排序方式: 共有56条查询结果,搜索用时 296 毫秒
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Claudia Maria Lincoln Silva Fred Bernardes Filho Glauber Voltan Jaci Maria Santana Marcel Nani Leite Filipe Rocha Lima Luisiane de Avila Santana Natlia Aparecida de Paula Patricia Toscano Barreto Nogueira Onofre Wilson Marques-Junior Vanessa Aparecida Tomaz Carmem Sílvia Vilela Pinese Marco Andrey Cipriani Frade 《PLoS neglected tropical diseases》2021,15(8)
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Glauber P Arêas R?de BB Schuab Felipe PG Neves Rosana R Barros 《Memórias do Instituto Oswaldo Cruz》2014,109(7):935-939
Streptococcus pyogenes is responsible for a variety of infectious
diseases and immunological complications. In this study, 91 isolates of S.
pyogenes recovered from oropharynx secretions were submitted to
antimicrobial susceptibility testing, emm typing and pulsed-field
gel electrophoresis (PFGE) analysis. All isolates were susceptible to ceftriaxone,
levofloxacin, penicillin G and vancomycin. Resistance to erythromycin and clindamycin
was 15.4%, which is higher than previous reports from this area, while 20.9% of the
isolates were not susceptible to tetracycline. The macrolide resistance phenotypes
were cMLSB (10) and iMLSB (4). The ermB gene was predominant,
followed by the ermA gene. Thirty-two emm types and
subtypes were found, but five (emm1, emm4,
emm12, emm22, emm81) were detected in
48% of the isolates. Three new emm subtypes were identified
(emm1.74, emm58.14, emm76.7).
There was a strong association between emm type and PFGE clustering.
A variety of PFGE profiles as well as emm types were found among
tetracycline and erythromycin-resistant isolates, demonstrating that antimicrobial
resistant strains do not result from the expansion of one or a few clones. This study
provides epidemiological data that contribute to the development of suitable
strategies for the prevention and treatment of such infections in a poorly studied
area. 相似文献
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Karimov JH Cerillo AG Gasbarri T Solinas M Bevilacqua S Glauber M 《Innovations (Philadelphia, Pa.)》2010,5(5):378-380
In this piece of work, we attempt to highlight our approach and early experience with minimally invasive aortic valve replacement with aortic Freedom Solo stentless bioprosthesis performed through an upper manubrium-limited ministernotomy in the second intercostal space. The novel suturing technique is required for stentless aortic bioprosthesis implantation, and this, in its turn, will predetermine and influence the surgeon's choice for operative access. In our department, the feasibility of the approach was first assessed; aortic valve was replaced by stentless bioprosthesis in a total of 23 patients (mean age 57 ± 12 years). In all cases, a cardiopulmonary bypass was established by a central ascending aorta cannulation and peripheral percutaneous venous cannula insertion. This approach was found to be technically reproducible and safe. The surgical technique used is described in this article. 相似文献
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Glauber S.F. da SilvaHumberto Giusti Luiz G.S. BrancoMogens L. Glass 《Journal of thermal biology》2011,36(8):521-526
The control of pulmonary ventilation in South American lungfish Lepidosiren paradoxa is poorly understood. Interactions between temperature and hypoxia are particularly relevant due to large seasonal variations of its habitat. Therefore, we tested the hypothesis that the ventilatory responses to aerial hypoxia of Lepidosiren are highly dependent on ambient temperature. We used a pneumotachograph to measure pulmonary ventilation (VE), tidal volume (VT) and respiratory frequency (fR) during normoxic (21% O2) and hypoxic (12%, 10% and 7% O2) conditions at two temperatures (25 and 35 °C). Blood gases, arterial PO2 (PaO2), arterial PCO2 (PaCO2) and arterial pH (pHa) were also evaluated. At 25 °C, VE increased significantly at 10% and 7% hypoxic levels when compared to the control value (21% O2). At 35 °C, all hypoxic levels elicited a significant increase of VE relative to control values. VE is augmented mostly by increases of respiratory frequency (fR), and there were significant interactions (p<0.001) between aerial hypoxia and temperature. PaCO2 increased from ∼22 mmHg (normoxic value at 25 °C) to ∼32 mmHg (normoxic value at 35 °C). Concomitantly, the pHa decreased from 7.51 (25 °C) to 7.38 (35 °C). Hypoxia-induced hyperventilation caused a reduction in PaCO2 and an increase in pHa, which were more pronounced at 35 °C than at 25 °C, reflecting an increased hyperventilation under the high temperature. In conclusion, the magnitude of ventilatory response is highly temperature-dependent in L. paradoxa, which is important for an animal experiencing large seasonal variations. 相似文献
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Araujo Gde S Fonseca FL Pontes B Torres A Cordero RJ Zancopé-Oliveira RM Casadevall A Viana NB Nimrichter L Rodrigues ML Garcia ES Souza Wd Frases S 《PloS one》2012,7(1):e29561
Capsule production is common among bacterial species, but relatively rare in eukaryotic microorganisms. Members of the fungal Cryptococcus genus are known to produce capsules, which are major determinants of virulence in the highly pathogenic species Cryptococcus neoformans and Cryptococcus gattii. Although the lack of virulence of many species of the Cryptococcus genus can be explained solely by the lack of mammalian thermotolerance, it is uncertain whether the capsules from these organisms are comparable to those of the pathogenic cryptococci. In this study, we compared the characteristic of the capsule from the non-pathogenic environmental yeast Cryptococcus liquefaciens with that of C. neoformans. Microscopic observations revealed that C. liquefaciens has a capsule visible in India ink preparations that was also efficiently labeled by three antibodies generated to specific C. neoformans capsular antigens. Capsular polysaccharides of C. liquefaciens were incorporated onto the cell surface of acapsular C. neoformans mutant cells. Polysaccharide composition determinations in combination with confocal microscopy revealed that C. liquefaciens capsule consisted of mannose, xylose, glucose, glucuronic acid, galactose and N-acetylglucosamine. Physical chemical analysis of the C. liquefaciens polysaccharides in comparison with C. neoformans samples revealed significant differences in viscosity, elastic properties and macromolecular structure parameters of polysaccharide solutions such as rigidity, effective diameter, zeta potential and molecular mass, which nevertheless appeared to be characteristics of linear polysaccharides that also comprise capsular polysaccharide of C. neoformans. The environmental yeast, however, showed enhanced susceptibility to the antimicrobial activity of the environmental phagocytes, suggesting that the C. liquefaciens capsular components are insufficient in protecting yeast cells against killing by amoeba. These results suggest that capsular structures in pathogenic Cryptococcus species and environmental species share similar features, but also manifest significant difference that could influence their potential to virulence. 相似文献
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Secchiero P Rimondi E di Iasio MG Voltan R Gonelli A Zauli G 《Journal of cellular physiology》2012,227(5):1829-1837
A range of cell types of mesenchymal origin express α-smooth muscle actin (α-SMA), a protein that plays a key role in controlling cell motility and differentiation along the fibrocyte and myofibroblast lineages. Although α-SMA is often expressed in stromal cells associated to a variety of cancers including hematological malignancies, up to now the role of anti-cancer drugs on α-SMA has not been deeply investigated. In this study, we demonstrated that Nutlin-3, the small molecule inhibitor of the MDM2/p53 interactions, significantly up-regulated the mRNA and protein levels of α-SMA in normal macrophages as well as in p53(wild-type) but not in p53(mutated/null) myeloid leukemic cells. The p53-dependence of α-SMA up-regulation induced by Nutlin-3 was demonstrated in experiments performed with siRNA for p53. Of note, Nutlin-3 mediated up-regulation of α-SMA in OCI leukemic cells was accompanied by cell adhesion to plastic substrate and by reduced cell migratory response in transwell assays. Notably, the role of α-SMA induction in the modulation of myeloid cell migration was clearly documented in α-SMA gene knockdown experiments. In addition, Nutlin-3 significantly up-regulated α-SMA expression in primary endothelial cells, but not in fibroblasts and mesenchymal stem cells (MSC). Conversely, transforming growth factor-β1 up-regulated α-SMA in fibroblasts and MSC, but not in macrophages and endothelial cells. Taken together, these data indicate that Nutlin-3 is a potent inducer of α-SMA in both normal and leukemic myeloid cells as well as in endothelial cells. 相似文献
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Rodrigo Almeida-Paes Susana Frases Glauber de Sousa Araújo Manoel Marques Evangelista de Oliveira Gary J. Gerfen Joshua D. Nosanchuk Rosely Maria Zancopé-Oliveira 《Applied and environmental microbiology》2012,78(24):8623-8630
Sporothrix schenckii is the etiological agent of sporotrichosis, the main subcutaneous mycosis in Latin America. Melanin is an important virulence factor of S. schenckii, which produces dihydroxynaphthalene melanin (DHN-melanin) in conidia and yeast cells. Additionally, l-dihydroxyphenylalanine (l-DOPA) can be used to enhance melanin production on these structures as well as on hyphae. Some fungi are able to synthesize another type of melanoid pigment, called pyomelanin, as a result of tyrosine catabolism. Since there is no information about tyrosine catabolism in Sporothrix spp., we cultured 73 strains, including representatives of newly described Sporothrix species of medical interest, such as S. brasiliensis, S. schenckii, and S. globosa, in minimal medium with tyrosine. All strains but one were able to produce a melanoid pigment with a negative charge in this culture medium after 9 days of incubation. An S. schenckii DHN-melanin mutant strain also produced pigment in the presence of tyrosine. Further analysis showed that pigment production occurs in both the filamentous and yeast phases, and pigment accumulates in supernatants during stationary-phase growth. Notably, sulcotrione inhibits pigment production. Melanin ghosts of wild-type and DHN mutant strains obtained when the fungus was cultured with tyrosine were similar to melanin ghosts yielded in the absence of the precursor, indicating that this melanin does not polymerize on the fungal cell wall. However, pyomelanin-producing fungal cells were more resistant to nitrogen-derived oxidants and to UV light. In conclusion, at least three species of the Sporothrix complex are able to produce pyomelanin in the presence of tyrosine, and this pigment might be involved in virulence. 相似文献
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Live recombinant vectors entered the AIDS vaccine field with the realization that live attenuated HIV vaccines posed too great a safety risk, and that subunit vaccines elicited antibodies which lacked the breadth or potency needed to induce sterilizing immunity. Vectored vaccines provided a means to bring the cellular arm of the immune system into play by mimicking natural viral infection. By delivering antigens within host cells, processing and presentation could occur for induction of cellular immune responses. This recombinant vector approach, either alone or combined with other strategies, has produced impressive results. Recombinants have been generated from DNA and RNA viruses and bacteria. With few exceptions, each vector poses some risk, yet each possesses unique features that make it attractive. In addition to safety, key considerations in vector selection have included previous success as a vaccine against the wild-type agent or other pathogens; ability to induce potent, persistent immune responses; ability to target mucosal inductive sites and antigen presenting cells; lack of integration into the host genome; presence of pre-existing immunity in people; ease of mucosal administration; cloning capacity; ease of engineering and production; and stability of the final product. Here we up-date the status of several live recombinant vectors that have shown good potential in pre-clinical studies. Some have progressed to human clinical trials, and others will shortly. The abundance of vectors, coupled with the complexity arising from use of combination regimens with other vaccine types and heterologous vectors, will necessitate selection of the most promising candidates for large-scale efficacy trials in people. The sooner comparative studies can be designed and implemented in which live recombinant vectors containing the same inserted genes are evaluated head-to-head, the closer we will be to an eventual vaccine. 相似文献