梓醇保护L-谷氨酸和Aβ25-35损伤PC12细胞作用比较作用比较

目的观察梓醇对L-Glu和Aβ25-35损伤PC12细胞的保护作用的异同。方法常规培养神经元样PCI2细胞，预先加入梓醇及对照生理盐水24h后分别加L—Glu 5mmol／L和Aβ25-35 20μmol／L损伤24h，K252a干预组细胞在梓醇前1h加入200nmol／LK252a。MTT法测定细胞存活率，放射配基结合分析测定M2受体密度。结果梓醇100μmol／L明显提高细胞存活率（P〈0．01），10μmol／L、100μmol／L升高M2受体密度（P〈0．05，P〈0．01），K252a部分阻断梓醇对Aβ25-35损伤细胞的保护作用，对梓醇保护L—Glu损伤的阻断作用更强。结论梓醇对L—Glu和Aβ25-35损伤PC12细胞保护作用有差异。     

梓醇保护L-谷氨酸和Aβ25-35损伤PC12细胞作用比较作用比较

目的观察梓醇对L-Glu和Aβ25-35损伤PC12细胞的保护作用的异同。方法常规培养神经元样PCI2细胞，预先加入梓醇及对照生理盐水24h后分别加L—Glu 5mmol／L和Aβ25-35 20μmol／L损伤24h，K252a干预组细胞在梓醇前1h加入200nmol／LK252a。MTT法测定细胞存活率，放射配基结合分析测定M2受体密度。结果梓醇100μmol／L明显提高细胞存活率（P〈0．01），10μmol／L、100μmol／L升高M2受体密度（P〈0．05，P〈0．01），K252a部分阻断梓醇对Aβ25-35损伤细胞的保护作用，对梓醇保护L—Glu损伤的阻断作用更强。结论梓醇对L—Glu和Aβ25-35损伤PC12细胞保护作用有差异。     

蛇毒神经生长因子对PC12细胞凋亡的保护作用

目的 建立β-淀粉样蛋白诱导大鼠嗜铬瘤PC12细胞凋亡的体外AD细胞模型,研究蛇毒神经生长因子(NGF)的保护作用.方法 以荧光显微镜观察细胞形态变化,四唑氮蓝(MTT)法,乳酸脱氢酶(LDH)释放法,流式细胞术等检测凝聚态β-淀粉样蛋白毒性片断Aβ25-35诱导的PC12凋亡,同时检测蛇毒NGF的干预作用.结果 MTT法、LDH释放率显示凝聚态Aβ25-35对PC12细胞的毒性作用呈剂量依赖,20μmol·L-1 Aβ25-35作用组细胞LDH释放率随NGF作用的浓度增高而降低;荧光显微镜观察20μmol·L-1 Aβ25-35作用于PC12细胞出现凋亡改变,NGF预处理细胞的形态明显改善;流式细胞仪分析,Aβ25-35作用PC12细胞凋亡率具有剂量依赖关系,100ng*mL-1NGF预处理的细胞凋亡率降低(P＜0.05).结论 凝聚态Aβ25-35对PC12 细胞具有毒性作用;蛇毒NGF有对抗Aβ25-35致PC12细胞凋亡的作用.     

MCI-186对Aβ_(25-35)诱导PC12细胞氧化损伤韵神经保护作用

目的 探讨MCI-186(edaravone)对阿尔茨海默病(AD)细胞损伤的保护作用.方法 利用淀粉样β蛋白25-35(Aβ_(25-35))诱导PCI2细胞制备成AD细胞模型;采用MTT法确定Aβ_(25-35)抑制PC12细胞生长的半数抑制浓度(IC_(50))和MCF-186对AD细胞保护作用最强时的浓度;利用邻菲罗啉化学发光法测定羟自由基(.OH)含量,确定MCI-186清除.OH最强作用时的浓度.结果 Aβ_(25-35)诱导PC12细胞的IC_(50)是29.76 μmol/L,此浓度的Aβ_(25-35)对PC12细胞生长的最大抑制率发生在36 h;30 μol/L Aβ_(25-35)诱导PC12细胞36 h可以制成理想的AD细胞模型.20 μmol/L MCI-186清除.OH作用最强,即对AD细胞的保护作用最强.结论 MCI-186可以通过清除Aβ_(25-35)产生的.OH,在AD中发挥其神经细胞保护作用.     

银杏总内酯对β-淀粉样肽25-35片段所致小鼠学习记忆障碍的影响

阿尔采末病(AD)的主要神经病理变化是老年斑、神经纤维缠结和血管淀粉样变,临床表现为记忆障碍和认知功能低下.研究发现AD患者脑内细胞外沉积的凝聚态的β-淀粉样肽(β-Amyloid peptide, β-AP)具有神经毒性,并可导致一系列病理行为[1].已知β-淀粉样肽是老年斑的一种重要组成成分,特别是β-AP中第25-35片段肽链的凝聚态比溶解态更具强的神经毒性作用[2].本研究采用一次性icv凝聚态β-AP25-35制成的痴呆动物模型观察银杏总内酯对此模型的保护作用.     

银杏叶聚戊烯醇对Aβ_(25-35)诱导dPC12细胞损伤的保护作用研究

目的:研究银杏叶聚戊烯醇(GP)对β淀粉样肽25-35(Aβ_(25-35))诱导dPC12细胞损伤的保护作用,为其用于阿尔茨海默病(AD)的治疗提供参考。方法:以神经生长因子(NGF)诱导PC12细胞分化为具有神经活性的dPC12细胞后,将dPC12细胞分为正常对照组(DMSO培养基)、Aβ_(25-35)处理组(DMSO培养基)和GP试验组(分别含25、50、100、200、400μg/mL GP的DMSO培养基),培养24 h后,Aβ_(25-35)处理组和GP试验组细胞均加入25μmol/L Aβ_(25-35)诱导细胞损伤(即复制AD细胞模型),24 h后采用MTT法测定细胞存活率。另取细胞分为正常对照组(DMSO培养基)、Aβ_(25-35)处理组(DMSO培养基)和GP试验组(分别含25、50、100、200μg/mL GP的DMSO培养基),同法处理后检测细胞培养液中乳酸脱氢酶(LDH)、活性氧(ROS)、丙二醛(MDA)水平。结果:与Aβ_(25-35)处理组比较,50、100、200、400μg/m L GP试验组dPC12细胞的存活率明显升高(P<0.05或P<0.01),100、200μg/mL GP试验组细胞培养液中LDH、ROS和MDA水平以及50μg/m L GP试验组细胞培养液中ROS水平均显著降低(P<0.05或P<0.01),且呈一定的浓度依赖性。结论:GP对Aβ_(25-35)致dPC12损伤有一定的保护作用,为一种潜在的AD治疗药物。     

苯氧茚酮类衍生物的保护神经细胞和改善小鼠学习记忆作用

目的观察新型乙酰胆碱酯酶抑制剂苯氧茚酮类衍生物(YKY-1~7)对谷氨酸诱导PC12细胞神经毒性的保护作用和对Aβ25~35致痴呆小鼠学习记忆能力的改善作用。方法2mmol·L-1谷氨酸诱导PC12细胞兴奋毒性损伤,观察YKY-1~7对谷氨酸致PC12细胞兴奋毒性的保护作用;小鼠侧脑室注射(icv)凝聚态Aβ25~358μg制作痴呆模型,次日,igYKY-72·5、5、10mg·kg-1,连续10d,测试小鼠被动回避的学习记忆能力,大脑皮层、海马和血清中的乙酰胆碱酯酶(AChE)活性以及大脑皮层局部脑血流量。结果7个苯氧茚酮类衍生物中有6个对谷氨酸诱导的PC12细胞兴奋毒性损伤具有较好的保护作用,其中YKY-7的作用最强。YKY-7可明显改善Aβ25~35所致痴呆小鼠的学习记忆能力,对皮层和海马组织中AChE活性有相对较弱的选择性抑制作用,对皮层局部脑血流量也有一定的提高作用。结论所合成的多数苯氧茚酮类衍生物对神经细胞具有保护作用;对Aβ25~35icv致痴呆模型小鼠学习记忆功能有较大的改善作用,其作用可能与一定程度的选择性抑制大脑皮层和海马AChE活性有关。     

肉苁蓉对抗β-淀粉样肽神经细胞的毒性作用研究

目的：研究中药肉苁蓉对神经母细胞瘤细胞烟碱型乙酰胆碱受体表达的影响及其对抗β淀粉样蛋白（AB）神经毒性作用机制，以探讨其在阿尔茨海默病（alzheimer’s disease，AD）治疗中的作用。方法：比色法测定细胞MTT还原率筛选肉苁蓉安全浓度范围，并用Aβ25～35处理细胞后，测定MTT还原率，蛋白质印迹法（Western blotting）测定烟碱型乙酰胆碱受体a3、a7蛋白表达的变化；TBA比色法测定脂质过氧化产物（丙二醛）的水平。结果：肉苁蓉能提高细胞a3及a7烟碱型乙酰胆碱受体亚单位蛋白质表达水平；并能对抗Aβ25～35引起的a3和a7受体亚单位蛋白质水平降低；同时能减弱Aβ25～35引起的细胞损伤和脂质过氧化水平升高。这些作用随浓度的增加而增强。结论：肉苁蓉能上调烟碱型乙酰胆碱受体亚单位蛋白表达水平，且能对抗Aβ25～35明，的神经毒性作用，在AD的治疗中可能起到一定作用。     

积雪草苷对阿尔茨海默病的治疗作用

目的探讨积雪草苷对小鼠学习记忆的增强作用和对PC12细胞的神经保护作用。方法 2012年8月~2013年1月期间建立东莨菪碱诱导的学习记忆紊乱的小鼠模型和Aβ25-35诱导的PC12细胞调亡的AD细胞模型,分别用水迷宫法测定小鼠的学习记忆功能和二甲基噻唑二苯基四唑溴盐(MTT)分析法研究细胞活性的改变。结果小鼠腹腔注射东莨菪碱4mg/kg可造成明显的记忆障碍(P0.01),给予积雪草苷(50~200mg/kg)对记忆有明显改善作用,能显著减少错误次数、缩短到达平台时间(P0.01);积雪草苷(100μmol/L)明显减少Aβ诱导PC12的细胞凋亡(P0.05)。结论积雪草苷对小鼠学习记忆的增强作用和对PC12细胞有神经保护作用     

白果内酯对抗淀粉样β-肽25-35所致PC12细胞毒作用(英文)

目的:观察白果内酯对β-淀粉样蛋白片段25-35(Aβ25-35)所致PC12细胞毒性的影响。方法:用噻唑兰(MTF)及乳酸脱氢酶法检测PC12细胞的存活率;硫代巴比妥酸法测定细胞脂质过氧化;并同时检测了细胞内抗氧化酶活性。结果:白果内酯(25-100)μmol·L~(-1)剂量依赖性地抑制Aβ25-35(100 μmol·L~(-1))引起的细胞存活率下降,脂质过氧化及抗氧化酶活性下降。结论:白果内酯具有对抗Aβ25-35引起的PC12细胞毒性的作用。     

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.     

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.     

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.