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991.
Wen-Ni He Jun-Gui Dai Li-Jun Wu De-An Guo 《Journal of Asian natural products research》2013,15(9):760-764
Asiatic acid is a major pentacyclic triterpene isolated from Centella asiatica. It shows a variety of bioactivities. In order to obtain its derivatives, potentially useful for detailed pharmacological studies, the substrate was subjected to incubations with selected micro-organisms. In this work, asiatic acid was converted into three new compounds: 2α,3β,23,30-tetrahydroxyurs-12-ene-28-oic acid (1), 2α,3β,22β,23-tetrahydroxyurs-12-ene-28-oic acid (2), and 2α,3β,22β,23,30-pentahydroxyurs-12-ene-28-oic acid (3) by the fungus Alternaria longipes AS 3.2875. The structures of the three metabolites were determined by 1D and 2D NMR spectral data. 相似文献
992.
993.
Junjie Zhao Xuhong Fu Hao Chen Lingqiang Min Jie Sun Jingyi Yin Jianping Guo Haojie Li Zhaoqing Tang Yuanyuan Ruan Xuefei Wang Yihong Sun Liyu Huang 《British journal of cancer》2021,124(2):425
BACKGROUND A large proportion of gastric cancer patients are susceptible to chemoresistance, while the underlying mechanism remains obscure. Stress granules (SGs) play a self-defence role for tumour cells in inhibiting chemotherapy-induced apoptosis. As an SG assembly effector, G3BP1 (Ras-GTPase-activating protein SH3 domain-binding protein) has been reported to be overexpressed in gastric cancer; thus, here we aim to explore its potent roles in gastric cancer chemoresistance.METHODS Kaplan–Meier analysis was used to compare survival rates in gastric cancer patients with different G3BP1 expression. The influence of G3BP1 on gastric cancer cell chemoresistance and apoptosis were evaluated by in vitro and in vivo approaches. The interaction between G3BP1 and YWHAZ was assessed by immunohistochemistry, immunoprecipitation and immunofluorescence.RESULTS G3BP1 was associated with the poor outcome of gastric cancer patients who received adjuvant chemotherapy. G3BP1 knockdown significantly increased the sensitivity of gastric cancer cells to chemotherapy drugs. Mechanically, cell apoptosis and pro-apoptotic-associated molecules were significantly elevated upon G3BP1 depletion. Gene co-expression network analyses identified YWHAZ as the critical interlayer of G3BP1; as a result, G3BP1 interacted with YWHAZ to sequester Bax into the cytoplasm. Clinically, G3BP1highYWHAZhigh gastric cancer patients displayed the worst outcome compared with other patients after chemotherapy.CONCLUSIONS The expression of G3BP1 and YWHAZ could predict the adjuvant chemotherapy benefit in gastric cancer patients.Subject terms: Gastric cancer, Cell death 相似文献
994.
目的:比较ACL TOP全自动血凝分析仪上Von Clauss法与PT衍生法(PT-der法)测定纤维蛋白原(FIB)的精密性及其临床应用价值。方法:用Von Clauss法与PT衍生法分别对新鲜混合血浆400例临床样本进行检测。结果:两种方法测定FIB的重复性良好;对临床样本按PT-der法检测结果分阶段做分析,FIB在1.50 g/L~3.50 g/L时,两种方法测定结果相近,差异无统计学意义(P〉0.05),FIB〈1.50 g/L或FIB〉3.50 g/L时,PT-der法结果偏高,差异有统计学意义(P〈0.05)。结论在ACL TOP全自动血凝分析仪上,当PT-der法测出的FIB值在1.50 g/L~3.50 g/L时,直接报告结果,当PT-der法测出的FIB〈1.50 g/L或FIB值〉3.50 g/L时,以Von Clauss法复查的结果发出报告,两者结合应用可确保工作质量,提高实际工作效益。 相似文献
995.
996.
融入“思政元素”的情景教学法在住院医师规范化培训中的应用 《医学教育管理》2022,8(2):188-192
目的探讨融入“思政元素”的情景教学法对在肝病科住院医师规范化培训(简称规培)中的应用效果。方法选取进行住院医师规范化培训的学生48人,随机分为两组,试验组采用融入“思政元素”的情景教学法,对照组采用传统教学法,对两组规范化培训学生理论考试、实践技能考核成绩及教学评价满意度进行比较。结果两组学生理论考试成绩无明显差异(P>0.05);两组学生临床实践技能得分比较,试验组在接诊患者、临床思维路径分析、医嘱处置、病案书写、医患沟通能力和实践技能总成绩得分均优于对照组(P<0.05);两组学生教学效果调查问卷比较,试验组在提升学习兴趣、提升自主学习能力、团结协作能力、职业道德素养和总体教学满意度方面得分均明显高于对照组(P<0.05)。结论融入“思政元素”的情景教学法在肝病科住院医师规范化培训中应用,具有良好的效果。 相似文献
997.
背景:以天然可吸收的壳聚糖为膜载体,加入具有抗菌消炎、促进创面愈合的槲皮素制成复合膜,拟通过动物模型对该膜的药理作用进行初步观察。目的:观察槲皮素壳聚糖复合药膜对NaOH所致大鼠口腔溃疡的治疗作用。方法:采用NaOH烧灼法制备SD大鼠口腔溃疡模型80只,随机分为4组,空白对照组不采取任何处理措施,壳聚糖膜组在溃疡处贴壳聚糖膜,复合膜组在溃疡处贴槲皮素与壳聚糖复合药膜,冰硼散组在溃疡处喷洒冰硼散,2次/d,直至溃疡完全愈合为止。另外从上述实验动物中取SD大鼠10只,在大鼠背部脊柱两侧制作全层皮肤缺损模型,创面制作后次日,空白对照组不做任何处理,冰硼散组创面涂抹冰硼散液,壳聚糖组创面涂抹壳聚糖液,复合溶液组创面涂抹槲皮素壳聚糖液,2次/d,连续给药3d。结果与结论:复合膜组各时间点的溃疡面积均小于空白对照组(P<0.01),且给药后第2,4天的溃疡面积也小于冰硼散组(P<0.05)。在溃疡表面感染程度上复合膜组明显好于空白对照组(P<0.01),与冰硼散组之间差异无显著性意义。复合溶液组创面组织中超氧化物歧化酶活力明显高于空白对照组(P<0.01),而丙二醛含量低于空白对照组(P<0.01)。结果可见槲皮素壳聚糖复合药膜可促进溃疡面愈合,这可能与其提高创面组织中超氧化物歧化酶活性,降低丙二醛含量有关。 相似文献
998.
背景:特异的兴奋性神经递质受体过度活化时便发生细胞的兴奋性中毒,有关NMDA受体和AMPA受体活化致细胞兴奋性中毒死亡通路较为明确,但关于红藻氨酸(Kainate,KA)受体的功能到目前为止仍未明了。目的:探究小鼠海马内注射KA之后KA1受体的再分布状况对中枢神经元兴奋性中毒的影响。方法:成年雄性C57BL6小鼠海马内注射KA或PBS,2h后进行Bederson体征评分、全脑切片免疫组化分析和死亡神经元检测。结果与结论:海马内注射KA2h后,Bederson体征评分表明中枢神经功能出现明显损伤;KA1受体表达的变化主要出现在海马CA1和CA3区,在CA1区的表达上调明显,并开始出现神经元死亡,4~6h后可见大量神经元死亡。结果表明KA促使KA1受体亚单位在海马神经元CA区重新分布,增加神经元对兴奋性氨基酸毒性的敏感性,导致神经细胞死亡,中枢神经功能缺失。 相似文献
999.
Fangfang Zhao Nianli Zou Fuyan Wang Mingping Guo Ping Liu Xintian Wen Sanjie Cao Yong Huang 《Virus genes》2013,46(3):454-464
The complete genome of a QX-like infectious bronchitis virus (IBV) strain Sczy3 isolated recently in Sichuan was sequenced. The genome contains 27,695 nucleotides (nt), and possesses a genomic structure similar to other IBV strains. Sequence comparisons demonstrated that the Sczy3 genome had the highest nt sequence identity with QX-like IBVs and was most dissimilar to the Massachusetts type IBV. Differences in the sequences of genes present in the Sczy3 genome and other IBVs gene sequences were also identified. Phylogenic analysis showed that the entire genome and most of the Sczy3 genes were located in the same cluster as LX4. Recombination analysis showed that Sczy3 is a chimeric strain derived from LX4 (major parental sequence) and H120 (minor parental sequence) suggesting that recombination occurred in a region containing the 3′ terminal 5a sequence (83 nt), the 5′ terminal 5b sequence (222 nt), and the 5′ terminal nucleocapsid protein gene sequence (132 nt). Mutations and intergenic recombination may have played an important role in the evolution of IBVs. 相似文献
1000.
Katelynn Toomer Kimberly Sauls Diana Fulmer Lilong Guo Kelsey Moore Janiece Glover Rebecca Stairley Joyce Bischoff Robert A. Levine Russell A. Norris 《Anatomical record (Hoboken, N.J. : 2007)》2019,302(1):117-124
Mitral valve prolapse (MVP) affects 2.4% of the population and has poorly understood etiology. Recent genetic studies have begun to unravel the complexities of MVP and through these efforts, mutations in the FLNA (Filamin-A) gene were identified as disease causing. Our in vivo and in vitro studies have validated these genetic findings and have revealed FLNA as a central regulator of valve morphogenesis. The mechanisms by which FLNA mutations result in myxomatous mitral valve disease are currently unknown, but may involve proteins previously associated with mutated regions of the FLNA protein, such as the small GTPase signaling protein, R-Ras. Herein, we report that Filamin-A is required for R-Ras expression and activation of the Ras–Mek–Erk pathway. Loss of the Ras/Erk pathway correlated with hyperactivation of pSmad2/3, increased extracellular matrix (ECM) production and enlarged mitral valves. Analyses of integrin receptors in the mitral valve revealed that Filamin-A was required for β1-integrin expression and provided a potential mechanism for impaired ECM compaction and valve enlargement. Our data support Filamin-A as a protein that regulates the balance between Erk and Smad activation and an inability of Filamin-A deficient valve interstitial cells to effectively remodel the increased ECM production through a β1-integrin mechanism. As a consequence, loss of Filamin-A function results in increased ECM production and generation of a myxomatous phenotype characterized by improperly compacted mitral valve tissue. Anat Rec, 302:117–124, 2019. © 2018 Wiley Periodicals, Inc. 相似文献