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991.
Cytochrome P450 (CYP) epoxygenases metabolize arachidonic acid into epoxyeicosatrienoic acids (EETs), which play important and diverse roles in the cardiovascular system. The anti-inflammatory, anti-apoptotic, pro-angiogenic, and anti-hypertensive properties of EETs in the cardiovascular system suggest a beneficial role for EETs in diabetic nephropathy. This study investigated the effects of endothelial specific overexpression of CYP2J2 epoxygenase on diabetic nephropathy in streptozotocin-induced diabetic mice. Endothelial CYP2J2 overexpression attenuated renal damage as measured by urinary microalbumin and glomerulosclerosis. These effects were associated with inhibition of TGF-β/Smad signaling in the kidney. Indeed, overexpression of CYP2J2 prevented TGF-β1-induced renal tubular epithelial-mesenchymal transition in vitro. These findings highlight the beneficial roles of the CYP epoxygenase-EET system in the pathogenesis of diabetic nephropathy.  相似文献   
992.
Alcohol dehydrogenases (ADH) are a class of enzymes that catalyze the reversible oxidation of alcohols to corresponding aldehydes or ketones, by using either nicotinamide adenine dinucleotide (NAD) or nicotinamide adenine dinucleotide phosphate (NADP), as coenzymes. In this study, a short-chain ADH gene was identified in Bombyx mori by 5'-RACE PCR. This is the first time the coding region of BmADH has been cloned, expressed, purified and then characterized. The cDNA fragment encoding the BmADH protein was amplified from a pool of silkworm cDNAs by PCR, and then cloned into E. coli expression vector pET-30a(+). The recombinant His-tagged BmADH protein was expressed in E. coli BL21 (DE3), and then purified by metal chelating affinity chromatography. The soluble recombinant BmADH, produced at low-growth temperature, was instrumental in catalyzing the ethanol-dependent reduction of NAD(+), thereby indicating ethanol as one of the substrates of BmADH.  相似文献   
993.
Introduction – Cortex Mori, one of the well‐known traditional Chinese herbal medicines, is derived from the root bark of Morus alba L. according to the China Pharmacopeia. Stilbene glycosides are the main components isolated from aqueous extracts of Morus alba and their content varies depending on where Cortex Mori was collected. We have established a qualitative and quantitative method based on the bioactive stilbene glycosides for control of the quality of Cortex Mori from different sources. Objective – To develop a high‐performance liquid chromatography coupled with ultraviolet absorption detection for simultaneous quantitative determination of five major characteristic stilbene glycosides in 34 samples of the root bark of Morus alba L. (Cortex Mori) from different sources. Methodology – The analysis was performed on an ODS column using methanol‐water‐acetic acid (18: 82: 0.1, v/v/v) as the mobile phase and the peaks were monitored at 320 nm. Results – All calibration curves showed good linearity (r ≥ 0.9991) within test ranges. This method showed good repeatability for the quantification of these five components in Cortex Mori with intra‐ and inter‐day standard deviations less than 2.19% and 1.45%, respectively. Conclusion – The validated method was successfully applied to quantify the five investigated components, including a pair of cis‐trans‐isomers 1 and 2 and a pair of isomers 4 and 5 in 34 samples of Cortex Mori from different sources. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   
994.
以胶原蛋白过量沉积为主要特征的纤维化是临床肺部疾患常见的病理现象。该研究利用RT-PCR技术检测不同剂量TNF-α和IL-13对人肺成纤维细胞IL-13Rα1、IL-13Rα2和Ⅰ型胶原蛋白转录水平的影响;ELISA检测细胞培养上清sIL-13Rα2分泌量;羟脯氨酸法定量分析各组肺成纤维细胞胶原蛋白生成情况。结果发现:在实验剂量条件下,TNF-α和IL-13对人肺成纤维细胞IL-13Rα1的表达无显著影响;两者均能不同程度地上调IL-13Rα2的表达;与对照组相比,TNF-α对胶原蛋白的表达有下调作用,IL-13则无显著影响。  相似文献   
995.
Tobacco bacterial wilt, Ralstonia solanacearum, is an important disease affecting the root and stem. The disease causes extensive damage to flue-cured tobacco all over the word. Field trials were conducted in 2008 and 2009 at Longyan, Fujian Province, China, to evaluate garlic intercropping for enhancing the biological control of R. solanacearum in flue-cured tobacco fields. The results of the study demonstrate that tobacco bacterial wilt was clearly inhibited by intercropping garlic in 2008 and 2009. The appearance of the disease in intercropped fields was delayed for about 15 days. The total number of R. solanacearum in root system soils was significantly lower in intercropped fields than in monocultured fields in 2008. These numbers were between 138×104 and 161×104 cfu g–1 dry soil in intercropped fields. The corresponding values in monocultured fields were 357×104 cfu g–1 dry soil. The monetary value of tobacco leaves was obviously higher in intercropped fields than in monocultured ones. The per cent increase in monetary values in the intercropped fields was between 14 and 34%. Consequently, intercropping tobacco with garlic might be very useful for enhancing biological control of R. solanacearum in flue-cured tobacco fields.  相似文献   
996.
张士灌区土壤中镉形态的探讨   总被引:13,自引:0,他引:13  
陈涛  吴燕玉  孔庆新  谭方 《生态学报》1985,5(4):300-306
本文研究了张士灌区土壤中镉的形态。交换态占78%,可给态占18%,不溶态和碱溶态只占3—4%。在田间酸性土壤中,Cl~-是无机配位体的主要成分。镉主要与Cl~-络合而形成[CdCl]~-和CdCl_2。土壤中加入石灰和钙、镁、磷肥、HCO_3~-增多,镉与之生成Cd(HCO_3)_2沉淀。在长期淹水状况下,S~-增多,镉与S~-产生CdS沉淀,难以被水稻吸收。  相似文献   
997.
紫胶虫最佳生长地的植被条件分析   总被引:1,自引:0,他引:1  
本文在对紫胶产区进行调查的基础上,分析了云南紫胶虫最佳生长地的植被条件、对其中的四种群落类型从植物种类成分、群落结构和群落生态等方面进行分析。根据丰富的寄主资源和有利于紫胶虫越冬的气候条件指出“暖热性稀树灌草丛”及“河谷季雨林次生林和灌丛”是云南紫胶虫及其主要寄主植物的适生类型。本文在总结紫胶产区的经验基础上,提出了开发利用的意见和改造的措施。  相似文献   
998.
Summary An ultrastructural analysis is presented of the cuticular and neural structures formed by the prothoracic leg and wing imaginal discs of maleDrosophila melanogaster larvae during culture in vitro with 0.2 g/ml of -ecdysone. A pupal cuticle, and subsequently an imaginal cuticle with a well-defined epicuticle and a laminated endocuticle is formed. The ultrastructure of the epidermis and of cuticular structures such as bristles, trichomes, apodemes, and tracheoles is very similar to that found in situ. Dendrites and nerve cell bodies are formed in vitro, and sensory axons form nerve bundles similar to those of normal appendages in situ, despite their isolation from the central nervous system. It is concluded that at the ultrastructural level, differentiation in vitro closely parallels the normal course of development.  相似文献   
999.
1000.
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