scholarly journals Recent Trends in the Serologic Diagnosis of Syphilis

2014 ◽  
Vol 22 (2) ◽  
pp. 137-147 ◽  
Author(s):  
Muhammad G. Morshed ◽  
Ameeta E. Singh
Keyword(s):  
Congenital Syphilis ◽  
Point Of Care ◽  
Low Cost ◽  
Ease Of Use ◽  
Serologic Response ◽  
Serologic Tests ◽  
Traditional Algorithm ◽  
Previously Treated ◽  
Recent Trends ◽  
Made In

ABSTRACTComplexities in the diagnosis of syphilis continue to challenge clinicians. While direct tests (e.g., microscopy or PCR) are helpful in early syphilis, the mainstay of diagnosis remains serologic tests. The traditional algorithm using a nontreponemal test (NTT) followed by a treponemal test (TT) remains the standard in many parts of the world. More recently, the ability to automate the TT has led to the increasingly widespread use of reverse algorithms using treponemal enzyme immunoassays (EIAs). Rapid, point-of-care TTs are in widespread use in developing countries because of low cost, ease of use, and reasonable performance. However, none of the current diagnostic algorithms are able to distinguish current from previously treated infections. In addition, the reversal of traditional syphilis algorithms has led to uncertainty in the clinical management of patients. The interpretation of syphilis tests is further complicated by the lack of a reliable gold standard for syphilis diagnostics, and the newer tests can result in false-positive reactions similar to those seen with older tests. Little progress has been made in the area of serologic diagnostics for congenital syphilis, which requires assessment of maternal treatment and serologic response as well as clinical and laboratory investigation of the neonate for appropriate management. The diagnosis of neurosyphilis continues to require the collection of cerebrospinal fluid for a combination of NTT and TT, and, while newer treponemal EIAs look promising, more studies are needed to confirm their utility. This article reviews current tests and discusses current controversies in syphilis diagnosis, with a focus on serologic tests.

scholarly journals A rotationally focused flow (RFF) microfluidic biosensor by density difference for early-stage detectable diagnosis

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Noori Kim ◽  
Kyungsup Han ◽  
Pei-Chen Su ◽  
Insup Kim ◽  
Yong-Jin Yoon
Keyword(s):  
Early Detection ◽  
Optical Sensors ◽  
Early Stage ◽  
Point Of Care ◽  
Low Cost ◽  
Ease Of Use ◽  
Wavelength Shift ◽  
Label Free ◽  
Protein Biomarkers ◽  
Microfluidic Biosensor

AbstractLabel-free optical biosensors have received tremendous attention in point-of-care testing, especially in the emerging pandemic, COVID-19, since they advance toward early-detection, rapid, real-time, ease-of-use, and low-cost paradigms. Protein biomarkers testings require less sample modification process compared to nucleic-acid biomarkers’. However, challenges always are in detecting low-concentration for early-stage diagnosis. Here we present a Rotationally Focused Flow (RFF) method to enhance sensitivity(wavelength shift) of label-free optical sensors by increasing the detection probability of protein-based molecules. The RFF is structured by adding a less-dense fluid to focus the target-fluid in a T-shaped microchannel. It is integrated with label-free silicon microring resonators interacting with biotin-streptavidin. The suggested mechanism has demonstrated 0.19 fM concentration detection along with a significant magnitudes sensitivity enhancement compared to single flow methods. Verified by both CFD simulations and fluorescent flow-experiments, this study provides a promising proof-of-concept platform for next-generation lab-on-a-chip bioanalytics such as ultrafast and early-detection of COVID-19.

scholarly journals Analysis of Broadest Impact Implementation for a Developing Point of Care Device Using Antibody Antigen Reactions

2021 ◽  
Vol 6 (Spring 2021) ◽  
Author(s):  
Sienna Dugan ◽  
Gabrielle J. Gonzales ◽  
Kelly Little
Keyword(s):  
Sustainable Development ◽  
Selection Criteria ◽  
Clinical Laboratory ◽  
Democratic Republic Of Congo ◽  
Point Of Care ◽  
Low Cost ◽  
Turnaround Time ◽  
Ease Of Use ◽  
Medical Community ◽  
Chip Technology

With the recent launch of the Global Development Lab in the Hunter and Stephanie Hunt Institute for Engineering and Humanity, fellows, faculty, and industry professionals have been working to create meaningful solutions to promote a resilient humanity, addressing the UN’s Sustainable Development Goals and challenges. The Institute has taken on Dr. Ali Beskok’s project, the development of a low cost, portable, Point-of-Care-Device for humanitarian and health applications. This paper provides a systematic review of current Point-of-Care-Devices using antibody antigen reactions. Additionally, it provides aspects of a market analysis and a literature review. Its overarching goal is to make recommendations regarding a disease the developing device could test for through antibody antigen reactions that would most positively affect global health. Traditionally, biomedical engineers have developed technologies in response to the needs of the developed world’s medical community. These approaches often do not address the needs of the majority of the world’s peoples afflicted with both communicable and non-communicable diseases as the developments are far too costly and those with most need have, at best, limited access to supporting clinical laboratory infrastructure in developing countries. A gap in care has emerged as a result of these conditions. As a result, Drs. Beskok and Koklu have developed a Lab-on-a-Chip technology that can test for a chosen disease with a turnaround time of just a few seconds and a detection limit of 1 ng of antigen per 1 mL of sample fluid. In contrast to other commonly used PoCD’s, this technology can be adapted for detection of various diseases in various settings. This is a great improvement to current devices on the market in specificity, sensitivity, and ease of use, therefore making it particularly useful in high-throughput, low-skill staffing environments. In creating disease selection criteria for Dr. Beskok and his team’s device, several factors were taken into consideration. Generally, the selection criteria consists of diseases that result in a high DALY value, are communicable, identifiable with antibody-antigen reactions, and can be tested for using urine. The diseases that were identified with this criterion were Tuberculosis and Malaria. Various antibody-antigen recommendations for diagnosis, advantages, and limitations of the proposed Point-of-Care-Device are discussed in the Proposed Disease section. In addition, current funding for each disease is overviewed. In order to make the greatest impact, deployment of the PoCD in the Sub-Saharan region, most specifically the Democratic Republic of Congo and Sierra Leone are recommended. Furthermore, children under the age of 5 who suffer from malnutrition should be given special attention. Focusing in these locations and populations will best aid in accomplishing the third Sustainable Development Goal set out by the UN: to ensure healthy lives and promote wellbeing for all at all ages.

scholarly journals Point-of-Care Testing for Infectious Diseases: Past, Present, and Future

2017 ◽  
Vol 55 (8) ◽  
pp. 2313-2320 ◽  
Author(s):  
Thomas R. Kozel ◽  
Amanda R. Burnham-Marusich
Keyword(s):  
Infectious Diseases ◽  
New Technologies ◽  
Point Of Care ◽  
Low Cost ◽  
Ease Of Use ◽  
Lateral Flow Immunoassay ◽  
Point Of Care Testing ◽  
Resource Limited Settings ◽  
Resource Limited ◽  
Potential Use

ABSTRACT Point-of-care (POC) diagnostics provide rapid actionable information for patient care at the time and site of an encounter with the health care system. The usual platform has been the lateral flow immunoassay. Recently, emerging molecular diagnostics have met requirements for speed, low cost, and ease of use for POC applications. A major driver for POC development is the ability to diagnose infectious diseases at sites with a limited infrastructure. The potential use in both wealthy and resource-limited settings has fueled an intense effort to build on existing technologies and to generate new technologies for the diagnosis of a broad spectrum of infectious diseases.

scholarly journals Highly sensitive interleukin 6 detection by employing commercially ready liposomes in an LFA format

2021 ◽  
Author(s):  
Simone Rink ◽  
Barbara Kaiser ◽  
Mark-Steven Steiner ◽  
Axel Duerkop ◽  
Antje J. Baeumner
Keyword(s):  
Interleukin 6 ◽  
Point Of Care ◽  
Low Cost ◽  
Ease Of Use ◽  
Commercial Application ◽  
Sulforhodamine B ◽  
Highly Sensitive ◽  
Order Of Magnitude ◽  
Lateral Flow Assays ◽  
Commercial Applications

AbstractRecent years have confirmed the ubiquitous applicability of lateral flow assays (LFA) in point-of-care testing (POCT). To make this technology available for low abundance analytes, strategies towards lower limits of detections (LOD), while maintaining the LFA’s ease of use, are still being sought. Here, we demonstrate how liposomes can significantly improve the LOD of traditional gold nanoparticle (AuNP)–based assays while fully supporting a ready-to-use system for commercial application. We fine-tuned liposomes towards photometric and fluorescence performance on the synthesis level and applied them in an established interleukin 6 (IL-6) immunoassay normally using commercial AuNP labels. IL-6’s low abundance (< 10 pg mL−1) and increasing relevance as prognostic marker for infections make it an ideal model analyte. It was found that liposomes with a high encapsulant load (150 mmol L−1 sulforhodamine B (SRB)) easily outperform AuNPs in photometric LFAs. Specifically, liposomes with 350 nm in diameter yield a lower LOD even in complex matrices such as human serum below the clinically relevant range (7 pg mL−1) beating AuNP by over an order of magnitude (81 pg mL−1). When dehydrated on the strip, liposomes maintained their signal performance for over a year even when stored at ambient temperature and indicate extraordinary stability of up to 8 years when stored as liquid. Whereas no LOD improvement was obtained by exploiting the liposomes’ fluorescence, an extraordinary gain in signal intensity was achieved upon lysis which is a promising feature for high-resolution and low-cost detection devices. Minimizing the procedural steps by inherently fluorescent liposomes, however, is not feasible. Finally, liposomes are ready for commercial applications as they are easy to mass-produce and can simply be substituted for the ubiquitously used AuNPs in the POCT market. Graphical abstract

scholarly journals Validation of a point-of-care rapid diagnostic test for hepatitis C for use in resource-limited settings

2019 ◽  
Vol 11 (4) ◽  
pp. 314-315
Author(s):  
James S Leathers ◽  
Maria Belen Pisano ◽  
Viviana Re ◽  
Gertine van Oord ◽  
Amir Sultan ◽  
...  
Keyword(s):  
Point Of Care ◽  
Low Cost ◽  
Rapid Diagnosis ◽  
Direct Acting Antivirals ◽  
Resource Limited Settings ◽  
Rapid Diagnosis Test ◽  
Resource Limited ◽  
Specificity And Sensitivity ◽  
Hcv Screening ◽  
Direct Acting

Abstract Background Treatment of HCV with direct-acting antivirals has enabled the discussion of HCV eradication worldwide. Envisioning this aim requires implementation of mass screening in resource-limited areas, usually constrained by testing costs. Methods We validated a low-cost, rapid diagnosis test (RDT) for HCV in three different continents in 141 individuals. Results The HCV RDT showed 100% specificity and sensitivity across different samples regardless of genotype or viral load (in samples with such information, 90%). Conclusions The HCV test validated in this study can allow for HCV screening in areas of need when properly used.

scholarly journals Rapid and Sensitive Detection of miRNA Based on AC Electrokinetic Capacitive Sensing for Point-of-Care Applications

Sensors ◽  
2021 ◽  
Vol 21 (12) ◽  
pp. 3985
Author(s):  
Nan Wan ◽  
Yu Jiang ◽  
Jiamei Huang ◽  
Rania Oueslati ◽  
Shigetoshi Eda ◽  
...  
Keyword(s):  
Limit Of Detection ◽  
Point Of Care ◽  
Low Cost ◽  
Clinical Diagnostics ◽  
Detection Methods ◽  
Capacitive Sensing ◽  
Application Potential ◽  
Mirna Detection ◽  
Mirna 25 ◽  
Low Sensitivity

A sensitive and efficient method for microRNAs (miRNAs) detection is strongly desired by clinicians and, in recent years, the search for such a method has drawn much attention. There has been significant interest in using miRNA as biomarkers for multiple diseases and conditions in clinical diagnostics. Presently, most miRNA detection methods suffer from drawbacks, e.g., low sensitivity, long assay time, expensive equipment, trained personnel, or unsuitability for point-of-care. New methodologies are needed to overcome these limitations to allow rapid, sensitive, low-cost, easy-to-use, and portable methods for miRNA detection at the point of care. In this work, to overcome these shortcomings, we integrated capacitive sensing and alternating current electrokinetic effects to detect specific miRNA-16b molecules, as a model, with the limit of detection reaching 1.0 femto molar (fM) levels. The specificity of the sensor was verified by testing miRNA-25, which has the same length as miRNA-16b. The sensor we developed demonstrated significant improvements in sensitivity, response time and cost over other miRNA detection methods, and has application potential at point-of-care.

scholarly journals A glucose meter interface for point-of-care gene circuit-based diagnostics

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Evan Amalfitano ◽  
Margot Karlikow ◽  
Masoud Norouzi ◽  
Katariina Jaenes ◽  
Seray Cicek ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Synthetic Biology ◽  
Molecular Diagnostics ◽  
Point Of Care ◽  
Low Cost ◽  
Gene Circuit ◽  
Reporter Systems ◽  
Glucose Meter ◽  
Pandemic Response ◽  
Glucose Output

AbstractRecent advances in cell-free synthetic biology have given rise to gene circuit-based sensors with the potential to provide decentralized and low-cost molecular diagnostics. However, it remains a challenge to deliver this sensing capacity into the hands of users in a practical manner. Here, we leverage the glucose meter, one of the most widely available point-of-care sensing devices, to serve as a universal reader for these decentralized diagnostics. We describe a molecular translator that can convert the activation of conventional gene circuit-based sensors into a glucose output that can be read by off-the-shelf glucose meters. We show the development of new glucogenic reporter systems, multiplexed reporter outputs and detection of nucleic acid targets down to the low attomolar range. Using this glucose-meter interface, we demonstrate the detection of a small-molecule analyte; sample-to-result diagnostics for typhoid, paratyphoid A/B; and show the potential for pandemic response with nucleic acid sensors for SARS-CoV-2.

scholarly journals Demonstration of a Label-Free and Low-Cost Optical Cavity-Based Biosensor Using Streptavidin and C-Reactive Protein

Biosensors ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 4
Author(s):  
Donggee Rho ◽  
Seunghyun Kim
Keyword(s):  
Limit Of Detection ◽  
Point Of Care ◽  
Low Cost ◽  
Optical Cavity ◽  
Sample Volume ◽  
Small Sample ◽  
Label Free ◽  
C Reactive Protein ◽  
Reactive Protein ◽  
Cavity Structure

An optical cavity-based biosensor (OCB) has been developed for point-of-care (POC) applications. This label-free biosensor employs low-cost components and simple fabrication processes to lower the overall cost while achieving high sensitivity using a differential detection method. To experimentally demonstrate its limit of detection (LOD), we conducted biosensing experiments with streptavidin and C-reactive protein (CRP). The optical cavity structure was optimized further for better sensitivity and easier fluid control. We utilized the polymer swelling property to fine-tune the optical cavity width, which significantly improved the success rate to produce measurable samples. Four different concentrations of streptavidin were tested in triplicate, and the LOD of the OCB was determined to be 1.35 nM. The OCB also successfully detected three different concentrations of human CRP using biotinylated CRP antibody. The LOD for CRP detection was 377 pM. All measurements were done using a small sample volume of 15 µL within 30 min. By reducing the sensing area, improving the functionalization and passivation processes, and increasing the sample volume, the LOD of the OCB are estimated to be reduced further to the femto-molar range. Overall, the demonstrated capability of the OCB in the present work shows great potential to be used as a promising POC biosensor.

scholarly journals Revisiting Electrochemical Biosensing in the 21st Century Society for Inflammatory Cytokines Involved in Autoimmune, Neurodegenerative, Cardiac, Viral and Cancer Diseases

Sensors ◽  
2020 ◽  
Vol 21 (1) ◽  
pp. 189
Author(s):  
Susana Campuzano ◽  
Paloma Yáñez-Sedeño ◽  
José Manuel Pingarrón
Keyword(s):  
Point Of Care ◽  
Low Cost ◽  
Accurate Determination ◽  
Test Time ◽  
Electrochemical Biosensing ◽  
Recent Developments ◽  
Inflammatory Processes ◽  
Human Skills ◽  
Cancer Diseases

The multifaceted key roles of cytokines in immunity and inflammatory processes have led to a high clinical interest for the determination of these biomolecules to be used as a tool in the diagnosis, prognosis, monitoring and treatment of several diseases of great current relevance (autoimmune, neurodegenerative, cardiac, viral and cancer diseases, hypercholesterolemia and diabetes). Therefore, the rapid and accurate determination of cytokine biomarkers in body fluids, cells and tissues has attracted considerable attention. However, many currently available techniques used for this purpose, although sensitive and selective, require expensive equipment and advanced human skills and do not meet the demands of today’s clinic in terms of test time, simplicity and point-of-care applicability. In the course of ongoing pursuit of new analytical methodologies, electrochemical biosensing is steadily gaining ground as a strategy suitable to develop simple, low-cost methods, with the ability for multiplexed and multiomics determinations in a short time and requiring a small amount of sample. This review article puts forward electrochemical biosensing methods reported in the last five years for the determination of cytokines, summarizes recent developments and trends through a comprehensive discussion of selected strategies, and highlights the challenges to solve in this field. Considering the key role demonstrated in the last years by different materials (with nano or micrometric size and with or without magnetic properties), in the design of analytical performance-enhanced electrochemical biosensing strategies, special attention is paid to the methods exploiting these approaches.

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