芦丁对大鼠肠缺血再灌注损伤的保护作用

目的 观察芦丁对肠缺血再灌注损伤的保护作用,探讨其可能的机制.方法 将40只健康Wistar大鼠随机分为4组(每组10只):A组为假手术对照组,B组为 缺血再灌注组,C组为缺血再灌注+维生素C组,D组为缺血再灌注+芦丁组.所有大鼠均行开腹手术并分离肠系膜上动脉.A组不夹闭肠系膜上动脉,B组、C组、D组夹闭肠系膜上动脉45 min,再复灌60 min.C组于复灌前10 min静脉给予维生素C注射液180 mg/kg,D组于复灌前10 min静脉给予芦丁注射液50 mg/kg.复灌60 min后由腹主动脉穿刺采血制备血清检测SOD、MPO、D-乳酸、内毒素,处死动物取小肠组织,制备肠组织匀浆检测SOD、MPO.结果 B组与A组相比,B组大鼠血清及肠组织中SOD含量明显减少,MPO水平增高,血清中D-乳酸和内毒素的水平增高;D组与B组比较,D组中血清及肠组织的SOD含量显著增加,MPO水平下降,血清中的D-乳酸和内毒素水平有所减少,并且,D组血清及肠组织的SOD含量高于C组,MPO的水平低于C组,血清中D-乳酸和内毒素的水平比C组低.结论 芦丁具有保护肠缺血再灌注损伤的作用,其机制可能是降低氧自由基的水平,恢复SOD活性,抑制脂质过氧化反应,保护了肠道屏障功能,使得细菌"移位"减少,并抑制炎症反应.     

山茛菪碱对大鼠骨骼肌缺血再灌注损伤的保护作用

目的观察山莨菪碱对大量骨骼肌缺血再灌注损伤的影响.方法24只健康SD大鼠,随机分为三组,A组(对照组)8只,仅麻醉及颈外静脉插管术;B组(缺血再灌注损伤组)8只,缺血4小时之后放开止血带,再灌注4小时;C组(山莨菪碱处理组)8只,再灌注即刻颈外静脉给山莨菪碱5mg/kg.观察山莨菪碱对大鼠再灌注损伤血浆乳酸脱氢酶(LDH)、肌酸肌酶(CK)、丙二醛(MDA)和骨骼肌组织髓过氧化物酶(MPO)、MDA和湿重/干重值(W/D)的影响,并观察骨骼肌超微结构的变化.结果山莨菪碱能明显降低大鼠骨骼肌缺血再灌注损伤所引起的血浆LDH、MDA、CK和骨骼肌组织MPO、MDA、W/D水平的升高,减轻其组织超微结构的损伤.结论山莨菪碱对骨骼肌缺血再灌注损伤具有保护作用.     

转化生长因子β_1、细胞间黏附分子1在大鼠肺缺血再灌注损伤中的作用

目的 观察大鼠肺缺血再灌注中内源性转化生长因子β1(TGF-β1)和细胞间黏附分子1(ICAM-1)在肺缺血中的作用.方法 采用60只SD大鼠建立肺缺血再灌注模型,分为假手术组(S),再灌注组(IR),每组又分为0、1、2、4、8 h五个亚组.检测TGF-β1,ICAM-1及髓过氧化物酶(MPO)含量.结果 S组TGF-β1、ICAM-1只有少量表达;IR组TGF-β1和ICAM-1于再灌注后明显高于S组,MPO含量在IR组缺血再灌注后亦明显比S组增加(P＜0.05或P＜0.01).结论 TGF-β1参与肺缺血再灌注损伤后的修复,而ICAM-1参与肺缺血再灌注损伤后的损伤.     

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。     

凉膈散对肠缺血再灌注损伤大鼠肠道的保护作用

目的:观察凉膈散对大鼠缺血再灌注(I/R)损伤肠黏膜的保护作用.方法:健康Wistar大鼠168只,随机分为正常组、假手术组、模型组、凉膈散治疗组和凉隔散防治组,其中正常组8只,其他4组各40只.正常组不予任何处理,假手术组只分离不夹闭肠系膜上动脉,其余3组通过夹闭肠系膜上动脉建立大鼠小肠I/R模型,根据缺血45min后再灌注3、12、24、48和72h5个时相点义分为5组,每组8只大鼠.测定各组5个时点动物小肠黏膜病理损伤Chiu氏评分、门静脉血浆D-乳酸值、小肠组织匀浆丙二醛(MDA)含量和超氧化物歧化酶(SOD)活力、肠黏膜细胞凋亡指数及Bax表达水平.结果:模型组动物肠黏膜结构破坏明显,Chiu氏评分、血浆D-乳酸值明显升高.小肠匀浆MDA含量升高、SOD活力降低,肠黏膜细胞凋亡指数及Bax表达水平升高.凉膈散干预后,可减轻小肠黏膜病理损伤程度、与模型组比较,除3h外,门静脉血浆D-乳酸值下降,小肠组织匀浆MDA含量降低和SOD活力升高、肠黏膜细胞凋亡指数及Bax表达水平均下降.结论:I/R损伤可破坏肠黏膜屏障功能,凉膈散可通过减少机体氧自由基的生成而保护肠黏膜.     

清营泻瘀方对肠缺血再灌注损伤大鼠的保护作用及机制

目的：探讨清营泻瘀方对肠缺血再灌注损伤大鼠的保护作用及可能机制。方法：40只SD大鼠,随机分为假手术组（n=8）、肠缺血再灌注模型组（n=16）和清营泻瘀方治疗组（n=16）,后2组按造模后处死时间的不同又分别分为术后2h组和术后24h组,每组8只。采用夹闭肠系膜上动脉45min的方法诱导肠缺血再灌注损伤模型,分别观察再灌注后2h和24h肠黏膜的病理改变以及血清中TNF—α、IL-10和血浆中D-乳酸的水平。结果：通过夹闭肠系膜上动脉45min的方法成功诱导出肠缺血再灌注损伤模型,清营泻瘀方治疗组能够减轻肠黏膜的损伤,降低血中TNF—α和D-乳酸的含量（P〈0．05）,晚期降低IL-10水平（P〈0．05）。结论：清营泻瘀方对肠缺血再灌注损伤大鼠有显著的保护作用,其机制可能与荡涤肠胃宿垢、减少细菌移位、调节炎症介质平衡和保护肠屏障有关。     

雌激素对骨骼肌缺血再灌注损伤的保护作用

目的：探讨17β-雌二醇对大鼠骨骼肌缺血再灌注损伤的作用。方法：制作右后肢缺血再灌注模型，30只大鼠随机分为3组，假手术组；缺血再灌注对照组：骨骼肌缺血再灌注＋生理盐水；雌激素干预组：骨骼肌缺血再灌注＋雌激素干预。用全自动生化分析仪测定血浆肌酸磷酸激酶（CPK）、乳酸脱氢酶（LDH），用硫代巴比妥酸比色法测定丙二醛（MDA），用比色法测定小腿三头肌组织中髓过氧化酶（MPO）活性；高倍显微镜观察小腿三头肌组织结构变化。结果：缺血再灌注对照组、雌激素干预组与假手术组比较，血浆CPK、LDH、MDA及MPO含量明显升高（P〈0.01），雌激素干预组与缺血再灌注对照组相比血浆CPK、LDH、MDA及MPO含量明显降低（P〈0.01）；缺血再灌注对照组、雌激素干预组均可见骨骼肌损伤，缺血再灌注对照组明显重于雌激素干预组。结论：雌激素对肢体骨骼肌缺血再灌注损伤具有保护作用，其作用与抑制中性粒细胞的效应有关。     

雌激素对骨骼肌缺血再灌注损伤的保护作用

目的:探讨17β-雌二醇对大鼠骨骼肌缺血再灌注损伤的作用.方法:制作右后肢缺血再灌注模型,30只大鼠随机分为3组,假手术组;缺血再灌注对照组:骨骼肌缺血冉灌注+生理盐水;雌激素干预组:骨骼肌缺血再灌注+雌激素干预.用全自动牛化分析仪测定血浆肌酸磷酸激酶(CPK)、乳酸脱氢酶(LDH),用硫代巴比妥酸比色法测定丙二醛(MDA),用比色法测定小腿三头肌组织中髓过氧化酶(MPO)活性;高倍显微镜观察小腿三头肌组织结构变化.结果:缺血再灌注对照组、雌激素十预组与假手术组比较,血浆CPK、LDH、MDA及MPO含量明显升高(P<0.01),雌激素干预组与缺血再灌注对照组相比血浆CPK、LDH、MDA及MPO含量明硅降低(P<0.01);缺血冉灌注对照组、雌激素干预组均可见骨骼肌损伤,缺血再灌注对照组明显重于雌激素干预组.结论:雌激素对肢体骨骼肌缺血再灌注损伤具有保护作用,其作用与抑制中性粒细胞的效应有关.     

促红细胞生成素对大鼠肾缺血再灌注细胞间黏附分子-1及P选择素表达的影响

目的:探讨重组人促红细胞生成素(rHuEPO)对大鼠肾缺血再灌注细胞间黏附分子-1(ICAM-1)及P选择素(Ps)表达的影响。方法:将大鼠随机分为假手术组、模型组、治疗组,后2组建立肾缺血再灌注模型,造模前治疗组尾静脉一次性注射rHuEPO3000u·kg-1,其余2组给予生理盐水,各组再按再灌注时间分为1、6、12、24h取材组(n=6),测定各时间点肾髓过氧化物酶(MPO)水平,观察肾组织病理学变化,检测肾组织ICAM-1和Ps的表达情况。结果:与模型组比较,治疗组病理学变化明显改善,MPO、ICAM-1和Ps水平明显降低(P<0.05或P<0.01)。结论:rHuEPO可能通过抑制细胞间黏附分子介导的炎症反应,减轻肾缺血再灌注损伤。     

山莨菪碱对大鼠骨骼肌缺血再灌注损伤的保护作用

目的：观察山莨菪碱对大量骨骼肌缺血再灌注损伤的影响。方法：24只健康SD大鼠，随机分为三组，A组（对照组）8只，仅麻醉及颈外静脉插管术，B组（缺血再灌注损伤组）8只，缺血4小时之后放开止血带，再灌注4小时；C组（山莨菪碱处理组）8只，再灌注即刻颈外静脉给山莨菪碱5mg/kg，观察山莨菪碱对大鼠再灌注损伤血浆乳酸脱氢酶（LDH），肌酸肌酶（CK）、丙二醛（MDA）和骨骼肌组织髓过氧化物酶（MPO）、MDA和湿重／干重值（W／D）的影响，并观察骨骼肌超微结构的变化。结果：山莨菪碱能明显降低大鼠骨骼肌缺血再灌注损伤所引起的血浆LDH，MDA，CK和骨骼肌组织MPO，MDA，W／D水平的升高，减轻其组织超微结构的损伤。结论：山莨菪碱对骨骼肌缺血再灌注损伤具有保护作用。     

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.     

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.     

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.