982 resultados para DIAZ, JOSE JAVIER
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BACKGROUND The anti-human epidermal growth factor receptor 2 (HER2) humanized monoclonal antibody trastuzumab improves the outcome in patients with HER2-positive metastatic breast cancer. However, most cases of advanced disease eventually progress. Pertuzumab, an anti-HER2 humanized monoclonal antibody that inhibits receptor dimerization, has a mechanism of action that is complementary to that of trastuzumab, and combination therapy with the two antibodies has shown promising activity and an acceptable safety profile in phase 2 studies involving patients with HER2-positive breast cancer. METHODS We randomly assigned 808 patients with HER2-positive metastatic breast cancer to receive placebo plus trastuzumab plus docetaxel (control group) or pertuzumab plus trastuzumab plus docetaxel (pertuzumab group) as first-line treatment until the time of disease progression or the development of toxic effects that could not be effectively managed. The primary end point was independently assessed progression-free survival. Secondary end points included overall survival, progression-free survival as assessed by the investigator, the objective response rate, and safety. RESULTS The median progression-free survival was 12.4 months in the control group, as compared with 18.5 months in the pertuzumab group (hazard ratio for progression or death, 0.62; 95% confidence interval, 0.51 to 0.75; P<0.001). The interim analysis of overall survival showed a strong trend in favor of pertuzumab plus trastuzumab plus docetaxel. The safety profile was generally similar in the two groups, with no increase in left ventricular systolic dysfunction; the rates of febrile neutropenia and diarrhea of grade 3 or above were higher in the pertuzumab group than in the control group. CONCLUSIONS The combination of pertuzumab plus trastuzumab plus docetaxel, as compared with placebo plus trastuzumab plus docetaxel, when used as first-line treatment for HER2-positive metastatic breast cancer, significantly prolonged progression-free survival, with no increase in cardiac toxic effects. (Funded by F. Hoffmann-La Roche/Genentech; ClinicalTrials.gov number, NCT00567190.)
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BACKGROUND Vorapaxar is a new oral protease-activated receptor 1 (PAR-1) antagonist that inhibits thrombin-induced platelet activation. METHODS In this multinational, double-blind, randomized trial, we compared vorapaxar with placebo in 12,944 patients who had acute coronary syndromes without ST-segment elevation. The primary end point was a composite of death from cardiovascular causes, myocardial infarction, stroke, recurrent ischemia with rehospitalization, or urgent coronary revascularization. RESULTS Follow-up in the trial was terminated early after a safety review. After a median follow-up of 502 days (interquartile range, 349 to 667), the primary end point occurred in 1031 of 6473 patients receiving vorapaxar versus 1102 of 6471 patients receiving placebo (Kaplan-Meier 2-year rate, 18.5010 vs. 19.9%; hazard ratio, 0.92; 95% confidence interval [CI], 0.85 to 1.01; P=0.07). A composite of death from cardiovascular causes, myocardial infarction, or stroke occurred in 822 patients in the vorapaxar group versus 910 in the placebo group (14.7% and 16.4%, respectively; hazard ratio, 0.89; 95% CI, 0.81 to 0.98; P=0.02). Rates of moderate and severe bleeding were 7.2% in the vorapaxar group and 5.2% in the placebo group (hazard ratio, 1.35; 95% CI, 1.16 to 1.58; P<0.001). Intracranial hemorrhage rates were 1.1% and 0.2%, respectively (hazard ratio, 3.39; 95% CI, 1.78 to 6.45; P<0.001). Rates of nonhemorrhagic adverse events were similar in the two groups. CONCLUSIONS In patients with acute coronary syndromes, the addition of vorapaxar to standard therapy did not significantly reduce the primary composite end point but significantly increased the risk of major bleeding, including intracranial hemorrhage. (Funded by Merck; TRACER ClinicalTrials.gov number, NCT00527943.)
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Triatoma matogrossensis is a Hemiptera that belongs to the oliveirai complex, a vector of Chagas' disease that feeds on vertebrate blood in all life stages. Hematophagous insects' salivary glands (SGs) produce potent pharmacologic compounds that counteract host hemostasis, including anticlotting, antiplatelet, and vasodilatory molecules. Exposure to T. matogrossensis was also found to be a risk factor associated with the endemic form of the autoimmune skin disease pemphigus foliaceus, which is described in the same regions where Chagas' disease is observed in Brazil. To obtain a further insight into the salivary biochemical and pharmacologic diversity of this kissing bug and to identify possible allergens that might be associated with this autoimmune disease, a cDNA library from its SGs was randomly sequenced. We present the analysis of a set of 2,230 (SG) cDNA sequences, 1,182 of which coded for proteins of a putative secretory nature.
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Purpose - The purpose of this paper is to present a method to analyze the noise in aircraft cabins through the VHF Aeronautical Communication Channel, aimed at examining an environment that has the possibility of communication problems between the aircraft crew and the professionals responsible for the controls on land. Design/methodology/approach - This analysis includes equipment normally used for identification and comparison of electromagnetic noise, the cabin and the environment that are present in an airport, as well as equipment for frequency analysis and intensity of those signals. The analysis is done in a reverse way, eliminating situations that are not common in the examined environment, until the identification of the situation with the irregularity. Findings - According to the results, the implementation of the Fourier transform for noise analysis in the cabin was efficient. These results demonstrate that through this transformation, the noise sources can be identified in the environments in cases where there is much spectrum pollution. Research limitations/implications - This kind of noise analysis is important, considering the importance of having good accuracy in airport environment analysis. Originality/value - The paper presents the main trends in the future of aviation communications, and describes the new applications that aim to minimize problems with the current VHF channel.
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A taxonomic and annotated functional description of microbial life was deduced from 53 Mb of metagenomic sequence retrieved from a planktonic fraction of the Neotropical high Andean (3,973 meters above sea level) acidic hot spring El Coquito (EC). A classification of unassembled metagenomic reads using different databases showed a high proportion of Gammaproteobacteria and Alphaproteobacteria (in total read affiliation), and through taxonomic affiliation of 16S rRNA gene fragments we observed the presence of Proteobacteria, micro-algae chloroplast and Firmicutes. Reads mapped against the genomes Acidiphilium cryptum JF-5, Legionella pneumophila str. Corby and Acidithiobacillus caldus revealed the presence of transposase-like sequences, potentially involved in horizontal gene transfer. Functional annotation and hierarchical comparison with different datasets obtained by pyrosequencing in different ecosystems showed that the microbial community also contained extensive DNA repair systems, possibly to cope with ultraviolet radiation at such high altitudes. Analysis of genes involved in the nitrogen cycle indicated the presence of dissimilatory nitrate reduction to N2 (narGHI, nirS, norBCDQ and nosZ), associated with Proteobacteria-like sequences. Genes involved in the sulfur cycle (cysDN, cysNC and aprA) indicated adenylsulfate and sulfite production that were affiliated to several bacterial species. In summary, metagenomic sequence data provided insight regarding the structure and possible functions of this hot spring microbial community, describing some groups potentially involved in the nitrogen and sulfur cycling in this environment. Citation: Jimenez DJ, Andreote FD, Chaves D, Montana JS, Osorio-Forero C, et al. (2012) Structural and Functional Insights from the Metagenome of an Acidic Hot Spring Microbial Planktonic Community in the Colombian Andes. PLoS ONE 7(12): e52069. doi:10.1371/journal.pone.0052069
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The aim of this study was the isolation of the LAAO from Lachesis muta venom (LmLAAO) and its biochemical, functional and structural characterization. Two different purification protocols were developed and both provided highly homogeneous and active LmLAAO. It is a homodimeric enzyme with molar mass around 120 kDa under non-reducing conditions, 60 kDa under reducing conditions in SDS-PAGE and 60852 Da by mass spectrometry. Forty amino acid residues were directly sequenced from LmLAAO and its complete cDNA was identified and characterized from an Expressed Sequence Tags data bank obtained from a venom gland. A model based on sequence homology was manually built in order to predict its three-dimensional structure. LmLAAO showed a catalytic preference for hydrophobic amino acids (K-m of 0.97 mmol/L with Leu). A mild myonecrosis was observed histologically in mice after injection of 100 mu g of LmLAAO and confirmed by a 15-fold increase in CK activity. LmLAAO induced cytotoxicity on AGS cell line (gastric adenocarcinoma, IC50: 22.7 mu g/mL) and on MCF-7 cell line (breast adenocarcinoma, IC50:1.41 mu g/mL). It presents antiparasitic activity on Leishmania brasiliensis (IC50: 2.22 mu g/nnL), but Trypanosoma cruzi was resistant to LmLAAO. In conclusion, LmLAAO showed low systemic toxicity but important in vitro pharmacological actions. (C) 2012 Elsevier Ltd. All rights reserved.
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Oxidative stress and mitochondrial impairment are essential in the ischemic stroke cascade and eventually lead to tissue injury. C-Phycocyanin (C-PC) has previously been shown to have strong antioxidant and neuroprotective actions. In the present study, we assessed the effects of C-PC on oxidative injury induced by tert-butylhydroperoxide (t-BOOH) in SH-SY5Y neuronal cells, on transient ischemia in rat retinas, and in the calcium/phosphate-induced impairment of isolated rat brain mitochondria (RBM). In SH-SY5Y cells, t-BOOH induced a significant reduction of cell viability as assessed by an MTT assay, and the reduction was effectively prevented by treatment with C-PC in the low micromolar concentration range. Transient ischemia in rat retinas was induced by increasing the intraocular pressure to 120 mmHg for 45 min, which was followed by 15 min of reperfusion. This event resulted in a cell density reduction to lower than 50% in the inner nuclear layer (INL), which was significantly prevented by the intraocular pre-treatment with C-PC for 15 min. In the RBM exposed to 3 mM phosphate and/or 100 mu M Ca2+, C-PC prevented in the low micromolar concentration range, the mitochondrial permeability transition as assessed by mitochondrial swelling, the membrane potential dissipation, the increase of reactive oxygen species levels and the release of the pro-apoptotic cytochrome c. In addition, C-PC displayed a strong inhibitory effect against an electrochemically-generated Fenton reaction. Therefore, C-PC is a potential neuroprotective agent against ischemic stroke, resulting in reduced neuronal oxidative injury and the protection of mitochondria from impairment. (C) 2012 Elsevier Inc. All rights reserved.
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Knowledge of hospital costs is highly important for public health decision-making. This study aimed to estimate direct hospital costs related to pneumococcal meningitis in children 13 years or younger in the city of Sao Jose dos Campos, Sao Paulo State, Brazil, from January 1999 to December 2008. Data were obtained from medical records. Hospital costs were calculated according to the mixed method for measurement of quantities of items with identified costs and value attribution to items consumed (micro-costing and gross-costing). All costs were calculated according to monetary values for November 2009 and in Brazilian currency (Real). Epi Info 3.5.1 was used for frequencies and means analysis. Forty-one cases were reported. Direct hospital costs varied from R$ 1,277.90 to R$ 19,887.56 (mean = R$ 5,666.43), or 10 to 20 times the mean cost of hospitalization for other diseases. Hospital staff labor was the highest cost, followed by medication, procedures, supplies, and lab tests.
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Two novel sesquiterpene lactones were isolated from crude extract of the Eremanthus seidelii leaves. Reliable structural elucidations to these lactones were established by 1D and 2D NMR spectroscopic techniques and high-resolution electrospray mass spectrometry data. (C) 2012 Elsevier Ltd. All rights reserved.
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Tuberculosis (TB) is a major infectious disease caused by Mycobacterium tuberculosis (Mtb). According to the World Health Organization (WHO), about 1.8 million people die from TB and 10 million new cases are recorded each year. Recently, a new series of naphthylchalcones has been identified as inhibitors of Mtb protein tyrosine phosphatases (PTPs). In this work, 100 chalcones were designed, synthesized, and investigated for their inhibitory properties against MtbPtps. Structure-activity relationships (SAR) were developed, leading to the discovery of new potent inhibitors with IC50 values in the low-micromolar range. Kinetic studies revealed competitive inhibition and high selectivity toward the Mtb enzymes. Molecular modeling investigations were carried out with the aim of revealing the most relevant structural requirements underlying the binding affinity and selectivity of this series of inhibitors as potential anti-TB drugs.
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Oxygen-deficient TiO2 films with enhanced visible and near-infrared optical absorption have been deposited by reactive sputtering using a planar diode radio frequency magnetron configuration. It is observed that the increase in the absorption coefficient is more effective when the O-2 gas supply is periodically interrupted rather than by a decrease of the partial O-2 gas pressure in the deposition plasma. The optical absorption coefficient at 1.5 eV increases from about 1 x 10(2) cm(-1) to more than 4 x 10(3) cm(-1) as a result of the gas flow discontinuity. A red-shift of similar to 0.24 eV in the optical absorption edge is also observed. High resolution transmission electron microscopy with composition analysis shows that the films present a dense columnar morphology, with estimated mean column width of 40nm. Moreover, the interruptions of the O-2 gas flow do not produce detectable variations in the film composition along its growing direction. X-ray diffraction and micro-Raman experiments indicate the presence of the TiO2 anatase, rutile, and brookite phases. The anatase phase is dominant, with a slight increment of the rutile and brookite phases in films deposited under discontinued O-2 gas flow. The increase of optical absorption in the visible and near-infrared regions has been attributed to a high density of defects in the TiO2 films, which is consistent with density functional theory calculations that place oxygen-related vacancy states in the upper third of the optical bandgap. The electronic structure calculation results, along with the adopted deposition method and experimental data, have been used to propose a mechanism to explain the formation of the observed oxygen-related defects in TiO2 thin films. The observed increase in sub-bandgap absorption and the modeling of the corresponding changes in the electronic structure are potentially useful concerning the optimization of efficiency of the photocatalytic activity and the magnetic doping of TiO2 films. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4724334]
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The exploration of novel synthetic methodologies that control both size and shape of functional nanostructure opens new avenues for the functional application of nanomaterials. Here, we report a new and versatile approach to synthesize SnO2 nanocrystals (rutile-type structure) using microwave-assisted hydrothermal method. Broad peaks in the X-ray diffraction spectra indicate the nanosized nature of the samples which were indexed as a pure cassiterite tetragonal phase. Chemically and physically adsorbed water was estimated by TGA data and FT-Raman spectra to account for a new broad peak around 560 cm(-1) which is related to defective surface modes. In addition, the spherical-like morphology and low dispersed distribution size around 3-5 nm were investigated by HR-TEM and FE-SEM microscopies. Room temperature PL emission presents two broad bands at 438 and 764 nm, indicating the existence of different recombination centers. When the size of the nanospheres decreases, the relative intensity of 513 nm emission increases and the 393 nm one decreases. UV-Visible spectra show substantial changes in the optical absorbance of crystalline SnO2 nanoparticles while the existence of a small tail points out the presence of localized levels inside the forbidden band gap and supplies the necessary condition for the PL emission.
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The arene-ruthenium complex [Ru(eta(6)-C10H14)(dppf)Cl]PF6 (1) was used as a precursor for the syntheses of the [Ru(eta(6)-C10H14)(dppf)Br]PF6 (2), [Ru(eta(6)-C10H14)(dppf)I]PF6 (3). [Ru(eta(6)-C10H14)(dppf)SnF3]PF6 (4) and [Ru(eta(6)-C10H14)(dppf)Cl][SnCl3]center dot 0.45CH(2)Cl(2) (5) complexes by its reactions with KBr, Kl, SnF2 and SnCl2. respectively. All of the compounds were characterized by NMR, IR, Fe-57 and Sn-119-Mossbauer spectroscopy, and cyclic voltammetry. The single-crystal X-ray structure analysis of the [Ru(eta(6)-C10H14)(dppf)Cl] [SnCl3]center dot 0.45CH(2)Cl(2) complex revealed the expected piano-stool geometry. Cyclic voltammograms of the complexes showed only one quasi-reversible electrochemical process, involving the oxidation of Fe(II) and Ru(II) at the same potential, which was confirmed by exhaustive electrolysis experiments. Fe-57-Mossbauer parameters obtained for the complexes (1-5) were fitted with one doublet corresponding to a site of one iron(II). The Sn-119-Mossbauer parameters of the complex (4) indicate that tin is tetra covalent. (c) 2012 Elsevier Ltd. All rights reserved.
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Background: Acute respiratory distress syndrome (ARDS) is associated with high in-hospital mortality. Alveolar recruitment followed by ventilation at optimal titrated PEEP may reduce ventilator-induced lung injury and improve oxygenation in patients with ARDS, but the effects on mortality and other clinical outcomes remain unknown. This article reports the rationale, study design, and analysis plan of the Alveolar Recruitment for ARDS Trial (ART). Methods/Design: ART is a pragmatic, multicenter, randomized (concealed), controlled trial, which aims to determine if maximum stepwise alveolar recruitment associated with PEEP titration is able to increase 28-day survival in patients with ARDS compared to conventional treatment (ARDSNet strategy). We will enroll adult patients with ARDS of less than 72 h duration. The intervention group will receive an alveolar recruitment maneuver, with stepwise increases of PEEP achieving 45 cmH(2)O and peak pressure of 60 cmH2O, followed by ventilation with optimal PEEP titrated according to the static compliance of the respiratory system. In the control group, mechanical ventilation will follow a conventional protocol (ARDSNet). In both groups, we will use controlled volume mode with low tidal volumes (4 to 6 mL/kg of predicted body weight) and targeting plateau pressure <= 30 cmH2O. The primary outcome is 28-day survival, and the secondary outcomes are: length of ICU stay; length of hospital stay; pneumothorax requiring chest tube during first 7 days; barotrauma during first 7 days; mechanical ventilation-free days from days 1 to 28; ICU, in-hospital, and 6-month survival. ART is an event-guided trial planned to last until 520 events (deaths within 28 days) are observed. These events allow detection of a hazard ratio of 0.75, with 90% power and two-tailed type I error of 5%. All analysis will follow the intention-to-treat principle. Discussion: If the ART strategy with maximum recruitment and PEEP titration improves 28-day survival, this will represent a notable advance to the care of ARDS patients. Conversely, if the ART strategy is similar or inferior to the current evidence-based strategy (ARDSNet), this should also change current practice as many institutions routinely employ recruitment maneuvers and set PEEP levels according to some titration method.
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Global dengue virus spread in tropical and sub-tropical regions has become a major international public health concern. It is evident that DENV genetic diversity plays a significant role in the immunopathology of the disease and that the identification of polymorphisms associated with adaptive responses is important for vaccine development. The investigation of naturally occurring genomic variants may play an important role in the comprehension of different adaptive strategies used by these mutants to evade the human immune system. In order to elucidate this role we sequenced the complete polyprotein-coding region of thirty-three DENV-3 isolates to characterize variants circulating under high endemicity in the city of São José de Rio Preto, Brazil, during the onset of the 2006-07 epidemic. By inferring the evolutionary history on a local-scale and estimating rates of synonymous (dS) and nonsynonimous (dN) substitutions, we have documented at least two different introductions of DENV-3 into the city and detected 10 polymorphic codon sites under significant positive selection (dN/dS > 1) and 8 under significant purifying selection (dN/dS < 1). We found several polymorphic amino acid coding sites in the envelope (15), NS1 (17), NS2A (11), and NS5 (24) genes, which suggests that these genes may be experiencing relatively recent adaptive changes. Furthermore, some polymorphisms correlated with changes in the immunogenicity of several epitopes. Our study highlights the existence of significant and informative DENV variability at the spatio-temporal scale of an urban outbreak.