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排序方式: 共有295条查询结果,搜索用时 15 毫秒
1.
Kinga Michno David Knight Jorge M. Campussano Diana van de Hoef Gabrielle L. Boulianne 《PloS one》2009,4(9)
Much of our current understanding about neurodegenerative diseases can be attributed to the study of inherited forms of these disorders. For example, mutations in the presenilin 1 and 2 genes have been linked to early onset familial forms of Alzheimer''s disease (FAD). Using the Drosophila central nervous system as a model we have investigated the role of presenilin in one of the earliest cellular defects associated with Alzheimer''s disease, intracellular calcium deregulation. We show that expression of either wild type or FAD-mutant presenilin in Drosophila CNS neurons has no impact on resting calcium levels but does give rise to deficits in intracellular calcium stores. Furthermore, we show that a loss-of-function mutation in calmodulin, a key regulator of intracellular calcium, can suppress presenilin-induced deficits in calcium stores. Our data support a model whereby presenilin plays a role in regulating intracellular calcium stores and demonstrate that Drosophila can be used to study the link between presenilin and calcium deregulation. 相似文献
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Isabelle Audo Kinga Bujakowska Elise Orhan Charlotte M. Poloschek Sabine Defoort-Dhellemmes Isabelle Drumare Susanne Kohl Tien D. Luu Odile Lecompte Eberhart Zrenner Marie-Elise Lancelot Aline Antonio Aurore Germain Christelle Michiels Claire Audier Mélanie Letexier Jean-Paul Saraiva Bart P. Leroy Christina Zeitz 《American journal of human genetics》2012,91(1):209
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Common reed (Phragmites australis (Cav.) Trin. ex Steud.) plants were harvested from four natural water ecosystems of the Bogdanka river catchment (Poznań, Poland) four times throughout the 2014 vegetative season. Over the year, average metal contents followed different decreasing trends according to the analyzed tissue: Zn > Cu ≈ Pb > Cd (rhizomes) and Zn > Pb > Cu > Cd (leaves), and mean translocation ratios (leaves/rhizomes) were found as follows: 0.93, 0.70, 0.65, 0.40 for Zn, Pb, Cd and Cu, respectively. Metal content increased gradually during the growing season, and in the case of Cu, Cd and Pb exceeded the upper limit of average concentration detected in plants from natural ecosystems. However, the content of salicylic acid did not follow the increase of metal accumulation. In rhizomes, the highest production of the metabolite was observed in May and reached 324 ng g?1 fresh weight (FW) (mean value). Afterwards, a significant drop to 50 ng g?1 FW was observed. Simultaneously, the highest values of total salicylic acid in P. australis leaves were observed in July and accompanied the intensive development of the aboveground biomass of the plant (11.3 µg g?1 FW–mean value). Subsequently, its content in leaves showed a significant decrease down to 2.1 µg g?1 FW in November. Multivariate regression analysis revealed significant interactions between analyzed metals influencing the plant response to metal-derived stress. Cu and Zn showed antagonistic properties considering their uptake and the induction of salicylic acid biosynthesis, whereas non-essential metals (Pb and Cd) acted similarly and stimulated the formation of salicylic acid glucoside. 相似文献
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Banach K Bojarska E Kazimierczuk Z Magnowska L Bzowska A 《Nucleosides, nucleotides & nucleic acids》2005,24(5-7):465-469
A new kinetic model is presented for analysis of experimental data of oxidation process catalyzed by milk xanthine oxidase. The kinetics for two substrates, xanthine and its analog 2-chloroadenine, in a broad pH range (5.8-9.0) are best described by an equation which is a rational function of degree 2:3 and 2:2, respectively. 相似文献
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Alpha-adrenergic blockade: a possible mechanism of tocolytic action of certain benzodiazepines in a postpartum rat model in vivo 总被引:3,自引:0,他引:3
Benzodiazepines are frequently used for the treatment of maternal psychiatric disorders during pregnancy. Besides their anxiolytic effect, they are reported to exert a direct relaxing action on several smooth muscle preparations, including the uterus. In the present study, the possibility of the involvement of alpha(1)-adrenergic receptors in this peripheral effect is investigated. The tocolytic potencies of diazepam, midazolam and nitrazepam are assessed in vivo in a postpartum rat model, together with other drugs known to bind to alpha-adrenoceptors (e.g. alpha(1)-antagonists, tricyclic compounds and droperidol). The interactions of some benzodiazepines and norepinephrine were also examined in an isolated in vitro system. The affinities of these agents for the receptor in question were additionally tested by radioligand displacement assay. A correlation was found between the tocolytic potencies and inhibition constants of the tested drugs, suggesting that the smooth muscle-relaxing effect of these benzodiazepines is mediated through modulation of the alpha(1)-adrenergic receptors. 相似文献
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Bychowska A Theilacker C Czerwicka M Marszewska K Huebner J Holst O Stepnowski P Kaczyński Z 《Carbohydrate research》2011,(17):2816-2819
Wall teichoic acid (WTA) was isolated from Enterococcus faecium strain U0317 and structurally characterized using 1H, 13C, and 31P NMR spectroscopy, including two-dimensional COSY, TOCSY, ROESY, HMQC, and HMBC experiments. Further compositional determination was undertaken using classical chemical methods and HF treatment followed by GLC and GLC–MS analyses. The repeating unit of WTA consisted of two residues of 2-acetamido-2-deoxy-d-galactose, glycerol (Gro), and phosphate, and has the structure shown below:→6)-α-d-GalpNAc-(1→3)-β-d-GalpNAc-(1→2)-Gro-(3→P→ 相似文献
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Péter Poczai Kinga Klára Mátyás István Szabó Ildikó Varga Jaakko Hyvönen István Cernák Ahmad Mosapour Gorji Kincső Decsi János Taller 《Plant Molecular Biology Reporter》2011,29(4):906-918
The globally widespread genus Nymphaea exhibits a wide range of morphological and taxonomical diversity. The intrusion of a cultivated variety by progressive propagation
and its affect on aquatic habitat is demonstrated in this case study. We have studied the genetic diversity, population, and
stand structure of the neophyte Nymphaea × ‘Panama Pacific’ as well as other species found in Lake Hévíz and dikes nearby using inter-simple sequence repeat (ISSR)
markers. The ISSR assay revealed a low genetic variability for the small populations of Nymphaea caerulea, Nymphaea lotus var. thermalis, and a medium level for Nymphaea alba, Nymphaea rubra var. longiflora, and Nymphaea × ‘Panama Pacific’. The evolutionary genetic status of individuals found in the overlapping cultivation area of Nymphaea × ‘Panama Pacific’ and N. caerulea was affirmed to be of hybrid origin by reticulate network analysis and with morphological parameters. The Bayesian analysis
of hybrid classes and the segregation of the ISSR markers also confirmed the hybrid origin of the individuals in question
and revealed that they are falling into F2 or latter genotype frequency classes, indicating the viability and fertility of
the hybrids. The set of analyzed species by phylogenetic network analysis of ISSR data has been divided into three major groups
according to their evolutionary patterns (subg. Barachyceras, Lotos, and Nymphaea). Our results are in accordance with these three major subgenera within Nymphaea. 相似文献