Intraoperative management of heart–lung interactions: “From hypothetical prediction to improved titration”

Extensive literature describes the suitability of dynamic parameters to predict responsiveness in fluid. However, based on heart–lung interactions, these parameters can have serious limitations, including the use of protective lung ventilation. Although the latter seems to be beneficial for healthy patients undergoing high-risk surgery, the intraoperative interpretation of dynamic parameters to predict fluid responsiveness can be hazardous. In this context, the attending physician could, alternatively, titrate the need of fluids with a small fluid challenge, which remains unaffected by low tidal volume, the presence of arrhythmia, or the presence of spontaneous ventilation. When intraoperative prediction of fluid responsiveness is required in mechanically ventilated patients, “improved” titration should be preferred to a hypothetical prediction.     

Safety of 25- and 50-mg capsules in the initiation of zonisamide therapy in patients with epilepsy: an uncontrolled,open-label study

SUMMARY

Objective: This study was designed to assess the safety of 25- and 50-mg dosage strengths of zonisamide for initial titration in patients with epilepsy.

Research design and methods: This phase 3, multicenter, open-label, uncontrolled study conducted at 26 study sites in the United States included male and female patients with epilepsy ≥ 12?years of age. After a screening visit, subjects began zonisamide therapy at a dosage depending on their body weight. Zonisamide was titrated to 100?mg/day.

Main outcome measures: At the study's conclusion, information regarding adverse events (AEs) and body weight was recorded.

Results: One hundred forty-three subjects enrolled and received at least one zonisamide dose. Of these subjects, 125 reached at least the 100-mg dosage before terminating the study. Eighty-two subjects (57.3%) experienced at least one AE. Most commonly reported AEs included headache, somnolence, asthenia, rhinitis, nausea, and rash. No significant change in patient body weight was noted during the study (95% confidence interval: –0.1, 0.6).

Conclusions: Study limitations include the open-label design and the lack of direct comparison between lower (25- and 50-mg) and higher (100-mg) starting dosages. Despite these limitations, the 25- and 50-mg zonisamide dosage formulations were well tolerated in this study.     

酸碱滴定法定量测定白蛋白制品中辛酸钠含量

本文报道的用酸碱滴定法定量测定白蛋白制品中辛酸钠含量,是通过使用混合溶解液使水醚两相混溶后直接滴定。运用三因素调优法原理,选择出混合溶解液中各组份的最佳浓度及其用量和最佳萃取条件。方法的回收率为99.8％±0.89％(n=16),变异系数CV为0.89％(n=16),说明该法准确可靠。     

两种滴定方法治疗癌痛的疗效及经济学评价

目的:针对阿片类药物治疗癌性疼痛,探讨临床常用的两种滴定方法的疗效、不良反应及费用情况。方法:两组癌性疼痛患者(n=30)分别口服吗啡滴定(观察组)和口服盐酸羟考酮缓释片(对照组)进行滴定。记录疼痛缓解程度、不良反应和1周内的镇痛药物费用。结果:两种方法均能很好地缓解疼痛,总缓解率分别达到96.7%和96.6%。观察组的不良反应发生率高于对照组(P<0.05)。治疗1周内观察组的成本-效果比低于对照组。结论:两组滴定镇痛疗效相当。使用吗啡滴定费用低但是不良反应发生率高,患者依从性稍差;使用盐酸羟考酮滴定则反之。两种方法各有优缺点,可根据患者实际情况选择使用。     

海参胶囊盐分测定检验方法的改进

根据GB/T 12457中氯化钠的测定,针对海参提取物的样品特性,进行煮制法、沉淀蛋白法和灰化法三种前处理改进,再直接滴定法测定样品中的盐分含量。通过实验对比,得出灰化法操作简便、测量结果准确度高等优点,适用于海参胶囊中盐分的测定,对样品能起到控制盐分的目的。     

苯扎溴铵酊处方改进及苯扎溴铵的含量测定

目的：改进苯扎溴铵酊处方,并建立容量分析法测定苯扎溴铵醇溶液（苯扎溴铵酊去除曙红成分）中苯扎溴铵的含量。方法在建立容量分析法测定苯扎溴铵的含量时,发现曙红在不同程度上均能影响含量测定结果,故将曙红成分从处方中删去。采用四苯硼钠（0.02 mol/L）为滴定液,滴定苯扎溴铵醇溶液中苯扎溴铵的含量。结果苯扎溴铵酊制剂更改为苯扎溴铵醇溶液,在含量测定中,滴定终点变化明显,易于判断。苯扎溴铵在浓度0.4~1.4 mg/mL的范围内与消耗四苯硼钠滴定液体积呈良好线性关系,r=0.9995,回归方程为V=18.3C-0.32。高、中、低3种剂量苯扎溴铵的平均回收率为99.12%,R SD为0.84%。结论本实验方法简便、快捷、准确,可作为苯扎溴铵醇溶液的质量控制标准。     

绿色荧光标记重组人偏肺病毒空斑形成滴度测定方法的建立

目的 建立用于绿色荧光标记的重组人偏肺病毒(GFP-rhMPV)空斑形成滴度测定方法.方法 基因组中插入绿色荧光蛋白基因的hMPV全序列cDNA质粒和主要蛋白质表达质粒转入细胞293T后获得感染性重组hMPV.GFP-rhMPV在Vero-E6细胞中连续传代提升病毒滴度并保存.将等倍稀释的重组病毒液接种常规制备的Vero-E6细胞单层,用含或不含胰酶的低熔点琼脂精凝胶覆盖细胞,孵育一定时间后,采用荧光显微镜下计数荧光空斑数和抗原抗体蓝斑形成法计算病毒滴度.结果 感染后3 d,荧光显微镜下GFP-rhMPV可在低熔点琼脂糖凝胶覆盖层下形成分界较为清晰的绿色荧光集落,接种后3 d荧光空斑相对独立,便于计数.蓝斑形成法在感染后第5天蓝斑较大,易观察.此前拯救获得的GFP-rhMPV在宿主细胞Vero-E6中的复制滴度可达1×106 PFU以上.结论 成功建立了GFP-rhMPV的空斑形成实验滴度定量检测方法,为hMPV的致病机制、防治手段研究奠定了基础.     

盐酸小檗碱不同测定方法的比较

目的：以盐酸小檗碱为例，比较滴定法和薄层色谱法。方法：采用滴定法和薄层色谱法测定盐酸小檗碱的含量。结论：薄层色谱法较滴定法更为准确，简便。     

氯硝柳胺测定方法研究进展

利用氯硝柳胺的理化特性,可采取多种不同方法对其进行定性或定量测定。但不同方法的精密度和准确度不同,可根据应用需求进行选择。本文主要对氯硝柳胺的生物测定法、滴定法、紫外-可见分光光度法、色谱法和电化学分析法进行综述。     

Long-lasting increase in the set point for cocaine self-administration after escalation in rats

Rationale: When access time to a continuous schedule of drug self-administration is restricted, animals tend to limit intake to a certain level over time and across doses. This observation suggests an endogenous constraint or set point that determines the individual’s preferred level of pharmacological effects. Objectives: To assess whether the transition to increased levels of drug intake is associated with a change in set point. Methods: Two groups of rats were trained on a 1-h continuous schedule of cocaine self-administration (250 μg/injection), after which access to cocaine was increased to 6 h in one group (Long Access or LgA rats) or kept to 1 h in the other group (Short Access or ShA rats). After 22 sessions on this regimen, different doses of cocaine were tested (31.25, 62.5, 125, and 250 μg/injection). For each dose, the post-response time-out period was reduced to 4 s to reduce any temporal limitations on self-injections and subjects were tested several times. Results: In LgA rats, the first hour intake escalated over time and eventually reached a level 200% greater than that of ShA rats. Though all rats maintained relatively constant intake across doses, LgA rats took nearly two times as much cocaine than ShA rats. When access to cocaine for LgA rats was reduced to 1 h, intake returned very slowly toward pre-escalation levels but was still elevated even after 2 months of reduced availability. Conclusions: These data suggest that the transition to escalated levels of intake is associated with a long-lasting change in cocaine set point. Received: 12 February 1999 / Final version: 21 May 1999