Human glabrous skin contains crystallized urea dendriform structures in the stratum corneum which affect the hydration levels.

Glabrous skin is hair-free skin with a high density of sweat glands, which is found on the palms, and soles of mammalians, covered with a thick stratum corneum. Dry hands are often an occupational problem which deserves attention from dermatologists. Urea is found in the skin as a component of the natural moisturizing factor and of sweat. We report the discovery of dendrimer structures of crystalized urea in the stratum corneum of palmar glabrous skin using laser scanning microscopy. The chemical and structural nature of the urea crystallites was investigated in vivo by non-invasive techniques. The relation of crystallization to skin hydration was explored. We analysed the index finger, small finger and tenar palmar area of 18 study participants using non-invasive optical methods, such as laser scanning microscopy, Raman microspectroscopy and two-photon tomography. Skin hydration was measured using corneometry. Crystalline urea structures were found in the stratum corneum of about two-thirds of the participants. Participants with a higher density of crystallized urea structures exhibited a lower skin hydration. The chemical nature and the crystalline structure of the urea were confirmed by Raman microspectroscopy and by second harmonic generated signals in two-photon tomography. The presence of urea dendrimer crystals in the glabrous skin seems to reduce the water binding capacity leading to dry hands. These findings highlight a new direction in understanding the mechanisms leading to dry hands and open opportunities for the development of better moisturizers and hand disinfection products and for diagnostic of dry skin.

Revealing the Meissner Corpuscles in Human Glabrous Skin Using In Vivo Non-Invasive Imaging Techniques.

The presence of mechanoreceptors in glabrous skin allows humans to discriminate textures by touch. The amount and distribution of these receptors defines our tactile sensitivity and can be affected by diseases such as diabetes, HIV-related pathologies, and hereditary neuropathies. The quantification of mechanoreceptors as clinical markers by biopsy is an invasive method of diagnosis. We report the localization and quantification of Meissner corpuscles in glabrous skin using in vivo, non-invasive optical microscopy techniques. Our approach is supported by the discovery of epidermal protrusions which are co-localized with Meissner corpuscles. Index fingers, small fingers, and tenar palm regions of ten participants were imaged by optical coherence tomography (OCT) and laser scan microscopy (LSM) to determine the thickness of the stratum corneum and epidermis and to count the Meissner corpuscles. We discovered that regions containing Meissner corpuscles could be easily identified by LSM with an enhanced optical reflectance above the corpuscles, caused by a protrusion of the strongly reflecting epidermis into the stratum corneum with its weak reflectance. We suggest that this local morphology above Meissner corpuscles has a function in tactile perception.

Applying sunscreen SPF 50 with high antioxidant capacity during fifteen days improves the dermis echogenicity and reduces the reddish skin undertone.

BACKGROUND: Of the many effects induced by UV radiation on the skin, erythema is one of the most well-known features, which is a cutaneous inflammatory reaction correlated with acute photodamage. The utilization of sunscreen may reduce this process. AIMS: To evaluate the utilization of a sunscreen SPF50 with high antioxidant capacity during 15 days by young men without photoprotection habits. METHODS: For this, we evaluated erythema, skin hydration properties, and dermis echogenicity using skin imaging techniques. Forty male participants (aged between 18 and 28 years old), 36 without previous photoprotection habits, were recruited, and the erythema was evaluated using a visual score and skin colorimeter. Macroscopic images (VivaCam®) were also obtained. Dermis echogenicity was evaluated using high-frequency ultrasonography. All the participants received a sunscreen SPF 50 to use for 15 days. RESULTS: The visual score presented a strong correlation (r = 0.8657) with the colorimeter results. Visually and using the biophysical methodologies was possible to observe the reduction of the visual erythema. The dermis echogenicity also improved, probably correlated with the acute inflammation reduction. No alterations were observed in the skin hydration and skin barrier parameters. CONCLUSIONS: The utilization of complementary and correlated different skin biophysical and imaging techniques in this study allows a better comprehension regarding the skin early photoaging process due the direct sun exposure. The utilization with a SPF 50 sunscreen with high antioxidant potential allows for a reduction in the erythema after 15 days of usage, a quick result, however, did not improved the skin barrier or SC hydration.

Film-Forming Properties of Topical Formulations for Skin and Hair: In Vivo and In Vitro Studies Using Biophysical and Imaging Techniques.

The film-forming effect is an important property of formulations for skin improvement and hair protection. Reflectance confocal microscopy, an advanced imaging technique, is an important tool for its evaluation. Thus, the aim of this study was to evaluate the film-forming properties of cosmetic formulations based on starches and containing a Spirulina maxima extract after their application to skin and hair, using sensorial analysis and instrumental measurements, with emphasis on reflectance confocal microscopy. Two formulations based on starches and PEG-75 lanolin containing or not (Vehicle) a Spirulina maxima dry extract were developed. The rheological behavior and sensorial properties of both formulations were evaluated. The film-forming property on the skin was evaluated in terms of skin hydration by RCM imaging analysis and transepidermal water loss (TEWL). The hair tresses were evaluated in terms of mechanical properties and RCM imaging analysis. The formulations showed pseudoplastic behavior and a low hysteresis area. In addition, the presence of Spirulina in the formulation did not interfere in the rheological parameters. Both formulations reduced TEWL and maintained the stratum corneum water content. The protective effect was also observed in the hair, since the application of the formulation with Spirulina showed a better performance in the tensile test when compared to vehicle. Thus, the proposed formulation showed film formation on the skin and hair surface that brought immediate benefits such as a reduction of TEWL. Finally, the formulations were shown to have film-forming effects and their use can be suggested for skin and hair protection against daily damage.

Eco-friendly sunscreen formulation based on starches and PEG-75 lanolin increases the antioxidant capacity and the light scattering activity in the visible light.

Most modern sunscreens contain physical filters, which scatter the sunlight, increasing the photons' pathway in the upper stratum corneum. This effect can lead to a better efficacy of the UV filters and improve the diffuse reflection. However, the addition of nanosized inorganic UV filters reduces the antioxidant capacity of sunscreen formulations. Two cream formulations (F1, F2) which differ in the ingredient PEG75 Lanolin (F2), have been characterized for their radical protection factor (RPF) and their optical properties in vitro using electron paramagnetic resonance (EPR) spectroscopy and UV/VIS spectrometry. The RPF for PEG-75 Lanolin was also determined. Furthermore, their radical protection properties were analyzed on porcine skin ex vivo after visible light irradiation by EPR. The structure of each formulation in the skin surface was determined by reflectance confocal microscopy in vivo. The addition of lanolin increased the reflectance and reduced the transmittance for visible light, improving the scattering drastically. Besides, the antioxidant capacity was also increased for F2, something unpublished until now. F1 presented a lower scattering provided by starches. The sunscreens showed high scattering properties and antioxidant capacity, especially for F2, which presented the lowest radical formation in the skin model. These results are consistent with the RPF measurements where F2 has a higher RPF value (193 ± 3 × 1014 radicals/mg) than F1 (155 ± 4 × 1014 radicals/mg) and for PEG-75 Lanolin (37 ± 1 × 1014 radicals/mg). The combination of starches and PEG-75 Lanolin is the first solution to provide both, light scattering and antioxidant capacity, in sunscreens.

Skin photoaging in young men: A clinical study by skin imaging techniques.

OBJECTIVE: Differences in skin physiology and lifestyle among people can influence the skin damage caused by solar radiation. Photoprotection habits play an important role to prevent skin photoaging. Thus, the objective of the present study was to evaluate the skin changes resulting from solar exposure in young men by skin imaging techniques. METHODS: Twenty-three male, aged 18-28 years, with and without photoprotection habits participated in the study. Instrumental measurements in terms of dermis thickness and echogenicity (20 mHz ultrasound - DermaScanC® ), morphological and structural skin characterization (Reflectance Confocal Microscopy - VivaScope® 1500) and high-resolution imaging (Visioface® ) were performed in the malar region of the face. RESULTS: Pigmentation disorders, telangiectasia, wrinkles and lower dermis echogenicity were observed in the skin of subjects without photoprotection habits. Reflectance Confocal Microscopy images showed an irregular honeycomb pattern (35%), polycyclic papillae (40%) and coarse collagen fibres (35%), which are related to photoaging. CONCLUSION: Sun exposure without photoprotection results in a loss of dermal echogenicity and changes in the epidermis structure and collagen fibres regardless of chronological age. Thus, the study adds data for a discussion about correct photoprotection habits among young people and can help to increase the use of sunscreens for male public.

OBJECTIFS: Les différences de physiologie cutanée et de mode de vie peuvent influer sur les lésions cutanées causées par le rayonnement solaire. Les habitudes de photoprotection jouent un rôle important dans la prévention du photovieillissement cutané. Dans ce contexte, l'objectif de l'étude était d'évaluer les changements cutanés résultants de l'exposition au soleil chez les jeunes hommes à l'aide de techniques d'imagerie cutanée. MÉTHODES: L'étude a inclus 23 hommes, âgés de 18 à 28 ans, avec et sans habitudes de photoprotection. Des mesures instrumentales d'épaisseur et d'échogénicité du derme (échographie 20 mHz - DermaScanC®), de caractérisation morphologique et structurale de la peau (Reflectance Confocal Microscopy - VivaScope® 1500) et des images haute résolution (Visioface®) ont été réalisées dans la région malaire du visage. RÉSULTATS: Des troubles de la pigmentation, des télangiectasies, des rides et une moindre échogénicité du derme ont été observés sur la peau d'individus sans habitudes de photoprotection. Les images de microscopie confocale à réflectance ont montré un motif en nid d'abeille irrégulier (35%), des papilles polycycliques (40%) et des fibres de collagène épaisses (35%), qui sont liés au photovieillissement. CONCLUSION: L'exposition au soleil sans photoprotection entraîne une perte d'échogénicité cutanée et des modifications de la structure de l'épiderme et des fibres de collagène, quel que soit l'âge chronologique. Enfin, l'étude agrège les données pour une discussion sur les bonnes habitudes de photoprotection chez les jeunes et peut aider à augmenter l'utilisation des écrans solaires par le public masculin.

Design and Characterization of Topical Formulations: Correlations Between Instrumental and Sensorial Measurements.

The interaction between cosmetic emulsions and the skin's surface is an important factor to consider in the development of topical formulations. Two important ingredients in cosmetic formulations are waxes and polymers. The physical and mechanical properties of formulations directly impact the interface skin-formulation. To evaluate this interaction, it is important to study the rheology, texture, and sensory properties. In this context, the aim of the study was to evaluate the influence of waxes and polymers on the rheological behavior, texture profile, and sensorial properties of topical formulations and the correlation between these parameters. The best combination of a wax and a polymer was determined by full factorial design of experiments and applied to develop eight formulations that were tested in relation to rheological, mechanical, and sensorial properties. The polymer helps with the spreadability of the formulation, and the wax had a strong influence on the parameters related to the structure of emulsions. A correlation between these parameters was observed. This way, it was possible to compare theoretical and practical data, except between the flow index and the work of shear. Finally, it was possible to predict sensorial aspects from rheological and texture parameters, making the formulation process easier and more integrated with all stages of the development of new topical formulations. Thus, the present study introduces a new proposal in the development of cosmetics.

Evaluation of polymorphisms in pbp4 gene and genetic diversity in penicillin-resistant, ampicillin-susceptible Enterococcus faecalis from hospitals in different states in Brazil.

The aim of the present study was to verify whether penicillin-resistant, ampicillin-susceptible Enterococcus faecalis (PRASEF) occurred in Brazil prior to the beginning of the 21st century, and to verify whether ampicillin susceptibility can predict susceptibility to other ß-lactams in E. faecalis with this inconsistent phenotype. The presence of polymorphisms in the pbp4 gene and genetic diversity among the isolates were investigated. Of 21 PRASEF analyzed, 5 (23.8%) and 4 (19.0%) were imipenem and piperacillin resistant simultaneously by disk diffusion and broth dilution respectively, contradicting the current internationally accepted standards of susceptibility testing. Sequencing of pbp4 gene revealed an amino acid substitution (Asp-573→Glu) in all PRASEF isolates but not in the penicillin-susceptible, ampicillin-susceptible E. faecalis. Most PRASEF (90.5%) had related pulsed-field gel electrophoresis profiles, but were different from other PRASEF described to date. Results demonstrate that penicillin-resistant, ampicillin-susceptible phenotype was already a reality in the 1990s in E. faecalis isolates in different Brazilian states, and some of these isolates were also imipenem- and piperacillin-resistant; therefore, internationally accepted susceptibility criteria cannot be applied to these isolates. According to pbp4 gene sequencing, this study suggests that a specific amino acid substitution in pbp4 gene found in all PRASEF analyzed is associated with penicillin resistance.

Comportamento de homens e mulheres quanto ao consumo de cosméticos e a importância na indicação de produtos e adesão ao tratamento / Cosmetics consumption behaviour among men and women and the importance in products indication and treatment adherence

Introdução: Os cosméticos apresentam-se em destaque no comércio não só no Brasil, mas mundialmente. Há grande necessidade do conhecimento das motivações de compra dos consumidores para o desenvolvimento de produtos mais bem direcionados e melhora na adesão de tratamentos dermatológicos. Objetivo: Conhecer os hábitos de consumo cosmético e fornecer um link da área farmacêutica com a área médica. Métodos: Estudo observacional analítico do tipo transversal, realizado por meio de questionário. Resultados: A principal alteração na pele masculina é a oleosidade, nas mulheres além dessa há a preocupação com manchas. O consumo de produtos de higiene é unânime em ambos os sexos. As mulheres se mostram mais preocupadas com o tratamento e prevenção de danos solares. A maioria das mulheres utiliza produtos antiacne e maquiagens. Produtos para cabelo apresentam a mesma tendência de vendas tanto para homens quanto para mulheres, não sendo o mesmo observado entre os produtos para pele. Conclusões: Homens e mulheres apresentam diferentes motivações no momento de adquirir produtos cosméticos. A forma de relacionamento do consumidor com os produtos tem mudado expressivamente, e ele vem buscando expressar sua individualidade perante a sociedade. Isso reflete a necessidade do conhecimento médico de tais motivações a fim de melhorar a adesão dos pacientes ao tratamento.

Introduction: Cosmetics stands outs in commerce, not only in Brazil but also worldwide. There is great need for knowledge on buying motivations of consumers for the development of better-targeted products and improved adhesion to dermatological treatments. Objective: To know the cosmetic consumption habits and provide a link from the pharmaceutical with the medical area. Methods: An analytical observational study, cross-sectional, was conducted by questionnaire. Results: Main change in male skin is oiliness; in women, besides oiliness, there is concern with blemishes. The consumption of hygiene products is unanimous in both sexes. Women are more concerned with the treatment and prevention of sun damage. The vast majority of women use anti-acne products and makeup. Hair products have the same sales trend for both men and women, but this is not observed among products for skin. Conclusions: Men and women have different motivations when buying cosmetics. The way consumers relate with products has changed dramatically and they are seeking to express their individuality in society. This reflects a need for medical knowledge of such motivations in order to improve patients' adherence to treatment.