58 resultados para event sequences


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Two experiments were conducted to investigate the effect of a threatening stimulus in human adults in a temporal bisection task. In Experiment I. for two anchor duration conditions (400/800 vs. 800/1600 ms), the participants completed trials in which the probe duration was followed by an aversive stimulus or a nonaversive stimulus. The results showed that the duration was judged longer when the participants expected an aversive rather than a nonaversive stimulus. In Experiment 2, the effect of the temporal localization of the aversive stimulus was also tested, with the aversive stimulus being presented at the beginning or at the end of the probe duration. The results revealed a temporal overestimation in each condition compared to the trials in which no aversive stimulus was presented. Furthermore, the temporal overestimation was greater when the expectation for the forthcoming threatening stimulus was longer. This temporal overestimation is explained in terms of a speeding-up of the neural timing system in response to the increase in the arousal level produced by the expectation of a threatening stimulus.

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Background:. Although the role of the lung alveolar macrophage (AM) as a mediator of acute lung injury (ALI) after lung ischemia/reperfusion (I/R) has been suggested by animal experiments, it has not been determined whether AMs mediate ALI after intestinal I/R. The objective of this study was to determine the effect of AM elimination on ALI after intestinal I/R in rats. Mwthods: Male Wistar rats (n = 90) were randomly divided into three groups: the clodronate-liposomes (CLOD-LIP) group received intratracheal treatment with CLOD-LIP; the liposomes (LIP) group received intratracheal treatment with LIP; and the nontreated (UNTREAT) group received no treatment. Twenty-four hours later each group was randomly divided into three subgroups: the intestinal I/R subgroup was subjected to 45-minute intestinal ischemia and 2-hour reperfusion; the laparotomy (LAP) subgroup was subjected to LAP and sham procedures; the control (CTR) subgroup received no treatment. At the end of reperfusion, ALI was quantitated in all the animals by the Evans blue dye (EBD) method. Results: ALI values are expressed as EBD lung leakage (mu g EBD/g dry lung weight). EBD lung leakage values in the CLOD-LIP group were 32.59 +/- 12.74 for I/R, 27.74 +/- 7.99 for LAP, and 33.52 +/- 10.17 for CTR. In the LIP group, lung leakage values were 58.02 +/- 18.04 for I/R, 31.90 +/- 8.72 for LAP, and 27.17 +/- 11.48 for CTR. In the UNTREAT group, lung leakage values were 55.60 +/- 10.96 for I/R, 35.99 +/- 6.89 for LAP, and 30.83 +/- 8.41 for CTR. Within each group, LAP values did not differ from CTR values. However, in the LIP and UNTREAT groups, values for both the LAP and CTR subgroups were lower than values for the I/R subgroup (p < 0.001). The CLOD-LIP I/R subgroup value was less (p < 0.001) than the I/R subgroup values in the LIP and UNTREAT groups. These results indicated that I/R provokes ALI that can be prevented by CLOD-LIP treatment, and further suggested that AMs are essential for ALI occurrence induced by intestinal I/R in rats.

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Background The protease-activated receptor 1 (PAR-1), the main platelet receptor for thrombin, represents a novel target for treatment of arterial thrombosis, and SCH 530348 is an orally active, selective, competitive PAR-1 antagonist. We designed TRA.CER to evaluate the efficacy and safety of SCH 530348 compared with placebo in addition to standard of care in patients with non-ST-segment elevation (NSTE) acute coronary syndromes (ACS) and high-risk features. Trial design TRA.CER is a prospective, randomized, double-blind, multicenter, phase III trial with an original estimated sample size of 10,000 subjects. Our primary objective is to demonstrate that SCH 530348 in addition to standard of care will reduce the incidence of the composite of cardiovascular death, myocardial infarction (MI), stroke, recurrent ischemia with rehospitalization, and urgent coronary revascularization compared with standard of care alone. Our key secondary objective is to determine whether SCH 530348 will reduce the composite of cardiovascular death, MI, or stroke compared with standard of care alone. Secondary objectives related to safety are the composite of moderate and severe GUSTO bleeding and clinically significant TIMI bleeding. The trial will continue until a predetermined minimum number of centrally adjudicated primary and key secondary end point events have occurred and all subjects have participated in the study for at least I year. The TRA.CER trial is part of the large phase III SCH 530348 development program that includes a concomitant evaluation in secondary prevention. Conclusion TRA.CER will define efficacy and safety of the novel platelet PAR-1 inhibitor SCH 530348 in the treatment of high-risk patients with NSTE ACS in the setting of current treatment strategies. (Am Heart J 2009; 158:327-34.)

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Previously we found that levels of LRRC49 (leucine rich repeat containing 49; FLJ20156) transcripts were elevated in ER-positive breast tumors compared with ER-negative breast tumors. The LRRC49 gene is located on chromosome 15q23 in close proximity to the THAP10 (THAP domain containing 10) gene. These two genes have a bidirectional organization being arranged head-to-head on opposite strands, possibly sharing the same promoter region. Analysis of the promoter region of this gene pair revealed the presence of potential estrogen response elements (EREs), suggesting the potential of this promoter to be under the control of estrogen. We used quantitative real-time PCR (qPCR) to evaluate the expression of LRRC49 and THAP10 in a series of 72 primary breast tumors, and found reduced LRRC49 and THAP10 expression in 61 and 46% of the primary breast tumors analyzed, respectively. In addition, the occurrence of LRRC49/THAP10 promoter hypermethylation was examined by methylation specific PCR (MSP) in a sub-group of the breast tumors. Hypermethylation was observed in 57.5% of the breast tumors analyzed, and the levels of mRNA expression of both genes were inversely correlated with promoter hypermethylation. We investigated the effects of 17 beta-estradiol on LRRC49 and THAP10 expression in MCF-7 breast cancer cells and found both transcripts to be up-regulated 2- to 3-fold upon 17 beta-estradiol treatment. Our results show that the transcripts of LRRC49/THAP10 bidirectional gene pair are co-regulated by estrogen and that hypermethylation of the bidirectional promoter region simultaneously silences both genes. Further studies will be necessary to elucidate the role of LRRC49/THAP10 down-regulation in breast cancer.

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Positron emission tomography studies during speech have indicated a failure to show the normal activation of auditory cortical areas in stuttering individuals. In the present study, P300 event-related potentials were used to investigate possible effects of behavioral treatment on the pattern of signal amplitude and latency between waves. In order to compare variations in P300 measurements, a control group paired by age and gender to the group of stutterers, was included in the study. Findings suggest that the group of stutterers presented a significant decrease in stuttering severity after the fluency treatment program. Regarding P300 measurements, stutterers and their controls presented results within normal limits in all testing situations and no significant statistical variations between pre and post treatment testing. When comparing individual results between the testing situations, stutterers presented a higher average decrease in wave latency for the right ear following treatment. The results are discussed in light of previous P300 event-related potentials and functional imaging studies with stuttering adults. Educational objectives: The reader will learn about and be able to describe the: (1) use of P300 event-related potentials in the study of stuttering; (2) differences between stuttering and non-stuttering adults; and (3) effects of behavioral fluency treatment on cerebral activity in stuttering speakers. (C) 2011 Elsevier Inc. All rights reserved.

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Molecular epidemiological data concerning the hepatitis B virus (HBV) in Chile are not known completely. Since the HBV genotype F is the most prevalent in the country, the goal of this study was to obtain full HBV genome sequences from patients infected chronically in order to determine their subgenotypes and the occurrence of resistance-associated mutations. Twenty-one serum samples from antiviral drug-naive patients with chronic hepatitis B were subjected to full-length PCR amplification, and both strands of the whole genomes were fully sequenced. Phylogenetic analyses were performed along with reference sequences available from GenBank (n = 290). The sequences were aligned using Clustal X and edited in the SE-AL software. Bayesian phylogenetic analyses were conducted by Markov Chain Monte Carlo simulations (MCMC) for 10 million generations in order to obtain the substitution tree using BEAST. The sequences were also analyzed for the presence of primary drug resistance mutations using CodonCode Aligner Software. The phylogenetic analyses indicated that all sequences were found to be the HBV subgenotype F1b, clustered into four different groups, suggesting that diverse lineages of this subgenotype may be circulating within this population of Chilean patients. J. Med. Virol. 83: 1530-1536, 2011. (C) 2011 Wiley-Liss, Inc.

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Our objective was to assess the prognostic value of (18)F-FDG PET after 2 cycles of chemotherapy using doxorubicin, bleomycin, vinblastine, and dacarbazine (ABVD) in Hodgkin lymphoma (HL) patients overall and in subgroups of patients with early and advanced stages and with low and high risks according to the International Prognostic Score (IPS). Methods: One hundred fifteen patients with newly diagnosed HL were prospectively included in the study. All underwent standard ABVD therapy followed by consolidation radiotherapy in cases of bulky disease. After 2 cycles of ABVD, the patients were evaluated with PET (PET2). Prognostic analysis compared the 3-y event-free survival (EFS) rate to the PET2 results, clinical data, and IPS. Results: Of the 104 evaluated patients, 93 achieved complete remission after first-line therapy. During a median follow-up of 36 mo, relapse or disease progression was seen in 22 patients. Treatment failure was seen in 16 of the 30 PET2-positive patients and in only 6 of the 74 PET2-negative patients. PET2 was the only significant prognostic factor. The 3-y EFS was 53.4% for PET2-positive patients and 90.5% for PET2-negative ones (P < 0.001). When patients were categorized according to low or high IPS risk and according to early or advanced stage of disease, PET2 was also significantly associated with treatment outcome. Conclusion: PET2 is an accurate and independent predictor of EFS in HL. A negative interim (18)F-FDG PET result is highly predictive of treatment success in overall HL patients, as well as in subgroups with early or advanced-stage disease and with low or high IPS risk.

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In the kallikrein-kinin and renin-angiotensin systems the main receptors, B-1 and B-2 (kinin receptors) and AT(1) and AT(2) (angiotensin receptors) respectively, are seven-transmembrane domain G-protein-coupled receptors. Considering that the B, agonists Des-Arg(9)-BK (Arg-Pro-Pro-Gly-Phe-Ser-Pro-Phe), Lys-desArg(9)-BK or Des-Arg(10)-KD (Lys-Arg-Pro-Pro-Gly-Phe-Ser-Pro-Phe) and the AT, agonist (Asp-Arg-Val-Tyr-lle-His-Pro-Phe) have the same two residues at the C-terminal region (i.e. Pro-Phe), we hypothesized that TM V and TM VI of the B-1 receptor could play an essential role in agonist binding and activity, being these regions receptor sites for binding the C-terminal sequences of Des-Arg-kinins similarly to that observed to AT, receptor. To investigate this hypothesis, we replaced Arg(212) for Ala at the top of the TM V and the sequence 274-282 (CPYHFFAFL) in TM VI of the rat kinin B, receptor by the 32 receptor homologous sequence, 289-297 (FPFQISTFL) and subsequently analyzed the consequences of these mutations by competition binding and functional assays. Despite correct expression, observed at the mRNA and protein level by RT-PCR and confocal microscopy, respectively, no agonist binding and function was verified for the mutated receptors. Therefore, our results suggest an important role for Arg(212) in the TM V and a region of TM VI of rat B, receptor in the interaction with the C-terminal residues of Des-Arg-kinins, similar to that observed with AngII. (c) 2007 Elsevier B.V. All rights reserved.

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The lateral part of intermediate layer of superior colliculus (SCI) is a critical substrate for successful predation by rats. Hunting-evoked expression of the activity marker Fos is concentrated in SCI while prey capture in rats with NMDA lesions in SCI is impaired. Particularly affected are rapid orienting and stereotyped sequences of actions associated with predation of fast moving prey. Such deficits are consistent with the view that the deep layers of SC are important for sensory guidance of movement. Although much of the relevant evidence involves visual control of movement, less is known about movement guidance by somatosensory input from vibrissae. Indeed, our impression is that prey contact with whiskers is a likely stimulus to trigger predation. Moreover, SCI receives whisker and orofacial somatosensory information directly from trigeminal complex, and indirectly from zona incerta, parvicelular reticular formation and somatosensory barrel cortex. To better understand sensory guidance of predation by vibrissal information we investigated prey capture by rats after whisker removal and the role of superior colliculus (SC) by comparing Fos expression after hunting with and without whiskers. Rats were allowed to hunt cockroaches, after which their whiskers were removed. Two days later they were allowed to hunt cockroaches again. Without whiskers the rats were less able to retain the cockroaches after capture and less able to pursue them in the event of the cockroach escaping. The predatory behaviour of rats with re-grown whiskers returned to normal. In parallel, Fos expression in SCI induced by predation was significantly reduced in whiskerless animals. We conclude that whiskers contribute to the efficiency of rat prey capture and that the loss of vibrissal input to SCI, as reflected by reduced Fos expression, could play a critical role in predatory deficits of whiskerless rats. (C) 2011 IBRO. Published by Elsevier Ltd. All rights reserved.

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This study describes increased sarcolemmal permeability and myofilamentar damage that occur together with lipid peroxidation and protein nitration in the myocardium in severe sepsis induced by cecal ligation and puncture. Male C57BL/6 mice were submitted to moderate and severe septic injury and sham operation. Using light and laser confocal microscopy, diffuse foci of myocytolysis associated with focal disruption of the actin/myosin contractile apparatus could be seen in hearts with severe septic injury. The myocardial expressions of the sarcomeric proteins myosin and actin were downregulated by both severe and moderate injuries. The detection of albumin staining in the cytoplasm of myocytes to evaluate sarcolemmal permeability provided evidence of severe and mild injury of the plasma membrane in hearts with severe and moderate septic injury, respectively. The administration of a superoxide scavenger caused marked reduction of sarcolemmal permeability, indicating the involvement of free radicals in its genesis. On electron microscopy, these changes were seen to correspond to spread blocks of a few myocytes with fragmentation and dissolution of myofibrils, intracellular edema, and, occasionally, rupture of the sarcolemma. In addition, oxidative damage to lipids, using anti-4-hydroxynonenal, an indicator of oxidative stress and disruption of plasma membrane lipids, and to proteins, using antinitrotyrosine, a stable biomarker of peroxynitrite-mediated protein nitration, was demonstrated. These findings make plausible the hypothesis that increased sarcolemmal permeability might be a primary event in myocardial injury in severe sepsis possibly due to oxidative damage to lipids and proteins that could precede phenotypic changes that characterize a septic cardiomyopathy.

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There are data suggesting that women swallow liquids at a lower flow rate and ingest smaller volumes in each swallow than men. Our objective in this work was to compare swallowing in asymptomatic men and women by videofluoroscopy. We studied 18 men [age = 33-77 years, mean = 61 (10) years] and 12 women [age = 29-72 years, mean = 53 (15) years] who swallowed in duplicate 5 and 10 ml of liquid and paste barium boluses. None of the volunteers had dysphagia, neurologic diseases, or oral, pharyngeal, or esophageal diseases. The videofluoroscopic examination showed that for the 5-ml bolus, women had a longer oropharyngeal transit [liquid: men, 0.63 (0.21) s, women, 0.88 (0.39) s; paste: men, 0.64 (0.35) s, women, 0.94 (0.58) s], longer oral transit [liquid: men, 0.41 (0.21) s, women, 0.59 (0.35) s; paste: men, 0.39 (0.28) s, women, 0.59 (0.42) s], and longer pharyngeal clearance [liquid: men, 0.36 (0.11) s, women, 0.45 (0.16) s; paste: men, 0.42 (0.25) s, women, 0.56 (0.27) s] compared with men (p < 0.05). We conclude that there are differences in swallowing between men and women, with women having a longer oropharyngeal transit than men for a 5-ml bolus.

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Phylogenetic relationships among 21 species of mosquitoes in subgenus Nyssorhynchus were inferred from the nuclear white and mitochondrial NADH dehydrogenase subunit 6 (ND6) genes. Bayestan phylogenetic methods found that none of the three Sections within Nyssorhynchus (Albimanus, Argyritarsis, Myzorhynchella) were supported in all analyses, although Myzorhynchella was found to be monophyletic at the combined genes Within the Albimanus Section the monophyly of the Stroder Subgroup was strongly supported and within the Myzorhynchella Section Anopheles anrunesi and An lutzu formed a strongly supported monophyletic group The epidemiologically significant Albitarsis Complex showed evidence of paraphyly (relative to An lanet-Myzorhynchella) and discordance across gene trees, and the previously synonomized species of An. dunhami and An goeldii were recovered as sister species Finally, there was evidence of complexes in several species, including An antunesi, An deaneorum, and An. strodei (c) 2010 Elsevier B.V. All rights reserved

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The origin of tropical forest diversity has been hotly debated for decades. Although specific mechanisms vary, many such explanations propose some vicariance in the distribution of species during glacial cycles and several have been supported by genetic evidence in Neotropical taxa. However, no consensus exists with regard to the extent or time frame of the vicariance events. Here, we analyse the cytochrome oxidase II mitochondrial gene of 250 Sabethes albiprivus B mosquitoes sampled from western Sao Paulo in Brazil. There was very low population structuring among collection sites (Phi(ST) = 0.03, P = 0.04). Historic demographic analyses and the contemporary geographic distribution of genetic diversity suggest that the populations sampled are not at demographic equilibrium. Three distinct mitochondrial clades were observed in the samples, one of which differed significantly in its geographic distribution relative to the other two within a small sampling area (similar to 70 x 35 km). This fact, supported by the inability of maximum likelihood analyses to achieve adequate fits to simple models for the population demography of the species, suggests a more complex history, possibly involving disjunct forest refugia. This hypothesis is supported by a genetic signal of recent population growth, which is expected if population sizes of this forest-obligate insect increased during the forest expansions that followed glacial periods. Although a time frame cannot be reliably inferred for the vicariance event leading to the three genetic clades, molecular clock estimates place this at similar to 1 Myr before present.

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This work presents an analysis of a lowermost stratospheric air intrusion event over the coast of Brazil, which may have been responsible for a secondary surface cyclogenesis over the southwestern Atlantic Ocean. The surface cyclone initiated at 0600 UTC 17 April 1999 in a cold air mass in the rear of a cold front after a primary cyclone developed over the same region. The analysis of the secondary cyclone revealed the presence of lowermost stratospheric air intrusion characterized by anomalous potential vorticity (PV), dry air, and high concentration of ozone in atmospheric column. The system developed on the eastern side of an upper level core of PV anomaly, which induced a cyclonic wind circulation at lower levels and favored the onset of the secondary cyclone. In midlevels (500 hPa), the cutoff low development contributed to reduce the propagation speed of the wave pattern. This feature seemed to (1) allow the low-level cold/dry air to heat/moisten associated with sensible and latent fluxes transferred from the ocean to the atmosphere, which intensified a baroclinic zone parallel to the coast, and (2) contribute to the long duration of the system. The present analysis indicates that this secondary cyclone development could be the result of the coupling between the PV anomaly in the upper levels and low-level air-sea interaction.

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Tribe Pogonieae (Orchidaceae), as Currently known, comprises live genera distributed from South to North America and Eastern Asia. Phylogenetic inferences within Cleistes and among genera of tribe Pogonieae were made based oil nrDNA (ITS) and cpDNA (trnL-F, rps16, rbcL, and psaB) Sequence data and maximum parsimony. Eighteen species of Cleistes, members of all other genera of Pogonieae, and outgroups were sampled. Analyses based oil individual DNA regions provided similar topologies. All evidence indicates that Cleistes is paraphyletic. The North American C. divaricata and C bifaria are more closely related to the temperate genera Isotria and Pogonia than to their Central and South American congeners, the latter Constituting a monophyletic group characterized by the production of nectar as reward, tuberous roots, and their distribution in Central and South America. The Amazonian Duckeella is sister to the remainder of Pogonieae. Taxonomic and biogeographic implications are discussed, and morphological synapomorphies are given For clades obtained in the inferred molecular phylogeny. (C) 2008 Gesellschaft fur Biologische Systematik. Published by Elsevier GmbH. All rights reserved.