Characterization of the peripheral vascular function by a hemodynamical response to a passive postural change in the lower limb

Revista Lusófona de Ciências e Tecnologias da SaúdeO estudo da função vascular periférica tem beneficiado do desenvolvimento de diversas técnicas e metodologias de avaliação o as quais permitem caracterizar a função com um mínimo de invasibilidade. O estudo do significado de diversas variáveis transcutâneas tem ajudado a melhor compreender as complexas relações que regem a perfusão dos tecidos in vivo. No presente estudo procurámos avaliar o perfil de resposta de um grupo de indivíduos saudáveis jovens de ambos os sexos (n=23, 22,4 ± 2,2 anos), a uma manobra dinâmica (provocação) envolvendo a variação postural passiva do membro inferior (A: elevação da perna e B: decúbito dorsal) de modo a caracterizar a função vascular periférica por meio de variáveis transcutâneas (tc). A perfusão local medida por Fluxometria de Laser Doppler (LDF) , a Perda Trans-epidérmica de água (PTEA) as pressões parciais de oxigénio e dióxido de carbono transcutâneos e a oximetria de pulso foram escolhidas e, um intervalo de confiança de 95% adoptado. LDF, PTEA e tcpO 2 são, manifestamente, as variáveis que melhor permitem seguir o processo em cada fase experimental. Em A foram registadas, durante a provocação, diferenças significativas na perfusão sanguínea e na pressão transcutânea de oxigénio e PTEA, especialmente nas mulheres, enquanto que o perfil de resposta obtido em B foi idêntico em ambos os grupos e comparável B hiperémia reactiva. Qualquer dos protocolos permitiu evidenciar uma relação inversamente recíproca entre a PTEA e o LD. Os resultados obtidos confirmam a utilidade destas metodologias na avaliação da função vascular periférica, confirmando as relações entre PTEA e LDF as quais devem ser adequadamente aprofundadas.The study of the peripheral vascular function benefits from the development of several evaluation techniques and methodologies which allow for the characterization of the function without invasion of the tissue. The study of the meaning of several transcutaneous variables has helped to understand the complex relationships that rule the perfusion of the tissues in vivo. In the present study, we attempted to evaluate the profile of response of a group of healthy young individuals from both genders (n=23, 22,4 ± 2,2 years), to a dynamic maneuver (provocation) involving the postural passive change of the inferior member (A: elevation of the leg and B: dorsal decubitus), to perform the characterization of the peripheral vascular function through transcutaneous variables (tc). The local perfusion, measured by Laser Doppler flowmetry (LDF), the Trans Epidermal Water Loss (TEWL), the transcutaneous partial pressures of oxygen and carbon and the pulse oximetry were chosen and a confidence interval of 95% was adopted. LDF, TEWL and tcpO2 are, clearly, the variables that allow for a better follow up of the process in each experimental phase. In A, during the provocation, significant differences in the blood perfusion and in the oxygen transcutaneous pressure and TEWL were registered, especially in women. The profile response obtained in B was identical in both groups and comparable to the reactive hyperemia. Any of the protocols allowed to evidence an inversely reciprocal relationship between TEWL and LDF. The obtained results confirm the usefulness of these methodologies in the evaluation of the peripheral vascular function, confirming the relationships between TEWL and LDF, which should be appropriately studied

Skin Barrier Function Evaluation by Bi-compartmental Analisys of TEWL Dynamical Measurements: Validation of New Analytical Conditions

This paper reviews a methodology based on mathematical modelling of data of transepidermal water loss (TEWL) after conducting a plastic occlusion stress test (POST), to assess the hydric skin dynamic by kinetic parameters. Although simple to implement, this method is time-consuming, since it normally involves collecting data for at least 30 minutes. This research is aimed at optimizing the protocol by reducing the total time of the experiment by collecting more points during the initial stage. It was possible to significantly reduce analysis time, which is advantageous both for researchers and for volunteers since, on the one hand, there is a reduction in the cost of research, and on the other hand it ensures the comfort of the study participants

Investigations of olive oil industry by-products extracts with potential skin benefits in topical formulations

Funding Information: This work was supported by Sovena Portugal Consumer Goods through the project 569 Oil4Health: From Olive to Health LISBOA-01-0247-FEDER-038554, funded by the 570 Portugal 2020 program?Programa Operacional Regional de Lisboa. This research was also funded by FCT (Funda??o para a Ci?ncia e a Tecnologia) through iMed.ULisboa UID/DTP/04138/2019 and UIDB/04138/2020), principal investigator grants CEECIND/03143/2017 (L. M. Gon?alves). Joana Marto is financed through FCT, I.P., under the Scientific Employment Stimulus?Institutional Call (CEECINST/00145/2018). Marta Martins is financed through FCT, I.P., under the Scientific Employment Stimulus?Institutional Call (CEECINST/00102/2018). The work was supported by the Marine and Environmental Sciences Centre?MARE (UIDB04292/2020; UIDP/04292/2020). Funding Information: Funding: This work was supported by Sovena Portugal Consumer Goods through the project 569 Oil4Health: From Olive to Health LISBOA-01-0247-FEDER-038554, funded by the 570 Portugal 2020 program—Programa Operacional Regional de Lisboa. This research was also funded by FCT (Fundação para a Ciência e a Tecnologia) through iMed.ULisboa UID/DTP/04138/2019 and UIDB/04138/2020), principal investigator grants CEECIND/03143/2017 (L. M. Gonçalves). Joana Marto is financed through FCT, I.P., under the Scientific Employment Stimulus—Institutional Call (CEECINST/00145/2018). Marta Martins is financed through FCT, I.P., under the Scientific Employment Stimulus—Institutional Call (CEECINST/00102/2018). The work was supported by the Marine and Environmental Sciences Centre—MARE (UIDB04292/2020; UIDP/04292/2020). Publisher Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland.The by-products of olive oil industry are a major ecological issue due to their phenolic content, highly toxic organic load, and low pH. However, they can be recovered and reused, since their components have antioxidant, anti-inflammatory, and photoprotector properties. In this work, oil-in-water creams containing three different olive oil industry by-products extracts were produced without the use of organic solvents. First, the extracts were thoroughly characterized in vitro for cytotoxicity, inhibition of skin enzymes, and antioxidant and photoprotection capacities. Safety studies were then performed, including ocular and skin irritation tests, ecotoxicity evaluation, and in vivo Human Repeat Insult Patch Test. The results obtained in this initial characterization supported the incorporation of the extracts in the cream formulations. After preparation, the creams were characterized for their organoleptic, physicochemical, droplet size and rheological properties, and microbial contamination. The results showed that all formulations were semi-solid creams, with stable pH, compatible with the skin, without microbial contamination, and with the expected droplet size range. The rheological analysis showed shear-thinning behavior with yield stress, with the viscosity decreasing with increasing shear rate. The oscillatory results suggest that the creams have a strong network structure, being easily rubbed into the skin. Finally, compatibility, acceptability and antioxidant efficacy were evaluated in vivo, in human volunteers. No adverse reactions were observed after application of the formulations on skin and the cream with the highest concentrations of phenolic compounds showed the highest antioxidant efficiency. In conclusion, the results suggest that olive oil industry by-products extracts have valuable properties that favor their re-use in the cosmetic industry. The example presented here showed their successful incorporation into creams and their impact in these formulations’ appearance, pH, and rheological performance, as well as their in vivo compatibility with skin and antioxidant efficiency.publishersversionpublishe

Transcutaneous flow related variables measured in vivo: the effects of gender

BACKGOUND: The identification of potential sources of error is a crucial step for any new assessment technique. This is the case for transcutaneous variables, such as flow and arterial gases, which have been applied as functional indicators of various aspects of human health. Regarding gender, a particular subject-related determinant, it is often claimed that women present higher transcutaneous oxygen pressure (tcpO(2)) values than men. However, the statistical significance of this finding is still uncertain. METHODS: The haemodynamical-vascular response to a local reactive hyperaemia procedure (the tourniquet cuff manoeuvre) was studied in two previously selected group of volunteers (n = 16; 8 women and 8 men). The effect of gender was assessed under standardised experimental conditions, using the transcutaneous flow-related variables tcpO(2)-tcpCO(2) and Laser-doppler Flowmetry (LDF). RESULTS: Regarding tcpO(2), statistically significant differences between genders were not found, although higher values were consistently found for the gases in the female group. Regarding LDF, high statistically significant differences (p < 0.005) were found, with the men's group presenting the highest values and variability. Other derived parameters used to characterise the vascular response following the cuff-deflation (t-peak) were similar in both groups. CONCLUSIONS: The relative influence of gender was not clearly demonstrated using these experimental conditions. However the gender-related LDF differences suggest that further investigation should be done on this issue. Perhaps in the presence of certain pathological disparities involving peripheral vascular regulation, other relationships may be found between these variables

Modelação de variáveis biológicas : estudo sobre a descrição quantitativa de parâmetros funcionais da pele in vivo

Tese de doutoramento, Farmácia (Biofarmácia e Farmacocinética), Universidade de Lisboa, Faculdade de Farmácia, 2010A microcirculação cutânea, monitorizada através de fluxometria de laser-doppler (LDF) a que por vezes se adiciona a gasometria transcutânea (tcpO2), é utilizada na obtenção de informação sobre a função vascular, especialmente quando associada a manobras dinâmicas. O objectivo do presente trabalho foi desenvolver um método baseado em modelos cinéticos, e suportado por pressupostos fisiológicos, que permitisse a avaliação da microcirculação de forma mais rigorosa e comparável. Foram incluídos 54 voluntários saudáveis, de ambos os sexos distribuídos em 2 grupos de idades (Grupo I: 30 voluntários, 18-35 anos; Grupo II: 24 voluntários, 35-65 anos). Foram realizadas 4 manobras dinâmicas de alteração da microcirculação (alteração da postura, redução da perfusão por alteração da postura e por oclusão suprasistólica, e alteração da inspiração de Oxigénio). Foram avaliadas a microcirculação, a tcpO2 e o LDF. A Perda Trans-Epidérmica de Água (PTEA) eo CO2, transcutâneo (tcpCO2) foram também registados. Desenvolveram-se 2 modelos compartimentais que foram ajustados aos dados de tcpO2 com a ajuda dos dados de LDF. Seleccionou-se o melhor modelo, validando-se o processo de análise. Para testar a capacidade do modelo em discriminar condições patológicas específicas, foram incluídos 6 doentes com Diabetes tipo II, e submetidos às manobras de redução da perfusão e alteração do Oxigénio inspirado. Todos os voluntários deram o seu consentimento informado. O modelo monocompartimental foi o que melhor se ajustou aos dados experimentais. O parâmetro mais relevante deste modelo, o tempo de semi-vida de eliminação do Oxigénio, foi comparado entre os grupos controlo e de doentes. Este parâmetro é superior nos doentes em relação aos voluntários saudáveis, em todas as manobras consideradas, apresentando uma capacidade discriminativa superior em relação ao parâmetro mais comum utilizado na prática clínica

An Experimental In Vivo Model to Characterize “Heavy Legs” Symptom in Topical Formulations

The “Heavy legs” symptom is regarded as an early expression of chronic venous failure, estimated to affect 40% of the population in developing countries. A new methodology is proposed to approach the “tired or heavy legs” symptom. Seven females with this complaint applied a standard topical formulation during 28 days in one leg randomly chosen. Local blood flow records were obtained instantaneously and during postural change with a laser doppler flowmeter (LDF). High-frequency sonography and local morphometry were also obtained at Days 0, 14, and 28. When compared with D0, LDF values present a significant decrease of both basal and dynamical values after Day 14 and Day 28 suggesting that this effect may result from the formulation application, also involving the related massage. Centimetric measurements and sonographic analysis also supported those inferences. The proposed methodology can evaluate the dynamical changes of  “heavy legs” symptom and eventually be very useful to assess the related claim support

Effects of Starch Incorporation on the Physicochemical Properties and Release Kinetics of Alginate-Based 3D Hydrogel Patches for Topical Delivery

The development of printable hydrogel inks for extrusion-based 3D printing is opening new possibilities to the production of new and/or improved pharmaceutical forms, specifically for topical application. Alginate and starch are natural polysaccharides that have been extensively exploited due to their biocompatibility, biodegradability, viscosity properties, low toxicity, and relatively low cost. This research work aimed to study the physicochemical and release kinetic effects of starch incorporation in alginate-based 3D hydrogel patches for topical delivery using a quality by design approach. The incorporation of a pregelatinized starch is also proposed as a way to improve the properties of the drug delivery system while maintaining the desired quality characteristics. Critical material attributes and process parameters were identified, and the sensitivity and adequacy of each parameter were statistically analyzed. The impact of alginate, starch, and CaCl2&middot;2H2O amounts on relevant quality attributes was estimated crosswise. The amount of starch revealed a synergetic impact on porosity (p = 0.0021). An evident increase in the size and quantity of open pores were detected in the as printed patches as well as after crosslinking (15.6 &plusmn; 5.2 &micro;m). In vitro drug release studies from the optimized alginate-starch 3D hydrogel patch, using the probe Rhodamine B, showed an initial high burst release, followed by a controlled release mechanism. The results obtained also showed that the viscoelastic properties, printing accuracy, gelation time, microstructure, and release rates can be modulated by varying the amount of starch added to the system. Furthermore, these results can be considered an excellent baseline for future drug release modulation strategies