A new potent natural antioxidant mixture provides global protection against oxidative skin cell damage.

Oxidative stress occurs when there is an over production of free radicals and cells are not able to neutralize them by their own antioxidant mechanisms. These excess of free radicals will attack cellular macromolecules leading to cell damage, function impairment or death. Because of that, antioxidant substances have been largely used in products to offer complementary protection. In this study a new mixture of three known antioxidants (cocoa, green tea and alpha-tocopherol) was evaluated and its antioxidant protection was assessed focusing on its capacity to protect main cell macromolecules. Results have shown that it has a high antioxidant capacity by protecting lipids, DNA and proteins against oxidative damage. The antioxidant effect of the mixture on cells was also investigated and it was able to reduce oxidative stress generated by lipopolisacharide in human fibroblasts. Finally, as the mixture has proved to be highly antioxidant, its effect on cell senescence was evaluated, and it was demonstrated that fibroblasts in culture had delayed senescence when treated with these actives on a mixture. All results together provide important data about a new antioxidant mixture that uses a small amount of actives and is able to protect cell against oxidative damages in a global way.

Flow cytometry as a tool in the evaluation of blood leukocyte function in Chelonia mydas (Linnaeus, 1758) (Testudines, Cheloniidae).

Chelonia mydas is a sea turtle that feeds and nests on the Brazilian coast and a disease called fibropapillomatosis is a threat to this species. Because of this, it is extremely necessary to determine a methodology that would enable the analysis of blood leukocyte function in these sea turtles. In order to achieve this aim, blood samples were collected from C. mydas with or without fibropapillomas captured on the São Paulo north coast. Blood samples were placed in tubes containing sodium heparin and were transported under refrigeration to the laboratory in sterile RPMI 1640 cell culture medium. Leukocytes were separated by density gradient using Ficoll-PaqueTM Plus, Amershan Biociences. The following stimuli were applied in the assessment of leukocyte function: Phorbol Miristate-Acetate (PMA) for oxidative burst activity evaluation and Zymosan A (Saccharomyces cerevisiae) Bio Particles, Alexa Fluor 594 conjugate for phagocytosis evaluation. Three cell populations were identified: heterophils, monocytes and lymphocytes. Monocytes were the cells responsible for phagocytosis and oxidative burst.

Flow cytometry as a tool in the evaluation of blood leukocyte function in Chelonia mydas (Linnaeus, 1758) (Testudines, Cheloniidae) / A citometria de fluxo como ferramenta para avaliar a função celular de leucócitos sangüíneos de Chelonia mydas (Testudines, Cheloniidae)

Chelonia mydas is a sea turtle that feeds and nests on the Brazilian coast and a disease called fibropapillomatosis is a threat to this species. Because of this, it is extremely necessary to determine a methodology that would enable the analysis of blood leukocyte function in these sea turtles. In order to achieve this aim, blood samples were collected from C. mydas with or without fibropapillomas captured on the São Paulo north coast. Blood samples were placed in tubes containing sodium heparin and were transported under refrigeration to the laboratory in sterile RPMI 1640 cell culture medium. Leukocytes were separated by density gradient using Ficoll-PaqueTM Plus, Amershan Biociences®. The following stimuli were applied in the assessment of leukocyte function: Phorbol Miristate-Acetate (PMA) for oxidative burst activity evaluation and Zymosan A (Saccharomyces cerevisiae) Bio Particles®, Alexa Fluor® 594 conjugate for phagocytosis evaluation. Three cell populations were identified: heterophils, monocytes and lymphocytes. Monocytes were the cells responsible for phagocytosis and oxidative burst.

Chelonia mydas é uma tartaruga marinha que freqüenta o litoral brasileiro para alimentação e nidificação e uma doença denominada fibropapilomatose é uma das mais importantes ameaças à sobrevivência dessa espécie. Desta forma, a definição de uma metodologia que permita analisar a função dos leucócitos sangüíneos torna-se extremamente necessária. Foram utilizadas amostras sangüíneas de C. mydas com e sem fibropapilomas capturadas no litoral norte do estado de São Paulo. As amostras sangüíneas foram colocadas em tubos contendo heparina sódica e transportadas em meio de cultura celular RPMI 1640 estéril e sob refrigeração. Os leucócitos foram obtidos por gradiente de densidade usando Ficoll-PaqueTM Plus, Amershan Biociences®. Os estímulos aplicados foram Miristato Acetato de Phorbol (PMA) para avaliação de burst oxidativo e Zymosan A (Saccharomyces cerevisiae) Bio Particles®, Alexa Fluor® 594 conjugate para avaliação de fagocitose. Foram identificadas três populações celulares: heterófilos, monócitos e linfócitos. Os monócitos foram as células responsáveis pela fagocitose e pelo burst oxidativo.

A vaccine against S. pyogenes: design and experimental immune response.

Streptococcus pyogenes causes severe invasive infections: the post-streptococcal sequelae of acute rheumatic fever (RF) and rheumatic heart disease (RHD), acute glomerulonephritis, and uncomplicated pharyngitis and pyoderma. Efforts to produce a vaccine against S. pyogenes began several decades ago, and different models have been proposed. Here, we describe the methodology used in the development of a new vaccine model, consisting of both T and B protective epitopes constructed as synthetic peptides and recombinant proteins. Two adjuvants were tested in an experimental inbred mouse model: a classical Freund's adjuvant and a new adjuvant (AFCo1) that induces mucosal immune responses and is obtained by calcium precipitation of a proteoliposome derived from the outer membrane of Neisseria meningitides B. The StreptInCor vaccine epitope co-administrated with AFCo1 adjuvant induced mucosal (IgA) and systemic (IgG) antibodies as preferential Th1-mediated immune responses. No autoimmune reactions were observed, suggesting that the vaccine epitope is safe.

Variations in behavior, innate immunity and host resistance to B16F10 melanoma growth in mice that present social stable hierarchical ranks.

The present study analyzed the effect of social stable hierarchical dominance/submissive relationships in C57BL/6 mice on behavior, innate immunity, serum corticosterone levels and host resistance to B16F10 melanoma growth. Adult mice (90 days old) kept in pairs since weaning, were analyzed for dominant/submissive ranking in three consecutive days according to the presence or absence of fighting and/or anticipatory submissive responses. Only the pairs of mice where dominant/submissive relationships were clearly stated were employed. Results showed that submissive mice presented in relation to dominants: (1) decreased time spent in the central open-field area; (2) decreased number of entries into the open arms and decreased time spent in the exploration of the open arms of the plus maze; (3) increased time spent in exploration of the plus-maze closed arms; (4) decreased number of entries and in the time spent in the exploration of the third part of the plus-maze open arms; (5) increased number of B16F10 metastasis in the lungs; (6) decreased NK cell cytotoxicity measured in vitro in the peripheral blood and spleen; (7) decreased basal but not in S. aureus induced oxidative burst in both neutrophils and monocytes and (8) similar basal serum levels of corticosterone. The present behavioral findings show that submissive mice, within a stable social hierarchy, present anxiety like-responses a fact that would make than more prone to stressful stimuli. This condition would be responsible for the decreases presently observed on basal neutrophil oxidative burst, NK cell activity and resistance to B16F10 tumor growth. Together the obtained data show that mice that present stable hierarchical relationships display neuro-immune alterations comparable to those reported in mice under a situation of chronic social stress.