Objective: The modified barium swallow study (MBS) or the videofluoroscopic swallow study (VFSS) has been the gold standard for dysphagia diagnosis. Fiberoptic endoscopic evaluation of swallowing (FEES) is also gaining popularity in diagnosing dysphagia. This study aimed to compare the efficacy of FEES with that of MBS in patients with dysphagia. Methods: The study included 24 patients who underwent FEES and MBS simultaneously. The Eating Assessment Tool-10 questionnaire was administered to assess swallowing symptoms. The FEES and MBS data, including residue, penetration, and aspiration, were compared. The sensitivity, specificity, positive predictive value, and negative predictive value of each diagnostic test were analyzed. Results: The two tests showed no significant differences for swallowing of semi-solid foods and drinking liquids from a cup. However, significant differences were observed in the swallowing of thin liquid, thick liquid, puree, and solid diets (P＜0.05). FEES demonstrated higher sensitivity than MBS for aspiration (86.67% vs. 60.00%) and penetration (94.12% vs. 88.24%), and also had higher negative predictive values for aspiration (81.82% vs. 60.00%) and penetration (87.50% vs. 77.78%). Six cases exhibited silent aspiration, of which FEES identified five cases and MBS identified three cases. Conclusion The results of this study showed that FEES has a higher sensitivity for penetration and aspiration compared to MBS. FEES also enabled better sensory assessments of the larynx, which is not possible with MBS, thus allowing for the evaluation of the cough reflex. FEES and MBS have their respective strengths and limitations, and they can be used complementarily based on specific clinical situations.

Compared with other treatments, surgical resection is an effective treatment method with the lowest local recurrence rate and the highest survival rate for hepatocellular carcinoma (HCC). To achieve excellent results after surgical treatment, it is essential to carefully select patients who are suitable for hepatic resection and minimize postoperative complications and liver function decline through standardized surgical methods and pre- and postoperative management. However, domestic and international treatment guidelines only broadly recommend the application of hepatic resection for HCC with a single tumor and good liver function. Hence, practical treatment guidelines are required that can be standardized and used according to the varying clinical environments, including indications for hepatic resection, preoperative evaluation, basic principles of hepatic resection, minimally invasive hepatic resection, pre- and postoperative patient management, surgical treatment considerations in specific infection situations, and follow-up after surgical resection. Accordingly, an expert group from the Korean Liver Cancer Association Research Committee has developed practical recommendations based on expert consensus regarding the surgical treatment of HCC through a Delphi study.

Purpose: This study evaluated the role of donor kidney ultrasonography (US) for predicting functional kidney volume and identifying ideal kidney grafts in deceased donor kidney transplantation. Methods: In total, 272 patients who underwent deceased donor kidney transplantation from 2000 to 2020 at Samsung Medical Center were enrolled. Donor kidney information (i.e., right or left) was provided to the radiologist who performed US image re-analysis. To binarize each kidney’s ultrasound parameters, an optimal cutoff value for estimated glomerular filtration rate (eGFR) of less than 30 mL/min/1.73 m2 within 1 year after kidney transplantation was selected using the receiver operating characteristic curve with a specificity >60%. Cox regression analysis was performed for an eGFR less than 30 mL/min/1.73 m2 within 1 year after kidney transplantation and graft failure within 2 years after kidney transplantation. Results: The product of renal length and cortical thickness was a statistically significant predictor of graft function. The odds ratios of an eGFR less than 30 mL/min/1.73 m2 within a year after kidney transplantation and the hazard ratio of graft failure within 2 years after kidney transplantation were 5.91 (P=0.003) and 5.76 (P=0.022), respectively. Conclusion Preoperative US of the donor kidney can be used to evaluate donor kidney function and can predict short-term graft survival. An imaging modality such as US should be included in the donor selection criteria as an additional recommendation. However, the purpose of this study was not to narrow the expanded criteria but to avoid catastrophic consequences by identifying ideal donor kidneys using preoperative US.

Melanogenesis is the production of melanin from tyrosine by a series of enzyme-catalyzed reactions, in which tyrosinase and DOPA oxidase play key roles. The melanin content in the skin determines skin pigmentation. Abnormalities in skin pigmentation lead to various skin pigmentation disorders. Recent research has shown that the expression of EMP2 is much lower in melanoma than in normal melanocytes, but its role in melanogenesis has not yet been elucidated. Therefore, we investigated the role of EMP2 in the melanogenesis of MNT1 human melanoma cells. We examined TRP-1, TRP-2, and TYR expression levels during melanogenesis in MNT1 melanoma cells by gene silencing of EMP2. Western blot and RT-PCR results confirmed that the expression levels of TYR and TRP-2 were decreased when EMP2 expression was knocked down by EMP2 siRNA in MNT1 cells, and these changes were reversed when EMP2 was overexpressed. We verified the EMP2 gene was knocked out of the cell line (EMP2 CRISPR/Cas9) by using a CRISPR/Cas9 system and found that the expression levels of TRP-2 and TYR were significantly lower in the EMP2 CRISPR/Cas9 cell lines. Loss of EMP2 also reduced migration and invasion of MNT1 melanoma cells. In addition, the melanosome transfer from the melanocytes to keratinocytes in the EMP2 KO cells cocultured with keratinocytes was reduced compared to the cells in the control coculture group. In conclusion, these results suggest that EMP2 is involved in melanogenesis via the regulation of TRP-2 expression.

Advanced or metastatic breast cancer affects multiple organs and is a leading cause of cancer-related death. Cancer metastasis is associated with epithelial-mesenchymal metastasis (EMT). However, the specific signals that induce and regulate EMT in carcinoma cells remain unclear. PRR16/Largen is a cell size regulator that is independent of mTOR and Hippo signalling pathways. However, little is known about the role PRR16 plays in the EMT process. We found that the expression of PRR16 was increased in mesenchymal breast cancer cell lines. PRR16 overexpression induced EMT in MCF7 breast cancer cells and enhances migration and invasion. To determine how PRR16 induces EMT, the binding proteins for PRR16 were screened, revealing that PRR16 binds to Abl interactor 2 (ABI2). We then investigated whether ABI2 is involved in EMT. Gene silencing of ABI2 induces EMT, leading to enhanced migration and invasion. ABI2 is a gene that codes for a protein that interacts with ABL proto-oncogene 1 (ABL1) kinase. Therefore, we investigated whether the change in ABI2 expression affected the activation of ABL1 kinase. The knockdown of ABI2 and PRR16 overexpression increased the phosphorylation of Y412 in ABL1 kinase. Our results suggest that PRR16 may be involved in EMT by binding to ABI2 and interfering with its inhibition of ABL1 kinase. This indicates that ABL1 kinase inhibitors may be potential therapeutic agents for the treatment of PRR16-related breast cancer.

Purpose: This study aimed to analyze the rate of delivery within the jurisdiction of local governments in Korea. Methods: Information regarding the population, number of women of childbearing age, and number of births was extracted from the Korean Statistics Information Service, National Health Insurance Service, and health map of the National Medical Center. We defined the rate of delivery within the jurisdiction of the local government as the ratio of the number of deliveries delivered by maternity facilities in the region to the total number of deliveries of pregnant women living in the region. Results: The average nationwide delivery rate in the jurisdiction of local governments was 48.0%. The Si area was the highest at 54.9%, and the Gun area was the lowest at 22.1%. Compared to 2014, the national average delivery rate in the jurisdiction decreased by 4.3%; however, the gun area increased by 4.9%. The geographic maternity service area was 122 in 2014; however, this number decreased to 104 in 2020. Conclusion The national average rate of delivery in the jurisdiction of local governments was 48.0%, and the rate decreased between 2014 and 2020.

Background: Tacrolimus, a calcineurin inhibitor, is an immunosuppressant used in post-transplantation maintenance therapy. The drug has a narrow therapeutic range and requires periodic therapeutic drug monitoring. Although many studies have reported the effects of intrapatient variability of tacrolimus on survival, rejection, and complications in renal transplant recipients, very few studies have reported these effects in liver transplant recipients. The purpose of this study was to evaluate the effect of intrapatient variability of tacrolimus on clinical outcomes after liver transplantation. Methods: Intrapatient variability was calculated using individual, averaged tacrolimus concentrations. Patients were divided into two groups according to their median variability value:high-variability and low-variability groups. The rate of deviation from the therapeutic range, incidence of acute rejection, posttransplant diabetes, incidence of infection, and estimated glomerular filtration rate (eGFR) after transplantation were compared between the groups. Results: Of the total patients (n=82), the high-variability group (n=41) exhibited significantly greater deviation from the therapeutic range (65.92% vs. 56.84%; p<0.001). There was no significant difference in acute rejection or posttransplantation diabetes incidence or eGFR; however, the number of infection in the first 6 months was significantly lower in the low-variability group (0.4 vs. 0.9 times; p=0.039). Multiple linear regression analysis showed that the number of infection significantly increased as intrapatient variability increased (p=0.015). Conclusion High intrapatient variability in tacrolimus concentrations was strongly associated with an increased frequency of deviation from the suggested therapeutic range and an increased number of infection.

Background: Tacrolimus, a calcineurin inhibitor, is an immunosuppressant used in post-transplantation maintenance therapy. The drug has a narrow therapeutic range and requires periodic therapeutic drug monitoring. Although many studies have reported the effects of intrapatient variability of tacrolimus on survival, rejection, and complications in renal transplant recipients, very few studies have reported these effects in liver transplant recipients. The purpose of this study was to evaluate the effect of intrapatient variability of tacrolimus on clinical outcomes after liver transplantation. Methods: Intrapatient variability was calculated using individual, averaged tacrolimus concentrations. Patients were divided into two groups according to their median variability value:high-variability and low-variability groups. The rate of deviation from the therapeutic range, incidence of acute rejection, posttransplant diabetes, incidence of infection, and estimated glomerular filtration rate (eGFR) after transplantation were compared between the groups. Results: Of the total patients (n=82), the high-variability group (n=41) exhibited significantly greater deviation from the therapeutic range (65.92% vs. 56.84%; p<0.001). There was no significant difference in acute rejection or posttransplantation diabetes incidence or eGFR; however, the number of infection in the first 6 months was significantly lower in the low-variability group (0.4 vs. 0.9 times; p=0.039). Multiple linear regression analysis showed that the number of infection significantly increased as intrapatient variability increased (p=0.015). Conclusion High intrapatient variability in tacrolimus concentrations was strongly associated with an increased frequency of deviation from the suggested therapeutic range and an increased number of infection.

Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-infected pneumonia emerged in Wuhan, China in December 2019. In this retrospective multicenter study, we investigated the clinical course and outcomes of novel coronavirus disease 2019 (COVID-19) from early cases in Republic of Korea. Methods: All of the cases confirmed by real time polymerase chain reaction were enrolled from the 1st to the 28th patient nationwide. Clinical data were collected and analyzed for changes in clinical severity including laboratory, radiological, and virologic dynamics during the progression of illness. Results: The median age was 40 years (range, 20–73 years) and 15 (53.6%) patients were male. The most common symptoms were cough (28.6%) and sore throat (28.6%), followed by fever (25.0%). Diarrhea was not common (10.7%). Two patients had no symptoms. Initial chest X-ray (CXR) showed infiltration in 46.4% of the patients, but computed tomography scan confirmed pneumonia in 88.9% (16/18) of the patients. Six patients (21.4%) required supplemental oxygen therapy, but no one needed mechanical ventilation. Lymphopenia was more common in severe cases. Higher level of C-reactive protein and worsening of chest radiographic score was observed during the 5–7 day period after symptom onset. Viral shedding was high from day 1 of illness, especially from the upper respiratory tract (URT). Conclusion The prodromal symptoms of COVID-19 were mild and most patients did not have limitations of daily activity. Viral shedding from URT was high from the prodromal phase. Radiological pneumonia was common from the early days of illness, but it was frequently not evident in simple CXR. These findings could be plausible explanations for the easy and rapid spread of SARS-CoV-2 in the community.

PURPOSE: With the emergence of next-generation sequencing (NGS) technology, profiling a wide range of genomic alterations has become a possibility resulting in improved implementation of targeted cancer therapy. In Asian populations, the prevalence and spectrum of clinically actionable genetic alterations has not yet been determined because of a lack of studies examining high-throughput cancer genomic data. MATERIALS AND METHODS: To address this issue, 1,071 tumor samples were collected from five major cancer institutes in Korea and analyzed using targeted NGS at a centralized laboratory. Samples were either fresh frozen or formalin-fixed, paraffin embedded (FFPE) and the quality and yield of extracted genomic DNA was assessed. In order to estimate the effect of sample condition on the quality of sequencing results, tissue preparation method, specimen type (resected or biopsied) and tissue storage time were compared. RESULTS: We detected 7,360 non-synonymous point mutations, 1,164 small insertions and deletions, 3,173 copy number alterations, and 462 structural variants. Fifty-four percent of tumors had one or more clinically relevant genetic mutation. The distribution of actionable variants was variable among different genes. Fresh frozen tissues, surgically resected specimens, and recently obtained specimens generated superior sequencing results over FFPE tissues, biopsied specimens, and tissues with long storage duration. CONCLUSION: In order to overcome, challenges involved in bringing NGS testing into routine clinical use, a centralized laboratory model was designed that could improve the NGS workflows, provide appropriate turnaround times and control costs with goal of enabling precision medicine.
Academies and Institutes ; Asian Continental Ancestry Group ; DNA ; Humans ; Korea ; Methods ; Paraffin ; Point Mutation ; Precision Medicine ; Prevalence