Determinants of plasma concentrations of nicotine and cotinine during cigarette smoking and transdermal nicotine treatment

Objective: Interindividual variability in plasma concentrations of nicotine and its proximate metabolite, cotinine, is considerable during smoking and transdermal nicotine treatment, even among individuals taking in nominally similar doses of nicotine. This report explores the determinants of this variability and the utility of baseline (smoking) plasma concentrations to predict concentrations during transdermal nicotine treatment. Methods: Data were analysed from a smoking cessation study (n = 466), and from a pharmacokinetic study (n = 12). Multiple regression models examined the relationships of plasma concentrations to individual characteristics such as smoking pattern, absorbed dose of nicotine, and pharmacokinetic parameters. Results: Plasma concentrations of nicotine and cotinine were highly variable in both studies. Indirect estimates of plasma clearance (baseline plasma concentration divided by cigarettes per day) together with other factors could account for 18 to 33% of the variability during transdermal nicotine treatment in the smoking cessation study. In contrast, 75 to 99% was accounted for by direct measurements of plasma clearances and systemic dose of nicotine in the pharmacokinetic study. Conclusion: Plasma concentrations of nicotine and cotinine during transdermal nicotine treatment are poorly predicted by clinical history or baseline plasma concentrations. This is a result of inadequate characterisation of highly variable individual pharmacokinetic parameters and absorbed dose of nicotine. Considering the interindividual variability of plasma nicotine and cotinine concentrations together with the lack of clinical end-points for transdermal nicotine dosing, it seems logical to investigate the utility of a therapeutic drug monitoring approach for transdermal nicotine treatment – particularly for high dose regimens (> 22 mg per 24 hours). Received: 7 May 1996 / Accepted in revised form: 21 August 1996     

胃癌病人NK细胞活性变化机理的初步研究

应用~(51)Cr释放试验和效靶结合试验,同时测定了正常人和胃癌病人外周血NK细胞活性与靶结合细胞数(TBC),研究了正常人及病人血浆对NK细胞功能的影响。发现正常人NK细胞活性与靶结合细胞数之间的关系呈直线正相关,但在NK活性降低的病人中靶结合细胞数却无明显改变,二者无相关性,而病人的血浆对正常人外周血NK活性则有明显的抑制作用(P<0.05),且抑制率与胃癌人NK细胞活性存有着负相关的关系,提示胃癌病人血浆具有抑制NK细胞活性的物质。     

The estimation of the plasma free fraction of cyclosporine in rabbits and heart transplant patients: The application of a physiological model of renal clearance

We estimated the free fraction (f_u) of cyclosporine (CyA) in the plasma from concentrations of CyA in urine (C_u) and plasma (C_p), urine flow rate (UF), and glomerular filtration rate in rabbits and in heart transplant patients. Following intravenous administration of CyA (5–30 mg kg^?1) in ten NZW rabbits and oral administration of CyA (4.8–12.1 mg kg^?1) in nine heart transplant patients, CyA concentrations in urine and plasma were measured by HPLC. The ratios of C_u to C_p and UF data were fitted to a physiological model of renal clearance using NONMEM. The free fraction of cyclosporine in the rabbits and the heart transplant patients was 0.0122 and 0.14, respectively. Because of the relatively low permeability of CyA across the tubular epithelium, no apparent equilibrium between C_u and C_p at any urine flow rate was reached and, therefore, the C_u to C_p ratio will not be equal to f_u.     

抗体阴性重症肌无力的短程血浆置换疗法初探

血浆置换(plasma exchange,PE)在重症肌无力(MG)上的疗效已有报道,但缺乏明确一致的置换方案。我们对12例MG患者进行了37人次的短程PE,各例均在10d内行3～4次置换术,术前和术后第7天按Mantegazza肌力评分表进行临床疗效评定,结果除1例外,均获得肯定疗效,仅1人次发生较严重的副反应。4例抗体阴性病人置换后均获显著疗效,提示抗体阴性MG血浆中存在某些未知的致病因子。短程PE可供选择作为MG危象的治疗方案。     

浆细胞病患者IL-4产生细胞数减少的意义及机制探讨

本文运用APAAP法检测了16名浆细胞患者外周血细胞在PHA刺激下产生IL-4的能力。发现浆细胞病组阳性细胞比率明显低于正常对照组(P<0.001),且阳性细胞比率与患者血清中多克隆IgM、IgA水平呈正相关(r=0.806和r=0.703)。在正常人外周血中加入CRP50mg/L,经PHA刺激后IL-4产生细胞也明显减少。作者假设,由于IL-6增高引起CRP等急性期相蛋白大量分泌,使IL-4产生受到明显抑制,从而使B细胞激活发生障碍是浆细胞病中多克隆免疫球蛋白合成抑制的主要原因。     

人工心脏瓣膜置换术后PT-INR测定监测口服抗凝药的研究

人工心脏瓣膜置换术后患者口服抗凝治疗不当所致的出血与栓塞占远期并发症的首位。血浆凝血酶原时间（PT）是对人工心脏瓣膜置换术后患者口服抗凝药监测简便、敏感、快速、实用的实验室首选指标，其报告方式的标准化对临床医生有着非常重要的指导意义，国际标准化比率（PT-INR）作为一个较好的监测抗凝药物水平的表示方法，已被WHO推荐使用，但对于人工心脏瓣膜置换术后患者口服抗凝药治疗时PT-INR值的允许范围各地报告不一，为此，我们对我院收治的行人工心脏瓣膜置换术后患者口服华法令治疗时PT监测的情况进行了总结和研究，以探讨适合本地区人工心脏瓣膜置换术后患者口服抗凝药治疗监测中PT-INR的允许范围，为临床合理用药提供安全可靠的实验室监测指标。现报告如下。     

冠心病患者血浆D-二聚体水平测定及其临床意义

目的:探讨D-二聚体(D-dimer)含量与冠心病(CHD)临床类型、病变程度的关系,以了解D-二聚体在冠心痛诊断和预后判断方面的临床意义。方法:用Liatest法检测急性心肌梗死(AMI)21例、不稳定型心绞痛(UA)27例、稳定型心绞痛(SA)22例、健康者30例的血浆D-二聚体水平。结果:D-二聚体阳性发生率与含量在UA和AMI组明显高于SA组和对照组(P<0.01),且AMI组的D-二聚体含量明显高于UA组(P<0.01),SA组的D-二聚体无明显增高。结论:冠心病患者存在凝血和纤溶功能异常,且异常程度与病情严重程度密切相关。     

RP—HPLC测定人血浆中洛伐他汀浓度及药动学研究

用ＲＰ－ＨＰＬＣ测定人血浆中洛伐他汀浓度。以甲醇－水（８３∶１７，Ｖ／Ｖ）为流动相，色谱柱采用ＨＹＰＥＲＳＩＬＢＤＳ－Ｃ１８（５μｍ）不锈钢柱，紫外２３７ｎｍ波长检测。血浆样品经环己烷－异丙醇（９５∶５）萃取浓缩后进样测定。洛伐他汀浓度在２．５～８０ｎｇ／ｍｌ范围内线性良好，ｒ＝０．９９６８。测定含洛伐他汀２０．０ｎｇ／ｍｌ的血浆样品，其日内（ｎ＝７）及日间（ｎ＝７）的ＲＳＤ分别为９．８％和８．５％。回收率平均为（１０１．３±５．５）％。测定了１０名健康志愿者单次ｐｏ洛伐他汀片剂８０ｍｇ后不同时间的血药浓度，计算了相应的药动学参数。     

利培酮对氯氮平血浓度影响的研究

目的　了解利培酮对氯氮平血浓度的影响及二药合用的疗效与不良反应。方法　对 5 0例原服用氯氮平治疗的难治性精神分裂症患者合并利培酮治疗 ,分别于合并治疗前及后 1月、2月、3月测定氯氮平血浓度 ,同时评定PANSS ,TESS量表。结果　合用利培酮后 ,氯氮平血浓度无明显升高 ,PANSS评分明显降低(P <0 .0 1) ,TESS评分有所增加。结论　利培酮对氯氮平血浓度无明显影响 ,二药合用能增加疗效 ,不良反应有所增加。