300 resultados para thiobarbituric acid reactive substance


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We have shown that the ethanolic extract of Lafoensia pacari inhibits eosinophilic inflammation induced by Toxocara canis infection, and that ellagic acid is the secondary metabolite responsible for the anti-eosinophilic activity seen in a model of beta-glucan peritonitis. In the present study, we investigated the preventive and curative effects of L. pacari extract and ellagic acid on allergic lung inflammation using a murine model of ovalbumin-induced asthma. In bronchoalveolar lavage fluid, preventive (22-day) treatment with L. pacari (200 mg/kg) and ellagic acid (10 mg/kg) inhibited neutrophil counts (by 75% and 57%) and eosinophil counts (by 78% and 68%). L. pacari reduced IL-4 and IL-13 levels (by 67% and 73%), whereas ellagic acid reduced IL-4, IL-5 and IL-13 (by 67%, 88% and 85%). To investigate curative anti-inflammatory effects, we treated mice daily with ellagic acid (0.1, 1, or 10 mg/kg), also treating selected mice with L. pacari (200 mg/kg) from day 18 to day 22. The highest ellagic acid dose reduced neutrophil and eosinophil numbers (by 59% and 82%), inhibited IL-4, IL-5, and IL-13 (by 62%,61%, and 49%). Neither L. pacari nor ellagic acid suppressed ovalbumin-induced airway hyperresponsiveness or cysteinyl leukotriene synthesis in lung homogenates. In mice treated with ellagic acid (10 mg/kg) or L. pacari (200 mg/kg) at 10 min after the second ovalbumin challenge, eosinophil numbers were 53% and 69% lower, respectively. Cytokine levels were unaffected by this treatment. L. pacari and ellagic acid are effective eosinophilic inflammation suppressors, suggesting a potential for treating allergies. (c) 2007 Elsevier B.V All rights reserved.

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The present article describes an L-amino acid oxidase from Bothrops atrox snake venom as with antiprotozoal activities in Trypanosoma cruzi and in different species of Leishmania (Leishmania braziliensis, Leishmania donovani and Leishmania major). Leishmanicidal effects were inhibited by catalase, suggesting that they are mediated by H(2)O(2) production. Leishmania spp. cause a spectrum of diseases, ranging from self-healing ulcers to disseminated and often fatal infections, depending on the species involved and the host`s immune response. BatroxLAAO also displays bactericidal activity against both Gram-positive and Gram-negative bacteria. The apoptosis induced by BatroxLAAO on HL-60 cell lines and PBMC cells was determined by morphological cell evaluation using a mix of fluorescent dyes. As revealed by flow cytometry analysis, suppression of cell proliferation with BatroxLAAO was accompanied by the significant accumulation of cells in the G0/G1 phase boundary in HL-60 cells. BatroxLAAO at 25 mu g/mL and 50 mu g/mL blocked G0-G1 transition, resulting in G0/G1 phase cell cycle arrest, thereby delaying the progression of cells through S and G2/M phase in HL-60 cells. This was shown by an accentuated decrease in the proportion of cells in S phase, and the almost absence of G2/M phase cell population. BatroxLAAO is an interesting enzyme that provides a better understanding of the ophidian envenomation mechanism, and has biotechnological potential as a model for therapeutic agents. (C) 2011 Elsevier Masson SAS. All rights reserved.

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Background Very few studies have investigated, in the elderly, the effect of rheumatic inflammatory states on phagocyte function and free radical production. The objective of this article is to evaluate phagocytosis by neutrophils and the production of nitric oxide (.NO) by monocytes in elderly women recruited among patients of the Brazilian Public Health System. Methods: Forty patients aged more than 60 years with rheumatic inflammatory diseases were studied. Phagocytosis was measured by flow cytometry. .NO production was measured by the total nitrite assay and conventional inflammation markers were determined. Data were analyzed with the Mann Whitney nonparametric test and P<0.05 was considered significant. Results. C-reactive protein levels and white blood cell counts were significantly higher in inflammation than in the control group (P<0.05). The phagocytosis fluorescence intensity per neutrophil and the percentual of neutrophils expressing phagocytosis were significantly higher (P<0.05) in the test than in the control group. Furthermore, there was significant .NO overproduction by monocytes, (P<0.05). Conclusion: Phagocytosis and .NO production are affected by rheumatic states. This suggests that the increased .NO levels may play a part in the increased oxidative stress in rheumatic diseases in elderly women. J. Clin. Lab. Anal. 25:47-51, 2011. (C) 2011 Wiley-Liss, Inc.

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Snake Venom L-amino acid oxidases (LAAOs E.C. 1.4.3.2) are flavoenzymes broadly found in various snake venom compositions. LAAOs have become an attractive subject for molecular biology, biochemistry, physiology and medicine due to their actions on various cells and biological effects on platelets, apoptosis, hemorrhage and others. In this review we try to summarize some of these reports, with special emphasis on apoptosis, anti-protozoa, bactericidal and anti-viral activities.

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An L-amino acid oxidase (Bp-LAAO) from Bothrops pauloensis snake venom was highly purified using sequential chromatography steps on CM-Sepharose, Phenyl-Sepharose CL4B, Benzamidine Sepharose and C18 reverse-phase HPLC. Purified Bp-LAAO showed to be a homodimeric acidic glycoprotein with molecular weight around 65 kDa under reducing conditions in SDS-PAGE. The best substrates for Bp-LAAO were L-Met, L-Leu, L-Phe and L-Ile and the enzyme showed a strong reduction of its catalytic activity upon L-Met and L-Phe substrates at extreme temperatures. Bp-LAAO showed leishmanicidal, antitumoral and bactericidal activities dose dependently. Bp-LAAO induced platelet aggregation in platelet-rich plasma and this activity was inhibited by catalase. Bp-LAAC-cDNA of 1548 bp codified a mature protein with 516 amino acid residues corresponding to a theoretical isoelectric point and molecular weight of 6.3 and 58 kDa, respectively. Additionally, structural and phylogenetic studies identified residues under positive selection and their probable location in Elp-LAAO and other snake venom LAAOs (svLAAOs). Structural and functional investigations of these enzymes can contribute to the advancement of toxinology and to the elaboration of novel therapeutic agents. (C) 2009 Elsevier Masson SAS. All rights reserved.

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Background: Periodontal disease has been associated with many chronic inflammatory systemic diseases, and a common chronic inflammation pathway has been suggested for these conditions. However, few studies have evaluated whether periodontal disease, in the absence of other known inflammatory conditions and smoking, affects circulating markers of chronic inflammation. This study compared chronic inflammation markers in control individuals and patients with periodontal disease and observed whether non-surgical periodontal therapy affected inflammatory disease markers after 3 months. Methods: Plasma and serum of 20 controls and 25 patients with periodontal disease were obtained prior to and 3 months after non-surgical periodontal therapy. All patients were non-smokers, they did not use any medication, and they had no history or detectable signs and symptoms of systemic diseases. Periodontal and systemic parameters included probing depth, bleeding on probing, clinical attachment level, hematologic parameters, as well as the following inflammatory markers: interleukin (IL)-6, high-sensitivity C-reactive protein (hs-CRP), CD40 ligand, monocyte chemoattractant protein (MCP)-1, soluble P-selectin (sP-selectin), soluble vascular adhesion molecule (sVCAM)-1, and soluble intercellular adhesion molecule (sICAM)-1. Results: There were no differences in the hematologic parameters of the patients in the control and periodontal disease groups. Among the tested inflammatory markers, IL-6 concentrations were higher in the periodontal disease group at baseline compared to the controls (P=0.006). Therapy was highly effective (P<0.001 for all the analyzed clinical parameters), and a decrease in circulating IL-6 and hs-CRP concentrations was observed 3 months after therapy (P=0.001 and P=0.006, respectively). Our results also suggest that the CD40 ligand marker may have been different in the control and periodontal disease groups prior to the therapy (P=0.009). Conclusions: In apparently otherwise healthy patients, periodontal disease is associated with increased circulating concentrations of IL-6 and hs-CRP, which decreased 3 months after non-surgical periodontal therapy. With regard to the CD40 ligand, MCP-1, sP-selectin, sVCAM-1, and sICAM-1, no changes were seen in the periodontal disease group between baseline and 3 months after therapy. J Periodontol 2009;80:594-602.

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The goal of this study is to produce oleanolic acid derivatives by biotransformation process using Mucor rouxii and evaluate their antimicrobial activity against oral pathogens. The microbial transformation was carried out in shake flasks at 30A degrees C for 216 h with shaking at 120 rpm. Three new derivatives, 7 beta-hydroxy-3-oxo-olean-12-en-28-oic acid, 7 beta,21 beta-dihydroxy-3-oxo-olean-12-en-28-oic acid, and 3 beta,7 beta,21 beta-trihydroxyolean-12-en-28-oic acid, and one know compound, 21 beta-hydroxy-3-oxo-olean-12-en-28-oic acid, were isolated, and the structures were elucidated on the basis of spectroscopic analyses. The antimicrobial activity of the substrate and its transformed products was evaluated against five oral pathogens. Among these compounds, the derivative 21 beta-hydroxy-3-oxo-olean-12-en-28-oic acid displayed the strongest activity against Porphyromonas gingivalis, which is a primary etiological agent of periodontal disease. In an attempt to improve the antimicrobial activity of the derivative 21 beta-hydroxy-3-oxo-olean-12-en-28-oic acid, its sodium salt was prepared, and the minimum inhibitory concentration against P. gingivalis was reduced by one-half. The biotransformation process using M. rouxii has potential to be applied to the production of oleanolic acid derivatives. Research and antimicrobial activity evaluation of new oleanolic acid derivatives may provide an important contribution to the discovery of new adjunct agents for treatment of dental diseases such as dental caries, gingivitis, and periodontitis.

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The present study reports on the preparation and testing of a desoxycholate amphotericin B (D-AMB) sustained delivery system based on poly(lactic-co-glycolic acid) (PLGA) and dimercaptosuccinic acid (DMSA) polymeric blends (Nano-D-AMB) aimed at reducing the number of AMB administrations required to treat mycosis. BALB/c mice were infected with the yeast Paracoccidioides brasiliensis intravenously to mimic the chronic form of paracoccidioidomycosis. At 30 days post-infection, the animals were treated with Nano-D-AMB [6 mg/kg of encapsulated D-AMB, intraperitoneally (ip), interval of 72 h] or D-AMB (2 mg/kg, ip, interval of 24 h). Drug efficacy was investigated by the fungal burden recovery from tissues. Toxicity was assessed by renal and hepatic biochemical parameters, physical appearance of the animals and haematological investigation. The control groups used were non-infected and the infected mice mock treated with PBS. Nano-D-AMB presented results comparable to free D-AMB, with a marked antifungal efficacy. The Nano-D-AMB-treated group presented lower loss of body weight and absence of stress sign (piloerection and hypotrichosis) observed after D-AMB treatment. No renal [blood urea nitrogen (BUN), creatinine] or hepatic (pyruvic and oxalacetic glutamic transaminases) biochemical abnormalities were found. The micronucleus assay showed no significant differences in both the micronucleus frequency and percentage of polychromatic erythrocytes for Nano-D-AMB, indicating the absence of genotoxicity and cytotoxic effects. The D-AMB-coated PLGA-DMSA nanoparticle showed antifungal efficacy, fewer undesirable effects and a favourable extended dosing interval. Nano-D-AMB comprises an AMB formulation able to lessen the number of drug administrations. Further studies would elucidate whether Nano-D-AMB would be useful to treat systemic fungal infections such as paracoccidioidomycosis, candidiasis, aspergillosis and cryptococcosis.

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The in vitro inhibitory activity of crude EtOH/H(2)O extracts from the leaves and stems of Rosmarinus officinalis L. was evaluated against the following microorganisms responsible for initiating dental caries: Streptococcus mutans, salivarius, S. sobrinus, S. mitts 5 sanguinis, and Enterococcus faecalis. Minimum inhibitory concentrations (MIC) were determined with the broth microdilution method. The bioassay-guided fractionation of the leaf extract, which displayed the higher antibacterial activity than the stem extract, led to the identification of carnosic acid (2) and carnosol (3) as the major compounds in the fraction displaying the highest activity, as identified by HPLC analysis. Rosmarinic acid (1), detected in another fraction, did not display any activity against the selected microorganisms. HPLC Analysis revealed the presence of low amounts of ursolic acid (4) and oleanolic acid (5) in the obtained fractions. The results suggest that the antimicrobial activity of the extract from the leaves of R. officinalis may be ascribed mainly to the action of 2 and 3.

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In this study the interaction between magnetic nanoparticles (MNPs) surface-coated with meso-2,3-dimercaptosuccinic acid (DMSA) with both bovine serum albumin (BSA) and human serum albumin (HSA) was investigated. The binding of the MNP-DMSA was probed by the fluorescence quenching of the BSA and HSA tryptophan residue. Magnetic resonance and light microscopy analyses were carried out in in vivo tests using female Swiss mice. The binding constants (K(b)) and the complex stoichiometries (n) indicate that MNP-DMSA/BSA and MNP-DMSA/HSA complexes have low association profiles. After five minutes following intravenous injection of MNP-DMSA into mice`s blood stream we found the lung firstly target by the MNP-DMSA, followed by the liver in a latter stage. This finding suggests that the nanoparticle`s DMSA-coating process probably hides the thiol group, through which albumin usually binds. This indicates that biocompatible MNP-DMSA is a very promising material system to be used as a drug delivery system (DDS), primarily for lung cancer treatment.

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The electrochemical oxidation of ethanol at Sn((1-x))Ir (x) O(2) electrodes (with x = 0.01, 0.05, 0.1 and 0.3) was studied in 0.1 mol L(-1) HClO(4) solution. Electrolysis experiments were carried out and the reaction products were analyzed by Liquid Chromatography. It was found that the amounts of the reaction products depended on the composition of the electrode. In situ infrared reflectance spectroscopy measurements were performed to identify the adsorbed intermediates and to postulate a reaction mechanism for ethanol electrooxidation on these electrode materials. As evidence, acetaldehyde and acetic acid were formed through a successive reaction process. Carbon dioxide was also identified as the end product, showing that the cleavage of the carbon-carbon bond occurred. These results indicate that the synthesized catalysts are able to lead to the total combustion of organic compounds. Analysis of the water bending band at different potentials illustrated its role at the electrode interface.

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One major challenge for the widespread application of direct methanol fuel cells (DMFCs) is to decrease the amount of platinum used in the electrodes, which has motivated a search for novel electrodes containing platinum nanoparticles. In this study, platinum nanoparticles were electrodeposited on layer-by-layer (LbL) films from TiO(2) and poly(vinyl sulfonic) (PVS), by immersing the films into a H(2)PtCl(6) solution and applying a 100 mu A current during different electrode position times. Scanning tunnel microscopy (STM) and atomic force microscopy (AFM) images showed increased platinum particle size and electrode roughness for increasing electrodeposition times. The potentiodynamic profile of the electrodes indicated that oxygen-like species in 0.5 mol L(-1) H(2)SO(4) were formed at less positive potentials for the smallest platinum particles. Electrochemical impedance spectroscopy measurements confirmed the high reactivity for the water dissociation and the large amount of oxygen-like species adsorbed on the smallest platinum nanoparticles. This high oxophilicity of the smallest nanoparticles was responsible for the electrocatalytic activity of Pt-TiO(2)/PVS systems for methanol electrooxidation, according to the Langmuir-Hinshelwood bifunctional mechanism. Significantly, the approach used here combining platinum electrodeposition and LbL matrices allows one to both control the particle size and optimize methanol electrooxidation, being therefore promising for producing membrane-electrode assemblies of DMFCs.

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We investigated three amino derivatives of ortho-aminobenzoic or anthranilic acid (o-Abz): a) 2-Amino-benzamide (AbzNH(2)); b) 2-Amino-N-methyl-benzamide (AbzNHCH(3)) and c) 2-Amino-N-N`-dimethyl-bezamide (AbzNH(CH(3))(2)), see Scheme 1. We describe the results of ab-initio calculations on the structural characteristics of the compounds and experimental studies about solvent effects in their absorption and steady-state and time-resolved emission properties. Ab-initio calculations showed higher stability for the rotameric conformation in which the oxygen of carbonyl is near to the nitrogen of ortho-amino group. The derivatives present decrease in the delocalization of pi electron, and absorption bands are blue shifted compared to the parent compound absorption, the extent of the effect increasing from to Abz-NH(2) to Abz-NHCH(3) Abz-NH(CH(3))(2). Measurements performed in several solvents have shown that the the dependence of Stokes shift of the derivatives with the orientational polarizability follows the Onsager-Lippert model for general effects of solvent. However deviation occurred in solvents with properties of Bronsted acids, or electron acceptor characteristics, so that hydrogen bonds formed with protic solvents predominates over intramolecular hydrogen bond. In most solvents the fluorescence decay of AbzNH(2) and AbzNHCH(3) was fitted to a single exponential with lifetimes around 7.0 ns and no correlation with polarity of the solvent was observed. The fluorescence decay of AbzN(CH(3))(2) showed lifetimes around 2.0 ns, consistent with low quantum yield of the compound. The spectroscopic properties of the monoamino derivative AbzNHCH(3) are representative of the properties presented by Abz labelled peptides and fatty acids previously studied.

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The title compound, C(8)H(14)N(2)O(5)S 2(H(2)O), 2-amino-3-(N-oxipiridin-4-ilsulfanil)-propionic acid dihydrate, is obtained by the reaction of cysteine and 4-nitropyridine N-oxide in dimethylformamide, removing the NO(2) group from the benzene ring and releasing nitrous acid into the solution. The molecule exists as a Zwitterion. Hydrogen bond interactions involving the title molecule and water molecules allow the formation of R(5)(5)(23) edge fused rings parallel to (010). Water molecules are connected independently, forming infinite chains (wires), in square wave form, along the b-axis. The chirality of the cysteine molecule used in the synthesis is retained in the title molecule. A density functional theory (DFT) optimized structure at the B3LYP/6-311G(3df,2p) level allows comparison of calculated and experimental IR spectra.

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Substance P (SP) is a neuropeptide that can modulate inflammatory mediator release through activation of NK(1) receptors (NK(1)R). Some studies have also suggested the involvement of SP in lipopolysaccharide (LPS)-induced fever. However, the precise contribution of this neuropeptide to the pathways activated during fever is unknown. In this study we investigated the effect of a selective NK(1)R antagonist, SR140333B, on the febrile response induced by LPS and cytokines. Our results show that the systemic injection of SR140333B did not modify the fever induced by LPS at a dose that is able to reduce protein extravasation induced by SP in the skin. On the other hand, intracerebroventricular administration of 5R140333B significantly reduced the fever induced by peripheral injection of LPS. These data emphasize an important role for SP in the central nervous system during the febrile response to LPS, and are reinforced by the fact that intracerebroventricular injection of SP also induced fever in a dose-dependent manner in captopril-treated rats. Considering that the febrile response can result from the generation of several endogenous pyrogens, among them interleukin (IL)-1 beta and macrophage inflammatory protein-1 alpha (CCL3/MIP-1 alpha), we also examined the effect of SR140333B on the fever induced by these cytokines which act through prostaglandin-dependent and independent mechanisms, respectively. Surprisingly, SR140333B did not modify the febrile response to IL-1 beta or CCL3/MIP-1 alpha. Altogether these data suggest that the central action of SP is essential for LPS-, but not for IL-1 beta- or CCL3/MIP-1 alpha-induced fever. (C) 2011 Elsevier B.V. All rights reserved.