头孢尼西钠中相关物质的检测

目的:建立头孢尼西钠中有关物质的HPLC检测方法。方法:采用高效液相色谱法,C18柱(250mm×4.6mm,5μm),以0.01mol/L磷酸二氢钾溶液(冰醋酸调节pH为3.5)-乙腈(79:21)为流动相,检测波长为254nm。结果:头孢尼西与各有关物质达到了较好的分离,1-磺甲基-5-巯基四氮唑二钠与7-氨基头孢烷酸的校正因子分别为0.8829,0.7594,检测限分别为0.02,0.04ng。头孢尼西钠和甲酰基头孢尼西定量限分别为0.08,0.62ng;检测限分别为0.03,0.21ng。结果:本法操作简便、专属性强、准确度高、重复性好,可用于头孢尼西钠中有关物质的测定。     

HPLC测定头孢尼西钠的含量及有关物质

目的建立HPLC测定头孢尼西钠含量及有关物质。方法采用HPLC,以Kromasil 100AC18(150 mm×4.60 mm,5μm)为分析柱,以甲醇-0.025 mol/L磷酸二氢铵(15∶85)为流动相;紫外检测波长为272 nm;流速为1.0 ml/min;柱温为40℃。结果头孢尼西钠的检测限为1.0 ng,线性范围为0.10-0.30 mg/ml,精密度的相对标准偏差小于0.17%(n=5)。结论该方法简单、快速、准确、专属性好,可用于头孢尼西钠的质量控制。     

RP-HPLC测定注射用复方甘草酸苷中甘草酸铵含量和有关物质

目的:采用高效液相色谱法测定注射用复方甘草酸苷中甘草酸铵的含量和有关物质。方法:采用 Symmetry C_(18)色谱柱(4.6 mm×250 mm,5 μm),以2%醋酸-乙腈(65:35)为流动相,流速为1.0 mL·min~(-1),检测波长为256 nm,进样量为20μL。结果:甘草酸铵线性范围为40～400μg·mL~(-1)(r=0.9999),最小检测量为6.23 ng。结论:本法精密度好,结果准确、可靠、灵敏,可用于注射用复方甘草酸苷含量测定和有关物质检查。     

HPLC法测定注射用头孢他美钠的含量及有关物质

目的 建立高效液相色谱法测定注射用头孢他美钠的含量和有关物质.方法 采用Thermo Hypersil BDS C18柱(250mm×4.6mm,5μm),以0.013mmol/L庚烷磺酸钠、0.02mol/L磷酸二氢钾溶液-甲醇(75:25,用10％磷酸调pH值至3.4)为流动相;检测波长为263nm;柱温为35℃;结果 头孢他美钠浓度在0.1～402.4μg/mL范围内,峰面积与浓度线性关系好r=0.9999(n=8),最低检出限为0.4ng(S/N=3),定量限为2ng(S/N=10).结论 该法简便、准确、灵敏度高,专属性强,可以用于注射用头孢他美钠含量测定和有关物质检查.     

固相萃取HPLC测定人血浆中头孢西酮及在药动学研究中的应用

目的:建立反相高效液相色谱办法测定人血浆中头孢西酮浓度,并用于注射用头孢西酮钠人体药代动力学研究。方法:采用高效液相色谱紫外检测法,血浆中加入内标后经固相萃取,色谱柱为 Apollo C_(18)(5μm,250 mm×4.6 mm)。流动相为乙腈-0.02 mol·L~(-1)醋酸铵溶液(18∶82)(pH 5.0),流速1 mL·min~(-1),检测波长为278 nm。结果:本方法线性检测范围为0.5～250μg·mL~(-1),线性关系良好(r=0.9996);最低检测浓度为0.5μg·mL~(-1);方法绝对回收率为67.2%～84.0%,相对回收率为91.1%～102.1%;日内、日间 RSD 均小于8%。结论:本方法灵敏度高,操作简便,可用于人血浆中头孢西酮的浓度测定及临床药代动力学研究。     

反相高效液相色谱法测定注射用头孢米诺钠含量及其有关物质

目的采用反相高效液相色谱法测定注射用头孢米诺钠含量及其有关物质。方法色谱柱为ZorbaxODSC18柱(250mm×4.6mm,5μm),流动相为水(980mL水和10mL冰醋酸混合)-甲醇(990∶10),检测波长为254nm,流速为1mL/min,柱温为30℃。结果头孢米诺钠线性范围是0.25～3.0mg/mL(r=0.9998),最低检出限为0.1μg/mL,最低定量限为0.4μg/mL,平均回收率为100.02%,RSD为0.83%。结论该方法简便、快速,结果准确、可靠,适用于头孢米诺钠含量及其有关物质的测定。     

HPLC测定头孢尼西钠的含量及有关物质

目的 建立HPLC测定头孢尼西钠含量及有关物质.方法 采用HPLC,以Kromasil 100A C18(150 mm×4.60 mm,5 μm)为分析柱,以甲醇-0.025 mol/L磷酸二氢铵(15∶85)为流动相;紫外检测波长为272 nm;流速为1.0 ml/min;柱温为40 ℃.结果 头孢尼西钠的检测限为1.0 ng,线性范围为0.10～0.30 mg/ml,精密度的相对标准偏差小于0.17%(n＝5).结论 该方法简单、快速、准确、专属性好,可用于头孢尼西钠的质量控制.     

HPLC法同时测定注射用艾迪（冻干）中人参皂苷Rg1和人参皂苷Re的含量

目的:建立注射用艾迪(冻干)中人参皂苷Rg_1和人参皂苷Re的含量测定方法。方法:色谱柱为Hypersil C_(18)柱(250mm×4.6mm,5μm),流动相为乙腈-0.05%磷酸溶液(19∶81),流速为1.0mL·min~(-1),检测波长为203nm。结果:人参皂苷Rg_1浓度在20～200μg·mL~(-1),人参皂苷Re浓度在10～100μg·mL~(-1)范围内与峰面积呈良好的线性关系,相关系数分别为0.9997和0.9996;平均回收率分别为100.3%和97.6%(n=9)。结论:本法快速,准确,重复性好,可作为注射用艾迪(冻干)的质量控制方法。     

采用HPLC法测定注射用头孢美唑钠中的有关物质

目的 建立注射用头孢美唑钠有关物质的测定方法.方法 采用反相-HPLC方法,色谱柱为XBridge Shield RP18柱(250mm×4.6mm,5μm);流动相为0.05mol/L醋酸铵溶液(用冰醋酸调节pH值至4.5)-甲醇(80:20);检测波长254nm;流速为0.8mL/min;柱温:25℃.结果 在该色谱条件下,已知杂质5-巯基-1-甲基四氮唑与其它杂质、各杂质峰与主峰之间的分离均良好,头孢美唑钠和5-巯基-1-甲基四氮唑的检测限均为2ng,在o.5～50μg/mL的浓度范围内,头孢美唑钠和5-巯基-1-甲基四氮唑的线性均良好,r分别为0.9999和0.9999.结论 该方法操作简便,结果准确、灵敏,可用于注射用头孢美唑钠中包括特异杂质5-巯基-1-甲基四氮唑在内的有关物质的测定.     

高效液相色谱法测定甲氧氯普胺及其片剂的含量和有关物质

目的:建立高效液相色谱法测定甲氧氯普胺及其片剂的含量和有关物质。方法:采用 C_(18)色谱柱(250 mm×4.6 mm,5μm),流动相为磷酸二氢钾溶液(pH 4.0)-乙腈(100:25),流速0.8 mL·min~(-1),检测波长240 nm。结果:甲氧氯普胺在39.65～158.59μg·mL~(-1)范围内,线性关系良好,回归方程 Y=23.7X 6.3,r=0.9999。平均回收率为99.2%(n=9)。最低检出限为0.086μg·mL~(-1)。结论:本方法快速、简便、准确,专属性强。     

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.