阿霉素对人乳腺癌细胞凋亡及去磷酸化RB蛋白表达的影响

目的 :探讨阿霉素 (ADR)体外诱导人乳腺癌化疗敏感细胞 (MCF 7 S)凋亡与去磷酸化RB蛋白表达之间的关系。方法 :应用MTT比色法检测ADR对体外培养的MCF 7 S细胞增殖抑制作用 ,同时应用末端标记 (TUNEL)法观测ADR对MCF 7 S细胞凋亡程度的影响。采用免疫细胞化学法检测去磷酸化RB蛋白的表达水平。结果 :ADR抑制MCF 7 S细胞增殖呈剂量依赖性 ,半数抑制浓度 (IC50 )为0 .12 8mg·L-1;ADR作用组MCF 7 S细胞的凋亡率(apoptoticrate ,AR)为 0 .2 6 1,较对照组 (0 .0 4 5 )明显增高 (P <0 .0 1) ;ADR作用组MCF 7 S细胞的去磷酸化RB蛋白表达量MOD(阳性细胞平均光密度 )×area(阳性面积相对比 )均数是 987± 2 0 7,较对照组132± 32显著增高 (P <0 .0 1) ;ADR能促进MCF 7 S细胞内去磷酸化RB蛋白的表达。在ADR作用组 ,MCF 7 S细胞的凋亡率与去磷酸化RB蛋白表达量呈正相关 (P <0 .0 5 )。结论 :ADR抑制MCF 7 S细胞增殖和诱导MCF 7 S细胞凋亡可能与细胞内去磷酸化RB蛋白表达水平有关。     

甲基莲心碱对耐阿霉素人乳腺癌细胞凋亡抗性的影响

目的　探讨甲基莲心碱 (neferine ,Nef)对耐阿霉素人乳腺癌细胞 (MCF 7/Adr)凋亡抗性的影响及其机制。方法　应用Tunel法和PI染色流式细胞仪检测细胞凋亡 ,间接免疫荧光流式细胞仪检测P gp的表达 ,高效液相色谱法(HPLC)检测细胞内阿霉素 (ADR)的浓度。结果　①MCF 7/Adr细胞能耐受 5mg·L- 1 ADR诱导的凋亡 ,而 1 ,5 ,1 0μmol·L- 1 Nef可使 5mg·L- 1 ADR诱导的MCF 7/Adr细胞凋亡从 7 95 %分别增加至 2 1 3 % ,2 7 9% ,61 3 % ;② 1 0μmol·L- 1 Nef可使MCF 7/Adr细胞内ADR积累由 0 52 μg·(1 0 6 cells) - 1 增加到 1 50 μg·(1 0 6 cells) - 1 ;③ 1 0 μmol·L- 1Nef作用 2 4h后 ,MCF 7/Adr细胞P gp的表达明显下降。结论　甲基莲心碱能逆转MCF 7/Adr细胞的凋亡抗性 ,其作用机制可能与抑制P gp的功能和表达、增加ADR在MCF 7/Adr细胞内的积累有关     

人参皂甙-Rh2对人乳腺癌MCF7/AdrR细胞增殖和凋亡的影响

目的 研究人参皂甙-Rh2(GS-Rh2)对乳腺癌MCF7//AdrR细胞增殖和凋亡的影响.方法 以MCF7/AdrR细胞不加药物干预,作为对照组;以Rh2单独作用于MCF7/AdrR细胞,作为Rh2组;以低浓度阿霉素(ADM)单独作用于MCFT/AdrR细胞,作为ADM组;以Rh2和阿霉素联用于MCF7/AdrR细胞,作为Rh2+ADM组.用MTF比色法观察GS-Rh2对体外培养的MCF7//AdrR细胞生长的抑制作用;用荧光显微镜观察用药前后MCF7/AdrR细胞的形态学变化;用流式细胞仪检测凋亡细胞和细胞周期变化;用Western blot的方法检测Fas、Bax、Bcl-2及Bcl-xL蛋白表达的变化.结果 MCF7/AdrR细胞经GS-Rh2作用后,生长受抑制,呈剂量和时间依赖性;显微镜显示,经GS-Rh2作用后,MCF7/AdrR细胞呈较明显的凋亡形态学改变,GS-Rh2能将细胞周期阻滞于G0/G1期,同时可能参与促凋亡蛋白Fas、Bax表达升高及抑制凋亡蛋白Bcl-2表达降低;但在GS-Rh2处理前后Bcl-xL无明显变化.结论 GS-Rh2能抑制体外培养的MCF7/AdrR细胞增殖并诱导其凋亡,且这种作用可能是通过上调Fas、Bax表达、下调Bcl-2表达以及阻滞细胞周期而实现.     

杠柳苷元抑制人乳腺癌细胞增殖作用的研究

目的 观察杠柳苷元(periplogenin)对人乳腺癌细胞MCF7的抑制作用并考察其抑制作用的机理.方法 使用四氮唑盐(MTT)法测定杠柳苷元对MCF7细胞的增殖抑制效果,并使用蛋白免疫印迹法测定其中凋亡蛋白的表达.结果 杠柳苷元对MCF7细胞起到了明显的抑制作用,其抑制作用呈剂量依赖性,蛋白免疫印迹法也观察到杠柳苷元促进MCF7细胞内凋亡相关蛋白的表达,其表达呈时间依赖性.结论 杠柳苷元具有显著的体外抑制MCF7细胞增殖的作用,其抑制作用是通过促进MCF7细胞凋亡而发挥的.     

RNA干扰对乳腺癌细胞株MCF-7/Adr多药耐药性的逆转

目的研究小分子干扰RNA对乳腺癌耐药细胞株MCF7/Adr多药耐药性的逆转作用。方法设计针对mdrl基因的SiRNA,转染进MCF-7/Adr细胞;用荧光定量PCR检测mdrlmRNA的表达,流式细胞仪分析Pgp表达,MTT法检测阿霉素对MCF-7/Adr细胞的半数抑制浓度(IC50)。结果该SiRNA能使耐药细胞株MCF-7/Adr的mdrlmRNA和Pgp表达水平分别显著下调(P<0.01),并使阿霉素对MCF7/Adr的IC50显著降低(P<0.01)。结论RNA干扰可逆转乳腺癌MCF7/Adr细胞株的多药耐药性。     

甲基莲心碱对耐阿霉素人乳腺癌细胞内阿霉素积累的影响

目的　研究甲基莲心碱 (Nef)对耐阿霉素人乳腺癌细胞MCF 7/Adr内阿霉素 (ADM )积累的影响。方法　MTT法检测Nef对多药耐药性 (MDR)的逆转作用 ,高效液相色谱 (HPLC)法检测细胞内阿霉素浓度。结果　Nef能降低阿霉素对MCF 7/Adr细胞IC50 值 ,能提高MCF 7/Adr细胞内ADM的浓度。结论　Nef逆转MCF 7/Adr细胞多药耐药的机制与其增加多药耐药细胞内抗癌药物积累有关。     

载脂蛋白A-Ⅱ与阿霉素耐药的相关性研究

目的检测载脂蛋白A-Ⅱ(apolipoprotein A-Ⅱ,APOA-Ⅱ)与阿霉素(adriamycin,ADM)耐药的相关性。方法 IC_(50)分析细胞对ADM的敏感性;激光共聚焦检测MCF7/W细胞、MCF7/ADM细胞及APOA-Ⅱ高表达的MCF7/W细胞内ADM的分布;RT-PCR和Western blot分别检测MCF7/W和MCF7/ADM细胞内APOA-Ⅱ基因及蛋白的表达;IC_(50)分析高表达APOA-Ⅱ的HEK293细胞的药敏性以及高表达APOA-Ⅱ的乳腺癌细胞T47D、MDA-MB231的药敏性。结果MCF7/ADM细胞与MCF7/W细胞相比,耐药指数达13.0(P<0.05);MCF7/W细胞中的ADM在细胞核中大量聚集,而MCF7/ADM细胞中ADM则几无细胞核分布;同时,高表达APOA-Ⅱ蛋白的MCF7/W细胞,其细胞核中ADM的分布明显少于正常表达APOA-Ⅱ的MCF7/W细胞;MCF7/ADM细胞中APOA-Ⅱ的基因及蛋白表达水平均高于亲本细胞(P<0.05);转染了APOA-Ⅱ的HEK293细胞对ADM的敏感性明显降低(P<0.05);并且转染了APOA-Ⅱ的乳腺癌细胞T47D、MDA-MB231对ADM的药敏性也降低(P<0.05)。结论APOA-Ⅱ蛋白与乳腺癌ADM耐药相关,为临床ADM的化疗提供了一定的指导意义。     

黄癸素对三阴性乳腺癌MDA-MB-231细胞的体内外抑制作用

目的观察黄癸素对人三阴性乳腺癌(TNBC)细胞MDA-MB-231及其裸鼠模型肿瘤的抑制作用。方法采用MTT法观察黄癸素对乳腺癌细胞MCF-7及MDA-MB-231的增殖抑制作用;建立MDA-MB-231细胞裸鼠移植瘤模型,观察黄癸素灌胃给药对荷瘤的抑制作用。TUNEL法检测肿瘤组织中细胞凋亡状况。结果黄癸素可明显抑制MDA-MB-231细胞增殖,具有明显的浓度依赖性和时间依赖性,作用48h的IC50为(1.26±0.30)mg·L-1,而对MCF-7细胞的IC50则为(32.07±9.09)mg·L-1。在体实验结果显示,中、高剂量(90、120 mg·kg-1)黄癸素对MDA-MB-231细胞裸鼠移植瘤有明显的抑制作用,抑瘤率分别为42.26%和71.57%(P<0.01)。TUNEL法表明黄癸素组细胞凋亡率明显高于空白组。结论黄癸素有抑制人三阴性乳腺癌细胞MDA-MB-231肿瘤生长、促进瘤组织凋亡的作用。     

雷公藤甲素增加乳腺癌细胞对阿霉素敏感性的实验研究

目的探索雷公藤甲素对于人耐药乳腺癌细胞的抑制作用及其对阿霉素化疗敏感性的影响。方法体外培养阿霉素耐药乳腺癌细胞MCF-7/ADR细胞株,采用不同浓度的雷公藤甲素和阿霉素单药或联合用药处理。利用四甲基偶氮唑盐比色法(MTT法)检测各组细胞的增殖活性,利用流式细胞术检测各组细胞凋亡及细胞周期。结果雷公藤甲素可抑制阿霉素耐药乳腺癌癌细胞的增殖,且存在着明显的剂量-效应关系。与单独使用雷公藤甲素或者阿霉素相比,雷公藤甲素联合阿霉素组的细胞凋亡率明显增高。结论雷公藤甲素不仅能对耐药乳腺癌细胞的增殖产生抑制作用,同时也可以增强乳腺癌细胞对阿霉素化疗的敏感性。     

连花清瘟胶囊对乳腺癌MCF－7细胞增殖抑制与诱导凋亡作用的观察

目的：研究连花清瘟胶囊抗肿瘤的药理作用。方法应用MTT法检测连花清瘟胶囊对乳腺癌 MCF－7细胞增殖的抑制程度,AO／EB双荧光染色法检测细胞凋亡形态,DNA琼脂糖凝胶电泳观察细胞 DNA 片段。结果在浓度为200～2667μg? mL －1内,连花清瘟胶囊对乳腺癌MCF－7细胞的增殖有显著的抑制作用,其抑制作用随药物浓度的增加而增强,对MCF－7细胞增殖抑制率由10．50％增加到43．83％,与对照组比较呈显著差异性（P＜0．05vs正常组）。连花清瘟胶囊明显影响乳腺癌MCF－7细胞的染色质,发生固缩等凋亡形态的变化及细胞凋亡的 DNA梯带形状。结论连花清瘟胶囊具有抑制乳腺癌细胞增殖和诱导其凋亡的抗肿瘤的药理作用。     

Efficacy of gut lavage,hemodialysis, and hemoperfusion in the therapy of paraquat or diquat intoxication

Clinical and in vitro investigations were carried out to test the efficacy of gut lavage, hemodialysis, and hemoperfusion in the treatment of poisoning with paraquat or diquat. In a patient suffering from diquat intoxication 130 times more diquat was removed by gut lavage 30 h after ingestion than was removed by complete aspiration of the gastric contents.Determination of in vitro clearances for paraquat and diquat by hemodialysis showed that, at serum concentrations of 1–2 ppm, such as are frequently encountered in poisoning in man, toxicologically relevant quantities of herbicide cannot be removed from the body. At a concentration of 20 ppm, on the other hand, hemodialysis proved to be effective, the clearance being 70 ml/min at a blood flow rate of 100 ml/min. The efficacy of hemoperfusion with coated activated charcoal was on the whole better. Especially at concentrations around 1–2 ppm, the clearance values for hemoperfusion were some 5–7 times higher than those for hemodialysis.In a patient suffering from paraquat poisoning, both hemodialysis as well as hemoperfusion were carried out. The in vitro results could be confirmed: At serum concentrations of paraquat less than 1 ppm no clearance could be obtained by hemodialysis while by hemoperfusion with activated charcoal quite high clearance values were measured and the serum level dropped down to zero.

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Zusammenfassung Klinische Untersuchungen und Laboratoriumsversuche wurden durchgeführt, um die Wirksamkeit von Darmspülung, Hämodialyse und Hämoperfusion bei Paraquat- und Deiquat-Vergiftungen zu prüfen.Bei einem Patienten wurde 30 Std nach Deiquat-Aufnahme durch Darmspülung 130mal mehr Deiquat entfernt als durch vollständige Aspiration des Mageninhaltes. In vitro-Versuche ergaben, daß bei Blutserumkonzentrationen von 1–2 ppm, die bei Vergiftungen oft gemessen werden, durch Hämodialyse keine toxikologisch relevanten Paraquat- oder Deiquat-Mengen entfernt werden können. Dagegen erwies sich die Hämodialyse bei 20 ppm und einer Blutumlaufgeschwindigkeit von 100 ml/min mit einer Clearance von 70 ml/min als wirksam. Die Hämoperfusion mit beschicheter Aktivkohle war in diesen Versuchen aber eindeutig überlegen, denn insbesondere bei Konzentrationen um 1–2 ppm waren die Clearance-Werte 5–7mal höher als bei der Hämodialyse.Die in vitro-Ergebnisse wurden bei einem Patienten mit einer Paraquat-Vergiftung bestätigt: Bei Konzentrationen unter 1 ppm war die Hämodialyse wirkungslos, während durch Hämoperfusion relativ hohe Clearance-Werte erreicht wurden, so daß der Serumspiegel rasch unter die Nachweisgrenze abfiel.

     

In vitro studies on sterically stabilized liposomes (SL) as enzyme carriers in organophosphorus (OP) antagonism

This study describes a new approach for organophosphorous (OP) antidotal treatment by encapsulating an OP hydrolyzing enzyme, OPA anhydrolase (OPAA), within sterically stabilized liposomes. The recombinant OPAA enzyme was derived from Alteromonas strain JD6. It has broad substrate specificity to a wide range of OP compounds: DFP and the nerve agents, soman and sarin. Liposomes encapsulating OPAA (SL)* were made by mechanical dispersion method. Hydrolysis of DFP by (SL)* was measured by following an increase of fluoride ion concentration using a fluoride ion selective electrode. OPAA entrapped in the carrier liposomes rapidly hydrolyze DFP, with the rate of DFP hydrolysis directly proportional to the amount of (SL)* added to the solution. Liposomal carriers containing no enzyme did not hydrolyze DFP. The reaction was linear and the rate of hydrolysis was first order in the substrate. This enzyme carrier system serves as a biodegradable protective environment for the recombinant OP-metabolizing enzyme, OPAA, resulting in prolongation of enzymatic concentration in the body. These studies suggest that the protection of OP intoxication can be strikingly enhanced by adding OPAA encapsulated within (SL)* to pralidoxime and atropine.     

Aquatic Insects and Trace Metals: Bioavailability,Bioaccumulation, and Toxicity

Abstract

The uptake of metals from food and water sources by insects is thought to be additive. For a given metal, the proportions taken up from water and food will depend both on the bioavailable concentration of the metal associated with each source and the mechanism and rate by which the metal enters the insect. Attempts to correlate insect trace metal concentrations with the trophic level of insects should be made with a knowledge of the feeding relationships of the individual taxa concerned. Pathways for the uptake of essential metals, such as copper and zinc, exist at the cellular level, and other nonessential metals, such as cadmium, also appear to enter via these routes. Within cells, trace metals can be bound to proteins or stored in granules. The internal distribution of metals among body tissues is very heterogeneous, and distribution patterns tend to be both metal and taxon specific. Trace metals associated with insects can be both bound on the surface of their chitinous exoskeleton and incorporated into body tissues. The quantities of trace meals accumulated by an individual reflect the net balance between the rate of metal influx from both dissolved and particulate sources and the rate of metal efflux from the organism. The toxicity of metals has been demonstrated at all levels of biological organization: cell, tissue, individual, population, and community. Much of the literature pertaining to the toxic effects of metals on aquatic insects is based on laboratory observations and, as such, it is difficult to extrapolate the data to insects in nature. The few experimental studies in nature suggest that trace metal contaminants can affect both the distribution and the abundance of aquatic insects. Insects have a largely unexploited potential as biomonitors of metal contamination in nature. A better understanding of the physico-chemical and biological mechanisms mediating trace metal bioavailability and exchange will facilitate the development of general predictive models relating trace metal concentrations in insects to those in their environment. Such models will facilitate the use of insects as contaminant biomonitors.     

Steroidal sapogenin contents in some domestic plants

In order to find out the values of the steroid resources for the future use. the compositions and contents of steroidal sapogenins from 13 domestic plants have been investigated. As a result,Dioscorea nipponica, D. quinqueloba andSmilax china were found to have large amount of diosgenin. And pennogenin inTrillium kamtschaticum andParis verticillata, yuccagenin inAllium fistulosum, hecogenin inAgave americana and neochlorogenin inSolanum nigum were appeared to be major steroidal sapogenins.     

Alzheimer’s disease – current trends in basic and clinical research. Highlights from the 16th ECNP

Advances in the molecular biological knowledge of neuronal nicotinic acetylcholine receptors (nAChRs) have led to a growing interest by the pharmaceutical industry in the development of novel compounds that selectively modulate nAChR function. The ability of (-)-nicotine, an activator of nAChRs, to enhance attentional aspects of cognition in animals and humans, to exert neuroprotective and anxiolytic-like effects, and presumably to mediate the negative correlation between smoking and Alzheimer's (and Parkinson's) Disease, has focused interest on the potential therapeutic utility of modulators of nAChR function for treatment of some of the deficits associated with these progressive, neurodegenerative conditions. Numerous compounds are known which activate nAChRs and which might serve as lead compounds toward the development of such agents. The pharmacologic diversity of neuronal nAChR subtypes suggests the possibility of developing selective compounds which would have more favourable side-effect profiles than existing agents. This broader class of agents, collectively called cholinergic channel modulators (ChCMs), is anticipated to encompass compounds which would have more favourable side-effect profiles than existing agents, which generally exhibit low selectivity. This selectivity may be achieved by preferentially activating some subtypes of nAChRs (i.e., Cholinergic Channel Activators, ChCAs) or inhibiting the function of other subtypes (Cholinergic Channel Inhibitors, ChCIs). An overview of the biology of nAChRs and the rationale for the use of ChCMs for the treatment of dementia related to neurodegenerative diseases are presented, followed by a discussion of lead compounds and compounds under consideration for clinical evaluation.