Perfluoroalkyl substances (PFAS) are widely used in industry and daily life due to their useful properties. They have a long half-life, accumulate in the body, and there is evidence that they are associated with biomarkers of lipid metabolism and liver damage. This may suggest non-alcoholic fatty liver disease (NAFLD) caused by PFAS. However, since there has been no study analyzing the relationship between PFAS and NAFLD in the entire population in Korea. We sought to confirm the relationship between serum PFAS concentration and NAFLD prevalence in Korean adults using the Korean National Environmental Health Survey (KoNEHS) cycle 4.

Perfluoroalkyl substances (PFAS) are widely used in industry and daily life due to their useful properties. They have a long half-life, accumulate in the body, and there is evidence that they are associated with biomarkers of lipid metabolism and liver damage. This may suggest non-alcoholic fatty liver disease (NAFLD) caused by PFAS. However, since there has been no study analyzing the relationship between PFAS and NAFLD in the entire population in Korea. We sought to confirm the relationship between serum PFAS concentration and NAFLD prevalence in Korean adults using the Korean National Environmental Health Survey (KoNEHS) cycle 4.

Perfluoroalkyl substances (PFAS) are widely used in industry and daily life due to their useful properties. They have a long half-life, accumulate in the body, and there is evidence that they are associated with biomarkers of lipid metabolism and liver damage. This may suggest non-alcoholic fatty liver disease (NAFLD) caused by PFAS. However, since there has been no study analyzing the relationship between PFAS and NAFLD in the entire population in Korea. We sought to confirm the relationship between serum PFAS concentration and NAFLD prevalence in Korean adults using the Korean National Environmental Health Survey (KoNEHS) cycle 4.

Background: s/Aims: Reported incidence of extrahepatic bile duct cancer is higher in Asians than in Western populations. Korea, in particular, is one of the countries with the highest incidence rates of extrahepatic bile duct cancer in the world. Although research and innovative therapeutic modalities for extrahepatic bile duct cancer are emerging, clinical guidelines are currently unavailable in Korea. The Korean Society of Hepato-Biliary-Pancreatic Surgery in collaboration with related societies (Korean Pancreatic and Biliary Surgery Society, Korean Society of Abdominal Radiology, Korean Society of Medical Oncology, Korean Society of Radiation Oncology, Korean Society of Pathologists, and Korean Society of Nuclear Medicine) decided to establish clinical guideline for extrahepatic bile duct cancer in June 2021. Methods: Contents of the guidelines were developed through subgroup meetings for each key question and a preliminary draft was finalized through a Clinical Guidelines Committee workshop. Results: In November 2021, the finalized draft was presented for public scrutiny during a formal hearing. Conclusions The extrahepatic guideline committee believed that this guideline could be helpful in the treatment of patients.

Background/Aims: Endoscopic ultrasound-guided fine-needle aspiration/biopsy (EUS-FNA/B) is essential in diagnosing solid pancreatic lesions (SPLs), but without rapid on-site evaluation (ROSE), a repeat EUS-FNA/B is crucial for clarifying an inconclusive diagnosis. We aimed to evaluate factors associated with improved diagnostic performance of repeat EUS-FNA/B for initially inconclusive SPL diagnoses without ROSE. Methods: Of 5,894 patients subjected to EUS-FNA/B, 237 (4.0%) with an initially inconclusive diagnosis of SPLs were retrospectively enrolled from five tertiary medical centers between January 2016 and June 2021. Diagnostic performance and procedural factors of EUS-FNA/B were analyzed. Results: The diagnostic accuracies of first and repeat EUS-FNA/B were 96.2% and 67.6%, respectively. Of 237 patients with an inconclusive diagnosis from initial EUS-FNA/B, 150were pathologically diagnosed after repeat EUS-FNA/B. In multivariate analysis of repeat EUS-FNA/B, tumor location (body/tail vs head: odds ratio [OR], 3.74; 95% confidence inter-val [CI], 1.48 to 9.46), number of needle passes (≥4 vs ≤3: OR, 4.80; 95% CI, 1.44 to 15.99),needle type (FNB vs FNA: OR, 3.26; 95% CI, 1.44 to 7.36), needle size (22 gauge vs 19/20 gauge: OR, 2.35; 95% CI, 1.19 to 4.62), and suction method (suction vs others: OR, 5.19;95% CI, 1.30 to 20.75) were associated with a significantly improved diagnostic performance. Conclusions Repeat EUS-FNA/B is essential for patients with an inconclusive EUS-FNA/B without ROSE. To improve the diagnostic performance of repeated EUS-FNA/B, it is recom-mended that 22-gauge FNB needles, ≥4 needle passes, and suction methods are used.

Background: Severe fever with thrombocytopenia syndrome virus (SFTSV) is transmitted through tick bites. Ticks are potential vectors for the bacterium Coxiella burnetii that causes Query fever. Here, we analyzed SFTSV and C. burnetii co-infection rates in ticks in rural areas of Jeju Island, South Korea. Methods: Free ticks were collected from the natural environment of the island between 2016 and 2019, and SFTSV RNA was extracted. Additionally, ribosomal RNA gene sequencing was used to identify Coxiella species. Results: Haemaphysalis longicornis was the most common tick species followed by H. flava. Tick number gradually increased from April, peaked in August, and was lowest in March. Of all the collected ticks, 82.6% (2,851/3,458) were nymphs, 17.9% (639/3,458) adults, and 0.1% (4/3,458) larvae. SFTSV-infected ticks comprised 12.6% of all ticks; their numbers were the lowest in November–December, increased from January, and were mostly identified in the adult stage during June–August. C. burnetii infections were detected in 4.4% of the SFTSVinfected H. longicornis ticks. C. burnetii co-infection was mainly observed in the nymph stage of H. longicornis, with the highest infection rate in January, followed by December and November. Conclusion Our findings suggest that Jeju Island has a high SFTSV and potential C. burnetii infection in ticks. This study provides important insights regarding SFTS and Q fever risk to humans in South Korea.

BACKGROUND: Bone growth factors, particularly bone morphogenic protein-2 (BMP-2), are required for effective treatment of significant bone loss. Despite the extensive development of bone substitutes, much remains to be desired for wider application in clinical settings. The currently available bone substitutes cannot sustain prolonged BMP-2 release and are inconvenient to use. In this study, we developed a ready-to-use bone substitute by sequential conjugation of BMP to a three-dimensional (3D) poly(L-lactide) (PLLA) scaffold using novel molecular adhesive materials that reduced the operation time and sustained prolonged BMP release. METHODS: A 3D PLLA scaffold was printed and BMP-2 was conjugated with alginate-catechol and collagen. PLLA scaffolds were conjugated with different concentrations of BMP-2 and evaluated for bone regeneration in vitro and in vivo using a mouse calvarial model. The BMP-2 release kinetics were analyzed using ELISA. Histological analysis and microCT image analysis were performed to evaluate new bone formation. RESULTS: The 3D structure of the PLLA scaffold had a pore size of 400 lm and grid thickness of 187–230 lm. BMP-2 was released in an initial burst, followed by a sustained release for 14 days. Released BMP-2 maintained osteoinductivity in vitro and in vivo. Micro-computed tomography and histological findings demonstrate that the PLLA scaffold conjugated with 2 lg/ml of BMP-2 induced optimal bone regeneration. CONCLUSION The 3D-printed PLLA scaffold conjugated with BMP-2 enhanced bone regeneration, demonstrating its potential as a novel bone substitute.

Purpose: The optimal short-course chemotherapeutic regimen for rectal cancer has not been clearly defined until now. KROG 10-01 and KROG 11-02 prospective trials investigated the efficacy and safety of 1- and 2-week chemoradiotherapy (CRT), respectively. Materials and Methods: Patients eligible for KROG 10-01 and KROG 11-02 involved those with clinical T3-4N0-2M0 rectal cancers. They received preoperative CRT and total mesorectal excision. Patients in KROG 10-01 received radiation of 25 Gy in 5 fractions during 1 week with 5-fluorouracil/leucovorin. Patients in KROG 11-02 received radiation of 33 Gy in 10 fractions for 2 weeks with oral capecitabine. Results: A total of 150 patients consisting of 70 patients from KROG 10-01 and 80 patients from KROG 11-02 were collectively analyzed. With a median follow-up time of 89.2 months, the 5-year overall survival rate was 86.5% in 1-week CRT and 85.3% in 2-week CRT (p=0.841). The 5-year recurrence-free survival rate was 83.5% in 1-week CRT and 77.1% in 2-week CRT (p=0.448). One patient (1.4%) in 1-week CRT and 11 patients (13.8%) in 2-week CRT exhibited pathologic complete regression (ypT0N0M0) after radiotherapy (p=0.006). One-week CRT had significantly higher acute hematologic (12.8% vs. 3.8%, p=0.040) and nonhematologic (38.6% vs. 16.3%, p=0.002) toxicity than 2-week CRT. Conclusion Both 1- and 2-week schedules of CRT showed favorable survival outcomes after 7 years of follow-up. But, 2-week course achieved more increased tumor response and decreased acute toxicity than 1-week course.

Subclinical hypothyroidism (SCH), characterized by elevated serum thyroid-stimulating hormone (TSH) levels and normal free thyroxine levels, usually presents without symptoms, and is often discovered incidentally during routine blood test. The Task Force of the Korean Thyroid Association Committee of Clinical Practice Guidelines has established a guideline to evaluate and manage SCH; the guideline emphasizes the implementation of diagnostic criteria based on the TSH reference range for Koreans and focuses on the proven health benefits of levothyroxine (LT4) treatment. Based on the Korea National Health and Nutrition Examination Survey (2013-2015), serum TSH level of 6.8 mIU/L is considered the reference value for SCH. SCH can be categorized as mild (TSH 6.8-10.0 mIU/L) or severe (TSH ＞10.0 mIU/L), and patients are classified as adults (age ＜70 years) or elderly patients (age ≥70years) depending on the health effects of LT4 treatment. An initial increase in serum TSH levels should be reassessed with a subsequent measurement, along with the thyroid peroxidase antibody test, preferably 2-3 months after the initial evaluation. Usually, LT4 treatment is not recommended for mild SCH in adults; however, treatment is necessary for severe SCH in patients with underlying coronary artery disease or heart failure and can be considered for coexisting dyslipidemia. LT4 treatment is not recommended for mild or even severe SCH in elderly patients, in general. Patients with SCH who receive LT4 treatment, the LT4 dosage should be personalized, and serum TSH levels should be monitored to ensure optimal LT4 dosage (dosage that is neither excessive nor insufficient). Patients with SCH who do not receive LT4 treatment require periodic follow-up at appropriate testing intervals determined by disease severity. The guideline also provides several educational points applicable in clinical settings.