熊果酸对HL60细胞作用机制的初步研究

目的探讨熊果酸在体外对急性早幼粒白血病HL60细胞增殖抑制和诱导凋亡作用。方法采用体外细胞培养技术,荧光显微镜观察细胞结构变化、MTT法观察细胞生长抑制作用、流式细胞仪检测细胞凋亡及周期变化。结果 MTT法证实熊果酸对HL60细胞具有增殖抑制和杀伤效应,并呈浓度和时间依赖性。显微镜下可见HL60细胞出现典型凋亡细胞形态学改变。流式细胞仪检测细胞周期阻滞于G0/G1期。结论熊果酸在体外可抑制急性早幼粒白血病HL60细胞增殖,诱导细胞凋亡。     

通关藤诱导白血病细胞U937,HL60细胞凋亡的实验研究

目的探讨通关藤抑制白血病细胞增殖作用及其机制。方法以不同浓度的通关藤提取物制剂处理白血病细胞U937、HL60,1~5 d,以四甲基偶氮唑盐(MTT)法检测对细胞增殖的影响,以Annexin V/PI双染法检测细胞的凋亡程度,Western blot检测凋亡相关蛋白caspase3,PARP改变,以JC-1染色法检测线粒体跨膜电位(ΔΨm)水平。结果通关藤提取物制剂呈时间和剂量依赖性抑制U937、HL60细胞增殖,50μL/mL时能明显降低线粒体跨膜电位(ΔΨm),活化caspase 3,剪切PARP,诱导细胞凋亡。结论通关藤提取物制剂对U937、HL60白血病细胞有显著的抑制和诱导凋亡作用,能通过降低线粒体跨膜电位途径触发白血病细胞凋亡。     

毛兰素诱导人白血病HL—60细胞的凋亡

目的：研究毛兰素对HL－60细胞增殖的抑制作用,探讨其诱导细胞凋亡的机制。方法：用MTT比色法测定了毛兰素对HL－60细胞增殖的抑制作用：应用荧光显微镜、透射电镜、DNA电泳及流式细胞仪观察了药物对细胞凋亡的诱导作用,并用免疫组化的方法从基因水平阐述了凋亡的发生。结果：毛兰素20－81．9nmol/L在72h内显著抑制HL－60细胞增殖,作用24h后,对HL－60细胞的IC50为38nmol/L,而阳性对照药长春新碱对HL－60细胞的IC50为101nmol/L,前者明显优于后者;形态学观察可见凋亡的特征性改变;琼脂糖电泳出现典型的DNA“ladder”;流式细胞仪结果表明细胞被阻滞于G2／M期;免疫组化可见bcl-2表达下降,bax表达升高。结论：毛兰素显著抑制HL－60细胞的生长,该抑制作用可能是通过诱导细胞凋亡和改变HL－60细胞bcl-2和bax基因的表达而实现的。     

熊果酸对HL-60细胞株凋亡及Bcl-2和bax表达的影响

目的探讨熊果酸(UA)抑制人急性髓性白血病细胞系(HL-60)细胞增殖和诱导凋亡作用,并观察Bcl-2和bax基因表达的影响。方法体外培养HL-60细胞。MTT比色法检测增殖活性;流式细胞术(FCM)检测细胞凋亡和细胞周期分布;Western Blot分析Bcl-2和bax基因表达。结果 UA显著抑制HL-60细胞增殖,呈浓度依赖性;UA呈浓度依赖性诱导HL-60细胞凋亡,明显阻滞于细胞周期G1期;UA以浓度依赖方式下调Bcl-2蛋白表达和上调bax蛋白表达。结论 UA抑制HL-60细胞增殖和诱导凋亡,其作用机制与下调Bcl-2上调bax蛋白表达相关。     

鱼腥草黄酮提取物对肿瘤细胞的抑制作用

目的研究鱼腥草黄酮类提取物在体外对人白血病细胞HL60、小鼠黑色素瘤细胞株B16BL6增殖抑制和凋亡的影响.方法(1)采用纯化水回流提取,大孔树脂分离的方法提取鱼腥草中黄酮类化合物;(2)应用MTT法检测黄酮类化合物对HL60和B16BL6肿瘤细胞株的细胞抑制率;(3)采用FCM法检测其对肿瘤细胞凋亡的影响.结果(1)鱼腥草黄酮提取物有抑制HL60和B16BL6细胞生长的作用,50%增值抑制浓度值分别为0.410,0.122 g·L-1,(2)鱼腥草黄酮提取物能诱导HL60和B16BL6细胞的凋亡.结论鱼腥草黄酮提取物能抑制HL60和B16BL6肿瘤细胞生长,具诱导凋亡的作用,为鱼腥草的抗肿瘤效应提供实验依据.     

消瘤平体外诱导人白血病HL-60细胞凋亡及机制研究

目的研究消瘤平对人白血病细胞增殖的抑制及诱导凋亡的作用,揭示其抗白血病的部分作用机制。方法体外常规培养HL-60细胞,以不同浓度的消瘤平作用于细胞,MTT法检测细胞生长抑制率;流式细胞术检测凋亡率和细胞周期;ELISA法检测培养上清液中Caspase-3、Fas和Bcl-2的含量。结果与空白对照组相比,作用24 h后,消瘤平显著抑制HL-60细胞的增殖,且呈时间和剂量依赖性;提高HL-60细胞的凋亡率,并诱导出现G2-M细胞周期阻滞;消瘤平作用48 h后,Caspase-9和Fas蛋白表达量增加,Bcl-2表达减少。结论消瘤平抑制人白血病HL-60细胞的作用机制与阻滞细胞周期于G2-M期和诱导细胞凋亡有关,其诱导凋亡作用可能通过上调Caspase-9、Fas和下调Bcl-2而实现。     

三丁酸甘油酯对白血病细胞株HL-60体外作用的研究

目的探讨三丁酸甘油酯(TB)对白血病细胞株HL-60细胞增殖的抑制作用,并对其作用机制进行初步探讨。方法采用MTT法观察细胞增殖变化。应用免疫组化检测抑癌基因P16的表达。应用流式细胞仪观察细胞周期的改变。通过DNA电泳观察细胞凋亡。结果TB可以抑制细胞增殖。1.0 mmol/L的TB作用72 h,有典型的DNA梯形条带。细胞周期阻滞在G0/G1期。结论TB能抑制HL-60细胞增殖,诱导细胞凋亡,其机制可能与上调P16表达有关。     

孤啡肽对HL-60细胞增殖及凋亡的影响

目的研究孤啡肽对白血病细胞株HL-60细胞增殖及凋亡的影响。方法选择人急性早幼粒细胞白血病细胞株HL-60为实验模型,应用MTT比色法、形态学观察及流式细胞术(FCM)等方法对孤啡肽诱导其凋亡情况进行研究。结果孤啡肽能显著抑制HL-60细胞增殖,使细胞周期阻滞于G_0/G_1期,细胞凋亡率增加,FCM DNA直方图上G_0/G_1峰前有明显的亚二倍体凋亡峰,表明孤啡肽能明显抑制HL-60细胞的生长,诱导其发生凋亡,且存在时间依赖性,而剂量依赖性不明显。结论孤啡肽对HL-60细胞有增殖抑制和诱导凋亡作用。     

蚯蚓提取物体内和体外抗肿瘤作用的研究

目的探讨蚯蚓提取物对Eca-109、Hella、K562细胞的生长抑制作用及机制。方法应用四甲基偶氮唑盐(MTT)比色分析,流式细胞仪测定细胞凋亡、细胞周期及观察小鼠体内肿瘤体积和重量。结果蚯蚓提取物Ⅰ,Ⅱ,Ⅲ中只有成分Ⅱ的高、中剂量(900,450 mg/L)对Eca-109、Hella、K562细胞有明显的抑制作用。体内300,600 mg/L灌胃小鼠对肿瘤有明显的抑制作用。Hella细胞检测有凋亡细胞出现,细胞周期检测,细胞被阻滞在G0-G1期,DNA合成受阻故使肿瘤细胞受抑制,肿瘤体积缩小。结论蚯蚓提取物Ⅱ对肿瘤细胞增殖有明显的抑制作用,主要通过细胞凋亡和肿瘤细胞受阻于G0-G1期,使DNA合成减少。     

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.     

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.     

Synthesis,Cytotoxicity and Antileishmanial Activity of Some N-(2-(indol-3-yl)ethyl)-7-chloroquinolin-4-amines

We report herein the condensation of 4,7-dichloroquinoline (1) with tryptamine (2) and D-tryptophan methyl ester (3) . Hydrolysis of the methyl ester adduct (5) yielded the free acid (6) . The compounds were evaluated in vitro for activity against four different species of Leishmania promastigote forms and for cytotoxic activity against Kb and Vero cells. Compound (5) showed good activity against the Leishmania species tested, while all three compounds displayed moderate activity in both Kb and Vero cells.     

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.