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111.
Nan Zhang Zhentai Han Guiling Sun Angela Hoffman Iain W. Wilson Yanfang Yang Qian Gao Jianqiang Wu Dan Xie Jungui Dai Deyou Qiu 《Biochemical and biophysical research communications》2014
Taxol is a well-known effective anticancer compound. Due to the inability to synthesize sufficient quantities of taxol to satisfy commercial demand, a biotechnological approach for a large-scale cell or cell-free system for its production is highly desirable. Several important genes in taxol biosynthesis are currently still unknown and have been shown to be difficult to isolate directly from Taxus, including the gene encoding taxoid 9α-hydroxylase. Ginkgo biloba suspension cells exhibit taxoid hydroxylation activity and provides an alternate means of identifying genes encoding enzymes with taxoid 9α-hydroxylation activity. Through analysis of high throughput RNA sequencing data from G. biloba, we identified two candidate genes with high similarity to Taxus CYP450s. Using in vitro cell-free protein synthesis assays and LC–MS analysis, we show that one candidate that belongs to the CYP716B, a subfamily whose biochemical functions have not been previously studied, possessed 9α-hydroxylation activity. This work will aid future identification of the taxoid 9α-hydroxylase gene from Taxus sp. 相似文献
112.
Yang J Luo H Li Y Li J Cai Z Su X Dai D Du W Chen T Chen M 《Cell biochemistry and biophysics》2012,62(1):221-228
Accurate assessment of human epidermal growth factor receptor (HER) 2 is essential for efficient selection of patients who
may benefit from therapies targeting this surface receptor (e.g., trastuzumab). Intratumoral heterogeneity of HER2 expression
may potentially contribute to inaccurate assessment of HER2 status. To clarify intratumoral heterogeneity of HER2 expression
and its potential clinical impact on assessment of HER2 status, we analyzed 148 endoscopic biopsy specimens and 117 excisional
tumor specimens collected from 148 patients with primary gastric cancer. Specifically, we assessed HER2 protein overexpression
and gene amplification using, respectively, immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH). There
were 28 IHC-positive cases and 25 FISH-positive cases among these 148 patients. Heterogeneous HER2 protein expression was
demonstrated in 23 of 29 (79.3%) IHC-positive cases, while gene expression heterogeneity was found in 11 of 25 (44.0%) FISH-positive
cases. Intratumoral heterogeneity was the main reason of discordant results between IHC and FISH or between endoscopic biopsy
and excisional tumor specimens. The clinical significance and impact of intratumoral HER2 expression heterogeneity on treatment
outcome in gastric cancer require further studies. 相似文献
113.
为探究DNA序列元件对不同启动子调节转基因稳定表达的影响,利用遍在染色质开放元件 (Ubiquitous chromatin opening elements,UCOE) 和基质黏附序列 (Scaffold/matrix-attachment regions,MAR) 分别与含增强子的oct4基因启动子、含CpG岛的sox2基因启动子和不含调控元件的nanog基因启动子以及同时包含增强子和CpG岛的CMV启动子组合构建pOCT4-MAR、pOCT4-UCOE、pSOX2-MAR、pSOX2-UCOE、pNANOG-MAR、pNANOG-UCOE、pCMV-UCOE、pCMV-MAR等质粒,分析这些质粒稳定转染后的表达量和嵌合表达差异。结果发现,UCOE与含增强子元件的oct4启动子组合能较稳定高效表达,而MAR与含CpG岛的sox2启动子组合能较稳定高效表达。利用排除位置效应原因的嵌合表达对染色质高级结构调控基因表达的稳定性分析表明:(1) 通常情况下UCOE比MAR调节的表达载体的表达更高效和更稳定;UCOE连接含CpG岛的启动子形成开放染色质调节的高表达更稳定;(2) MAR与启动子上TATA盒或增强子可能通过染色质环产生高表达,但相对不稳定。结论:染色质调节元件UCOE和MAR与启动子调控元件之间能通过染色质开放状态或染色质环调控基因稳定表达。 相似文献
114.
Truong Xuan Dai Hoang Nghia Son Ho Nguyen Quynh Chi Hoang Nghia Quang Huy Nguyen Thai Minh Nguyen Thi Thuy Tram Nguyen Thi Thuong Huyen To Minh Quan Doan Chinh Chung Truong Hai Nhung Tran Thi Minh Tran Hong Diem Nguyen Thi Phuong Mai Le Thanh Long 《Current issues in molecular biology》2021,43(3):2210
Astronauts are always faced with serious health problems during prolonged spaceflights. Previous studies have shown that weightlessness significantly affects the physiological function of female astronauts, including a change in reproductive hormones and ovarian cells, such as granulosa and theca cells. However, the effects of microgravity on these cells have not been well characterized, especially in granulosa cells. This study aimed to investigate the effects of simulated microgravity (SMG) on the proliferation and morphology of porcine granulosa cells (pGCs). pGC proliferation from the SMG group was inhibited, demonstrated by the reduced O.D. value and cell density in the WST-1 assay and cell number counting. SMG-induced pGCs exhibited an increased ratio of cells in the G0/G1 phase and a decreased ratio of cells in the S and G2/M phase. Western blot analysis indicated a down-regulation of cyclin D1, cyclin-dependent kinase 4 (cdk4), and cyclin-dependent kinase 6 (cdk6), leading to the prevention of the G1-S transition and inducing the arrest phase. pGCs under the SMG condition showed an increase in nuclear area. This caused a reduction in nuclear shape value in pGCs under the SMG condition. SMG-induced pGCs exhibited different morphologies, including fibroblast-like shape, rhomboid shape, and pebble-like shape. These results revealed that SMG inhibited proliferation and induced morphological changes in pGCs. 相似文献
115.
The Involvement of Corin in the Progression of Diabetic Erectile Dysfunction in a Rat Model by Down‐Regulating ANP /NO/cGMP Signal Pathway 下载免费PDF全文
116.
既往的研究表明,动脉压力感受性反射(ABR)功能下降在高血压靶器官损伤中起独立作用。为进一步研究ABR功能下降致器官损伤的可能机制,实验采用去窦弓神经(SAD)大鼠作为ABR受损的动物模型,分别测定清醒、自由活动状态下SAD及对照的假手术组大鼠24h动脉血压、心率、血压波动性(BPV)及心率波动性(HRV)。并采用放免法测定血浆、心脏和肾脏组织的血管紧张素Ⅱ(AngⅡ)含量。结果发现,SAD术后1周大鼠的24h平均收缩压(SBP)、舒张压(DBP)均显著高于对照组及术后18周的慢性期SAD大鼠。SAD术后18周,24h平均SBP、DBP及HR与假手术对照组均无显著差异;24h收缩压波动性(SBPV)和舒张压波动性(DBPV)均显著高于对照组大鼠。SAD大鼠术后1周的血浆、心脏和肾脏组织的AngⅡ含量及术后18周的血浆AngⅡ水平与对照组之间相比无显著差异。而在术后慢性期(18周),SAD大鼠的心肌及肾组织AngⅡ含量显著高于假手术对照组大鼠。在术后18周时,接受慢性应激刺激的SAD大鼠,其血浆、心肌及肾组织中AngⅡ水平显著高于同处应激状态下的假手术对照组大鼠及未接受应激刺激的SAD大鼠。这些结果表明,SAD术后急性期血压增高,但在慢性期平均血压并无增高,仅BPV增高;慢性期心、肾组织内AngⅡ的分泌增加。在慢性期接受应激可致AngⅡ过度分泌,上述结果提示,BPV增高和心、肾组织AngⅡ含量升高与SAD大鼠发生心脏、肾脏等器官损害有关。 相似文献
117.
Chuan Li Zhaonan Sun Fang Yuan Zhicheng Zhao Jiehong Zhang Baotong Zhang Hongyue Li Tong Liu Xiangchen Dai 《Journal of cellular and molecular medicine》2020,24(6):3438-3448
Indoleamine 2, 3-dioxygenase (IDO)-mediated regulation of tryptophan metabolism plays an important role in immune tolerance in transplantation, but it has not been elucidated which mechanism specifically induces the occurrence of immune tolerance. Our study revealed that IDO exerts immunosuppressive effects through two pathways in mouse heart transplantation, ‘tryptophan depletion’ and ‘tryptophan metabolite accumulation’. The synergism between IDO+DC and TC (tryptophan catabolic products) has stronger inhibitory effects on T lymphocyte proliferation and mouse heart transplant rejection than the two intervention factors alone, and significantly prolong the survival time of donor-derived transplanted skin. This work demonstrates that the combination of IDO+DC and TC can induce immune tolerance to a greater extent, and reduce the rejection of transplanted organs. 相似文献
118.
Removal and recovery of phosphorous from swine wastewater by demonstration crystallization reactor and struvite accumulation device 总被引:10,自引:0,他引:10
Suzuki K Tanaka Y Kuroda K Hanajima D Fukumoto Y Yasuda T Waki M 《Bioresource technology》2007,98(8):1573-1578
A demonstration crystallization reactor and struvite accumulation device for the removal and recovery of phosphorous was constructed and their performance was evaluated using actual swine wastewater for 3.5 years. The wastewater pH was increased by aeration, and the concentrations of total P and soluble PO(4)-P were reduced by a struvite crystallization reaction induced under a high pH condition. A 30% MgCl(2) addition was effective in enhancing the struvite crystallization reaction. The concentrations of suspended solids, total Zn and total Cu, were also decreased by the settling function of the reactor. On removing the efficiencies of these components, no noticeable seasonal fluctuation in performance was observed during the 3.5-year operation. In terms of maximum yield, 171g struvite was obtained from 1m(3) swine wastewater by the demonstration accumulation device for struvite recovery. The recovered struvite needed only air-drying before use since it was approximately 95% pure even without washing. 相似文献
119.
120.
Hui Liu Chongwen Li Jing Dong Yao Dai Pengyang Wang Biao Shi Ying Zhao Xiaodan Zhang 《Liver Transplantation》2024,14(17):2304234
Low-bandgap mixed tin (Sn)-lead (Pb) perovskite solar cells promise efficiency beyond the pure-Pb ones. However, the difference in the interaction rate of SnI2 and PbI2 with organic salts causes spatial distribution heterogeneity of Sn2+ and Pb2+ in mixed Sn─Pb perovskite layers. This causes a Sn-rich surface, which can trigger more severe Sn2+ oxidation and nonradiative recombination. A strategy, of introducing indium ion (In3+) into the perovskite precursor solution to compete with Sn2+ when reacting with organic salts is developed. Therefore, the nucleation and crystallization of perovskite films are well-controlled, leading to improved film quality with a more balanced Sn/Pb ratio on the film surface. Additionally, In3+ has a lower reduction potential compared to Sn2+ which can generate an extra energy barrier for Sn2+ oxidation. The improved film quality and reduced surface oxidation result in accelerated electron transfer and reduced carrier recombination rate. The modified devices achieve a power conversion efficiency (PCE) of 23.34%, representing one of the highest PCEs in mixed Sn─Pb solar cells made with PCBM. 相似文献