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1.
Skin Res Technol ; 29(5): e13346, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-37231932

RESUMO

INTRODUCTION: The fundamental function of the epidermis is to provide an inside-out barrier to water loss and an outside-in barrier to penetration of external irritants. Transepidermal water loss (TEWL) has been extensively used as a method of estimating the skin barrier quality, typically without any consideration of directionality. The validity of TEWL as an estimate of skin permeability to external substances has been controversial in vitro and in vivo. The aim of this work was to assess the relationship between TEWL and the penetration of a topically applied external marker (caffeine) in healthy skin in vivo before and following a challenge to the barrier. METHODS: The skin barrier was challenged by application of aqueous solutions of mild cleanser products under occlusion for 3 h on the forearms of nine human participants. Skin barrier quality was evaluated before and after the challenge by measuring the TEWL rate and the permeated amount of topically applied caffeine using in vivo confocal Raman microspectroscopy. RESULTS: No skin irritation was observed following the skin barrier challenge. TEWL rates and the caffeine penetrated amount in the stratum corneum after the challenge were not correlated. A weak correlation was observed when the changes were corrected to water-only treatment. TEWL values can be influenced by environmental conditions as well as the skin temperature and water content. CONCLUSIONS: Measuring TEWL rates is not always representative of the outside-in barrier. TEWL may be useful in differentiating large changes in skin barrier function (e.g., between healthy and compromised skin) but is less sensitive to small variations following topical application of mild cleansers.


Assuntos
Cafeína , Água , Humanos , Cafeína/farmacologia , Cafeína/metabolismo , Água/metabolismo , Temperatura Cutânea , Epiderme/metabolismo , Células Epidérmicas , Perda Insensível de Água
2.
J Exp Biol ; 226(3)2023 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-36651236

RESUMO

In lizards there is considerable variation in the ability to dissipate environmental/endogenous heat loads through evaporative cooling via panting, which effects how long lizards can spend exposed to high solar heat loads. We recently described the differing capacities of lizards to depress body temperature (Tb) through evaporative cooling via panting. Here, we link panting and Tb depression with rates of evaporative water loss and its metabolic costs under high heat loads. We used flow-through respirometry to measure evaporative water loss rates and metabolism of 17 lizard species from the American Southwest while simultaneously measuring Tb. We exposed lizards to air temperatures (Ta) ranging from 35°C to their critical thermal maximum (CTmax) while marking the onset of panting. We then estimated pre-panting Q10 values for metabolism to partition increases in metabolism associated with the van't Hoff effect from the mechanical cost of panting with increasing heat loads. We found that evaporative cooling costs substantially varied among species, with panting effort significantly affecting lizards' evaporative capacity. Lizard evaporation rates ranged from 0.32 to 1.5 g H2O h-1, with individuals losing as much as 6% h-1 of body mass while panting. Lizards also experienced an increase of up to 7.9-fold in metabolic rate while panting, although the overall energetic costs of panting remained relatively low compared with evaporative water costs. Across species, there was a significant positive relationship between the overall rate of evaporative heat loss and the maximum Ta-Tb gradient a species could maintain. While evaporative cooling may be an effective mechanism for reducing Tb and extending activity in hot environments for many species, it has significant metabolic and water balance costs that should be considered, as habitats with high environmental heat loads can be especially costly to an animal's water budgets.


Assuntos
Lagartos , Perda Insensível de Água , Animais , Metabolismo Basal , Regulação da Temperatura Corporal , Temperatura Corporal , Temperatura Alta , Água
3.
Ann Work Expo Health ; 66(7): 907-922, 2022 08 07.
Artigo em Inglês | MEDLINE | ID: mdl-35510991

RESUMO

Skin hydration and the barrier properties of the stratum corneum have been reported to be influential factors in the potential for retention of solid and semi-solid substances on the skin surface. The measurement of these characteristics of the skin, however, remains relatively uncommon in exposure assessments performed by industrial or occupational hygienists, even when the focus of the assessment is exposure to the skin. This study provides measurements of skin hydration using multiple instruments and multiple relevant skin site locations for comparative analysis. Three different measurement metrics, trans-epidermal water loss (TEWL), hydration index (HI), and percent hydration, were measured for 25 healthy volunteers at two different body locations for comparison: the center of the volar forearm, as previously recommended for interindividual comparison of hydration and barrier property measurements, and also the palmar tip of the index finger. The purpose of the comparative measurements was to allow for comparison between other published baseline volar forearm measurements and the palmar skin, which has not often been quantitatively assessed and reported in the literature, but is a relevant skin surface for sampling of the hands. This comparison will allow for consideration of the potential influence of palmar wipe sampling protocols on TEWL or skin hydration, and for the evaluation of the influence of skin hydration and TEWL on measured dermal transfer values. Collectively, the skin hydration levels and barrier properties at these two different measurement locations were found to be statistically significantly different, and as a result it is suggested that they be measured and recorded separately. Both measurement types and locations are likely to be important for the purposes of establishing skin hydration and health. Volar forearm measurements can also be important for understanding the underlying condition and barrier function of the skin, and palmar index finger measurements are necessary to understand the influence of both TEWL and skin hydration on quantitative dermal loading and transfer of solids and semi-volatile materials.


Assuntos
Exposição Ocupacional , Água , Epiderme/metabolismo , Humanos , Medição de Risco , Água/metabolismo , Perda Insensível de Água
4.
J Mech Behav Biomed Mater ; 127: 105058, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35051810

RESUMO

In this study, the effect of one cycle of winter to summer seasonal transition on the mechanical and physical properties of skin was investigated in vivo. Fourteen healthy skin volunteers aged between 22 and 42 years were studied at the volar lower and upper arms. The findings indicate a 22.15% and 34.29% decrease in trans-epidermal water loss (TEWL) and the average epidermal roughness (AER), respectively. Also, improved skin properties were observed such as a 25.48% rise in average epidermal hydration (AEH), 22.59% in skin thickness, 38.64% and 21.92% in melanin and redness, respectively, as well as an 8.25% rise in its firmness and 23.14% in elasticity when strained with uniaxial deformations. An inverse correlation was established between TEWL and AEH with a linear relationship between stratum corneum roughness versus TEWL as well as thickness and hydration. Also, the skin firmness exhibited a direct proportionality with TEWL and an inverse correlation with skin hydration where these relationships were stronger in summer than in winter. Furthermore, time-dependent results demonstrated three-staged elastic, viscoelastic and creep deformations with high, moderate and low strain rates respectively at both anatomical locations. The winter season displayed lower skin firmness and elasticity of 0.37 mm and 0.04 mm compared to 0.40 mm and 0.06 mm in summer accordingly. Anatomically, the two arm regions displayed different results with the upper arm having more consistent results than the lower arm. These results will find relevance in sensor skins and exoskeletons in Medicare, robotic and military technologies as well as innovations in cosmetics and dermatology.


Assuntos
Medicare , Perda Insensível de Água , Adulto , Idoso , Epiderme , Humanos , Estações do Ano , Pele/metabolismo , Estados Unidos , Adulto Jovem
5.
J Pharm Pharm Sci ; 23: 437-450, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33156995

RESUMO

PURPOSE: The main aim of the current research was to develop and apply a dermatopharmacokinetic (DPK) approach for the bioequivalence assessment of metronidazole (MTZ) topical cream products, indicated in the treatment of rosacea. METHODS: A DPK methodology using tape stripping (TS) technique was developed by investigating the factors that may influence the TS results viz. tapes, dose durations, number of tapes to be used, pressure application, dose applied and gravimetric analysis of the tapes. An initial dose duration study was performed on 6 healthy participants to determine an appropriate application time duration using the Emax model. The SC thickness was normalised between participants using TEWL measurements. A pivotal study was conducted using both the arms of 10 healthy human participants to demonstrate the ability of the TS method for bioequivalence assessment by comparing the reference product to itself as a positive control and including products with higher and lower strengths of MTZ to serve as negative controls in order to confirm bioinequivalence. RESULTS: Whereas the reference was found to be bioequivalent when compared to itself, the creams containing 0.56% and 0.95% MTZ (negative controls) were not bioequivalent (bioinequivalent). Furthermore, another product containing 0.75% MTZ was also assessed and was found to be bioequivalent to the reference product. In addition, the use of both forearms of each participant offered an important advantage of significantly reducing the number of human subjects required to demonstrate BE with a high statistical power of > 80%. CONCLUSION: The data obtained provides compelling evidence that the developed TS method has the potential to be a cost-effective surrogate alternative for lengthy and expensive clinical trials. Consequently, its application can facilitate faster development of generic products which would, in turn, lower the economic burden of healthcare.


Assuntos
Fármacos Dermatológicos/administração & dosagem , Metronidazol/administração & dosagem , Modelos Biológicos , Administração Cutânea , Adulto , Fármacos Dermatológicos/farmacocinética , Relação Dose-Resposta a Droga , Feminino , Humanos , Masculino , Metronidazol/farmacocinética , Projetos Piloto , Absorção Cutânea , Creme para a Pele , Equivalência Terapêutica , Fatores de Tempo , Perda Insensível de Água , Adulto Jovem
6.
Int J Clin Pract ; 74 Suppl 187: e13603, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32639641

RESUMO

Urea is an emollient widely used in clinical dermatology to moisturise and protect the skin. Non-invasive techniques can be useful in evaluating and quantifying the moisturising and hydrating properties of topically applied urea. Amongst these, transepidermal water loss, skin conductance and capacitance are the most widely used. Dynamic tests and mapping of skin moisturisation are additional features that can be used to evaluate the dynamics of water into the stratum corneum. Ultrasound and mechanical properties can be used to investigate the effects on skin smoothness and tone. In conclusion, urea is a fundamental ingredient of cosmetic and dermatological formulations and can have several positive effects on skin function. These can be easily investigated and monitored using non-invasive techniques measuring the stratum corneum function.


Assuntos
Cosméticos , Ureia , Cosméticos/farmacologia , Emolientes/farmacologia , Epiderme , Humanos , Ureia/farmacologia , Perda Insensível de Água
7.
J Dermatol Sci ; 98(1): 20-25, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32063461

RESUMO

BACKGROUND: We developed the first-of-its-kind handheld confocal Raman spectroscopy (CRS) system to quantify the concentration of natural moisturizing factors in the skin. OBJECTIVE: To evaluate the feasibility of our handheld CRS system and propose a novel quantitative index to measure skin barrier function. METHODS: This prospective study included 30 atopic dermatitis (AD) patients and 14 healthy volunteers. All AD participants were assessed using the Scoring Atopic Dermatitis (SCORAD) severity instrument, a vapometer for trans-epidermal water loss and a moisture meter for skin surface moisture. A handheld CRS operating at 785 nm laser was used to measure the biochemical constituents of the skin up to a depth of ∼100 µm. We trained a linear kernel-based support vector machine (SVM) model for eczema classification based on the water, ceramide and urocanic acid content. A novel Eczema Biochemical Index (EBI) was then formulated using the skin constituents measured from the AD participants to stage disease severity. RESULTS: The SVM model used to classify healthy participants and AD patients obtained high cross-validated area under the curve of 0.857 and accuracy of 0.841, with high sensitivity and specificity values of 0.857 and 0.833 respectively. EBI can be used to stratify AD patients of varying severity, based on the biochemical constituents in the skin. CONCLUSION: As compared to the standard CRS system, the handheld CRS offers higher portability and provides Raman measurements at various body regions with similar sensitivity. This suggests that a handheld CRS device could be a valuable point-of-care resource in both research and clinical use.


Assuntos
Dermatite Atópica/diagnóstico , Sistemas Automatizados de Assistência Junto ao Leito , Análise Espectral Raman/instrumentação , Adulto , Estudos de Casos e Controles , Ceramidas/análise , Dermatite Atópica/imunologia , Dermatite Atópica/patologia , Epiderme/química , Epiderme/imunologia , Epiderme/patologia , Estudos de Viabilidade , Feminino , Voluntários Saudáveis , Humanos , Concentração de Íons de Hidrogênio , Masculino , Estudos Prospectivos , Curva ROC , Índice de Gravidade de Doença , Máquina de Vetores de Suporte , Ácido Urocânico/análise , Água/análise , Perda Insensível de Água/imunologia
8.
J Cosmet Dermatol ; 19(5): 1231-1238, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31498557

RESUMO

BACKGROUND: For the evaluation results of skin sensitivity, such as clinical parameters, stinging test records and biophysical assessments dates might be impacted by many factors, the influence factors need to be further explored, and the skin sensitivity evaluation process and methodology needed distinction and normalization. In this study, we investigated the changes of sensitive skin indexes and lactic acid stinging test results in different seasons, facial regions, skin photo-type, and living habits. METHODS: Twenty-four healthy subjects had completed this study. Lactic acid stinging test was performed in different seasons. Transepidermal water loss (TEWL), skin hydration, sebum secretion, and pH were measured in an environment-controlled room. Correlations between stinging responses, skin biophysical parameters, and sensitive skin inducements in different seasons were statistically analyzed. RESULTS: Skin TEWL, hydration, sebum secretion, and pH values on different facial parts were various. Two-way correlation analysis between the results of lactic acid stinging test in different seasons and the sensitivity factors showed differences between summer, autumn, and winter. The mean scores of lactic acid stinging test increased in autumn. Linear regression analysis of skin sensitivity factors in type III and type IV photobiology skin found that the frequency of sleeping time and eating spicy food in the past of week could infect the sensitive skin evaluation dates statistically (P < .05). DISCUSSION/CONCLUSIONS: Skin sensitivity assessment results were impacted by seasonal transformation, living habits and customs, and facial regions. These indicted that we should consider above interfering factors when evaluated the skin sensitivity for getting more precise dates.


Assuntos
Dermatite de Contato/diagnóstico , Fenômenos Fisiológicos da Pele , Testes Cutâneos/métodos , Pele/fisiopatologia , Adulto , Dermatite de Contato/fisiopatologia , Face , Feminino , Voluntários Saudáveis , Humanos , Concentração de Íons de Hidrogênio , Pessoa de Meia-Idade , Estações do Ano , Sebo/metabolismo , Pele/química , Pele/metabolismo , Perda Insensível de Água , Adulto Jovem
9.
Allergy ; 74(10): 1934-1944, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-30989659

RESUMO

BACKGROUND: Many skin and mucosal inflammatory disorders, such as atopic dermatitis, have been associated with an impaired epithelial barrier function, which allows allergens, pollutants, or microbes to enter the tissue and activate the immune response. The aim of this study was to establish a method to directly assess in vivo the epidermal barrier function by electrical impedance (EI) spectroscopy. METHODS: Mice epidermal barrier was damaged by epicutaneous application of proteases and cholera toxin and by tape stripping. EI and transepidermal water loss (TEWL) were measured before and after the application. Additionally, histological analysis, immunofluorescence staining, and RT-PCR were performed on skin biopsies to evaluate the epithelial barrier. RESULTS: A few hours after papain application, a dose-dependent reduction of EI was detected, reflecting the decreased barrier function. At the same time, an increase of TEWL was observed, with a significant negative correlation with EI, demonstrating that EI changes were directly linked to barrier defects. Twenty-four and 48 hours after the treatment, EI starts to increase to background levels, indicating tissue healing and restoration of skin barrier. Barrier disruption was confirmed by histological analysis showing an impaired stratum corneum and higher cellular infiltration after papain application. In addition, immunofluorescence staining and RT-PCR showed downregulation of molecules involved in the barrier function, such as filaggrin, occludin, and claudin-1, and mRNA levels of filaggrin, loricrin, and involucrin. Comparable results were observed after tape stripping and cholera toxin treatment. CONCLUSION: Electrical impedance spectroscopy is a rapid and reliable diagnostic tool to detect skin barrier defects.


Assuntos
Espectroscopia Dielétrica , Epiderme/fisiologia , Fenômenos Fisiológicos da Pele , Animais , Biópsia , Modelos Animais de Doenças , Proteínas Filagrinas , Humanos , Camundongos , Perda Insensível de Água
10.
J Cosmet Dermatol ; 18(3): 835-842, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30043423

RESUMO

BACKGROUND: Moisturizer is an important component of many cosmetic products. It helps to maintain the skin's integrity and its barrier functions. Recently, magnetic masks that seek to improve the properties of the skin have been developed and have become a new cosmetic trend. However, scientific proof of their stated properties is lacking. AIMS: To test whether iron oxide contained in a face mask with magnetic properties in an oily matrix with a freeze-dried aloe-vera base increases moisturization of the skin and improves skin barrier function. METHODS: Formulations were prepared containing an oil phase (67.3% wt.) and a solid phase (32.7% wt.). The moisturizing properties of the mask were tested by measuring in vivo electrochemical impedance spectroscopy, contact angle, and visual appearance. Meanwhile, human panel tests were performed to evaluate the sensory perception of potential users. RESULTS: The moisturizing effect of the iron oxide mask is clearly superior to that of the other tested samples. Water retention and low transepidermal water loss (TEWL) were evidenced for the iron oxide magnetic mask. Its occlusive action on the skin resulted in larger water contact angles and enhances the barrier effect. A favorable sensory perception on the part of the users was obtained for the iron oxide magnetic mask. CONCLUSION: The presence of iron oxide and the magnetic property of the mask enhance occlusive behavior, diminishing the TEWL. Sensory analysis of the iron oxide magnetic mask performed by human panel tests shows that they possess characteristics including neutral odor, and easy, pleasant-feeling application.


Assuntos
Cosméticos/administração & dosagem , Compostos Férricos/administração & dosagem , Fenômenos Magnéticos , Higiene da Pele/métodos , Perda Insensível de Água/efeitos dos fármacos , Adulto , Aloe/química , Emolientes/administração & dosagem , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Extratos Vegetais/administração & dosagem , Pele/efeitos dos fármacos , Pele/metabolismo
11.
J Exp Biol ; 221(Pt 17)2018 09 06.
Artigo em Inglês | MEDLINE | ID: mdl-29950448

RESUMO

Evaporative cooling is a prerequisite for avian occupancy of hot, arid environments, and is the only avenue of heat dissipation when air temperatures (Ta) exceed body temperature (Tb). Whereas diurnal birds can potentially rehydrate throughout the day, nocturnal species typically forgo drinking between sunrise and sunset. We hypothesized that nocturnal birds have evolved reduced rates of evaporative water loss (EWL) and more economical evaporative cooling mechanisms compared with diurnal species, permitting nocturnal species to tolerate extended periods of intense heat without becoming lethally dehydrated. We used phylogenetically informed regressions to compare EWL and evaporative cooling efficiency [ratio of evaporative heat loss (EHL) and metabolic heat production (MHP); EHL/MHP] among nocturnal and diurnal birds at high Ta We analyzed variation in three response variables: (1) slope of EWL at Ta between 40 and 46°C, (2) EWL at Ta=46°C and (3) EHL/MHP at Ta=46°C. Nocturnality emerged as a weak, negative predictor, with nocturnal species having slightly shallower slopes and reduced EWL compared with diurnal species of similar mass. In contrast, nocturnal activity was positively correlated with EHL/MHP, indicating a greater capacity for evaporative cooling in nocturnal birds. However, our analysis also revealed conspicuous differences among nocturnal taxa. Caprimulgids and Australian owlet-nightjars had shallower slopes and reduced EWL compared with similarly sized diurnal species, whereas owls had EWL rates comparable to those of diurnal species. Consequently, our results did not unequivocally demonstrate more economical cooling among nocturnal birds. Owls predominately select refugia with cooler microclimates, but the more frequent and intense heat waves forecast for the 21st century may increase microclimate temperatures and the necessity for active heat dissipation, potentially increasing owls' vulnerability to dehydration and hyperthermia.


Assuntos
Aves/fisiologia , Regulação da Temperatura Corporal , Temperatura Alta , Características de História de Vida , Perda Insensível de Água , África Austral , Animais , Ritmo Circadiano , Clima Desértico , América do Norte , Austrália do Sul
12.
J Cosmet Laser Ther ; 20(4): 205-210, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28001455

RESUMO

Skin aging, as a natural course, is a gradual process. It can be classified as either intrinsic or photo-aging. In recent years, as the attention to lower face wrinkles and laxity has raised significantly, the demands to facial rejuvenation also increased, along with a variety of technologies coming into being. Fractional bipolar RF as a novel means of rejuvenation has been used in clinical practice, but questions remain in terms of its efficacy and safety. Considering a large population in our country and huge demands for skin tightening, we did this research to evaluate the efficacy and safety of fractional bipolar radiofrequency.


Assuntos
Terapia por Radiofrequência , Ritidoplastia/instrumentação , Envelhecimento da Pele/efeitos da radiação , Adulto , Idoso , Face , Feminino , Humanos , Hiperpigmentação/etiologia , Masculino , Pessoa de Meia-Idade , Dor Processual/etiologia , Satisfação do Paciente , Ondas de Rádio/efeitos adversos , Rejuvenescimento , Ritidoplastia/efeitos adversos , Ritidoplastia/métodos , Envelhecimento da Pele/fisiologia , Perda Insensível de Água
13.
Physiol Biochem Zool ; 90(6): 663-672, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29068263

RESUMO

Water constraints can mediate evolutionary conflict either among individuals (e.g., parent-offspring conflict, sexual conflict) or within an individual (e.g., cost of reproduction). During pregnancy, water is of particular importance because the female provides all water needed for embryonic development and experiences important maternal shifts in behavior and physiology that, together, can compromise female water balance if water availability is limited. We examined the effect of pregnancy on evaporative water loss and microhabitat selection in a viviparous snake, the aspic viper. We found that both physiological (increased metabolism and body temperature) and morphological (body distension) changes contribute to an increased evaporative water loss in pregnant females. We also found that pregnant females in the wild select warmer and moister basking locations than nonreproductive females, likely to mitigate the conflict between thermal needs and water loss. Water resources likely induce significant reproductive constraints across diverse taxa and thus warrant further consideration in ecological research. From an evolutionary perspective, water constraints during reproduction may contribute to shaping reproductive effort.


Assuntos
Viperidae/fisiologia , Viviparidade não Mamífera/fisiologia , Perda Insensível de Água/fisiologia , Animais , Feminino
14.
Skin Res Technol ; 23(4): 597-601, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28517733

RESUMO

BACKGROUND/PURPOSE: Although measuring transepidermal water loss (TEWL) is important to assess the barrier function of the stratum corneum (SC), the commercially available instruments are rather expensive. Recently launched Model H4500 employs a closed-chamber system to measure TEWL and is more reasonably priced compared to devices currently in general use. METHODS: To check the reproducibility of the obtained data with H4500, we conducted measurements on the volar forearms of healthy volunteers and compared these data with those measured with Vapometer® and Tewameter® . Then, we checked the correlations between the TEWL data obtained with these different devices on the same volar forearms of 15 healthy volunteers before and after the artificial production of barrier damage of the SC by tape stripping or by 0.5% aqueous solution of sodium lauryl sulfate. RESULTS: The obtained intra-class correlation coefficient (ICC, [1, 1]) with 95% CI of H4500 was 0.927 (0.835-0.978). Namely, an excellent correlation could be found in the values of TEWL measured with these three different instruments not only on healthy skin but also on the artificially barrier-damaged skin. CONCLUSIONS: H4500 is considered to be practical for daily use because of its performance as well as its reasonable price as compared with conventional devices.


Assuntos
Dermatologia/instrumentação , Fenômenos Fisiológicos da Pele , Perda Insensível de Água/fisiologia , Adulto , Dermatologia/economia , Desenho de Equipamento , Feminino , Antebraço , Voluntários Saudáveis , Humanos , Masculino , Reprodutibilidade dos Testes , Adulto Jovem
15.
Eur J Pharm Biopharm ; 116: 138-148, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28012990

RESUMO

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


Assuntos
Absorção Cutânea/fisiologia , Pele/metabolismo , Quimiocinas/metabolismo , Sistemas de Liberação de Medicamentos/métodos , Humanos , Concentração de Íons de Hidrogênio , Peptídeo Hidrolases/metabolismo , Sebo/metabolismo , Dodecilsulfato de Sódio/metabolismo , Tensoativos/metabolismo , Fita Cirúrgica , Técnicas de Cultura de Tecidos/métodos , Perda Insensível de Água/fisiologia
16.
Skin Res Technol ; 23(2): 186-193, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-27514310

RESUMO

BACKGROUND: Rosacea is a common chronic inflammatory disorder affecting facial skin. Currently, no accurate and objective method is available for assessing the severity of rosacea. Most studies use the National Rosacea Society Standard (NRSS) grading method, which lacks objectivity and yields varying results. METHODS: Eighteen patients with rosacea were included. Clinical severity was assessed on the basis of the NRSS grade, Investigators' Global Assessment, Patients' Global Assessment, and Dermatology Quality of Life Index. A skin color analysis system was used to measure the facial area showing erythema, and biophysical parameters of facial skin (transepidermal water loss and skin surface hydration) were examined. To find statistical significant in classification severity of the rosacea, statistical analysis was performed with all parameters. RESULTS: A significant correlation (P < 0.05) was found between the NRSS grade, facial area showing erythema, and biophysical parameters. The latter two factors differed significantly among patients with rosacea of different levels of severity (mild, moderate, severe; P < 0.05). CONCLUSION: Color imaging systems can be useful and reliable for evaluating the severity of rosacea, in addition to biophysical parameter assessment. The combination of these two analytical methods enabled objective and quantitative evaluation of the severity of rosacea.


Assuntos
Colorimetria/métodos , Dermoscopia/métodos , Rosácea/diagnóstico , Rosácea/fisiopatologia , Índice de Gravidade de Doença , Pigmentação da Pele , Perda Insensível de Água , Diagnóstico por Computador/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
17.
J Exp Biol ; 219(Pt 12): 1820-6, 2016 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-27045096

RESUMO

Feeding on the blood of vertebrates is a risky task for haematophagous insects and it can be reasonably assumed that it should also be costly in terms of energetic expenditure. Blood circulates inside vessels and it must be pumped through narrow tubular stylets to be ingested. We analysed the respiratory pattern and the energetic cost of taking a blood meal in Rhodnius prolixus using flow-through and stop-flow respirometry to measure carbon dioxide emission, oxygen consumption and water loss before and during feeding. We observed an increase of up to 17-fold in the metabolic rate during feeding and a change in the respiratory pattern, which switched from a discontinuous cyclic pattern during resting to a continuous pattern when the insects started to feed, remaining in this condition unchanged for several hours. The energetic cost of taking a meal was significantly higher when bugs fed on a living host, compared with feeding on an artificial feeder. No differences were observed between feeding on blood or on saline solution in vitro, revealing that the substrate for feeding (vessels versus membrane) and not the nature of the fluid was responsible for such a difference in the energetic cost. Water loss significantly increased during feeding, but did not vary with feeding method or type of food. The mean respiratory quotient in resting bugs was 0.83, decreasing during feeding to 0.52. These data constitute the first metabolic measures of an insect during blood feeding and provide the first insights into the energetic expenditure associated with haematophagy.


Assuntos
Metabolismo Energético , Respiração , Rhodnius/fisiologia , Animais , Dióxido de Carbono/metabolismo , Comportamento Alimentar , Ninfa/fisiologia , Consumo de Oxigênio , Rhodnius/crescimento & desenvolvimento , Perda Insensível de Água
18.
Curr Probl Dermatol ; 49: 61-70, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26844898

RESUMO

Due to the ease of skin accessibility, a large variety of invasive and noninvasive in vitro and in vivo methods have been developed to study barrier function. The measurement of the transepidermal water loss (TEWL) is most widely used in clinical studies. The different methods of determining TEWL, as well as skin hydration, skin pH, tape stripping and other modern less widely used methods to assess skin barrier function, are reviewed, including Raman spectroscopy and imaging methods such as optical coherence tomography and laser scanning microscopy. The modern imaging methods are important developments in the last decades which, however, determine the structure and, hence, cannot replace the measurement of TEWL in questions related to function.


Assuntos
Fenômenos Fisiológicos da Pele , Pele/metabolismo , Perda Insensível de Água , Bioengenharia/métodos , Humanos , Imagem Molecular , Testes do Emplastro , Permeabilidade , Pele/química , Pele/patologia , Análise Espectral , Tomografia de Coerência Óptica
19.
Burns ; 42(2): 336-44, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26774602

RESUMO

Objective scar assessment tools were designed to help identify problematic scars and direct clinical management. Their use has been restricted by their measurement of a single scar property and the bulky size of equipment. The Scarbase Duo(®) was designed to assess both trans-epidermal water loss (TEWL) and colour of a burn scar whilst being compact and easy to use. Twenty patients with a burn scar were recruited and measurements taken using the Scarbase Duo(®) by two observers. The Scarbase Duo(®) measures TEWL via an open-chamber system and undertakes colorimetry via narrow-band spectrophotometry, producing values for relative erythema and melanin pigmentation. Validity was assessed by comparing the Scarbase Duo(®) against the Dermalab(®) and the Minolta Chromameter(®) respectively for TEWL and colorimetry measurements. The intra-class correlation coefficient (ICC) was used to assess reliability with standard error of measurement (SEM) used to assess reproducibility of measurements. The Pearson correlation coefficient (r) was used to assess the convergent validity. The Scarbase Duo(®) TEWL mode had excellent reliability when used on scars for both intra- (ICC=0.95) and inter-rater (ICC=0.96) measurements with moderate SEM values. The erythema component of the colorimetry mode showed good reliability for use on scars for both intra-(ICC=0.81) and inter-rater (ICC=0.83) measurements with low SEM values. Pigmentation values showed excellent reliability on scar tissue for both intra- (ICC=0.97) and inter-rater (ICC=0.97) with moderate SEM values. The Scarbase Duo(®) TEWL function had excellent correlation with the Dermalab(®) (r=0.93) whilst the colorimetry erythema value had moderate correlation with the Minolta Chromameter (r=0.72). The Scarbase Duo(®) is a reliable and objective scar assessment tool, which is specifically designed for burn scars. However, for clinical use, standardised measurement conditions are recommended.


Assuntos
Cicatriz/diagnóstico por imagem , Colorimetria/métodos , Adulto , Queimaduras/complicações , Cicatriz/etiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Imagem de Banda Estreita , Variações Dependentes do Observador , Reprodutibilidade dos Testes , Espectrofotometria , Perda Insensível de Água
20.
Clin Exp Dermatol ; 40(5): 547-55, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25475067

RESUMO

BACKGROUND: Noninvasive methods of assessment are widely used in clinical trials. However, such methods have not been established in atopic dermatitis (AD), which is a chronic inflammatory skin disease. AIM: To demonstrate, using biomedical tools, the benefits of a new substance, taxifolin glycoside (TAX), in an AD model, the NC/Nga mouse. METHODS: We evaluated the efficacy of topical TAX for AD by measuring clinical skin severity score, cytokine expression and serum IgE level, and by using biomedical measures (vapometry and corneometry). Topical TAX was applied to AD-induced NC/Nga mice for 3 weeks. The anti-inflammatory effects of this compound were demonstrated noninvasively using biomedical tools and immunological assays. RESULTS: Our method of AD assessment using biomedical tools is more objective and accurate than visual inspection. The results obtained using the biomedical tools were identical to those obtained using immunological assays. CONCLUSIONS: In vivo biomedical tools are useful for diagnosing and monitoring treatment effects in AD.


Assuntos
Anti-Inflamatórios não Esteroides/uso terapêutico , Dermatite Atópica/tratamento farmacológico , Quercetina/análogos & derivados , Administração Tópica , Animais , Citocinas/sangue , Dermatite Atópica/sangue , Dermatite Atópica/fisiopatologia , Modelos Animais de Doenças , Imunoglobulina E/sangue , Camundongos , Quercetina/uso terapêutico , Perda Insensível de Água/fisiologia
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