1.Combination of Aβ40, Aβ42, and Tau Plasma Levels to Distinguish Amyloid-PET Positive Alzheimer Patients from Normal Controls
Seungyeop BAEK ; Jinny Claire LEE ; Byung Hyun BYUN ; Su Yeon PARK ; Jeong Ho HA ; Kyo Chul LEE ; Seung-Hoon YANG ; Jun-Seok LEE ; Seungpyo HONG ; Gyoonhee HAN ; Sang Moo LIM ; YoungSoo KIM ; Hye Yun KIM
Experimental Neurobiology 2025;34(1):1-8
Alzheimer disease (AD) diagnosis is confirmed using a medley of modalities, such as the detection of amyloid-β (Aβ) neuritic plaques and neurofibrillary tangles with positron electron tomography (PET) or the appraisal of irregularities in cognitive function with examinations. Although these methods have been efficient in confirming AD pathology, the rising demand for earlier intervention during pathogenesis has led researchers to explore the diagnostic potential of fluid biomarkers in cerebrospinal fluid (CSF) and plasma. Since CSF sample collection is invasive and limited in quantity, biomarker detection in plasma has become more attractive and modern advancements in technology has permitted more efficient and accurate analysis of plasma biomolecules. In this study, we found that a composite of standard factors, Aβ40 and total tau levels in plasma, divided by the variation factor, plasma Aβ42 level, provide better correlation with amyloid neuroimaging and neuropsychological test results than a level comparison between total tau and Aβ42 in plasma. We collected EDTA-treated blood plasma samples of 53 subjects, of randomly selected 27 AD patients and 26 normal cognition (NC) individuals, who received amyloid-PET scans for plaque quantification, and measured plasma levels of Aβ40, Aβ42, and total tau with digital enzyme-linked immunosorbent assay (ELISA) in a blinded manner. There was difficulty distinguishing AD patients from controls when analyzing biomarkers independently. However, significant differentiation was observed between the two groups when comparing individual ratios of total-tau×Aβ40/Aβ42. Our results indicate that collectively comparing fluctuations of these fluid biomarkers could aid in monitoring AD pathogenesis.
2.Korean Practice Guidelines for Gastric Cancer 2024: An Evidence-based, Multidisciplinary Approach (Update of 2022 Guideline)
In-Ho KIM ; Seung Joo KANG ; Wonyoung CHOI ; An Na SEO ; Bang Wool EOM ; Beodeul KANG ; Bum Jun KIM ; Byung-Hoon MIN ; Chung Hyun TAE ; Chang In CHOI ; Choong-kun LEE ; Ho Jung AN ; Hwa Kyung BYUN ; Hyeon-Su IM ; Hyung-Don KIM ; Jang Ho CHO ; Kyoungjune PAK ; Jae-Joon KIM ; Jae Seok BAE ; Jeong Il YU ; Jeong Won LEE ; Jungyoon CHOI ; Jwa Hoon KIM ; Miyoung CHOI ; Mi Ran JUNG ; Nieun SEO ; Sang Soo EOM ; Soomin AHN ; Soo Jin KIM ; Sung Hak LEE ; Sung Hee LIM ; Tae-Han KIM ; Hye Sook HAN ; On behalf of The Development Working Group for the Korean Practice Guideline for Gastric Cancer 2024
Journal of Gastric Cancer 2025;25(1):5-114
Gastric cancer is one of the most common cancers in both Korea and worldwide. Since 2004, the Korean Practice Guidelines for Gastric Cancer have been regularly updated, with the 4th edition published in 2022. The 4th edition was the result of a collaborative work by an interdisciplinary team, including experts in gastric surgery, gastroenterology, endoscopy, medical oncology, abdominal radiology, pathology, nuclear medicine, radiation oncology, and guideline development methodology. The current guideline is the 5th version, an updated version of the 4th edition. In this guideline, 6 key questions (KQs) were updated or proposed after a collaborative review by the working group, and 7 statements were developed, or revised, or discussed based on a systematic review using the MEDLINE, Embase, Cochrane Library, and KoreaMed database. Over the past 2 years, there have been significant changes in systemic treatment, leading to major updates and revisions focused on this area.Additionally, minor modifications have been made in other sections, incorporating recent research findings. The level of evidence and grading of recommendations were categorized according to the Grading of Recommendations, Assessment, Development and Evaluation system. Key factors for recommendation included the level of evidence, benefit, harm, and clinical applicability. The working group reviewed and discussed the recommendations to reach a consensus. The structure of this guideline remains similar to the 2022 version.Earlier sections cover general considerations, such as screening, diagnosis, and staging of endoscopy, pathology, radiology, and nuclear medicine. In the latter sections, statements are provided for each KQ based on clinical evidence, with flowcharts supporting these statements through meta-analysis and references. This multidisciplinary, evidence-based gastric cancer guideline aims to support clinicians in providing optimal care for gastric cancer patients.
3.Optimizing extraction of microbial DNA from urine: Advancing urinary microbiome research in bladder cancer
Chuang-Ming ZHENG ; Ho Won KANG ; Seongmin MOON ; Young Joon BYUN ; Won Tae KIM ; Yung Hyun CHOI ; Sung-Kwon MOON ; Xuan-Mei PIAO ; Seok Joong YUN
Investigative and Clinical Urology 2025;66(3):272-280
Purpose:
This study aimed to evaluate and optimize microbial DNA extraction methods from urine, a non-invasive sample source, to enhance DNA quality, purity, and reliability for urinary microbiome research and biomarker discovery in bladder cancer.
Materials and Methods:
A total of 302 individuals (258 with genitourinary cancers and 44 with benign urologic diseases) participated in this study. Urine samples were collected via sterile catheterization, resulting in 445 vials for microbial analysis. DNA extraction was performed using three protocols: the standard protocol (SP), water dilution protocol (WDP), and chelation-assisted protocol (CAP). DNA quality (concentration, purity, and contamination levels) was assessed using NanoDrop spectrophotometry.Microbial analysis was conducted on 138 samples (108 cancerous and 30 benign) using 16S rRNA sequencing. Prior to sequencing on the Illumina MiSeq platform, Victor 3 fluorometry was used for validation.
Results:
WDP outperformed other methods, achieving significantly higher 260/280 and 260/230 ratios, indicating superior DNA purity and reduced contamination, while maintaining reliable DNA yields. CAP was excluded due to poor performance across all metrics. Microbial abundance was significantly higher in WDP-extracted samples (p<0.0001), whereas SP demonstrated higher alpha diversity indices (p<0.01), likely due to improved detection of low-abundance taxa. Beta diversity analysis showed no significant compositional differences between SP and WDP (p=1.0), supporting the reliability of WDP for microbiome research.
Conclusions
WDP is a highly effective and reliable method for microbial DNA extraction from urine, ensuring high-quality and reproducible results. Future research should address sample variability and crystal precipitation to further refine microbiome-based diagnostics and therapeutics.
4.Combination of Aβ40, Aβ42, and Tau Plasma Levels to Distinguish Amyloid-PET Positive Alzheimer Patients from Normal Controls
Seungyeop BAEK ; Jinny Claire LEE ; Byung Hyun BYUN ; Su Yeon PARK ; Jeong Ho HA ; Kyo Chul LEE ; Seung-Hoon YANG ; Jun-Seok LEE ; Seungpyo HONG ; Gyoonhee HAN ; Sang Moo LIM ; YoungSoo KIM ; Hye Yun KIM
Experimental Neurobiology 2025;34(1):1-8
Alzheimer disease (AD) diagnosis is confirmed using a medley of modalities, such as the detection of amyloid-β (Aβ) neuritic plaques and neurofibrillary tangles with positron electron tomography (PET) or the appraisal of irregularities in cognitive function with examinations. Although these methods have been efficient in confirming AD pathology, the rising demand for earlier intervention during pathogenesis has led researchers to explore the diagnostic potential of fluid biomarkers in cerebrospinal fluid (CSF) and plasma. Since CSF sample collection is invasive and limited in quantity, biomarker detection in plasma has become more attractive and modern advancements in technology has permitted more efficient and accurate analysis of plasma biomolecules. In this study, we found that a composite of standard factors, Aβ40 and total tau levels in plasma, divided by the variation factor, plasma Aβ42 level, provide better correlation with amyloid neuroimaging and neuropsychological test results than a level comparison between total tau and Aβ42 in plasma. We collected EDTA-treated blood plasma samples of 53 subjects, of randomly selected 27 AD patients and 26 normal cognition (NC) individuals, who received amyloid-PET scans for plaque quantification, and measured plasma levels of Aβ40, Aβ42, and total tau with digital enzyme-linked immunosorbent assay (ELISA) in a blinded manner. There was difficulty distinguishing AD patients from controls when analyzing biomarkers independently. However, significant differentiation was observed between the two groups when comparing individual ratios of total-tau×Aβ40/Aβ42. Our results indicate that collectively comparing fluctuations of these fluid biomarkers could aid in monitoring AD pathogenesis.
5.Combination of Aβ40, Aβ42, and Tau Plasma Levels to Distinguish Amyloid-PET Positive Alzheimer Patients from Normal Controls
Seungyeop BAEK ; Jinny Claire LEE ; Byung Hyun BYUN ; Su Yeon PARK ; Jeong Ho HA ; Kyo Chul LEE ; Seung-Hoon YANG ; Jun-Seok LEE ; Seungpyo HONG ; Gyoonhee HAN ; Sang Moo LIM ; YoungSoo KIM ; Hye Yun KIM
Experimental Neurobiology 2025;34(1):1-8
Alzheimer disease (AD) diagnosis is confirmed using a medley of modalities, such as the detection of amyloid-β (Aβ) neuritic plaques and neurofibrillary tangles with positron electron tomography (PET) or the appraisal of irregularities in cognitive function with examinations. Although these methods have been efficient in confirming AD pathology, the rising demand for earlier intervention during pathogenesis has led researchers to explore the diagnostic potential of fluid biomarkers in cerebrospinal fluid (CSF) and plasma. Since CSF sample collection is invasive and limited in quantity, biomarker detection in plasma has become more attractive and modern advancements in technology has permitted more efficient and accurate analysis of plasma biomolecules. In this study, we found that a composite of standard factors, Aβ40 and total tau levels in plasma, divided by the variation factor, plasma Aβ42 level, provide better correlation with amyloid neuroimaging and neuropsychological test results than a level comparison between total tau and Aβ42 in plasma. We collected EDTA-treated blood plasma samples of 53 subjects, of randomly selected 27 AD patients and 26 normal cognition (NC) individuals, who received amyloid-PET scans for plaque quantification, and measured plasma levels of Aβ40, Aβ42, and total tau with digital enzyme-linked immunosorbent assay (ELISA) in a blinded manner. There was difficulty distinguishing AD patients from controls when analyzing biomarkers independently. However, significant differentiation was observed between the two groups when comparing individual ratios of total-tau×Aβ40/Aβ42. Our results indicate that collectively comparing fluctuations of these fluid biomarkers could aid in monitoring AD pathogenesis.
6.Korean Practice Guidelines for Gastric Cancer 2024: An Evidence-based, Multidisciplinary Approach (Update of 2022 Guideline)
In-Ho KIM ; Seung Joo KANG ; Wonyoung CHOI ; An Na SEO ; Bang Wool EOM ; Beodeul KANG ; Bum Jun KIM ; Byung-Hoon MIN ; Chung Hyun TAE ; Chang In CHOI ; Choong-kun LEE ; Ho Jung AN ; Hwa Kyung BYUN ; Hyeon-Su IM ; Hyung-Don KIM ; Jang Ho CHO ; Kyoungjune PAK ; Jae-Joon KIM ; Jae Seok BAE ; Jeong Il YU ; Jeong Won LEE ; Jungyoon CHOI ; Jwa Hoon KIM ; Miyoung CHOI ; Mi Ran JUNG ; Nieun SEO ; Sang Soo EOM ; Soomin AHN ; Soo Jin KIM ; Sung Hak LEE ; Sung Hee LIM ; Tae-Han KIM ; Hye Sook HAN ; On behalf of The Development Working Group for the Korean Practice Guideline for Gastric Cancer 2024
Journal of Gastric Cancer 2025;25(1):5-114
Gastric cancer is one of the most common cancers in both Korea and worldwide. Since 2004, the Korean Practice Guidelines for Gastric Cancer have been regularly updated, with the 4th edition published in 2022. The 4th edition was the result of a collaborative work by an interdisciplinary team, including experts in gastric surgery, gastroenterology, endoscopy, medical oncology, abdominal radiology, pathology, nuclear medicine, radiation oncology, and guideline development methodology. The current guideline is the 5th version, an updated version of the 4th edition. In this guideline, 6 key questions (KQs) were updated or proposed after a collaborative review by the working group, and 7 statements were developed, or revised, or discussed based on a systematic review using the MEDLINE, Embase, Cochrane Library, and KoreaMed database. Over the past 2 years, there have been significant changes in systemic treatment, leading to major updates and revisions focused on this area.Additionally, minor modifications have been made in other sections, incorporating recent research findings. The level of evidence and grading of recommendations were categorized according to the Grading of Recommendations, Assessment, Development and Evaluation system. Key factors for recommendation included the level of evidence, benefit, harm, and clinical applicability. The working group reviewed and discussed the recommendations to reach a consensus. The structure of this guideline remains similar to the 2022 version.Earlier sections cover general considerations, such as screening, diagnosis, and staging of endoscopy, pathology, radiology, and nuclear medicine. In the latter sections, statements are provided for each KQ based on clinical evidence, with flowcharts supporting these statements through meta-analysis and references. This multidisciplinary, evidence-based gastric cancer guideline aims to support clinicians in providing optimal care for gastric cancer patients.
7.Combination of Aβ40, Aβ42, and Tau Plasma Levels to Distinguish Amyloid-PET Positive Alzheimer Patients from Normal Controls
Seungyeop BAEK ; Jinny Claire LEE ; Byung Hyun BYUN ; Su Yeon PARK ; Jeong Ho HA ; Kyo Chul LEE ; Seung-Hoon YANG ; Jun-Seok LEE ; Seungpyo HONG ; Gyoonhee HAN ; Sang Moo LIM ; YoungSoo KIM ; Hye Yun KIM
Experimental Neurobiology 2025;34(1):1-8
Alzheimer disease (AD) diagnosis is confirmed using a medley of modalities, such as the detection of amyloid-β (Aβ) neuritic plaques and neurofibrillary tangles with positron electron tomography (PET) or the appraisal of irregularities in cognitive function with examinations. Although these methods have been efficient in confirming AD pathology, the rising demand for earlier intervention during pathogenesis has led researchers to explore the diagnostic potential of fluid biomarkers in cerebrospinal fluid (CSF) and plasma. Since CSF sample collection is invasive and limited in quantity, biomarker detection in plasma has become more attractive and modern advancements in technology has permitted more efficient and accurate analysis of plasma biomolecules. In this study, we found that a composite of standard factors, Aβ40 and total tau levels in plasma, divided by the variation factor, plasma Aβ42 level, provide better correlation with amyloid neuroimaging and neuropsychological test results than a level comparison between total tau and Aβ42 in plasma. We collected EDTA-treated blood plasma samples of 53 subjects, of randomly selected 27 AD patients and 26 normal cognition (NC) individuals, who received amyloid-PET scans for plaque quantification, and measured plasma levels of Aβ40, Aβ42, and total tau with digital enzyme-linked immunosorbent assay (ELISA) in a blinded manner. There was difficulty distinguishing AD patients from controls when analyzing biomarkers independently. However, significant differentiation was observed between the two groups when comparing individual ratios of total-tau×Aβ40/Aβ42. Our results indicate that collectively comparing fluctuations of these fluid biomarkers could aid in monitoring AD pathogenesis.
8.Korean Practice Guidelines for Gastric Cancer 2024: An Evidence-based, Multidisciplinary Approach (Update of 2022 Guideline)
In-Ho KIM ; Seung Joo KANG ; Wonyoung CHOI ; An Na SEO ; Bang Wool EOM ; Beodeul KANG ; Bum Jun KIM ; Byung-Hoon MIN ; Chung Hyun TAE ; Chang In CHOI ; Choong-kun LEE ; Ho Jung AN ; Hwa Kyung BYUN ; Hyeon-Su IM ; Hyung-Don KIM ; Jang Ho CHO ; Kyoungjune PAK ; Jae-Joon KIM ; Jae Seok BAE ; Jeong Il YU ; Jeong Won LEE ; Jungyoon CHOI ; Jwa Hoon KIM ; Miyoung CHOI ; Mi Ran JUNG ; Nieun SEO ; Sang Soo EOM ; Soomin AHN ; Soo Jin KIM ; Sung Hak LEE ; Sung Hee LIM ; Tae-Han KIM ; Hye Sook HAN ; On behalf of The Development Working Group for the Korean Practice Guideline for Gastric Cancer 2024
Journal of Gastric Cancer 2025;25(1):5-114
Gastric cancer is one of the most common cancers in both Korea and worldwide. Since 2004, the Korean Practice Guidelines for Gastric Cancer have been regularly updated, with the 4th edition published in 2022. The 4th edition was the result of a collaborative work by an interdisciplinary team, including experts in gastric surgery, gastroenterology, endoscopy, medical oncology, abdominal radiology, pathology, nuclear medicine, radiation oncology, and guideline development methodology. The current guideline is the 5th version, an updated version of the 4th edition. In this guideline, 6 key questions (KQs) were updated or proposed after a collaborative review by the working group, and 7 statements were developed, or revised, or discussed based on a systematic review using the MEDLINE, Embase, Cochrane Library, and KoreaMed database. Over the past 2 years, there have been significant changes in systemic treatment, leading to major updates and revisions focused on this area.Additionally, minor modifications have been made in other sections, incorporating recent research findings. The level of evidence and grading of recommendations were categorized according to the Grading of Recommendations, Assessment, Development and Evaluation system. Key factors for recommendation included the level of evidence, benefit, harm, and clinical applicability. The working group reviewed and discussed the recommendations to reach a consensus. The structure of this guideline remains similar to the 2022 version.Earlier sections cover general considerations, such as screening, diagnosis, and staging of endoscopy, pathology, radiology, and nuclear medicine. In the latter sections, statements are provided for each KQ based on clinical evidence, with flowcharts supporting these statements through meta-analysis and references. This multidisciplinary, evidence-based gastric cancer guideline aims to support clinicians in providing optimal care for gastric cancer patients.
9.COL6A1 expression as a potential prognostic biomarker for risk stratification of T1 high grade bladder cancer: Unveiling the aggressive nature of a distinct non-muscle invasive subtype
Kyeong KIM ; Young Joon BYUN ; Chuang-Ming ZHENG ; Sungmin MOON ; Soo Jeong JO ; Ho Won KANG ; Won Tae KIM ; Yung Hyun CHOI ; Sung-Kwon MOON ; Wun-Jae KIM ; Xuan-Mei PIAO ; Seok Joong YUN
Investigative and Clinical Urology 2024;65(1):94-103
Purpose:
T1 high grade (T1HG) bladder cancer (BC) is a type of non-muscle invasive BC (NMIBC) that is recognized as an aggressive subtype with a heightened propensity for progression. Current risk stratification methods for NMIBC rely on clinicopathological indicators; however, these approaches do not adequately capture the aggressive nature of T1HG BC. Thus, new, more accurate biomarkers for T1HG risk stratification are needed. Here, we enrolled three different patient cohorts and investigated expression of collagen type VI alpha 1 (COL6A1), a key component of the extracellular matrix, at different stages and grades of BC, with a specific focus on T1HG BC.
Materials and Methods:
Samples from 298 BC patients were subjected to RNA sequencing and real-time polymerase chain reaction.
Results:
We found that T1HG BC and muscle invasive BC (MIBC) exhibited comparable expression of COL6A1, which was significantly higher than that by other NMIBC subtypes. In particular, T1HG patients who later progressed to MIBC had considerably higher expression of COL6A1 than Ta, T1 low grade patients, and patients that did not progress, highlighting the aggressive nature and higher risk of progression associated with T1HG BC. Moreover, Cox and Kaplan–Meier survival analyses revealed a significant association between elevated expression of COL6A1 and poor progression-free survival of T1HG BC patients (multivariate Cox hazard ratio, 16.812; 95% confidence interval, 3.283–86.095; p=0.001 and p=0.0002 [log-rank test]).
Conclusions
These findings suggest that COL6A1 may be a promising biomarker for risk stratification of T1HG BC, offering valuable insight into disease prognosis and guidance of personalized treatment decisions.
10.Colletotrichum Jasminigenum-induced Infectious Sclerokeratitis: A Case Report
In Seok JEONG ; Woong Sun YOO ; In Young CHUNG ; Seong Wook SEO ; Jung Hyun BYUN ; Seong Jae KIM
Journal of the Korean Ophthalmological Society 2024;65(5):337-341
Purpose:
We present a case of Colletotrichum jasminigenum (C. jasminigenum)-induced Infectious sclerokeratitis.Case summary: An 81-year-old patient presented to our hospital with left eye pain and decreased vision that had started 7 days prior. He had a history of left eye pterygium excision a decade earlier. Examination using a slit lamp revealed a nasal conjunctival defect, scleral melting, deep stromal infiltration with a feathery margin, and hypopyon. Considering the suspicion of fungal sclerokeratitis, we performed a smear analysis and potassium hydroxide (KOH) and culture testing. The KOH test revealed hyphae, leading to systemic fluconazole and topical fluconazole and natamycin. Subsequently, we performed surgery, including debridement of the necrotic scleral area, conjunctival rotation and scleral grafting, and anterior chamber irrigation with intracameral and intravitreal voriconazole injections, due to progressive corneal infiltration and scleral melting. Additionally, we switched to using systemic and topical voriconazole. The culture yielded fungi, with DNA sequencing confirming C. jasminigenum as the causative agent. Following treatment, the lesion improved, and no signs of recurrence were observed.
Conclusions
Voriconazole is an effective treatment for C. jasminigenum-induced fungal sclerokeratitis.

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