Differentiated thyroid cancer demonstrates a wide range of clinical presentations, from very indolent cases to those with an aggressive prognosis. Therefore, diagnosing and treating each cancer appropriately based on its risk status is important. The Korean Thyroid Association (KTA) has provided and amended the clinical guidelines for thyroid cancer management since 2007. The main changes in this revised 2024 guideline include 1) individualization of surgical extent according to pathological tests and clinical findings, 2) application of active surveillance in low-risk papillary thyroid microcarcinoma, 3) indications for minimally invasive surgery, 4) adoption of World Health Organization pathological diagnostic criteria and definition of terminology in Korean, 5) update on literature evidence of recurrence risk for initial risk stratification, 6) addition of the role of molecular testing, 7) addition of definition of initial risk stratification and targeting thyroid stimulating hormone (TSH) concentrations according to ongoing risk stratification (ORS), 8) addition of treatment of perioperative hypoparathyroidism, 9) update on systemic chemotherapy, and 10) addition of treatment for pediatric patients with thyroid cancer.

Background: The benefits of transradial access (TRA) over transfemoral access (TFA) for bifurcation percutaneous coronary intervention (PCI) are uncertain because of the limited availability of device selection. This study aimed to compare the procedural differences and the in-hospital and long-term outcomes of TRA and TFA for bifurcation PCI using secondgeneration drug-eluting stents (DESs). Methods: Based on data from the Coronary Bifurcation Stenting Registry III, a retrospective registry of 2,648 patients undergoing bifurcation PCI with second-generation DES from 21 centers in South Korea, patients were categorized into the TRA group (n = 1,507) or the TFA group (n = 1,141). After propensity score matching (PSM), procedural differences, in-hospital outcomes, and device-oriented composite outcomes (DOCOs; a composite of cardiac death, target vessel-related myocardial infarction, and target lesion revascularization) were compared between the two groups (772 matched patients each group). Results: Despite well-balanced baseline clinical and lesion characteristics after PSM, the use of the two-stent strategy (14.2% vs. 23.7%, P = 0.001) and the incidence of in-hospital adverse outcomes, primarily driven by access site complications (2.2% vs. 4.4%, P = 0.015), were significantly lower in the TRA group than in the TFA group. At the 5-year follow-up, the incidence of DOCOs was similar between the groups (6.3% vs. 7.1%, P = 0.639). Conclusion The findings suggested that TRA may be safer than TFA for bifurcation PCI using second-generation DESs. Despite differences in treatment strategy, TRA was associated with similar long-term clinical outcomes as those of TFA. Therefore, TRA might be the preferred access for bifurcation PCI using second-generation DES.

Objective: The Scales for Outcomes in Parkinson’s Disease–Cognition (SCOPA-Cog) was developed to assess cognition in patients with Parkinson’s disease (PD). In this study, we aimed to evaluate the validity and reliability of the Korean version of the SCOPACog (K-SCOPA-Cog). Methods: We enrolled 129 PD patients with movement disorders from 31 clinics in South Korea. The original version of the SCOPA-Cog was translated into Korean using the translation-retranslation method. The test–retest method with an intraclass correlation coefficient (ICC) and Cronbach’s alpha coefficient were used to assess reliability. Spearman’s rank correlation analysis with the Montreal Cognitive Assessment-Korean version (MOCA-K) and the Korean Mini-Mental State Examination (K-MMSE) were used to assess concurrent validity. Results: The Cronbach’s alpha coefficient was 0.797, and the ICC was 0.887. Spearman’s rank correlation analysis revealed a significant correlation with the K-MMSE and MOCA-K scores (r = 0.546 and r = 0.683, respectively). Conclusion Our results demonstrate that the K-SCOPA-Cog has good reliability and validity.

Objective: Traumatic brain injury (TBI) is one of the major causes of death and disability in children. Understanding the epidemiologic characteristics of TBI in children is the first step for developing preventative strategies, optimizing care systems, and rehabilitating the injury. Methods: This is a cross-sessional study based on the Emergency Department-based Injury In-depth Surveillance (EDIIS) in Korea. We identified children (aged 0 to 18 years) who presented with TBI in emergency departments between January 2011 and December 2018. Subjects were classified into four groups according to age and development: infant and toddler group (0-2 years), pre-school group (3-5 years), school-aged group (6-11 years), and adolescent group (12-18 years). Epidemiologic characteristics and outcomes were compared according to age groups, and temporal variability in incidence was evaluated. Results: During the 8-year study period, 45,734 children with TBI were included in the analysis. A higher incidence of TBI was observed in males, road accidents, and school/educational facilities as compared to the lesser-aged group (all P<0.01). Motor vehicle collisions were more common in the older group, but falls were more common in the younger group. Compared to the infant/toddler group, the adolescent group had higher intracranial injuries (8.1% vs. 16.8%; adjusted odds ratio [AOR], 1.8; 95% confidence interval [CI], 1.6-2.0) and mortality rate (0.2% vs. 1.3%; AOR, 2.0; 95% CI, 1.3-3.0). Conclusion The epidemiological characteristics of TBI in children are different for each group. It is necessary to develop differentiated preventative strategies and treatment systems based on the age groups of children.

Background: The Omicron variant has become the most prevalent SARS-CoV-2 variant. Omicron is known to induce milder lesions compared to the original Wuhan strain. Fatal infection of the Wuhan strain into the brain has been well documented in COVID-19 mouse models and human COVID-19 cases, but apparent infections into the brain by Omicron have not been reported in human adult cases or animal models. In this study, we investigated whether Omicron could spread to the brain using K18-hACE2 mice susceptible to SARS-CoV-2 infection. Results: K18-hACE2 mice were intranasally infected with 1 × 105 PFU of the original Wuhan strain and the Omicron variant of SARS-CoV-2. A follow-up was conducted 7 days post infection. All Wuhan-infected mice showed > 20% body weight loss, defined as the lethal condition, whereas two out of five Omicron-infected mice (40%) lost > 20% body weight. Histopathological analysis based on H&E staining revealed inflammatory responses in the brains of these two Omicron-infected mice. Immunostaining analysis of viral nucleocapsid protein revealed severe infection of neuron cells in the brains of these two Omicron-infected mice. Lymphoid depletion and apoptosis were observed in the spleen of Omicron-infected mice with brain infection. Conclusion Lethal conditions, such as severe body weight loss and encephalopathy, can occur in Omicron-infected K18-hACE2 mice. Our study reports, for the first time, that Omicron can induce brain infection with lymphoid depletion in the mouse COVID-19 model.

Background/Aims: To analyze various adverse events (AEs) related to the peroral endoscopic myotomy (POEM) procedure and to analyze whether these AEs are related to an extended hospital stay. Methods: Patients admitted for POEM for esophageal motility disorders from August 2012 to February 2020 at 5 centers were retrospectively collected. Length of hospital stay, AEs during or after the POEM procedure were analyzed. Results: Of the 328 patients, 63.1% did not have any AEs, but 2.4% had major AEs, and 33.4% had minor AEs. Major AEs included mucosal injury, bleeding, and hemothorax, accounting for 1.5%, 0.6%, and 0.3%, respectively. Among the minor AEs, pneumoperitoneum was the most common gas-related AEs. Among non-gas-related minor AEs, pneumonia was the most common at 4.6%, followed by pain, fever, and pleural effusion. All major AEs had meaningful delayed discharge and significantly extended hospital stay compared to the no AEs group (median differences range 4.5-9.0 days). Among gas-related minor AEs, except for 4 cases of emphysema, the extended hospital stay was meaningless. All non-gas-related minor AEs was associated with a significant prolongation of hospital stay compared to that in the no AEs group (median differences range 2.0-4.0 days). Conclusions In conclusion, most gas-related minor AEs do not significantly affect the patient’s clinical course. However, subcutaneous emphysema and minor non-gas related AEs such as pneumonia, pain, fever, and pleural effusion can prolong the hospital stay, therefore careful observation is required. Efforts will be made to reduce major AEs that significantly prolong hospitalization.

The global burden of chronic liver disease (CLD) is substantial. Due to the limited indication of and accessibility to antiviral therapy in viral hepatitis and lack of effective pharmacological treatment in nonalcoholic fatty liver disease, the beneficial effects of antidiabetics and non–antidiabetics in clinical practice have been continuously investigated in patients with CLD. In this narrative review, we focused on non-antidiabetic drugs, including ursodeoxycholic acid, silymarin, dimethyl4,4’-dimethoxy-5,6,5’,6’-dimethylenedixoybiphenyl-2,2’-dicarboxylate, L-ornithine L-aspartate, branched chain amino acids, statin, probiotics, vitamin E, and aspirin, and summarized their beneficial effects in CLD. Based on the antioxidant, anti-inflammatory properties, and regulatory functions in glucose or lipid metabolism, several non–antidiabetic drugs have shown beneficial effects in improving liver histology, aminotransferase level, and metabolic parameters and reducing risks of hepatocellular carcinoma and mortality, without significant safety concerns, in patients with CLD. Although the effect as the centerpiece management in patients with CLD is not robust, the use of these non-antidiabetic drugs might be potentially beneficial as an adjuvant or combined treatment strategy.

Background/Aims: Nonalcoholic fatty liver disease (NAFLD) is closely related to gut-microbiome. There is a paucity of research on which strains of gut microbiota affect the progression of NAFLD. This study explored the NAFLD-associated microbiome in humans and the role of Lactobacillus in the progression of NAFLD in mice. Methods: The gut microbiome was analyzed via next-generation sequencing in healthy people (n=37) and NAFLD patients with elevated liver enzymes (n=57). Six-week-old male C57BL/6J mice were separated into six groups (n=10 per group; normal, Western, and four Western diet + strains [109 colony-forming units/g for 8 weeks; L. acidophilus, L. fermentum, L. paracasei, and L. plantarum]). Liver/body weight ratio, liver pathology, serum analysis, and metagenomics in the mice were examined. Results: Compared to healthy subjects (1.6±4.3), NAFLD patients showed an elevated Firmicutes/Bacteroidetes ratio (25.0±29.0) and a reduced composition of Akkermansia and L. murinus (P<0.05). In the animal experiment, L. acidophilus group was associated with a significant reduction in liver/body weight ratio (5.5±0.4) compared to the Western group (6.2±0.6) (P<0.05). L. acidophilus (41.0±8.6), L. fermentum (44.3±12.6), and L. plantarum (39.0±7.6) groups showed decreased cholesterol levels compared to the Western group (85.7±8.6) (P<0.05). In comparison of steatosis, L. acidophilus (1.9±0.6), L. plantarum (2.4±0.7), and L. paracasei (2.0±0.9) groups showed significant improvement of steatosis compared to the Western group (2.6±0.5) (P<0.05). Conclusions Ingestion of Lactobacillus, such as L. acidophilus, L. fermentum, and L. plantarum, ameliorates the progression of nonalcoholic steatosis by lowering cholesterol. The use of Lactobacillus can be considered as a useful strategy for the treatment of NAFLD.

Purpose: Alpha-fetoprotein (AFP) is a prognostic marker for hepatocellular carcinoma (HCC). We investigated the prognostic value of AFP levels in patients who achieved complete response (CR) to transarterial chemoembolization (TACE) for HCC. Materials and Methods: Between 2005 and 2018, 890 patients with HCC who achieved a CR to TACE were recruited. An AFP responder was defined as a patient who showed elevated levels of AFP (>10 ng/mL) during TACE, but showed normalization or a >50% reduction in AFP levels after achieving a CR. Results: Among the recruited patients, 569 (63.9%) with naïve HCC and 321 (36.1%) with recurrent HCC after complete resection were treated. Before TACE, 305 (34.3%) patients had multiple tumors, 219 (24.6%) had a maximal tumor size >3 cm, and 22 (2.5%) had portal vein tumor thrombosis. The median AFP level after achieving a CR was 6.36 ng/mL. After a CR, 473 (53.1%) patients experienced recurrence, and 417 (46.9%) died [median progression-free survival (PFS) and overall survival (OS) of 16.3 and 62.8 months, respectively]. High AFP levels at CR (>20 ng/mL) were independently associated with a shorter PFS [hazard ratio (HR)=1.403] and OS (HR=1.284), together with tumor multiplicity at TACE (HR=1.518 and 1.666, respectively). AFP non-responders at CR (76.2%, n=359 of 471) showed a shorter PFS (median 10.5 months vs. 15.5 months, HR=1.375) and OS (median 41.4 months vs. 61.8 months, HR=1.424) than AFP responders (all p=0.001). Conclusion High AFP levels and AFP non-responders were independently associated with poor outcomes after TACE. AFP holds clinical implications for detailed risk stratification upon achieving a CR after TACE.

BACKGROUND: In order to produce and isolate the exosome derived from the cell of interests, a serum free environment (starvation) has been essential for excluding the unknown effect from serum-derived exosomes. Recently, serum-free culture media have been developed as a substitute for serum supplemented media so that MSC proliferates with maintaining the original characteristics of the cells in a serum free condition. Due to the different properties of the exosomes representing the states and characteristics of the origin cells, a study is needed to compare the properties of the cell-derived exosomes according to the cell culture media. METHODS: To compare the cell culture condition on exosomes, human umbilical cord mesenchymal stem cells (UCMSCs) were cultured with two different media, serum containing media, 10% FBS supplemented DMEM (NM) and serum-free chemically defined media, CellCor TM CD MSC (CDM). To remove FBS-derived exosomes from UCMSC cultured with NM, the medium was replaced with FBS-free DMEM for starvation during exosome isolation. The production yield and expression levels of angiogenic and pro-inflammatory factors were compared. And, the subpopulations of exosome were classified depending on the surface properties and loaded cytokines. Finally, the wound healing and angiogenic effects have been evaluated using in vitro assays. RESULTS: The UCMSC-derived exosomes under two different cell culture media could be classified into subpopulations according to the surface composition and loaded cytokines. Especially, exosome derived from UCMSC cultured with CDM showed higher expression levels of cytokines related to regenerative bioactivities which resulted in enhanced wound healing and angiogenesis. CONCLUSION CDM has the advantages to maintain cell proliferation even during the period of exosome isolations and eliminate unknown side effects caused by serumderived exosomes. Additionally, exosomes derived from UCMSC cultured with CDM show better wound healing and angiogenic effects due to a lot of regeneration-related cytokines and less pro-inflammatory cytokines compared to with NM.