一种简单、精确计算EC_(50)的方法

提出了一种计算药物量 -效曲线参数半数效量 ( EC50 )的新方法 ,可精确计算落在两已知浓度间的 EC50 ,不需绘图测算或计算机曲线拟合。该方法比常用的绘图计算的方法更加快速、精确和简单 ,能广泛应用于药效动力学研究。

胺苯磺隆对水稻的药害研究

胺苯磺隆对油菜安全，对水稻有药害。（１）水培条件下，以幼根长度计，胺苯磺隆对水稻幼苗的ＥＣ５０＝１ｍｇ／Ｌ。（２）土培条件下，浸种露白后直接播种于含胺苯磺隆的土壤，培养２０天，以植株鲜重计，药液在土壤中的ＥＣ５０为１３０８μｇ／ｋｇ。育秧４天、７天的秧苗移栽于含胺苯磺隆的土壤，培养２０天，以植株鲜重计，药液在土壤中的ＥＣ５０分别为４６５２μｇ／ｋｇ、４４μｇ／ｋｇ。（３）７天秧苗进行移栽培养，由胺苯磺隆处理浓度可知：在土壤中胺苯磺隆的临界浓度是２２２μｇ／ｋｇ，胺苯磺隆浓度在２．２２μｇ／ｋｇ以下时，对水稻生长有促进作用，药剂浓度超过２２２μｇ／ｋｇ后逐渐升高，抑制作用逐渐增大。

右美托咪定镇静下瑞芬太尼抑制光棒插管反应的药效学观察

目的测定瑞芬太尼在右美托咪定镇静下抑制光棒插管反应的半数有效效应室浓度(EC50)。方法择期乳腺肿瘤手术患者36例,年龄18~59岁,ASAⅠ~Ⅱ级,体重指数﹤30 kg/m2。入室后统一用18G套管针开放下肢静脉,静卧15 min后开始静脉输注负荷剂量右美托咪定1. 0μg/kg (10 min泵完),后以0. 5μg/(kg·min)持续泵入,待患者意识消失,脑电双频指数值降至60~65时,靶控输注瑞芬太尼(Minto模型),第1例患者瑞芬太尼初始效应室浓度为3. 0 ng/m L,待效应室浓度与血浆浓度达到平衡,利用非窥喉光棒技术经口气管内插管。入选样本从发生插管阳性反应的前一例阴性反应病例开始计算。瑞芬太尼的效应室浓度采用改良序贯法进行试验,相邻效应室靶浓度之间比率为1. 20。结果瑞芬太尼在右美托咪定镇静下抑制光棒插管反应的EC50为2. 85 ng/m L,95%可信区间为2. 61~3. 12 ng/m L。结论右美托咪定镇静下瑞芬太尼抑制光棒插管反应的半数有效效应室浓度为2. 85 ng/m L。

“妇乐安”杀灭阴道毛滴虫的试验

目的：研制一种杀灭阴道毛滴虫的药物。方法：用“妇乐安”作直接杀灭阴道毛滴虫的试验及在对倍稀释下的杀虫试验，测定在２ ｈ 内的 Ｅ Ｃ５０ 。结果：“妇乐安”的 Ｅ Ｃ５０ 在２ ｈ 内为１∶１２５ ， 在１ ｄ 内为１∶５００ 。结论：“妇乐安”能直接、迅速杀灭阴道毛滴虫，而且在较低浓度下，也具有效的杀虫效果。在广东地区药源丰富，是一种具有开发价值的药物。

Surrogate potency assays:Comparison of binding profiles complements dose response curves for unambiguous assessment of relative potencies

Surface plasmon resonance(SPR) systems are widely used for detailed characterization of antibody activities including antigen and Fc-receptor binding. During the later stages of development, where the focus is to ensure that established critical quality attributes(CQAs) are maintained during cell culture,purification and formulation processes, analysis is simplified, and relative potencies are often determined. Here, simulation of binding data revealed that relative potency values, determined via parallel line analysis(PLA) and half maximal effective concentration(EC50) analysis accurately reflect changes in active concentration only if binding kinetics remain unchanged. Changes in the association rate constant shifted dose response curves, and therefore relative potencies, in the same way as changes in analyte concentration do. However, for interactions characterized by stable binding, changes in the dissociation rate constant did not result in any shift, suggesting that this type of change may go unnoticed in the dose response curve. Thus, EC50 and PLA analyses of dose response curves obtained with an anti-TNF-α antibody were complemented with the Biacore functionality for sensorgram comparison analysis, whereby changes in antigen and Fc-receptor binding profiles could be detected. Next, analysis of temperature stressed TNF-α antibody revealed that calibration free concentration analysis(CFCA) data correlated perfectly with relative potency values. Together, these results demonstrate that combinations of SPR based dose response curves, sensorgram comparison and CFCA can be used to strengthen the confidence in relative potency assessments, and suggest that SPR can potentially be used as a surrogate potency assay in the quality control of biotherapeutic medicines.

氮营养形态和Ni^(2+)浓度对三角褐指藻的影响

近海海水中的氮营养元素和镍(Ni)对浮游植物的生长均有较大的影响,但它们对浮游植物的共同影响却研究较少。本文利用浮游植物荧光仪(Phyto-PAM)研究了在不同氮源下(硝态氮、尿素),不同Ni^(2+)浓度处理对三角褐指藻(Phaeodactylum tricornutum Bohlin)叶绿素a(Chl a)、光能转化效率(F_(v)/F_(m))和最大电子传递速率(rETR max)的影响。结果表明,与对照组相比,2种氮源下,低浓度(10μg·L^(-1))Ni^(2+)处理对三角褐指藻Chl a含量均有显著的促进作用(P<0.05),且尿素氮源高于硝酸盐氮源(P<0.05)。但是,当Ni^(2+)浓度>1 mg·L^(-1)后,均抑制三角褐指藻Chl a含量,且抑制程度呈现递增趋势(P<0.05)。应用Graphpad Prism8.0计算Ni^(2+)对三角褐指藻不同胁迫时间的Chl a、F_(v)/F_(m)和rETR_(max)半抑制浓度(EC_(50))。硝酸钠为氮源时,不同时间的Chl a EC_(50)值均低于尿素氮源。以上结果表明,随着近岸海区尿素浓度增加,三角褐指藻生长能显著被低浓度的Ni^(2+)所促进,对高浓度Ni^(2+)的耐受性增强,进而可能影响近海海洋初级生产力和浮游植物群落结构。