BACKGROUND: Osteoporosis, characterized by decreased bone mineral density due to an imbalance between osteoblast and osteoclast activity, poses significant challenges in bone healing, particularly in postmenopausal women. Current treatments, such as bisphosphonates, are effective but associated with adverse effects like medication-related osteonecrosis of the jaw, necessitating safer alternatives. METHODS: This study investigated the use of L-serine-incorporated gelatin sponges for bone regeneration in calvarial defects in an ovariectomized rat model of osteoporosis. Thirty rats were divided into three groups: a control group, a group treated with a gelatin sponge containing an amino acid mixture, and a group treated with a gelatin sponge containing L-serine. Bone regeneration was assessed using micro-computed tomography (micro-CT) and histological analyses. RESULTS: The L-serine group showed a significant increase in bone volume (BV) and bone area compared to the control and amino acid groups. The bone volume to total volume (BV/TV) ratio was also significantly higher in the L-serine group.Immunohistochemical analysis demonstrated that L-serine treatment suppressed the expression of cathepsin K, a marker of osteoclast activity, while increasing serine racemase activity. CONCLUSION These findings suggest that L-serine-incorporated gelatin sponges not only enhance bone formation but also inhibit osteoclast-mediated bone resorption, providing a promising and safer alternative to current therapies for osteoporosis-related bone defects. Further research is needed to explore its clinical applications in human patients.

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*

BACKGROUND: Osteoporosis, characterized by decreased bone mineral density due to an imbalance between osteoblast and osteoclast activity, poses significant challenges in bone healing, particularly in postmenopausal women. Current treatments, such as bisphosphonates, are effective but associated with adverse effects like medication-related osteonecrosis of the jaw, necessitating safer alternatives. METHODS: This study investigated the use of L-serine-incorporated gelatin sponges for bone regeneration in calvarial defects in an ovariectomized rat model of osteoporosis. Thirty rats were divided into three groups: a control group, a group treated with a gelatin sponge containing an amino acid mixture, and a group treated with a gelatin sponge containing L-serine. Bone regeneration was assessed using micro-computed tomography (micro-CT) and histological analyses. RESULTS: The L-serine group showed a significant increase in bone volume (BV) and bone area compared to the control and amino acid groups. The bone volume to total volume (BV/TV) ratio was also significantly higher in the L-serine group.Immunohistochemical analysis demonstrated that L-serine treatment suppressed the expression of cathepsin K, a marker of osteoclast activity, while increasing serine racemase activity. CONCLUSION These findings suggest that L-serine-incorporated gelatin sponges not only enhance bone formation but also inhibit osteoclast-mediated bone resorption, providing a promising and safer alternative to current therapies for osteoporosis-related bone defects. Further research is needed to explore its clinical applications in human patients.

BACKGROUND: Osteoporosis, characterized by decreased bone mineral density due to an imbalance between osteoblast and osteoclast activity, poses significant challenges in bone healing, particularly in postmenopausal women. Current treatments, such as bisphosphonates, are effective but associated with adverse effects like medication-related osteonecrosis of the jaw, necessitating safer alternatives. METHODS: This study investigated the use of L-serine-incorporated gelatin sponges for bone regeneration in calvarial defects in an ovariectomized rat model of osteoporosis. Thirty rats were divided into three groups: a control group, a group treated with a gelatin sponge containing an amino acid mixture, and a group treated with a gelatin sponge containing L-serine. Bone regeneration was assessed using micro-computed tomography (micro-CT) and histological analyses. RESULTS: The L-serine group showed a significant increase in bone volume (BV) and bone area compared to the control and amino acid groups. The bone volume to total volume (BV/TV) ratio was also significantly higher in the L-serine group.Immunohistochemical analysis demonstrated that L-serine treatment suppressed the expression of cathepsin K, a marker of osteoclast activity, while increasing serine racemase activity. CONCLUSION These findings suggest that L-serine-incorporated gelatin sponges not only enhance bone formation but also inhibit osteoclast-mediated bone resorption, providing a promising and safer alternative to current therapies for osteoporosis-related bone defects. Further research is needed to explore its clinical applications in human patients.

BACKGROUND: Osteoporosis, characterized by decreased bone mineral density due to an imbalance between osteoblast and osteoclast activity, poses significant challenges in bone healing, particularly in postmenopausal women. Current treatments, such as bisphosphonates, are effective but associated with adverse effects like medication-related osteonecrosis of the jaw, necessitating safer alternatives. METHODS: This study investigated the use of L-serine-incorporated gelatin sponges for bone regeneration in calvarial defects in an ovariectomized rat model of osteoporosis. Thirty rats were divided into three groups: a control group, a group treated with a gelatin sponge containing an amino acid mixture, and a group treated with a gelatin sponge containing L-serine. Bone regeneration was assessed using micro-computed tomography (micro-CT) and histological analyses. RESULTS: The L-serine group showed a significant increase in bone volume (BV) and bone area compared to the control and amino acid groups. The bone volume to total volume (BV/TV) ratio was also significantly higher in the L-serine group.Immunohistochemical analysis demonstrated that L-serine treatment suppressed the expression of cathepsin K, a marker of osteoclast activity, while increasing serine racemase activity. CONCLUSION These findings suggest that L-serine-incorporated gelatin sponges not only enhance bone formation but also inhibit osteoclast-mediated bone resorption, providing a promising and safer alternative to current therapies for osteoporosis-related bone defects. Further research is needed to explore its clinical applications in human patients.

BACKGROUND: Osteoporosis, characterized by decreased bone mineral density due to an imbalance between osteoblast and osteoclast activity, poses significant challenges in bone healing, particularly in postmenopausal women. Current treatments, such as bisphosphonates, are effective but associated with adverse effects like medication-related osteonecrosis of the jaw, necessitating safer alternatives. METHODS: This study investigated the use of L-serine-incorporated gelatin sponges for bone regeneration in calvarial defects in an ovariectomized rat model of osteoporosis. Thirty rats were divided into three groups: a control group, a group treated with a gelatin sponge containing an amino acid mixture, and a group treated with a gelatin sponge containing L-serine. Bone regeneration was assessed using micro-computed tomography (micro-CT) and histological analyses. RESULTS: The L-serine group showed a significant increase in bone volume (BV) and bone area compared to the control and amino acid groups. The bone volume to total volume (BV/TV) ratio was also significantly higher in the L-serine group.Immunohistochemical analysis demonstrated that L-serine treatment suppressed the expression of cathepsin K, a marker of osteoclast activity, while increasing serine racemase activity. CONCLUSION These findings suggest that L-serine-incorporated gelatin sponges not only enhance bone formation but also inhibit osteoclast-mediated bone resorption, providing a promising and safer alternative to current therapies for osteoporosis-related bone defects. Further research is needed to explore its clinical applications in human patients.

Foix-Chavany-Marie syndrome (FCMS), or bilateral anterior opercular syndrome, is a rare form of pseudobulbar palsy characterized by an automatic-voluntary dissociation of the facio-pharyngo-glosso-masticatory muscles. Although dysphagia is a major clinical feature of FCMS, few studies have described its longitudinal progression, particularly in the context of epileptic encephalopathy. This paper reports a 32-year-old male with long-standing Lennox-Gastaut syndrome secondary to childhood herpes simplex encephalitis who developed FCMS with rapidly progressive dysphagia. Brain magnetic resonance imaging revealed multifocal old infarcts involving the bilateral frontoparietal opercular regions on a background of chronic encephalomalacia. Clinically, the patient exhibited classic automatic-voluntary dissociation. Serial videofluoroscopic swallowing studies (VFSS) over two months revealed rapid deterioration, from selective penetration with preserved semisolid swallowing to universal silent aspiration across all consistencies. Unlike typical FCMS caused by acute bilateral ischemic stroke, this case suggests a cumulative, epileptic network-mediated mechanism. The VFSS findings support a functional decompensation model, in which exhaustion of the swallowing network reserve may lead to abrupt functional collapse without radiologic evidence of a new structural lesion. Serial VFSS provides critical functional insight into the disease progression in FCMS and may guide appropriate decisions regarding long-term enteral nutrition.

Objective: To test the feasibility and usability of an artificial intelligence (AI)-guided mobile cognitive telerehabilitation program for patients with stroke or older adults with mild cognitive impairment (MCI). Methods: Thirteen participants with cognitive impairment (Mini-Mental State Examination [MMSE] score≤26; nine with stroke and four with MCI) were enrolled in the study. Each participant was provided with an AI-guided mobile cognitive rehabilitation program (Zenicog®). Participants were instructed to complete 24 sessions within 6 weeks, and those with sufficient adherence (≥70%, 17 sessions) were included in the analysis. Cognitive assessments included the MMSE, digit span, and Trail Making Tests A & B. The usability questionnaire investigated equitable use and flexibility in use, simple and intuitive use, perceptible information, tolerance for error, low physical effort, size and space for use, overall product quality, overall satisfaction. Results: Eleven participants completed the study, and 10 participants met adherence criteria. The MMSE score increased significantly from 24.00 [21.00, 25.75] at baseline to 27.50 [26.00, 28.75] after intervention. The overall product quality (Likert scale: 1–5) score was 4.00±0.87. The lowest score in the usability questionnaire was for tolerance for error. Female participants and participants with <12 years’ education gave lower scores for tolerance for error and equitable/ flexibility in use, respectively. Conclusion The AI-guided mobile cognitive telerehabilitation program is feasible and potentially beneficial for improving cognitive function in patients with stroke or older adults with MCI. Individuals who are less familiar with electronic devices require special consideration to improve their usability.

Purpose: Esophagojejunostomy leakage (EJL) remains one of the most critical complications following total gastrectomy for gastric cancer. This study aimed to evaluate the evolving therapeutic approaches and clinical outcomes of EJL using data from a large-scale multicenter retrospective cohort. Methods: Among 6,577 patients who underwent total gastrectomy or proximal gastrectomy with double tract reconstruction at nine institutions from 2003 to 2024, 196 (3.0%) developed EJL. Of these, 162 patients with comprehensive clinical data were included in the final analysis. The study examined treatment modalities, changes in management over time, patient characteristics, surgical variables, and clinical outcomes. Four groups were defined according to treatment approach: conservative, endoscopic, reoperation, and multimodal (combined) therapy. Results: Endoscopic therapy was first introduced in 2011 and has progressively supplanted reoperation, now comprising 32.5% of cases. The average time to EJL diagnosis was 8.4 days after surgery. Overall in-hospital mortality was 6.1% (10/162). When conservative management was excluded, endoscopic treatment demonstrated the highest rate of therapeutic success (94.3%, p = 0.004). Both the duration until diet resumption and length of hospital stay were notably reduced in the endoscopic and conservative groups compared with reoperation and multimodal therapy (p < 0.001). Moreover, although the highest post-leakage hospitalization costs were observed with multimodal treatment (p < 0.001), overall hospitalization expenses were significantly lower for patients managed conservatively or with endoscopic intervention (p < 0.001). Conclusion Over the past two decades, management of EJL has shifted toward endoscopic approaches. Endoscopic therapies yield superior clinical outcomes and should be considered a primary option for appropriate candidates.

Background: Poor outcomes after acute ischemic stroke (AIS) revascularization are anticipated in patients with dementia due to advanced age, comorbidities, and reduced disease awareness. This study investigated clinical characteristics and short-term outcomes of AIS revascularization in patients undergoing dementia treatment. Methods: We retrospectively reviewed patients who underwent AIS revascularization therapy at eight centers of the Catholic University of Korea. Patients receiving anti-dementia medication for cognitive impairment before stroke onset were analyzed. Clinical characteristics and outcomes, including the modified Rankin Scale (mRS) score, hemorrhagic transformation, and mortality, were collected. Results: Among 1,379 patients who received AIS revascularization over 5 years, 13 (0.94%; mean age 83 years; 8 females) had a preexisting diagnosis of dementia (Alzheimer’s disease in 11, mild cognitive impairment in 2) and were on anti-dementia medication. Two patients underwent intravenous thrombolysis combined with endovascular therapy, whereas 11 underwent endovascular therapy alone. Most patients (11/13, 84.6%) presented with an unclear onset time. Stroke lesions were located in the right middle cerebral artery (MCA) in seven cases, left MCA in three, bilateral MCAs in one, and posterior circulation in two. Hemorrhagic transformation occurred in six patients (46%), of whom three (23%) were symptomatic. The mRS scores at discharge were 6 in two patients, 5 in one patient, 4 in nine patients, and 3 in one patient. Four patients died within 3 months of stroke onset. Conclusion The proportion of patients with cognitive impairment receiving anti-dementia medication among those undergoing stroke revascularization therapy was very small. The rates of hemorrhagic transformation and mortality were high. None of the patients achieved favorable outcomes at discharge.