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排序方式: 共有1921条查询结果,搜索用时 203 毫秒
941.
Natural genetic transformation is widely distributed in bacteria. It is a genetically programmed process that is inherent to the species. Transformation requires a specialized membrane-associated machinery for uptake of exogenous double-stranded DNA. It also requires dedicated cytosolic proteins, some of which have been characterized only recently, for the processing of internalized single-stranded DNA fragments into recombination products. A series of observations made in Bacillus subtilis and Streptococcus pneumoniae led to the recent emergence of a picture of a unique, highly integrated machine localized at the cell poles. This dynamic machine, which we propose to name the transformasome, involves both membrane and cytosolic proteins, to internalize, protect, and process transforming DNA. This review attempts to summarize these recent observations with special emphasis on the early stages in DNA processing. 相似文献
942.
943.
Renaud Respaud Denis Marchand Christelle Parent Thibaut Pelat Philippe Thullier Jean-Fran?ois Tournamille Marie-Claude Viaud-Massuard Patrice Diot Mustapha Si-Tahar Laurent Vecellio Nathalie Heuzé-Vourc’h 《MABS-AUSTIN》2014,6(5):1347-1355
Most monoclonal antibodies (mAbs) are administered to patients intravenously to ensure high bioavailability as rapidly as possible. The airways, however, are an attractive delivery route for mAbs for the treatment of lung diseases, making it possible to increase their concentration in the target organ while limiting their systemic passage. Several challenges must be overcome for translation into clinical practice. For example, the drug and device must be paired for the efficient and reliable deposition of a pharmacologically active and safe mAb in the lung region of interest. Mesh nebulizers appear to be the most effective aerosol-producing devices for delivering large amounts of biopharmaceutical while limiting protein instability during nebulization. We used metrological and analytic methods to analyze the effect of both antibody concentration and surfactant addition on aerosol performance and antibody integrity. These two factors had a limited effect on aerosol performance, but affected antibody aggregation. The addition of surfactants to antibody formulations at concentrations appropriate for lung administration markedly reduced the formation of medium or large aggregates, as shown by dynamic light scattering and fluorescence microscopy. Aggregation was also dependent on the type of mesh nebulizer, highlighting the need to optimize drug and device together. 相似文献
944.
945.
Francois P Tu Quoc PH Bisognano C Kelley WL Lew DP Schrenzel J Cramton SE Götz F Vaudaux P 《FEMS immunology and medical microbiology》2003,35(2):135-140
The contribution of in vivo biofilm-forming potential of Staphylococcus aureus and Staphylococcus epidermidis was studied in an experimental model of foreign body infections. Increasing inocula (from 10(2) to 10(7) organisms) of ica-positive strains of S. aureus and S. epidermidis and their ica-negative isogenic mutants (the ica locus codes for a major polysaccharide component of biofilm) were injected into subcutaneously implanted tissue cages in guinea pigs. Surprisingly, bacterial counts and time-course of tissue cage infection by ica-positive strains of S. aureus or S. epidermidis were equivalent to those of their respective ica-negative mutants, in the locally infected fluids and on tissue-cage-inserted plastic coverslips. 相似文献
946.
Serrano-Wu MH Laurent DR Carroll TM Dodier M Gao Q Gill P Quesnelle C Marinier A Mazzucco CE Regueiro-Ren A Stickle TM Wu D Yang H Yang Z Zheng M Zoeckler ME Vyas DM Balasubramanian BN 《Bioorganic & medicinal chemistry letters》2003,13(8):1419-1423
The synthesis and antifungal activity of 5'- and 5'-6'-substituted azasordarin derivatives are described. Modification of the 5'-position led to the discovery of the spirocyclopentyl analogue 7g, which is the first azasordarin to register single-digit MIC values versus Aspergillus spp. Further investigation identified the 5'-i-Pr derivative 7b, which displays superior pharmacokinetic properties compared to other azasordarins. 相似文献
947.
Characterization and screening of plant probiotic traits of bacteria isolated from rice seeds cultivated in Argentina 总被引:1,自引:0,他引:1
Ruiz D Ruiza D Agaras B de Werra P de Werrab P Wall LG Valverde C 《Journal of microbiology (Seoul, Korea)》2011,49(6):902-912
Many seeds carry endophytes, which ensure good chances of seedling colonization. In this work, we have studied the seed-borne
bacterial flora of rice varieties cultivated in the northeast of Argentina. Surface-sterilized husked seeds of the rice cultivars
CT6919, El Paso 144, CAMBA, and IRGA 417 contained an average of 5×106 CFU/g of mesophilic and copiotrophic bacteria. Microbiological, physiological, and molecular characterization of a set of
39 fast-growing isolates from the CT6919 seeds revealed an important diversity of seed-borne mesophiles and potential plant
probiotic activities, including diazotrophy and antagonism of fungal pathogens. In fact, the seed-borne bacterial flora protected
the rice seedlings against Curvularia sp. infection. The root colonization pattern of 2 Pantoea isolates from the seeds was studied by fluorescence microscopy of the inoculated axenic rice seedlings. Both isolates strongly
colonized the site of emergence of the lateral roots and lenticels, which may represent the entry sites for endophytic spreading.
These findings suggest that rice plants allow grain colonization by bacterial species that may act as natural biofertilizers
and bioprotectives early from seed germination. 相似文献
948.
Beau I Mehrpour M Codogno P 《The international journal of biochemistry & cell biology》2011,43(4):460-464
The autophagosome is a double-membrane bound compartment that initiates macroautophagy, a degradative pathway for cytoplasmic material terminating in the lysosomal compartment. The discovery of ATG genes involved in the formation of autophagosomes has greatly increased our understanding of the molecular basis of macroautophagy, and its role in cell function. Macroautophagy plays a pivotal role in cell fitness by removing obsolete organelles and protein aggregates. Its stimulation is an adaptive response to stressful situations, such as nutrient deprivation, intended to maintain a level of ATP compatible with cell survival. Macroautophagy is central for organ homeostasis, embryonic development, and longevity. Malfunctioning autophagy is observed in many human diseases including cancer, neurodegenerative diseases, cardiac and muscular diseases, infectious and inflammatory diseases, diabetes, and obesity. Discovering potential drug therapies that can be used to modulate macroautophagy is a major challenge, and likely to enhance the therapeutic arsenal against many human diseases. 相似文献
949.
Single-molecule sequencing enables DNA or RNA to be sequenced directly from biological samples, making it well-suited for
diagnostic and clinical applications. Here we review the properties and applications of this rapidly evolving and promising
technology. 相似文献
950.
The clinical manifestations of cerebral malaria (CM) are well correlated with underlying major pathophysiological events occurring during an acute malaria infection, the most important of which, is the adherence of parasitized erythrocytes to endothelial cells ultimately leading to sequestration and obstruction of brain capillaries. The consequent reduction in blood flow, leads to cerebral hypoxia, localized inflammation and release of neurotoxic molecules and inflammatory cytokines by the endothelium. The pharmacological regulation of these immunopathological processes by immunomodulatory molecules may potentially benefit the management of this severe complication. Adjunctive therapy of CM patients with an appropriate immunomodulatory compound possessing even moderate anti-malarial activity with the capacity to down regulate excess production of proinflammatory cytokines and expression of adhesion molecules, could potentially reverse cytoadherence, improve survival and prevent neurological sequelae. Current major drug discovery programmes are mainly focused on novel parasite targets and mechanisms of action. However, the discovery of compounds targeting the host remains a largely unexplored but attractive area of drug discovery research for the treatment of CM. This review discusses the properties of the plant immune-modifier curcumin and its potential as an adjunctive therapy for the management of this complication. 相似文献