Bo Hae Kim

Chemotherapy-induced oral mucositis (CIOM) is a debilitating complication with limited therapeutic options. Mesenchymal stem cells (MSCs) promote tissue repair through paracrine signaling, and stem cell-derived nanovesicles (SC-NVs) have emerged as a scalable, cell-free therapeutic alternative. However, the regenerative potential of SC-NVs has not been investigated in the context of CIOM. This study evaluated the regenerative effects of SC-NVs derived from human adipose-derived MSCs (AD MSCs) in vitro assays and a rat CIOM model. Transcriptomic profiling showed enrichment of wound healing and angiogenesis-related genes in AD MSCs. SC-NVs were produced by serial extrusion and characterized by nanoscale size and reproducible protein content. Following intralesional injection, SC-NVs localized to the ulcer bed and remained detectable for up to 5 days. SC-NV treatment enhanced epithelial regeneration, promoted angiogenesis, and reduced inflammatory markers in vitro and in vivo. These findings support SC-NVs as a scalable, cell-free therapeutic platform for CIOM.

Oral mucositis, a common complication in chemotherapy patients, causes severe pain and ulceration, yet effective treatment options remain limited. However, the development of new therapies is hindered by the significant limitations of conventional preclinical models, including low physiological relevance, ethical concerns, and high costs. Organ‐on‐a‐chip (OoC) technology has emerged as a promising alternative by replicating human tissue microenvironments with enhanced physiological relevance. In this study, a three‐channel oral mucosa (OM)‐on‐a‐chip was developed, recapitulating the oral epithelium (EP), lamina propria (LP), and capillary (CP) regions. This chip features a CP channel designed as an independent structure separated from the other regions, enabling simulation of in vivo vascular drug delivery. In addition, incorporation of a spheroid outgrowth model enhances physiological relevance while significantly reducing fabrication time. To validate its potential as an alternative to animal testing, chemotherapy‐induced mucositis was modeled by 5‐fluorouracil (5‐FU) treatment and compared with an established animal model. Furthermore, keratinocyte growth factor (KGF) administration demonstrated the capability of the chip to reproduce both vascular and topical drug delivery responses. Taken together, OM‐on‐a‐chip provides a practical platform for modeling oral mucositis and evaluating therapeutic efficacy, showing strong potential for drug screening and translation.

Aim: This study aimed to investigate the incidence of near‐miss events related to medical device use errors (MUEs) in intensive care units (ICUs) and to identify their root causes using the Ishikawa diagram. Methods: This observational study was conducted in a referral hospital ICU in South Korea between August and September 2023, involving 60 nurses (29 MICU, 31 SICU) who completed anonymized questionnaires on near‐miss events related to five commonly used medical devices. Root causes were analyzed with a modified Ishikawa diagram. Data were processed using SPSS software. Independent t ‐tests, ANOVA, and Pearson correlation were used for continuous variables, while chi‐square and Fisher's exact tests were applied to categorical data. One‐way ANOVA identified major contributing factors. Results: Each participant experienced an average of 2.11 ± 12.53 near‐miss events per device per year, with the highest incidence in IV line sets. A positive correlation was found between near‐miss frequency and years of work experience. Root cause analysis (RCA) showed that the most common contributing factors were work environment factors, especially high patient load. The main contributing factors included chronic fatigue (personal factors), frequent device malfunctions (medical device usability factors), and insufficient education programs (unit communication and culture/education factors). Conclusions: The study highlights the importance of improving working conditions, updating outdated equipment, and strengthening educational programs to reduce MUEs and improve patient safety in ICUs.

Background: Poststroke dysphagia is a common condition that can lead to complications such as aspiration pneumonia and malnutrition, significantly affecting the quality of life. Most patients recover their swallowing function spontaneously, but in others difficulties persist beyond six months. Can we predict this in advance? On the other hand, there have been recent attempts to use machine learning to predict disease prognosis. Therefore, this study aims to investigate whether machine learning can predict the long-term prognosis for poststroke dysphagia using early videofluoroscopic swallowing study (VFSS) data. Methods: Data from VFSSs performed within 1 month of onset and swallowing status at 6 months were collected retrospectively in patients with dysphagia who experienced their first acute stroke at a university hospital. We selected 14 factors (lip closure, bolus formation, mastication, apraxia, tongue-to-palate contact, premature bolus loss, oral transit time, triggering of pharyngeal swallow, vallecular residue, laryngeal elevation, pyriform sinus residue, coating of the pharyngeal wall, pharyngeal transit time, and aspiration) from the VFSS data, scored them, and analyzed whether they could predict the long-term prognosis using five machine learning algorithms: Random forest, CatBoost classifier, K-neighbor classifier, Light gradient boosting machine, Extreme gradient boosting. These algorithms were combined through an ensemble method to create the final model. Results: In total, we collected data from 448 patients, of which 70% were used for training and 30% for testing. The final model was evaluated using accuracy, precision, recall, F1-score, and Area Under the Receiver Operating Characteristic Curve (AUC), resulting in values of 0.98, 0.94, 0.84, 0.88, and 0.99, respectively. Conclusions: Machine learning models using early VFSS data have shown high accuracy and predictive power in predicting the long-term prognosis of patients with poststroke dysphagia, and they are likely to provide useful information for clinicians.

Objectives. Effective treatment of laryngeal cancer requires clinical decision-making that balances survival outcomes with the preservation of essential functions, such as voice and swallowing. This study, led by the Clinical Practice Guideline Committee of the Korean Society of Head and Neck Surgery, aims to establish evidence-based recommendations to guide surgeons in optimizing treatment decisions for patients with laryngeal cancer.Methods. A literature search was performed in the PubMed, Embase, Cochrane Library, and KoreaMed databases by a literature search expert and subsequently reviewed by a panel of 39 committee experts. The Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) method was employed to assess the quality of evidence and develop and report the recommendations. The strength of each recommendation reflects the guideline panel’s confidence that the benefits of an intervention outweigh its risks for the target population. After drafting the guidelines, Delphi questionnaires were distributed to members of the Korean Society of Head and Neck Surgery and an external reviewer panel.Results. In total, 15 evidence-based recommendations are provided, addressing six critical aspects of laryngeal cancer treatment: early-stage treatment, treatment of locally advanced cancer, neck management, adjuvant therapy, swallowing rehabilitation, and salvage treatment for recurrent tumors.Conclusion. The guidelines provide evidence-based, validated recommendations to support clinicians in making optimal treatment decisions for laryngeal cancer.

Background and Objectives: Inconsistencies in nasal nitric oxide (nNO) values, due to anatomical variations and comorbidities, challenge the accurate assessment of upper airway inflammation severity. We hypothesized that changes in nNO levels following treatment for chronic rhinitis would be consistent and provide relative value. This study aimed to evaluate the correlation between changes in nNO levels and symptomatic improvements following treatment for chronic rhinitis.Methods: This prospective observational study included 46 participants diagnosed with chronic rhinitis between December 2021 and November 2023. nNO measurements, evaluations of four nasal and two ocular symptoms, and quality of life questionnaires were conducted at baseline and after one month of treatment. Baseline laboratory tests included serum total immunoglobulin E levels, blood eosinophil percentages, and skin prick tests.Results: The Total Nasal Symptom Score (TNSS), TNSS with ocular symptoms (TNSS eye), and Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ) scores significantly decreased following treatment (all p<0.001). nNO levels also decreased significantly after treatment (p=0.036). Moreover, changes in nNO were significantly correlated with changes in TNSS, TNSS eye, and RQLQ scores (p=0.047, r=0.294; p=0.021, r=0.340; and p=0.004, r=0.419, respectively).Conclusion: In patients with chronic rhinitis, changes in TNSS, TNSS eye, and RQLQ scores were correlated with changes in nNO levels after treatment. nNO may serve as a potential objective evaluation tool for chronic rhinitis, particularly in patients who have difficulty reporting symptoms.

Multiple cranial neuropathies (MCN) can be caused by various etiologies, such as autoimmune diseases, neurovascular diseases, tumors, or infections. Among the various etiologies of MCN, malignant lymphoma is a major cause. Anaplastic lymphoma kinase-negative anaplastic large cell lymphoma (ALK-ALCL) is an extremely rare subtype of T-cell lymphoma that exhibits aggressive behavior, particularly when affecting the central nervous system (CNS). The rarity of ALK-ALCL often leads to a relative delay in diagnosis compared to other types of lymphoma. We experienced a patient with MCN, for whom malignant lymphoma was suspected and diagnosed with ALK-ALCL, which simultaneously involved multiple cranial nerves, bilateral submandibular glands (SMGs), and the stomach within a relatively short time. Herein, we report our diagnostic experience of ALK-ALCL, along with a literature review.

Botulinum neurotoxin (BNT) injection into the cricopharyngeus muscle (CPM) under ultrasound (US) guidance is a minimally invasive technique performed to relieve cricopharyngeal dysphagia by reducing CPM spasticity. This technique is basically accessible only to both lateral sides of the CPM. This cadaveric study aimed to evaluate whether US-guided injection could effectively deliver BNT to abundant areas of gross nerve endings within the CPM. We utilized a newly modified Sihler’s staining method to identify regions with abundant neural endings within the CPM while preserving the three-dimensional morphology of the muscle in 10 sides of 5 fresh cadavers. A mixture of 0.2 mL dye was injected into the 16 sides of CPM under US guidance in 8 cadavers. Nerve endings were abundant in posterolateral areas of the CPM; the injected dye was identified at the posterolateral area on 12 sides (12/16 side, 75%) without diffusion into the posterior cricoarytenoid muscle. The injection failed on four sides (two sides of the prevertebral fascia and two sides of the esophagus below the CPM). These results suggest that US-guided injection could be a feasible technique as it can deliver BNT to the most abundant nerve distribution areas within the CPM in most cases.