yonsei university college of medicine

INTRODUCTION: Clopidogrel is an antiplatelet agent that is widely used for the secondary prevention of cardiovascular and cerebrovascular events. The genotype of cytochrome P450 2C19 ( CYP2C19 ) differentially affects the liver's metabolism of clopidogrel, which may influence the drug's response and efficacy for cardiovascular event prevention. In contrast to prior studies of patients with coronary artery diseases, little is known about whether the CYP2C19 genotype influences the preventive efficacy of clopidogrel in patients who had a stroke...

OBJECTIVES: Related innate immune system activation and diagnostic factors of sepsis are not fully understood. The aim of this study was to analyze the clinical value of full-length tryptophanyl-tRNA synthetase (WRS) induced through inflammatory stimuli for the detection of sepsis and prediction of mortality in critically ill patients. METHODS: This was a retrospective analysis of blood samples collected prospectively from patients in the medical intensive care unit (ICU) at Yonsei University College of Medicine, from March 2015 to June 2018...

PURPOSE: To compare clinical outcomes of small-incision lenticule extraction (SMILE) between manifest refraction (MR) and vector planning for myopic astigmatism with high ocular residual astigmatism (ORA). SETTING: Yonsei University College of Medicine and Eyereum Eye Clinic, Seoul, South Korea. DESIGN: Prospective, randomized, comparative case series. METHODS: Patients with myopic astigmatism and ORA of 0.75 diopters (D) or greater were randomized into the MR or vector planning group and underwent SMILE without applying any nomogram for cylinder correction...

BACKGROUND: The importance of self-directed learning (SDL) and collaborative learning has been emphasized in medical education. This study examined if there were changes in the pattern of SDL and group cohesion from the time of admission to medical school under the criterion-referenced grading system, increased group activities, and interaction of medical education curriculum. Second, it was examined whether group cohesion influences self-directed learning. METHODS: The participants were 106 medical students (71 males, 35 females) who enrolled in Yonsei University College of Medicine in Seoul, South Korea in March 2014...

PURPOSE: Major liver resection and radical lymph node dissection has been accepted as a definite treatment of choice for hilar cholangiocarcinoma (HC). However, the perioperative and survival outcomes of right hemihepatectomy (RH) and left hemihepatectomy (LH) still remain controversial. Thus, this study aimed to compare the surgical and oncological outcomes of RH and LH in HC patients. METHODS: From January 2000 to January 2018, a total of 326 patients underwent surgical resection for HC at Yonsei University College of Medicine in Seoul, Korea...

An additional affiliation for the first author was not indicated. Hyewon Lee is also affiliated with: Department of Internal Medicine, Yonsei University College of Medicine, Gangnam Severance Hospital, Seoul, South Korea.

PURPOSE: Transvaginal ultrasound imaging provides useful information for diagnosing endometrial pathologies and reproductive health. Endometrium segmentation in transvaginal ultrasound (TVUS) images is very challenging due to ambiguous boundaries and heterogeneous textures. In this study, we developed a new segmentation framework which provides robust segmentation against ambiguous boundaries and heterogeneous textures of TVUS images. METHODS: To achieve endometrium segmentation from TVUS images, we propose a new segmentation framework with a discriminator guided by four key points of the endometrium (namely, the endometrium cavity tip, the internal os of the cervix, and the two thickest points between the two basal layers on the anterior and posterior uterine walls)...

PURPOSE: To assess the agreement of decentration measurements between tangential curvature topography and tomography pachymetry difference maps after a small-incision lenticule extraction (SMILE) procedure. SETTING: Yonsei University College of Medicine and Eyereum Eye Clinic, Seoul, South Korea. DESIGN: Retrospective case series. METHODS: Decentrations and pupillary offset (angle κ) were analyzed and compared using two different methods...

We investigated the overall frequency of anti-phospholipid syndrome (APS) occurrence in Korean patients with consecutively detected anti-phospholipid antibodies with an interval of 12 weeks (persistent aPLs). We retrospectively reviewed the results of blood tests of aPLs in 14,889 patients in whom aPL tests were performed at Yonsei University College of Medicine, Severance Hospital, from January 2012 to August 2018, and included 833 patients with persistent aPLs. We obtained clinical and laboratory data including anti-cardiolipin antibodies IgM and IgG, anti-beta2 glycoprotein1 IgM and IgG, and lupus anticoagulant (LAC)...

PURPOSE: To evaluate the clinical outcomes, vector parameters, and aberrations between mechanical photorefractive keratectomy (PRK) and transepithelial PRK in eyes with low myopia. SETTING: Yonsei University College of Medicine and Eyereum Eye Clinic, Seoul, Korea. DESIGN: Retrospective, comparative case series. METHODS: Eighty-four eyes of 84 patients with low myopia (≤2.00 diopters) were treated with mechanical or transepithelial PRK (41 eyes and 43 eyes, respectively), with the application of a large optical zone (OZ)...

BACKGROUND AND AIM: Adequate tissue acquisition is important in making treatment decisions for patients with upper gastrointestinal subepithelial tumors (SETs). This study aimed to compare the outcomes of endoscopic ultrasonography-guided fine-needle biopsy (EUS-FNB) with those of the unroofing biopsy technique. METHODS: This study was a single-center, prospective comparative study conducted at Severance Hospital, Yonsei University College of Medicine. A total of 39 patients with SETs ≥15 mm were enrolled between January 2016 and August 2017...

Background: The ability to predict the severity of disease is important to reduce morbidity and mortality in patients with acute pancreatitis (AP). Vitamin D deficiency has been associated with severity in various diseases. Objective: This study was conducted to assess vitamin D as a predictor of disease severity in patients with AP. Methods: Patients with AP were prospectively enrolled at Yonsei University Wonju College of Medicine from March 2015 to September 2017...

BACKGROUND: The effects of the flipped classroom have been demonstrated in various fields of education in recent years. Training in emergency medicine is also beginning to gradually implement the flipped classroom; however, its practical effect in emergency medicine contexts is not yet clear. OBJECTIVE: The present study investigates the effects of the flipped classroom on advanced cardiopulmonary life support (ACLS) training implemented among practicum students in emergency medicine...

PURPOSE: To evaluate the changes in corneal higher-order aberrations (HOAs) after corneal wavefront-guided transepithelial photorefractive keratectomy (PRK) and small-incision lenticule extraction (SMILE). SETTING: Yonsei University College of Medicine and Eyereum Eye Clinic, South Korea. DESIGN: Retrospective case series. METHODS: Medical records of patients having either corneal wavefront-guided transepithelial PRK or small-incision lenticule extraction were examined...

Macrofollicular variant papillary thyroid carcinoma (MFV-PTC) is defined as papillary thyroid carcinoma with macrofollicles of >200 μm in more than 50% of the cross-sectional area of the specimen. The aim of this study was to evaluate the clinicopathologic characteristics of the MFV-PTC treated in the Yonsei University College of Medicine.Between September 2007 and July 2012, 18,697 patients with PTC were treated in our institution. Of these, 10 patients (0.05%) were diagnosed as the MFV-PTC in final pathologic report...

The present study aimed to elucidate the clinicopathological characteristics of resected mucinous cystic neoplasm (MCN) with ovarian-type stroma and identify a surgical approach for MCN treatment, on the basis of Republic of Korean (Yonsei University College of Medicine, Seoul, South Korea) and Japanese (Nippon Medical School, Tokyo, Japan) bi-institutional collaboration. The present study retrospectively reviewed 55 MCNs with ovarian-type stroma using pathological re-examination. Clinicopathological features and preoperative clinical parameters were evaluated to predict malignant alterations in MCNs...

BACKGROUND: Neutrophil to lymphocyte ratio (NLR) and platelet to lymphocyte ratio (PLR) predict severity in various diseases. In this study, we evaluated the value of NLR and PLR as prognostic factors in acute pancreatitis (AP). METHODS: Patients with AP were prospectively enrolled from March 2014 to September 2016 at Yonsei University Wonju College of Medicine. NLR and PLR were obtained at admission and were compared with other known prognostic scoring systems...

PURPOSE: To evaluate the changes in biomechanically corrected intraocular pressure (IOP) and new dynamic corneal response parameters measured by a dynamic Scheimpflug analyzer before and after transepithelial photorefractive keratectomy (PRK) and femtosecond laser-assisted laser in situ keratomileusis (LASIK). SETTING: Yonsei University College of Medicine and Eyereum Eye Clinic, Seoul, South Korea. DESIGN: Retrospective case series. METHODS: Medical records of patients having transepithelial PRK or femtosecond-assisted LASIK were examined...

Anaplastic thyroid cancer (ATC) constitutes less than 2% of total thyroid cancers but accounts for 20-40% of thyroid cancer-related deaths. Cancer stem cell drug resistance represents a primary factor hindering treatment. This study aimed to develop targeted agents against thyroid malignancy, focusing on individual and synergistic effects of HNHA (histone deacetylase), lenvatinib (FGFR), and sorafenib (tyrosine kinase) inhibitors. Patients with biochemically and histologically proven papillary thyroid cancer (PTC) and ATC were included...

Background: Lung transplantation is the last treatment option for end-stage lung disease, and the number of lung transplantations has been steadily increasing. Hyperbilirubinemia is a rare complication after lung transplantation. The aim of this study was to review rare causes of hyperbilirubinemia after lung transplantation at our center. Methods: In this single-center study, we retrospectively reviewed the records of 116 consecutive lung transplantation patients who underwent lung transplantation at Severance Hospital and Gangnam Severance Hospital of Yonsei University College of Medicine in South Korea between December 22, 2010 and January 1, 2016...