银杏叶提取物对大鼠肾缺血再灌注损伤保护作用的初步研究

目的　观察银杏叶提取物对大鼠肾脏缺血再灌注损伤的保护作用。方法　将 34只健康雄性SD大鼠随机分为假手术对照组、肾脏缺血再灌注组、银杏叶提取物处理组。肾脏缺血再灌注组、银杏叶提取物处理组肾缺血 1h再灌注 2 4h ,测定血清肌酐 (Cr)、肾组织丙二醛 (MDA)、超氧化物歧化酶 (SOD)变化。结果　银杏叶提取物处理组与肾脏缺血组相比明显降低MDA含量 (P <0 .0 5 ) ,明显升高SOD活性 (P <0 .0 1) ,血肌酐无明显升高 (P <0 .0 5 )。结论　银杏叶提取物通过抗氧化 ,对急性肾缺血再灌注损伤有保护作用     

脂氧素A_4对大鼠肺缺血再灌注损伤氧化损伤的影响

目的探讨脂氧素A_4对大鼠肺缺血再灌注损伤氧化应激的影响。方法取36只大鼠(体重220~280g)随机分为假手术组、缺血再灌注组和脂氧素A_4干预组。阻断左肺门45min后再灌注2h建立肺缺血再灌注损伤模型,脂氧素A_4干预组在大鼠恢复血供前5min股静脉注射脂氧素A4 0.1mg/kg。收集标本,检测肺组织的湿/干重量(W/D)比值、支气管肺泡灌洗液的蛋白总量(TP)、检测肺组织匀浆中丙二醛(MDA)含量、超氧化物歧化酶(SOD)活性。结果缺血再灌注组肺组织W/D比值、MDA水平和支气管肺泡灌洗液中总蛋白均较假手术组明显升高,而SOD活性较假手术组明显降低(P0.05)。脂氧素A_4干预组的上述指标高于明显低于缺血再灌注组,而SOD活性较缺血再灌注组明显升高(P0.05)。结论脂氧素A_4对大鼠肺缺血再灌注损伤有一定的保护作用,其机制可能是脂氧素A_4清除自由基抗氧化作用。     

刺五加注射液对肠缺血再灌注损伤保护作用的实验研究

目的：通过建立大鼠肠系膜上动脉缺血再灌注（IR）模型,观察刺五加注射液对大鼠肠缺血再灌注损伤的保护作用。方法：健康Wistar大鼠40只随机分为A假手术组,B缺血再灌注组,C缺血再灌注＋生理盐水组,D缺血再灌注＋刺五加注射液组。后两组分别静脉注射生理盐水和刺五加注射液。实验结束后分别观察小肠粘膜损伤程度并行病理评分,检测各组超氧化物歧化酶（SOD）活性、丙二醛（MDA）、NO^2-／NO^3-和D-乳酸浓度。结果：D组与B组和C组比较,小肠组织匀浆SOD活性上升（P〈0．05）,MDA浓度降低（P〈0．01）,血浆中NO^2-／NO^3-浓度上升（P〈0．05）,D-乳酸明显降低（P〈0．01）,小肠粘膜损伤程度明显减轻（P〈0．01）。小肠粘膜损伤病理评分与D-乳酸水平呈正相关,与NO^2-／NO^3-水平和SOD活性呈负相关。结论：刺五加注射液对大鼠肠IR损伤有一定的保护作用,作用机制与其清除氧自由基,防止脂质过氧化和保护小肠粘膜上皮细胞有关。     

丙泊酚对大鼠脑缺血再灌注损伤后的保护作用及机制研究

目的 研究丙泊酚对脑缺血再灌注损伤后的保护作用机制.方法 30只大鼠随机分为假手术组、缺血再灌注组、丙泊酚治疗组,采用线栓法制做大脑中动脉缺血2h再灌注模型,再灌注24h后断头取脑,测定各组大鼠脑梗死体积和脑组织含水量,并检测各组大鼠脑组织超氧化物歧化酶(SOD)、丙二醛(MDA)、一氧化氮(NO).结果 丙泊酚治疗组脑梗死体积、脑含水量均低于缺血再灌注组,差异有统计学意义(P＜0.05).丙泊酚治疗组能提高脑组织SOD活性,降低MDA活力、NO含量,同缺血再灌注组比较差异有统计学意义(P＜0.05).结论 丙泊酚能减小脑梗死体积,减轻脑水肿,抗自由基损伤,对大鼠脑缺血再灌注损伤有一定保护作用.     

莲心碱对大鼠缺血再灌注损伤心肌的保护作用

目的:研究莲心碱对大鼠缺血再灌注损伤心肌的保护作用.方法:实验大鼠24只,随机分为3组,每组8只.假手术组:冠状动脉左前降支(LAD)处穿一丝线,但不结扎;损伤对照组:结扎冠状动脉LAD,造成心肌缺血再灌注损伤;药物组:结扎冠状动脉LAD前静脉注射莲心碱5 mg&#8226;kg 1.测定每组大鼠血清中磷酸肌酸激酶(CPK)、乳酸脱氢酶(LDH)活性,丙二醛(MDA)含量,心肌梗死范围(IS).结果:与假手术组和损伤对照组比较,药物组血清CPK、LDH活性与MDA含量明显降低(P＜0.01),心肌梗死面积减少(P＜0.05).结论:莲心碱对大鼠缺血再灌注损伤心肌有保护作用.     

银杏叶提取物对大鼠肾缺血再灌注损伤保护作用的初步研究

目的观察银杏叶提取物对大鼠肾脏缺血再灌注损伤的保护作用.方法将34只健康雄性SD大鼠随机分为假手术对照组、肾脏缺血再灌注组、银杏叶提取物处理组.肾脏缺血再灌注组、银杏叶提取物处理组肾缺血1 h再灌注24 h,测定血清肌酐(Cr)、肾组织丙二醛(MDA)、超氧化物歧化酶(SOD)变化.结果银杏叶提取物处理组与肾脏缺血组相比明显降低MDA含量(P＜0.05),明显升高SOD活性(P＜0.01),血肌酐无明显升高(P＜0.05).结论银杏叶提取物通过抗氧化,对急性肾缺血再灌注损伤有保护作用.     

人参皂苷Rg1对大鼠肠缺血/再灌注损伤的影响

目的观察人参皂苷Rg1(ginsenoside Rg1)对大鼠肠缺血/再灌注后肠组织损伤的影响,并探讨其机制。方法制备SD大鼠肠缺血/再灌注损伤模型。实验分为3组(n=10):假手术组、缺血/再灌注组(对照组)、人参皂苷Rg1干预组(治疗组)。比较各组大鼠肠黏膜肿瘤坏死因子α(TNF-α)水平、白细胞介素6(IL-6)水平、丙二醛(MDA)含量、超氧化物歧化酶(SOD)活性的变化;用Chiu氏评分法观察肠黏膜的损伤情况。结果与假手术组相比,对照组TNF-α、IL-6水平明显升高,MDA含量明显增高,SOD活性明显降低,小肠损伤评分明显升高;与对照组相比,治疗组TNF-α、IL-6水平明显降低,MDA含量明显降低,SOD活性明显升高,小肠损伤评分明显降低。结论人参皂苷Rg1对大鼠肠缺血/再灌注后的肠道有保护作用,该保护作用可能与减少TNF-α、IL-6、MDA含量,提高SOD活性有关。     

瑞芬太尼预处理对脑缺血/再灌注大鼠脑组织MDA含量和SOD活性的影响

目的观察瑞芬太尼预处理对脑缺血/再灌注(I/R)大鼠丙二醛(MDA)含量和超氧化物歧化酶(SOD)活性的影响,以探讨其脑保护作用的机制。方法成年Wistar大鼠54只随机分为3组:假手术(Sham)组、缺血/再灌注(IR)组和瑞芬太尼预处理(Rem)组,每组18只。采用大鼠4条血管阻断方法制备大鼠全脑I/R模型,各组在大鼠脑缺血15min后,设再灌注6、12、24h组,相应时间点检测各组脑组织MDA含量和SOD活性,光镜下观察脑组织病理变化。结果与Sham组比较,IR组MDA含量明显升高,SOD活性明显降低(P均<0.05),与IR组比较,Rem组可显著减少大鼠脑I/R损伤后MDA含量,提高SOD活性(P均<0.05)。结论瑞芬太尼预处理对大鼠脑I/R损伤有一定的保护作用,其机制可能与抑制自由基损伤有关。     

小牛血去蛋白注射液对大鼠脑缺血再灌注损伤的保护作用

目的：研究小牛血去蛋白注射液(depmteinised calf blood iniection，DCBI)对大鼠脑缺血及再灌注损伤的保护作用。方法：采用SD大鼠双侧颈总动脉结扎法制作不完全性脑缺血再灌注模型，观察DCBI对脑缺血再灌注SD大鼠的脑组织水含量，脑组织丙二醛(MDA)含量的影响，并通过光镜观察其病理组织学变化。结果：缺血组与缺血再灌注组脑组织水含量、MDA含量较假手术组明显增高；DCBI组脑组织水含量、MDA含量较缺血组与缺血再灌注组下降。病理组织学检查可见缺血组与假手术组相比大脑皮层细胞出现肿胀改变。缺血再灌注组脑组织水肿加剧，细胞周围呈海绵状。用药组脑细胞仅有轻度肿胀改变。结论：DCBI对大鼠脑缺血及缺血再灌注损伤具有保护作用。     

西维来司钠对大鼠脑缺血/再灌注损伤的保护作用及机制

目的探讨西维来司钠对大鼠脑缺血/再灌注损伤的保护作用及机制。方法 90只大鼠随机分成6组,假手术组、I/R组和西维来司钠低、中、高剂量(10、30、90 mg.L-1)组及尼莫地平组。采用改良Zea Longa线栓法制备大鼠局灶性脑缺血(2 h)/再灌注(24 h)损伤模型,西维来司钠各组于再灌注0、3、6 h腹腔注射西维来司钠溶液(sivelestat sodium,SIV,ONO-5046),假手术组和I/R组给予等体积的NS。再灌注24 h,采用改良的Zea Longa评分法对大鼠进行神经行为学评分后,进行缺血脑组织形态学观察及SOD、MDA、MPO活性测定。免疫组化检测缺血脑组织Caspase-3和Caspase-1(ICE)的表达,ELISA法检测缺血侧脑组织匀浆NE的含量。结果西维来司钠可以降低大鼠脑缺血/再灌注损伤的神经功能缺损评分,能不同程度地改善脑组织学损伤,并且升高SOD活性,降低脑组织中MDA、MPO活性,减少脑组织Caspase-3和Caspase-1(ICE)的表达和NE的含量。结论西维来司钠对大鼠脑缺血/再灌注损伤有保护作用,作用机制之一可能与抗炎、抗氧化、抗凋亡有关。     

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.     

Synthesis,Cytotoxicity and Antileishmanial Activity of Some N-(2-(indol-3-yl)ethyl)-7-chloroquinolin-4-amines

We report herein the condensation of 4,7-dichloroquinoline (1) with tryptamine (2) and D-tryptophan methyl ester (3) . Hydrolysis of the methyl ester adduct (5) yielded the free acid (6) . The compounds were evaluated in vitro for activity against four different species of Leishmania promastigote forms and for cytotoxic activity against Kb and Vero cells. Compound (5) showed good activity against the Leishmania species tested, while all three compounds displayed moderate activity in both Kb and Vero cells.     

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.