Background: Reference materials are essential for the quality assurance of molecular detection methods. We developed and characterized synthetic norovirus GI and GII RNA reference materials. Methods: Norovirus GI and GII RNA sequences including the ORF1–ORF2 junction region were designed based on 1,495 reported norovirus sequences and synthesized via plasmid preparation and in vitro transcription. The synthetic norovirus GI and GII RNAs were evaluated using six commercial norovirus detection kits used in Korea and subjected to homogeneity and stability analyses. A multicenter study involving five laboratories and using four commercial real-time PCR norovirus detection assays was conducted for synthetic norovirus RNA characterization and uncertainty measurements. Results: The synthetic norovirus GI and GII RNAs were positively detected using the six commercial norovirus detection kits and were homogeneous and stable for one year when stored at –20°C or –70°C. All data from the five laboratories were within a range of 1.0 log copies/μL difference for each RNA, and the overall mean concentrations for norovirus GI and GII RNAs were 7.90 log copies/μL and 6.96 log copies/μL, respectively. Conclusions The synthetic norovirus GI and GII RNAs are adequate for quality control based on commercial molecular detection reagents for noroviruses with high sequence variability. The synthetic RNAs can be used as reference materials in norovirus molecular detection methods.

Objective: Dysphagia is a common clinical condition characterized by difficulty in swallowing. It is sub-classified into oropharyngeal dysphagia, which refers to problems in the mouth and pharynx, and esophageal dysphagia, which refers to problems in the esophageal body and esophagogastric junction. Dysphagia can have a significant negative impact one’s physical health and quality of life as its severity increases. Therefore, proper assessment and management of dysphagia are critical for improving swallowing function and preventing complications. Thus a guideline was developed to provide evidence-based recommendations for assessment and management in patients with dysphagia. Methods: Nineteen key questions on dysphagia were developed. These questions dealt with various aspects of problems related to dysphagia, including assessment, management, and complications. A literature search for relevant articles was conducted using Pubmed, Embase, the Cochrane Library, and one domestic database of KoreaMed, until April 2021. The level of evidence and recommendation grade were established according to the Grading of Recommendation Assessment, Development and Evaluation methodology. Results: Early screening and assessment of videofluoroscopic swallowing were recommended for assessing the presence of dysphagia. Therapeutic methods, such as tongue and pharyngeal muscle strengthening exercises and neuromuscular electrical stimulation with swallowing therapy, were effective in improving swallowing function and quality of life in patients with dysphagia. Nutritional intervention and an oral care program were also recommended. Conclusion This guideline presents recommendations for the assessment and management of patients with oropharyngeal dysphagia, including rehabilitative strategies.

Purpose: The aim of this study was to evaluate the bio-durability and bone regeneration capacity of the non-crosslinked collagen membrane in rabbit calvarial defect models. Materials and Methods: Four circular defects with 8 mm diameter were made in each of calvarium of 10 male rabbits. The following groups was randomly assigned to each defect - 1) Control, 2) membrane group containing noncross-linked collagen membrane only (M), 3) bone graft group (B), 4) bone graft with membrane group (B+M). Animals were sacrificed and samples were harvested at 2 weeks (n=5) and 8 weeks (n=5). Histologic sections were prepared and histomorphometric analysis was performed.Result: Histologic results showed well adaptation of the non-cross-linked membrane on each defect and normal healing response at 2 weeks. At 8 weeks, the membranes were partially biodegraded. Histomorphometrically, B and B+M group showed the significantly greater total augmented area (B+M group, 10.44±1.49, P=0.016; B group, 9.13±0.53, P=0.032) and new bone formation (B+M group, 2.89±0.93, P=0.008; B group, 2.85±1.15, P=0.008) compared to control group. Collapsing of the central portion of the membrane, membrane group showed greater value in new bone formation at 8 weeks (1.78±0.68, P=0.032). Conclusion Within the limitations of this study, the non-cross-linked collagen membrane fabricated using the improved decellularized method was shown to be effective for the regeneration of calvarial bone defects. In addition, prolonged barrier function might be provided using this collagen membrane.

Background: We evaluated the achievement of low-density lipoprotein cholesterol (LDL-C) targets in patients with type 2 diabetes mellitus (T2DM) according to up-to-date Korean Diabetes Association (KDA), European Society of Cardiology (ESC)/European Atherosclerosis Society (EAS), and American Diabetes Association (ADA) guidelines. Methods: This retrospective cohort study collected electronic medical record data from patients with T2DM (≥20 years) managed by endocrinologists from 15 hospitals in Korea (January to December 2019). Patients were categorized according to guidelines to assess LDL-C target achievement. KDA (2019): Very High-I (atherosclerotic cardiovascular disease [ASCVD]) <70 mg/dL; Very High-II (target organ damage [TOD], or cardiovascular risk factors [CVRFs]) <70 mg/dL; high (others) <100 mg/dL. ESC/EAS (2019): Very High-I (ASCVD): <55 mg/dL; Very High-II (TOD or ≥3-CVRF) <55 mg/dL; high (diabetes ≥10 years without TOD plus any CVRF) <70 mg/dL; moderate (diabetes <10 years without CVRF) <100 mg/dL. ADA (2019): Very High-I (ASCVD); Very High-II (age ≥40+ TOD, or any CVRF), for high intensity statin or statin combined with ezetimibe. Results: Among 2,000 T2DM patients (mean age 62.6 years; male 55.9%; mean glycosylated hemoglobin 7.2%) ASCVD prevalence was 24.7%. Of 1,455 (72.8%) patients treated with statins, 73.9% received monotherapy. According to KDA guidelines, LDL-C target achievement rates were 55.2% in Very High-I and 34.9% in Very High-II patients. With ESC/EAS guidelines, target attainment rates were 26.6% in Very High-I, 15.7% in Very High-II, and 25.9% in high risk patients. Based on ADA guidelines, most patients (78.9%) were very-high risk; however, only 15.5% received high-intensity statin or combination therapy. Conclusion According to current dyslipidemia management guidelines, LDL-C goal achievement remains suboptimal in Korean patients with T2DM.

Purpose: We aimed to investigate manifestations and patterns of care for patients with brain metastasis (BM) from breast cancer (BC) and compared their overall survival (OS) from 2005 through 2014 in Korea. Materials and Methods: We retrospectively reviewed 600 BC patients with BM diagnosed between 2005 and 2014. The median follow-up duration was 12.5 months. We categorized the patients into three groups according to the year when BM was initially diagnosed (group I [2005-2008], 98 patients; group II [2009-2011], 200 patients; and group III [2012-2014], 302 patients). Results: Over time, the median age at BM diagnosis increased by 2.2 years (group I, 49.0 years; group II, 48.3 years; and group III, 51.2 years; p=0.008). The percentage of patients with extracranial metastasis was 73.5%, 83.5%, and 86.4% for group I, II, and III, respectively (p=0.011). The time interval between BC and BM was prolonged in patients with stage III primary BC (median, 2.4 to 3 years; p=0.029). As an initial brain-directed treatment, whole-brain radiotherapy alone decreased from 80.0% in 2005 to 41.1% in 2014. Meanwhile, stereotactic radiosurgery or fractionated stereotactic radiotherapy alone increased from 13.3% to 34.7% during the same period (p=0.005). The median OS for group I, II, and III was 15.6, 17.9, and 15.0 months, respectively, with no statistical significance. Conclusion The manifestations of BM from BC and the pattern of care have changed from 2005 to 2014 in Korea. However, the OS has remained relatively unchanged over the 10 years.

Objective: Unlike common acute urinary tract infections, obstructive urinary tract infections caused by urinary calculus can be fatal because they can progress to sepsis and cause shock or disseminated intravascular coagulation. The evidence of patients with obstructive urinary tract infections caused by urinary tract stones visiting the emergency center is still lacking. Methods: Seventy-seven patients who visited the emergency room with obstructive urinary tract infections caused by urinary calculus from January 2016 to December 2018 were enrolled in this study and divided into two groups: sepsis group and non-sepsis group. Results: The lymphocyte count, platelet count, neutrophil-lymphocyte ratio, serum creatinine, and C-reactive protein were significantly different in the sepsis-positive and negative groups. Percutaneous nephrostomy was also significantly higher in the sepsis-positive group. The area under the receiver operating characteristic curve was calculated to evaluate the ability of the neutrophil-lymphocyte ratio and platelet-lymphocyte ratio to predict a septic urinary tract infection. The neutrophil-lymphocyte ratio and platelet-lymphocyte ratio were 0.659 and 0.550, respectively. Multivariate logistic regression analysis showed that diabetic patients, percutaneous nephrostomy, and serum creatinine were associated with septic obstructive urinary tract infection. Conclusion In patients with an obstructive urinary tract infection who were referred to the emergency center, diabetic patients and those with high blood urea nitrogen and creatinine levels are at high risk of sepsis. In such cases, rapid diagnosis and treatment, such as percutaneous nephrostomy, are necessary.

Irritation fibroma is a reactive hyperplastic lesion caused by chronic stimuli with low intensity in the oral cavity. Irritation fibroma is common in middle-aged females but it may also occur at any age and sex. Clinical characteristics of irritation fibroma are similar to other reactive lesions or benign tumors, therefore, histological examination is essential to make an accurate diagnosis. This case report presents two cases of irritation fibroma occurred on the gingiva in young males. Two male patients in their 20s and 30s of age visited the clinic for the evaluation and treatment of painless gingival overgrowth in the anterior region. Clinically, the lesions were well-defined and firm, with similar color and texture to the adjacent normal gingiva. Excisional biopsy under local anesthesia was conducted with a scalpel, and the lesions were completely removed. Histopathologically, connective tissue consisting of dense collagen bundles, proliferation of fibroblasts and minor infiltrated inflammatory cells were observed. Based on the clinical and histopathological findings, the diagnosis of irritation fibroma was confirmed in both cases.

Objectives: ：The aim of this study was to examine socio-demographic variables and the correlation of their factors and mental health with resilience in adolescents. Methods: ：Participants were 4,325 middle and high school students living in Jeollanam-do, South Korea. Participants completed self-report questionnaires examining socio-demographic characteristics and including the following self-rating scales: the resilience test, the adolescent mental health and problem behavior screening questionnaire-II (AMPQ-II). Results: ：The resilience test scores were positively correlated with the adolescent mental health and problem behavior screening questionnaire-II scores (p<0.001). In multiple regression analysis, below average academic achievement (OR 4.05, 95%CI 2.62-6.27, p<0.001), perceived poor relationship with parents (OR 2.91, 95%CI 2.28-3.71, p<0.001), body dissatisfaction (OR 2.09, 95%CI 1.57-2.79, p<0.001), middle school students (OR 2.02, 95%CI 1.59-2.56, p<0.001), male (OR 1.95, 95%CI 1.55-2.46, p<0.001), low socioeconomic status (OR 1.68, 95%CI 1.11-2.52, p=0.014), low maternal education level (OR 1.64, 95%CI 1.09-2.48, p=0.018) showed significant negative correlation with resilience. Conclusion ：Resilience needs to be considered to promote mental health of adolescents. Specifically, interventions providing psychological support should target adolescents with factors correlated low resilience

Objectives: ：The aim of this study was to examine socio-demographic variables and the correlation of their factors and mental health with resilience in adolescents. Methods: ：Participants were 4,325 middle and high school students living in Jeollanam-do, South Korea. Participants completed self-report questionnaires examining socio-demographic characteristics and including the following self-rating scales: the resilience test, the adolescent mental health and problem behavior screening questionnaire-II (AMPQ-II). Results: ：The resilience test scores were positively correlated with the adolescent mental health and problem behavior screening questionnaire-II scores (p<0.001). In multiple regression analysis, below average academic achievement (OR 4.05, 95%CI 2.62-6.27, p<0.001), perceived poor relationship with parents (OR 2.91, 95%CI 2.28-3.71, p<0.001), body dissatisfaction (OR 2.09, 95%CI 1.57-2.79, p<0.001), middle school students (OR 2.02, 95%CI 1.59-2.56, p<0.001), male (OR 1.95, 95%CI 1.55-2.46, p<0.001), low socioeconomic status (OR 1.68, 95%CI 1.11-2.52, p=0.014), low maternal education level (OR 1.64, 95%CI 1.09-2.48, p=0.018) showed significant negative correlation with resilience. Conclusion ：Resilience needs to be considered to promote mental health of adolescents. Specifically, interventions providing psychological support should target adolescents with factors correlated low resilience