scholarly journals Clinical Application of the Novel Cell-Based Biosensor for the Ultra-Rapid Detection of the SARS-CoV-2 S1 Spike Protein Antigen: A Practical Approach

Biosensors ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 224
Author(s):  
Sophie Mavrikou ◽  
Vasileios Tsekouras ◽  
Kyriaki Hatziagapiou ◽  
Foteini Paradeisi ◽  
Petros Bakakos ◽  
...  
Keyword(s):  
Mammalian Cells ◽  
Early Stage ◽  
False Negative ◽  
Sample Pretreatment ◽  
High Sensitivity ◽  
Spike Protein ◽  
The Novel ◽  
Major Step ◽  
Negative Results ◽  
Potential Applicability

The availability of antigen tests for SARS-CoV-2 represents a major step for the mass surveillance of the incidence of infection, especially regarding COVID-19 asymptomatic and/or early-stage patients. Recently, we reported the development of a Bioelectric Recognition Assay-based biosensor able to detect the SARS-CoV-2 S1 spike protein expressed on the surface of the virus in just three minutes, with high sensitivity and selectivity. The working principle was established by measuring the change of the electric potential of membrane-engineered mammalian cells bearing the human chimeric spike S1 antibody after attachment of the respective viral protein. In the present study, we applied the novel biosensor to patient-derived nasopharyngeal samples in a clinical set-up, with absolutely no sample pretreatment. More importantly, membrane-engineered cells were pre-immobilized in a proprietary biomatrix, thus enabling their long-term preservation prior to use as well as significantly increasing their ease-of-handle as test consumables. The plug-and-apply novel biosensor was able to detect the virus in positive samples with a 92.8% success rate compared to RT-PCR. No false negative results were recorded. These findings demonstrate the potential applicability of the biosensor for the early, routine mass screening of SARS-CoV-2 on a scale not yet realized.

scholarly journals Development of a Portable, Ultra-Rapid and Ultra-Sensitive Cell-Based Biosensor for the Direct Detection of the SARS-CoV-2 S1 Spike Protein Antigen

Sensors ◽  
2020 ◽  
Vol 20 (11) ◽  
pp. 3121 ◽  
Author(s):  
Sophie Mavrikou ◽  
Georgia Moschopoulou ◽  
Vasileios Tsekouras ◽  
Spyridon Kintzios
Keyword(s):  
Mammalian Cells ◽  
Direct Detection ◽  
Early Stage ◽  
Cross Reactivity ◽  
Considerable Change ◽  
Concept Development ◽  
Spike Protein ◽  
The Novel ◽  
Membrane Bound ◽  
Eventual Control

One of the key challenges of the recent COVID-19 pandemic is the ability to accurately estimate the number of infected individuals, particularly asymptomatic and/or early-stage patients. We herewith report the proof-of-concept development of a biosensor able to detect the SARS-CoV-2 S1 spike protein expressed on the surface of the virus. The biosensor is based on membrane-engineered mammalian cells bearing the human chimeric spike S1 antibody. We demonstrate that the attachment of the protein to the membrane-bound antibodies resulted in a selective and considerable change in the cellular bioelectric properties measured by means of a Bioelectric Recognition Assay. The novel biosensor provided results in an ultra-rapid manner (3 min), with a detection limit of 1 fg/mL and a semi-linear range of response between 10 fg and 1 μg/mL. In addition, no cross-reactivity was observed against the SARS-CoV-2 nucleocapsid protein. Furthermore, the biosensor was configured as a ready-to-use platform, including a portable read-out device operated via smartphone/tablet. In this way, we demonstrate that the novel biosensor can be potentially applied for the mass screening of SARS-CoV-2 surface antigens without prior sample processing, therefore offering a possible solution for the timely monitoring and eventual control of the global coronavirus pandemic.

scholarly journals Visualization of Lesions of Metaphyses and Epiphyses of Bones in Newborns and Young Children

2021 ◽  
pp. 82-90
Author(s):  
N. A. Sholokhova
Keyword(s):  
Young Children ◽  
False Negative ◽  
Age Groups ◽  
High Sensitivity ◽  
Negative Results ◽  
False Negative Results ◽  
Inflammatory Processes ◽  
Group 5 ◽  
Magnetic Resonance Imaging Mri ◽  
Diagnostic Capabilities

The aim of this study was to determine the diagnostic capabilities of various methods of radiological diagnostics for lesions of the metaphyses and epiphyses of bones in newborns and young children.The study involved 108 children in the age group 5 days – 12 months with pathological changes in the pineal gland and bone metaphysis. The possibilities and advantages of standard radiography (СR), ultrasound examination (US) and magnetic resonance imaging (MRI) in the early and differential diagnosis of the osteomyelitis process and epiphyseolysis have been determined. High sensitivity (98 %), specificity (99 %) and accuracy (98 %) for ultrasound and sensitivity (94 %), specificity (89 %) and accuracy (95 %) of MRI in diagnosing osteomyelitis in patients of this age groups. At the same time, the possibilities of standard radiography at the stages of early diagnosis of inflammatory processes in the distal parts of the bones were limited due to a number of factors. The use of diagnostic algorithms greatly facilitates the work of a radiologist and reduces the number of false negative results during the initial treatment of patients.

CLINICAL APPLICATION OF COVID-19 REPORTING AND DATA SYSTEM IN COMPUTED TOMOGRAPHY OF BILATERAL PNEUMONIA DIAGNOSTIC

2021 ◽  
Vol 31 (4) ◽  
pp. 40-45
Author(s):  
Ugnė Kulnickaitė ◽  
Laura Dobrovaitė ◽  
Kamilė Grigaitė ◽  
Edvardas Jukna
Keyword(s):  
Computed Tomography ◽  
False Negative ◽  
High Sensitivity ◽  
Chest Ct ◽  
Data System ◽  
Negative Results ◽  
Radiological Society ◽  
Evaluation Scheme ◽  
False Negative Results ◽  
Standardized Reporting

Background: the 2019 coronavirus disease pandemic (COVID-19) has spread at an astonishing speed across the world, causing major morbidity and mortality. Computed tomography (CT) examination plays an important role in crisis areas in the diagnosis of COVID-19. COVID-19 Reporting and Data System (CO-RADS) has a five-point scale of suspicion for COVID-19 pneumonia in chest CT picture which standardizes the evaluation scheme and simplifies reporting. Aim: to summarise and present the role of COVID-19 Reporting and Data System in computed tomography of bilateral pneumonia diagnostic. Materials and methods: recently published studies were reviewed to evaluate COVID-19 Reporting and Data System scale as effective tool to detect COVID-19 pneumonia on chest CT scans. Databases from the subscription list of Lithuanian University of Health Sciences were selected: Medline (PubMed), SpringerLink and ScienceDirect. Results: chest CT features, as bilateral involvement, subpleural or peripherally distributed GGO, consolidation, reticulation, crazy paving pattern, air bronchogram signs, intralobular septal thickening, pulmonary vascular enlargement, are considered to be characteristic manifestations of COVID-19 infection. Studies show that Dutch Radiological Society presented CO-RADS scale sensitivity and specificity may vary from 61-88% and 66,4-98%, respectively. Conclusion: chest CT scan has a high sensitivity for COVID-19 diagnosis and could reduce false negative results obtained from RT-PCR tests. Furthermore, a standardized reporting system could increase clarification, minimize reporting variability and help radiologists recognize the results they observe, especially, for less experienced specialists.

Immunogenicity of Golimumab and its Clinical Relevance in Patients With Ulcerative Colitis

2019 ◽  
Vol 25 (9) ◽  
pp. 1532-1540 ◽  
Author(s):  
Omoniyi J Adedokun ◽  
George R Gunn ◽  
Jocelyn H Leu ◽  
Cynthia Gargano ◽  
Zhenhua Xu ◽  
...  
Keyword(s):  
Ulcerative Colitis ◽  
False Negative ◽  
Injection Site Reaction ◽  
High Sensitivity ◽  
Fold Increase ◽  
Drug Interference ◽  
Negative Results ◽  
Drug Concentrations ◽  
Antidrug Antibody ◽  
Antibody Titers

Abstract Background Antidrug antibody (ADA) detection with standard bridging enzyme immunoassays (EIA) can yield false-negative results or underestimate titers through drug interference. A more sensitive assay was needed to determine clinical impact of antigolimumab antibodies. Methods A high-sensitivity, drug-tolerant EIA (DT-EIA) was developed and cross-validated against the original EIA, and samples from induction/maintenance studies in golimumab-treated patients with ulcerative colitis were analyzed for ADAs using both methods. Immunogenicity results were compared, and pharmacokinetic, efficacy, and safety associations were evaluated. Results An 8-fold increase in ADA-positive patients (21.8% DT-EIA vs 2.8% EIA) reflected DT-EIA improved sensitivity and drug tolerance. Most newly detected ADA-positive patients (using DT-EIA) had low antibody titers, whereas most with high antibody titers were ADA-positive with original EIA. With DT-EIA, week 44 median trough serum golimumab concentrations among ADA-positive patients were approximately half vs ADA-negative (0.51 vs 0.85 µg/mL [50 mg q4w]; 0.85 vs 1.60 µg/mL [100 mg q4w]). Antidrug antibody impact on golimumab concentrations was more notable at titers ≥1:100. During induction, ADAs had no notable impact on efficacy. During maintenance, proportions of patients maintaining clinical response through week 54 were lower using DT-EIA: 38.1% ADA-positive and 52.8% ADA-negative. Antidrug antibody status had no impact on injection-site reaction incidence. Conclusions A more sensitive DT-EIA identified higher proportions of ADA-positive patients. A trend of decreasing drug concentrations with increasing ADA titers was observed. Pharmacokinetic impact was better elucidated with DT-EIA. Although development of ADA did not preclude efficacy, a trend toward decreased efficacy in ADA-positive vs ADA-negative patients was observed during maintenance treatment. Antidrug antibody status did not impact safety.

scholarly journals Specific circulating immune complexes in acute chagas' disease

1987 ◽  
Vol 29 (1) ◽  
pp. 26-32 ◽  
Author(s):  
Ricardo Corral ◽  
Héctor Freilij ◽  
Saúl Grinstein
Keyword(s):  
Chagas Disease ◽  
Immune Complexes ◽  
False Negative ◽  
High Sensitivity ◽  
Circulating Immune Complexes ◽  
Chronic Patients ◽  
Negative Results ◽  
Acute Toxoplasmosis ◽  
Acute Chagas Disease ◽  
Cruzi Infection

The presence of circulating immune complexes formed by IgM and IgG (CIC-IgM and CIC-IgG) was investigated, using antigen-specific enzyme-immunoassays (ELISA), in 30 patients with acute Chagas' disease who showed parasitemia and inoculation chagoma. Control population consisted of patients with chronic T. cruzi infection (30), acute toxoplasmosis 10), leishmaniasis (8), rheumatoid arthritis (3) and healthy individuals with negative serology for Chagas* disease (30). Acute chagasic patients were 100% CIC-IgG and 96.66% CIC-IgM positive whereas immunofluorescence tests yielded 90% and 86.66% of positivity for specific IgG and IgM antibodies, respectively. Chronic patients were 68% CIC-IgG and 0% CIC-IgM positive. The 30 negative and the 21 cross-reaction controls proved negative for ELISA (CIC-IgM and CIC-IgG). The high sensitivity of ELISA assays would allow early immunologic diagnosis, as well as prompt treatment, of acute T. cruzi infection, thus eliminating the problem of the false-positive and false-negative results which affects traditional methods for detection of circulating antibodies.

scholarly journals C4orf41 and TTC-15 are mammalian TRAPP components with a role at an early stage in ER-to-Golgi trafficking

2011 ◽  
Vol 22 (12) ◽  
pp. 2083-2093 ◽  
Author(s):  
P. James Scrivens ◽  
Baraa Noueihed ◽  
Nassim Shahrzad ◽  
Sokunthear Hul ◽  
Stephanie Brunet ◽  
...  
Keyword(s):  
Mammalian Cells ◽  
Multidisciplinary Approach ◽  
Early Stage ◽  
Binary Interaction ◽  
The Novel ◽  
Novel Proteins ◽  
Bona Fide ◽  
Interaction Map ◽  
Equivalent Complex

TRAPP is a multisubunit tethering complex implicated in multiple vesicle trafficking steps in Saccharomyces cerevisiae and conserved throughout eukarya, including humans. Here we confirm the role of TRAPPC2L as a stable component of mammalian TRAPP and report the identification of four novel components of the complex: C4orf41, TTC-15, KIAA1012, and Bet3L. Two of the components, KIAA1012 and Bet3L, are mammalian homologues of Trs85p and Bet3p, respectively. The remaining two novel TRAPP components, C4orf41 and TTC-15, have no homologues in S. cerevisiae. With this work, human homologues of all the S. cerevisiae TRAPP proteins, with the exception of the Saccharomycotina-specific subunit Trs65p, have now been reported. Through a multidisciplinary approach, we demonstrate that the novel proteins are bona fide components of human TRAPP and implicate C4orf41 and TTC-15 (which we call TRAPPC11 and TRAPPC12, respectively) in ER-to-Golgi trafficking at a very early stage. We further present a binary interaction map for all known mammalian TRAPP components and evidence that TRAPP oligomerizes. Our data are consistent with the absence of a TRAPP I–equivalent complex in mammalian cells, suggesting that the fundamental unit of mammalian TRAPP is distinct from that characterized in S. cerevisiae.

Pearls and Pitfalls of Interpretation in CT Colonography

2020 ◽  
Vol 71 (2) ◽  
pp. 140-148
Author(s):  
Michael Schonberger ◽  
Philippe Lefere ◽  
Abraham H. Dachman
Keyword(s):  
Computed Tomography ◽  
Sensitivity And Specificity ◽  
False Positive ◽  
Ct Colonography ◽  
False Negative ◽  
High Sensitivity ◽  
Negative Results ◽  
False Negative Results ◽  
The Common

The accuracy of computed tomography (CT) colonography (CTC) requires that the radiologist be well trained in the recognition of pitfalls of interpretation. In order to achieve a high sensitivity and specificity, the interpreting radiologist must be well versed in the causes of both false-positive and false-negative results. In this article, we review the common and uncommon pitfalls of interpretation in CTC.

scholarly journals Proteomic Analysis ofTrichinella spiralisMuscle Larval Excretory-Secretory Proteins Recognized by Early Infection Sera

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Li Wang ◽  
Zhong Quan Wang ◽  
Dan Dan Hu ◽  
Jing Cui
Keyword(s):  
Molecular Weight ◽  
Serine Proteases ◽  
Trichinella Spiralis ◽  
Early Stage ◽  
False Negative ◽  
Hypothetical Protein ◽  
Secretory Proteins ◽  
Dnase Ii ◽  
Negative Results ◽  
Protective Antibodies

Although the excretory-secretory (ES) proteins ofTrichinella spiralismuscle larvae are the most commonly used diagnostic antigens for trichinellosis, their main disadvantage is the false negative results during the early stage of infection and cross-reaction of their main components (43, 45, 49, and 53 kDa) with sera of patients with other helminthiasis. The aim of this study was to identify early specific diagnostic antigens inT. spiralisES proteins with 30–40 kDa. The ES proteins were analyzed by two-dimensional electrophoresis (2-DE), and a total of approximately 150 proteins spots were detected with isoelectric point (pI) varying from 4 to 7 and molecular weight from 14 to 66 kDa. When probed with sera from infected mice at 18 days postinfection, ten protein spots with molecular weight of 30–40 kDa were recognized and identified by MALDI-TOF/TOF-MS. All of ten spots were successfully identified and characterized to correlate with five different proteins, including two potential serine proteases, one antigen targeted by protective antibodies, one deoxyribonuclease (DNase) II, and one conserved hypothetical protein. These proteins might be the early specific diagnostic antigens for trichinellosis.

scholarly journals Prozone-like phenomenon in travellers with fatal malaria: report of two cases

2015 ◽  
Vol 9 (03) ◽  
pp. 321-324 ◽  
Author(s):  
Lurdes Santos ◽  
Nuno Rocha Pereira ◽  
Paulo Andrade ◽  
Paulo Figueiredo Dias ◽  
Carlos Lima Alves ◽  
...  
Keyword(s):  
Diagnostic Tests ◽  
False Negative ◽  
Specific Antigen ◽  
Malaria Diagnosis ◽  
High Sensitivity ◽  
Rapid Diagnostic Tests ◽  
Microscopy Observation ◽  
Negative Results ◽  
False Negative Results ◽  
Potential Benefits

Malaria diagnosis remains a concern in non-endemic countries, with rapid diagnosis being crucial to improve patients’ outcome. Rapid diagnostic tests have high sensitivity but they also have flaws and false-negative results that might jeopardize malaria diagnosis. Some false-negative results might relate to a prozone-like effect. The authors describe two patients with false-negative rapid diagnostic tests in which a prozone-like effect might have been involved. The authors highlight that these tests should not be used without accompanying light microscopy observation of blood films and discuss potential benefits of using rapid diagnostic tests with more than one specific antigen for Plasmodium falciparum.

Exploring 'best practice' for nucleic acid detection of Neisseria gonorrhoeae

Sexual Health ◽  
2008 ◽  
Vol 5 (1) ◽  
pp. 17 ◽  
Author(s):  
David M. Whiley ◽  
Suzanne M. Garland ◽  
Geoffrey Harnett ◽  
Gary Lum ◽  
David W. Smith ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Neisseria Gonorrhoeae ◽  
Best Practice ◽  
Current Knowledge ◽  
False Negative ◽  
High Sensitivity ◽  
Nucleic Acid Detection ◽  
Predictive Values ◽  
Neisseria Species ◽  
Negative Results

Nucleic acid detection tests (NADT) have considerable benefits for the detection of Neisseria gonorrhoeae (GC), including high sensitivity across a range of specimen types and use under widely differing settings and conditions. However, sexual health practitioners and others who use data generated by NADT for GC should be aware of some important limitations of these tests. False-positive results caused by cross reaction with commensal Neisseria species have been observed in many assays, and have lead to unacceptably low positive-predictive values in some patient populations. Further, false-negative results can be caused by GC sequence variation, with some gonococci lacking certain NADT target sequences. This review examines the issues associated with gonococcal NADT and considers best practice for use of these assays based on current knowledge. We emphasise the need for supplementary testing and extensive assay validation, and suggest appropriate strategies for these requirements irrespective of the setting in which they are used. Further, we highlight the need to maintain culture-based testing for certain specimen sites as well as for antimicrobial resistance surveillance.

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