Application of biophysical and skin imaging techniques to evaluate the film-forming effect of cosmetic formulations.

OBJECTIVE: Products with film-forming effect, or 'second skin', which guarantees an immediate protective effect after application, is a highlight, especially when composed of natural ingredients. Thus, the objective of this study was to evaluate the immediate film-forming effect on skin of a gel and emulsion formulations added with Kappaphycus alvarezii and Caesalpinia spinosa extracts through biophysical and skin imaging techniques, especially with the Reflectance Confocal Microscopy (RCM). METHODS: The measurements were done in the forearm region before (baseline) and 1 h after of application of the developed formulation and its control. The parameters related to the stratum corneum water content, transepidermal water loss (TEWL), cutaneous microrelief and morphological and structural characteristics of the epidermis were analysed through the following biophysical and skin imaging techniques: Corneometer® CM 825, Tewameter® TM 300, Visioscan® VC98 and Vivascope® 1500, respectively. A sensorial analysis was also performed to study how the formulations were perceived on the skin. RESULTS: The obtained results showed that the active ingredient under study allows the film formation on the skin surface, leading to a reduction of TEWL and skin desquamation. The obtained images from RCM showed a reduction of furrows on the skin surface and a film formation after a single application of the formulations. However, these effects were more pronounced in the emulsion formulation, which suggests a synergistic effect of the active ingredient under study with the emollients of formulation composition. This result was also observed in the sensorial analysis, as both formulations added with the active substance were well evaluated. CONCLUSION: The presence of Kappaphycus alvarezii and Caesalpinia spinosa extracts in the studied cosmetic formulations, enabled a film formation on a skin surface, bringing benefits as a reduction of transepidermal water loss and skin desquamation, as well as a furrows reduction and an improvement of stratum corneum after 1 h of application. Finally, the skin imaging techniques can be suggested as an excellent tool to evaluate a film-forming effect of cosmetic formulations.

OBJECTIF: Les produits ayant un effet filmogène, ou « deuxième peau ¼ qui garantit un effet protecteur immédiat après l'application, sont un plus, notamment lorsqu'ils sont composés d'ingrédients naturels. L'objectif de cette étude visait ainsi à évaluer l'effet filmogène immédiat sur la peau de formulations avec gel et émulsion enrichies d'extraits de Kappaphycus alvarezii et de Caesalpinia spinosa grâce à des techniques d'imagerie cutanée et biophysique, en particulier par microscopie confocale par réflectance (MCR). MÉTHODES: Les mesures ont été effectuées dans la région de l'avant-bras avant (référence) et 1 h après l'application de la formulation développée et de son contrôle. Les paramètres liés à la teneur en eau de la couche cornée, perte d'eau transépidermique (Transepidermal Water Loss, TEWL), au microrelief cutané et aux caractéristiques structurelles et morphologiques de l'épiderme ont été analysés à l'aide des techniques d'imagerie cutanée et biophysique suivantes : Corneometer® CM 825, Tewameter® TM 300, Visioscan® VC98 et Vivascope® 1500, respectivement. Une analyse sensorielle a également été réalisée pour étudier comment les formulations étaient perçues sur la peau. RÉSULTATS: Les résultats obtenus ont montré que le principe actif étudié permet la formation d'un film à la surface de la peau, entraînant une réduction de la TEWL et de la desquamation de la peau. Les images obtenues par MCR ont montré une réduction des sillons à la surface de la peau et la formation d'un film après une seule application des formulations. Ces effets étaient toutefois davantage prononcés avec la formulation de type émulsion, ce qui suggère un effet synergique du principe actif étudié avec les émollients contenus dans la formulation. Ce résultat a également été observé dans l'analyse sensorielle, car les deux formulations enrichies en substance active ont été bien évaluées. CONCLUSION: La présence d'extraits de Kappaphycus alvarezii et de Caesalpinia spinosa dans les préparations cosmétiques étudiées a permis la formation d'un film à la surface de la peau, procurant des bénéfices sous forme d'une réduction de la perte d'eau transépidermique et de la desquamation de la peau, de même qu'une réduction des sillons et une amélioration de la couche cornée 1 h après l'application. Enfin, les techniques d'imagerie cutanée peuvent être proposées comme excellent outil d'évaluation de l'effet filmogène des préparations cosmétiques.

Characterization of oily mature skin by biophysical and skin imaging techniques.

BACKGROUND: The skin is a complex biological system and may suffer change according to the environmental factors, as higher temperatures can increase sebum excretion, presenting oiliness and acne. These alterations can persist during the aging and provoke more changes in aged skin. In this study we evaluated the mature oily skin characteristics using biophysical and skin imaging techniques. MATERIAL AND METHODS: Sixty healthy female subjects, aged between 39 and 55 years old were recruited and separated into 2 groups according to their skin type: normal/dry and oily skin. The skin was evaluated in terms of stratum corneum water content, transepidermal water loss (TEWL) sebum content, dermis thickness and echogenicity, skin microrelief, and pores content. RESULTS: The mature oily skin presented no significant differences when compared to the normal/dry skin on the stratum corneum water content and TEWL parameters. The sebum content was significantly higher on the oily skin group. The microrelief analysis showed an increase of skin roughness values in the oily skin and increase of scaliness in the normal/dry skin. The oily skin showed lower dermis echogenicity mainly in the frontal region and higher dermis thickness when compared to normal/dry skin. CONCLUSION: The mature oily skin showed different characteristics from normal/dry skin in terms of sebum content, microrelief parameters, and dermis thickness. This way, the characterization of mature oily skin in an objective way is very important to development of dermocosmetic products for more effective treatments focused specially on this type of skin.

A detailed description of an economical setup for electroporation of chick embryos in ovo.

One of the challenges of the postgenomic era is characterizing the function and regulation of specific genes. For various reasons, the early chick embryo can easily be adopted as an in vivo assay of gene function and regulation. The embryos are robust, accessible, easily manipulated, and maintained in the laboratory. Genomic resources centered on vertebrate organisms increase daily. As a consequence of optimization of gene transfer protocols by electroporation, the chick embryo will probably become increasingly popular for reverse genetic analysis. The challenge of establishing chick embryonic electroporation might seem insurmountable to those who are unfamiliar with experimental embryological methods. To minimize the cost, time, and effort required to establish a chick electroporation assay method, we describe and illustrate in great detail the procedures involved in building a low-cost electroporation setup and the basic steps of electroporation.

A detailed description of an economical setup for electroporation of chick embryos in ovo

One of the challenges of the postgenomic era is characterizing the function and regulation of specific genes. For various reasons, the early chick embryo can easily be adopted as an in vivo assay of gene function and regulation. The embryos are robust, accessible, easily manipulated, and maintained in the laboratory. Genomic resources centered on vertebrate organisms increase daily. As a consequence of optimization of gene transfer protocols by electroporation, the chick embryo will probably become increasingly popular for reverse genetic analysis. The challenge of establishing chick embryonic electroporation might seem insurmountable to those who are unfamiliar with experimental embryological methods. To minimize the cost, time, and effort required to establish a chick electroporation assay method, we describe and illustrate in great detail the procedures involved in building a low-cost electroporation setup and the basic steps of electroporation.

Use of electromyography to assess pain in the upper trapezius and lower back muscles within a fatigue protocol / Uso da eletromiografia na análise de dor dos músculos trapézio superior e lombares durante protocolo de fadiga

OBJECTIVE: The aim of this study was to investigate whether muscle fatigue indices obtained using surface electromyography and calculated in the time and frequency domains would be capable of objectively diagnosing pain and discriminating between subjects with and without pain in the upper trapezius muscle and the lower back muscles. METHODS: Forty-seven individuals underwent a muscle fatigue test for thirty-five seconds at 80% of the maximal voluntary contraction (MVC), while EMG and muscle force data were recorded. The RMS value and the median frequency (MF) were calculated within consecutive one-second windows. Linear regression analysis was used to obtain the slope coefficients and the respective y-axis intercept values, which were considered to be localized muscle fatigue indices. RESULTS: In the frequency domain, the slope coefficients were negative for both muscles, while in the time domain, the coefficient for the upper trapezius was positive and the coefficient for the lower back muscles was negative (p<0.01). Significant differences were also found in the frequency domain between subjects with and without pain in the upper trapezius (p<0.01). The subjects with pain had significantly lower force values than the subjects without pain (p<0.05), in both the upper trapezius and the lower back muscles. CONCLUSION: The force values associated with the fatigue indices (MF slope and y-axis intercept) were able to predict the presence of pain in the upper trapezius (p<0.05), but not in the lower back muscles.

OBJETIVO: A proposta do estudo foi investigar se índices de fadiga, obtidos a partir de eletromiografia de superfície, calculados no domínio do tempo e da frequência, são capazes de diagnosticar a dor objetivamente, discriminando entre sujeitos com e sem dor no trapézio superior e nos músculos lombares. MÉTODOS: Quarenta e sete indivíduos foram submetidos a um teste de fadiga muscular por 35s a 80% da contração voluntária máxima (CVM), enquanto EMG e força muscular foram registradas. O valor RMS e a mediana da frequência (MF) foram calculados em janelas consecutivas de 1s. Análise de regressão linear foi utilizada para obter os coeficientes de inclinação e seus respectivos valores de interseção no eixo y, os quais foram considerados índices de fadiga muscular localizada. RESULTADOS: Os coeficientes de inclinação analisados no domínio da frequência apresentaram comportamento similar, sendo negativos para ambos os músculos, enquanto que, no domínio tempo, o trapézio superior apresentou coeficientes positivos, e músculos lombares, coeficientes negativos (p<0,01). Diferenças significativas também foram identificadas no domínio da frequência entre os sujeitos com e sem dor no trapézio superior (p<0,01). Os indivíduos com dor apresentaram valores de força significativamente menores que os sujeitos sem dor (p<0,05), tanto nos músculos lombares quanto no trapézio superior. CONCLUSÃO: Os valores de força associados aos índices de fadiga (inclinação da MF e intersecção do eixo y) foram hábeis para predizer a presença de dor no trapézio superior (p<0,05), mas não nos músculos lombares.

Análise da resistência externa e da atividade eletromiográfica do movimento de extensão de quadril realizado segundo o método Pilates / Analysis of the external resistance and electromyographic activity of hip extension performed according to the Pilates method

OBJETIVOS: Comparar a ativação elétrica do reto femoral (RF), do bíceps femoral cabeça longa (BF) e semitendíneo (ST) e o torque de resistência (T R) do movimento de extensão de quadril (EQ) realizado com a mola fixada em duas posições distintas no Cadillac. MÉTODOS: 12 sujeitos realizaram 5 repetições de EQ com a mola fixada em duas posições (alta e baixa). Dados de eletromiografia (EMG) e eletrogoniometria foram coletados simultaneamente. O root mean square foi calculado e normalizado com base na contração voluntária máxima. Para o cálculo do T R, foram usados diagramas de corpo livre (DCL) e equações de movimento. ANOVA one-way foi usada para verificar as diferenças para EMG entre as posições de mola (p<0,05). RESULTADOS: Com a mola fixa na posição alta, o T R foi classificado como decrescente e ocorreu no "sentido" de flexão na maior parte da amplitude de movimento (ADM). Para posição baixa, o T R foi descrescente até 60º de flexão de quadril no sentido de flexão e, a partir daí, assumiu um comportamento crescente no sentido da extensão. CONCLUSÕES: A análise EMG pareceu acompanhar o T R, apresentando valores maiores para o RF na posição baixa e maiores valores de ativação para o BF e ST na posição alta, onde a demanda externa foi maior. Dados de EMG e T R fornecem informações complementares para prescrição de exercícios no Pilates.

OBJECTIVES: To compare the electrical activation of the rectus femoris (RF), long head of the biceps femoris (BF) and semitendinosus (ST) and the resistance torque (T R) of the hip extension (HE) movement performed on the Pilates Cadillac with the attachable spring in two different positions. METHODS: Twelve subjects performed five hip extensions with the attachable spring in two positions (high and low). Electromyography (EMG) and electrogoniometry data were colleted simultaneously. The root mean square (RMS) was calculated and normalized based on the maximal voluntary contraction. A free-body diagram (FBD) and movement equations were used to calculate T R. One-way ANOVA was used to investigate EMG differences between spring positions (p<0.05). RESULTS: When the spring was in the high position, T R was classified as descending and occurred in the "direction" of flexion over most of the range of motion (ROM). In the low position, T R descended until 60º of hip flexion, in the direction of flexion, and from there it took on an ascending pattern in the direction of extension. CONCLUSIONS: The EMG analysis seemed to follow the T R, with higher values for the RF in the low position and higher activation values for the BF and ST in the high position, where the external demand was greater. EMG and T R data supply complementary information for prescribing Pilates exercises.