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991.
Sebastien L'hoste Abderrahmen Chargui Radia Belfodil Christophe Duranton Isabelle Rubera Baharia Mograbi Chantal Poujeol Michel Tauc Philippe Poujeol 《Free radical biology & medicine》2009,46(8):1017-1031
The aim of this study was to characterize the role of CFTR during Cd2+-induced apoptosis. For this purpose primary cultures and cell lines originated from proximal tubules (PCT) of wild-type cftr+/+ and cftr?/? mice were used. In cftr+/+ cells, the application of Cd2+ (5 μM) stimulated within 8 min an ERK1/2-activated CFTR-like Cl? conductance sensitive to CFTRinh-172. Thereafter Cd2+ induced an apoptotic volume decrease (AVD) within 6 h followed by caspase-3 activation and apoptosis. The early increase in CFTR conductance was followed by the activation of volume-sensitive outwardly rectifying (VSOR) Cl? and TASK2 K+ conductances. By contrast, cftr?/? cells exposed to Cd2+ were unable to develop VSOR currents, caspase-3 activity, and AVD process and underwent necrosis. Moreover in cftr+/+ cells, Cd2+ enhanced reactive oxygen species (ROS) production and induced a 50% decrease in total glutathione content (major ROS scavenger in PCT). ROS generation and glutathione decrease depended on the presence of CFTR, since they did not occur in the presence of CFTRinh-172 or in cftr?/? cells. Additionally, Cd2+ exposure accelerates effluxes of fluorescent glutathione S-conjugate in cftr+/+ cells. Our data suggest that CFTR could modulate ROS levels to ensure apoptosis during Cd2+ exposure by modulating the intracellular content of glutathione. 相似文献
992.
993.
Nathalie Sibille Xavier Hanoulle Fanny Bonachera Dries Verdegem Isabelle Landrieu Jean-Michel Wieruszeski Guy Lippens 《Journal of biomolecular NMR》2009,43(4):219-227
Adding the 13C labelled 2-keto-isovalerate and 2-oxobutanoate precursors to a minimal medium composed of 12C labelled glucose instead of the commonly used (2D, 13C) glucose leads not only to the 13C labelling of (I, L, V) methyls but also to the selective 13C labelling of the backbone Cα and CO carbons of the Ile and Val residues. As a result, the backbone (1H, 15N) correlations of the Ile and Val residues and their next neighbours in the (i + 1) position can be selectively identified in HN(CA) and HN(CO) planes. The availability of a selective HSQC spectrum corresponding
to the sole amide resonances of the Ile and Val residues allows connecting them to their corresponding methyls by the intra-residue
NOE effect, and should therefore be applicable to larger systems. 相似文献
994.
The aim of this study was to clarify the importance of the soluble fraction on cell wall decomposition. Wheat plant was chosen as a model and was harvested at three stages of maturity: anthesis (A stage), 20 days after anthesis (B stage) and physiological maturity (PM stage). Wheat third internode (numbered down from the ear) were selected for this study. Internode age influenced the cumulative CO(2) kinetics with internodes from wheat stem harvested at anthesis mineralizing 62.1%+/-2.2 of added residue C whereas those harvested at the B and PM stages mineralized 58.8%+/-1.4 and 51.6%+/-1.7, respectively of the added C. Chemical analyses revealed that maturation of the selected internodes mainly altered residue quality by modifying the proportion of soluble to cell wall fractions rather than the quality of these fractions. The hexose to pentose ratios were good biomarkers of microbial sugars for both soluble and cell wall fractions, as were the uronic acids, which are not commonly determined in soil decomposition studies. This study clearly demonstrated that the contents of the internode soluble fraction did not affect the extent of cell wall C mineralization. Therefore, the soluble content of crop residues would not regulate the soil microbial populations able to mineralize cell wall C. However, this needs to be validated on a broader range of residue types with different nature of cell wall C or soluble compounds. 相似文献
995.
Laurent Mottron Michelle Dawson Isabelle Soulières 《Philosophical transactions of the Royal Society of London. Series B, Biological sciences》2009,364(1522):1385-1391
According to the enhanced perceptual functioning (EPF) model, autistic perception is characterized by: enhanced low-level operations; locally oriented processing as a default setting; greater activation of perceptual areas during a range of visuospatial, language, working memory or reasoning tasks; autonomy towards higher processes; and superior involvement in intelligence. EPF has been useful in accounting for autistic relative peaks of ability in the visual and auditory modalities. However, the role played by atypical perceptual mechanisms in the emergence and character of savant abilities remains underdeveloped. We now propose that enhanced detection of patterns, including similarity within and among patterns, is one of the mechanisms responsible for operations on human codes, a type of material with which savants show particular facility. This mechanism would favour an orientation towards material possessing the highest level of internal structure, through the implicit detection of within- and between-code isomorphisms. A second mechanism, related to but exceeding the existing concept of redintegration, involves completion, or filling-in, of missing information in memorized or perceived units or structures. In the context of autistics'' enhanced perception, the nature and extent of these two mechanisms, and their possible contribution to the creativity evident in savant performance, are explored. 相似文献
996.
This article first proposes a reduction strategy of the activated sludge process model with alternated aeration. Initiated with the standard activated sludge model (ASM1), the reduction is based on some biochemical considerations followed by linear approximations of nonlinear terms. Two submodels are then obtained, one for the aerobic phase and one for the anoxic phase, using four state variables related to the organic substrate concentration, the ammonium and nitrate‐nitrite nitrogen, and the oxygen concentration. Then, a two‐step robust estimation strategy is used to estimate both the unmeasured state variables and the unknown inflow ammonium nitrogen concentration. Parameter uncertainty is considered in the dynamics and input matrices of the system. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009 相似文献
997.
An outcome of the photochemistry during oxygenic photosynthesis is the rapid turn over of the D1 protein in the light compared
to the other proteins of the photosystem II (PS II) reaction center. D1 is a major factor of PS II instability and its replacement
a primary event of the PS II repair cycle. D1 also undergoes redox-dependent phosphorylation prior to its degradation. Although
it has been suggested that phosphorylation modulates D1 metabolism, reversible D1 phosphorylation was reported not to be essential
for PS II repair in Arabidopsis. Thus, the involvement of phosphorylation in D1 degradation is controversial. We show here that nitric oxide donors inhibit
in vivo phosphorylation of the D1 protein in Spirodela without inhibiting degradation of the protein. Thus, D1 phosphorylation is not tightly linked to D1 degradation in the intact
plant. 相似文献
998.
Estelle Dumont Véronique Fontaine Christophe Vuylsteker Hélène Sellier Sylvie Bodèle Najia Voedts Rosemonde Devaux Marlène Frise Komlan Avia Jean-Louis Hilbert Nasser Bahrman Eric Hanocq Isabelle Lejeune-Hénaut Bruno Delbreil 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2009,118(8):1561-1571
To increase yield in pea (Pisum sativum L.), autumn sowing would be preferable. Hence, frost tolerance of pea became a major trait of interest for breeders. In order
to better understand the cold acclimation in pea, Champagne a frost tolerant line and Terese, a frost sensitive line, and
their recombinant inbred lines (RIL) were studied. RIL frost tolerance was evaluated by a frost damage scale under field as
well as controlled conditions. A quantitative trait loci (QTL) approach was used to identify chromosomal regions linked to
frost tolerance. The detected QTL explained from 6.5 to 46.5% of the phenotypic variance. Amongst them, those located on linkage
groups 5 and 6 were consistent with over all experiments, in field as well as in controlled environments. In order to improve
the understanding of the frost tolerance mechanisms, several cold acclimation key characters such as concentration of sugars,
electrolyte leakage, osmotic pressure, and activity of RuBisCO were assessed. Some of these physiological QTL colocalised
with QTL for frost damage, in particular two raffinose QTL on LG5 and LG6 and one RuBisCO activity QTL on LG6, explaining
8.8 to 27.0% of the phenotypic variance. In addition, protein quantitative loci were mapped; some of them colocalised with
frost damage and physiological QTL on LG5 and LG6, explaining 16.0–43.6% of the phenotypic variance. Raffinose metabolism
and RuBisCO activity and its effect on photosynthesis might play a major role in cold acclimation of pea.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
999.
1000.