氨基糖苷类药物衍生荧光性质的研究及应用

氨基糖苷类药物庆大霉素、卡那霉素及小诺霉素本身有微弱荧光,当它们在碱性条件下加入L-精氨酸、硼酸并加热水解后,可产生较强荧光,这是因为氨基糖苷类药物水解后成为糖,糖在精氨酸,硼酸存在下可产生强的荧光.由此可建立庆大霉素、卡那霉素及小诺霉素这类氨基糖苷类抗生素衍生荧光法.庆大霉素、卡那霉素均在1.0×10-6～1.5×10-5 mol/L范围内与荧光强度呈良好线性关系(r=0.9996,r=0.9994),小诺霉素在4.0×10-7～8.0×10-6 mol/L范围内与荧光强度呈良好线性关系(r=0.9986),三者检出限分别为5.8×10-7,6.1×10-7和3.0×10-8 mol/L.     

采用HPLC—ELSD法分析小诺霉素及其有关物质

目的:建立小诺霉素及其有关物质的分析方法,为该类药提供质量控制标准。方法:应用高效液相色谱法-蒸发光散射检测器(HPLC-ELSD)分析了小诺霉素及其有关物质。采用的色谱条件如下:DiamonsiL C_(18)(150 mm×4.6mm,5μm)柱,流动相为0.2mol·L~(-1)三氟醋酸-甲醇(94:6),流速为0.6mL·min~(-1),漂移管温度为110℃,气体流速为2.80L·min~(-1)。结果:在选定的色谱条件下,小诺霉素和庆大霉素复合组分(包括小诺霉素产品中的主要杂质C_(1a))可达到很好的分离,小诺霉素与C_(1a)的非衍生化分离尚属首次。小诺霉素峰面积的对数与进样量的对数间呈较好的线性关系(r=0.9999),小诺霉素的平均回收率为101.3％(RSD=1.6％),最低检出量为100ng。结论:方法快速、简便,重现性好,可用于控制小诺霉素中的有关物质含量。     

HPLC-ELSD法测定阿卡波糖发酵液中麦芽糖、葡萄糖和阿卡波糖的含量

目的 建立HPLC-ELSD法测定阿卡波糖发酵液中麦芽糖,葡萄糖和阿卡波糖的含量.方法 采用Inertsil氨基柱(4.6mm×250mm,5μm),柱温:30℃:乙腈-水(75:25)为流动相,流速:1.3mL/min; ELSD气化室温度95℃;气体流速:3L/min;气体压力:1.5×1 05Pa.结果 麦芽糖在8～400μg范围内与峰面积有良好的线性关系(r=0.9991),葡萄糖在4～200μg范围内与峰面积有良好的线性关系(r=0.9994),阿卡波糖在1.6～80μg范围内与峰面积有良好的线性关系(r=0.9985),葡萄糖峰,麦芽糖峰和阿卡波糖峰完全分离.结论方法可靠,简便,准确,可用于同时检测阿卡波糖发酵液中底物和产物.     

高效液相色谱-蒸发光散射检测法测定硫酸阿米卡星

目的:建立HPLC-ELSD法测定氨基糖苷类抗生素硫酸阿米卡星。方法:采用Zorbax Extend C18(150 mm×4.6mm,5μm)柱;以水-氨水-冰醋酸(96:3.6:0.4)为流动相,流速为0.4 mL·min-1;柱温:30℃;蒸发光散射检测,检测器漂移管温度:40℃,雾化气体压力:350 kPa。结果:硫酸阿米卡星在49.94-3995.5μg·mL-1范围内线性关系良好,r=0.9991;平均回收率为101.8％;系统精密度RSD=0.8％。同时阿米卡星与已知杂质A能良好分离。结论:本方法操作简便,快速,方法的精密度、准确性、重现性均能很好地满足质量控制的要求,是一种比较理想的阿米卡星含量测定分析方法。     

警惕小诺霉素的不良反应

小诺霉素是氨基糖苷类抗生素,具有抗菌谱广、体内无蓄积、耐药性小、毒性低(尤其是耳、肾毒性均比其它氨基糖苷类抗生素低)、临床使用不需做皮试等优点,近年来临床应用较广泛。但亦发现了一些不良反应,总结如下。 1 过敏反应 1.1 药疹 樊国斌报道,用小诺霉素出现药疹2例。年龄2.5岁,47岁,用药剂量30,60mg,bid,im,均在用药当天出现红色皮疹,迅速遍布胸、背部及四肢,其中1例出现水泡并开始破溃,伴高烧(39.2℃),经对症处理后分别3,5d症状缓解或消退。 1.2 皮肤紫癜 陈水生报告1例,男,7岁,用小诺霉素30mg,bid,im,翌日4时,双臂、下肢对称出现紫癜,下肢侧面较多,大小不等,高出皮肤,紫红色,压之不退色。经会诊考虑为小诺霉素所致过敏性紫癜,停药,用含小诺霉素0.3mg的0.2ml溶液作皮试,呈阳性反应。 1.3 过敏性休克 潘国平报道2例患者,用小诺     

8种氨基糖苷类抗生素的电喷雾离子阱质谱

目的探讨8种结构相似的氨基糖苷类抗生素的质谱裂解规律。方法在正离子检测方式下，用电喷雾离子阱质谱法对庆大霉素、小诺霉素、西索霉素、依替米星、奈替米星、威替米星、卡那霉素A和妥布霉素进行多级质谱分析。结果各化合物在二级质谱分析时，均可发生B环与C环之间的糖苷键断裂，生成脱去C环（氨基葡萄糖）的碎片离子m/z 322（庆大霉素、小诺霉素和西索霉素）、m/z 350（依替米星、奈替米星和威替米星）和m/z 324（卡那霉素和妥布霉素）；在三级质谱分析时，则进一步发生A环（氨基葡萄糖）与B环（脱氧链霉胺）之间的糖苷键断裂，生成A环或B环的碎片离子m/z 163和 m/z 191或m/z 160和m/z 162。 结论通过多级质谱分析可获得氨基糖苷类抗生素分子丰富的结构信息，并可用于该类化合物的快速结构解析和定量分析。     

氨基糖苷类抗生素在蒸发光散射检测器中响应因子的一致性考察

目的考察不同的氨基糖苷类抗生素在蒸发光散射检测器中的响应因子是否一致,进而考察ELSD在该类药的有关物质检查、多组分同类物质的相对比例测定及氨基糖苷类新药基准品的建立等方面应用的可能性。方法用HPLC-ELSD法测定了一组氨基糖苷类抗生素(阿米卡星、西索米星、奈替米星、依替米星和一类新药威替米星)的线性方程。色谱条件:Diamonsil C₁₈柱150 mm×4.6 mm,5 μm;流动相0.2 mol·L^-1三氟醋酸-甲醇(94∶6);流速0.6 mL·min^-1。检测器条件:漂移管温度110℃,气体流速2.80 L·min^-1。结果上述5种物质的线性方程间无显著性差异(P＞0.05)。结论5种不同氨基糖苷类抗生素在蒸发光散射检测器中的响应因子一致,可以尝试用HPLC-ELSD法测定该类药中的有关物质、控制多组分药物的相对比例并建立一类新药基准品。     

HILIC-HPLC-ELSD测定山药中尿囊素的含量

目的:建立山药中尿囊素的HILIC-HPLC-ELSD含量测定方法。方法:色谱柱为Waters XBridge HILIC(150 mm×4.6 mm,5μm);流动相为乙腈-水(85∶15);流速为0.8 ml·min-1;雾化压力:40 psi;漂移管温度:80℃;雾化器温度:50℃。结果:尿囊素在1.5~7.5μg范围内线性关系良好(r=0.998 1),线性方程为Y=1.67X+2.35,检出限为25 ng,平均回收率为99.9%,RSD=0.72%(n=9)。结论:该方法简单、可靠,可用于山药中尿囊素的质量控制。     

微生物比浊法检定抗生素G-418效价

采用微生物比浊法检定抗生素G-418的效价。在本实验的浓度范围内（3．761μg／nd～8．77μg／nd），标准曲线线性方程为y=-0．9184X＋0．9917，回归方程为y=-0．9215X＋0．9927，r=-1．0002，其浓度与吸收度的线性关系良好，标准曲线成立。样品检测可靠性测验，回归显著（P〈0．05），S-T为平行直线，实验结果可靠。采用微生物比浊法测定G-418的效价，具有耗时短，灵敏度高，操作简便，不需要特殊设备，且人为影响因素少等诸多特点，值得推广应用。     

HPLC-ELSD法检测康艾扶正颗粒中黄芪甲苷含量

目的建立测定康艾扶正颗粒中黄芪甲苷含量的HPLC-ELSD法。方法采用HPLC-ELSD法,phenom ene×Luna 5 u C18色谱柱(150 mm×4.60 mm,5μm),以乙腈-水(34∶66)为流动相,流速:1.0 m l.m in-1。ELSD参数:漂移管温度110℃,气体流速2.8 L.m in-1。结果在选择的色谱条件下黄芪甲苷与其它组分分离良好,对照品在2.064~10.32μg范围内呈良好的线性关系(r=0.9999),平均回收率为100.48%,RSD为1.06%。结论HPLC-ELSD法可用于康艾扶正颗粒中黄芪甲苷含量测定。     

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.     

Pharmacological treatment of COVID-19: an opinion paper

The precocity and efficacy of the vaccines developed so far against COVID-19 has been the most significant and saving advance against the pandemic. The development of vaccines has not prevented, during the whole period of the pandemic, the constant search for therapeutic medicines, both among existing drugs with different indications and in the development of new drugs. The Scientific Committee of the COVID-19 of the Illustrious College of Physicians of Madrid wanted to offer an early, simplified and critical approach to these new drugs, to new developments in immunotherapy and to what has been learned from the immune response modulators already known and which have proven effective against the virus, in order to help understand the current situation.     

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.