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51.
Carina Carneiro de Melo Moura Alexandre M. Fernandes Alexandre Aleixo Helder Farias Pereira de Araújo Erich de Freitas Mariano Michael Wink 《Ibis》2020,162(4):1198-1210
We focus on reconstructing a spatiotemporal scenario of diversification of a widespread South American species, the Pectoral Sparrow Arremon taciturnus (Aves: Passerellidae). This species is widely distributed in both the humid and the dry forests of South America and therefore provides an interesting model for understanding the connection between different biomes of South America. We examined nucleotide sequences of the mitochondrial genes Cytochrome b (cyt-b) and NADH subunit 2 (ND2) from 107 specimens, and one nuclear marker (intron 7 of the β-fibrinogen gene) from a subset of samples collected across the distribution ranges of A. t. taciturnus and A. t. nigrirostris. Six major lineages were recovered in the phylogenies that displayed high levels of variance of allele frequencies and corresponded to distinct geographical locations. The estimation of divergence times provided evidence that diversification of the six lineages of the Pectoral Sparrow occurred throughout the Late Pleistocene across major cis-Andean biomes and Amazonian interfluves. Our dataset for A. taciturnus provides further evidence that rivers in Amazonia constitute barriers promoting allopatric speciation, with occasional sharing of alleles among lineages, particularly those with adjacent distributions. 相似文献
52.
α‐ l‐iduronidase gene‐based therapy using the phiC31 system to treat mucopolysaccharidose type I mice 下载免费PDF全文
Roberta Sessa Stilhano Priscila Keiko Matsumoto Martin Suely Maymone de Melo Vivian Yochiko Samoto Giovani Bravin Peres Yara Maria Correa da Silva Michelacci Flavia Helena da Silva Vanessa Gonçalves Pereira Vania D'Almeida Adriana Taveira da Cruz Miriam Galvonas Jasiulionis Sang Won Han 《The journal of gene medicine》2015,17(1-2):1-13
53.
M. Teresa Telleria Ireneia Melo Margarita Dueñas Isabel Salcedo Esperanza Beltrán-Tejera J. Laura Rodríguez-Armas María P. Martín 《Mycological Progress》2013,12(4):687-692
Using morphological and molecular data, the new species Sistotremastrum guttuliferum is described from specimens collected in the Azores archipelago, Madeira and Canary Islands. Morphologically, this new species differs from S. niveocremeum and S. suecicum by the small oil drops in the cytoplasm of subicular hyphae and the spore size. An updated key of Sistotremastrum species is provided. 相似文献
54.
Claudia Quezada Wallys Garrido Carlos Oyarzún Katia Fernández Rodrigo Segura Rómulo Melo Paola Casanello Luis Sobrevia Rody San Martín 《Journal of cellular physiology》2013,228(3):602-608
Glioblastoma multiforme (GBM) cells are characterised by their extreme chemoresistance. The activity of multiple‐drug resistance (MDR) transporters that extrude antitumor drugs from cells plays the most important role in this phenomenon. To date, the mechanism controlling the expression and activity of MDR transporters is poorly understood. Activity of the enzyme ecto‐5′‐nucleotidase (CD73) in tumor cells, which hydrolyses AMP to adenosine, has been linked to immunosuppression and prometastatic effects in breast cancer and to the proliferation of glioma cells. In this study, we identify a high expression of CD73 in surgically resected samples of human GBM. In primary cultures of GBM, inhibition of CD73 activity or knocking down its expression by siRNA reversed the MDR phenotype and cell viability was decreased up to 60% on exposure to the antitumoral drug vincristine. This GBM chemosensitization was caused by a decrease in the expression and activity of the multiple drug associated protein 1 (Mrp1), the most important transporter conferring multiple drug resistance in these cells. Using pharmacological modulators, we have recognized the adenosine A3 receptor subtype in mediation of the chemoresistant phenotype in these cells. In conclusion, we have determined that the activity of CD73 to trigger adenosine signaling sustains chemoresistant phenotype in GBM cells. J. Cell. Physiol. 228: 602–608, 2013. © 2012 Wiley Periodicals, Inc. 相似文献
55.
de Oliveira LC Ribeiro CT Mendes Dde M Oliveira TC Costa-Cruz JM 《Memórias do Instituto Oswaldo Cruz》2002,97(1):119-121
Several studies have shown that chronic alcoholics have increased susceptibility to infections due to higher exposure to infectious agents as well as breakdown in their immune defenses. As Strongyloides stercoralis infection is usually more relevant in immunocompromised patients, the aim of this study was to evaluate the frequency of S. stercoralis infection in alcoholics. Thus, coproparasitological examination was carried out in 145 subjects, from which 45 were chronic alcoholics (mean age of 45.7 +/- 11.0 years), 10 were nonalcoholic cirrhotic patients (mean age of 50.2 +/- 13.1 years), and 90 were asymptomatic nonalcoholic subjects (mean age of 46.7 +/- 10.1 years), which served as controls. From the alcoholics, 9 had hepatic cirrhosis, 9 had chronic pancreatitis and 27 had neither cirrhosis nor pancreatitis. For the diagnosis of strongyloidiasis, the Baermann-Moraes and Lutz methods were used in three fecal samples from each subject. Samples were collected at alternated days, and three slides of each sample were analyzed for each method, thus totalizing 2,610 slides examined. The frequency of strongloidiasis in the total alcoholic group (33.3%) and in the subgroups of alcoholics, i.e., patients with hepatic cirrhosis (44.4%), with chronic pancreatitis (33.3%), and those with no cirrhosis or pancreatitis (29.6%) was statistically higher than that found in the control group (5.5%). None of the individuals with nonalcoholic hepatic cirrhosis had S. stercoralis infection. Our results showed that the chronic alcoholism itself is an important factor that predisposes to strongyloidiasis. 相似文献
56.
Vera Maria Ferro Vargas Sayonara Bresolin Migliavacca Andra Cssia de Melo Rubem Cesar Horn Regis Rolim Guidobono Isabel Cristina Fernandes de S Ferreira Maria Heloisa Degrazia Pestana 《Mutation Research - Genetic Toxicology and Environmental Mutagenesis》2001,490(2)
The genotoxicity of river water and sediment including interstitial water was evaluated by microscreen phage-induction and Salmonella/microsome assays. Different processes used to fractionate the sediment sample were compared using solvents with different polarities. The results obtained for mutagenic activity using the Salmonella/microsome test were negative in the water and interstitial water samples analysed using the direct concentration method. The responses in the microscreen phage-induction assay showed the presence of genotoxic or indicative genotoxic activity for at least one water sample of each site analysed using the same concentration method. Similar results were obtained for interstitial water samples, i.e. absence of mutagenic activity in the Salmonella/microsome test and presence of genotoxic activity in the microscreen phage-induction assay. Metal contamination, as evidenced by the concentrations in stream sediments, may also help explain some of these genotoxic results. Stream sediment organic extracts showed frameshift mutagenic activity in the ether extract detected by Salmonella/microsome assay. The concentrates evaluated by microscreen phage-induction assay identified the action of organic compounds in the non-polar, medium polar and polar fractions. Thus, the microscreen phage-induction assay has proven to be a more appropriate methodology than the Salmonella/microsome test to analyse multiple pollutants in this ecosystem where both organic compounds and heavy metals are present. 相似文献
57.
Background
Although simulation studies show that combining multiple breeds in one reference population increases accuracy of genomic prediction, this is not always confirmed in empirical studies. This discrepancy might be due to the assumptions on quantitative trait loci (QTL) properties applied in simulation studies, including number of QTL, spectrum of QTL allele frequencies across breeds, and distribution of allele substitution effects. We investigated the effects of QTL properties and of including a random across- and within-breed animal effect in a genomic best linear unbiased prediction (GBLUP) model on accuracy of multi-breed genomic prediction using genotypes of Holstein-Friesian and Jersey cows.Methods
Genotypes of three classes of variants obtained from whole-genome sequence data, with moderately low, very low or extremely low average minor allele frequencies (MAF), were imputed in 3000 Holstein-Friesian and 3000 Jersey cows that had real high-density genotypes. Phenotypes of traits controlled by QTL with different properties were simulated by sampling 100 or 1000 QTL from one class of variants and their allele substitution effects either randomly from a gamma distribution, or computed such that each QTL explained the same variance, i.e. rare alleles had a large effect. Genomic breeding values for 1000 selection candidates per breed were estimated using GBLUP modelsincluding a random across- and a within-breed animal effect.Results
For all three classes of QTL allele frequency spectra, accuracies of genomic prediction were not affected by the addition of 2000 individuals of the other breed to a reference population of the same breed as the selection candidates. Accuracies of both single- and multi-breed genomic prediction decreased as MAF of QTL decreased, especially when rare alleles had a large effect. Accuracies of genomic prediction were similar for the models with and without a random within-breed animal effect, probably because of insufficient power to separate across- and within-breed animal effects.Conclusions
Accuracy of both single- and multi-breed genomic prediction depends on the properties of the QTL that underlie the trait. As QTL MAF decreased, accuracy decreased, especially when rare alleles had a large effect. This demonstrates that QTL properties are key parameters that determine the accuracy of genomic prediction.Electronic supplementary material
The online version of this article (doi:10.1186/s12711-015-0124-6) contains supplementary material, which is available to authorized users. 相似文献58.
59.
60.
Several fish surveys were carried out in recent years at Sedlo Seamount, Azores, north-eastern central Atlantic Ocean. An objective of the surveys was to determine the species composition of the demersal fish species living in the area. Four types of sampling gears (bottom trawl and three types of longline) were used at Sedlo Seamount resulting in very different species composition by gear and a very complete coverage of the fish fauna of the area. A list of fishes caught with these sampling methods is presented, along with other specific auxiliary information. Altogether 78 species from 43 families were listed for Sedlo Seamount, and as far as is known, 15 species were recorded for the first time for Azorean waters. 相似文献