RP-HPLC法同时测定壳聚糖止血海绵中3组分的含量

目的:建立壳聚糖止血海绵中地塞米松磷酸钠、替硝唑及克林霉素的RP-HPLC含量测定方法。方法:色谱柱为Dis- covery C18柱(150 mm×4．6 mm,5μm);流动相为乙腈-0．05 mol·L-1磷酸二氢钾缓冲液-三乙胺(35:65:0．3),用磷酸调pH至5．3;流速1．0 ml·min-1;检测波长210 nm。结果:地塞米松磷酸钠、替硝唑、克林霉素分别在2-10μg·ml-1(r=0．999 7)、6 -30μg·ml-1(r=0．999 8)、30-150μg·ml-1(r=0．999 8)线性范围内呈现良好的线性关系。3组分的平均回收率分别为99．4％(RSD=2．1％);98．7％(RSD=1．7％)、99．2％(RSD=1．9％)。结论:本法操作简便、快速、结果准确。可作为该制剂的质控方法。     

止血带对克林霉素在兔骨组织中分布的影响

目的:建立高效液相色谱法测定兔骨组织中的克林霉素,并对其在使用止血带后,在骨组织的分布特征进行研究。方法:以乙腈-四氢呋喃-磷酸盐缓冲溶液(30∶1∶70,pH 5)为流动相,柱温40℃;流速0.8mL·min-1;以替硝唑为内标,以LunaC18柱(250mm×4.6mm,5μm)进行分离,检测波长为205nm。测定静脉注射克林霉素(20mg·kg-1)后30,60,90,120min(A、B、C、D)上止血带分别阻断血液循环30,60,90min实验组与未止血对照组的骨组织中药物含量。结果:克林霉素在10.58～264.5μg·mL-1范围内线性关系良好,日内RSD≤2.17%,日间RSD≤2.99%。实验组克林霉素含量与对照组比较,差异有极显著性(P<0.01);相同止血时机,不同止血时间30,60,90min组之间比较,无显著性差异(P>0.05);不同止血时机组,A组与B、C、D组比较差异有极显著性(P<0.01),B、C、D组骨组织的克林霉素含量较高,3组之间差异无显著性(P>0.05)。结论:方法准确可靠、简便、重现性好,上止血带组骨组织中克林霉素含量明显低于无止血带组,止血时机是影响克林霉素骨组织分布的主要因素。     

HPLC法测定复方苯妥英钠凝胶剂中克林霉素磷酸酯的含量

目的:建立HPLC法测定复方苯妥英钠凝胶剂中克林霉素磷酸酯的含量。方法:采用ZORBAX SB-C18色谱柱(250mm×46 mm,5μm);流动相为0.1 mol·L-1的磷酸二氢钾(用磷酸调p H 2.5)-乙腈(75∶25);流速0.8 ml·min-1;检测波长210 nm;柱温:25℃;进样量10μl。结果:克林霉素磷酸酯在3.00~18.00μg范围内线性关系良好(r=0.999 5);平均回收率为101.11%(RSD=0.34%,n=6)。结论:本方法简单,灵敏,重复性好,可用于复方苯妥英钠凝胶剂中克林霉素磷酸酯的含量测定。     

高效液相色谱法测定克林霉素磷酸酯片含量

目的用离子抑制反相色谱法测定克林霉素磷酸酯片中克林霉素的含量。方法采用C18柱,流动相为磷酸二氢钾(KH2PO40.1mol·L-1)-乙腈(775∶225),流速1.0ml·min-1,柱温为室温,进样量20μl,检测波长210nm,外标法定量。结果本法测定克林霉素线性范围为0.04～1.00g·L-1,平均回收率为(99.5±1.55)%。结论该法简单、快速、准确。可用于克林霉素磷酸酯片中克林霉素的含量测定。     

HPLC法测定人血浆中替硝唑的浓度

目的建立测定人血浆中替硝唑浓度的HPLC法。方法采用Diamomil C_(18)(200 mm×4.6 mm,5μm)色谱柱;流动相为乙腈-水(20:80,V/V);流速1.0 mL·min~(-1);检测波长310 nm;内标为甲硝唑。结果替硝唑血药浓度在0.5～50mg·L~(-1)内线性关系良好(r=0.9990);替硝唑低、中、高3种浓度的方法回收率为94.89%～99.53%,提取回收率为89.55%～95.60%,日内RSD<2%(n=5),日间RSD<5%(n=5)。结论本方法操作简便,准确可靠,可用于替硝唑临床血药浓度监测和药动学研究。     

HPLC法同时测定复方痤疮凝胶中三种药物的含量

目的建立HPLC法同时测定复方痤疮凝胶中甲硝唑、克林霉素磷酸酯、维A酸含量的方法。方法色谱柱:Venusil XBP(L)C18柱(4.6 mm×250 mm,5μm)为固定相,以磷酸盐缓冲液(取15 mol.L-1磷酸二氢钾溶液,磷酸溶液调节pH值至3.0)-乙腈为流动相进行梯度洗脱;进样量:20μl;柱温:30℃;流速:1.0 ml.min-1;紫外检测波长:克林霉素磷酸酯214 nm,甲硝唑和维A酸350 nm。结果主成分峰与相邻杂质峰分离度大于1.5。甲硝唑、克林霉素磷酸酯和维A酸回归方程依次分别为:Y=30.33X-3.25(r=0.999 6);Y=3.825 8X+15.55(r=0.999 8);Y=149.43X-12.06(r=0.999 9);线性范围分别为:50～350、60～420、0.1～100 mg.L-1。平均回收率为:99.90%、99.71%、99.02%。结论该法操作方便,结果准确可靠,可用于复方痤疮凝胶中的甲硝唑、克林霉素磷酸酯、维A酸的含量测定。     

HPLC双波长切换法同时测定复方唑克搽剂中甲硝唑和盐酸克林霉素的含量

目的：建立高效液相色谱法同时测定复方唑克搽剂中甲硝唑和盐酸克林霉素的含量.方法：采用Thermo Syncronics C18（250 mm×4.6 mm,5 μm） 色谱柱;流动相为0.05 mol·L-1磷酸二氢钾溶液（用25%氢氧化钾调节pH至7.5）-乙腈（55：45）;流速为1.0 ml·min-1;柱温为30℃;波长切换,0～5 min在230 nm波长下测定甲硝唑含量,5～10 min在210 nm波长下测定盐酸克林霉素含量.结果：甲硝唑在198.50～1 389.50 μg·ml-1（r=0.999 9）,盐酸克林霉素在102.74～719.18 μg· ml-1（r=0.999 9）的浓度范围内呈良好的线性关系;甲硝唑的平均加样回收率为98.09%,RSD为0.37%（n=9）,盐酸克林霉素的平均加样回收率为98.05%,RSD为0.60%（n=9）.结论：该方法简便、准确,结果稳定,可为复方唑克搽剂的质量评价提供依据.     

止血带下克林霉素在兔肌肉组织中的分布特性

目的建立高效液相色谱法测定兔肌肉组织中的克林霉素,并对止血带下肌肉组织中克林霉素的分布特征进行研究。方法色谱条件为乙腈-四氢呋喃-磷酸盐缓冲液（30∶1∶70,pH=5）为流动相;柱温：40℃;流速：0.8mL·min^-1;替硝唑为内标,LunaC18柱（250mm×4.6mm,5μm）进行分离,检测波长为205nm。测定静脉注射克林霉素30,60,90,120min后上止血带分别阻断血液循环30,60,90min实验组与未止血对照组的肌肉组织中药物含量。结果克林霉素在10.58-264.5μg·mL^-1内线性关系良好,日内RSD≤2.58%,日间RSD≤4.20%。实验组克林霉素含量与对照组比较,P〈0.01;相同止血时机,不同止血时间药物含量比较,P〉0.05;不同止血时机（30,60,90,120min）药物含量比较,P〈0.01;给药后60min上止血带阻断肢体血液循环,克林霉素在肌肉组织的含量最高,为39.30μg·g^-1。结论方法准确可靠、简便、重复性好;实验组克林霉素含量与对照组有显著性差异;围手术期预防感染,上止血带时机是影响克林霉素组织分布的主要因素,给药后60min止血,药物可充分分布到肌肉软组织中,提高预防感染效果。     

RP-HPLC法测定母乳中克林霉素的浓度

目的:建立以反相高效液相色谱法测定母乳中克林霉素浓度的方法。方法:采用液-液萃取高效液相色谱法,以替硝唑为内标进行测定,色谱柱为LunaC18,流动相为乙腈:四氢呋喃:磷酸盐缓冲液(pH5)=30:1:70,柱温为40℃,流速为0.8mL.min-1,检测波长为205nm。结果:克林霉素乳汁浓度在0.529～10.580μg.mL-1范围内线性关系良好(r=0.9967),最低检测限为0.2μg.mL-1;平均方法回收率为98.84%,低、中、高浓度的日内、日间RSD均<5%。结论:本方法简便、快速、灵敏、准确,重现性好,可用于克林霉素在母乳中的药物浓度测定。     

HPLC法测定复方克林霉素乳膏中盐酸克林霉素和甲硝唑的含量

目的建立复方克林霉素乳膏中盐酸克林霉素和甲硝唑的含量测定方法。方法采用HPLC对盐酸克林霉素和甲硝唑的含量进行测定。盐酸克林霉素:色谱柱为ZORBAX SB-C18(4.6×150 mm,5μm),以磷酸二氢钾-乙腈(55∶45)为流动相,检测波长为210 nm,柱温为25℃,流速1.0 ml/min;甲硝唑:色谱柱为ZORBAX SB-C18(4.6×150 mm,5μm),以甲醇-水(20∶80)为流动相,检测波长为320 nm,柱温为30℃,流速1.0 ml/min。结果复方克林霉素乳膏中盐酸克林霉素含量在90.2~901.6μg/ml范围内线性关系良好(r=0.9999),平均回收率102.3%(n=6),精密度RSD=0.53%;甲硝唑含量在12.9~414.0μg/ml范围内线性关系良好(r=0.9999),平均回收率103.1%(n=6),精密度RSD=0.01%。结论该方法简单,结果准确、重现性好,可作为该制剂的质量控制方法 。     

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.