灵芝多糖引起的小鼠脾细胞核DNA,RNA含量及核质比的…

灵芝多糖可引起外培养的小鼠脾细胞核ＤＮＡ，ＲＮＡ含量显著增加，细胞内微结构改变，细胞质和细胞核的平均截面积明显增加，核质比呈下降趋势，提示灵芝多糖诱导脾细胞ＤＮＡ和蛋白质合成的同时，促进细胞增殖。     

灵芝多糖降血糖的机理探讨

目的 观察灵芝多糖降血糖的作用，探讨它降血糖的可能机理。方法 应用药物建立糖尿大鼠模型、分组并给予不同剂量的灵芝多糖，观察血糖、胰岛素、葡萄糖激酶等指标。结果 灵芝多糖能显著降低血糖，增加胰岛素的分泌，修复胰岛细胞，增加葡萄激酶的活性。结论 口服灵芝多糖可降低糖尿病大鼠的高血糖、升高胰岛素水平，可能是通过灵芝多糖对胰岛细胞的不同程度的修复；灵芝多糖可促进糖尿病大鼠体内的葡萄糖磷酸化。     

段木栽培及袋栽灵芝多糖对体外培养小鼠脾淋巴细胞增殖活性的比较

目的 比较段木栽培灵芝多糖(wood-cultured Ganoderma lucidum polysaccharides, GL-PS-WC) 及袋栽灵芝多糖(bag-cultured Ganoderma lucidum polysaccharides, GL-PS-BC)对体外培养小鼠脾淋巴细胞增殖活性的影响,探讨袋栽灵芝多糖替代段木栽培灵芝多糖的可能性。 方法检测两种灵芝多糖对混合淋巴细胞培养(MLC)反应的影响;观察对刀豆蛋白A (Con A)、细菌脂多糖(LPS)诱导淋巴细胞增殖的影响以及对环孢素A (CsA)、丝裂霉素C(Mit C)、足叶乙苷(VP-16) 等抑制MLC反应的影响。结果当质量浓度为0.2～12.8 mg·L^-1时,两种灵芝多糖均可促进MLC反应,增强Con A或LPS诱导的淋巴细胞增殖,并拮抗CsA, Mit C或VP-16对MLC反应的抑制作用。未发现两种多糖之间有显著性差异。结论GL-PS-WC及GL-PS-BC对体外培养脾淋巴细胞的增殖活性有类似作用。     

灵芝多糖的提取与检测

灵芝是一种滋补强壮、扶正固本的传统中药。现代医药工作者对灵芝进行了广泛深入的研究，证明灵芝含有多种有效成份，具有广泛的生物学作用，其中灵芝多糖为主要有效成份之一。目前，已从赤灵芝多糖中分离鉴定了18个灵芝多糖均一体，经现代基础医学筛选研究，证实了灵芝多糖具有免疫调节，促进核酸蛋白质的合成代谢，抗衰老等一系列药理作用［’］。灵芝已有片剂、糖浆剂、胶囊剂、注射剂等剂型。其提取工艺有水提法、醇提法等。为探讨各种生产工艺与灵芝多糖有效成份提取量间的关系，本文选取与生产工艺有关的若干因素作了多糖含量测定的比…     

灵芝孢子粉多糖Lzps-1的化学研究及其总多糖的抗肿瘤活性

目的研究微波软化灵芝孢子粉中的多糖组分及其抗肿瘤活性。方法用水提取微波软化灵芝孢子粉总多糖，总多糖经分级沉淀得到多糖组分Lzps-C，再采用DEAE-cellulose和Sephadex G-50柱色谱进行分离纯化，用化学和光谱方法分析其结构。结果从微波软化灵芝孢子粉的水提物中分得一个多糖Lzps-1，其平均分子量为8 000，为葡聚糖。微波软化灵芝孢子粉的水提物得到的总多糖Lzps对小鼠Lewis肺癌、小鼠S₁₈₀肉瘤有较好的抑制作用，并能明显提高荷Lewis肺癌小鼠NK活性。结论Lzps-1是首次从灵芝孢子粉中分离得到。Lzps具有抗癌活性。     

灵芝孢子多糖抗移植性肿瘤实验研究

目的研究灵芝孢子多糖的抗癌作用。方法采用小鼠抗移植性肿瘤实验方法。结果灵芝孢子多糖分别以150 mg.kg-13、00 mg.kg-1和600 mg.kg-1剂量连续12天灌胃给药,对小鼠移植性肝癌Heps的抑瘤率为53.77%~65.25%;连续8天灌胃给药,对小鼠移植性肉瘤S180的抑瘤率为50.39%~55.04%,皆呈良好的抑瘤作用。灵芝孢子多糖可分别提高Heps和S180荷瘤小鼠的脾指数和胸腺指数。结论灵芝孢子多糖有良好的抑瘤作用,并可增强Heps和S180荷瘤小鼠的非特异性免疫功能。     

灵芝多糖研究新进展

灵芝多糖是灵芝的主要活性成分之一，具有广泛的生理活性。本文对近年来灵芝多糖在免疫调节、抗肿瘤、清除自由基、抗血栓血凝、降血糖及护肝等方面的新进展，以及灵芝多糖的深层发酵条件和结构分析研究中的新结果作了简要综述。     

灵芝多糖对混合淋巴细胞培养反应中白细胞介素2生成和T细胞亚类的影响(英文)

利用混合淋巴细胞培养反应研究了灵芝多糖的免疫作用机理。结果表明培养12h,灵芝多糖(25,50,100,200μg/ml)可促进白细胞介素2的分泌,且具有剂量依赖关系。培养4d后,可增加总的细胞回收量以及Lyt 2~+和L3T4~+细胞的回收量。灵芝多糖还明显增强细胞毒T细胞的功能,在浓度为200μg/ml时,其杀伤活性增加100％。     

栽培灵芝与灵芝孢子粉有效成分含量比较

本文比较了栽培灵芝与灵芝孢子粉的有效成分的含量。结果表明：栽培灵芝总多糖为0．42％，灵芝孢子粉总多糖为0．75％；栽培灵芝水解氨基酸与灵芝孢子粉水解氨基酸总量分别为17．16％和3312％；两者都含有人体必须微量元素。     

灵芝多糖对混合淋巴细胞培养反应中白细胞介素2生成和T细胞亚类的影响(英文)

利用混合淋巴细胞培养反应研究了灵芝多糖的免疫作用机理。结果表明培养12h,灵芝多糖(25,50,100,200μg/ml)可促进白细胞介素2的分泌,且具有剂量依赖关系。培养4d后,可增加总的细胞回收量以及Lyt 2⁺和L3T4⁺细胞的回收量。灵芝多糖还明显增强细胞毒T细胞的功能,在浓度为200μg/ml时,其杀伤活性增加100%。     

HYPOTHESIS: CYTOTOXIC LYMPHOCYTE GRANULE SERINE PROTEASES ACTIVATE TARGET CELL ENDONUCLEASES TO TRIGGER APOPTOSIS

Upon interaction with target cells, cytotoxic T lymphocytes and natural killer cells vectorially secrete highly specialized cytoplasmic granules containing perforin and a family of serine proteases (granzymes). This granule exocytosis mechanism of cytolysis is of patho-physiological importance, and usually results in target cell DNA fragmentation. Neither perforin nor granzymes possess inherent nuclease activity, but in combination they can induce target cell apoptosis. Perforin forms transmembrane pores in the target cell, thereby enabling granzymes to access target cell substrates. The target cell substrates of granzymes are unknown, but granzyme A binding and cleavage of the nuclear shuttle protein nucleolin in target cells demonstrates that granzymes may act on nuclear substrates. Furthermore, the presence of granzyme B and other granzyme activities in the nucleus of cytotoxic lymphocytes indicates that granzymes can be transported from the cytoplasm to the nucleus. It is hypothesized that perforin enables effector granzymes to enter the target cell cytoplasm and following their transport into the nucleus, granzymes cleave specific target cell nuclear proteins to activate autolytic endonucleases that fragment DNA. In cytotoxic effectors, these nuclear substrates are normally protected from granzymes by endogenous inhibitors.     

NLS bioconjugates for targeting therapeutic genes to the nucleus

One of the major steps limiting non-viral gene transfer efficiency is the entry of plasmid DNA from the cytoplasm into the nucleus of transfected cells. Trafficking of nuclear proteins from the cytoplasm into the nucleus through nuclear pore complexes is mediated by the presence of nuclear localization sequences (NLS) on proteins. Viral DNA and RNA also require interaction with cellular machinery for efficient nuclear import. In this article, we review the various strategies used to provide plasmid DNA with nuclear localization sequences, and discuss the possibility of developing efficient gene delivery systems based on these strategies.     

人支气管永生化HBE细胞形态计量学分析

目的:探索人支气管永生化HBE细胞超微结构的三维形态结构特征并与人肺腺癌A549细胞进行比较分析。方法:按常规方法制备HBE细胞与A549细胞的透射电镜样品。用Image-ProPlus图像分析软件设计网格测试系统,应用体视学原理和方法,分别测算HBE细胞和A549细胞核的体视学参数包括核体密度(VVn)、核表面积密度(SVn)、核表面积与体积比(RSVn)、核数密度(NVn)、核平均体积(vn)、核平均表面积(sn)和核浆比(Rnp);核仁的体视学参数包括核仁体密度(VVnu)、核仁表面积密度(SVnu)、核仁表面积与体积比(RSVnu)、核仁数密度(NVnu)、核仁平均体积(vnu)、核仁平均表面积(snu)等共13种体视学参数的数值。结果:①HBE细胞核平均体积(vn)和核平均表面积(sn)分别为206.74μm3和184.75μm2,明显小于A549细胞;②HBE细胞核及核仁的表面积与体积比(RSVn)分别为0.9192和2.3536,均大于A549细胞;③HBE细胞核浆比为0.3829,小于A549细胞。结论:HBE细胞核及核仁的形态与肺腺癌A549细胞有差异,其核和核仁的表面积、体积及形态大小均小于A549细胞。     

凋亡诱导因子的研究进展

在细胞正常生理状态下,凋亡诱导因子定位在线粒体内膜上,与呼吸链复合体Ⅰ互相作用,催化电子从泛醌到细胞色素C的传递。当细胞受到凋亡信号刺激后,凋亡诱导因子变成可溶性蛋白,从线粒体释放到细胞浆中,再通过其核定位信号序列进入细胞核内,和其他因子一起作用于染色体,使染色体凝聚和DNA呈大片段断裂(约50kb),最终诱导细胞凋亡。凋亡诱导因子受p53、Bcl-2家族、Hsp70等多种因子的调节。     

氧化苦参碱诱导人乳腺癌细胞MCF-7凋亡的实验研究

目的　研究氧化苦参碱对MCF 7细胞的诱导凋亡作用机制。方法　用光学显微镜、电子显微镜、激光共聚焦显微镜、流式细胞仪和DNA凝胶电泳等技术观察细胞凋亡。结果　实验显示氧化苦参碱作用于体外培养的MCF 7细胞可诱导发生凋亡 ,凋亡细胞表现为细胞固缩 ,核染色质聚集或碎裂、胞质空泡化等 ;DNA电泳可见DNA梯形条带 ;激光共聚焦显微镜示DNA含量下降 ,流式细胞仪检测sub G1峰在G1期前出现 ,S期细胞比例增高。结论　氧化苦参碱对体外培养MCF 7细胞生长有抑制作用 ,机制与通过阻止细胞周期的进程 ,启动细胞自身调控程序 ,诱导肿瘤细胞凋亡有关     

抗阿霉素的中国仓鼠卵巢上皮细胞系的抗药性

用细胞生物学和SDS-PAGE电泳方法,研究抗阿霉素(Dox)CHO细胞系(RCl)的特性。用间接免疫荧光法,未测到RCl超表达P-糖蛋白。RCl降低Dox的摄入,增加膜的流动性,Dox在CHO中主要分布在细胞核,在RCl中则分布在细胞质和细胞核。RCl中有一种分子质量为30—40 kDa的核蛋白的表达被抑制,而在敏感CHO中其表达正常。     

Antioxidant activities of Ganoderma lucidum polysaccharides and their role on DNA damage in mice induced by cobalt-60 gamma-irradiation

In this study, the radio-protective effects of Ganoderma lucidum polysaccharides (GLP) were investigated in a mouse animal model exposed to (60)Co gamma-irradiation. Each of three batches of mice were divided into five groups (negative control, positive gamma irradiated control, and low, middle and high dosage GLP groups). Different batches of animals were used to evaluate the impact of GLP on peripheral white blood cell count, immune organ index; DNA damage, lipid peroxidation; micronuclei formation, and nucleated cell count in bone marrow induced by (60)Co gamma-irradiation. DNA strand-break and micronuclei frequency were significantly reduced and glutathione peroxidase activity and nucleated cell count in bone marrow were significantly increased by GLP treatment in a dose-dependent manner. GLP intervention also increased the activity of superoxide dismutase and decreased the level of malondialdehyde in middle and high GLP treatment groups. No adverse effects were observed on peripheral white blood cells and immune organ or body weight in either the control groups or GLP treated gamma exposed mice. These findings suggest that GLP possesses marked antioxidant capacity which plays an important role in the prevention of radiation damage in mice induced by (60)Co gamma-irradiation.     

Intracellular routing of plasmid DNA during non-viral gene transfer

Gene transfer using non-viral vectors is a promising approach for the safe delivery of therapeutic DNA in genetic and acquired human diseases. Whereas the lack of specific immune response favors the use of plasmid-cationic polymer complexes, the limited efficacy and short duration of transgene expression impose major hurdles in the application of non-viral gene delivery techniques. Here, we review the major cellular, metabolic and physico-chemical impediments that non-viral vectors encounter before plasmid DNA enters the nucleus. Following endocytosis of DNA-polycation complexes, a large fraction of the DNA is targeted to the lysosomes. Since the cytosolic release of heterologous DNA is a prerequisite for nuclear translocation, entrapment and degradation of plasmid DNA in endo-lysosomes constitute one of the major impediments to efficient gene transfer. Plasmid DNA that escapes the endo-lysosomal compartment encounters the diffusional and metabolic barriers of the cytoplasm, reducing greatly the number of intact plasmids that reach the nucleosol. Nuclear translocation of DNA requires either the disassembly of the nuclear envelope or active nuclear transport via the nuclear pore complex. A better understanding of the cellular and molecular basis of non-viral vector trafficking from the extracellular compartment into the nucleus may provide strategies to overcome those obstacles that limit the efficiency of gene delivery.