浙江眼镜蛇(Naja naja atra)蛇毒镇痛多肽的分离纯化及其性质的研究

研究浙江眼镜蛇(Naja naja natra)蛇毒的镇痛活性组分，为寻找镇痛效果好，而无成瘾性的新型镇痛药奠定基础。采用CM-Sephadex离子交换色谱和Sephadex G-50凝胶过滤色谱对浙江产眼镜蛇蛇毒中的镇痛活性组分进行分离纯化。采用PAGE IEF及HPLC上等实验方法对产物纯度进行鉴定。采用SDS-PAGE法和HPLC法测定产物的分子质量，用IEF法测定产物的等电点，用小鼠热板法与醋酸扭体法考察产物的镇痛活性。结果表明眼镜蛇毒经3次柱色谱后，产物AAP经鉴定为单一组分。AAP经SDS-PAGE法和HPLC法测定的分子质量分别是7．28Mr和7．25Mr，等电点是9．58。AAP的痛阈提高百分率和扭体抑制率分别为91．3％，77．2％。眼镜蛇毒经3次柱色谱后得到具有镇痛活性的单一组分。     

舟山眼镜蛇毒神经毒素的分离纯化及镇痛作用研究

目的从舟山眼镜蛇毒中分离纯化神经毒素,并测定其部分理化性质及镇痛活性。方法应用SP-Sephadex C-50离子交换色谱法分离眼镜蛇毒粗毒,用Sephadex G-50凝胶过滤色谱、CM-Sephadex C-25离子交换色谱纯化神经毒素;SDS-PAGE(Tris-Tricine系统)鉴定纯度;用Meier方法测定毒性;用热板法观察神经毒素的镇痛作用。结果应用SP-Sephadex C-50离子交换柱层析,从舟山眼镜蛇毒中分离得到14个蛋白峰,其中6个组分(NNAV-Ⅶ ~Ⅻ)经鉴定为含有神经毒素组分,将神经毒活性最强的组分XI经Sephadex G-50、CM-Sephadex C-25纯化得神经毒素纯品NTⅪ。该纯品分子量12.3kD,小白鼠静脉注射和腹腔注射的LD50分别为1.9875、2.2217 mg·kg-1。NTXI能显著提高小鼠对热板刺激的痛阈。腹腔注射0.2mg·kg-1NTXI可使小鼠的热板痛阈提高84.35%。NTXI的镇痛作用具有时效性,给药后2h起效,4h作用达峰值。结论舟山眼镜蛇毒中分离得到一个神经毒素纯品NTⅪ,具有镇痛作用。     

广东眼镜蛇毒低分子量多肽的分离纯化与性质鉴定

目的从广东眼镜蛇粗毒中分离纯化出色谱纯的低分子量多肽并对其部分性质进行鉴定。方法采用化学沉淀法对蛇粗毒进行预处理,经Sephadex G-50凝胶过滤和UND Sphere S阳离子交换层析得到高纯度低分子量多肽,用SDS-PAGE及HPLC对产物纯度进行鉴定,并用SDS-PAGE和质谱法测定分子量,采用蛙心灌流法考察产物是否具有心脏毒性。结果结果表明,经分离纯化后得到两种低分子量多肽GI2和GI3,均为单一组分,可达到色谱纯,SDS-PAGE法测得GI2分子量为14 300 Da,质谱法测得GI3分子量为6 725.8 Da,仅GI2具有心脏毒性,收率分别为9.5%和10.1%。结论通过化学沉淀预处理,并经2次柱色谱可从广东眼镜蛇毒中分离得到两种色谱纯的低分子量多肽,且收率较高。     

舟山眼镜蛇毒蕈碱样多肽MP的部分理化性质测定

目的对舟山眼镜蛇毒蕈碱样多肽MP成分进行纯化及部分理化性质测定。方法采用色谱技术纯化蛇毒MP成分,质谱仪测定其相对分子质量(Mr);Edman降解法分析部分氨基酸序列,与已知成分比对;以卵磷脂为底物测定MP组分的磷脂酶A2活性;采用Bliss法测定MP对小鼠的急性毒性。结果 MP的Mr为13 260,其N端16位氨基酸序列为NLYQFKNMIQCTVPSR,与已知蛇毒磷脂酶A2基本一致,并具有较强的磷脂酶A2活性;腹腔注射MP对小鼠的LD50值为14.3 mg/kg。结论 MP为一种眼镜蛇毒磷脂酶A2。     

眼镜蛇神经毒素的规模化制备及其镇痛作用的研究

目的 建立一种快速、规模化制备眼镜蛇毒神经毒素的方法.方法 采用CM-sephadex C-25和CM-sepharose fast flow离子交换柱层析纯化经初步处理的眼镜蛇毒;SDS-PAGE和HPLC检测产物的纯度;离体蛙心和红细胞溶血试验检查产物的心脏毒性和溶血性;小白鼠热板模型、醋酸扭体模型和大白鼠电刺激嘶叫模型评价产物的镇痛作用.结果 制备的产物可达到电泳纯和HPLC单一峰,无心脏毒性和溶血活性,镇痛作用强,但起效慢.结论 所用工艺适合眼镜蛇毒神经毒素工业化制备的需要.     

舟山眼镜蛇毒细胞毒素的分离纯化及其体外抗肿瘤活性

目的从眼镜蛇毒中分离纯化细胞毒素 F(CTX F)并鉴定其活性。方法应用凝胶过滤、离子交换柱色谱及疏水柱色谱等方法从舟山眼镜蛇毒中分离纯化CTX F ,以SRB法观察CTX F对体外培养癌细胞的杀伤作用。结果眼镜蛇毒粗毒经凝胶过滤获得 4个蛋白峰 ,将CTX所在第Ⅳ峰用阳离子交换柱色谱获A、B、C、D、E、F和G等7个组分 ,其中E、F和G具CTX活性 ,将F组分再经凝胶过滤和疏水色谱进一步纯化得不含磷酯酶A2 (PLA2 )的CTX纯品 ,暂定名为CTX F ,它对多种癌细胞株有杀伤作用。结论应用凝胶过滤、离子交换和疏水色谱等方法可从眼镜蛇毒中获得不含PLA2 的CTX ,其组分F有抗肿瘤活性     

东亚钳蝎(ButhusmarthensiiKarsch)毒镇痛活性肽的分离纯化及其镇痛作用研究

本文采用凝胶过滤及离子交换层析法从东亚钳蝎毒中分离纯化出一种蝎毒镇痛活性肽（ＳｃｏｒｐｉｏｎＡｎａｌｇｅｓｉｃＰｅｐｔｉｄｅ简称ＳＡＰ）．ＳＡＰ经ＰＡＧＥ得单一条带，ＨＰＬＣ层析为单一峰；以ＳＤＳ－ｐＡＧＥ法测定其分子量为９１２０，等电聚焦法测定ＳＡＰ的等电点为７．８５，ＳＡＰ对热比较稳定．用小鼠醋酸扭体法等３种动物实验模型测定ＳＡＰ的镇痛作用，结果表明均有较强的镇痛活性．     

江浙蝮蛇毒镇痛组分的分离纯化及其理化性质

目的　分离筛选江浙蝮蛇毒中主要镇痛组分 ,研究其分子量、等电点、纯度、氨基酸序列、稳定性等理化性质 ,以及镇痛作用、机体耐受性和依赖性等药理学性质。方法　采用离子交换和分子筛 ,以柱层析法分离蛇毒组分。用生化测定方法 ,测定其理化性质。用热板法和醋酸扭体法等确定最佳镇痛组分 ,并用纳洛酮催促和自然戒断实验、耐受性实验考察其依赖性和耐受性。结果　分离获得 14个蛋白组分 ,经ED50 /LD50 筛选出最佳镇痛组分C4 ,鉴定结果表明纯度为电泳纯 ,HPLC相对纯度为 92 .16 % ,分子量 16 .6ku ,等电点 8.8,氨基酸序列与磷脂酶A2 同源 ,为一种新的镇痛蛋白 ,并获得其紫外吸收特征峰、镇痛耐受和依赖性等性质。结论　C4组分具有显著的镇痛效果 ,未发现耐受性和依赖性 ,值得进一步研究开发。     

尖吻蝮蛇毒中一种新类凝血酶的分离纯化

用阴离子交换色谱和凝胶过滤色谱技术,从尖吻蝮蛇毒中纯化得到一个具有凝血活性的组分.经Superdex 75 HR10/30预装柱检测,纯度达99.91%.SDS-PAGE显示为单一条带,还原、非还原条件下分子量分别为59.25k、52.58k.该组分的凝血酶比活为41.5u/mg,精氨酸酯酶比活为14.29u/mg,但不激活血浆凝血因子ⅩⅢ.EDTA不能抑制其凝血活性,而苯甲磺酰氟则产生不可逆抑制作用.结果表明该酶是一种新尖吻蝮蛇毒类凝血酶.     

吴茱萸不同组分镇痛作用及安全范围研究

目的研究吴茱萸不同组分发挥镇痛作用的治疗指数和安全范围。方法采用经典的急性毒性试验方法,进行吴茱萸不同组分的急性致死量试验;采用经典的小鼠热板法,进行吴茱萸不同组分的镇痛药效实验。采用Bliss法,计算各组分的急性毒性试验的LD50和LD5以及发挥镇痛药效的ED50和ED95,求得不同组分发挥镇痛作用的治疗指数(TI),安全系数(SF)。结果吴茱萸挥发油LD50值为2.6995mL.kg-.1d-1,LD5值为1.9853m.lkg-.1d-1;ED50值为0.4625mL.kg-.1d-1,ED95值为0.9996 mL.kg-.1d-1;计算得TI为5.837,SF为1.986。吴茱萸水提组分无法作出LD50,MTD试验结果按含生药量计算为80.0 g.kg-.1d-1;ED50值为1.3515 g.kg-1.d-1,ED95值为4.3435 g.kg-1.d-1。结论吴茱萸水提组分和挥发油组分均有一定的镇痛作用,并呈现一定的量效关系,且吴茱萸水提组分发挥镇痛作用的安全范围大于挥发油组分。     

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.     

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.     

Pharmacological treatment of COVID-19: an opinion paper

The precocity and efficacy of the vaccines developed so far against COVID-19 has been the most significant and saving advance against the pandemic. The development of vaccines has not prevented, during the whole period of the pandemic, the constant search for therapeutic medicines, both among existing drugs with different indications and in the development of new drugs. The Scientific Committee of the COVID-19 of the Illustrious College of Physicians of Madrid wanted to offer an early, simplified and critical approach to these new drugs, to new developments in immunotherapy and to what has been learned from the immune response modulators already known and which have proven effective against the virus, in order to help understand the current situation.     

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.