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111.
Tavernier ML Petit E Lesur D Wadouachi A Courtois B Courtois J Michaud P 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》2008,863(2):266-272
Ion-exchange chromatography has been applied to purification of unsaturated oligoglucuronans. After an isocratic elution on a strong anion-exchange column, the collected fractions were desalted by low pressure size exclusion chromatography. However, this efficient separation was limited by the time required to desalt. So, we developed a reversed-phase chromatography method using back ionization of oligomers. Two C18 columns were tested with trifluoroacetic acid (TFA 0.7%) as eluent. Different selectivities and column stabilities were observed in this acidic condition. The scale up for semi-preparative applications enabled us to recover pure unsaturated oligoglucuronans without desalting step. 相似文献
112.
Francine P. Favaro Lucas Alvizi Roseli M. Zechi-Ceide Debora Bertola Temis M. Felix Josiane de Souza Salmo Raskin Stephen R.F. Twigg Andrea M.J. Weiner Pablo Armas Ezequiel Margarit Nora B. Calcaterra Gregers R. Andersen Simon J. McGowan Andrew O.M. Wilkie Antonio Richieri-Costa Maria L.G. de Almeida Maria Rita Passos-Bueno 《American journal of human genetics》2014
113.
Nonideal nest box selection by tree swallows breeding in farmlands: Evidence for an ecological trap?
Animals are expected to select a breeding habitat using cues that should reflect, directly or not, the fitness outcome of the different habitat options. However, human‐induced environmental changes can alter the relationships between habitat characteristics and their fitness consequences, leading to maladaptive habitat choices. The most severe case of such nonideal habitat selection is the ecological trap, which occurs when individuals prefer to settle in poor‐quality habitats while better ones are available. Here, we studied the adaptiveness of nest box selection in a tree swallow (Tachycineta bicolor) population breeding over a 10‐year period in a network of 400 nest boxes distributed along a gradient of agricultural intensification in southern Québec, Canada. We first examined the effects of multiple environmental and social habitat characteristics on nest box preference to identify potential settlement cues. We then assessed the links between those cues and habitat quality as defined by the reproductive performance of individuals that settled early or late in nest boxes. We found that tree swallows preferred nesting in open habitats with high cover of perennial forage crops, high spring insect biomass, and high density of house sparrows (Passer domesticus), their main competitors for nest sites. They also preferred nesting where the density of breeders and their mean number of fledglings during the previous year were high. However, we detected mismatches between preference and habitat quality for several environmental variables. The density of competitors and conspecific social information showed severe mismatches, as their relationships to preference and breeding success went in opposite direction under certain circumstances. Spring food availability and agricultural landscape context, while related to preferences, were not related to breeding success. Overall, our study emphasizes the complexity of habitat selection behavior and provides evidence that multiple mechanisms may potentially lead to an ecological trap in farmlands. 相似文献
114.
The human cystatin C gene (CST3), mutated in hereditary cystatin C amyloid angiopathy,is located on chromosome 20 总被引:5,自引:4,他引:5
Magnus Abrahamson M. Quamrul Islam Josiane Szpirer Claude Szpirer Göran Levan 《Human genetics》1989,83(3):223-226
Summary Hereditary cystatin C amyloid angiopathy has recently been shown to be caused by a point mutation in the cystatin C gene. To determine the chromosomal localization of the gene, 20 human-rodent somatic cell hybrids and a fulllength cystatin C cDNA probe were used. Southern blot analysis of BamHI digested cell hybrid DNA revealed that the probe recognizes a 10.6 kb human specific fragment and that this fragment cosegregates with human chromosome 20. Therefore, the human cystatin C gene (CST3) was assigned to chromosome 20. 相似文献
115.
A unique family of endothelial cell polypeptide mitogens: the antigenic and receptor cross-reactivity of bovine endothelial cell growth factor, brain-derived acidic fibroblast growth factor, and eye-derived growth factor-II 总被引:9,自引:0,他引:9 下载免费PDF全文
A B Schreiber J Kenney J Kowalski K A Thomas G Gimenez-Gallego M Rios-Candelore J Di Salvo D Barritault J Courty Y Courtois 《The Journal of cell biology》1985,101(4):1623-1626
Bovine brain, hypothalamus, pituitary, and retina contain potent anionic polypeptide mitogens for endothelial cells. Immunological assays using murine monoclonal antibodies against bovine endothelial cell growth factor (ECGF) and radioreceptor assays using [125I]ECGF were performed to determine the cross-reactivity of ECGF with bovine acidic pI brain-derived fibroblast growth factor (acidic FGF) and bovine eye-derived growth factor-II [EDGF-II). We observed that acidic FGF and EDGF-II are recognized by anti-ECGF monoclonal antibodies and compete with [125I] ECGF for receptor occupancy. Furthermore, the biological activity of ECGF, acidic FGF, and EDGF-II is potentiated by the glycosaminoglycan, heparin. These results argue that ECGF, acidic FGF, and EDGF-II belong to a common family of polypeptide growth factors. 相似文献
116.
Elodie A. Courtois Kyle G. Dexter Charles Eliot Timothy Paine Didier Stien Julien Engel Christopher Baraloto Jérôme Chave 《Ecology and evolution》2016,6(9):2854-2864
Plant responses to natural enemies include formation of secondary metabolites acting as direct or indirect defenses. Volatile terpenes represent one of the most diverse groups of secondary metabolites. We aimed to explore evolutionary patterns of volatile terpene emission. We measured the composition of damage‐induced volatile terpenes from 202 Amazonian tree species, spanning the angiosperm phylogeny. Volatile terpenes were extracted with solid‐phase micro extraction and desorbed in a gas chromatography–mass spectrometry for compound identification. The chemical diversity of the terpene blend showed a strong phylogenetic signal as closely related species emitted a similar number of compounds. Closely related species also tended to have compositionally similar blends, although this relationship was weak. Meanwhile, the ability to emit a given compound showed no significant phylogenetic signal for 200 of 286 compounds, indicating a high rate of diversification in terpene synthesis and/or great variability in their expression. Three lineages (Magnoliales, Laurales, and Sapindales) showed exceptionally high rates of terpene diversification. Of the 70 compounds found in >10% of their species, 69 displayed significant correlated evolution with at least one other compound. These results provide insights into the complex evolutionary history of volatile terpenes in angiosperms, while highlighting the need for further research into this important class of compounds. 相似文献
117.
Brahim Lachili Isabelle Hininger Henri Faure Josiane Arnaud Marie-Jeanne Richard Alain Favier Anne-Marie Roussel 《Biological trace element research》2001,83(2):103-110
Iron overload could promote the generation of free radicals and result in deleterious cellular damages. A physiological increase
of oxidative stress has been observed in pregnancy. A routine iron supplement, especially a combined iron and vitamin C supplementation,
without biological justifications (low hemoglobin [Hb] and iron stores) could therefore aggravate this oxidative risk. We
investigated the effect of a daily combined iron supplementation (100 mg/d as fumarate) and vitamin C (500 mg/d as ascorbate)
for the third trimester of pregnancy on lipid peroxidation (plasma TBARS), antioxidant micronutriments (Zn, Se, retinol, vitaminE,
(β-carotene) and antioxidant metalloenzymes (RBC Cu-Zn SOD and Se-GPX). The iron-supplemented group (n=27) was compared to a control group (n=27), age and number of pregnancies matched. At delivery, all the women exhibited normal Hb and ferritin values. In the supplemented
group, plasma iron level was higher than in the control group (26.90±5.52 mmol/L) and TBARs plasma levels were significantly
enhanced (p<0.05) (3.62±0.36 vs 3.01±0.37 mmol/L). No significant changes were observed in plasma trace elements and red blood cell antioxidant
metalloenzymes. Furthermore, the α-tocopherol plasma level was lowered in the iron-supplemented groups, suggesting an increased
utilization of vitamin E.
These data show that pharmalogical doses of iron, associated with high vitamin C intakes, can result in uncontrolled lipid
peroxidation. This is predictive of adverse effects for the mother and the fetus. This study illustrates the potential harmful
effects of iron supplementation when prescribed only on the assumption of anemia and not on the bases of biological criteria. 相似文献
118.
Functional interaction between PARP-1 and PARP-2 in chromosome stability and embryonic development in mouse 总被引:8,自引:0,他引:8
Ménissier de Murcia J Ricoul M Tartier L Niedergang C Huber A Dantzer F Schreiber V Amé JC Dierich A LeMeur M Sabatier L Chambon P de Murcia G 《The EMBO journal》2003,22(9):2255-2263
The DNA damage-dependent poly(ADP-ribose) polymerases, PARP-1 and PARP-2, homo- and heterodimerize and are both involved in the base excision repair (BER) pathway. Here, we report that mice carrying a targeted disruption of the PARP-2 gene are sensitive to ionizing radiation. Following alkylating agent treatment, parp-2(-/-)-derived mouse embryonic fibroblasts exhibit increased post-replicative genomic instability, G(2)/M accumulation and chromosome mis-segregation accompanying kinetochore defects. Moreover, parp-1(-/-)parp-2(-/-) double mutant mice are not viable and die at the onset of gastrulation, demonstrating that the expression of both PARP-1 and PARP-2 and/or DNA-dependent poly(ADP-ribosyl) ation is essential during early embryogenesis. Interestingly, specific female embryonic lethality is observed in parp-1(+/-)parp-2(-/-) mutants at E9.5. Meta phase analyses of E8.5 embryonic fibroblasts highlight a specific instability of the X chromosome in those females, but not in males. Together, these results support the notion that PARP-1 and PARP-2 possess both overlapping and non-redundant functions in the maintenance of genomic stability. 相似文献
119.
The present article describes two new applications of plastic-based cell culture systems in the plant biotechnology domain.
Different types of bioreactors are used at Nestlé R&D Center-Tours for large scale culture of plants cells to produce metabolites
or recombinant proteins and for mass propagation of selected plant varieties by somatic embryogenesis. Particularly, recent
studies are directed to cut down the production costs of these two processes by developing disposable cell culture systems.
For large scale culture, two novel flexible plastic-based disposable bioreactors have been developed from 10 to 100 l working
volumes, validated with several plant species (“Wave and Undertow” and “Slug Bubble” bioreactors). Vegetative propagation
of elite plant varieties is achieved through somatic embryogenesis in liquid medium. A pilot scale process has been recently
set up for the industrial propagation of Coffea canephora (Robusta coffee). The current production capacity is 2.5–3.0 million embryos per year. The pre-germination of the embryos
was previously conducted by temporary immersion in liquid medium in 10-l glass bioreactors. An improved process has been developed
using a 10-l disposable bioreactor consisting in a bag containing a rigid plastic box (“Box-in-Bag” bioreactor), insuring,
amongst other advantages, a higher light transmittance to the biomass due to its horizontal design. 相似文献
120.
Ana Paula Kallaur Josiane Lopes Sayonara Rangel Oliveira Andrea Name Colado Simão Edna Maria Vissoci Reiche Elaine Regina Delicato de Almeida Helena Kaminami Morimoto Wildea Lice Carvalho Jennings de Pereira Daniele Frizon Alfieri Sueli Donizete Borelli Domacio Ramon Kaimen-Maciel Michael Maes 《Molecular neurobiology》2016,53(8):5191-5202