Stratum Corneum Water Research Articles

Association between itching and the serum zinc levels in patients with varicose veins

BackgroundVaricose veins commonly occur in the lower extremities and can cause pain and discomfort in the affected area. Many patients with varicose veins suffer from itching, but its cause has not been sufficiently explained. In recent years, the role of zinc in maintaining the integrity of skin has been reported, and zinc supplementation has been suggested to be effective in relieving itching. The objective of this study is to elucidate the relationship between itching and serum zinc concentration in patients with varicose veins.MethodsWe measured the stratum corneum water content, TEWL and zinc levels in each participant. The study subjects were 11 patients with varicose veins who were experiencing itching (2 males and 9 females, mean age: 65.9 ± 9.4 years old) and 13 patients without itching (6 males and 7 females, mean age: 59.3 ± 9.5 years old). The control group was comprised of 9 healthy individuals without varicose veins (mean age: 41.7 ± 7.0 years old).ResultsThe level of stratum corneum water content was significantly lower in the patients experiencing itching compared to those without the symptom, and it was significantly lower in both patient groups than in the control group. Transepidermal water loss (TEWL) was significantly higher in the patients experiencing itching than those without the symptom, and it was significantly higher in both patient groups than in the control group. In addition, zinc level was significantly lower in the patients with itching compared to those without itching or the control group. For all study participants, relationships between the stratum corneum water content and TEWL against serum zinc were examined. There was a positive correlation between the stratum corneum water content and serum zinc, and a negative correlation was found between TEWL and serum zinc.ConclusionOur novel findings suggested that the development of varicose veins leads to decrease in serum zinc, causing dry skin which could contribute to itching.

Pilot study on benefits of applying a hot towel for 10 s to the skin of elderly nursing home residents during bed baths: Towards safe and comfortable bed baths

This study examined the effects of applying a hot towel to the skin of elderly people for 10 s (AHT10s) during a bed bath. We hypothesized from our previous studies that AHT10s would increase the stratum corneum water content and improve the skin barrier function of the elderly and invited residents (n = 21) of long-term care facilities to participate in this crossover study. Each participant received a bed bath with AHT10s and also a bed bath without hot towel application. The stratum corneum water content and transepidermal water loss (TEWL) were measured during bed bathing sessions and the experience was subjectively evaluated by participants. The TEWL increased significantly when bed bath did not involve AHT10s, but there was no such significant increase when AHT10s was performed. AHT10s also raised the skin surface temperature and provided warmth and comfort to all participants. These results suggest that, in the target population, AHT10s will lead to TEWL advantages and provide warmth and comfort.

Development and photoprotective effect of a sunscreen containing the antioxidants Spirulina and dimethylmethoxy chromanol on sun-induced skin damage

The literature claims that incorporation of antioxidants into sunscreens provides additional skin photoprotection by scavenging free radicals formed due to sun radiation, but there are limited in vivo studies that support this hypothesis. This study aims to examine whether addition of antioxidants to a broad-spectrum sunscreen increases its photoprotective effect in real-use conditions. Sunscreen formulations composed of stable UV filters (Tinosorb® S, Tinosorb® M, Uvinul® APlus, and Uvinul® T150) alone or in combination with antioxidants (Spirulina and dimethylmethoxy chromanol-loaded solid lipid nanoparticles) were developed and their appearance, odor, rheological behavior, Sun Protection Factor (SPF), and UVA protection were analyzed. Next, it was conducted a 3-month, single-blind clinical study with 44 healthy subjects (30–50years). Before and 28, 54, and 84days after twice-daily self application of the sunscreens on the face, the stratum corneum water content, transepidermal water loss, dermis echogenicity, and skin elasticity and pigmentation were measured. At the end of the study period, the volunteers answered a questionnaire containing terms related to sensory characteristics of the formulations. All formulations were stable and exhibited non-Newtonian and pseudoplastic behavior, in vivo SPF 30, and good UVA protection. Antioxidant supplementation to the sunscreen formulation significantly improved the skin pigmentation, the collagen degradation on the dermis and thereby the skin net elasticity after 84days of treatment compared to the sunscreen alone. Concerning safety, all formulations were considered non-irritant according to the sensorial analyses, whose results agreed with the clinical study findings.

Relationship between biochemical factors and skin symptoms in chronic venous disease.

Chronic venous disease (CVD) is a common venous disease of the lower extremities and patients often develop symptoms of itching and skin roughness. An easy to use and objective skin examination was recently developed that allows measurement of the level of stratum corneum content and transepidermal water loss (TEWL), which can indicate the status of the barrier function of the stratum corneum. Previous studies demonstrated that histamine production from mast cells, and tryptase and matrix metalloprotease-9 levels were associated with skin inflammation. This study aimed to clarify the relationship between dry skin and inflammatory mediators that mediate the skin symptoms of CVD subjects. The study enrolled 27 subjects with CVD and a control group consisting of 9 volunteers. The itching onset frequency was higher in women (70.4%) compared with men (50.0%). To analyze the mechanisms involved in itching we measured blood inflammatory mediators pre- and post-sclerotherapy. There was a significant decrease in Substance P, histamine, IgE, and tryptase levels post-sclerotherapy compared with those at pre-sclerotherapy. These levels were associated with the severity of itching. In addition, compared with the control subjects, there was a significant increase in the stratum corneum water content and a decrease in the TEWL in the 27 patients with CVD. This was associated with a decrease in the itching symptoms. Our findings indicate that sclerotherapy decreased levels of inflammatory mediators, increased stratum corneum water content and decreased TEWL, which coincided with reduced itching in CVD patients, indicating they might be therapeutic targets.

Topical Formulation Containing Beeswax-Based Nanoparticles Improved In Vivo Skin Barrier Function.

Lipid nanoparticles have shown many advantages for treatment/prevention of skin disorders with damaged skin barrier function. Beeswax is a favorable candidate for the development of nanosystems in the cosmetic and dermatological fields because of its advantages for the development of products for topical application. In the present study, beeswax-based nanoparticles (BNs) were prepared using the hot melt microemulsion technique and incorporated to a gel-cream formulation. The formulation was subsequently evaluated for its rheological stability and effect on stratum corneum water content (SCWC) and transepidermal water loss (TEWL) using in vivo biophysical techniques. BNs resulted in mean particle size of 95.72 ± 9.63nm and zeta potential of -9.85 ± 0.57mV. BN-loaded formulation showed shear thinning behavior, well adjusted by the Herschel-Bulkley model, and a small thixotropy index that were stable for 28days at different temperatures. BN-loaded formulation was also able to simultaneously decrease the TEWL and increase the SCWC values 28days after treatment. In conclusion, the novel beeswax-based nanoparticles showed potential for barrier recovery and open the perspective for its commercial use as a novel natural active as yet unexplored in the field of dermatology and cosmetics for treatment of skin diseases with damaged skin barrier function.

Sensitive Skin: Assessment of the Skin Barrier Using Confocal Raman Microspectroscopy

Background/Aims: Sensitive skin (SS), a frequently reported condition in the Western world, has been suggested to be underlined by an impaired skin barrier. The aim of this study was to investigate the skin barrier molecular composition in SS subjects using confocal Raman microspectroscopy (CRS), and to compare it with that of non-SS (NSS) individuals as well as atopic dermatitis (AD) and allergic rhinoconjunctivitis (AR) subjects, who frequently report SS. Methods: Subjects with SS (n = 29), NSS (n = 30), AD (n = 11), and AR (n = 27) were included. Stratum corneum (SC) thickness, water, ceramides/fatty acids, and natural moisturizing factor (NMF) were measured by CRS along with transepidermal water loss and capacitance on the ventral forearm, thenar, and cheek. Sebum levels were additionally measured on the forearm and cheek. Results: No differences between SS and NSS subjects were found regarding SC thickness, water, and NMF content, yet a trend towards lower ceramides/fatty acids was observed in the cheek. Compared to AD subjects, the SS group showed higher ceramides/fatty acid content in the forearm, whereas no differences emerged with AR. The correlation of macroscopic biophysical techniques and CRS was weak, yet CRS confirmed the well-known lower content of NMF and water, and thinner SC in subjects with filaggrin mutations. Conclusion: The skin barrier in SS is not impaired in terms of SC thickness, water, NMF, and ceramides/fatty acid content. The failure of biophysical techniques to follow alterations in the molecular composition of the skin barrier revealed by CRS emphasizes a strong need in sensitive and specific tools for in vivo skin barrier analysis.

Acerola (Malpighia emarginata DC.) Juice Intake Suppresses UVB-Induced Skin Pigmentation in SMP30/GNL Knockout Hairless Mice.

Background/AimsAcerola (Malpighia emarginata DC.) is a fruit that is known to contain high amounts of ascorbic acid (AA) and various phytochemicals. We have previously reported that AA deficiency leads to ultraviolet B (UVB)-induced skin pigmentation in senescence marker protein 30 (SMP30)/gluconolactonase (GNL) knockout (KO) hairless mice. The present study was undertaken to investigate the effects of acerola juice (AJ) intake on the skin of UVB-irradiated SMP30/GNL KO mice.Research design/Principal findingsFive-week old hairless mice were given drinking water containing physiologically sufficient AA (1.5 g/L) [AA (+)], no AA [AA (-)] or 1.67% acerola juice [AJ]. All mice were exposed to UVB irradiation for 6 weeks. UVB irradiation was performed three times per week. The dorsal skin color and stratum corneum water content were measured every weekly, and finally, the AA contents of the skin was determined. The skin AA and stratum corneum water content was similar between the AA (+) and AJ groups. The L* value of the AA (+) group was significantly decreased by UVB irradiation, whereas AJ intake suppressed the decrease in the L* value throughout the experiment. Moreover, in the AJ group, there was a significant decrease in the expression level of dopachrome tautomerase, an enzyme that is involved in melanin biosynthesis.ConclusionThese results indicate that AJ intake is effective in suppressing UVB-induced skin pigmentation by inhibiting melanogenesis-related genes.

A new topical panthenol-containing emollient: skin-moisturizing effect following single and prolonged usage in healthy adults, and tolerability in healthy infants

Purpose: Two studies were conducted with a new topical panthenol-containing emollient (NTP-CE) to investigate the skin-moisturizing effect in healthy adults and tolerability in healthy infants.Methods: In Study 1 (N = 44), a single skin application of NTP-CE was performed followed by a 4-week twice-daily application. Skin hydration and stratum corneum (SC) water content change (using Raman spectroscopy) were measured. In the 4-week Study 2 (N = 65, aged 3–25 months), NTP-CE tolerability was assessed using a 5-point scoring system; skin hydration was determined in a subset (N = 21).Results: In Study 1, mean AUC0 − 24 h for skin capacitance change from baseline was 302.03 i.u. with NTP-CE and −15.90 i.u. in control areas (p < .001). With NTP-CE (at 4 h), the water content within the upper SC part was reduced (−45.10 vs. −13.39 g/cm2, p = .013) and the water gradient increased (0.51 vs. 0.11 g/cm4, p = .036), indicating relocation of water into deeper layers. In Study 2, there was no statistically significant change from baseline in mean cutaneous tolerability scores. At days 7, 14, and 28, skin hydration had increased by 42%, 54%, and 49%, respectively (all p < .001).Conclusions: Single and prolonged NTP-CE usage is associated with sustained and deep skin moisturization. NTP-CE is well tolerated by healthy infants.

On the Variation of Water Diffusion Coefficient in Stratum Corneum With Water Content

Water permeability and transient water sorption data in human and porcine stratum corneum (SC) are analyzed in conjunction with equilibrium water sorption data and a dynamic skin swelling model to develop a quantitative model for water diffusivity in the SC as a function of its water content. The recommended function (model 1) is phenomenological and treats the SC as a uniform, swellable slab. This approach yields satisfactory agreement with experimental data over a wide range of RH and associated equilibrium SC water content, Cw. It is supported by two alternative approaches. Model 2 considers the SC to be a multilaminate membrane consisting of alternating lipid and protein layers. Diffusivity in the protein phase is estimated from water diffusivity in other keratinized tissues, whereas diffusivity in the lipid phase is assumed to be linearly related to the swelling strain on intercellular lipids. Model 3 uses an analysis previously suggested by Stockdale to rationalize transepidermal water loss data in humans over a wide range of relative humidity. All models yield similar results for 0.20 ≤ Cw ≤ 0.78 g/cm3, the usual range of SC water content in vivo.

Quantification of Multi-Scale Mechanics and Failure of Human Stratum Corneum

Human stratum corneum (SC) acts as an essential mechanical barrier to the inhospitable external environment. Maintaining skin barrier function by preventing rupture is of fundamental importance to healthcare. Cracking, chapping and the formation of exudative lesions all result from a mechanical failure of SC tissue. At macroscopic length scales, SC exhibits well defined mechanical properties. These properties, such as the elastic modulus, are strongly influenced by SC water content. Using a combination of uniaxial tensometry and macrophotography, we quantify variations in the Poisson's ratio and toughness of SC as a function of ambient humidity. These parameters are essential for accurate modeling of skin mechanics and have not previously been reported. Macroscopic measurements of SC mechanical properties however assume the tissue is homogeneous in composition and cannot describe the mechanisms of failure at the microscale. SC exhibits a rich topography across many length scales and large sample to sample variations in toughness suggest the microstructure of SC is likely to influence the onset of failure rather than the physical limits of the material. We demonstrate that structural heterogeneities cause the formation of heterogeneous micro-strains within uniaxially stressed tissue, with peak strains coinciding with sites of crack nucleation. We further study the influence of structural heterogeneities and SC water content on the failure mechanics of the SC. Crack propagation timescales, strain energy release rates and crack morphologies vary dramatically with tissue hydration. Examinations of crack interfaces at different length scales further illustrate that while topographical canyons and follicular holes influence cracking to a small degree, failure of the SC is governed by rupture of intercellular corneodesmosome plaques, leaving the structural integrity of corneocyte cells intact. These results provide key biophysical insights into the mechanics of fracture in soft heterogeneous tissues.

Acetyl hexapeptide-3 in a cosmetic formulation acts on skin mechanical properties - clinical study

abstract Acetyl hexapeptide-3 has been used in anti-aging topical formulations aimed at improving skin appearance. However, few basic studies address its effects on epidermis and dermis, when vehiculated in topical formulations. Thus, the objective of this study was to determine the clinical efficacy of acetyl hexapeptide-3 using biophysical techniques. For this purpose, formulations with and without acetyl hexapeptide-3 were applied to the ventral forearm and the face area of forty female volunteers. Skin conditions were evaluated after 2 and 4-week long daily applications, by analyzing the stratum corneum water content and the skin mechanical properties, using three instruments, the Corneometer(r) CM 825, CutometerSEM 575 and ReviscometerRV600. All formulations tested increased the stratum corneum water content in the face region, which remained constant until the end of the study. In contrast, only formulations containing acetyl hexapeptide-3 exhibit a significant effect on mechanical properties, by decreasing the anisotropy of the face skin. No significant effects were observed in viscoelasticity parameters. In conclusion, the effects of acetyl hexapeptide-3 on the anisotropy of face skin characterize the compound as an effective ingredient for improving conditions of the cutaneous tissue, when used in anti-aging cosmetic formulations.

Dietary Milk Sphingomyelin Prevents Disruption of Skin Barrier Function in Hairless Mice after UV-B Irradiation.

Exposure to ultraviolet-B (UV-B) irradiation causes skin barrier defects. Based on earlier findings that milk phospholipids containing high amounts of sphingomyelin (SM) improved the water content of the stratum corneum (SC) in normal mice, here we investigated the effects of dietary milk SM on skin barrier defects induced by a single dose of UV-B irradiation in hairless mice. Nine week old hairless mice were orally administrated SM (146 mg/kg BW/day) for a total of ten days. After seven days of SM administration, the dorsal skin was exposed to a single dose of UV-B (20 mJ/cm2). Administration of SM significantly suppressed an increase in transepidermal water loss and a decrease in SC water content induced by UV-B irradiation. SM supplementation significantly maintained covalently-bound ω-hydroxy ceramide levels and down-regulated mRNA levels of acute inflammation-associated genes, including thymic stromal lymphopoietin, interleukin-1 beta, and interleukin-6. Furthermore, significantly higher levels of loricrin and transglutaminase-3 mRNA were observed in the SM group. Our study shows for the first time that dietary SM modulates epidermal structures, and can help prevent disruption of skin barrier function after UV-B irradiation.

Proposed human stratum corneum water domain in chemical absorption.

Compounds with varying physical and chemical properties may have different affinities to the stratum corneum (SC) and/or its intercellular lipids, keratin protein, and possible water domains. To better understand the mechanism of percutaneous absorption, we utilized 21 carbon-14 labeled chemicals, with wide hydrophilicity (log P = -0.05 to 6.17), and quantified their absorption/adsorption properties for a short incubation time (15 min) with regards to intact SC membrane, delipidized SC membrane and SC lipid. A facile method was developed for SC/lipid absorption, providing a more equivalent procedure and comparable data. SC lipid absorption of chemical solutes positively correlated with the octanol/water partition coefficient (log P). Differences between the percent dose of chemical absorption to intact SC and the total percent dose contributed by the protein and lipid domains suggest the possibility and significance of a water domain. Absorption rate experiments showed a longer lag time for intact SC than for delipidized SC or SC lipid, suggesting that the water domain may delay chemical binding to protein and lipid domains, and may be a factor in the resistance of many chemicals to current decontamination methods. Copyright © 2015 John Wiley & Sons, Ltd.

Effect of orally administered collagen hydrolysate on gene expression profiles in mouse skin: a DNA microarray analysis.

Dietary collagen hydrolysate has been hypothesized to improve skin barrier function. To investigate the effect of long-term collagen hydrolysate administration on the skin, we evaluated stratum corneum water content and skin elasticity in intrinsically aged mice. Female hairless mice were fed a control diet or a collagen hydrolysate-containing diet for 12 wk. Stratum corneum water content and skin elasticity were gradually decreased in chronologically aged control mice. Intake of collagen hydrolysate significantly suppressed such changes. Moreover, we used DNA microarrays to analyze gene expression in the skin of mice that had been administered collagen hydrolysate. Twelve weeks after the start of collagen intake, no significant differences appeared in the gene expression profile compared with the control group. However, 1 wk after administration, 135 genes were upregulated and 448 genes were downregulated in the collagen group. This suggests that gene changes preceded changes of barrier function and elasticity. We focused on several genes correlated with functional changes in the skin. Gene Ontology terms related to epidermal cell development were significantly enriched in upregulated genes. These skin function-related genes had properties that facilitate epidermal production and differentiation while suppressing dermal degradation. In conclusion, our results suggest that altered gene expression at the early stages after collagen administration affects skin barrier function and mechanical properties. Long-term oral intake of collagen hydrolysate improves skin dysfunction by regulating genes related to production and maintenance of skin tissue.

Integrated approach in the assessment of skin compatibility of cosmetic formulations with green coffee oil.

Green coffee oil (GCO) has been used in cosmetic formulations due to its emollient and anti-ageing properties. However, there are insufficient studies about its safety when applied in cosmetic formulations. Cytotoxicity of GCO and of formulations containing 2.5-15% of GCO was evaluated by the MTT reduction assay, in human keratinocytes. Formulations containing 15% of GCO and the vehicle were applied under in use conditions in the volar forearm of human volunteers during 3days. Transepidermal water loss, stratum corneum water content and erythema index were evaluated each 24h using biophysical techniques. The same formulations were probed for skin tolerance through a patch test. Neither pure GCO nor its formulations showed cytotoxic effects in concentrations up to 100μg mL(-1) . Transepidermal water loss values showed a slight reduction when the formulation containing GCO was applied. Stratum corneum water content and erythema index did not show significant differences, as the results observed in the first day of the study were maintained throughout 3days. None of the volunteers display any reaction after using an occlusive patch. The results obtained in the study indicate that GCO seems to be safe for topical applications and showed good skin compatibility under the experimental conditions of the study.

Immediate and extended effects of abrasion on stratum corneum natural moisturizing factor.

Natural moisturizing factor (NMF), principally comprised of hygroscopic amino acids and derivatives that absorb moisture from the surrounding environment, serves as the primary humectant of the stratum corneum (SC). Acute barrier disruption has been shown to differentially affect the concentration of NMF in the SC. This study measured the recovery kinetics of NMF after mechanical damage of the SC, which is not well understood. The study population included 20 healthy female volunteers (18-72-year old) with no history of dermatological disorders. Transepidermal water loss (TEWL), erythema, and SC water and NMF were measured at all sites before abrasion, 30 min following abrasion, and 1-3, 6, 8, and 10 days following abrasion. Measurements obtained from the abraded site were compared with those obtained from an untreated site. As expected, both TEWL and erythema increased significantly with abrasion. Erythema and TEWL values remained higher at the abraded site for 2 and 6 days, respectively, after abrasion. No changes in NMF component levels in the SC were observed at 30 min after abrasion. One day following abrasion, reduced levels of glycine, histidine pH4, trans-urocanic acid (tUca) pH4, and tUca pH8 were observed. In addition, a significantly lower level of serine was observed at the abraded site 2 and 6 days following abrasion. Within 8 days after abrasion, these components returned to levels comparable to those observed in untreated skin. Throughout the study, no differences were observed in the level of water in the SC. These results demonstrate that acute barrier disruption induced by mechanical abrasion has relatively little impact on biochemical events responsible for NMF generation. Though reductions in certain NMF components were observed, abrasion had no measureable effect on SC water content over the duration of the study. This implies that the reduced NMF components may not contribute substantially to water retention in the SC. The reduced components belong to a group of NMF molecules thought to be principally derived through degradation of S-100 proteins in the epidermis. NMF components measured in this study that are derived from sweat and/or urea cycling were not impacted. These data imply that while abrasion elicits clinical signs of barrier disruption within the SC, effects on its biochemical constituents and ability to retain water are relatively minor.

Clinical Efficacy of Dermocosmetic Formulations Containing Spirulina Extract on Young and Mature Skin: Effects on the Skin Hydrolipidic Barrier and Structural Properties

Introduction: Spirulina is a unicellular blue-green alga rich in vitamins, minerals, pigments, proteins, polysaccharides, which indicates a high potential use in anti-aging cosmetic products as well as for skin protection. Preliminary studies showed antioxidant potential, immediate benefits on the skin microrelief and hydration and skin compatibility of formulations containing Spirulina extract. Thus, the objective of this study is to evaluate the long term clinical efficacy of dermocosmetic formulations containing Spirulina extract on young and mature skin using biophysical and skin imaging techniques. Methods: 40 healthy female volunteers participated in the clinical efficacy study, aged between 18- 39 (Young group) and 40- 65 (Mature group). The gel-cream formulation, supplemented, or not (vehicle - FGV) with 0.1% (w/w) of Spirulina extract (FGA) was applied twice daily on the volunteers face region. The effects were evaluated in terms of skin hydration, transepidermal water loss - TEWL, skin microrelief, sebum content and morphological and structural epidermal features before and after a 28-day-period of application of the formulations. Results: The formulation containing Spirulina extract increased stratum corneum water content and reduced the TEWL in both groups. However, a significant reduction in the older group, that received the formulation with Spirulina extract, was observed when compared to the younger group and to the vehicle formulation. Only the formulation containing the active ingredient under study reduced significantly the sebum content on the volunteer’s skin. It was also noted an improvement of the skin microrelief by the reduction of the surface roughness and after the treatment the keratinocytes were more uniformly distributed and homogeneous. Conclusion: The formulation containing Spirulina extract improved skin conditions and provided long term skin benefits such as hydration, protection of the skin barrier function and oil control. Finally, Spirulina extract stands out as a unique active ingredient for effective multifunctional dermocosmetic formulations for the care of young and mature skin.

Reliability of Repeated Measurements on Post‐Burn Scars with Corneometer CM 825®

The water content in burn scars, the parameter of stratum corneum water holding capacity, is an important feature in evaluation of biophysical properties of scars. Nevertheless, quantifiying this parameter is a challenge. In this study, the reliability of repeated water content measurements with Corneometer CM825(®) on (burn) scars was investigated. Intra-observer reliability, inter-observer reliability and day-by-day variability were examined on 30 scars by means of intra-class correlation coefficient (ICC) and within-subject coefficient of variation (WSCV). Bland-Altman plots with '95% limits of agreement' were constructed. Results revealed excellent ICC values (ICCintra =0.985; ICCinter =0.984) with relatively low WSCV (WSCVintra =6.3%; WSCVinter =10.6%) for respectively intra- and inter-observer reliability. However, the Bland-Altman plot showed that more than 5% of differences were expected to exceed 4a.u., the limit of what has been defined as a clinically acceptable difference. Results for day-by-day variability showed good ICC value (ICCday-by-day =0.849) and higher WSCV (WSCVday-by-day =20.5%). The Corneometer CM825(®) is an objective and sensitive instrument for water content measurements. On the basis of our results, we concluded that the instrument can be used in clinical trials, but only under very strict conditions with standardized test protocol, preferably in combination with the evaluation of other physiological parameters.

Cherenkoscopy Is a Novel Imaging Technique With the Potential to Improve Accuracy and Detect Radiation Therapy Misadministrations During Whole Breast Radiation Therapy

Water content and sebum amount of irradiated and non-irradiated stratum corneum was measured by corneometer and sebumeter on the first and last day of RT, at 2 weeks, 4 weeks, and 3 months after RT. Sebum composition was analyzed by chromatography. Symptoms (pain and pruritus) were measured by Visual Analog Scale (VAS) and signs (erythema, dryness, and desquamation) were graded blind by a dermatologist. Eligibility criteria included women aged between 30 to 65 years and no surgical resection in the measurement site. The primary endpoint was the water content recovery rate between Weeks 2 and 4 post-RT (B vs C). The recovery rate was analyzed by Wilcoxon signed-rank test. Results: Seventy-six patients were analyzed. On the last day of RT and at 2 weeks post RT, water content was significantly decreased in group B (n Z 30) and C (n Z 32) vs A (n Z 14) (p < 0.05). At 4 weeks post RT, water content in group B returned to pre RT levels without significantly difference from group A (P Z 0.70), and reduction in water content was sustained in group C (p < 0.05). At 3 months post RT, the differences between three groups were not statistically significant. No adverse effects related to a moisturizer were noted. The water content recovery rate between Weeks 2 4 was significantly improved in group B vs C (0.242 vs 0.055, p < 0.05). The sebum amount and proportion of wax ester were markedly decreased in both irradiated and non-irradiated side after RT. The decrease of sebum sustained to 3 months post RT in irradiated side. Pain VAS score was improved in group A vs C on the last day of RT (p < 0.05) and in group B vs C at 3 months post-RT (p < 0.05). No difference was found on pruritus. Dryness and desquamation were significantly improved with moisturizer application (p < 0.05), but no effect on erythema. Conclusions: RT significantly reduced stratum corneum water content and induced quantifiable persistent sebaceous gland damage. Two week treatment of a heparinoid moisturizer after RT effectively improved RT-induced skin dryness. The prophylactic application of a moisturizer prevented severe skin dryness and can improve symptoms related to RD. Author Disclosure: M. Ogita: None. K. Sekiguchi: None. K. Akahane: None. J. Kawamori: None. R. Ito: None. C. Haga: None. S. Arai: None. O. Takahashi: None.

Water sorption evaluation of stratum corneum

• Porcine skin is a well-accepted and readily available model of the human skin barrier. • Skin function is largely dependent on stratum corneum water balance. • Moisture absorption/desorption isotherm curves for human and porcine SC were studied. • Great influence of the stratum corneum thickness on the permeability properties. Skin function is largely dependent on SC water balance. Animal skin is frequently used as an alternative to human skin in percutaneous absorption studies. Porcine skin is a well-accepted and readily available model of the human skin barrier. It is important to assess how similar porcine skin water permeability is to that of human skin to confirm the validity of the model. Moisture absorption/desorption isotherm curves for human and porcine SC were obtained. The apparent diffusion coefficients of porcine SC calculated were slightly smaller than that of human SC. Besides, when SC thickness was considered, diffusion coefficients were obtained, with porcine SC having a significant higher permeability. The higher thickness of the porcine SC compensates its higher diffusion per thickness unit, leading to similar apparent diffusion coefficients, thus indicating the suitability of the porcine SC for the skin permeation studies.