RESUMO
BACKGROUND: Chronological skin aging causes the modification of genetic material through enzymes and proteins changes. The process reduces cellular proliferation, along with loss of tissue elasticity, reduced ability to regulate aqueous exchanges, and inefficient tissue replication. Appearance is negatively affected by cumulative changes in coloration, texture, and elasticity over time. The increase in the population's average life expectancy boosts the search for cosmetic therapies that can delay aging, mostly for the noninvasive modalities. Among the various options, radiofrequency therapy is a technique that can help reduce the effects of skin aging. AIM: Therefore, this study aims to review clinical evidence provided by scientific literature on the benefits of using radiofrequency therapy in reducing skin aging effects. METHODS: A review of the literature concerning skin aging, characteristics of radiofrequency therapy, and radiofrequency therapy in the treatment of skin laxity and mechanism of action was conducted using PubMed. RESULTS: The included studies have suggested that the mechanism of radiofrequency action is heating the dermis while preserving the epidermis. This heating causes immediate collagen denaturation, which is followed by the formation of new collagen, naturally providing skin tightening and greater elasticity. CONCLUSION: Even when used as single therapeutic modality, radiofrequency seems to meet the expectations in reducing the effects of skin aging.
Assuntos
Técnicas Cosméticas , Dermatologia/métodos , Medicina Baseada em Evidências/métodos , Terapia por Radiofrequência/métodos , Envelhecimento da Pele/efeitos da radiação , Colágeno/metabolismo , Derme/fisiologia , Derme/efeitos da radiação , Elasticidade/efeitos da radiação , Eletrodos , Epiderme/fisiologia , Epiderme/efeitos da radiação , Humanos , Desnaturação Proteica/efeitos da radiação , Terapia por Radiofrequência/instrumentação , Envelhecimento da Pele/fisiologia , Resultado do TratamentoRESUMO
High telomerase activity is always associated with actively dividing cells, however the detection of this activity in dividing Leishmania and Trypanosoma cruzi cells has always been disappointingly low. Recently, we have found that Leishmania major telomerase activity can be activated by heat, which combined with dilutions of the nuclear extracts produced an increase in activity comparable to cancer cells. Here we examined whether T. cruzi telomerase shares the same physicochemical properties of primer specificity and overall features of the L. major. Our studies revealed that no telomerase inhibitory factors were present in the nuclear lysates of T. cruzi however the enzyme was activated by heat and was very resilient to heat denaturation. We also showed the extension primer specificity, susceptibility to RNase-A and RNase-H digestion, and the effect of telomerase inhibitors.
Assuntos
Telomerase/metabolismo , Trypanosoma cruzi/enzimologia , Inibidores Enzimáticos/metabolismo , Estabilidade Enzimática , Temperatura Alta , Desnaturação Proteica/efeitos da radiação , Estabilidade Proteica , Ribonuclease H/metabolismo , Ribonuclease Pancreático/metabolismo , Especificidade por Substrato , Telomerase/antagonistas & inibidores , Telomerase/químicaRESUMO
Here we studied the telomerase activity of the human parasite Leishmania major. In this organism we have detected a high activity of this enzyme once several parameters such as heat activation, sequence of extension primer, and protein concentration are adjusted. The activity was not only heat activated, but also very resistant to heat denaturation. We believe L. major telomerase is an important activity and it may provide an adequate drug therapy target.
Assuntos
Temperatura Alta , Leishmania major/enzimologia , Leishmania major/efeitos da radiação , Proteínas de Protozoários/metabolismo , Telomerase/metabolismo , Animais , Desnaturação Proteica/efeitos da radiaçãoRESUMO
The conformational changes and aggregation process of beta-lactoglobulin (beta-LG) subjected to gamma irradiation are presented. Beta-LG in solutions of different protein concentrations (3 and 10 mg/ml) and in solid state with different water activities (a(w)) (0.22; 0.53; 0.74) was irradiated using a Cobalt-60 radiation source at dose level of 1-50 kGy. Small-angle X-ray scattering (SAXS) was used to study the conformational changes of beta-LG due to the irradiation treatment. The irradiated protein was also examined by high performance size exclusion chromatography (HPSEC) and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) under nonreducing and reducing conditions and fluorescence. SAXS analysis showed that the structural conformation of irradiated beta-LG in solid state at different a(w) and dose level was essentially the same as the nonirradiated beta-LG. The scattering data also showed that the irradiation of beta-LG in solution promoted the formation of oligomers. Interestingly, from the data analysis and model building, it could be shown that the formed oligomers are linear molecules, built by linear combinations of beta-LG dimers (tetramers, hexamers, etc). The formation of oligomers was also evidenced by SDS-PAGE analysis and HPSEC chromatograms, in which products with higher molecular mass than that of the dimeric beta-LG were detected. Formation of intermolecular cross-linking between tyrosyl radicals are proposed to be at least partially responsible for this occurrence. From the results it could be shown that the samples irradiated in solution presented some conformational changes under gamma irradiation, resulting in well ordered oligomers and aggregates formed by cross-linking of beta-LG dimers subunits, while the samples irradiated in the solid state were not modified.