外源DMSO和ASA对微囊藻毒素胁迫下烟草细胞ROS生成和抗氧化系统的影响

采用2μg/mL微囊藻毒素-RR(MC-RR)、2μg/mL MC-RR 0.5%二甲基亚砜(DMSO)和2μg/mL MC-RR 2 mmol/L抗坏血酸(ASA)分别处理烟草悬浮细胞,研究上述各处理对烟草悬浮细胞活性氧(ROS)产生和抗氧化系统的影响。结果表明,与对照相比,MC-RR单独处理后烟草悬浮细胞中ROS、膜脂过氧化产物丙二醛(MDA)和细胞内源ASA的含量及超氧化物歧化酶(SOD)和过氧化物酶(POD)的活性明显升高,还原型谷胱甘肽(GSH)的含量有一个先降后升的变化过程。在分别加入外源抗氧化剂DMSO或ASA后,细胞内ROS和MDA含量下降,ASA、GSH含量和SOD、POD酶活性基本可恢复到对照水平。以上结果说明,微囊藻毒素单独处理细胞可造成氧化胁迫,其所诱导的ROS的大量积累很有可能是其产生细胞毒害的关键因子,外源抗氧化剂ASA和DMSO可缓解MC-RR对细胞的毒害作用,对细胞起一定保护作用。     

DBP致雌性仔鼠卵巢的氧化应激及VC的干预作用

为探明邻苯二甲酸二丁酯(DBP)宫内暴露对雌性仔鼠卵巢脂质过氧化水平的影响及维生素C(Vit C)的抗氧化应激作用。本研究将20只Wistar孕鼠随机分为5组,分别为高(500 mg/kg)、低(100 mg/kg)剂量DBP染毒组以及高(500 mg/kg)、低(100 mg/kg)剂量DBP+Vit C(125 g/L)干预组和对照(玉米油)组,每组4只。自妊娠第1~19天,每天1次灌胃染毒DBP(10 m L/kg);采用自由饮水方式进食Vit C(约40 m L/d)。待雌性仔鼠出生21 d时,取其卵巢组织,称重,并测定MDA、GSH含量和GSH-Px、SOD、CAT活性。研究发现,与对照组相比,高、低剂量DBP染毒组MDA含量均明显升高,SOD、CAT、GSH-Px活性均明显降低(p0.05)。高、低剂量DBP+Vit C干预组的仔鼠卵巢组织中MDA含量与相同剂量DBP染毒组相比显著下降,GSH-Px、SOD、CAT活性显著升高(p0.05)。综上所述,DBP宫内暴露可致雌性仔鼠卵巢组织产生脂质过氧化反应,诱导氧化应激,造成潜在生殖毒性,抗氧化剂Vit C对于DBP所致生殖系统的氧化损伤具有一定的保护作用。这为进一步开展DBP生殖发育毒性的机制研究和预防干预提供理论依据。     

薄芝糖肽对小鼠实验性肝损伤的保护作用

目的观察薄芝糖肽注射液对四氯化碳(CCl4)肝中毒小鼠的抗氧化作用.方法小鼠腹腔注射40% CCl4液体石蜡诱发急性肝损伤.然后治疗组给予薄芝糖肽注射液,以盐水代替薄芝糖肽注射液作为阴性对照,以联苯双酯代替薄芝糖肽注射液作为治疗阳性对照.以血清谷丙转氨酶(ALT)活性和肝组织中脂质过氧化产物(MDA)、抗氧化剂还原型谷胱甘肽(GSH)含量作为观测指标.结果注射CCl4各组小鼠都出现ALT活力急剧升高,肝组织中MDA含量明显增多,同时GSH含量明显减少,证实急性肝损伤模型成立,并且表明与过氧化作用有关.经薄芝糖肽治疗的小鼠,ALT活力在几天之内恢复到正常水平,与盐水对照组差异显著(p＜0.05);薄芝糖肽一方面抑制CCl4诱导的MDA含量升高,同时又可抑制GSH含量的减少(p＜0.05).结论用CCl4造成实验性小鼠肝损伤,小鼠血清谷丙转氨酶大幅度升高,肝组织中脂质过氧化产物丙二醛明显增高的同时,抗氧化剂还原型谷胱甘肽含量明显降低.经薄芝糖肽注射液治疗,可使ALT在几天之内降至正常,同时使肝组织中抗氧化剂还原型谷胱甘肽含量明显回升,使过氧化产物得到尽快清除.提示薄芝糖肽具有直接或间接的抗氧化作用.     

朱砂七粗多糖的提取及生物活性的研究

首次从朱砂七中提取粗多糖(PCCP),研究了PCCP对.OH自由基、O2-.自由基和DPPH.自由基的清除能力以及抗脂质过氧化能力,选用人肝癌细胞HepG2,经MTT染色法研究其体外抗肿瘤活性。结果显示,PC-CP的浓度在8.48 mg/mL时,对.OH、O2-.和DPPH.的清除率分别达到了52.3%、54.7%和38.3%;PCCP的浓度在8.48 mg/mL时,对脂质过氧化的抑制率达到了62.0%;PCCP的浓度在277.78μg/mL时,对人肝癌细胞HepG2的抑制率达到了42.6%,表明PCCP具有一定的体外抗氧化能力和体外抗肿瘤活性。     

黄皮种子脱水敏感性与脂质过氧化作用

黄皮种子自然脱水时,种子的发芽率和发芽指数迅速下降;种子浸泡液的电导率和可溶性物质的量大大增加;线粒体膜和质膜ATPase的活性下降;种子中SOD活性先上升,然后下降;脂质过氧化产物MDA和脂质氢过氧化物的量大大增加。DDC、MDA和Fe2 促进脂质过氧化作用,降低种子生活力;ASA和甘露醇对脂质过氧化有抑制作用,提高种子生活力。     

原核表达的萝卜PHGPx和谷胱甘肽对NIH3T3细胞氧化损伤的联合保护作用

将大肠杆菌中高效表达的萝卜磷脂氢谷胱甘肽过氧化物酶(RsPHGPx)及其底物还原型谷胱甘肽(GSH)联合作用于H2O2、过氧化叔丁基(t-BHP)以及磷脂氢过氧化物(PLPCOOH)损伤的小鼠NIH3T3成纤维细胞,研究其对于细胞过氧化损伤的保护作用。发现单独加入10 μg/ml RsPHGPx并不能明显保护细胞应对过氧化损伤,但是10 μg/ml RsPHGPx与3 mg/ml GSH共同作用,可显著提高GSH对细胞过氧化损伤的保护效果,提高细胞存活率,降低细胞膜脂质过氧化水平和胞内活性氧(ROS)水平,保护细胞维持形态完整和抑制细胞凋亡。这一联合作用结果说明RsPHGPx的催化作用可以快速清除细胞内多种过氧化物,高效地保护细胞免受过氧化损伤,为RsPHGPx的应用提供了实验依据。     

不同来源肝细胞在体外降脂药物评价中药效反应的对比

目的:通过对比不同来源的人肝癌细胞系HepG2和原代大鼠肝细胞在体外降脂药物评价中药效反应,指导两种肝细胞在体外降脂药物评价中的实际应用。方法:用游离脂肪酸(油酸/棕榈酸,2:1)诱导HepG2细胞、原代大鼠肝细胞脂肪变性,并用100μmol·L-1苯扎贝特干预,检测细胞内甘油三酯(TG)、总胆固醇(TC)、活性氧(ROS)含量,细胞内脂滴数目、并检测细胞上清液中丙二醛(MDA)含量和超氧化物歧化酶(SOD)活性。结果:FFA刺激使HepG2细胞和原代大鼠肝细胞脂质沉积(TG、脂滴)和氧化应激(ROS、MDA、SOD)水平上升。苯扎贝特对HepG2细胞1 mmol·L-1FFA造模组和原代大鼠肝细胞0.5 mmol·L-1FFA造模组脂质沉积和氧化应激水平改善显著;而HepG2细胞0.5 mmol·L-1FFA造模组和原代大鼠肝细胞1 mmol·L-1FFA造模组脂质沉积和氧化应激水平在苯扎贝特干预后变化不明显。结论:在相同FFA造模浓度,原代大鼠肝细胞病理特征变化更为明显;苯扎贝特对两种肝细胞在脂质沉积和氧化应激水平的作用也不完全相同。因而HepG2细胞和原代大鼠肝细胞在体外降脂药物评价中药效反应是不完全相同的。     

几种天然有机多酚酸体外抗脂质过氧化研究

通过天然有机多酚酸对H2O2诱导小鼠肝匀浆脂质过氧化和自发脂质过氧化的保护作用的体外实验,比较研究绿原酸、咖啡酸、迷迭香酸、阿魏酸、丹参素、原儿茶醛和3-羟基肉桂酸体外抗氧化能力的强弱,探讨其抗氧化能力产生机理及构效关系。结果表明,7种多酚酸对H2O2诱导小鼠肝匀浆脂质过氧化的保护作用强弱依次为迷迭香酸咖啡酸原儿茶醛绿原酸阿魏酸丹参素3-羟基肉桂酸,其最大和最小抑制率相差2.4倍;对小鼠肝脏组织自发脂质过氧化的抑制率大小顺序为迷迭香酸、原儿茶醛、绿原酸、咖啡酸、阿魏酸、丹参素、3-羟基肉桂酸,最高和最低抑制率相差近90%。7种天然有机酸抗脂质过氧化作用因化合物结构不同存在显著差异。     

蜂胶黄酮对小鼠脑so D 、 GsH 一Px 、 MDA 的影响

目的：研究蜂胶黄酮对小鼠脑组织的抗氧化系统的作用,以期探讨蜂胶黄酮的抗衰老作用机制。方法：以小鼠为实验对象,以其脑SOD、GSH—Px、MDA为指标,考察蜂胶黄酮的抗衰老作用。结果：蜂胶乙醇提取物（EEP）可使脑组织中SOD、GSH—Px活性明显增高,和空白组相比具有显著差异（P〈0、01）;使脑组织MDA明显降低,和空白组相比具有显著差异（P〈0．01）。结论：EEP可有效地提高脑组织中抗氧化酶的活性,降低脑MBA的含量,抑制和／或减轻脂质过氧化反应,从而防止了自由基过氧化对脑组织的损伤,可能是有效的脑组织保护荆。     

镉致黑斑蛙肝脏氧化损伤与金属硫蛋白含量的变化

为观察镉对黑斑蛙(Rana nigromaculata)肝脏脂质过氧化产物和金属硫蛋白含量的影响,将黑斑蛙暴露于10.0mg·mL-1浓度的镉溶液中30d,分别测定了黑斑蛙在暴露4、10d和30d时肝脏组织中镉(Cd)、还原型谷胱甘肽(GSH)、金属硫蛋白(MT)和过氧化产物丙二醛(MDA)的含量。实验结果表明,黑斑蛙肝脏中镉的积累量、GSH和MT含量均随着镉暴露时间的延长而显著升高,具有明显的时间-效应关系;在镉暴露的第10天,肝MDA含量明显高于对照组。提示镉可对黑斑蛙肝脏造成氧化损伤,而GSH、MT含量的升高则可能是机体抗氧化损伤的机理之一。     

Interactions of an antitumor platinum compound with deoxyribonucleic acid, histones, L-amino acids, poly-L-amino acids, nucleosides and nucleotides

Interaction of cis-dichloro(dipyridine)platinum(II) (cis-PPC) with calf thymus DNA, calf thymus histone, l-amino acids, poly-l-amino acids, nucleosides, and nucleotides has been evaluated by equilibrium dialysis technics. At least a 28 % decrease in the association of cis-PPC with DNA occurs when the platinum compound is pre-incubated with l-amino acids. The greatest decrease in association is seen upon pre-incubation of the platinum compound with the free amino acids. Glut, Asp, Lys, Arg, and CySH, before the addition of a sack containing a solution of DNA. The low level of association between DNA and the amino acids tends to rule out competition between cis-PPC and amino acids for DNA association sites. cis-PPC was repelled from sacks containing positively charged poly-l-Lys, poly-l-Arg, and calf thymus histone; however, in the presence of poly-l-Glut and poly-l-Asp, cis-PPC associated with these negatively charged polymers to a considerable degree. Enhanced chloride dissociation from cis-PPC was observed in the presence of all of the amino acids and the nucleotides GMP, CMP, UMP, and TMP, but not in the presence of AMP or the nucleosides rG and dG. In the presence of calf thymus histone, the association of cis-PPC with calf thymus DNA was reduced by more than 50% at histone/DNA ratios of 0.8–1.0.These data suggest that cis-PPC or cis-Pt(II) may associate with electron-rich areas of not only nucleic acids and proteins but also with body pools of free nucleotides and amino acids. The presence of positively charged histones shielding DNA strands in vivo suggests that the most probable point of platinum-DNA association would be at de-repressed areas of DNA which are undergoing RNA synthesis. The aquated form of the platinum complex may also associate with acidic proteins which appear to be involved in the positive control of RNA synthesis and, as a result, this interaction may be of pharmacological significance.     

Copper amine oxidases: Current state of knowledge

Summary A brief review on the structure nd functions of the copper-pyrroloquinoline quinone amine oxidases is presented. Data concerning the metal and organic cofactors are reported, giving special emphasis to their structural relationship with the protein molecule and mechanistic properties. Information on the functional role of these enzymes with respect to polyamine metabolism are also given.     

三种常见实蝇的形态学、生物学和生态学比较

对瓜实蝇Bactrocera (Tetradacus) minax (Enderlein)、桔小实蝇Bactrocera (Bactrocera) dorsalis (Hendel)和桔大实蝇Bactrocera (Zeugodacus) cucurbitae (Coquillett)的形态学、生物学、生态学等方面进行了比较和分析,包括三种实蝇在国内外的分布情况,对寄主选择的差异,各种虫态的形态特征,发育历期和生活史,并对它们的危害状况和防治方法分别作了介绍,可为3种实蝇的鉴定和防治提供参考.     

Variations in the coordination environment of Co, Cu and Zn complexes prepared from a tridentate (imino)pyridine ligand and their structural comparisons

The variations in the coordination environment of Co(II), Cu(II) and Zn(II) complexes with the neutral, tridentate ligand bis[1-(cyclohexylimino)ethyl]pyridine (BCIP) are reported. Analogous syntheses were carried out utilizing either the M(BF₄)₂ · xH₂O or MCl₂ · xH₂O metal salts (where M = Co(II), Cu(II) or Zn(II)) with one equivalent of BCIP. When the hydrated metal starting material was used, cationic, octahedral complexes of the type [M(BCIP)₂]²⁺ were isolated as the tetrafluoroborate salt (4, 5). Conversely, when the hydrated chloride metal salt was used as the starting material, only neutral, pentacoordinate [M(BCIP)Cl₂] complexes (1-3) formed. All complexes were characterized by X-ray diffraction studies. The three complexes that are five coordinate have distortions due mainly to the pyridine di-imine bite angle. The [Cu(BCIP)Cl₂] (2) also exhibits deviations in the Cu(II)-Cl bond distances with values of 2.4242(9) and 2.2505(9) Å, which are not seen in the analogous Zn(II) and Co(II) structures. Similarly, the two six coordinate complexes (5, 6) are also altered by the ligand frame bite angle giving rise to distorted octahedral geometries in each complex. The [Cu(BCIP)₂](BF₄)₂ (6) also exhibits Cu(II)-N_imine bond lengths that are on average 0.14 Å longer than those found in the analogous 5 coordinate complex, [Cu(BCIP)Cl₂]. In addition to X-ray analysis, all complexes were also characterized by UV/Vis and IR spectroscopy with ¹H NMR spectroscopy being used for the analysis of the Zn(II) analogue (3).     

Resonance light scattering spectrometric study of poly diallyldimethylammonium chloride–antibody–antigen system

The interaction of antigen (Ag) and antibody (Ab) with poly diallyldimethylammonium chloride (PDDA) in aqueous solutions has been studied by optical absorption and resonance light‐scattering (RLS) spectroscopies. The formation of the three‐component‐complex is due to aggregates of Ab or Ag with PDDA by electrostatic interaction and aggregates of Ab with Ag by immunoreaction. The influences of some experimental factors, including incubation time, pH value, concentration of PDDA and concentration of Ab, on the aggregation process have also been studied. A linear relationship between the concentration of Ag and the RLS intensity was found. Under the optimal conditions, for a given concentration of Ab (4.6 µg/mL), the enhancement of RLS intensity is in proportion to the concentration of Ag in the range 0.03–0.83 µg/mL. The RLS could, in combination with immunoassay, be a rapid and sensitive detection method for Ag. Copyright © 2009 John Wiley & Sons, Ltd.     

多马胺能药物对鲇鱼促性腺激素（GtH）分泌活动的影响

以珠江流域鲇鱼（silurus asotus)为实验材料,研究了多巴胺（DA）能药物（DA及其D－2型受体拮抗物 ,DOM）对鲇鱼促性腺激素（GtH)释放的影响,结果表明,在性腺发育的各个时期,单独注射DOM（5ug/g)均不能显著提高鲇鱼血液基础GtH水平,当DOM与LHRH－A联合注射时能显著增强LHRH－A刺激GtH释放的作用;DA只能抑制GnRH诱导的GtH释放,对基础GtH释放无抑制作用,这种生殖内分泌调节方式与鲇形目的革胡子鲇（Clarias gariepinus)和大鳍Hu（Mystus macropterus)相似,而与鲤形目的鲁科（Cyrpindiae)鱼类不同。     

Poly(dG)-poly(dC) DNA appears shorter than poly(dA)-poly(dT) and possibly adopts an A-related conformation on a mica surface under ambient conditions

Three types of DNA: approximately 2700 bp polydeoxyguanylic olydeoxycytidylic acid [poly(dG)-poly(dC)], approximately 2700 bp polydeoxyadenylic polydeoxythymidylic acid [poly(dA)-poly(dT)] and 2686 bp linear plasmid pUC19 were deposited on a mica surface and imaged by atomic force microscopy. Contour length measurements show that the average length of poly(dG)-poly(dC) is approximately 30% shorter than that of poly(dA)-poly(dT) and the plasmid. This led us to suggest that individual poly(dG)-poly(dC) molecules are immobilized on mica under ambient conditions in a form which is likely related to the A-form of DNA in contrast to poly(dA)-poly(dT) and random sequence DNA which are immobilized in a form that is related to the DNA B-form.     

汉坦病毒在原代人胚肾与人胚肺细胞中增殖及其特性的研究

近年来研究发现,汉坦病毒能在多种细胞株及人体细胞中增殖、适应.国内学者用人胚肺二倍体细胞(2BS)体外适应该病毒成功,但有关原代人胚肺、肾细胞的报道尚少.作者选用两株病毒及两种原代人胚细胞用于体外感染、观察,应用免疫荧光间接法及胶体金包埋前染色电镜技术对宿主细胞中增殖的病毒进行了动态观察及特异性定位研究,现报告如下.1 材料和方法1.1 细胞的分离和培养1.1.1 人胚细胞:取正常孕妇5—7个月水囊引产胚肾及肺组织,按常规方法分散细胞,5—7天后长满单层.1.1.2 非洲绿猴肾上皮细胞(VeroE6):由安徽省医学科学研究所倪大石惠赠.1.2     

基于平稳小波变换的EEG视觉的信号修正

眼球运动和眨眼会在眼球周围产生电信号,这种电信号的存在直接影响到对EEG信号的分析特征提取及EEG模式的分类等研究。本文提出了一种基于小波阈值滤噪方法来修正EEG信号中出现的视觉伪信号(OA)。这种用于EEG视觉伪信号处理的小波方法的实现过程如下：1)用平稳小波变换(SWT)对原始EEG信号进行处理;2)设置低频带信号的系数阈值;3)对滤噪后的信号进行重构。实验结果表明这种方法同时适用于眨眼和眼球运动产生的伪信号。最后,通过对采集的信号处理前后做了对比,说明其有效性。