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51.
52.
Torfs H Poels J Detheux M Dupriez V Van Loy T Vercammen L Vassart G Parmentier M Vanden Broeck J 《Invertebrate neuroscience : IN》2002,4(3):119-124
The bioluminescent Ca2+-sensitive reporter protein, aequorin, was employed to develop an insect cell-based functional assay system for monitoring
receptor-mediated changes of intracellular Ca2
+-concentrations. Drosophila Schneider 2 (S2) cells were genetically engineered to stably express both apoaequorin and the insect tachykinin-related peptide
receptor, STKR. Lom-TK III, an STKR agonist, was shown to elicit concentration-dependent bioluminescent responses in these S2-STKR-Aeq cells.
The EC50 value for the calcium effect detected by means of aequorin appeared to be nearly identical to the one that was measured by
means of Fura-2, a fluorescent Ca2
+-indicator. In addition, this aequorin-based method was also utilised to study receptor antagonists. Experimental analysis
of the effects exerted by spantide I, II and III, three potent substance P antagonists, on Lom-TK III-stimulated S2-STKR-Aeq cells showed that these compounds antagonise STKR-mediated responses in a concentration-dependent
manner. The rank order of inhibitory potencies was spantide III > spantide II > spantide I.
Revised version received: 12 September 2001
Electronic Publication 相似文献
53.
利用RNAi技术大规模分析基因功能的研究 总被引:1,自引:0,他引:1
将双链RNA导入细胞内会干扰与之同源的基因的表达 ,使生物体产生相应的功能缺陷表型 ,这种作用称为RNAi(RNAinterference)。针对人类、植物、微生物等大规模基因组测序后所面临的功能鉴定难题 ,着重探讨了RNAi的机制及其研究进展。复合物RISC和酶Dicer的发现揭示了RNAi导致同源基因沉默的作用机理。通过使用RNAi这种反向遗传学工具可使生物体产生相应的功能缺陷表型 ,从而确定未知基因的功能。因此RNAi对大规模分析动、植物基因功能的研究具有重要的作用。 相似文献
54.
55.
Jham GN Nikolova-Damyavova B Viera M Natalino R Rodrigues AC 《Phytochemical analysis : PCA》2003,14(5):310-314
Reverse-phase HPLC with refractive index and light scattering detectors in isocratic and gradient elution modes, respectively, was applied for the separation of the major triacylglycerols (TAG) in coffee lipids. Twelve TAG species could be identified and determined using a linear gradient of acetonitrile in dichloromethane: dichloroethane. The quantitative evaluation was based on the relative area percentages derived directly from a data-station. The procedure was applied to determine the TAG composition of three types of coffee beans harvested in two coffee producing areas in Brazil and dried by two commonly used procedures. No significant differences in the TAG compositions due to the type, origin and drying procedure were found. 相似文献
56.
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58.
Soares HC de Melo Reis RA De Mello FG Ventura AL Kurtenbach E 《Journal of neurochemistry》2000,75(3):1071-1075
In the chick retina, the D1 dopaminergic system differentiates very early, as shown by receptor-mediated increases in intracellular cyclic AMP concentration and the presence of [(3)H]SCH23390-specific binding sites. Here, we characterized, by RT-PCR, the expression of defined D1 receptor subtypes D(1A), D(1B), and D(1D) during the development of the chick retina. Total RNA was extracted from retinas of 6-day-old embryos (E6) to 1-day-old hatched chickens and reverse-transcribed. The resulting cDNA was amplified using D(1A)-, D(1B)-, or D(1D)-specific primers, and the PCR-amplified products were analyzed by electrophoresis. The fragment corresponding to D(1A) receptor was detected in developing retina as early as E7, whereas the fragment corresponding to D(1B) was observed starting around E10. No PCR product corresponding to D(1D) was observed in the retina, although it was detected in chick brain. As synaptogenesis in chick retina begins after E11 and [(3)H]SCH 23390 D1 binding sites increase after this stage, the present results show that expression of D(1B) receptor increases during synaptogenesis, whereas D(1A) is the receptor subtype associated with the D1-like actions of dopamine early in retina development. 相似文献
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60.
壳聚糖反渗透膜的制备初探 总被引:1,自引:0,他引:1
谢宪章 《天然产物研究与开发》1998,10(1):65-68
本文介绍了从虾、蟹甲壳制取壳聚糖用于制备反渗透膜的方法。运用正交试验设计分析制膜条件对膜性能的影响。 相似文献