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101.
Five new guaiane sesquiterpenes, 1 – 5 , were isolated from the culture broth of the endophytic fungus Xylaria sp. YM 311647, isolated from Azadirachta indica A. Juss . The structures of these compounds were elucidated on the basis of spectroscopic analyses, and their inhibitory activities against five pathogenic fungi were evaluated. All guaiane sesquiterpenes showed moderate or weak antifungal activities in a broth microdilution assay. 相似文献
102.
LC-MS/MS determination of helicid in human plasma and its application in pharmacokinetic studies 总被引:1,自引:0,他引:1
Xie H Jia Y Tan Z Zhang W Chen R Sun H Shen J Zhou H 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》2011,879(30):3607-3611
Helicid is a traditional Chinese medicine used to treat headache and insomnia with definite effects. To facilitate pharmacokinetic studies of helicid in man, a sensitive and specific LC-MS/MS method for the quantitative detection of helicid in human plasma was developed and validated. The method involved the addition of bergeninum as the internal standard (IS), protein precipitation, HPLC separation, and quantification by MS/MS system using negative electrospray ionization in the multiple reaction monitoring mode (MRM). The precursor→product ion transitions were monitored at m/z 282.8→120.9 for helicid and m/z 326.9→192.2 for the IS, respectively. The lower limit of quantification (LLOQ) was 0.2 μg/L. The calibration curves for helicid was linear over a concentration range of 0.2-20 μg/L. The intra- and inter-batch analyses of QC samples at 0.4, 2, 20 μg/L indicated good precision (%R.S.D. between 2.69 and 5.47%) and accuracy (between 96.15 and 105.05%). The helicid was stable in human plasma stored at room temperature for at least 24h, 4°C for at least 24h, -20°C for at least 1 month, and for routine three freeze-thaw cycles. This accurate and specific assay provides a useful method for evaluating the pharmacokinetic profile of helicid in humans. 相似文献
103.
Xiao‐Bing Gao Katherine V. Yao Hongling Du John D. Elsworth Hugh S. Taylor 《Journal of cellular and molecular medicine》2011,15(4):747-755
Parkinson’s disease (PD) is a neurodegenerative disorder caused by the loss of dopaminergic neurons. Adult human endometrial derived stem cells (HEDSC), a readily obtainable type of mesenchymal stem‐like cell, were used to generate dopaminergic cells and for transplantation. Cells expressing CD90, platelet derived growth factor (PDGF)‐Rβ and CD146 but not CD45 or CD31 were differentiated in vitro into dopaminergic neurons that exhibited axon projections, pyramidal cell bodies and dendritic projections that recapitulate synapse formation; these cells also expressed the neural marker nestin and tyrosine hydroxylase, the rate‐limiting enzyme in dopamine synthesis. Whole cell patch clamp recording identified G‐protein coupled inwardly rectifying potassium current 2 channels characteristic of central neurons. A 1‐methyl 4‐phenyl 1,2,3,6‐tetrahydro pyridine induced animal model of PD was used to demonstrate the ability of labelled HEDSC to engraft, migrate to the site of lesion, differentiate in vivo and significantly increase striatal dopamine and dopamine metabolite concentrations. HEDSC are a highly inducible source of allogenic stem cells that rescue dopamine concentrations in an immunocompetent PD mouse model. 相似文献
104.
A mixed culture of moderately thermophilic microorganisms was enriched from acid mine drainage samples collected from several chalcopyrite mines in China. Such mixed culture can be used to effectively extract copper from chalcopyrite. Furthermore, after being adapted to gradually increased concentration of chalcopyrite concentrate, the tolerance of the mixed culture to chalcopyrite concentrate was brought up to 80 g/L. The effects of several leaching parameters on copper recovery in stirred tank reactor also had been investigated. The results of the investigation show that it was possible to achieve a copper extraction rate of 75% in 44 days at a pulp density of 8%. The leaching rate of chalcopyrite concentrate tended to increase with dissolved total iron concentration. At low pH ranges, more microscopic counts of microorganisms were found in the solution. Furthermore, the analysis of leached residues indicates that the passivation of chalcopyrite concentrate was mainly due to a mass of jarosite and PbSO(4) on the mineral surface, other than the elemental sulphur layer. The bacterial community composition was analyzed by using Amplified Ribosomal DNA Restriction Analysis. Two moderately thermophilic bacteria species were identified as Leptospirillum ferriphilum and Acidithiobacillus caldus with abundance of 67% and 33% in the bio-pulp, respectively. 相似文献
105.
106.
Xie C Kang J Li Z Schauss AG Badger TM Nagarajan S Wu T Wu X 《The Journal of nutritional biochemistry》2012,23(9):1184-1191
Recent studies have shown that some flavonoids are modulators of proinflammatory cytokine production. In this study, velutin, a unique flavone isolated from the pulp of açaí fruit (Euterpe oleracea Mart.), was examined for its effects in reducing lipopolysaccharide-induced proinflammatory cytokine tumor necrosis factor (TNF)-α and interleukin (IL)-6 production in RAW 264.7 peripheral macrophages and mice peritoneal macrophages. Three other structurally similar and well-studied flavones, luteolin, apigenin and chrysoeriol, were included as controls and for comparative purposes. Velutin exhibited the greatest potency among all flavones in reducing TNF-α and IL-6 production. Velutin also showed the strongest inhibitory effect in nuclear factor (NF)-κB activation (as assessed by secreted alkaline phosphatase reporter assay) and exhibited the greatest effects in blocking the degradation of inhibitor of NF-κB as well as in inhibiting mitogen-activated protein kinase p38 and JNK phosphorylation; all of these are important signaling pathways involved in production of TNF-α and IL-6. The present study led to the discovery of a strong anti-inflammatory flavone, velutin. This compound effectively inhibited the expression of proinflammatory cytokines TNF-α and IL-6 in low micromole levels by inhibiting NF-κB activation and p38 and JNK phosphorylation. 相似文献
107.
为了探讨雌激素作用于神经系统的机理,采用硫酸镍铵增强显色的免疫组化SP法研究了新的雌激素受体(ER-β)在成年雌雄大鼠脑内的分布。研究证实ER-β免疫阳性物质主要位于神经元的细胞核内,但在个别脑区也可在胞浆甚至突起内检测到。最强的ER-β免疫阳性信号见于前嗅核、大脑皮质、小脑浦肯野细胞、斜角带垂直部、蓝斑和三叉神经运动核等部位;中等强度的染色见于隔内侧核、杏仁外侧核、黑质、中央灰质等部位;较弱的阳性反应见于下丘脑与杏仁复合体的部分核团。在一些部位还存在表达水平甚至细胞内定位模式的性别差异,如前庭上核内的表达只见于雌性;雄性大鼠三叉神经运动核内ER-β蛋白主要表达于胞浆内,细胞核为阴性;而在雌性大鼠该部位ER-β蛋白主要位于细胞核等。以上结果表明ER-β蛋白在大鼠脑内分布广泛并具有一定的性别差异,在与学习记忆有关的脑区如大脑皮质和基底前脑内有很高的表达,提示在脑组织内雌激素可能通过ER-β这一新的信号途径发挥多种重要的调控作用,如学习记忆等。 相似文献
108.
Human saliva contains a large number of proteins and peptides (salivary proteome) that help maintain homeostasis in the oral cavity. Global analysis of human salivary proteome is important for understanding oral health and disease pathogenesis. In this study, large-scale identification of salivary proteins was demonstrated by using shotgun proteomics and two-dimensinal gel electrophoresis-mass spectrometry (2-DE-MS). For the shotgun approach, whole saliva proteins were prefractionated according to molecular weight. The smallest fraction, presumably containing salivary peptides, was directly separated by capillary liquid chromatography (LC). However, the large protein fractions were digested into peptides for subsequent LC separation. Separated peptides were analyzed by on-line electrospray tandem mass spectrometry (MS/MS) using a quadrupole-time of flight mass spectrometer, and the obtained spectra were automatically processed to search human protein sequence database for protein identification. Additionally, 2-DE was used to map out the proteins in whole saliva. Protein spots 105 in number were excised and in-gel digested; and the resulting peptide fragments were measured by matrix-assisted laser desorption/ionization-mass spectrometry and sequenced by LC-MS/MS for protein identification. In total, we cataloged 309 proteins from human whole saliva by using these two proteomic approaches. 相似文献
109.
Wang B Zhang S Cui S Yang B Zhao Y Chen H Hao X Shen Q Zhou J 《Biotechnology letters》2012,34(1):19-28
Two new types of stable ternary complexes were formed by mixing chitosan with DOTAP/pDNA lipoplex and DOTAP with chitosan/pDNA
polyplex via non-covalent conjugation for the efficient delivery of plasmid DNA. They were characterized by atomic force microscopy,
gel retarding, and dynamic light scattering. The DOTAP/CTS/pDNA complexes were in compacted spheroids and irregular lump of
larger aggregates in structure, while the short rod- and toroid-like and donut shapes were found in CTS/DOTAP/pDNA complexes.
The transfection efficiency of the lipopolyplexes showed higher GFP gene expression than DOTAP/pDNA and CTS/pDNA controls
in Hep-2 and Hela cells, and luciferase gene expression 2–3-fold than DOTAP/pDNA control and 70–120-fold than CTS/pDNA control
in Hep-2 cells. The intracellular trafficking was examined by confocal laser scanning microscopy. Rapid pDNA delivery to the
nucleus enchanced by chitosan was achieved after 4 h transfection. 相似文献
110.
Mayilvahanan Shanmugam Dan Li Shumin Gao Nadezhda Fefelova Vikas Shah Antanina Voit Ronald Pachon Ghassan Yehia Lai-Hua Xie Gopal J. Babu 《PloS one》2015,10(2)
The functional importance of threonine 5 (T5) in modulating the activity of sarcolipin (SLN), a key regulator of sarco/endoplasmic reticulum (SR) Ca2+ ATPase (SERCA) pump was studied using a transgenic mouse model with cardiac specific expression of threonine 5 to alanine mutant SLN (SLNT5A). In these transgenic mice, the SLNT5A protein replaces the endogenous SLN in atria, while maintaining the total SLN content. The cardiac specific expression of SLNT5A results in severe cardiac structural remodeling accompanied by bi-atrial enlargement. Biochemical analyses reveal a selective downregulation of SR Ca2+ handling proteins and a reduced SR Ca2+ uptake both in atria and in the ventricles. Optical mapping analysis shows slower action potential propagation in the transgenic mice atria. Doppler echocardiography and hemodynamic measurements demonstrate a reduced atrial contractility and an impaired diastolic function. Together, these findings suggest that threonine 5 plays an important role in modulating SLN function in the heart. Furthermore, our studies suggest that alteration in SLN function can cause abnormal Ca2+ handling and subsequent cardiac remodeling and dysfunction. 相似文献