硝酸异山梨酯对大鼠心肌后期预适应的诱导作用

目的：探讨硝酸异山梨酯（ISDN）能否诱导大鼠后期预适应及其可能机制。方法：采用大鼠在体缺血再灌注（I／R）模型，将动物随机分为生理盐水组、ISDN给药组、假手术组、后期缺血预适应组、生理盐水＋I，R组、ISDN＋I，R组、生理盐水＋格列苯脲＋I／R组、ISDN＋格列苯脲＋I／R组。前两组于给药24h后，测定心肌组织中的SOD和诱导型一氧化氮合成酶的含量，含I／R组于给药24h后进行缺血40min再灌注1．5h后测心肌梗死范围、心肌组织及血清学指标。结果：ISDN组心肌组织中诱导型一氧化氮合成酶浓度昵显比生理盐水组高（P〈0．01）；后期缺血预适应组和ISDN＋I／R组与生理盐水＋I/R组相比，心肌梗死面积、血清肌酸激酶和乳酸脱氢酶含量明显减少（前两者P〈0．05，后者P〈0．01），心肌组织中NO和锰-SOD显著增加，丙二醛显著下降（P〈0．05）。结论：ISDN能诱导心肌后期预适应，其机制与NO和诱导型一氧化氮合成酶的升高以及机体的抗氧化能力增强有关。     

雷米普利对糖尿病大鼠心脏的药理性预适应作用

目的：评价雷米普利对糖尿病大鼠心脏的药理性预适应作用。材料和方法：大鼠尾静脉注射链脲菌素（45mg／kg）制备糖尿病模型。随机分为4组：缺血／再灌注（I／R）组，缺血预适应（IP）组，雷米普利（RAM）药理性预适应组，雷米普利＋缺血预适应（RAM＋IP）组。RAM组及RAM＋IP组每天用雷米普利（1mg／kg）灌胃，共4周。4周后全部大鼠行心肌30min缺血继之2h再灌注，IP组及RAM＋IP组于30min缺血前行心肌缺血预适应。连续监测ST-段变化以及缺血期室性心律失常发生情况，TTC染色测定心肌梗死范围，TUNEL法检测心肌细胞凋亡，免疫组化法测定Bcl-2与Bax的表达，光、电镜下观察心肌形态学改变。结果：与I／R组比较，IP及RAM组均见缺血心脏ST-段抬高幅度显著降低（P〈0．05），室早出现时间推迟（P〈0．05），持续时间缩短（P〈0．05），室速、室颤发生率降低（P〈0．05），心肌梗死范围缩小（P〈0．01），心肌细胞凋亡减轻（P〈0．001），Bcl-2／Bax比值升高（P〈0．05），形态学观察见心肌损伤减轻；RAM＋IP组可见室早持续时间缩短（P〈0．05），室速、室颤发生率降低（P〈0．05），心肌梗死范围缩小（P〈0．01），心肌细胞凋亡减轻（P〈0．001），Bcl-2／Bax比值升高（P〈0．05）。与IP组比较，RAM＋IP组上述各指标无明显差异。结论：IP对患糖尿病4周的大鼠具有心脏保护效应，长期服用RAM对糖尿病心肌具有药物预适应作用，均可增强糖尿病大鼠心脏对缺血／再灌注损伤的耐受性，但二者联用无协同效应。     

CYP2家族表氧化酶在心肌缺血再灌注损伤中的表达及MS-PPOH的抑制性效应

目的：为进一步认识心肌缺血再灌注损伤中的介导因素，本文研究了CYP2家族表氧化酶在大鼠心肌缺血再灌注损伤中的表达特征及表氧化酶特异性抑制剂MS-PPOH的作用。方法：雄性SD大鼠随机分成5组：假手术组，缺血40min组，缺血／再灌注15min组、60min组和180min组。取缺血心肌，共聚焦法检测超氧化物自由基水平；RT-PCR法测定CYP281／2、2E1、2C6、2J3 mRNA表达；ELISA法检测14，15-二氢二十碳三烯酸（DHET）含量；制备心微粒体，Western blot法检测CYP2C、2J3蛋白水平。结果：缺血再灌注损伤中，超氧化物自由基的水平在再灌注15min达高峰，较假手术组升高110%（P〈0．01）。CYP2C6 mRNA表达上调，于再灌注15min达到峰值（P〈0．05）；CYP2E1 mRNA水平呈时间依赖性降低，再灌注180min降至假手术组的43．9％（P〈0．01）；CYP2B1/mRNA的表达在再灌注不同时间点未见明显差异。CYP2C蛋白于再灌注15min表达上调，较假手术组升高42％（P〈0．05）；CYP2J3蛋白呈时间依赖性表达升高，再灌注180min组较假手术组上升80．7％（P〈0．01）。缺血心肌14，15-DHET含量在再灌注阶段明显升高。MS-PPOHl5 mg／kg除降低血浆CK、LDH活力（P均〈O．05）外，并抑制心肌超氧化物自由基的生成（P〈0．05）、显著降低缺血心肌14，15-DHET含量（P〈0．01），同时明显缩小心肌梗死面积（P〈0．05）。结论：CYP2家族表氧化酶不同亚型在心肌缺血再灌注损伤中变化特征各异。CYP2C6 mRNA和蛋白表达与超氧化物自由基生成呈相关性，提示CYP2C6参与介导心肌缺血再灌注损伤中活性氧的产生。CYP2J3非活性氧的主要来源，本文中CYP2J3蛋白表达上调滞后于超氧化物自由基的生成，提示其升高可能为活性氧促发的反馈性保护机制。表氧化酶抑制剂MS-PPOH能明显减轻心肌缺血再灌注损伤。     

脑利钠肽后处理对高血脂大鼠缺血／再灌注心肌的保护作用

目的观察脑利钠肽后处理对高血脂大鼠缺血／再灌注心肌的保护作用。方法高血脂SD大鼠24只,随机分为3组：假手术组、缺血／再灌注组、脑利钠肽后处理组,每组8只。制备大鼠心肌缺血／再灌注模型。测定血清肌酸激酶（CK）、超氧化物岐化酶（SOD）、丙二醛（MDA）含量和心肌梗死范围。结果再灌注结束后,脑利钠肽后处理组和缺血／再灌注组CK明显高于假手术组[分别为（758．11±39．94）,（815．19±40．85）,（219．17±22．63）U／L,P〈0．01],脑利钠肽后处理组CK低于缺血／再灌注组（P〈0．05）。脑利钠肽后处理组血清中SOD含量高于缺血／再灌注组,MDA含量低于缺血／再灌注组（P〈0．05）。脑利钠肽后处理组坏死区与缺血区比值低于缺血／再灌注组[分别为（33．0±5．2）％,（38．4±3．1）％,P〈0．05]。结论脑利钠肽后处理对高血脂大鼠缺血／再灌注心肌具有保护作用。     

碟脉灵注射液对心肌缺血再灌注大鼠脂质过氧化的影响

目的：观察碟脉灵注射液对大鼠心肌缺血再灌注损伤脂质过氧化的影响。方法：将雄性Wistar大鼠30只（250～300g），随机分为假手术组、再灌模型组、碟脉灵组，每组10只。在乙醚麻醉下制备在体大鼠心肌缺血再灌注模型，各组动物在冠脉结扎60min时，各组大鼠分别舌下静脉注射碟脉灵注射液或生理盐水5ml/kg，然后松解结扎线进行再灌注。再灌注120min后，分别取血及心脏测血清及心肌中丙二醛（MDA）含量及超氧化物歧化酶（SOD）活性，并对大鼠心脏进行N—BT染色测心肌梗死面积（MIS）。结果：碟脉灵注射液能显低降缺血再灌注大鼠血清及心肌中MDA含量及升高血清及心肌中SOD活性（P〈0．05）；亦能显缩小缺血再灌注大鼠MIS（P〈0．05）。结论：碟脉灵注射液对缺血再灌注造成的心肌损伤具有明显的保护作用，可能与增强机体对自由基的清除能力，减少脂质过氧化产物的堆积有关。     

无创性延迟肢体缺血预适应保护糖尿病大鼠缺血／再灌注心肌

目的：研究无创性肢体缺血预适应（NDLIP）对糖尿病（DM）大鼠心肌缺血／再灌注（I／R）损伤的影响。方法：大鼠经尾静脉一次性注射链脲佐菌素（STZ）造成急性DM模型后,被随机分为I／R、心脏缺血预适应（CIP）和NDLIP三组。NDLIP组连续3d经历左后肢缺血预适应。第4天,各组动物均经历I／R损伤,CIP组于缺血前行心肌缺血预适应。连续监测血压和心电图变化,观察NDLIP对DM大鼠I／R损伤后心肌电生理功能、心肌梗死范围和心肌酶学的影响,并测定心肌组织中超氧化物歧化酶（SOD）、谷胱甘肽过氧化物酶（GSH—Px）活性及丙二醛（MDA）含量。结果：成模动物表现出血糖明显升高,体重下降（P〈0．01）。与I／R组比较,NDLIP及CIP组ST一段抬高幅度降低,室早和室速出现时间推迟,持续时间缩短,室性心律失常发生率降低（P〈0．05）,心肌梗死范围缩小（P〈0．01）,心肌细胞乳酸脱氢酶（LDH）、肌酸激酶（CK）及其同工酶（CK—MB）的释放减少（P〈0．05,P〈0．01）,心肌SOD、GSH—Px活性升高（P〈0．01）,MDA含量减少（P〈0．05,P〈0．01）。结论：NDLIP可减轻DM大鼠I／R后心肌细胞损伤,从而减少心肌酶漏出、改善心脏生理功能,具有与CIP程度相当的心脏保护作用,其机制与调节心肌氧化．抗氧化系统功能平衡有关。     

右美托咪定预处理对大鼠心肌缺血再灌注损伤的保护作用及补体3蛋白的影响

目的：探讨右美托咪定预处理对大鼠心肌缺血再灌注损伤的保护作用及对补体3（C3）蛋白的影响。方法：sD雄性大鼠45只,随机分为3组（n=15）：假手术组（Sham组）、缺血再灌注组（I／R组）、右美托咪定预处理组（DEX组）。DEX组自缺血前2h持续静脉输注右美托咪定5mL·kg^-1（用0．9％氯化钠注射液将右美托咪定稀释为1gg·mL^-1）直到结扎心脏冠状动脉左前降支前停止,输注时间为2h;Sham组72．I／R组在相同的时间内按照5mL·kg^-1速率输注等量0．9％氯化钠注射液。再灌注120min时,取心脏组织,测定心肌梗死面积,用蛋白质印迹法（Westernblot）测定心肌组织中c3蛋白的表达。结果：与Sham组比较,I／R组和DEX组的心肌梗死面积、C3蛋白表达明显升高（P〈0．05）;与I／R组比较,DEX组的心肌梗死面积和C3蛋白表达明显降低（P〈0．05）。结论：右美托咪定预处理能够减轻大鼠心肌缺血再灌注损伤,其机制与减少补体3蛋白表达有关。     

腺苷对心肌缺血再灌注心律失常的保护作用

目的观察腺苷对在体大鼠心肌缺血／再灌注（I／R）心律失常的影响，探讨其可能的作用机制。方法健康Wister大鼠36只，随机分成3组假手术组、对照组、腺苷组，每组12只。开胸结扎左冠状动脉前降支30分钟，再灌注45分钟．制作大鼠心肌缺血／再灌注损伤模型。假手术组只穿线不结扎冠状动脉。腺苷组于结扎前1分钟给予腺W（0．4ml／kg）左心室内注入，对照组给予等量生理盐水左心室内注入。观察再灌注室性心动过速（VT）、室颤（VF）发生率和死亡率；检测左心室心肌组织超氧化物歧化酶（SOD）及丙二醛（MDA）含量。结果①腺苷组大鼠再灌注VT及VF发生率及死亡率均较对照组明显降低（P〈0.01）；②与对照组比较，腺苷组大鼠SOD活力提高（P〈0．05），而MDA生成量明显减少（P〈0．01）。结论心肌缺血再灌注可导致缺血心肌进一步损伤，腺苷具有抗大鼠I／R心律失常作用，可能与抑制缺血再灌注氧自由基的产生有关。     

生长激素预处理对大鼠心肌缺血再灌注后细胞凋亡与能量代谢的影响

目的研究生长激素预处理对大鼠心肌缺血再灌注后心肌细胞凋亡及能量代谢的影响。方法42只大鼠采用完全随机设计方法分为3组，假手术组14只（假手术24h）、心肌缺血再灌注组14只、生长激素组14只，后2组均缺血30min，再灌注24h，其中生长激素组的每只大鼠术前皮下肌肉注射生长激素1 U／kg，连续7d，其中第7次皮下注射于手术前进行。前2组每只大鼠相应皮下肌肉注射生理盐水0．5ml／d。每组中均抽取8只大鼠，以TUNEL法检测缺血区心肌细胞凋亡情况，每组中剩余的抽取5只大鼠，以高效液相色谱法测定缺血区心肌三磷酸腺苷（ATP）并进行心肌组织病理、电镜超微结构观察。结果与假手术组比较，心肌缺血再灌注组再灌注24h后缺血区心肌细胞凋亡率和ATP消耗程度均明显上升（P〈0．05），心肌组织病理和超微结构改变明显；与心肌缺血再灌注组比较，生长激素组再灌注24h后缺血区心肌细胞凋亡率和ATP消耗程度均明显改善（P〈0．05），心肌组织病理和超微结构改变明显减轻。结论生长激素能减少心肌缺血再灌注后心肌细胞凋亡和ATP的消耗，说明生长激素对心肌缺血再灌注后的心肌具有保护作用。     

非拉尼特对大鼠缺血-再灌注心肌的保护作用

目的 探讨阿魏酸硝酸酯类药物非拉尼特（FLNT）对大鼠缺血-再灌注心肌的保护作用及其机制。方法采用大鼠在体缺血-再灌注模型，将动物随机分为6组。假手术组（对冠脉只穿线不结扎）；模型对照组（给予等剂量的0.5%羧甲基纤维素钠溶液）；FLNT低、中、高剂量药物组（分别给予FLNT 2，4，8 mg·kg^-1）；阳性对照组（给予硝酸甘油 2 mg·kg^-1）。大鼠进行缺血40 min，再灌注3 h后测定心肌梗死范围、心肌组织及血清学指标，并定时记录心电图。结果FLNT组心肌梗死面积、血清肌酸激酶和乳酸脱氢酶活性明显减少（P＜0.05），心肌组织中一氧化氮（NO）含量和超氧化物歧化酶（SOD）活性显著增加, 丙二醛含量显著下降（P＜0.05）。能显著地阻止T波的升高（P＜0.05）和R波的降低（P＜0.05），降低病理性Q波的产生。结论FLNT对大鼠缺血 再灌注心肌有保护作用，其机制与NO升高以及机体的抗氧化能力增强有关.     

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.     

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.     

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.