179 resultados para multiple locus sequence typing


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Moyamoya disease (MMD) is an uncommon cerebrovascular disorder characterized by progressive stenosis of the terminal portion of the internal carotid artery and its main branches. Direct and indirect bypass techniques have been devised with the aim of promoting neoangiogenesis. The current study aimed to investigate the role of multiple cranial burr hole (MCBH) operations in the prevention of cerebral ischemic attacks in children with MMD. Seven children suffering from progressive MMD were submitted to the MCBH and arachnoid opening technique. Ten to 20 burr holes were drilled in the fronto-temporo-parieto-occipital area of each hemisphere in each patient, depending on the site and extent of the disease. All patients were evaluated pre- and postoperatively by means of Barthel index (BI), CT, MR, angio-MR, and angiography. Patients had no recurrence of ischemic attacks postoperatively. Neoangiogenesis was observed in both hemispheres. One patient developed a persistent subdural collection after surgery, thus requiring placement of a subdural-peritoneal shunt. Postoperative BI was statistically significantly improved (P = 0.02). This report suggests that MCBH for revascularization in MMD is a simple procedure with a relatively low risk of complications and effective for preventing cerebral ischemic attacks in children. In addition, MCBH may be placed as an adjunct to other treatments for MMD.

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Brain derived neurotrophic factor (BDNF) has been related to neuroprotection in a series of central nervous system diseases, although its role in multiple sclerosis (MS) was only partially investigated. In this work, we aimed to evaluate the plasma levels of BDNF from 29 MS patients and 24 control subjects. MS patients had decreased levels of BDNF in comparison with healthy controls. BDNF levels increased significantly after MS relapse. Our results provide some evidence for the involvement of BDNF in the pathogenesis of MS and suggest a role for this neurotrophin during the recovery of acute demyelinating inflammatory lesion. (C) 2009 Elsevier Ireland Ltd. All rights reserved.

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Background: The tumor necrosis factor (TNF) gene is located within the highly polymorphic major histocompatibility complex region, exhibiting the -308 CA promoter region polymorphism and six microsatellites (TNFa-f) spanning the region nearby the TNF locus. Objective: In the present Study, we evaluated the frequency of -308 CA and TNFa-e polymorphisms and respective haplotypes (in chromosomal sequence: TNFd-TNFe-308GA-TNFc-TNFa-TNFb), in 222 patients with AIDS, 52 of whom exhibited cytomegalovirus retinitis, and in 202 healthy HIV-negative individuals. Method: TNF microsatellite and single nucleotide polymorphism typings were performed by PCR followed by polyacrylamide gel electrophoresis. Results: The TNF-308A allele and the 4-3-C-2-7-1 haplotype were associated with susceptibility to AIDS, whereas the TNFb4 allele and the 3-3-C-1-11-4 haplotype were associated with protection against AIDS development. The TNFc2 allele and the 4-1-G-2-2-1 haplotype, which contains the TNFc2 allele, were associated with cytomegalovirus retinitis. Conclusion: This study highlights that polymorphic sites spanning the region nearby the TNF locus are associated with AIDS per se and with cytomegalovirus retinitis in AIDS patients. (C) 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins

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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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Twenty-five extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli clinical isolates from Rio de Janeiro, Brazil were characterized by isoelectric focusing, PCR and sequencing of bla(ESBL) genes, plasmid-mediated quinolone resistance determinants, phylogenetic groups, replicon typing, pulsed-field electrophoresis, and multilocus sequencing typing. Twenty-three (92%) ESBL-producing E. coli isolates were positive for bla(CTX-M) genes, aac(6`)-lb-cr, and qnrB. Genetic relatedness of ESBL producers clustered seven (28%) CTX-M-15-producing isolates as sequence type (ST) 410, clonal complex (CC) 23, and two (8%) as clone O25-ST131. Our results illustrate the predominance of phylo-group A (52%), ST410 (CC 23) and CTX-M-15 among ESBL-producing E. coli isolates from hospitals in Rio de Janeiro.

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The objective of this study was to describe multiple Doppler ultrasound parameters of ductus venosus and inferior vena cava in fetuses at gestational ages ranging from 22 to 38 weeks. In this prospective observational study, Doppler ultrasound exams were performed in 45 healthy fetuses at 22, 26, 34, and 38 weeks. Maximum venous velocity, minimum venous velocity, venous pulsatility index, and venous acceleration time (VAT) (defined as the time between minimum and maximum venous velocity) were evaluated at those gestational periods. Increase in the velocities and decrease in the pulsatility index were observed in these vessels throughout gestational age. The VAT increased with gestational age. The VAT, a Doppler parameter still not described elsewhere, increased during pregnancy could be related to a longer period of time needed to fill the atrium in bigger hearts. In this study, we provide reference values for VAT in healthy fetuses.

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P>According to the hygiene hypothesis, the increased incidence of allergic and autoimmune diseases in developed countries is mainly explained by the decreased contact between the human population and certain environmental agents as lactobacillus, mycobacteria and helminths. In this study, we evaluated the effect of multiple infections with Strongyloides venezuelensis on the development of experimental autoimmune encephalomyelitis (EAE) in Lewis rats. Multiple infections before EAE induction were not able to change the evolution of the disease. No alterations were observed in weight loss, clinical score and inflammation intensity at the central nervous system. The presence of significant levels of parasite-specific IgG1 but not IgG2b suggested a Th2 polarization. However, the percentage and absolute number of CD4+CD25+Foxp3+ T cells were not changed, being their levels in the spleen and lymph nodes of infected rats comparable to the ones found in normal animals. These results suggest that a Th2-polarized response without concomitant expansion of Foxp3+ regulatory T cells was not able to modify EAE progression. Even though these results do not threaten the hygiene hypothesis, they suggest that this paradigm might be an oversimplification. They also emphasize the need of a study to compare the immunoregulatory ability associated with different helminth spp.

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Considering that the importance of cancer/testis (CT) antigens in multiple myeloma (MM) biology is still under investigation, the present study aimed to: (1) identify genes differentially expressed in MM using microarray analysis of plasma cell samples, separated according to the number of expressed CTs; (2) examine possible pathways related to MM pathogenesis; (3) validate the expression of candidate genes by quantitative real-time PCR (RQ-PCR). Three samples predominantly positive (>6 expressed), including the U266 cell line, and three samples predominantly negative (0 or 1 expressed CT for the 13 analyzed CT antigens), were submitted for microarray analysis. Validation by RQ-PCR from 24 MM samples showed that the ITGAS gene was downregulated in predominantly positive (>6 expressed CTs, p = 0.0030) and in tumor versus normal plasma cells (p = 0.0182). The RhoD gene was overexpressed in tumor plasma cells when compared to normal plasma cells (p = 0.0339). Results of the microarray analysis corroborate the hypothesis that MM could be separated into predominantly positive and predominantly negative expression. The differential expression of ITGA5 and RhoD suggests disruption of the focal adhesion pathway in MM and offers a new target field to be explored in this disease.

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We assessed the role of NK-1 receptors (NK1R) expressing neurons in the locus coeruleus (LC) on cardiorespiratory responses to hypercapnia. To this end, we injected substance P-saporin conjugate (SP-SAP) to kill NK-1 immunoreactive (NK1R-ir) neurons or SAP alone as a control. Immunohistochemistry for NK1R, tyrosine hydroxylase (TH-ir) and Glutamic Acid Decarboxylase (GAD-ir) were performed to verify if NK1R-expressing neurons, catecholaminergic and/or GABAergic neurons were eliminated. A reduced NK1R-ir in the LC (72%) showed the effectiveness of the lesion. SP-SAP lesion also caused a reduction of TH-ir (66%) and GABAergic neurons (70%). LC SP-SAP lesion decreased by 30% the ventilatory response to 7% CO(2) and increased the heart rate (fH) during hypercapnia but did not affect MAP. The present data suggest that different populations of neurons (noradrenergic, GABAergic, and possibly others) in the LC express NK1R modulating differentially the hypercapnic ventilatory response, since catecholaminergic neurons are excitatory and GABAergic ones are inhibitory. Additionally, NK1R-ir neurons in the LC, probably GABAergic ones, seem to modulate fH during CO(2) exposure, once our previous data demonstrated that catecholaminergic lesion does not affect this variable. (C) 2010 Elsevier B.V. All rights reserved.

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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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An analyzer-based X-ray phase-contrast imaging (ABI) setup has been mounted at the Brazilian Synchrotron Light Laboratory (LNLS) for multiple imaging radiography (MIR) purposes. The algorithm employed for treating the MIR data collected at LNLS is described, and its reliability in extracting the distinct types of contrast that can be obtained with MIR is demonstrated by analyzing a test sample (thin polyamide wire). As a practical application, the possibility of studying ophthalmic tissues, corneal sequestra in this case, via MIR is investigated. (C) 2007 Elsevier B.V. All rights reserved.

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The neotropical tick Amblyomma cajennense is a significant pest to domestic animals, the most frequently human-biting tick in South America and the main vector of Brazilian spotted fever (caused by Rickettsia rickettsii), a deadly human disease. The purpose of this study is to characterize the adult A. cajennense salivary gland transcriptome by expressed sequence tags (ESTs). We report the analysis of 1754 clones obtained from a cDNA library, which reveal mainly transcripts related to proteins involved in the hemostatic processes, especially proteases and their inhibitors. Remarkably, five types of possible serine protease inhibitors were found, including a molecule with a distinguished structure that contains repeats of the active motif of hirudin inhibitors. Besides, other components that may be active over the host immune system or acting as defensins against infecting microorganisms were also described, including a molecule similar to insect venom allergens. The conjunction of components from this transcriptome suggests a diverse strategy of A. cajennense tick during feeding, but emphasized in the coagulation system. (c) 2008 Published by Elsevier Ltd.

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Recent studies found that isolates of Toxoplasma gondii from Brazil were biologically and genetically different from those in North America and Europe. However, to date only a small number of isolates have been analysed from different animal hosts in Brazil. In the present study DNA samples of 46 T. gondii isolates from cats in 11 counties in Sao Paulo state, Brazil were genetically characterised using 10 PCR restriction fragment length polymorphism markers including SAG1, SAG2, SAG3, STUB, GRA6, c22-8, c29-2, L358, PKI and Apico. An additional marker, CS3, that locates on chromosome VIIa and has previously been shown to be linked to acute virulence of T. gondii was also used to determine its association to virulence in mice. Genotyping of these 46 isolates revealed a high genetic diversity with 20 genotypes but no clonal Type I, II or III lineage was found. Two of the 46 isolates showed mixed infections. Combining genotyping data in this study with recent reported results from chickens, dogs and cats in Brazil (total 125 isolates) identified 48 genotypes and 26 of these genotypes had single isolates. Four of the 48 genotypes with multiple isolates identified from different hosts and locations are considered the common clonal lineages in Brazil. These lineages are designated as Types BrI, BrII, BrIII and BrIV. These results indicate that the T. gondii population in Brazil is highly diverse with a few successful clonal lineages expanded into wide geographical areas. In contrast to North America and Europe, where the Type II clonal lineage is overwhelmingly predominant, no Type II strain was identified from the 125 Brazil isolates. Analysis of mortality rates in infected mice indicates that Type BrI is highly virulent, Type BrIII is non-virulent, whilst Type BrII and BrIV lineages are intermediately virulent. In addition, allele types at the CS3 locus are strongly linked to mouse-virulence of the parasite. Thus, T. gondii has an epidemic population structure in Brazil and the major lineages have different biological traits. (C) 2007 Australian Society for Parasitology Inc. Published by Elsevier Ltd. All rights reserved.

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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.

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The alpha-lactalbumin is a subunit of lactose-synthase, an enzyme responsible for lactose production, a disaccharide that influences milk production. Sequence variations of bovine alpha-lactalbumin have been associated with differences in milk yield. This study aimed to analyze allelic frequency differences at position-1689 (g. AG) and+15 (g. AG) of the alpha-lactalbumin gene in Holstein (Bos taurus) and Nellore (Bos indicus) cows. Blood samples were analyzed from 34 Holstein, 104 Nellore, and 99 Dairy Nellore cows using PCR-RFLP. The different RFLP patterns were sequenced and a novel sequence variation on nucleotide-46 was identified. An adenine at this position was designated as the A allele and a guanine was designated B allele. The frequencies of alleles A-1689, A-46, and A+15 differed between Holstein and both Nellore breeds. The results show that differences in alpha-lactalbumin allelic variants in the 5`-flanking and the 5`-UTR region might be associated with differences in milk production between Holstein cows and cows from Nellore breeds. However, the lack of difference between Nellore and Dairy Nellore suggests that other sequence variantions that regulate milk production might be responsible for the selection of Dairy Nellore cows with superior milk production.