1.Mock communities to assess biases in nextgeneration sequencing of bacterial species representation
Younjee HWANG ; Ju Yeong KIM ; Se Il KIM ; Ji Yeon SUNG ; Hye Su MOON ; Tai-Soon YONG ; Ki Ho HONG ; Hyukmin LEE ; Dongeun YONG
Annals of Clinical Microbiology 2025;28(1):3-
Background:
The 16S rRNA-targeted next-generation sequencing (NGS) has been widely used as the primary tool for microbiome analysis. However, whether the sequenced microbial diversity absolutely represents the original sample composition remains unclear. This study aimed to evaluate whether 16S rRNA gene-targeted NGS accurately captures bacterial community composition.
Methods:
Mock communities were constructed using equal amounts of DNA from 18 bacterial strains in three formats: genomic DNA, recombinant plasmids, and polymerase chain reaction (PCR) templates. The V3V4 region of the 16S rRNA gene was amplified and sequenced using the Illumina MiSeq.
Results:
Data regression analysis revealed that the recombinant plasmid produced more accurate and precise correlation curve than that by the gDNA and PCR products, with a slope closest to 1 (1.0082) and the highest R² value (0.9975). Despite the same input amount of bacterial DNA, the NGS read distribution varied across all three mock communities. Using multiple regression analysis, we found that the guanine-cytosine (GC) content of the V3V4 region, 16S rRNA gene, size of gDNA, and copy number of 16S rRNA were significantly associated with the NGS output of each bacterial species.
Conclusion
This study demonstrated that recombinant plasmids are the preferred option for quality control and that NGS output is biased owing to certain bacterial characteristics, such as %GC content, gDNA size, and 16S rRNA gene copy number. Further research is required to develop a system that compensates for NGS process biases using mock communities.
2.Evaluation of the physical activity of individuals with spinal cord injury in Korea: a cross-sectional study
Se-Hee PARK ; Na Young LEE ; Jae-Yeon KIM ; Min-Goo LEE
Journal of the Korean Medical Association 2025;68(4):242-252
Purpose:
In Korea, the absence of a modified physical activity (PA) questionnaire specifically tailored for Koreans hinders the accurate assessment of PA among individuals with spinal cord injury (SCI). This study aimed to evaluate PA levels in individuals with SCI using a modified PA questionnaire and to provide insights into their PA patterns in Korea.
Methods:
A self-reported questionnaire was developed by revising and adapting the Korean version of the International Physical Activity Questionnaire (K-IPAQ) during an advisory meeting. Between April and June 2023, 176 individuals with SCI from metropolitan areas in Korea were recruited to assess their weekly PA. PA was quantified in Metabolic Equivalent Task-min/week (MET-min/week) by multiplying the reported PA duration.
Results:
The average PA level among individuals with SCI in Korea was 2,907.2±194.8 MET-min/week. By intensity, high-intensity activities accounted for 2,760.0±280.5 MET-min/week, moderate-intensity activities for 1,148.8±89.0 MET-min/week, and low-intensity activities for 1,869.4±110.3 MET-min/week. Approximately half of the participants met the World Health Organization (WHO) recommendations for PA.
Conclusion
Although Korean individuals with SCI demonstrated higher average PA levels compared to findings from other countries and the WHO recommendations, only about half of the participants met the WHO’s guidelines. These results underscore the need to strengthen efforts to promote PA participation among individuals with SCI.
3.Delayed Diagnosis of Brachial Plexus Injury Due to Vertebral Arteriovenous Fistula Caused by Blunt Trauma
Jin Gee PARK ; Jae Yeon KIM ; Young Sook PARK ; Hyun Jung CHANG ; Eun Sol CHO ; Da Hye KIM ; Jeong Hwan LEE ; Se Jin KIM
Journal of Electrodiagnosis and Neuromuscular Diseases 2025;27(1):18-22
Vertebral arteriovenous fistula (VAVF) is a rare lesion characterized by an abnormal connection between the extracranial vertebral artery and the surrounding venous plexus. It typically arises due to penetrating injury, although it can occasionally result from blunt trauma. Brachial plexus injury (BPI) is also infrequently associated with VAVF. We present a rare case of VAVF caused by blunt trauma, which resulted in BPI. The patient, who had previously sustained a C2 fracture and C2–3 myelopathy from a bicycle accident, presented with new-onset weakness in the right upper extremity. His previous clinical history led to an initial suspicion of either an exacerbation of a pre-existing lesion or a shoulder injury. However, electromyography indicated that the weakness was due to BPI. Further evaluations later revealed VAVF to be the primary cause of the BPI. VAVF must be recognized as a rare potential reason for BPI, as timely intervention is essential for improving patient recovery and prognosis.
4.Mock communities to assess biases in nextgeneration sequencing of bacterial species representation
Younjee HWANG ; Ju Yeong KIM ; Se Il KIM ; Ji Yeon SUNG ; Hye Su MOON ; Tai-Soon YONG ; Ki Ho HONG ; Hyukmin LEE ; Dongeun YONG
Annals of Clinical Microbiology 2025;28(1):3-
Background:
The 16S rRNA-targeted next-generation sequencing (NGS) has been widely used as the primary tool for microbiome analysis. However, whether the sequenced microbial diversity absolutely represents the original sample composition remains unclear. This study aimed to evaluate whether 16S rRNA gene-targeted NGS accurately captures bacterial community composition.
Methods:
Mock communities were constructed using equal amounts of DNA from 18 bacterial strains in three formats: genomic DNA, recombinant plasmids, and polymerase chain reaction (PCR) templates. The V3V4 region of the 16S rRNA gene was amplified and sequenced using the Illumina MiSeq.
Results:
Data regression analysis revealed that the recombinant plasmid produced more accurate and precise correlation curve than that by the gDNA and PCR products, with a slope closest to 1 (1.0082) and the highest R² value (0.9975). Despite the same input amount of bacterial DNA, the NGS read distribution varied across all three mock communities. Using multiple regression analysis, we found that the guanine-cytosine (GC) content of the V3V4 region, 16S rRNA gene, size of gDNA, and copy number of 16S rRNA were significantly associated with the NGS output of each bacterial species.
Conclusion
This study demonstrated that recombinant plasmids are the preferred option for quality control and that NGS output is biased owing to certain bacterial characteristics, such as %GC content, gDNA size, and 16S rRNA gene copy number. Further research is required to develop a system that compensates for NGS process biases using mock communities.
5.Mock communities to assess biases in nextgeneration sequencing of bacterial species representation
Younjee HWANG ; Ju Yeong KIM ; Se Il KIM ; Ji Yeon SUNG ; Hye Su MOON ; Tai-Soon YONG ; Ki Ho HONG ; Hyukmin LEE ; Dongeun YONG
Annals of Clinical Microbiology 2025;28(1):3-
Background:
The 16S rRNA-targeted next-generation sequencing (NGS) has been widely used as the primary tool for microbiome analysis. However, whether the sequenced microbial diversity absolutely represents the original sample composition remains unclear. This study aimed to evaluate whether 16S rRNA gene-targeted NGS accurately captures bacterial community composition.
Methods:
Mock communities were constructed using equal amounts of DNA from 18 bacterial strains in three formats: genomic DNA, recombinant plasmids, and polymerase chain reaction (PCR) templates. The V3V4 region of the 16S rRNA gene was amplified and sequenced using the Illumina MiSeq.
Results:
Data regression analysis revealed that the recombinant plasmid produced more accurate and precise correlation curve than that by the gDNA and PCR products, with a slope closest to 1 (1.0082) and the highest R² value (0.9975). Despite the same input amount of bacterial DNA, the NGS read distribution varied across all three mock communities. Using multiple regression analysis, we found that the guanine-cytosine (GC) content of the V3V4 region, 16S rRNA gene, size of gDNA, and copy number of 16S rRNA were significantly associated with the NGS output of each bacterial species.
Conclusion
This study demonstrated that recombinant plasmids are the preferred option for quality control and that NGS output is biased owing to certain bacterial characteristics, such as %GC content, gDNA size, and 16S rRNA gene copy number. Further research is required to develop a system that compensates for NGS process biases using mock communities.
6.Evaluation of the physical activity of individuals with spinal cord injury in Korea: a cross-sectional study
Se-Hee PARK ; Na Young LEE ; Jae-Yeon KIM ; Min-Goo LEE
Journal of the Korean Medical Association 2025;68(4):242-252
Purpose:
In Korea, the absence of a modified physical activity (PA) questionnaire specifically tailored for Koreans hinders the accurate assessment of PA among individuals with spinal cord injury (SCI). This study aimed to evaluate PA levels in individuals with SCI using a modified PA questionnaire and to provide insights into their PA patterns in Korea.
Methods:
A self-reported questionnaire was developed by revising and adapting the Korean version of the International Physical Activity Questionnaire (K-IPAQ) during an advisory meeting. Between April and June 2023, 176 individuals with SCI from metropolitan areas in Korea were recruited to assess their weekly PA. PA was quantified in Metabolic Equivalent Task-min/week (MET-min/week) by multiplying the reported PA duration.
Results:
The average PA level among individuals with SCI in Korea was 2,907.2±194.8 MET-min/week. By intensity, high-intensity activities accounted for 2,760.0±280.5 MET-min/week, moderate-intensity activities for 1,148.8±89.0 MET-min/week, and low-intensity activities for 1,869.4±110.3 MET-min/week. Approximately half of the participants met the World Health Organization (WHO) recommendations for PA.
Conclusion
Although Korean individuals with SCI demonstrated higher average PA levels compared to findings from other countries and the WHO recommendations, only about half of the participants met the WHO’s guidelines. These results underscore the need to strengthen efforts to promote PA participation among individuals with SCI.
7.Mock communities to assess biases in nextgeneration sequencing of bacterial species representation
Younjee HWANG ; Ju Yeong KIM ; Se Il KIM ; Ji Yeon SUNG ; Hye Su MOON ; Tai-Soon YONG ; Ki Ho HONG ; Hyukmin LEE ; Dongeun YONG
Annals of Clinical Microbiology 2025;28(1):3-
Background:
The 16S rRNA-targeted next-generation sequencing (NGS) has been widely used as the primary tool for microbiome analysis. However, whether the sequenced microbial diversity absolutely represents the original sample composition remains unclear. This study aimed to evaluate whether 16S rRNA gene-targeted NGS accurately captures bacterial community composition.
Methods:
Mock communities were constructed using equal amounts of DNA from 18 bacterial strains in three formats: genomic DNA, recombinant plasmids, and polymerase chain reaction (PCR) templates. The V3V4 region of the 16S rRNA gene was amplified and sequenced using the Illumina MiSeq.
Results:
Data regression analysis revealed that the recombinant plasmid produced more accurate and precise correlation curve than that by the gDNA and PCR products, with a slope closest to 1 (1.0082) and the highest R² value (0.9975). Despite the same input amount of bacterial DNA, the NGS read distribution varied across all three mock communities. Using multiple regression analysis, we found that the guanine-cytosine (GC) content of the V3V4 region, 16S rRNA gene, size of gDNA, and copy number of 16S rRNA were significantly associated with the NGS output of each bacterial species.
Conclusion
This study demonstrated that recombinant plasmids are the preferred option for quality control and that NGS output is biased owing to certain bacterial characteristics, such as %GC content, gDNA size, and 16S rRNA gene copy number. Further research is required to develop a system that compensates for NGS process biases using mock communities.
8.Mock communities to assess biases in nextgeneration sequencing of bacterial species representation
Younjee HWANG ; Ju Yeong KIM ; Se Il KIM ; Ji Yeon SUNG ; Hye Su MOON ; Tai-Soon YONG ; Ki Ho HONG ; Hyukmin LEE ; Dongeun YONG
Annals of Clinical Microbiology 2025;28(1):3-
Background:
The 16S rRNA-targeted next-generation sequencing (NGS) has been widely used as the primary tool for microbiome analysis. However, whether the sequenced microbial diversity absolutely represents the original sample composition remains unclear. This study aimed to evaluate whether 16S rRNA gene-targeted NGS accurately captures bacterial community composition.
Methods:
Mock communities were constructed using equal amounts of DNA from 18 bacterial strains in three formats: genomic DNA, recombinant plasmids, and polymerase chain reaction (PCR) templates. The V3V4 region of the 16S rRNA gene was amplified and sequenced using the Illumina MiSeq.
Results:
Data regression analysis revealed that the recombinant plasmid produced more accurate and precise correlation curve than that by the gDNA and PCR products, with a slope closest to 1 (1.0082) and the highest R² value (0.9975). Despite the same input amount of bacterial DNA, the NGS read distribution varied across all three mock communities. Using multiple regression analysis, we found that the guanine-cytosine (GC) content of the V3V4 region, 16S rRNA gene, size of gDNA, and copy number of 16S rRNA were significantly associated with the NGS output of each bacterial species.
Conclusion
This study demonstrated that recombinant plasmids are the preferred option for quality control and that NGS output is biased owing to certain bacterial characteristics, such as %GC content, gDNA size, and 16S rRNA gene copy number. Further research is required to develop a system that compensates for NGS process biases using mock communities.
9.Evaluation of the physical activity of individuals with spinal cord injury in Korea: a cross-sectional study
Se-Hee PARK ; Na Young LEE ; Jae-Yeon KIM ; Min-Goo LEE
Journal of the Korean Medical Association 2025;68(4):242-252
Purpose:
In Korea, the absence of a modified physical activity (PA) questionnaire specifically tailored for Koreans hinders the accurate assessment of PA among individuals with spinal cord injury (SCI). This study aimed to evaluate PA levels in individuals with SCI using a modified PA questionnaire and to provide insights into their PA patterns in Korea.
Methods:
A self-reported questionnaire was developed by revising and adapting the Korean version of the International Physical Activity Questionnaire (K-IPAQ) during an advisory meeting. Between April and June 2023, 176 individuals with SCI from metropolitan areas in Korea were recruited to assess their weekly PA. PA was quantified in Metabolic Equivalent Task-min/week (MET-min/week) by multiplying the reported PA duration.
Results:
The average PA level among individuals with SCI in Korea was 2,907.2±194.8 MET-min/week. By intensity, high-intensity activities accounted for 2,760.0±280.5 MET-min/week, moderate-intensity activities for 1,148.8±89.0 MET-min/week, and low-intensity activities for 1,869.4±110.3 MET-min/week. Approximately half of the participants met the World Health Organization (WHO) recommendations for PA.
Conclusion
Although Korean individuals with SCI demonstrated higher average PA levels compared to findings from other countries and the WHO recommendations, only about half of the participants met the WHO’s guidelines. These results underscore the need to strengthen efforts to promote PA participation among individuals with SCI.
10.The Moderating Effect of Resilience on the Relationship Between the Relevance to Victims With Post-Trauma Psychiatric Symptoms of Community Residents After Seoul Halloween Crowd Crush
Se Youl KIM ; Sra JUNG ; Mi Yeon LEE ; Kang-Seob OH ; Young-Chul SHIN ; Dong-Won SHIN ; Junhyung KIM ; Eun Soo KIM ; Sun Wook JUNG ; Kwang-yeol LEE ; Nahyun OH ; Sung Joon CHO ; Sang-Won JEON
Psychiatry Investigation 2024;21(11):1183-1192
Objective:
This study aimed to examine the psychiatric impact of the Seoul Halloween crowd crush on individuals related to the victims compared to the general population. It also explores the moderating effect of resilience on the relationship between trauma exposure and psychiatric symptoms.
Methods:
In total, 2,220 participants completed various post-incident questionnaires (Patient Health Questionnaire-9, Generalized Anxiety Disorder-7, Hwa-byung symptom scale, post-traumatic stress disorder checklist for DSM-5, and Brief Resilience Scale) 30 days after the incident. Moderation analyses were conducted using the PROCESS macro in the statistical package for the social sciences.
Results:
Individuals related to the victims exhibited higher symptom severity and a greater risk for clinically significant levels of depression, anxiety, anger, and post-traumatic stress disorder (PTSD) (odds ratio=3.28, 3.33, 1.51, and 4.39 respectively). The impact of relevance to victims on anxiety and PTSD symptoms was moderated by resilience, with a stronger effect observed for individuals with low resilience (β=3.51, 95% confidence interval [CI] 2.78–4.24 for anxiety and β=14.53, 95% CI 12.43–16.63 for PTSD) than for those with high resilience (β=1.69, 95% CI 0.72–2.65 for anxiety and β=8.33, 95% CI 5.56–11.09 for PTSD).
Conclusion
When related to the victims, it was found that not only PTSD, but also depression, anxiety, and anger could intensify. Resilience emerged as a potential buffer against these adverse effects, emphasizing its significance in mitigating the psychiatric impact of community trauma.

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