1.Roots of the Large-Scale Household Humidifier Disinfectant Poisoning Tragedy: Regulatory and Surveillance Shortcomings in Korea
Dong-Uk PARK ; Kyung Ehi ZOH ; Dae Hwan CHO ; Soyoung PARK ; Jeonghwa HWANG ; Cheong-Hak CHOI ; Dong-Hee KOH ; Yeyong CHOI ; Jinyoung PARK
Journal of Korean Medical Science 2025;40(15):e144-
The multi-decade household humidifier disinfectant poisoning tragedy (HHDT) in South Korea highlights the importance of investigating government failures. This study aims to identify and discuss key failures and shortcomings in the South Korean authorities’ approach to regulating humidifier disinfectants (HDs) and monitoring cases of chemical poisoning. We reviewed both the HD risk prevention measures that the South Korean Ministry of Environment (KME) should have implemented under the Toxic Chemicals Control Act (TCCA) (1991–2013).Polyhexamethylene guanidine phosphate (PHMG), a new chemical, was approved for use as a disinfectant under the TCCA. KME declared PHMG non-hazardous based solely on preproduction documentation provided by the industry. In addition, the Korea Disease Control and Prevention Agency (KDCPA) failed to detect the HHDT that had accumulated each year for more than a decade. KME’s neglect of its responsibilities, coupled with KDCPA’s lack of chemical poisoning surveillance systems, led to the accumulation of widespread HHDT.
2.A Nationwide Survey on Infection Prevention and Control in Acute Care Hospitals of Korea
Sun Hee NA ; Yubin SEO ; Hye Jin SHI ; In Sun HWANG ; Kyong A SHIN ; Kwang Yul SON ; Sung Ran KIM ; Myoungjin SHIN ; Hee-jung SON ; Ji Youn CHOI ; Heekyung CHUN ; Sook-Kyung PARK ; Jeongsuk SONG ; Namyi KIM ; Jacob LEE ; Joong Sik EOM
Journal of Korean Medical Science 2025;40(4):e41-
Background:
Healthcare-associated infections impose a significant burden on antibiotic usage, healthcare expenditures, and morbidity. Therefore, it is crucial to revise policies to minimize such losses. This nationwide survey aimed to evaluate infection prevention and control (IPC) components in healthcare facilities and encourage improvements in acute care hospitals with inadequate infection prevention settings. This study aims to enhance the infection control capabilities of healthcare facilities.
Methods:
From December 27, 2021, to May 13, 2022, we conducted a survey of 1,767 acute care hospitals in the Republic of Korea. A survey was conducted to evaluate the infection control components in 1,767 acute care hospitals. Infection control officers provided direct responses to a systematically developed questionnaire. Subsequently, 10% of the respondents were randomly selected for the site investigation.
Results:
Overall, 1,197 (67.7%) hospitals responded to the online survey. On-site investigations were conducted at 125 hospitals. Hospitals with ≥ 150 beds are advised to have an IPC team under Article 3 of the Medical Service Act; however, only 87.0% (598/687) of hospitals with ≥ 100 beds had one. Conversely, 22.7% (116/510) of hospitals with < 100 beds had an IPC team. Regulations for hand hygiene, waste management, healthcare worker protection and safety, environmental cleaning, standard precautions, and prevention of the transmission of multidrug-resistant pathogens were present in 84.2%, 80.1%, 77.4%, 76.2%, 75.8%, and 63.5% of the hospitals, respectively. Hospitals with < 100 beds had low availability of all categories of standard operating procedures.
Conclusion
This study is the first national survey of acute care hospitals in the Republic of Korea. The data presented in the current study will improve the understanding of IPC status and will help establish a survey system. Our survey provides a basis for improving policies related to IPC in healthcare facilities.
3.Non-Linear Association Between Physical Activities and Type 2Diabetes in 2.4 Million Korean Population, 2009–2022: A Nationwide Representative Study
Wonwoo JANG ; Seokjun KIM ; Yejun SON ; Soeun KIM ; Hayeon LEE ; Jaeyu PARK ; Kyeongmin LEE ; Jiseung KANG ; Damiano PIZZOL ; Jiyoung HWANG ; Sang Youl RHEE ; Dong Keon YON
Journal of Korean Medical Science 2025;40(12):e42-
Background:
Although excessive physical activity (PA) does not always confer additional health benefits, there is a paucity of studies that have quantitatively examined the doseresponse relationship between PA and type 2 diabetes. Therefore, this study investigated the relationship between the type 2 diabetes prevalence and intensity, frequency, and metabolic equivalent of task (MET) score of PA in a large population sample.
Methods:
We conducted a nationwide cross-sectional analysis examining sociodemographic variables, PA habits, and type 2 diabetes prevalence in 2,428,448 participants included in the Korea Community Health Survey. The non-linear association between MET score and odds ratios (ORs) for type 2 diabetes prevalence was plotted using a weighted generalized additive model. Categorical analysis was used to examine the joint association of moderate-intensity PA (MPA) and vigorous-intensity PA (VPA), and the influence of PA frequency.
Results:
MET score and diabetes prevalence revealed a non-linear association with the nadir at 1,028 MET-min/week, beyond which ORs increased with additional PA. Joint analysis of MPA and VPA showed the lowest OR of 0.79 (95% confidence interval, 0.75–0.84) for those engaging in 300–600 MET-min/week of MPA and > 600 MET-min/week of VPA concurrently, corresponding with World Health Organization recommendations. Additionally, both “weekend warriors” and “regularly active” individuals showed lower ORs compared to the inactive, although no significant difference was noted between the active groups.
Conclusion
In a large South Korean sample, higher PA is not always associated with a lower prevalence of type 2 diabetes, as the association follows a non-linear pattern; differences existed across sociodemographic variables. Considering the joint association, an adequate combination of MPA and VPA is recommended. The frequency of PA does not significantly influence the type 2 diabetes prevalence.
4.Association of COX-2 Selectivity in Pain Medication Use with Endometriosis Incidence:Retrospective Cohort Study
Jongchan PARK ; Hye Jin CHANG ; Kyung Joo HWANG ; Sun Hyung YUM ; Chang Eun PARK ; Joo Hee KIM ; Miran KIM
Yonsei Medical Journal 2025;66(6):374-382
Purpose:
This retrospective cohort study aimed to investigate the association between the use of pain medications with varying cyclooxygenase-2 (COX-2) selectivity and the incidence of endometriosis (EMS) in women.
Materials and Methods:
Medical records from January 1, 1994, to December 31, 2022, were retrospectively analyzed. The cohort included 33406 patients diagnosed with any pain-related condition who were prescribed either selective COX-2 inhibitors or nonsteroidal anti-inflammatory drugs (NSAIDs). Patients were followed for up to 5 years from the cohort entry date. The incidence of EMS was compared between the two medication groups using Cox proportional hazards models, adjusting for confounding factors such as age, past drug use, and prior diagnosis.
Results:
The incidence rates of EMS were 3.00 per 1000 person-years in the COX-2 inhibitor group and 3.97 per 1000 person-years in the NSAIDs group. After adjustment for confounders, the hazard ratio for EMS incidence in the COX-2 inhibitor group compared to the NSAIDs group was 0.77 [95% confidence interval (CI), 0.63 to 0.93; p<0.01], indicating a significantly lower risk in the COX-2 inhibitor group. Subgroup analysis revealed that this association was particularly significant in younger women aged 20– 44 years, with a hazard ratio of 0.71 (95% CI, 0.54 to 0.95; p<0.05) in this age group.
Conclusion
The findings suggest that COX-2 inhibitors may reduce the incidence of EMS compared to traditional NSAIDs, highlighting their potential as a strategic option for managing EMS, particularly among younger women. Further prospective studies are needed to confirm these findings.
5.Comparison of tissue-based and plasma-based testing for EGFR mutation in non–small cell lung cancer patients
Yoon Kyung KANG ; Dong Hoon SHIN ; Joon Young PARK ; Chung Su HWANG ; Hyun Jung LEE ; Jung Hee LEE ; Jee Yeon KIM ; JooYoung NA
Journal of Pathology and Translational Medicine 2025;59(1):60-67
Background:
Epidermal growth factor receptor (EGFR) gene mutation testing is crucial for the administration of tyrosine kinase inhibitors to treat non–small cell lung cancer. In addition to traditional tissue-based tests, liquid biopsies using plasma are increasingly utilized, particularly for detecting T790M mutations. This study compared tissue- and plasma-based EGFR testing methods.
Methods:
A total of 248 patients were tested for EGFR mutations using tissue and plasma samples from 2018 to 2023 at Pusan National University Yangsan Hospital. Tissue tests were performed using PANAmutyper, and plasma tests were performed using the Cobas EGFR Mutation Test v2.
Results:
All 248 patients underwent tissue-based EGFR testing, and 245 (98.8%) showed positive results. Of the 408 plasma tests, 237 (58.1%) were positive. For the T790M mutation, tissue biopsies were performed 87 times in 69 patients, and 30 positive cases (38.6%) were detected. Plasma testing for the T790M mutation was conducted 333 times in 207 patients, yielding 62 positive results (18.6%). Of these, 57 (27.5%) were confirmed to have the mutation via plasma testing. Combined tissue and plasma tests for the T790M mutation were positive in nine patients (13.4%), while 17 (25.4%) were positive in tissue only and 12 (17.9%) in plasma only. This mutation was not detected in 28 patients (43.3%).
Conclusions
Although the tissue- and plasma-based tests showed a sensitivity of 37.3% and 32.8%, respectively, combined testing increased the detection rate to 56.7%. Thus, neither test demonstrated superiority, rather, they were complementary.
6.Complete or incomplete revascularization in patients with left main culprit lesion acute myocardial infarction with multivessel disease: a retrospective observational study
Sun Oh KIM ; Hong-Ju KIM ; Jong-Il PARK ; Kang-Un CHOI ; Jong-Ho NAM ; Chan-Hee LEE ; Jang-Won SON ; Jong-Seon PARK ; Sung-Ho HER ; Ki-Yuk CHANG ; Tae-Hoon AHN ; Myung-Ho JEONG ; Seung-Woon RHA ; Hyo-Soo KIM ; Hyeon-Cheol GWON ; In-Whan SEONG ; Kyung-Kuk HWANG ; Seung-Ho HUR ; Kwang-Soo CHA ; Seok-Kyu OH ; Jei-Keon CHAE ; Ung KIM
Journal of Yeungnam Medical Science 2025;42(1):18-
Background:
Complete revascularization has demonstrated better outcomes in patients with acute myocardial infarction (AMI) and multivessel disease. However, in the case of left main (LM) culprit lesion AMI with multivessel disease, there is limited evidence to suggest that complete revascularization is better.
Methods:
We reviewed 16,831 patients in the Korea Acute Myocardial Infarction Registry who were treated from July 2016 to June 2020, and 399 patients were enrolled with LM culprit lesion AMI treated with percutaneous coronary intervention. We categorized the patients as those treated with complete revascularization (n=295) or incomplete revascularization (n=104). The study endpoint was major adverse cardiac and cerebrovascular events (MACCE), a composite of all-cause death, myocardial infarction, ischemia-driven revascularization, stent thrombosis, and stroke. We performed propensity score matching (PSM) and analyzed the incidence of MACCE at 1 year.
Results:
After PSM, the two groups were well balanced. There was no significant difference between the two groups in MACCE at 1 year (12.1% vs. 15.2%; hazard ratio, 1.28; 95% confidence interval, 0.60–2.74; p=0.524) after PSM. The components of MACCE and major bleeding were also not significantly different.
Conclusion
There was no significant difference in clinical outcomes between the groups treated with complete or incomplete revascularization for LM culprit lesion AMI with multivessel disease.
7.Constitutional Chromosome 21 Abnormality in B-ALL with iAMP21 in a Patient Developing Treatment-Related Myelodysplastic Syndrome
Inhwa KIM ; Su Hyun YOON ; Sunghan KANG ; Kyung-Nam KOH ; Mi Young KIM ; Young-Uk CHO ; Sang-Hyun HWANG ; Seongsoo JANG ; Eul-Ju SEO ; Beom Hee LEE ; Sunghee MIN ; Hyunwoo BAE ; Ho Joon IM ; Hyery KIM
Clinical Pediatric Hematology-Oncology 2025;32(1):23-28
The initial molecular cytogenetic characteristics of blasts plays a significant role in determining the treatment course of B-cell acute lymphoblastic leukemia (B-ALL).B-ALL with intrachromosomal amplification of chromosome 21 (iAMP21) has been well known to have unfavorable prognosis. Also, there are previously recognized germline mutations that increase the risk of ALL, such as trisomy 21, Down syndrome. This case report is about a 16-year-old girl who presented with lymphadenitis, purpura, and fever followed by initial lab of elevated white blood cell with blasts.She had some notable facial features, but no typical Down syndrome related one.Bone marrow biopsy and fluorescence in situ hybridization finalized the diagnosis as B-ALL with iAMP21, high-risk group. The minimal residual disease-negative complete remission was achieved after the induction chemotherapy with Korean multicenter high-risk protocol. However, abnormal karyotype was sustained in bone marrow. Microarrays with her buccal swab raised the possibility that the abnormal karyotype was not from the leukemic blasts but rather from the germline. Although she underwent scheduled chemotherapy uneventfully as slow early responder type, thrombocytopenia and abnormal karyotype persisted, leading to the diagnosis of acute myeloid leukemia. Additional chemotherapy and peripheral blood stem cell transplantation was performed which resulted in engraftment. This case highlights the discovery of a constitutional genetic aberration, which played like a silent yet critical background factor for B-ALL with iAMP21. As the number of reported cases are limited, the role of germline chromosome 21 mutation as the indicator for prognosis of B-ALL should be studied further.
8.Piperine Regulates Melanogenesis through ERK Activation and Proteasomal Degradation of MITF
Jun Hyeong LEE ; Jieun LEE ; Sukanya DEJ-ADISAI ; Jae Sung HWANG
Biomolecules & Therapeutics 2025;33(2):408-414
Melanin is a bio-pigment molecule synthesized by melanocytes. Its role is to shield the skin from ultraviolet radiation. Nonetheless, aberrant melanin production, whether excessive or deficient, can lead to conditions such as vitiligo, freckles, melanocytic nevi, and even melanoma. The biosynthetic pathway of melanin is known as melanogenesis, which is regulated by various transcription factors and enzymatic processes. Piperine (PPN), an alkaloid compound extracted from Piper retrofractum Vahl., was investigated for its potential anti-fungal and anti-inflammatory effects. Our hypothesis centered on the inhibition of melanin biosynthesis in response to PPN treatment. Subsequently, it was observed that PPN treatment resulted in a dose-dependent reduction in melanin production, accompanied by a decrease in tyrosinase activity. Furthermore, PPN was found to downregulate the protein levels of key melanogenesis-related genes. Additionally, PPN was observed to elevate the phosphorylation levels of ERK. To assess the role of ERK signaling in PPN-induced melanogenesis regulation, PD98059, an ERK inhibitor, was used. When Melan-A cells were treated with PD98059, the reduced expression level of MITF and melanin content induced by piperine were restored. Additionally, phosphorylation of ERK increased the phosphorylation of MITF at Ser73. This phosphorylated MITF leads to ubiquitination, and ultimately, the protein level of MITF decreases through proteasomal degradation. Likewise, when Melan-A cells were treated with MG132, a proteasomal inhibitor, the reduced expression level of MITF and melanin content induced by piperine were restored.Consequently, PPN can be a potential candidate for application as a skin whitening agent or in formulations to mitigate hyperpigmentation.
9.Association of COX-2 Selectivity in Pain Medication Use with Endometriosis Incidence:Retrospective Cohort Study
Jongchan PARK ; Hye Jin CHANG ; Kyung Joo HWANG ; Sun Hyung YUM ; Chang Eun PARK ; Joo Hee KIM ; Miran KIM
Yonsei Medical Journal 2025;66(6):374-382
Purpose:
This retrospective cohort study aimed to investigate the association between the use of pain medications with varying cyclooxygenase-2 (COX-2) selectivity and the incidence of endometriosis (EMS) in women.
Materials and Methods:
Medical records from January 1, 1994, to December 31, 2022, were retrospectively analyzed. The cohort included 33406 patients diagnosed with any pain-related condition who were prescribed either selective COX-2 inhibitors or nonsteroidal anti-inflammatory drugs (NSAIDs). Patients were followed for up to 5 years from the cohort entry date. The incidence of EMS was compared between the two medication groups using Cox proportional hazards models, adjusting for confounding factors such as age, past drug use, and prior diagnosis.
Results:
The incidence rates of EMS were 3.00 per 1000 person-years in the COX-2 inhibitor group and 3.97 per 1000 person-years in the NSAIDs group. After adjustment for confounders, the hazard ratio for EMS incidence in the COX-2 inhibitor group compared to the NSAIDs group was 0.77 [95% confidence interval (CI), 0.63 to 0.93; p<0.01], indicating a significantly lower risk in the COX-2 inhibitor group. Subgroup analysis revealed that this association was particularly significant in younger women aged 20– 44 years, with a hazard ratio of 0.71 (95% CI, 0.54 to 0.95; p<0.05) in this age group.
Conclusion
The findings suggest that COX-2 inhibitors may reduce the incidence of EMS compared to traditional NSAIDs, highlighting their potential as a strategic option for managing EMS, particularly among younger women. Further prospective studies are needed to confirm these findings.
10.Association of COX-2 Selectivity in Pain Medication Use with Endometriosis Incidence:Retrospective Cohort Study
Jongchan PARK ; Hye Jin CHANG ; Kyung Joo HWANG ; Sun Hyung YUM ; Chang Eun PARK ; Joo Hee KIM ; Miran KIM
Yonsei Medical Journal 2025;66(6):374-382
Purpose:
This retrospective cohort study aimed to investigate the association between the use of pain medications with varying cyclooxygenase-2 (COX-2) selectivity and the incidence of endometriosis (EMS) in women.
Materials and Methods:
Medical records from January 1, 1994, to December 31, 2022, were retrospectively analyzed. The cohort included 33406 patients diagnosed with any pain-related condition who were prescribed either selective COX-2 inhibitors or nonsteroidal anti-inflammatory drugs (NSAIDs). Patients were followed for up to 5 years from the cohort entry date. The incidence of EMS was compared between the two medication groups using Cox proportional hazards models, adjusting for confounding factors such as age, past drug use, and prior diagnosis.
Results:
The incidence rates of EMS were 3.00 per 1000 person-years in the COX-2 inhibitor group and 3.97 per 1000 person-years in the NSAIDs group. After adjustment for confounders, the hazard ratio for EMS incidence in the COX-2 inhibitor group compared to the NSAIDs group was 0.77 [95% confidence interval (CI), 0.63 to 0.93; p<0.01], indicating a significantly lower risk in the COX-2 inhibitor group. Subgroup analysis revealed that this association was particularly significant in younger women aged 20– 44 years, with a hazard ratio of 0.71 (95% CI, 0.54 to 0.95; p<0.05) in this age group.
Conclusion
The findings suggest that COX-2 inhibitors may reduce the incidence of EMS compared to traditional NSAIDs, highlighting their potential as a strategic option for managing EMS, particularly among younger women. Further prospective studies are needed to confirm these findings.

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