997 resultados para MAIN-SEQUENCE STARS


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P>We have developed a two-step PCR assay that amplifies a region of the ceja-1 sequence that is specific for virulent strains of Paracoccidioides brasiliensis. An internal region of the ceja-1 sequence was chosen for designing primers that were utilised in a single tube heminested PCR protocol to amplify DNA from six virulent strains. PCR specificity was determined by the absence of amplified products with genomic DNA from four non-virulent strains of P. brasiliensis and from eight fungal pathogens, one bacterium, two protozoa, one worm and mouse and human genomic DNA (leucocytes). The fact that the PCR product was only obtained with the genetic material from virulent isolates of P. brasiliensis suggested that this partial amplified sequence might be a marker of virulence for this fungus. The diagnostic potential of this PCR was confirmed by the successful amplification of this fragment with genomic DNA obtained in lymph node aspirate from a patient with paracoccidioidomycosis.

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Objectives This prospective study evaluated the association of obesity and hypertension with left atrial (LA) volume over 10 years. Background Although left atrial enlargement (LAE) is an independent risk factor for atrial fibrillation, stroke, and death, little information is available about determinants of LA size in the general population. Methods Participants (1,212 men and women, age 25 to 74 years) originated from a sex-and age-stratified random sample of German residents of the Augsburg area (MONICA S3). Left atrial volume was determined by standardized echocardiography at baseline and again after 10 years. Left atrial volume was indexed to body height (iLA). Left atrial enlargement was defined as iLA >= 35.7 and >= 33.7 ml/m in men and women, respectively. Results At baseline, the prevalence of LAE was 9.8%. Both obesity and hypertension were independent predictors of LAE, obesity (odds ratio [OR]: 2.4; p < 0.001) being numerically stronger than hypertension (OR: 2.2; p < 0.001). Adjusted mean values for iLA were significantly lower in normal-weight hypertensive patients (25.4 ml/m) than in obese normotensive individuals (27.3 ml/m; p = 0.016). The highest iLA was found in the obese hypertensive subgroup (30.0 ml/m; p < 0.001 vs. all other groups). This group also presented with the highest increase in iLA (+6.0 ml/m) and the highest incidence (31.6%) of LAE upon follow-up. Conclusions In the general population, obesity appears to be the most important risk factor for LAE. Given the increasing prevalence of obesity, early interventions, especially in young obese individuals, are essential to prevent premature onset of cardiac remodeling at the atrial level. (J Am Coll Cardiol 2009; 54: 1982-9) (C) 2009 by the American College of Cardiology Foundation

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As a consequence of selective pressure exerted by the immune response during hepatitis C virus (HCV) infection, a high rate of nucleotide mutations in the viral genome is observed which leads to the emergence of viral escape mutants. The aim of this study was to evaluate the evolution of the amino acid (aa) sequence of the HCV nonstructural protein 3 (NS3) in viral isolates after liver transplantation. Six patients with HCV-induced liver disease undergoing liver transplantation (LT) were followed up for sequence analysis. Hepatitis C recurrence was observed in all patients after LT. The rate of synonymous (dS) nucleotide substitutions was much higher than that of nonsynonymous (dN) ones in the NS3 encoding region. The high values of the dS/dN ratios suggest no sustained adaptive evolution selection pressure and, therefore, absence of specific NS3 viral populations. Clinical genotype assignments were supported by phylogenetic analysis. Serial samples from each patient showed lower mean nucleotide genetic distance when compared with samples of the same HCV genotype and subtype. The NS3 samples studied had an N-terminal aa sequence with several differences as compared with reference ones, mainly in genotype 1b-infected patients. After LT, as compared with the sequences before, a few reverted aa substitutions and several established aa substitutions were observed at the N-terminal of NS3. Sites described to be involved in important functions of NS3, notably those of the catalytic triad and zinc binding, remained unaltered in terms of aa sequence. Rare or frequent aa substitutions occurred indiscriminately in different positions. Several cytotoxic T lymphocyte epitopes described for HCV were present in our 1b samples. Nevertheless, the deduced secondary structure of the NS3 protease showed a few alterations in samples from genotype 3a patients, but none were seen in 1b cases. Our data, obtained from patients under important selective pressure during LT, show that the NS3 protease remains well conserved, mainly in HCV 3a patients. It reinforces its potential use as an antigenic candidate for further studies aiming at the development of a protective immune response.

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Functional orthopedic therapy corrects growth discrepancies between the maxilla and mandible, possibly through postural changes in the musculature and modulation of the mandibular condylar cartilage growth. Using Wistar rats, we tested the hypothesis that chondrocytes respond to forces generated by a mandibular propulsor appliance by changes in gene expression, and that integrins are important mediators in this response. Immunohistochemical analyses demonstrated that the use of the appliance for different periods of time modulated the expression of fibronectin, alpha 5 and alpha v integrin subunits, as well as cell proliferation in the cartilage. In vitro, cyclic distension of condylar cartilage-derived cells increased fibronectin mRNA, as well as Insulinlike Growth Factor-I and II mRNA and cell proliferation. A peptide containing the Arginine-Glycine-Asparagine sequence (RGD), the main cell-binding sequence in fibronectin, blocked almost all these effects, confirming that force itself modulates the growth of the rat condylar cartilage, and that RGD-binding integrins participate in mechanotransduction.

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Coronary artery bypass graft (CABG) surgery has long been adopted as the treatment of choice for patients with left main (LM) coronary obstructions. In the past, randomised trials and observational studies have shown an advantage in survival of CABG against medical treatment. Recent studies comparing CABG with percutaneous coronary intervention (PCI) suggested that angioplasty may play a role as an alternative choice. However, well designed randomised trials to evaluate the relative merits of both therapeutic approaches are lacking. In this article, we review the current scientific evidences and outline issues that currently still need to be addressed in comparing CABG versus PCI for the treatment of LM disease.

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The sumoylation pathway is a post-translational modification of nuclear proteins widespread among several organisms. SMT3C is the main protein involved in this process and it is covalently conjugated to a diverse assortment of nuclear protein targets. To date, 3 SUMO paralogues (SMT3C, A/B) have been characterized in mammals and plants. In this work we characterized two SUMO related genes, named SMT3B and SMT3C throughout Schistosoma mansoni life cycle. The SmSMTB/C encodes for proteins sharing significant amino acid homology with SMT3. Phylogenetical analyses revealed that both SmSMT3B/C are distinct proteins. Additionally, SmSMT3B and C are expressed in cercariae, adult worms, eggs and schistosomula however SinSMT3C gene showed an expression level 7 to 9 fold higher than SmSMT3B in eggs, schistosomula and adult worms. The comparison between the SmSMT3C genomic and cDNA sequences established that the encoding sequence is interrupted by 3 introns of 70, 37 and 36 bp. Western Blot has shown SMT3 conjugates are present in nuclear and total protein fractions of adults and cercariae. Therefore our results suggest a functional sumoylation pathway, and the presence of two paralogues also suggests the specificity of substrates for SMT3 in S. mansoni. (c) 2008 Elsevier Ireland Ltd. All rights reserved.

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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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Renal ischemia/reperfusion (I/R) injury is one of the frequent causes of acute renal failure (ARF) due to the complex, interrelated sequence of events, that result in damage to and death of kidney cells. Cells of the proximal tubular epithelium are especially susceptible to I/R injury, leading to acute tubular necrosis, which plays a pivotal role in the pathogenesis of ARE Several models have been explicated to assess morphological changes, including those of Jabonski et al. and Goujon et al. We compared the 2 models for histopathological evaluation of 30- or 120-minute periods of renal ischemia followed by 24-hour reperfusion in rats. Several changes were observed after application of the 2 models: proximal tubular cell necrosis, loss of brush border, vacuolization, denudation of tubular basement membrane as a consequence of flattening of basal cells, and presence of intratubular exfoliated cells in the lumen of proximal convoluted tubules at various stages of degeneration (karyorexis, kariopyknosis and karyolysis). Evaluating tubular lesions after 2 periods of experimental ischemia with light microscopy allowed us to conclude that the Goujon classification better characterized the main changes in cortical renal tubules after ischemia.

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Purpose: To evaluate the diagnostic image quality of post-gadolinium water excitation-magnetization-prepared rapid gradient-echo (WE-MPRAGE) sequence in abdominal examinations of noncooperative patients at 1.5 Tesla (T) and 3.0T MRI. Materials and Methods: Eighty-nine consecutive patients (48 males and 41 females; mean age +/- standard deviation, 54.6 +/- 16.6 years) who had MRI examinations including postgadolinium WE-MPRAGE were included in the study. Of 89 patients, 33 underwent noncooperative protocol at 1.5T. 10 under-went noncooperative protocol at 3.0T, and 46 underwent cooperative protocol at 3.0T. Postgadolinium WE-MPRAGE, MPRAGE, and three-dimensional gradient-echo sequences of these three different groups were qualitatively evaluated for image quality, extent of artifacts, lesion conspicuity, and homogeneity of fat-attenuation by two reviewers retrospectively, independently, and blindly. The results were compared using Wilcoxon signed rank and Mann-Whitney U tests. Kappa statistics were used to measure the extent of agreement between the reviewers. Results: The average scores indicated that the images were diagnostic for WE-MPRAGE at 1.5T and 3.0T in noncooperative patients. WE-MPRAGE achieved homogenous fat-attenuation in 31/33 (94%) of noncooperative patients at 1.5T and 10/10 (100%) of noncooperative patients at 3.0T. WE-MPRAGE at 3.0T had better results for image quality, extent of artifacts, lesion conspicuity and homogeneity of fat-attenuation compared with WE-MPRAGE at 1.5T. in noncooperative patients (P = 0.0008, 0.0006, 0.0024, and 0.0042: respectively). Kappa statistics varied between 0.76 and 1.00, representing good to excellent agreement. Conclusion: WE-MPRAGE may be used as a T1-weighted postgadolinium fat-attenuated sequence in noncooperative patients, particularly at 3.0T MRI.

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Context: Mutations in TAC3 and TACR3 (encoding neurokinin B and its receptor) have been identified in Turkish patients with idiopathic hypogonadotropic hypogonadism (IHH), but broader populations have not yet been tested and genotype-phenotype correlations have not been established. Objective: A broad cohort of normosmic IHH probands was screened for mutations in TAC3/TACR3 to evaluate the prevalence of such mutations and define the genotype/phenotype relationships. Design and Setting: The study consisted of sequencing of TAC3/TACR3, in vitro functional assays, and neuroendocrine phenotyping conducted in tertiary care centers worldwide. Patients or Other Participants: 345 probands, 18 family members, and 292 controls were studied. Intervention: Reproductive phenotypes throughout reproductive life and before and after therapy were examined. Main Outcome Measure: Rare sequence variants in TAC3/TACR3 were detected. Results: In TACR3, 19 probands harbored 13 distinct coding sequence rare nucleotide variants [three nonsense mutations, six nonsynonymous, four synonymous (one predicted to affect splicing)]. In TAC3, one homozygous single base pair deletion was identified, resulting in complete loss of the neurokinin B decapeptide. Phenotypic information was available on 16 males and seven females with coding sequence variants in TACR3/TAC3. Of the 16 males, 15 had microphallus; none of the females had spontaneous thelarche. Seven of the 16 males and five of the seven females were assessed after discontinuation of therapy; six of the seven males and four of the five females demonstrated evidence for reversibility of their hypogonadotropism. Conclusions: Mutations in the neurokinin B pathway are relatively common as causes of hypogonadism. Although the neurokinin B pathway appears essential during early sexual development, its importance in sustaining the integrity of the hypothalamic-pituitary-gonadal axis appears attenuated over time. (J Clin Endocrinol Metab 95: 2857-2867, 2010)

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Objective: To study the prevalence of abnormal gastroesophageal reflux in infants with Robin sequence who had severe respiratory obstruction treated with nasopharyngeal intubation and to evaluate the efficacy of nonsurgical treatment. Design: Longitudinal prospective study. Setting: Hospital de Reabilitacao de Anomalias Craniofaciais, University of Sao Paulo, Brazil. Patients: Twenty infants with severe isolated Robin sequence treated with nasopharyngeal intubation. Interventions: We performed 24-hour esophageal pH monitoring on each child at 2, 4, and 6 months of age. Respiratory and feeding status were evaluated. We considered abnormal gastroesophageal reflux as reflux index values above the 95th percentile of the Vandenplas reference for normal children. Results: The prevalence of reflux index above the 95th percentile at the first exam was 6/20, a value significantly higher than the reference (5/103, p < .01). At the second and third exams, reflux index values were decreased. Ninety percent of the infants showed improvement of respiratory difficulty and developed oral feeding capacity. Conclusions: The prevalence of abnormal gastroesophageal reflux is higher in infants with severe cases of Robin sequence than in normal infants. Nonsurgical procedures improved respiratory and feeding difficulties of most of these infants.

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To understand the biology and evolution of ruminants, the cattle genome was sequenced to about sevenfold coverage. The cattle genome contains a minimum of 22,000 genes, with a core set of 14,345 orthologs shared among seven mammalian species of which 1217 are absent or undetected in noneutherian (marsupial or monotreme) genomes. Cattle-specific evolutionary breakpoint regions in chromosomes have a higher density of segmental duplications, enrichment of repetitive elements, and species-specific variations in genes associated with lactation and immune responsiveness. Genes involved in metabolism are generally highly conserved, although five metabolic genes are deleted or extensively diverged from their human orthologs. The cattle genome sequence thus provides a resource for understanding mammalian evolution and accelerating livestock genetic improvement for milk and meat production.

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Objective: To evaluate oral feeding capacity, the swallowing process, and risk for aspiration, both clinically and during fiberoptic endoscopic evaluation of swallowing, in infants with isolated Robin sequence treated exclusively with nasopharyngeal intubation and feeding facilitating techniques. Design: Longitudinal and prospective study. Setting: Hospital de Reabilitacao de Anomalies Craniofaciais, University of Sao Paulo, Bauru, Brazil. Patients: Eleven infants with isolated Robin sequence, under 2 months of age, treated with nasopharyngeal intubation. Interventions: Feeding facilitating techniques were applied in all infants throughout the study period. The infants were evaluated clinically and through fiberoptic endoscopic evaluation of swallowing at first, second, and, if necessary, third week of hospitalization (T1, T2, T3). The mean volume of ingested milk was registered during clinical evaluation, and events were registered during feeding. Results: The respiratory status of all infants was improved after nasopharyngeal intubation; 72% of them presented risk for aspiration during fiberoptic endoscopic evaluation of swallowing at T1. This risk was less frequent when thickened milk was given to the infants and at subsequent evaluations (T2 and T3). Conclusions: Nasopharyngeal intubation aids in stabilizing the airway in isolated Robin sequence, but it does not relate directly to feeding. The risk for aspiration was present in most of the infants, mainly during the first week of hospitalization, and improved within a few weeks, after the use of feeding facilitating techniques.

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At the end of 2002 and throughout 2003, there was a severe outbreak of infectious laryngotracheitis (ILT) in an intensive production area of commercial hens in the Sao Paulo State of Brazil. ILT virus was isolated from 28 flocks, and 21 isolates were genotyped by polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) using four genes and eight restriction enzymes, and by partial sequencing of the infected cell protein 4 (ICP4) and thymidine kinase (TK) genes. Three groups resulted from the combinations of PCR-RFLP patterns: 19 field isolates formed Group I, and the remaining two isolates together with the chicken embryo origin (CEO) vaccine strains formed Group II. Group III comprised the tissue-culture origin (TCO) vaccine strain by itself. The PCR-RFLP results agreed with the sequencing results of two ICP4 gene fragments. The ICP4 gene sequence analysis showed that the 19 field isolates classified into Group I by RFLP-PCR were identical among themselves, but were different to the TCO and CEO vaccines. The two Group II isolates could not be distinguished from one of the CEO vaccines. The nucleotide and amino acid sequence analyses discriminated between the Brazilian and non-Brazilian isolates, as well as between the TCO and CEO vaccines. Sequence analysis of the TK gene enabled classification of the field isolates (Group I) as virulent and non-vaccine. This work shows that the severe ILT outbreak was caused by a highly virulent, non-vaccine strain.