scholarly journals Validation of a direct-to-PCR COVID-19 detection protocol utilizing mechanical homogenization: A model for reducing resources needed for accurate testing

PLoS ONE ◽  
2021 ◽  
Vol 16 (8) ◽  
pp. e0256316
Author(s):  
Zachary P. Morehouse ◽  
Lyson Samikwa ◽  
Caleb M. Proctor ◽  
Harry Meleke ◽  
Mercy Kamdolozi ◽  
...  

Efficient and effective viral detection methodologies are a critical piece in the global response to COVID-19, with PCR-based nasopharyngeal and oropharyngeal swab testing serving as the current gold standard. With over 100 million confirmed cases globally, the supply chains supporting these PCR testing efforts are under a tremendous amount of stress, driving the need for innovative and accurate diagnostic solutions. Herein, the utility of a direct-to-PCR method of SARS-CoV-2 detection grounded in mechanical homogenization is examined for reducing resources needed for testing while maintaining a comparable sensitivity to the current gold standard workflow of nasopharyngeal and oropharyngeal swab testing. In a head-to-head comparison of 30 patient samples, this initial clinical validation study of the proposed homogenization-based workflow demonstrated significant agreeability with the current extraction-based method utilized while cutting the total resources needed in half.

2019 ◽  
Vol 72 (8) ◽  
pp. 1278-1284 ◽  
Author(s):  
Mikkel Herly ◽  
Felix Christoph Müller ◽  
Mathias Ørholt ◽  
Joachim Hansen ◽  
Sophie Sværke ◽  
...  

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Christian S. Guay ◽  
Mariam Khebir ◽  
T. Shiva Shahiri ◽  
Ariana Szilagyi ◽  
Erin Elizabeth Cole ◽  
...  

Abstract Background Real-time automated analysis of videos of the microvasculature is an essential step in the development of research protocols and clinical algorithms that incorporate point-of-care microvascular analysis. In response to the call for validation studies of available automated analysis software by the European Society of Intensive Care Medicine, and building on a previous validation study in sheep, we report the first human validation study of AVA 4. Methods Two retrospective perioperative datasets of human microcirculation videos (P1 and P2) and one prospective healthy volunteer dataset (V1) were used in this validation study. Video quality was assessed using the modified Microcirculation Image Quality Selection (MIQS) score. Videos were initially analyzed with (1) AVA software 3.2 by two experienced investigators using the gold standard semi-automated method, followed by an analysis with (2) AVA automated software 4.1. Microvascular variables measured were perfused vessel density (PVD), total vessel density (TVD), and proportion of perfused vessels (PPV). Bland–Altman analysis and intraclass correlation coefficients (ICC) were used to measure agreement between the two methods. Each method’s ability to discriminate between microcirculatory states before and after induction of general anesthesia was assessed using paired t-tests. Results Fifty-two videos from P1, 128 videos from P2 and 26 videos from V1 met inclusion criteria for analysis. Correlational analysis and Bland–Altman analysis revealed poor agreement and no correlation between AVA 4.1 and AVA 3.2. Following the induction of general anesthesia, TVD and PVD measured using AVA 3.2 increased significantly for P1 (p < 0.05) and P2 (p < 0.05). However, these changes could not be replicated with the data generated by AVA 4.1. Conclusions AVA 4.1 is not a suitable tool for research or clinical purposes at this time. Future validation studies of automated microvascular flow analysis software should aim to measure the new software’s agreement with the gold standard, its ability to discriminate between clinical states and the quality thresholds at which its performance becomes unacceptable.


2012 ◽  
Vol 19 (1) ◽  
pp. 21-48 ◽  
Author(s):  
Scott Urban ◽  
Tobias Straumann

The US recession of 1937–8 is one of the deepest on record. Yet it did not produce a global depression – quite unlike 1930. According to the standard view, this reflected an unfettering of central banking after the collapse of the international gold standard circa 1931. We challenge this view. While Germany and a couple of Central and Eastern European countries were sheltered by binding exchange controls, most countries were still constrained by their golden fetters, as our new exchange rate regime classification suggests. The underlying policy regime was surprisingly similar to that of the 1929–30 downturn. What mattered was a quick reversal in US policy in 1938 and, for many countries, a more plentiful stock of international reserves.


2016 ◽  
Vol 41 (8) ◽  
pp. 1272-1277 ◽  
Author(s):  
Matilde Jo Allingstrup ◽  
Jens Kondrup ◽  
Anders Perner ◽  
Poul Lunau Christensen ◽  
Tom Hartvig Jensen ◽  
...  

SLEEP ◽  
2021 ◽  
Vol 44 (Supplement_2) ◽  
pp. A161-A161
Author(s):  
Chris Fernandez ◽  
Sam Rusk ◽  
Nick Glattard ◽  
Yoav Nygate ◽  
Fred Turkington ◽  
...  

Abstract Introduction Despite an appreciable rise in sleep wellness and sleep medicine A.I. research publications, public data corpuses, institutional support, and health A.I. research funding opportunities, the availability of controlled-retrospective, hybrid-retrospective-prospective, and prospective-RCT quality clinical validation study evidence is limited with respect to their potential clinical impact. Furthermore, only a few practical examples of A.I. technologies are validated, in use today clinically, and widely adopted, to assist in sleep diagnoses and treatment. In this study, we contribute to this growing body of clinical A.I. validation evidence and experimental design methodologies with an interoperable A.I. scoring engine in Adult and Pediatric populations. Methods Stratified random sampling with proportionate allocation was applied to a database of N&gt;10,000 retrospective diagnostic clinical polysomnography (PSG), selected by evidence grading standards, with controls applied for OSA severity, diagnoses; sleep, psychiatric, neurologic, neurodevelopmental, cardiac, pulmonary, metabolic disorders, medications; benzodiazepines, antidepressants, stimulants, opiates, sleep aids, demographic groups of interest; sex, adult age, pediatric age, BMI, weight, height, and patient-reported sleepiness, to establish representative N=100 Adult and N=100 Pediatric samples. Double Blinded scoring was prospectively collected for each sample by 3 experienced RPSGT certified sleep technologists randomized from a pool of 9 scorers. Sensitivity (PA), Specificity (NA), Accuracy (OA), Kappa (K), and 95% Bootstrap CI’s are presented for sleep stages, OSA/CSA, hypopnea 3%/4%, arousals, limb movements, Cheyenne-Stokes respiration, periodic breathing, atrial fibrillation, and other events, and normative, mild, moderate, and severe OSA categories for global-AHI and REM-AHI. Results for Sleep Staging and OSA Severity Diagnostic Accuracy are summarized. Results A.I. scoring performance meet but in most cases exceeded initial clinical validation study (N=72 Adults, 2017) PA, NA, OA, K point-estimates and confidence-interval results for the 26 event types and 8 AHI-categories evaluated. The Adult sample showed 87%/94% Sensitivity/Specificity across all stages (Wake/N1/N2/N3/REM) and 94%/96% Sensitivity/Specificity for AHI&gt;=15. The Pediatric sample showed 87%/93% Sensitivity/Specificity staging, 89%/98% Sensitivity/Specificity AHI&gt;=15. Observed Accuracy was &gt;90% for Adults and Pediatrics all 26 events and 7 AHI-categories analyzed, except REM-AHI&gt;=5 (85%/82% Adults/Pediatrics). Conclusion We provide clinical validation evidence that demonstrates interoperable A.I. scoring performance in representative Adult and Pediatric patient clinical PSG samples when compared to prospective, double-blind scoring panel. Support (if any):


2019 ◽  
Vol 30 (7) ◽  
pp. 1062-1068.e2 ◽  
Author(s):  
Nischal Koirala ◽  
Nikunj Chauhan ◽  
Dustin Thompson ◽  
Zahra Karimloo ◽  
Kevin Wunderle ◽  
...  

2020 ◽  
Vol 09 (04) ◽  
pp. 353-356
Author(s):  
Guillaume Herzberg ◽  
Marion Burnier

Abstract Background The current gold-standard technique for radial styloidectomy is arthroscopic. The use of only two dorsal portals may not allow a crystal-clear view of the dorsal arthritic rim of the radius because of the dorsal capsule synovitis. Objectives To propose a new technique for isolated arthroscopic radial styloidectomy. The addition of a volar radial portal and a sequential procedure are presented. Patients and Methods Two trochars for alternatively viewing from volar radial or 3–4 are used. A 1–2 portal is used for instrumentation with a motorized burr. We have been using the three-portal technique in 34 cases (26 isolated). Results This modification of the classic arthroscopic radial styloidectomy is technically easy and the view of the dorsal rim of the radius provides a clear definition and treatment of the dorso-radial arthritic pathology. Conclusions The authors recommend this technical trick to perform an easy and comprehensive isolated palliative or curative arthroscopic radial styloidectomy.


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