贵州珍珠菜属药用植物的种类与分布

本文通过资源调查、资料考证及标本分类学研究,总结整理了贵州珍珠菜属药用植物的种类、地理分布、生境及其民间疗效.贵州有珍珠菜属药用植物30种,其中贵州药用新资源4种,贵州特有种准特有种药用植物3种,贵州珍稀名贵中草药1种,具有良好的开发利用价值.     

冬虫夏草及其伪劣商品的鉴别

冬虫夏草为名贵滋补药。明代即出口日本，现畅销国际市场，是中国传统的出口商品，享有极高的声誉。近年来国内外市场需求增大，而产量小，价格上扬，伪品、掺杂品增多。本文提出实用鉴别方法，以利保证冬虫夏草的质量。     

A commercial mixture of the brominated flame retardant pentabrominated diphenyl ether (DE-71) induces respiratory burst in human neutrophil granulocytes in vitro.

Polybrominated diphenyl ethers (PBDEs) are widely used brominated flame retardants (BFRs), which have become ubiquitous in the environment. This study investigates the effects of the pentabrominated diphenyl ether mixture, DE-71, on human neutrophil granulocytes in vitro. DE-71 enhanced production of reactive oxygen species (ROS) in a concentration-dependent manner measured as lucigenin-amplified chemiluminescence. Octabrominated diphenyl ether (OBDE), decabrominated diphenyl ether (DBDE), and the non-brominated diphenyl ether did not induce ROS formation at the concentrations tested. DPI (4 microM), an inhibitor of the NADPH oxidase completely inhibited DE-71 induced ROS formation, highlighting a role for NADPH oxidase activation. The protein kinase C inhibitor BIM (0.25 microM) and the selective chelator of intracellular calcium, BAPTA-AM (5 microM), also inhibited NADPH oxidase activation, indicating a calcium-dependent activation of PKC. ROS formation was also inhibited by the tyrosine kinase inhibitor tyrphostin (1 microM), the phospholipase C inhibitor ET-18-OCH3 (5 microM), and the phosphatidylinositol-3 kinase inhibitor LY294002 (25 microM). Alterations in intracellular calcium were measured using fura-2/AM, and a significant increase was measured after exposure to DE-71 both with and without extracellular calcium. The tetra brominated compound BDE-47 also enhanced ROS formation in a concentration dependent manner. The combination of DE-71 with the bacteria-derived N-formyl peptide fMLP and PCB153 induced an additive effect in the lucigenin assay. We suggest that tyrosine kinase mediated activation of PI3K could result in enhanced activation of calcium-dependent PKC by enhanced PLC activity, followed by intracellular calcium release leading to ROS formation in neutrophil granulocytes.     

Oxidized high-density lipoprotein induces neuron death

High-density lipoprotein (HDL) exists within the brain and is highly vulnerable to oxidative modifications. The focus of the present study was to determine the effect of HDL and oxidized HDL (oxHDL) upon neurons, astrocytes, and microglia. Administration of highly oxidized HDL, but not native, minimally, or moderately modified HDL resulted in a dose- and time-dependent increase in oxidative stress and death of cultured rat embryonic neurons. Astrocyte and microglia cultures treated with highly oxidized HDL displayed increased reactive oxygen species formation but no toxicity. Application of oxHDL exacerbated oxidative stress and neuron death induced by beta-amyloid peptide. Studies using pharmacological inhibitors implicate the involvement of calcium and reactive oxygen species in oxHDL-induced neuronal loss. Neural cells expressing increased levels of BCL-2 had decreased levels of oxidative stress and neuron death following exposure to oxHDL. Together, these data demonstrate that oxHDL increases oxidative stress in neurons, astrocytes, and microglia which ultimately culminate in neuron death.     

芦荟对大鼠肝微粒体脂质过氧化损伤体外模型的影响

目的: 探讨芦荟的抗氧化作用及其剂量效应关系。方法: 通过大鼠微粒体的提取,制备了VC/Fe2+和过氧基异丙苯(CHP)脂质过氧化损伤模型,检测不同剂量芦荟轧汁干预对丙二醛(MDA)含量变化的影响,观察芦荟清除活性氧的抗氧化作用。结果: 在CHP微粒体脂质过氧化激发模型中,各芦荟干预组的MDA含量均较对照组显著降低(P﹤0.01),在VC/Fe2+模型中,低剂量芦荟轧汁干预组与高剂量干预组MDA含量较阳性对照组显著下降(P﹤0.05),并且高剂量组降低更加明显(P﹤0.01)。但中剂量芦荟轧汁组MDA含量反而较阳性对照组有一定的升高。结论: 芦荟轧汁在抗氧化方面存在着双向效应,在一定剂量范围内有着较好的抗氧化作用,可能是芦荟的医疗保健功效的机制之一;但特定的剂量又可激发活性氧的生成。     

银杏内酯B对内皮细胞损伤的保护作用及机制

目的探讨银杏内酯B(GB)对TNFα刺激内皮细胞引起的氧化应激性损伤的保护作用及机制。方法用分子探针2,7-DCF测定细胞内ROS的产生量以及用Western blot测定ERK2激酶和转录因子AP-1的蛋白表达。结果TNFα(5ng/ml)作用24h后,脑血管内皮细胞(BVEC)中ROS的产生量明显增加(P<0.05),细胞内AP-1、ERK2的蛋白表达显著增强;但GB(50mg/L)和NAC(20mM)能显著性抑制TNFα诱导的细胞内ROS的产生和AP-1、ERK2的表达(P<0.05)。结论GB能抑制TNFα诱导的BVEC内ROS的水平,此作用可能是通过抑制ROS介导的ERK2激酶及转录因子AP-1的表达而实现。     

用荧光探针JC-1检测氧化应激对精子线粒体膜电位的影响

目的：利用荧光探针JC-1观察氧化应激对精子线粒体膜电位的变化。方法：用FeSO4/H2O2体系诱导精子氧化损伤模型，利用新型荧光探针JC 1标记精子线粒体,在FACS Calibur流式细胞仪上检测JC 1荧光强度的变化。结果：正常精子线粒体维持较高的膜电位,JC 1在线粒体内形成聚合物, 红色荧光占主导地位。FeSO4/H2O2体系导致线粒体膜电位下降, JC 1聚合物分解成单体,红色荧光强度减弱。结论：氧化应激导致精子线粒体膜电位下降; JC 1结合流式细胞仪是一种理想的检测线粒体膜电位的手段。     

云南省16个县(市)黄胸鼠体表恙螨种类调查

目的了解云南省黄胸鼠（Rattus flavipectus）体表恙螨的寄生、种类组成、优势种及其空间分布型.方法选取云南省16个县（市）作为调查点,在现场用鼠笼加食饵诱捕黄胸鼠,收集耳壳及耳窝全部恙螨,用Hoyer＇s液封片后在显微镜下分类、鉴定.恙螨种群的空间分布格局用分布型指数中的聚块指数（m＊/m）测定.结果在所调查的16个县（市）中,从13个县（市）捕获黄胸鼠725只,共采集恙螨2 710只,经鉴定隶属3亚科10属42种.印度囊棒恙螨（Ascoschoengastia indica）、微板无前恙螨（Walchia micropelta）、李氏囊棒恙螨（A.leechi）、蒙大微恙螨（Microtrombicula munda）为优势螨种,其带螨率和螨指数较高,依次分别为6.8%、5.5%、3.9%、4.3%和1.65、0.64、0 43、0 42.结论黄胸鼠体表恙螨种类复杂,数量丰富,呈聚集型分布.     

活性氧与线粒体损伤

活性氧(reactive oxygen species,ROS)是细胞代谢不可避免的产物。细胞内高水平的ROS直接或间接地参与细胞信号传导,诱导细胞凋亡,是肿瘤及许多其它疾病的共同发病机制。线粒体是细胞能量生成的重要细胞器,也是广受关注的细胞调节氧化应激的中枢。但ROS与线粒体损伤之间的关系,至今尚未完全清楚。近年来的研究表明,线粒体是ROS产生的主要场所,又是ROS作用最敏感的部位。ROS通过氧化线粒体心磷脂、线粒体DNA和线粒体重要的蛋白质对线粒体造成氧化损伤,进而诱导细胞凋亡。     

细菌脂多糖对小鼠生长发育和骨骼发育的影响

目的:研究细菌脂多糖(LPS)对小鼠宫内胎儿死亡(IUFD)、生长发育迟缓(IUGR)和骨骼发育迟缓的影响。方法:LPS低中高组小鼠于妊娠d15-17分别腹腔注射不同剂量LPS(25μg/kg、50μg/kg、75μg/kg),LPS+2-苯叔丁基硝酮(PBN,活性氧ROS拮抗剂)组在LPS(75μg/kg)处理前30min和后3h经腹腔各给予100mg/kg的PBN,对照组给予等容量生理盐水。孕鼠于妊娠d18处死。另给药1d时取LPS高剂量组LPS+PBN组和对照组于LPS处理后6h处死孕鼠。结果:①小鼠妊娠d15-17给予LPS后,中高剂量组平均每窝死胎数明显高于对照组,活胎体重、身长和尾长下降,并呈明显的剂量-效应关系;LPS高剂量导致IUGR和骨骼发育迟缓;PBN处理明显抑制LPS对胎儿的作用。②LPS使母肝、胎肝和胎盘组织脂质过氧化,GSH含量显著降低。PBN显著抑制LPS的这些作用。结论:母鼠妊娠晚期接触LPS引起IUFD、IUGR和骨骼发育迟缓,ROS至少部分参与了LPS的引起IUFD、IUGR和骨骼发育迟缓。