黄芩苷对脑缺血-再灌注损伤大鼠神经细胞凋亡及相关基因表达的影响

目的:研究黄芩苷对大鼠局灶性脑缺血-再灌注损伤后神经细胞凋亡以及半胱氨酸天冬氨酸蛋白酶(caspase)-3、热休克蛋白(HSP)70表达的影响。方法:96只Wistar大鼠随机分为假手术组、脑缺血再灌注模型组、黄芩苷组(50,100,200 mg·kg-1),以及尼莫地平(0．4 mg·kg-1)组。利用大鼠大脑中动脉内栓线阻断法制备局灶性脑缺血-再灌注损伤模型,通过HE染色、流式细胞术、免疫组化以及RT- PCR等方法,观察黄芩苷对大鼠局灶性脑缺血-再灌注损伤后脑组织病理形态学改变、神经细胞凋亡率以及caspase-3、HSP70表达的影响。结果:黄芩苷可明显改善脑缺血-再灌注损伤所致的大鼠脑组织病理形态学改变,降低神经细胞凋亡率,抑制促凋亡基因caspase-3的表达,促进抑凋亡基因HSP70的表达。结论:黄芩苷对大鼠局灶性脑缺血-再灌注损伤具有保护作用,其作用机制可能与黄芩苷抑制caspase-3表达,促进HSP70表达,从而发挥抗凋亡作用有关。     

黄芩苷对大鼠脑缺血再灌注损伤后海马神经元HSP70表达的影响

目的研究黄芩苷对大鼠局灶性脑缺血再灌注损伤后海马神经元热休克蛋白质(HSP)70表达的影响。方法Wistar大鼠随机分为假手术组、脑缺血再灌注模型组、黄芩苷组(50，100和200 mg·kg^-1)以及尼莫地平0.4 mg·kg^-1组。利用大鼠大脑中动脉内栓线阻断法制备局灶性脑缺血再灌注损伤模型，通过HE染色、流式细胞术、免疫组织化学以及RT-PCR等方法，观察黄芩苷对缺血再灌注损伤大鼠脑组织病理形态学改变、神经细胞凋亡率以及HSP70表达的影响。结果黄芩苷可明显改善缺血再灌注损伤所致的大鼠脑组织病理形态学改变,降低神经细胞凋亡率，促进HSP70基因的转录与翻译。结论黄芩苷对大鼠局灶性脑缺血再灌注损伤具有保护作用，其作用机制可能与黄芩苷促进HSP70表达、抑制神经细胞凋亡有关。     

黄芪提取物对大鼠局灶性脑缺血再灌注损伤后炎症因子及细胞凋亡的作用

目的研究黄芪提取物(EA)对局灶性脑缺血再灌注损伤的保护作用机制。方法采用线栓法大鼠局灶性脑缺血再灌注损伤模型,以免疫组化法观察EA对缺血再灌注后大鼠脑组织中TNFα表达的影响、以放免法观察对IL1β水平的影响、以TUNEL法观察对脑组织细胞凋亡的影响。结果与模型组比较,EA(20、40、80mg·kg-1,ig)能减少TNFα的表达、降低IL1β水平和减少细胞凋亡数。结论EA对大鼠局灶性脑缺血再灌注后脑组织中TNFα及IL1β的升高和神经元的凋亡有明显的抑制作用。     

吗啡预处理对脑缺血-再灌注后神经元凋亡、Bcl-2及Bax表达的影响

目的探讨吗啡预处理对大鼠脑缺血-再灌注损伤后神经元凋亡、Bel-2及Bax蛋白表达的影响。方法 Wistar大鼠32只随机分成假手术组、模型组、吗啡1mg·kg~(-1)组、吗啡7mg·kg~(-1)组,各8只。四动脉阻断法建立脑缺血模型。缺血前60min腹腔注射给药,假手术组和模型组给予生理盐水。脑缺血8min、再灌注24h后取大鼠的脑组织,HE染色观察海马区脑组织病理学改变、TUNEL法检测神经元凋亡、免疫组化法观察Bcl-2及Bax蛋白表达。结果吗啡预处理使海马神经元病理改变减轻、凋亡细胞数及Bax表达减少(P<0.01),而Bcl-2表达增加(P<0.01);且吗啡7mg·kg~(-1)组减少神经元凋亡及改善神经元病理变化的作用更为显著(P<0.01)。结论吗啡预处理可减少缺血-再灌注损伤后神经元凋亡,其作用机制可能与其影响Bcl-2和Bax蛋白表达有关。吗啡7mg·kg~(-1)预处理的保护作用更为显著。     

杜仲提取物预处理对脑缺血再灌注损伤大鼠抗氧化能力及一氧化氮的影响

目的观察杜仲提取物预处理对大鼠脑缺血再灌注损伤中抗氧化能力及一氧化氮的影响,探讨杜仲提取物抗脑缺血再灌注损伤的作用机制。方法雄性SD大鼠120只,随机分为假手术组、模型组、尼莫地平预处理(12 mg·kg~(-1))组和杜仲提取物不同剂量预处理(分别给予200、400、800 mg·kg~(-1)·d~(-1))组,均n=20。各给药组均在制模前预先灌胃给药14 d,采用线栓法制备大鼠局灶性脑缺血再灌注损伤模型,假手术组只分离血管,不留置线栓,假手术及模型组分别给予同体积蒸馏水。缺血2 h再灌注24 h后,用2,3,5-氯化三苯基四氮唑(TTC)染色测定梗死面积,HE染色观察病理形态改变,检测血清及脑组织中丙二醛(MDA)、超氧化物歧化酶(SOD)、一氧化氮(NO)含量及诱导型一氧化氮合酶(iNOS)活性。结果与模型组相比,杜仲提取物各剂量组大鼠脑梗死面积减少(P<0.05)。杜仲提取物中、高剂量组血清和脑组织中的MDA和NO含量及iNOS活性均显著降低,SOD活性显著升高(P<0.05),与尼莫地平组相比无显著差异(P>0.05)。结论杜仲提取物预处理减轻脑缺血再灌注损伤的机制可能是提高抗氧化能力并降低NO水平。     

银杏内酯上调CGRP对大鼠脑缺血再灌注损伤产生保护作用

目的　研究银杏内酯对大鼠局灶性脑缺血再灌注损伤的保护作用与降钙素基因相关肽 (CGRP)的关系。方法　大脑中动脉线栓法 (MCAO)制作大鼠局灶性脑缺血再灌注损伤模型。 6 0只SD♂大鼠随机分为假手术组 (sham)、脑缺血再灌注模型组 (MCAO)、溶媒对照组 (MCAO +vehicle)、银杏内酯低剂量 (MCAO +ginkgolide 10mg·kg-1)、中剂量(MCAO +ginkgolide 2 0mg·kg-1)和高剂量 (MCAO +ginkgolide 4 0mg·kg-1)治疗组 ,每组 10只大鼠。术后对大鼠进行神经缺陷评分 ,并取脑组织测量梗死体积。另 6 0只大鼠 ,分组、实验方法及步骤同上 ,术后取梗死侧脑组织制成匀浆 ,放射免疫法测量脑组织降钙素基因相关肽和内皮素(ET)含量。结果　银杏内酯能明显改善缺血再灌注损伤大鼠神经缺陷症状 ,缩小脑梗死体积 ,剂量依赖性升高缺血脑组织中已降低的CGRP含量和CGRP/ET值。结论　银杏内酯升高缺血脑组织中CGRP含量 ,使缺血脑组织中比例失衡的CGRP/ET值向正常恢复 ,可能是银杏内酯对缺血脑组织产生保护作用的机制之一     

氟比洛芬酯预处理对大鼠全脑缺血/再灌注时脑组织TXA_2/PGI_2的影响

目的探讨氟比洛芬酯预处理对大鼠全脑缺血/再灌注损伤的影响。方法72只♂SD大鼠,体重250～350g,随机分为4组(n=18):假手术组(SH组)、模型组(Model组)、氟比洛芬酯5mg·kg-1组(F5组)和氟比洛芬酯10mg·kg-1组(F10组)。采用夹闭双侧颈总动脉20min合并低血压法建立全脑缺血/再灌注(I/R)模型。F5组和F10组分别于缺血前15min静注氟比洛芬酯5mg·kg-1+空白乳剂0.5ml.kg-1、氟比洛芬酯10mg·kg-1。于再灌注6、24、72h时行神经功能缺陷评分(NDS)、HE染色观察海马CA1区细胞损伤情况、放射免疫法测定额区皮质血栓素A2(TXA2)和前列环素(PGI2)含量。结果氟比洛芬酯5mg·kg-1组(F5组)或氟比洛芬酯10mg·kg-1组(F10组)预处理可明显减轻大鼠全脑缺血/再灌注后海马CA1区损伤,提高神经功能缺陷评分(NDS),降低脑组织中TXA2含量和TXA2/PGI2值,且F10组较F5组海马CA1区损伤更轻。结论氟比洛芬酯预处理可减轻全脑缺血/再灌注损伤,其机制可能与降低TXA2值和TXA2/PGI2值有关。     

黄芪提取物对大鼠局灶性脑缺血再灌注血脑屏障损伤的影响

目的 研究黄芪提取物(extract of astragalus,EA)对大鼠局灶性脑缺血(MCAO)再灌注的血脑屏障损伤的影响。方法 采用线栓法制备MCAO再灌注模型,观察EA对缺血再灌注大鼠的神经功能障碍、脑梗死体积和脑含水量、外周血循环内皮细胞(CEC)含量、缺血脑组织中细胞间粘附分子(ICAM-1)的表达、缺血侧脑组织皮质血脑屏障超微结构的病理学变化的影响。结果 EA80 mg·kg^-1,EA(40,80 mg·kg^-1)、EA(20,40,80 mg·kg^-1)可分别改善缺血再灌注2,8,24 h大鼠的神经功能障碍;能明显降低外周血中的CEC含量,明显减轻缺血脑组织的脑水肿和脑梗死体积,对脑缺血再灌注后血脑屏障超微结构的病理改变有一定的改善作用;能减少ICAM-1免疫反应阳性血管数。结论 EA对局灶性脑缺血再灌注损伤大鼠有一定的保护作用,作用机制可能与其保护血管内皮细胞,减轻脑缺血再灌注后的血脑屏障损伤有关。     

异丙酚对大鼠局灶性脑缺血和蛋白激酶C γ亚单位的作用

目的观察异丙酚对大鼠局灶性脑缺血和脑内蛋白激酶Cγ亚单位(PKCγ)变化的作用。方法♂SD大鼠随机分为Ⅰ:假手术组,Ⅱ:损伤组,Ⅲ:异丙酚(25mg·kg-1)+损伤组,Ⅳ:异丙酚(50mg·kg-1)+损伤组,Ⅴ:脂肪乳剂+损伤组,每组8例。采用大脑中动脉线栓法缺血3h再灌注24h。异丙酚和脂肪乳剂于再灌注前30min腹腔注射。通过原位末端脱氧核苷酸转移酶标记法观察局灶性脑缺血产生的神经细胞凋亡和异丙酚作用效果,免疫细胞化学法观察各组PKCγ蛋白在脑内表达变化的差异。结果再灌注24h后Ⅱ、Ⅲ、Ⅳ、Ⅴ组大鼠体重较缺血前降低(P<0.01),和Ⅰ组比较:Ⅱ、Ⅲ、Ⅳ、Ⅴ组大鼠再灌注24h后出现明显的神经体征缺陷(P<0.01),Ⅱ组大鼠额叶皮层和纹状体区域大量神经细胞凋亡,纹状体PKCγ蛋白表达明显下降。Ⅱ、Ⅲ、Ⅳ、Ⅴ组大鼠纹状体区域凋亡细胞密度与PKCγ染色阳性面积均没有差异(P>0.05)。结论再灌注前30min腹腔注射异丙酚对大鼠局灶性脑缺血再灌注损伤所致的神经细胞凋亡和PKCγ表达降低无保护作用。     

雷公藤多苷对大鼠局灶性脑缺血再灌注损伤的保护作用

目的:观察雷公藤多苷(TwP)对局灶性脑缺血再灌注损伤大鼠的保护作用。方法:180只大鼠随机分为脑缺血再灌注组,TwP大、中、小剂量组,阳性对照组,假手术组。灌胃给药,采用大脑中动脉局灶性缺血再灌注模型,测定再灌注2 h缺血侧脑组织含水量、超氧化物歧化酶(SOD)、丙二醛含量及大脑皮层神经元细胞内[Ca2+]i水平。结果:与假手术组相比,脑缺血再灌注组脑组织丙二醛含量增加、SOD活性降低、含水量及[Ca2+]i显著升高(P<0.01);与脑缺血再灌注组相比,TwP大、中、小剂量组,阳性对照组脑组织丙二醛含量减少、SOD活性升高、[Ca2+]i显著下降(P<0.01或P<0.05),TwP大、中剂量组,阳性对照组脑组织含水量显著降低(P<0.01);TwP各剂量组间结果亦有显著差异(P<0.01或P<0.05)。结论:TwP能减轻大鼠急性脑缺血再灌注损伤引起的脑水肿、降低脑组织丙二醛含量,提高SOD活性,降低细胞内钙积累;且随着剂量增加,变化显著增强,提示雷公藤多苷对大鼠急性脑缺血再灌注损伤具有保护作用。     

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.     

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.     

Lung disease and PKCs

The lung offers a rich opportunity for development of therapeutic strategies focused on isozymes of protein kinase C (PKCs). PKCs are important in many cellular responses in the lung, and existing therapies for pulmonary disorders are inadequate. The lung poses unique challenges as it interfaces with air and blood, contains a pulmonary and systemic circulation, and consists of many cell types. Key structures are bronchial and pulmonary vessels, branching airways, and distal air sacs defined by alveolar walls containing capillaries and interstitial space. The cellular composition of each vessel, airway, and alveolar wall is heterogeneous. Injurious environmental stimuli signal through PKCs and cause a variety of disorders. Edema formation and pulmonary hypertension (PHTN) result from derangements in endothelial, smooth muscle (SM), and/or adventitial fibroblast cell phenotype. Asthma, chronic obstructive pulmonary disease (COPD), and lung cancer are characterized by distinctive pathological changes in airway epithelial, SM, and mucous-generating cells. Acute and chronic pneumonitis and fibrosis occur in the alveolar space and interstitium with type 2 pneumocytes and interstitial fibroblasts/myofibroblasts playing a prominent role. At each site, inflammatory, immune, and vascular progenitor cells contribute to the injury and repair process. Many strategies have been used to investigate PKCs in lung injury. Isolated organ preparations and whole animal studies are powerful approaches especially when genetically engineered mice are used. More analysis of PKC isozymes in normal and diseased human lung tissue and cells is needed to complement this work. Since opposing or counter-regulatory effects of selected PKCs in the same cell or tissue have been found, it may be desirable to target more than one PKC isozyme and potentially in different directions. Because multiple signaling pathways contribute to the key cellular responses important in lung biology, therapeutic strategies targeting PKCs may be more effective if combined with inhibitors of other pathways for additive or synergistic effect. Mechanisms that regulate PKC activity, including phosphorylation and interaction with isozyme-specific binding proteins, are also potential therapeutic targets. Key isotypes of PKC involved in lung pathophysiology are summarized and current and evolving therapeutic approaches to target them are identified.     

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.