been discussed. Copyright © 2017 Elsevier B.V. All rights reserved.

Anthropometric Characteristics and Sex Influence Magnitude of Skin Cooling following Exposure to Whole Body Cryotherapy

Science.gov (United States)

Hammond, L. E.; Cuttell, S.; Nunley, P.; Meyler, J.

2014-01-01

This study explored whether anthropometric measures influence magnitude of skin cooling following exposure to whole body cryotherapy (WBC). Height, weight, body fat percentage, and lean mass were measured in 18 male and 14 female participants. Body surface area, body surface area to mass ratio, body mass index, fat-free mass index, and fat mass index were calculated. Thermal images were captured before and after WBC (−60°C for 30 seconds, −110°C for 2 minutes). Skin temperature was measured at the chest, arm, thigh, and calf. Mean skin temperature before and after WBC and change in mean skin temperature (ΔT sk) were calculated. ΔT sk was significantly greater in females (12.07 ± 1.55°C) than males (10.12 ± 1.86°C; t(30) = −3.09, P = .004). A significant relationship was observed between body fat percentage and ΔT sk in the combined dataset (P = .002, r = .516) and between fat-free mass index and ΔT sk in males (P = .005, r = .622). No other significant associations were found. Skin response of individuals to WBC appears to depend upon anthropometric variables and sex, with individuals with a higher adiposity cooling more than thinner individuals. Effects of sex and anthompometrics should be considered when designing WBC research or treatment protocols. PMID:25061612

Multivariate Models for Prediction of Human Skin Sensitization Hazard

Science.gov (United States)

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

2016-01-01

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

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

Science.gov (United States)

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.

First genomic survey of human skin fungal diversity

Science.gov (United States)

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

Skin immune sentinels in health and disease.

Science.gov (United States)

Nestle, Frank O; Di Meglio, Paola; Qin, Jian-Zhong; Nickoloff, Brian J

2009-10-01

Human skin and its immune cells provide essential protection of the human body from injury and infection. Recent studies reinforce the importance of keratinocytes as sensors of danger through alert systems such as the inflammasome. In addition, newly identified CD103(+) dendritic cells are strategically positioned for cross-presentation of skin-tropic pathogens and accumulating data highlight a key role of tissue-resident rather than circulating T cells in skin homeostasis and pathology. This Review focuses on recent progress in dissecting the functional role of skin immune cells in skin disease.

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

NARCIS (Netherlands)

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

2013-01-01

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

Noninvasive radio frequency for skin tightening and body contouring.

Science.gov (United States)

Weiss, Robert A

2013-03-01

The medical use of radio frequency (RF) is based on an oscillating electrical current forcing collisions between charged molecules and ions, which are then transformed into heat. RF heating occurs irrespective of chromophore or skin type and is not dependent on selective photothermolysis. RF can be delivered using monopolar, bipolar, and unipolar devices, and each method has theoretical limits of depth penetration. A variant of bipolar delivery is fractional RF delivery. In monopolar configurations, RF will penetrate deeply and return via a grounding electrode. Multiple devices are available and are detailed later in the text. RF thermal stimulation is believed to result in a microinflammatory process that promotes new collagen. By manipulating skin cooling, RF can also be used for heating and reduction of fat. Currently, the most common uses of RF-based devices are to noninvasively manage and treat skin tightening of lax skin (including sagging jowls, abdomen, thighs, and arms), as well as wrinkle reduction, cellulite improvement, and body contouring.

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

International Nuclear Information System (INIS)

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

1996-01-01

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

Primary Cilia Negatively Regulate Melanogenesis in Melanocytes and Pigmentation in a Human Skin Model.

Science.gov (United States)

Choi, Hyunjung; Shin, Ji Hyun; Kim, Eun Sung; Park, So Jung; Bae, Il-Hong; Jo, Yoon Kyung; Jeong, In Young; Kim, Hyoung-June; Lee, Youngjin; Park, Hea Chul; Jeon, Hong Bae; Kim, Ki Woo; Lee, Tae Ryong; Cho, Dong-Hyung

2016-01-01

The primary cilium is an organelle protruding from the cell body that senses external stimuli including chemical, mechanical, light, osmotic, fluid flow, and gravitational signals. Skin is always exposed to the external environment and responds to external stimuli. Therefore, it is possible that primary cilia have an important role in skin. Ciliogenesis was reported to be involved in developmental processes in skin, such as keratinocyte differentiation and hair formation. However, the relation between skin pigmentation and primary cilia is largely unknown. Here, we observed that increased melanogenesis in melanocytes treated with a melanogenic inducer was inhibited by a ciliogenesis inducer, cytochalasin D, and serum-free culture. However, these inhibitory effects disappeared in GLI2 knockdown cells. In addition, activation of sonic hedgehog (SHH)-smoothened (Smo) signaling pathway by a Smo agonist, SAG inhibited melanin synthesis in melanocytes and pigmentation in a human skin model. On the contrary, an inhibitor of primary cilium formation, ciliobrevin A1, activated melanogenesis in melanocytes. These results suggest that skin pigmentation may be regulated partly by the induction of ciliogenesis through Smo-GLI2 signaling.

Primary Cilia Negatively Regulate Melanogenesis in Melanocytes and Pigmentation in a Human Skin Model.

Directory of Open Access Journals (Sweden)

Hyunjung Choi

Full Text Available The primary cilium is an organelle protruding from the cell body that senses external stimuli including chemical, mechanical, light, osmotic, fluid flow, and gravitational signals. Skin is always exposed to the external environment and responds to external stimuli. Therefore, it is possible that primary cilia have an important role in skin. Ciliogenesis was reported to be involved in developmental processes in skin, such as keratinocyte differentiation and hair formation. However, the relation between skin pigmentation and primary cilia is largely unknown. Here, we observed that increased melanogenesis in melanocytes treated with a melanogenic inducer was inhibited by a ciliogenesis inducer, cytochalasin D, and serum-free culture. However, these inhibitory effects disappeared in GLI2 knockdown cells. In addition, activation of sonic hedgehog (SHH-smoothened (Smo signaling pathway by a Smo agonist, SAG inhibited melanin synthesis in melanocytes and pigmentation in a human skin model. On the contrary, an inhibitor of primary cilium formation, ciliobrevin A1, activated melanogenesis in melanocytes. These results suggest that skin pigmentation may be regulated partly by the induction of ciliogenesis through Smo-GLI2 signaling.

Folate in Skin Cancer Prevention

OpenAIRE

Williams, J.D.; Jacobson, Elaine L.; Kim, H.; Kim, M.; Jacobson, M.K.

2012-01-01

Skin, the largest, most exposed organ of the body, provides a protective interface between humans and the environment. One of its primary roles is protection against exposure to sunlight, a major source of skin damage where the UV radiation (UVR) component functions as a complete carcinogen. Melanin pigmentation and the evolution of dark skin is an adaptive protective mechanism against high levels of UVR exposure. Recently, the hypothesis that skin pigmentation balances folate preservation an...

Elevation of telomerase activity in chronic radiation ulcer of human skin

International Nuclear Information System (INIS)

Li Xiaoying; Zhao Po; Wang Dewen; Yang Zhixiang

1997-01-01

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

Convective Heat Transfer Coefficients of the Human Body under Forced Convection from Ceiling

DEFF Research Database (Denmark)

Kurazumi, Yoshihito; Rezgals, Lauris; Melikov, Arsen Krikor

2014-01-01

The average convective heat transfer coefficient for a seated human body exposed to downward flow from above was determined. Thermal manikin with complex body shape and size of an average Scandinavian female was used. The surface temperature distribution of the manikin’s body was as the skin...... of the convective heat transfer coefficient of the whole body (hc [W/(m2•K)]) was proposed: hc=4.088+6.592V1.715 for a seated naked body at 20ºC and hc=2.874+7.427V1.345 for a seated naked body at 26ºC. Differences in the convective heat transfer coefficient of the whole body in low air velocity range, V

An in vitro human skin test for assessing sensitization potential.

Science.gov (United States)

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

2016-05-01

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

Applications for Electrical Impedance Tomography (EIT) and Electrical Properties of the Human Body.

Science.gov (United States)

Lymperopoulos, Georgios; Lymperopoulos, Panagiotis; Alikari, Victoria; Dafogianni, Chrisoula; Zyga, Sofia; Margari, Nikoletta

2017-01-01

Electrical Impedance Tomography (EIT) is a promising application that displays changes in conductivity within a body. The basic principle of the method is the repeated measurement of surface voltages of a body, which are a result of rolling injection of known and small-volume sinusoidal AC current to the body through the electrodes attached to its surface. This method finds application in biomedicine, biology and geology. The objective of this paper is to present the applications of Electrical Impedance Tomography, along with the method's capabilities and limitations due to the electrical properties of the human body. For this purpose, investigation of existing literature has been conducted, using electronic databases, PubMed, Google Scholar and IEEE Xplore. In addition, there was a secondary research phase, using paper citations found during the first research phase. It should be noted that Electrical Impedance Tomography finds use in a plethora of medical applications, as the different tissues of the body have different conductivities and dielectric constants. Main applications of EIT include imaging of lung function, diagnosis of pulmonary embolism, detection of tumors in the chest area and diagnosis and distinction of ischemic and hemorrhagic stroke. EIT advantages include portability, low cost and safety, which the method provide, since it is a noninvasive imaging method that does not cause damage to the body. The main disadvantage of the method, which blocks its wider spread, appears in the image composition from the voltage measurements, which are conducted by electrodes placed on the periphery of the body, because the injected currents are affected nonlinearly by the general distribution of the electrical properties of the body. Furthermore, the complex impedance of the skin-electrode interface can be modelled by using a capacitor and two resistor, as a result of skin properties. In conclusion, Electrical Impedance Tomography is a promising method for the

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

Science.gov (United States)

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

2017-11-18

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

Water vapour loss measurements on human skin.

NARCIS (Netherlands)

Valk, Petrus Gerardus Maria van der

1984-01-01

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

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

Science.gov (United States)

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

2017-11-01

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

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

OpenAIRE

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

2016-01-01

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

Skin Diseases: Skin Health and Skin Diseases

Science.gov (United States)

Skip Navigation Bar Home Current Issue Past Issues Skin Diseases Skin Health and Skin Diseases Past Issues / Fall 2008 Table of Contents ... acne to wrinkles Did you know that your skin is the largest organ of your body? It ...

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

International Nuclear Information System (INIS)

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

1996-01-01

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

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

Science.gov (United States)

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

2014-01-01

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

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

Directory of Open Access Journals (Sweden)

Karin Lehner

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

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

Science.gov (United States)

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

2013-01-01

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

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

Science.gov (United States)

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

2013-01-01

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

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

Directory of Open Access Journals (Sweden)

Shasha Tao

2013-01-01

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

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

Science.gov (United States)

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

2016-01-01

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

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

Science.gov (United States)

2012-03-01

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

[Physiological features of skin ageing in human].

Science.gov (United States)

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

2013-01-01

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

Chronic effects of UV on human skin

International Nuclear Information System (INIS)

Cesarini, J.P.

1996-01-01

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

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

Science.gov (United States)

Li, Jingting; Sen, George L

2015-12-14

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

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

Science.gov (United States)

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

2017-09-01

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

Radio-sterilization and processing of frozen human skin

International Nuclear Information System (INIS)

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

2006-01-01

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

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

Science.gov (United States)

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

2018-01-23

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

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

Science.gov (United States)

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

2016-12-05

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

First Insights into the Diverse Human Archaeome: Specific Detection of Archaea in the Gastrointestinal Tract, Lung, and Nose and on Skin

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Kaisa Koskinen

2017-11-01

Full Text Available Human-associated archaea remain understudied in the field of microbiome research, although in particular methanogenic archaea were found to be regular commensals of the human gut, where they represent keystone species in metabolic processes. Knowledge on the abundance and diversity of human-associated archaea is extremely limited, and little is known about their function(s, their overall role in human health, or their association with parts of the human body other than the gastrointestinal tract and oral cavity. Currently, methodological issues impede the full assessment of the human archaeome, as bacteria-targeting protocols are unsuitable for characterization of the full spectrum of Archaea. The goal of this study was to establish conservative protocols based on specifically archaea-targeting, PCR-based methods to retrieve first insights into the archaeomes of the human gastrointestinal tract, lung, nose, and skin. Detection of Archaea was highly dependent on primer selection and the sequence processing pipeline used. Our results enabled us to retrieve a novel picture of the human archaeome, as we found for the first time Methanobacterium and Woesearchaeota (DPANN superphylum to be associated with the human gastrointestinal tract and the human lung, respectively. Similar to bacteria, human-associated archaeal communities were found to group biogeographically, forming (i the thaumarchaeal skin landscape, (ii the (methanoeuryarchaeal gastrointestinal tract, (iii a mixed skin-gastrointestinal tract landscape for the nose, and (iv a woesearchaeal lung landscape. On the basis of the protocols we used, we were able to detect unexpectedly high diversity of archaea associated with different body parts.

Analysis of human skin tissue by millimeter-wave reflectometry

NARCIS (Netherlands)

Smulders, P.F.M.

2013-01-01

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

SU-F-T-82: Dosimetric Evaluation of a Shield Used for Hemi-Body Skin Electron Irradiation

Energy Technology Data Exchange (ETDEWEB)

Rivers, C; Singh, A [Roswell Park Cancer Institute, Buffalo, NY (United States); AlDahlawi, I; Wang, I; Podgorsak, M [Roswell Park Cancer Institute, Buffalo, NY (United States); State University of New York at Buffalo, Buffalo, NY (United States)

2016-06-15

Purpose: We had several mycosis fungoides patients with a limited disease to about half of the skin surface. A custom-made plywood shield was used to protect the non-targeted skin region with our total skin electron irradiation (TSEI) technique. We report a dosimetric evaluation for our “hemi-body” skin electron irradiation technique. Methods: The technique is similar to our clinical total skin electron irradiation (TSEI), performed with a six-pair dual field (Stanford technique) at an extended source-to-skin distance (SSD) of 377 cm, with the addition of a plywood shield placed 50 cm from the patient. The shield is made of three layers of standard 5/8″ thick plywood (total thickness of 4.75 cm) that are clamped securely on an adjustable-height stand. Gafchromic EBT3 films were used in assessing the shield’s transmission factor and the extend of the dose penumbra region. To verify the dose delivered for hemi-body skin radiation in a real patient treatment, in-vivo dosimetry using Gafchromic EBT3 films were performed. Film pieces were taped on the patient skin to measure the dose received during the first two fractions, placed on the forehead and upper body (shielded region); and also at the level of pelvic area, left thigh, and left ankle. Results: The shield transmission factor was found to be 10%, and the width of the penumbra (80-to-20% dose fall-off) was about 12 cm. In-vivo dosimetry of a real case confirmed the expected shielded area dose. Conclusion: Hemi-Body skin electron irradiation at an extended SSD is feasible with the addition of a plywood shield at a distance from patient skin. The penumbra dose region and the shield’s transmission factor should be evaluated prior to clinical use. We have treated several hemi-body skin patients with our custom-made plywood shield, the current patient measurements are representative of these for other patients as well.

Method of protecting human skin from actinic radiation

International Nuclear Information System (INIS)

Fusaro, R.M.

1975-01-01

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

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

NARCIS (Netherlands)

Derler, S.; Gerhardt, L.C.

2012-01-01

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

Effects of whole body cryotherapy and cold water immersion on knee skin temperature

OpenAIRE

Costello, J. T.; Donnelly, A. E.; Karki, A.; Selfe, J.

2014-01-01

This study sought to a) compare and contrast the effect of 2 commonly used cryotherapy treatments, 4 min of −110°C whole body cryotherapy and 8°C cold water immersion, on knee skin temperature and b) establish whether either protocol was capable of achieving a skin temperature (

Cylindrical SUV distribution model for detecting skin lesions in body trunk FDG-PET/CT images

International Nuclear Information System (INIS)

Nemoto, Mitsutaka; Nomura, Yukihiro; Masutani, Yoshitaka; Yoshikawa, Takeharu; Hayashi, Naoto; Yoshioka, Naoki; Ohtomo, Kuni; Hanaoka, Shouhei

2010-01-01

We have been developing a computerized detection method for skin lesions in body trunk fluorodeoxyglucose-positron emission tomography (FDG-PET)/CT images. Spots on the skin with a high standard uptake value (SUV) are due not only to glucose metabolism in skin lesions but also to the physiological metabolism of organs near the skin. The distribution pattern of regional SUV on the skin is important information for the differential diagnosis of such high-SUV spots. In this study, we have developed a new skin lesion detection method based on a cylindrical SUV distribution model of the skin. The shape of the SUV distribution model is an approximation of the body trunk, and the SUV distribution model includes standard values for regional skin SUV. Classifier ensembles based on CT image features, SUV features, and subtraction features between the SUVs in FDG-PET images and the values in the SUV distribution model are used to extract and classify candidate regions for skin lesions. In a study of skin lesion detection using FDG-PET/CT images in 36 clinical cases, the true-positive rate was 61.7%, with 11.7 false-positive regions per case. The training results of the classifier ensemble for extracting and classifying candidate regions showed the effective features for detecting skin lesions in the study. (author)

Skin Aging Remedies in Traditional Persian Medicine

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Shirbeigi

2015-03-01

Full Text Available Context Traditional persian medicine (TPM is an ancient temperamental medicine with a rich literature about aging mechanism. Temperament has an important function in maintaining the ideal healthy status of human body. Aging process and skin aging could be postponed by applying herbal medicine and some specific traditional rules. Evidence Acquisition The aim of this review study was gathering and discussing the mechanism of whole body aging and skin aging from perspective of TPM and introducing remedies to prevent it. Skin aging is caused by external and internal factors. According to TPM, loss of fat and water content in different skin layers is the main cause of skin aging and it could be avoided by considering simple essential commands. Results Skin aging begins with whole body aging process and entire body gets cold and dry in elderly. Wrinkle formation is highly associated with loss of “skin natural moisture”. In the management, specific food supplements, simple massage therapy as well as herbal drugs were suggested. The current investigation was performed to show the knowledge of ancient Iranian scientists on aging process and related interventions. Conclusions Reported herbal drugs might be beneficial for further studies for the management of skin aging and aging process.

Skin injuries on the body and thigh of dairy cows

DEFF Research Database (Denmark)

Enevoldsen, Carsten; Gröhn, Y.T.; Thysen, Iver

1994-01-01

An epidemiological study was conducted in 18 dairy herds with the objective to characterize those groups of cows where skin injuries to the body and thighs occurred most frequently. Data were analyzed with multivariable logistic regression. The epidemiologic patterns were different in first and l...

Regional differences in the skin blood flow at various sites of the body studied by xenon 133

International Nuclear Information System (INIS)

Tsuchida, Y.

1987-01-01

Normal skin blood flow was measured by the xenon 133 clearance method at different anatomic sites of the body and the following results were obtained. First, the skin blood flow of the face and anterior chest was significantly greater than that of the deltoid region (P less than 0.01). The skin blood flow of the dorsal side of the hand and foot was significantly lower than that of the deltoid region (P less than 0.01). A tendency was observed for the skin blood flow to decrease gradually from the upper part of the body to the lower part of the body. For example, the ratio of the highest value at the face to the lowest value at the dorsal side of the foot was about 2.5:1, indicating a remarkable difference among the various sites of the body. The skin blood flow at the dorsum of the hand was significantly higher by about 25.4 percent than that of the foot (P less than 0.01). Second, the skin blood flow at the left side of the deltoid region was higher by about 5 percent than that of the right side (P less than 0.01). Bilateral comparison of the skin blood flow at the dorsal side of the hand and foot showed that the values were almost the same on the left and right

Characterisation of mechanical behaviour of human skin in vivo

NARCIS (Netherlands)

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

2000-01-01

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

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

Science.gov (United States)

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

2014-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2010-07-21

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

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

International Nuclear Information System (INIS)

Sharma, Rakesh

2010-01-01

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

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

Science.gov (United States)

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

2016-01-01

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

First donation of human skin obtained from corpse

International Nuclear Information System (INIS)

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

2007-01-01

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

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

Science.gov (United States)

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

2014-06-01

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

A novel model of human skin pressure ulcers in mice.

Directory of Open Access Journals (Sweden)

Andrés A Maldonado

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

Assessing human skin with diffuse reflectance spectroscopy and colorimetry

Science.gov (United States)

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

2012-02-01

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

Skin Conditions

Science.gov (United States)

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, ...

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

Science.gov (United States)

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

2015-01-01

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

The multitasking organ: recent insights into skin immune function.

Science.gov (United States)

Di Meglio, Paola; Perera, Gayathri K; Nestle, Frank O

2011-12-23

The skin provides the first line defense of the human body against injury and infection. By integrating recent findings in cutaneous immunology with fundamental concepts of skin biology, we portray the skin as a multitasking organ ensuring body homeostasis. Crosstalk between the skin and its microbial environment is also highlighted as influencing the response to injury, infection, and autoimmunity. The importance of the skin immune network is emphasized by the identification of several skin-resident cell subsets, each with its unique functions. Lessons learned from targeted therapy in inflammatory skin conditions, such as psoriasis, provide further insights into skin immune function. Finally, we look at the skin as an interacting network of immune signaling pathways exemplified by the development of a disease interactome for psoriasis. Copyright © 2011 Elsevier Inc. All rights reserved.

Point-Structured Human Body Modeling Based on 3D Scan Data

Directory of Open Access Journals (Sweden)

Ming-June Tsai

2018-01-01

Full Text Available A novel point-structured geometrical modelling for realistic human body is introduced in this paper. This technique is based on the feature extraction from the 3D body scan data. Anatomic feature such as the neck, the arm pits, the crotch points, and other major feature points are recognized. The body data is then segmented into 6 major parts. A body model is then constructed by re-sampling the scanned data to create a point-structured mesh. The body model contains body geodetic landmarks in latitudinal and longitudinal curves passing through those feature points. The body model preserves the perfect body shape and all the body dimensions but requires little space. Therefore, the body model can be used as a mannequin in garment industry, or as a manikin in various human factor designs, but the most important application is to use as a virtue character to animate the body motion in mocap (motion capture systems. By adding suitable joint freedoms between the segmented body links, kinematic and dynamic properties of the motion theories can be applied to the body model. As a result, a 3D virtual character that is fully resembled the original scanned individual is vividly animating the body motions. The gaps between the body segments due to motion can be filled up by skin blending technique using the characteristic of the point-structured model. The model has the potential to serve as a standardized datatype to archive body information for all custom-made products.

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

Science.gov (United States)

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

2018-05-01

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

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

International Nuclear Information System (INIS)

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

1986-01-01

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

Triceps skin fold thickness as a measure of body fat in Nigerian ...

African Journals Online (AJOL)

Background: Skin fold thickness (SFT) at selected areas offers a simple method of subcutaneous fat assessment and provides a good estimate of obesity and body fat distribution. The triceps SFT has been shown to be one of the best and most popular sites for SFT measurement in children. Objective: To assess the body fat ...

The cutaneous citadel: a holistic view of skin and immunity.

Science.gov (United States)

Spellberg, B

2000-06-23

Human skin has 4 major functions: endogenous homeostasis (e.g. regulation of body temperature and fluid balance), metabolism (e.g. Vitamin D synthesis), sensory input, and to serve as a barrier to external threats (e.g. infection, mechanical injury, ultraviolet light). It is the latter function which concerns this review, for the skin's remarkable success in protecting the human body from the outside world is a major component of our immune system. The eminent pathologist, Virchow, whose work in the mid 19th century revolutionized many aspects of medical understanding, viewed the skin as an effective but inanimate barrier (1). However, recent technologies have elucidated a highly complex, dynamic interplay between the skin and other members of the immune system.

Molecular cartography of the human skin surface in 3D

Science.gov (United States)

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

2015-01-01

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

Getting under the skin of epidermal morphogenesis.

Science.gov (United States)

Fuchs, Elaine; Raghavan, Srikala

2002-03-01

At the surface of the skin, the epidermis serves as the armour for the body. Scientists are now closer than ever to understanding how the epidermis accomplishes this extraordinary feat, and is able to survive and replenish itself under the harshest conditions that face any tissue. By combining genetic engineering with cell-biological studies and with human genome data analyses, skin biologists are discovering the mechanisms that underlie the development and differentiation of the epidermis and hair follicles of the skin. This explosion of knowledge paves the way for new discoveries into the genetic bases of human skin disorders and for developing new therapeutics.

Finite element modeling for predicting the contact pressure between a foam mattress and the human body in a supine position.

Science.gov (United States)

Lee, Wookjin; Won, Byeong Hee; Cho, Seong Wook

2017-01-01

In this paper, we generated finite element (FE) models to predict the contact pressure between a foam mattress and the human body in a supine position. Twenty-year-old males were used for three-dimensional scanning to produce the FE human models, which was composed of skin and muscle tissue. A linear elastic isotropic material model was used for the skin, and the Mooney-Rivlin model was used for the muscle tissue because it can effectively represent the nonlinear behavior of muscle. The contact pressure between the human model and the mattress was predicted by numerical simulation. The human models were validated by comparing the body pressure distribution obtained from the same human subject when he was lying on two different mattress types. The experimental results showed that the slope of the lower part of the mattress caused a decrease in the contact pressure at the heels, and the effect of bone structure was most pronounced in the scapula. After inserting a simple structure to function as the scapula, the contact pressure predicted by the FE human models was consistent with the experimental body pressure distribution for all body parts. These results suggest that the models proposed in this paper will be useful to researchers and designers of products related to the prevention of pressure ulcers.

Interactions of mean body and local skin temperatures in the modulation of human forearm and calf blood flows: a three-dimensional description.

Science.gov (United States)

Caldwell, Joanne N; Matsuda-Nakamura, Mayumi; Taylor, Nigel A S

2016-02-01

The inter-relationships between mean body and local skin temperatures have previously been established for controlling hand and foot blood flows. Since glabrous skin contains many arteriovenous anastomoses, it was important to repeat those experiments on non-glabrous regions using the same sample and experimental conditions. Mild hypothermia (mean body temperature 31.4 °C), normothermia (control: 36.0 °C) and moderate hyperthermia (38.3 °C) were induced and clamped (climate chamber and water-perfusion garment) in eight males. Within each condition, five localised thermal treatments (5, 15, 25, 33, 40 °C) were applied to the left forearm and right calf. Steady-state forearm and calf blood flows were measured (venous occlusion plethysmography) for each of the resulting 15 combinations of clamped mean body and local skin temperatures. Under the normothermic clamp, cutaneous blood flows averaged 4.2 mL 100 mL(-1) min(-1) (±0.28: forearm) and 5.4 mL 100 mL(-1) min(-1) (±0.27: calf). When mildly hypothermic, these segments were unresponsive to localised thermal stimuli, but tracked those changes when normothermic and moderately hyperthermic. For deep-body (oesophageal) temperature elevations, forearm blood flow increased by 5.1 mL 100 mL(-1) min(-1) °C(-1) (±0.9) relative to normothermia, while the calf was much less responsive: 3.3 mL 100 mL(-1) min(-1) °C(-1) (±1.5). Three-dimensional surfaces revealed a qualitative divergence in the control of calf blood flow, with vasoconstrictor tone apparently being released more gradually. These descriptions reinforce the importance of deep-tissue temperatures in controlling cutaneous perfusion, with this modulation being non-linear at the forearm and appearing linear for the calf.

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

Directory of Open Access Journals (Sweden)

Almudena Pérez-Sánchez

2018-03-01

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

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

Science.gov (United States)

Pérez-Sánchez, Almudena; Micol, Vicente

2018-01-01

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

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

Directory of Open Access Journals (Sweden)

Nisma Mujahid

2017-06-01

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

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

Science.gov (United States)

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

2017-06-13

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

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

NARCIS (Netherlands)

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

2002-01-01

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

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

Science.gov (United States)

Barbero, Ana M; Frasch, H Frederick

2009-02-01

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

Characterization of the mechanical behavior of human skin by means of impedance spectroscopy

Science.gov (United States)

Pavšelj, N.; Mitar, M.; Hart, F. X.; Miklavčič, D.

2010-04-01

There is increased interest for the use of impedance spectroscopy to measure skin dielectric properties in vivo. The aim of such measurements can be either to evaluate the hydration state of the skin, to detect diseased states such as skin cancer, to follow the progress of transdermal drug delivery, or simply to gather data on skin tissue impedance to be used in theoretical studies. However, obtaining reliable data can be difficult. Namely, skin is a highly nonhomogeneous multi-layered structure whose composition and dimensions differ depending on the location on the body and interindividual variations. Also, impedance measurements on skin are accompanied by a number of artefacts. We performed a series of impedance measurements using an Agilent/HP 4284A precision LCR meter with parallel plate electrodes pressed on the skin, at different locations on the body. We observed substantial impedance changes over the course of the measurement. These changes can be mainly attributed to skin deformation caused by the electrodes pressing against skin. The analysis showed that skin mechanical properties and layer thicknesses can be inferred from these temporal changes. Such data on mechanical properties of skin tissue give valuable extra information, crucial for successful estimation of the impedance of different skin layers.

Human body communication performance simulations

OpenAIRE

Mufti, H. (Haseeb)

2016-01-01

Abstract Human Body Communication (HBC) is a novel communication method between devices which use human body as a transmission medium. This idea is mostly based on the concept of wireless biomedical monitoring system. The on-body sensor nodes can monitor vital signs of a human body and use the body as a transmission medium. This technology is convenient for long durations of clinical monitoring with the option of more mobil...

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

Science.gov (United States)

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

2017-10-02

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

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

Science.gov (United States)

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

2017-08-01

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

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

NARCIS (Netherlands)

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

2016-01-01

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

Differences between the most used equations in BAT-human studies to estimate parameters of skin temperature in young lean men.

Science.gov (United States)

Martinez-Tellez, Borja; Sanchez-Delgado, Guillermo; Acosta, Francisco M; Alcantara, Juan M A; Boon, Mariëtte R; Rensen, Patrick C N; Ruiz, Jonatan R

2017-09-05

Cold exposure is necessary to activate human brown adipose tissue (BAT), resulting in heat production. Skin temperature is an indirect measure to monitor the body's reaction to cold. The aim of this research was to study whether the most used equations to estimate parameters of skin temperature in BAT-human studies measure the same values of temperature in young lean men (n = 11: 23.4 ± 0.5 years, fat mass: 19.9 ± 1.2%). Skin temperature was measured with 26 ibuttons at 1-minute intervals in warm and cold room conditions. We used 12 equations to estimate parameters of mean, proximal, and distal skin temperature as well as skin temperature gradients. Data were analysed with Temperatus software. Significant differences were found across equations to measure the same parameters of skin temperature in warm and cold room conditions, hampering comparison across studies. Based on these findings, we suggest to use a set of 14 ibuttons at anatomical positions reported by ISO STANDARD 9886:2004 plus five ibuttons placed on the right supraclavicular fossa, right middle clavicular bone, right middle upper forearm, right top of forefinger, and right upper chest.

The use of ex vivo human skin tissue for genotoxicity testing

Energy Technology Data Exchange (ETDEWEB)

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

2012-06-01

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

The use of ex vivo human skin tissue for genotoxicity testing

International Nuclear Information System (INIS)

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

2012-01-01

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

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

Directory of Open Access Journals (Sweden)

Noah K. Tenai

2016-05-01

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

Thermal Harvesting Potential of the Human Body

Science.gov (United States)

Thielen, Moritz; Kara, Gökhan; Unkovic, Ivana; Majoe, Dennis; Hierold, Christofer

2018-02-01

Thermoelectric energy harvesting of human body heat might supplement or even replace conventional energy storage in wearable devices for healthcare and the Internet of Humans. Although a number of thermal harvesters are presented in the literature, no conclusive data can be found on the amount of available thermal energy provided by different individuals and activities. We here present the results of an observational study with 56 test subjects of different ages (children, adults and elderly) and gender, performing predefined activities (sitting, walking) in varying environments (indoor, outdoor). Our study showed a statistical difference of thermal potential and skin properties between age groups, but not between genders. On average, stationary elderly test subjects produced ˜ 32% less heat flux compared to minors (mean: children = 13.9 mW/cm2, adults = 11.4 mW/cm2, elderly = 9.4 mW/cm2). This potentially correlates with an increase in thermal skin resistance with age (children = 494 cm2 K/W, adults = 549 cm2 K/W, elderly = 835 cm2 K/W). The mean harvested power varied from 12.2 μW/cm2 (elderly) to 26.2 μW/cm2 (children) for stationary, and from 20.2 μW/cm2 (elderly) to 69.5 μW/cm2 (children) for active subjects inside of a building. The findings of this study can be used to better anticipate the available energy for different usage scenarios of thermal harvesters and optimize wearable systems accordingly.

Thermal Harvesting Potential of the Human Body

Science.gov (United States)

Thielen, Moritz; Kara, Gökhan; Unkovic, Ivana; Majoe, Dennis; Hierold, Christofer

2018-06-01

Thermoelectric energy harvesting of human body heat might supplement or even replace conventional energy storage in wearable devices for healthcare and the Internet of Humans. Although a number of thermal harvesters are presented in the literature, no conclusive data can be found on the amount of available thermal energy provided by different individuals and activities. We here present the results of an observational study with 56 test subjects of different ages (children, adults and elderly) and gender, performing predefined activities (sitting, walking) in varying environments (indoor, outdoor). Our study showed a statistical difference of thermal potential and skin properties between age groups, but not between genders. On average, stationary elderly test subjects produced ˜ 32% less heat flux compared to minors (mean: children = 13.9 mW/cm2, adults = 11.4 mW/cm2, elderly = 9.4 mW/cm2). This potentially correlates with an increase in thermal skin resistance with age (children = 494 cm2 K/W, adults = 549 cm2 K/W, elderly = 835 cm2 K/W). The mean harvested power varied from 12.2 μW/cm2 (elderly) to 26.2 μW/cm2 (children) for stationary, and from 20.2 μW/cm2 (elderly) to 69.5 μW/cm2 (children) for active subjects inside of a building. The findings of this study can be used to better anticipate the available energy for different usage scenarios of thermal harvesters and optimize wearable systems accordingly.

Warm hands, cold heart: progressive whole-body cooling increases warm thermosensitivity of human hands and feet in a dose-dependent fashion.

Science.gov (United States)

Filingeri, Davide; Morris, Nathan B; Jay, Ollie

2017-01-01

What is the central question of this study? Investigations on inhibitory/facilitatory modulation of vision, touch and pain show that conditioning stimuli outside the receptive field of testing stimuli modulate the central processing of visual, touch and painful stimuli. We asked whether contextual modulation also exists in human temperature integration. What is the main finding and its importance? Progressive decreases in whole-body mean skin temperature (the conditioning stimulus) significantly increased local thermosensitivity to skin warming but not cooling (the testing stimuli) in a dose-dependent fashion. In resembling the central mechanisms underlying endogenous analgesia, our findings point to the existence of an endogenous thermosensory system in humans that could modulate local skin thermal sensitivity to facilitate thermal behaviour. Although inhibitory/facilitatory central modulation of vision and pain has been investigated, contextual modulation of skin temperature integration has not been explored. Hence, we tested whether progressive decreases in whole-body mean skin temperature (T sk ; a large conditioning stimulus) alter the magnitude estimation of local warming and cooling stimuli applied to hairy and glabrous skin. On four separate occasions, eight men (27 ± 5 years old) underwent a 30 min whole-body cooling protocol (water-perfused suit; temperature, 5°C), during which a quantitative thermosensory test, consisting of reporting the perceived magnitude of warming and cooling stimuli (±8°C from 30°C baseline) applied to the hand (palm/dorsum) and foot (sole/dorsum), was performed before cooling and every 10 min thereafter. The cooling protocol resulted in large progressive reductions in T sk [10 min, -3.36°C (95% confidence interval -2.62 to -4.10); 20 min, -5.21°C (-4.47 to -5.95); and 30 min, -6.32°C (-5.58 to -7.05); P fashion. In highlighting a novel feature of human temperature integration, these findings point to the existence

Air Ambient-Operated pNIPAM-Based Flexible Actuators Stimulated by Human Body Temperature and Sunlight.

Science.gov (United States)

Yamamoto, Yuki; Kanao, Kenichiro; Arie, Takayuki; Akita, Seiji; Takei, Kuniharu

2015-05-27

Harnessing a natural power source such as the human body temperature or sunlight should realize ultimate low-power devices. In particular, macroscale and flexible actuators that do not require an artificial power source have tremendous potential. Here we propose and demonstrate electrically powerless polymer-based actuators operated at ambient conditions using a packaging technique in which the stimulating power source is produced by heat from the human body or sunlight. The actuating angle, force, and reliability are discussed as functions of temperature and exposure to sunlight. Furthermore, a wearable device platform and a smart curtain actuated by the temperature of human skin and sunlight, respectively, are demonstrated as the first proof-of-concepts. These nature-powered actuators should realize a new class of ultimate low-power devices.

Effects of whole body cryotherapy and cold water immersion on knee skin temperature.

Science.gov (United States)

Costello, J T; Donnelly, A E; Karki, A; Selfe, J

2014-01-01

This study sought to (a) compare and contrast the effect of 2 commonly used cryotherapy treatments, 4 min of -110 °C whole body cryotherapy and 8 °C cold water immersion, on knee skin temperature and (b) establish whether either protocol was capable of achieving a skin temperature (cryotherapy (19.0±0.9 °C) compared to cold water immersion (20.5±0.6 °C). However, from 10 to 60 min post, the average, minimum and maximum skin temperatures were lower (p<0.05) following the cold water treatment. Finally, neither protocol achieved a skin temperature believed to be required to elicit an analgesic effect. © Georg Thieme Verlag KG Stuttgart · New York.

Dragon Skin - How It Changed Body Armor Testing in the United States Army

Science.gov (United States)

2015-09-01

members of this committee who have their kids at one time or another wearing body armor in theater, either Iraq or Afghanistan. And that includes... YouTube has pictures of Dragon Skin body armor testing on the Internet and Wikipedia has posted a carefully documented description of the history of

Essential role of RAB27A in determining constitutive human skin color.

Directory of Open Access Journals (Sweden)

Yasuko Yoshida-Amano

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

Histological and Ultrastructural Effects of Ultrasound-induced Cavitation on Human Skin Adipose Tissue.

Science.gov (United States)

Bani, Daniele; Quattrini Li, Alessandro; Freschi, Giancarlo; Russo, Giulia Lo

2013-09-01

In aesthetic medicine, the most promising techniques for noninvasive body sculpturing purposes are based on ultrasound-induced fat cavitation. Liporeductive ultrasound devices afford clinically relevant subcutaneous fat pad reduction without significant adverse reactions. This study aims at evaluating the histological and ultrastructural changes induced by ultrasound cavitation on the different cell components of human skin. Control and ultrasound-treated ex vivo abdominal full-thickness skin samples and skin biopsies from patients pretreated with or without ultrasound cavitation were studied histologically, morphometrically, and ultrastructurally to evaluate possible changes in adipocyte size and morphology. Adipocyte apoptosis and triglyceride release were also assayed. Clinical evaluation of the effects of 4 weekly ultrasound vs sham treatments was performed by plicometry. Compared with the sham-treated control samples, ultrasound cavitation induced a statistically significant reduction in the size of the adipocytes (P ultrasound treatment caused a significant reduction of abdominal fat. This study further strengthens the current notion that noninvasive transcutaneous ultrasound cavitation is a promising and safe technology for localized reduction of fat and provides experimental evidence for its specific mechanism of action on the adipocytes.

Skin picking disorder with co-occurring body dysmorphic disorder

DEFF Research Database (Denmark)

Grant, Jon E; Redden, Sarah A; Leppink, Eric W

2015-01-01

There is clinical overlap between skin picking disorder (SPD) and body dysmorphic disorder (BDD), but little research has examined clinical and cognitive correlates of the two disorders when they co-occur. Of 55 participants with SPD recruited for a neurocognitive study and two pharmacological st...... unique clinical and cognitive aspects of SPD may be more pronounced. Future work should explore possible subgroups in SPD and whether these predict different treatment outcomes....

The human skin double-stranded DNA virome: topographical and temporal diversity, genetic enrichment, and dynamic associations with the host microbiome.

Science.gov (United States)

Hannigan, Geoffrey D; Meisel, Jacquelyn S; Tyldsley, Amanda S; Zheng, Qi; Hodkinson, Brendan P; SanMiguel, Adam J; Minot, Samuel; Bushman, Frederic D; Grice, Elizabeth A

2015-10-20

Viruses make up a major component of the human microbiota but are poorly understood in the skin, our primary barrier to the external environment. Viral communities have the potential to modulate states of cutaneous health and disease. Bacteriophages are known to influence the structure and function of microbial communities through predation and genetic exchange. Human viruses are associated with skin cancers and a multitude of cutaneous manifestations. Despite these important roles, little is known regarding the human skin virome and its interactions with the host microbiome. Here we evaluated the human cutaneous double-stranded DNA virome by metagenomic sequencing of DNA from purified virus-like particles (VLPs). In parallel, we employed metagenomic sequencing of the total skin microbiome to assess covariation and infer interactions with the virome. Samples were collected from 16 subjects at eight body sites over 1 month. In addition to the microenviroment, which is known to partition the bacterial and fungal microbiota, natural skin occlusion was strongly associated with skin virome community composition. Viral contigs were enriched for genes indicative of a temperate phage replication style and also maintained genes encoding potential antibiotic resistance and virulence factors. CRISPR spacers identified in the bacterial DNA sequences provided a record of phage predation and suggest a mechanism to explain spatial partitioning of skin phage communities. Finally, we modeled the structure of bacterial and phage communities together to reveal a complex microbial environment with a Corynebacterium hub. These results reveal the previously underappreciated diversity, encoded functions, and viral-microbial dynamic unique to the human skin virome. To date, most cutaneous microbiome studies have focused on bacterial and fungal communities. Skin viral communities and their relationships with their hosts remain poorly understood despite their potential to modulate states

Cultured skin microbiota attracts malaria mosquitoes

NARCIS (Netherlands)

Verhulst, Niels O.; Beijleveld, Hans; Knols, Bart Gj; Takken, Willem; Schraa, Gosse; Bouwmeester, Harro J.; Smallegange, Renate C.

2009-01-01

Host-seeking of the African malaria mosquito, Anopheles gambiae sensu stricto, is guided by human odours. The precise nature of the odours, and the composition of attractive blends of volatiles, remains largely unknown. Skin microbiota plays an important role in the production of human body odours.

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

Science.gov (United States)

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

2017-01-01

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

RNA isolation for transcriptomics of human and mouse small skin biopsies

Directory of Open Access Journals (Sweden)

Breit Timo M

2011-10-01

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

Physics of the Human Body

CERN Document Server

Herman, Irving P

2007-01-01

Physics of the Human Body comprehensively addresses the physical and engineering aspects of human physiology by using and building on first-year college physics and mathematics. Topics include the mechanics of the static body and the body in motion, the materials properties of the body, muscles in the body, the energetics of body metabolism, fluid flow in the cardiovascular and respiratory systems, the acoustics of sound waves in speaking and hearing, vision and the optics of the eye, the electrical properties of the body, and the basic engineering principles of feedback and control in regulating all aspects of function. The goal of this text is to understand physical issues concerning the human body, in part by developing and then using simple and subsequently more refined models of the macrophysics of the human body. Many chapters include a brief review of the necessary physical principles. There are problems at the end of each chapter; solutions to selected problems are also provided. This text is geared t...

Shaping Vulnerable Bodies at the Thin Boundary between Environment and Organism: Skin, DNA Repair, and a Genealogy of DNA Care Strategies.

Science.gov (United States)

von Schwerin, Alexander

2015-09-01

This paper brings together the history of risk and the history of DNA repair, a biological phenomenon that emerged as a research field in between molecular biology, genetics, and radiation research in the 1960s. The case of xeroderma pigmentosum (XP), an inherited hypersensitivity to UV light and, hence, a disposition to skin cancer will be the starting point to argue that, in the 1970s and 1980s, DNA repair became entangled in the creation of new models of the human body at risk - what is here conceptually referred to as the vulnerability aspect of body history - and new attempts at cancer prevention and enhancement of the body associated with the new flourishing research areas of antimutagenesis and anticarcinogenesis. The aim will be to demonstrate that DNA repair created special attempts at disease prevention: molecular enhancement, seeking to identify means to increase the self-repair abilities of the body at the molecular level. Prevention in this sense meant enhancing the body's ability to cope with the environmental hazards of an already toxic world. This strategy has recently been adopted by the beauty industry, which introduced DNA care as a new target for skin care research and anti-aging formulas.

Body Basics Library

Science.gov (United States)

... Body Basics articles explain just how each body system, part, and process works. Use this medical library to find out about basic human anatomy, how ... Teeth Skin, Hair, and Nails Spleen and Lymphatic System ... Visit the Nemours Web site. Note: All information on TeensHealth® is for ...

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

DEFF Research Database (Denmark)

Pappinen, Sari; Hermansson, Martin; Kuntsche, Judith

2008-01-01

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

Aesthetic skin branding: a novel form of body art with adverse clinical sequela.

Science.gov (United States)

Karamanoukian, Raffy; Ukatu, Chidi; Lee, Edward; Hyman, Josh; Sundine, Michael; Kobayashi, Mark; Evans, Gregory R D

2006-01-01

Branding is a form of body art wherein third-degree burns are inflicted on the skin to produce permanent scars. This method of scarification is a common practice among many indigenous cultures and has become exceedingly common in western societies. As with other forms of body art, branding is not a manifestation of a psychiatric disorder but, rather, a method of self-expression. The process can be performed through the use of electrocautery, laser, chemicals, freezing, and hot metal. Complications arising from the procedure include acute infection, transmission of blood-borne pathogens, allergic reactions, and sequelae arising from third-degree burns. In addition, skin branding has been shown to be associated with substance abuse and high-risk behaviors among adolescents. The purpose of this article is to present the following case report and review to familiarize clinicians with this dangerous method of body art.

Multiphoton spectroscopy of human skin in vivo

Science.gov (United States)

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

2012-03-01

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

Low power cw-laser signatures on human skin

International Nuclear Information System (INIS)

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

2011-01-01

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

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

Science.gov (United States)

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

2017-12-01

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

The Significance of Epidermal Lipid Metabolism in Whole-Body Physiology

DEFF Research Database (Denmark)

Kruse, Vibeke; Neess, Ditte; Færgeman, Nils J

2017-01-01

The skin is the largest sensory organ of the human body. The skin not only prevents loss of water and other components of the body, but also is involved in regulation of body temperature and serves as an essential barrier, protecting mammals from both routine and extreme environments. Given...... the importance of the skin in temperature regulation, it is surprising that adaptive alterations in skin functions and morphology only vaguely have been associated with systemic physiological responses. Despite that impaired lipid metabolism in the skin often impairs the epidermal permeability barrier...... and insulation properties of the skin, its role in regulating systemic physiology and metabolism is yet to be recognized....

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

Science.gov (United States)

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

2014-02-24

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

Total body topical 5-fluorouracil for extensive non-melanoma skin cancer

NARCIS (Netherlands)

van Ruth, Serge; Jansman, Frank G. A.; Sanders, Cornelis J.

Background Topical 5-fluorouracil 5% cream is one of the treatment modalities for non-melanoma skin cancer (NMSC). There is a lack of suitable therapies to treat patients with extensive NMSC. In this paper we report two patients with extensive NMSC treated by total body application of topical

Triceps skin fold thickness as a measure of body fat in Nigerian

African Journals Online (AJOL)

owner

2012-11-26

Nov 26, 2012 ... and body fat distribution.2,3 Skin fold thickness measure- ments are a well ... different recognized areas for the measurement of SFT, ..... 'western children.' These .... Asia Pacific J Clin ... sity in children and young people:.

Deposition of contaminant aerosol on human skin

DEFF Research Database (Denmark)

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

2006-01-01

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

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

Science.gov (United States)

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

2017-01-01

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

Methodological assessment of skin and limb blood flows in the human forearm during thermal and baroreceptor provocations.

Science.gov (United States)

Brothers, R Matthew; Wingo, Jonathan E; Hubing, Kimberly A; Crandall, Craig G

2010-09-01

Skin blood flow responses in the human forearm, assessed by three commonly used technologies-single-point laser-Doppler flowmetry, integrated laser-Doppler flowmetry, and laser-Doppler imaging-were compared in eight subjects during normothermic baseline, acute skin-surface cooling, and whole body heat stress (Δ internal temperature=1.0±0.2 degrees C; Pforearm blood flow (FBF) measures obtained using venous occlusion plethysmography and Doppler ultrasound were made during the aforementioned perturbations. Relative to normothermic baseline, skin blood flow decreased during normothermia+LBNP (Pcooling (Peffect of device: P>0.05 for all conditions). Similarly, no differences were identified across all perturbations between FBF measures using plethysmography and Doppler ultrasound (P>0.05 for all perturbations). These data indicate that when normalized to maximum, assessment of skin blood flow in response to vasoconstrictor and dilator perturbations are similar regardless of methodology. Likewise, FBF responses to these perturbations are similar between two commonly used methodologies of limb blood flow assessment.

Measurement of the deposition of aerosol particles to skin, hair and clothing

International Nuclear Information System (INIS)

Bell, K.F.

1999-01-01

In the event of a nuclear accident, there are several routes whereby human populations may receive a radioactive dose from material released to the environment. The dose from radioactive aerosol deposited onto the surfaces of the human body has previously been estimated by assuming that aerosol deposition velocities (defined as the flux of aerosol onto a surface divided by the aerosol concentration above the surface) onto human body surfaces are similar to the values for inanimate surfaces. However, Jones (1990) modelled the effects on health of fallout material deposited on skin and clothing and found that the number of early deaths from skin dose was sensitively dependent on aerosol deposition velocity. He also pointed out that there was a lack of experimentally derived data on aerosol deposition velocities to human body surfaces and that the above mentioned assumption may not be valid. The purpose of the present work is to measure aerosol deposition velocities onto human body surfaces, the resultant data to allow more accurate nuclear accident consequence modelling. Aerosol deposition velocities onto human body surfaces in simulated indoor conditions have been measured by releasing tracer aerosols of three mean particle diameters (2.6, 6.2 and 9.2μm) into a test chamber containing volunteers. The skin, hair and clothing of the volunteers were sampled and analysed for deposited aerosol by Neutron Activation Analysis. Aerosol deposition velocities onto skin in the range 1.3 - 15 x 10 -3 ms -1 were recorded, values which are approximately an order of magnitude higher than the equivalent values onto the floor of the test room. These values suggest that the exposure route of radioactive aerosol particles deposited on the skin may be more significant than hitherto had been assumed. The possible mechanisms leading to this relatively high deposition were investigated experimentally and the results suggested that a combination of factors such as the body's electrostatic

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

Directory of Open Access Journals (Sweden)

Muya Shu

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

Cutaneous in vivo metabolism of topical lidocaine formulation in human skin

DEFF Research Database (Denmark)

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

2009-01-01

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

Reproducible pattern of microRNA in normal human skin

DEFF Research Database (Denmark)

Holst, Line; Kaczkowski, Bogumil; Gniadecki, Robert

2010-01-01

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

Reproducible pattern of microRNA in normal human skin

DEFF Research Database (Denmark)

Holst, Line; Kaczkowski, Bogumil; Gniadecki, Robert

2010-01-01

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

Human body temperature and new approaches to constructing temperature-sensitive bacterial vaccines.

Science.gov (United States)

White, Matthew D; Bosio, Catharine M; Duplantis, Barry N; Nano, Francis E

2011-09-01

Many of the live human and animal vaccines that are currently in use are attenuated by virtue of their temperature-sensitive (TS) replication. These vaccines are able to function because they can take advantage of sites in mammalian bodies that are cooler than the core temperature, where TS vaccines fail to replicate. In this article, we discuss the distribution of temperature in the human body, and relate how the temperature differential can be exploited for designing and using TS vaccines. We also examine how one of the coolest organs of the body, the skin, contains antigen-processing cells that can be targeted to provoke the desired immune response from a TS vaccine. We describe traditional approaches to making TS vaccines, and highlight new information and technologies that are being used to create a new generation of engineered TS vaccines. We pay particular attention to the recently described technology of substituting essential genes from Arctic bacteria for their homologues in mammalian pathogens as a way of creating TS vaccines.

About possibility of temperature trace observing on a human skin through clothes by using computer processing of IR image

Science.gov (United States)

Trofimov, Vyacheslav A.; Trofimov, Vladislav V.; Shestakov, Ivan L.; Blednov, Roman G.

2017-05-01

One of urgent security problems is a detection of objects placed inside the human body. Obviously, for safety reasons one cannot use X-rays for such object detection widely and often. For this purpose, we propose to use THz camera and IR camera. Below we continue a possibility of IR camera using for a detection of temperature trace on a human body. In contrast to passive THz camera using, the IR camera does not allow to see very pronounced the object under clothing. Of course, this is a big disadvantage for a security problem solution based on the IR camera using. To find possible ways for this disadvantage overcoming we make some experiments with IR camera, produced by FLIR Company and develop novel approach for computer processing of images captured by IR camera. It allows us to increase a temperature resolution of IR camera as well as human year effective susceptibility enhancing. As a consequence of this, a possibility for seeing of a human body temperature changing through clothing appears. We analyze IR images of a person, which drinks water and eats chocolate. We follow a temperature trace on human body skin, caused by changing of temperature inside the human body. Some experiments are made with observing of temperature trace from objects placed behind think overall. Demonstrated results are very important for the detection of forbidden objects, concealed inside the human body, by using non-destructive control without using X-rays.

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

Science.gov (United States)

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

2017-06-06

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

Oxidative stress and CCN1 protein in human skin connective tissue aging

Directory of Open Access Journals (Sweden)

Zhaoping Qin

2016-06-01

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

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

Science.gov (United States)

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

2012-01-01

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

Skin hydration, microrelief and greasiness of normal skin in Antarctica.

Science.gov (United States)

Tsankov, N; Mateev, D; Darlenski, R

2018-03-01

The skin is the primary defence of the human body against external factors from physical, chemical, mechanical and biologic origin. Climatic factors together with low temperature and sun radiation affect the skin. The effect of climatic conditions in Antarctica on healthy skin has not been previously addressed. The aim of this study was to evaluate the changes in the skin hydration, greasiness and microrelief due to the extreme climatic environmental factors during the stay of the members of the Bulgarian Antarctic expedition. Fifty-nine Caucasian healthy subjects, 42 men and 17 women with mean age 50.9 years (27-68), were enrolled. The study was performed in five consecutive years from 2011 to 2016 at the Bulgarian Antarctic base camp at Livingston Island. The study protocol consisted of two parts: study A: duration of 15 days with measurement of skin physiology parameters on a daily basis, and study B: five measurements at baseline and at days 14, 30, 45 and 50 upon arrival in Antarctica. We measured three biophysical parameters related to skin physiology at cheek skin by an impedance measuring device. No statistically significant difference between parameters at the different measurement points. There is a variation in skin hydration reaching its lower point at day 11 and then returning to values similar to baseline. Initially, an increase in skin greasiness was witnessed with a sharp depression at day 11 and final values at day 15 resembling the ones at baseline. An increase, although not statistically significant, in skin roughness was observed in the first 15 days of the study. Study B showed no statistically significant variances between values of the three parameters. Our studies show the pioneer results of the effect of Antarctic climate on human skin physiology. © 2017 European Academy of Dermatology and Venereology.

[Comparison of body temperatures in children measured using 3 different thermometers: tympanic, skin and digital axillary].

Science.gov (United States)

Padilla-Raygoza, Nicolás; Ruiz-Paloalto, M Laura; Díaz-Guerrero, Rosalina; Olvera-Villanueva, Georgina; Maldonado, Angélica; Raygoza-Mendoza, María Del Pilar

2014-01-01

To compare body temperature measurements using tympanic, skin and digital axillary thermometers. Hospitalized or outpatient children from the General Hospital Celaya, ISSSTE Hospital Clinic and General Hospital No. 4 IMSS, and the pediatric private service in Celaya, Guanajuato, from 1 day of life until 16 years old, were recruited over a one month period, after their parents signed the consent form. The order of each institution was selected by simple randomization. Body temperatures were measured in triplicate using tympanic, skin and digital axillary thermometers. The sample consisted of 554 children. The Pearson r between the tympanic and digital axillary thermometers was 0.57 to 0.65, with a positive linear relationship (P<.05); between the skin and the digital axillary thermometers, it was between 0.47 and 0.52 with a positive linearrelationship (P<.05). The intra-observer Kappa for the tympanic thermometer was 0.86, and for the inter-observer was 0.77; for the skin thermometer it was 0.82 and 0.67, respectively, and for the digital axillary thermometer it was 0.86 for intra-observer reliability and 0.78 for inter -observer reliability. Tympanic and axillary thermometers showed better precision in measuring the body temperature in children than skin thermometers. Copyright © 2013 Elsevier España, S.L. All rights reserved.

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

Science.gov (United States)

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

2016-08-01

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

A collaborative European exercise on mRNA-based body fluid/skin typing and interpretation of DNA and RNA results

DEFF Research Database (Denmark)

van den Berge, M; Carracedo, A; Gomes, I

2014-01-01

The European Forensic Genetics Network of Excellence (EUROFORGEN-NoE) undertook a collaborative project on mRNA-based body fluid/skin typing and the interpretation of the resulting RNA and DNA data. Although both body fluids and skin are composed of a variety of cell types with different function...

Skin graft influence in human tissue radiated in nude mice regeneration

International Nuclear Information System (INIS)

Miranda, Jurandir Tomaz de

2016-01-01

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

Significant changes in the skin microbiome mediated by the sport of roller derby

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James F. Meadow

2013-03-01

Full Text Available Diverse bacterial communities live on and in human skin. These complex communities vary by skin location on the body, over time, between individuals, and between geographic regions. Culture-based studies have shown that human to human and human to surface contact mediates the dispersal of pathogens, yet little is currently known about the drivers of bacterial community assembly patterns on human skin. We hypothesized that participation in a sport involving skin to skin contact would result in detectable shifts in skin bacterial community composition. We conducted a study during a flat track roller derby tournament, and found that teammates shared distinct skin microbial communities before and after playing against another team, but that opposing teams’ bacterial communities converged during the course of a roller derby bout. Our results are consistent with the hypothesis that the human skin microbiome shifts in composition during activities involving human to human contact, and that contact sports provide an ideal setting in which to evaluate dispersal of microorganisms between people.

Friction of Human Skin against Different Fabrics for Medical Use

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Luís Vilhena

2016-03-01

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

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

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Paulina Carvajal-Vidal

2017-11-01

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

Dynamic representations of human body movement.

Science.gov (United States)

Kourtzi, Z; Shiffrar, M

1999-01-01

Psychophysical and neurophysiological studies suggest that human body motions can be readily recognized. Human bodies are highly articulated and can move in a nonrigid manner. As a result, we perceive highly dissimilar views of the human form in motion. How does the visual system integrate multiple views of a human body in motion so that we can perceive human movement as a continuous event? The results of a set of priming experiments suggest that motion can readily facilitate the linkage of different views of a moving human. Positive priming was found for novel views of a human body that fell within the path of human movement. However, no priming was observed for novel views outside the path of motion. Furthermore, priming was restricted to those views that satisfied the biomechanical constraints of human movement. These results suggest that visual representation of human movement may be based upon the movement limitations of the human body and may reflect a dynamic interaction of motion and object-recognition processes.

Chronologic and actinically induced aging in human facial skin

International Nuclear Information System (INIS)

Gilchrest, B.A.; Szabo, G.; Flynn, E.; Goldwyn, R.M.

1983-01-01

Clinical and histologic stigmata of aging are much more prominent in habitually sun-exposed skin than in sun-protected skin, but other possible manifestations of actinically induced aging are almost unexplored. We have examined the interrelation of chronologic and actinic aging using paired preauricular (sun-exposed) and postauricular (sun-protected) skin specimens. Keratinocyte cultures derived from sun-exposed skin consistently had a shorter in vitro lifespan but increased plating efficiency compared with cultures derived from adjacent sun-protected skin of the same individual, confirming a previous study of different paired body sites. Electron microscopic histologic sections revealed focal abnormalities of keratinocyte proliferation and alignment in vitro especially in those cultures derived from sun-exposed skin and decreased intercellular contact in stratified colonies at late passage, regardless of donor site. One-micron histologic sections of the original biopsy specimens revealed no striking site-related keratinocyte alterations, but sun-exposed specimens had fewer epidermal Langerhans cells (p less than 0.001), averaging approximately 50 percent the number in sun-protected skin, a possible exaggeration of the previously reported age-associated decrease in this cell population. These data suggest that sun exposure indeed accelerates aging by several criteria and that, regardless of mechanism, environmental factors may adversely affect the appearance and function of aging skin in ways amenable to experimental quantitation

Permeation of chromium salts through human skin in vitro

DEFF Research Database (Denmark)

Gammelgaard, Bente; Fullerton, A; Avnstorp, C

1992-01-01

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

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

Science.gov (United States)

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

2013-01-01

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

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

Science.gov (United States)

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

2018-03-01

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

The Impact of Environmental and Endogenous Damage on Somatic Mutation Load in Human Skin Fibroblasts.

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Natalie Saini

2016-10-01

Full Text Available Accumulation of somatic changes, due to environmental and endogenous lesions, in the human genome is associated with aging and cancer. Understanding the impacts of these processes on mutagenesis is fundamental to understanding the etiology, and improving the prognosis and prevention of cancers and other genetic diseases. Previous methods relying on either the generation of induced pluripotent stem cells, or sequencing of single-cell genomes were inherently error-prone and did not allow independent validation of the mutations. In the current study we eliminated these potential sources of error by high coverage genome sequencing of single-cell derived clonal fibroblast lineages, obtained after minimal propagation in culture, prepared from skin biopsies of two healthy adult humans. We report here accurate measurement of genome-wide magnitude and spectra of mutations accrued in skin fibroblasts of healthy adult humans. We found that every cell contains at least one chromosomal rearrangement and 600–13,000 base substitutions. The spectra and correlation of base substitutions with epigenomic features resemble many cancers. Moreover, because biopsies were taken from body parts differing by sun exposure, we can delineate the precise contributions of environmental and endogenous factors to the accrual of genetic changes within the same individual. We show here that UV-induced and endogenous DNA damage can have a comparable impact on the somatic mutation loads in skin fibroblasts. Trial Registration: ClinicalTrials.gov NCT01087307.

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

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Zou Y

2017-10-01

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

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

Science.gov (United States)

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

2018-01-01

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

On the importance of body posture and skin modelling with respect to in situ electric field strengths in magnetic field exposure scenarios

Science.gov (United States)

Schmid, Gernot; Hirtl, Rene

2016-06-01

The reference levels and maximum permissible exposure values for magnetic fields that are currently used have been derived from basic restrictions under the assumption of upright standing body models in a standard posture, i.e. with arms laterally down and without contact with metallic objects. Moreover, if anatomical modelling of the body was used at all, the skin was represented as a single homogeneous tissue layer. In the present paper we addressed the possible impacts of posture and skin modelling in scenarios of exposure to a 50 Hz uniform magnetic field on the in situ electric field strength in peripheral tissues, which must be limited in order to avoid peripheral nerve stimulation. We considered different body postures including situations where body parts form large induction loops (e.g. clasped hands) with skin-to-skin and skin-to-metal contact spots and compared the results obtained with a homogeneous single-layer skin model to results obtained with a more realistic two-layer skin representation consisting of a low-conductivity stratum corneum layer on top of a combined layer for the cellular epidermis and dermis. Our results clearly indicated that postures with loops formed of body parts may lead to substantially higher maximum values of induced in situ electric field strengths than in the case of standard postures due to a highly concentrated current density and in situ electric field strength in the skin-to-skin and skin-to-metal contact regions. With a homogeneous single-layer skin, as is used for even the most recent anatomical body models in exposure assessment, the in situ electric field strength may exceed the basic restrictions in such situations, even when the reference levels and maximum permissible exposure values are not exceeded. However, when using the more realistic two-layer skin model the obtained in situ electric field strengths were substantially lower and no violations of the basic restrictions occurred, which can be explained by the

Measurement of interstitial cetirizine concentrations in human skin

DEFF Research Database (Denmark)

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

1999-01-01

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

Effect of fluocinolone acetonide cream on human skin blood flow

International Nuclear Information System (INIS)

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

1975-01-01

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

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

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M. A. Bezuglyi

2018-01-01

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

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

Science.gov (United States)

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

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

The response of human skin commensal bacteria as a reflection of UV radiation: UV-B decreases porphyrin production.

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Yanhan Wang

Full Text Available Recent global radiation fears reflect the urgent need for a new modality that can simply determine if people are in a radiation risk of developing cancer and other illnesses. Ultraviolet (UV radiation has been thought to be the major risk factor for most skin cancers. Although various biomarkers derived from the responses of human cells have been revealed, detection of these biomarkers is cumbersome, probably requires taking live human tissues, and varies significantly depending on human immune status. Here we hypothesize that the reaction of Propionibacterium acnes (P. acnes, a human resident skin commensal, to UV radiation can serve as early surrogate markers for radiation risk because the bacteria are immediately responsive to radiation. In addition, the bacteria can be readily accessible and exposed to the same field of radiation as human body. To test our hypothesis, P. acnes was exposed to UV-B radiation. The production of porphyrins in P. acnes was significantly reduced with increasing doses of UV-B. The porphyrin reduction can be detected in both P. acnes and human skin bacterial isolates. Exposure of UV-B to P. acnes- inoculated mice led to a significant decrease in porphyrin production in a single colony of P. acnes and simultaneously induced the formation of cyclobutane pyrimidine dimers (CPD in the epidermal layers of mouse skin. Mass spectrometric analysis via a linear trap quadrupole (LTQ-Orbitrap XL showed that five peptides including an internal peptide (THLPTGIVVSCQNER of a peptide chain release factor 2 (RF2 were oxidized by UV-B. Seven peptides including three internal peptides of 60 kDa chaperonin 1 were de-oxidized by UV-B. When compared to UV-B, gamma radiation also decreased the porphyrin production of P. acnes in a dose-dependent manner, but induced a different signature of protein oxidation/de-oxidation. We highlight that uncovering response of skin microbiome to radiation will facilitate the development of pre

The response of human skin commensal bacteria as a reflection of UV radiation: UV-B decreases porphyrin production.

Science.gov (United States)

Wang, Yanhan; Zhu, Wenhong; Shu, Muya; Jiang, Yong; Gallo, Richard L; Liu, Yu-Tsueng; Huang, Chun-Ming

2012-01-01

Recent global radiation fears reflect the urgent need for a new modality that can simply determine if people are in a radiation risk of developing cancer and other illnesses. Ultraviolet (UV) radiation has been thought to be the major risk factor for most skin cancers. Although various biomarkers derived from the responses of human cells have been revealed, detection of these biomarkers is cumbersome, probably requires taking live human tissues, and varies significantly depending on human immune status. Here we hypothesize that the reaction of Propionibacterium acnes (P. acnes), a human resident skin commensal, to UV radiation can serve as early surrogate markers for radiation risk because the bacteria are immediately responsive to radiation. In addition, the bacteria can be readily accessible and exposed to the same field of radiation as human body. To test our hypothesis, P. acnes was exposed to UV-B radiation. The production of porphyrins in P. acnes was significantly reduced with increasing doses of UV-B. The porphyrin reduction can be detected in both P. acnes and human skin bacterial isolates. Exposure of UV-B to P. acnes- inoculated mice led to a significant decrease in porphyrin production in a single colony of P. acnes and simultaneously induced the formation of cyclobutane pyrimidine dimers (CPD) in the epidermal layers of mouse skin. Mass spectrometric analysis via a linear trap quadrupole (LTQ)-Orbitrap XL showed that five peptides including an internal peptide (THLPTGIVVSCQNER) of a peptide chain release factor 2 (RF2) were oxidized by UV-B. Seven peptides including three internal peptides of 60 kDa chaperonin 1 were de-oxidized by UV-B. When compared to UV-B, gamma radiation also decreased the porphyrin production of P. acnes in a dose-dependent manner, but induced a different signature of protein oxidation/de-oxidation. We highlight that uncovering response of skin microbiome to radiation will facilitate the development of pre-symptomatic diagnosis

Physics of the human body

CERN Document Server

Herman, Irving P

2016-01-01

This book comprehensively addresses the physics and engineering aspects of human physiology by using and building on first-year college physics and mathematics. Topics include the mechanics of the static body and the body in motion, the mechanical properties of the body, muscles in the body, the energetics of body metabolism, fluid flow in the cardiovascular and respiratory systems, the acoustics of sound waves in speaking and hearing, vision and the optics of the eye, the electrical properties of the body, and the basic engineering principles of feedback and control in regulating all aspects of function. The goal of this text is to clearly explain the physics issues concerning the human body, in part by developing and then using simple and subsequently more refined models of the macrophysics of the human body. Many chapters include a brief review of the underlying physics. There are problems at the end of each chapter; solutions to selected problems are also provided. This second edition enhances the treat...

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

Directory of Open Access Journals (Sweden)

Natalia T Meier

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

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

Science.gov (United States)

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

2013-01-01

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

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

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

2013-01-01

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

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

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

2013-01-01

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

Human Skin 3D Bioprinting Using Scaffold-Free Approach.

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

2017-02-01

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

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

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Schneider, K; Akkan, Z

2004-06-01

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

Artificial skin in perspective: concepts and applications.

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Brohem, Carla A; Cardeal, Laura B da Silva; Tiago, Manoela; Soengas, María S; Barros, Silvia B de Moraes; Maria-Engler, Silvya S

2011-02-01

Skin, the largest organ of the human body, is organized into an elaborate layered structure consisting mainly of the outermost epidermis and the underlying dermis. A subcutaneous adipose-storing hypodermis layer and various appendages such as hair follicles, sweat glands, sebaceous glands, nerves, lymphatics, and blood vessels are also present in the skin. These multiple components of the skin ensure survival by carrying out critical functions such as protection, thermoregulation, excretion, absorption, metabolic functions, sensation, evaporation management, and aesthetics. The study of how these biological functions are performed is critical to our understanding of basic skin biology such as regulation of pigmentation and wound repair. Impairment of any of these functions may lead to pathogenic alterations, including skin cancers. Therefore, the development of genetically controlled and well characterized skin models can have important implications, not only for scientists and physicians, but also for manufacturers, consumers, governing regulatory boards and animal welfare organizations. As cells making up human skin tissue grow within an organized three-dimensional (3D) matrix surrounded by neighboring cells, standard monolayer (2D) cell cultures do not recapitulate the physiological architecture of the skin. Several types of human skin recombinants, also called artificial skin, that provide this critical 3D structure have now been reconstructed in vitro. This review contemplates the use of these organotypic skin models in different applications, including substitutes to animal testing. © 2010 John Wiley & Sons A/S.

Foreign Body Retrieval

Medline Plus

Full Text Available ... single exam. The transducer sends out high-frequency sound waves (that the human ear cannot hear) into ... patient's skin to send and receive the returning sound waves), as well as the type of body ...

Foreign Body Retrieval

Medline Plus

Full Text Available ... sends out high-frequency sound waves (that the human ear cannot hear) into the body and then ... the transducer (the device placed on the patient's skin to send and receive the returning sound waves), ...

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

International Nuclear Information System (INIS)

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

1999-01-01

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

Skin Sodium Concentration Correlates with Left Ventricular Hypertrophy in CKD.

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Schneider, Markus P; Raff, Ulrike; Kopp, Christoph; Scheppach, Johannes B; Toncar, Sebastian; Wanner, Christoph; Schlieper, Georg; Saritas, Turgay; Floege, Jürgen; Schmid, Matthias; Birukov, Anna; Dahlmann, Anke; Linz, Peter; Janka, Rolf; Uder, Michael; Schmieder, Roland E; Titze, Jens M; Eckardt, Kai-Uwe

2017-06-01

The pathogenesis of left ventricular hypertrophy in patients with CKD is incompletely understood. Sodium intake, which is usually assessed by measuring urinary sodium excretion, has been inconsistently linked with left ventricular hypertrophy. However, tissues such as skin and muscle may store sodium. Using 23 sodium-magnetic resonance imaging, a technique recently developed for the assessment of tissue sodium content in humans, we determined skin sodium content at the level of the calf in 99 patients with mild to moderate CKD (42 women; median [range] age, 65 [23-78] years). We also assessed total body overhydration (bioimpedance spectroscopy), 24-hour BP, and left ventricular mass (cardiac magnetic resonance imaging). Skin sodium content, but not total body overhydration, correlated with systolic BP ( r =0.33, P =0.002). Moreover, skin sodium content correlated more strongly than total body overhydration did with left ventricular mass ( r =0.56, P skin sodium content is a strong explanatory variable for left ventricular mass, unaffected by BP and total body overhydration. In conclusion, we found skin sodium content to be closely linked to left ventricular mass in patients with CKD. Interventions that reduce skin sodium content might improve cardiovascular outcomes in these patients. Copyright © 2017 by the American Society of Nephrology.

Two Proximal Skin Electrodes — A Respiration Rate Body Sensor

Directory of Open Access Journals (Sweden)

Viktor Avbelj

2012-10-01

Full Text Available We propose a new body sensor for extracting the respiration rate based on the amplitude changes in the body surface potential differences between two proximal body electrodes. The sensor could be designed as a plaster-like reusable unit that can be easily fixed onto the surface of the body. It could be equipped either with a sufficiently large memory for storing the measured data or with a low-power radio system that can transmit the measured data to a gateway for further processing. We explore the influence of the sensor’s position on the quality of the extracted results using multi-channel ECG measurements and considering all the pairs of two neighboring electrodes as potential respiration-rate sensors. The analysis of the clinical measurements, which also include reference thermistor-based respiration signals, shows that the proposed approach is a viable option for monitoring the respiration frequency and for a rough classification of breathing types. The obtained results were evaluated on a wireless prototype of a respiration body sensor. We indicate the best positions for the respiration body sensor and prove that a single sensor for body surface potential difference on proximal skin electrodes can be used for combined measurements of respiratory and cardiac activities.

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

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

1997-01-01

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

The Protective Role of Melanin Against UV Damage in Human Skin

OpenAIRE

Brenner, Michaela; Hearing, Vincent J.

2008-01-01

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

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

NARCIS (Netherlands)

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

2007-01-01

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

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

OpenAIRE

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

2008-01-01

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

Differential susceptibility of primary cultured human skin cells to hypericin PDT in an in vitro model.

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Popovic, A; Wiggins, T; Davids, L M

2015-08-01

Skin cancer is the most common cancer worldwide, and its incidence rate in South Africa is increasing. Photodynamic therapy (PDT) has been shown to be an effective treatment modality, through topical administration, for treatment of non-melanoma skin cancers. Our group investigates hypericin-induced PDT (HYP-PDT) for the treatment of both non-melanoma and melanoma skin cancers. However, a prerequisite for effective cancer treatments is efficient and selective targeting of the tumoral cells with minimal collateral damage to the surrounding normal cells, as it is well established that cancer therapies have bystander effects on normal cells in the body, often causing undesirable side effects. The aim of this study was to investigate the cellular and molecular effects of HYP-PDT on normal primary human keratinocytes (Kc), melanocytes (Mc) and fibroblasts (Fb) in an in vitro tissue culture model which represented both the epidermal and dermal cellular compartments of human skin. Cell viability analysis revealed a differential cytotoxic response to a range of HYP-PDT doses in all the human skin cell types, showing that Fb (LD50=1.75μM) were the most susceptible to HYP-PDT, followed by Mc (LD50=3.5μM) and Kc (LD50>4μM HYP-PDT) These results correlated with the morphological analysis which displayed distinct morphological changes in Fb and Mc, 24h post treatment with non-lethal (1μM) and lethal (3μM) doses of HYP-PDT, but the highest HYP-PDT doses had no effect on Kc morphology. Fluorescent microscopy displayed cytoplasmic localization of HYP in all the 3 skin cell types and additionally, HYP was excluded from the nuclei in all the cell types. Intracellular ROS levels measured in Fb at 3μM HYP-PDT, displayed a significant 3.8 fold (phuman skin cells thus highlighting the efficacy and indeed, the potential bystander effect of if administered in vivo. This study contributes toward our knowledge of the cellular response of the epidermis to photodynamic therapies and

Structure and Function of Skin: The Application of THz Radiation in Dermatology

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Jo, Seong Jin; Kwon, Oh Sang

Skin, the largest organ of human being, is a soft membrane covering the exterior of the body. It protects the host from mechanical injuries, toxic materials, pathogenic organisms, and so on. Although its basic function is protection from the environment like this, it is not a simple and static shield but a complex and dynamic organ which performs important roles in maintaining the homeostasis of the body. Skin controls evaporation to prevent massive water loss, and regulates body temperature by controlling the blood flow of skin and perspiration [1]. It is responsible for the synthesis of vitamin D and a storage center for lipid and water. In addition, skin contains nerve endings and provides sensation for temperature, touch, pressure, and vibration.

Temperature modulation of the visible and near infrared absorption and scattering coefficients of human skin.

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Khalil, Omar S; Yeh, Shu-Jen; Lowery, Michael G; Wu, Xiaomao; Hanna, Charles F; Kantor, Stanislaw; Jeng, Tzyy-Wen; Kanger, Johannes S; Bolt, Rene A; de Mul, Frits F

2003-04-01

We determine temperature effect on the absorption and reduced scattering coefficients (mu(a) and mu(s)(')) of human forearm skin. Optical and thermal simulation data suggest that mu( a) and mu(s)(') are determined within a temperature-controlled depth of approximately 2 mm. Cutaneous mu(s)(') change linearly with temperature. Change in mu(a) was complex and irreversible above body normal temperatures. Light penetration depth (delta) in skin increased on cooling, with considerable person-to-person variations. We attribute the effect of temperature on mu(s)(') to change in refractive index mismatch, and its effect on mu(a) to perfusion changes. The reversible temperature effect on mu (s)(' ) was maintained during more than 90 min. contact between skin and the measuring probe, where temperature was modulated between 38 and 22 degrees C for multiple cycles While temperature modulated mu(s)(' ) instantaneously and reversibly, mu(a) exhibited slower response time and consistent drift. There was a statistically significant upward drift in mu(a) and a mostly downward drift in mu( s)(') over the contact period. The drift in temperature-induced fractional change in mu(s)(') was less statistically significant than the drift in mu(s)('). Deltamu( s)(') values determined under temperature modulation conditions may have less nonspecific drift than mu(s)(') which may have significance for noninvasive determination of analytes in human tissue.

A methodology for extracting the electrical properties of human skin

International Nuclear Information System (INIS)

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

2013-01-01

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

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

International Nuclear Information System (INIS)

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

2007-01-01

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

Variables influencing the frictional behaviour of in vivo human skin

NARCIS (Netherlands)

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

2013-01-01

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

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

NARCIS (Netherlands)

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

2008-01-01

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

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

Science.gov (United States)

Andega, S; Kanikkannan, N; Singh, M

2001-11-09

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

Characterization of ionizing radiation effects on human skin allografts; Caracterizacao dos efeitos da radiacao ionizante em pele humana para aloenxerto

Energy Technology Data Exchange (ETDEWEB)

Bourroul, Selma Cecilia

2004-07-01

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

Quantitative second-harmonic generation imaging to detect osteogenesis imperfecta in human skin samples

Science.gov (United States)

Adur, J.; Ferreira, A. E.; D'Souza-Li, L.; Pelegati, V. B.; de Thomaz, A. A.; Almeida, D. B.; Baratti, M. O.; Carvalho, H. F.; Cesar, C. L.

2012-03-01

Osteogenesis Imperfecta (OI) is a genetic disorder that leads to bone fractures due to mutations in the Col1A1 or Col1A2 genes that affect the primary structure of the collagen I chain with the ultimate outcome in collagen I fibrils that are either reduced in quantity or abnormally organized in the whole body. A quick test screening of the patients would largely reduce the sample number to be studied by the time consuming molecular genetics techniques. For this reason an assessment of the human skin collagen structure by Second Harmonic Generation (SHG) can be used as a screening technique to speed up the correlation of genetics/phenotype/OI types understanding. In the present work we have used quantitative second harmonic generation (SHG) imaging microscopy to investigate the collagen matrix organization of the OI human skin samples comparing with normal control patients. By comparing fibril collagen distribution and spatial organization, we calculated the anisotropy and texture patterns of this structural protein. The analysis of the anisotropy was performed by means of the two-dimensional Discrete Fourier Transform and image pattern analysis with Gray-Level Co-occurrence Matrix (GLCM). From these results, we show that statistically different results are obtained for the normal and disease states of OI.

Origins and early development of human body knowledge.

Science.gov (United States)

Slaughter, Virginia; Heron, Michelle

2004-01-01

As a knowable object, the human body is highly complex. Evidence from several converging lines of research, including psychological studies, neuroimaging and clinical neuropsychology, indicates that human body knowledge is widely distributed in the adult brain, and is instantiated in at least three partially independent levels of representation. Sensorimotor body knowledge is responsible for on-line control and movement of one's own body and may also contribute to the perception of others' moving bodies; visuo-spatial body knowledge specifies detailed structural descriptions of the spatial attributes of the human body; and lexical-semantic body knowledge contains language-based knowledge about the human body. In the first chapter of this Monograph, we outline the evidence for these three hypothesized levels of human body knowledge, then review relevant literature on infants' and young children's human body knowledge in terms of the three-level framework. In Chapters II and III, we report two complimentary series of studies that specifically investigate the emergence of visuo-spatial body knowledge in infancy. Our technique is to compare infants'responses to typical and scrambled human bodies, in order to evaluate when and how infants acquire knowledge about the canonical spatial layout of the human body. Data from a series of visual habituation studies indicate that infants first discriminate scrambled from typical human body picture sat 15 to 18 months of age. Data from object examination studies similarly indicate that infants are sensitive to violations of three-dimensional human body stimuli starting at 15-18 months of age. The overall pattern of data supports several conclusions about the early development of human body knowledge: (a) detailed visuo-spatial knowledge about the human body is first evident in the second year of life, (b) visuo-spatial knowledge of human faces and human bodies are at least partially independent in infancy and (c) infants' initial

Virtually naked: virtual environment reveals sex-dependent nature of skin disclosure.

Directory of Open Access Journals (Sweden)

Anna M Lomanowska

Full Text Available The human tendency to reveal or cover naked skin reflects a competition between the individual propensity for social interactions related to sexual appeal and interpersonal touch versus climatic, environmental, physical, and cultural constraints. However, due to the ubiquitous nature of these constraints, isolating on a large scale the spontaneous human tendency to reveal naked skin has remained impossible. Using the online 3-dimensional virtual world of Second Life, we examined spontaneous human skin-covering behavior unhindered by real-world climatic, environmental, and physical variables. Analysis of hundreds of avatars revealed that virtual females disclose substantially more naked skin than virtual males. This phenomenon was not related to avatar hypersexualization as evaluated by measurement of sexually dimorphic body proportions. Furthermore, analysis of skin-covering behavior of a population of culturally homogeneous avatars indicated that the propensity of female avatars to reveal naked skin persisted despite explicit cultural norms promoting less revealing attire. These findings have implications for further understanding how sex-specific aspects of skin disclosure influence human social interactions in both virtual and real settings.

Degradation and protection of DNAzymes on human skin.

Science.gov (United States)

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

2016-10-01

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

Phages in the Human Body.

Science.gov (United States)

Navarro, Ferran; Muniesa, Maite

2017-01-01

Bacteriophages, viruses that infect bacteria, have re-emerged as powerful regulators of bacterial populations in natural ecosystems. Phages invade the human body, just as they do other natural environments, to such an extent that they are the most numerous group in the human virome. This was only revealed in recent metagenomic studies, despite the fact that the presence of phages in the human body was reported decades ago. The influence of the presence of phages in humans has yet to be evaluated; but as in marine environments, a clear role in the regulation of bacterial populations could be envisaged, that might have an impact on human health. Moreover, phages are excellent vehicles of genetic transfer, and they contribute to the evolution of bacterial cells in the human body by spreading and acquiring DNA horizontally. The abundance of phages in the human body does not pass unnoticed and the immune system reacts to them, although it is not clear to what extent. Finally, the presence of phages in human samples, which most of the time is not considered, can influence and bias microbiological and molecular results; and, in view of the evidences, some studies suggest that more attention needs to be paid to their interference.

The skin microbiome: impact of modern environments on skin ecology, barrier integrity, and systemic immune programming.

Science.gov (United States)

Prescott, Susan L; Larcombe, Danica-Lea; Logan, Alan C; West, Christina; Burks, Wesley; Caraballo, Luis; Levin, Michael; Etten, Eddie Van; Horwitz, Pierre; Kozyrskyj, Anita; Campbell, Dianne E

2017-01-01

Skin barrier structure and function is essential to human health. Hitherto unrecognized functions of epidermal keratinocytes show that the skin plays an important role in adapting whole-body physiology to changing environments, including the capacity to produce a wide variety of hormones, neurotransmitters and cytokine that can potentially influence whole-body states, and quite possibly, even emotions. Skin microbiota play an integral role in the maturation and homeostatic regulation of keratinocytes and host immune networks with systemic implications. As our primary interface with the external environment, the biodiversity of skin habitats is heavily influenced by the biodiversity of the ecosystems in which we reside. Thus, factors which alter the establishment and health of the skin microbiome have the potential to predispose to not only cutaneous disease, but also other inflammatory non-communicable diseases (NCDs). Indeed, disturbances of the stratum corneum have been noted in allergic diseases (eczema and food allergy), psoriasis, rosacea, acne vulgaris and with the skin aging process. The built environment, global biodiversity losses and declining nature relatedness are contributing to erosion of diversity at a micro-ecological level, including our own microbial habitats. This emphasises the importance of ecological perspectives in overcoming the factors that drive dysbiosis and the risk of inflammatory diseases across the life course.

Variables influencing the frictional behaviour of in vivo human skin

NARCIS (Netherlands)

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

2013-01-01

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

Modeling the behavior of human body tissues on penetration

Science.gov (United States)

Conci, A.; Brazil, A. L.; Popovici, D.; Jiga, G.; Lebon, F.

2018-02-01

Several procedures in medicine (such as anesthesia, injections, biopsies and percutaneous treatments) involve a needle insertion. Such procedures operate without vision of the internal involved areas. Physicians and anesthetists rely on manual (force and tactile) feedback to guide their movements, so a number of medical practice is strongly based on manual skill. In order to be expert in the execution of such procedures the medical students must practice a number of times, but before practice in a real patient they must be trained in some place and a virtual environment, using Virtual Reality (VR) or Augmented Reality (AR) is the best possible solution for such training. In a virtual environment the success of user practices is improved by the addition of force output using haptic device to improve the manual sensations in the interactions between user and computer. Haptic devices enable simulate the physical restriction of the diverse tissues and force reactions to movements of operator hands. The trainees can effectively "feel" the reactions to theirs movements and receive immediate feedback from the actions executed by them in the implemented environment. However, in order to implement such systems, the tissue reaction to penetration and cutting must be modeled. A proper model must emulate the physical sensations of the needle action in the skin, fat, muscle, and so one, as if it really done in a patient that is as they are holding a real needle and feeling each tissue resistance when inserting it through the body. For example an average force value for human skin puncture is 6.0 N, it is 2.0 N for subcutaneous fat tissue and 4.4 N for muscles: this difference of sensations to penetration of each layers trespassed by the needle makes possible to suppose the correct position inside the body. This work presents a model for tissues before and after the cutting that with proper assumptions of proprieties can model any part of human body. It was based on experiments

Body odour of monozygotic human twins: a common pattern of odorant carboxylic acids released by a bacterial aminoacylase from axilla secretions contributing to an inherited body odour type.

Science.gov (United States)

Kuhn, Fabian; Natsch, Andreas

2009-04-06

It is currently not fully established whether human individuals have a genetically determined, individual-specific body odour. Volatile carboxylic acids are a key class of known human body odorants. They are released from glutamine conjugates secreted in axillary skin by a specific Nalpha-acyl-glutamine-aminoacylase present in skin bacteria. Here, we report a quantitative investigation of these odorant acids in 12 pairs of monozygotic twins. Axilla secretions were sampled twice and treated with the Nalpha-acyl-glutamine-aminoacylase. The released acids were analysed as their methyl esters with comprehensive two-dimensional gas chromatography and time-of-flight mass spectrometry detection. The pattern of the analytes was compared with distance analysis. The distance was lowest between samples of the right and the left axilla taken on the same day from the same individual. It was clearly greater if the same subject was sampled on different days, but this intra-individual distance between samples was only slightly lower than the distance between samples taken from two monozygotic twins. A much greater distance was observed when comparing unrelated individuals. By applying cluster and principal component analyses, a clear clustering of samples taken from one pair of monozygotic twins was also confirmed. In conclusion, the specific pattern of precursors for volatile carboxylic acids is subject to a day-to-day variation, but there is a strong genetic contribution. Therefore, humans have a genetically determined body odour type that is at least partly composed of these odorant acids.

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

Science.gov (United States)

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

2012-01-01

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

Your Skin

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... Safe Videos for Educators Search English Español Your Skin KidsHealth / For Kids / Your Skin What's in this ... body) are really dead skin cells. Bye-Bye Skin Cells These old cells are tough and strong, ...

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

Science.gov (United States)

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

2014-01-01

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

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

Science.gov (United States)

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

2014-07-01

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

The physiological and phenotypic determinants of human tanning measured as change in skin colour following a single dose of ultraviolet B radiation.

Science.gov (United States)

Wong, Terence H; Jackson, Ian J; Rees, Jonathan L

2010-07-01

Experimental study of the in vivo kinetics of tanning in human skin has been limited by the difficulties in measuring changes in melanin pigmentation independent of the ultravioletinduced changes in erythema. The present study attempted to experimentally circumvent this issue. We have studied erythemal and tanning responses following a single exposure to a range of doses of ultraviolet B irradiation on the buttock and the lower back in 98 subjects. Erythema was assessed using reflectance techniques at 24 h and tanning measured as the L* spectrophotometric score at 7 days following noradrenaline iontophoresis. We show that dose (P skin colour (P skin colour (P = 0.0365) or, as an alternative to skin colour, skin type (P = 0.0193) predict tanning, with those with lighter skin tanning slightly more to a defined UVB dose. If erythema is factored into the regression, then only dose and body site remain significant predictors of tanning: therefore neither phototype nor pigmentary factors, such as baseline skin colour, or eye or hair colour, predict change in skin colour to a unit erythemal response.

Biophysics of skin and its treatments structural, nanotribological, and nanomechanical studies

CERN Document Server

Bhushan, Bharat

2017-01-01

This book provides a comprehensive overview of the structural, nanotribological and nanomechanical properties of skin with and without cream treatment as a function of operating environment. The biophysics of skin as the outer layer covering human or animal body is discussed as a complex biological structure. Skin cream is used to improve skin health and create a smooth, soft, and flexible surface with moist perception by altering the surface roughness, friction, adhesion, elastic modulus, and surface charge of the skin surface. .

Cultured skin microbiota attracts malaria mosquitoes

Directory of Open Access Journals (Sweden)

Takken Willem

2009-12-01

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

Rheological investigation of body cream and body lotion in actual application conditions

Science.gov (United States)

Kwak, Min-Sun; Ahn, Hye-Jin; Song, Ki-Won

2015-08-01

The objective of the present study is to systematically evaluate and compare the rheological behaviors of body cream and body lotion in actual usage situations. Using a strain-controlled rheometer, the steady shear flow properties of commercially available body cream and body lotion were measured over a wide range of shear rates, and the linear viscoelastic properties of these two materials in small amplitude oscillatory shear flow fields were measured over a broad range of angular frequencies. The temperature dependency of the linear viscoelastic behaviors was additionally investigated over a temperature range most relevant to usual human life. The main findings obtained from this study are summarized as follows: (1) Body cream and body lotion exhibit a finite magnitude of yield stress. This feature is directly related to the primary (initial) skin feel that consumers usually experience during actual usage. (2) Body cream and body lotion exhibit a pronounced shear-thinning behavior. This feature is closely connected with the spreadability when cosmetics are applied onto the human skin. (3) The linear viscoelastic behaviors of body cream and body lotion are dominated by an elastic nature. These solid-like properties become a criterion to assess the selfstorage stability of cosmetic products. (4) A modified form of the Cox-Merz rule provides a good ability to predict the relationship between steady shear flow and dynamic viscoelastic properties for body cream and body lotion. (5) The storage modulus and loss modulus of body cream show a qualitatively similar tendency to gradually decrease with an increase in temperature. In the case of body lotion, with an increase in temperature, the storage modulus is progressively decreased while the loss modulus is slightly increased and then decreased. This information gives us a criterion to judge how the characteristics of cosmetic products are changed by the usual human environments.

Reconstruction of segmented human voxel phantoms for skin dosimetry

International Nuclear Information System (INIS)

Antunes, Paula C.G.; Siqueira, Paulo de Tarso D.; Yoriyaz, Helio; Fonseca, Gabriel P.; Reis, Gabriela; Furnari, Laura

2009-01-01

High-resolution medical images along with methods that simulate the interaction of radiation with matter, as the Monte Carlo radiation transport codes, have been widely used in medical physics procedures. These images provide the construction of realistic anatomical models, which after being coupled to these codes, may drive to better assessments of dose distributions on the patient. These anatomical models constructed from medical images are known as voxel phantoms (voxel - volume element of an image). Present day regular images are unsuitable to correctly perform skin dose distribution evaluations. This inability is due to improper skin discrimination in most of the current medical images, once its thickness stands below the resolution of the pixels that form the image. This paper proposes the voxel phantom reconstruction by subdividing and segmenting the elements that form the phantom. It is done in order to better discriminate the skin by assigning it more adequate thickness and actual location, allowing a better dosimetric evaluation of the skin. This task is an important issue in many radiotherapy procedures. Particular interest lays in Total Skin Irradiation (TSI) with electron beams, where skin dose evaluation stands as the treatment key point of the whole body irradiation. This radiotherapy procedure is under implementation at the Hospital das Clinicas da Universidade de Sao Paulo (HC-USP). (author)

Permeability of commercial solvents through living human skin

DEFF Research Database (Denmark)

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

1995-01-01

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

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

NARCIS (Netherlands)

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

2004-01-01

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

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

International Nuclear Information System (INIS)

Castro, E.

2008-01-01

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

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

Science.gov (United States)

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

2018-02-01

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

3D skin length deformation of lower body during knee joint flexion for the practical application of functional sportswear.

Science.gov (United States)

Choi, Jiyoung; Hong, Kyunghi

2015-05-01

With the advent of 3D technology in the design process, a tremendous amount of scanned data is available. However, it is difficult to trace the quantitative skin deformation of a designated location on the 3D body surface data during movement. Without identical landmarks or reflective markers, tracing the same reference points on the different body postures is not easy because of the complex shape change of the body. To find the least deformed location on the body, which is regarded as the optimal position of seams for the various lengths of functional compression pants, landmarks were directly marked on the skin of six subjects and scanned during knee joint flexion. Lines of non-extension (LoNE) and maximum stretch (LoMS) were searched for, both by tracing landmarks and newly drawn guidelines based on ratio division in various directions. Considering the waist as the anchoring position of the pants, holistic changes were quantified and visualized from the waistline in lengthwise and curvilinear deformation along the dermatomes of the lower body for various lengths of pants. Widthwise and unit area skin deformation data of the skin were also provided as guidelines for further use such as streamlined pants or design of other local wearing devices. Copyright © 2014 Elsevier Ltd and The Ergonomics Society. All rights reserved.

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

NARCIS (Netherlands)

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

2012-01-01

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

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

Directory of Open Access Journals (Sweden)

Yira Bermudez

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

Microneedle Enhanced Delivery of Cosmeceutically Relevant Peptides in Human Skin

Science.gov (United States)

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

2014-01-01

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

Microneedle enhanced delivery of cosmeceutically relevant peptides in human skin.

Directory of Open Access Journals (Sweden)

Yousuf H Mohammed

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

Analogs of human genetic skin disease in domesticated animals

Directory of Open Access Journals (Sweden)

Justin Finch, MD

2017-09-01

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

[Survival Strategies of Aspergillus in the Human Body].

Science.gov (United States)

Tashiro, Masato; Izumikawa, Koichi

2017-01-01

 The human body is a hostile environment for Aspergillus species, which originally live outside the human body. There are lots of elimination mechanisms against Aspergillus inhaled into the human body, such as high body temperature, soluble lung components, mucociliary clearance mechanism, or responses of phagocytes. Aspergillus fumigatus, which is the primary causative agent of human infections among the human pathogenic species of Aspergillus, defend itself from the hostile human body environment by various mechanisms, such as thermotolerance, mycotoxin production, and characteristic morphological features. Here we review mechanisms of defense in Aspergillus against elimination from the human body.

Synchrotron-based nu-XRF mapping and mu-FTIR microscopy enable to look into the fate and effects of tattoo pigments in human skin

OpenAIRE

Schreiver , Ines; Hesse , Bernhard; Seim , Christian; Castillo-Michel , Hiram; Villanova , Julie; Laux , Peter; Dreiack , Nadine; Penning , Randolf; Tucoulou , Remi; Cotte , Marine; Luch , Andreas

2017-01-01

International audience; The increasing prevalence of tattoos provoked safety concerns with respect to particle distribution and effects inside the human body. We used skin and lymphatic tissues from human corpses to address local biokinetics by means of synchrotron X-ray fluorescence (XRF) techniques at both the micro (mu) and nano (nu) scale. Additional advanced mass spectrometry-based methodology enabled to demonstrate simultaneous transport of organic pigments, heavy metals and titanium di...

Radiative human body cooling by nanoporous polyethylene textile.

Science.gov (United States)

Hsu, Po-Chun; Song, Alex Y; Catrysse, Peter B; Liu, Chong; Peng, Yucan; Xie, Jin; Fan, Shanhui; Cui, Yi

2016-09-02

Thermal management through personal heating and cooling is a strategy by which to expand indoor temperature setpoint range for large energy saving. We show that nanoporous polyethylene (nanoPE) is transparent to mid-infrared human body radiation but opaque to visible light because of the pore size distribution (50 to 1000 nanometers). We processed the material to develop a textile that promotes effective radiative cooling while still having sufficient air permeability, water-wicking rate, and mechanical strength for wearability. We developed a device to simulate skin temperature that shows temperatures 2.7° and 2.0°C lower when covered with nanoPE cloth and with processed nanoPE cloth, respectively, than when covered with cotton. Our processed nanoPE is an effective and scalable textile for personal thermal management. Copyright © 2016, American Association for the Advancement of Science.

Breathable and Stretchable Temperature Sensors Inspired by Skin

Science.gov (United States)

Chen, Ying; Lu, Bingwei; Chen, Yihao; Feng, Xue

2015-06-01

Flexible electronics attached to skin for healthcare, such as epidermal electronics, has to struggle with biocompatibility and adapt to specified environment of skin with respect to breath and perspiration. Here, we report a strategy for biocompatible flexible temperature sensors, inspired by skin, possessing the excellent permeability of air and high quality of water-proof by using semipermeable film with porous structures as substrate. We attach such temperature sensors to underarm and forearm to measure the axillary temperature and body surface temperature respectively. The volunteer wears such sensors for 24 hours with two times of shower and the in vitro test shows no sign of maceration or stimulation to the skin. Especially, precise temperature changes on skin surface caused by flowing air and water dropping are also measured to validate the accuracy and dynamical response. The results show that the biocompatible temperature sensor is soft and breathable on the human skin and has the excellent accuracy compared to mercury thermometer. This demonstrates the possibility and feasibility of fully using the sensors in long term body temperature sensing for medical use as well as sensing function of artificial skin for robots or prosthesis.

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

Science.gov (United States)

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

2012-01-01

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

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

Science.gov (United States)

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

2014-06-01

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

The Paediatric skin at risk: Challenges in burns, surgery and specific infections

NARCIS (Netherlands)

M.G.A. Baartmans (Martin)

2012-01-01

textabstractThe skin, the largest human organ, provides the body shape and is the main organ that protects our body against intruders such as heat, cold, trauma, or infections. A number of important functions are listed here: - Regulation of body temperature - Sensory function: touch, feel and pain

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

Science.gov (United States)

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

2016-07-01

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

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

Science.gov (United States)

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

2017-03-01

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

Skin Blood Perfusion and Oxygenation Colour Affect Perceived Human Health

Science.gov (United States)

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

2009-01-01

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

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

NARCIS (Netherlands)

Geertsma RE; Wassenaar C; LGM

2000-01-01

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

Dosimetry of skin-contact exposure to tritium gas contaminated surfaces

International Nuclear Information System (INIS)

Legare, M.

1990-12-01

The radiological hazards from tritium are usually associated with exposure to tritium oxide either by inhalation, ingestion or permeation through skin. However, exposure from skin contact with tritium gas contaminated surfaces represents a different radiological hazard in tritium removal facilities and future fusion power plants. Previous experiments on humans and more recent experiments on hairless rats at Chalk River Laboratories have shown that when a tritium gas-contaminated surface is brought into contact with intact skin, high concentrations of organically-bound tritium in urine and skin are observed which were not seen from single tritiated water (liquid or vapour form) contamination. The results of the rat experiments, which involved measurements of tritium activity in urine and skin, after contact with contaminated stainless steel, are described. These results are also compared to previous data from human experiments. The effect of various exposure conditions and different contaminated surfaces such as brass, aluminum and glass are analysed and related to the results from contaminated stainless steel exposure. Dosimetric models are being developed in order to improve the basis for dose assessment for this mode of tritium uptake. The presently studied model is explained along with the assumptions and methods involved in its derivation. The features of 'STELLA', the software program used to implement the model, are discussed. The methods used to estimate skin and whole body dose from a model are demonstrated. Finally, some experiments for improving the accuracy of the model are proposed. Briefly, this study compares the results from animal and human experiments as well as different exposure conditions, and determines the range of whole body and skin dose that may be involved from skin-contact intake. This information is essential for regulatory purposes particularly in the derivation of doses for skin-contact contamination. (15 figs., 7 tabs., 29 refs.)

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

Science.gov (United States)

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

2017-05-30

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

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

Science.gov (United States)

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

2016-12-01

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

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

Directory of Open Access Journals (Sweden)

Vishnu Hosur

2017-08-01

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

Skin blood flow and local temperature independently modify sweat rate during passive heat stress in humans.

Science.gov (United States)

Wingo, Jonathan E; Low, David A; Keller, David M; Brothers, R Matthew; Shibasaki, Manabu; Crandall, Craig G

2010-11-01

Sweat rate (SR) is reduced in locally cooled skin, which may result from decreased temperature and/or parallel reductions in skin blood flow. The purpose of this study was to test the hypotheses that decreased skin blood flow and decreased local temperature each independently attenuate sweating. In protocols I and II, eight subjects rested supine while wearing a water-perfused suit for the control of whole body skin and internal temperatures. While 34°C water perfused the suit, four microdialysis membranes were placed in posterior forearm skin not covered by the suit to manipulate skin blood flow using vasoactive agents. Each site was instrumented for control of local temperature and measurement of local SR (capacitance hygrometry) and skin blood flow (laser-Doppler flowmetry). In protocol I, two sites received norepinephrine to reduce skin blood flow, while two sites received Ringer solution (control). All sites were maintained at 34°C. In protocol II, all sites received 28 mM sodium nitroprusside to equalize skin blood flow between sites before local cooling to 20°C (2 sites) or maintenance at 34°C (2 sites). In both protocols, individuals were then passively heated to increase core temperature ~1°C. Both decreased skin blood flow and decreased local temperature attenuated the slope of the SR to mean body temperature relationship (2.0 ± 1.2 vs. 1.0 ± 0.7 mg·cm(-2)·min(-1)·°C(-1) for the effect of decreased skin blood flow, P = 0.01; 1.2 ± 0.9 vs. 0.07 ± 0.05 mg·cm(-2)·min(-1)·°C(-1) for the effect of decreased local temperature, P = 0.02). Furthermore, local cooling delayed the onset of sweating (mean body temperature of 37.5 ± 0.4 vs. 37.6 ± 0.4°C, P = 0.03). These data demonstrate that local cooling attenuates sweating by independent effects of decreased skin blood flow and decreased local skin temperature.

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

International Nuclear Information System (INIS)

Diffey, Brian

2004-01-01

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

Studies of the in vivo radiosensitivity of human skin fibroblasts

International Nuclear Information System (INIS)

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

2007-01-01

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

What is a Human Body?

DEFF Research Database (Denmark)

Nissen, Ulrik Becker

2017-01-01

The essay offers an overview of different understandings of what a body is. As such, it can be read as an overview of what we mean, when we speak of a “human body”. However, the article also goes a step further; in the last section, a responsive understanding of the human body is outlined....... This is understood as responsiveness in three ways: viz an embodied self that responds to natural life, other human beings and, ultimately, to God....

The effect of nerve blockade on forearm and finger skin blood flow during body heating and cooling.

Science.gov (United States)

Saumet, J L; Degoute, C S; Saumet, M; Abraham, P

1992-08-01

To determine the role of the active cutaneous vasodilatator response in forearm and finger skin, direct assessment of only skin blood flow was performed before and after musculocutaneous and median nerve blockade during whole body heating and cooling. Forearm laser Doppler flow (LDF forearm), forearm heat thermal clearance (HTC forearm), and finger laser Doppler flow (LDF finger) were monitored in the nerve blocked skin and contralateral untreated skin (control). In the pre-blockade period, no significant differences were found between experimental and control arm skin. After nerve block a significant increase occurred only in LDF finger, which rose from 4.3 +/- 0.6 to 6.0 +/- 0.5 volts (p less than 0.05). During whole body heating LDF forearm and HTC forearm increased significantly on both arms. The increase in LDF forearm was greater (p less than 0.05) in control (18.3 +/- 1.2 volts) than in nerve blocked skin (14.6 +/- 1.8 volts) and occurred earlier. The same tendency was observed in HTC forearm between nerve blocked skin (0.522 +/- 0.06 W.m-1.degrees C-1) and control 0.671 +/- 0.037 W.m-1.degrees C-1) (NS). LDF raise up to 6.6 +/- 0.5 and 6.8 +/- 0.5 volts in the blocked finger and in the control respectively. During cooling LDF finger in the control decreased to 1.3 +/- 0.1 volt and was significantly (p less than 0.05) lower than in the resting period, and lower than that in the nerve blocked finger (3.4 +/- 0.8 volts) (p less than 0.05). We conclude that the active vasodilatator system plays an important role as far as the timing and the amplitude of the cutaneous vasodilatator response to whole body heating in the forearm but not in the finger. At thermal neutrality, the vascular vasoconstrictor tone is high to the finger but not to the forearm. The vasoconstrictor response to cooling occurred only in the finger.

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

NARCIS (Netherlands)

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

2010-01-01

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

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

Science.gov (United States)

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

2017-09-01

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

Universal in vivo Textural Model for Human Skin based on Optical Coherence Tomograms.

Science.gov (United States)

Adabi, Saba; Hosseinzadeh, Matin; Noei, Shahryar; Conforto, Silvia; Daveluy, Steven; Clayton, Anne; Mehregan, Darius; Nasiriavanaki, Mohammadreza

2017-12-20

Currently, diagnosis of skin diseases is based primarily on the visual pattern recognition skills and expertise of the physician observing the lesion. Even though dermatologists are trained to recognize patterns of morphology, it is still a subjective visual assessment. Tools for automated pattern recognition can provide objective information to support clinical decision-making. Noninvasive skin imaging techniques provide complementary information to the clinician. In recent years, optical coherence tomography (OCT) has become a powerful skin imaging technique. According to specific functional needs, skin architecture varies across different parts of the body, as do the textural characteristics in OCT images. There is, therefore, a critical need to systematically analyze OCT images from different body sites, to identify their significant qualitative and quantitative differences. Sixty-three optical and textural features extracted from OCT images of healthy and diseased skin are analyzed and, in conjunction with decision-theoretic approaches, used to create computational models of the diseases. We demonstrate that these models provide objective information to the clinician to assist in the diagnosis of abnormalities of cutaneous microstructure, and hence, aid in the determination of treatment. Specifically, we demonstrate the performance of this methodology on differentiating basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) from healthy tissue.

Human Body Exergy Metabolism

OpenAIRE

Mady, Carlos Eduardo Keutenedjian

2013-01-01

The exergy analysis of the human body is a tool that can provide indicators of health and life quality. To perform the exergy balance it is necessary to calculate the metabolism on an exergy basis, or metabolic exergy, although there is not yet consensus in its calculation procedure. Hence, the aim of this work is to provide a general method to evaluate this physical quantity for human body based on indirect calorimetry data. To calculate the metabolism on an exergy basis it is necessary to d...

Ultrasonic evaluation of local human skin anisotropy

Czech Academy of Sciences Publication Activity Database

Tokar, Daniel; Převorovský, Zdeněk; Hradilová, Jana

2014-01-01

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

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

Directory of Open Access Journals (Sweden)

Alasdair Anderson

2014-01-01

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

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

OpenAIRE

Schreiber, Sylvia

2010-01-01

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

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

Science.gov (United States)

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

2013-06-01

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

Do Masculine Men Smell Better? An Association Between Skin Color Masculinity and Female Preferences for Body Odor.

Science.gov (United States)

Carrito, Mariana L; Santos, Isabel M; Alho, Laura; Ferreira, Jacqueline; Soares, Sandra C; Bem-Haja, Pedro; Silva, Carlos F; Perrett, David I

2017-03-01

A recent study claimed face skin color as a sexually dimorphic variable that influences attractiveness preferences in mate choice. Thereby, skin color may assume the role of a mate quality signal influencing attractiveness preferences. As body odor is linked to attractiveness, this study aimed to explore whether the odors of men with more masculine facial skin color would be evaluated more positively than odors from less masculine men. Female raters were presented with body odors of 18 men and were asked to rate them in various characteristics. Multilevel modeling revealed that the odors of the donors with more masculine color were rated not only as more attractive, more pleasant, and sexier, but also healthier. This indicates that odor associated with men with more masculine skin color is attractive, just as other sexually dimorphic traits. Furthermore, we found a negative relation between skin color masculinity and perceived odor maleness. Regarding this last finding, a new discussion is introduced with respect to the influence of cognitive stereotypes in odor judgments. Altogether, the study supports the possibility that chemosensory signals may be communicating signs of mate quality associated with masculinity. © The Author 2017. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Female upper body and breast skin temperature and thermal comfort following exercise.

Science.gov (United States)

Ayres, B; White, J; Hedger, W; Scurr, J

2013-01-01

Breast support reduces breast pain and movement during exercise, however, an extra layer of clothing may affect thermoregulation. This preliminary study investigated female upper body and breast skin temperature and thermal comfort following short-duration exercise. Eight female participants with C-cup breasts had thermal images (infra-red camera, FLIR systems) of the bare breasts, the breasts in two sports bras (composite and polyester) and the abdomen, taken before and after 20 min of exercise at 28(o)C. Following exercise, bare-breast, bra and abdomen temperatures reduced by 0.61(o)C, 0.92(o)C and 2.06(o)C, respectively. The polyester sports bra demonstrated greater thermal comfort and enabled a greater change in skin temperature than the composite sports bra. It is concluded that following short-duration exercise, sports bras reduced the cooling ability of the breast. Material properties of the bras affect thermal comfort and post-exercise skin temperature; this should be an important consideration for sports bra manufacturers. This study investigates the effect of sports bras on thermal regulation of the breast following exercise. Sports bras negatively affected the cooling ability of the skin on the breast, with the material properties of the bra affecting thermal comfort following exercise. These results present important considerations for sports bra manufacturers.

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

Science.gov (United States)