Delayed O-methylation of l-DOPA in MB-COMT-deficient mice after oral administration of l-DOPA and carbidopa

1.?Catechol-O-methyltransferase (COMT) is involved in the O-methylation of l-DOPA, dopamine, and other catechols. The enzyme is expressed in two isoforms: soluble (S-COMT), which resides in the cytoplasm, and membrane-bound (MB-COMT), which is anchored to intracellular membranes.

2.?To obtain specific information on the functions of COMT isoforms, we studied how a complete MB-COMT deficiency affects the total COMT activity in the body, peripheral l-DOPA levels, and metabolism after l-DOPA (10?mg kg^?1) plus carbidopa (30?mg kg^?1) administration by gastric tube in wild-type (WT) and MB-COMT-deficient mice. l-DOPA and 3-O-methyl-l-DOPA (3-OMD) levels were assayed in plasma, duodenum, and liver.

3.?We showed that the selective lack of MB-COMT did not alter the total COMT activity, COMT enzyme kinetics, l-DOPA levels, or the total O-methylation of l-DOPA but delayed production of 3-OMD in plasma and peripheral tissues.     

LC-MS/MS法分析人血浆中西格列汀浓度及其应用研究

摘要：目的 建立一种测定人血浆中西格列汀浓度的液相色谱-串联质谱（LC-MS/MS）分析方法,并将该方法应 用于西格列汀在人体内的药代动力学研究。方法 以西格列汀-d4为内标,血浆样品经CleanertPPT沉淀板沉淀后, 通过Diamonsil C18色谱柱（100 mm×4.6 mm,5 μm）进行分离,使用甲醇-10 mmol/L甲酸铵水溶液（含10%甲醇,0.1% 甲酸）作为流动相,进行梯度洗脱,流速为0.5 mL/min。通过电喷雾电离源（ESI）,以多反应监测（MRM）模式进行正离 子检测。从选择性、残留、线性范围与定量下限、精密度与准确度、基质效应和回收率、稳定性方面进行方法学验证。 同时考察健康人口服西格列汀片100 mg后的主要药代动力学参数。结果 西格列汀、西格列汀-d4的MRM离子对 分别为 m/z 408.0→235.2、m/z 412.1→239.0。人血浆中西格列汀在 0.5～1 000 μg/L 浓度范围内线性关系良好（R2> 0.99）,定量下限为0.5 μg/L;定量下限和质控样品的批内、批间精密度（RSD）在0.83%~12.80%之间,准确度（RE）在± 10.0%以内。健康人口服西格列汀片100 mg后主要药代动力学参数：达峰时间（Tmax）、达峰浓度（Cmax）、、生物利用度 （AUC）、半衰期（T1/2）分别为（2.44±1.29）h、（375±138）μg/L、（2 915±585）h·μg/L、（11.10±2.41）h。结论 本LC-MS/ MS分析方法敏感度高且样品处理方法简单快速,满足生物分析的法规要求,可应用于人体内西格列汀的药代动力学 研究。     

应用非线性混合效应模型法考察儿童疾病因素对环孢素药动学的影响

目的:考察疾病因素对于环孢素A(CsA)在儿童体内药动学的影响,促进个体化用药。方法:收集150例包括再生障碍性贫血(AA)、嗜血细胞综合征(HPS)和难治性肾病综合征(RNS)不同病种患儿的CsA血药浓度数据和临床资料。采用非线性混合效应模型法考察疾病种类因素对于CsA药动学的影响。采用Bayesian最大后验概率法获取并比较CsA在不同病种患者中药动学参数的差异。用拟合优度(goodness-of-fit)、自举法(bootstrap)、直观预测检验法(VPC)、正态化预测分布误差(NPDE)对最终模型的预测性能进行验证。结果:最终模型药动学参数的群体典型值分别为:吸收速率常数(k_a)1.22 h^-1,吸收时滞时间(T_lag)0.45 h,表观分布容积(V_d)218.18 L,口服清除率(CL)14.45 L·h^-1。拟合优度、自举验证、VPC和NPDE结果表明最终模型稳定,预测结果可靠。模型结构显示只有患者的体质量和AST值是影响CsA清除率的显著性因素。CsA在AA、HPS和RNS患者中的药动学参数差异无显著性(P>0.05)。结论:本研究成功获取了CsA在儿童AA、HPS和RNS患者中的药动学参数,上述疾病因素不会显著影响CsA在儿童体内的药动学过程。     

吉西他滨低剂量延时输注的研究进展

吉西他滨（gemcitabine,GEM）为抗嘧啶核苷酸代谢类药物。目前,GEM的标准给药方式为1 000~1 250 mg·m^-2,30 min静脉快速输注。但是,药理学研究表明,GEM延时输注可使细胞内有活性的GEM三磷酸盐达到最佳的蓄积速度,提示GEM延时输注在药动学方面要优于30 min快速输注。故本文对GEM低剂量延时输注的相关研究进行综述,以期为临床用药提供相关依据。     

Ratiometric delivery of two therapeutic candidates with inherently dissimilar physicochemical property through pH-sensitive core–shell nanoparticles targeting the heterogeneous tumor cells of glioma

Currently, combination drug therapy is one of the most effective approaches to glioma treatment. However, due to the inherent dissimilar pharmacokinetics of individual drugs and blood brain barriers, it was difficult for the concomitant drugs to simultaneously be delivered to glioma in an optimal dose ratio manner. Herein, a cationic micellar core (Cur-M) was first prepared from d-α-tocopherol-grafted-ε-polylysine polymer to encapsulate the hydrophobic curcumin, followed by dopamine-modified-poly-γ-glutamic acid polymer further deposited on its surface as a anion shell through pH-sensitive linkage to encapsulate the hydrophilic doxorubicin (DOX) hydrochloride. By controlling the combinational Cur/DOX molar ratio at 3:1, a pH-sensitive core–shell nanoparticle (PDCP-NP) was constructed to simultaneously target the cancer stem cells (CSCs) and the differentiated tumor cells. PDCP-NP exhibited a dynamic diameter of 160.8?nm and a zeta-potential of –30.5?mV, while its core–shell structure was further confirmed by XPS and TEM. The ratiometric delivery capability of PDCP-NP was confirmed by in vitro and in vivo studies, in comparison with the cocktail Cur/DOX solution. Meanwhile, the percentage of CSCs in tumors was significantly decreased from 4.16% to 0.95% after treatment with PDCP-NP. Overall, PDCP-NP may be a promising carrier for the combination therapy with drug candidates having dissimilar physicochemical properties.     

Puerarin-loaded PEG-PE micelles with enhanced anti-apoptotic effect and better pharmacokinetic profile

Puerarin (PUE) is the most abundant isoflavonoid in kudzu root. It is widely used as a therapeutic agent for the treatment of cardiovascular diseases. However, the short elimination half-life, poor-bioavailability, and acute intravascular hemolysis of PUE are the main obstacles to its widespread clinical applications. Whereas PEG-PE micelles possess the ability to release medicine slowly, enhance the cellular uptake of drugs and improve their biocompatibility. Therefore, it was aim to fabricate puerarin-loaded PEG-PE (PUE@PEG-PE) micelles to improve the pharmaceutical properties of drugs. It can be observed from the TEM images that PUE@PEG-PE micelles appeared obvious core-shell structure and remained well-dispersed without aggregation and adhesion. PUE was successfully embedded in the core of PEG-PE micelles, which was confirmed by FT-IR and ¹H NMR spectra. In vitro studies showed that PUE@PEG-PE micelles exhibited a sustained release behavior in pH 7.4 PBS buffer and decreased hemolysis rate of PUE. Compared with PUE, PUE@PEG-PE micelles showed a 3.2-fold increase in the half-life of PUE and a 1.58-fold increase in bioavailability. In addition, the PUE@PEG-PE micelles exerted enhanced protective effect against isoprenaline-induced H9c2 cells apoptosis compared with PUE, as evident by decreased percentage of Hoechst-positive cells, Caspase 3 activity, Bax expression, and increased Bcl-2 expression. Notably, the PEG-PE micelles exhibited favorable cellular uptake efficiency on H9c2 cells, and this may account for their enhanced anti-apoptotic effect of the incorporated drug. Altogether, the PUE@PEG-PE micelles were not only able to control the drug release but also offered promise to enhance the pharmacokinetic and pharmacodynamic potential of PUE.     

万古霉素个体化给药流程的建立及案例分析

目的：建立万古霉素个体化给药流程,并将其应用于临床实践。方法：临床药师依据万古霉素血药浓度监测结果和患者情况,应用建立的流程协助临床制定万古霉素初始给药方案,运用JPKD-vancomycin下的万古霉素群体药动学模型,结合贝叶斯反馈程序解读血药浓度监测结果、推算患者个体化给药剂量、预测调整后给药方案的血药浓度结果,有助于万古霉素个体化给药。结果：万古霉素个体化给药流程应用于万古霉素血药浓度的解读,为临床制定万古霉素个体化给药方案提供依据。结论：建立了万古霉素个体化给药流程,有助于协助临床合理用药,可提高万古霉素临床疗效和减少相关不良反应发生。     

UPLC-MS/MS法同时检测大鼠血浆中参芪扶正注射液主要成分的含量及其药动学

目的：建立超高效液相-三重四极杆质谱联用（UPLC-MS/MS）法同时测定大鼠血浆中黄芪甲苷、毛蕊异黄酮-7-O-β-D葡萄糖苷和党参炔苷的浓度,研究参芪扶正注射液在大鼠体内的药动学。方法：血浆样品加入适量内标,50%甲醇-乙腈沉淀蛋白,离心后取上清进样。采用ACE Excel 1.7 C₁₈柱（50 mm×2.1 mm,2.1 μm）,柱温：40℃,流速：0.6 mL·min^-1,流动相由0.1%甲酸水和0.1%甲酸-乙腈组成,采用梯度洗脱,分析时间2.5 min。质谱采用ESI源,正离子检测。大鼠尾静脉注射参芪扶正注射液浓缩液,眼眶采血测定血浆中药物浓度,药动学参数以DAS 3.0软件处理。结果：黄芪甲苷、毛蕊异黄酮-7-O-β-D葡萄糖苷、党参炔苷的浓度分别在5~2 000 ng·mL^-1、2~800 ng·mL^-1、10~4 000 ng·mL^-1内均呈良好线性关系（R ≥ 0.991 5）;日内、日间精密度良好,RSD均小于13.3%（n=6）;提取回收率均在79.0%~97.1%之间,RSD均小于11.4%（n=6）。药动学结果表明,黄芪甲苷、党参炔苷和毛蕊异黄酮-7-O-β-D葡萄糖苷在大鼠体内的AUC_0-t分别为（38.84±17.20）、（23.11±6.84）、（5.32±0.36）μg·min·L^-1,t_1/2分别为（56.44±28.25）、（47.48±9.54）、（10.01±4.42）min,CL分别为（0.15±0.06）、（1.18±0.47）、（0.47±0.11）mL·min^-1·kg^-1。结论：本法简便、快速、灵敏度高、专属性好,可用于参芪扶正口服液大鼠血浆中黄芪甲苷、毛蕊异黄酮-7-O-β-D葡萄糖苷和党参炔苷的含量测定及药动学研究。     

中国群体药动学研究论文的质量评价

目的：系统评价中国学者发表的群体药动学（PPK）论文的质量,为规范论文写作,推动该学科的发展提供参考。方法：检索Pubmed、Scopus、Web of Science、中国知网、维普和万方医学数据库自建库起至2016年底,由中国研究机构的学者撰写的PPK论文。根据新近发表的相关推荐意见和指南进行论文质量评价。结果：共纳入155篇中文和115篇英文论文。论文质量随时间有提高趋势,且英文论文的质量总体上高于中文论文。目前,论文质量主要在以下方面存在缺陷或内容不完整：摘要部分的"药物给药途径"、引言部分的"研究药物的药动学背景";方法和结果部分的"研究对象和建模数据的情况"、"数据探索性分析方法"和"候选模型的筛选";讨论部分的"研究局限性"。结论：研究者须重视与改进上述存在的问题,严格按照相关规范要求提高论文质量。     

HPLC-MS/MS法定量研究氧化白藜芦醇对沙奎那韦在大鼠体内药动学的影响

目的:应用高效液相色谱-串联质谱(HPLC-MS/MS)技术建立大鼠血浆中沙奎那韦的定量测定方法,并用于氧化白藜芦醇对沙奎那韦在大鼠体内药动学研究。方法:液相色谱分离采用C₁₈反相色谱柱(150mm×2.1mm,5.0μm),流动相为乙腈/水(含0.2mmol·L^-1甲酸铵),流速为300μL·min^-1;质谱检测采用电喷雾正离子(ESI^+)模式,多反应监测。血浆样品采用液-液萃取方式提取,检测反应为m/z671.4→570.4(沙奎那韦),m/z721.4→296.2(利托那韦,内标)。将10只SD大鼠分为2组,对照组与实验组分别灌胃给予沙奎那韦(30mg·kg^-1)、沙奎那韦(30mg·kg^-1)+氧化白藜芦醇(40mg·kg^-1),于不同时间取血,测定血药浓度。结果:沙奎那韦在1.0~100.0ng·mL^-1范围内呈良好的线性关系(r=0.998 5),日内和日间精密度均小于12.16%,偏差为0.89%~6.24%,回收率为67.85%~82.38%,血浆样品稳定性好。同时服用氧化白藜芦醇时,大鼠体内沙奎那韦达峰浓度C_max、C_max1显著降低,而C_max、T_max、t_1/2、CL/F均无显著差异。结论:HPLC-MS/MS测定方法准确度高、专属性强、灵敏度高、快速高效。沙奎那韦的药时曲线存在双峰现象;氧化白藜芦醇可以显著降低沙奎那韦的达峰浓度,但对口服生物利用度等其他药动学参数没有显著性影响。