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71.
72.
Figueiredo RT Fernandez PL Dutra FF González Y Lopes LC Bittencourt VC Sassaki GL Barreto-Bergter E Bozza MT 《The Journal of biological chemistry》2010,285(52):40714-40723
Pseudallescheria boydii (Scedosporium apiospermum) is a saprophytic fungus widespread in the environment, and has recently emerged as an agent of localized as well as disseminated infections, particularly mycetoma, in immunocompromised and immunocompetent hosts. We have previously shown that highly purified α-glucan from P. boydii activates macrophages through Toll-like receptor TLR2, however, the mechanism of P. boydii recognition by macrophage is largely unknown. In this work, we investigated the role of innate immune receptors in the recognition of P. boydii. Macrophages responded to P. boydii conidia and hyphae with secretion of proinflammatory cytokines. The activation of macrophages by P. boydii conidia required functional MyD88, TLR4, and CD14, whereas stimulation by hyphae was independent of TLR4 and TLR2 signaling. Removal of peptidorhamnomannans from P. boydii conidia abolished induction of cytokines by macrophages. A fraction highly enriched in rhamnomannans was obtained and characterized by NMR, high performance TLC, and GC-MS. Preparation of rhamnomannans derived from P. boydii triggered cytokine release by macrophages, as well as MAPKs phosphorylation and IκBα degradation. Cytokine release induced by P. boydii-derived rhamnomannans was dependent on TLR4 recognition and required the presence of non-reducing end units of rhamnose of the rhamnomannan, but not O-linked oligosaccharides from the peptidorhamnomannan. These results imply that TLR4 recognizes P. boydii conidia and this recognition is at least in part due to rhamnomannans expressed on the surface of P. boydii. 相似文献
73.
74.
Structural analysis of an Echinococcus granulosus actin-fragmenting protein by small-angle x-ray scattering studies and molecular modeling
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Grimm ED Portugal RV de Oliveira Neto M Martins NH Polikarpov I Zaha A Ferreira HB 《Biophysical journal》2006,90(9):3216-3223
The Echinococcus granulosus actin filament-fragmenting protein (EgAFFP) is a three domain member of the gelsolin family of proteins, which is antigenic to human hosts. These proteins, formed by three or six conserved domains, are involved in the dynamic rearrangements of the cytoskeleton, being responsible for severing and capping actin filaments and promoting nucleation of actin monomers. Various structures of six domain gelsolin-related proteins have been investigated, but little information on the structure of three domain members is available. In this work, the solution structure of the three domain EgAFFP has been investigated through small-angle x-ray scattering (SAXS) studies. EgAFFP exhibits an elongated molecular shape. The radius of gyration and the maximum dimension obtained by SAXS were, respectively, 2.52 +/- 0.01 nm and 8.00 +/- 1.00 nm, both in the absence and presence of Ca2+. Two different molecular homology models were built for EgAFFP, but only one was validated through SAXS studies. The predicted structure for EgAFFP consists of three repeats of a central beta-sheet sandwiched between one short and one long alpha-helix. Possible implications of the structure of EgAFFP upon actin binding are discussed. 相似文献
75.
Potamotrygonidae is the representative family of South American freshwater elasmobranchs. It is a monophyletic group containing
20 species grouped into three genera. Three species belonging to two genera of this family were collected from the middle
Negro River, Amazonas, Brazil, and studied cytogenetically: Paratrygon aiereba, Potamotrygon motoro and Potamotrygon orbignyi. Paratrygon aiereba presented 2n = 90 chromosomes and 4M+2SM+10ST+74A. Both species of Potamotrygon presented 2n = 66 chromosomes and differed in their chromosomal formulas: P. motoro had 18M+12SM+10ST+26A and P. orbignyi had 22M+10SM+8ST+26A. No sex heteromorphism was detected. The Fundamental Number (FN) was 106 for the three species. A system
of multiple NORs was found in the three species, but with interspecific differences in terms of location and position of the
active Ag-NORs sites. Paratrygon aiereba presented only four sites on the short arms of two chromosomal pairs, both in terminal regions. Potamotrygon motoro presented seven sites, on the long and short arms, all in terminal regions of non-homologous chromosomes; P. orbignyi presented eight sites on the long arms, all in terminal regions, of non-homologous chromosomes. The constitutive heterochromatin
was in pericentromeric regions of all chromosomes, and no significant interspecific difference was found in relation to this
marker. 相似文献
76.
A comparative analysis of G-banded karyotypes was performed for seven species of Chiroptera, representing two families (Phyllostomidae
and Molossidae). Despite the differences in diploid and fundamental numbers, extensive homologies between six karyotypes were
identified: A . planirostris, P. lineatus, S. lilium, G. soricina, P. hastatus (Phyllostomidae) and M. rufus (Molossidae). Robertsonian rearrangements and pericentric inversions account for the differences between the karyotypes of
phyllostomid and molossid species. The homologies and rearrangements observed reinforce the monophiletic origin of phyllostomids
and the inclusion of species in different subfamilies. In situ hybridization with genomic DNA revealed considerable conservation of the karyotypes, including C. perspicillata, that did not show G-band homologies with the other species analyzed. For the first time, chromosomal evidence is presented
of a common origin for Phyllostomidae and Molossidae. 相似文献
77.
78.
Antimicrobial resistance of Pseudomonas aeruginosa biofilms 总被引:10,自引:0,他引:10
Drenkard E 《Microbes and infection / Institut Pasteur》2003,5(13):1213-1219
Resistance to antimicrobial agents is the most important feature of biofilm infections. As a result, infections caused by bacterial biofilms are persistent and very difficult to eradicate. Although several mechanisms have been postulated to explain reduced susceptibility to antimicrobials in bacterial biofilms, it is becoming evident that biofilm resistance is multifactorial. The contribution of each of the different mechanisms involved in biofilm resistance is now beginning to emerge. 相似文献
79.
JH Lee JM Lee EM Ramos T Gillis JS Mysore S Kishikawa T Hadzi AE Hendricks MR Hayden PJ Morrison M Nance CA Ross RL Margolis F Squitieri C Gellera E Gomez-Tortosa C Ayuso O Suchowersky RJ Trent E McCusker A Novelletto M Frontali R Jones T Ashizawa S Frank MH Saint-Hilaire SM Hersch HD Rosas D Lucente MB Harrison A Zanko RK Abramson K Marder J Sequeiros G Bernhard Landwehrmeyer;On behalf of the Registry Study of the European Huntington’s Disease Network 《Biochemical and biophysical research communications》2012,426(3):404-408
80.
GB Menezes FA Pereira CA Duarte TM Carmo HP Silva Filho MA Zarife MA Krieger EA Reis MG Reis 《Memórias do Instituto Oswaldo Cruz》2012,107(5):680-683
The hepatitis C virus (HCV) can be detected in blood and other bodily fluids, such as saliva, semen and gastric juices. The aim of this study was to compare the HCV viral loads in the serum and saliva of infected patients. Twenty-nine patients with detectable HCV RNA in their serum and saliva were included in this study. The HCV viral loads were determined through quantitative real-time polymerase chain reactions. The median viral RNA levels were 5.78 log10 copies in the serum and 3.32 log10 copies in the saliva. We observed that the salivary HCV viral load was significantly lower than the viral load in the serum. Further studies are required to understand the role of saliva in the diagnosis, management and potential transmission of HCV. 相似文献