平律复方抗实验性心律失常的作用

目的 研究平律复方（PL，由苦参、豆根、麦冬、五味子、甘草、党参等组成）抗实验性心律失常的作用及机制。方法 采用氯仿、氯化钙及心肌缺血再灌注三种心律失常动物模型，监测标准11导联心电图；测定缺血再灌注大鼠血清肌酸激酶（CK）和乳酸脱氢酶（LDH）活性；放射配基受体结合法分析心肌血小板激活因子（platelet activating factor，PAF）受体蛋白表达水平；RT—PCR法检测PAF受体mRNA表达水平；测定心肌脂质过氧化产物丙二醛（MDA）含量和超氧化物歧化酶（SOD）活性。     

甘草酸二铵对大鼠心肌缺血再灌注损伤脂质过氧化及心肌酶活性的影响

目的:观察甘草酸二铵(DG)对大鼠心肌缺血再灌注损伤脂质过氧化及心肌酶活性的影响。方法:雄性wistar大鼠30只,随机分为假手术组、缺血再灌注组和DG20mg·kg-1组。每组10只。采用在体大鼠心肌缺血30min再灌注60min损伤模型,再灌注60min后分别用比色法测定心肌丙二醛(MDA)含量、超氧化物歧化酶(SOD)、三磷酸腺苷酶(ATP酶)、血清磷酸肌酸激酶(CPK)和乳酸脱氢酶(LDH)水平,并用酶组织化学方法检测心肌组织琥珀酸脱氢酶(SDH)的活性。结果:DG能显著降低心肌组织中MDA含量和SDH的活性(P<0.05,P<0.01),提高SOD和ATP酶活性(P<0.05,P<0.01),并减少心肌CPK和LDH的释放(P<0.05,P<0.01)。结论:DG具有保护大鼠心肌缺血再灌注损伤的作用,其作用机理可能与其降低心肌脂质过氧化,增强心肌细胞SOD、SDH和ATP酶活性有关。     

安心颗粒抗心律失常及心肌缺血的作用研究

目的研究安心颗粒对心律失常和心肌缺血的改善作用。方法制备氯化钙、氯仿和乌头碱所致的小鼠心律失常模型及异丙肾上腺素（ISO）引起的小鼠心肌缺血模型,经安心颗粒治疗后,通过观察室颤发生率和心动过速的发生时间等指标评价其抗心律失常作用;通过检测血清超氧化物歧化酶（SOD）、脂质过氧化产物丙二醛（MDA）、乳酸脱氢酶（LDH）和磷酸肌酸激酶（CK）等指标评价其改善心肌缺血的作用。结果安心颗粒可降低氯仿诱发小鼠的室颤发生率;延迟氯化钙引起大鼠室性心动过速的发生时间;提高大鼠对乌头碱的耐受剂量。在ISO所致心肌缺血模型中,安心颗粒可增加SOD的活性,减少MDA的含量,降低血清LDH、CK的水平。结论安心对氯仿、氯化钙和乌头碱引起的心率失常及ISO引起的心肌缺血均有较好的改善作用。     

葡萄糖酸锌对大鼠缺血再灌注损伤心肌细胞凋亡和细胞超微结构的影响

目的观察心肌缺血再灌注损伤过程中心电图变化,肌酸激酶（CK）和乳酸脱氢酶（LDH）活性,细胞凋亡和心肌细胞超微结构的变化,分析葡萄糖酸锌对心肌的保护作用及其可能机制。方法建立大鼠在体心肌缺血再灌注损伤模型。用心电监测心律失常发生率、比色法测定血清中CK,LDH、流式细胞仪检测细胞凋亡和电镜观察心肌细胞超微结构。结果与模型组相比,葡萄糖酸锌三个不同剂量组大鼠心律失常发生率、血清中CK和LDH活性、细胞凋亡指数降低（P〈0.01）,心肌细胞超微结构损伤明显减轻。结论葡萄糖酸锌对缺血再灌注损伤心肌具有保护作用,可能与其抑制细胞凋亡和减轻心肌细胞超微结构病理改变有关。     

原花青素对大鼠心肌缺血再灌注损伤的保护作用

目的：观察原花青素（procyanidin,PC）对大鼠心肌缺血再灌注损伤的保护作用，方法：结扎大鼠冠状动脉左前降支（LAD）40min，复灌120min后复制出大鼠心肌缺血再灌注损伤模型，观察PC对大鼠心肌酶学，心梗面积和脂质过氧化的影响。结果：PC能减少心肌细胞磷酸肌酶激酶（CPK）和乳酸脱氢酶（LDH）的释放，明显缩小心肌梗死面积，能显提高大鼠血清和心肌组织中超氧化物歧化酶（SOD）活性，降低心肌和血清脂质过氧化代谢产物丙二醛（MDA）含量，结论：PC对大鼠心肌缺血再灌注损伤有保护作用，其机制可能与清除自由基，抑制脂质过氧化反应有关。     

三羟异黄酮对大鼠心肌缺血-再灌注损伤的保护作用

目的 观察三羟异黄酮（GST）对大鼠心肌缺血-再灌注损伤（IRI）的影响, 并探讨其机制. 方法 应用大鼠心肌缺血 再灌注模型, 观察GST对再灌注心律失常的影响, 并测定其血清乳酸脱氢酶（LDH）活性、磷酸肌酸激酶（CK）活性、丙二醛（MDA）含量和超氧化物岐化酶（SOD）活性. 结果 GST能显著降低再灌注心律失常的发生率, 降低室颤发生率, 缩短心律失常持续时间, 降低血清LDH、CK 、MDA的含量, 提高血清SOD的活性. 结论 GST能抑制IRI过程中心肌电活动紊乱, 对心肌有明显的保护作用, 其机制之一可能与其提高抗氧化酶活性, 减少脂质过氧化反应, 保护细胞的结构完整性有关.     

金纳多对大鼠心肌缺血再灌注损伤的保护作用

目的观察金纳多对心肌缺血再灌注损伤的保护作用。方法采用在体大鼠结扎冠状动脉前降支10min后,松扎再灌注30min造成心肌缺血再灌注模型,计算心肌梗死范围(MIS),测定血清磷酸肌酸激酶(CK)、乳酸脱氢酶(LDH)、超氧化物歧化酶(SOD)、丙二醛(MDA)含量,观察心律失常发生情况。结果金纳多对心肌缺血10min再灌注损伤30min大鼠,可明显缩小MIS,降低血清CK、LDH活性和MDA含量,提高SOD活性,降低心律失常的发生率。结论金纳多对大鼠心肌缺血再灌注损伤具有保护作用。     

1-肉桂基-4-(2,3,4-三甲氧基苄基)-四氢吡嗪盐酸盐对大鼠心肌缺血再灌性心律失常的保护作用

采用整体大鼠心肌缺血再灌注模型，观察1-肉桂基-4-(2,3,4-三甲氧基苄基)-四氢吡嗪盐酸盐（CTTP）对缺血再灌性心律失常的保护作用. 于结扎前3 min, CTTP 2.5或5 mg·kg^-1 iv，可显著降低缺血再灌损伤引起的室性心律失常发生率，缩短持续时间；能明显减少心肌谷草转氨酶，肌酸激酶和乳酸脱氢酶释放量；升高超氧化物歧化酶活性，减少脂质过氧化反应代谢产物丙二醛含量. 提示CTTP抗心肌缺血再灌注心律失常的作用，可能与降低心肌脂质过氧化和增强氧自由基清除酶的活性有关.     

青钱柳多糖对大鼠心肌缺血再灌注损伤的保护作用

目的:探讨青钱柳多糖对大鼠心肌缺血再灌注损伤(MIRI)的保护作用。方法:将50只Wistar大鼠随机分为5组,即假手术组、对照组、青钱柳多糖低剂量组(100 mg·kg^-1)、青钱柳多糖中剂量组(200 mg·kg^-1)、青钱柳多糖高剂量组(400 mg·kg^-1)。连续给药7 d,在末次给药1 h后,对大鼠的冠状动脉左前降支进行结扎手术以复制心肌缺血再灌注损伤模型。检查各组大鼠的心脏功能,并测定血清中肌酸激酶(CK)、乳酸脱氢酶(LDH)和心肌组织中超氧化物歧化酶(SOD)的活性以及丙二醛(MDA)的含量。同时,利用TTC染色法对各组大鼠心肌梗死范围进行测定。结果:与对照组比较,青钱柳多糖能使大鼠心脏的收缩功能得到明显恢复,大幅降低血清中CK和LDH的水平及心肌组织中MDA含量,提高心肌组织中SOD的活性,并有效降低心肌梗死范围(差异均有统计学意义P<0.05)。结论:青钱柳多糖对心肌缺血再灌注损伤大鼠的心肌细胞有保护作用,其作用机制可能与抗脂质过氧化、清除机体自由基有关。     

重组人骨形态发生蛋白-7对大鼠心肌缺血再灌注损伤的影响

为探讨重组人骨形态发生蛋白-7(rhBMP-7)对大鼠心肌缺血再灌注损伤的保护作用,建立Wist-ar大鼠心肌缺血再灌注模型。随机分为对照组(C组)、缺血再灌注组(I组)和rhBMP-7处理组(B组),每组10只。B组于血流阻断前10min股静脉给予rhBMP-7250μg/kg,C组和I组给予等量生理盐水。于血流再灌注后24h取血检测乳酸脱氢酶(LDH)和磷酸肌酸激酶(CPK)含量;心肌匀浆检测丙二醛(MDA)含量、超氧化物歧化酶(SOD)活性;电镜下观察心肌组织学变化。结果表明,rhBMP-7处理组大鼠心肌缺血再灌注24h后,其心肌酶含量和MDA均明显低于I组,SOD活性增加(P<0·01);心肌细胞的坏死程度也明显轻于I组。结论:rhBMP-7降低心肌脂质过氧化,增强心肌抗氧化酶活力,对心肌缺血再灌注损伤具有保护作用。     

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.     

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.     

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.