1.Stem Cell-Based Approaches in Parkinson’s Disease Research
Min Seong KIM ; Subeen YOON ; Jiwoo CHOI ; Yong Jun KIM ; Gabsang LEE
International Journal of Stem Cells 2025;18(1):21-36
Parkinson’s disease (PD) is a neurodegenerative condition characterized by the loss of midbrain dopaminergic neurons, leading to motor symptoms. While current treatments provide limited relief, they don’t alter disease progression. Stem cell technology, involving patient-specific stem cell-derived neurons, offers a promising avenue for research and personalized regenerative therapies. This article reviews the potential of stem cell-based research in PD, summarizing ongoing efforts, their limitations, and introducing innovative research models. The integration of stem cell technology and advanced models promises to enhance our understanding and treatment strategies for PD.
2.Stem Cell-Based Approaches in Parkinson’s Disease Research
Min Seong KIM ; Subeen YOON ; Jiwoo CHOI ; Yong Jun KIM ; Gabsang LEE
International Journal of Stem Cells 2025;18(1):21-36
Parkinson’s disease (PD) is a neurodegenerative condition characterized by the loss of midbrain dopaminergic neurons, leading to motor symptoms. While current treatments provide limited relief, they don’t alter disease progression. Stem cell technology, involving patient-specific stem cell-derived neurons, offers a promising avenue for research and personalized regenerative therapies. This article reviews the potential of stem cell-based research in PD, summarizing ongoing efforts, their limitations, and introducing innovative research models. The integration of stem cell technology and advanced models promises to enhance our understanding and treatment strategies for PD.
3.Stem Cell-Based Approaches in Parkinson’s Disease Research
Min Seong KIM ; Subeen YOON ; Jiwoo CHOI ; Yong Jun KIM ; Gabsang LEE
International Journal of Stem Cells 2025;18(1):21-36
Parkinson’s disease (PD) is a neurodegenerative condition characterized by the loss of midbrain dopaminergic neurons, leading to motor symptoms. While current treatments provide limited relief, they don’t alter disease progression. Stem cell technology, involving patient-specific stem cell-derived neurons, offers a promising avenue for research and personalized regenerative therapies. This article reviews the potential of stem cell-based research in PD, summarizing ongoing efforts, their limitations, and introducing innovative research models. The integration of stem cell technology and advanced models promises to enhance our understanding and treatment strategies for PD.
4.In Vitro Diagnostics Certification for Creatinine Assays in Korea over 7 Years: Achievements and Future Outlook
Eun-Jung CHO ; Joonsang YU ; Jeayeon RYU ; Jiwoo SEO ; Hyunae LEE ; Chan-Ik CHO ; Tae-Dong JEONG ; Sollip KIM ; Woochang LEE ; Sail CHUN ; Won-Ki MIN
Annals of Laboratory Medicine 2025;45(5):493-502
Background:
An international reference measurement laboratory network for creatinine (Cr) is lacking; therefore, Korea developed an independent evaluation and certification system. The in vitro diagnostics (IVD) certification program, launched in 2017, formed part of a broader Cr standardization initiative intended to enhance accuracy at the manufacturing stage.
Methods:
The program was designed to evaluate analytical systems, including all reagent lots, calibrators, and instrument models, twice annually. Bias, imprecision, total error (TE), and linearity were evaluated based on established acceptance criteria. A post-certification process allows submission for a second challenge and validation of corrective actions.
Results:
Between 2017 and 2023, 489 analytical systems were evaluated. Average acceptance rates for bias, imprecision, TE, and linearity were 70.8%, 95.9%, 87.7%, and 87.8%, respectively. The lowest acceptance rate for bias evaluation was 8.7% for the kinetic Jaffe method without compensation in 2018. Over the 7-year period, the mean absolute percentage bias (absBias%), coefficient of variation (CV), and TE were 4.62%, 1.37%,and 7.29%, respectively. The highest absBias% (7.94%) was observed in the 0.0 ≤ Cr < 1.0target value range. Since 2019, a consistent reduction in absBias% has been observed.
Conclusions
This program is a pioneering response to the absence of a global certification program for Cr assays. It offers significant advantages, including comprehensive evaluations, fee-free participation, and a robust post-certification process. Continuous participation and improvement efforts by manufacturers have contributed to enhanced accuracy in Cr assays.
6.Changes in the importance and performance of low-sodium management among childcare center cooks in Yongin, South Korea, after salinometer support programs: a descriptive study
Jiwoo MIN ; Youngmi LEE ; Yunhee CHANG ; Yujin LEE
Korean Journal of Community Nutrition 2024;29(4):304-317
Objectives:
This study aimed to evaluate the importance and performance of sodium reduction practices among childcare center cooks in the Yongin area before and after a 3-month salinometer support program.
Methods:
In total, 313 cooks employed in childcare centers in Yongin were surveyed before and after participating in a salinometer support program. The survey included questions on general information, sodium-related dietary habits, and perceived importance and performance levels of sodium reduction approaches in the purchasing, cooking, and serving areas. The centers were divided into childcare centers registered as group-feeding facilities (FS group, n = 68) and those not registered as such (non-FS group, n = 245). The differences between the two groups were analyzed.
Results:
The overall importance levels increased significantly after the program in both the FS-group (P < 0.001) and non-FS group (P = 0.005). The overall performance levels also increased significantly in both groups (P < 0.001 for all). Consequently, the significant difference between the importance and performance levels disappeared in both groups after the program. However, unlike the FS group, which showed no significant differences between the importance and performance levels after the program in all three areas, the non-FS group still demonstrated lower performance levels than importance levels in the purchasing (P = 0.011) and serving (P = 0.034) areas after the program.
Conclusions
The use of salinometers significantly enhanced the performance and importance of low-sodium management practices among cooks in childcare centers, especially in the FS group. The continuous monitoring of salinity measurements and tailored education specialized for the FS and non-FS groups are recommended.
7.Association of Myosteatosis with Nonalcoholic Fatty Liver Disease, Severity, and Liver Fibrosis Using Visual Muscular Quality Map in Computed Tomography
Hwi Seung KIM ; Jiwoo LEE ; Eun Hee KIM ; Min Jung LEE ; In Young BAE ; Woo Je LEE ; Joong-Yeol PARK ; Hong-Kyu KIM ; Chang Hee JUNG
Diabetes & Metabolism Journal 2023;47(1):104-117
Background:
The association of myosteatosis measured using visual muscular quality map in computed tomography (CT) with nonalcoholic fatty liver disease (NAFLD), its severity, and fibrosis was analyzed in a large population.
Methods:
Subjects (n=13,452) with abdominal CT between 2012 and 2013 were measured total abdominal muscle area (TAMA) at L3 level. TAMA was segmented into intramuscular adipose tissue and skeletal muscle area (SMA), which was further classified into normal attenuation muscle area (NAMA) and low attenuation muscle area (LAMA). The following variables were adopted as indicators of myosteatosis: SMA/body mass index (BMI), NAMA/BMI, NAMA/TAMA, and LAMA/BMI. NAFLD and its severity were assessed by ultrasonography, and liver fibrosis was measured by calculating the NAFLD fibrosis score (NFS) and fibrosis-4 index (FIB-4) scores.
Results:
According to multiple logistic regression analyses, as quartiles of SMA/BMI, NAMA/BMI, and NAMA/TAMA increased, the odds ratios (ORs) for NAFLD decreased in each sex (P for trend <0.001 for all). The ORs of moderate/severe NAFLD were significantly higher in the Q1 group than in the Q4 group for SMA/BMI, NAMA/BMI, and NAMA/TAMA in men. The ORs of intermediate/high liver fibrosis scores assessed by NFS and FIB-4 scores increased linearly with decreasing quartiles for SMA/BMI, NAMA/BMI, and NAMA/TAMA in each sex (P for trend <0.001 for all). Conversely, the risk for NAFLD and fibrosis were positively associated with LAMA/BMI quartiles in each sex (P for trend <0.001 for all).
Conclusion
A higher proportion of good quality muscle was associated with lower risks of NAFLD and fibrosis.
8.Long-Term Changes in the Mortality Rates of Thyroid Cancer in Korea: Analysis of Korean National Data from 1985 to 2020
Yun Mi CHOI ; Min-Ju KIM ; Jiwoo LEE ; Mi Kyung KWAK ; Min Ji JEON ; Tae Yong KIM ; Eun-Gyoung HONG ; Won Bae KIM ; Won Gu KIM
Endocrinology and Metabolism 2023;38(5):588-595
Background:
Thyroid cancer mortality has been largely overlooked as relatively stable given the large gap between thyroid cancer incidence and mortality. This study evaluated long-term trends in age-standardized mortality rates (ASMRs) throughout Korea and compared them with mortality data reported by the Surveillance, Epidemiology, and End Results (SEER).
Methods:
Cancer-specific mortality data from 1985 to 2020 were obtained from Statistics Korea. ASMRs from thyroid cancer were calculated based on the Korean mid-year resident registration population of 2005. We assessed SEER*Explorer and downloaded the mortality data.
Results:
The ASMR increased from 0.19 to 0.77/100,000 between 1985 and 2002 but decreased continuously to 0.36/100,000 in 2020. The annual percent change (APC) in the ASMR between 1985 and 2003 and between 2003 and 2020 was 6.204 and −4.218, respectively, with similar patterns observed in both men and women. The ASMR of the SEER showed a modest increase from 1988 to 2016 and then stabilized. In subgroup analysis, the ASMR of the old age group (≥55 years) increased significantly from 0.82 in 1985 to 3.92/100,000 in 2002 (APC 6.917) but then decreased again to 1.86/100,000 in 2020 (APC −4.136). ASMRs according to the age group in the SEER showed a relatively stable trend even in the elderly group.
Conclusion
The ASMR of thyroid cancer in Korea had increased from 1985 to 2002 but has since been steadily decreasing. This trend was mainly attributed to elderly people aged 55 or over. The absolute APC value of Korea was much higher than that of the SEER.
9.Recent Changes in the Incidence of Thyroid Cancer in Korea between 2005 and 2018: Analysis of Korean National Data
Yun Mi CHOI ; Jiwoo LEE ; Mi Kyung KWAK ; Min Ji JEON ; Tae Yong KIM ; Eun-Gyoung HONG ; Won Bae KIM ; Won Gu KIM
Endocrinology and Metabolism 2022;37(5):791-799
Background:
In this study, we evaluated the recent changes in the standardized, age-specific, stage-specific incidence rates (IRs) of thyroid cancer in Korea and compared them with the incidence data reported by the Surveillance, Epidemiology, and End Results Program.
Methods:
The analysis was conducted using the incidence data (2005 to 2018) from the Statistics Korea and Korea Central Cancer Registry.
Results:
The age-standardized IR (SIR) of thyroid cancer increased from 24.09 per 100,000 in 2005 to 74.83 in 2012 (annual percent change [APC], 14.5). From 2012 to 2015, the SIR decreased to 42.52 (APC, –17.9) and then remained stable until 2018 (APC, 2.1). This trend was similar in both men and women. Regarding age-specific IRs, the IRs for ages of 30 years and older showed a trend similar to that of the SIR; however, for ages below 30 years, no significant reduction was observed from the vertex of IR in 2015. Regarding stage-specific IRs, the increase was more prominent in those with regional disease (APC, 17.4) than in those with localized disease until 2012; then, the IR decreased until 2015 (APC, –16.1). The average APC from 2005 to 2018 increased in men, those under the age of 30 years, and those with regional disease.
Conclusion
The SIR in Korea peaked in 2012 and decreased until 2015 and then remained stable until 2018. However, in young individuals under the age of 30 years, the IR did not significantly decrease but tended to increase again. In terms of stage-specific IRs, the sharpest increase was seen among those with regional disease.
10.Prognostic Value of Triglyceride and Glucose Index for Incident Type 2 Diabetes beyond Metabolic Health and Obesity
Hwi Seung KIM ; Jiwoo LEE ; Yun Kyung CHO ; Eun Hee KIM ; Min Jung LEE ; Hong-Kyu KIM ; Joong-Yeol PARK ; Woo Je LEE ; Chang Hee JUNG
Endocrinology and Metabolism 2021;36(5):1042-1054
Background:
Metabolically healthy obese (MHO) phenotype is metabolically heterogeneous in terms of type 2 diabetes (T2D). Previously, the triglyceride and glucose (TyG) index has been considered for identifying metabolic health and future risk of T2D. This study aimed to evaluate the risk of incident T2D according to obesity status and metabolic health, categorized by four different criteria and the TyG index.
Methods:
The study included 39,418 Koreans without T2D at baseline. The risk of T2D was evaluated based on four different definitions of metabolic health and obesity status and according to the baseline TyG index within each metabolic health and obesity group.
Results:
During the median follow-up at 38.1 months, 726 individuals developed T2D. Compared with the metabolically healthy non-obese (MHNO) group with low TyG index, the MHO group with high TyG index showed increased risk of T2D in all four definitions of metabolic health with multivariate-adjusted hazard ratios of 2.57 (95% confidence interval [CI], 1.76 to 3.75), 3.72 (95% CI, 2.15 to 6.43), 4.13 (95% CI, 2.67 to 6.38), and 3.05 (95% CI, 2.24 to 4.15), when defined by Adult Treatment Panel III, Wildman, Karelis, and homeostasis model assessment (HOMA) criteria, respectively.
Conclusion
MHO subjects with high TyG index were at an increased risk of developing T2D compared with MHNO subjects, regardless of the definition of metabolic health. TyG index may serve as an additional factor for predicting the individual risk of incident T2D in MHO subjects.

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