诺司咪唑含量测定方法的探讨

目的:建立了测定诺司咪唑含量的高效液相色谱法和胶束电动毛细管色谱法。方法:高效液相色谱法的实验条件:选用Dikma Diamonsil~(TM)(钻石)C_(18)色谱柱(4.6 mm×250 mm,5μm),乙腈-0.05mol·L~(-1)磷酸二氢钠水溶液(42:58,含0.2％三乙胺,pH 3.0),流速:1mL·min~(-1),检测波长:278 nm;进样量:20μL;柱温:30℃;胶束电动毛细管色谱法的实验条件:采用石英毛细管柱(未涂层)68.5 cm×75μm,有效柱长60 cm,优化选择40 mmol·L~(-1)磷酸二氢钠+25mmol·L~(-1)SDS(pH 6.0)为电泳介质,操作电压25 kV,柱温:30℃,检测波长:278 nm。结果:本法简便、灵敏、准确。两法线性范围分别为:0.8～30.0μg·mL~(-1)和27～269 μg·mL~(-1),回归方程分别为A=-602.7+5 334.0C(r=0.999 9)和A=0.007 9+0.174C(r=0.999 7),高效液相色谱法的平均回收率为99.8％(n=5)。结论:本文建立的方法可用于诺司咪唑的含量测定。     

HPLC法测定盐酸多培沙明含量及有关物质

目的:采用高效液相色谱法测定盐酸多培沙明含量及有关物质。方法:色谱柱为VP-ODS C_(18)柱(150 mm×4．6 mm,5μm),流动相为50 mmol·L~(-1)枸橼酸溶液(含50 mmol·L~(-1)枸橼酸钠)-乙腈(90:10),流速为1 mL·min~(-1),检测波长为280 nm。结果:盐酸多培沙明的线性范围为4～600μg·mL~(-1)(r=0．999 98),平均回收率为99．92％(RSD为0．26％);各杂质峰与主峰达到基线分离。结论:本方法简便、快速,结果准确,重复性好。     

高效毛细管电泳法测定加替沙星含量

目的:采用高效毛细管电泳法测定加替沙星含量。方法:采用未涂层弹性石英毛细管柱,56 cm×50 μm(有效长度50 cm);压力进样,压力:138 kPa;进样时间:15 s;电压:15 kV;柱温25℃;检测波长293 nm;运行缓冲液:100mmol·L~(-1)磷酸二氢钠溶液-甲醇(85:15,用1mol·L~(-1)氢氧化钠溶液调pH至9.0);运行时间:30min。结果:线性范围为0.05～2 mg·mL~(-1);平均回收率为99.3％,RSD=0.9％。结论:方法简便、准确,重现性良好。     

混合取代基—β—环糊精—毛细管电泳法分离测定麻黄碱和伪麻黄碱

目的:建立毛细管电泳法同时分离测定同分异构的2对手性化合物麻黄碱和伪麻黄碱的含量。方法:Waters CapillaryIon Analyzer,50μm×60cm空心熔融石英毛细管柱,柱上紫外检测。电泳条件:分离用缓冲液为25mmol·L~(-1)的磷酸-Tris 缓冲液,含18mmol·L~(-1)的羧甲基-β-环糊精和7.5mmol·L~(-1)的β-环糊精-硫酸酯,pH3.02。分离电压:18kV;温度:25℃;虹吸进样,高度10cm,时间1s;紫外检测波长214nm。结果:左旋伪麻黄碱、右旋麻黄碱、左旋麻黄碱和右旋伪麻黄碱线性范围分别为23.7～237μg·ml~(-1),25.0～250μg·mL~(-1),25.0～250μg·mL~(-1),25.4～254μg·mL~(-1),以信噪比等于3:1为标准,最小检测浓度均为5.0μg·mL~(-1);日内和日间精密度RSD在2.4％～4.3％之间。结论:方法分离效率高、简便、快速、成本低。     

离子对—HPLC法测定盐酸二甲双胍含量及有关物质

目的:建立离子对-HPLC法测定盐酸二甲双胍含量及有关物质的方法。方法:采用Inertsil C_(18)色谱柱(5μm,4.6mm×150mm);以甲醇-5mmol·L~(-1)磷酸二氢钾溶液(含有10mmol·L~(-1)十二烷基磺酸钠,用磷酸调节pH至3.5±0.05),(64:36)为流动相;流速1.0mL·min~(-1);紫外检测波长:233nm用于含量测定,218nm用于有关物质检测;柱温:室温。结果:离子对-HPLC法测定盐酸二甲双胍的线性范围为5～500μg·mL~(-1);相关系数r=0.999 9;日内精密度RSD=0.82％,日间精密度RSD=1.9％(n=5);双氰胺的线性范围为0.08～0.80μg·mL~(-1);相关系数r=0.9999;日内精密度RSD=0.68％,日间精密度RSD=2.3％(n=5);盐酸二甲双胍含量测定高、中、低3种浓度的回收率分别为99.24％,99.53％,99.18％;RSD分别为0.15％,0.18％,0.22％。结论:本法简便、快速、准确、专属性好。     

高糖抑制牛主动脉内皮细胞诱导型和结构型一氧化氮合酶的表达

目的:研究高糖对新生小牛主动脉内皮细胞(BAEC)一氧化氮合酶(NOS)表达的影响。方法:BAEC培养并传代于含正常葡萄糖(5.5mmol·L~(-1),NGBAEC),高糖(25 mmol·L~(-1),HG-BAEC)或高渗(葡萄糖5.5 甘露醇19.5 mmol·L~(-1),Mann-BAEC)的无酚红M1640培养基.Griess反应检测脂多糖(LPS)诱导的一氧化氮(NO)产生.Westem blot法检测结构型NOS(ecNOS)及诱导型NOS(iNOS)表达。结果:LPS(0.25-2 mg·L~(-1))剂量依赖性刺激BAEC产生NO,并在LPS 1 mg·L~(-1)达峰值。高糖显著抑制LPS诱导的NO产生(亚硝酸μmol·L~(-1):HG-BAEC 43±8,vs NG-BAEC 71±11,Mann-BAEC 70±9,n=4,P<0.01)。同样,与NG-和Mann-BAEC相比,HG-BAEC iNOS表达下降39.9％和39.3％,ecNOS表达下降28％和24％,而NG-与Mann-BAEC之间,LPS诱导的NO产量和iNOS和ecNOS的表达无差别。结论:高糖抑制BAEC NO的释放,与NOS的低表达有关。     

用IE—HPLC、PAGE分析合成的硫代寡核苷酸相关物质“n—1”、“n—2”和“n—3”

目的:分析合成的n=20-mer硫代寡核苷酸中相关物质“n-1”、“ n-2”和“ n-3”杂质失败序列。方法:离子交换高效液相色谱(IE-HPLC)法和聚丙烯酰胺凝胶电泳法(PAGE)。色谱柱为Gen-Pak~(TM)FAX离子交换柱(4.6 mm×100mm),流动相A为62.5mmol·L~(-1)三羟甲基氨基甲烷盐酸(Tris·Cl),pH 8.15,流动相B为62.5mmol·L~(-1) Tris·Cl,pH 8.15,2.5 mol·L~(-1) LiCl,流动相C为100％乙腈;梯度洗脱条件为B:30％→50％ 30 min,C:恒为20％;流速为0.75mL·min~(-1);检测波长为260nm。PAGE分析采用20％变性聚丙烯酰胺凝胶,恒定功率25W进行电泳。结果:IE-HPLC分离纯化出3种相关物质,通过PAGE印证了它们是由于合成偶联不完全而产生的n-1、n-2和n-3的杂质失败序列。结论:所用离子交换高效液相色谱法能将合成的硫代寡核苷酸中相关物质“n-1”、“n-2”和“n-3”杂质失败序列与全序列n一一分离出来,对硫代寡核苷酸的纯化和分析具有重要的参考价值。     

高效液相色谱—手性配位基交换流动相法拆分甲状腺片中甲状腺素对映体

目的:运用正相高效液相色谱-手性配位基交换流动相法,建立甲状腺片中甲状腺素对映体(L-,D-T_4)的拆分方法。方法:通过流动相中添加L-脯氨酸、醋酸铜及三乙胺对甲状腺片中甲状腺素对联体进行测定。最佳色谱条件为流动相:乙腈-水(35:65),每升流动相水中(未加乙腈)含有0.1mmol·L~(-1)醋酸铜(Ⅱ),0.2 mmol·L~(-1)L-脯氨酸和0.5mmol·L~(-1)三乙胺;pH为5.42;柱温:40℃;流速:1.0mL·min~(-1);色谱柱:Hypersil SiO_25μm(4.6mm×250mm);紫外测定波长:225nm。结果:在所建立的色谱条件下甲状腺素L-,D-2种异构体得到基线分离,并测定了甲状腺片中的L-,D-T_4的含量,结果显示同一厂家不同批号甲状腺片中L-,D-T_4含量不同。结论:所建立的方法简便、快速、准确、成本低,可作为样品的检测及药品质量控制方法。     

高效液相色谱法测定黄连药材中小檗碱型生物碱的含量

目的:分离并测定黄连药材中小檗碱型生物碱的含量。方法:采用ODS柱(15 mm×6.0 mm),以乙腈-50 mmol·L~(-1)磷酸二氢钾溶液(磷酸调 pH=3.0)(50:50),内含 25 mmol·L~(-1)SDS为流动相,345nm检测。结果:在以上条件下,药根碱、表小檗碱、黄连碱、巴马亭和小檗碱5种生物碱可以完全分离,测定了8种不同黄连药材中4种生物碱的含量。结论:本法可用于黄连药材的研究,也可用于黄连等含小檗碱中药材及制剂的常规检验。     

反相高效液相色谱法测定血清中奥氮平的浓度

目的:用HPLC测定人血清中奥氮平浓度。方法:采用高效液相色谱法。色谱柱为C_(18);流动相;50mmol·L~(-1)醋酸铵氨水缓冲液(pH9.9):甲醇(19:81),流速为1.2ml·min~(-1);检测波长257nm,外标法定量。结果:标准曲线在9.76-390.5ng·ml~(-1)内线性关系良好(r=0.9998);最低检测浓度为1.22ng·ml~(-1):平均回收率为(97.20±3.66)％:日内RSD<6.18％,日间RSD<6.62％。结论:本法简便,快速准确,适宜血清中奥氮平的测定。     

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.