FAM19A5, a novel secretory protein highly expressed in the brain, is potentially associated with the progression of Alzheimer's disease (AD). However, its role in the AD pathogenesis remains unclear. Here, we investigated the potential function of FAM19A5 in the context of AD. We generated APP/PS1 mice with partial FAM19A5 deficiency, termed APP/PS1/FAM19A5+/LacZ mice. Compared with control APP/PS1 mice, APP/PS1/FAM19A5+/LacZ mice exhibited significantly lower Aβ plaque density and prolonged the lifespan of the APP/PS1 mice. To further explore the therapeutic potential of targeting FAM19A5, we developed a FAM19A5 antibody. Administration of this antibody to APP/PS1 mice significantly improved their performance in the Y-maze and passive avoidance tests, indicating enhanced cognitive function. This effect was replicated in 5XFAD mice, a model of early-onset AD characterized by rapid Aβ accumulation. Additionally, FAM19A5 antibody treatment in 5XFAD mice led to enhanced exploration of novel objects and increased spontaneous alternation behavior in the novel object recognition and Y-maze tests, respectively, indicating improved cognitive function. These findings suggest that FAM19A5 plays a significant role in AD pathology and that targeting with FAM19A5 antibodies may be a promising therapeutic strategy for AD.

Extra-pulmonary neuroendocrine carcinoma is a rare and aggressive cancer. Although several biological and histological markers have been suggested as prognostic factors for this cancer, the prognostic importance of systemic inflammatory markers, including the neutrophil-lymphocyte ratio and platelet-lymphocyte ratio, is unclear. This study aimed to evaluate the association between systemic inflammatory markers and the prognosis of extra-pulmonary neuroendocrine carcinoma. We retrospectively analyzed the clinical data of 85 patients with unresectable or metastatic extra-pulmonary neuroendocrine carcinoma who received platinum-based chemotherapy as first-line chemotherapy from August 2007 to November 2019. We used time-dependent receiver operating characteristic curve analysis to determine the cut-off values. The cut-off values for the neutrophil-lymphocyte ratio and platelet-lymphocyte ratio were 3.0 and 158.5, respectively. There was no significant difference in the Eastern Cooperative Oncology Group performance status score, Ki-67 index, or response to chemotherapy between groups. The high neutrophil-lymphocyte ratio group showed significantly worse overall survival (high vs. low, median 11.1 vs. 21.0 months, log-rank p=0.004) and shorter median progression-free survival, but the latter was not statistically significant. The high platelet-lymphocyte ratio group also showed significantly worse progression-free survival and overall survival than the low platelet-lymphocyte ratio group (high vs. low:median 5.6 vs. 9.8 months, log-rank p=0.047 and median 13.8 vs. 21.0 months, log-rank p=0.013, respectively). In multivariable analysis, a high neutrophil-lymphocyte ratio was an independent prognostic factor for overall survival. The neutrophil-lymphocyte ratio is a potent and readily available prognostic factor for extra-pulmonary neuroendocrine carcinoma.

Polyacrylamide gel (PAAG) has been used for augmentation mammoplasty in certain countries, such as China or Eastern European countries. However, owing to various complications, its use is currently banned in most countries. Nevertheless, because of the migratory stream of female from these countries, we also encounter patients with PAAG mammoplasty in Korea. Owing to the various imaging features of PAAG mammoplasty, it may interfere with the identification of malignancy or other pathologic conditions. Therefore, it is important to identify the imaging findings related to PAAG mammoplasty. However, there is limited literature on the radiologic findings of complications related to PAAG mammoplasty in Korea. Herein we report four cases of PAAG mammoplasty, the complications faced, and depict various radiologic features through multimodality imaging.

Liver cancer is a common tumor and currently the second leading cause of cancer-related mortality globally. Liver cancer is highly related to inflammation as more than 90% of liver cancer arises in the context of hepatic inflammation, such as hepatitis B virus and hepatitis C virus infection. Despite significant improvements in the therapeutic modalities for liver cancer, patient prognosis is not satisfactory due to the limited efficacy of current drug therapies in anti-metastatic activity. Therefore, developing new effective anti-cancer agents with anti-metastatic activity is important for the treatment of liver cancer. In this study, SP-8356, a verbenone derivative with anti-inflammatory activity, was investigated for its effect on the growth and migration of liver cancer cells. Our findings demonstrated that SP-8356 inhibits the proliferation of liver cancer cells by inducing apoptosis and suppressing the mobility and invasion ability of liver cancer cells. Functional studies revealed that SP-8356 inhibits the mitogen-activated protein kinase and nuclear factor-kappa B signaling pathways, which are related to cell proliferation and metastasis, resulting in the downregulation of metastasis-related genes. Moreover, using an orthotopic liver cancer model, tumor growth was significantly decreased following treatment with SP-8356. Thus, this study suggests that SP-8356 may be a potential agent for the treatment of liver cancer with multimodal regulation.

Background/Aims: To analyze the incidence and risk factors of outcomes after liver transplantation (LT) in the Korean population. Methods: This study analyzed data from the liver cohort of Korean Organ Transplantation Registry (KOTRY) who had LT between May 2014 and December 2017. Study measures included the incidence of post-LT outcomes in recipients of living donor LT (LDLT) and deceased donor LT (DDLT). Cox multivariate proportional hazards model was used to determine the potential risk factors predicting the outcomes. Results: A total of 2,563 adult recipients with LT (LDLT, n=1,956; DDLT, n=607) were included, with mean±standard deviation age of 53.9±8.9 years, and 72.2% were male. The post-LT outcomes observed in each LDLT and DDLT recipients were death (4.0% and 14.7%), graft loss (5.0% and 16.1%), rejection (7.0% and 12.0%), renal failure (2.7% and 13.8%), new onset of diabetes (12.5% and 15.4%), and hepatocellular carcinoma (HCC) recurrence (both 6.7%). In both LDLT and DDLT recipients, the most common post-LT complications were renal dysfunction (33.6% and 51.4%), infection (26.7% and 48.4%), and surgical complication (22.5% and 23.9%). Incidence of these outcomes were generally higher among recipients of DDLT than LDLT. Multivariate analysis indicated recipient age and DDLT as significant risk factors associated with death and graft loss. DDLT and ABO incompatible transplant were prognostic factors for rejection, and HCC beyond Milan criteria at pre-transplant was a strong predictor of HCC recurrence. Conclusions This study is a good indicator of the post-LT prognosis in the Korean population and suggests a significant burden of post-LT complications.

Background: Ear-loop-type Korean Filter 94 masks (KF94 masks, equivalent to the N95 and FFP2) are broadly used in health care settings in Korea for the coronavirus disease 2019 pandemic. Methods: A prospective randomized open-label study was designed to identify differences in the fitting performance between mask wearing methods in three different types of KF94 mask with ear loops between January to March 2021. General-fitting involved wearing an earloop-type KF94 mask, and tight-fitting involved wearing a mask aided by a clip connecting the ear loops. Each of the 30 participants wore three types of masks according to a randomly assigned order in both methods and performed a total of six quantitative fit tests (QNFTs) according to the occupational safety and health administration protocol. Results: All fit factors (FFs) measured by the QNFT were significantly higher for tight-fitting method with the clip in all KF94 masks (P < 0.001). However, the total FFs were very low, with a median (interquartile range) of 6 (3–23) and 29 (9–116) for general-fitting and tight-fitting, respectively. When wearing tightly, the horizontal 3-fold type mask with adjustable ear-loop length had the highest FF, with a median of 125, and the QNFT pass rate (FF ≥ 100) increased significantly from 4 (13%) to 18 (60%). Conclusion Even with sufficient filter efficiency, ear-loop-type-KF94 masks do not provide adequate protection. However, in relatively low-risk environments, wearing a face-seal adjustable KF94 mask and tight wearing with a clip can improve respiratory protection for healthcare workers.

Background: Point-of-care ultrasound (POCUS) is an essential tool in emergency medicine (EM). We aimed to investigate the current status and perception of POCUS use in emergency medical centers in Korea. Methods: A cross-sectional, nationwide survey was conducted using a mobile survey of physicians at emergency medical centers in Korea. The first message was sent on November 27, 2020, and the second message was sent on December 3, 2020 to the non-responders.The questionnaire comprised 6 categories and 24 questionnaires on demographics, current practice, education, perception, and barriers to the use of POCUS. Results: A total of 467 physicians participated in the survey (a response rate of 32% among 1,458 target physicians), of which 43% were residents and 57% were EM specialists. Most of the respondents (96%) answered that they use POCUS, of which 89% reported using it at least once a week. The most frequently used types of POCUS were focused assessment with sonography for trauma (68%) and echocardiography (66%). Musculoskeletal, male genital, and pediatric scans were rarely performed tests but ranked as of the scans physicians most wanted to learn. About 73% of the respondents received ultrasound education, and 41% received ultrasound education at their own institutions. Nevertheless, educationrelated barriers are still the biggest deterrent to POCUS use (60%). In addition, multivariate multinomial logistic regression analysis revealed that the greater the number of ultrasound devices and the total number of physicians in the emergency center, the more likely they were to use POCUS every day. Conclusion This study found that most physicians currently working in emergency medical centers in Korea more frequently perform various types of ultrasound scans compared to those 10 years prior. To further promote the use of POCUS, it is important to have an appropriate number of ultrasound devices and physicians in the emergency center along with systematic POCUS education.

Background: Ear-loop-type Korean Filter 94 masks (KF94 masks, equivalent to the N95 and FFP2) are broadly used in health care settings in Korea for the coronavirus disease 2019 pandemic. Methods: A prospective randomized open-label study was designed to identify differences in the fitting performance between mask wearing methods in three different types of KF94 mask with ear loops between January to March 2021. General-fitting involved wearing an earloop-type KF94 mask, and tight-fitting involved wearing a mask aided by a clip connecting the ear loops. Each of the 30 participants wore three types of masks according to a randomly assigned order in both methods and performed a total of six quantitative fit tests (QNFTs) according to the occupational safety and health administration protocol. Results: All fit factors (FFs) measured by the QNFT were significantly higher for tight-fitting method with the clip in all KF94 masks (P < 0.001). However, the total FFs were very low, with a median (interquartile range) of 6 (3–23) and 29 (9–116) for general-fitting and tight-fitting, respectively. When wearing tightly, the horizontal 3-fold type mask with adjustable ear-loop length had the highest FF, with a median of 125, and the QNFT pass rate (FF ≥ 100) increased significantly from 4 (13%) to 18 (60%). Conclusion Even with sufficient filter efficiency, ear-loop-type-KF94 masks do not provide adequate protection. However, in relatively low-risk environments, wearing a face-seal adjustable KF94 mask and tight wearing with a clip can improve respiratory protection for healthcare workers.

Background: Point-of-care ultrasound (POCUS) is an essential tool in emergency medicine (EM). We aimed to investigate the current status and perception of POCUS use in emergency medical centers in Korea. Methods: A cross-sectional, nationwide survey was conducted using a mobile survey of physicians at emergency medical centers in Korea. The first message was sent on November 27, 2020, and the second message was sent on December 3, 2020 to the non-responders.The questionnaire comprised 6 categories and 24 questionnaires on demographics, current practice, education, perception, and barriers to the use of POCUS. Results: A total of 467 physicians participated in the survey (a response rate of 32% among 1,458 target physicians), of which 43% were residents and 57% were EM specialists. Most of the respondents (96%) answered that they use POCUS, of which 89% reported using it at least once a week. The most frequently used types of POCUS were focused assessment with sonography for trauma (68%) and echocardiography (66%). Musculoskeletal, male genital, and pediatric scans were rarely performed tests but ranked as of the scans physicians most wanted to learn. About 73% of the respondents received ultrasound education, and 41% received ultrasound education at their own institutions. Nevertheless, educationrelated barriers are still the biggest deterrent to POCUS use (60%). In addition, multivariate multinomial logistic regression analysis revealed that the greater the number of ultrasound devices and the total number of physicians in the emergency center, the more likely they were to use POCUS every day. Conclusion This study found that most physicians currently working in emergency medical centers in Korea more frequently perform various types of ultrasound scans compared to those 10 years prior. To further promote the use of POCUS, it is important to have an appropriate number of ultrasound devices and physicians in the emergency center along with systematic POCUS education.

Background and Objectives: Smoking is well-established as a risk factor for coronary artery disease. However, recent studies demonstrated favorable results, including reduced mortality, among smokers, which are referred to as the “smoker's paradox”. This study examined the impact of smoking on clinical outcomes in patients with acute myocardial infarction (AMI) undergoing percutaneous coronary intervention (PCI). Methods: Patients with AMI undergoing PCI between 2004 and 2014 were enrolled and classified according to smoking status. The primary endpoint was a composite of major adverse cardiovascular events (MACE) including cardiac death, myocardial infarction, stroke, and revascularization. Results: Among the 10,683 patients, 4,352 (40.7%) were current smokers. Smokers were 10.7 years younger and less likely to have comorbidities such as hypertension, diabetes mellitus, chronic kidney disease, stroke, and prior PCI. Smokers had less MACE (hazard ratio [HR], 0.644; 95% confidence interval [CI], 0.594–0.698; p<0.001) and cardiac death (HR, 0.494; 95% CI, 0.443–0.551; p<0.001) compared to nonsmokers during the 5 years in an unadjusted model. However, after propensity-score matching, smokers showed higher risk of MACE (HR, 1.125; 95% CI, 1.009–1.254; p=0.034) and cardiac death (HR, 1.190; 95% CI, 1.026–1.381; p=0.022). Smoking was a strong independent predictor of lung cancer (propensityscore matched HR, 2.749; 95% CI, 1.416–5.338; p=0.003). Conclusions In contrast to the unadjusted model, smoking is associated with worse cardiovascular outcome and higher incidence of lung cancer after adjustment of various confounding factors. This result can be explained by the characteristics of smokers, which were young and had fewer comorbidities.