Interpreting High Sensitivity Troponins in Various Acute Clinical Settings - Increased Significance to the Present.Day Cardiologist

High-sensitivity cardiac troponins expedite the evaluation of patients with chest pain in the emergency department. The utility of troponins extends beyond the acute coronary syndromes to accurate the diagnosis of myocardial injury. Troponins are best friends for physicians;however, they are a double-edged sword if not interpreted appropriately. Misdiagnosis is harmful with regard to patient outcomes. The present review focuses on the recent updates in the understanding and interpretation of high-sensitivity troponins in various acute clinical settings. Common mistakes and gray zones in the interpretation of troponins, the concept of myocardial injury versus infarction, newer entities like myocardial infarction (MI) with Nonobstructive Coronary Arteries, recent controversies over the definition of periprocedural MI, complementary role of imaging in the diagnosis of myocardial injury and the role of troponins in the current COVID-19 pandemic are discussed.Copyright © 2022 Saudi Center for Organ Transplantation.

Silicon photonic chip-based biosensor for COVID-19 and flu detection with high sensitivity and specificity

Since the end of 2021, Omicron, the new variant of SARS-CoV-2, has continued to spread as the predominant strain of COVID-19. Compared to previous variants, Omicron causes milder symptoms, which are similar to symptoms of other common respiratory infections, such as flu. In this work, we develop a silicon photonic chip-based biosensor for COVID-19 and flu detection using subwavelength grating micro-ring resonator. The biosensor realizes the detection of two pathogens with high sensitivity (1.31 fg/mL) and specificity. Besides, the microfluidic channel offers a promising solution for point-of-care detection. © 2023 SPIE.

Long COVID Syndrome: A Case-Control Study.

BACKGROUND: Acute coronavirus disease 2019 (COVID-19) causes various cardiovascular complications. However, it is unknown if there are cardiovascular sequelae in the medium and long-term. The aim of this study was dual. Firstly, we wanted to investigate symptomatology and health-related quality of life (HRQoL) at medium-term follow-up (6 months post-COVID). Secondly, we wanted to assess whether history of COVID-19 and persistent shortness of breath at medium-term follow-up are associated with ongoing inflammation, endothelial dysfunction, and cardiac injury. METHODS: A case-control study was performed. Virologically proven COVID-19 cases and age- and gender-matched controls were interviewed to assess symptoms and HRQoL. Biochemical tests were also performed. RESULTS: The study comprised 174 cases and 75 controls. The mean age of the participants was 46.1±13.8 years. The median follow-up was 173.5 days (interquartile range 129-193.25 days). There was no significant difference in the demographics between cases and controls. At follow-up, cases had a higher frequency of shortness of breath, fatigue, arthralgia, abnormal taste of food (P <.001), and anosmia. Cases also exhibited worse scores in the general health and role physical domains of the Short Form Survey-36. High-sensitivity C-reactive protein (hsCRP) was significantly higher in the cases, and there was a positive correlation of hsCRP with time. Significant determinants of shortness of breath were age, female gender and white cell count, troponin I, and lower hemoglobin levels at follow-up. CONCLUSION: Post-COVID-19 patients have persistent symptomatology at medium-term follow-up. Higher hsCRP in cases and the positive association of hsCRP with time suggest ongoing systemic inflammation in patients persisting for months after COVID-19.

Functional Nanomaterials for Electrochemical SRAS-CoV-2 Biosensors: a Review

The pandemic outbreak of COVID-19 has posed a threat to public health globally, and rapid and accurate identification of the viruses is crucial for controlling COVID-19. In recent years, nanomaterial-based electrochemical sensing techniques hold immense potential for molecular diagnosis with high sensitivity and specificity. In this review, we briefly introduced the structural characteristics and routine detection methods of SARS-CoV-2, then summarized the associated properties and mechanisms of the electrochemical biosensing methods. On the above basis, the research progress of electrochemical biosensors based on gold nanomaterials, oxide nanomaterials, carbon-based nanomaterials and other nanomaterials for rapid and accurate detection of virus were reviewed. Finally, the future applications of nanomaterial-based biosensors for biomolecular diagnostics were pointed out. © 2023 Science Press. All rights reserved.

Automatic Detection of COVID-19 Using Ensemble Transfer Learning Based on Lung CT Scans

In order to curb the rapid spread of COVID-19, early and accurate detection is required. Computer Tomography (CT) scans of the lungs can be utilized for accurate COVID-19 detection because these medical images highlight COVID-19 infection with high sensitivity. Transfer learning was implemented on six state-of-the-art Convolutional Neural Networks (CNNs). From these six CNNs, the three with the highest accuracies (based on empirical experiments) were selected and used as base learners to produce hard voting and soft voting ensemble classifiers. These three CNNs were identified as Vgg16, EfficientNetB0 and EfficientNetB5. This study concludes that the soft voting ensemble classifier, with base learners Vgg16 and EfficientNetB5, outperformed all other ensemble classifiers with different base learners and individual models that were investigated. The proposed classifier achieved a new state-of-the-art accuracy on the SARS-CoV-2 dataset. The accuracy obtained from this framework was 98.13%, the recall was 98.94%, the precision was 97.40%, the specificity was 97.30% and the F1 score was 98.16%. © 2023, ICST Institute for Computer Sciences, Social Informatics and Telecommunications Engineering.

A Microfluidic Biosensor for Rapid Detection of Covid-19

We have designed, fabricated, and tested a MEMS-based impedance biosensor for accurate and rapid detection of severe acute respiratory syndrome coronavirus 2 (SARS-COV-2) using of clinical samples. The device consists of focusing region that concentrate low quantities of the virus present in the samples to a detectable threshold, trap region hat maximize the captured virus, and detection region to detect the virus with high selectivity and sensitivity, using an array of interdigitated electrodes (IDE) coated with a specific antibody. Changes in the impedance value due to the binding of the SARS-COV-2 antigen to the antibody will indicate positive or negative result. The device was able to detect inactivated SARS-COV-2 antigen present in phosphate buffer saline (PBS) with a concentration as low as 50 TCID50/ml in 30 minutes. In addition, the biosensor was able to detect SARS-COV-2 in clinical samples (swabs) with a sensitivity of 84 TCID50/ml, also in 30 minutes. © 2023 IEEE.

Functional Nanomaterials for Electrochemical SRAS-CoV-2 Biosensors: a Review

The pandemic outbreak of COVID-19 has posed a threat to public health globally, and rapid and accurate identification of the viruses is crucial for controlling COVID-19. In recent years, nanomaterial-based electrochemical sensing techniques hold immense potential for molecular diagnosis with high sensitivity and specificity. In this review, we briefly introduced the structural characteristics and routine detection methods of SARS-CoV-2, then summarized the associated properties and mechanisms of the electrochemical biosensing methods. On the above basis, the research progress of electrochemical biosensors based on gold nanomaterials, oxide nanomaterials, carbon-based nanomaterials and other nanomaterials for rapid and accurate detection of virus were reviewed. Finally, the future applications of nanomaterial-based biosensors for biomolecular diagnostics were pointed out. © 2023 Science Press. All rights reserved.

Research on a New Optical Fiber Sensor with High Sensitivity

In order to improve the sensitivity and linearity of the sensor, it is proposed to change the surface roughness of the optical fiber and the type of probe. Firstly, the D-type optical fiber with rough surface is prepared by the self-built wheel optical fiber side polishing system, and then one end of the optical fiber is coated with a layer of Ag film,which can be used as a mirror, so as to obtain the D-type optical fiber probe. Finally, when detecting the sensing characteristics of the probe, it is found that the change of the refractive index of the measured solution will cause the absorption of different energy, which will change the optical power received by the optical power meter. A series of experiments results show that the prepared D-type optical fiber sensor not only has very strong stability, but also has very good linearity. In particular, the sensitivity and linear correlation coefficient of the sensor with polishing loss of 18 dB are as high as 66. 02 dB/RIU and 99. 58%,respectively. The measurement and calculation of the accuracy of refractive index show that the accuracy can be as high as 0. 000 04. The results show that the sensing structure has the potential to be widely used in biochemical sensing (such as COVID-19 pandemic) and realtime monitoring of environmental pollution. © 2022 Sichuan Institute of Piezoelectric and Acoustooptic Technology. All rights reserved.

Investigation of Serum Interleukin 6, High-Sensitivity C-Reactive Protein and White Blood Cell Levels during the Diagnosis and Treatment of Paediatric Appendicitis Patients Before and during the COVID-19 Pandemic.

Introduction: In this study, we prospectively investigated changes in serum interleukin-6 (IL-6), high-sensitivity C-reactive protein (hsCRP) and full white blood cell (WBC) counts during the diagnosis and treatment of paediatric patients with appendicitis. We also investigated the effects of the COVID-19 pandemic on the diagnosis and treatment processes of paediatric appendicitis patients. Materials and Methods: A non-perforated appendicitis group (n = 110), a perforated appendicitis group (n = 35) and an appendicitis + COVID-19 group (n = 8) were formed. Blood samples were taken upon admission and every day until the three studied parameters returned to normal values. To investigate the effects of the COVID-19 pandemic on paediatric appendicitis patients, the perforated appendicitis rates and the times from the onset of the first symptoms to the operation before and during the pandemic were compared. Results: WBC, IL-6, and hsCRP dropped below the upper limits on the second postoperative day in the non-perforated appendicitis group, four to six days postoperatively in the perforated appendicitis group, and three to six days postoperatively in the appendicitis + COVID-19 group. These parameters were not within normal range in patients who developed complications during follow-up. The time from the onset of abdominal pain to the surgery was significantly longer during than before the pandemic in both the non-perforated appendicitis group and the perforated appendicitis group. Conclusions: Our results show that WBC, IL-6, and hsCRP are useful laboratory parameters that can complete clinical examinations in the diagnosis of appendicitis in paediatric patients and the identification of complications that may develop postoperatively.

Use and Prognostic Implications of Cardiac Troponin in COVID-19.

Myocardial injury is common in patients with COVID-19 and is associated with an adverse prognosis. Cardiac troponin (cTn) is used to detect myocardial injury and assist with risk stratification in this population. SARS-CoV-2 infection can play a role in the pathogenesis of acute myocardial injury due to both direct and indirect damage to the cardiovascular system. Despite the initial concerns about an increased incidence of acute myocardial infarction (MI), most cTn increases are related to chronic myocardial injury due to comorbidities and/or acute nonischemic myocardial injury. This review will discuss the latest findings on this topic.

RETRACTED ARTICLE: Deep learning system to screen coronavirus disease 2019 pneumonia

The Editor in Chief has retracted this article (1) because the data published here was previously presented by a different set of authors at arXiv pre-print server (2) and a large amount of text, some figures and tables have been re-used without appropriate citation or acknowledgment. The pre-print has been published (3). Author Benson Babu agrees to this retraction. Authors Charmine Butt, Jagpal Gill and David Chun did not respond to any correspondence regarding this retraction. © Springer Science+Business Media, LLC, part of Springer Nature 2020.

High anti-SARS-CoV-2 seroprevalence among unvaccinated mother-child pairs from a rural setting of north-eastern Tanzania during the second wave of COVID-19.

Background: The reported infection rates, and the burden of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) in low- and middle-income countries, including sub-Saharan Africa, are relatively low compared to Europe and America, partly due to limited testing capabilities. Unlike many countries, in Tanzania, neither mass screening nor restrictive measures such as lockdowns have been implemented to date. The prevalence of SARS-CoV-2 infection in rural mainland Tanzania is largely unknown. Methods: Between April and October 2021, we conducted a cross-sectional study to assess anti-SARS-CoV-2 seroprevalence among mother-child pairs (n=634 children, n=518 mothers) in a rural setting of north-eastern Tanzania. Findings: We found a very high prevalence of anti-SARS-CoV-2 antibody titres with seroprevalence rates ranging from 29% among mothers and 40% among children, with a dynamic peak in seropositivity incidence at the end of July/early in August being revealed. Significant differences in age, socioeconomic status and body composition were associated with seropositivity in mothers and children. No significant associations were observed between seropositivity and comorbidities, including anaemia, diabetes, malaria, and HIV. Interpretations: The SARS-CoV-2 transmission in a rural region of Tanzania during 2021 was high, indicating a much higher infection rate in rural Tanzania compared to that reported in the UK and USA during the same period. Ongoing immune surveillance may be vital to monitoring the burden of viral infection in rural settings without access to molecular genotyping where a load of communicable diseases may mask COVID-19. Surveillance could be implemented in tandem with the intensification of vaccination strategies.

Why C-reactive protein is one of the most requested tests in clinical laboratories?

C-reactive protein (CRP) is an acute-phase protein which is synthesized by the liver in response to the secretion of several inflammatory cytokines including interleukin 6 (IL-6), IL-1 and tumor necrosis factor (TNF). CRP was the first acute-phase protein to be described and adopted in clinical laboratories as an exquisitely sensitive systemic marker of inflammation and tissue damage. The measurement of CRP is widely used for the diagnosis and monitoring of inflammatory conditions, including sepsis, trauma, and malignancies. In the last decades, impressive advances in analytical methods (from qualitative to high-sensitivity assays), automation and availability of results in a short time, not only translated in an increasing demand for the right management of systemic inflammatory diseases, but also in evaluating subclinical inflammatory processes underlying atherothrombotic events. CRP measurement is one of the most requested laboratory tests for both the wide range of clinical conditions in which it may assure a valuable information and some analytical advantages due to the evidence that it is a "robust biomarker". Even recently, the measurement of CRP received new interest, particularly as a biomarker of severity of Coronavirus disease 2019 (COVID-19), and it deserves further concern for improving demand appropriateness and result interpretation.

An international, stepped wedge, cluster-randomized trial investigating the 0/1-h algorithm in suspected acute coronary syndrome in Asia: the rational of the DROP-Asian ACS study.

BACKGROUND: More than half of the world's population lives in Asia. With current life expectancies in Asian countries, the burden of cardiovascular disease is increasing exponentially. Overcrowding in the emergency departments (ED) has become a public health problem. Since 2015, the European Society of Cardiology recommends the use of a 0/1-h algorithm based on high-sensitivity cardiac troponin (hs-cTn) for rapid triage of patients with suspected non-ST elevation acute coronary syndrome (NSTE-ACS). However, these algorithms are currently not recommended by Asian guidelines due to the lack of suitable data. METHODS: The DROP-Asian ACS is a prospective, stepped wedge, cluster-randomized trial enrolling 4260 participants presenting with chest pain to the ED of 12 acute care hospitals in five Asian countries (UMIN; 000042461). Consecutive patients presenting with suspected acute coronary syndrome between July 2022 and Apr 2024 were included. Initially, all clusters will apply "usual care" according to local standard operating procedures including hs-cTnT but not the 0/1-h algorithm. The primary outcome is the incidence of major adverse cardiac events (MACE), the composite of all-cause death, myocardial infarction, unstable angina, or unplanned revascularization within 30 days. The difference in MACE (with one-sided 95% CI) was estimated to evaluate non-inferiority. The non-inferiority margin was prespecified at 1.5%. Secondary efficacy outcomes include costs for healthcare resources and duration of stay in ED. CONCLUSIONS: This study provides important evidence concerning the safety and efficacy of the 0/1-h algorithm in Asian countries and may help to reduce congestion of the ED as well as medical costs.

Evaluation of a high-sensitivity SARS-CoV-2 antigen test on the fully automated light-initiated chemiluminescent immunoassay platform.

OBJECTIVES: To describe a high-sensitivity SARS-CoV-2 antigen test that is based on the fully automated light-initiated chemiluminescent immunoassay (LiCA®), and to validate its analytical characteristics and clinical agreement on detecting SARS-CoV-2 infection against the reference molecular test. METHODS: Analytical performance was validated and detection limits were determined using different types of nucleocapsid protein samples. 798-pair anterior nasal swab specimens were collected from hospitalized patients and asymptomatic screening individuals. Agreement between LiCA® antigen and real-time reverse transcription polymerase chain reaction (rRT-PCR) was evaluated. RESULTS: Repeatability and within-lab precision were 1.6-2.3%. The C5∼C95 interval was -5.1-4.6% away from C50. Detection limits in average (SD) were 325 (±141) U/mL on the national reference panel, 0.07 (±0.04) TCID50/mL on active viral cultures, 0.27 (±0.09) pg/mL on recombinant nucleocapsid proteins and 1.07 (±1.01) TCID50/mL on inactivated viral suspensions, respectively. LiCA detected a median of 374-fold (IQR 137-643) lower levels of the viral antigen than comparative rapid tests. As reference to the rRT-PCR method, overall sensitivity and specificity were determined to be 97.5% (91.4-99.7%) and 99.9% (99.2-100%), respectively. Total agreement between both methods was 99.6% (98.7-99.9%) with Cohen's kappa 0.98 (0.96-1). A positive detection rate of 100% (95.4-100%) was obtained as Ct≤37.8. CONCLUSIONS: The LiCA® system provides an exceptionally high-sensitivity and fully automated platform for the detection of the SARS-CoV-2 antigen in nasal swabs. The assay may have high potential use for large-scale population screening and surveillance of COVID-19 as an alternative to the rRT-PCR test.

Electrochemical biosensing based on graphene for detection of the SARS-Co V-2 Nucleocapsid Protein

Monitoring and controlling infection is required in order to prevent the progression of the coronavirus severe acute respiratory syndrome 2(SARS-Co- V-2). To accomplish this goal, the development and implementation of sensitive, quick and accurate diagnostic methods are essential. Electrochemical sensors have exposed large application possibilities in biological detection due to the advantages of high sensitivity, short time-consuming and specificity. Here, we report the improvement of a sensitive electrochemical sensor capable of detecting the presence of the SARS-CoV-2 virus using graphene-modified interdigitated working electrodes functionalized with antibodies targeting the SARS-CoV-2 nucleocapsid protein (N protein). © 2022 IEEE.

High sensitivity SARS-CoV-2 detection using graphene oxide-multiplex qPCR.

The emerging pandemic of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) critically challenges early and accurate virus diagnoses. However, the current gold standard for SARS-CoV-2 detection, reverse transcription-quantitative polymerase chain reaction (RT-qPCR), has reportedly failed to detect low-viral loads. One compound, graphene oxide (GO), which adsorbs single-stranded DNA (ssDNA), has been widely applied in molecular pathogen detection. This study presents a highly sensitive GO-multiplex qPCR method for simultaneous detection of two SARS-CoV-2 genes (RdRP and E) and one reference gene (RNase P). In a GO-multiplex qPCR system, GO pre-absorbs each forward primer to form specific GO-forward primer composites before entering the amplification system. Target gene amplification is confined within the primer-enriched composites, thus, improving the sensitivity of the assay. Compared to conventional multiplex qPCR, GO-multiplex qPCR reduces the limit of detection by 10-fold to 10 copies/reaction. Hence, the GO-multiplex qPCR assay can be effectively used for SARS-CoV-2 detection.

Admission high-sensitivity cardiac troponin levels as a prognostic indicator for in-hospital mortality rates in the elderly and very elderly COVID-19 patients.

BACKGROUND: Elevation of cardiac troponin (cTn) is associated with the worst prognosis not only in cardiovascular disease but also in non-cardiovascular disease. The aim of this study is to verify if cTn has a prognostic role in elderly and very elderly coronavirus disease 2019 (COVID-19) patients. METHODS: This study enrolled consecutive COVID-19 elderly patients hospitalized at INRCA hospital, with available admission high sensitivity cardiac troponin T (HS-cTnT) level. Patients were divided into three groups based on HS-cTnT level: group A (Hs-cTnT ≤ 40 pg/ml), group B (Hs-cTnT 41-100 pg/ml), and group C (Hs-cTnT ≥ 101 pg/ml). The correlation between HS-cTnT levels and mortality rates was analyzed. RESULTS: 461 patients (mean age 86 years; 59% female) were divided into group A (261 patients), group B (129 patients), and group C (71 patients). Group C resulted significantly older, more affected by heart failure, chronic obstructive pulmonary disease, chronic kidney disease, and dementia, and with higher levels of creatinine, C-reactive protein, pro-calcitonin, interleukin-6, ferritin, NT-proBNP, D-dimer then group A and group B. Mortality rate increased significantly across groups (group A: 18.4%; group B: 36.4%; group C: 62.0%; p<0.001). Group C had a significant increase in mortality risk compared to group A, both univariate analysis (HR 3.78) and multivariate analysis (model 2 HR 3.10; model 3 HR 3.59; model 4 HR 1.72). CONCLUSION: HS-cTnT has demonstrated a prognostic role in elderly and very elderly COVID-19 patients. HS-cTnT is a simple and inexpensive laboratory exam that gives clinicians important information on mortality risk stratification.

Absorption-Modulated SiO2@Au Core-Satellite Nanoparticles for Highly Sensitive Detection of SARS-CoV-2 Nucleocapsid Protein in Lateral Flow Immunosensors.

The worldwide spread of coronavirus disease 2019 (COVID-19) highlights the need for rapid, simple, and accurate tests to detect various variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The antigen test, based on the lateral flow immunoassay (LFI), is a suitable "first line of defense" test that enables early identification and timely isolation of patients to minimize viral transmission among communities. However, it is generally less accurate than nucleic acid testing, and its sensitivity needs improvement. Here, a novel rapid detection method is designed to sensitively detect SARS-CoV-2 using isolated gold nanoparticle (AuNP)-assembled SiO2 core-satellite nanoparticles (SiO2@Au CSNPs). Well-grown AuNP satellites in the synthesis of SiO2@Au CSNPs significantly enhanced their light absorption, increased the detection sensitivity, and lowered the detection limit by 2 orders of magnitude relative to conventional gold colloids. The proposed system enabled highly sensitive detection of the SARS-CoV-2 nucleocapsid protein with a detection limit of 0.24 pg mL-1 within 20 min. This is the first study to develop a highly sensitive antigen test using the absorption-modulated SiO2@Au CSNPs. Our findings demonstrate the capacity of this platform to serve as an effective sensing strategy for managing pandemic conditions and preventing the spread of viral infections.

High-Sensitivity Troponin I is an Indicator of Poor Prognosis in Patients with Severe COVID-19 Related Pneumonia.

Objective: Critical covid-19 patients have complications with acute myocardial injury is still unclear. We observed a series of critically ill patients, paying particular attention to the impact of myocardial injury at admission on short-term outcome. Methods: We prospectively collected and analyzed data from a series of severe covid-19 patients confirmed by real-time RT-PCR. Data were obtained from electronic medical records including clinical charts, nursing records, laboratory findings, and chest x-rays were from Feb 8, 2020, to April 7, 2020. The Acute Physiology and Chronic Health Evaluation (APACHE II) score, CURB-65 Pneumonia Severity Score, Sequential Organ Failure Assessment (SOFA) Score and pneumonia severity index (PSI) score were made within 24 hours of admission. Cardiac injury was diagnosed as hs-cTnI were above >28 pg/mL. The short-term outcome was defined as mortality in hospital. Results: A total of 100 patients met the diagnostic criteria of severe patients with COVID-19 during 2020.02.08-2020.04.07. The CURB 65, APACH2, SOFA, and PSI score were significantly higher in Critical group than in Severe group. Univariate regression analysis showed that oxygen flow, PO2/FiO2, SOFA and hs-cTnI were closely related to short-term outcome. The corresponding ROC of hs-cTnI, oxygen flow and SOFA for patient death prediction were 0.949, 0.906 and 0.652. hs-cTnI at 47.8 ng/liter predicted death, sensitivity 92.8%, specificity 92.9%; Oxygen flow at 5.5 liter/minute predicted death sensitivity 100%, specificity 77.9%; SOFA score at 5 predicted death sensitivity 100%, specificity 73.8%. Conclusion: Our cohort study demonstrated that inhaled oxygen flow, SOFA score, and myocardial injury at admission in critically ill COVID-19 patients were important indicators for predicting short-term death of patients, the hs-cTnI can be as a risk stratification, which may provide a simple method for the physicians to identify high-risk patients and give reasonable treatment in time.