Background: Retinitis pigmentosa (RP) comprises a heterogeneous group of inherited retinal dystrophies. The genetic landscape of RP has been characterized; however, knowledge gaps regarding age-specific genetic variation trends in Korean patients remain. We comprehensively characterized the age-stratified genetic landscape of RP in Korean patients, with a focus on identifying novel mutational trends and clinically actionable insights. Methods: We performed targeted next-generation sequencing of 199 genes associated with RP and related disorders in a cohort of 403 unrelated patients clinically diagnosed as having RP. We analyzed the inheritance patterns, variation spectrum, and prevalence of pathogenic variants, stratifying the results by age, and conducted copy number variation (CNV) analysis. Results: A genetic diagnosis was achieved for 193 of the 403 patients (48%). The diagnostic yield was highest in patients diagnosed before 20 yrs of age (60%), with lower yields in older age groups. Although USH2A and EYS, the most common causative genes in autosomal recessive inheritance, were frequently identified, RPGR pathogenic variants accounted for a significantly larger proportion of genetically solved cases diagnosed before the age of 20 yrs (27%–28%) than in those with later-onset disease (9%–15%). CNVs were identified in 4% of genetically solved cases. Conclusions The results underscore distinct, age-related genetic contributions to RP in Korean patients, with RPGR variants demonstrating relevance in early-onset disease, and provide diagnostic insights to improve current practices. These findings can aid in prioritizing gene therapy targets and refining screening strategies.

Purpose: Biliary atresia (BA) is a rare but progressive cholangiopathy and the leading cause of pediatric liver transplantation worldwide. The Korean Association of Pediatric Surgeons (KAPS) has conducted three national surveys (2001, 2011, and 2023) to assess long-term trends in the diagnosis, treatment, and outcomes of BA. This study provides a comparative analysis of the 2nd and 3rd national surveys, with reference to selected findings from the 1st survey. Methods: This study included 453 patients from the 3rd national survey (2011–2021) and 435 patients from the 2nd survey (2001–2010), all of whom underwent Kasai portoenterostomy. Data were collected via electronic case report forms from pediatric surgical centers nationwide. Comparisons were made regarding demographics, clinical features, diagnostic patterns, operative details, follow-up outcomes, and survival. Kaplan–Meier analysis was used to evaluate long-term survival. Results: The mean number of BA patients per year remained stable between surveys (43.5 in the 2nd, 41.18 in the 3rd), though centralization of care increased, with 61.5% of cases managed by two major institutions in the 3rd survey. The median age at surgery decreased, and the use of preoperative imaging (especially magnetic resonance cholangiopancreatography) increased. The 10-year native liver survival rate declined from 59.8% to 53.7%, while overall 10-year survival improved slightly (92.9% to 93.2%). Postoperative complications, such as cholangitis and liver failure, persisted but were better categorized. The 3rd survey also reported improved mortality (4.9%) and reduced follow-up loss (11.5%) compared to the 2nd survey. Conclusion While overall survival after Kasai operation has remained high and even improved, native liver survival has slightly declined. The findings reflect earlier diagnosis, more consistent diagnostic imaging, and increasing centralization of care. These trends underscore the importance of long-term nationwide data collection in guiding future strategies for BA management in Korea.

Purpose: This study aims to investigate and compare the incidence, demographic characteristics, clinical manifestations, preoperative diagnostic methods, anatomical classifications, associated anomalies, operative treatments, and postoperative outcomes of patients with intestinal atresia treated by the members of the Korean Association of Pediatric Surgeons (KAPS) through three nationwide surveys. Methods: KAPS conducted 3 national surveys in 1998, 2010, and 2024 to examine the patients diagnosed with intestinal atresia. In preparation for the survey, we developed a customized case registration form to obtain data on patient sex, birth weight, gestational age, clinical manifestations, preoperative diagnostic methods, anatomical types, associated anomalies, operative treatments, and postoperative outcomes. Authorized KAPS members completed the case registration form. Results: The first, second, and third national surveys included 218, 222, and 236 individuals diagnosed with intestinal atresia, respectively. The male-to-female ratios were 1.5:1, 1.1:1, and 1.1:1, respectively. The first, second, and third national surveys revealed that 34.3%, 43.3%, and 53.4% of patients were born before 37 weeks of gestation, respectively. Additionally, 28.7%, 32.0%, and 40.7% of patients had a birth weight under 2,500 g. In the third national survey, duodenoduodenostomy was the most common procedure, performed in 70 out of 82 patients diagnosed with duodenal atresia. Resection and anastomosis were the main surgical procedures conducted in 47 out of 54 cases of jejunal atresia and 74 out of 92 cases of ileal atresia. The mortality rates in the first, second, and third national surveys were 13.8%, 3.6%, and 1.3% respectively, with the lowest rate observed in the third national survey. Conclusion These national surveys offer valuable insights into the current state of intestinal atresia, including specific surgical interventions and postoperative outcomes in South Korea. For pediatric surgeons aiming to enhance their understanding of intestinal atresia and its treatment options, these surveys could be an indispensable resource and guide.

Purpose: Laparoscopic appendectomy, a routine surgical procedure for acute appendicitis, is commonly performed in general hospitals. However, postoperative outcomes based on surgical subspecialty have not been well established. This study aimed to compare surgical outcomes of laparoscopic appendectomy across different surgical subspecialties using risk-adjusted cumulative summation (RA-CUSUM) analysis. Methods: A retrospective analysis was conducted on 631 patients undergoing laparoscopic appendectomy between July 2020 and December 2022. Surgeons were categorized into gastrointestinal (GI) or non-GI groups and senior or young groups. Surgical failure was defined as operation time exceeding the mean plus 2 standard deviations, presence of postoperative complications, or readmission within 30 days after surgery. RA-CUSUM analysis was employed to evaluate surgical failure within each group. Results: The GI group performed more partial cecectomies (P = 0.017) and had longer operation times (P = 0.019) than the non-GI group. The senior group exhibited shorter operation time (P < 0.001), reduced length of stay (P = 0.011), and a higher complication rate (P < 0.001) than the young group. RA-CUSUM analysis indicated a decrease in surgical failure as accumulation progressed in both senior and young groups, as well as in the GI and non-GI groups. Conclusion Outcomes of laparoscopic appendectomy varied by subspecialty and length of experience. However, each surgeon showed trends of decreasing surgical failure over time. These results suggest that the surgeon’s subspecialty minimally affects the outcomes of laparoscopic appendectomy, reflecting its fundamental nature within general surgery.

Background: Previous studies have demonstrated the inhibitory effect of hydrogen-rich water on biofilm formation. However, hydrogen-rich electrolyzed water (HEW) has not been evaluated as mouthwash, despite being economical, convenient, and biologically safe. We assessed the antibiofilm effects of HEW on Streptococcus mutans and its potential as a mouthwash. Methods: The effect of HEW on S. mutans growth was assessed by measuring bacterial colony-forming units, and biofilm formation capacity was examined by crystal violet staining after culturing on a polystyrene plate. The effect of HEW on biofilm formation-related gene expression in S. mutans was assessed by real-time polymerase chain reaction. Finally, the effect of HEW on salivary S. mutans and plaque maturation was evaluated in 24 participants; after gargling with HEW twice daily, the salivary S. mutans count was quantified using a Caries Risk Test bacteria kit (Ivoclar Vivadent AG), and plaque maturation was compared using quantitative light-induced fluorescence imaging. Results: Exposure to HEW resulted in no significant changes in S. mutans growth but a significant reduction in biofilm formation in vitro (p<0.001). Furthermore, the gene expression of glucosyltransferases (gtfB, gtfC) was significantly lower than that in the control group treated with tap water (p<0.05, p<0.01). S. mutans counts and plaque maturation were significantly lower in participants who gargled with HEW than in those who gargled with tap water (p<0.01). Conclusion Our data suggest that oral rinsing with HEW exerts antibiofilm effects on S. mutans, indicating that it can be used as a mouthwash to treat dental biofilm-dependent diseases.

Background: Hand hygiene is considered the simplest and most cost-effective method of infection prevention. Regular observation and feedback on hand hygiene compliance are key strategies for its enhancement. This study evaluated the effectiveness of hand hygiene surveillance, including direct observation and feedback, by comprehensively analyzing the reported hand hygiene compliance within the Korean National Healthcare-Associated Infections Surveillance System from 2019 to 2022. Methods: Participating medical institutions included general hospitals and hospitals with infection control departments that consented to participate. Hand hygiene surveillance was conducted using direct observation. Collected data, including healthcare workers, clinical areas, hand hygiene moments, and hand hygiene compliance, were recorded to calculate hand hygiene compliance rates. Additionally, the volume of alcohol-based hand sanitizers used per patient per day was investigated as an indirect indicator of hand hygiene compliance. The study was conducted from July 2019 to December 2022. Results: Hand hygiene compliance increased from 87.2% in Q3 2019 to 89.9% in 2022. Nurses and medical technologists showed the highest compliance rates, whereas doctors showed the lowest compliance rates. Intensive care units excelled in compliance, whereas emergency de partments lagged. Compliance was highest after patient contact and lowest when the patient’s surroundings were touched. Larger hospitals consumed more alcohol-based hand sanitizers than smaller hospitals did. Conclusion This study confirmed an improvement in hand hygiene compliance through sustained surveillance, indicating its contribution not only to preventing infection transfer within healthcare facilities but also to fostering a culture of hand hygiene in the country.

Purpose: This study aimed to develop standardized guidelines for telephone consultations and assess the impact of computerization on clinical utility. Methods: Guidelines for patient classification were developed for 14 symptoms, validated by experts, and integrated into a real-time computer program. Patient classification involved categorizations of ‘observation,’ ‘outpatient,’ and ‘emergency’.Subsequent to computerization, a survey was conducted to evaluate its usefulness. Results: Items with an Item-Content Validity Index (I-CVI) score of 0.75 or lower were removed or adjusted within the guidelines. Analysis of 200 consultation records indicated that lung cancer (87 cases) was the most common disease and the most prevalent symptom was pain (57 cases). Among 93 cases classified as ‘observation’, 6 patients visited the emergency room. Among 30 cases categorized as ‘outpatient’, 24 patients visited a clinic, and 6 patients visited the emergency room. Of the 19 cases classified as ‘emergency’, 18 patients actually visited the emergency room. User satisfaction from 12 nurses was very high, with an average score of 3.7/4. Conclusion Due to the standardized telephone triage and the concurrent implementation of a computerized program, healthcare professionals can conveniently and comprehensively analyze big data pertaining to patients’ symptoms. Ultimately, nurses were able to receive help with more specialized telenursing.

Viral load and the duration of viral shedding of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are important determinants of the transmission of coronavirus disease 2019.In this study, we examined the effects of viral doses on the lung and spleen of K18-hACE2 transgenic mice by temporal histological and transcriptional analyses. Approximately, 1×105 plaque-forming units (PFU) of SARS-CoV-2 induced strong host responses in the lungs from 2 days post inoculation (dpi) which did not recover until the mice died, whereas responses to the virus were obvious at 5 days, recovering to the basal state by 14 dpi at 1×102 PFU. Further, flow cytometry showed that number of CD8+ T cells continuously increased in 1×102 PFU-virusinfected lungs from 2 dpi, but not in 1×105 PFU-virus-infected lungs. In spleens, responses to the virus were prominent from 2 dpi, and number of B cells was significantly decreased at 1×105PFU; however, 1×102 PFU of virus induced very weak responses from 2 dpi which recovered by 10 dpi. Although the defense responses returned to normal and the mice survived, lung histology showed evidence of fibrosis, suggesting sequelae of SARS-CoV-2 infection. Our findings indicate that specific effectors of the immune response in the lung and spleen were either increased or depleted in response to doses of SARS-CoV-2. This study demonstrated that the response of local and systemic immune effectors to a viral infection varies with viral dose, which either exacerbates the severity of the infection or accelerates its elimination.