不同粒径马钱子粉的急性毒性实验

目的通过运用超细粉碎技术,观察普通马钱子粉与超细马钱子粉对小鼠的急性毒性实验.方法运用急性毒性实验方法,所得数据用“改良寇氏法”计算.结果普通马钱子粉LD50为223.95mg*kg-1,95%的可信限为208.19～240.94mg*kg-1;超细马钱子粉LD50为198.09mg*kg-1,95%可信限181.41～216.34mg*kg-1.结论马钱子粉经超细粉碎后可增加其在体内的吸收.     

中药仙鹤复方提取物急性毒性试验及对小鼠移植性肿瘤H22的抗肿瘤作用研究

目的 研究中药仙鹤复方乙醇提取物的急性毒性,以及中药仙鹤复方乙醇提取物和水提取多糖对小鼠移植性肿瘤H22的抑瘤作用,进而对中药仙鹤复方进行抗肿瘤活性研究.方法 测定中药仙鹤复方乙醇提取物的LD50,建立荷实体型肝癌H22小鼠模型,观察中药仙鹤复方乙醇提取物和水提取多糖的抑瘤作用.结果 中药仙鹤复方乙醇提取物的LD50为26.95g·kg-1,95%可信区间为21.99～33.01g·kg-1;中药仙鹤复方乙醇提取物9.25g·kg-1·d-1剂量组与中药仙鹤复方水提取多糖8.05g·kg-1·d-1剂量组时小鼠移植性肿瘤H22均有明显的抑制作用,其抑瘤率分别为49.2%(P＜0.01)和33.7%(P＜0.01).结论 中药鹤复方乙醇提取物和水提取多糖对小鼠移植性肿瘤H22有抑制作用.     

褪黑激素对U14的抑制作用

目的探讨褪黑激素(melatonin,MT)对U14的抑瘤作用及对常用化疗药环磷酰胺(cytoxan,CTX)的增效作用.方法用小鼠移植性肿瘤模型,观察药物对荷U14小鼠的肿瘤抑制率的影响.在可耐受剂量下治疗小鼠的实体瘤U14,观察药物对小鼠脾脏重量及肝脏组织结构的影响.结果高剂量MT(80mg*kg-1*d-1,sc)组对小鼠U14有抑制作用,抑瘤率为27.1%(P<0.05).高剂量组及低剂量MT(40mg*kg-1*d-1,sc)组与CTX(25mg*kg-1*d-1×1,ip)合用对U14的抑瘤作用可相加.高剂量MT与CTX合用对小鼠脾脏重量及肝脏组织结构均无明显影响.结论MT有抑制U14的作用,与CTX合用具有疗效相加的作用,毒性无明显增加.     

中药CHH复方对小鼠S180肉瘤的抑制作用

目的:探讨中药CHH复方对S180肉瘤荷瘤小鼠的抑瘤作用,为实验研究提供数据参考.方法:以环磷酰胺作为对照组,分析5 mg·kg-1,10 mg·kg-1,20 mg·kg-1剂量的中药CHH复方皮下注射,观察对小鼠S180肉瘤的抑瘤率.结果:5 mg·kg-1剂量的抑瘤率27.4%、10 mg·kg-1剂量的抑瘤率41.6%、20 mg·kg-1剂量的抑瘤率66.0%.结论:试验结果提示CHH复方对小鼠肉瘤S180有明显的抑制作用.     

Fascaplysin对ICR小鼠S180移植瘤的抑制作用及体内安全性的初步观察

目的：研究Fascaplysin对ICR小鼠移植性骨肉瘤S180瘤体的体内抑制作用。方法：急性毒性实验采用LD50数据处理程序1.01版计算LD50。皮下注射技术建立荷S180骨肉瘤的ICR小鼠动物模型,并随机分为空白对照组（注射生理盐水）、阳性对照组（CTX,30 mg.kg-1.d-1）、Fascaplysin高剂量组（20 mg.kg-1.d-1）和Fascaplysin低剂量组（5 mg.kg-1.d-1）共4组,观察相应处理10 d后各组小鼠移植瘤生长状况（抑瘤率）及瘤组织病理学形态变化。结果：阳性对照组、Fascaplysin高剂量组和Fascaplysin低剂量组的抑瘤率分别为（53±9）%、（52±10）%和（30±12）%;给药期间Fascaplysin对ICR小鼠肝、肾组织未产生明显的病理性影响,而对ICR小鼠体内S180移植瘤组织的病理性影响较为明显。结论：一定剂量的Fascaplysin对ICR小鼠S180移植性骨肉瘤生长具有较好的抑制作用,是一个有潜力的抗癌药物。     

山豆根不同组分小鼠急性毒性比较研究

目的比较山豆根全组分、水提组分、醇提组分、总生物碱提取物对小鼠的急性毒性,为山豆根的临床安全使用提供实验依据。方法采用经典的急性毒性实验方法测定山豆根全组分的最大耐受量（MTD）及水提组分、醇提组分、总生物碱提取物的小鼠口服半数致死量（LD50）,观察其急性毒性症状谱,记录累积死亡数及小鼠体重变化。结果山豆根全组分的MTD为10.68g·kg-1,水提组分、醇提组分、总生物碱提取物的小鼠口服LD50及95%可信限分别为17.469（15.450～19.701）g·kg-1、27.135（24.869～29.622）g·kg-1、13.399（12.016～14.899）g·kg-1,主要毒性症状是烦躁、多动、呼吸急促、抽搐。结论山豆根不同组分急性毒性大小顺序依次是总生物碱提取物、水提组分、全组分、醇提组分,其毒性成分与致毒机制尚待进一步研究。     

百草枯对小鼠的急性毒性试验

目的 观察百草枯(Paraquat,PQ)对小鼠的急性毒性,计算其半数致死量(LD50).方法 给小鼠灌服不同浓度的PQ溶液,通过观察小鼠的活动和毒性反应,记录小鼠的死亡数,用概率单位法计算LD50.结果 给药后不同时间内,小鼠出现自由活动减少,濒死时呼吸频率加快、张口呼吸、鼻翼扇动等中毒症状,死亡高峰在2 h内,死亡原因为多脏器损伤.♂小鼠LD50=106.99 mg·kg-1,95%可信限范围为97.01～118.03 mg·kg-1;♀小鼠LD50=86.40 mg·kg-1,95%可信限范围74.54～100.14 mg·kg-1.结论 PQ属于中等毒农药,♀小鼠更敏感.     

来氟米特3-甲基异构体急性毒性试验

目的观察来氟米特3-甲基异构体经口给药的急性毒性试验（LD50的测定）。方法给小鼠灌服不同浓度来氟米特3-甲基异构体混悬液,通过观察小鼠的活动和毒性反应,记录小鼠的死亡数,用Bliss法计算LD50。结果动物给药后不同时间内很快表现为兴奋,继而动物出现抽搐,后精神差,静伏少动,步态蹒跚,濒死时精神极差,呼吸频率加快、张口呼吸、鼻翼扇动等中毒症状。LD50=1537mg.kg-1,95%的可信限=1252.3～1879.8mg.kg-1,LD5=646.99mg.kg-1,LD95=3651.3mg.kg-1。结论来氟米特3-甲基异构体急性毒性很小。     

亚硒酸锰(Ⅲ)-叶绿酸钠的制备及其对小鼠的急性毒性和小鼠肝癌H22的初步试验

目的:制备亚硒酸锰(Ⅲ)-叶绿酸钠,并测定其对小鼠的急性毒性及对小鼠肝癌H22的抑制情况.方法:以蚕沙提取叶绿素,由叶绿素制备脱镁叶绿酸,与锰络合后制得锰(Ⅲ)叶绿酸,再以亚硒酸化合制得亚硒酸锰(Ⅲ)-叶绿酸钠;测定亚硒酸锰(Ⅲ)-叶绿酸钠的急性毒性及对小鼠肝癌H22的抑制情况.结果:作者首次合成了亚硒酸锰(Ⅲ)-叶绿酸钠.测得其LD50=1175 mg.kg-1(95%的可信区间为851～1621 mg.kg-1;其对小鼠肝癌H22的抑癌率为45～47%(灌胃剂量为500 mg.kg-1).结论:亚硒酸锰(Ⅲ)-叶绿酸钠常温下性质稳定,毒性小,对小鼠肝癌H22有明显的抑制作用,可进一步做临床试验.     

亚硒酸锰（Ⅱ）—叶绿酸钠的制备及其对小鼠的急性毒性和小鼠肝癌H …

目的:制备亚硒酸锰(Ⅲ)-叶绿酸钠,并测定其对小鼠的急性毒性及对小鼠肝癌H22的抑制情况.方法:以蚕沙提取叶绿素,由叶绿素制备脱镁叶绿酸,与锰络合后制得锰(Ⅲ)叶绿酸,再以亚硒酸化合制得亚硒酸锰(Ⅲ)-叶绿酸钠;测定亚硒酸锰(Ⅲ)-叶绿酸钠的急性毒性及对小鼠肝癌H22的抑制情况.结果:作者首次合成了亚硒酸锰(Ⅲ)-叶绿酸钠.测得其LD50=1175 mg.kg-1(95%的可信区间为851～1621 mg.kg-1;其对小鼠肝癌H22的抑癌率为45～47%(灌胃剂量为500 mg.kg-1).结论:亚硒酸锰(Ⅲ)-叶绿酸钠常温下性质稳定,毒性小,对小鼠肝癌H22有明显的抑制作用,可进一步做临床试验.     

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.