Pim-3基因转染对心肌缺氧／复氧损伤的保护作用

目的：克隆原癌基因Pim-3并构建其GFP表达质粒，探讨Pim-3对心肌细胞遭受缺氧／复氧损伤时所起的保护作用。方法：采用RT-PCR从Wistar大鼠心肌组织中提取并克隆Pim3基因，经酶切和连接反应构建GFP表达质粒，分别为pEGFP-N2-Pim-3质粒和pEGFP-N2（空载质粒），经脂质体转染人原代培养的心肌中，随机分为七组，分别为对照组、对照＋pEGFP-N2组、对照＋pEGFP-N2-Pim-3组、缺氧复氧损伤组、缺氧复氧损伤＋pEGFP-N2组、缺氧复氧损伤＋pEGFPN2-Pim-3组、缺氧预适应处理组。实验结束时全自动生化仪检测培养液中乳酸脱氢酶（LDH）活性、四唑盐（MTT）比色试验测定细胞存活率、TUNEL法与P1-An-nexin V法测定心肌细胞凋亡、流式细胞仪测定心肌细胞线粒体膜电位（△ψm），并且测定Pim-3 mRNA及蛋白表达水平（RT-PCR、Western-blotting法）的改变。结果：经酶切证实和测序鉴定，成功克隆大鼠Pim-3基吲，并且细胞转染效率达15％；在缺氧复氧损伤后，pEGFP-N2-Pim-3转染组较pEGFP-N2转染组／未转染组的LDH值明显降低（p〈0．01），细胞存活率则明显升高（P〈0．01），凋亡细胞明显减少（P〈0．01），线粒体膜电位（△皿m）则明显升高（P〈0．01）；电镜结果表明转染了pEGFP-N2-Pim-3的心肌细胞线粒体膜大都完整，嵴清晰，较之pEGFP-N2转染组／未转染组损伤明显减轻；RT-PCR和Western-blotting结果显示，Pim-3在正常组几乎不表达，缺氧复氧损伤组明显升高（p〈0．01），缺氧预处理组的表达则比缺氧复氧损伤组更为升高（P〈0．05）。结论：外源性Pim-3基因转染人心肌细胞，对心肌细胞的缺氧／复氧损伤具有明显的保护作用。     

大蒜素对培养乳鼠心肌细胞缺氧/复氧损伤细胞凋亡的影响

目的 探讨大蒜素对培养乳鼠心肌细胞缺氧／复氧损伤的保护作用及对心肌细胞凋亡的影响。方法 利用乳鼠培养心肌细胞缺氧／复氧（A／R）损伤模型,将培养心肌细胞分为正常对照组（C组）、缺氧预处理组（AP组）、缺氧/复氧组（A／R组）、大蒜素预处理组（G组）,测定各组缺氧后、复氧后细胞损伤指标乳酸脱氢酶（LDH）、丙二醛（MDA）、超氧化物歧化酶（SOD）含量,并应用DNA琼脂糖凝胶电泳及原位末端标记（TUNEL）法检测各组凋亡指数（AI）。结果G、AP组LDII、MDA明显较A／R组降低（P＜0．01）,SOD明显增高（P〈0．01）;A／R、AP、G组AI较C组明显增高（P〈0．01）,AP、G组AI较A／R组显著降低（P〈0．01）,G组AI较AP组稍高（P〉0．05）。结论 大蒜素具有抗心肌细胞凋亡作用。可减轻心肌细胞A／R损伤。     

常压慢性缺氧致大鼠心肌重构形态学观察

目的建立慢性缺氧心肌肥大大鼠模型,观察SD大鼠在常压慢性持续缺氧下心肌重构导致的形态学变化。方法SD幼鼠于常压慢性持续缺氧14、21、28d后分别测量检测右心室／左心室加室间隔比值[RV／（LV＋S）],右心室／体质量（RV／BW）比值,用Hoechst33258双染色法进行形态学观察,用原位末端标记（Tunel）法进行心肌细胞凋亡形态及计量分析。结果慢性缺氧组RV／（CV＋S）、RV／BW比值均明显高于正常对照组（P〈0．01）,并且RV／（LV＋S）、RV／BW比值随时间增加而增高（P〈0．01）。慢性缺氧组大鼠右心室心肌细胞凋亡指数明显均高于正常对照组（P〈0．01）,并且心肌细胞凋亡指数随着缺氧时间的延长而增高（P〈0．01）。结论慢性缺氧可诱导大鼠右心室重构,包括心肌肥大和心肌细胞凋亡,且大鼠右心室心肌肥大程度和心肌细胞凋亡随着缺氧时间的延长而增加。     

阿片受体激活对培养心肌细胞缺氧／复氧损伤的保护作用

目的：观察δ阿片受体激活剂D-丙（2）-D-亮（5）脑啡肽（DADLE）对培养心肌细胞缺氧／复氧（H／R）损伤的保护作用。方法：采用培养的SD大鼠乳鼠的心肌细胞，建立H／R损伤模型，检测指标包括：（1）心肌细胞形态；（2）心肌细胞存活率；（3）超氧化物歧化酶（SOD）活性；（4）丙二醛（MDA）含量；（5）乳酸脱氢酶（LDH）活性。结果-模型组缺氧后心肌细胞存活率降低，复氧30min后进一步下降，各个时间点细胞内SOD活性下降，MDA含量升高，LDH活性升高，与正常组比较差异有统计学意义（P〈0．01），复氧60min后各指标逐渐趋于正常状态；DADLE 1μmaol／L组细胞存活率升高，LDH活性降低，MDA含量逐渐趋于正常，SOD活性逐渐回升，表明经DADLE干预后，心肌细胞抗损伤能力加强，发生损伤的程度减轻；δ阿片受体抑制剂纳曲吲哚10μmol／L抑制DADLE的保护作用。结论：DADLE通过δ阿片受体对乳鼠心肌细胞H／R损伤具有保护作用。     

硫酸锌预处理对成年大鼠缺氧/复氧心肌细胞超微结构的影响

目的研究硫酸锌预处理对成年大鼠缺氧/复氧心肌细胞超微结构的影响。方法 分离培养SD成年大鼠心肌细胞,建立心肌细胞缺氧/复氧损伤模型,将细胞随机分为正常组(N组)、缺氧/复氧组(H/R组)、缺氧预处理组(HP组)、硫酸锌(Zn SO4)预处理组(Zn P组),分别进行相应处理,然后用透射电镜对各组心肌细胞超微结构进行观察,并进行线粒体评分。结果 N组、HP组、Zn P组超微结构优于H/R组,且线粒体评分较H/R组低,差异均有统计学意义(P<0.05);HP组、Zn P组超微结构变化相似,且两组线粒体评分比较,差异无统计学意义(P>0.05),但均高于N组,差异有统计学意义(P<0.05)。结论 缺氧/复氧可造成成年大鼠心肌细胞超微结构的损伤,Zn SO4预处理、缺氧预处理均能减轻该损伤,且二者效果相当。     

落新妇苷对心脏移植排斥反应中活化T细胞p38丝裂原激活蛋白激酶信号传导通路的影响

目的：用小鼠心脏移植急性排斥反应体外模型，探讨落新妇苷对心脏移植排斥反应中活化T细胞p3S丝裂原激活蛋白激酶（p38MAPK）信号传导通路的影响。方法：分离BALB／C小鼠心肌细胞（2×10^5个·mL^-1）和C57BL／6小鼠的睥细胞（1×10“个·mL^-1），前者做刺激细胞，后者做反应细胞，进行混合细胞培养，建立小鼠心脏移植急性排斥反应体外模型。实验分3组：对照组，心肌细胞与脾细胞混合培养；落新妇苷组，在对照组基础上加入落新妇苷（15mg·L^-1）；落新妇苷加p38MAPK抑制剂组，在对照组基础上加入落新妇苷（15mg·L^-1）和p38MAPK抑制剂SB203580（5μmol·L^-1）。TUNEL法检测T淋巴细胞凋亡情况。RT-PCR和Western blot法检测T细胞p38MAPK表达情况。结果：落新妇苷组T细胞凋亡指数和p38MAPK表达均明显高于对照组（P＜0．01）。落新妇苷加p38MAPK抑制剂组T细胞凋亡指数和p38MAPK表达均明显低于落新妇苷组（P＜0．01），而与对照组相比差异无显著性（P＞0．05）。结论：落新妇苷诱导心脏移植排斥反应中活化T细胞凋亡与其激活p38MAPK信号传导通路有关。     

通心络胶囊对糖尿病小鼠视网膜 p38 MAPK信号通路的影响

目的：观察通心络胶囊对糖尿病小鼠视网膜p38丝裂原活化蛋白激酶（ p38 MAPK）信号通路的影响,探讨其视网膜保护作用的可能机制。方法 KK／Upj-Ay小鼠40只随机分为糖尿病模型组、通心络低、中、高剂量组,每组10只,另设C57BL／6（C57）小鼠10只作为对照组。按照分组给予不同剂量处理因素,疗程3个月,观察体质量,测定空腹血糖（FBG）,取眼球行HE 染色,Western-blot 检测视网膜p38MAPK、JNK、ERK 总蛋白及磷酸化p38MAPK、JNK、ERK（ p-p38MAPK、p-JNK、p-ERK）的表达。结果与对照组比较,模型组体质量、FBG及p-p38MAPK、p-JNK、p-ERK表达均显著增高,通心络胶囊能够减轻视网膜病理损伤,降低p-p38 MAPK表达（ P ＜0?．05）,而不影响体质量、FBG及p-JNK、p-ERK表达（ P ＞0．05）;且各组p38MAPK、JNK、ERK 总蛋白表达差异无统计学意义（ P ＞0．05）。结论 p38 MAPK信号通路可能参与了糖尿病视网膜损害的发生发展。通心络胶囊可减轻糖尿病小鼠视网膜病理损伤,其机制可能与降低p38MAPK蛋白磷酸化水平有关。     

p38MAPK/14-3-3γ通路在LPS预处理对抗心肌细胞缺氧/复氧损伤中的作用

目的研究p38MAPK/14-3-3γ通路在LPS预处理对抗缺氧/复氧(A/R)损伤中的作用。方法采用原代培养乳鼠心肌细胞,建立A/R损伤模型及APC、LPS预处理保护模型。实验结束后测定p38MAPK磷酸化蛋白表达及14-3-3γ蛋白表达,同时检测培养液中乳酸脱氢酶(LDH)活性、四唑盐(MTT)比色试验测定细胞存活率、TUNEL法检测细胞凋亡、线粒体肿胀实验检测线粒体通透性转换孔(mPTP)开放、流式细胞仪检测线粒体膜电位。结果 LPS预处理对随后心肌A/R损伤有类似APC的保护作用,同时伴随p38MAPK的磷酸化水平升高和14-3-3γ蛋白表达升高;给予SB203850特异性阻断p38MAPK通路,则14-3-3γ蛋白表达明显下调,并且心肌细胞LDH值升高,细胞存活率下降,心肌细胞的凋亡指数升高,mPTP开放加剧,线粒体膜电位降低。结论 LPS预处理对心肌细胞A/R损伤有保护作用,其机制可能是通过激活p38 MAPK,上调14-3-3γ的表达实现。     

协同刺激分子B7-H1在自发性流产患者的表达及其生物学意义

目的研究协同刺激分子B7‐H1在自发性流产患者的表达及其生物学意义。方法 ELISA法检测正常未孕者（A组,52例）、正常妊娠者（B组,49例）、自发性流产患者（C组,52例）和自发性流产后再妊娠者（D组,17例）血清可溶性B7‐H1（sB7‐H1）的含量。免疫组化法检测正常妊娠行人工流产术患者（E组,20例）和自发性流产患者（F组,21例）绒毛膜和蜕膜中B7‐H1的表达。结果 A、B、C、D组血清sB7‐H1含量无统计学差异（P＞0．05）。E组蜕膜中B7‐H1的表达高于F组（P＜0．05）,但两组绒毛膜中B7‐H1的表达无统计学差异（P＞0．05）。结论 B7‐H1参与了正常妊娠过程;其异常表达对自发性流产的发生有重要意义。     

银杏叶提取物对缺氧复氧诱导的大鼠皮层神经元凋亡和Bcl-2蛋白表达的影响

目的 观察银杏叶提取物（EGb）及其活性成份银杏总内酯（Gin）对缺氧复氧诱导的大鼠皮层神经元凋亡的保护作用。方法 选用胎龄14～16d的SD胎鼠的大脑皮层细胞进行原代培养,建立缺氧复氧（H／R）神经元损伤模型。实验分为正常组、缺氧复氧（H／R）组、药物实验（EGb、Gjn）组、阳性对照（MK-801）组。应用MTF、TUNEL及Western blot方法。结果 EGb和Gin均能提高皮层神经元缺氧复氧后的存活率,EGb和Gin组神经元的凋亡率低于H／R组且Bcl-2蛋白表达量较H／R组升高。结论 EGb和Gin可部分拮抗缺氧复氧条件下体外培养的皮层神经元的凋亡,该保护作用与其诱导Bcl-2蛋白表达有关。     

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.