68 resultados para POTENTIAL USE
em Biblioteca Digital da Produção Intelectual da Universidade de São Paulo (BDPI/USP)
Resumo:
particularly neutrophil chemoattraction. Herein, the role of C5a in the genesis of inflammatory hypernociception was investigated in rats and mice using the specific C5a receptor antagonist PMX53 (AcF-[OP(D-Cha)WR]). Experimental approach: Mechanical hypernociception was evaluated with a modification of the Randall-Selitto test in rats and electronic pressure meter paw test in mice. Cytokines were measured by ELISA and neutrophil migration was determined by myeloperoxidase activity. Key results: Local pretreatment of rats with PMX53 (60-180 mg per paw) inhibited zymosan-, carrageenan-, lipopolysaccharide (LPS)- and antigen-induced hypernociception. These effects were associated with C5a receptor blockade since PMX53 also inhibited the hypernociception induced by zymosan- activated serum and C5a but not by the direct-acting hypernociceptive mediators, prostaglandin E-2 and dopamine. Underlying the C5a hypernociceptive mechanisms, PMX53 did not alter the cytokine release induced by inflammatory stimuli. However, PMX53 inhibited cytokine-induced hypernociception. PMX53 also inhibited the recruitment of neutrophils induced by zymosan but not by carrageenan or LPS, indicating an involvement of neutrophils in the hypernociceptive effect of C5a. Furthermore, the C5a-induced hypernociception was reduced in neutrophil-depleted rats. Extending these findings in rats, blocking C5a receptors also reduced zymosan- induced joint hypernociception in mice. Conclusions and implications: These results suggest that C5a is an important inflammatory hypernociceptive mediator, acting by a mechanism independent of hypernociceptive cytokine release, but dependent on the presence of neutrophils. Therefore, we suggest that inhibiting the action of C5a has therapeutic potential in the control of inflammatory pain.
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Leather industries which promote hide stabilization by the conventional chrome-tanning process are a major source of pollution because of the resultant chromium-rich wastes. In this work, an extensive characterization of such a chromium-rich waste sludge is presented, regarding its chemical composition (XRF), crystalline phase contents (XRD), organic carbon content (TOC), thermal behavior by thermogravimetry (TG) and differential scanning calorimetry (DSC), as well as its stability under chemical attack (the concentration of important ions in the leachates being determined by capillary electrophoresis) and when submitted to temperatures as high as 1100 degrees C, in air. The material showed the tendency to produce some undesirable, and previously non-detected hexavalent chromium when exposed to high temperatures, but after washing off the soluble salts and the elimination of the organic matter by firing, the resultant material was succesfully tested as a ceramic pigment in a conventional glaze composition usually employed in the ceramic the industry. (C) 2009 Elsevier Ltd and Techna Group S.r.l. All rights reserved.
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In this work, the biodegradation mechanism of phenol and sub products (such as catechol and hydroquinone) in Chromobacterium violaceum was investigated by cloning and molecular characterization of a phenol monooxygenase gene in Escherichia coli. This gene (Cvmp) is very similar (74 and 59% of similarity and identity, respectively) to the ortholog from Ralstonia eutropha, bacteria capable of utilizing phenol as the sole carbon source. The phenol biodegradation ability of E. coli recombinant strains was tested by cell-growth in a minimal medium containing phenol as the sole source of carbon and release of intermediary metabolites (catechol and hydroquinone). Interestingly, during the growth of these strains on phenol, catechol, and hydroquinone accumulated transiently in the medium. These metabolites were further analyzed by HPLC. These results indicated that phenol can be initially orto or para hydroxylated to produce cathecol or hydroquinone, respectively, followed by meta-cleavage of aromatic rings. To verify this information, the metabolites obtained from HPLC were submitted to LC/MS to confirm their chemical structure, thereby indicating that the recombinant strains utilize two different routes simultaneously, leading to different ring-fission substrates for the metabolism of phenol. (C) KSBB
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Neutrophil migration is responsible for tissue damage observed in inflammatory diseases and is also implicated in inflammatory nociception. The use of lectins has been demonstrated to be effective in different activities including anti-inflammatory, antimicrobial, and in cancer therapy. In this study, we addressed the potential use of a lectin from Canavalia grandiflora seeds (ConGF) to control neutrophil migration and inflammatory hypernociception. Pretreatment of the animals intravenously (15 min before) with ConGF inhibited neutrophil migration to the peritoneal cavity in a dose-dependent fashion confirmed by an inhibition of rolling and adhesion of leukocytes by intravital microscopy. Another set of experiments showed that pretreatment of the animals with ConGF inhibited the mechanical hypernociception in mice induced by the i.pl. injection of carrageenan or formalin. This anti-nociceptive effect correlated with an effective blockade of neutrophil influx, as assessed by the hind paw tissue myeloperoxidase levels. Furthermore, ConGF had important inhibitory effects on the mouse carrageenan-induced paw edema. In addition, animals treated with ConGF showed inhibition of cytokines release. In conclusion, we demonstrated that the lectin ConGF inhibits neutrophil migration and mechanical inflammatory hypernociception.
Resumo:
The thermoluminescence (TL) characteristics of quartz are highly dependent of its thermal history. Based on the enhancement of quartz luminescence occurred after heating, some authors proposed to use quartz TL to recover thermal events that affected quartz crystals. However, little is know about the influence of the temperature of quartz crystallization on its TL characteristics. In the present study, we evaluate the TL sensitivity and dose response curves of hydrothermal and metamorphic quartz with crystallization temperatures from 209 +/- 15 to 633 +/- 27 degrees C determined through fluid inclusion and mineral chemistry analysis. The studied crystals present a cooling thermal history, which allow the acquiring of their natural TL without influence of heating after crystallization. The TL curves of the studied samples present two main components formed by different peaks overlapped around 110 C and 200-400 degrees C. The TL sensitivity in the 200-400 degrees C region increases linearly with the temperature of quartz crystallization. No relationship was observed between temperatures of quartz crystallization and saturation doses (<100 Gy). The elevated TL sensitivity of the high temperature quartz is attributed to the control exerted by the temperature of crystallization on the substitution of Si(4+) by ions such as Al(3+) and Ti(4+), which produce defects responsible for luminescence phenomena. The linear relationship observed between TL in the 200-400 degrees C region and crystallization temperature has potential use as a quartz geothermometer. The relative abundance of quartz in the earth crust and the easiness to measure TL are advantageous in relation to geothermometry methods based on chemistry of other minerals. (C) 2010 Elsevier Ltd. All rights reserved.
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An investigation was carried out to study the potential use of the angular distribution of scattered photons by human breast samples for a rapid identification of neoplasias of breast tissues. This technique has possible applications as diagnostic aid for breast cancer. In this work, a commercial powder diffractometer was used to obtain the scattering profiles from breast tissues histopathologically classified as normal breast tissues, fibroadenomas (benign breast diseases) and carcinomas (malignant breast diseases), in the interval 0.02 angstrom(-1) < x < 0.62 angstrom(-1). The experimental methods and data corrections are discussed in detail, and they included background subtraction, polarization, self-attenuation and geometric effects. The validation of the experimental procedure was achieved through an analysis of water sample. The results showed that the scattering profile is a unique impression of each type of tissue, being correlated with their microscopic morphological features. Multivariate analysis was applied to these profiles in order to verify if the information carried by these scattering profiles allow the differentiation between normal, benign and malignant breast tissues. The statistical analysis results showed that a correct identification of 75% of the analyzed samples is accomplished. The values of sensibility and specificity of this method in correctly differentiating between normal and neoplastic samples were 95.6% and 82.3%, respectively, while the values for differentiation between benign and malignant neoplasias were 78.6% and 62.5%. These initial results indicate the feasible use of commercial powder diffractometer to provide a rapid diagnostic with a high sensitivity.
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Head and neck squamous cell carcinoma (HNSCC) is a heterogeneous disease affecting the epithelium of the oral cavity, pharynx and larynx. Conditions of most patients are diagnosed at late stages of the disease, and no sensitive and specific predictors of aggressive behavior have been identified yet. Therefore, early detection and prognostic biomarkers are highly desirable for a more rational management of the disease. Hypermethylation of CpG islands is one of the most important epigenetic mechanisms that leads to gene silencing in tumors and has been extensively used for the identification of biomarkers. In this study, we combined rapid subtractive hybridization and microarray analysis in a hierarchical manner to select genes that are putatively reactivated by the demethylating agent 5-aza-2'-deoxycytidine (5Aza-dC) in HNSCC cell lines (FaDu, UM-SCC-14A, UM-SCC-17A, UM-SCC-38A). This combined analysis identified 78 genes, 35 of which were reactivated in at least 2 cell lines and harbored a CpG island at their 5' region. Reactivation of 3 of these 35 genes (CRABP2, MX1, and SLC15A3) was confirmed by quantitative real-time polymerase chain reaction (PCR; fold change, >= 3). Bisulfite sequencing of their CpG islands revealed that they are indeed differentially methylated in the HNSCC cell lines. Using methylation-specific PCR, we detected a higher frequency of CRABP2 (58.1% for region 1) and MX1 (46.3%) hypermethylation in primary HNSCC when compared with lymphocytes from healthy individuals. Finally, absence of the CRABP2 protein was associated with decreased disease-free survival rates, supporting a potential use of CRABP2 expression as a prognostic biomarker for HNSCC patients.
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The seeds of Theobroma cacao (cacao) are the source of cocoa, the raw material for the multi-billion dollar chocolate industry. Cacao`s two most important traits are its unique seed storage triglyceride (cocoa butter) and the flavor of its fermented beans (chocolate). The genome of T. cacao is being sequenced, and to expand the utility of the genome sequence to the improvement of cacao, we are evaluating Theobroma grandiflorum, the closest economically important species of Theobroma for its potential use in a comparative genomic study. T. grandiflorum differs from cacao in important agronomic traits such as flavor of the fermented beans, disease resistance to witches` broom and abscission of mature fruits. By comparing genomic sequences and analyzing viable inter-specific hybrids, we hope to identify the key genes that regulate cacao`s most important traits. We have investigated the utility in T. grandiflorum of three types of markers (microsatellite markers, single-strand conformational polymorphism markers and single nucleotide polymorphism (SNP) markers) developed in cacao. Through sequencing of amplicons of 12 diverse individuals of both cacao and T. grandiflorum, we have identified new intra- and inter-specific SNPs. Two markers which had no overlap of alleles between the species were used to genotype putative inter-specific hybrid seedlings. Sequence conservation was significant and species-specific differences numerous enough to suggest that comparative genomics of T. grandiflorum and T. cacao will be useful in elucidating the genetic differences that lead to a variety of important agronomic trait differences.
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The main objective of this research was to evaluate the potential use of a bench-scale anaerobic sequencing batch biofilm reactor (ASBBR) containing mineral coal as inert support for removal Of Sulfide and organic matter effluents from an ASBBR (1.2 m(3)) utilized for treatment of sulfate-rich wastewater. The cycle time was 48 h, including the steps of feeding (2 h), reaction with continuous liquid recirculation (44 h) and discharge (2 h). COD removal efficiency was up to 90% and the effluents total sulfide concentrations (H(2)S, HS(-), S(2-)) remained in the range of 1.5 to 7.5 mg.l(-1) during the 50 days of operation (25 cycles). The un-ionized Sulfide and ionized sulfides were converted by biological process to elemental sulfur (S(0)) under oxygen limited conditions. The results obtained in the bench-scale reactor were used to design an ASBBR in pilot scale for use in post-treatment to achieve the emission standards (sulfide and COD) for sulfate reduction. The pilot-scale reactor, with a total volume of 0.43 m(3), the COD and total sulfide removal achieved 88% and 57%, respectively, for a cycle time of 48 h (70 days of operation or 35 cycles).
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This study presents a methodology for the characterization of construction and demolition (C&D) waste recycled aggregates based on a combination of analytical techniques (X-ray fluorescence (XRF), soluble ions, semi-quantitative X-ray diffraction (XRD), thermogravimetric analysis (TCA-DTG) and hydrochloric acid (HCl) selective dissolution). These combined analytical techniques allow for the estimation of the amount of cement paste, its most important hydrated and carbonated phases, as well as the amount of clay and micas. Details of the methodology are presented here and the results of three representative C&D samples taken from the Sao Paulo region in Brazil are discussed. Chemical compositions of mixed C&D aggregate samples have mostly been influenced by particle size rather than the visual classification of C&D into red or grey and geographical origin. The amount of measured soluble salts in C&D aggregates (0.15-25.4 mm) is lower than the usual limits for mortar and concrete production. The content of porous cement paste in the C&D aggregates is around 19.3% (w/w). However, this content is significantly lower than the 43% detected for the C&D powders (< 0.15 min). The clay content of the powders was also high, potentially resulting from soil intermixed with the C&D waste, as well as poorly burnt red ceramic. Since only about 50% of the measured CaO is combined with CO(2), the powders have potential use as raw materials for the cement industry. (C) 2008 Elsevier Ltd. All rights reserved.
Resumo:
Methylobacterium mesophilicum, originally isolated as an endophytic bacterium from citrus plants, was genetically transformed to express green fluorescent protein (GFP). The GFP-labeled strain of M. mesophilicum was inoculated into Catharanthus roseus (model plant) seedlings and further observed colonizing its xylem vessels. The transmission of this endophyte by Bucephalogonia xanthophis, one of the insect vectors that transmit Xylella fastidiosa subsp. pauca, was verified by insects feeding from fluids containing the GFP bacterium followed by transmission to plants and isolating the endophyte from C. roseus plants. Forty-five days after inoculation, the plants exhibited endophytic colonization by M. mesophilicum, confirming this bacterium as a nonpathogenic, xylem-associated endophyte. Our data demonstrate that M. mesophilicum not only occupy the same niche of X. fastidiosa subsp. pauca inside plants but also may be transmitted by B. xanthophis. The transmission, colonization, and genetic manipulation of M. mesophilicum is a prerequisite to examining the potential use of symbiotic control to interrupt the transmission of X. fastidiosa subsp. pauca, the bacterial pathogen causing Citrus variegated chlorosis by insect vectors.
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BACKGROUND: The interaction between lipoxygenase-active soybean flour (LOX) and ascorbic acid (AA), on colour, rheological and sensory properties of wheat bread was studied with the aim of reducing the applied quantity of additives in bread formulations. RESULTS: The ascorbic acid (0-500 ppm) and active soybean flour (0-1%) mixture improved bread-crumb colour by lowering the yellow hue in a higher proportion than those expressed by the components alone, characterising a synergistic mechanism ((y) over cap (b) = 15.1- (1.7 x LOX) - (0.5 x AA) - (5.8 x LOX x AA), where : (y) over cap (b) represent the estimated value for the yellow hue parameter). No differences in flavour and porosity were seen between the samples. As supported by the instrumental methods, breads made with active soybean flour and ascorbic acid (LOX + AA) had whiter crumbs and were softer and springier than controls as assessed by a trained sensory panel. In summary, the combination of both active soybean flour and ascorbic acid showed synergism, promoting a greater bleaching effect than when used alone. CONCLUSION: These results suggest the potential use of active soybean flour as a synergistic ingredient in the substitution of artificial additives in bread making. Since the interaction on the bleaching response was not linear and active soybean flour showed a higher iron concentration (66.40 +/- 4.23 mu g g(-1)) than non-active soybean flour (52.30 +/- 0.40 mu g g(-1)), more studies are warranted to establish the biochemical mechanisms involved in this interaction. (c) 2007 Society of Chemical Industry.
Resumo:
BACKGROUND: Aqueous two-phase micellar systems (ATPMS) are micellar surfactant solutions with physical properties that make them very efficient for the extraction/concentration of biological products. In this work the main proposal that has been discussed is the possible applicability and importance of a novel oscillatory flow micro-reactor (micro-OFR) envisaged for parallel screening and/or development of industrial bioprocesses in ATPMS. Based on the technology of oscillatory flow mixing (OFM), this batch or continuous micro-reactor has been presented as a new small-scale alternative for biological or physical-chemical applications. RESULTS: ATPMS experiments were carried out in different OFM conditions (times, temperatures, oscillation frequencies and amplitudes) for the extraction of glucose-6-phosphate dehydrogenase (G6PD) in Triton X-114/buffer with Cibacron Blue as affinity ligand. CONCLUSION: The results suggest the potential use of OFR, considering this process a promising and new alternative for the purification or pre-concentration of bioproducts. Despite the applied homogenization and extraction conditions have presented no improvements in the partitioning selectivity of the target enzyme, when at rest temperature they have influenced the partitioning behavior in Triton X-114 ATPMS. (C) 2011 Society of Chemical Industry
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Lactic acid bacteria ( LAB) are currently used by food industries because of their ability to produce metabolites with antimicrobial activity against gram-positive pathogens and spoilage microorganisms. The objectives of this study were to identify naturally occurring bacteriocinogenic or bacteriocinogenic-like LAB in raw milk and soft cheese and to detect the presence of nisin-coding genes in cultures identified as Lactococcus lactis. Lactic acid bacteria cultures were isolated from 389 raw milk and soft cheese samples and were later characterized for the production of antimicrobial substances against Listeria monocytogenes. Of these, 58 (14.9%) LAB cultures were identified as antagonistic; the nature of this antagonistic activity was then characterized via enzymatic tests to confirm the proteinaceous nature of the antimicrobial substances. In addition, 20 of these antagonistic cultures were selected and submitted to genetic sequencing; they were identified as Lactobacillus plantarum (n = 2) and Lactococcus lactis ssp. lactis (n = 18). Nisin genes were identified by polymerase chain reaction in 7 of these cultures. The identified bacteriocinogenic and bacteriocinogenic-like cultures were highly variable concerning the production and activity of antimicrobial substances, even when they were genetically similar. The obtained results indicated the need for molecular and phenotypic methodologies to properly characterize bacteriocinogenic LAB, as well as the potential use of these cultures as tools to provide food safety.