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51.
Krauskopf A Lhote P Mutter M Dufour JF Ruegg UT Buetler TM 《The Journal of biological chemistry》2003,278(43):41685-41690
Based on our previous results, we investigated whether cyclosporin A (CsA)-induced vasopressin type 1A receptor up-regulation was mediated by free radicals. We report that CsA analogues with different affinities for cyclophilin and calcineurin were able to up-regulate vasopressin type 1A receptor and to generate free radicals in smooth muscle cells independently of calcineurin. Further, we demonstrate that the antioxidant N-acetyl-L-cysteine blocked the increase in vasopressin type 1A receptor mRNA and protein levels induced by CsA and that low concentrations of prooxidants were able to directly increase vasopressin type 1A receptor mRNA and protein levels. In addition, short exposure to CsA or pro-oxidants was sufficient to significantly increase vasopressin type 1A receptor mRNA and protein levels. Using cell-permeable forms of superoxide dismutase and catalase, we finally show that superoxide mediates the CsA-induced effects on vasopressin type 1A receptor. These results provide strong evidence that CsA-induced superoxide generation is causally involved in vasopressin type 1A receptor expression and demonstrate for the first time that low physiological concentrations of radicals, most probably superoxide, are able to directly affect cellular signaling to increase vasopressin type 1A receptor expression in rat aortic smooth muscle cells. 相似文献
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Myles S Faith Kathleen L Keller Patty Matz Susan L Johnson Rebecca Lewis Marie Alexandra Jorge Clare Ridley Helen Han Shoshanna Must Moonseong Heo Angelo Pietrobelli Steven B Heymsfield David B Allison 《Twin research》2002,5(5):472-475
"Project Grow-2-Gether" is a child nutrition study of same-sex, 3- to 7-year-old monozygotic and dizygotic twin pairs. The study attempts to bridge two bodies of literature that have rarely interfaced with respect to obesity and ingestive behavior: the first being behavioral genetic approaches to obesity-related traits, and the second being developmental approaches focusing on parent-child relationships. The overarching aim of Project Grow-2-Gether is to disentangle genetic from potential home-environmental influences on child eating behavior and body fat. This paper reviews the rationale for Project Grow-2-Gether, its procedures, and core phenotypic measurement battery. A focus of the study is acquisition of controlled food intake measurements obtained in the laboratory, measurement of specific home environmental variables, and multi-method evaluation of parent-child feeding relations. Future directions may involve longitudinal assessment of child growth and molecular analyses for specific genes that influence child eating behavior. 相似文献
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Oliveira ME Reguenga C Gouveia AM Guimarães CP Schliebs W Kunau WH Silva MT Sá-Miranda C Azevedo JE 《Biochimica et biophysica acta》2002,1567(1-2):13-22
Peroxisomal biogenesis is a complex process requiring the action of numerous peroxins. One central component of this machinery is Pex14p, an intrinsic peroxisomal membrane protein probably involved in the docking of Pex5p, the receptor for PTS1-containing proteins (peroxisomal targeting signal 1-containing proteins). In this work the membrane topology of mammalian Pex14p was studied. Using a combination of protease protection assays and CNBr cleavage, we show that the first 130 amino acid residues of Pex14p are highly protected from exogenously added proteases by the peroxisomal membrane itself. Data indicating that this domain is responsible for the strong interaction of Pex14p with the organelle membrane are presented. All the other Pex14p amino acid residues are exposed to the cytosol. The properties of recombinant human Pex14p were also characterised. Heterologous expressed Pex14p was found to be a homopolymer of variable stoichiometry. Finally, in vitro binding assays indicate that homopolymerisation of Pex14p involves a domain comprising amino acid residues 147-278 of this peroxin. 相似文献
54.
A new in vitro model is proposed for studying the spatiotemporal distributions of activated clotting factors, in which clotting is activated in a thin layer of non-stirred plasma supplemented with a fluorogenic substrate and is monitored by fluorescence from its cleavage product. Analysis of the spatiotemporal dynamics of factor XIa and kallikrein in glass-activated human plasma provides evidence that both contact factors remain restricted to the glass surface and possibly a narrow boundary zone (<0.1 mm). The kinetics of factor XIa and kallikrein studied by a new method (in non-stirred plasma) coincided with those studied fluorimetrically with full stirring: their concentrations rapidly rose for the first few minutes after activation and then slowly declined. Factor XI and prekallikrein activation is likely to be restricted by the limited number of sites available for binding to the surface. The maximum concentration of the active factors was estimated at 2 x 10(8) molecules per mm(2) at the glass surface (irrespective of stirring). At the plastic surface, this value was 15--30 times lower. 相似文献
55.
Alexandra H. Cunha Núria N. Marbá Marieke M. van Katwijk Christopher Pickerell Miguel Henriques Guillaume Bernard M. Adelaide Ferreira Silvia Garcia Joxe M. Garmendia Pablo Manent 《Restoration Ecology》2012,20(4):427-430
Sharing experiences and results among scientists and managers working on seagrass restoration was the main objective of the first European Seagrass Restoration Workshop that gathered researchers from around Europe. The meeting was the first forum in Europe that allowed for scientists, NGOs, and managers to interact and share their experiences relating to seagrass restoration and management. The results show that none of the seagrass restoration programs developed in Europe by the participants during the last 10 years was successful. Furthermore, an informal review of data published in seagrass restoration success, showed that the results reported were biased because they were mostly based on a very short monitoring period (i.e. < 1 year). Numerous decision trees, guidelines, and restoration models have been developed to aid seagrass restoration management, but the results of this workshop point toward a new paradigm in seagrass restoration were efforts should shift to give priority to natural restoration potential, with an emphasis on the fact that restoration should never be considered the first alternative when planning for the mitigation of coastal development projects or to justify mitigation as a compensation measure for economic activities. 相似文献
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The objective of this study was to determine the location of protein P7, the RNA packaging factor, in the procapsid of the φ6 cystovirus. A comparison of cryo-electron microscopy high-resolution single particle reconstructions of the φ6 complete unexpanded procapsid, the protein P2-minus procapsid (P2 is the RNA directed RNA-polymerase), and the P7-minus procapsid, show that prior to RNA packaging the P7 protein is located near the three-fold axis of symmetry. Difference maps highlight the precise position of P7 and demonstrate that in P7-minus particles the P2 proteins are less localized with reduced densities at the three-fold axes. We propose that P7 performs the mechanical function of stabilizing P2 on the inner protein P1 shell which ensures that entering viral single-stranded RNA is replicated. 相似文献
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