瑞芬太尼预处理和缺血预处理对大鼠肝脏缺血再灌注早期细胞凋亡的影响

目的观察瑞芬太尼预处理和缺血预处理对大鼠肝脏缺血再灌注损伤早期细胞凋亡的影响及其机制。方法SD大鼠72只,随机分为假手术组(S组),缺血再灌注组(IR组),瑞芬太尼预处理组(R组),缺血预处理组(IP组)。分别在再灌注1、3、5h处死6只大鼠,取左肝内叶组织免疫组织化学法分别测定各组Bcl-2和Bax的表达,原位细胞凋亡法测定肝细胞凋亡的情况,光镜、电镜观察肝脏组织病理变化。结果与S组相比,IR组细胞凋亡指数、Bax表达均增高(P<0.05),而瑞芬太尼预处理和缺血预处理组减弱了缺血再灌注上述指标的升高(P<0.05),二者没有区别;IR组Bcl-2表达减少(P<0.05),瑞芬太尼预处理和缺血再灌注组可增强其在肝组织的表达(P<0.05),二者没有区别。病理检查显示瑞芬太尼预处理和缺血预处理减轻肝缺血再灌注损伤。结论瑞芬太尼预处理及缺血预处理都有抑制大鼠肝脏缺血再灌注损伤早期细胞凋亡的作用,均与上调Bcl-2蛋白表达、下调Bax蛋白表达有关,瑞芬太尼可模拟缺血预处理的抗细胞凋亡作用。     

咪达唑仑对大鼠肝脏缺血再灌注损伤时细胞凋亡的影响

目的探讨咪达唑仑对大鼠肝脏缺血再灌注时细胞凋亡的影响及其保护作用。方法成年健康SD大鼠54只,随机分为3组:假手术组(Sham组)、缺血再灌注组(IR组)、咪达唑仑组(M组),每组18只。制作70%肝脏缺血再灌注模型,实验结束后即刻取肝左叶做标本。用免疫组织化学法检测Bcl-2与Bax蛋白表达量,TUNEL法检测肝细胞凋亡指数(AI)。结果与Sham组比较,各组肝组织Bcl-2、Bax蛋白含量、凋亡指数差异有统计学意义(P<0.05);与IR组比较,M组Bcl-2蛋白表达增加、Bax蛋白表达和AI减少(P<0.05)。IR、M组各组内各时相以再灌注6h最高。结论咪达唑仑可以通过调节Bcl-2、Bax蛋白表达,使肝细胞凋亡减轻,从而对大鼠缺血再灌注肝脏有一定的保护作用。     

缺血预适应对大鼠肢体缺血再灌注后肝损伤的影响

目的:观察缺血预适应(IPC)对大鼠肢体缺血再灌注(LIR)后肝脏损伤和细胞凋亡的影响,以进一步探讨IPC对肢体缺血再灌注后肝脏功能的保护作用.方法:将实验用雄性Wistar大鼠18只,随机分为对照组、缺血再灌注(IR)组和缺血预适应加再灌注(IPC+IR)组,每组6只.测定各组动物血浆中丙氨酸氨基转移酶(ALT)、天冬氨酸氨基转移酶(AST)、透明质酸(HA)和乳酸脱氢酶(LDH);检测肝组织细胞的DNA双链百分率;利用原位脱氧核糖核苷酸末端转移酶介导的缺口末端标记法(TUNEL法)检测各组肝细胞凋亡情况;采用免疫组织化学方法检测各组动物肝组织Bcl-2和Bax比值及Caspase-3.结果:大鼠LIR后血浆中ALT、AST、HA、LDH含量均明显增加;LIR后肝组织细胞DNA双链百分率降低,凋亡细胞百分率增高.Bcl-2/Box蛋白比值减小,Caspase-3蛋白表达明显增强.IPC+IR组上述各指标较IR组改善,但与对照组比较差异仍有统计学意义(P<0.05或P<0.01).结论:肢体缺血再灌注可以导致肝脏的损伤,缺血预适应可以减轻损伤的发生,其保护效应可能与其抑制肝细胞凋亡有关.     

瑞芬太尼对大鼠肝脏缺血再灌注早期细胞凋亡的影响

目的:观察瑞芬太尼对大鼠肝脏缺血再灌注早期细胞凋亡的影响及其机制。方法:SD大鼠54只分为假手术组(S组),生理盐水对照组(C组),瑞芬太尼预处理组(R组)。缺血均为30 min,瑞芬太尼预处理组为缺血前输注瑞芬太尼30 min,生理盐水对照组以相同的速率及容积输注生理盐水。分别在再灌注1,3,5 h处死6只大鼠,取左肝组织检测细胞凋亡及Bc1-2和Bax表达水平。结果:与S组相比,C组细胞凋亡指数、Bax蛋白表达均增高,而瑞芬太尼预处理减弱了缺血再灌注上述指标的升高(P<0.05);C组Bc1-2蛋白表达减少,瑞芬太尼预处理可增强其在肝组织的表达(P<0.05)。光镜和电镜检查显示瑞芬太尼预处理减轻肝缺血再灌注损伤。结论:瑞芬太尼预处理可以抑制大鼠肝脏缺血再灌注损伤早期细胞凋亡,其机制与上调Bc1-2蛋白表达、下调Bax蛋白表达有关。     

七氟醚对大鼠缺血再灌注心肌凋亡相关基因表达的影响

目的探讨七氟醚预处理对大鼠心脏缺血再灌注过程中心肌细胞Bcl-2及Bax基因表达的影响。方法24只SD大鼠随机分成3组（n=8）：假手术对照组（C组）、缺血再灌注对照组（IR组）和七氟醚预处理组（s组）。IR组与S组接受左冠脉3h阻断和3h再灌注。七氟醚预处理组在缺血前吸入七氟醚,30min后洗脱15min。取心肌缺血区组织,RT-PCR测Bcl-2及Bax基因的mRNA表达,免疫印迹法（Western-blot）测蛋白表达。结果与C组相比较,IR组和S组Bcl-2的mRNA和蛋白表达均下调,而S组高于IR组;Bax的mRNA和蛋白表达IR及S组均高于C组,IR组则高于S组。结论七氟醚预处理抑制心肌细胞凋亡可能与上调Bd-2基因的表达、下调Bax基因的表达有关。     

丙泊酚对大鼠肝脏缺血再灌注损伤Bcl-2和P53表达的影响

目的探讨丙泊酚对大鼠肝脏缺血再灌注损伤时Bcl-2和P53表达的影响及其保护作用。方法健康成年雄性SD大鼠54只,随机分为3组:假手术组(Ⅰ组)、缺血再灌注组(Ⅱ组)、丙泊酚组(Ⅲ组)。每组根据再灌注时间不同又分为3个时间段(1、2、3h)。制作70%肝脏缺血再灌注模型,实验结束后即刻取肝左叶做标本。用免疫组织化学法检测Bcl-2与P53蛋白表达量,原位细胞凋亡检测(TUNEL)法检测肝细胞凋亡指数(AI),光镜下观察肝组织的病理学变化。结果与Ⅰ组比较,Ⅱ、Ⅲ组肝组织Bcl-2、P53蛋白含量、凋亡指数差异均有统计学意义(P<0.05);与Ⅱ组比较,Ⅲ组Bcl-2蛋白表达增加、P53蛋白表达和AI减少(P<0.05);光镜下Ⅲ组的肝细胞病理学变化轻于Ⅱ组。结论丙泊酚可以通过调节Bcl-2、P53蛋白表达,使肝细胞凋亡减轻,从而对大鼠缺血再灌注肝脏有一定的保护作用。     

SIRT3-FOXO1介导自噬在H9C2心肌细胞缺血再灌注损伤中的保护作用

目的　探究沉默信息调节因子2相关酶类3（SIRT3）-叉头盒转录因子O1（FOXO1）通路介导自噬在心肌细胞缺血再灌注损伤中的作用。方法　慢病毒感染H9C2心肌细胞构建SIRT3过表达稳定株。实验分4组：正常对照（NC）组、缺血再灌注（IR）组、SIRT3过表达+缺血再灌注（S+IR）组、SIRT3过表达+IR+SIRT3抑制剂（S+IR+3-TYP）组。Western blot检测SIRT3、乙酰化FOXO1（Ac-FOXO1）、自噬标记蛋白LC3B、Beclin1及凋亡相关蛋白Bcl-2、Bax的表达;流式细胞分析仪检测细胞凋亡率;全自动生化仪检测细胞培养上清液中乳酸脱氢酶（LDH）水平。结果　与NC组相比,IR组SIRT3表达降低,Ac-FOXO1表达升高,自噬标记蛋白LC3B、Beclin1表达升高,抗凋亡蛋白Bcl-2表达降低,促凋亡蛋白Bax表达升高,LDH水平和细胞凋亡率升高（P＜0.05）。与IR组相比较,S+IR组SIRT3表达升高,Ac-FOXO1表达降低,LC3B、Beclin1表达升高,Bcl-2表达升高,Bax表达降低,LDH水平和细胞凋亡率降低（P＜0.05）;加入SIRT3抑制剂3-TYP后,与S+IR组相比,SIRT3表达水平无明显变化,但Ac-FOXO1表达升高,LC3B、Beclin1表达降低,Bcl-2表达降低,Bax表达升高,LDH水平和细胞凋亡率升高（P＜0.05）。结论　SIRT3-FOXO1通路激活可提高H9C2心肌细胞自噬水平,对心肌缺血再灌注损伤有保护作用。     

落新妇苷预处理对大鼠肝脏缺血再灌注损伤和Bcl-2、Bax表达的影响

摘 要 目的：探讨落新妇苷对大鼠肝脏缺血再灌注损伤（HIRI）的保护作用及其相关机制。方法: SD大鼠分为Sham 组(假手术组)、HIRI 组(缺血再灌注组)、试验药物组(落新妇苷组),建立大鼠HIRI模型,于再灌注4h、8h、16h后取血液及肝脏标本。检测血清ALT、AST;光镜下检查肝脏细胞损伤程度;Western Blot检测肝组织中Bcl-2、Bax蛋白的表达;TUNEL 染色检测肝组织中的凋亡细胞。结果: 试验药物组ALT和AST水平较HIRI组明显降低(P<0.05)。光镜下观察示试验药物组肝细胞损伤明显减轻。Western Blot结果示试验药物组Bcl-2蛋白的表达较HIRI 组显著升高,Bax蛋白的表达较HIRI 组显著降低(P<0.05)。试验药物组的肝脏细胞凋亡百分比较HIRI 组显著降低(P<0.05)。结论:落新妇苷预处理可减轻大鼠HIRI,其作用机制可能与增加Bcl-2表达、抑制Bax表达,从而抑制细胞凋亡有关。     

舒芬太尼对大鼠肠缺血-再灌注时肝组织Bcl-2和Bax蛋白表达的影响

目的 探讨舒芬太尼对大鼠肠缺血-再灌注(I-R)时肝组织Bcl-2和Bax蛋白表达的影响.方法 24只成年健康Wistar大鼠随机均分为假手术组(S组)、肠缺血-再灌注组(I-R组)和舒芬太尼组(SF组)三组.通过夹闭肠系膜上动脉1h后再灌注6h建立肠I-R损伤模型,SF组在夹闭前10 min给予舒芬太尼1 μg/kg,继之以0.05μg·kg-1·min-1的速率泵注.免疫组化法检测各组肝组织Bcl-2和Bax蛋白表达量.结果 与S组比较,I-R组和SF组Bcl 2和Bax蛋白含量均升高(P＜0.05),I-R组Bcl-2/Bax比值降低(P＜0.05),SF组Bcl-2/Bax比值升高(P＜0.05).与I-R组比较,SF组Bcl-2蛋白含量和Bcl-2/Bax比值均升高(P＜0.05),Bax蛋白含量降低(P＜0.05).结论 舒芬太尼可能通过调节Bcl-2和Bax蛋白表达减轻肠I-R时的肝损伤.     

白藜芦醇预处理对心肌细胞缺血/再灌注损伤的细胞凋亡的影响

目的观察白藜芦醇预处理对心肌细胞缺血再灌注损伤的细胞凋亡的影响。方法培养乳鼠心肌细胞,模拟I/R损伤,随机分为阴性对照组、缺血再灌组及白藜芦醇预处理组,采用TUNEL染色法及Annexin V-FITC/PI双标记流式细胞术检测心肌细胞凋亡;底物酶解法检测caspase-3活性;免疫组织化学法结合计算机图像分析检测心肌细胞Bcl-2/Bax蛋白的表达。结果Res预处理使得心肌细胞凋亡率由(39.7±5.4)%降至(8.3±0.8)%,caspase-3的相对活性由5.9±0.7降至2.8±0.4,P<0.05。Res预处理可使Bcl-2表达的光密度值由99.5±4.8升至138.9±8.4,Bax表达的光密度值由140.7±8.6降至125.3±5.8,P<0.05。结论白藜芦醇预处理可通过促进抗凋亡蛋白Bcl-2的表达、抑制促凋亡蛋白Bax的表达,抑制凋亡过程中关键酶caspase-3的活性,减少I/R引起的心肌细胞凋亡。     

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.