石胆草碳苷B改善阿尔茨海默病小鼠模型的研究

目的:探究石胆草碳苷B(CB)对淀粉样β蛋白片段25-35(Aβ_25-35)诱导阿尔茨海默病(AD)的干预作用及其作用机制,为临床治疗AD提供实验基础。方法:将40只雄性昆明小鼠随机分为正常组、模型组、多奈哌齐组(10 mg·kg^-1)、CB组(10 mg·kg^-1)。除正常组外,其余各组小鼠脑内注射Aβ_25-35(300μmol·L^-1)建立AD小鼠模型。Y迷宫、新物体识别实验检测小鼠学习记忆能力;HE染色、尼氏染色和电镜观察海马病理变化;酶联免疫吸附法检测脑内Aβ_1-42/Aβ_1-40、磷酸化Tau蛋白(p-Tau)水平;生化法检测血清中丙二醛(MDA)、超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)的含量或活性;流式细胞术检测脑内活性氧(ROS)水平;蛋白免疫印迹法(WB)检测脑内LC₃B,Beclin-1和P62相关自噬蛋白水平。体外培养PC-12细胞,结合自噬抑制剂3-甲基腺嘌呤(3-MA...     

运动对快速老化小鼠海马突触素表达的影响

目的研究运动对快速老化小鼠（SAMP8）海马突触素表达的影响,探讨运动改善阿尔茨海默病（AD）学习记忆功能的机制。方法 3月龄SAMP8小鼠40只随机分为运动组（采用跑笼运动训练）和对照组,2个月后HE染色观察2组海马神经元形态改变;免疫组化技术检测2组海马突触素表达。结果 5月龄SAMP8小鼠对照组海马部分神经元细胞变性、死亡,核浓缩,空泡变性;运动组偶有神经元细胞变性、死亡,大部分细胞形态正常。海马突触素表达运动组较对照组显著增高（P〈0.05）。结论运动可以延缓SAMP8小鼠海马神经元变性,提高海马突触素表达,这可能是运动改善AD学习记忆功能的重要机制之一。     

mTOR-自噬通路对脓毒症小鼠海马小胶质细胞表型的影响

目的 探讨哺乳动物雷帕霉素靶蛋白（mTOR）-自噬通路对脓毒症小鼠海马小胶质细胞表型的影响。方法 54 只雄性 ICR 小鼠,按照随机数字表法分为 3 组（n=18）：假手术组（Sham 组）、脓毒症组（CLP 组）和脓毒症+mTOR抑制剂雷帕霉素组（CLP+Ra组）。Sham组只进行开腹手术操作;CLP组采用盲肠结扎穿孔术制备脓毒症小鼠模型;CLP+Ra 组于造模前 6 h腹腔注射雷帕霉素（1.5 mg/kg）。于造模后 24 h各组取 6只,采用酶联免疫吸附试验（ELISA）法检测海马组织肿瘤坏死因子（TNF）-α、白细胞介素（IL）-1β、IL-10和转化生长因子（TGF）-β水平;采用免疫荧光染色法检测海马组织切片离子钙接头蛋白分子（Iba）-1/CD86和 Iba-1/CD206阳性细胞数量;采用蛋白免疫印迹法测定海马组织 mTOR磷酸化（p-mTOR）水平、自噬相关蛋白微管相关蛋白 1轻链 3Ⅱ（LC3Ⅱ）和 Beclin-1表达情况。结果 与 Sham组比较,CLP组 TNF-α、IL-1β、IL-10和 TGF-β水平升高,Iba-1/CD86和 Iba-1/CD206阳性细胞数量增加,p-mTOR水平上调,LC3Ⅱ和 Beclin-1表达下调（均 P＜0.05）。与 CLP组比较,CLP+Ra组 TNF-α和 IL-1β水平降低,IL-10和 TGF-β水平升高,Iba-1/CD86阳性细胞数量减少,Iba-1/CD206阳性细胞数量增加,p-mTOR水平下调,LC3Ⅱ和 Beclin-1表达上调（均 P＜0.05）。结论 mTOR-自噬通路通过调节小胶质细胞表型转化,影响脓毒症小鼠海马炎症反应。     

拟人参皂苷-F11对SAMP8小鼠认知障碍的改善作用及机制

目的阿尔茨海默病(AD)是一种常见的、以认知障碍为主要症状的中枢神经系统退行性疾病。β-淀粉样蛋白(Aβ)聚集形成的淀粉样斑块(SP)和过度磷酸化的Tau蛋白引发的神经原纤维缠结(NFT)是AD临床上的主要病理特征。拟人参皂苷F11(PF11)是西洋参茎叶中分离提取的一种三萜皂苷化合物,本文通过自发快速老化(SAMP8)模型小鼠,从Aβ沉积和Tau过度磷酸化等方面,结合神经行为学、免疫组织化学和蛋白质免疫印迹等手段,进一步评价PF11对AD模型动物认知障碍的改善作用及潜在机制。方法灌胃给予6月龄雄性SAMP 8快速衰老小鼠PF11(2,8和32 mg·kg~(-1)),在给药3个月后进行行为学实验,并检测APP和β-分泌酶(BACE1)、晚期内含体Rab7和循环内含体Rab11的表达。结果灌胃给予PF11(8和32 mg·kg~(-1))3个月可以显著改善SAMP8小鼠的识别记忆和空间学习记忆障碍,显著增加SAMP8小鼠海马和皮质中突触后致密蛋白95的水平;显著降低SAMP8小鼠海马和皮质中胞浆淀粉样蛋白前体蛋白(APP)和β-分泌酶(BACE1)的水平,减少海马和皮质中APP与晚期内含体(LE)的共定位,从而降低脑内Aβ的沉积;PF11可以显著提高SAMP8小鼠海马和皮质中异常降低的亮氨酸羧甲基转移酶(LCMT-1)水平,增加甲基化蛋白磷酸酶2A(PP2A)的水平,从而减少过度磷酸化的Tau。结论 PF11能够明显改善SAMP8小鼠的认知障碍,其机制与抑制海马和皮质脑区中APP淀粉样剪切途径进而减少Aβ沉积,以及增加PP2A活力进而减少Tau蛋白的过度磷酸化相关。     

荭草苷对APP/PS1转基因痴呆小鼠认知功能和海马自噬的影响

目的探究荭草苷对APP/PS1转基因小鼠认知功能的影响及其可能的作用机制。方法实验动物分为3组:7月龄的转基因模型组(Tg)、荭草苷处理转基因组(Tg+Ori)、同月龄的野生型C57BL/6J小鼠作为非转基因对照组(NT),每组8只。Tg+Ori组连续30 d每天腹腔注射荭草苷(10 mg·kg~(-1)),NT和Tg组注射同等剂量的生理盐水。水迷宫实验检测学习记忆能力,免疫组化检测β淀粉样蛋白(Aβ),免疫印迹检测自噬相关蛋白。结果与NT组相比,Tg组小鼠学习记忆能力受损,海马出现大量Aβ斑块, LC3-Ⅱ、p62、Cathepsin D蛋白表达升高;与Tg组相比,Tg+Ori组小鼠学习记忆能力增强,海马Aβ斑块减少,LC3-Ⅱ、p6、Cathepsin D蛋白水平降低;组间Beclin-1蛋白水平无明显差异。结论荭草苷能够改善转基因小鼠认知功能,减少海马Aβ沉积,促进自噬溶酶体降解。     

表没食子儿茶素没食子酸酯对APP/PS1转基因小鼠认知功能和海马自噬的影响

目的探讨表没食子儿茶素没食子酸酯(EGCG)对APP/PSl转基因小鼠海马神经元自噬的作用。方法8月龄APP/PSl转基因小鼠随机分为模型组(Tg)、EGCG低剂量组(Tg/EGCG-L)、高剂量组(Tg/EGCG-H),同月龄C57BL/6J小鼠作为对照组(NT)。采用Morris水迷宫检测各组小鼠学习、记忆能力;Western blot检测各组小鼠海马ULK1、P62、LC3Ⅱ/LC3Ⅰ的蛋白表达;免疫组织化学方法检测mTOR的表达;ELISA法检测Aβ1-42水平。结果与NT组比较,Tg组小鼠寻找平台的逃避潜伏期延长及穿越目的象限的次数减少(P<0.05),海马ULK1表达降低、P62、LC3Ⅱ/LC3Ⅰ、Aβ1-42表达升高(P<0.05),EGCG治疗组较Tg组各异常指标均明显改善(P<0.05)。结论EGCG可以改善APP/PSl小鼠空间学习记忆能力,其机制可能与提高海马神经元自噬活性,减少脑内Aβ沉积有关。     

下调蛋白激酶PINK1对Aβ_(25-35)所致阿尔茨海默病痴呆模型大鼠病理变化的影响

目的线粒体功能障碍是阿尔茨海默病(AD)发生发展过程中非常重要的机制之一。线粒体自噬可以清除受损的线粒体。磷酸酶及张力蛋白同源物诱导的蛋白激酶1(PINK1)是一种与线粒体自噬相关的蛋白激酶。本研究主要观察蛋白激酶PINK1对Aβ25-35所致阿尔茨海默病痴呆模型大鼠病理学的影响。方法体内采用采用5月龄雄性SD大鼠和同月龄纯合雄性PINK1-/-大鼠(SD背景),侧脑室注射Aβ25-35。采用Y迷宫、新物体辨别实验、避暗实验和Morris水迷宫实验考察学习记忆和认知能力,转棒实验和自发活动考察运动功能。ELISA检测大鼠海马炎症因子IL-18,IL-1β和TNF-α的含量,Western蛋白印迹法检测海马突触相关蛋白PSD95和SYP的表达,免疫荧光和Western蛋白印迹法检测Neun的表达。用线粒体分离试剂盒提取线粒体,观察LC3与线粒体共定位。体外采用si RNA下调PC12细胞PINK1表达,再加入Aβ25-35,确认PINK1下调后是否加重了Aβ25-35对细胞的损伤:观察细胞形态,考察细胞死亡率;JC-1染色考察线粒体膜电位;LPS作用于BV2细胞一定时间后,取条件培养基,加入PC12细胞(含PINK1 si RNA组),考察细胞死亡率,确认PINK1 si RNA组细胞是否对LPS诱导小胶质细胞所释放的炎症因子更敏感。结果行为学实验结果显示,PINK1-/-对动物的运动能力没有影响,但在避暗实验中与SD和SD+Aβ25-35组大鼠相比,PINK1-/-+Aβ组大鼠错误次数显著增加。与SD组大鼠相比,PINK1-/-、PINK1-/-+Aβ25-35组SYP,PSD95和Neun的表达显著减少;炎症因子IL-18,IL-1β和TNF-α的含量显著增加;PINK1-/-组LC3与线粒体的共定位显著减少。PINK1-/-+Aβ组LC3与线粒体的共定位显著增加。体外实验结果显示,与单独孵育Aβ25-35组细胞相比,PINK1沉默后给予Aβ25-35细胞生存率显著降低;线粒体膜电位显著降低;且PINK1沉默后给予条件培养基,细胞生存率也显著降低。结论PINK1敲除加重了Aβ25-35所致AD模型大鼠长时记忆障碍,加重Aβ25-35所致AD痴呆模型大鼠突触功能障碍,神经元损伤以及神经炎症。PINK1敲除抑制了部分线粒体自噬,加重了Aβ25-35对细胞的损伤,且对LPS诱导小胶质细胞所释放的炎症因子更敏感。     

G蛋白在快速老化痴呆小鼠SAMP8脑组织中的表达

目的:观察在不同月龄小鼠SAMP8皮质和海马中G蛋白的表达情况.方法:利用Western-blot方法检测Gαq/11、Gαi和GαS蛋白在8月龄和18月龄快速老化痴呆小鼠SAMP8的表达,并以正常老化小鼠SAMR1作为对照研究.结果:与同月龄SAMR1相比,Gαq/11、Gαi和Gαs蛋白在8月龄小鼠SAMP8皮质和海马组织中的表达无明显异常(P＞0.05),而到18月龄时,SAMP8皮质部位Gαq/11表达量低于SAMR1(P＜0.05),海马部位Gαq/11和Gαi的表达量低于SAMR1(P＜0.05).结论:18月龄SAMP8脑组织中Gαq/11和Gαi的异常表达参与了阿尔茨海默病(AD)的病理进展,并有望作为AD治疗的一个靶点.     

安石榴苷基于调整肠道菌群改善APP/PS1阿尔兹海默病小鼠认知功能的实验研究

目的 研究安石榴苷对APP/PS1双转基因阿尔兹海默病(Alzheimer’s disease, AD)小鼠认知功能的作用及其对肠道菌群的影响。方法 将48只APP/PS1双转基因小鼠随机分为模型组和低、中、高剂量实验组,每组12只;另取12只C57BL6小鼠作为正常对照。低、中、高剂量实验组分别按12.5,25.0和50.0 mg·kg^-1的剂量给予1.25,2.50和5.00 mg·mL^-1安石榴苷溶液;对照组和模型组均给予等量蒸馏水。5组小鼠每天灌胃1次,每次0.2 mL,连续2个月。用Morris水迷宫检测小鼠的认知功能,用16S rDNA检测肠道菌群,用蛋白质印迹法检测脑组织内淀粉样蛋白β_1-42(amyloidβ-protein_1-42, Aβ_1-42)的表达水平,用免疫组织化学检测海马磷酸化微管相关蛋白(phosphorylation-microtubule associated protein, p-Tau)蛋白的表达水平。结果 低、高剂量实验组和对照组、模型组...     

瑞香素对阿尔茨海默病模型小鼠自噬的影响

目的 探讨瑞香素对阿尔茨海默病(Alzheimer’s disease,AD)自噬的影响以及对AD神经保护的作用机制。方法 选用APP/PS1双转基因模型小鼠,3个月龄后开始灌胃给药。药物治疗3个月后,通过Morris水迷宫试验观察瑞香素对AD模型小鼠空间探索和记忆能力的影响;采用ELISA试剂盒检测AD模型小鼠海马脑组织Aβ1-40、Aβ1-42水平;利用Western blotting检测瑞香素对AD模型小鼠海马组织微管相关蛋白轻链3Ⅱ(microtubule-associated proteins light chain 3Ⅱ,LC3-Ⅱ)、beclin-1及p62表达水平的影响。结果 Morris水迷宫试验显示,APP/PS1双转基因模型小鼠逃避潜伏期较对照组明显延长,原象限停留时间明显缩短;瑞香素组小鼠逃避潜伏期较模型组明显缩短,原象限停留时间明显延长。与对照组比较,APP/PS1双转基因模型小鼠脑组织中Aβ水平增多,而瑞香素减少模型小鼠Aβ水平;Western blotting结果显示AD模型小鼠海马区LC3-Ⅱ及beclin-1显著降低,p62显著增加,而瑞香素可上调AP...     

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.     

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.