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991.
992.
Abstract 1,3-β- and 1,4-β-glucan synthases from Saprolegnia were inhibited in vitro by Congo red. This dye was found to be a non competitive inhibitor which prevented initiation and elongation of polymer chains. 相似文献
993.
994.
Genome Sequence of Staphylococcus aureus Newbould 305, a Strain Associated with Mild Bovine Mastitis
Damien Bouchard Vincent Peton Sintia Almeida Caroline Le Maréchal Anderson Miyoshi Vasco Azevedo Nadia Berkova Lucie Rault Patrice Fran?ois Jacques Schrenzel Sergine Even David Hernandez Yves Le Loir 《Journal of bacteriology》2012,194(22):6292-6293
Staphylococcus aureus is a major etiological agent of mastitis in ruminants. We report here the genome sequence of bovine strain Newbould 305, isolated in the 1950s in a case of bovine mastitis and now used as a model strain able to reproducibly induce chronic mastitis in cows. 相似文献
995.
Patrice Faure Sophie Bouvard Corinne Roucard Alain Favier Serge Halimi 《Journal of trace elements in medicine and biology》2005,18(3):269-276
In the present study, we investigated the protective effect of zinc on the glucose-induced cytotoxicity in HeLa wild and HeLa-tat cells (30 and 20 mmol/l glucose, respectively). HeLa cells transfected with the protein Tat exhibit a lower antioxidant defense system. Incubation of HeLa wild and HeLa-tat cells with high glucose levels led to a rapid increase in generation of reactive oxygen species (ROS). As expected in the presence of high glucose concentrations, the viability was reduced for both cell lines. The redox status essentially regulated by thiol groups may play an important role in the apoptotic process. Thus, we developed a new method using the p-nitrophenyl disulfide to measure cytosolic thiol groups in intact cells. Cellular zinc was measured using inductively coupled plasma mass spectrometry. Intracellular thiol groups and intracellular zinc concentrations were significantly lower in HeLa cells cultured in hyperglycemic conditions, and their concentrations were significantly lower in HeLa-tat cells than in HeLa wild cells. However, the generation of ROS and the induction of apoptosis by a glucose specific mechanism were prevented by zinc (50 micromol/l) and the intracellular thiol groups and zinc concentrations significantly increased in both cell lines to become similar to the initial values. These results suggest that the glucose oxidation and its subsequent effects on the cells can be prevented by a biological antioxidant such as zinc. 相似文献
996.
Helene Jourdan‐Pineau Joy Folly Pierre‐Andre Crochet Patrice David 《Evolution; international journal of organic evolution》2012,66(11):3624-3631
Theory predicts that positive heterozygosity‐fitness correlations (HFCs) arise as a consequence of inbreeding, which is often assumed to have a strong impact in small, fragmented populations. Yet according to empirical data, HFC in such populations seem highly variable and unpredictable. We here discuss two overlooked phenomena that may contribute to this variation. First, in a small population, each generation may consist of a few families. This generates random correlations between particular alleles and fitness (AFCs, allele‐fitness correlations) and results in too liberal tests for HFC. Second, in some contexts, small populations receiving immigrants may be more impacted by outbreeding depression than by inbreeding depression, resulting in negative rather than positive HFC. We investigated these processes through a case study in tadpole cohorts of Pelodytes punctatus living in small ponds. We provide evidence for a strong family structure and significant AFC in this system, as well as an example of negative HFC. By simulations, we show that this negative HFC cannot be a spurious effect of family structure, and therefore reflects outbreeding depression in the studied population. Our example suggests that a detailed examination of AFC and HFC patterns can provide valuable insights into the internal genetic structure and sources of fitness variation in small populations. 相似文献
997.
998.
999.
1000.
Rodolphe Boivin François-P. Chalifour Patrice Dion 《Molecular & general genetics : MGG》1988,213(1):50-55
Summary A simple method based upon the use of a Tn5 derivative, Tn5-Lux, has been devised for the introduction and stable expression of the character of bioluminescence in a variety of gram-negative bacteria. In Tn5-Lux, the luxAB genes of Vibrio harveyi encoding luciferase are inserted on a SalI-BglII fragment between the kanamycin resistance (Kmr) gene and the right insertion sequence. The transposon derivative was placed on a transposition suicide vehicle by in situ recombination with the Tn5 suicide vector pGS9, to yield pDB30. Mating between Escherichia coli WA803 (pDB30) and a strain from our laboratory, Pseudomonas sp. RB100C, gave a Kmr transfer frequency of 10-6 per recipient, a value 10 times lower than that obtained with the original suicide vehicle pGS9. Tn5-Lux was also introduced by insertion mutagenesis in other strains of gram-negative soil bacteria. The bioluminescence marker was expressed in the presence of n-decanal, and was monitored as chemiluminescence in a liquid scintillation counter. The recorded light intensities were fairly comparable among the strains, and ranged between 0.2 to 1.8x106 cpm for a cell density of 103 colony forming units/ml. Nodules initiated by bioluminescent strains of Rhizobium leguminosarum on two different hosts were compared for intensity of the bioluminescence they produced. 相似文献