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.

The first edition of ‘A Standardized Pathology Report for Gastric Cancer’ was initiated by the Gastrointestinal Pathology Study Group of the Korean Society of Pathologists and published 17 years ago. Since then, significant advances have been made in the pathologic diagnosis, molecular genetics, and management of gastric cancer (GC). To reflect those changes, a committee for publishing a second edition of the report was formed within the Gastrointestinal Pathology Study Group of the Korean Society of Pathologists. This second edition consists of two parts: standard data elements and conditional data elements.The standard data elements contain the basic pathologic findings and items necessary to predict the prognosis of GC patients, and they are adequate for routine surgical pathology service. Other diagnostic and prognostic factors relevant to adjuvant therapy, including molecular biomarkers, are classified as conditional data elements to allow each pathologist to selectively choose items appropriate to the environment in their institution. We trust that the standardized pathology report will be helpful for GC diagnosis and facilitate large-scale multidisciplinary collaborative studies.

The first edition of ‘A Standardized Pathology Report for Gastric Cancer’ was initiated by the Gastrointestinal Pathology Study Group of the Korean Society of Pathologists and published 17 years ago. Since then, significant advances have been made in the pathologic diagnosis, molecular genetics, and management of gastric cancer (GC). To reflect those changes, a committee for publishing a second edition of the report was formed within the Gastrointestinal Pathology Study Group of the Korean Society of Pathologists. This second edition consists of two parts: standard data elements and conditional data elements. The standard data elements contain the basic pathologic findings and items necessary to predict the prognosis of GC patients, and they are adequate for routine surgical pathology service. Other diagnostic and prognostic factors relevant to adjuvant therapy, including molecular biomarkers, are classified as conditional data elements to allow each pathologist to selectively choose items appropriate to the environment in their institution. We trust that the standardized pathology report will be helpful for GC diagnosis and facilitate large-scale multidisciplinary collaborative studies.

Background: The purpose of this study was to evaluate the effect of vanishing twin (VT) on maternal serum marker concentrations and nuchal translucency (NT). Methods: This is a secondary analysis of a multicenter prospective cohort study in 12 institutions. Serum concentrations of pregnancy-associated plasma protein-A in the first trimester and alpha-fetoprotein (AFP), total human chorionic gonadotrophin, unconjugated estriol, and inhibin A in the second trimester were measured, and NT was measured between 10 and 14 weeks of gestation. Results: Among 6,793 pregnant women, 5,381 women were measured for serum markers in the first or second trimester, including 65 cases in the VT group and 5,316 cases in the normal singleton group. The cases in the VT group had a higher median multiple of the median value of AFP and inhibin A than the normal singleton group. The values of other serum markers and NT were not different between the two groups. After the permutation test with adjustment,AFP and inhibin A remained significant differences. The frequency of abnormally increased AFP was also higher in the VT group than in the normal singleton group. Conclusion VT can be considered as an adjustment factor for risk assessment in the secondtrimester serum screening test.

Background: Acral melanoma is the most common subtype of melanoma among Koreans, and regional or distant metastasis is an indicator of poor prognosis. Yes-associated protein (YAP), a key effector of the Hippo pathway, is known to induce tumor progression and metastasis in various cancers. Objective: We aimed to analyze the clinical and histopathological characteristics of acral melanoma among Koreans and to evaluate their association with YAP expression. Methods: This retrospective review included 27 patients with acral melanoma. Clinical features including age, sex, lesion site, and stage were obtained from the medical records and images. Biopsy slides of patients with acral melanoma were reviewed, and immunohistochemical staining for YAP was performed. Results: The rate of YAP expression was significantly higher in patients having acral melanoma with regional or distant lymph node (LN) metastasis than in those without metastasis (n=4/5, 80.0% vs. n=2/22, 9.1%; p=0.004). Histopathologically, the rate of YAP expression was higher in patients having acral melanoma with lymphovascular invasion than in those without lymphovascular invasion (n=4/8, 50.0% vs. n=2/19, 10.5%; p=0.044). Among the 27 lesions, 14 (51.9%) were on stress-bearing sites such as the forefoot and heel. However, the rate of YAP expression did not differ significantly between weight-bearing and non-weight-bearing locations (p=0.834). Conclusion YAP expression is significantly associated with metastasis, especially LN metastasis, in patients with acral melanoma. Therefore, YAP expression may be used as a prognostic factor for LN metastasis and a target for novel treatments in patients with melanoma.

Background: Skin aging can be divided into intrinsic and extrinsic processes, and occur due to several factors. Although the interest in skin youthfulness is increasing globally, research on facial skin youthfulness and lifestyle is limited. Objective: This study aimed to evaluate the association between facial skin youthfulness and biophysical facial skin parameters in Korean women over 50 years of age. We further investigated lifestyle factors that make people appear younger than their chronological age. Methods: We surveyed the essential information and lifestyle of subjects by questionnaires, and measured the biophysical parameters of the facial skin. We then performed clinical facial assessments, and the values were compared with the chronologic age. The associations between age differences, biophysical parameters, and living habits were evaluated. Results: We identified a positive correlation between age and melanin index (r=0.245, p＜0.001) and erythema index (r=0.119, p=0.002). The melanin index was statistically significantly lower in the group without regular outdoor activities (144.66±43.24 vs. 137.00±55.48, p=0.043). The melanin index and erythema index were the significant differences that defined younger perceived age than chronological age. The perceived age was younger in the group who wore a hat when performing outdoor activities than the group who did not (3.70±1.84 vs. 3.40±1.94, p=0.034). Conclusion To retain youthful skin, it is essential to reduce sun exposure, as this factor can affect the melanin and erythema indices by inducing photoaging. Therefore, avoiding the sun bia proper methods, such as wearing a hat and sunscreen during outdoor activities, is recommended to maintain skin youthfulness.

Background/Aims: In Korea, medications are available by prescription from a physician, or can be purchased over-the-counter (OTC) without a prescription. Education regarding both prescribed and OTC drugs is important to minimize side effects and avoid drug abuse. The risk of side effects due to polypharmacy is increasing due to the growing number of elderly patients with comorbidities. Methods: There are various clinical guidelines for physicians, but it is difficult for patients and their caregivers to find published guidelines regarding drug use. In this regard, experts from nine subspecialties of internal medicine, geriatric medicine, and guideline development methodology formed a working group to develop guidelines for safe drug use under the Clinical Practice Guidelines Committee of the Korean Association of Internal Medicine. Results: The main contents of this guideline are 1) safe and effective drug administration, 2) the proper use of analgesics (acetaminophen and nonsteroidal anti-inflammatory drugs), 3) the proper use of tranquilizers and sleeping pills to prevent drug abuse, 4) points to be aware of when taking multiple medications. Conclusions The guidelines were developed for patients and their caregivers to understand the general principles and precautions for drug use, including commonly used painkillers, mood stabilizers, sleeping pills, and polypharmacy. These guidelines could also be used as educational materials for physicians, nurses, and healthcare workers to educate patients and their caregivers.

Background: A coronavirus disease 2019 (COVID-19) outbreak started in February 2020 and was controlled at the end of March 2020 in Daegu, the epicenter of the coronavirus outbreak in Korea. The aim of this study was to describe the clinical course and outcomes of patients with COVID-19 in Daegu. Methods: In collaboration with Daegu Metropolitan City and Korean Center for Diseases Control, we conducted a retrospective, multicenter cohort study. Demographic, clinical, treatment, and laboratory data, including viral RNA detection, were obtained from the electronic medical records and cohort database and compared between survivors and non-survivors. We used univariate and multi-variable logistic regression methods and Cox regression model and performed Kaplan–Meier analysis to determine the risk factors associated with the 28-day mortality and release from isolation among the patients. Results: In this study, 7,057 laboratory-confirmed patients with COVID-19 (total cohort) who had been diagnosed from February 18 to July 10, 2020 were included. Of the total cohort, 5,467 were asymptomatic to mild patients (77.4%) (asymptomatic 30.6% and mild 46.8%), 985 moderate (14.0%), 380 severe (5.4%), and 225 critical (3.2%). The mortality of the patients was 2.5% (179/7,057). The Cox regression hazard model for the patients with available clinical information (core cohort) (n = 2,254) showed the risk factors for 28-day mortality: age > 70 (hazard ratio [HR], 4.219, P = 0.002), need for O 2 supply at admission (HR, 2.995; P = 0.001), fever (> 37.5°C) (HR, 2.808; P = 0.001), diabetes (HR, 2.119; P = 0.008), cancer (HR, 3.043; P = 0.011), dementia (HR, 5.252; P = 0.008), neurological disease (HR, 2.084; P = 0.039), heart failure (HR, 3.234;P = 0.012), and hypertension (HR, 2.160; P = 0.017). The median duration for release from isolation was 33 days (interquartile range, 24.0–46.0) in survivors. The Cox proportional hazard model for the long duration of isolation included severity, age > 70, and dementia. Conclusion Overall, asymptomatic to mild patients were approximately 77% of the total cohort (asymptomatic, 30.6%). The case fatality rate was 2.5%. Risk factors, including older age, need for O 2 supply, dementia, and neurological disorder at admission, could help clinicians to identify COVID-19 patients with poor prognosis at an early stage.

Background/Aims: In Korea, medications are available by prescription from a physician, or can be purchased over-the-counter (OTC) without a prescription. Education regarding both prescribed and OTC drugs is important to minimize side effects and avoid drug abuse. The risk of side effects due to polypharmacy is increasing due to the growing number of elderly patients with comorbidities. Methods: There are various clinical guidelines for physicians, but it is difficult for patients and their caregivers to find published guidelines regarding drug use. In this regard, experts from nine subspecialties of internal medicine, geriatric medicine, and guideline development methodology formed a working group to develop guidelines for safe drug use under the Clinical Practice Guidelines Committee of the Korean Association of Internal Medicine. Results: The main contents of this guideline are 1) safe and effective drug administration, 2) the proper use of analgesics (acetaminophen and nonsteroidal anti-inflammatory drugs), 3) the proper use of tranquilizers and sleeping pills to prevent drug abuse, 4) points to be aware of when taking multiple medications. Conclusions The guidelines were developed for patients and their caregivers to understand the general principles and precautions for drug use, including commonly used painkillers, mood stabilizers, sleeping pills, and polypharmacy. These guidelines could also be used as educational materials for physicians, nurses, and healthcare workers to educate patients and their caregivers.

Valproic acid is a clinically used mood stabilizer and antiepileptic drug. Valproic acid has been suggested as a teratogen associated with the manifestation of neurodevelopmental disorders, such as fetal valproate syndrome and autism spectrum disorders, when taken during specific time window of pregnancy. Previous studies proposed that prenatal exposure to valproic acid induces abnormal proliferation and differentiation of neural progenitor cells, presumably by inhibiting histone deacetylase and releasing the condensed chromatin structure. Here, we found valproic acid up-regulates the transcription of T-type calcium channels by inhibiting histone deacetylase in neural progenitor cells. The pharmacological blockade of T-type calcium channels prevented the increased proliferation of neural progenitor cells induced by valproic acid. Differentiated neural cells from neural progenitor cells treated with valproic acid displayed increased levels of calcium influx in response to potassium chloride-induced depolarization. These results suggest that prenatal exposure to valproic acid up-regulates T-type calcium channels, which may contribute to increased proliferation of neural progenitor cells by inducing an abnormal calcium response and underlie the pathogenesis of neurodevelopmental disorders.