18 resultados para genomic walking

em Biblioteca Digital da Produção Intelectual da Universidade de São Paulo


Relevância:

20.00% 20.00%

Publicador:

Resumo:

The frequency distribution of SNPs and haplotypes in the ABCB1, SLCO1B1 and SLCO1B3 genes varies largely among continental populations. This variation can lead to biases in pharmacogenetic studies conducted in admixed populations such as those from Brazil and other Latin American countries. The aim of this study was to evaluate the influence of self-reported colour, geographical origin and genomic ancestry on distributions of the ABCB1, SLCO1B1 and SLCO1B3 polymorphisms and derived haplotypes in admixed Brazilian populations. A total of 1039 healthy adults from the north, north-east, south-east and south of Brazil were recruited for this investigation. The c.388A>G (rs2306283), c.463C>A (rs11045819) and c.521T>C (rs4149056) SNPs in the SLCO1B1 gene and c.334T>G (rs4149117) and c.699G>A (rs7311358) SNPs in the SLCO1B3 gene were determined by Taqman 5'-nuclease assays. The ABCB1 c.1236C>T (rs1128503), c.2677G>T/A (rs2032582) and c.3435C>T (rs1045642) polymorphisms were genotyped using a previously described single-base extension/termination method. The results showed that genotype and haplotype distributions are highly variable among populations of the same self-reported colour and geographical region. However, genomic ancestry showed that these associations are better explained by a continuous variable. The influence of ancestry on the distribution of alleles and haplotype frequencies was more evident in variants with large differences in allele frequencies between European and African populations. Design and interpretation of pharmacogenetic studies using these transporter genes should include genomic controls to avoid spurious conclusions based on improper matching of study cohorts from Brazilian populations and other highly admixed populations.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Trypanosoma cruzi, the agent of Chagas disease, is a complex of genetically diverse isolates highly phylogenetically related to T. cruzi-like species, Trypanosoma cruzi marinkellei and Trypanosoma dionisii, all sharing morphology of blood and culture forms and development within cells. However, they differ in hosts, vectors and pathogenicity: T. cruzi is a human pathogen infective to virtually all mammals whilst the other two species are non-pathogenic and bat restricted. Previous studies suggest that variations in expression levels and genetic diversity of cruzipain, the major isoform of cathepsin L-like (CATL) enzymes of T. cruzi, correlate with levels of cellular invasion, differentiation, virulence and pathogenicity of distinct strains. In this study, we compared 80 sequences of genes encoding cruzipain from 25 T. cruzi isolates representative of all discrete typing units (DTUs TcI-TcVI) and the new genotype Tcbat and 10 sequences of homologous genes from other species. The catalytic domain repertoires diverged according to DTUs and trypanosome species. Relatively homogeneous sequences are found within and among isolates of the same DTU except TcV and TcVI, which displayed sequences unique or identical to those of TcII and TcIII, supporting their origin from the hybridization between these two DTUs. In network genealogies, sequences from T. cruzi clustered tightly together and closer to T. c. marinkellei than to T. dionisii and largely differed from homologues of T. rangeli and T. b. brucei. Here, analysis of isolates representative of the overall biological and genetic diversity of T. cruzi and closest T. cruzi-like species evidenced DTU- and species-specific polymorphisms corroborating phylogenetic relationships inferred with other genes. Comparison of both phylogenetically close and distant trypanosomes is valuable to understand host-parasite interactions, virulence and pathogenicity. Our findings corroborate cruzipain as valuable target for drugs, vaccine, diagnostic and genotyping approaches.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Background and objective: Field exercise tests have been increasingly used for pulmonary risk assessment. The 6-min walking distance (6MWD) is a field test commonly employed in clinical practice; however, there is limited evidence supporting its use as a risk assessment method in abdominal surgery. The aim was to assess if the 6MWD can predict the development of post-operative pulmonary complications (PPCs) in patients having upper abdominal surgery (UAS). Methods: This prospective cohort study included 137 consecutive subjects undergoing elective UAS. Subjects performed the 6MWD on the day prior to surgery, and their performance were compared with predicted values of 6MWD (p6MWD) using a previously validated formula. PPCs (including pneumonia, tracheobronchitis, atelectasis with clinical repercussions, bronchospasm and acute respiratory failure) were assessed daily by a pulmonologist blinded to the 6MWD results. 6MWD and p6MWD were compared between subjects who developed PPC (PPC group) and those who did not (no PPC group) using Student's t-test. Results: Ten subjects experienced PPC (7.2%) and no significant difference was observed between the 6MWD obtained in the PPC group and no PPC group (466.0 +/- 97.0 m vs 485.3 +/- 107.1 m; P = 0.57, respectively). There was also no significant difference observed between groups for the p6MWD (100.7 +/- 29.1% vs 90.6 -/+ 20.9%; P > 0.05). Conclusions: The results of the present study suggest that the 6-min walking test is not a useful tool to identify subjects with increased risk of developing PPC following UAS.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Background: This study assessed the relationship between lower limb hemodynamics and metabolic parameters with walking tolerance in patients with intermittent claudication (IC). Patients and methods: Resting ankle-brachial index (ABI), baseline blood flow (BF), BF response to reactive hyperemia (BFRH), oxygen uptake (VO2), initial claudication distance (ICD) and total walking distance (TWD) were measured in 28 IC patients. Pearson and Spearman correlations were calculated. Results: ABI, baseline BF and BF response to RH did not correlate with ICD or TWD. VO2 at first ventilatory threshold and VO(2)peak were significantly and positively correlated with ICD (r = 0.41 and 0.54, respectively) and TWD (r = 0.65 and 0.71, respectively). Conclusions: VO(2)peak and VO2 at first ventilatory threshold, but not ABI, baseline BF and BFHR were associated with walking tolerance in IC patients. These results suggest that VO2 at first ventilatory threshold may be useful to evaluate walking tolerance and improvements in IC patients.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Several studies have demonstrated that one exercise session (ES) on a cycloergometer or ergometric treadmill causes a reduction in blood pressure (BP). However, there are few similar studies on walking, which is the exercise modality most available to the elderly. We investigated the immediate and 24-h effects of walking on BP in independent, community-living elderly individuals. Volunteers participated in a single ES and resting control session (CS). Before and after each session, BP was measured by auscultatory and oscillometric methods. After each session, 24-h ambulatory blood pressure monitoring was conducted. An accelerometer was installed 48 h before the sessions and left in place for 5 days. The mean volunteer age was 67.7 +/- 3.5 years; 11 were hypertensive patients under treatment, and 12 were normotensive. In the total sample, there were immediate 14mm Hg and 12 mm Hg reductions in systolic BP (SBP) after the ES according to the auscultatory and oscillometric methods, respectively. Diastolic BP (DBP) was reduced by 4 mm Hg after the ES according to both methods. SBP during wakefulness and sleep and DBP during wakefulness were lower after the ES than after the CS (P<0.01), when wakefulness and sleep were determined individually (variable-time pattern) using data from the activity monitors and provided by the volunteers. The variable-time pattern was more effective in detecting reductions in BP than the fixed-time pattern. Hypertension Research (2012) 35, 457-462; doi: 10.1038/hr.2011.227; published online 9 February 2012

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Background To better characterize the pathophysiology of juvenile nasopharyngeal angiofibroma (JNA), endothelial and stromal cells were evaluated by genomic imbalances in association with transcript expression levels of genes mapped on these altered regions. Methods. High-resolution comparative genomic hybridization (HR-CGH) was used in laser-captured endothelial and stromal cells from 9 JNAs. Ten genes were evaluated by quantitative real-timereverse transcription polymerase chain reaction (qRT-PCR) in 15 cases. Results. Although gains were more frequently detected in endothelial cells, 57% of chromosomal alterations were common by both components. Gene expression analyses revealed a positive correlation between endothelial and stromal components for ASPM, CDH1, CTNNB1, FGF18, and SUPT16H. A significant difference was found for FGF18 and AURKB overexpression in stromal cells and AR down-expression in endothelial cells. Conclusions. A similar pattern of gene expression and chromosomal imbalances in both exponents would suggest a common mechanism of functional regulation. AURKB, FGF18, and SUPT16H were identified as potential molecular markers in JNA. (C) 2011 Wiley Periodicals, Inc. Head Neck 34: 485-492, 2012

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Objective: To compare gross motor development of preterm infants (PT) without cerebral palsy with healthy full-term (FT) infants, according to Alberta Infant Motor Scale (AIMS); to compare the age of walking between PT and FT; and whether the age of walking in PT is affected by neonatal variables. Methods: Prospective study compared monthly 101 PT and 52 FT, from the first visit, until all AIMS items had been observed. Results: Mean scores were similarity in their progression, except from the eighth to tenth months. FT infants were faster in walking attainment than PT. Birth weight and length and duration of neonatal nursery stay were related to walking delay. Conclusion: Gross motor development between PT and FT were similar, except from the eighth to tenth months of age. PT walked later than FT infants and predictive variables were birth weight and length, and duration of neonatal intensive unit stay.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The Xylella fastidiosa comparative genomic database is a scientific resource with the aim to provide a user-friendly interface for accessing high-quality manually curated genomic annotation and comparative sequence analysis, as well as for identifying and mapping prophage-like elements, a marked feature of Xylella genomes. Here we describe a database and tools for exploring the biology of this important plant pathogen. The hallmarks of this database are the high quality genomic annotation, the functional and comparative genomic analysis and the identification and mapping of prophage-like elements. It is available from web site http://www.xylella.lncc.br.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Aim. The aim of this study was to evaluate whether an association of elastic stockings and walking for a short period in the late afternoon reduces leg edema. Methods. Volume changes of the legs of sixteen patients (32 limbs), who walked on a treadmill for 30 minutes using elastic compression stockings, were analyzed in a quantitative, cross-over randomized (in order of arrival at the clinic) study. They were submitted to volumetry using the water displacement technique and subsequently required to put on 20/30 made-to-measure compression stockings (Sigvaris). The patients walked on a treadmill for 30 minutes and after removing the stockings volumetry of the legs was again performed. Legs were assessed using the CEAP classification and divided into groups. Analysis of variance was used for statistical analysis with an alpha error of 5% being considered acceptable. Results. When participants walked wearing compression stockings, there was a reduction in leg volume. When the CEAP classification was evaluated, it was noted that there was a statistically significant difference for the CEAP C0, C1 and C2 categories of legs using stockings compared to those that did not use. Conclusion. Compression stockings have a synergistic effect with walking in the late afternoon thus reducing edema of the lower limbs. [Int Angiol 2012;31:490-3]

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Abstract Background Citrus canker is a disease that has severe economic impact on the citrus industry worldwide. There are three types of canker, called A, B, and C. The three types have different phenotypes and affect different citrus species. The causative agent for type A is Xanthomonas citri subsp. citri, whose genome sequence was made available in 2002. Xanthomonas fuscans subsp. aurantifolii strain B causes canker B and Xanthomonas fuscans subsp. aurantifolii strain C causes canker C. Results We have sequenced the genomes of strains B and C to draft status. We have compared their genomic content to X. citri subsp. citri and to other Xanthomonas genomes, with special emphasis on type III secreted effector repertoires. In addition to pthA, already known to be present in all three citrus canker strains, two additional effector genes, xopE3 and xopAI, are also present in all three strains and are both located on the same putative genomic island. These two effector genes, along with one other effector-like gene in the same region, are thus good candidates for being pathogenicity factors on citrus. Numerous gene content differences also exist between the three cankers strains, which can be correlated with their different virulence and host range. Particular attention was placed on the analysis of genes involved in biofilm formation and quorum sensing, type IV secretion, flagellum synthesis and motility, lipopolysacharide synthesis, and on the gene xacPNP, which codes for a natriuretic protein. Conclusion We have uncovered numerous commonalities and differences in gene content between the genomes of the pathogenic agents causing citrus canker A, B, and C and other Xanthomonas genomes. Molecular genetics can now be employed to determine the role of these genes in plant-microbe interactions. The gained knowledge will be instrumental for improving citrus canker control.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Abstract Background Citrus bacterial canker is a disease that has severe economic impact on citrus industries worldwide and is caused by a few species and pathotypes of Xanthomonas. X. citri subsp. citri strain 306 (XccA306) is a type A (Asiatic) strain with a wide host range, whereas its variant X. citri subsp. citri strain Aw12879 (Xcaw12879, Wellington strain) is restricted to Mexican lime. Results To characterize the mechanism for the differences in host range of XccA and Xcaw, the genome of Xcaw12879 that was completed recently was compared with XccA306 genome. Effectors xopAF and avrGf1 are present in Xcaw12879, but were absent in XccA306. AvrGf1 was shown previously for Xcaw to cause hypersensitive response in Duncan grapefruit. Mutation analysis of xopAF indicates that the gene contributes to Xcaw growth in Mexican lime but does not contribute to the limited host range of Xcaw. RNA-Seq analysis was conducted to compare the expression profiles of Xcaw12879 and XccA306 in Nutrient Broth (NB) medium and XVM2 medium, which induces hrp gene expression. Two hundred ninety two and 281 genes showed differential expression in XVM2 compared to in NB for XccA306 and Xcaw12879, respectively. Twenty-five type 3 secretion system genes were up-regulated in XVM2 for both XccA and Xcaw. Among the 4,370 common genes of Xcaw12879 compared to XccA306, 603 genes in NB and 450 genes in XVM2 conditions were differentially regulated. Xcaw12879 showed higher protease activity than XccA306 whereas Xcaw12879 showed lower pectate lyase activity in comparison to XccA306. Conclusions Comparative genomic analysis of XccA306 and Xcaw12879 identified strain specific genes. Our study indicated that AvrGf1 contributes to the host range limitation of Xcaw12879 whereas XopAF contributes to virulence. Transcriptome analyses of XccA306 and Xcaw12879 presented insights into the expression of the two closely related strains of X. citri subsp. citri. Virulence genes including genes encoding T3SS components and effectors are induced in XVM2 medium. Numerous genes with differential expression in Xcaw12879 and XccA306 were identified. This study provided the foundation to further characterize the mechanisms for virulence and host range of pathotypes of X. citri subsp. citri.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Background Trypanosomatids of the genera Angomonas and Strigomonas live in a mutualistic association characterized by extensive metabolic cooperation with obligate endosymbiotic Betaproteobacteria. However, the role played by the symbiont has been more guessed by indirect means than evidenced. Symbiont-harboring trypanosomatids, in contrast to their counterparts lacking symbionts, exhibit lower nutritional requirements and are autotrophic for essential amino acids. To evidence the symbiont’s contributions to this autotrophy, entire genomes of symbionts and trypanosomatids with and without symbionts were sequenced here. Results Analyses of the essential amino acid pathways revealed that most biosynthetic routes are in the symbiont genome. By contrast, the host trypanosomatid genome contains fewer genes, about half of which originated from different bacterial groups, perhaps only one of which (ornithine cyclodeaminase, EC:4.3.1.12) derived from the symbiont. Nutritional, enzymatic, and genomic data were jointly analyzed to construct an integrated view of essential amino acid metabolism in symbiont-harboring trypanosomatids. This comprehensive analysis showed perfect concordance among all these data, and revealed that the symbiont contains genes for enzymes that complete essential biosynthetic routes for the host amino acid production, thus explaining the low requirement for these elements in symbiont-harboring trypanosomatids. Phylogenetic analyses show that the cooperation between symbionts and their hosts is complemented by multiple horizontal gene transfers, from bacterial lineages to trypanosomatids, that occurred several times in the course of their evolution. Transfers occur preferentially in parts of the pathways that are missing from other eukaryotes. Conclusion We have herein uncovered the genetic and evolutionary bases of essential amino acid biosynthesis in several trypanosomatids with and without endosymbionts, explaining and complementing decades of experimental results. We uncovered the remarkable plasticity in essential amino acid biosynthesis pathway evolution in these protozoans, demonstrating heavy influence of horizontal gene transfer events, from Bacteria to trypanosomatid nuclei, in the evolution of these pathways.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The tumorigenesis of pituitary adenomas is poorly understood. Mutations of the PIK3CA proto-oncogene, which encodes the p110-α catalytic subunit of PI3K, have been reported in various types of human cancers regarding the role of the gene in cell proliferation and survival through activation of the PI3K/Akt signaling pathway. Only one Chinese study described somatic mutations and amplification of the PIK3CA gene in a large series of pituitary adenomas. The aim of the present study was to determine genetic alterations of PIK3CA in a second series that consisted of 33 pituitary adenomas of different subtypes diagnosed by immunohistochemistry: 6 adrenocorticotropic hormone-secreting microadenomas, 5 growth hormone-secreting macroadenomas, 7 prolactin-secreting macroadenomas, and 15 nonfunctioning macroadenomas. Direct sequencing of exons 9 and 20 assessed by qPCR was employed to investigate the presence of mutations and genomic amplification defined as a copy number ≥4. Previously identified PIK3CA mutations (exon 20) were detected in four cases (12.1%). Interestingly, the Chinese study reported mutations only in invasive tumors, while we found a PIK3CA mutation in one noninvasive corticotroph microadenoma. PIK3CA amplification was observed in 21.2% (7/33) of the cases. This study demonstrates the presence of somatic mutations and amplifications of the PIK3CA gene in a second series of pituitary adenomas, corroborating the previously described involvement of the PI3K/Akt signaling pathway in the tumorigenic process of this gland.