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991.
Isabela T. Pereira Edneia A. S. Ramos Erico T. Costa Anamaria A. Camargo Graciele C. M. Manica Liliane M. B. Klassen Andressa Chequin Karin Braun-Prado Fábio de O. Pedrosa Emanuel M. Souza Fabricio F. Costa Giseli Klassen 《PloS one》2014,9(9)
Metastasis accounts for more than 90% of cancer deaths. Cells from primary solid tumors may invade adjacent tissues and migrate to distant sites where they establish new colonies. The tumor microenvironment is now recognized as an important participant in the signaling that induces cancer cell migration. An essential process for metastasis is extracellular matrix (ECM) degradation by metalloproteases (MMPs), which allows tumor cells to invade local tissues and to reach blood vessels. The members of this protein family include gelatinase A, or MMP-2, which is responsible for the degradation of type IV collagen, the most abundant component of the basal membrane, that separates epithelial cells in the stroma. It is known that fibronectin is capable of promoting the expression of MMP-2 in MCF7 breast cancer cells in culture. In addition, it was already shown that the MMP2 gene expression is regulated by epigenetic mechanisms. In this work, we showed that fibronectin was able to induce MMP2 expression by 30% decrease in its promoter methylation. In addition, a histone marker for an open chromatin conformation was significantly increased. These results indicate a new role for fibronectin in the communication between cancer cells and the ECM, promoting epigenetic modifications. 相似文献
992.
Eleonora Aquilini Susana Merino Miguel Regué Juan M. Tomás 《Journal of bacteriology》2014,196(3):556-567
We report here the identification of waa clusters with the genes required for the biosynthesis of the core lipopolysaccharides (LPS) of two Plesiomonas shigelloides strains. Both P. shigelloides
waa clusters shared all of the genes besides the ones flanking waaL. In both strains, all of the genes were found in the waa gene cluster, although one common core biosynthetic gene (wapG) was found in a different chromosome location outside the cluster. Since P. shigelloides and Klebsiella pneumoniae share a core LPS carbohydrate backbone extending up at least to the second outer-core residue, the functions of the common P. shigelloides genes were elucidated by genetic complementation studies using well-defined K. pneumoniae mutants. The function of strain-specific inner- or outer-core genes was identified by using as a surrogate acceptor LPS from three well-defined K. pneumoniae core LPS mutants. Using this strategy, we were able to assign a proteomic function to all of the P. shigelloides
waa genes identified in the two strains encoding six new glycosyltransferases (WapA, -B, -C, -D, -F, and -G). P. shigelloides demonstrated an important variety of core LPS structures, despite being a single species of the genus, as well as high homologous recombination in housekeeping genes. 相似文献
993.
Silvia E. Burkart Rolando J. C. León María C. Conde Susana B. Perelman 《Plant Ecology》2011,212(6):1009-1024
In order to provide a baseline for management decisions, we evaluated vegetation heterogeneity among 38 remnant grasslands
located on high agronomic potential soils along a five degree-east–west transect in the cropping Pampa. This extensive region
has been cultivated for well over a century, small-scale traditional forms of agriculture were progressively replaced with
large-scale industrial forms and its cropped area has more than doubled in the last 25 years, threatening the maintenance
of biodiversity associated to productive soils. We characterized the diversity of this grassland patches, identified its main
environmental drivers and searched for factors that favor their invasion by exotic plant species. Vegetation samples were
analysed through Canonical Correspondence Analysis, proportional distribution of functional groups was compared and regression
models were estimated to identify variables associated with exotic species importance. Water availability, determined by climate
and soil characteristics, was the main driving factor of floristic heterogeneity in these grasslands. Exotic richness, mostly
of Eurasian species, increases toward the east, related to proximity to the entrance port. The functional group of C4 native grasses seems to be responsible for biotic resistance to invasion. More than 80% of the species recorded during the
first vegetation registers in 1930 are still present, while the number of exotics was seven-fold increased. Despite covering
small areas as isolated stands, these are hot spots of native biodiversity and must be the object of increasing attention
for conservation and restoration in order to protect the biodiversity of an extensive agricultural landscape. 相似文献
994.
Susana Jos de Paggi 《Zoologischer Anzeiger》2002,241(4):363-368
The discovery of this species in plankton samples taken at five stations in the Iguazú River and Uruguay River (in a reservoir and an affluent) is reported. Data on the morphology and measurements of individuals collected are shown. This species had previously been registered in Brazil, South America, where it has dispersed widely. The Iguazú River, tributary of the Paraná River, and the Uruguay River could constitute an important dispersal path from Brazilian territory to aquatic environments of Del Plata basin which contains 85% of the freshwater of Argentina. 相似文献
995.
Susana Campoy Jesús Aranda Gerard lvarez Jordi Barb Montserrat Llagostera 《Applied microbiology》2006,72(5):3154-3160
A temperate bacteriophage (F108) has been isolated through mitomycin C induction of a Pasteurella multocida serogroup A strain. F108 has a typical morphology of the family Myoviridae, presenting a hexagonal head and a long contractile tail. F108 is able to infect all P. multocida serogroup A strains tested but not those belonging to other serotypes. Bacteriophage F108, the first P. multocida phage sequenced so far, presents a 30,505-bp double-stranded DNA genome with cohesive ends (CTTCCTCCCC cos site). The F108 genome shows the highest homology with those of Haemophilus influenzae HP1 and HP2 phages. Furthermore, an F108 prophage attachment site in the P. multocida chromosome has been established to be inside a gene encoding tRNALeu. By using several chromosomal markers that are spread along the P. multocida chromosome, it has been demonstrated that F108 is able to perform generalized transduction. This fact, together with the absence of pathogenic genes in the F108 genome, makes this bacteriophage a valuable tool for P. multocida genetic manipulation. 相似文献
996.
997.
998.
Karine Cavalcanti Maurício Sena-Evangelista Lucia Fatima Campos Pedrosa Maria Sanali Moura Oliveira Paiva Paula Cristina Silveira Dias Diana Quitéria Cabral Ferreira Sílvia Maria Franciscato Cozzolino Tanize Espírito Santo Faulin Dulcinéia Saes Parra Abdalla 《PloS one》2015,10(3)
Objective
Statins treatment may modify the levels of zinc and selenium, minerals that can improve vascular function and reduce oxidative damage and inflammation in atherosclerotic patients. This study aimed to evaluate the effects of rosuvastatin, alone or associated with zinc and selenium supplementation, on lipid profile, antioxidant enzymes and mineral status in coronary artery disease patients.Material and Methods
A double-blind randomized clinical trial was performed in which patients (n = 76) were treated with 10 mg rosuvastatin over 4 months associated or not with zinc (30 mg/d) and selenium (150 μg/d) supplementation. The following parameters were analyzed before and after the intervention: anthropometric measurements, lipid profile, high sensitivity C-reactive protein (hs-CRP), electronegative low density lipoprotein (LDL(-)) concentrations, activities of glutathione peroxidase (GPx), superoxide dismutase (SOD), zinc and selenium concentrations in blood plasma and erythocytes. Significance was determined using an α of 5% (two-tailed).Results
We found that rosuvastatin therapy was efficient in reducing total cholesterol, LDL-cholesterol, non-HDL cholesterol, triglycerides, and hs-CRP independently of mineral supplementation. Neither treatment was associated with significant changes in LDL(-). Similarly, the antioxidant enzymes GPx and SOD activity were unchanged by treatments. Neither treatment was associated with significant differences in concentrations of zinc or selenium in blood plasma and erythocytes of studied groups.Conclusion
Rosuvastatin treatment did not affect zinc and selenium levels in coronary artery disease patients. The zinc and selenium supplementation at doses used in this study did not change lipid profile or SOD and GPx activity in patients receiving rosuvastatin. Further studies should be focused on testing alternative doses and supplements in different populations to contribute for a consensus on the ideal choice of antioxidants to be used as possible complementary therapies in atherosclerotic patients.Trial Registration
ClinicalTrials.gov NCT01547377 相似文献999.
A better knowledge of the physiological basis of salinity tolerance is essential to understanding the ecology and evolutionary history of organisms that have colonized inland saline waters. Coleoptera are amongst the most diverse macroinvertebrates in inland waters, including saline habitats; however, the osmoregulatory strategies they employ to deal with osmotic stress remain unexplored. Survival and haemolymph osmotic concentration at different salinities were examined in adults of eight aquatic beetle species which inhabit different parts of the fresh—hypersaline gradient. Studied species belong to two unrelated genera which have invaded saline waters independently from freshwater ancestors; Nebrioporus (Dytiscidae) and Enochrus (Hydrophilidae). Their osmoregulatory strategy (osmoconformity or osmoregulation) was identified and osmotic capacity (the osmotic gradient between the animal’s haemolymph and the external medium) was compared between species pairs co-habiting similar salinities in nature. We show that osmoregulatory capacity, rather than osmoconformity, has evolved independently in these different lineages. All species hyperegulated their haemolymph osmotic concentration in diluted waters; those living in fresh or low-salinity waters were unable to hyporegulate and survive in hyperosmotic media (> 340 mosmol kg-1). In contrast, the species which inhabit the hypo-hypersaline habitats were effective hyporegulators, maintaining their haemolymph osmolality within narrow limits (ca. 300 mosmol kg-1) across a wide range of external concentrations. The hypersaline species N. ceresyi and E. jesusarribasi tolerated conductivities up to 140 and 180 mS cm-1, respectively, and maintained osmotic gradients over 3500 mosmol kg-1, comparable to those of the most effective insect osmoregulators known to date. Syntopic species of both genera showed similar osmotic capacities and in general, osmotic responses correlated well with upper salinity levels occupied by individual species in nature. Therefore, osmoregulatory capacity may mediate habitat segregation amongst congeners across the salinity gradient. 相似文献
1000.