细胞保护作用是抗抑郁剂作用的共同通路之一

目的：探讨抗抑郁剂可能的共同作用机制。方法：以MTT比色法检测细胞活性状态;以Fura 2-AM荧光标记法测定胞内Ca^2 浓度：以RT-PCR法检测神经生长因子(NGF)mRNA水平。结果：以高浓度皮质酮0．2mmol/L处理PC12细胞48h以模拟抑郁症脑神经细胞损伤状态,发现目前三类经典抗抑郁剂,包括三环抗抑郁剂地昔帕明(DIM)0．625—10μmol／L,5-HT重摄取抑制剂氟西丁(FLU)0．625—10μmol／L,单胺氧化酶A抑制剂马氯贝胺(MOC)2．5—40μmol／L对皮质酮损伤的PC12细胞具有显著的保护作用,而抗精神病药氯丙嗪和抗焦虑药地西泮无此作用、DIM1,5μmol/L或FLU1,5μmol/L几显著减弱皮质酮0．1mmol／L处理PC12细胞48h诱导的胞内Ca^2 超载,进一步研究发现,DIM或FLU 10μmol／L处理PC12细胞48h显著提高NGF mRNA的表达水平。结论：尽管各类抗抑郁剂结构迥异,但细胞保护作用可能是其共同作用通路,而减弱胞内Ca^2 超载和提高NGF等神经营养因子的表达是抗抑郁药的细胞保护作用机制之一。     

A study on Se-methylseienocysteine inducing hepatocellular carcinoma cell apoptosis and its mechanism

目的 研究硒-甲基硒代半胱氨酸(MSC)对肝癌SMMC-7721细胞株抑制及凋亡的作用,探讨其分子机制.方法 试验分空白对照组和MSC组(细胞培养体系中加入MSC).MTT法观察细胞增殖;流式细胞术检测细胞周期及凋亡率;透射电镜观察细胞超微结构的改变;琼脂糖凝胶电泳法观察DNA的“梯状”条带;Western blot方法检测凋亡诱导因子(AIF)蛋白表达.结果 随着MSC浓度和作用时间增加,细胞抑制率上升.肝癌细胞株SMMC-7721在MSC浓度为25、30、100、200μmol/L下,24 h细胞抑制率分别为(14.44±3.83)％、(21.15±0.61)％、(50.61±2.10)％、(64.25±0.87)％,48 h细胞抑制率分别为(35.97±2.08)％、(57.41±2.61)％、(74.71±1.59)％、(91.68±1.33)％(P＜0.05).MSC组细胞周期出现S期阻滞,并出现凋亡峰,50、l00μmol/L浓度的MSC干预48 h后,肝癌SMMC-7721细胞株凋亡率分别为28.46％、50.73％.MSC组细胞呈凋亡表现,核固缩、碎裂,染色质浓缩,边集.MSC 50μmol/L或100 μmol/L组培养48h后,DNA琼脂糖凝胶电泳可见典型的梯状条带;而空白对照组细胞DNA在电泳上未见梯状条带.经MSC干预后,AIF蛋白表达呈浓度依赖性增多(P＜0.05).结论 MSC对肝癌MMC-7721细胞株有抑制增殖、促进凋亡的作用.其机制可能通过调控AIF表达激活非Caspases依赖凋亡通路实现的.     

硒-甲基硒代半胱氨酸诱导肝癌SMMC-7721细胞株的凋亡及机制探讨

目的研究硒-甲基硒代半胱氨酸(MSC)对肝癌SMMC-7721细胞株抑制及凋亡的作用,探讨其分子机制。方法试验分空白对照组和MSC组(细胞培养体系中加入MSC)。MTT法观察细胞增殖;流式细胞术检测细胞周期及凋亡率;透射电镜观察细胞超微结构的改变;琼脂糖凝胶电泳法观察DNA的"梯状"条带;Western blot方法检测凋亡诱导因子(AIF)蛋白表达。结果随着MSC浓度和作用时间增加,细胞抑制率上升。肝癌细胞株SMMC-7721在MSC浓度为25、50、100、200μmol/L下,24h细胞抑制率分别为(14.44±3.83)%、(21.15±0.61)%、(50.64±2.40)%、(64.25±0.87)%,48h细胞抑制率分别为(35.97±2.08)%、(57.41±2.61)%、(74.71±1.59)%、(91.68±1.33)%(P<0.05)。MSC组细胞周期出现S期阻滞,并出现凋亡峰,50、100μmol/L浓度的MSC干预48h后,肝癌SMMC-7721细胞株凋亡率分别为28.46%、50.73%。MSC组细胞呈凋亡表现,核固缩、碎裂,染色质浓缩,边集。MSC 50μmol/L或100μmol/L组培养48h后,DNA琼脂糖凝胶电泳可见典型的梯状条带;而空白对照组细胞DNA在电泳上未见梯状条带。经MSC干预后,AIF蛋白表达呈浓度依赖性增多(P<0.05)。结论 MSC对肝癌MMC-7721细胞株有抑制增殖、促进凋亡的作用。其机制可能通过调控AIF表达激活非Caspases依赖凋亡通路实现的。     

姜黄素对Aβ25-35诱导去血清培养PC12细胞周期变化与凋亡的影响

目的：探讨姜黄素（Curcumin，Cur）对β-淀粉样肽（25—35）[βamyloid peptide-（25-35），Aβ25-35]诱导体外去血清培养的PC12细胞周期变化与细胞凋亡的影响。方法：种人培养瓶或板的PC12细胞贴壁后用常用的去血清培养法使细胞同步于G0期，用MTT比色法分析细胞存活率；流式细胞仪检测分析细胞周期的改变与凋亡的时间关系，Hoechst33258-PI荧光染色观察细胞核凋亡的形态学改变；DNA电泳观察细胞凋亡时特异性梯状条带（DNA—Ladder）；结果（1）用终浓度分别为0～20μmol／L的姜黄素（Cur）处理去血清培养PC12细胞24h，     

山楂叶总黄酮对H_2O_2诱导PC12细胞凋亡的保护作用

目的探讨山楂叶总黄酮(FMCL)对H2O2诱导的PC12细胞凋亡的保护作用及机制。方法用H2O2刺激PC12细胞使其发生凋亡,MTT法检测PC12细胞活性,倒置显微镜观察细胞生长状况和形态变化,琼脂糖凝胶电泳观察DNA梯状图谱,流式细胞仪检测PC12细胞亚二倍体比率及线粒体膜电位的变化。结果与模型组比较FMCL 100、30mg.L-1两组PC12细胞活性增强,贴壁生长数量增多,而圆缩脱落者减少,未见典型DNA梯状图谱,凋亡比率下降,线粒体膜电位回升,且在一定范围内存在剂量依赖关系。结论山楂叶总黄酮可抑制H2O2诱导的PC12细胞凋亡,其机制可能与抑制线粒体途径的细胞凋亡有关。     

槲皮素诱导人白血病HL-60细胞凋亡(英文)

目的:研究槲皮素是否能诱导人白血病HL-60细胞凋亡.方法:应用琼脂糖凝胶电泳法观察DNA碎片;采用流式细胞仪检测DNA断裂;电镜技术观察凋亡的形态学改变,用MTT测定法测定细胞增殖.结果:槲皮素15-120 μmol·L~(-1)诱导HL-60细胞凋亡,电镜观察到典型的形态学改变,电泳显示梯状条带,槲皮素能剂量依赖性地触发DNA降解及抑制细胞增生(IG_(50)和95％可信区间分别为43(30-61)μmol·L~(-1).结论:槲皮素诱导人白血病HL-60细胞凋亡.     

天麻素通过抑制细胞凋亡保护谷氨酸诱导的PC12细胞损伤

目的：研究天麻素（Gastrodin）对谷氨酸诱导的大鼠肾上腺嗜铬细胞瘤PC12细胞损伤的影响及可能机制。方法：以谷氨酸建立体外培养PC12细胞损伤模型并采用MTT比色法测定细胞存活率;AO/EB双染法经荧光显微镜观察细胞凋亡形态;采用流式细胞术检测细胞内活性氧含量以及Annexin V/PI染色后的细胞凋亡率;Western blot法检测细胞内Caspase-3蛋白表达。结果：天麻素可明显抑制谷氨酸诱导的PC12细胞凋亡,在0.1～10μmol/L剂量呈一定的量效关系;同时,天麻素可明显抑制谷氨酸引起的活性氧（ROS）的累积,降低谷氨酸诱导的活性Caspase-3蛋白的表达,降低PC12细胞的凋亡率,在0.1～10μmol/L剂量呈量效相关性。结论：在一定剂量范围内,天麻素对谷氨酸损伤的PC12细胞具有保护作用,其机制可能与减少ROS的生成,阻止氧化损伤的发生,抑制Caspase-3途径依赖的细胞凋亡相关。     

一氧化氮诱导PC12细胞凋亡及芍药苷的保护作用

目的:探讨一氧化氮诱导PC12细胞凋亡及芍药苷保护作用的可能机制.方法:MTT和乳酸脱氢酶活性测定细胞存活率,DNA凝胶电泳观察DNA的断裂情况,流式细胞仪测定细胞凋亡率、检测线粒体跨膜电位.结果:500 μmol·L-1 硝普钠(SNP)可诱导PC12细胞凋亡,细胞线粒体跨膜电位明显下降.预先经过 0.1、1和10 μmol·L-1 等浓度芍药苷处理后, SNP诱导的PC12细胞凋亡明显减少,同时明显减弱一氧化氮对线粒体跨膜电位的影响.结论:芍药苷可抑制一氧化氮诱导PC12细胞凋亡,其作用机制可能与其稳定细胞线粒体跨膜电位有关.     

曲格列酮对白血病NB4细胞的增殖抑制作用及其作用机制

目的:探讨过氧化物酶体增殖物激活受体γ(PPARγ)激动剂曲格列酮(troglitazone,TGZ)对白血病NB4细胞的增殖抑制作用及其作用机制。方法:以不同浓度的TGZ(0～80μmol/L)作用于体外培养的NB4细胞0、24、48、72h,应用MTT法检测细胞生长抑制率,Hoechst33258染色法检测细胞凋亡,琼脂糖凝胶电泳观察细胞凋亡时的DNA梯状条带。用免疫印迹法(Western Blot)检测Caspase-3及其裂解底物多聚(ADP-核糖)聚合酶PARP[(poly(ADP-ribose)polymerase)]表达水平的变化,并对凋亡调节蛋白Bax及Bcl-2的表达水平进行检测。结果:20μmol/L以上的TGZ可显著抑制细胞的生长,在Hoechst染色后可见典型的细胞凋亡现象,并呈现出明显的量-效与时-效关系,药物作用72h后在琼脂糖凝胶电泳上可见明显的DNA梯状条带。WesternBlot检测结果表明,Caspase-3被活化出现20000的亚单位,同时PARP被裂解出现89000的亚单位片段。药物作用48h后凋亡抑制蛋白Bcl-2的表达水平明显降低,而促凋亡蛋白Bax的表达水平显著升...     

木豆素A对皮质酮诱导的PC12细胞损伤的保护作用

利用皮质酮诱导PC12细胞损伤模型,研究木豆素A对皮质酮诱导的PC12细胞的保护作用并探讨相应的保护途径。采用100μmol.L1皮质酮与PC12细胞作用48 h,诱导PC12细胞损伤,然后与不同浓度的木豆素A孵育24 h。检测细胞存活率、LDH渗漏量、细胞内Ca2+浓度及caspase-3活性。结果显示,PC12细胞与皮质酮孵育48 h后细胞存活率明显降低,而LDH漏出量、细胞内Ca2+浓度及caspase-3活性均显著升高;木豆素A(4.0、8.0及16.0μmol.L1)具有改善作用,但量效关系不明显。研究表明,木豆素A对皮质酮诱导的PC12细胞损伤具有明显的保护作用,其保护作用可能是通过降低Ca2+浓度及caspase-3活性来实现的。     

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.     

Pharmacological treatment of COVID-19: an opinion paper

The precocity and efficacy of the vaccines developed so far against COVID-19 has been the most significant and saving advance against the pandemic. The development of vaccines has not prevented, during the whole period of the pandemic, the constant search for therapeutic medicines, both among existing drugs with different indications and in the development of new drugs. The Scientific Committee of the COVID-19 of the Illustrious College of Physicians of Madrid wanted to offer an early, simplified and critical approach to these new drugs, to new developments in immunotherapy and to what has been learned from the immune response modulators already known and which have proven effective against the virus, in order to help understand the current situation.     

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.