35 resultados para Lipid vectors

em Biblioteca Digital da Produção Intelectual da Universidade de São Paulo (BDPI/USP)


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Background: American cutaneous leishmaniasis (ACL) is a re-emerging disease in the state of Sao Paulo, Brazil. It is important to understand both the vector and disease distribution to help design control strategies. As an initial step in applying geographic information systems (GIS) and remote sensing (RS) tools to map disease-risk, the objectives of the present work were to: (i) produce a single database of species distributions of the sand fly vectors in the state of Sao Paulo, (ii) create combined distributional maps of both the incidence of ACL and its sand fly vectors, and (iii) thereby provide individual municipalities with a source of reference material for work carried out in their area. Results: A database containing 910 individual records of sand fly occurrence in the state of Sao Paulo, from 37 different sources, was compiled. These records date from between 1943 to 2009, and describe the presence of at least one of the six incriminated or suspected sand fly vector species in 183/645 (28.4%) municipalities. For the remaining 462 (71.6%) municipalities, we were unable to locate records of any of the six incriminated or suspected sand fly vector species (Nyssomyia intermedia, N. neivai, N. whitmani, Pintomyia fischeri, P. pessoai and Migonemyia migonei). The distribution of each of the six incriminated or suspected vector species of ACL in the state of Sao Paulo were individually mapped and overlaid on the incidence of ACL for the period 1993 to 1995 and 1998 to 2007. Overall, the maps reveal that the six sand fly vector species analyzed have unique and heterogeneous, although often overlapping, distributions. Several sand fly species - Nyssomyia intermedia and N. neivai - are highly localized, while the other sand fly species - N. whitmani, M. migonei, P. fischeri and P. pessoai - are much more broadly distributed. ACL has been reported in 160/183 (87.4%) of the municipalities with records for at least one of the six incriminated or suspected sand fly vector species, while there are no records of any of these sand fly species in 318/478 (66.5%) municipalities with ACL. Conclusions: The maps produced in this work provide basic data on the distribution of the six incriminated or suspected sand fly vectors of ACL in the state of Sao Paulo, and highlight the complex and geographically heterogeneous pattern of ACL transmission in the region. Further studies are required to clarify the role of each of the six suspected sand fly vector species in different regions of the state of Sao Paulo, especially in the majority of municipalities where ACL is present but sand fly vectors have not yet been identified.

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The phylogeography of South American lineages is a topic of heated debate. Although a single process is unlikely to describe entire ecosystems, related species, which incur similar habitat limitations, can inform the history for a subsection of assemblages. We compared the phylogeographic patterns of the cytochrome oxidase I marker from Anopheles triannulatus (N = 72) and previous results for A. darlingi (N = 126) in a broad portion of their South American distributions. Both species share similar population subdivisions, with aggregations northeast of the Amazon River, in southern coastal Brazil and 2 regions in central Brazil. The average (ST) between these groups was 0.39 for A. triannulatus. Populations northeast of the Amazon and in southeastern Brazil are generally reciprocally monophyletic to the remaining groups. Based on these initial analyses, we constructed the a priori hypothesis that the Amazon and regions of high declivity pose geographic barriers to dispersal in these taxa. Mantel tests confirmed that these areas block gene flow for more than 1000 km for both species. The efficacy of these impediments was tested using landscape genetics, which could not reject our a priori hypothesis but did reject simpler scenarios. Results form summary statistics and phylogenetics suggest that both lineages originated in central Amazonia (south of the Amazon River) during the late Pleistocene (579 000 years ago) and that they followed the same paths of expansion into their contemporary distributions. These results may have implications for other species sharing similar ecological limitations but probably are not applicable as a general paradigm of Neotropical biogeography.

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Antioxidants probably play an important role in the etiology of type 2 diabetes (DM2). This study evaluated the effects of supplementation with lipoic acid (LA) and alpha-tocopherol on the lipid profile and insulin sensitivity of DM2 patients. A randomized, double-blind, placebo-controlled trial involving 102 DM2 patients divided into four groups to receive daily supplementation for 4 months with: 600 mg LA (n = 26); 800 mg alpha-tocopherol (n = 25); 800 mg alpha-tocopherol + 600 mg LA (n = 25); placebo (n = 26). Plasma alpha-tocopherol, lipid profile, glucose, insulin, and the HOMA index were determined before and after supplementation. Differences within and between groups were compared by ANOVA using Bonferroni correction. Student`s t-test was used to compare means of two independent variables. The vitamin E/total cholesterol ratio improved significantly in patients supplemented with vitamin E + LA and vitamin E alone (p <= 0.001). There were improvements of the lipid fractions in the groups receiving LA and vitamin E alone or in combination, and on the HOMA index in the LA group, but not significant. The results suggest that LA and vitamin E supplementation alone or in combination did not affect the lipid profile or insulin sensitivity of DM2 patients. (C) 2011 Elsevier Ireland Ltd. All rights reserved.

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Bovine rumen protein with two levels of residual lipids (1.9% or 3.8%) was subjected to thermoplastic extrusion under different temperatures and moisture contents. Protein Solubility in different buffers, disulphide cross-linking and molecular weight distribution were determined on the extrudates. After extrusion, samples with 1.9% residual lipids content had a higher concentration of protein insoluble by undetermined forces, irrespective of feed moisture and processing temperature used. Lipid content of 3.8% in the feed material resulted in more protein participating in the extrudate network through non-covalent interactions (hydrophobic and electrostatic) and disulphide bonds. A small dependency of the extrusion process on moisture and temperature and a marked dependency on lipid content, especially phospholipid, was observed, Electrophoresis under non-reducing conditions showed that protein extrusion with low feed moisture promoted high molecular breakdown inside the barrel, probably due to intense shear force, and further protein aggregation at the die end. (C) 2009 Elsevier Ltd. All rights reserved.

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The antioxidant activity of mate tea, the roasted product derived from yerba mate (Ilex paraguarienis), was observed in vitro and in animal models, but studies in humans are lacking. The aim of this study was to investigate the effects of mate tea supplementation on plasma susceptibility to oxidation and on antioxidant enzyme gene expression in healthy nonsmoking women, after acute or prolonged ingestion. We evaluated plasma total antioxidant status (TAS), the kinetics of diene conjugate generation, and thiobarbituric acid reactive substance (TBARS) contents in plasma, as well as mRNA levels of antioxidant gluthatione peroxidase (GPx), superoxide dismutase (SOD), and catalase (CAT). After the supplementation period with mate tea, lipid peroxidation was acutely lowered, an effect that was maintained after prolonged administration. Total antioxidant status and the level of antioxidant enzyme gene expression were also demonstrated after prolonged consumption. These results suggest that regular consumption of mate tea may increase antioxidant defense of the body by multiple mechanisms.

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This study aimed at evaluating the effect of increasing organic loading rates and of enzyme pretreatment on the stability and efficiency of a hybrid upflow anaerobic sludge blanket reactor (UASBh) treating dairy effluent. The UASBh was submitted to the following average organic loading rates (OLR) 0.98 Kg.m(-3).d(-1), 4.58 Kg.m(-3).d(-1), 8.89 Kg.m(-3).d(-1) and 15.73 Kg.m(-3).d(-1), and with the higher value, the reactor was fed with effluent with and without an enzymatic pretreatment to hydrolyze fats. The hydraulic detention time was 24 h, and the temperature was 30 +/- 2 degrees C. The reactor was equipped with a superior foam bed and showed good efficiency and stability until an OLR of 8.89 Kg.m(-3).d(-1). The foam bed was efficient for solid retention and residual volatile acid concentration consumption. The enzymatic pretreatment did not contribute to the process stability, propitiating loss in both biomass and system efficiency. Specific methanogenic activity tests indicated the presence of inhibition after the sludge had been submitted to the pretreated effluent It was concluded that continuous exposure to the hydrolysis products or to the enzyme caused a dramatic drop in the efficiency and stability of the process, and the single exposure of the biomass to this condition did not inhibit methane formation. (C) 2011 Elsevier B.V. All rights reserved.

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Methods used for lipid analysis in embryos and oocytes usually involve selective lipid extraction from a pool of many samples followed by chemical manipulation, separation and characterization of individual components by chromatographic techniques. Herein we report direct analysis by matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) of single and intact embryos or oocytes from various species. Biological samples were simply moisturized with the matrix solution and characteristic lipid ( represented by phosphatidylcholines, sphingomyelins and triacylglycerols) profiles were obtained via MALDI-MS. As representative examples, human, bovine, sheep and fish oocytes, as well as bovine and insect embryos were analyzed. MALDI-MS is shown to be capable of providing characteristic lipid profiles of gametes and embryos and also to respond to modifications due to developmental stages and in vitro culture conditions of bovine embryos. Investigation in developmental biology of the biological roles of structural and reserve lipids in embryos and oocytes should therefore benefit from these rapid MALDI-MS profiles from single and intact species.-Ferreira, C. R., S. A. Saraiva, R. R. Catharino, J. S. Garcia, F. C. Gozzo, G. B. Sanvido, L. F. A. Santos, E. G. Lo Turco, J. H. F. Pontes, A. C. Basso, R. P. Bertolla, R. Sartori, M. M. Guardieiro, F. Perecin, F. V. Meirelles, J. R. Sangalli, and M. N. Eberlin. Single embryo and oocyte lipid fingerprinting by mass spectrometry. J. Lipid Res. 2010. 51: 1218-1227.

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The processing of fish roe leads to changes in its chemical composition, the extent of which depends on the techniques and additives employed. This study aimed to investigate the effects of ripening temperature and the use of sodium benzoate and citric acid on the quality of ripened cod roe, with respect to the contents of volatile base nitrogen (VBN), trimethylamine (TMA), biogenic amines (BA) and on the lipid composition. In comparison with fresh roes, ripened roes presented higher contents of VBN, TMA, BA and the proportion of free fatty acids regardless of the temperature and additives used during the ripening process. The greatest increases were observed in the samples ripened at 17 degrees C without additives, in which histamine was detected at 8.8 mg/100 g. A low ripening temperature was the main factor responsible for minimising changes in the cod roe composition. The addition of sodium benzoate as a preservative or citric acid to decrease the pH value had a significant effect in maintaining the quality of the cod roes, mainly at high ripening temperature. (C) 2011 Elsevier Ltd. All rights reserved.

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Background: The cytochrome P450 isoenzyme 3A5 (CYP3A5) has an important role on biotransformation of xenobiotics. CYP3A5 SNPs have been associated with variations on enzyme activity that can modify the metabolism of several drugs. Methods: In order to evaluate the influence of CYP3A5 variants on response to lowering-cholesterol drugs, 139 individuals with hypercholesterolemia were selected. After a wash-out period of 4 weeks, individuals were treated with atorvastatin (10 mg/day/4 weeks). Genomic DNA was extracted by a salting-out procedure. CYP3A5*3C, CYP3A5*6 and CYP3A5*1D were analyzed by PCR-RFLP and DNA sequencing. Results: >Frequencies of the CYP3A5*3C and CYP3A5*1D alleles were lower in individuals of African descent (*3C: 47.8% and *1D: 55.2%) than in non-Africans (*3C: 84.9% and *1D 84.8%, p<0.01). Non-Africans carrying *3A allele (*3C and *1D combined alleles) had lower total and LDL-cholesterol response to atorvastatin than non-*3A allele carriers (p<0.05). Conclusion: CYP3A5*3A allele is associated with reduced cholesterol-lowering response to atorvastatin in non-African individuals. (C) 2008 Elsevier B.V. All rights reserved.

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The aim of this study was to investigate endothelial venous function, mflammatory markers, and systemic oxidative stress after an oral lipid overload (OLO). We studied 18 healthy adults (9 men; age, 29.2 +/- 0.9 years; body mass index, 22.3 +/- 0.4 kg/m(2)). Blood samples were collected in the fasting state and 3, 4, and 5 hour after the OLO (1000 kcal, 58% fat) for metabolic variables, oxidative stress, inflammatory markers, adiponectin, and resistin. Changes in vein diameter to phenylephrine, acetylcholine, and sodium nitroprusside (dorsal hand vein technique) were measured before and after the OLO. Oral lipid overload increased triglycerides (61 +/- 6 vs 134 +/- 17 mg/dL, P <.001), insulin (7.2 +/- 0.8 vs 10.7 +/- 1.3 mu U/mL, P <.05), and resistin (5.38 +/- 0.5 vs 6.81 +/- 0.7 ng/mL, P <.05) and reduced antioxidant capacity (plasma total antioxidant capacity: 186.7 +/- 56 vs 161.8 +/- 50 U Trolox per microliter plasma, P <.01), vascular reactivity (171.3 +/- 85 vs 894.4 +/- 301 ng/mL, P <.001), and maximum acetylcholine venodilation (105.9% +/- 9% vs 61.0% +/- 7%, P <.05). No changes were observed for sodium nitroprusside. Post-OLO triglycerides were positively correlated with phenylephrine dose (rho = 0.38, P <.05) and resistin (rho = 0.43, P <.01) and negatively correlated with the maximum acetylcholine venodilation (rho = -0.36, P <.05). In conclusion, an OLO impaired venoconstriction responsiveness in healthy subjects, probably because of a reduction in the antioxidant capacity. (C) 2008 Elsevier Inc. All rights reserved.

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Free fatty acids (FFA) are important mediators of proton transport across membranes. However, information concerning the influence of the Structural features of both FFA and the membrane environment on the proton translocation mechanisms across phospholipid membranes is relatively scant. The effects of FFA chain length, unsaturation and membrane composition on proton transport have been addressed in this study by means of electrical measurements in planar lipid bilayers. Proton conductance (G(H)(+)) was calculated from open-circuit voltage and short-circuit current density measurements. We found that cis-unsaturated FFA caused a more pronounced effect on proton transport as compared to Saturated and trans-unsaturated FFA. Cholesterol and cardiolipin decreased membrane leak conductance. Cardiolipin also decreased proton conductance. These effects indicate a dual modulation of protein-independent proton transport by FFA: through a flip-flop mechanism and by modifying a proton diffusional pathway. Moreover the membrane phospholipid composition was shown to importantly affect both processes. (C) 2009 Elsevier Inc. All rights reserved.

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Eumenitin, a novel cationic antimicrobial peptide from the venom of solitary wasp Eumenes rubronotatus, was characterized by its effects on black lipid membranes of negatively charged (azolectin) and zwitterionic (1,2-diphytanoyl-sn-glycero-3-phosphocholine (DPhPC) or DPhPC-cholesterol) phospholipids: surface potential changes, single-channel activity, ion selectivity, and pore size were studied. We found that eumenitin binds preferentially to charged lipid membranes as compared with zwitterionic ones. Eumenitin is able to form pores in azolectin (G(1) = 118.00 +/- 3.67 pS or G(2) = 160.00 +/- 7.07 pS) and DPhPC membranes (G = 61.13 +/- 7.57 pS). Moreover, cholesterol addition to zwitterionic DPhPC membranes inhibits pore formation activity but does not interfere with the binding of peptide. Open pores presented higher cation (K (+)) over anion (Cl-) selectivity. The pore diameter was estimated at between 8.5and 9.8 angstrom in azolectin membranes and about 4.3 angstrom in DPhPC membranes. The results are discussed based on the toroidal pore model for membrane pore-forming activity and ion selectivity. (c) 2007 Elsevier Ltd. All rights reserved.

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Aims: The ATP-binding cassette transporters, ABCA1 and ABCG1, are LXR-target genes that play an important role in reverse cholesterol transport. We examined the effects of inhibitors of the cholesterol absorption (ezetimibe) and synthesis (statins) on expression of these transporters in HepG2 cells and peripheral blood mononuclear cells (PBMCs) of individuals with primary (and nonfamilial) hypercholesterolemia (HC). Materials & methods: A total of 48 HC individuals were treated with atorvastatin (10 mg/day/4 weeks) and 23 were treated with ezetimibe (10 mg/day/4 weeks), followed by simvastatin (10 mg/day/8 weeks) and simvastatin plus ezetimibe (10 mg of each/day/4 weeks). Gene expression was examined in statin- or ezetimibe-treated and control HepG2 cells as well as PBMCs using real-time PCR. Results: In PBMCs, statins and ezetimibe downregulated ABCA1 and ABCG1 mRNA expression but did not modulate NR1H2 (LxR-beta) and NR1H3 (LXR-alpha) levels. Positive correlations of ABCA1 with ABCG1 and of NR1H2 with NR1H3 expressions were found in all phases of the treatments. In HepG2 cells, ABCA1 mRNA levels remained unaltered while ABCG1 expression was increased by statin (1.0-10.0 mu M) or ezetimibe (5.0 mu M) treatments. Atorvastatin upregulated NR1H2 and NR1H3 only at 10.0 mu M, meanwhile ezetimibe (1.0-5.0 mu M) downregulated NR1H2 but did not change NR1H3 expression. Conclusion: Our findings reveal that lipid-lowering drugs downregulate ABCA1 and ABCG1 mRNA expression in PBMCs of HC individuals and exhibit differential effects on HepG2 cells. Moreover, they indicate that the ABCA1 and ABCG1 transcript levels were not correlated directly to LXR mRNA expression in both cell models treated with lipid-lowering drugs.

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Objective: This study reports the effects of feeding with a combination of inulin-type fructans (ITF) and fish oil (FO) on mineral absorption and bioavailability as part of a semipurified diet offered to rats. Methods: Male Wistar rats (n = 24) were fed a 15% lipid diet (soybean oil [SO] or a 1:0.3 fish:soybean oil mixture [FSO]) and diets containing the same sources of lipids supplemented with 10% ITF (Raftilose Synergy 1) ad libitum for 15 d. Feces and urine were collected for mineral analyses during the last 5 d of the test period. Fatty acid composition was determined in liver and cecal mucosa homogenates. Liver and bone mineral analyses were performed by atomic absorption spectrophotometry. Bone biomechanical analyses were evaluated by a 3-point bending test. Results: Compared with the controls, ITF-fed rats had enlarged ceca and a significant decrease in cecal content pH (P < 0.001). The apparent mineral absorption was improved in these rats, and this effect was enhanced by dietary combination with FO for all minerals except for magnesium. Addition of ITF to the diet resulted in higher bone mineral content (calcium and zinc) and bone strength, but increased bone mineral content was only statistically significant in FO-fed animals. A decrease in liver iron stores (P = 0.015) was observed in rats fed FO, considering that ITF consumption returned to levels comparable to the SO control group. Conclusion: These findings confirm the positive influence of ITF on mineral bioavailability, which was potentiated by addition of FO to the diet. (C) 2009 Published by Elsevier Inc.