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151.
Marie Josephe Amiot Beatrice Romier Thi-Mai Anh Dao Raphaelle Fanciullino Joseph Ciccolini Remy Burcelin Laurent Pechere Claude Emond Jean-François Savouret Eric Seree 《Biochimie》2013
We have developed an innovative soluble galenic form to overcome the low absorption of trans-Resveratrol (t-Res) as a dry powder. We present here data on pharmacokinetics, bioavailability, and toxicity of t-Res in human volunteers treated with this soluble form, plus additional data on biological effects in rodents. Fifteen healthy volunteers of both sexes received 40 mg of t-Res in two forms, the soluble formulation (caplets) and the original powder (capsules), in a crossover design. Blood samples were collected at 15 min, 30 min, and every hour for 5 h. Plasma concentrations of t-Res and its metabolites were analyzed by liquid chromatography and mass spectrometry. The single dose (40 mg) of the soluble t-Res was well absorbed and elicited biologically efficient blood levels (0.1–6 μM) for several hours, despite metabolization into glucuronide and sulfate conjugates coupled to renal elimination. In contrast, t-Res administered as a dry powder barely elicited efficient blood levels for a short duration. The new formulation led to 8.8-fold higher t-Res levels in plasma versus the powder. t-Res metabolism was not modified and neither intolerance nor toxicity were observed during the study and the following week. The soluble formulation elicited a robust anti-inflammatory effect in various tissues of mice fed a high-fat diet, while dry powder t-Res was almost inactive. Our data suggest that significant improvements in t-Res bioavailability and efficiency can be obtained by this soluble galenic form, also allowing lower doses. The use of t-Res in human therapy is thus greatly facilitated and the toxicity risk is reduced. 相似文献
152.
P. Pévet L. Agez B. Bothorel M. Saboureau F. Gauer V. Laurent 《Chronobiology international》2013,30(1-2):39-51
In mammals, the complex interaction of neural, hormonal, and behavioral outputs from the suprachiasmatic nucleus (SCN) drives circadian expression of events, either directly or through coordination of the timing of peripheral oscillators. Melatonin, one of the endocrine output signals of the clock, provides the organism with circadian information and can be considered as an endogenous synchronizer, able to stabilize and reinforce circadian rhythms and to maintain their mutual phase‐relationship at the different levels of the circadian network. Moreover, exogenous melatonin, through an action on the circadian clock, affects all levels of the circadian network. The molecular mechanisms underlying this chronobiotic effect have also been investigated in rats. REV‐ERB α seems to be the initial molecular target. 相似文献
153.
Mylène Desorme Alexandra Montembault Jean-Michel Lucas Cyrille Rochas Thierry Bouet Laurent David 《Carbohydrate polymers》2013
We investigated the spinning of hydroalcoholic chitosan solutions. The dope composition was optimized in order to obtain a continuous alcogel fiber by water evaporation on heating the extruded hydroalcoholic solution. This alcogel fiber was then neutralized in aqueous alkali baths and washed in water to eliminate the residual alcohol and salts before final drying. Depending on the alcohol content in the filament at the neutralization step, on specific alcohol–chitosan interactions and on the nature and concentration of the coagulation base, the process yielded semicrystalline chitosan fibers with different proportions of anhydrous and hydrated allomorphs. Contrarily to the classical annealing method, the formation of mainly anhydrous crystals was obtained without significant molecular weight decrease by neutralizing the polymer in hydrophobic conditions. The control of allomorph content was shown to be related to the hydrophobicity of the solvent (alcohol fraction) at the neutralization step. 相似文献
154.
Paulo De Sa Peixoto Guillaume Laurent Thierry Aza?s Gervaise Mosser 《The Journal of biological chemistry》2013,288(11):7528-7535
In vivo, collagen I, the major structural protein in human body, is found assembled into fibrils. In the present work, we study a high concentrated collagen sample in its soluble, fibrillar, and denatured states using one and two dimensional {1H}-13C solid-state NMR spectroscopy. We interpret 13C chemical shift variations in terms of dihedral angle conformation changes. Our data show that fibrillogenesis increases the side chain and backbone structural complexity. Nevertheless, only three to five rotameric equilibria are found for each amino acid residue, indicating a relatively low structural heterogeneity of collagen upon fibrillogenesis. Using side chain statistical data, we calculate equilibrium constants for a great number of amino acid residues. Moreover, based on a 13C quantitative spectrum, we estimate the percentage of residues implicated in each equilibrium. Our data indicate that fibril formation greatly affects hydroxyproline and proline prolyl pucker ring conformation. Finally, we discuss the implication of these structural data and propose a model in which the attractive force of fibrillogenesis comes from a structural reorganization of 10 to 15% of the amino acids. These results allow us to further understand the self-assembling process and fibrillar structure of collagen. 相似文献
155.
Julien Benoit El Mabrouk Essid Wissem Marzougui Hayet Khayati Ammar Renaud Lebrun Rodolphe Tabuce Laurent Marivaux 《Journal of human evolution》2013
We report the discovery of three isolated primate petrosal fragments from the fossiliferous locality of Chambi (Tunisia), a primate-bearing locality dating from the late early to the early middle Eocene. These fossils display a suite of anatomical characteristics otherwise found only in strepsirhines, and as such might be attributed either to Djebelemur or/and cf. Algeripithecus, the two diminutive stem strepsirhine primates recorded from this locality. Although damaged, the petrosals provide substantial information regarding the ear anatomy of these advanced stem strepsirhines (or pre-tooth-combed primates), notably the patterns of the pathway of the arterial blood supply. Using μCT-scanning techniques and digital segmentation of the structures, we show that the transpromontorial and stapedial branches of the internal carotid artery (ICA) were present (presence of bony tubes), but seemingly too small to supply enough blood to the cranium alone. This suggests that the ICA was not the main cranial blood supply in stem strepsirhines, but that the pharyngeal or vertebral artery primitively ensured a great part of this role instead, an arterial pattern that is reminiscent of modern cheirogaleid, lepilemurid lemuriforms and lorisiforms. This could explain parallel loss of the ICA functionality among these families. Specific measurements made on the cochlea indicate that the small strepsirhine primate(s) from Chambi was (were) highly sensitive to high frequencies and poorly sensitive to low frequencies. Finally, variance from orthogonality of the plane of the semicircular canals (SCs) calculated on one petrosal (CBI-1-569) suggests that Djebelemur or cf. Algeripithecus likely moved (at least its head) in a way similar to that of modern mouse lemurs. 相似文献
156.
157.
Farhana Ayub Laurent Seychelles Olaf Strauch Martina Wittke Ralf-Udo Ehlers 《Applied microbiology and biotechnology》2013,97(18):8049-8055
The free-living, bacterial-feeding nematode Panagrolaimus sp. (strain NFS 24-5) has potential for use as live food for marine shrimp and fish larvae. Mass production in liquid culture is a prerequisite for its commercial exploitation. Panagrolaimus sp. was propagated in monoxenic liquid culture on Escherichia coli and parameters, like nematode density, population dynamics and biomass were recorded and compared with life history table data. A mean maximum nematode density of 174,278 mL?1 and a maximum of 251,000 mL?1 were recorded on day 17 after inoculation. Highest average biomass was 40 g L?1 at day 13. The comparison with life history table data indicated that the hypothetical potential of liquid culture is much higher than documented during this investigation. Nematode development is delayed in liquid culture and egg production per female is more than five times lower than reported from life history trait analysis. The latter assessed a nematode generation time of 7.1 days, whereas the process time at maximum nematode density in liquid culture was 16 days indicating that a reduction of the process time can be achieved by further investigating the influence of nematode inoculum density on population development. The results challenge future research to reduce process time and variability and improve population dynamics also during scale-up of the liquid culture process. 相似文献
158.
159.
Justin Eyquem Laurent Poirot Roman Galetto Andrew M. Scharenberg Julianne Smith 《Biotechnology and bioengineering》2013,110(8):2225-2235
Integrative gene transfer is widely used for bioproduction, drug screening, and therapeutic applications but usual viral methods lead to random and multicopy insertions, contribute to unstable transgene expression and can disturb endogenous gene expression. Homologous targeting of an expression cassette using rare‐cutting endonucleases is a potential solution; however the number of studied loci remains limited. Furthermore, the behavior and performance of various types of gene cassettes following gene targeting is poorly defined. Here we have evaluated three loci for gene targeting, including one locus compatible with the proposed Safe Harbor criteria for human translational applications. Using optimized conditions for homologous gene targeting, reporter genes under the control of different promoters were efficiently inserted at each locus in both sense and antisense orientations. Sustainable expression was achieved at all three loci without detectable disturbance of flanking gene expression. However, the promoter, the integration locus and the cassette orientation have a strong impact on transgene expression. Finally, single targeted integrations exhibited greatly improved transgene expression stability versus multicopy or random integration. Taken together, our data suggest a potential set of loci for site‐specific transgene integration, suitable for a variety of biotechnological applications. Biotechnol. Bioeng. 2013; 110: 2225–2235. © 2013 Wiley Periodicals, Inc. 相似文献
160.
Sébastien L'Hoste Alexei Diakov Olga Andrini Mathieu Genete Laurent Pinelli Teddy Grand Mathilde Keck Marc Paulais Laurent Beck Christoph Korbmacher Jacques Teulon Stéphane Lourdel 《生物化学与生物物理学报:生物膜》2013
Several Cl− channels have been described in the native renal tubule, but their correspondence with ClC-K1 and ClC-K2 channels (orthologs of human ClC-Ka and ClC-Kb), which play a major role in transcellular Cl− absorption in the kidney, has yet to be established. This is partly because investigation of heterologous expression has involved rat or human ClC-K models, whereas characterization of the native renal tubule has been done in mice. Here, we investigate the electrophysiological properties of mouse ClC-K1 channels heterologously expressed in Xenopus laevis oocytes and in HEK293 cells with or without their accessory Barttin subunit. Current amplitudes and plasma membrane insertion of mouse ClC-K1 were enhanced by Barttin. External basic pH or elevated calcium stimulated currents followed the anion permeability sequence Cl− > Br− > NO3− > I−. Single-channel recordings revealed a unit conductance of ~ 40 pS. Channel activity in cell-attached patches increased with membrane depolarization (voltage for half-maximal activation: ~ − 65 mV). Insertion of the V166E mutation, which introduces a glutamate in mouse ClC-K1, which is crucial for channel gating, reduced the unit conductance to ~ 20 pS. This mutation shifted the depolarizing voltage for half-maximal channel activation to ~ + 25 mV. The unit conductance and voltage dependence of wild-type and V166E ClC-K1 were not affected by Barttin. Owing to their strikingly similar properties, we propose that the ClC-K1/Barttin complex is the molecular substrate of a chloride channel previously detected in the mouse thick ascending limb (Paulais et al., J Membr. Biol, 1990, 113:253–260). 相似文献