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Objective: To identify whether cutoff for sensitivity advertised by three pregnancy tests in urine are compatible to those reported by the manufacturer and to describe their diagnostic performance.
Methods: The urine of a male volunteer was used to dilute recombinant β-hCG at defined concentrations of 0, 6.25, 12.5, 25, 50, and 100 mIU/mL. The tubes containing each of the concentrations were coded and blindly assessed for positivity in three different lots of hCG tests: Strip Test Plus®, BioEasy®, and Visitect Pregnancy®. The sample size was calculated for an alpha error of 5%, with a power of 99%.
Results: All three brands, in their three lots analyzed, had 100% of sensitivity for detecting β-hCG, with 100% negative predictive value, using only negative controls and samples with concentrations equal or higher than the test cutoff (n = 180/brand). The accuracy of the tests was 83% (BioEasy®), 84%(Visitect®) and 91% (Strip Test Plus®). Strip Test Plus® had the best positive likelihood ratio (52.5), while Visitect® had the best negative likelihood ratio (zero).
Conclusion: The three brands have adequate sensitivity for the advertised cutoffs. The Strip Test Plus® test had the best performance to identify urinary concentrations of β-hCG > 12.5 mIU/mL, and consequently, to confirm pregnancy, while Visitect® had the best performance to exclude β-hCG in urine (negative post-test probability: zero).
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http://dx.doi.org/10.1590/s0104-42302011000500008 | DOI Listing |
Talanta
September 2025
Karamanoglu Mehmetbey University, Kamil Ozdag Science Faculty, Department of Chemistry, Karaman, 70100, Turkey.
Biogenic amines (BAs) are organic nitrogen compounds formed through microbial decarboxylation of amino acids during food spoilage and biological metabolism. Therefore, the development of rapid, selective, and cost-effective detection strategies for BAs is significant for ensuring food safety and quality. In this study, a new dicyanoisophorone-based fluorescent probe (IPC) was developed, capable of fluorescence detection of aliphatic primary amines (e.
View Article and Find Full Text PDFGlob Chang Biol
September 2025
Department of Agronomy, Purdue University, West Lafayette, Indiana, USA.
Understanding how interactive management practices and climatic behavior influence soybean [Glycine max (L.) Merr.] productivity is imperative to inform future production systems under changing climate.
View Article and Find Full Text PDFAnal Chem
September 2025
College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, China.
A series of molecular logic gates with multiple biocomputing capabilities have been successfully fabricated by using four antibiotic residues [tetracycline (TET), chloramphenicol (CHL), kanamycin (KAN), and streptomycin (STR)] as inputs. The lateral flow strip biosensor was utilized to realize the visual and portable sensing of logic events. Four basic logic gates (OR, AND, XOR, and INHIBIT) and three cascade logic circuits (OR-INHIBIT-AND, 3AND-OR, and XOR-INHIBIT-OR-AND) were constructed.
View Article and Find Full Text PDFMikrochim Acta
September 2025
College of Food Science and Engineering, Northwest A&F University, 22 Xinong Road, Yangling, 712100, Shaanxi, China.
Salmonella typhimurium (S. typhimurium) A dual-mode colorimetric/photothermal immunochromatographic strip (ICS) employing hollow polydopamine nanoparticles (h-PDA) is reported for the ultrasensitive detection of Salmonella typhimurium (S. typhimurium).
View Article and Find Full Text PDFCureus
August 2025
Department of Orthodontics, Kothiwal Dental College and Research Centre, Moradabad, IND.
Introduction: This study aimed to evaluate and compare the inflammatory responses of two cordless gingival retraction systems by assessing the levels of interleukin-1 beta (IL-1β) and tumor necrosis factor-alpha (TNF-α) in gingival crevicular fluid (GCF). The objectives were to measure IL-1β and TNF-α levels before and after retraction using kaolin-based and polyvinyl acetate-based cordless gingival retraction materials at baseline, 1 h, and 24 h, and to compare the inflammatory profiles of these materials.
Materials And Methods: This in-vivo comparative study used a split-mouth design, with each of the 10 enrolled patients serving as their own control by receiving both kaolin-based paste (Traxodent®, Premier Dental Products, Plymouth Meeting, PA, USA) and polyvinyl acetate-based strip (Merocel®, Medtronic, Minneapolis, MN, USA) on different endodontically treated teeth requiring full-coverage crowns, thereby minimizing interindividual variability.