1.Optimal tacrolimus levels for reducing CKD risk and the impact of intrapatient variability on CKD and ESRD development following liver transplantation
Soon Kyu LEE ; Ho Joong CHOI ; Young Kyoung YOU ; Pil Soo SUNG ; Seung Kew YOON ; Jeong Won JANG ; Jong Young CHOI
Clinical and Molecular Hepatology 2025;31(1):131-146
Background/Aims:
This study aimed to identify the risk factors for chronic kidney disease (CKD) and end-stage renal disease (ESRD) following liver transplantation (LT), with a specific focus on tacrolimus levels and intrapatient variability (IPV).
Methods:
Among the 1,076 patients who underwent LT between 2000 and 2018, 952 were included in the analysis. The tacrolimus doses and levels were recorded every 3 months, and the IPV was calculated using the coefficient of variability. The cumulative incidence rates of CKD and ESRD were calculated based on baseline kidney function at the time of LT. The impact of tacrolimus levels and their IPV on the development of CKD and ESRD was evaluated, and the significant risk factors were identified.
Results:
Within a median follow-up of 97.3 months, the 5-year cumulative incidence rates of CKD (0.58 vs. 0.24) and ESRD (0.07 vs. 0.01) were significantly higher in the acute kidney injury group than in the normal glomerular filtration rate (GFR) group. In the normal GFR group, the tacrolimus levels were identified as a risk factor for CKD, with a level of ≤4.5 ng/mL suggested as optimal for minimizing the risk of CKD. Furthermore, the IPV of tacrolimus levels and doses emerged as a significant risk factor for CKD development in both groups (p<0.05), with tenofovir disoproxil fumarate also being a risk factor in HBV-infected patients. The IPV of tacrolimus levels was also a significant factor in ESRD development (p<0.05).
Conclusions
This study elucidated the optimal tacrolimus trough level and highlighted the impact of IPV on the CKD and ESRD development post-LT.
2.Optimal tacrolimus levels for reducing CKD risk and the impact of intrapatient variability on CKD and ESRD development following liver transplantation
Soon Kyu LEE ; Ho Joong CHOI ; Young Kyoung YOU ; Pil Soo SUNG ; Seung Kew YOON ; Jeong Won JANG ; Jong Young CHOI
Clinical and Molecular Hepatology 2025;31(1):131-146
Background/Aims:
This study aimed to identify the risk factors for chronic kidney disease (CKD) and end-stage renal disease (ESRD) following liver transplantation (LT), with a specific focus on tacrolimus levels and intrapatient variability (IPV).
Methods:
Among the 1,076 patients who underwent LT between 2000 and 2018, 952 were included in the analysis. The tacrolimus doses and levels were recorded every 3 months, and the IPV was calculated using the coefficient of variability. The cumulative incidence rates of CKD and ESRD were calculated based on baseline kidney function at the time of LT. The impact of tacrolimus levels and their IPV on the development of CKD and ESRD was evaluated, and the significant risk factors were identified.
Results:
Within a median follow-up of 97.3 months, the 5-year cumulative incidence rates of CKD (0.58 vs. 0.24) and ESRD (0.07 vs. 0.01) were significantly higher in the acute kidney injury group than in the normal glomerular filtration rate (GFR) group. In the normal GFR group, the tacrolimus levels were identified as a risk factor for CKD, with a level of ≤4.5 ng/mL suggested as optimal for minimizing the risk of CKD. Furthermore, the IPV of tacrolimus levels and doses emerged as a significant risk factor for CKD development in both groups (p<0.05), with tenofovir disoproxil fumarate also being a risk factor in HBV-infected patients. The IPV of tacrolimus levels was also a significant factor in ESRD development (p<0.05).
Conclusions
This study elucidated the optimal tacrolimus trough level and highlighted the impact of IPV on the CKD and ESRD development post-LT.
3.Optimal tacrolimus levels for reducing CKD risk and the impact of intrapatient variability on CKD and ESRD development following liver transplantation
Soon Kyu LEE ; Ho Joong CHOI ; Young Kyoung YOU ; Pil Soo SUNG ; Seung Kew YOON ; Jeong Won JANG ; Jong Young CHOI
Clinical and Molecular Hepatology 2025;31(1):131-146
Background/Aims:
This study aimed to identify the risk factors for chronic kidney disease (CKD) and end-stage renal disease (ESRD) following liver transplantation (LT), with a specific focus on tacrolimus levels and intrapatient variability (IPV).
Methods:
Among the 1,076 patients who underwent LT between 2000 and 2018, 952 were included in the analysis. The tacrolimus doses and levels were recorded every 3 months, and the IPV was calculated using the coefficient of variability. The cumulative incidence rates of CKD and ESRD were calculated based on baseline kidney function at the time of LT. The impact of tacrolimus levels and their IPV on the development of CKD and ESRD was evaluated, and the significant risk factors were identified.
Results:
Within a median follow-up of 97.3 months, the 5-year cumulative incidence rates of CKD (0.58 vs. 0.24) and ESRD (0.07 vs. 0.01) were significantly higher in the acute kidney injury group than in the normal glomerular filtration rate (GFR) group. In the normal GFR group, the tacrolimus levels were identified as a risk factor for CKD, with a level of ≤4.5 ng/mL suggested as optimal for minimizing the risk of CKD. Furthermore, the IPV of tacrolimus levels and doses emerged as a significant risk factor for CKD development in both groups (p<0.05), with tenofovir disoproxil fumarate also being a risk factor in HBV-infected patients. The IPV of tacrolimus levels was also a significant factor in ESRD development (p<0.05).
Conclusions
This study elucidated the optimal tacrolimus trough level and highlighted the impact of IPV on the CKD and ESRD development post-LT.
4.Evaluation of Burnout and Contributing Factors in Imaging Cardiologists in Korea
You-Jung CHOI ; Kang-Un CHOI ; Young-Mee LEE ; Hyun-Jung LEE ; Inki MOON ; Jiwon SEO ; Kyu KIM ; So Ree KIM ; Jihoon KIM ; Hong-Mi CHOI ; Seo-Yeon GWAK ; Minkwan KIM ; Minjeong KIM ; Kyu-Yong KO ; Jin Kyung OH ; Jah Yeon CHOI ; Dong-Hyuk CHO ; On behalf of the Korean Society of Echocardiography Heart Imagers of Tomorrow
Journal of Korean Medical Science 2024;40(5):e21-
Background:
We aimed to examine the prevalence of burnout among imaging cardiologists in Korea and to identify its associated factors.
Methods:
An online survey of imaging cardiologists affiliated with university hospitals in Korea was conducted using SurveyMonkey ® in November 2023. The validated Korean version of the Maslach Burnout Inventory-Human Service Survey was used to assess burnout across three dimensions: emotional exhaustion, depersonalization, and lack of personal accomplishment. Data on demographics, work environment factors, and job satisfaction were collected using structured questionnaires.
Results:
A total of 128 imaging cardiologists (46.1% men; 76.6% aged ≤ 50 years) participated in the survey. Regarding workload, 74.2% of the respondents interpreted over 50 echocardiographic examinations daily, and 53.2% allocated > 5 of 10 working sessions per week to echocardiographic laboratory duties. Burnout levels were high, with a significant proportion of participants experiencing emotional exhaustion (28.1%), depersonalization (63.3%), and a lack of personal accomplishment (92.2%). Younger age (< 50 years) was correlated with higher emotional exhaustion risk, while more research time was protective against burnout in the depersonalization domain. Factors, such as being single, living with family, and specific job satisfaction facets, including uncontrollable workload and value mismatch, were associated with varying levels of burnout risk across different dimensions
Conclusion
Our study underscores the high burnout rates among Korean imaging cardiologists, attributed to factors such as the subjective environment and job satisfaction.Hence, evaluating and supporting cardiologists in terms of individual values and subjective factors are important to effectively prevent burnout..
5.Evaluation of Burnout and Contributing Factors in Imaging Cardiologists in Korea
You-Jung CHOI ; Kang-Un CHOI ; Young-Mee LEE ; Hyun-Jung LEE ; Inki MOON ; Jiwon SEO ; Kyu KIM ; So Ree KIM ; Jihoon KIM ; Hong-Mi CHOI ; Seo-Yeon GWAK ; Minkwan KIM ; Minjeong KIM ; Kyu-Yong KO ; Jin Kyung OH ; Jah Yeon CHOI ; Dong-Hyuk CHO ; On behalf of the Korean Society of Echocardiography Heart Imagers of Tomorrow
Journal of Korean Medical Science 2024;40(5):e21-
Background:
We aimed to examine the prevalence of burnout among imaging cardiologists in Korea and to identify its associated factors.
Methods:
An online survey of imaging cardiologists affiliated with university hospitals in Korea was conducted using SurveyMonkey ® in November 2023. The validated Korean version of the Maslach Burnout Inventory-Human Service Survey was used to assess burnout across three dimensions: emotional exhaustion, depersonalization, and lack of personal accomplishment. Data on demographics, work environment factors, and job satisfaction were collected using structured questionnaires.
Results:
A total of 128 imaging cardiologists (46.1% men; 76.6% aged ≤ 50 years) participated in the survey. Regarding workload, 74.2% of the respondents interpreted over 50 echocardiographic examinations daily, and 53.2% allocated > 5 of 10 working sessions per week to echocardiographic laboratory duties. Burnout levels were high, with a significant proportion of participants experiencing emotional exhaustion (28.1%), depersonalization (63.3%), and a lack of personal accomplishment (92.2%). Younger age (< 50 years) was correlated with higher emotional exhaustion risk, while more research time was protective against burnout in the depersonalization domain. Factors, such as being single, living with family, and specific job satisfaction facets, including uncontrollable workload and value mismatch, were associated with varying levels of burnout risk across different dimensions
Conclusion
Our study underscores the high burnout rates among Korean imaging cardiologists, attributed to factors such as the subjective environment and job satisfaction.Hence, evaluating and supporting cardiologists in terms of individual values and subjective factors are important to effectively prevent burnout..
6.Evaluation of Burnout and Contributing Factors in Imaging Cardiologists in Korea
You-Jung CHOI ; Kang-Un CHOI ; Young-Mee LEE ; Hyun-Jung LEE ; Inki MOON ; Jiwon SEO ; Kyu KIM ; So Ree KIM ; Jihoon KIM ; Hong-Mi CHOI ; Seo-Yeon GWAK ; Minkwan KIM ; Minjeong KIM ; Kyu-Yong KO ; Jin Kyung OH ; Jah Yeon CHOI ; Dong-Hyuk CHO ; On behalf of the Korean Society of Echocardiography Heart Imagers of Tomorrow
Journal of Korean Medical Science 2024;40(5):e21-
Background:
We aimed to examine the prevalence of burnout among imaging cardiologists in Korea and to identify its associated factors.
Methods:
An online survey of imaging cardiologists affiliated with university hospitals in Korea was conducted using SurveyMonkey ® in November 2023. The validated Korean version of the Maslach Burnout Inventory-Human Service Survey was used to assess burnout across three dimensions: emotional exhaustion, depersonalization, and lack of personal accomplishment. Data on demographics, work environment factors, and job satisfaction were collected using structured questionnaires.
Results:
A total of 128 imaging cardiologists (46.1% men; 76.6% aged ≤ 50 years) participated in the survey. Regarding workload, 74.2% of the respondents interpreted over 50 echocardiographic examinations daily, and 53.2% allocated > 5 of 10 working sessions per week to echocardiographic laboratory duties. Burnout levels were high, with a significant proportion of participants experiencing emotional exhaustion (28.1%), depersonalization (63.3%), and a lack of personal accomplishment (92.2%). Younger age (< 50 years) was correlated with higher emotional exhaustion risk, while more research time was protective against burnout in the depersonalization domain. Factors, such as being single, living with family, and specific job satisfaction facets, including uncontrollable workload and value mismatch, were associated with varying levels of burnout risk across different dimensions
Conclusion
Our study underscores the high burnout rates among Korean imaging cardiologists, attributed to factors such as the subjective environment and job satisfaction.Hence, evaluating and supporting cardiologists in terms of individual values and subjective factors are important to effectively prevent burnout..
7.Evaluation of Burnout and Contributing Factors in Imaging Cardiologists in Korea
You-Jung CHOI ; Kang-Un CHOI ; Young-Mee LEE ; Hyun-Jung LEE ; Inki MOON ; Jiwon SEO ; Kyu KIM ; So Ree KIM ; Jihoon KIM ; Hong-Mi CHOI ; Seo-Yeon GWAK ; Minkwan KIM ; Minjeong KIM ; Kyu-Yong KO ; Jin Kyung OH ; Jah Yeon CHOI ; Dong-Hyuk CHO ; On behalf of the Korean Society of Echocardiography Heart Imagers of Tomorrow
Journal of Korean Medical Science 2024;40(5):e21-
Background:
We aimed to examine the prevalence of burnout among imaging cardiologists in Korea and to identify its associated factors.
Methods:
An online survey of imaging cardiologists affiliated with university hospitals in Korea was conducted using SurveyMonkey ® in November 2023. The validated Korean version of the Maslach Burnout Inventory-Human Service Survey was used to assess burnout across three dimensions: emotional exhaustion, depersonalization, and lack of personal accomplishment. Data on demographics, work environment factors, and job satisfaction were collected using structured questionnaires.
Results:
A total of 128 imaging cardiologists (46.1% men; 76.6% aged ≤ 50 years) participated in the survey. Regarding workload, 74.2% of the respondents interpreted over 50 echocardiographic examinations daily, and 53.2% allocated > 5 of 10 working sessions per week to echocardiographic laboratory duties. Burnout levels were high, with a significant proportion of participants experiencing emotional exhaustion (28.1%), depersonalization (63.3%), and a lack of personal accomplishment (92.2%). Younger age (< 50 years) was correlated with higher emotional exhaustion risk, while more research time was protective against burnout in the depersonalization domain. Factors, such as being single, living with family, and specific job satisfaction facets, including uncontrollable workload and value mismatch, were associated with varying levels of burnout risk across different dimensions
Conclusion
Our study underscores the high burnout rates among Korean imaging cardiologists, attributed to factors such as the subjective environment and job satisfaction.Hence, evaluating and supporting cardiologists in terms of individual values and subjective factors are important to effectively prevent burnout..
8.A novel histologic description of the fibrous networks in the lid-cheek junction and infraorbital region
Sang-Hee LEE ; Kyu-Ho YI ; Jung-Hee BAE ; You-Jin CHOI ; Young-Chun GIL ; Kyung-Seok HU ; Eqram RAHMAN ; Hee-Jin KIM
Anatomy & Cell Biology 2024;57(1):25-30
The aim of this study was to identify the anatomical feature of retaining ligament and fat compartment on the lower eyelid and infraorbital region using a histological method, and to investigate clear definitions for them which could be used generally in the clinical area. Eighteen specimens from eight fresh Korean cadavers were stained with Masson trichrome or hematoxylin and eosin. The ligamentous and fascial fibrous tissue were clearly identified. The ligamentous fibrous tissue which traversed in the superficial and deep fat layer was skin ligament and orbicularis retaining ligament (ORL). The fascial fibrous tissue enclosed the orbicularis oculi muscle (OOc) and circumferencial adipose tissue. Based on the ligamentous and fascial structure, three fat compartments, septal, suborbicularis oculi and infraorbital fat compartment, could be identified.The OOc attached to orbital rim and dermis by ORL and skin ligament, and the muscle fascicle and fat fascicle provided the connection point to the ORL and skin ligament as enclosing all muscle and fat tissue. The combination of the force made by the skin ligament in the lower eyelid and ORL may decide the level and form of the infraorbital grooves.
9.Identification of acute myocardial infarction and stroke events using the National Health Insurance Service database in Korea
Minsung CHO ; Hyeok-Hee LEE ; Jang-Hyun BAEK ; Kyu Sun YUM ; Min KIM ; Jang-Whan BAE ; Seung-Jun LEE ; Byeong-Keuk KIM ; Young Ah KIM ; JiHyun YANG ; Dong Wook KIM ; Young Dae KIM ; Haeyong PAK ; Kyung Won KIM ; Sohee PARK ; Seng Chan YOU ; Hokyou LEE ; Hyeon Chang KIM
Epidemiology and Health 2024;46(1):e2024001-
OBJECTIVES:
The escalating burden of cardiovascular disease (CVD) is a critical public health issue worldwide. CVD, especially acute myocardial infarction (AMI) and stroke, is the leading contributor to morbidity and mortality in Korea. We aimed to develop algorithms for identifying AMI and stroke events from the National Health Insurance Service (NHIS) database and validate these algorithms through medical record review.
METHODS:
We first established a concept and definition of “hospitalization episode,” taking into account the unique features of health claims-based NHIS database. We then developed first and recurrent event identification algorithms, separately for AMI and stroke, to determine whether each hospitalization episode represents a true incident case of AMI or stroke. Finally, we assessed our algorithms’ accuracy by calculating their positive predictive values (PPVs) based on medical records of algorithm- identified events.
RESULTS:
We developed identification algorithms for both AMI and stroke. To validate them, we conducted retrospective review of medical records for 3,140 algorithm-identified events (1,399 AMI and 1,741 stroke events) across 24 hospitals throughout Korea. The overall PPVs for the first and recurrent AMI events were around 92% and 78%, respectively, while those for the first and recurrent stroke events were around 88% and 81%, respectively.
CONCLUSIONS
We successfully developed algorithms for identifying AMI and stroke events. The algorithms demonstrated high accuracy, with PPVs of approximately 90% for first events and 80% for recurrent events. These findings indicate that our algorithms hold promise as an instrumental tool for the consistent and reliable production of national CVD statistics in Korea.
10.PIK3CA Mutation is Associated with Poor Response to HER2-Targeted Therapy in Breast Cancer Patients
Ju Won KIM ; Ah Reum LIM ; Ji Young YOU ; Jung Hyun LEE ; Sung Eun SONG ; Nam Kwon LEE ; Seung Pil JUNG ; Kyu Ran CHO ; Cheol Yong KIM ; Kyong Hwa PARK
Cancer Research and Treatment 2023;55(2):531-541
Purpose:
Mutations in the PIK3CA gene occur frequently in breast cancer patients. Activating PIK3CA mutations confer resistance to human epidermal growth factor receptor 2 (HER2)-targeted treatments. In this study, we investigated whether PIK3CA mutations were correlated with treatment response or duration in patients with HER2-positive (HER2+) breast cancer.
Materials and Methods:
We retrospectively reviewed the clinical information of patients with HER2+ breast cancer who received HER2-targeted therapy for early-stage or metastatic cancers. The pathologic complete response (pCR), progression-free survival (PFS), and overall survival were compared between patients with wild-type PIK3CA (PIK3CAw) and those with mutated PIK3CA (PIK3CAm). Next-generation sequencing was combined with examination of PFS associated with anti-HER2 monoclonal antibody (mAb) treatment.
Results:
Data from 90 patients with HER2+ breast cancer were analyzed. Overall, 34 (37.8%) patients had pathogenic PIK3CA mutations. The pCR rate of the PIK3CAm group was lower than that of the PIK3CAw group among patients who received neoadjuvant chemotherapy for early-stage cancer. In the metastatic setting, the PIK3CAm group showed a significantly shorter mean PFS (mPFS) with first-line anti-HER2 mAb. The mPFS of second-line T-DM1 was lower in the PIK3CAm group than that in the PIK3CAw group. Sequencing revealed differences in the mutational landscape between PIK3CAm and PIK3CAw tumors.
Conclusion
Patients with HER2+ breast cancer with activating PIK3CA mutations had lower pCR rates and shorter PFS with palliative HER2-targeted therapy than those with wild-type PIK3CA. Precise targeted-therapy is needed to improve survival of patients with HER2+/PIK3CAm breast cancer.

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