紫杉醇脂质体在家兔体内的药动学研究

目的 建立家兔血浆中紫杉醇HPLC检测方法,研究紫杉醇脂质体在家兔体内的药动学规律.方法 家兔血样采用叔丁基甲醚提取后在Hypersil C18柱上以甲醇:水(65:35)为流动相,检测波长为227 nm,地西泮为内标条件下进行检测.结果 血药浓度在0.1～40.0 mg/L范围内线性关系良好(r=0.9997),提取回收率大于82.0%,日内、日间精密度分析RSD＜6.0%.用本法对家兔耳缘静脉注射紫杉醇脂质体(12 mg/kg)后药动学进行研究,经DAS2.0软件拟合,脂质体制剂中紫杉醇血药浓度经时曲线符合二室模型,主要药动学参数如下:t1/2α为1.21±0.21 h,t1/2β为33.56±6.69 h,Vd为0.81±0.09 L,CL为0.04±0.01 L/h,AUC0-t为321.11±18.46 mg·h-1·L-1,AUC0→∞为722.20±170.36 mg·h-1·L-1,K10为0.04±0.01/h,K12为0.25±0.04/h,K21为0.32±0.06/h.结论 本实验方法简便易行,结果可靠,可用于紫杉醇脂质体的药动学研究.     

多西紫杉醇脂质体家兔体内药动学

目的:研究多西紫杉醇脂质体在家兔体内的药动学。方法:18只家兔随机分为3组,分别在耳缘静脉单剂量(7.5mg·kg-1)注射多西紫杉醇普通脂质体、长循环脂质体和市售注射液,用高效液相色谱法测定各时间点血药浓度。结果:血药浓度-时间数据均符合二房室模型;t1/2α分别为(0.31±0.11),(0.32±0.06),(0.17±0.04)h;t1/2β分别为(11.2±1.3),(10.5±1.1),(8.5±1.0)h;Vd分别为(8.6±1.1),(6.3±0.6),(13.7±3.6)L;AUC0→24分别为(22.8±3.6),(29.3±6.0),(13.4±2.4)mg.h.L-1;AUC0→∞分别为(28.7±5.0),(37.0±9.1),(15.1±2.8)mg.h.L-1;CL分别为(0.54±0.08),(0.42±0.07),(1.10±0.18)L.h-1。2种脂质体与注射液相比,t1/2α,t1/2β,Vd,CL,AUC0→24及AUC0→∞均有显著性或极显著性差异;脂质体之间Vd和CL差异有显著性。结论:与普通注射液相比,家兔静注两种脂质体后,均具有较长的消除半衰期,更大的药-时曲线下面积,较低的总体消除率和较小的表观分布容积,说明脂质体制剂具有长效和缓释的特点;经PEG修饰的长循环脂质体较之普通脂质体,在能够维持较长的体内循环时间的同时,能够更好地浓集于靶组织,减少药物对其他组织的不良反应并增加疗效。     

喹诺酮类药物对茶碱药代动力学的影响

目的探讨喹诺酮类药物对茶碱药代动力学是否存在显著影响,为临床合理用药提供参考。方法采用自身对照法,测定家兔iv 10mg.kg-1茶碱及每天1次灌服喹诺酮类药物,连续6d,再iv 10mg.kg-1茶碱后血浆中茶碱浓度,计算药动学参数。结果合用氟罗沙星前后茶碱在家兔体内按一室模型处理。合用前后茶碱的的药动学参数分别为,K:0.154±0.035h-1,0.151±0.044 h-1;T1/2:4.70±1.12 h,4.90±1.38 h;V:0.562±0.180 L.kg-1,0.556±0.166 L.kg-1;AUC0~10:93.70±32.87 mg.h.L-1,100.20±43.11 mg.h.L-1;AUC0~∞:147.87±68.08 mg.h.L-1,157.16±80.69 mg.h.L-1;CL:0.090±0.046 L.kg-1.h-1,0.091±0.052 L.kg-1.h-1;Cm ax:19.91±5.25 mg.L-1,20.12±5.24 mg.L-1。以上合参数均无显著性差异(P>0.05)。合用氟罗沙星后茶碱的血浆浓度有一定波动,但无统计学意义(P>0.05)。合用芦氟沙星前后茶碱在家兔体内呈一室模型。茶碱的药动学参数分别为,K:0.147±0.017 h-1,0.148±0.018 h-1;T1/2:4.76±0.54 h,4.74±0.56 h;V:0.581±0.089 L.kg-1,0.555±0.075 L.kg-1;AUC0~10:91.42±11.14 mg.h.L-1,94.97±10.20mg.h.L-1;AUC0~∞:119.48±14.96 mg.h.L-1,124.05±14.76 mg.h.L-1;CL:0.085±0.011 L.kg-1.h-1,0.082±0.010L.kg-1.h-1;Cmax:18.48±2.53 mg.L-1,19.16±2.34mg.L-1。合用芦氟沙星前后茶碱各参数均无显著性差异(P>0.05)。合用芦氟沙星后茶碱的血浆浓度有升高趋势,但无统计学意义(P>0.05)。合用培氟沙星前后茶碱在家兔体内呈一室模型。茶碱的药动学参数分别为,K:0.150±0.038 h-1,0.110±0.018 h-1,P<0.01;T1/2:4.95±1.67 h,6.69±2.01 h,P<0.01;V:0.584±0.149 L.kg-1,0.511±0.126 L.kg-1,P<0.05;AΜC0~10:97.71±40.09 mg.h.L-1,126.11±42.72 mg.h.L-1,P<0.01;AΜC0~∞:136.05±83.40 mg.h.L-1,202.10±99.81 mg.h.L-1,P<0.01;CL:0.091±0.038 L.kg-1.h-1,0.056±0.018 L.kg-1.h-1,P<0.01;Cmax:18.94±4.89 mg.L-1,21.82±5.40 mg.L-1,P<0.05。合用加替沙星前后茶碱在家兔体内按一室模型处理。合用前后茶碱的药动学参数分别为,K:0.147±0.035 h-1,0.127±0.026 h-1;T1/2:4.89±0.98 h,5.62±1.09h;V:0.541±0.162 L.kg-1,0.538±0.154 L.kg-1;AΜC0~10:97.81±29.87 mg.h.L-1,107.27±39.54mg.h.L-1;AΜC0~∞:153.32±65.64 mg.h.L-1,174.01±71.03 mg.h.L-1;CL:0.081±0.034 mg.h.L-1,0.074±0.033 L.kg-1.h-1;Cmax:20.51±5.12 mg.L-1,20.60±5.05 mg.L-1。合用加替沙星前后茶碱各参数除T1/2(P<0.05)外无显著差异。结论氟罗沙星、芦氟沙星对茶碱的血药浓度及药代动学参数没有显著影响;培氟沙星对茶碱的血药浓度及药代动学参数有显著影响;加替沙星对茶碱的血药浓度及除T1/2的药代动学参数没有显著影响。     

大鼠灌胃给予维血宁颗粒后虎杖苷血药浓度测定及药动学研究

目的:建立大鼠血浆中虎杖苷浓度的反相高效液相色谱(RP-HPLC)测定方法。方法:色谱柱为Diamonsil C18(200mm×4.6mm,5μm),流动相为乙腈-水(20∶80,V/V),流速为1.0mL·min-1,柱温为35℃,检测波长为303nm。大鼠ig维血宁颗粒后,测定不同时间血药浓度。采用DAS2.0药动学软件对血药浓度-时间数据进行拟合,计算相应药动学参数。结果:大鼠灌胃给予维血宁颗粒后,虎杖苷在大鼠体内药动学主要参数为:tmax=(0.403±0.063)h,Cmax=(1.715±0.097)mg·L-1,Ka=(6.894±3.275)h-1,t1/2α=(0.202±0.142)h,t1/2β=(2.484±1.624)h,CL/F=(32.229±22.027)L·h-1·kg-1,V1/F=(14.447±12.013)L·kg-1,AUC(0～t)=(1.511±0.550)mg·h·L-1,AUC(0～∞)=(1.955±0.765)mg·h·L-1。结论:虎杖苷在大鼠体内的药动学过程符合二室模型,进入体内分布迅速,代谢消除速度也较快。     

克拉霉素对茶碱在兔体内药动学的影响

目的研究克拉霉素对茶碱在新西兰兔体内药动学的影响.方法采用自身对照法,用HPLC测定合用克拉霉素后,茶碱不同时间间隔血药浓度,经3P97程序进行模型判别及参数计算.结果合用克拉霉素注射液后茶碱的t1/3β由(3.24±0.76)h延长至(4.90±1.16)h(P＜0.01);AUC由(75.02±22.41)mg·h·L-1增至(98.18±27.91)mg·h·L-1(P＜0.01);CL由(0.20±0.08)L·h-1下降至(0.13±0.04)L·h-1(P＜0.05).结论克拉霉素注射液与茶碱在兔体内合用可影响茶碱的t1/3β,AUC,CL.     

罗红霉素对家兔体内格列吡嗪药动学的影响

目的:研究罗红霉素在健康和糖尿病家兔体内对格列吡嗪胶囊代谢的影响。方法:健康对照组家兔和糖尿病组家兔各5只,每只口服格列吡嗪5mg。经2周清洗期后,每只家兔口服罗红霉素50.0mg,每天2次,持续3天,第4天口服相同剂量格列吡嗪。所有家兔均在给予格列吡嗪前及给药后0.5、1.5、3、5、7、9、11、24、35h,经耳缘静脉采血,用HPLC法测定各时间点格列吡嗪的血药浓度,测得的血药浓度结果用药动学软件DAS 2.0进行曲线拟合,采用自身对照法分析给予罗红霉素前后格列吡嗪药动学的变化。结果:格列吡嗪在家兔体内的药动学符合单室模型,健康对照组家兔单用格列吡嗪,其t1/2、Cmax、AUC分别为(2.9±0.4)h,(5815±940)μg/L,(58919±860)μg.h.L-1;加用罗红霉素后其t1/2、Cmax、AUC分别为(3.5±0.9)h,(6165±764),(76515±1830)μg.h.L-1。糖尿病组家兔单用格列吡嗪,其t1/2、Cmax、AUC分别为(1.7±0.4)h,(4307±580)μg/L,(32469±786)μg.h.L-1;加用罗红霉素后其t1/2、Cmax、AUC分别为(3.2±1.5)h,(8531±1479)μg/L,(76489±1588)μg.h.L-1。给予罗红霉素前后格列吡嗪的t1/2、Cmax、AUC差异均存有统计学意义(P<0.05)。结论:罗红霉素对家兔体内格列吡嗪的药动学有明显的影响,临床合用两药时需要注意调整剂量以防发生低血糖危害。     

甲磺酸帕珠沙星的人体药动学

目的:研究甲磺酸帕珠沙星在健康人体内的药动学特征。方法:12名健康志愿者(男女各6名)单剂量和多剂量静脉滴注甲磺酸帕珠沙星氯化钠注射液300mg,滴注时间30min。血浆用20%高氯酸水溶液沉淀蛋白,上清液直接用高效液相色谱-荧光检测血浆中帕珠沙星药物浓度。结果:最小检测限小于0.028mg.L-1,提取回收率大于90%,日内、日间变异(RSD小于10%)。静脉滴注甲磺酸帕珠沙星在健康人体内的药动学特征用3P97程序拟合为二房室模型,其主要药动力学参数单剂量时和多剂量时的Cmax,t1/2β,AUC0-t,AUC0-∞,Vc和CL分别为(7.2±0.8)mg.L-1和(7.3±0.8)mg.L-1,(2.04±0.17)h和(2.24±0.23)h,(14.0±1.5)mg.L.h-1和(14.3±1.5)mg.L.h-1,(13.1±1.5)mg.L.h-1和(13.3±1.2)mg.L.h-1,(27.2±4.6)L和(25.3±8.8)L,(22.1±2.6)L.h-1和(23.7±2.1)L.h-1。单剂量时和多剂量间的药动学参数,除了t1/2β和MRT有性别差异外,其余无明显差异。结论:静脉滴注甲磺酸帕珠沙星后无论单剂量和多剂量的药动学参数基本一致,说明连续300mg,bid,静脉滴注5d体内无明显累积,药动学参数如t1/2β,MRT可能存在性别差异,其原因尚不清。     

家兔体内异环磷酰胺的药动学

目的:研究异环磷酰胺在兔体内的药动学。方法:随机选用家兔6只,根据体质量予相应剂量的异环磷酰胺静脉注射,在5,10,20,30,45min及1,1.5,2,2.5,3,5,7h取血1mL。血清样品用C18固体萃取小柱处理,用高效液相测定药物浓度。所测定数据用3P97程序处理,以获得相关的药动学参数。结果:异环磷酰胺在2.5~200mg.L-1(r=0.999)范围内线性良好;绝对回收率在89.3%~93.6%之间。拟合的最佳房室模型为二室模型;测定的药动学参数为:tα/2=0.44±0.12h,tβ/2=5.3±3.1h,k21=0.25±0.43h-1,k10=1.2±0.4h-1,k12=0.39±0.50h-1,V=1.44±0.25L,CL=1.7±0.8L.h-1,AUC0-∞=140.5±39.3mg.L-1.h,AUC0-t=128.4±34.3mg.L-1.h。结论:异环磷酰胺在兔体内的代谢符合二室房室模型。     

他克莫司在肝移植患者体内的药动学

目的:考察口服他克莫司(FK506)胶囊在肝移植患者体内的药动学特征,为临床调整个体化给药方案提供科学依据.方法:22例肝移植患者,给予FK506为基础的免疫抑制治疗,术后24 h后开始服用FK506,剂量为(0.13±0.04)mg·kg-1·d-1,每12 h服用1次.受试者在服药前(0 h)和服药后0.33,0.66,1,1.5,2,3,4,6,8,10,12 h共12个时间点分别取外周静脉血,用MEIA法进行药物浓度测定,PKBP-N1软件计算药动学参数,并绘制血药浓度-时间曲线.结果:FK506口服后血药浓度一时间曲线为一级吸收二室开放模型,22例肝移植受者在口服FK506后,血药浓度迅速上升达到峰值,然后迅速下降,PK参数分别为t1/2a为(1.2±2.1)h,t1/2β(21.0±10.1)h,Ka(2.2±0.9)·h-1,CLs(0.64±0.3)L·h-1·kg-1,AUG0-12为(136.2±33.7)μg·h·L-1.本实验中和AUC相关性最好的是G、C4、C8,r分别为0.95,0.94,0.91.结论:肝移植患者口服FK506药动学个体差异大,用药应个体化.根据PKBP-N1分析得到的药动学参数,能较好的体现患者的药动学信息,根据单点血药浓度可以比较准确的预测AUC0-12.     

奈韦拉平片血药浓度测定及健康人体药动学

目的:建立高效液相色谱法测定人血浆中奈韦拉平浓度,并研究了奈韦拉平片的健康人体药动学。方法:采用高效液相色谱法测定奈韦拉平血浆药物浓度,并应用本法研究10名健康受试者单剂量口服奈韦拉平片200mg后的药动学。结果:奈韦拉平在62.5~4 000μg.L-1范围线性良好(r=0.999 9),回收率,日间、日内差等均符合生物样品分析要求。药动学研究结果表明,奈韦拉平片体内过程符合一房室开放模型,主要药动学参数:Cmax为(2 357±387)μg.L-1;tmax为(3.7±1.1)h;t1/2ka为(0.7±0.9)h;t1/2ke为(54.1±15.4)h;CL/F为(1.2±0.3)L.h-1;V/F为(93.4±18.1)L;AUC0-t为(154.5±34.5)mg.h.L-1,AUC0-∞为(173.7±44.1)mg.h.L-1。结论:本方法便捷,灵敏,准确,适用于奈韦拉平血药浓度测定和药动学研究,本研究药动学结果可为临床用药提供依据。     

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.