1.Kogene PowerChek Multiplex Real-time PCR Kits Versus the BioFire FilmArray Gastrointestinal Panel:Roles of Crossing Point Values and Melting Curves in Interpreting the FilmArray Gastrointestinal Panel
In Young YOO ; Sungjin JO ; Joo An KWON ; Jay Ho HAN ; Hae Kyung LEE ; Yeon-Joon PARK
Annals of Laboratory Medicine 2025;45(6):574-582
Background:
Various molecular methods are used to rapidly detect gastrointestinal pathogens, highlighting the importance of understanding the performance of the associated kits in detail. We comprehensively assessed the performance of Kogene PowerChek multiplex real-time PCR kits (PowerChek Bacterial/Viral Kits) with the FilmArray GI Panel.
Methods:
Residual stool specimens (N = 246), initially tested utilizing the FilmArray GI Panel (May 2023–Jan 2024), were reanalyzed using PowerChek Bacterial/Viral Kits. Discrepancies were resolved by performing additional molecular assays and reviewing culture results when available. True positives (TPs)/true negatives were defined by concordant results in at least two assays. We determined cycle threshold (Ct)/crossing point (Cp) distributions between the TP and false positive (FP) groups and analyzed melting curves for the FilmArray GI Panel FPs.
Results:
The positive-percent agreement (PPA) of the PowerChek Bacterial/Viral Kits was 50–100%, with lower values for Salmonella spp., rotavirus, and astrovirus, whereas the FilmArray GI Panel showed 100% PPA across all targets. Both platforms demonstrated > 99% negative-percent agreement, except for enteropathogenic Escherichia coli (EPEC) and adenovirus (PowerChek Bacterial/Viral Kits) or EPEC, enteroaggregative E. coli, norovirus, and Salmonella spp. (FilmArray GI Panel). The FPs showed higher Ct/Cp values with both kits, and these values were significantly higher for adenovirus (PowerChek Viral Kit), EPEC, and norovirus (FilmArray GI Panel). Melting curve analysis of four norovirus FPs (FilmArray GI Panel) revealed atypical patterns in three cases.
Conclusions
The FilmArray GI Panel demonstrated higher sensitivity than the PowerChek Kits. For norovirus, melting curve analysis will help avoid FPs.
2.Prevalence and Molecular Characterization of Vancomycin Variable Enterococcus faecium Isolated From Clinical Specimens
In Young YOO ; Joo An KWON ; Miran LEE ; Seung-Hyun JUNG ; Jung Ok KIM ; Sung Il HA ; Yeon-Joon PARK
Annals of Laboratory Medicine 2024;44(5):450-454
Vancomycin variable Enterococcus (VVE) bacteria are phenotypically susceptible to vancomycin, but they harbor the vanA gene. We aimed to ascertain the prevalence of VVE among clinically isolated vancomycin-susceptible Enterococcus faecium (VSE) isolates, as well as elucidate the molecular characteristics of the vanA gene cluster within these isolates. Notably, we investigated the prevalence and structure of the vanA gene cluster of VVE. Between June 2021 and May 2022, we collected consecutive, non-duplicated vancomycin-susceptible Enterococcus faecium (VSE) samples. Real-time PCR was performed to detect the presence of vanA, vanB, and vanC. Overlapping PCR with sequencing and whole -genome sequencing were performed for structural analysis. Sequence types (STs) were determined by multilocus sequence typing. Exposure testing was performed to assess the ability of the isolates to acquire vancomycin resistance. Among 282 VSE isolates tested, 20 isolates (7.1%) were VVE. Among them, 17 isolates had partial deletions in the IS1216 or IS1542 sequences in vanS (N = 10), vanR (N = 5), or vanH (N = 2). All VVE isolates belonged to the CC17 complex and comprised five STs, namely ST17 (40.0%), ST1421 (25.0%), ST80 (25.0%), ST787 (5.0%), and ST981 (5.0%). Most isolates were related to three hospital-associated clones (ST17, ST1421, and ST80). After vancomycin exposure, 18 of the 20 VVEs acquired vancomycin resistance. Considering the high reversion rate, detecting VVE by screening VSE for vanA is critical for appropriate treatment and infection control.
3.Prevalence and Molecular Characterization of Vancomycin Variable Enterococcus faecium Isolated From Clinical Specimens
In Young YOO ; Joo An KWON ; Miran LEE ; Seung-Hyun JUNG ; Jung Ok KIM ; Sung Il HA ; Yeon-Joon PARK
Annals of Laboratory Medicine 2024;44(5):450-454
Vancomycin variable Enterococcus (VVE) bacteria are phenotypically susceptible to vancomycin, but they harbor the vanA gene. We aimed to ascertain the prevalence of VVE among clinically isolated vancomycin-susceptible Enterococcus faecium (VSE) isolates, as well as elucidate the molecular characteristics of the vanA gene cluster within these isolates. Notably, we investigated the prevalence and structure of the vanA gene cluster of VVE. Between June 2021 and May 2022, we collected consecutive, non-duplicated vancomycin-susceptible Enterococcus faecium (VSE) samples. Real-time PCR was performed to detect the presence of vanA, vanB, and vanC. Overlapping PCR with sequencing and whole -genome sequencing were performed for structural analysis. Sequence types (STs) were determined by multilocus sequence typing. Exposure testing was performed to assess the ability of the isolates to acquire vancomycin resistance. Among 282 VSE isolates tested, 20 isolates (7.1%) were VVE. Among them, 17 isolates had partial deletions in the IS1216 or IS1542 sequences in vanS (N = 10), vanR (N = 5), or vanH (N = 2). All VVE isolates belonged to the CC17 complex and comprised five STs, namely ST17 (40.0%), ST1421 (25.0%), ST80 (25.0%), ST787 (5.0%), and ST981 (5.0%). Most isolates were related to three hospital-associated clones (ST17, ST1421, and ST80). After vancomycin exposure, 18 of the 20 VVEs acquired vancomycin resistance. Considering the high reversion rate, detecting VVE by screening VSE for vanA is critical for appropriate treatment and infection control.
4.Prevalence and Molecular Characterization of Vancomycin Variable Enterococcus faecium Isolated From Clinical Specimens
In Young YOO ; Joo An KWON ; Miran LEE ; Seung-Hyun JUNG ; Jung Ok KIM ; Sung Il HA ; Yeon-Joon PARK
Annals of Laboratory Medicine 2024;44(5):450-454
Vancomycin variable Enterococcus (VVE) bacteria are phenotypically susceptible to vancomycin, but they harbor the vanA gene. We aimed to ascertain the prevalence of VVE among clinically isolated vancomycin-susceptible Enterococcus faecium (VSE) isolates, as well as elucidate the molecular characteristics of the vanA gene cluster within these isolates. Notably, we investigated the prevalence and structure of the vanA gene cluster of VVE. Between June 2021 and May 2022, we collected consecutive, non-duplicated vancomycin-susceptible Enterococcus faecium (VSE) samples. Real-time PCR was performed to detect the presence of vanA, vanB, and vanC. Overlapping PCR with sequencing and whole -genome sequencing were performed for structural analysis. Sequence types (STs) were determined by multilocus sequence typing. Exposure testing was performed to assess the ability of the isolates to acquire vancomycin resistance. Among 282 VSE isolates tested, 20 isolates (7.1%) were VVE. Among them, 17 isolates had partial deletions in the IS1216 or IS1542 sequences in vanS (N = 10), vanR (N = 5), or vanH (N = 2). All VVE isolates belonged to the CC17 complex and comprised five STs, namely ST17 (40.0%), ST1421 (25.0%), ST80 (25.0%), ST787 (5.0%), and ST981 (5.0%). Most isolates were related to three hospital-associated clones (ST17, ST1421, and ST80). After vancomycin exposure, 18 of the 20 VVEs acquired vancomycin resistance. Considering the high reversion rate, detecting VVE by screening VSE for vanA is critical for appropriate treatment and infection control.
5.Prevalence and Molecular Characterization of Vancomycin Variable Enterococcus faecium Isolated From Clinical Specimens
In Young YOO ; Joo An KWON ; Miran LEE ; Seung-Hyun JUNG ; Jung Ok KIM ; Sung Il HA ; Yeon-Joon PARK
Annals of Laboratory Medicine 2024;44(5):450-454
Vancomycin variable Enterococcus (VVE) bacteria are phenotypically susceptible to vancomycin, but they harbor the vanA gene. We aimed to ascertain the prevalence of VVE among clinically isolated vancomycin-susceptible Enterococcus faecium (VSE) isolates, as well as elucidate the molecular characteristics of the vanA gene cluster within these isolates. Notably, we investigated the prevalence and structure of the vanA gene cluster of VVE. Between June 2021 and May 2022, we collected consecutive, non-duplicated vancomycin-susceptible Enterococcus faecium (VSE) samples. Real-time PCR was performed to detect the presence of vanA, vanB, and vanC. Overlapping PCR with sequencing and whole -genome sequencing were performed for structural analysis. Sequence types (STs) were determined by multilocus sequence typing. Exposure testing was performed to assess the ability of the isolates to acquire vancomycin resistance. Among 282 VSE isolates tested, 20 isolates (7.1%) were VVE. Among them, 17 isolates had partial deletions in the IS1216 or IS1542 sequences in vanS (N = 10), vanR (N = 5), or vanH (N = 2). All VVE isolates belonged to the CC17 complex and comprised five STs, namely ST17 (40.0%), ST1421 (25.0%), ST80 (25.0%), ST787 (5.0%), and ST981 (5.0%). Most isolates were related to three hospital-associated clones (ST17, ST1421, and ST80). After vancomycin exposure, 18 of the 20 VVEs acquired vancomycin resistance. Considering the high reversion rate, detecting VVE by screening VSE for vanA is critical for appropriate treatment and infection control.
6.Isoflavone‑enriched soybean leaves (Glycine max) restore loss of dermal collagen fibers induced by ovariectomy in the Sprague Dawley rats
Dae Young YOO ; Cheng‑liang XIE ; Joo Yeon JEONG ; Ki Hun PARK ; Sang Soo KANG ; Dong Hoon LEE
Laboratory Animal Research 2024;40(1):115-120
Phytoestrogens, such as isoflavones, are known for their capacity to simulate various physiological impacts of estro‑ gen in the human body. Our research evaluated the effects of isoflavone-enriched soybean leaves (IESL) on collagen fiber loss prompted by ovariectomy in Sprague Dawley (SD) rats, thereby simulating menopausal changes in women.IESL, bolstered with an increased concentration of isoflavones through a metabolite farming process, contained a significantly higher amount of isoflavones than regular soybean leaves. Our results indicate that the administration of IESL can counteract the decrease in relative optical density and dermal thickness of collagen fibers caused by ova‑ riectomy in SD rats, with more pronounced effects observed at higher isoflavone dosages. These outcomes suggest that soybean leaves rich in isoflavones may hold potential benefits in combating collagen degradation and skin aging symptoms related to menopause. Further research is needed to fully understand the exact molecular pathways at play and the potential clinical relevance of these findings.
7.Serologic Biomarkers for Hepatic Fibrosis in Obese Children with Nonalcoholic Steatohepatitis
Jung Yeon JOO ; In Hyuk YOO ; Hye Ran YANG
Pediatric Gastroenterology, Hepatology & Nutrition 2024;27(4):236-245
Purpose:
The prevalence of nonalcoholic steatohepatitis (NASH) is increasing with the increasing prevalence of childhood obesity. Although NASH has a high risk of progression to liver fibrosis and cirrhosis, few studies have reported noninvasive markers for predicting hepatic fibrosis in children. This study aimed to evaluate and compare the diagnostic accuracies of serologic biomarkers and scoring systems for hepatic fibrosis in obese children with NASH.
Methods:
A total of 96 children were diagnosed with NASH based on liver biopsy findings and divided into two groups according to the degree of liver fibrosis: mild (stage 0–1) or advanced (stage 2–4). Clinical and laboratory parameters and serum levels of hyaluronic acid and type IV collagen were measured. The aspartate aminotransferase/platelet ratio index (APRI) and fibrosis-4 (FIB-4) score were calculated.
Results:
Among the noninvasive markers, only serum type IV collagen level and FIB-4 were significantly different between the two groups. The area under the receiver operating curve of each biomarker and scoring system was 0.80 (95% confidence interval [CI]: 0.70–0.90) for type IV collagen at an optimal cutoff of 148 ng/mL (sensitivity 69.8%, specificity 84.6%), followed by 0.69 (95% CI: 0.57–0.83) for APRI, 0.68 (95% CI: 0.56–0.80) for FIB-4, and 0.65 (95% CI: 0.53-0.77) for hyaluronic acid.
Conclusion
Type IV collagen as a single noninvasive serologic biomarker for hepatic fibrosis and FIB-4 as a hepatic fibrosis score are beneficial in predicting advanced hepatic fibrosis and determining proper diagnosis and treatment strategies before fibrosis progresses in obese children with NASH.
8.Inflammatory Cytokines and Cognition in Alzheimer’s Disease and Its Prodrome
Su Jeong SEONG ; Ki Woong KIM ; Joo Yun SONG ; Kee Jeong PARK ; Young Tak JO ; Jae Hyun HAN ; Ka Hee YOO ; Hyun Jun JO ; Jae Yeon HWANG
Psychiatry Investigation 2024;21(10):1054-1064
Objective:
The aim of this study was to investigate the association between blood levels of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) and cognitive impairments among elderly individuals.
Methods:
Peripheral concentration of TNF-α and IL-6 were measured in all subjects. To assess individual cognitive function, the Consortium to Establish a Registry for Alzheimer’s Disease Neuropsychological Assessment Battery (CERAD-NP) was used, and standardized scores (z-scores) were calculated for each test. Cytokine levels were compared between the diagnostic groups, and correlations between blood inflammatory factor levels and z-scores were analyzed.
Results:
The 37 participants included 8 patients with Alzheimer’s disease (AD), 15 subjects with mild cognitive impairment (MCI), and 14 cognitively healthy controls. TNF-α and IL-6 levels were higher in patients with AD than in healthy controls. TNF-α levels were higher in the AD group than in the MCI group. However, after adjusting for age, the associations between diagnosis and TNF-α and IL-6 were not significant. The higher the plasma IL-6 level, the lower the z-scores on the Boston Naming Test, Word List Learning, Word List Recognition, and Constructional Recall. The higher the serum TNF-α level, the lower the z-scores on the Word List Learning and Constructional Recall. Negative correlation between serum TNF-α level and the z-score on Word List Learning remained significant when age was adjusted.
Conclusion
The difference in the blood levels of TNF-α and IL-6 between the diagnostic groups may be associated with aging. However, elevated TNF-α levels were associated with worse immediate memory performance, even after adjusting for age.
9.Evidence-based clinical recommendations for hypofractionated radiotherapy: exploring efficacy and safety - Part 2. Lung (non-small cell lung cancer)
Yoo-Kang KWAK ; Kyung Su KIM ; Gyu Sang YOO ; Hwa Kyung BYUN ; Yeon Joo KIM ; Yeon-Sil KIM ; Soo-Yoon SUNG ; Jin Ho SONG ; Byoung Hyuck KIM
Radiation Oncology Journal 2024;42(2):104-115
Several recent studies have investigated the use of hypofractionated radiotherapy (HFRT) for various cancers. However, HFRT for non-small cell lung cancer (NSCLC) with or without concurrent chemotherapy is not yet widely used because of concerns about serious side effects and the lack of evidence for improved treatment results. Investigations of HFRT with concurrent chemotherapy in NSCLC have usually been performed in single-arm studies and with a small number of patients, so there are not yet sufficient data. Therefore, the Korean Society for Radiation Oncology Practice Guidelines Committee planned this review article to summarize the evidence on HFRT so far and provide it to radiation oncology clinicians. In summary, HFRT has demonstrated promising results, and the reviewed data support its feasibility and comparable efficacy for the treatment of locally advanced NSCLC. The incidence and severity of esophageal toxicity have been identified as major concerns, particularly when treating large fraction sizes. Strategies, such as esophagus-sparing techniques, image guidance, and dose constraints, may help mitigate this problem and improve treatment tolerability. Continued research and clinical trials are essential to refine treatment strategies, identify optimal patient selection criteria, and enhance therapeutic outcomes.
10.Evidence-based clinical recommendations for hypofractionated radiotherapy: exploring efficacy and safety - Part 1. Brain and head and neck
Soo-Yoon SUNG ; Jin Ho SONG ; Byoung Hyuck KIM ; Yoo-Kang KWAK ; Kyung Su KIM ; Gyu Sang YOO ; Hwa Kyung BYUN ; Yeon Joo KIM ; Yeon-Sil KIM
Radiation Oncology Journal 2024;42(1):17-31
Advances in radiotherapy (RT) techniques, including intensity-modulated RT and image-guided RT, have allowed hypofractionation, increasing the fraction size over the conventional dose of 1.8–2.0 Gy. Hypofractionation offers advantages such as shorter treatment times, improved compliance, and under specific conditions, particularly in tumors with a low α/β ratio, higher efficacy. It was initially explored for use in RT for prostate cancer and adjuvant RT for breast cancer, and its application has been extended to various other malignancies. Hypofractionated RT (HFRT) may also be effective in patients who are unable to undergo conventional treatment owing to poor performance status, comorbidities, or old age. The treatment of brain tumors with HFRT is relatively common because brain stereotactic radiosurgery has been performed for over two decades. However, re-irradiation of recurrent lesions and treatment of elderly or frail patients are areas under investigation. HFRT for head and neck cancer has not been widely used because of concerns regarding late toxicity. Thus, we aimed to provide a comprehensive summary of the current evidence for HFRT for brain tumors and head and neck cancer and to offer practical recommendations to clinicians faced with the challenge of choosing new treatment options.

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