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https://scholarworks.korea.ac.kr/kumedicine/handle/2020.sw.kumedicine/528
2024-03-29T01:12:12ZPerformance Evaluation of Microscanner Plus, an Automated Image-Based Cell Counter, for Counting CD4+ T Lymphocytes in HIV Patients
https://scholarworks.korea.ac.kr/kumedicine/handle/2021.sw.kumedicine/65219
Title: Performance Evaluation of Microscanner Plus, an Automated Image-Based Cell Counter, for Counting CD4+ T Lymphocytes in HIV Patients
Authors: Jang, Woong Sik; Lee, Junmin; Park, Seoyeon; Lim, Chae Seung; Kim, Jeeyong
Abstract: Counting CD4+ T lymphocytes using flow cytometry is a standard method for monitoring patients with HIV infections. Simpler and cheaper alternatives to flow cytometry are in high demand because getting access to flow cytometers is difficult or impossible in resource-limited settings. We evaluated the performance of the Microscanner Plus, a simple and automated image-based cell counter, in determining CD4 counts against a flow cytometer. CD4 count results of the Microscanner Plus and flow cytometer were compared using samples from 47 HIV-infected patients and 87 healthy individuals. All CV% for precision and reproducibility tests were less than 10%. The Microscanner Plus's lowest detectable CD4 count was determined to be 15.27 cells/mu L of whole blood samples. The correlation coefficient (R) between Microscanner Plus and flow cytometry for CD4 counting in 134 clinical samples was very high, at 0.9906 (p < 0.0001). The automated Microscanner Plus showed acceptable analytical performance for counting CD4+ T lymphocytes and may be particularly useful for monitoring HIV patients in resource-limited settings.2024-01-01T00:00:00ZSimple Point-of-Care Nucleic Acid Amplification Test for Rapid SARS-CoV-2 Infection Diagnosis
https://scholarworks.korea.ac.kr/kumedicine/handle/2021.sw.kumedicine/64229
Title: Simple Point-of-Care Nucleic Acid Amplification Test for Rapid SARS-CoV-2 Infection Diagnosis
Authors: Jee, Hyunseul; Choi, Minkyeong; Park, In Su; Lee, Junmin; Jang, Woong Sik; Lim, Chae Seung
Abstract: After three years of the SARS-CoV-2 pandemic, the demand for developing field-deployable point-of-care (PoC) molecular diagnostic tests has increased. Although RT-qPCR is the molecular diagnostic gold standard and is accurate, it is not readily applied to point-of-care testing (POCT). Meanwhile, rapid diagnostic kits have the disadvantage of low sensitivity. Recently, rapid isothermal nucleic acid amplification technology has emerged as an alternative for rapid diagnosis. Here, we developed a rapid SARS-CoV-2 reverse transcription loop-mediated isothermal amplification (RT-LAMP)-lateral flow assay (LFA) kit. This kit includes a Chelex-100/boiling nucleic acid extraction device and a one-step amplification detection apparatus capable of performing the entire process, from RNA extraction to detection, and diagnosing SARS-CoV-2 infection within 40 min without contamination. The detection limits of the rapid SARS-CoV-2 RT-LAMP-LFA kit were 100 plaque-forming units (PFUs) mL-1 and 10-1 PFU mL-1 for RNA samples extracted using the Chelex-100/boiling nucleic acid extraction device and commercial AdvansureTM E3 system, respectively. The sensitivity and specificity of the rapid SARS-CoV-2 RT-LAMP-LFA kit were 97.8% and 100%, respectively. Our SARS-CoV-2 RT-LAMP-LFA kit exhibited high sensitivity and specificity within 40 min without requiring laboratory instruments, suggesting that the kit could be used as a rapid POC molecular diagnostic test for SARS-CoV-2.2023-09-01T00:00:00ZRapid Detection of Mycobacterium Tuberculosis Using a Novel Point-of-Care BZ TB/NTM NALF Assay: Integrating LAMP and LFIA Technologies
https://scholarworks.korea.ac.kr/kumedicine/handle/2021.sw.kumedicine/63243
Title: Rapid Detection of Mycobacterium Tuberculosis Using a Novel Point-of-Care BZ TB/NTM NALF Assay: Integrating LAMP and LFIA Technologies
Authors: Kim, Ha Nui; Lee, Junmin; Yoon, Soo-Young; Jang, Woong Sik; Lim, Chae Seung
Abstract: Tuberculosis (TB) is one of the leading causes of infectious mortality from a single infectious agent, Mycobacterium tuberculosis (MTB). This study evaluated the performance of the newly developed BZ TB/NTM NALF assay, which integrated loop-mediated isothermal amplification and lateral flow immunochromatographic assay technologies, for the detection of MTB. A total of 80 MTB-positive samples and 115 MTB-negative samples were collected, all of which were confirmed by TB real-time PCR (RT-PCR) using either AdvanSure (TM) TB/NTM RT-PCR Kit or Xpert((R)) MTB/RIF Assay. The performance of the BZ TB/NTM NALF assay was evaluated by calculating its sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) in comparison to those of the RT-PCR methods. Compared to the RT-PCR, the sensitivity, specificity, PPV, and NPV of BZ TB/NTM NALF assay were 98.7%, 99.1%, 98.7%, and 99.1%, respectively. The concordance rate between BZ TB/NTM NALF and RT-PCR was 99.0%. Rapid and simple detection of MTB is essential for global case detection and further elimination of TB. The performance of the BZ TB/NTM NALF Assay is acceptable with a high concordance with RT-PCR, indicating that it is reliable for use in a low-resource environment.2023-04-01T00:00:00ZMagnetic-Fluorescent Nanocluster Lateral Flow Assay for Rotavirus Detection
https://scholarworks.korea.ac.kr/kumedicine/handle/2021.sw.kumedicine/62942
Title: Magnetic-Fluorescent Nanocluster Lateral Flow Assay for Rotavirus Detection
Authors: Fu, Hong En; Koo, Thomas Myeongseok; Kim, Myeong Soo; Ko, Min Jun; Park, Bum Chul; Oh, Kyuha; Cho, Younhyung; Jung, Jae-Wan; Kim, Sungil; Jang, Woong Sik; Lim, Chae Seung; Kim, Young Keun
Abstract: Rotavirus is a leading cause of death in young children worldwide. Although vaccines are currently available and reduce the disease burden, most low-income countries rely on diagnosis by point-of-care testing owing to its rapidity, simplicity, and affordability; however, its sensitivity remains a problem. Magnetically assisted antigen enrichment improves the sensitivity with increased fluorescence intensity. However, magnetic nanoparticles (NPs) strongly absorb ultraviolet light, limiting the combination of magnetic NPs and quantum dots (QDs). Therefore, this study aimed to establish a magnetic-fluorescent nanocluster composed of magnetite (Fe3O4) NPs and CdSe-CdS core-shell QDs for a high-sensitivity lateral flow assay (LFA). Inducing a solvophobic interaction mediated by solvent polarity increased the interparticle distance. Consequently, the self-assembled nanoclusters exhibited a QD-embedded structure with Fe3O4 NPs on the outer layer. The magnetic enrichment enhanced the detection limit of the rotavirus antigen up to 1.0 x 101 TCID50/mL, where TCID50 represents the median tissue culture infectious dose. The clinical trial results showed that the established LFA platform outperformed commercial test kits. Thus, this study provides a nanotechnology-based LFA platform with increased sensitivity for inhibiting the propagation of viruses.2023-04-01T00:00:00Z