左乙拉西坦对癫痫大鼠认知功能及海马组织中NPY和NCAM-mRNA表达的影响

目的:研究左乙拉西坦对癫痫大鼠海马组织中NPY和NCAM-mRNA的表达及左乙拉西坦对癫痫大鼠认知功能的影响.方法:将96只Wistar大鼠随机分为盐水组(NS)24只、模型组(Li-PILO) 24只、模型组十左乙拉西坦组(Li-PILO+LEV) 24只和左乙拉西坦组(LEV)24只,将Li-PILO+ LEV组和LEV组予以LEV200mg/kg每日一次灌胃,连续4周.应用PCR方法分别在1周、2周和4周动态检测4组大鼠海马组织中NPY和NCAM-mRNA的表达,Morris水迷宫检测大鼠的认知功能.结果:与盐水组相比,造模组大鼠海马组织中NPY和NCAM-mRNA表达水平显著升高(P＜0.05),Li-PILO+LEV组显著低于造模组;水迷宫中造模组大鼠逃避潜伏期延长(P＜0.05),穿越平台数减少(P＜0.05),与造模组相比Li-PILO+ LEV组大鼠逃避潜伏期明显缩短(P＜0.05);大鼠穿越平台次数显著增加(P＜0.05).结论:癫痫发作时大鼠海马组织中NPY和NCAM-mRNA的表达水平明显升高,左乙拉西坦能抑制癫痫大鼠海马组织中NPY和NCAM-mRNA的表达并在治疗癫痫的同时,还会改善癫痫大鼠的认知功能.     

左乙拉西坦对癫痫大鼠认知功能的影响研究

目的:通过氯化锂-匹罗卡品(Li-pilo)诱导的癫痫大鼠模型,观察左乙拉西坦(LEV)对癫痫大鼠空间学习记忆能力及海马组织中突触素(SYN)表达的影响。方法:将96只SD大鼠随机分为NS组(生理盐水组),Li-pilo+LEV组(治疗组),Li-pilo组(模型组),LEV组(正常给药组),每组24只,于建模成功后7d,14d,28d通过RT-PCR方法观察各组大鼠海马组织中SYNmRNA的表达水平,并于第4周应用Morris水迷宫评价大鼠的学习记忆能力。结果:Morris水迷宫测试中Li-pilo+LEV组逃避潜伏期较Li-pilo组短(P<0.05);Li-pilo+LEV组穿越平台次数较Li-pilo组多(P<0.05)。PT-PCR测试各时间点NS组和Li-pilo+LEV组大鼠海马中SYNmRNA的表达量高于Li-pilo组(P<0.05)。结论:Li-pilo点燃的癫痫大鼠学习记忆能力减退,左乙拉西坦可改善癫痫大鼠的学习记忆能力,该作用可能与其调节海马组织中SYNmRNA的表达有关。     

离子对高效液相色谱法测定大鼠尿中草酸含量

目的:建立以离子对高效液相色谱法测定大鼠尿中草酸含量。方法:采用色谱柱Symmetry ShieldTM RP18(4.6 mm×250 mm,5μm),保护柱为Symmetry C18(3.9 mm×20 mm,5μm),以乙腈-0.02 mol.L-1磷酸二氢钾溶液(含0.02 mol.L-1四丁基硫酸氢铵,用KOH调pH2.7)(5∶95)为流动相,流速为0.8 mL.min-1,紫外检测波长为220 nm,柱温为40℃。结果:本方法最低检测浓度为5μg.mL-1,尿中草酸高浓度线性范围为67.5～2 160μg.mL-1(r2=0.999 8),低浓度线性范围为6.75～216μg.mL-1(r2=0.997 8),提取回收率>75%,相对回收率为89.2%～105.3%,日内和日间RSD均≤10.2%。结论:本方法简单快速、回收率高、精密度良好,适用于大鼠尿中草酸含量的测定。     

左乙拉西坦对海人酸致痫大鼠血清NSE和MBP变化的影响

目的:建立海人酸(KA)致痫大鼠模型并观察癫痫大鼠血清神经元特异性烯醇酶(NSE)和髓鞘碱性蛋白(MBP)的变化及左乙拉西坦(LEV)对其水平的影响,以探讨左乙拉西坦在癫痫脑损伤中是否具有保护的作用。方法:清结级Wistar雄性4~5周龄幼鼠72只,随机分为对照组24只,立体定向右侧海马注射生理盐水,KA组24只,注射海人酸,LEV治疗组24只,注射KA造模成功前12h胃管内注入LEV200mg/kg,以后未处死大鼠均每日给药一次。分别于致痫后6h、24h、72h处死,采用ELISA法检测各组大鼠血清NSE和MBP含量。结果:(1)大鼠癫痫行为;对照组无大鼠癫痫发作,其余组均有行为学改变。LEV组幼鼠癫痫发作程度与KA组类似,但潜伏期较KA组延长。(2)血清NSE变化:KA组和LEV组血清NSE于在致痫后6h升高,24h达高峰,与对照组相比有差异(P<0.05),LEV组与KA组的NSE比较无显著差异(P>0.05)。(3)MBP变化:KA组和LEV组血清MBP于致痫后6h升高,72h达高峰,与对照组相比差异有统计学意义(P<0.05),LEV组与KA组的MBP比较无显著差异(P>0.05)。结论:KA致痫大鼠血清NSE、MBP水平显著增高,提示癫痫发作可造成一过性脑损伤,血清NSE、MBP可能作为判断癫痫脑损伤程度的敏感指标,LEV对KA致痫大鼠血清NSE、MBP水平无影响,提示LEV不能减轻亦不加重癫痫发作引起的脑损伤。     

海人酸致痫大鼠血清S100β与IL10的含量及左乙拉西坦对其含量的影响

目的:建立大鼠海人酸致痫模型,检测大鼠血清中S100β和白细胞介素(i-nterleukin,IL)-10的含量,以探讨LEV与神经保护之间的关系。方法:将96只28d龄Wistar大鼠随机分为正常对照组32只、KA组32只、左乙拉西坦(leve-tiracetamLEV)治疗组(LEV组)32只。在立体定位仪的精确定位下向右侧海马CA3区注射海人酸点燃大鼠,并观察癫痫行为分级,治疗组在KA注射前12h给予左乙拉西坦200mg/kg灌胃治疗每日一次,并分别于6h,12h,24h,72h处死各组大鼠,以免疫酶联吸附反应方法检测各组大鼠血清S100β和IL-10的含量。结果:①KA组与LEV组在KA注射后1～2h内出现痫性发作。②KA组与LEV组血清S100β含量与对照组比较,6h无明显变化(P>0.05),12h开始升高(P<0.05),24h达高峰(P<0.01),72h接近正常(P>0.05)。LEV组与KA组比较血清S100β含量在各时间点无显著差异(P>0.05)。③KA组与LEV组血清IL-10含量比较,6h开始升高(P>0.05),12h达高峰(P<0.01),24h开始下降(P<0.05),72h接近正常(P>0.05)。LEV组与KA组比较血清IL-10含量在各时间点无显著差异(P>0.05)。结论:KA致痫大鼠血清中S100β含量显著增高,其升高可能与癫痫所致的脑损伤有关,血清IL-10含量显著增高,提示IL-10与癫痫的病理生理之间存在着密切的关系,LEV对癫痫大鼠血清中S100β和IL-10的含量无影响,提示LEV不会导致脑损伤但亦不能减轻癫痫所致的脑损伤程度。     

大鼠体内白前苷B药物代谢动力学研究

目的 探讨白前苷B在大鼠体内的药物代谢动力学.方法 采用超高效液相色谱串联质谱(UPLC-MS/MS)法,色谱柱为Agilent Eclipse Plus C18柱(50 mm×2.1 mm,1.8μm),流动相为0.2％醋酸水溶液-甲醇(梯度洗脱),流速为0.3 mL/min,柱温为25℃,进样量为1μL;以槲皮素为...     

高效液相色谱法测定左乙拉西坦血药浓度

目的:建立左乙拉西坦HPLC方法学.方法:100 μL血清加入内标后二氯甲烷去蛋白处理,色谱柱为Attima硅胶柱(5 μm,4.6 mm×150 mm);流动相为磷酸盐缓冲液(50 mmol, pH 4.5)和乙腈(96∶ 4,V/V),流速1 mL/min;检测波长210 nm,检测灵敏度0.0001 AUFS;柱温37 ℃;进样量10 μL.结果:左乙拉西坦在4.5 min出峰,内标在6.5 min出峰,无干扰;线性关系良好,相关系数R=0.9999,线性范围1.25～160 μg/mL.结论:该方法准确,可用于临床LEV血清浓度的常规检测,促进临床合理用药以及个体化治疗.     

复方石韦片中绿原酸在大鼠血浆中的测定及药代动力学研究

目的 建立了高效液相色谱法测定大鼠血浆中绿原酸的含量及其在大鼠体内的药物动力学研究.方法 色谱条件采用Diomonsil C18反相柱(4.6mm×250mm,5μm),以乙腈-0.5％磷酸溶液(10∶90,v/v)为流动相,柱温为35℃,流速为1.0mL · min -1,检测波长为360nm,进样量为10μL.结果...     

RP-HPLC法测定大鼠血浆中的灯盏乙素含量

目的:建立大鼠血浆中灯盏乙素的RP-HPLC测定法.方法:RP-HPLC法,采用迪马C18柱(250 mm×4.6 mm,5 μm),甲醇-乙腈-0.01 mol/L乙酸铵溶液(pH 3.5)(22:8:70)为流动相,流速为1.0 ml/min,检测波长335 nm,柱温30 ℃.结果:线性范围为0.025～20.0 mg/L(r=0.999 9),最低定量浓度为25 ng/ml.结论:建立的大鼠血浆中灯盏乙素的反相液相色谱测定法灵敏、准确,可用于大鼠血浆中灯盏乙素浓度测定.     

HPLC测定大鼠血浆中的丁香酚

目的 建立测定大鼠血浆中丁香酚的HPLC法.方法 流动相为甲醇-0.5％冰醋酸(63:37),采用Allsphere ODS-2RP-18色谱柱(250 mm× 4.6 mm,5μm),流速0.8 mL· min-1,检测波长280nm,柱温30℃.结果 丁香酚0.0895～11.445 μg· mL-1与峰面积比的线...     

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.