基于纳米金催化鲁米诺-氯化汞化学发光新体系测定木犀草素

目的:基于纳米金对鲁米诺-氯化汞化学发光体系有良好的催化作用,建立测定木犀草素含量的高灵敏流动注射-化学发光分析法。方法:采用流动注射技术,实验研究了影响化学发光的各种因素;根据体系的化学发光光谱和紫外-可见吸收光谱结果,探讨了可能的化学发光机理。结果:0.1 mol·L-1氢氧化钠、4.0×10-4 mol·L-1鲁米诺、6.08×10-5 mol·L-1纳米金与1.0×10-3 mol·L-1 HgCl2组成最优的化学发光体系。在优化的实验条件下,本方法测定木犀草素的线性范围为2.0×10-9～1.0×10-7 g·mL-1(r=0.9929),检出限为1.5×10-9 g·mL-1,RSD为2.1%(C=1.0×10-8 g·mL-1,n=11)。纳米金作为电子转移的媒介,在鲁米诺-氯化汞反应过程中起催化作用;木犀草素和鲁米诺竞争与氯化汞发生反应,抑制了鲁米诺氧化成鲁米诺自由基,导致发光强度的降低。结论:利用本法成功地测定了血清与合成样品中木犀草素的含量。     

鲁米诺-Ag(Ⅲ)化学发光新体系用于石杉碱甲的测定

目的:建立测定石杉碱甲的流动注射化学发光法。方法:在碱性介质中,石杉碱甲对鲁米诺-Ag(Ⅲ)化学发光体系有显著的增敏作用,建立了化学发光检测石杉碱甲的新方法。结果:在优化的条件下,石杉碱甲浓度在1.0×10-8～5.0×10-7mol·L-1范围内与化学发光强度呈线性关系;对浓度为2.0×10-7 mol·L-1的石杉碱甲溶液11次平行测定的RSD为2.6%;检出限为8.0×10-9 mol·L-1。结论:该方法简单、快速、灵敏,适用于药物制剂中石杉碱甲的含量测定。     

流动注射-化学发光检测利福平

目的:建立一种流动注射-化学发光测定利福平的快速、灵敏新方法。方法:碱性条件下,利福平对luminol-KIO4化学发光体系有抑制作用,结合流动注射技术,建立了流动注射-化学发光检测利福平的新方法。结果:在优化条件下,利福平的线性范围是7.0×10-9～6.0×10-7 mol.L-1,检出限达3.2×10-9 mol.L-1。对3.0×10-8 mol.L-1和2.0×10-7mol.L-1利福平分别进行11次测定,相对标准偏差分别为0.8%和1.6%。分析速度为128个样品/时。将提出的新方法成功应用于利福平滴眼液和利福平胶囊中利福平含量的测定。结论:本方法操作简单快速,适合于利福平的分析。     

曙红Y化学发光体系的建立及其用于妥布霉素滴眼液的测定

目的建立曙红Y(EY)化学发光体系快速测定妥布霉素滴眼液的方法。方法在强碱性条件下EY与N-溴代丁二酰亚胺(NBS)发生作用,产生较强的化学发光(CL),妥布霉素对该体系的发光信号有增敏作用。当NBS为0.889 9 mg·mL-1、NaOH为20 mg·mL-1、EY为0.484 3 mg·mL-1时,用于妥布霉素的测定。结果妥布霉素在0.101 8¹0.18μg·mL-1内线性关系良好,线性相关系数r为0.999 6,检出限为6.388×10-2μg·mL-1。结论本方法分析速度快、灵敏度高,可以用于妥布霉素滴眼液的快速分析检测。     

流动注射化学发光法测定姜黄素

目的:以Ce(Ⅳ)作为氧化剂,建立化学发光法测定中药成分姜黄素。方法:用Ce(Ⅳ)直接氧化姜黄素能产生弱发光,而罗丹明B(RhB)能大大增强此弱发光,由此建立了测定姜黄素的FIA-CL分析法。结果:测定姜黄素的线性范围为5.0×10-9~1.0×10-7mol.L-1,其检出限为3.0×10-9mol.L-1;对于1.0×10-8mol.L-1姜黄素进行11次测定的RSD为2.9%。结论:本方法简便、快捷且具有较高的灵敏度,可用于中药姜黄中姜黄素的分析。     

导数差示脉冲极谱法用于抗生素的定量研究(英)

本文用一阶导数差示脉冲极谱法（FDDPP）对链霉素、青霉素G、土霉素,用二阶导数差示脉冲极谱法（SDDPP）对氯霉素、卡那霉素、核糖霉素进行了定量研究。链霉素、青霉素G、土霉素、氯霉素、卡那霉素、核糖霉素分别在200～700μg·ml-1,35～210μg·ml-1,10～60μg·ml-1,32～192μg·ml-1,150～900μg·ml-1,80～480μg·ml-1的范围内与导数差示脉冲极谱峰幅值呈极为显著的线性关系（P＜0.01）。链霉素、青霉素G、土霉素、氯霉素、卡那霉素、核糖霉素的峰电位、检测限分别为0.100V,5.6×10-8mol·L-1,－1.400V,8．0×10-9mol·L-1,－1.536V,6.9×10-7mol.L-1,－0.060V,60×10-9mol·L-1,－0.370V,4.6×10-8mol·L-1,和-0.105V,7．2×109mol·L-1。方法简便、快速、灵敏,结果准确。     

电化学发光增强法高灵敏度测定蜂蜜中四环素总量

目的:建立高灵敏度测定蜂蜜中四环素总量的电化学发光法。方法:基于四环素、土霉素、金霉素、强力霉素对钌联吡啶的电化学发光具有几乎完全相同的增强效应,建立本方法,并阐明其机理。结果:在最优实验条件下,钌联吡啶的电化学发光增强值与四环素、土霉素、金霉素、强力霉素的浓度的对数呈线性关系,线性范围为1.0×10-12～5.0×10-10 mol.L-1,检测限约为3×10-13 mol.L-1。精密度和准确度好。机理研究表明:四环素的电化学氧化产物增强了钌联吡啶的电化学发光。结论:该方法灵敏度极高,测定结果准确可靠,可用于蜂蜜中四环素总量的测定。     

HPLC-ELSD测定妥布霉素滴眼液的含量

目的建立高效液相色谱一蒸发光散射检测器检测法（HPLC—ELSD）测定妥布霉素滴眼液的含量。方法选用耐酸性的Agilent Zorbax SB-C18（4．6mm×250mm,5μm）色谱柱;流动相为0．2mol·L^-1三氟乙酸溶液,甲醇（92：8）,柱温为35℃,流速为0．8mL·min^-1,进样体积为10μL;ELSD检测器漂移管温度为45℃,雾化气体压力为3．5bar,信号增益（GA跗）为5。结果妥布霉素在55．6～1396．7μg,mL^-1内,其峰面积的对数与浓度的对数呈良好的线性关系（r=0．9997）,检测限和定量限分别为0．15μg·mL^-1和0．45μg·mL^-1。结论方法专属性强,准确可靠,适用于妥布霉素滴眼液产品质量控制。     

HPLC-MS/MS法检测兔离体角膜实验中妥布霉素及其药物动力学研究

目的:建立测定谷胱甘肽–碳酸氢钠林格液(GBR)溶液中妥布霉素的液质方法,并对其在家兔离体角膜实验中的药动学特征进行研究.方法:以GBR溶液为释放介质,用液质联用法测定妥布霉素在兔离体角膜中的累积释药量.色谱柱为Waters XTerra RP C18柱(150mm×4.6mm,3μm);流动相为2mM·L-1醋酸铵缓...     

毛细管电泳-激光诱导荧光分析仪组装与性能测试

目的组装一台毛细管电泳-激光诱导荧光分析仪。方法以473 nm半导体泵浦固体激光器为激发光源,自制的激光诱导荧光检测器采用共线型光学结构,用VB2为模型化合物进行该分析仪的性能评价。结果 VB2的浓度检出限为2.0×10-9mol·L-1(7.5×10-7 g·L-1),质量检出限为4.0×10-18 mol(1.5×10-15 g),在1.0×10-8～1.0×10-6 mol·L-1浓度范围内呈线性相关。结论自组装毛细管电泳-激光诱导荧光分析仪具有结构简单,操作方便,灵敏度高等优点。     

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.     

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.