Background: The clinical implications of myelin oligodendrocyte glycoprotein autoantibodies (MOG-Abs) are increasing. Establishing MOG-Ab assays is essential for effectively treating patients with MOG-Abs. We established an in-house cell-based assay (CBA) to detect MOG-Abs to identify correlations with patients’ clinical characteristics. Methods: We established the CBA using HEK 293 cells transiently overexpressing fulllength human MOG, tested it against 166 samples from a multicenter registry of central nervous system (CNS) inflammatory disorders, and compared the results with those of the Oxford MOG-Ab-based CBA and a commercial MOG-Ab CBA kit. We recruited additional patients with MOG-Abs and compared the clinical characteristics of MOG-Ab-associated disease (MOGAD) with those of neuromyelitis optica spectrum disorder (NMOSD). Results: Of 166 samples tested, 10 tested positive for MOG-Abs, with optic neuritis (ON) being the most common manifestation (4/15, 26.7%). The in-house and Oxford MOG-Ab CBAs agreed for 164/166 (98.8%) samples (κ = 0.883, P < 0.001); two patients (2/166, 1.2%) were only positive in our in-house CBA, and the CBA scores of the two laboratories correlated well (r = 0.663, P < 0.001). The commercial MOG-Ab CBA kit showed one falsenegative and three false-positive results. The clinical presentation at disease onset differed between MOGAD and NMOSD; ON was the most frequent manifestation in MOGAD, and transverse myelitis was most frequent in NMOSD. Conclusions The in-house CBA for MOG-Abs demonstrated reliable results and can potentially be used to evaluate CNS inflammatory disorders. A comprehensive, long-term study with a large patient population would clarify the clinical significance of MOG-Abs.

Background: and Purpose Despite the growing demands and challenges faced by patients with amyotrophic lateral sclerosis (ALS) in accessing healthcare services, our understanding of this access remains poor. This study aimed to investigate the healthcare utilization patterns and timing of nutritional and respiration support in patients with ALS in South Korea. Methods: A retrospective cohort study was conducted on patients diagnosed with ALS at a single tertiary hospital between 2016 and 2019 and followed up for 2 years. We evaluated patient characteristics, healthcare utilization (hospital admissions, outpatient visits, and emergency department [ED] visits), and the timing of nutritional and respiration support (noninvasive positive pressure ventilation [NIPPV], tracheostomy, gastrostomy, and nasogastric tube) at 6-month intervals from the first outpatient visit. Results: Among the 143 included patients, 73.4% were admitted at least once, 18.9% experienced unplanned admissions, and 30.1% visited the ED at least once during the study period.The most-common reason for ED visits was neurological symptoms during the first 6 months (59.1%), followed by respiratory symptoms. One fifth of patients who visited the ED underwent tracheostomy (20.9%) or NIPPV (20.9%). Two years after the first visit, 32.2% used a ventilator, and 13.3%, 26.6%, and 6.3% had undergone tracheostomy, gastrostomy, and nasogastric tube insertion, respectively. Conclusions During the 2 years following their first outpatient visit, 20% of patients with ALS experienced unplanned admissions and 30% visited the ED. An active and prompt supportivecare program should be implemented to ensure timely functional support in order to reduce these risks of unplanned admissions.

Background: Bronchiectasis is a chronic respiratory disease that leads to airway inflammation, destruction, and airflow limitation, which reflects its severity. Impulse oscillometry (IOS) is a non-invasive method that uses sound waves to estimate lung function and airway resistance. The aim of this study was to assess the usefulness of IOS in predicting the severity of bronchiectasis. Methods: We retrospectively reviewed the IOS parameters and clinical characteristics in 145 patients diagnosed with bronchiectasis between March 2020 and May 2021. Disease severity was evaluated using the FACED score, and patients were divided into mild and moderate/severe groups. Results: Forty-four patients (30.3%) were in the moderate/severe group, and 101 (69.7%) were in the mild group. Patients with moderate/severe bronchiectasis had a higher airway resistance at 5 Hz (R5), a higher difference between the resistance at 5 and 20 Hz (R5−R20), a higher resonant frequency (Fres), and a higher area of reactance (AX) than patients with mild bronchiectasis. R5 ≥0.43, resistance at 20 Hz (R20) ≥0.234, R5−R20 ≥28.3, AX ≥1.02, reactance at 5 Hz (X5) ≤−0.238, and Fres ≥20.88 revealed significant univariable relationships with bronchiectasis severity (p<0.05). Among these, only X5 ≤−0.238 exhibited a significant multivariable relationship with bronchiectasis severity (p=0.039). The receiver operating characteristic curve for predicting moderate- to-severe bronchiectasis of FACED score based on IOS parameters exhibited an area under the curve of 0.809. Conclusion The IOS assessed by the disease severity of FACED score can effectively reflect airway resistance and elasticity in bronchiectasis patients and serve as valuable tools for predicting bronchiectasis severity.

OBJECTIVES: We estimated the population prevalence of antibodies to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), including unreported infections, through a Korea Seroprevalence Study of Monitoring of SARS-CoV-2 Antibody Retention and Transmission (K-SEROSMART) in 258 communities throughout Korea. METHODS: In August 2022, a survey was conducted among 10,000 household members aged 5 years and older, in households selected through two stage probability random sampling. During face-to-face household interviews, participants self-reported their health status, COVID-19 diagnosis and vaccination history, and general characteristics. Subsequently, participants visited a community health center or medical clinic for blood sampling. Blood samples were analyzed for the presence of antibodies to spike proteins (anti-S) and antibodies to nucleocapsid proteins (anti-N) SARS-CoV-2 proteins using an electrochemiluminescence immunoassay. To estimate the population prevalence, the PROC SURVEYMEANS statistical procedure was employed, with weighting to reflect demographic data from July 2022. RESULTS: In total, 9,945 individuals from 5,041 households were surveyed across 258 communities, representing all basic local governments in Korea. The overall population-adjusted prevalence rates of anti-S and anti-N were 97.6% and 57.1%, respectively. Since the Korea Disease Control and Prevention Agency has reported a cumulative incidence of confirmed cases of 37.8% through July 31, 2022, the proportion of unreported infections among all COVID-19 infection was suggested to be 33.9%. CONCLUSIONS The K-SEROSMART represents the first nationwide, community-based seroepidemiologic survey of COVID-19, confirming that most individuals possess antibodies to SARS-CoV-2 and that a significant number of unreported cases existed. Furthermore, this study lays the foundation for a surveillance system to continuously monitor transmission at the community level and the response to COVID-19.

The objective of this study was to investigate the effect of different cooling rates and subsequent post-firing heat treatment on the final hardness of a metal-ceramic alloy. For this, Specimens of Pd-Ag-In-Sn alloy underwent simulated firing at two different cooling rates, followed by post-firing heat treatment. Hardness measurement, microstructure observation, and crystal structure analysis were conducted on the firing simulated and post-firing heat-treated specimens to analyze the causes of hardness variations. The experimental results showed that the difference in cooling rates during simulated firing had an impact on the final hardness of the alloy, and the specimens cooled at the slowest rate (Stage 3) exhibited higher hardness at all firing Stages compared to the specimens cooled at the highest rate (Stage 0). Regardless of the difference in cooling rates during the firing process, the hardness of the alloy significantly increased by the post-firing heat treatment. The increase in hardness by the post-firing heat treatment was attributed to the formation of fine precipitates in the matrix, and the precipitation reaction occurred as a result of the decrease in solubility of (Pd, Ag, Au) 3 (In, Sn, Zn) phase in the Pd-Ag-rich matrix. The clinical significance of this study is that performing the post-firing heat treatment demonstrates effectiveness in increasing the reduced hardness after porcelain firing in metal-ceramic alloys.

Purpose: We aimed to identify factors influencing smoking cessation success among cancer patients registered in an inpatient smoking cessation program at a single cancer center. Materials and Methods: The electronic medical records of enrolled patients with solid cancer were retrospectively reviewed. We evaluated factors associated with 6-month smoking cessation. Results: A total of 458 patients with cancer were included in this study. Their mean age was 62.9±10.3 years, and 56.3% of the participants had lung cancer. 193 (42.1%) had not yet begun their main treatment. The mean number of counseling sessions for the participants was 8.4±3.5, and 46 (10.0%) patients were prescribed smoking cessation medications. The 6-month smoking cessation success rate was 48.0%. Multivariate analysis showed that younger age (<65 years), cohabited status, early stage, and the number of counseling sessions were statistically significant factors affecting 6-month smoking cessation success (p<0.05). Initiation of a cessation program before cancer treatment was significantly associated with cessation success (odds ratio, 1.66; 95% confidence interval, 1.02–2.70; p=0.040). Conclusion Smoking cessation intervention must be considered when establishing a treatment plan immediately after a cancer diagnosis among smokers.

Background: The aim of this study is to investigate the clinical effectiveness of Ponto in Korea, a recently released percutaneous bone-anchored hearing implant. Methods: 16 patients with single-sided deafness (SSD) and mixed or conductive hearing loss who underwent Ponto implantation from December 2018 to September 2020 were enrolled in the study. Puretone audiometry, the Korean version of the Hearing in Noise Test (K-HINT), sound localization test (SLT), and Pupillometry were performed pre- and three months post-operation. Standardized questionnaires, the Hearing Handicap Inventory for the Elderly (HHIE) and Speech, Spatial and Qualities of Hearing Scale (SSQ), were administered. Results: The mean age of subjects was 55.5 (range, 48–67) years. Four males and 12 females participated in the study. The mean puretone average was 73.17 dB hearing level (HL) before surgery and significantly improved to 36.72 dB HL three months after surgery. The mean word recognition score improved from 26.0% to 90.75% after implantation. In the case of K-HINT, there was a significant difference in summation (Z = −2.250, P = 0.024) and head shadow effects (Z = −3.103, P = 0.002). There was no significant difference in root mean square error degree (RMSE) and hemifield identification scores for SLT testing. Pupillometry was performed to measure listening effort and the results revealed that the degree of pupillary dilatation decreased under the condition of quiet, 0 dB signal to noise ratio (SNR) and 3 dB SNR. The total score for HHIE decreased significantly (Z = −3.130, P = 0.002) while the SSQ score increased significantly (Z = −2.216, P = 0.027). Conclusions The Ponto bone-anchored hearing system showed significant clinical benefit in Korean patients with conductive and mixed hearing loss and SSD.

Purpose: The purpose of this study is three-fold: 1) to evaluate factors influencing hearing aid (HA) satisfaction; 2) to provide a profile of HA satisfaction in daily life; and 3) to examine the reasons why people gave up using HAs. Materials and Methods: Data for 1148 respondents were statistically analyzed and reported. Results: In the study, age (β=-0.03, p<0.01), level of education (β=1.21, p<0.01), HA purchase price (β=1.50, p<0.01), bilateral amplification (β=1.23, p<0.01), wearing time (β=0.28, p<0.01), and HA fitting and fine tuning on a regular basis (β=1.71, p<0.01) significantly influenced HA satisfaction. In addition, the authors observed that the most satisfactory factors were clarity of sound (53.5%), people’s trust in their HA (61.7%), and listening from a quiet environment (72.8%) in the domains of sound quality, HA features, and listening environments, respectively. Finally, with multiple choices being possible, 65% of the 40 respondents who no longer used HAs answered that their HAs ended up in a drawer since the background noise was annoying and distracting. Conclusion This study is significant in that it is a large-scale multi-center research to comprehensively examine the factors influencing HA satisfaction in South Korea. This data will provide helpful information that could lead to the successful rehabilitation of hearing loss with HAs.

Background: Prevention of chronic diseases such as hypertension and diabetes is important, but few studies have identified barriers to healthy lifestyle practices among adults in their 30-50s. Therefore, this study is intended to be used as basic data for establishing a prevention and control strategy for chronic diseases. Methods: This study is a qualitative content analysis study using the focus group interview methodology. According to the inductive content analysis method, data were analyzed through the steps of ‘making sense of the data and whole’, ‘open coding’, ‘grouping’, ‘categorization’, and ‘abstraction’. Results: The categories of barriers to healthy lifestyle practice were derived as follows. ‘Low interest in health care’ in the intrapersonal domain, ‘absence of an assistant’ in the interpersonal domain, ‘organizational environment in which it is difficult to a healthy lifestyle practice’ in the organizational domain, ‘lack of infrastructure’ and ‘restrictions on use of public health centers’ in the community domain. Conclusions For the prevention and management of chronic diseases, adults in their 30-50s should be encouraged to take an interest in healthy lifestyle practices and increase their will. For healthy lifestyle practice, it is necessary to allow family members and friends to participate as helpers. In addition, at work, employers should pay attention to workers' health management, adjust working hours, and reduce the burden of company dinner to create an organizational environment for healthy lifestyle practice. Lastly, infrastructure such as public sports facilities should be additionally expanded, and the contents of public health centers' programs should be promoted.

Background: The importance of infection with COVID-19 is being emphasized in dentistry with high risks such as aerosols. The purpose of this study is to investigate the knowledge and practice of infection control, stress and coping, and turnover of dental hygienists. Methods: Questionnaire was conducted knowledge and practice of infection control, occupational stress and coping, turnover. Survey data was investigated about 149 dental hygienists from February to March 2021 Data were analyzed t-test, ANOVA, Pearson’s correlation using statistical programs of PASW Statistics ver. 21.0. Results: Regarding occupational stress, relationship conflict was higher in the group with less than 2 years of experience (p＜0.05). Job anxiety, organizational system, inadequate compensation, and workplace culture were highly surveyed in the 3 to 5 year of experience. The group with more than 6 years of experience had the highest perception of lack of job autonomy (p＜0.05). The group with higher knowledge of infection control had lower mean inappropriate rewards and stress (p＜0.05). The group with high infection control performance had a lower average in items such as job instability, organizational system, inadequate compensation, workplace culture, and stress. And problem-focused coping ability was found to be high (p＜0.05). Infection control knowledge and performance were positively correlated (r=0.251, p＜0.01), infection control practice and stress were negatively correlated (r=−0.264, p＜0.01), and stress and emotional coping were positively correlated (r=0.367, p＜0.01). Stress was positively correlated with turnover rate (r=0.549, p＜0.01). Conclusion Infection control training was required to reduce occupational stress. Occupational stress was highly correlated with turnover, a holistic and systemic organizational operation and improvement of the quality of medical care were required to reduce stress.