Background: Osteoporosis is a significant public health issue in aging populations. Despite advances in pharmacotherapy, underdiagnosis and undertreatment remain prevalent even in patients with recent fractures. This study examined 20-year trends (2002– 2022) in anti-osteoporotic medication (AOM) usage in South Korea. Methods: Data from the Korean National Health Information Database were retrospectively analyzed. The study included individuals aged ≥50 years and analyzed prescription trends, medication adherence, measured by the medication possession ratio (MPR), and treatment initiation rates post-fracture. The AOMs examined included bisphosphonates, selective estrogen receptor modulators, denosumab (DMAB), teriparatide (TPTD), and romosozumab (ROMO). Results: Over two decades, AOM use has shifted significantly from oral to injectable formulations, with injectables surpassing oral medications in 2020; from 397,440 prescriptions in 2016 to 1,162,779 in 2022. Prescriptions for DMAB surged following its approval as a first-line therapy in 2019, increasing 2.65 times from 217,606 in 2019 to 575,595 in 2022. The MPR improved from 35.4% in 2003 to 73.2% in 2021, with females demonstrating higher adherence than males. Post-fracture treatment rates increased from 31.1% in 2006 to 39.9% in 2021 but remained below 50%. Vertebral fractures had the highest treatment initiation rates, while anabolic agents, such as TPTD and ROMO were underprescribed despite their efficacy. Conclusions This 20-year analysis highlights significant progress in osteoporosis management in South Korea, including a shift towards injectable therapies and improved adherence. However, the persistent undertreatment of high-risk patients underscores the requirement for enhanced access to anabolic agents, clinician education, and policy reforms to optimize post-fracture care.

Purpose: Patients undergoing breast surgery may experience chronic postoperative pain in the breasts, upper extremities, and axillary regions, and no established methods for preventing this pain are available at present. This study aimed to investigate whether coaptation of the transected intercostal nerve can prevent the development of neuropathic and chronic breast pain after mastectomy in implant-based breast reconstruction. Methods: A prospective, double-blind, randomized controlled trial was conducted by dividing patients who underwent implant-based breast reconstruction after mastectomy into a control group without nerve coaptation and an experimental group with nerve coaptation.Patient clinical information was collected, and a survey using the pain and quality of life scale was conducted at 6 and 12 months after surgery. Results: Fifteen patients completed the study, including seven in the control group and eight in the experimental group. The two groups showed no significant differences in terms of clinical factors. The experimental group exhibited lower Short-Form McGill Pain Questionnaire scores than the control group at 6 and 12 months postoperatively, with a statistically significant difference at 6 months. Numerical Rating Scale and Present Pain Intensity scores for both groups were in the “no to mild” range throughout the study period, with no statistically significant differences between the groups. Although the difference in the BREAST-Q™ results did not reach statistical significance, the experimental group showed an improvement in the quality of life. Conclusion Intercostal nerve coaptation after mastectomy in implant-based breast reconstruction may facilitate initial nerve recovery. Although trial results are needed to fully determine the clinical impact, our findings support the ongoing scientific and clinical efforts to use this technique.

This study aimed to establish an organoid culture model using small intestine tissues from male and female C57BL/6 mice and to compare it with rat organoid cultures derived from frozen tissues. Crypts were isolated from the small intestines of eight-week-old male and female mice and cultured in 3D extracellular matrix with Wnt, R-spondin, and Noggin. In addition, small intestine tissues from sixteen-week-old F344 rats were preserved in a storage solution immediately post-sacrifice and stored at –80°C before being transferred to a nitrogen tank. Upon thawing, crypts from frozen rat tissues failed to develop into organoids due to structural damage, suggesting the need for fresh tissues or optimized preservation methods. In contrast, mouse-derived organoids showed viability for 7 days, with distinct morphological changes and clear differentiation by Day 7. Quantitative real-time PCR analysis revealed that Lgr5, a stem cell marker, showed significantly higher expression in organoids than in tissues, confirming the successful establishment of the organoid culture. Among epithelial markers, the antimicrobial enzyme Lyz1 was more highly expressed in organoids, while Muc2, a key goblet cell marker, was more highly expressed in male tissues. The enterocyte marker Alp exhibited higher expression in male organoids compared to females, with no sex differences in tissues. These findings highlight sex-specific differences in gene expression related to small intestine differentiation and demonstrate the challenges in organoid culture from frozen rat tissues. The results suggest the importance of immediate tissue processing or improved preservation methods for successful organoid cultures.

Background: and Purpose This study evaluated the diagnostic utility of an anti-signal-recognition particle 54 (anti-SRP54) antibody-based enzyme-linked immunosorbent assay (ELISA) as well as the clinical, serological, and pathological characteristics of patients with SRP immune-mediated necrotizing myopathy (IMNM). Methods: We evaluated 87 patients with idiopathic inflammatory myopathy and 107 healthy participants between January 2002 and December 2023. The sensitivity and specificity of the ELISA for anti-SRP54 antibodies were assessed, and the clinical profiles of patients with antiSRP54 antibodies were determined. Results: The ELISA for anti-SRP54 antibodies had a sensitivity and specificity of 88% and 99%, respectively, along with a test–retest reliability of 0.92 (p<0.001). The 32 patients diagnosed with anti-SRP IMNM using a line-blot immunoassay included 28 (88%) who tested positive for anti-SRP54 antibodies using the ELISA, comprising 12 (43%) males and 16 (57%) females whose median ages at symptom onset and diagnosis were 43.0 years and 43.5 years, respectively. Symptoms included proximal muscle weakness in all 28 (100%) patients, neck weakness in 9 (32%), myalgia in 15 (54%), dysphagia in 5 (18%), dyspnea in 4 (14%), dysarthria in 2 (7%), interstitial lung disease in 2 (7%), and myocarditis in 2 (7%). The median serum creatine kinase (CK) level was 7,261 U/L (interquartile range: 5,086–10,007 U/L), and the median anti-SRP54 antibody level was 2.0 U/mL (interquartile range: 1.0–5.6 U/mL). The serum CK level was significantly higher in patients with coexisting anti-Ro-52 antibodies. Conclusions This study has confirmed the reliability of the ELISA for anti-SRP54 antibodies and provided insights into the clinical, serological, and pathological characteristics of South Korean patients with anti-SRP IMNM.

Background: and Purpose Treatments for neuromyelitis optica spectrum disorder (NMOSD) such as eculizumab, ravulizumab, satralizumab, and inebilizumab have significantly advanced relapse prevention, but they remain expensive. Rituximab is an off-label yet popular alternative that offers a cost-effective solution, but its real-world efficacy needs better quantification for guiding the application of newer approved NMOSD treatments (ANTs). This study aimed to determine real-world rituximab failure rates to anticipate the demand for ANTs and aid in resource allocation. Methods: We conducted a nationwide retrospective study involving 605 aquaporin-4-antibody-positive NMOSD patients from 22 centers in South Korea that assessed the efficacy and safety of rituximab over a median follow-up of 47 months. Results: The 605 patients treated with rituximab included 525 (87%) who received continuous therapy throughout the follow-up period (median=47 months, interquartile range=15–87 months). During this period, 117 patients (19%) experienced at least 1 relapse. Notably, 68 of these patients (11% of the total cohort) experienced multiple relapses or at least 1 severe relapse.Additionally, 2% of the patients discontinued rituximab due to adverse events, which included severe infusion reactions, neutropenia, and infections. Conclusions This study has confirmed the efficacy of rituximab in treating NMOSD, as evidenced by an 87% continuation rate among patients over a 4-year follow-up period. Nevertheless, the occurrence of at least one relapse in 19% of the cohort, including 11% who experienced multiple or severe relapses, and a 2% discontinuation rate due to adverse events highlight the urgent need for alternative therapeutic options.

Background: and Purpose Anti-agrin antibodies (agrin Abs) have recently been identified in patients with myasthenia gravis (MG), sometimes in conjunction with antibodies (Abs) to the acetylcholine receptor (AChR), muscle-specific tyrosine kinase (MuSK), or low-density lipoprotein receptor-related protein 4. This study aimed to develop an in-house cell-based assay (CBA) for detecting agrin Abs, and to test its application to serum samples collected from individuals diagnosed with MG. Methods: Agrin complementary DNA as cloned into a pCMV6-AC-GFP vector, which was subsequently transfected into human embryonic kidney 293T (HEK293T) cells. Transfected HEK293T cells were incubated with patient serum and antihuman immunoglobulin G Ab conjugated with a red fluorescent dye. Agrin Ab levels were measured using the CBA in 389 serum samples: 340 from patients with MG, 36 from patients with other neuromuscular diseases, and 13 from healthy controls. The presence of agrin Ab was determined based on the fluorescence intensity and colocalization using fluorescence microscopy. Results: The expression levels of agrin mRNA and protein in transfected HEK293T cells were confirmed using the reverse-transcription polymerase chain reaction and Western blotting, respectively. Agrin expression in cells was further confirmed by immunocytochemistry.Two (0.6%) of the 340 patients with MG tested positive for agrin Ab: 1 of 191 AChR-positive patients and 1 of 54 MuSK-positive patients. Conclusions We have developed and validated a novel CBA for detecting agrin Abs. This CBA was successfully applied to detect agrin Abs in serum samples obtained from individuals with MG.

Background: and Purpose We aimed to determine the proportion of Korean patients with early Alzheimer’s disease (AD) who are eligible to receive lecanemab based on the United States Appropriate Use Recommendations (US AUR), and also identify the barriers to this treatment. Methods: We retrospectively enrolled 6,132 patients with amnestic mild cognitive impairment or mild amnestic dementia at 13 hospitals from June 2023 to May 2024. Among them, 2,058 patients underwent amyloid positron emission tomography (PET) and 1,199 (58.3%) of these patients were amyloid-positive on PET. We excluded 732 patients who did not undergo brain magnetic resonance imaging between June 2023 and May 2024. Finally, 467 patients were included in the present study. Results: When applying the criteria of the US AUR, approximately 50% of patients with early AD were eligible to receive lecanemab treatment. Among the 467 included patients, 36.8% did not meet the inclusion criterion of a Mini-Mental State Examination (MMSE) score of ≥22. Conclusions Eligibility for lecanemab treatment was not restricted to Korean patients with early AD except for those with an MMSE score of ≥22. The MMSE criteria should therefore be reconsidered in areas with a higher proportion of older people, who tend to have lower levels of education.

Purpose: This study examined the associations of grit, self-leadership, and followership with nurses’ competency in evidence-based practice in South Korea. Methods: This descriptive correlational study included 203 nurses from a general hospital. Data collection was conducted from May 8 to June 21, 2024. Results: The mean score for competency in evidence-based practice was 4.16 of 7. Competency in evidence-based practice correlated positively with grit (r = .62, p < .001), self-leadership (r = .54, p < .001), and followership (r = .72, p < .001). Followership (β = 0.53, p < .001), grit (β = 0.24, p < .001) and research experience (β = 0.11, p = .024) significantly influenced competency in evidence-based practice. The model’s explanatory power was calculated to be 55.1%. Conclusion Followership and grit are key factors in developing strategies to enhance nurses’ competency in evidence-based practice. Additionally, providing support for research experience in clinical settings may further strengthen competency in evidence-based practice.

Background: Because of the low prevalence of inherited retinal diseases, reports on the distribution of retinitis pigmentosa (RP)-related genes in Korean patients are scarce. The aim of this study was to determine the mutation spectrum and allele frequency and observe the final diagnoses in a Korean cohort clinically diagnosed with RP. Methods: We used whole-exome sequencing (WES) to analyze a Korean cohort of 100 unrelated patients clinically diagnosed with RP. The possible pathogenicity of each variant was assessed based on the guidelines of the American College of Medical Genetics and Genomics and Association for Molecular Pathology, in-silico prediction tools, known clinical phenotypes, and inheritance patterns. Results: Definite causative genes were detected in 60/100 patients (60.0%). Of these 60 cases, USH2A was the most common causative gene (14/60, 23.3%), followed by EYS (13/60, 21.7%) and RP1 (6/60, 10.0%). The clinical diagnosis was redefined in 9 of the 60 probands (15.0%) with causative genes after WES. Five of the 60 patients (8.3%) carried a causative variant in CHM, and the clinical diagnosis was redefined as choroideremia. Leber congenital amaurosis was diagnosed in 2/60 probands (3.3%), and RDH12 and RPGRIP1 were the causative genes in each patient. One patient (1/60, 1.7%) was diagnosed with Bietti’s crystalline dystrophy, with CYP4V2 identified as the causative gene. In another patient (1/60, 1.7%), ABCA4 variants were detected with clinical findings suggestive of cone-rod dystrophy. Conclusion This study reports the mutational spectrum of a cohort of Korean patients with a clinical diagnosis of RP who were referred for genetic testing. This study adds valuable data regarding the frequency of genes as well as their relation to the age of symptom onset and relation to other inherited retinal degenerations.