935 resultados para Skin elasticity


Relevância:

70.00% 70.00%

Publicador:

Resumo:

Purpose: To formulate stable water in oil (W/O) emulsion containing hydroalcoholic crude extract of Ziziphus mauritiana leaves for skin rejuvenation. Methods: Placebo (base) without any plant extract and formulation with 4 % Ziziphus mauritiana extract were prepared by mixing. Samples of the emulsions were subjected to varying storage conditions, i.e., 8, 25, 40 oC and 40 oC + 75 % relative humidity for a period of 4 weeks to predict their stability. During this period, stability parameters, including liquefaction, phase separation, color, electrical conductivity, centrifugation and pH were monitored at specified time intervals. Skin rejuvenation was evaluated using 13 healthy human volunteers over a period of 8 weeks. During this period, various skin parameters such as erythema, melanin level, moisture content, elasticity and sebum content of the skin were evaluated at specified intervals. Results: Both the active formulation and placebo were stable in terms of liquifaction, phase separation and color at all the storage conditions of temperature and humidity. Active formulation showed statistically significant (p < 0.05) improvement in skin melanin as well as in skin moisture and sebum levels, whereas these properties were reduced or even absent in the placebo formulation (p > 0.05). Both active and placebo formulations changed skin elasticity and erythema significantly (p < 0.05). Conclusion: It is evident from the findings that the leaf extract of Ziziphus mauritiana possesses antiaging properties as well as exert skin lightening, moisturizing and viscoelastic effects on human skin.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Pentoxifylline (PTF), a methylxanthine derivative, has therapeutic use as an antifibrotic agent. In vitro, PTF inhibits the production of collagen and reduces the proliferation of fibroblasts in hypertrophic scars. This study aimed to evaluate changes in the elasticity of hypertrophic scars in the peribuccal area in burned patients, who presented with mouth-opening limitation. Eighteen patients were divided into two groups. The case group (n = 10) was treated with PTF 1 mg ml(-1), while in the control group (n = 8) no treatment was performed. Measurements of mouth opening (lip-to-lip and tooth-to-tooth distances in mm) were taken, before and after five therapeutic sessions with pentoxifylline with weekly intervals. The variations of these measures (Delta%) were calculated and submitted to statistical analyses. There was a significant improvement in the opening of the mouth, in vermilion distance (V = 3.20 mm) as much as the dental distance (DD = 4.19 mm) in the treated group, than in the control group. It was noted that pentoxifylline increases the elasticity of hypertrophic scars in the perioral area. (C) 2009 Elsevier Ltd and ISBI. All rights reserved.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Topical retinoids are used to treat photoaging; oral isotretinoin is gold standard for acne; off label indications, including photoaging, have been reported with insufficient evidence of efficacy. This is a randomized controlled phase II trial with clinical and histological assessment to evaluate efficacy and safety of oral isotretinoin for photoaging. Study population was comprised of 32 menopausal or sterilized women, aged 40-55, divided in 2 groups: A (21) received 20mg isotretinoin, 3 times per week, nightly moisturizer, and daily sunscreen, for three months; B (11) just moisturizer/sunscreen. Main outcome measures were: overall clinical assessment; profilometry, corneometer and elasticity tests in periocular regions and left forearm; before/after biopsies from left forearm in patients of B and in 10 randomly selected of A. Microscopic blinded evaluation of epidermal thickness, dermal elastosis, new collagen, p53 epidermal expression was performed by quantitative digital image analysis. All data were submitted to statistical analysis. Clinical evaluation showed slight improvement; profilometry, corneometer and skin elasticity tests presented significant difference in pre/post values (P = 0.001 to 0.028), but no differences between A/B. Histological findings and p53 expression were comparable between groups before treatment (P > 0.1); microscopic analysis showed no differences between groups for most variables, after treatment. Slight but significant difference between A/B for p53 with major reduction post isotretinoin [0.66±0.31 vs. 0.94±0.34 respectively (P = 0.04) was observed. There were minor side effects and no significant laboratory test alterations. We concluded that no significant clinical, microscopic changes but p53 epidermal expression reduction were observed. The role of ultra-violet induced p53 mutation in skin carcinogenesis reinforces retinoids chemoprevention. Oral isotretinoin seemed safe but not effective to treat photoaging. Caution should be considered for women prone to pregnancy. Further controlled studies are necessary. © 2010 The International Society of Dermatology.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Ablative procedures that are used for the improvement of a degenerative process that leads to a loss of skin elasticity and integrity, injure or destroy the epidermis and its basement membrane and lead to fibrosis of the papillary dermis. It was recently shown in clinical and laboratory trials that percutaneous collagen induction (PCI) by multiple needle application is a method for safely treating wrinkles and scars and smoothening the skin without the risk of dyspigmentation. In our study, we describe the effect of PCI on epidermal thickness and the induction of genes relevant for regenerative processes in the skin in a small animal model.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Dissertação (mestrado)—Universidade de Brasília, Faculdade de Ciências da Saúde, Programa de Pós-Graduação em Ciências da Saúde, 2012.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Using liposomes to deliver drugs to and through human skin is controversial, as their function varies with type and composition. Thus they may act as drug carriers controlling release of the medicinal agent. Alternatively, they may provide a localized depot in the skin so minimizing systemic effects or can be used for targeting delivery to skin appendages (hair follicles and sweat glands). Liposomes may also enhance transdermal drug delivery, increasing systemic drug concentrations. With such a multiplicity of functions, it is not surprising that mechanisms of liposomal delivery of therapeutic agents to and through the skin are unclear. Accordingly, this article provides an overview of the modes and mechanisms of action of different vesicles as drug delivery vectors in human skin. Our conclusion is that vesicles, depending on the composition and method of preparation, can vary with respect to size, lamellarity, charge, membrane fluidity or elasticity and drug entrapment. This variability allows for multiple functions ranging from local to transdermal effects. Application to dissimilar skins (animal or human) via diverse protocols may reveal different mechanisms of action with possible vesicle skin penetration reaching different depths, from surface assimilation to (rarely) the viable tissue and subsequent systemic absorption.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Cryosurgery is an efficient therapeutic technique used to treat benign and malignant cutaneous diseases. The primary active mechanism of cryosurgery is related to vascular effects on treated tissue. After a cryosurgical procedure, exuberant granulation tissue is formed at the injection site, probably as a result of angiogenic stimulation of the cryogen and inflammatory response, particularly in endothelial cells. To evaluate the angiogenic effects of freezing, as part of the phenomenon of healing rat skin subjected to previous injury. Two incisions were made in each of the twenty rats, which were divided randomly into two groups of ten. After 3 days, cryosurgery with liquid nitrogen was performed in one of incisions. The rats' samples were then collected, cut and stained to conduct histopathological examination, to assess the local angiogenesis in differing moments and situations. It was possible to demonstrate that cryosurgery, in spite of promoting cell death and accentuated local inflammation soon after its application, induces quicker cell proliferation in the affected tissue and maintenance of this rate in a second phase, than in tissue healing without this procedure. These findings, together with the knowledge that there is a direct relationship between mononuclear cells and neovascularization (the development of a rich system of new vessels in injury caused by cold), suggest that cryosurgery possesses angiogenic stimulus, even though complete healing takes longer to occur. The significance level for statistical tests was 5% (p<0,05).

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Bologna-type sausages were produced with 50% of their pork back-fat content replaced with gels elaborated with different ratios of pork skin, water, and amorphous cellulose (1:1:0, 1:1:0.1, 1:1:0.2, 1:1:0.3, and 1:1:0.4). The impact of such replacement on the physico-chemical characteristics and the consumer sensory profiling was evaluated. The modified treatments had 42% less fat, 18% more protein, and 8% more moisture than the control group. Treatments with amorphous cellulose had a lower cooking loss and higher emulsion stability. High amorphous cellulose content (1:1:0.3 and 1:1:0.4) increased hardness, gumminess, and chewiness. The gel formulated with the ratio of 1:1:0.2 (pork skin: water: amorphous cellulose gel) provided a sensory sensation similar to that provided by fat and allowed products of good acceptance to be obtained. Therefore, a combination of pork skin and amorphous cellulose is useful in improving technological quality and producing healthier and sensory acceptable bologna-type sausages.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Solar radiation, especially ultraviolet A (UVA) and ultraviolet B (UVB), can cause damage to the human body, and exposure to the radiation may vary according to the geographical location, time of year and other factors. The effects of UVA and UVB radiation on organisms range from erythema formation, through tanning and reduced synthesis of macromolecules such as collagen and elastin, to carcinogenic DNA mutations. Some studies suggest that, in addition to the radiation emitted by the sun, artificial sources of radiation, such as commercial lamps, can also generate small amounts of UVA and UVB radiation. Depending on the source intensity and on the distance from the source, this radiation can be harmful to photosensitive individuals. In healthy subjects, the evidence on the danger of this radiation is still far from conclusive.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The aim of this study was to evaluate the following acrylic resins: Clássico®, QC-20® and Lucitone®, recommended specifically for thermal polymerization, and Acron MC® and VIPI-WAVE®, made for polymerization by microwave energy. The resins were evaluated regarding their surface nanohardness and modulus of elasticity, while varying the polymerization time recommended by the manufacturer. They were also compared as to the presence of water absorbed by the samples. The technique used was nanoindentation, using the Nano Indenter XP®, MTS. According to an intra-group analysis, when using the polymerization time recommended by the manufacturer, a variation of 0.14 to 0.23 GPa for nanohardness and 2.61 to 3.73 GPa for modulus of elasticity was observed for the thermally polymerized resins. The variation for the resins made for polymerization by microwave energy was 0.15 to 0.22 GPa for nanohardness and 2.94 to 3.73 GPa for modulus of elasticity. The conclusion was that the Classico® resin presented higher nanohardness and higher modulus of elasticity values when compared to those of the same group, while Acron MC® presented the highest values for the same characteristics when compared to those of the same group. The water absorption evaluation showed that all the thermal polymerization resins, except for Lucitone®, presented significant nanohardness differences when submitted to dehydration or rehydration, while only Acron MC® presented no significant differences when submitted to a double polymerization time. Regarding the modulus of elasticity, it was observed that all the tested materials and products, except for Lucitone®, showed a significant increase in modulus of elasticity when submitted to a lack of hydration.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In this work, the modifications promoted by alkaline hydrolysis and glutaraldehyde (GA) crosslinking on type I collagen found in porcine skin have been studied. Collagen matrices were obtained from the alkaline hydrolysis of porcine skin, with subsequent GA crosslinking in different concentrations and reaction times. The elastin content determination showed that independent of the treatment, elastin was present in the matrices. Results obtained from in vitro trypsin degradation indicated that with the increase of GA concentration and reaction time, the degradation rate decreased. From thermogravimetry and differential scanning calorimetry analysis it can be observed that the collagen in the matrices becomes more resistant to thermal degradation as a consequence of the increasing crosslink degree. Scanning electron microscopy analysis indicated that after the GA crosslinking, collagen fibers become more organized and well-defined. Therefore, the preparations of porcine skin matrices with different degradation rates, which can be used in soft tissue reconstruction, are viable.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

There is a considerable debate about the potential influence of fetal programming on cardiovascular diseases in adulthood. In the present prospective epidemiological cohort study, the relationship between birthweight and arterial elasticity in 472 children between 5 and 8 years of age was assessed. LAEI (large artery elasticity index), SAEI (small artery elasticity index) and BP (blood pressure) were assessed using the HDI/PulseWave CR-2000 CardioVascular Profiling System. Blood concentrations of glucose, total cholesterol and its fractions [LDL (low-density lipoprotein)-cholesterol and HDL (high-density lipoprotein)-cholesterol] and triacylglycerols (triglycerides) were determined by automated enzymatic methods. Insulin was assessed by a chemiluminescent method, insulin resistance by HOMA (homoeostasis model assessment) and CRP (C-reactive protein) by immunonephelometry. Two linear regression models were applied to investigate the relationship between the outcomes, LAEI and SAEI, and the following variables: birthweight, gestational age, glucose, LDL-cholesterol, HDL-cholesterol, triacylglycerols, insulin, CRP, HOMA, age, gender, waist circumference, per capita income, SBP (systolic BP) and DBP (diastolic BP). LAEI was positively associated with birthweight (P=0.036), waist circumference (P<0.001) and age (P<0.001), and negatively associated with CRP (P=0.024) and SBP (P<0.001). SAEI was positively associated with birthweight (P=0.04), waist circumference (P=0.001) and age (P<0.001), and negatively associated with DBP (P<0.001). Arterial elasticity was decreased in apparently healthy children who had lower birthweights, indicating an earlier atherogenetic susceptibility to cardiovascular diseases in adolescence and adult life. Possible explanations for the results include changes in angiogenesis during critical phases of intrauterine life caused by periods of fetal growth inhibition and local haemodynamic anomalies