A Low-Protein, High-Carbohydrate Diet Increases Fatty Acid Uptake and Reduces Norepinephrine-Induced Lipolysis in Rat Retroperitoneal White Adipose Tissue

A low-protein, high-carbohydrate (LPHC) diet for 15 days increased the lipid content in the carcass and adipose tissues of rats. The aim of this work was to investigate the mechanisms of this lipid increase in the retroperitoneal white adipose tissue (RWAT) of these animals. The LPHC diet induced an approximately two- and tenfold increase in serum corticosterone and TNF-alpha, respectively. The rate of de novo fatty acid (FA) synthesis in vivo was reduced (50%) in LPHC rats, and the lipoprotein lipase activity increased (100%). In addition, glycerokinase activity increased (60%), and the phosphoenolpyruvate carboxykinase content decreased (27%). Basal [U-C-14]-glucose incorporation into glycerol-triacylglycerol did not differ between the groups; however, in the presence of insulin, [U-C-14]-glucose incorporation increased by 124% in adipocytes from only control rats. The reductions in IRS1 and AKT content as well as AKT phosphorylation in the RWAT from LPHC rats and the absence of an insulin response suggest that these adipocytes have reduced insulin sensitivity. The increase in NE turnover by 45% and the lack of a lipolytic response to NE in adipocytes from LPHC rats imply catecholamine resistance. The data reveal that the increase in fat storage in the RWAT of LPHC rats results from an increase in FA uptake from circulating lipoproteins and glycerol phosphorylation, which is accompanied by an impaired lipolysis that is activated by NE.

Boron uptake in normal melanocytes and melanoma cells and boron biodistribution study in mice bearing B16F10 melanoma for boron neutron capture therapy

Information on B-10 distribution in normal tissues is crucial to any further development of boron neutron capture therapy (BNCT). The goal of this study was to investigate the in vitro and in vivo boron biodistribution in B16F10 murine melanoma and normal tissues as a model for human melanoma treatment by a simple and rapid colorimetric method, which was validated by HR-ICP-MS. The B16F10 melanoma cell line showed higher melanin content than human melanocytes, demonstrating a greater potential for boronophenylalanine uptake. The melanocytes showed a moderate viability decrease in the first few minutes after BNCT application, stabilizing after 75 min, whereas the B16F10 melanoma showed the greatest intracellular boron concentration at 150 min after application, indicating a different boron uptake of melanoma cells compared to normal melanocytes. Moreover, at this time, the increase in boron uptake in melanoma cells was approximately 1.6 times higher than that in normal melanocytes. The B-10 concentration in the blood of mice bearing B16F10 melanoma increased until 90 min after BNCT application and then decreased after 120 min, and remained low until the 240th minute. On the other hand, the B-10 concentration in tumors was increased from 90 min and maximal at 150 min after application, thus confirming the in vitro results. Therefore, the present in vitro and in vivo study of B-10 uptake in normal and tumor cells revealed important data that could enable BNCT to be possibly used as a treatment for melanoma, a chemoresistant cancer associated with high mortality.

Ionic Transport and Water Vapor Uptake of Ammonium Exchanged Perfluorosulfonic Acid Membranes

Nafion membranes series N117 doped with ammonium, at different cation fractions (H+/NH4+), were investigated for ionic transport and water vapor uptake, for several water activities and temperatures. Ammonium cations change both properties of the polymer in a similar manner. Membrane ionic conductivity and water vapor uptake (lambda) decrease as the ammonium concentration increases in the polymer. Ionic transport activation energies are calculated and the transport mechanism of ammonium ions in Nafion is discussed. (C) 2012 The Electrochemical Society. [DOI: 10.1149/2.040203jes] All rights reserved.

Cu(GlyGlyHis) effects on MCF7 cells: Copper uptake, reactive oxygen species generation and membrane topography changes

Elevated levels of copper have been detected in various types of human cancer cells, such as breast cancer cells, and a number of mechanisms have been proposed to explain the action and influence of copper on tumor progress. In this work, we found that stimulating the proliferation of mammary epithelial MCF7 cells with the high-redox-potential copper complex Cu (GlyGlyHis) is associated with the copper-induced intracellular generation of reactive oxygen species (ROS) that induces lipid peroxidation and causes increased roughness of external cell membranes, which leads to the formation of larger cell domes. The results presented herein provide new insights into the molecular link between copper and the proliferation of breast cancer cells and, consequently, into the mechanism by which changes in redox balance and ROS accumulation regulates cell membrane roughness. (C) 2012 Elsevier Inc. All rights reserved.

Cadmium Uptake by Lettuce (Lactuca sativa L.) as Basis for Derivation of Risk Limits in Soils

The availability and uptake of Cd by lettuce (Lactuca sativa L.) in two common tropical soils (before and after liming) were studied in order to derive human health-based risk soil concentration. Cadmium concentrations ranging from 1 to 12 mg kg(-1) were added to samples from a clayey Oxisol and a sandy-loam Ultisol under glasshouse conditions. After incubation, a soil sample was taken from each pot, the concentration of Cd in the soil was determined, lettuce was grown during 36 d, and the edible parts were harvested and analyzed for Cd. A positive linear correlation was observed between total soil Cd and the Cd concentration in lettuce. The amount of Cd absorbed by lettuce grown in the Ultisol was about twice the amount absorbed in the Oxisol. Liming increased the soil pH and slightly reduced Cd availability and uptake. CaCl2 extraction was better than DTPA to reflect differences in binding strength of Cd between limed and unlimed soils. Risk Cd concentrations in the Ultisol were lower than in the Oxisol, reflecting the greater degree of uptake from the Ultisol. The derived risk Cd values were dependent on soil type and the exposure scenario.

Tissue distribution of DNA-Hsp65/TDM-loaded PLGA microspheres and uptake by phagocytic cells

This study aimed to demonstrate that microspheres, used as delivery vehicle of DNA-Hsp65/TDM [plasmid DNA encoding heat shock protein 65 (Hsp65) coencapsulated with trehalose dimycolate (TDM) into PLGA microspheres], are widely spread among several organs after intramuscular administration in BALB/c mice. In general, we showed that these particles were phagocytosed by antigen presenting cells, such as macrophages and dendritic cells. Besides, it was demonstrated herein that draining lymph node cells presented a significant increase in the number of cells expressing costimulatory molecules (CD80 and CD86) and MHC class II, and also that the administration of the DNA-Hsp65/TDM and vector/TDM formulations resulted in the up-regulation of CD80, CD86 and MHC class II expression when compared to control formulations (vector/TDM and empty). Regarding the intracellular trafficking we observed that following phagocytosis, the microspheres were not found in the late endosomes and/or lysosomes, until 15 days after internalization, and we suggest that these constructions were hydrolysed in early compartments. Overall, these data expand our knowledge on PLGA [poly (lactic-co- glycolic acid)] microspheres as gene carriers in vaccination strategies, as well as open perspectives for their potential use in clinical practice.

Deficiency symptoms and uptake of micronutrients by castor bean grown in nutrient solution

Castor bean is a nutrient-demanding species, but there is still little information on its micronutrient requirements. The objectives of this study were to evaluate the effects of levels of B (2.5, 12.5 and 25.0 µmol L-1), Cu (0.05, 0.25 and 0.50 µmol L-1), Mn (0.2, 1.0 and 2.0 µmol L-1) and Zn (0.2, 1.0 and 2.0 µmol L-1) in a nutrient solution on plant B, Cu, Mn and Zn concentrations and uptake, vegetative growth and fruit yield of castor bean "Iris", grown in greenhouse. The experiment was arranged in a completely randomized block design with three replicates. The first deficiency symptoms were observed for B, followed by Zn, Cu and Mn. The main changes in the cell ultrastructure due to lack of B were thickening of the cell walls and middle lamellae, distorted chloroplasts and tightly stacked thylakoids, besides the absence of starch grains. The Mn, Zn and Cu deficiencies led to disruption of chloroplasts, disintegration of thylakoids and absence of amyloplasts. The concentration and uptake of B, Cu, Mn, and Zn in castor bean plants increased with micronutrient supply in the solution. Fruit yield was drastically reduced by B and Mn deficiencies. On the other hand, the dry matter yield of the shoot and root of castor bean plants was not. In the treatment with full nutrient solution, the leaves accumulated 56 and 48 % of the total B and Mn taken up by the plants, respectively, and the seeds and roots 85 and 61 % of the total Cu and Zn taken up, respectively. This shows the high demand of castor bean Iris for B and Mn for fruit yield.

Corte foliar e tempo de transplantio para o uso de plântulas do sub-bosque na restauração florestal

O uso de plântulas da regeneração natural tem sido recomendado como estratégia para produção de mudas visando à restauração florestal, contudo muitos aspectos técnicos desse método ainda carecem de investigação científica. O objetivo deste trabalho foi avaliar o efeito da redução da área foliar e do transplantio imediato na sobrevivência e crescimento de mudas de espécies arbóreas produzidas a partir de plântulas obtidas da regeneração natural. Plântulas de Esenbeckia leiocarpa (Rutaceae), Eugenia ligustrina (Myrtaceae) e Maytenus salicifolia (Celastraceae), obtidas em remanescente de vegetação secundária de Floresta Estacional Semidecidual em Bofete, SP, foram extraídas do solo e submetidas aos tratamentos: I) redução de 50% da área de cada folha e transplantio imediato; II) nenhuma redução de área das folhas e transplantio imediato; III) redução de 50% da área de cada folha, manutenção das plântulas em água e transplantio 24 h após a coleta; e IV) nenhuma redução de área das folhas, manutenção das plântulas em água e transplantio 24 h após a coleta. As mudas foram avaliadas com relação à sobrevivência e ao crescimento em altura, ao longo de oito meses. Os resultados evidenciaram que nem o corte das folhas ou a manutenção das plântulas dentro de recipientes com água por 24 h antes do transplantio afetaram os parâmetros avaliados. Assim, para as espécies estudadas a redução da área foliar e o transplantio imediato são desnecessários para a produção de mudas em viveiro a partir de plântulas obtidas da regeneração natural.

Biosynthesis and uptake of copper nanoparticles by dead biomass of Hypocrea lixii isolated from the metal mine in the Brazilian Amazon Region

A biological system for the biosynthesis of nanoparticles (NPs) and uptake of copper from wastewater, using dead biomass of Hypocrea lixii was analyzed and described for the first time. The equilibrium and kinetics investigation of the biosorption of copper onto dead, dried and live biomass of fungus were performed as a function of initial metal concentration, pH, temperature, agitation and inoculum volume. The high biosorption capacity was observed for dead biomass, completed within 60 min of contact, at pH 5.0, temperature of 40 °C and agitation speed of 150 rpm with a maximum copper biosorption of 19.0 mg g(-1). The equilibrium data were better described using the Langmuir isotherm and kinetic analysis indicated that copper biosorption follows a pseudo-second-order model. The average size, morphology and location of NPs biosynthesized by the fungus were determined by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and transmission electron microscopy (TEM). NPs were mainly spherical, with an average size of 24.5 nm, and were synthesized extracellularly. The X-ray diffraction (XRD) analysis confirms the presence of metallic copper particles. Infrared spectroscopy (FTIR) study revealed that the amide groups interact with the particles, which was accountable for the stability of NPs. This method further confirmed the presence of proteins as stabilizing and capping agents surrounding the copper NPs. These studies demonstrate that dead biomass of Hypocrea lixii provides an economic and technically feasible option for bioremediation of wastewater and is a potential candidate for industrial-scale production of copper NPs.

Estimativa do índice de área foliar e temperatura em uma área de eucalipto

It is known that the presence of large masses of vegetation is a factor that can influence the microclimate of a region. In this paper we analyzed the correlation between leaf area index (LAI) and land surface temperature (LST), both estimated from remote sensing images from Landsat-5 TM in an area of eucalyptus plantation, and these estimates were compared to the observed data. The correlation between LAI and LST was not significant (16%), which indicates that there is no necessarily a direct influence of vegetation in the local temperature. The comparison between estimated and observed data shows that the application of remote sensing techniques in the estimative of interested variables is efficient, because the estimatives followed consistently the observed values.

Uptake of oxLDL and IL-10 production by macrophages requires PAFR and CD36 recruitment into the same lipid rafts

Macrophage interaction with oxidized low-density lipoprotein (oxLDL) leads to its differentiation into foam cells and cytokine production, contributing to atherosclerosis development. In a previous study, we showed that CD36 and the receptor for platelet-activating factor (PAFR) are required for oxLDL to activate gene transcription for cytokines and CD36. Here, we investigated the localization and physical interaction of CD36 and PAFR in macrophages stimulated with oxLDL. We found that blocking CD36 or PAFR decreases oxLDL uptake and IL-10 production. OxLDL induces IL-10 mRNA expression only in HEK293T expressing both receptors (PAFR and CD36). OxLDL does not induce IL-12 production. The lipid rafts disruption by treatment with βCD reduces the oxLDL uptake and IL-10 production. OxLDL induces co-immunoprecipitation of PAFR and CD36 with the constitutive raft protein flotillin-1, and colocalization with the lipid raft-marker GM1-ganglioside. Finally, we found colocalization of PAFR and CD36 in macrophages from human atherosclerotic plaques. Our results show that oxLDL induces the recruitment of PAFR and CD36 into the same lipid rafts, which is important for oxLDL uptake and IL-10 production. This study provided new insights into how oxLDL interact with macrophages and contributing to atherosclerosis development.

On the mechanisms that limit oxygen uptake during exercise in acute and chronic hypoxia: role of muscle mass

[EN] Peak aerobic power in humans (VO2,peak) is markedly affected by inspired O2 tension (FIO2). The question to be answered in this study is what factor plays a major role in the limitation of muscle peak VO2 in hypoxia: arterial O2 partial pressure (Pa,O2) or O2 content (Ca,O2)? Thus, cardiac output (dye dilution with Cardio-green), leg blood flow (thermodilution), intra-arterial blood pressure and femoral arterial-to-venous differences in blood gases were determined in nine lowlanders studied during incremental exercise using a large (two-legged cycle ergometer exercise: Bike) and a small (one-legged knee extension exercise: Knee)muscle mass in normoxia, acute hypoxia (AH) (FIO2 = 0.105) and after 9 weeks of residence at 5260 m (CH). Reducing the size of the active muscle mass blunted by 62% the effect of hypoxia on VO2,peak in AH and abolished completely the effect of hypoxia on VO2,peak after altitude acclimatization. Acclimatization improved Bike peak exercise Pa,O2 from 34 +/- 1 in AH to 45 +/- 1 mmHg in CH(P <0.05) and Knee Pa,O2 from 38 +/- 1 to 55 +/- 2 mmHg(P <0.05). Peak cardiac output and leg blood flow were reduced in hypoxia only during Bike. Acute hypoxia resulted in reduction of systemic O2 delivery (46 and 21%) and leg O2 delivery (47 and 26%) during Bike and Knee, respectively, almost matching the corresponding reduction in VO2,peak. Altitude acclimatization restored fully peak systemic and leg O(2) delivery in CH (2.69 +/- 0.27 and 1.28 +/- 0.11 l min(-1), respectively) to sea level values (2.65 +/- 0.15 and 1.16 +/- 0.11 l min(-1), respectively) during Knee, but not during Bike. During Knee in CH, leg oxygen delivery was similar to normoxia and, therefore, also VO2,peak in spite of a Pa,O2 of 55 mmHg. Reducing the size of the active mass improves pulmonary gas exchange during hypoxic exercise, attenuates the Bohr effect on oxygen uploading at the lungs and preserves sea level convective O2 transport to the active muscles. Thus, the altitude-acclimatized human has potentially a similar exercising capacity as at sea level when the exercise model allows for an adequate oxygen delivery (blood flow x Ca,O2), with only a minor role of Pa,O2 per se, when Pa,O2 is more than 55 mmHg.