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81.
目的 通过UHPLC-QTOF-MS/MS和分子对接技术阐明紫菀Aster tataricus中润肠通便作用的效应成分。方法 采用UHPLC-QTOF-MS/MS技术分析体内肠道内容物的成分,再利用SYBYL-X 2.0与Discovery Studio 4.0分子对接软件研究肠道内容物成分与M2受体、M3受体、蛋白激酶C(protein kinase C,PKC)蛋白的相互作用,明确各成分与靶标蛋白的结合强度。结果 体内肠道内容物中共鉴定出28个紫菀中的化学成分,有10个成分均可与M2受体、M3受体及PKC蛋白分子对接较好,其中astin J与3种靶标蛋白结合的平均打分值最高,这些成分均以非共价键方式与靶标蛋白结合,产生氢键、范德华力、经典作用力等相互作用。结论 紫菀中的astin J、asterin F、asterin A、异绿原酸A、异绿原酸B、异绿原酸C、绿原酸、槲皮素、山柰酚和木犀草素共10个成分可能是通过调节M受体及其下游信号通路PKC蛋白的表达发挥润肠通便的作用。 相似文献
82.
目的 探讨灵宝护心丹联合参松养心胶囊治疗窦性心动过缓的临床疗效。方法 选取2019年3月—2020年12月抚州市中医医院内科诊断为窦性心动过缓患者100例,随机分为对照组(50例)和治疗组(50例)。对照组给予参松养心胶囊(每天3次,每次4粒),治疗组在对照组的基础上给予灵宝护心丹(每天3次,每次4粒),治疗24周。治疗后比较两组的临床疗效、24 h动态心电图指标、心率变异性时域指标及不良反应。结果 治疗组中医证候有效率84.0%,对照组为60.0%,两组比较差异有统计学意义(P<0.05)。治疗组动态心电图总有效率86.0%,对照组64.0%,两组比较差异有统计学意义(P<0.05)。治疗后,两组平均心率、总心率、最快心率、最慢心率、24 h全部正常心室搏动间距(R wave-R wave,R-R)间期标准差(standard diviation of NN intervals,SDNN)、24 h连续5 min节段正常R-R间期的标准差(standard deviation of sequential five-minute R-R interval means,SDA... 相似文献
83.
霍山石斛Dendrobium huoshanense作为一种名贵的滋补类中药,收载于《中国药典》2020年版。多糖为其主要活性成分之一,具有免疫调节、保肝、抗肿瘤、抗氧化和抗炎等药理活性。通过查阅国内外文献,基于中国知网及PubMed等中英文文献数据库分析当前研究现状及研究热点;总结霍山石斛多糖(Dendrobium huoshanense polysaccharide,DHP)的提取分离、结构解析及其生物活性;分析其多糖成分与其他常用石斛品种的差异性。以期更好地开发利用DHP,为DHP产品的深入开发与研究及质量标准完善提供参考和思路。 相似文献
84.
目的 研究长链非编码RNA PCED1B-AS1调控核苷酸结合寡聚化结构域样受体3(NLR family pyrindomain containing 3, NLRP3)对巨噬细胞清除结核分枝杆菌和分泌炎症因子的影响。方法 在巨噬细胞RAW264.7中转染pcDNA-PCED1B-AS1,并用结核分枝杆菌感染,qRT-PCR方法检测PCED1B-AS1和TNF-α、IL-6 mRNA水平,用菌落形成实验检测巨噬细胞对结核分枝杆菌的清除作用,Western blot方法检测细胞中NLRP3蛋白表达水平。将NLRP3 小干扰RNA(small interfering RNA, siRNA)和pcDNA-PCED1B-AS1共转染到巨噬细胞中,用结核分枝杆菌感染,同样检测细胞中TNF-α、IL-6 mRNA水平和菌落量。结果 结核分枝杆菌感染后的巨噬细胞中PCED1B-AS1水平降低,TNF-α、IL-6 mRNA水平升高。转染pcDNA-PCED1B-AS1后的巨噬细胞经过结核分枝杆菌感染以后,细胞中PCED1B-AS1、TNF-α、IL-6 mRNA水平升高,形成的菌落量减少,细胞中NLRP3蛋白表达水平升高。NLRP3 siRNA可以逆转过表达PCED1B-AS1对结核分枝杆菌感染的巨噬细胞中TNF-α、IL-6 mRNA表达和菌落量形成的影响。结论 上调PCED1B-AS1促进巨噬细胞清除结核分枝杆菌,诱导细胞表达TNF-α、IL-6 mRNA的机制与上调NLRP3表达有关。 相似文献
85.
Experimental uremia in primates has been demonstrated to produce severe decrements in psychological functions which are related to the accumulation of toxic metabolites in blood. More recent neurophysiological research has referred uremic encephalopathy to disrupted sodium-potassium exchange in uremic brain. The present clinical investigations have found decrements in cognitive functioning with repeated testing in patients maintained on intermittent hemodialysis, which were correlated with plasma concentrations of potassium and creatinine. Power Spectral Density analyses of EEG indicated a shift to lower frequencies in these patients as compared to control subjects. No significant departure from normal functioning has been determined in patients receiving renal transplant tested within 60 days post-surgically. 相似文献
86.
The ontogeny of lymphocytes expressing J chain in the cytoplasm (J+) was studied in pig foetuses by the immunofluorescent technique. Peripheral blood lymphocytes were the first J+ cells in prenatal life. The spleen and lymph nodes contained J+ cells in the last days of gestation. J+ cells were found in the lamina propria of the gut and some glands of conventional but not of germ-free piglets. J chain was not detected on or in cell membranes at any developmental stage. 相似文献
87.
88.
O. Popanda G. Fox H. W. Thielmann 《Journal of molecular medicine (Berlin, Germany)》1995,73(5):259-268
To investigate whether DNA replication in malignant cells deviates from that of normal cells we compared DNA polymerases , , and from normal rat liver to the enzymes from fast-growing (malignant) Novikoff hepatoma cells. DNA polymerases were purified 300-fold by three chromatographic steps. Characterization included measurement of physicochemical constants (including sedimentation coefficients, diffusion coefficients, calculation of relative molecular masses), quantitation of catalytic activities using specific DNA primer templates (K
m values) and inhibitors (K
i values), and identification of polypeptides which are strongly associated with DNA polymerases. Comparison of physicochemical and catalytic properties of DNA polymerases from both sources revealed similarities but also some important differences. DNA primase associated with DNA polymerase , and 3–5 exonuclease accompanying DNA polymerases and had similar activities. In contrast, the DNA-binding domain of DNA polymerases and from hepatoma cells was altered since K
m values, determined with the specific primer templates gapped calf thymus DNA and poly(dA·dT), were higher. Furthermore, sedimentation and diffusion coefficients, Stokes' radii, and frictional coefficient ratios of DNA polymerases and from malignant cells significantly deviated. In addition, when the dNTP-binding sites were probed with specific inhibitors (aphidicolin, butylphenyl-dGTP, carbonyldiphosphonate, and dideoxy-TTP), significantly lower K
i values were obtained for the polymerases from Novikoff cells indicating lower affinity of the dNTP binding site to deoxyribonucleoside 5-triphosphates. Altered catalytic and molecular properties are possibly a consequence of malignant transformation. It is to be expected that similar changes occur in DNA polymerases of other tumors. In particular, diminished affinity to primer templates and weakened nucleotide binding leads to lowered specificity of nucleotide selection in the base-pairing process and is therefore likely to cause an enhanced mutation rate during malignant progression.Abbreviations
PCNA 3
Proliferating-cell nuclear antigen
This paper is dedicated to Prof. Dr. R. Neidlein on the occasion of his 65th birthday. 相似文献
89.
目的研究由南五味子属药用植物分离的戈米辛J(gomisinJ,GJ)和异型南五味子丁素(heteroclitinD,HD)对血管平滑肌的作用。方法采用离体大鼠胸主动脉标本,观察他们对高钾去极化收缩和对CaCl2、NA量效曲线的影响。结果GJ和HD能抑制KCl所致的收缩,其IC50(95%可信限)分别为3.8(2.4~5.9)和7.5(1.4~39)μmol/L;GJ和HD能使CaCl2量效曲线右移,最大效应降低,其pD′2值分别为5.13±0.07和4.77±0.18;GJ和HD也可使NA量效曲线右移和最大效应降低,其pD′2值分别为3.72±0.23和3.31±0.27。结论GJ和HD能抑制KCl、CaCl2和NA产生的血管收缩,而且对CaCl2的致缩作用强于对NA的收缩作用,提示他们具有钙拮抗活性。 相似文献
90.
Inhibition of signaling from Type 1 receptor tyrosine kinases via intracellular expression of single-chain antibodies 总被引:3,自引:0,他引:3
Summary Members of the Type I / epidermal growth factor receptor (EGFR)-related family of receptor tyrosine kinases have been implicated in the development of human cancer. We have taken a novel approach using the intracellular expression of single chain antibodies (scFv) to specifically inhibit thein vivo action of these receptors. A scFv is a recombinant protein analogous to an Fv domain which is the smallest high affinity binding portion of an antibody. We report here on the expression in mammalian cells of cDNAs encoding scFv-225 and scFv-FRP5 directed against the extracellular domain of, respectively, human EGFR and human ErbB-2. The scFvs were provided with a signal peptide which directs them to the secretory pathway of the cell. scFv-225, which competes with EGF for binding, functions in an autocrine fashion to inhibit EGF-dependent cell growth. scFv-FRP5 was also provided with an endoplasmic reticulum (ER) retention signal and inactivates ErbB-2 in an intracrine fashion, by preventing its appearance on the cell surface.Presented at the symposium "New Approaches in the Therapy of Breast Cancer", Georgetown University Medical Center, Washington DC, October 1994, generously supported by an education grant from Bristol-Myers Squibb. 相似文献