Positional information plays a crucial role in embryonic pattern formation, yet its role in tooth development remains unexplored. In this study, we investigated the regional specification of lingual and buccal dental mesenchyme during tooth development. Tooth germs at the cap stage were dissected from mouse mandibles, and their lingual and buccal mesenchymal regions were separated for bulk RNA sequencing. Gene ontology analysis revealed that odontogenesis, pattern specification, and proliferation-related genes were enriched in the lingual mesenchyme, whereas stem cell development, mesenchymal differentiation, neural crest differentiation, and regeneration-related genes were predominant in the buccal mesenchyme. Reaggregation experiments using Wnt1^creERT/+; R26R^tdT/+ and WT mouse models demonstrated that lingual mesenchyme contributes to tooth formation, while buccal mesenchyme primarily supports surrounding tissues. Furthermore, only the lingual part of tooth germs exhibited odontogenic potential when cultured in vitro and transplanted under the kidney capsule. Bulk RNA transcriptomic analysis further validated the regional specification of the lingual and buccal mesenchyme. These findings provide novel insights into the molecular basis of positional information in tooth development and pattern formation.
Animals ; Mice ; Odontogenesis/genetics* ; Tooth Germ/cytology* ; Mesoderm/cytology* ; Cell Differentiation ; Mesenchymal Stem Cells ; Tooth/embryology*

The administration of high-dose vitamins has been focused on in critically ill patients as adjunctive therapy for life-threatening conditions. We evaluated the association between serum vitamin C concentrations and patient prognosis. Methods: We retrospectively reviewed and collected clinical and biochemical data, including thiamine and vitamin C levels, of patients admitted to the pediatric intensive care unit (PICU). Results: In total, 177 patients were admitted to the PICU during the study period, and 63 children were enrolled in this study. The most common reason for PICU admission was sepsis (33.3%). The median thiamine and vitamin C levels were 3.6 µg/dl (interquartile range [IQR], 2.9–4.5 µg/dl) and 2.84 µg/ml (IQR, 1.61–4.55 µg/ml), respectively. Thiamine deficiency was observed in 10 patients (15.9%), and 17 (27.0%) had vitamin C deficiency. There were no differences in the vitamin levels according to the reason for PICU admission. Vitamin C levels were affected by nutritional status. The length of stay in the PICU and duration of mechanical ventilation were longer in patients with vitamin C deficiency than in those without (P=0.035 and P=0.010, respectively). The serum delta neutrophil index and C-reactive protein and lactate levels increased in the vitamin C-deficient group (P=0.028 and P=0.039, respectively). There was a significant difference in Pediatric Index of Mortality 3 scores according to vitamin C levels but not in mortality directly. Conclusions: Vitamin C deficiency was associated with elevated inflammatory marker levels, increased mechanical ventilation durations, and PICU admission. Our results support the potential benefits of vitamin C administration in critically ill children.

Background: As the global population ages, medical professionals are also aging. This study investigates the status of Korean anesthesiologists over the age of 60. Methods: Anesthesiologists aged 60 and older, residing and working in Korea, were invited to participate in this study via e-mail from February to March 2021 and by mail from June to August 2021. The survey consisted of 40 questions covering 10 topics, including health status, residence, work style, and economic status. Depending on the type of question, answers were ranked on a scale of 1, 2, and 3, with the most preferred response being selected. Results: A total of 63 responses were received, resulting in a response rate of 26.5%. Among the respondents, 56 were currently practicing as anesthesiologists and reported satisfaction with their clinical practice and life status. On average, they treated 24 patients per day without experiencing significant discomfort or inconvenience in their roles as senior physicians. Twenty-four respondents acknowledged physical discomfort related to aging, and nine expressed cautions regarding age-related changes. Fifty-two respondents indicated that reeducation for advanced medical practice as anesthesiologists was necessary. Conclusions Senior anesthesiologists in Korea are primarily working in secondary and tertiary hospitals and are satisfied with their current life status. A comprehensive evaluation of reeducation programs for advanced clinical practice and retirement strategies for senior anesthesiologists is needed to address the growing number of aging physicians in the workforce.

Background: Primary cutaneous CD30+ lymphoproliferative disorders (pcCD30-LPDs) are a diseases with various clinical and prognostic characteristics. Objective: Increasing our knowledge of the clinical characteristics of pcCD30-LPDs and identifying potential prognostic variables in an Asian population. Methods: Clinicopathological features and survival data of pcCD30-LPD cases obtained from 22 hospitals in South Korea were examined. Results: A total of 413 cases of pcCD30-LPDs (lymphomatoid papulosis [LYP], n=237; primary cutaneous anaplastic large cell lymphoma [C-ALCL], n=176) were included. Ninety percent of LYP patients and roughly 50% of C-ALCL patients presented with multiple skin lesions. Both LYP and C-ALCL affected the lower limbs most frequently. Multiplicity and advanced T stage of LYP lesions were associated with a chronic course longer than 6 months. Clinical morphology with patch lesions and elevated serum lactate dehydrogenase were significantly associated with LPDs during follow-up in LYP patients. Extracutaneous involvement of C-ALCL occurred in 13.2% of patients. Lesions larger than 5 cm and increased serum lactate dehydrogenase were associated with a poor prognosis in C-ALCL. The survival of patients with C-ALCL was unaffected by the anatomical locations of skin lesions or other pathological factors. Conclusion The multiplicity or size of skin lesions was associated with a chronic course of LYP and survival among patients with C-ALCL.

Background: Primary cicatricial alopecia (PCA) is a group of disorders causing irreversible hair loss because of hair follicle destruction. Although bacterial colonization is suspected to contribute to PCA pathogenesis, its role remains unclear. Objective: To investigate bacterial colonization patterns and antibiotic susceptibility profiles in patients with PCA compared to those with non-inflammatory scalp conditions. Methods: This retrospective study analyzed bacterial cultures from scalp swabs of 161 subjects (68 patients with PCA and 93 controls) at a tertiary hospital between June 2011 and December 2023. Bacterial species and antibiotic resistance rates were evaluated using subgroup analyses of neutrophilic PCA (NCA). Results: PCA cultures showed a higher prevalence of Staphylococcus aureus (24.3%) and S. lugdunensis (8.1%) than controls, where S. capitis (54.5%) was predominant. Gram-negative bacteria were more frequent in the PCA group (13.5%) than in the control group (9.9%), with Klebsiella spp.(10.9%) being the most prevalent. Resistance rates were significantly higher in PCA for benzylpenicillin, fusidic acid, erythromycin, clindamycin, oxacillin, and telithromycin (p<0.05). Methicillin-resistant S. aureus was identified in 15% of S. aureus isolates from NCA cases. Gram-negative bacteria in PCA also exhibited increased resistance to ampicillin and ampicillin/sulbactam. Conclusion PCA exhibits distinct bacterial colonization and elevated antibiotic resistance, particularly in the neutrophilic subtypes. Bacterial culture and susceptibility testing are essential for targeted therapies in clinical practice. Further multicenter microbiome analyses with mechanistic studies are needed to elucidate bacterial contributions to PCA pathogenesis.

Background: There is a growing demand for extending dosing intervals of dupilumab injections in patients with atopic dermatitis (AD) due to treatment burden and side effects. However, studies on successful dose reduction in real-world settings are lacking. Objective: To assess the efficacy of a patient-centered dupilumab tapering regimen and to propose guidelines for target patients, appropriate intervals, and timing for tapering. Methods: This single-center retrospective study included moderate to severe adult AD patients who underwent at least 16 weeks of dupilumab treatment. Interval prolongation was considered in controlled patients assessed by Eczema Area and Severity Index (EASI) score and serum inflammatory markers after at least 40 weeks of treatment with a standard regimen. Logistic regression model with generalized estimating equations was used to compare repetitive measurements over time between the two groups. Results: A total of 52 patients were included with 11 patients extending intervals to 3–4 weeks without flare-ups. The mean duration of dupilumab treatment before tapering was 53.27 weeks. The tapering group exhibited significantly lower body mass index. All patients of the tapering group showed EASI scores under 4 and immunoglobulin E (IgE) levels under 1,000 IU/mL at week 40. EASI scores and IgE levels remained consistently low after dose reduction, with a mean follow-up time of 14.36 months. Conclusion Patients with extended dosing intervals demonstrated sustained effectiveness. Dose tapering might be a valuable option for non-obese patients with positive clinical response characterized by an EASI score under 4 and IgE levels under 1,000 at week 40.

Background: Skin rejuvenation has become an increasingly popular noninvasive approach to address age-related changes such as sagging, wrinkles, and skin laxity. Energy-based devices (EBDs) and injectables are widely used, but their application requires careful customization based on individual patient characteristics to optimize outcomes and minimize potential adverse effects. Objective: This study aimed to explore clinical practice patterns among board-certified dermatologists in South Korea, focusing on their strategies for tailoring skin rejuvenation treatments to individual patients, including the integration of EBDs, injectables, and senotherapeutics. Methods: A structured survey comprising 10 questions was administered to 13 experienced dermatologists specializing in skin rejuvenation. The survey covered treatment strategies for patients with varying facial fat volumes, pain management approaches, and the use of EBDs, injectables and senotherapeutics. Results: High-intensity focused ultrasound (HIFU) and radiofrequency (RF) were the most employed EBDs, often combined with injectables for enhanced outcomes. For patients with higher facial fat, HIFU and deoxycholic acid injections were preferred for contouring and tightening. For those with lower facial fat, biostimulatory agents such as poly-D, L-lactic acid and microneedle RF were favored to restore volume and elasticity. Pain management strategies included topical anesthetics and stepwise protocols. Although less commonly used, senotherapeutics were occasionally prescribed for specific conditions, such as melasma and extensive photoaging. Conclusion Dermatologists in South Korea employ a variety of patient-specific strategies for skin rejuvenation, combining various EBDs, injectables, and senotherapeutics. These findings highlight the importance of personalized treatment protocols and the need for further research to optimize treatment efficacy and safety.

Background: The exposome encompasses all factors people encounter through life, with the skin constantly exposed. While particulate matter (PM) and sleep deprivation are known to contribute to barrier dysfunction, their combined effects remain unclear. Objective: To evaluate the independent and combined effects of PM exposure and short-term sleep deprivation on skin barrier function. Methods: Forty healthy Korean women (aged 24–58 years) were enrolled in this study. Forearms were divided into 4 sites: control, PM exposure, sleep deprivation, and PM plus sleep deprivation. Parameters such as trans-epidermal water loss (TEWL), hydration, elasticity, roughness, and redness were measured at baseline and post-exposure. RNA sequencing and reverse transcription-polymerase chain reaction were conducted on tape-stripped skin samples. Results: PM exposure significantly increased TEWL (+25.59%, p<0.01), roughness (+21.9%, p<0.01), and redness (+13.7%, p<0.0001) while reducing elasticity (−3.98%, p<0.01). Sleep deprivation modestly reduced elasticity (−1.39%, p<0.05) without affecting other parameters.Combined PM and sleep deprivation did not further exacerbate barrier dysfunction compared to PM alone. RNA sequencing revealed reduced FLG and LORICRIN expression and upregulated endoplasmic reticulum (ER) stress markers (HSP90B1, CANX) in both PM and sleep deprivation conditions. Conclusion PM exposure impaired skin barrier function, while short-term sleep deprivation alone did not significantly affect the barrier, either independently or in combination with PM.However, it was observed that the sleep deprivation-only, while not directly causing barrier damage, induced changes in ER stress-related gene expression in tape-stripped skin samples, like the PM exposure-only. This suggests that such signaling pathways could potentially exacerbate skin barrier deterioration.