Search

Background: Atrial fibrillation (AF) can lead to stroke, heart failure, and mortality and has a greater prevalence in dialysis patients than in the general population. Several studies have suggested that uremic toxins may contribute to the development of AF. However, the association between dialysis adequacy and incident AF has not been well established., Methods: In this retrospective nationwide cohort study, we analyzed data from the Korean National Periodic Hemodialysis Quality Assessment from 2013 to 2015 of patients who received outpatient maintenance hemodialysis 3× a week. The main exposure was single pooled Kt/V (spKt/V), which is the dialysis adequacy index, and the primary outcome was the development of AF. For the primary analysis, patients were categorized into quartiles according to baseline spKt/V. The lowest quartile, representing the lowest adequacy, was used as the reference group. Fine-Gray subdistribution hazard models were used, treating all-cause mortality as a competing risk., Results: Of 25 173 patients, the mean age was 60 (51-69) years, and 14 772 (58.7%) were men. During a median follow-up of 5.7 years, incident AF occurred in a total of 3883 (15.4%) patients. Participants with a higher spKt/V tended to have lower AF incidence. In survival analysis, a graded association was observed between the risk of incident AF and spKt/V quartiles: subdistribution hazard ratios and 95% CIs for the second, third, and the highest quartile compared with the lowest quartile were 0.90 (95% CI, 0.82-0.98), 0.84 (95% CI, 0.77-0.93), and 0.79 (95% CI, 0.72-0.88), respectively., Conclusions: This nationwide cohort study showed that a higher spKt/V is associated with a reduced risk of incident AF. These findings suggests that reducing uremic toxin burden through enhanced dialysis clearance may be associated with a lower risk of AF development in patients undergoing maintenance hemodialysis., Competing Interests: None.

Objective: In Korea, radiology has been positioned towards the early adoption of artificial intelligence-based software as medical devices (AI-SaMDs); however, little is known about the current usage, implementation, and future needs of AI-SaMDs. We surveyed the current trends and expectations for AI-SaMDs among members of the Korean Society of Radiology (KSR)., Materials and Methods: An anonymous and voluntary online survey was open to all KSR members between April 17 and May 15, 2023. The survey was focused on the experiences of using AI-SaMDs, patterns of usage, levels of satisfaction, and expectations regarding the use of AI-SaMDs, including the roles of the industry, government, and KSR regarding the clinical use of AI-SaMDs., Results: Among the 370 respondents (response rate: 7.7% [370/4792]; 340 board-certified radiologists; 210 from academic institutions), 60.3% (223/370) had experience using AI-SaMDs. The two most common use-case of AI-SaMDs among the respondents were lesion detection (82.1%, 183/223), lesion diagnosis/classification (55.2%, 123/223), with the target imaging modalities being plain radiography (62.3%, 139/223), CT (42.6%, 95/223), mammography (29.1%, 65/223), and MRI (28.7%, 64/223). Most users were satisfied with AI-SaMDs (67.6% [115/170, for improvement of patient management] to 85.1% [189/222, for performance]). Regarding the expansion of clinical applications, most respondents expressed a preference for AI-SaMDs to assist in detection/diagnosis (77.0%, 285/370) and to perform automated measurement/quantification (63.5%, 235/370). Most respondents indicated that future development of AI-SaMDs should focus on improving practice efficiency (81.9%, 303/370) and quality (71.4%, 264/370). Overall, 91.9% of the respondents (340/370) agreed that there is a need for education or guidelines driven by the KSR regarding the use of AI-SaMDs., Conclusion: The penetration rate of AI-SaMDs in clinical practice and the corresponding satisfaction levels were high among members of the KSR. Most AI-SaMDs have been used for lesion detection, diagnosis, and classification. Most respondents requested KSR-driven education or guidelines on the use of AI-SaMDs., Competing Interests: Eui Jin Hwang reports research grants from Lunit, Coreline Soft, and Monitor Corporation outside the present work. Chang Min Park reports research grants from Lunit and Coreline Soft outside the present work, and stock of Promedius, Lunit and Coreline Soft and stock options of Lunit and Coreline Soft., (Copyright © 2024 The Korean Society of Radiology.)

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.

Background and Aims: Reduced body muscle mass is a poor prognostic factor for inflammatory bowel disease (IBD). In this study, we investigated the prevalence of sarcopenia at diagnosis and its clinical significance in Korean patients with IBD., Methods: The prevalence of sarcopenia in IBD patients between June 1989 and December 2016 was investigated using a well-characterized referral center-based cohort. Abdominopelvic computed tomography within six months from IBD diagnosis was used for the evaluation. Sarcopenia was defined as an L3 skeletal muscle index of < 49 cm 2 /m 2 for male and < 31 cm 2 /m 2 for female. The clinical characteristics and outcomes were evaluated with respect to sarcopenia., Results: A total of 1,027 patients (854 Crohn's disease [CD]; 173 ulcerative colitis [UC]) were evaluated. Sarcopenia was found in 56.8% of the population (CD, 57.5%; UC, 53.2%), and male were more likely to be sarcopenic (CD, 94.3%; UC, 91.6%). There were no significant differences in the cumulative risk of using steroids, immunomodulators, biologics, and bowel resections (or colectomy) with or without sarcopenia during follow-up (median: CD, 5.8 years; UC, 3.7 years). In sarcopenic patients with CD, there was a significantly higher cumulative risk of perianal surgeries than in non-sarcopenic patients with CD (Log-rank test; P = 0.001). However, the risk of perianal surgeries was not significant in multivariate analysis (Odds ratio 1.368; 95% confidence interval 0.782-2.391; P = 0.272)., Conclusion: Sarcopenia at diagnosis may have no significant prognostic value for medical treatment and bowel resection, but it may be associated with perianal CD., (© 2023. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

It is unknown whether intensive control of blood pressure (BP) and lipids can delay the progression of chronic kidney disease (CKD). This study examined the combined association of strict targets of systolic BP (SBP) and low-density lipoprotein cholesterol (LDL-C) levels with adverse kidney outcomes. In total, 2012 patients from the KoreaN Cohort Study for Outcomes in Patients With CKD (KNOW-CKD) were classified into four groups according to SBP of 120 mmHg and LDL-C of 70 mg/dl: group 1, <120 and <70; group 2, <120 and ≥70; group 3, ≥120 and <70; group 4, ≥120 and ≥70. We constructed time-varying models treating two variables as time-varying exposures. The primary outcome was the progression of CKD, defined as a ≥50% decrease in estimated glomerular filtration rate from the baseline or the onset of kidney failure requiring replacement therapy. The primary outcome events occurred in 27.9%, 26.7%, 40.3%, and 39.1% from groups 1 to 4. In the time-varying model, the hazard ratios (95% confidence intervals) for the primary outcome were 0.48 (0.33-0.69), 0.78 (0.63-0.96), and 0.96 (0.74-1.23) for groups 1 to 3, respectively, compared with group 4. When less stringent cut-offs of SBP of 130 mmHg and LDL-C of 100 mg/dl were used, this graded association was lost, while only SBP was associated with adverse kidney outcomes. In this study, the lower targets of SBP of <120 mmHg and LDL-C < 70 mg/dl were synergistically associated with a lower risk of adverse kidney outcomes., (© 2023. The Author(s), under exclusive licence to The Japanese Society of Hypertension.)

Objective: To evaluate the completeness of the reporting of systematic reviews and meta-analyses published in a general radiology journal using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 guidelines., Materials and Methods: Twenty-four articles (systematic review and meta-analysis, n = 18; systematic review only, n = 6) published between August 2009 and September 2021 in the Korean Journal of Radiology were analyzed. Completeness of the reporting of main texts and abstracts were evaluated using the PRISMA 2020 statement. For each item in the statement, the proportion of studies that met the guidelines' recommendation was calculated and items that were satisfied by fewer than 80% of the studies were identified. The review process was conducted by two independent reviewers., Results: Of the 42 items (including sub-items) in the PRISMA 2020 statement for main text, 24 were satisfied by fewer than 80% of the included articles. The 24 items were grouped into eight domains: 1) assessment of the eligibility of potential articles, 2) assessment of the risk of bias, 3) synthesis of results, 4) additional analysis of study heterogeneity, 5) assessment of non-reporting bias, 6) assessment of the certainty of evidence, 7) provision of limitations of the study, and 8) additional information, such as protocol registration. Of the 12 items in the abstract checklists, eight were incorporated in fewer than 80% of the included publications., Conclusion: Several items included in the PRISMA 2020 checklist were overlooked in systematic review and meta-analysis articles published in the Korean Journal of Radiology . Based on these results, we suggest a double-check list for improving the quality of systematic reviews and meta-analyses. Authors and reviewers should familiarize themselves with the PRISMA 2020 statement and check whether the recommended items are fully satisfied prior to publication., Competing Interests: Chong Hyun Suh who is on the editorial board of the Korean Journal of Radiology was not involved in the editorial evaluation or decision to publish this article. All remaining authors have declared no conflicts of interest., (Copyright © 2022 The Korean Society of Radiology.)

Background: We aimed to examine the delay in antiviral initiation in rapid antigen test (RAT) false-negative children with influenza virus infection and to explore the clinical outcomes. We additionally conducted a medical cost-benefit analysis., Methods: This single-center, retrospective study included children (aged < 10 years) with influenza-like illness (ILI), hospitalized after presenting to the emergency department during three influenza seasons (2016-2019). RAT-false-negativity was defined as RAT-negative and polymerase chain reaction-positive cases. The turnaround time to antiviral treatment (TAT) was from the time when RAT was prescribed to the time when the antiviral was administered. The medical cost analysis by scenarios was also performed., Results: A total of 1,430 patients were included, 7.5% were RAT-positive (n = 107) and 2.4% were RAT-false-negative (n = 20). The median TAT of RAT-false-negative patients was 52.8 hours, significantly longer than that of 4 hours in RAT-positive patients (19.2-100.1, P < 0.001). In the multivariable analysis, TAT of ≥ 24 hours was associated with a risk of severe influenza infection and the need for mechanical ventilation (odds ratio [OR], 6.8, P = 0.009 and OR, 16.2, P = 0.033, respectively). The medical cost varied from $11.7-187.3/ILI patient., Conclusion: Antiviral initiation was delayed in RAT-false-negative patients. Our findings support the guideline that children with influenza, suspected of having severe or progressive infection, should be treated immediately., Competing Interests: The authors have no potential conflicts of interest to disclose., (© 2022 The Korean Academy of Medical Sciences.)

Abstract: Asthma is a heterogeneous disease characterized by chronic airway inflammation with a genetic predisposition. Butyrophilin-like 2 (BTNL2) is a member of the immunoglobulin superfamily that plays an important role in regulating T cell activation and immune homeostasis. Here, we aimed to investigate the association of the genetic variants of BTNL2 with childhood asthma and asthma-related traits by utilizing extreme asthma phenotypes and employing a genome-wide association study. Our study included 243 children with well-defined moderate to severe atopic asthma and 134 healthy children with no history of allergic diseases and allergic sensitization. DNA from these subjects was genotyped using AxiomTM Genome-Wide Array Plates. Although no single nucleotide polymorphisms (SNPs) reached a genome-wide threshold of significance, 3 SNPs, rs3817971, rs41355746, and rs41441651, at BTNL2 were significantly associated with moderate to severe atopic asthma after performing Bonferroni correction. These SNPs were also associated with the risk of allergic sensitization toward house dust mites and the presence and degree of bronchial hyperresponsiveness. Thus, we identified that BTNL2 was associated with atopic moderate to severe persistent asthma in Korean children, and this may play an important role in disease development and susceptibility., Competing Interests: The authors declare no conflict of interest., (Copyright © 2021 the Author(s). Published by Wolters Kluwer Health, Inc.)

Background: The prognosis of patients with advanced biliary tract cancer who have progressed on gemcitabine plus cisplatin is dismal. We aimed to investigate the efficacy and safety of second-line liposomal irinotecan plus fluorouracil and leucovorin in patients with metastatic biliary tract cancer that has progressed on gemcitabine plus cisplatin., Methods: This multicentre, open-label, randomised, phase 2b (NIFTY) study was done at five academic institutions in South Korea and included patients aged 19 years or older with histologically or cytologically confirmed metastatic biliary tract cancer that had progressed on first-line gemcitabine plus cisplatin and an Eastern Cooperative Oncology Group performance status of 0 or 1. By use of an interactive web-based response system integrated with an electronic data capture system, patients were randomly assigned (1:1) using permuted blocks (block size 4) to receive either intravenous liposomal irinotecan (70 mg/m 2 for 90 min) plus intravenous leucovorin (400 mg/m 2 for 30 min) and intravenous fluorouracil (2400 mg/m 2 for 46 h) every 2 weeks or leucovorin and fluorouracil only every 2 weeks, and were stratified by primary tumour site, previous surgery with curative intent, and participating centre. Study treatment was continued until the patient had disease progression or unacceptable toxicities, or withdrew consent. The primary endpoint was blinded independent central review (BICR)-assessed progression-free survival. The primary endpoint and safety were assessed in the full analysis set and the safety analysis set, respectively, both of which comprised all randomly assigned patients who received at least one dose of the study treatment. This trial is registered with ClinicalTrials.gov, NCT03524508, and enrolment is complete., Findings: Between Sept 5, 2018, and Feb 18, 2020, 193 patients were screened for eligibility, of whom 174 (88 in the liposomal irinotecan plus fluorouracil and leucovorin group and 86 in the fluorouracil plus leucovorin group) were enrolled and included in the full analysis and safety analysis sets. At a median follow-up of 11·8 months (IQR 7·7-18·7), the median BICR-assessed progression-free survival was significantly longer in the liposomal irinotecan plus fluorouracil and leucovorin group (7·1 months, 95% CI 3·6-8·8) than in the fluorouracil and leucovorin group (1·4 months, 1·2-1·5; hazard ratio 0·56, 95% CI 0·39-0·81; p=0·0019). The most common grade 3-4 adverse events were neutropenia (21 [24%] of 88 in the liposomal irinotecan plus fluorouracil and leucovorin group vs one [1%] of 86 in the fluorouracil and leucovorin group) and fatigue or asthenia (11 [13%] vs three [3%]). Serious adverse events occurred in 37 (42%) patients receiving liposomal irinotecan plus fluorouracil and leucovorin and 21 (24%) patients receiving fluorouracil and leucovorin. There were no treatment-related deaths., Interpretation: Adding liposomal irinotecan to fluorouracil and leucovorin significantly improved BICR-assessed progression-free survival in patients with advanced biliary tract cancer. Liposomal irinotecan plus fluorouracil and leucovorin could be considered a standard-of-care second-line therapy for advanced biliary tract cancer., Funding: Servier and HK inno., N Translation: For the Korean translation of the abstract see Supplementary Materials section., Competing Interests: Declaration of interests CY received honoraria from Servier, Bayer, AstraZeneca, Merck Sharp & Dohme, Eisai, Celgene, Bristol Myers Squibb, Debiopharm, Ipsen, Kyowa Kirin, Novartis, Boryung Pharmaceuticals, Merck Serono, Mundipharma, Roche, and Janssen, and received research grants from Servier, Bayer, AstraZeneca, Ono Pharmaceuticals, Celgene, Ipsen, Boryung Pharmaceuticals, Ildong Pharmaceuticals, CKD Pharmaceuticals, and HK inno.N. JHJ received honoraria from Boryung Pharmaceutical, Daewoong Pharmaceutical, Eisai, HK inno.N, Lilly, Novartis, Pfizer, and Roche. JC received honoraria from Roche, Bayer, Eisai, Ipsen, and Bristol Myers Squibb, and received research grants from Bayer and Dong-A Pharmaceuticals. GKAA reports research grants from Arcus, Agios, AstraZeneca, BioNtech, Bristol Myers Squibb, Celgene, Flatiron, Genentech/Roche, Genoscience, Incyte, Polaris, Puma, QED, Silenseed, and Yiviva, and personal consultation fees from Adicet, AstraZeneca, Alnylam, Autem, Bayer, Beigene, Berry Genomics, Cend, Celgene, CytomX, Eisai, Eli Lilly, Exelixis, Flatiron, Genentech/Roche, Genoscience, Helio, Incyte, Ipsen, Legend Biotech, Merck, Nerviano, QED, Redhill, Rafael, Servier, Silenseed, Sillajen, Sobi, Surface Oncology, Therabionics, Vector, and Yiviva. All other authors declare no competing interests., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Purpose: To determine the mechanism of infection, clinical features, and risk factors of endophthalmitis after scleral fixation of an intraocular lens., Methods: We included 15 patients with infectious endophthalmitis after scleral fixation of an intraocular lens between April 2004 and December 2017, as well as four patients found through a literature search. Thus, a total of 19 patients were analyzed., Results: Among 19 eyes, infectious endophthalmitis developed at a mean of 23 months (range: 1 day-10 years) after scleral fixation surgery. Nine eyes (47.4%) had early-onset endophthalmitis (≤6 weeks), and 10 eyes (52.6%) had delayed-onset endophthalmitis (>6 weeks). Eleven eyes (57.9%) had presumed microbial influx due to suture exposure. Those with delayed-onset endophthalmitis showed a higher rate of suture-related infection (80.0% vs. 33.3%) and culture of gram-negative bacteria (70.0% vs. 12.5%) than did those with early-onset endophthalmitis., Conclusions: Infectious endophthalmitis can develop late after scleral fixation of an intraocular lens, usually related to the exposed sutures, and the visual prognosis is poor. Eyes that have sutured scleral fixation should be monitored regularly, and preventive measures should be performed if an exposed suture is found., Competing Interests: None of the authors has any conflicts of interest to disclose.

Background: The incidence of hepatocellular carcinoma (HCC) has been increasing among the elderly populations. Trans-arterial chemoembolization (TACE), a widely used first-line non-curative therapy for HCCs is an issue in geriatrics. We investigated the prognosis of elderly HCC patients treated with TACE and determined the factors that affect the overall survival., Methods: We included 266 patients who were older than 65 years and had received TACE as initial treatment for HCC. We analyzed the skeletal muscle index (SMI) and visceral-to-subcutaneous fat ratio (VSR) around the third lumbar vertebrae using computed tomography scans. Muscle depletion with visceral adiposity (MDVA) was defined by falling below the median SMI and above the median VSR value sex-specifically. We evaluated the overall survival in association with MDVA and other clinical factors., Results: The mean age was 69.9 ± 4.5 years, and 70.3% of the patients were men. According to the Barcelona Clinic Liver Cancer (BCLC) staging system, 29, 136, and 101 patients were classified as BCLC 0, A, and B stages, respectively, and 79 (29.7%) had MDVA. During the median follow-up of 4.1 years, patients with MDVA had a shorter life expectancy than those without MDVA (P = 0.007) even though MDVA group had a higher objective response rate after the first TACE (82.3% vs. 75.9%, P = 0.035). Multivariate analysis revealed that MDVA (Hazard ratio [HR] 1.515) age (HR 1.057), liver function (HR 1.078), tumor size (HR 1.083), serum albumin level (HR 0.523), platelet count (HR 0.996), tumor stage (stage A, HR 1.711; stage B, HR 2.003), and treatment response after the first TACE treatment (HR 0.680) were associated with overall survival., Conclusions: MDVA is a critical prognostic factor for predicting survival in the elderly patients with HCC who have undergone TACE., (© 2021. The Author(s).)

Background and Objective: Global Lung Function Initiative (GLI) 2012 equations were developed to resolve the age-related disparity in interpreting spirometry results. Local validation of the equation is needed, especially in Northeast Asian children. This study evaluated the GLI equation in Korean children., Methods: Spirometry indices (FEV1, FVC, FEV1/FVC, and FEF25%-75%) and clinical information were gathered from three population-based birth cohorts. Predicted GLI reference values and z scores of spirometry results were calculated for 1239 healthy children. The mean, standard deviation of z scores were compared with the expected 0 and 1. Probabilities of falling below the lower limit of normal (LLN) (z score: -1.64) were compared with the expected value 5%. GLI z scores were assessed according to low (<-2), normal (≥-2 and ≤2), and high (>2) BMI z score groups., Results: Mean z scores significantly differed from 0 for FEV1/FVC in males (mean [95% confidence interval]: 0.18 [0.08, 0.27]) and forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC) in females (-0.23 [-0.31, -0.15] and -0.26 [-0.36, -0.16], respectively). The standard deviation was larger than 1 for all variables in males and FVC and FEV1/FVC in females. The probability of falling below the LLN was significantly larger than 5% for FEV1 (12.13% [9.64, 14.77]), FVC (15.86% [13.06, 18.81]), and forced expiratory flow at 25%-75% of forced vital capacity (FEF25%-75%) (7.31% [5.29, 9.49]) in males and FVC (11.91% [9.40, 14.60]) in females. FEV1 and FVC z scores increased across low to high body mass index (BMI) groups, and FEV1/FVC decreased from low to high BMI groups., Conclusion: GLI equations marginally differ from real-world values, which should be considered by pulmonologists in practice or research., (© 2021 Wiley Periodicals LLC.)

Background: The number of deaths from COVID-19 continues to surge worldwide. In particular, if a patient's condition is sufficiently severe to require invasive ventilation, it is more likely to lead to death than to recovery., Objective: The goal of our study was to analyze the factors related to COVID-19 severity in patients and to develop an artificial intelligence (AI) model to predict the severity of COVID-19 at an early stage., Methods: We developed an AI model that predicts severity based on data from 5601 COVID-19 patients from all national and regional hospitals across South Korea as of April 2020. The clinical severity of COVID-19 was divided into two categories: low and high severity. The condition of patients in the low-severity group corresponded to no limit of activity, oxygen support with nasal prong or facial mask, and noninvasive ventilation. The condition of patients in the high-severity group corresponded to invasive ventilation, multi-organ failure with extracorporeal membrane oxygenation required, and death. For the AI model input, we used 37 variables from the medical records, including basic patient information, a physical index, initial examination findings, clinical findings, comorbid diseases, and general blood test results at an early stage. Feature importance analysis was performed with AdaBoost, random forest, and eXtreme Gradient Boosting (XGBoost); the AI model for predicting COVID-19 severity among patients was developed with a 5-layer deep neural network (DNN) with the 20 most important features, which were selected based on ranked feature importance analysis of 37 features from the comprehensive data set. The selection procedure was performed using sensitivity, specificity, accuracy, balanced accuracy, and area under the curve (AUC)., Results: We found that age was the most important factor for predicting disease severity, followed by lymphocyte level, platelet count, and shortness of breath or dyspnea. Our proposed 5-layer DNN with the 20 most important features provided high sensitivity (90.2%), specificity (90.4%), accuracy (90.4%), balanced accuracy (90.3%), and AUC (0.96)., Conclusions: Our proposed AI model with the selected features was able to predict the severity of COVID-19 accurately. We also made a web application so that anyone can access the model. We believe that sharing the AI model with the public will be helpful in validating and improving its performance., (©Heewon Chung, Hoon Ko, Wu Seong Kang, Kyung Won Kim, Hooseok Lee, Chul Park, Hyun-Ok Song, Tae-Young Choi, Jae Ho Seo, Jinseok Lee. Originally published in the Journal of Medical Internet Research (https://www.jmir.org), 19.04.2021.)

Background: Patients with gastric cancer have an increased nutritional risk and experience a significant skeletal muscle loss after surgery. We aimed to determine whether muscle loss during the first postoperative year and preoperative nutritional status are indicators for predicting prognosis., Methods: From a gastric cancer registry, a total of 958 patients who received curative gastrectomy followed by chemotherapy for stage 2 and 3 gastric cancer and survived longer than 1 year were investigated. Clinical and laboratory data were collected. Skeletal muscle index (SMI) was assessed based on the muscle area at the L3 level on abdominal computed tomography., Results: Preoperative nutritional risk index (NRI) and postoperative decrement of SMI (dSMI) were significantly associated with overall survival (hazards ratio: 0.976 [95% CI: 0.962-0.991] and 1.060 [95% CI: 1.035-1.085], respectively) in a multivariate Cox regression analysis. Recurrence, tumor stage, comorbidity index were also significant prognostic indicators. Kaplan-Meier analyses exhibited that patients with higher NRI had a significantly longer survival than those with lower NRI (5-year overall survival: 75.8% vs. 63.0%, P <  0.001). In addition, a significantly better prognosis was observed in a patient group with less decrease of SMI (5-year overall survival: 75.7% vs. 66.2%, P = 0.009). A logistic regression analysis demonstrated that the performance of preoperative NRI and dSMI in mortality prediction was quite significant (AUC: 0.63, P <  0.001) and the combination of clinical factors enhanced the predictive accuracy to the AUC of 0.90 (P <  0.001). This prognostic relevance of NRI and dSMI was maintained in patients experiencing tumor recurrence and highlighted in those with stage 3 gastric adenocarcinoma., Conclusions: Preoperative NRI is a predictor of overall survival in stage 2 or 3 gastric cancer patients and skeletal muscle loss during the first postoperative year was significantly associated with the prognosis regardless of relapse in stage 3 tumors. These factors could be valuable adjuncts for accurate prediction of prognosis in gastric cancer patients.

Background: Although computed tomography (CT) is considered the gold standard for investigating skeletal muscles, diagnostic cutoff points for sarcopenia have not been established. We therefore suggested clinically relevant diagnostic cutoff points for sarcopenia based on reference values of skeletal muscle area (SMA) measured by CT scan in a large-sized healthy Asian population., Methods: This cross-sectional analysis included 11,845 subjects (7,314 men, 4,531 women) who underwent abdominal CT scans in South Korea. SMA including all muscles on the selected axial images of the L3 lumbar vertebrae level was demarcated using predetermined thresholds (-29 to +150 Hounsfield units). SMA indices (height-, weight-, and body mass index [BMI]-adjusted) were calculated., Results: When T-score < -2.0 was used as the cutoff for defining sarcopenia, the sex-specific cutoff points of SMA, SMA/height2, SMA/weight, and SMA/BMI were 119.3 and 74.2 cm2, 39.8 and 28.4 cm2/m2, 1.65 and 1.38 cm2/kg, and 4.97 and 3.46 in men and women, respectively. In both sexes, the SMA/BMI values peaked in the 20s and decreased gradually. The SMA/BMI yielded the highest diagnostic rate of sarcopenia (4.2% in men, 8.7% in women), while SMA/height2 provided the lowest yield (2.8% in men, 1.0% in women)., Conclusions: This is the first study to report the reference values of SMA and skeletal muscle indices (SMIs) measured on CT scans and to suggest cutoff points for diagnosis of sarcopenia based on T-score in Asian subjects. BMI-adjusted index (SMA/BMI) was the best index of CT-measured SMA to reflect the age-related muscle changes and to maximize the diagnostic yield for sarcopenia., (© The Author(s) 2020. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

There is limited data regarding the association between sarcopenia and clinical outcomes in patients who underwent transcatheter aortic valve implantation (TAVI). From the prospective ASAN-TAVI registry, we evaluated a total of 522 patients with severe aortic stenosis who underwent TAVI between March 2010 and November 2018. Routine pre-TAVI computed tomography scan was used to calculate the skeletal muscle index (SMI), which was defined as skeletal muscle area at the L3 level divided by height squared; subject patients were classified into the gender-specific tertile groups of SMI. The patients' mean age was 79 years and 49% were men. Mean SMI values were 41.3 ± 6.7 cm 2 /m 2 in men and 34.1 ± 6.5 cm 2 /m 2 in women. The Kaplan-Meier estimates of all-cause mortality at 12 months were higher in the low-tertile group than in the mid- and high-tertile groups (15.5%, 7.1%, and 6.2%, respectively; p = 0.036). In multivariate analysis, low-tertile of SMI was an independent predictor of mortality (vs high-tertile of SMI, hazard ratio 2.69; 95% confidence interval, 1.18 to 6.12; p = 0.019). The all-cause mortality was substantially higher in the groups with high-surgical risk plus low SMI tertile. The risk assessment with addition of SMI on conventional STS-PROM score was significantly improved by statistical measures of model reclassification and discrimination. In patients who underwent TAVI, sarcopenia measured by SMI was significantly associated with an increased risk of 1-year mortality. The prognostic impact of SMI-measured sarcopenia was more prominent in patients with high surgical risks., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Introduction: Optimal antithrombotic strategy following transcatheter aortic valve replacement (TAVR) is still unknown. We hypothesised that the direct factor Xa inhibitor edoxaban can potentially prevent subclinical leaflet thrombosis and cerebral embolisation compared with conventional dual antiplatelet therapy (DAPT) in patients undergoing TAVR., Methods and Analysis: The ADAPT-TAVR trial is an international, multicentre, randomised, open-label, superiority trial comparing edoxaban-based strategy and DAPT strategy in patients without an indication for oral anticoagulation who underwent successful TAVR. A total of 220 patients are randomised (1:1 ratio), 1-7 days after successful TAVR, to receive either edoxaban (60 mg daily or 30 mg daily if patients had dose-reduction criteria) or DAPT using aspirin (100 mg daily) plus clopidogrel (75 mg daily) for 6 months. The primary endpoint was an incidence of leaflet thrombosis on four-dimensional, volume-rendered cardiac CT imaging at 6 months post-TAVR. The key secondary endpoints were the number of new lesions and new lesion volume on brain diffusion-weighted MRI and the changes in neurological and neurocognitive function assessment between immediate post-TAVR and 6 months of study drug administration. Detailed clinical information on thromboembolic and bleeding events were also assessed., Ethics and Dissemination: Ethic approval has been obtained from the Ethics Committee/Institutional Review Board of Asan Medical Center (approval number: 2017-1317) and this trial is also approved by National Institute of Food and Drug Safety Evaluation of Republic of Korea (approval number: 31511). Results of this study will be disseminated in scientific publication in reputed journals., Trial Registration Number: NCT03284827., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2020. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: COVID-19, which is accompanied by acute respiratory distress, multiple organ failure, and death, has spread worldwide much faster than previously thought. However, at present, it has limited treatments., Objective: To overcome this issue, we developed an artificial intelligence (AI) model of COVID-19, named EDRnet (ensemble learning model based on deep neural network and random forest models), to predict in-hospital mortality using a routine blood sample at the time of hospital admission., Methods: We selected 28 blood biomarkers and used the age and gender information of patients as model inputs. To improve the mortality prediction, we adopted an ensemble approach combining deep neural network and random forest models. We trained our model with a database of blood samples from 361 COVID-19 patients in Wuhan, China, and applied it to 106 COVID-19 patients in three Korean medical institutions., Results: In the testing data sets, EDRnet provided high sensitivity (100%), specificity (91%), and accuracy (92%). To extend the number of patient data points, we developed a web application (BeatCOVID19) where anyone can access the model to predict mortality and can register his or her own blood laboratory results., Conclusions: Our new AI model, EDRnet, accurately predicts the mortality rate for COVID-19. It is publicly available and aims to help health care providers fight COVID-19 and improve patients' outcomes., (©Hoon Ko, Heewon Chung, Wu Seong Kang, Chul Park, Do Wan Kim, Seong Eun Kim, Chi Ryang Chung, Ryoung Eun Ko, Hooseok Lee, Jae Ho Seo, Tae-Young Choi, Rafael Jaimes, Kyung Won Kim, Jinseok Lee. Originally published in the Journal of Medical Internet Research (http://www.jmir.org), 23.12.2020.)

Objectives: To determine the accuracies of the American College of Radiology (ACR)-thyroid imaging reporting and data systems (TIRADS), Korean (K)-TIRADS, and European (EU)-TIRADS for diagnosing malignancy in thyroid nodules., Methods: Original studies reporting the diagnostic accuracy of TIRADS for determining malignancy on ultrasound were identified in MEDLINE and EMBASE up to June 23, 2019. The meta-analytic summary sensitivity and specificity were obtained for TIRADS category 5 (TR-5) and category 4 or 5 (TR-4/5), using a bivariate random effects model. To explore study heterogeneity, meta-regression analyses were performed., Results: Of the 34 eligible articles (37,585 nodules), 25 used ACR-TIRADS, 12 used K-TIRADS, and seven used EU-TIRADS. For TR-5, the meta-analytic sensitivity was highest for EU-TIRADS (78% [95% confidence interval, 64-88%]), followed by ACR-TIRADS (70% [61-79%]) and K-TIRADS (64% [58-70%]), although the differences were not significant. K-TIRADS showed the highest meta-analytic specificity (93% [91-95%]), which was similar to ACR-TIRADS (89% [85-92%]) and EU-TIRADS (89% [77-95%]). For TR-4/5, all three TIRADS systems had sensitivities higher than 90%. K-TIRADS had the highest specificity (61% [50-72%]), followed by ACR-TIRADS (49% [43-56%]) and EU-TIRADS (48% [35-62%]), although the differences were not significant. Considerable threshold effects were noted with ACR- and K-TIRADS (p ≤ 0.01), with subject enrollment, country of origin, experience level of reviewer, number of patients, and clarity of blinding in review being the main causes of heterogeneity (p ≤ 0.05)., Conclusions: There was no significant difference among these three international TIRADS, but the trend toward higher sensitivity with EU-TIRADS and higher specificity with K-TIRADS., Key Points: • For TIRADS category 5, the meta-analytic sensitivity was highest for the EU-TIRADS, followed by the ACR-TIRADS and the K-TIRADS, although the differences were not significant. • For TIRADS category 5, K-TIRADS showed the highest meta-analytic specificity, which was similar to ACR-TIRADS and EU-TIRADS. • Considerable threshold effects were noted with ACR- and K-TIRADS, with subject enrollment, country of origin, experience level of reviewer, number of patients, and clarity of blinding in review being the main causes of heterogeneity.

The association between non-alcoholic fatty liver disease (NAFLD) and diabetic kidney disease assessed using either albuminuria or proteinuria remains controversial. This study aimed to investigate the association between hepatic steatosis or fibrosis and albuminuria or proteinuria in Korean patients with type 2 diabetes mellitus (T2D).We enrolled 1108 patients with T2D and categorized as 3 groups; non-proteinuria (NP), isolated non-albumin proteinuria (iNAP), and albuminuria. Urinary albumin and protein levels were assessed as urinary albumin-to-creatinine ratio (uACR) and urinary protein-to-creatinine ratio (uPCR), respectively. Hepatic steatosis and fibrotic burden were assessed using the NAFLD liver fat score, Fibrosis-4 calculator (FIB-4) index, and NAFLD fibrosis score (NFS).The prevalence of significant steatosis was similar among groups (NP: 74.6% vs iNAP: 70.3% vs albuminuria: 79.9%, P = .085). The prevalence of significant fibrosis was significantly higher in the iNAP (18.7%) and albuminuria (16.5%) groups than in the NP group (9.5%, P = .001). Both uPCR and uACR showed a correlation with NFS (uPCR: r = 0.123, P < .001; uACR: r = 0.064, P = .033). In multivariate logistic regression analysis, uPCR ≥150 mg/g was found to have a stronger association with hepatic fibrosis than uACR ≥30 mg/g (adjusted odds ratio 1.55 [95% CI 1.03-2.33] vs adjusted odds ratio 1.16 [95% CI, 0.72-1.87]).In conclusion, patients with iNAP and albuminuria had a higher prevalence of hepatic fibrosis than those without proteinuria. Total proteinuria was associated with advanced liver fibrosis, whereas albuminuria was related to hepatic steatosis.

Mercury is a cumulative neurotoxic agent, exposure to high levels of which may increase the risk of psychiatric symptoms. The purpose of this study was to examine the associations between blood mercury and depression risk in Korean adults. We analyzed the Korean National Health and Nutrition Examination Survey (KNHANES) with 11,754 participants (male: 5834 female: 5920) aged ≥19 years from 2008 to 2013. The associations of blood mercury with risk of depression were estimated using multivariate logistic regression after adjustment for potential confounders. We found a significantly increased risk of depression in the highest quintile for blood mercury (multivariate OR = 2.05; 95% CI = 1.20-3.48; P trend = 0.03) among female, but not male. A stratification analysis by fish intake showed that the association between depression and blood mercury was strengthened (OR = 4.00; 95% CI = 1.51-10.6; P trend = 0.015) among females with the lowest tertile of fish intake. The results of this study suggest that higher levels of blood mercury, especially in cases of lower fish intake, are positively associated with the risk of depression in Korean women., Competing Interests: The authors declare no conflicts of interest.

Background: The number of children using home mechanical ventilation (HMV) has increased markedly in Europe and North America, but little is known about the situation in Korea. We described the clinical characteristics of children using HMV and investigated the current situation of HMV utilization in children., Methods: Data on HMV prescriptions in year 2016 for children under the age of 19 was retrieved from the National Health Insurance Service for nationwide information. For more detailed information, data from year 2016 to 2018 was also retrieved from a tertiary center, Severance Children's Hospital., Results: Nationwide, 416 children were prescribed with HMV in 2016, with an estimated prevalence of 4.4 per 100,000 children, of which 64.2% were male and mean age was 6-year-old. The estimated number of patients using invasive ventilators via tracheostomy was 202 (49%). Neuromuscular diseases were the most frequent cause (217; 52%), followed by central nervous system diseases (142; 34%), and cardiopulmonary diseases (57; 14%). In the tertiary center, a total of 62 children were prescribed with HMV (19 [31%] with non-invasive ventilation; 43 [69%] with invasive ventilation]. The number of children with HMV increased from 11 in 2016 to 29 in 2018. The mean age for initiation of HMV was 3.1 years and male patients comprised 65%. The most frequent diagnostic reason for HMV was central nervous system diseases (68%), followed by cardiopulmonary diseases (19%) and neuromuscular diseases (13%). Five patients died during the study period and five patients weaned from HMV., Conclusion: This study provides insights on the present situation of HMV utilization in Korean children., Competing Interests: The authors have no potential conflicts of interest to disclose., (© 2019 The Korean Academy of Medical Sciences.)

Background: The rapid development in big data analytics and the data-rich environment of intensive care units together provide unprecedented opportunities for medical breakthroughs in the field of critical care. We developed and validated a machine learning-based model, the Pediatric Risk of Mortality Prediction Tool (PROMPT), for real-time prediction of all-cause mortality in pediatric intensive care units., Methods: Utilizing two separate retrospective observational cohorts, we conducted model development and validation using a machine learning algorithm with a convolutional neural network. The development cohort comprised 1445 pediatric patients with 1977 medical encounters admitted to intensive care units from January 2011 to December 2017 at Severance Hospital (Seoul, Korea). The validation cohort included 278 patients with 364 medical encounters admitted to the pediatric intensive care unit from January 2016 to November 2017 at Samsung Medical Center., Results: Using seven vital signs, along with patient age and body weight on intensive care unit admission, PROMPT achieved an area under the receiver operating characteristic curve in the range of 0.89-0.97 for mortality prediction 6 to 60 h prior to death. Our results demonstrated that PROMPT provided high sensitivity with specificity and outperformed the conventional severity scoring system, the Pediatric Index of Mortality, in predictive ability. Model performance was indistinguishable between the development and validation cohorts., Conclusions: PROMPT is a deep model-based, data-driven early warning score tool that can predict mortality in critically ill children and may be useful for the timely identification of deteriorating patients.

Background: Anaphylaxis is increasing in young children. The aim of the present study was to analyze the clinical characteristics of anaphylaxis in Korean infants, with a focus on food triggers., Methods: The study analyzed the medical records of infants aged 0 to 2 years old who had been diagnosed with anaphylaxis in 23 secondary or tertiary hospitals in Korea., Results: We identified 363 cases of infantile anaphylaxis (66.9% male). Cutaneous symptoms were most prevalent (98.6%), followed by respiratory (83.2%), gastrointestinal (29.8%), and neurologic (11.6%) symptoms. Cardiovascular symptoms were noted in 7.7% of the cases. Most of the cases of anaphylaxis (338; 93.1%) were induced by foods. The most common trigger food was cow's milk and cow's milk products (43.8%), followed by hen's eggs (21.9%), walnuts (8.3%), wheat (7.7%), peanuts (4.8%), other nuts (3.0%), and fish (2.1%). In cow's milk-induced anaphylaxis cases, more than half the cases had cow's milk specific immunoglobulin E (sIgE) levels that were lower than the diagnostic decision points (DDPs), which is 5 kU A /L for those under the age of 1 and 15 kU A /L for those over the age of 1. In anaphylaxis induced by hen's egg, most of the cases (91.8%) had hen's egg sIgE levels that were higher than the DDP, which is 2 kU A /L for those under the age of 2 and 7 kU A /L for those over the age of 2. Of the infantile anaphylaxis cases, 46.8% had been treated with epinephrine, and 25.1% had been prescribed an epinephrine auto-injector., Conclusion: Cow's milk is the most frequent trigger food of anaphylaxis in Korean infants. However, we found no significant correlation between the sIgE level and clinical severity. Education is required regarding the importance of epinephrine as the first line therapy for anaphylaxis and on properly prescribing epinephrine for infants with a history of anaphylaxis., Competing Interests: The authors have no potential conflicts of interest to disclose., (© 2019 The Korean Academy of Medical Sciences.)

Background: The aim of this study was to describe the structure, organization, management, and staffing of pediatric critical care (PCC) in Korea., Methods: We directed a questionnaire survey for all Upper Grade General Hospitals (n = 43) in Korea in 2015. The first questionnaire was mainly about structure, organization, and staffing and responses were obtained from 32 hospitals. The second questionnaire was mainly about patients and management. Responses to second questionnaire were obtained from 18 hospitals., Results: Twelve from 32 Upper Grade General Hospitals had pediatric intensive care units (PICUs) and 11 of them had the PICU which was exclusive for children. Total number of PICU beds in Korea was 113. The ratio of the number of PICU beds to the number of children was 1:77,460 in Korea and this ratio is lower than that of other developed countries. The mean number of beds in the PICUs was 9.4 ± 9.3 (range, 2-30). There were 16 medical doctors who were assigned for PCC and only 5 of them were full time pediatric intensivists. In the 18 Upper Grade General Hospitals that responded to the second questionnaire survey, there were 97 patients in the PICUs with an average number of 5.7 ± 7.2 (range, 0-22) on the survey day. The mean age of the patients was 3.4 ± 5.6 years. The mean length of hospital stay was 82 ± 271 days. The mean Pediatric Risk of Mortality score III was 9.4 ± 7.8 at the time of admission to the PICUs., Conclusion: There is a considerable shortage of PICU beds compared to those in developed countries. In addition, the proportion of PICUs with PCC specialists is much lower than those in the US and European countries., Competing Interests: Disclosure: The authors have no potential conflicts of interest to disclose.

Background/aims: We evaluated the prevalence and characteristics of thyroid nodules detected by thyroid ultrasound (US) at health checkups and the associated clinical parameters., Methods: A total of 72,319 subjects who underwent thyroid US at three health checkup centers in Korea from January 2004 to December 2010 were included in this study. The correlations between the presence of thyroid nodules and other clinical parameters were analyzed., Results: The prevalence of thyroid nodules and cysts was 34.2% (n = 24,757). Thyroid nodules were more prevalent in women and older age groups. Among the subjects with thyroid nodules with size information (n = 24,686), 18,833 (76.3%) had nodules measuring ≤ 1.0 cm. Women and older age groups showed higher proportion of larger nodules. Percentage of women, age, body mass index (BMI), waist circumference, body fat composition, blood pressure, and the level of fasting glucose, total cholesterol, and low density lipoprotein cholesterol were higher in the subjects with thyroid nodules compared to those without nodules. The prevalence of metabolic syndrome and overt/subclinical thyrotoxic state was higher in the subjects with thyroid nodules. In the multivariable logistic regression analysis, women, age, BMI, metabolic syndrome, and thyrotoxicosis were independently associated with the presence of thyroid nodules., Conclusions: The high prevalence of thyroid nodules in people who underwent thyroid US at a health checkup suggests that increased detection of thyroid nodules resulted in an increased prevalence in the general population. However, metabolic disturbances may also have contributed to the increase in thyroid nodule prevalence in Korea.

Communication between people with normal hearing and hearing impairment is difficult. Recently, a variety of studies on sign language recognition have presented benefits from the development of information technology. This study presents a sign language recognition system using a data glove composed of 3-axis accelerometers, magnetometers, and gyroscopes. Each data obtained by the data glove is transmitted to a host application (implemented in a Window program on a PC). Next, the data is converted into angle data, and the angle information is displayed on the host application and verified by outputting three-dimensional models to the display. An experiment was performed with five subjects, three females and two males, and a performance set comprising numbers from one to nine was repeated five times. The system achieves a 99.26% movement detection rate, and approximately 98% recognition rate for each finger's state. The proposed system is expected to be a more portable and useful system when this algorithm is applied to smartphone applications for use in some situations such as in emergencies.

Background: This paper describes the background, aim, and design of a prospective birth-cohort study in Korea called the COhort for Childhood Origin of Asthma and allergic diseases (COCOA). COCOA objectives are to investigate the individual and interactive effects of genetics, perinatal environment, maternal lifestyle, and psychosocial stress of mother and child on pediatric susceptibility to allergic diseases., Methods/design: The participants in COCOA represents a Korean inner-city population. Recruitment started on 19 November, 2007 and will continue until 31 December, 2015. Recruitment is performed at five medical centers and eight public-health centers for antenatal care located in Seoul. Participating mother-baby pairs are followed from before birth to adolescents. COCOA investigates whether the following five environmental variables contribute causally to the development and natural course of allergic diseases: (1) perinatal indoor factors (i.e. house-dust mite, bacterial endotoxin, tobacco smoking, and particulate matters 2.5 and 10), (2) perinatal outdoor pollutants, (3) maternal prenatal psychosocial stress and the child's neurodevelopment, (4) perinatal nutrition, and (5) perinatal microbiome. Cord blood and blood samples from the child are used to assess whether the child's genes and epigenetic changes influence allergic-disease susceptibility. Thus, COCOA aims to investigate the contributions of genetics, epigenetics, and various environmental factors in early life to allergic-disease susceptibility in later life. How these variables interact to shape allergic-disease susceptibility is also a key aim.The COCOA data collection schedule includes 11 routine standardized follow-up assessments of all children at 6 months and every year until 10 years of age, regardless of allergic-disease development. The mothers will complete multiple questionnaires to assess the baseline characteristics, the child's exposure to environmental factors, maternal pre- and post-natal psychological stress, and the child's neurodevelopment, nutritional status, and development of allergic and respiratory illnesses. The child's microbiome, genes, epigenetics, plasma cytokine levels, and neuropsychological status, the microbiome of the residence, and the levels of indoor and outdoor pollutants are measured by standard procedures., Discussion: The COCOA study will improve our understanding of how individual genetic or environmental risk factors influence susceptibility to allergic disease and how these variables interact to shape the phenotype of allergic diseases.

Background: Thyroid cancer has increased globally, with a prominent increase in small, papillary thyroid cancers (PTC). The Korean population has a high iodine intake, high prevalence of BRAF V600E mutations, and family histories of thyroid cancer. We examined the clinicopathological characteristics and outcomes of thyroid cancers in Korean patients over four decades., Methods: The medical records of 4500 thyroid cancer patients, between 1962 and 2009 at a single center, including 3147 PTC patients, were reviewed., Results: The mean age of the patients was 46.8±13.2 years; women accounted for 82.9% of the patients, and the median follow-up duration was 4.8 years (mean 7.0±5.8 years, range 1-43 years). The number of patients visiting the clinic increased from 411 during 1962-1990 to 2900 during 2000-2009. Age at diagnosis increased from 39.6±12.9 to 48.6±12.4 years. The male to female ratio increased from 1:6 to 1:4.5. The proportion of small (<1 cm) tumors increased from 6.1% to 43.1%, and the proportion of cancers with lymph node (LN) involvement or extrathyroidal extension (ETE) decreased from 76.4% to 44.4% and from 65.5% to 54.8% respectively. Although there were decreases in the proportion of LN involvement and ETE, these decreasing rates were not proportional to the expected rates based on the decreased proportion of large tumors. The overall recurrence and mortality rates were 13.3% and 1.4%. The five-year recurrence rate significantly decreased (from 11% to 5.9%), and the five-year mortality also improved (from 1.5% to 0.2%)., Conclusions: The incidence of thyroid cancer has rapidly increased, with a decrease in tumors of large size, LN involvement, and ETE, although the decreasing rates of LN involvement and ETE were not as prominent as decreasing rates of large size tumors. The mortality and recurrence rates have also decreased. Future long-term follow-up of patients diagnosed in the most recent decade is needed to confirm the prognostic characteristics of Korean PTC patients.

Background: The occurrence of numerous cases of interstitial lung disease in children (chILD) every spring in Korea starting in 2006 raised suspicion about a causal relationship with the use of humidifier disinfectants (HDs). The aim of this study was to evaluate the association between HD use and the risk of chILD., Methods: This retrospective, 1∶3 matched case-control study consisted of 16 cases of chILD that had developed between 2010 and 2011. The three groups of parallel controls (patients with acute lobar pneumonia, asthma, and healthy children) were matched by age, gender, and index date. Indoor/outdoor environmental risk factors, including HD use, were investigated by asking the guardians to complete a questionnaire., Results: The median age of the affected children (43.8% male) was 26 months (18.25-36.25). The chILD group did not differ significantly from the control groups with respect to socio-demographic and clinical variables. Indoor and outdoor environmental factors were not associated with a risk of chILD. However, the previous use of HDs (OR; 2.73. 95% CI; 1.41-5.90, P = 0.00) were independently associated with an increased risk., Conclusions: This study showed that HDs, which are widely used in South Korea in the winter season, independently increased the risk of chILD in spring. Therefore, continuous monitoring and, if needed, changes in policy are essential to prevent and control pediatric diseases caused by toxic chemicals.

Background: The atopic diseases, which are the most common chronic diseases of childhood, are complex genetic diseases that involve the contribution of multiple genetic factors to disease pathophysiology. Chitotriosidase is involved in innate immunity, but the association of chitotriosidase with allergic diseases remains unclear., Objective: To examine the contribution of genetic variation of the chitotriosidase-encoding gene CHIT1 to atopic phenotypes in a Korean cohort of children., Methods: We identified CHIT1 variations in a Korean population and conducted association analyses using 295 atopic and 242 nonatopic children. An independent replication study was performed using DNA samples from 148 atopic and 243 nonatopic children. All children were unrelated. We performed Western blot analysis in each genotype in vitro to see whether the CHIT1 A442G variation affects the final protein expression levels., Results: In the case-control association analysis, atopy was significantly associated with a single A442G (rs1065761) polymorphism in CHIT1 (odds ratio = 1.32, P = .01). Children with the c.442G risk allele had significantly higher blood eosinophils (P = .001), total serum IgE (P = .007), and eosinophil cationic protein (P = .02) levels. The results of the replication stage analysis confirmed a significant association between the A442G polymorphism and childhood atopy. The joint analysis of the exploratory and replication studies displayed a stronger significant association. The relative protein expression levels of chitotriosidase were significantly higher in both cell lysate and media with the G transfection compared with the wild type., Conclusion: These results indicate that the nonsynonymous A442G polymorphism in CHIT1 is associated with risk of atopy., (Copyright © 2013 American College of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.)

Previous studies suggest that maternal characteristics may be associated with neonatal outcomes. However, the influence of maternal characteristics on birth weight (BW) has not been adequately determined in Korean populations. We investigated associations between maternal characteristics and BW in a sample of 813 Korean women living in the Seoul metropolitan area, Korea recruited using data from the prospective hospital-based COhort for Childhood Origin of Asthma and allergic diseases (COCOA) between 2007 and 2011. The mean maternal age at delivery was 32.3 ± 3.5 yr and prepregnancy maternal body mass index (BMI) was 20.7 ± 2.5 kg/m(2). The mean BW of infant was 3,196 ± 406 g. The overall prevalence of a maternal history of allergic disease was 32.9% and the overall prevalence of allergic symptoms was 65.1%. In multivariate regression models, prepregnancy maternal BMI and gestational age at delivery were positively and a maternal history of allergic disease and nulliparity were negatively associated with BW (all P < 0.05). Presence of allergic symptoms in the mother was not associated with BW. In conclusion, prepregnancy maternal BMI, gestational age at delivery, a maternal history of allergic disease, and nulliparity may be associated with BW, respectively.

Background: The prevalence of allergic rhinitis (AR) is increasing worldwide. Allergic diseases develop in susceptible subjects when they are exposed to specific environmental factors., Objective: We analyzed changes in the prevalence of AR and identified genetic and environmental factors in early childhood that affect risk., Methods: We used the International Study of Asthma and Allergies in Childhood questionnaire to collect data on AR, allergies, and environmental exposures from 4554 elementary school students from 5 areas of Seoul, Korea, in 2008. We also obtained DNA from 1050 subjects from 1 area of Seoul for genotype analysis of IL13., Results: We identified genetic and environmental factors during infancy and early childhood that increased the risk for current AR (resulting in a diagnosis of AR and AR symptoms in the past 12 months) in elementary school-aged children. These included allergic disease in parents and antibiotic use in infants, allergic disease in parents and exposure of infants to mold, and allergic disease in parents and moving an infant to a newly built house. The risk of current AR also increased in subjects with GA or AA at nucleotide 2044 in IL13 who had been exposed to mold in the home during infancy (adjusted odds ratio, 3.27; 95% CI, 1.75-6.11) compared with subjects who had GG at this position and had not been exposed to mold (adjusted odds ratio, 3.27; 95% CI, 1.75-6.11)., Conclusion: The prevalence of AR is increasing in Korean children. Children with a family history of allergic disease and exposure to specific environmental risk factors during infancy are more likely to have AR. Children with GA or AA at IL13(+2044) are at increased risk for AR when exposed to mold in the home during the first year of life., (Copyright © 2012 American Academy of Allergy, Asthma & Immunology. Published by Mosby, Inc. All rights reserved.)

Background: AdvanSure enzyme immunoassay (EIA) system is a recently developed multiple allergen screen test with specific immunoglobulin E (sIgE) detection assay, while ImmunoCAP fluorescent EIA (FEIA) has been widely used for sIgE detection. There has been no inter-assay comparison data for these two systems. We determined the detection performance of AdvanSure system compared to that of ImmunoCAP., Methods: We performed an inter-method comparison using sera from 199 Korean allergy patients, including asthma (39.7%), allergic rhinitis (54.8%), atopic dermatitis (36.2%) and food allergies (21.6%). We compared the sIgE detection performance for nine major inhalant and four food allergens., Results: 950 paired assay results were analyzed. Most allergen sIgE results showed above 0.5 intraclass correlation coefficient except Blattella germanica, alternaria and mugwort allergen. Intermethod comparison results showed multiple differences in a few allergens. The inter-method concordance was moderate to substantial for most allergens (κ=0.528-0.778, p<0.001), except for cat dander., Conclusion: AdvanSure system showed a good detection performance compared with ImmunoCAP in correlation and agreement in Korean allergy patients. However, in terms of differences in the methodologies used by these two systems, careful clinical correlation is needed for interpretation of AdvanSure EIA results., (Copyright © 2012 Elsevier B.V. All rights reserved.)

Background: Familial nonmedullary thyroid carcinoma (FNMTC) is frequently detected, but the prevalence or the aggressiveness of FNMTC is still unclear. We aimed to investigate the prevalence, clinical characteristics, and prognosis of FNMTC., Methods: This study included 3056 nonmedullary thyroid carcinoma (NMTC) patients who were pathologically confirmed to exhibit differentiated thyroid carcinoma from January 1962 through March 2010. The duration of follow-up was 6.2±6.2 years., Results: The prevalence of FNMTC was 9.6%; 37.9% of the FNMTC patients exhibited a parent-offspring relationship, and 62.1% exhibited a sibling relationship. FNMTC was smaller in tumor size (1.2±0.9 vs. 1.4±1.1 cm) and more multifocal (33.6% vs. 27.0%) than sporadic cases. FNMTC presented higher recurrence rates (29.5% vs. 19.8%) and shorter recurrence-free survival than sporadic NMTC (p=0.046). When we compared sporadic NMTC with parent-offspring or sibling FNMTC separately, parent-offspring FNMTC was more multifocal (39.3% vs. 27.0%), while sibling FNMTC was more prevalent in female patients (89.6% vs. 82.5%) and presented smaller tumors (1.2±0.8 vs. 1.4±1.1 cm) than sporadic NMTC. The recurrence rate was higher than that of sporadic NMTC in parent-offspring FNMTC (35.6% vs. 19.8%) but not in sibling FNMTC. Among the 123 parent-offspring FNMTC cases, the second generation exhibited an earlier age at the diagnosis (38±11 vs. 57±11 years), more extrathyroidal invasion (57.8% vs. 29.4%), a higher recurrence rate (50.0% vs. 19.0%), and shorter recurrence-free survival (p=0.015) than the first generation., Conclusion: FNMTC was found to have a very high prevalence in our population. Parent-offspring FNMTC demonstrated higher recurrence than sporadic NMTC; specifically, the second generation of parent-offspring FNMTC cases exhibited more aggressive clinical characteristics than the first generation.

The purpose of this study was to investigate the association between body mass index (BMI) and the prevalence of wheeze using nation-wide cross-sectional study in Korean children. Total 50,200 children from 427 elementary schools were randomly selected according to residential areas (metropolitan, provincial, rural, and industrial areas) by the cluster sampling method. The International Study of Asthma and Allergies in Childhood (ISAAC) questionnaires were used to measure the prevalence of wheeze. Among 31,026 respondents, 25,322 were analyzed. BMI was classified into quartiles based on BMI-for-age percentile. In all residential areas, pets at home and visible mold or moisture were associated with an increased prevalence of wheeze in both genders. However, other living environment factors were not consistently associated among residential areas and gender. Among girls, lowest BMI was negatively associated with prevalence of wheeze and highest BMI was positively associated in all residential areas. In multilevel logistic regression analysis, environmental tobacco smoking exposure, pets at home, visible mold or moisture, and being in the lowest and highest BMI quartile were significantly associated with the prevalence of wheeze in both genders. BMI has become an important risk factor for asthma symptoms among Korean children.

Background: Hashimoto's thyroiditis (HT) and higher levels of thyroid-stimulating hormone (TSH) have been proposed as risk factors for papillary thyroid cancer (PTC), but this issue is still being debated. The purpose of this study was whether HT was related to the risk of PTC over TSH., Methods: We enrolled 1329 patients (1028 with PTC, 52 with follicular thyroid cancer, and 249 with benign disease) of 1490 patients who underwent thyroidectomy., Results: The TSH concentration was not different among patients with PTC or benign disease. Our study showed that men (odds ratio [OR] = 1.54; p = .049) and the presence of HT (OR = 2.96; p <.001) increased the risk of PTC. Moreover, HT was associated with multifocal cancer (p = .005) and smaller tumor size (p = .031), but it did not influence the extrathyroidal invasion or nodal metastasis., Conclusion: Clinicians who deal with thyroid nodules should pay particular attention to HT because it is a stronger predictor for PTC than other risk factors., (Copyright © 2010 Wiley Periodicals, Inc.)

Background: To date, there is little evidence to support an association between symptoms of pediatric allergic disorders and psychosocial factors in the general population, particularly in Asian countries. The current study aims to investigate the relationship between psychosocial factors and symptoms of allergic disorders and to investigate the association between behavior problems and biomarkers of atopy., Methods: A cross-sectional survey of parental responses to the International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire and the Korean version of the Child Behavior Checklist (CBCL) was conducted from one elementary school in Seoul, Korea. Skin prick tests for 18 major allergens were also performed., Results: A total of 780 children with valid CBCL surveys were included in the study. Externalizing problems were significantly larger in children with asthmatic symptoms, while internalizing problems were significantly larger in children with symptoms of both asthma and allergic rhinitis. Social adaptations were significantly lower in children with symptoms of allergic rhinitis and atopic dermatitis. Boys with more positive allergens via the skin prick tests showed larger internalizing problems., Conclusions: While school children with allergic symptoms have been reported to have more difficulties with psychosocial adaptation, the patterns of psychosocial problems varied somewhat according to the types of atopic disorder. There was a positive relationship between atopy and behavior problems, especially in boys., (Copyright © 2010 S. Karger AG, Basel.)

Purpose: Classic cystic fibrosis is now known part of cystic fibrosis transmembrane conductance regulator (CFTR)-related disorders. These include a wide spectrum, from multi-system disorders, such as cystic fibrosis, to mono-symptomatic conditions, such as chronic pancreatitis or congenital bilateral absence of the vas deferens. However, respiratory disease is considered typical for the multi system disorder, cystic fibrosis, and is the major cause of morbidity and mortality. The purpose of this study was to evaluate the potential effects of CFTR gene mutations in Korean children with asthma., Materials and Methods: We selected 14 mutations identified in Korea and each of the 48 children with and without asthma were genotyped for the case-control study., Results: No significant differences were found in genotype and allele frequencies of the 9 polymorphisms observed between the non-asthma and asthma groups. In a haplotype determination based on a Bayesian algorithm, 8 haplotypes were assembled in the 98 individuals tested. However, we also did not find any significant differences in haplotype frequencies between the non-asthma and asthma groups., Conclusion: We have concluded that this study did not show any evidence in support of providing that CFTR genetic variations significantly contribute to the susceptibility of asthma in Korean children.

Background: Papillary thyroid microcarcinoma (PMC; 1 cm., Results: The prevalence of extrathyroidal invasion (52.2%) and initial nodal metastasis (34.9%) in patients with PMC was surprisingly high and almost as high as that for patients with PTC (72.4% and 51.8%, respectively). The rate of recurrent or persistent disease did not differ between patients with PMC and PTC (recurrent or persistent disease, 6.1% vs 14.1%; 53.4- vs 84.2-month follow-up; n = 98 vs 647; corrected p = .112). The frequency of BRAF(V600E) mutation was similar in patients with PMC and PTC (65.6% vs 67.2%). Immunohistochemical staining showed no different expression pattern according to the tumor size., Conclusion: These results suggest that PMC is not an occult cancer and it can act like larger PTC. Therefore, PMC should not be underestimated in practice.