促红细胞生成素促进脑梗死后神经元再生

目的观察促红细胞生成素(EPO)对脑梗死后神经元再生的作用。方法电凝并切断SCID小鼠左侧大脑中动脉,制作皮质脑梗死模型。24h后每天腹腔注射EPO,连续7d;对照组注射等量容积的PBS。每天腹腔注射bromodeoxyuidine(BrdU)用于标记分化细胞,连续10d。第35天取脑测定梗死边缘皮层神经元再生情况和皮层宽度变化。结果EPO治疗组皮质宽度指数为0·935±0·017,明显高于对照组的0·876±0·009(P<0·05)。在脑梗死边缘皮质中,EPO治疗组BrdU和NueN双标阳性的新生神经元为(16·8±4·3)HP,明显高于对照组的(3·5±1·5)HP(P<0·05)。结论EPO对于脑梗死后神经元的再生有促进作用。     

化学诱导兔脑缺血模型早期MSCT灌注成像实验性研究

目的应用化学诱导方法建立稳定可靠的兔脑局部缺血模型,探讨早期缺血性脑梗死多层螺旋CT（MSCT）灌注成像表现与最终梗死体积的关系。方法对34只健康新西兰大白兔成功栓塞,然后分别于栓塞后15min、30min、1h行MSCT灌注成像扫描,2、4、6、8、10、12、24h行颅脑CT平扫观察。结果应用月桂酸钠化学诱导方法成功建立稳定、可靠的脑局部缺血模型,经病理HE染色证实神经元变性坏死明显,大量神经元固缩,并可见到神经元周围空泡样改变。MSCT灌注成像表现：实验兔梗塞后20～30minCT脑血流量（CBF）灌注图可以清楚地显示不同程度的缺血状态,兔脑两侧相比有明显的色阶变化,一侧大脑半球局部呈低灌注状态。继续跟踪观察2、4、6、8、10、12、24hCT平扫发现大部分最终梗死体积与灌注图像获得的梗死范围基本一致。结论应用月桂酸钠化学诱导方法可成功建立稳定可靠的脑梗死模型,MSCT灌注扫描CBF灌注图像可最早于梗死后15～20min发现脑梗死病灶,并且大部分与最终梗死体积基本一致。     

小鼠局灶性脑缺血梗死灶的定量分析

目的:用小鼠持续性局灶性脑缺血模型,证明新建的透光法测定局灶性脑缺血梗死灶的实用性。方法:采用大脑中动脉阻塞法(MCAO)造成小鼠持续性局灶性脑缺血,于缺血后2 4h进行Bederson’s症状评分和爬板、悬挂试验,并以计算机图像分析技术测定和分析脑缺血梗死体积、脑半球面积、皮层及皮层下神经元密度;在大脑中动脉线栓手术前3d和术前1h分别腹腔注射Pranlukast 0 .1mg·kg-1或尼莫地平0 .4mg·kg-1,观察药物的神经保护作用。结果:透光测定的梗死体积与TTC染色测定的梗死体积、神经元密度密切相关,与神经症状综合评分具有等级相关。Pranlukast和尼莫地平能减少脑梗死体积和脑半球的缺血侧 非缺血侧比值,减轻神经症状和神经元死亡。结论:透光法结合神经症状综合评分法可用于小鼠局灶性脑缺血的定量分析和药物的神经保护作用评价。     

左旋氨氯地平对局灶性脑缺血小鼠模型脑梗死体积的影响

目的研究左旋氨氯地平对局灶性脑缺血小鼠模型脑梗死体积的影响,探讨左旋氨氯地平对缺血性脑梗死的神经保护作用。方法制备小鼠大脑中动脉脑缺血再灌模型,根据是否使用左旋氨氯地平随机分为3组：左旋氨氯地平缺血前处理组,缺血生理盐水处理组,假手术对照组;多普勒超声血流仪监测梗死侧脑区的脑血流量;TYC染色检测脑梗死体积。结果与缺血生理盐水处理组相比较,左旋氨氯地平缺血前处理组梗死侧脑区的脑血流量没有明显变化,而脑梗死体积较小,差异有统计学意义（P〈0．05）。结论使用左旋氨氯地平可能有助于减少缺血性脑梗死体积。     

罗格列酮对小鼠局灶性脑缺血再灌注损伤的保护作用

目的探讨过氧化物酶体增殖物激活受体γ(PPARγ)激动剂罗格列酮对脑缺血再灌注损伤的保护作用。方法采用线栓法制作小鼠大脑中动脉栓塞模型(MCAO)。将健康成年昆明小鼠随机分为缺血对照组、溶剂对照组(二甲基亚枫)、罗格列酮组。再灌注24小时后观察小鼠神经功能评分,2,3,5三苯基四氮唑(TTC)染色法测量脑梗死体积,干湿重法测量缺血侧脑含水量,常规HE染色观察病理变化。结果罗格列酮组小鼠神经功能评分明显低于缺血对照组、溶剂对照组(P均<0.01),脑梗死体积与其它两组相比分别降低了41%和39%(P均<0.01),脑水含量也明显降低(P均<0.05),脑组织病理学显著改善。结论罗格列酮对小鼠脑缺血再灌注损伤具有明显的保护作用。     

法舒地尔预处理对大鼠脑缺血再灌注损伤细胞色素C和caspase-3表达的影响

目的研究法舒地尔对大鼠局灶性脑缺血再灌注损伤细胞色素C(CytC)和caspase-3蛋白表达的影响,探讨其脑保护机制。方法线栓法制作大鼠中动脉缺血再灌注损伤模型。成年雄性SD大鼠120只随机分成3组:假手术组(Sham组)、脑缺血再灌注模型组(Mod组)、法舒地尔干预组(Fas组),再分为再灌注3h、12h、24h和48h,以及TTC染色组5个亚组,每组8只大鼠。缺血再灌注后进行神经功能缺损评分(NDS),免疫组织化学方法检测脑组织中CytC蛋白、cas-pase-3的表达,TTC染色测量鼠脑梗死体积并计算百分比。结果①Sham组大鼠无神经功能缺损,NDS评分为0,TTC染色亦未见脑组织梗死;Mod组和Fas组大鼠均有明显的神经功能缺损,TTC染色亦可见明显的脑组织梗死;但与Mod组相比,Fas组神经功能缺损少、NDS评分低(P<0.01),脑梗死体积减小(P<0.05)。②与Sham组相比,脑缺血再灌注后,Mod组和Fas组大鼠脑组织CytC和caspase-3的表达显著升高(P<0.01),其中CytC表达高峰出现在12h,caspase-3表达高峰出现在24h;Fas组和Mod组间比较显示Fas组CytC和caspase-3的表达又显著低于Mod组(P<0.01)。结论①法舒地尔能减轻大鼠脑局灶性缺血再灌注引起的神经功能缺损,减小脑梗死体积。②部分抑制脑缺血再灌注引起的CytC和caspase-3表达增加可能是法舒地尔的脑保护机制之一。     

玫瑰总黄酮对小鼠局灶性脑缺血模型的影响

摘要 目的：观察玫瑰总黄酮对小鼠局灶性脑缺血再灌注模型的保护作用。方法：采用线栓法阻塞左侧大脑中动脉,建立小鼠局灶性脑缺血再灌注模型。于手术前尼莫地平组、脑络通组、玫瑰总黄酮大、中、小剂量组分别给予相应的药物灌胃,假手术组、手术模型组、同时给予同体积0.5%CMC灌胃,每天1次,连续给药7d。末次给药1h后造模,手术清醒后,对小鼠神经功能评分,再灌注22h,测血清中S-100β蛋白含量,取脑组织TTC染片,计算脑梗死面积。结果：小鼠局灶性脑缺血再灌注模型复制成功,玫瑰总黄酮各剂量组均显著降低小鼠神经功能缺失评分,减少小鼠脑梗死面积,显著降低血清中S-100β蛋白的含量,显著改善脑组织中皮质区的病理损伤。结论：玫瑰总黄酮可通过降低血清中S-100β蛋白的含量,改善神经功能缺失评分,减少脑梗死面积,改善大脑皮质区的病变情况,从而减轻脑组织缺血再灌注的损伤。     

小鼠心梗模型的建立与早期心电图评价

目的 构建并优化小鼠心肌梗死模型,联合使用冠脉结扎术后即刻和术后4 h的两次肢体导联心电图对心梗发生情况进行早期评价。方法 C57BL/6J雄性小鼠29只,异氟烷吸入麻醉后,经左侧第3/4肋间进入胸腔,结扎冠状动脉左前降支建立模型,施行术后即刻和术后4 h肢体导联心电图评价心梗发生情况。术后24 h打开胸腔观察梗死情况,留取心脏标本进行TTC染色确定梗死区域并计算梗死面积。结果 小鼠行冠状动脉结扎术,术中死亡率为6.8%(2/29),术后早期(<4 h)死亡率为10.3%(3/29),24 h存活率为82.8%(24/29);术后24 h TTC染色明确梗死发生,则心梗模型建立,造模成功率为79.3%(23/29),平均梗死区域大小（梗死心肌重量/全心室重量）为（28±6）%;成功建立模型的小鼠在术后4 h心电图可见明显ST-T改变,提示心梗已发生。结论 成功建立小鼠心肌梗死模型,且联合使用术后即刻和术后4 h两次心电图可以作为小鼠心肌梗死模型快速无创的评价方法。     

线栓法大脑中动脉闭塞所致局灶性脑缺血再灌注鼠模型的脑水肿和脑梗死比的变化

目的:探讨短暂性右侧大脑中动脉闭塞所致局灶性脑缺血再灌注模型的脑梗死比和脑水肿的变化。方法:线栓法制作大鼠脑缺血/再灌注不同时间点模型,行TTC染色测量脑梗死比及干湿称重法测量脑含水量。结果:脑缺血再灌注6h时大鼠脑组织即有含水量的增加,并随着时间的推移呈上升趋势,且未损伤侧中段脑组织含水量升高最为显著。TTC染色在缺血再灌注6h即可见白色梗死灶,梗死比在再灌注72h内逐渐增加。结论:局灶性脑缺血再灌注72h内脑梗死比和脑水肿均呈进行性加重。     

小鼠局灶性脑缺血再灌注模型的建立与评价

目的 建立小鼠局灶性脑缺血再灌注（I/R）模型并予以评价.方法 将昆明小鼠60只随机分为假手术组30只,I/R模型组30只.改良线栓法制备小鼠大脑中动脉阻塞/再灌注（MCAO/R）模型.通过神经行为学评分、氯化三苯基四氮唑（TTC）染色法测定脑梗死比（％）、干湿重法测定脑含水量（％）及HE染色观察脑组织病理改变评价模型可靠性.结果 模型存活率为83.33％,造模总成功率为76.67％.假手术组的小鼠神经行为学评分为0分,脑梗死比为0,脑含水量（77.29±0.45）％.I/R模型组的小鼠神经行为学评分为（2.42±0.63）分,脑梗死比为（23.03±3.42）％,脑含水量（83.18±1.65）％,均较假手术组明显增高（P＜0.01）;病理检查出现典型脑梗死病理改变.结论 改良线栓法成功建立简便、可靠的小鼠局灶性I/R模型.     

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.