乙醇对胚胎发育与卵黄囊超微结构的影响

为研究发育敏感期暴露于乙醇不同时间对胚胎发育和胚胎卵黄囊超微结构的影响 .以体外全胚胎培养和电镜技术研究 0 .2g·L- 1乙醇不同时间作用时对胚胎发育影响及胚胎卵黄囊超微结构改变 .结果表明发育异常与乙醇作用存在时间 效应关系 .0 .2g·L- 18h对胚胎发育和形态分化无明显影响 ,随时间延长除胚胎头长 ,体长 ,卵黄囊直径 ,蛋白质和DNA含量等主要发育指标进一步受抑制外 ,胚胎畸形 ,死亡率明显升高 .卵黄囊超微结构变化程度与染毒时间和胚胎发育状况相一致 ,乙醇可导致卵黄囊细胞内微绒毛和溶酶体数量减少 ,线粒体等部分细胞器内膜肿胀 .上述结果提示卵黄囊结构损伤和破坏在乙醇所致的发育异常中起重要作用     

硫酸铝在体外对大鼠胚胎组织谷胱甘肽含量和卵黄囊细胞膜流动性的影响

目的　为探讨铝的发育毒性及机理。方法孕 9.5d大鼠胚胎于体外培养系统中给予不同剂量的硫酸铝 ,培养 4 8h后 ,观察胚胎生长发育和器官形态分化状况 ;应用二硫代双硝基苯甲酸 (DTNB)直接法测定胚胎组织谷胱甘肽 (GSH)含量 ;以 1,6 二苯己三烯为荧光探剂 ,用荧光偏振技术测定卵黄囊细胞膜脂质流动性。结果　当培养液中铝浓度为1.2mg·L- 1时 ,胚胎生长发育和分化明显被抑制 ;3.0mg·L- 1时 ,畸形胚胎发生率明显升高 ,主要有神经管闭合不全 ,脑发育不良和体翻转不全 ;6 .0mg·L- 1时 ,胚胎组织GSH含量和卵黄囊细胞膜脂质流动性显著降低。上述效应均呈现出一定的剂量 效应 (反应 )关系。结论　铝有潜在的致畸性和胚胎毒性 ,胚胎组织GSH含量和卵黄囊细胞膜流动性降低可能在铝致胚胎发育毒性中起重要作用     

三氯异氰尿酸对斑马鱼胚胎及幼鱼的发育毒性

目的探讨新型消毒剂三氯异氰尿酸(TCCA)对斑马鱼胚胎及幼鱼的发育毒性。方法选择受精后2 h的斑马鱼胚胎进行染毒:①将胚胎置于含有TCCA 50,100,150,200,250和300 mg·L~(-1)的培养液中暴露48 h,检测半数致死浓度(LC_(50))。②将胚胎置于含有TCCA 0,10.4,20.8和41.7 mg·L~(-1)的培养液中暴露96 h,分别于暴露后48,72和96 h检测胚胎死亡率、畸形率和心率,采用羟胺法于暴露后2,4和6 h检测胚胎组织超氧化物歧化酶(SOD)的活性,HE染色观察暴露后7 d幼鱼头部组织病理结构。结果 TCCA暴露48 h,斑马鱼胚胎LC_(50)为166.9 mg·L~(-1)。与正常对照组相比,暴露后96 h,TCCA 41.7 mg·L~(-1)组斑马鱼胚胎死亡率和畸形率显著升高(P<0.05),TCCA各剂量组心率显著下降(P<0.05);暴露后72h,TCCA41.7mg·L~(-1)组死亡率显著升高(P<0.05),20.8和41.7mg·L~(-1)组畸形率显著升高(P<0.05),心率显著下降(P<0.05);暴露后48 h,TCCA 41.7 mg·L~(-1)组畸形率显著升高(P<0.05)、心率显著下降(P<0.05)。TCCA暴露4和6 h,20.8和41.7 mg·L~(-1)组SOD活性较正常对照组显著下降(P<0.05)。TCCA暴露7 d后,与正常对照组相比,各浓度组斑马鱼幼鱼均出现脑和眼部间隙变大及眼部视网膜分层不明显的病理改变。结论 TCCA对斑马鱼胚胎发育有毒性作用,能引起胚胎发育早期SOD活性下降,造成幼鱼视网膜组织结构损伤。     

草乌的体外胚胎发育毒性研究

目的探讨生草乌对胚胎发育的毒性作用及机制。方法应用大鼠着床后体外全胚胎培养模型,将9.5dSD大鼠胚胎与含不同浓度生草乌的大鼠即刻离心血清共培养48h,观察其对大鼠胚胎生长发育和组织器官形态分化的影响。生草乌终浓度分别为:0、0.63、1.25、2.5和5mg生药/ml。结果随着生草乌剂量增加,胚胎生长发育和器官分化的各项指标均呈现下降趋势,有一定的剂量-效应关系。生草乌最大无作用剂量为1.25,2.5mg/ml以上剂量可诱发卵黄囊生长和血管分化不良、生长迟缓及形态分化异常,严重者出现体节紊乱、小头、心脏发育迟滞(心小,停留在心管期)及心脏空泡等。结论较高剂量生草乌对体外培养大鼠胚胎具有一定的毒性作用,建议孕妇妊娠期间(特别是妊娠前3个月)慎用或禁用草乌。     

褪黑素对苯妥英所致小鼠胚胎体外致畸效应的拮抗作用

采用体外着床后全胚培养模型研究苯妥英诱发的胚胎脂质过氧化和形态异常 ,确定褪黑素 (MT)的胚胎保护作用 .d 8.5的小鼠胚胎经苯妥英单独或与MT联合作用 4 8h后测定胚胎生长 ,形态发育 ,全胚蛋白质含量及脂质过氧化产物 .结果表明苯妥英导致胚胎生长发育迟滞并诱发脂质过氧化产物增高 4倍 .MT 1mmol·L- 1有轻微生长抑制作用 ,但可完全拮抗苯妥英诱发的脂质过氧化作用 ,并降低或完全拮抗苯妥英导致的形态生长发育异常 .表明MT有拮抗苯妥英胚胎致畸效应的作用     

β-氯氰菊酯对斑马鱼胚胎的发育毒性

目的以斑马鱼胚胎为模型,探讨一种高效氯氰菊酯β-氯氰菊酯对胚胎发育的影响。方法 丙酮为助溶剂,配制β-氯氰菊酯0.05,0.1,0.15,0.2,0.6和1 mg.L-1,采用换水式每12 h更换一半β-氯氰菊酯溶液,对斑马鱼胚胎进行96 h暴露处理,采用显微镜观察β-氯氰菊酯0.05,0.1,0.15,0.2,0.6和1 mg.L-1对斑马鱼胚胎发育形态,测定受精后24 h(24 hpf)自主抽动次数、48 hpf心率及孵化率、72和96 hpf体轴弯曲个体比例等。结果 与正常对照组比较,β-氯氰菊酯0.05,0.1,0.15,0.2,0.6和1 mg.L-1组斑马鱼胚胎在24 hpf前形态上未出现明显异常,48 hpf以后表现出体轴弯曲、心包囊肿等不同程度的毒性反应症状,β-氯氰菊酯0.2 mg.L-1组幼鱼胸鳍发育即受到严重抑制且黑色素减少体色偏黄;随着β-氯氰菊酯浓度的增加,斑马鱼胚胎在24 hpf时每分钟自主抽动次数由正常对照组的(0.72±0.19)次增加至(3.83±1.07)次(P<0.05);48 hpf孵化率由对照组的(15.5±4.3)%升高至(98.9±1.2)%(P<0.05)。β-氯氰菊酯0.05 mg.L-1组72 hpf和96 hpf体轴弯曲个体比例分别为6.6%和10%,β-氯氰菊酯1 mg.L-1组分别为97.8%和100%。结论 β-氯氰菊酯对斑马鱼胚胎的神经及形态发育均有明显抑制作用,并且呈现一定的时间剂量依赖性。     

全胚胎培养在环磷酰胺致畸与细胞凋亡研究中的应用

哺乳动物植入后全胚胎培养排除了母体等因素对胚胎发育的影响 ,并可人为控制实验条件 ,与组织、细胞培养及动物整体实验相比 ,具有许多明显的优点 ,可动态观察和研究药物致畸作用及机制。细胞凋亡是多细胞生物体内环境稳定和发育精确控制的基本条件 ,也是胚胎发生和发育过程中一定结构和功能器官形成的必要条件 ,过多的细胞凋亡或不适当的细胞凋亡最终导致先天性畸形的发生[1 ] 。本研究利用小鼠全胚胎培养方法观察了抗肿瘤药物环磷酰胺致畸作用 ,在获得畸形胚胎的基础上 ,对环磷酰胺致畸作用与细胞凋亡的关系进行了探讨。1　材料与方法1 1…     

菲并咪唑衍生物的体外抗肿瘤活性及其对斑马鱼胚胎发育的毒性效应研究

目的 设计合成菲并咪唑衍生物L271,并研究其外抗肿瘤活性,及其对斑马鱼胚胎发育的毒性效应.方法 以1,10-邻菲啰啉-5,6-二酮和2-甲基苯甲醛为原料,运用微波辅助合成技术制备了菲并咪唑衍生L271.采用噻唑蓝(MTT)比色法研究菲并咪唑衍生物L271对人宫颈癌细胞Hela和人肺腺癌细胞A549在体外生长的抑制作用.以斑马鱼为模型,研究L271对斑马鱼胚胎发育的形态、孵化率、死亡率和畸形率的影响,评价L271对斑马鱼胚胎发育的毒性效应.结果 经电喷雾质谱技术(ESI-MS)表征确证成功合成了目标化合物L271.新合成的菲并咪唑衍生物L271对人宫颈癌细胞Hela和人肺腺癌细胞A549均有增殖抑制作用,尤其对人宫颈癌细胞Hela的IC50值达到(8.38±0.09)μmol/L,与同等条件下吡柔比星的抗肿瘤活性相当[IC50=(6.97±0.07)μmol/L].与对照组相比,L271浓度≥15μmol/L暴露组能够引起斑马鱼出现尾鳍萎缩、脊柱弯曲、卵黄囊水肿和心包囊水肿等畸形现象;L271浓度≥30μmol/L可显著降低斑马鱼的孵化率和提高死亡率(P＜0.05);在48、72、96 hpf时,L271对斑马鱼胚胎半致死浓度LC5o分别是37.331μmol/L(95％CI:35.535-39.301)、34.911μmol/L(95％CI:33.213-36.729)、30.283μmol/L(95％CI:29.590-30.980);在L271浓度≥15μmol/L时,随着L271浓度的逐渐增加,各暴露组正常胚胎百分率渐下降,胚胎死亡率逐渐上升,而胚胎畸形率先升后降.结论 L271对人宫颈癌细胞Hela具有良好的抗肿瘤活性,且与吡柔比星的相当;L271浓度≤10μmol/L对斑马鱼胚胎发育无明显毒性效应.     

斑马鱼胚胎发育毒性评价方法的建立

目的以致胚胎毒性阳性药物全反式维甲酸（ATRA）及丙戊酸钠进行斑马鱼胚胎发育毒性试验,建立有效的斑马鱼胚胎发育毒性评价方法。方法采用水浴染毒法,将受精后2h（2hpf）的斑马鱼胚胎暴露于不同浓度梯度的阳性约物。分别在24、48、72和144hpf观察并记录畸形及死亡的胚胎数目。统计阳性药物的EC50和LG50,计算致畸指数（TI=LC50／EG50）。结果两种阳性药物所致斑马鱼胚胎发育早期（24～48hpf）与发育后期（72～144hpf）的畸形表现不同。在72hpf,两种阳性药物对胚胎孵化率均有明显抑制作甩144hpf可见ATRA（≥1．6×10^-3mg／L）和丙戊酸钠（≥1．25×10^2mg／L）严晕致畸作用,T1分别为10.35和5．72。两种阳性药物胚胎敛畸率及死亡率均呈明显的浓度依赖关系,且与已有动物试验及体外试验结果相符。结论以两种阳性药物建立有效的斑马鱼胚胎发育毒性评价方法,可进行进一步的验证。     

芙朴感冒颗粒对斑马鱼胚胎发育的影响

摘要：目的:研究芙朴感冒颗粒对斑马鱼胚胎发育的影响,为临床安全用药提供相关参考资料。方法:选择6 h的斑马鱼胚胎为实验模型,设置空白对照组和芙朴感冒颗粒低、中、高（10,20,50 g·L-1）浓度组,显微镜下观察并记录斑马鱼胚胎发育情况,检测自主运动次数、心率、畸形率、孵化率、泳速等,以初步分析芙朴感冒颗粒对斑马鱼胚胎发育的影响。结果:芙朴感冒颗粒可致斑马鱼胚胎发育畸形,主要表现为心包囊肿、充血和脊柱弯曲;芙朴感冒颗粒能明显抑制斑马鱼胚胎自主运动和心率;芙朴感冒颗粒低浓度时促进胚胎孵化和斑马鱼胚胎孵育后仔鱼的泳速,高浓度则抑制胚胎孵化和仔鱼泳速。结论:芙朴感冒颗粒可影响斑马鱼胚胎的正常发育。     

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.