Sistema de injeção em fluxo espectrofotométrico para monitorar peróxido de hidrogênio em processo de fotodegradação por reação foto-Fenton

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

Utilização de reações foto-Fenton na prevenção de contaminações agrícolas

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

Emprego de compostos organometálicos mononucleares de paládio(II) na ativação de macrófagos peritoneais de camundongos

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

Immunological and microbiological activity of Davilla elliptica St. Hill. (Dilleniaceae) against Mycobacterium tuberculosis

Mycobacterium tuberculosis is responsible for over 8 million cases of tuberculosis (TB) annually. Natural products may play important roles in the chemotherapy of TB. The immunological activity of Davilla elliptica chloroform extract (DECE) was evaluated in vitro by the determination of hydrogen peroxide (H2O2), nitric oxide (NO), and tumor necrosis factor-alpha (TNF-alpha) release in peritoneal macrophages cultures. DECE was also tested for its antimycobacterial activity against M. tuberculosis using the microplate alamar blue assay. DECE (50, 150, 250 µg/ml) stimulated the production of H2O2 (from 1,79 ± 0,23 to 7,27 ± 2,54; 15,02 ± 2,86; 20,5 ± 2,1 nmols) (means ± SD), NO (from 2,64 ± 1,02 to 25,59 ± 2,29; 26,68 ± 2,41; 29,45 ± 5,87 µmols) (means ± SD) and TNF-alpha (from 2,44 ± 1,46 to 30,37 ± 8,13; 38,68 ± 1,59; 41,6 ± 0,90 units/ml) (means ± SD) in a dose-dependent manner and also showed a promising antimycobacterial activity with a minimum inhibitory concentration of 62,5 µg/ml. This plant may have therapeutic potential in the immunological and microbiological control of TB.

Peróxido de hidrogênio: importância e determinação

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

Estudo da aplicação do processo foto-Fenton solar na degradação de efluentes de indústria de tintas

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

Uso de reações de fenton na remediação de solo contaminado com p,p´ DDT

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

Estudo do comportamento eletroquímico da enzima peroxidase na presença de peróxido de hidrogênio e ácido 5-aminossalicílico

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

Photo-Fenton process for treating biological laboratory wastewater containing formaldehyde

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

Prevalência e caracterização de espécies de lactobacilos vaginais em mulheres em idade reprodutiva sem vulvovaginites

OBJETIVO: identificar espécies de lactobacilos isolados do conteúdo vaginal de mulheres saudáveis e assintomáticas; determinar as espécies mais prevalentes e caracterizá-las fenotipicamente. MÉTODOS: lactobacilos foram isolados em meio seletivo a partir de amostras de conteúdo vaginal de 135 mulheres, sem queixa de corrimento e com diagnóstico laboratorial negativo para infecções vaginais, acompanhadas em um ambulatório de Planejamento Familiar. Os isolados foram identificados por PCR multiplex e, quando necessário, submetidos ao sequenciamento do gene RNAr 16S. Foram também avaliados quanto à acidificação do meio de cultura, à produção de ácido láctico, de H2O2, bacteriocinas e a capacidade de adesão às células epiteliais. RESULTADOS: oitenta e três cepas de lactobacilos foram isoladas e identificadas, sendo as espécies predominantes L. crispatus (30,1%), L. jensenii (26,5%), L. gasseri (22,9%) e L. vaginalis (8,4%). Apenas 20 destes isolados não produziram H2O2 em quantidades detectáveis. Das 37 linhagens selecionadas para teste de adesão a células epiteliais, 12 apresentaram adesão entre 50 a 69%, 10 apresentaram 70% ou mais, e as restantes pouca ou nenhuma adesão. Nenhum dos isolados produziu bacteriocinas. CONCLUSÕES: as espécies de lactobacilos mais prevalentes em mulheres sem vulvovaginites, isoladas em meio de cultura seletivo e identificadas por métodos moleculares, foram L. crispatus, L. jensenii e L. gasseri. Além de mais frequentes, tais linhagens também apresentaram melhor produção de H2O2 e atingiram menores valores de pH em meio de cultura.

Macrophage activation by Paepalanthus spp. extracts

Macrófagos são conhecidos por exercerem uma importante função de mecanismo de defesa quando estas células são estimuladas com produtos naturais e produtos bacterianos (dentre outros). Uma variedade de citocinas e compostos químicos são liberados para induzir sistema de defesa fundamental. Entre outros peróxido de hidrogênio (H2O2) tem sido identificado como moléculas tendo multifunções. Entretanto está bem estabelecido que (H2O2) está envolvido em inúmeros processos fisiológicos, como por exemplo, neurotransmissão, relaxamento da musculatura lisa ou regulação imune. Para a determinação de peróxido de hidrogênio (H2O2) em macrófago peritoneal em camundongos, determinou-se a ação imunomodulatória de extratos (etanólico e etanólico 70%) obtidos de quatro espécies do gênero Paepalanthus (Eriocaulaceae) na concentração de 10 mg/mL. Os estratos etanólicos 70 % de capítulos de P. Hilairei, P. robustus, P. vellozioides e P. speciocus apresentaram maior liberação de (H2O2) do que os outros extratos etanólicos.

Chloroquine is therapeutic in murine experimental model of paracoccidioidomycosis

Chloroquine, due to its basic properties, has been shown to prevent the release of iron from holotransferrin, thereby interfering with normal iron metabolism in a variety of cell types. We have studied the effects of chloroquine on the evolution of experimental paracoccidioidomycosis by evaluating the viable fungal recovery from lung, liver and spleen from infected mice and H2O2, NO production, tumor necrosis factor-alpha (TNF-alpha), interleukin (IL)-6, IL-10 levels and transferrin receptor (TfR) expression from uninfected and infected peritoneal macrophages. Chloroquine caused a significant decrease in the viable fungal recovery from all organs tested, during all periods of evaluation. Peritoneal macrophages from chloroquine-treated infected mice showed higher H2O2 production and TfR expression, and decreased levels of NO, endogenous and stimulated-TNF-alpha, IL-6 and IL-10 during the three evaluated periods. However, despite its suppressor effects on the macrophage function, the chloroquine therapeutic effect upon murine paracoccidioidomycosis was probably due to its effect on iron metabolism, blocking iron uptake by cells, and consequently restricting iron to fungus growth and survival.

EFFECT OF THE ADDITION OF CR AND NB ON THE MICROSTRUCTURE AND ELECTROCHEMICAL CORROSION OF HEAT-TREATABLE AL-ZN-MG ALLOYS

The effect of the addition of Cr and Nb on the microstructure and the electrochemical corrosion of the weldable, high-strength and stress corrosion cracking (SCC) resistant Al-5%Zn-1.67%Mg-0.23%Cu alloy (H) has been studied. Combined additions of the alloying elements, J (with Nb), L (with Cr) and O (with Cr and Nb) and different heat treatments, ST (cold-rolled), A (annealed), F (quenched), B (quenched and aged) and C (quenched in two steps and aged), to obtain different microstructures and hardness have been performed. To correlate the electrochemical corrosion with the microstructure of the specimens, corrosion potential (E(cor)) measurements in different chloride solutions were performed and optical microscopy, SEM, TEM and EDX were applied. In chloride solutions containing dissolved O-2 or H2O2, the present alloys were polarized up to the pitting attack. It was shown that the E(cor) measurements were very sensitive to the alloy composition and heat treatment, increasing in the order H < J < L < O < Al (for a given heat treatment) and F < A approximate to ST < B < C (for a given alloy). The MgZn2 precipitates of the annealed (A) and cold-rolled (ST) specimens were dissolved in chloride solutions containing oxidizing agents and pitting attack was shown to develop in the cavities where the precipitates were present. In the specimens B and C, the compositions of the precipitate free zones was found to be equal to that of the matrix solid solution and preferential intergranular attack was not evident, this being in agreement with their SCC resistance. The addition of Cr and Nb increased the pitting corrosion resistance. The effects of Cr and Nb were additive, that of Cr being predominant, either, in the E(cor) shift or in the increase in the pitting corrosion resistance.

Study of pulmonary experimental paracoccidioidomycosis by analysis of bronchoalveolar lavage cells: Resistant vs. susceptible mice

Adult Swiss (susceptible) and BALB/c (non-susceptible) mice were inoculated by the intravenous route with 1 x 10(6) yeast cells of Paracoccidioides brasiliensis, strain 18. Immunologic parameters, histopathology and features of the bronchoalveolar lavage (BAL) were evaluated at week 2, 4, 8 and 16 post-infection. The pulmonary infection was progressive in Swiss mice and regressive in BALB/c mice. The numbers of total cells, lymphocytes and polymorphonuclear neutrophils increased in BAL, as well as the percentages of giant cells, and CD4 and CD8 positive cells. The ultrastructural study of BAL cells revealed a predominance of macrophages and a frequency of 13.2% of type II pneumocytes. As the infection progressed, the number of fungal cells and spreading macrophages, as well as the stimulated release of H2O2 by macrophages, increased. The animals exhibited an exacerbation of the humoral immune response and a depression of cellular immunity during the infection. There was a good correlation between the intensity and the pattern of the pulmonary histopathology and the cellular findings in the BAL. The present model reproduces some anatomoclinical patterns of the human disease and shows that BAL may be a useful tool in monitoring the pulmonary infection caused by P. brasiliensis.

Spectrophotometric determination of formaldehyde with chromotropic acid in phosphoric acid medium assisted by microwave oven

In the present study. a spectrophotometric method for the determination of formaldehyde by using chromotropic acid was devised. in which the use of potentially hazardous and corrosive concentrated sulfuric acid was eliminated and advantageously C replaced by a mixture of H, concentrated H3PO4 and H2O2. The reaction between formaldehyde and chromotropic acid (CA) in a cone phosphoric acid medium was accelerate by irradiating the mixture with microwave energy for 35 s (1100 W), producing a violetred compound (lambda(max)=570 nm). Beer's Law is obeyed in a concentration range of 0.8-4.8 mg 1(-1) of formaldehyde with a good correlation coefficient (r = 0.9968). The proposed method was applied in the analysis of formaldehyde in commercial disinfectants. Recoveries were within 98.0-100.4%, with standard deviations ranging from 0.03 to 0.13%. (C) 2003 Elsevier B.V All rights reserved.