力达霉素标准品量值传递方法的研究

目的：建立力达霉素标准品量值传递的方法。方法：选用稳定物质头孢唑林为表征性参比物质；通过HPLC测定表征性参比物质与力达霉素发色团的标准曲线，以其斜率的比值表征二者的摩尔紫外吸收系数比值，并作为校正因子；通过表征性参比物质的量值结合校正因子来传递力达霉素的量值。结果：表征性参比物质与力达霉素的校正因子为36．58，RSD为2．5％(n=6)。结论：通过校正因子可将力达霉素标准品的量值准确的传递下去。     

妥布霉素微生物效价测定方法及验证

目的：用微生物效价测定方法测定妥布霉素的效价并对方法进行验证。方法：参照《欧洲药典》，用微生物管碟法测定妥布霉素的效价。结果：妥布霉供试品及标准品的浓度（Ig浓度）与抑菌圈区域直径呈线性关系，供试品的精密度测定结果令人满意。结论：用微生物效价测定方法测定妥布霉素的效价具有较高的准确性和重现性。     

力达霉素烯二炔发色团对肝癌的实验治疗

目的研究力达霉素发色团对肝癌的实验治疗。方法采用体内接种肿瘤法研究力达霉素发色团对小鼠肝癌22或裸鼠人肝癌Bel-7402的抗肿瘤作用。结果力达霉素发色团在肿瘤接种24h后1次静脉给药能明显抑制小鼠肝癌22的生长，当剂量达4．6、9．2、18．3μg／kg时，抑制率分别为59％、81％、85％。力达霉素发色团在接种肿瘤后72h给药的抑瘤效果不如接种后24h的效果强。力达霉素发色团（LDC）和力达霉素（LDM）均能抑制裸鼠肝癌Bel-7402肿瘤的生长。接种后d27。具有相同克分子数的LDC（18．5μg／kg）和LDM（250μg／kg）的抑瘤率分别为51．1％和45．9％，抑瘤效果相当。LDC对肿瘤生长的抑制作用存在剂量．效应关系。结论力达霉素发色团在动物体内能抑制小鼠肝癌和人裸鼠肝癌的生长，是力达霉素产生生物学作用的主要活性部分。     

力达霉素的蛋白和发色团相互作用的分析

目的:通过采用计算机模拟研究力达霉素发色团被蛋白质保护的作用机理的分析。方法:应用InsightⅡ和HyperChem等软件通过分子力学和分子动力学方法研究发色团和蛋白质之间的相互作用。结果:蛋白质通过静电引力和范德华力以及π电子同发色团相互作用。结论:力达霉素的蛋白质部分通过与发色团形成各种作用力使得发色团得到稳定存在,防止其进一步重排,从而为保证发色团发挥抗癌药效,提供科学依据。     

基因工程重组力达霉素的制备及抗肿瘤活性

目的 制备重组力达霉素rLDM,研究其抗肿瘤活性。方法 构建完整力达霉素辅基蛋白表达载体pET30-sldp,并在大肠埃希菌中诱导表达重组辅基蛋白rLDP,纯化后的rLDP蛋白与力达霉素发色团AE在体外进行组装制备rLDM,MTT法检测rLDM和LDM的体外抗肿瘤活性,利用流式细胞仪检测两者对肿瘤细胞周期的影响。结果 rLDP蛋白以可溶形式在大肠埃希菌中分泌表达,与发色团组装后经HPLC检测在340nm处出现特定吸收峰,表明rLDM制备成功;MTT实验结果显示rLDM和LDM对SKOV3细胞的IC50值相近,无显著性差异;流式细胞仪检测结果证明两者对SKOV3细胞周期的影响趋势相似。结论     

微生物法测定力达霉素的效价

建立力达葛素效价测定的微生物检定法，检定菌为枯草芽孢杆菌。当力达葛素的浓度为1.85～13.51μg／ml时，其抑菌圈直径与反应剂量呈线性关系，并与HPLC法进行比较，测定结果基本一致。     

协作标定首批国家标准品吉他霉素

中国药品生物制品检定所要求我所参加了首批国家标准品吉他霉素的协作标定工作.利用国际标准品,采用微生物效价测定的三剂量法,共完成17组数据.这17组数据经合并计算,结果均一.合并结果为1 462.2 u·mg-1.该批标准品经全国协作标定的最终效价为1 462 u·mg-1.我所标定结果与最终效价一致,现将标定结果报告如下.     

HPLC法替代生物效价测定富马酸阿奇霉素的含量

目的:富马酸阿奇霉素现行标准采用生物效价法测定含量,建立HPLC法测定其含量同时进行方法学验证.方法:采用资生堂C18色谱柱(250mm×4.6mm,5μm),流动相为0.002mol/L磷酸氢二铵(用氨水调节pH为10.0)-乙腈-异丙醇(15:60:25),检测波长210nm,柱温30℃.结果:在该色谱条件下,阿奇霉素主峰与富马酸峰分离良好,阿奇霉素在浓度为0.3048~0.7112mg/mL范围内线性关系良好,回归方程为Y=1000000X-483.4,r=0.999,精密度试验RSD为0.14%,平均回收率为99.5%(RSD=0.5%).结论:本法灵敏,简便,准确,重复性好,可作为富马酸阿奇霉素含量的测定方法替代生物效价测定法.     

恩拉霉素质量标准的建立

目的 建立恩拉霉素质量标准。方法 采用HPLC-PDA法建立鉴别及恩拉霉素组分检查方法，采用效价法建立恩拉霉素含量测定方法，并根据药品质量标准分析方法验证指导原则的要求，进行相应方法验证。结果 鉴别恩拉霉素组分检查方法专属性良好，在100~350u/mL范围内浓度与组分A与B峰面积之和具有良好的线性关系(r=0.9999)；效价含量测定方法专属性良好，在10~48u/mL范围内浓度与抑菌圈直径具有良好的线性关系(r=0.9995)，方法准确度回收率96.3%，RSD为2.9%。 结论 该质量标准考察项目全面，方法简单准确，可作为恩拉霉素质量控制的方法。     

纸片法快速测定庆大霉素发酵液生物效价

先用纸片法建立硫酸庆大霉素标准品的标准曲线，再用电子表格Excel软件对实验数据进行统计分析，求出标准曲线的斜率，可信限率并作图；然后进行可靠性试验；比较了纸片法和杯碟法测定发酵液生物效价的结果。实验表明，硫酸庆大霉素的浓度在0．229～1．092u／ml范围内，纸片的抑菌圈直径与反应剂量有线性关系，β的可性限率为4．5％。纸片法测定庆大霉素发酵液，操作简便，测定结果可靠，重现性好。此方法用于菌种发酵筛选，可加大样品检测数量，提高工作效率。     

新型疫苗的效力测定

2005年10月11～12日在美国马里兰州贝塞斯达召开了一次疫苗效力测定研讨会,会议由美国国立卫生研究院AIDS室、微生物学和传染病室、国家变态反应和传染病研究所疫苗研究中心(VRC)和AIDS研究办公室,与美国FDA生物制品评价和研究中心、国际AIDS疫苗倡议组织以及WHO/联合国AIDS规划署共同组织.这次会议除了重点讨论疟疾、结核病和HIV/AIDS疫苗的效力测定方法外,还讨论了其他疫苗的新型效力测定方法,大会试图在更普遍的意义上解决与所有这些新疫苗相关的关键问题.     

Estimation of Epidermal Carcinogenic Potency

Estimation of Epidermal Carcinogenic Potency. MCKEE, R. H.,NICOUCH, M. J., SCALA, R. A., AND LEWIS, S. C. (1990). Fundam.Appl. Toxicol. 15, 320–328. This report compared two statisticalmethods of estimating tumor latency, the Weibull distributionmodel and the Kaplan-Meier method. Parallelism of dose-responsecurves of different materials and quantitative reproducibilityof dermal carcinogenesis data were also examined. The Weibullmethod has the advantage of producing parameter estimates, evenwhen tumor yield is low. The Kaplan-Meier method, on the otherhand, is free of distribution assumptions. Overall, since thecomparisons of potency are made on the basis of parameters fromthe same assumed distribution on the same strain of animal,the Weibull estimates are favored. A comparison of dose-responsedata for benzo[a]pyrene and catalytically cracked clarifiedoil indicated that the slopes of the two dose-response curveswere significantly different. Thus the relative carcinogenicpotencies of different materials vary with dose, and potencycomparisons must necessarily be dose-specific. The quantitativereproducibility of dermal carcinogenesis bioassays was alsoassessed. The dose-response curves from the three studies ofone material had significantly different slopes. Thus the resultssuggested that there were sources of biological variabilitywhich could contribute to experimental error     

凝血酶效价测定方法的探讨

采用以人纤维蛋白原为底物,“挑丝法”观察其凝固终点,测定凝血酶效价,该法具有操作简便、测定准确、回收率高等优点。     

A Direct Comparison of Anti-microRNA Oligonucleotide Potency

Purpose  

Cataloguing endogenous miRNA targets by inhibiting miRNA function is fundamental to understanding the biological importance of each miRNA in gene regulatory pathways. Methods to down-regulate miRNA activity may help treat diseases where over-expression of miRNAs relates to the underlying pathophysiology. This study objectively evaluates the in vitro potency of different anti-miRNA oligonucleotides (AMOs) using various design and modification strategies described in the literature as well as some novel modification strategies.     

Potency variation of small-molecule chymase inhibitors across species

Chymases (EC 3.4.21.39) are mast cell serine proteinases that are variably expressed in different species and, in most cases, display either chymotryptic or elastolytic substrate specificity. Given that chymase inhibitors have emerged as potential therapeutic agents for treating various inflammatory, allergic, and cardiovascular disorders, it is important to understand interspecies differences of the enzymes as well as the behavior of inhibitors with them. We have expressed chymases from humans, macaques, dogs, sheep (MCP2 and MCP3), guinea pigs, and hamsters (HAM1 and HAM2) in baculovirus-infected insect cells. The enzymes were purified and characterized with kinetic constants by using chromogenic substrates. We evaluated in vitro the potency of five nonpeptide inhibitors, originally targeted against human chymase. The inhibitors exhibited remarkable cross-species variation of sensitivity, with the greatest potency observed against human and macaque chymases, with K_i values ranging from ∼0.4 to 72 nM. Compounds were 10-300-fold less potent, and in some instances ineffective, against chymases from the other species. The X-ray structure of one of the potent phosphinate inhibitors, JNJ-18054478, complexed with human chymase was solved at 1.8 Å resolution to further understand the binding mode. Subtle variations in the residues in the active site that are already known to influence chymase substrate specificity can also strongly affect the compound potency. The results are discussed in the context of selecting a suitable animal model to study compounds ultimately targeted for human chymase.     

头孢环己烯胺效价测定检定菌的选择

采用二种不同检定菌(枯草芽孢杆菌、金黄色葡萄球菌),对头孢环己烯胺进行效价测定,结果表明:用枯草芽孢杆菌作检定菌能得到满意的效果。同时制备的菌液比金黄色葡萄球菌,使用时间长、稳定、操作手续简化,应用方便。     

生物效价检测研究进展

目的介绍生物效价的含义、检测方法及近年来在生化药物、化学药物和中药领域中的研究进展,以期为药品质量控制方法研究提供思路和借鉴。方法概述生物效价检测的基本概念,包括生物效价含义、检测方法分类及其选用标准、检测思路,重点论述了生物效价检测在生化药物、化学药物、中药领域中的应用情况。结果和讨论生物效价检测将作为一种常规的分析手段应用于药品的质量控制中,生物检测结合化学检测的模式将是药物质量控制的必由之路。     

Potency matters: Thresholds govern endocrine activity

Whether thresholds exist for endocrine active substances and for endocrine disrupting effects of exogenous chemicals has been posed as a question for regulatory policy by the European Union. This question arises from a concern that the endocrine system is too complex to allow estimations of safe levels of exposure to any chemical with potential endocrine activity, and a belief that any such chemical can augment, retard, or disrupt the normal background activity of endogenous hormones. However, vital signaling functions of the endocrine system require it to continuously discriminate the biological information conveyed by potent endogenous hormones from a more concentrated background of structurally similar, endogenous molecules with low hormonal potential. This obligatory ability to discriminate important hormonal signals from background noise can be used to define thresholds for induction of hormonal effects, without which normal physiological functions would be impossible. From such thresholds, safe levels of exposure can be estimated. This brief review highlights how the fundamental principles governing hormonal effects – affinity, efficacy, potency, and mass action – dictate the existence of thresholds and why these principles also define the potential that exogenous chemicals might have to interfere with normal endocrine functioning.     

Potency and stability of extemporaneous nitroglycerin infusions.

The potency and stability of extemporaneous intravenous nitroglycerin (NTG) solutions prepared according to methods currently used in three hospitals were studied. Intravenous NTG solutions were prepared and packaged according to three hospitals' protocols. The NTG solutions varied in concentration (32 microgram/ml); source (one of two manufacturers' sublingual NTG tablets or 10% NTG adsorbate in lactose); and storage (ambient room temperature or refrigerated). The concentration of NTG in the i.v. solutions was determined spectrophotometrically. Nitroglycerin was found to be stable for at least 70 days when stored in glass containers, regardless of source, diluent (5% dextrose in water or normal saline) and storage temperature. The loss of NTG from solution, after storage for seven days in plastic i.v. bags, was greater when stored at room temperature (55%) than when refrigerated (30%). Adsorption was shown to be responsible for this phenomenon because intact drug was completely recovered from the plastic i.v. bags after methanol elution. The results of this study allow formulation of recommendations regarding the extemporaneous preparation of i.v. NTG solutions.