A Comparative Analysis of Two Commonly Used FDA-Approved Immunoassays for Fentanyl Detection.

BACKGROUND: Given the opioid epidemic, fentanyl screening in urine has become increasingly important. Immunoassays remain the most common screening methodology due to the high throughput and ease of integration into automated chemistry systems. The fentanyl ARK II from Ark Diagnostics is a widely used immunoassay, while a novel fentanyl assay called FEN2 by Lin-Zhi has become available on the Roche platform. Here, we evaluate and compare their performance. METHODS: Four hundred and thirty-four urine samples were analyzed for fentanyl across the Lin-Zhi FEN2 and ARK II assays on the Cobas c502 platform. Samples were analyzed immediately upon request for drug of abuse screening or frozen for subsequent analysis. For confirmation testing, a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method with a limit of detection of 1 ng/mL for fentanyl/norfentanyl was used. Any sample with either fentanyl or norfentanyl above the LC-MS/MS cutoff was deemed positive. RESULTS: The ARK II had 11 false negatives and 7 false positives, while the Lin-Zhi FEN2 had 12 false negatives and 2 false positives. This resulted in ARK II having a sensitivity and specificity of 90.4% and 97.8% respectively, while Lin-Zhi FEN2 had a sensitivity and specificity of 89.5% and 99.4%. CONCLUSIONS: Both the ARK II and Lin-Zhi FEN2 immunoassays detected fentanyl well. Overall, the Lin-Zhi assay had slightly better specificity than ARK II, in our data set. While some discrepant results were observed between the 2 immunoassay systems, most occurred near the immunoassay detection cutoffs.

In-Scanner Thoughts shape Resting-state Functional Connectivity: how participants "rest" matters.

Resting-state fMRI (rs-fMRI) scans-namely those lacking experimentally-controlled stimuli or cognitive demands-are often used to identify aberrant patterns of functional connectivity (FC) in clinical populations. To minimize interpretational uncertainty, researchers control for across-cohort disparities in age, gender, co-morbidities, and head motion. Yet, studies rarely, if ever, consider the possibility that systematic differences in inner experience (i.e., what subjects think and feel during the scan) may directly affect FC measures. Here we demonstrate that is the case using a rs-fMRI dataset comprising 471 scans annotated with experiential data. Wide-spread significant differences in FC are observed between scans that systematically differ in terms of reported in-scanner experience. Additionally, we show that FC can successfully predict specific aspects of in-scanner experience in a manner similar to how it predicts demographics, cognitive abilities, clinical outcomes and labels. Together, these results highlight the key role of in-scanner experience in shaping rs-fMRI estimates of FC.

Brief Report: Risk of Recurrent Interstitial Lung Disease From Osimertinib Versus Erlotinib Rechallenge After Symptomatic Osimertinib-Induced Interstitial Lung Disease.

Introduction: Interstitial lung disease (ILD) is the most frequent cause of drug-related mortality from EGFR tyrosine kinase inhibitors (TKIs). Yet, for patients with symptomatic osimertinib-induced ILD, the risk of recurrent ILD associated with EGFR TKI rechallenge, either with osimertinib or another TKI, such as erlotinib, is unclear. Methods: Retrospective study of 913 patients who received osimertinib treatment for EGFR mutation-positive NSCLC. Clinical characteristics, ILD treatment history, and subsequent anticancer therapy of patients with symptomatic osimertinib-induced ILD were collated. The primary end point was to compare the incidence of recurrent ILD with osimertinib versus erlotinib rechallenge. Results: Of 913 patients, 35 (3.8%) had symptomatic osimertinib-induced ILD, of which 12 (34%), 15 (43%), and eight (23%) had grade 2, 3 to 4, and 5 ILD, respectively. On ILD recovery, 17 patients had EGFR TKI rechallenge with eight received osimertinib and nine received erlotinib. The risk of recurrent ILD was higher with osimertinib rechallenge than erlotinib (p = 0.0498). Of eight, five (63%) developed recurrent ILD on osimertinib rechallenge, including three patients with fatal outcomes. In contrast, only one of nine patients (11%) treated with erlotinib had recurrent ILD. Median time to second ILD occurrence was 4.7 (range 0.7-12) weeks. Median time-to-treatment failure of patients with erlotinib rechallenge was 13.2 months (95% confidence interval: 8.6-15.0). Conclusions: The risk of recurrent ILD was considerably higher with osimertinib rechallenge than erlotinib. Osimertinib rechallenge should be avoided, whereas erlotinib may be considered in patients with symptomatic osimertinib-induced ILD.

In vitro biological evaluation and in silico studies of linear diarylheptanoids from Curcuma aromatica Salisb. as urease inhibitors.

Plants of the Zingiberaceae family, specifically those belonging to the Curcuma species, are commonly under consideration as potential therapeutic agents for the management of gastrointestinal diseases. In this study, we carried out a phytochemical study on Curcuma aromatica Salisb. (or so-called "Nghe trang" in Vietnamese) grown in Vietnam, which yields three newly discovered 3,5-diacetoxy diarylheptanoids (1-3) and six known 3,5-dihydroxyl diarylheptanoids (4-9). The bioactivity assessment shows that all isolated compounds, except compounds 3, 7, and 8, could inhibit urease. Compounds 4 and 9 significantly inhibit urease, with an IC50 value of 9.6 and 21.4 µM, respectively, more substantial than the positive control, hydroxyurea (IC50 = 77.4 µM). The structure-activity relationship (SAR) of linear diarylheptanoids was also established, suggesting that the hydroxyl groups at any position of skeleton diarylheptanoids are essential for exerting anti-urease action. Through a comparative analysis of the binding sites of hydroxyurea and diarylheptanoid compounds via our constructed in silico model, the mechanism of action of diarylheptanoid compounds is predicted to bind to the dynamic region close to the dinickel active center, resulting in a loss of catalytic activity. Such insights certainly help design and/or find diarylheptanoid-based compounds for treating gastric ulcers through inhibiting urease.

Estimation of trajectory of protective efficacy in infectious disease prevention trials using recurrent event times.

In studies of infectious disease prevention, the level of protective efficacy of medicinal products such as vaccines and prophylactic drugs tends to vary over time. Many products require administration of multiple doses at scheduled times, as opposed to one-off or continual intervention. Accurate information on the trajectory of the level of protective efficacy over time facilitates informed clinical recommendations and implementation strategies, for example, with respect to the timing of administration of the doses. Based on concepts from pharmacokinetic and pharmacodynamic modeling, we propose a non-linear function for modeling the trajectory after each dose. The cumulative effect of multiple doses of the products is captured by an additive series of the function. The model has the advantages of parsimony and interpretability, while remaining flexible in capturing features of the trajectories. We incorporate this series into the Andersen-Gill model for analysis of recurrent event time data and compare it with alternative parametric and non-parametric functions. We use data on clinical malaria disease episodes from a trial of four doses of an anti-malarial drug combination for chemoprevention to illustrate, and evaluate the performance of the methods using simulation. The proposed method out-performed the alternatives in the analysis of real data in terms of Akaike and Bayesian Information Criterion. It also accurately captured the features of the protective efficacy trajectory such as the area under curve in simulations. The proposed method has strong potential to enhance the evaluation of disease prevention measures and improve their implementation strategies.

Validated assays for the quantification of C9orf72 human pathology.

A repeat expansion mutation in the C9orf72 gene is the leading known genetic cause of FTD and ALS. The C9orf72-ALS/FTD field has been plagued by a lack of reliable tools to monitor this genomic locus and its RNA and protein products. We have validated assays that quantify C9orf72 pathobiology at the DNA, RNA and protein levels using knock-out human iPSC lines as controls. Here we show that single-molecule sequencing can accurately measure the repeat expansion and faithfully report on changes to the C9orf72 locus in what has been a traditionally hard to sequence genomic region. This is of particular value to sizing and phasing the repeat expansion and determining changes to the gene locus after gene editing. We developed ddPCR assays to quantify two major C9orf72 transcript variants, which we validated by selective excision of their distinct transcriptional start sites. Using validated knock-out human iPSC lines, we validated 4 commercially available antibodies (of 9 tested) that were specific for C9orf72 protein quantification by Western blot, but none were specific for immunocytochemistry. We tested 15 combinations of antibodies against dipeptide repeat proteins (DPRs) across 66 concentrations using MSD immunoassay, and found two (against poly-GA and poly-GP) that yielded a 1.5-fold or greater signal increase in patient iPSC-motor neurons compared to knock-out control, and validated them in human postmortem and transgenic mouse brain tissue. Our validated DNA, RNA and protein assays are applicable to discovery research as well as clinical trials.