Aline Soares Freire

Murine lung injury caused by Leptospira interrogans glycolipoprotein, a specific Na/K-ATPase inhibitor

BackgroundLeptospiral glycolipoprotein (GLP) is a potent and specific Na/K-ATPase inhibitor. Severe pulmonary form of leptospirosis is characterized by edema, inflammation and intra-alveolar hemorrhage having a dismal prognosis. Resolution of edema and inflammation determines the outcome of lung injury. Na/K-ATPase activity is responsible for edema clearance. This enzyme works as a cell receptor that triggers activation of mitogen-activated protein kinase (MAPK) intracellular signaling pathway. Therefore, injection of GLP into lungs induces injury by triggering inflammation.MethodsWe injected GLP and ouabain, into mice lungs and compared their effects. Bronchoalveolar lavage fluid (BALF) was collected for cell and lipid body counting and measurement of protein and lipid mediators (PGE2 and LTB4). The levels of the IL-6, TNFα, IL-1B and MIP-1α were also quantified. Lung images illustrate the injury and whole-body plethysmography was performed to assay lung function. We used Toll-like receptor 4 (TLR4) knockout mice to evaluate leptospiral GLP-induced lung injury. Na/K-ATPase activity was determined in lung cells by nonradioactive rubidium incorporation. We analyzed MAPK p38 activation in lung and in epithelial and endothelial cells.ResultsLeptospiral GLP and ouabain induced lung edema, cell migration and activation, production of lipid mediators and cytokines and hemorrhage. They induced lung function alterations and inhibited rubidium incorporation. Using TLR4 knockout mice, we showed that the GLP action was not dependent on TLR4 activation. GLP activated of p38 and enhanced cytokine production in cell cultures which was reversed by a selective p38 inhibitor.ConclusionsGLP and ouabain induced lung injury, as evidenced by increased lung inflammation and hemorrhage. To our knowledge, this is the first report showing GLP induces lung injury. GLP and ouabain are Na/K-ATPase targets, triggering intracellular signaling pathways. We showed p38 activation by GLP-induced lung injury, which was may be linked to Na/K-ATPase inhibition. Lung inflammation induced by GLP was not dependent on TLR4 activation.

Total zinc quantification by inductively coupled plasma-mass spectrometry and its speciation by size exclusion chromatography–inductively coupled plasma-mass spectrometry in human milk and commercial formulas: Importance in infant nutrition

This paper summarises results of zinc content and its speciation in human milk from mothers of preterm and full-term infants at different stages of lactation and from synthetic formula milks. Human milk samples (colostrum, 7th, 14th, and 28th day after delivery) from Spanish and Brazilian mothers of preterm and full-term infants (and also formula milks) were collected. After adequate treatment of the sample, total Zn was determined, while speciation analysis of the Zn was accomplished by size exclusion chromatography coupled online with the ICP-MS. It is observed that total zinc content in human milk decreases continuously during the first month of lactation, both for preterm and full term gestations. All infant formulas analysed for total Zn were within the currently legislated levels. For Zn speciation analysis, there were no differences between preterm and full term human milk samples. Moreover Zn species elute mainly associated with immunoglobulins and citrate in human milk whey. Interestingly the speciation in formula milk whey turned out to be completely different as the observed Zn(2+) was bound almost exclusively to low molecular weight ligands (citrate) and only comparatively very low amounts of the metal appeared to be associated with higher mass biomolecules (e.g. proteins).

Sediment quality in a metal-contaminated tropical bay assessed with a multiple lines of evidence approach

A sediment quality assessment was performed near to the main industrial source of metal contamination in Sepetiba Bay, Brazil, which represents one of the worst cases of trace metal contamination reported for coastal areas. Acute and chronic toxicity tests, benthic fauna community analysis and metal bioavailability evaluations were applied to identify risks to the benthic community. Significant amphipod mortality was observed close to the major pollution source and lower copepod fertility was observed for all stations. Equilibrium-partitioning and biotic-ligand models to predict pore water metal toxicity, which were based on acid-volatile sulfide (AVS) and organic carbon fraction (fOC) normalization approaches, suggested that metals are not likely to be available in sediment pore water. However, Cd, Pb and Zn concentrations were mainly (>50%) weakly bound to sediments, suggesting high potential bioavailability. Linking the chemical results with ecotoxicological responses, we observed that sediment-feeding organisms presented acute and chronic toxicities that were positively correlated to the metal concentrations in the sediments. Additionally, benthic fauna composition was dominated by tolerant species, revealing a trophic structure response to environmental contamination. These results reinforce the necessity of a multiple lines of evidence approach to establish sediment quality and to support environmental management decisions that are based on observed effects and potential extrapolation scenarios into the future.

Na/K-ATPase assay in the intact mice lung subjected to perfusion

BackgroundAmong the characteristics of acute respiratory distress syndrome (ARDS) is edema formation and its resolution depends on pneumocyte Na/K-ATPase activity. Increased concentration of oleic acid (OA) in plasma induces lung injury by targeting Na/K-ATPase and, thus, interfering in sodium transport.FindingsPresently, we adapted a radioactivity-free assay to detect Na/K-ATPase activity in perfused lung mice, comparing the inhibitory effect of ouabain and OA. We managed to perfuse only the lung, avoiding the systemic loss of rubidium. Rb+ incorporation into lung was measured by inductively coupled plasma optical emission spectrometry (ICP OES) technique, after lung tissue digestion. Na/K-ATPase activity was the difference between Rb+ incorporation with or without ouabain. Lung Na/K-ATPase was completely inhibited by perfusion with ouabain. However, OA caused a partial inhibition.ConclusionsIn the present work the amount of incorporated Rb+ was greater than seen in our previous report, showing that the present technique is trustworthy. This new proposed assay may allow researchers to study the importance of Na/K-ATPase activity in lung pathophysiology.

Use of Functionalized Resin for Matrix Separation and Trace Elements Determination in Petroleum Produced Formation Water byInductively Coupled Plasma Mass Spectrometry

This work approaches the development of a procedure for separation and determination of five trace metals (Co, Cd, Pb, Ni, and Cu) from petroleum produced formation water. This procedure uses a styrene divinyl-benzene polymeric resin modified with 4-(5′-bromo-2′-tiazolilazo) orcinol, and the determination was performed by inductively coupled plasma mass spectrometry. A response surface methodology using a Doehlert matrix was used to optimize the solid-phase extraction of the studied elements. By using 50.0 mL of sample solution for separation/preconcentration, limits of quantification of 2.4, 14, 10, 11, and 350 ng L− 1 were obtained for Co, Cd, Pb, Ni, and Cu, respectively. The developed procedure was applied for determination of these trace elements in produced formation water from offshore platforms in the Brazilian Northeast.

Biogeochemical factors controlling arsenic distribution in a densely populated tropical estuary (Guanabara Bay, RJ, Brazil)

The preferential arsenic (As) accumulation in the central sector of the Guanabara Bay (a heavily impacted coastal system located in SE Brazil) is different from most metal contaminants, which present higher concentrations at harbour areas and the rivers mouths that drain large areas with highly deficient pollution control. The estuary is characterised by organic contents and minerals gradients, which induce different redox conditions and different biogeochemical process. Elemental and isotopic analyses on bulk organic matter, mineralogical and textural analyses of sediments were conjugated with a three-step sequential extraction procedure, based on the BCR method (Community Bureau of Reference). This approach was used to evaluate the potential of arsenic mobility. The distribution of the sum of arsenic in the three fractions presented a significant positive correlation with manganese mainly in the oxidised fraction (F2), which corresponded to the most representative fraction conditioned by physicochemical processes. In the exchangeable fraction (F1), which represents the most reactive arsenic phase, this element seems to be associated with the labile organic matter. The high productivity in the central sector might result in a greater deposition of arsenic in the sediment through co-precipitation with manganese deposition in an oxidising environment. Organic matter and sulphide in reducing environments were also found to be important factors controlling the distribution and speciation of arsenic, as indicated by the oxidizable fraction (F3) data.

Monitoring bone changes due to calcium, magnesium, and phosphorus loss in rat femurs using Quantitative Ultrasound

Bone mineral density is an important parameter for the diagnosis of bone diseases, as well as for predicting fractures and treatment monitoring. Thus, the aim of the present study was to evaluate the potential of Quantitative Ultrasound (QUS) to monitor bone changes after calcium, phosphorus, and magnesium loss in rat femurs in vitro during a demineralization process. Four quantitative ultrasound parameters were estimated from bone surface echoes in eight femur diaphysis of rats. The echo signals were acquired during a decalcification process by Ethylenediaminetetraacetic Acid (EDTA). The results were compared to Quantitative Computed Tomography (QCT) and inductively coupled plasma optical emission spectrometry measurements for validation. Integrated Reflection Coefficient (IRC) reflection parameters and Frequency Slope of Reflection Transfer Function (FSRTF) during demineralization tended to decrease, while the backscattering parameter Apparent Integrated Backscatter (AIB) increased and Frequency Slope of Apparent Backscatter (FSAB) showed an oscillatory behavior with no defined trend. Results indicate a clear relation between demineralization and the corresponding decrease in the reflection parameters and increase in the scattering parameters. The trend analysis of the fall curve of the chemical elements showed a better relationship between IRC and QCT. It was possible to monitor bone changes after ions losses, through the QUS. Thus, it is an indication that the proposed protocol has potential to characterize bone tissue in animal models, providing consistent results towards standardization of bone characterization studies by QUS endorsing its use in humans.

Metal Bioavailability in Contaminated Estuarine Sediments from a Highly-Impacted Tropical Bay

The aim of this study is to assess possible spatial variability of trace metal (Cd, Cu, Pb and Zn) bioavailability along the main channel of a highly eutrophic tropical estuary (Iguaçu River estuary, Guanabara Bay, Brazil). Metal potentially-bioavailable concentrations (soluble in 1 mol L -1 HCl) and strongly-bound concentrations (soluble in concentrated HNO3) were sequentially extracted and determined by a Coupled Plasma Optical Emission Spectrometry (ICP OES). These sediments generally have high trace metal contents associated to weakly-bound fractions, while Zn was the most bioavailable metal (approximately 83% of Zn concentrations were weakly-bound to sediments) while Cu showed the greatest heterogeneity of proportion between weaklyand strongly-bound fractions. The employed sampling strategy combined results from sediments taken along and across the estuarine channel, evidencing that care is required when using only a single sampling transect along estuarine channels, particularly for metals sensitive to changes in geochemical partitioning during sediment transport and redistribution, as evidenced by the Cu concentrations in this work.

Avaliação do risco ambiental e comportamento geoquímico de metais em área impactada por resíduos industriais em Queimados (RJ).

Areas contaminadas por metais podem configurar serio risco a saude publica e ao meio ambiente. No final da decada de 1980 foi instalado um patio de estocagem provisoria de residuos industriais perigosos na area da empresa Centro Tecnologico de Residuos (CENTRES), no municipio de Queimados, RJ. A gestao inadequada destes residuos proporcionou um grande impacto ambiental ao solo da regiao. Entao, em 2009 foram amostrados solos desta empresa para que fossem avaliadas a mobilidade, toxicidade, biodisponibilidade e risco ambiental de Cd, Cr, Cu, Ni, Pb e Zn utilizando extracao sequencial para o fracionamento geoquimico (BCR), determinando-se as concentracoes destes metais por ICP OES. A soma de todas as fracoes geoquimicas mostraram que a amostra P1 e severamente contaminada por Zn, que as amostras P5 e P5.1 sao contaminadas por Cu, Ni, Pb e Zn, que a amostra P5.2 e contaminada por Ni, Pb e Zn e que a amostra P6 possui concentracoes de Ni que ultrapassam o valor de investigacao industrial preconizado pela legislacao brasileira. Geralmente, o Cd, o Ni e o Zn se mostraram como os metais mais moveis, devido ao enriquecimento das suas concentracoes na fracao soluvel e trocavel do solo (F1). O Pb so se mostrou altamente soluvel e trocavel em amostras de solos que foram severamente contaminadas com este metal. Por outro lado, o Cu e o Cr se mostraram pouco moveis, preferindo estar adsorvidos a fracao oxidavel do solo (F3) ou ao residuo (R) que contem a matriz silicatica e oxi-hidroxidos de alta cristalinidade. Finalmente, o codigo de avaliacao de risco (RAC) se mostrou uma ferramenta limitada ao superestimar o risco ambiental do Cd e do Ni e subestimar o do Cu.

AVALIAÇÃO DA APLICABILIDADE DE ÍNDICES DE POLUIÇÃO AQUÁTICA: ESTUDO DE CASO NO RIO PARAIBUNA (JUIZ DE FORA, MG, BRASIL)

Aguas superficiais contaminadas por metais podem configurar serio risco a saude publica e ao meio ambiente. A introducao descontrolada de varios poluentes no ambiente aquatico e atualmente um problema prioritario para a preservacao de fontes de agua potavel em muitos paises ao redor do mundo, inclusive no Brasil. A cidade de Juiz de Fora possui uma longa tradicao industrial, merecendo destaque a existencia de curtumes e de uma metalurgica que despejam efluentes sem tratamentos adequados nos corregos e rios da regiao. Uma avaliacao comparativa de diferentes parâmetros de forma isolada fornece apenas uma ideia limitada da poluicao com referencia aquele parâmetro em particular. Por isso, nos ultimos anos tem crescido o interesse pelo uso de indices de poluicao que integrem a influencia de diferentes parâmetros simultaneamente. O objetivo deste estudo foi avaliar o atual status da poluicao nas aguas superficiais de um trecho industrial do rio Paraibuna, na cidade de Juiz de Fora (MG) e determinar a aplicabilidade e as limitacoes de dois indices de poluicao aquaticos bem documentados. No presente trabalho, os resultados obtidos foram estatisticamente tratados e revelaram que as concentracoes de Ca, Cd, Cu, Mn, Na e Zn excediam muito os valores maximos permissiveis para alguns pontos amostrados tornando-os inserviveis ao consumo humano e a manutencao de uma adequada qualidade ambiental. Embora os dois indices de poluicao tenham sido estatisticamente iguais a utilizacao dos mesmos proporcionou interpretacoes discrepantes sobre o grau de poluicao nestas amostras de aguas superficiais.