蚯蚓纤溶酶的抗肿瘤作用

目的　观察蚯蚓纤溶酶 (EFE)对体外人癌细胞株及体内人癌裸鼠移植性肿瘤生长的影响 ,对该药进行临床前抗肿瘤药效学评价。方法　采用MTT法观察蚯蚓纤溶酶对体外人癌细胞的生长抑制作用 ;用人胃癌BGC82 3和人乳腺癌B37裸鼠移植性肿瘤模型对蚯蚓纤溶酶进行体内抗肿瘤药效学观察。结果　蚯蚓纤溶酶在体外对人癌细胞的生长无抑制作用 ;灌胃给予蚯蚓纤溶酶 2 0 0～ 10 0 0mg·kg-1,可明显抑制人胃癌BGC82 3和人乳腺癌B37裸鼠移植性肿瘤的生长。结论　蚯蚓纤溶酶具有抗肿瘤作用。     

蚯蚓纤溶酶的纯化及pH值、温度和胰蛋白酶对其纤溶活性的影响

目的纯化并鉴定蚯蚓纤溶酶 ,研究pH、温度和胰蛋白酶对其纤溶活性的影响。方法以赤子爱胜蚓为材料 ,采用硫酸铵盐析、DEAESepharoseCL 6B离子交换色谱、SephadexG 75凝胶过滤和制备电泳等分离技术纯化蚯蚓纤溶酶 ;利用纤维平板和聚丙烯酰胺凝胶电泳研究pH、温度和胰蛋白酶对蚯蚓纤溶酶纤溶活性的影响。结果分离得到纤溶酶 4种单一组分 :EFE 1、EFE 2、EFE 3、EFE 4 ;分子量分别为 2 70 0 0、2 80 0 0、2 30 0 0、330 0 0 ;4种组分对温度的适应范围较广 ;pH值对其纤溶活性的影响不尽相同 ,但都在pH低于 1.5时纤溶活性完全丧失 ;胰蛋白酶对纤溶酶 4种组分均无降解作用 ,对其纤溶活性无影响。结论纤溶酶口服药制剂宜制成肠溶型     

蚯蚓纤溶酶的分离纯化研究

目的从赤子爱胜蚓(Eisenia Foelide)中分离纯化出一种相对分子质量(Mr)较小的纤维蛋白溶解组分———蚯蚓纤溶酶(EFE),为其注射剂的研制开发打下基础。方法采用盐析、透析、凝胶过滤色谱、离子交换色谱等方法分离纯化EFE,用SDS-PAGE对纯化的活性组分进行Mr测定,用酶谱分析方法初步探讨蚯蚓中存在的其它纤溶酶活性组分。结果分离纯化得到了EFE单一组分,经SDS-PAGE EFE呈单一条带,Mr约为25 000。经酶谱分析发现纤溶酶活性组分Mr分布在25 000~50 000之间。结论反复使用色谱技术可分离纯化EFE,并得到单一组分。     

快速蛋白液相色谱法纯化威廉环毛蚓纤溶酶及其活性研究

摸索威廉环毛蚓纤溶酶的分离纯化工艺和研究蚯蚓纤溶酶(earthw fibrinolytic enzyme，EFE)体内外的抗栓溶栓活性。通过提取，分步盐析，再经AKTAbasic蛋白快速液相色谱进一步纯化，得一组有纤溶活性的同工酶，其中一种比活较大达2000IU／mg。药理试验表明该酶有明显的抗拴溶栓活性。     

蚯蚓纤溶酶的亲和层析纯化及部分性质

用牛血纤溶酶原Ｓｅｐａｒｏｓｅ４Ｂ亲和层析方法从蚯蚓粗提物丙酮粉中分离纯化一种纤维蛋白溶解酶。该酶为糖蛋白，含糖量约为１．４３％，Ｍｒ为３００００。实验结果表明此酶具有直接溶解纤维蛋白和激活纤溶酶原的间接溶解纤维蛋白的双重作用，并对人血凝块有明显的溶解作用。１％ＰＭＳＦ对酶有显著的抑制作用，说明此蚯蚓纤溶酶为典型的丝氨酸蛋白酶类酶。     

蚯蚓纤溶酶化学修饰的研究

以三聚氰氯为活化剂，采用活化聚乙二醇(PEG)对环毛蚯蚓纤溶酶进行化学修饰，优化了修饰条件，得到了PEG-EFE的加合物(修饰酶)，并研究了PEG-EFE的部分酶学性质。修饰酶的活力为天然酶的85％，结果表明酶的活性中心基本保持不变。对修饰酶的残留氨基测定表明，70％的可滴定氨基参加了反应，且EFE的活性改变较小，可以推测PEG是连接在蛋白质表面上的。     

糖链对蚯蚓纤溶酶纤溶活性的影响

应用以大豆胰蛋白酶抑制剂(SBTI)为配基的亲和色谱从赤子爱胜蚓中分离了蚯蚓纤溶酶,亲和介质Sepharose-4B对蚯蚓纤溶酶的吸附量为0.04 ms/g,以糖苷酶A去除固定在SBTI上的蚯蚓纤溶酶的糖链.辣根过氧化物酶标记的刀豆凝集素(ConA-HRP)亲和印迹和Schiffs染色结果表明.蚯蚓纤溶酶的糖链已基本去除,去除糖链后蚯蚓纤溶酶的活性降低约30%.     

一种体内溶栓活性优于总蚯蚓纤溶酶的组分

目的筛选高效低毒的蚯蚓纤溶酶单一组分。方法通过亲和色谱从赤子爱胜蚓获得含多组分的总蚯蚓纤溶酶(EFE)，经离子交换分离得到3个主要溶栓组分EfP-0-2，EfP-I-1和EfP-I-2，与EFE比较体内外溶栓效果和毒副作用。结果与其他组分比较，EfP-I-1的体外溶栓作用较强；当静脉注射4.5 mg·kg^-1时，各组分对纤维蛋白原的影响均不明显，只有EfP-I-1能显著溶解动静脉旁路血栓；当静脉注射达6 mg·kg^-1时，只有该组分对延长出血时间的影响不明显；急性毒性实验表明，该组分的LD₅₀是EFE的2.17倍。结论EfP-I-1有较高的体内外溶栓活性和较低的毒副作用。由于该组分在总EFE中所占比例较高，并易于分离纯化，故适于作为单一组分的溶栓药物进行开发。     

蚯蚓纤溶酶对人肝癌细胞侵袭转移潜能的影响

目的 探讨蚯蚓纤溶酶(EFE)对人肝癌细胞系SMMC-7721细胞侵袭、转移潜能的影响.方法 将不同浓度EFE作用于体外培养的SMMC-7721细胞,通过细胞-基质粘附实验检测SMMC-7721细胞与基质胶(matrigel)黏附性,transwell小室模型测定细胞侵袭能力和迁移能力的改变,逆转录聚合酶链反应(RT-PCR)和蛋白印迹(Western blot)分别检测不同药物浓度作用后细胞内黏着斑激酶(FAK)mRNA及蛋白表达量的变化.结果 与对照组相比,EFE 2、4、6 uku/ml作用于SMMC-7721细胞能降低肝癌细胞与基质胶的黏附性(P<0.01)、降低SMMC-7721细胞的侵袭力及迁移能力(P<0.05或P<0.01);同时能够下调FAK mRNA和蛋白的表达(P<0.01).结论 EFE能抑制肝癌SMMC-7721细胞的侵袭和转移,其机制可能与其抑制FAK的表达有关,EFE具有潜在的抗肝癌细胞侵袭、转移作用.     

海洋链霉菌发酵纤溶酶的分离纯化和酶学性质研究

目的 从筛选的1株海洋链霉菌MY0504发酵液中,分离得到1种新型纤溶酶并对其部分酶学性质进行初步研究。方法 采用高速离心、盐析、Sephadex G-75 凝胶过滤层析对纤溶酶进行分离纯化;采用纤维蛋白平板法测定纤溶活性, SDS－PAGE 电泳测定分子量,小鼠急毒实验检测安全性,并考察温度、pH、金属离子和抑制剂对酶活性的影响。结果 从发酵液提取纤溶酶的纯化倍数为7.15倍,酶活力回收率为32%,其分子量约为14kD,安全无毒。该酶在47℃以下稳定,适宜pH为7.0~9.0,最适pH值为8.0,Cu₂₊对该纤溶酶抑制作用显著,Ca₂₊有一定的促进作用。Aprotinin 强烈抑制纤溶酶活性,PMSF(苯甲基磺酰氟)可以完全抑制该纤溶酶活性,初步推测该酶是1种丝氨酸蛋白酶。结论 从海洋链霉菌MY0504发酵液中获得1种小分子量纤溶酶,为开发新的溶栓剂提供了新的选择和理论依据。     

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.