中药四性的生物热动力学研究——左金丸与反左金寒热药性的微量热学比较

目的 :从生物物理和生物化学的角度 ,探讨中药药性的客观真实性。方法 :利用微量热法 ,测定了大肠杆菌在左金丸、反左金水煮液作用下的生长热谱曲线 ,得到了相应的生物热动力学参数 ,结合本草文献报道 ,综合分析了左金丸与反左金的药性差异。结果 :左金丸、反左金水煮液均能不同程度地抑制细菌的生长 ,温热药方反左金使细菌指数生长期的生长速率常数显著减小 ,生长代谢过程中热量释放显著增加。寒凉药方左金丸则使细菌指数生长期的生长速率常数减小 ,生长代谢过程中热量释放有所增加 ,两者存在较稳定的差异。结论 :微量热法可作为刻划中药药性的有效的新方法。     

Accurate and early diagnosis of orthopedic device‐related infection by microbial heat production and sonication

Proper and rapid diagnosis of orthopedic device‐related infection is important for successful treatment. Sonication has been shown to improve the diagnostic performance. We hypothesized that the combination of sonication with a novel method called microcalorimetry will further improve and accelerate the diagnosis of implant infection. We prospectively included 39 consecutive patients (mean age 59 years, 62% males) at our institution from whom 29 orthopedic prostheses and 10 osteosynthesis material were explanted. The explanted device was sonicated. The resulting sonication fluid was analyzed using microcalorimetry. Using standardized criteria to define orthopedic device‐related infection, 12 cases (31%) were defined as infected. In all, positive periprosthetic tissue cultures were found. The sensitivity and specificity of microcalorimetry of sonication fluid were 100% and 97%, respectively. Mean time to detection, defined as time to reach a rising heat flow signal of 20 µW measured after equilibiration needed to get accurate measurement, was 10.9 h. In summary, microcalorimetry of sonication fluid is a reliable and a fast method in detecting the presence of microorganisms in orthopedic device‐related infection. © 2013 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 31:1700–1703, 2013     

人参不同提取部位对大鼠肝脏线粒体影响的微量热研究

目的:研究人参不同部位对线粒体作用的微量热差异,同时为作用于线粒体的药物筛选建立新的方法。方法:采用微量量热法,动态的观察正常线粒体以及在不同部位作用下的线粒体的热代谢过程,观测热谱图的变化并计算一系列的热动力学参数。结果:人参不同部位均可使线粒体恢复速率常数减慢,总发热量增加,最高发热量降低,停滞期缩短。结论:通过对结果的分析,表明人参不同部位通过对代谢过程中多项指标的影响,均可提高线粒体的能量利用率,其中尤以F2的作用最为明显。同时为微量量热法在中药的活性筛选中的应用提供了较好的佐证。     

Self-Micellization of Gemfibrozil 1-O-β Acyl Glucuronide in Aqueous Solution

Purpose. Phase II metabolism involves the conjugation of a polar moiety, such as sulfate or glucuronic acid, to a (relatively) nonpolar xenobiotic. Although it might be expected that such conjugates may exhibit amphiphilic character (e.g., surface activity and potential to form micelles), no detailed study of the micellization characteristics of any drug-glucuronide conjugates has yet been reported. Therefore, the aim of this study was to investigate the solution behavior and amphiphilic characteristics of gemfibrozil 1-O- glucuronide (GG), a model drug-glucuronide conjugate. Methods. Crude GG was extracted from the urine of volunteers dosed with 600 mg of gemfibrozil, and this material was then purified by reversed-phase high-performance liquid chromatography to yield a white solid. The amphiphilic properties of GG within the bulk aqueous phase were studied by isothermal titration microcalorimetry and ¹H-NMR spectrometry, whereas those at the aqueous/air interface were studied by surface tensiometry. Results. The results of each independent analytical technique were consistent with GG in aqueous solution exhibiting amphiphilic properties typical of a hydrophilic surfactant. The titration microcalorimetry and ¹H-NMR spectrometry data were in excellent agreement with each other, yielding critical micellization concentrations (cmc) for GG in 0.1 M acetate buffer of 18.1 ± 0.4 mM and 18.3 ± 0.3 mM, respectively. The profile and results of the surface tension measurements were consistent with GG localizing at the aqueous/air interface. Conclusion. These results confirm the hypothesis that a glucuronide conjugate of a relatively nonpolar xenobiotic, such as gemfibrozil, behaves as an amphiphile in aqueous solution. The implications of this observation include a likely basis for the previously observed concentration-dependence in the degradation rate of the acyl glucuronides of 2-phenylpropionic acid, as well as identifying a possible broader contributory effect to the structural dependencies in biliary choleresis of different glucuronide conjugates of xenobiotics.     

Real Time Detection of Photoreactivity in Pharmaceutical Solids and Solutions with Isothermal Microcalorimetry

Purpose. In this study an irradiation cell made as an accessory for an isothermal microcalorimeter is introduced, and its suitability for detection photoreactivity in pharmaceutical solutions and solids is demonstrated. The pharmaceuticals employed are chosen as sample materials to evaluate the usefulness and stability of the irradiation cell. Methods. An irradiation cell has been constructed and tested in an isothermal microcalorimeter with pharmaceutical solutions and solids known to be sensitive to daylight or UV light. Light is produced with an Xe-arc lamp, split into two parts and introduced into calorimetric vessels with optical light cables. One of the vessels containing the reference sample gives the response to the heat absorbed by the material (radiant power), and the other vessel containing the sample material gives the response also to the photoreaction. The two irradiation cells are positioned in the sample sides of two separate twin microcalorimetric units. Results. Nifedipine and L-ascorbic acid were found to be photosensitive in solutions and solid states, the extent of the degradation depending on the irradiation intensity and wavelength. The threshold values of the wavelength for the photoreactions, as well as the wavelengths for the maximum reaction rates, were estimated via the scanning irradiation measurements. The ability of photons with different energies to produce heat in the photosensitive reaction of nifedipine was calculated using constant measurements. Conclusions. The technique introduced offers a rapid and versatile method to study the photosensitivity of materials in any state. In the measurements, various conditions can be simulated and thus provide information on the real behavior of materials.     

Complex Formation Between The Anionic Polymer (PAA) and a Cationic Drug (Procaine HC1): Characterization by Microcalorimetric Studies

Purpose. Due to the importance of drug-polymer interactions in, inter alia, drug loading/release, supramolecular assemblies and DNA delivery for gene therapy, the aim of this study was therefore to establish the mechanism of interaction between a model polymer (Polyacrylic acid, PAA) and a model drug (procaine HCl). Methods. This was performed by studying the effect of salt (KCl) concentration on their heat released values using Isothermal Titration Microcalorimetry (ITM). The integrated released heat data were computer fitted to a one class binding model and the thermodynamic parameters (K_obs, H, and N) were determined. Results. As the KC1 concentration was increased, K_obs decreased thus establishing the salt dependence of the interaction. The linear variation of G_obs with S_obs indicated that their interaction was entropically driven. The stoichiometry of the interaction was calculated to be one procaine molecule per monomer of PAA. Dissection of the total observed free energy at each KC1 concentration indicated that the contribution of the non-electrostatic attractions to the interaction of PAA with procaine HC1 was greater than those of the electrostatic attractions. Conclusions. We have shown that the interaction between PAA and procaine HC1 is dependent upon the presence of counterions (monovalent ions) and is mainly entropically driven. The calculated stoichiometry indicated that one procaine HC1 molecule neutralised one carboxylic acid group on PAA. Although electrostatic interactions were necessary for initiating complex formation, the non-electrostatic forces were dominant in stabilising the PAA-procaine HC1 complex.     

不同产地黄连对大肠杆菌生长代谢影响的微量热学研究

目的 从生物热力学角度，研究不同产地黄连药效的差异，探讨中药品质评价的新思路。方法 利用微量热法，测定了不同产地黄连在37℃时对大肠杆菌生长代谢过程的热效应变化，根据热动力学参数，分析不同产地黄连的药效差异。结果 不同产地的黄连对大肠杆菌的生长代谢均有不同程度的抑制作用，使大肠杆菌生长速率常数减小，传代时间延长，最大产热功率降低，其中龙池味连的抑菌作用最强。结论 产地可对生药的质量产生影响，生物热力学方法可做为中药品质评价的新方法。     

微量热法对小檗碱类生物碱抑菌作用的量效关系研究

目的 测定黄连中的3种生物碱小檗碱、药根碱、巴马汀对痢疾杆菌生长代谢的影响,从热力学角度研究小檗碱类生物碱抑菌作用的量效关系。方法 以微量热法测定小檗碱类生物碱作用于痢疾杆菌生长代谢的热谱曲线,并得出相应的热动力学参数,如生长速率常数、产热功率、最大热功率出现时间、抑制率、传代时间等,根据热动力学模型,拟合了3种生物碱产热功率-质量浓度关系,并进行初步的量效关系分析。结果 小檗碱、药根碱、巴马汀对痢疾杆菌的生长代谢均有不同程度的抑制作用,在 0.08～1.20 mg/mL 内随着质量浓度的增加,最大热功率出现时间和传代时间延长,生长速率常数降低和最大产热功率降低,抑制率增加,且与药物质量浓度呈现一定的量效关系。结论 3种生物碱对痢疾杆菌的抑菌活性的强度顺序为小檗碱 ＞ 巴马汀 ＞ 药根碱,从热力学角度研究抑菌类中药的量效关系具有定量、灵敏、快速等优势。     

基于微量量热法的寒热中药对大肠杆菌生长热谱曲线的影响

目的：观察典型寒热中药黄连、制附子对大肠杆菌生长代谢作用的影响,探讨微量量热法用于中药寒热差异及量化研究的可行性。方法采用微量量热技术,测定大肠杆菌在不同浓度寒热中药水煎液干预下的生长热谱曲线,分析其热力学参数。结果黄连、制附子均可影响大肠杆菌产热效应,其效应影响与药物浓度具有正相关关系;黄连组的热焓值明显低于对照组,制附子组的热焓值明显高于对照组。结论微量量热技术是从生物体生命周期及能量代谢角度,观察中药寒热效应差异的客观化手段之一。     

Decreased responsiveness to immune complexes of granulocytes from patients with acute leukemia in remission demonstrated by microcalorimetry

Functional activity of granulocytes from healthy individuals and from patients with acute leukemia in remission was studied. The increase of heat production rate (metabolic activity) after stimulation of the blood cells with in vitro formed immune complexes was measured by microcalorimeters of heat conduction type. It was demonstrated that increased heat production rate after exposure to immune complexes was significantly lower (p<0.0005) in 9 patients with acute leukemia with a remission duration of less than 6 months than in 25 healthy volunteers.