排序方式: 共有22条查询结果,搜索用时 15 毫秒
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Ariane K. S. Martins Flaviano S. Martins Danielle A. Gomes Samir D. A. Elian Angélica T. Vieira Mauro M. Teixeira Denise C. Cara Regina M. D. Nardi Jacques R. Nicoli 《Archives of microbiology》2010,192(12):995-1003
The aim of the present study was to compare the effect of intragastric administration with two strains of Bifidobacterium
animalis subsp. lactis (Bifido A and Bifido B), in gnotobiotic and conventional mice, challenged with Salmonella Typhimurium. In vitro antagonism test showed that the two strains were able to produce antagonistic substances against various
pathogenic microorganisms. In an ex vivo antagonism test the production of antagonistic substances was observed only against
three out ten pathogens tested. Both Bifidobacterium strains were able to colonize and to maintain high population levels in the digestive tract of gnotobiotic mice. In addition,
the two strains had low and limited translocation ability and did not cause any histological lesion in any of the organs analyzed.
Both strains were able to reduce the fecal number of Salmonella in gnotobiotic mice challenged with the pathogen, but only Bifido B was able to confer a protection as demonstrated by a
lower mortality. Higher levels of sIgA and IL-10 were observed only in Bifido B mono-associated mice when compared to germ
free group. We could conclude that, among the parameters analyzed, the strain Bifido B exhibited the more desirable characteristics
to be used as a probiotic. 相似文献
13.
主动脉夹层分离的研究现状 总被引:1,自引:0,他引:1
主动脉夹层分离是一种临床上不常见但具有潜在灾难性、急危重的疾病。提高临床医师对该病的认识与了解,将有助于对其采取预防措施,提高救治水平。本文对该病近几年的研究进展作一综述。 相似文献
14.
Lily Mijouin Mélanie Hillion Yasmina Ramdani Thomas Jaouen Cécile Duclairoir-Poc Marie-Laure Follet-Gueye Elian Lati Florent Yvergnaux Azzedine Driouich Luc Lefeuvre Christine Farmer Laurent Misery Marc G. J. Feuilloley 《PloS one》2013,8(11)
Background
Skin is the largest human neuroendocrine organ and hosts the second most numerous microbial population but the interaction of skin neuropeptides with the microflora has never been investigated. We studied the effect of Substance P (SP), a peptide released by nerve endings in the skin on bacterial virulence.Methodology/Principal Findings
Bacillus cereus, a member of the skin transient microflora, was used as a model. Exposure to SP strongly stimulated the cytotoxicity of B. cereus (+553±3% with SP 10−6 M) and this effect was rapid (<5 min). Infection of keratinocytes with SP treated B. cereus led to a rise in caspase1 and morphological alterations of the actin cytoskeleton. Secretome analysis revealed that SP stimulated the release of collagenase and superoxide dismutase. Moreover, we also noted a shift in the surface polarity of the bacteria linked to a peel-off of the S-layer and the release of S-layer proteins. Meanwhile, the biofilm formation activity of B. cereus was increased. The Thermo unstable ribosomal Elongation factor (Ef-Tu) was identified as the SP binding site in B. cereus. Other Gram positive skin bacteria, namely Staphylococcus aureus and Staphylococcus epidermidis also reacted to SP by an increase of virulence. Thermal water from Uriage-les-Bains and an artificial polysaccharide (Teflose®) were capable to antagonize the effect of SP on bacterial virulence.Conclusions/Significance
SP is released in sweat during stress and is known to be involved in the pathogenesis of numerous skin diseases through neurogenic inflammation. Our study suggests that a direct effect of SP on the skin microbiote should be another mechanism. 相似文献15.
16.
A novel calmodulin-binding protein functions as a negative regulator of osmotic stress tolerance in Arabidopsis thaliana seedlings 总被引:2,自引:0,他引:2
Perruc E Charpenteau M Ramirez BC Jauneau A Galaud JP Ranjeva R Ranty B 《The Plant journal : for cell and molecular biology》2004,38(3):410-420
A clone for a novel Arabidopsisthaliana calmodulin (CaM)-binding protein of 25 kDa (AtCaMBP25) has been isolated by using a radiolabelled CaM probe to screen a cDNA expression library derived from A. thaliana cell suspension cultures challenged with osmotic stress. The deduced amino acid sequence of AtCaMBP25 contains putative nuclear localization sequences and shares significant degree of similarity with hypothetical plant proteins only. Fusion of the AtCaMBP25 coding sequence to reporter genes targets the hybrid protein to the nucleus. Bacterially expressed AtCaMBP25 binds, in a calcium-dependent manner, to a canonical CaM but not to a less conserved isoform of the calcium sensor. AtCaMBP25 is encoded by a single-copy gene, whose expression is induced in Arabidopsis seedlings exposed to dehydration, low temperature or high salinity. Transgenic plants overexpressing AtCaMBP25 exhibits an increased sensitivity to both ionic (NaCl) and non-ionic (mannitol) osmotic stress during seed germination and seedling growth. By contrast, transgenic lines expressing antisense AtCaMBP25 are significantly more tolerant to mannitol and NaCl stresses than the wild type. Thus, the AtCaMBP25 gene functions as a negative effector of osmotic stress tolerance and likely participates in stress signal transduction pathways. 相似文献
17.
Noam Cohen Einat Toister Yonatan Lati Meni Girshengorn Lilach Levin Lea Silberstein Dror Seliktar Eyal Epstein 《Cytotechnology》2018,70(3):1075-1083
Recent advances in the bioengineering field have introduced new opportunities enabling cell encapsulation in three-dimensional (3D) structures using either various natural or synthetic materials. However, such hydrogel scaffolds have not been fully biocompatible for cell cultivation due to the lack of physical stability or bioactivity. Here, we utilized a uniquely fabricated semi-synthetic 3D polyethylene glycol-fibrinogen (PEG-Fb) hydrogel scaffold, which exhibits both high stability and high bioactivity, to encapsulate HEK293 cells for the production of human recombinant acetylcholine esterase (AChE). To examine the beneficial bioactive effect of the PEG-Fb scaffold over 2D surfaces, an experimental system was established to compare the viability, proliferation and AChE secretion of encapsulated cells versus non-encapsulated surface-adherent cells in serum starvation. Our results show that the transfer of surface-adherent HEK293 cells from fully enriched medium with 10% FCS to 0.2% FCS resulted in an eightfold reduction in cell number and a fourfold reduction in AChE production. In contrast, the encapsulated cells were highly viable and about twofold more efficient in AChE production. In addition, they had round morphology with a twofold larger cell diameter, supporting the observation of increased AChE production. These results suggest a role of the PEG-Fb scaffold in providing a supportive microenvironment in reduced serum conditions that enhances encapsulated cell functions, opening new directions to study the implementation of this platform in large-scale pharmaceutical protein production. 相似文献
18.
T. Schaap J. Zlotogora E. Elian Y. Barak G. Bach 《American journal of human genetics》1981,33(4):531-539
A genetic analysis was performed in an isolate in which metachromatic leukodystrophy (MLD) and aryl sulfatase A (ASA) pseudodeficiency are relatively frequent. The frequency of matings at risk and the frequency of ASA pseudodeficiency among parents of MLD patients are compatible with allelism between the gene determining MLD and the gene determining ASA pseudodeficiency. Two independent pedigrees including MLD patients and ASA-deficient healthy individuals also fit the model of allelism. 相似文献
19.
Summary A patient with pure trisomy of the short arm of chromosome 17 in 60% of the examined cells is reported. She presented a variant chromosome 1 with partial pericentric inversion and increased centromeric heterochromatin in one chromosome 17. The cytogenetic findings are discussed. The clinical findings are compared to those found in other reported cases of partial trisomy 17 and a delineation of a pure trisomy 17p attempted. 相似文献
20.
Marco A. Ataide Warrison A. Andrade Dario S. Zamboni Donghai Wang Maria do Carmo Souza Bernardo S. Franklin Samir Elian Flaviano S. Martins Dhelio Pereira George Reed Katherine A. Fitzgerald Douglas T. Golenbock Ricardo T. Gazzinelli 《PLoS pathogens》2014,10(1)
Cyclic paroxysm and high fever are hallmarks of malaria and are associated with high levels of pyrogenic cytokines, including IL-1β. In this report, we describe a signature for the expression of inflammasome-related genes and caspase-1 activation in malaria. Indeed, when we infected mice, Plasmodium infection was sufficient to promote MyD88-mediated caspase-1 activation, dependent on IFN-γ-priming and the expression of inflammasome components ASC, P2X7R, NLRP3 and/or NLRP12. Pro-IL-1β expression required a second stimulation with LPS and was also dependent on IFN-γ-priming and functional TNFR1. As a consequence of Plasmodium-induced caspase-1 activation, mice produced extremely high levels of IL-1β upon a second microbial stimulus, and became hypersensitive to septic shock. Therapeutic intervention with IL-1 receptor antagonist prevented bacterial-induced lethality in rodents. Similar to mice, we observed a significantly increased frequency of circulating CD14+CD16−Caspase-1+ and CD14dimCD16+Caspase-1+ monocytes in peripheral blood mononuclear cells from febrile malaria patients. These cells readily produced large amounts of IL-1β after stimulation with LPS. Furthermore, we observed the presence of inflammasome complexes in monocytes from malaria patients containing either NLRP3 or NLRP12 pyroptosomes. We conclude that NLRP12/NLRP3-dependent activation of caspase-1 is likely to be a key event in mediating systemic production of IL-1β and hypersensitivity to secondary bacterial infection during malaria. 相似文献