Assay sensitivity

测定灵敏度
  • 文章类型: Journal Article
    河口生态系统面临着越来越大的人为压力,需要有效的监测方法来减轻它们对它们所拥有的生物多样性的影响。使用基于环境DNA(eDNA)的检测方法越来越被认为是一种有前途的工具,潜在的侵入性监测技术。将这种eDNA分析整合到大型生态系统的监测框架中仍然具有挑战性,需要更深入地了解eDNA模式可能提供对物种存在和群落组成空间和时间的见解的规模和分辨率。Scheldt河口,以其多样化的栖息地和复杂的水流为特征,是西欧最大的潮汐河流系统之一。直到现在,获取有关在该生态系统中生活和迁移的鱼类群落的准确信息仍然具有挑战性,因此将我们的知识限制在特定的位置。探索基于eDNA的监测的潜力,我们同时将装料网捕鱼和eDNA元编码结合起来,评估谢尔特河口鱼类群落的时空变化。总的来说,我们使用eDNA元转录编码在河口检测到71种鱼类,与在不同研究地点收集的历史鱼类群落数据部分重叠,而在同一调查期间,只有42种使用集装网捕鱼。两种检测方法发现的群落组成因采样地点而异,由与盐度梯度的明显相关性驱动。采样深度和潮汐对eDNA元编码数据的影响有限,在此研究系统中,可以显着减少未来eDNA鱼类监测活动的eDNA采样工作量。我们的结果进一步表明,使用eDNAmetabarcoding可以检测到鱼类物种发生的季节性变化。结合eDNA元编码和堆网捕鱼进一步增强了我们对这一重要水道的不同鱼类种群的理解,允许更高的分辨率和更有效的监控策略。
    Estuarine ecosystems face increasing anthropogenic pressures, necessitating effective monitoring methods to mitigate their impacts on the biodiversity they harbour. The use of environmental DNA (eDNA) based detection methods is increasingly recognized as a promising tool to complement other, potentially invasive monitoring techniques. Integrating such eDNA analyses into monitoring frameworks for large ecosystems is still challenging and requires a deeper understanding of the scale and resolution at which eDNA patterns may offer insights in species presence and community composition space and time. The Scheldt estuary, characterized by its diverse habitats and complex currents, is one of the largest Western European tidal river systems. Until now, it remains challenging to obtain accurate information on fish communities living in and migrating through this ecosystem, consequently confining our knowledge to specific locations. To explore the potential of eDNA based monitoring, we simultaneously combine stow net fishing with eDNA metabarcoding, to assess spatiotemporal shifts in the Scheldt estuary\'s fish communities. In total, we detected 71 fish species in the estuary using eDNA metabarcoding, partly overlapping with historic fish community data gathered at the different study locations and in contrast to only 42 species using stow net fishing during the same survey period. Community compositions found by both detection methods varied among sampling locations, driven by a clear correlation to the salinity gradient. Limited effects of sampling depth and tide were observed on the eDNA metabarcoding data, allowing a significant reduction of the eDNA sampling effort for future eDNA fish monitoring campaigns in this study system. Our results further demonstrate that seasonal shifts in fish species occurrence can be detected using eDNA metabarcoding. Combining eDNA metabarcoding and stow net fishing further enhances our understanding of this vital waterway\'s diverse fish populations, allowing a higher resolution and more efficient monitoring strategy.
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  • 文章类型: Journal Article
    疼痛强度是疼痛临床试验中最常用的结果域。为了最小化II型错误的机会(即,得出结论认为治疗没有有益效果,事实上,它确实如此),所使用的疼痛强度测量应该对有效疼痛治疗产生的变化敏感。在这里,我们试图确定疼痛强度等级的组合,以平衡可靠性和有效性的需求与最小化评估负担的需求。我们使用来自完成的4臂心理疼痛治疗临床试验(N=164名成年人)的数据进行了二次分析。Current,最坏,至少,在治疗前后使用0至10个数值评定量表(NRS-11)对过去24小时的平均疼痛强度进行4次评估。我们使用这些评级创建了各种综合评分,并评估了它们的可靠性(克朗巴赫的阿尔法)和有效性(即,与黄金标准评分的关联是通过平均16个评分和检测治疗疗效组间差异的敏感性)。我们发现,对于每一项措施,可靠性随着用于创建度量的评级数量的增加而增加,并且需要三天或更长时间的评级才能与黄金标准有足够的联系。关于敏感性,研究结果表明,需要由四天的评分组成的综合评分,以最大限度地提高检测治疗效果的机会,特别是在样本量较小的情况下。总之,使用3天或4天的评估数据可能是最佳做法.结果:由至少三天的疼痛评分组成的综合评分似乎需要最大限度地提高可靠性和有效性,同时最大限度地减少评估负担。试验注册:clinicaltrials.govNCT01800604。
    Pain intensity is the most commonly used outcome domain in pain clinical trials. To minimize the chances of type II error (ie, concluding that a treatment does not have beneficial effects, when in fact it does), the measure of pain intensity used should be sensitive to changes produced by effective pain treatments. Here we sought to identify the combination of pain intensity ratings that would balance the need for reliability and validity against the need to minimize assessment burden. We conducted secondary analyses using data from a completed 4-arm clinical trial of psychological pain treatments (N = 164 adults). Current, worst, least, and average pain intensity in the past 24 hours were assessed 4 times before and after treatment using 0 to 10 numerical rating scale-11. We created a variety of composite scores using these ratings and evaluated their reliability (Cronbach\'s alphas) and validity (ie, associations with a gold standard score created by averaging 16 ratings and sensitivity for detecting between-group differences in treatment efficacy). We found that for each measure, reliability increased as the number of ratings used to create the measures increased and that ratings from 3 or more days were needed to have adequately strong associations with the gold standard. Regarding sensitivity, the findings suggest that composite scores made up of ratings from 4 days are needed to maximize the chances of detecting treatment effects, especially with smaller sample sizes. In conclusion, using data from 3 or 4 days of assessment may be the best practice. PERSPECTIVE: Composite scores made up of at least 3 days of pain ratings appear to be needed to maximize reliability and validity while minimizing the assessment burden. TRIAL REGISTRATION: clinicaltrials.gov NCT01800604.
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  • 文章类型: Journal Article
    在动物中对药物进行临床前评估有助于研究人员为人体试验选择潜在的信息性临床实验室标志物。为了评估动物凝血酶生成(TG)测定的实用性,我们研究了动物血浆对TG触发物的敏感性,人组织因子(TF),和活化因子XI(FXIa)。汇集的人类,鼠标,rat,豚鼠,兔子,牛,绵羊,和山羊血浆被用于这项研究。通过荧光和光密度测量TF或FXIa触发的TG和凝血,分别。凝血酶峰高(TPH)和时间(TPT),凝块时间(CT),和纤维蛋白凝块密度(FCD)均进行分析。每个测定参数的触发低和高灵敏度边界(LSB和HSB)定义为TF和FXIa浓度,提供最大参数值的20%和80%,除非基线(无触发)值超过最大值的20%,在这种情况下,LSB来源于基线值的120%。对于TF和FXIa,正常人样品显示出比大多数动物样品更低的TPHHSB。动物样本,除了老鼠,与人类相比,FXIa的TPTLSB较低。大多数啮齿动物和兔样品在不存在TG触发因素的情况下产生基线TG,这与血液凝固的预激活一致。FCD对任一血浆中的TF和FXIa均不敏感。动物血浆对人类TF和FXIa的敏感性差异很大,这表明在测试使用之前需要优化触发浓度,这使得将动物模型结果外推至人类的过程变得复杂。
    Preclinical evaluation of drugs in animals helps researchers to select potentially informative clinical laboratory markers for human trials. To assess the utility of animal thrombin generation (TG) assay, we studied the sensitivity of animal plasmas to triggers of TG, human Tissue Factor (TF), and Activated Factor XI (FXIa). Pooled human, mouse, rat, guinea pig, rabbit, bovine, sheep, and goat plasmas were used in this study. TF- or FXIa-triggered TG and clotting were measured via fluorescence and optical density, respectively. Thrombin peak height (TPH) and time (TPT), clot time (CT), and fibrin clot density (FCD) were all analyzed. The trigger low and high sensitivity borders (LSB and HSB) for each assay parameter were defined as TF and FXIa concentrations, providing 20 and 80% of the maximal parameter value, unless the baseline (no trigger) value exceeded 20% of the maximal, in which case, LSB was derived from 120% of baseline value. Normal human samples demonstrated lower TPH HSB than most of the animal samples for both TF and FXIa. Animal samples, except mice, demonstrated lower TPT LSB for FXIa versus humans. Most rodent and rabbit samples produced baseline TG in the absence of TG triggers that were consistent with the pre-activation of blood coagulation. FCD was not sensitive to both TF and FXIa in either of the plasmas. Animal plasmas have widely variable sensitivities to human TF and FXIa, which suggests that optimization of trigger concentration is required prior to test use, and this complicates the extrapolation of animal model results to humans.
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  • 文章类型: Journal Article
    在许多传统治疗领域中找到改善的干预措施的必要性是高度优先的。这有可能降低许多患者的医疗费用和不良结果。通常,临床疗效是衡量治疗任何有益效果的主要评价标准.尽管,可能存在其他几个因素(例如副作用,成本负担,不那么虚弱,不太密集,等。),这可以允许一些对患者亚组有利的稍微不太有效的治疗选择。这通常导致非劣效性(NI)测试。由于伦理原因,NI试验可能包括也可能不包括安慰剂组。然而,当包括时,与不含安慰剂的双臂试验相比,由此产生的三臂试验更谨慎,因为其需要的假设不那么严格.在这篇文章中,当感兴趣的功能是风险差异时,我们考虑Frequentist和Bayesian两种方法在具有二元结局的三组试验中检测NI.首先提出了一种改进的Frequentist方法,然后是贝叶斯对应物。贝叶斯方法在许多主动控制试验中具有天然的优势,包括NI试验,因为它可以无缝地集成大量的先验信息。此外,我们讨论了样本量计算,并在两个范式之间得出了有趣的联系。
    Necessity for finding improved intervention in many legacy therapeutic areas are of high priority. This has the potential to decrease the expense of medical care and poor outcomes for many patients. Typically, clinical efficacy is the primary evaluating criteria to measure any beneficial effect of a treatment. Albeit, there could be situations when several other factors (e.g. side-effects, cost-burden, less debilitating, less intensive, etc.) which can permit some slightly less efficacious treatment options favorable to a subgroup of patients. This often leads to non-inferiority (NI) testing. NI trials may or may not include a placebo arm due to ethical reasons. However, when included, the resulting three-arm trial is more prudent since it requires less stringent assumptions compared to a two-arm placebo-free trial. In this article, we consider both Frequentist and Bayesian procedures for testing NI in the three-arm trial with binary outcomes when the functional of interest is risk difference. An improved Frequentist approach is proposed first, which is then followed by a Bayesian counterpart. Bayesian methods have a natural advantage in many active-control trials, including NI trial, as it can seamlessly integrate substantial prior information. In addition, we discuss sample size calculation and draw an interesting connection between the two paradigms.
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  • 文章类型: Journal Article
    疼痛相关结果的变异性会妨碍慢性疼痛临床试验的测定敏感性。在这些试验中对结果的期望可能是这种变异性的一部分,从而阻碍了新型疼痛治疗的发展。在开始研究治疗(活性或安慰剂)之前测量参与者的期望很少,变量,而且往往是未经验证的。努力优化和标准化测量,分析,和管理的期望是必要的。在这篇聚焦文章中,我们概述了药物和非药物疼痛治疗临床试验中基线预期与疼痛相关结局之间关系的研究结果.我们强调了在临床试验分析中调整参与者期望的潜在好处,并利用患者访谈的结果来讨论与期望测量相关的关键问题。最后,我们提出了有关未来研究的建议,重点是更好地理解将这些措施纳入临床试验分析的效用。观点:这篇重点文章概述了慢性疼痛治疗临床试验中参与者的基线预期和疼痛相关结果之间的关系。系统研究集中在预期的测量和在临床试验分析中调整预期的影响可以提高测定灵敏度。
    Variability in pain-related outcomes can hamper assay sensitivity of chronic pain clinical trials. Expectations of outcome in such trials may account for some of this variability, and thereby impede development of novel pain treatments. Measurement of participants\' expectations prior to initiating study treatment (active or placebo) is infrequent, variable, and often unvalidated. Efforts to optimize and standardize measurement, analysis, and management of expectations are needed. In this Focus Article, we provide an overview of research findings on the relationship between baseline expectations and pain-related outcomes in clinical trials of pharmacological and nonpharmacological pain treatments. We highlight the potential benefit of adjusting for participants\' expectations in clinical trial analyses and draw on findings from patient interviews to discuss critical issues related to measurement of expectations. We conclude with suggestions regarding future studies focused on better understanding the utility of incorporating these measures into clinical trial analyses. PERSPECTIVE: This focus article provides an overview of the relationship between participants\' baseline expectations and pain-related outcomes in the setting of clinical trials of chronic pain treatments. Systematic research focused on the measurement of expectations and the impact of adjusting for expectations in clinical trial analyses may improve assay sensitivity.
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  • 文章类型: Journal Article
    背景:镇痛药在控制正畸疼痛中的功效:系统回顾和荟萃分析。程丙,谢特,WangJ.BMC口腔健康2020;20:259。
    背景:系统综述由国家自然科学基金委员会资助(编号:81771114和编号81970967).作者没有实际或潜在的利益冲突。
    方法:系统评价和荟萃分析数据。
    BACKGROUND: The efficacy of analgesics in controlling orthodontic pain: a systematic review and meta- analysis. Cheng C, Xie T, Wang J. BMC Oral Health 2020; 20:259.
    BACKGROUND: The systematic review was funded by grants from the National Natural Science Foundation of China (No. 81771114 and No. 81970967). The authors have no actual or potential conflicts of interest.
    METHODS: Systematic review with meta-analysis of data.
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  • 文章类型: Journal Article
    本研究旨在确定当前的商业免疫测定法是否足以检测抗Omicron抗体。我们分析了Omicron感染后1-2个月的23名未接种疫苗的个体的抗SARS-CoV-2抗体反应。使用临床OmicronBA.1菌株和四种商业SARS-CoV-2免疫测定用活病毒中和测定法测试所有血液样品。我们评估了三种抗刺性免疫测定法(SARS-CoV-2IgGIIQuant[AbbottS],万泰抗SARS-CoV-2抗体ELISA[万泰],Elecsys抗SARS-CoV-2S测定[Roche])和一种抗核衣壳免疫测定(AbbottSARS-CoV-2IgG测定[AbbottN])。用活病毒中和测定法在所有样品中检测Omicron中和抗体。雅培S的检出率,万泰,罗氏,雅培N免疫测定为65.2%,69.6%,86.9%,和91.3%,分别。雅培S和万泰免疫测定的灵敏度显着低于活病毒中和测定(p=0.004,p=0.009;Fisher精确检验)。用抗S免疫测定获得的抗体浓度与Omicron中和抗体浓度相关。这些数据提供了一些商业免疫测定法检测由Omicron感染引起的抗体的性能丧失的临床证据。它强调了通过使抗原适应循环的SARS-CoV-2菌株来优化这些测定的需要。
    The present study aimed to determine whether current commercial immunoassays are adequate for detecting anti-Omicron antibodies. We analyzed the anti-SARS-CoV-2 antibody response of 23 unvaccinated individuals 1-2 months after an Omicron infection. All blood samples were tested with a live virus neutralization assay using a clinical Omicron BA.1 strain and four commercial SARS-CoV-2 immunoassays. We assessed three anti-Spike immunoassays (SARS-CoV-2 IgG II Quant [Abbott S], Wantaï anti-SARS-CoV-2 antibody ELISA [Wantaï], Elecsys Anti-SARS-CoV-2 S assay [Roche]) and one anti-Nucleocapsid immunoassay (Abbott SARS-CoV-2 IgG assay [Abbott N]). Omicron neutralizing antibodies were detected in all samples with the live virus neutralization assay. The detection rate of the Abbott S, Wantai, Roche, and Abbott N immunoassays were 65.2%, 69.6%, 86.9%, and 91.3%, respectively. The sensitivities of Abbott S and Wantai immunoassays were significantly lower than that of the live virus neutralization assay (p = 0.004, p = 0.009; Fisher\'s exact test). Antibody concentrations obtained with anti-S immunoassays were correlated with Omicron neutralizing antibody concentrations. These data provide clinical evidence of the loss of performance of some commercial immunoassays to detect antibodies elicited by Omicron infections. It highlights the need to optimize these assays by adapting antigens to the circulating SARS-CoV-2 strains.
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  • 文章类型: Journal Article
    对于只有不稳定的参考治疗可用且使用安慰剂在伦理上是合理的适应症,三臂“黄金标准”设计具有实验性,非劣效性试验推荐参考组和安慰剂组.在这样的设计中,参考或实验治疗的疗效证明是必需的。它们的缺点是,如果参考不能有效,则只能从试验中得出很少的结论。为了克服这一点,我们研究新颖的单阶段,适应性测试策略,其中仅在参考显示出足够的功效时才测试非劣效性,否则测试实验治疗优于安慰剂的δ$$\\delta$$-优越性。有了适当选择的优势,δ$$\\delta$$-优势间接显示非劣效性。我们优化了几个决策规则的样本量,发现自然,数据驱动的测试策略,如果参考的功效测试显著,则测试非劣效性,导致最小的总体和安慰剂样本量。我们证明,在样本量的特定限制下,该程序控制家庭错误率。发现所有最佳样本量都满足此约束。最后,我们展示了如何以有效的方式解释相关的安慰剂辍学率,并将新的测试策略应用于现实生活中的数据集。
    For indications where only unstable reference treatments are available and use of placebo is ethically justified, three-arm \"gold standard\" designs with an experimental, reference and placebo arm are recommended for non-inferiority trials. In such designs, the demonstration of efficacy of the reference or experimental treatment is a requirement. They have the disadvantage that only little can be concluded from the trial if the reference fails to be efficacious. To overcome this, we investigate novel single-stage, adaptive test strategies where non-inferiority is tested only if the reference shows sufficient efficacy and otherwise δ $$ \\delta $$ -superiority of the experimental treatment over placebo is tested. With a properly chosen superiority margin, δ $$ \\delta $$ -superiority indirectly shows non-inferiority. We optimize the sample size for several decision rules and find that the natural, data driven test strategy, which tests non-inferiority if the reference\'s efficacy test is significant, leads to the smallest overall and placebo sample sizes. We proof that under specific constraints on the sample sizes, this procedure controls the family-wise error rate. All optimal sample sizes are found to meet this constraint. We finally show how to account for a relevant placebo drop-out rate in an efficient way and apply the new test strategy to a real life data set.
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  • 文章类型: Journal Article
    根据ICHS7B指南,在首次人体测试之前,对候选药物进行hERG阻滞的筛选,以预测与罕见情况相关的延迟复极化的可能性,但危及生命,室性快速性心律失常.新的ICHE14Q&As指南允许hERG结果在以后的临床开发中用于决策(Q&As5.1和6.1)。要走这条路,hERG测定应按照新的ICHS7BQ&A2.1指南进行,这需要记录温度的最佳实践考虑,电压协议,刺激频率,记录/数据质量,和浓度验证。本研究调查了西沙必利对hERG的阻断,多非利特,特非那定,索他洛尔,和E-4031-通常用于证明测定灵敏度的阳性对照-使用手动全细胞膜片钳方法和以0.2Hz呈现的动作电位样电压方案。在室温和接近生理温度下进行记录。使用在真实膜片钳实验和卫星实验期间收集的样品测量药物浓度。结果显示温度对E-4031,特非那定,还有索他洛尔,但不是西沙必利和多非利特。西沙必利和特非那定显示大量浓度损失,主要是由于与灌注器的非特异性结合。使用从真实和卫星实验测得的浓度来评估块的效力,产生了可比的结果,这表明卫星样本采集可能仅适用于具有非特异性结合问题的药物。总之,这项研究为5个hERG阳性对照提供了阻滞效力,并作为hERG测定的案例研究,并根据新的ICHE14/S7BQ&As说明结果。
    According to the ICH S7B guideline, drug candidates are screened for hERG block prior to first-in-human testing to predict the likelihood of delayed repolarization associated with a rare, but life-threatening, ventricular tachyarrhythmia. The new ICH E14 Q&As guideline allows hERG results to be used in later clinical development for decision-making (Q&As 5.1 and 6.1). To pursue this path, the hERG assay should be conducted following the new ICH S7B Q&A 2.1 guideline, which calls for best practice considerations of the recording temperature, voltage protocol, stimulation frequency, recording/data quality, and concentration verification. This study investigated hERG block by cisapride, dofetilide, terfenadine, sotalol, and E-4031 - positive controls commonly used to demonstrate assay sensitivity - using the manual whole cell patch clamp method and an action potential-like voltage protocol presented at 0.2 Hz. Recordings were conducted at room and near physiological temperature. Drug concentrations were measured using samples collected during real patch clamp experiments and satellite experiments. Results showed temperature effects for E-4031, terfenadine, and sotalol, but not cisapride and dofetilide. Cisapride and terfenadine showed substantial concentration losses, largely due to nonspecific binding to the perfusion apparatus. Using concentrations measured from the real and satellite experiments to assess block potencies yielded comparable results, indicating that satellite sample collection may be viable for drugs with nonspecific binding concerns only. In summary, this study provides block potencies for 5 hERG positive controls, and serves as a case study for hERG assays conducted, and results illustrated in accordance with the new ICH E14/S7B Q&As.
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