Publications by authors named "Nagatsuka H"
Article Synopsis
- Limited research exists on coronal cementum formation, particularly in impacted wisdom teeth.
- A histological and analytical examination of an impacted wisdom tooth from a 46-year-old female revealed widespread coronal cementum on the enamel with connections between them.
- Findings suggest that the presence of reduced enamel epithelium may be linked to coronal cementogenesis in impacted teeth, highlighting differences in the types of cementum formed.
Article Synopsis
- The study investigated how exercise in low oxygen (hypoxic) and normal oxygen (normoxic) conditions affects gastric emptying and intestinal cell damage in healthy males.
- Participants ran for 60 minutes at 70% of their maximum speed, with slower running and delayed gastric emptying observed in hypoxic conditions.
- Despite increased nausea and some indicators of intestinal damage being assessed, no significant differences in plasma levels of stress hormones were found between the two conditions, suggesting hypoxia can hinder digestive functions during endurance exercise.
Article Synopsis
- Some forms of Sjögren's syndrome (SS) cause systemic symptoms due to lymphocyte infiltration in various organs, which the study seeks to understand better using minor salivary gland tissues.
- The research involved a retrospective analysis of labial gland biopsies from female patients over 60 years old, combining clinical data with molecular techniques for gene expression and tissue imaging.
- Results revealed that secondary SS showed more severe epithelial damage and lymphocyte activity compared to primary SS, indicating that analyzing these FFPE samples can reveal significant histological differences between the two types of SS.
The polarization balance of M1/M2 macrophages with different functions is important in osteogenesis and bone repair processes. In a previous study, we succeeded in developing honeycomb tricalcium phosphate (TCP), which is a cylindrical scaffold with a honeycomb arrangement of straight pores, and we demonstrated that TCP with 300 and 500 μm pore diameters (300TCP and 500TCP) induced bone formation within the pores. However, the details of the influence of macrophage polarization on bone formation using engineered biomaterials, especially with respect to the geometric structure of the artificial biomaterials, are unknown.
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- The study addresses the challenge of inconsistent labeling in medical images, which affects diagnosis using deep learning models, particularly for oral exfoliative cytology.
- Researchers developed a convolutional neural network (CNN) by using annotations from multiple oral pathologists, processing six whole-slide images into 14,535 labeled tiles.
- The probabilistic model outperformed other approaches, achieving the highest classification performance and accuracy, suggesting that this method could enhance the reliability of AI in capturing diverse medical diagnoses.
Cisplatin is a platinum-based compound that is widely used for treating inoperable oral squamous cell carcinoma (OSCC) in Japan; however, resistance to cisplatin presents a challenge and innovative approaches are required. We aimed to investigate the therapeutic potential of targeting the chemokine receptor CXCR4, which is involved in angiogenesis and tumor progression, using the CXCR4 inhibitor AMD3100, in combination with cisplatin. AMD3100 induced necrosis and bleeding in OSCC xenografts by inhibiting angiogenesis.
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- Cancer cells are genetically unstable, leading to diverse subclones within tumors, which complicates treatment strategies, particularly in oral squamous cell carcinoma (OSCC).
- CX3C motif ligand 1 (CX3CL1) exhibits both anti- and pro-tumor functions depending on the tumor phenotype, influencing cancer behavior differently in laboratory conditions versus the living organism.
- In aggressive OSCC, CX3CL1 promotes metastasis through the lymphatic system, correlating with poorer patient outcomes, making it a critical marker for monitoring cancer progression.
Background: Squamous cell carcinoma (SCC) of the dorsum of the tongue is extremely rare, and it clinically resembles various benign lesions. Somatic mutations in TP53 and some driver genes were implicated in the development of SCC; however, the somatic genetic characteristics of dorsal tongue SCC remain unknown. With a detailed analysis of gene mutations in dorsal tongue SCC, we aimed to better understand its biology.
View Article and Find Full Text PDFCancer cachexia causes skeletal muscle atrophy, impacting the treatment and prognosis of patients with advanced cancer, but no treatment has yet been established to control cancer cachexia. We demonstrated that transcutaneous application of carbon dioxide (CO2) could improve local blood flow and reduce skeletal muscle atrophy in a fracture model. However, the effects of transcutaneous application of CO2 in cancer-bearing conditions are not yet known.
View Article and Find Full Text PDFRisk factors for post-extraction infection of mandibular third molar: A retrospective clinical study.
J Stomatol Oral Maxillofac Surg
September 2024
Post-extraction infection is one of the most concerning complications of mandibular third molar extraction, which is the most common procedure in oral and maxillofacial surgery. We investigated risk factors for post-extraction infection by retrospectively analyzing 2,513 teeth/cases of mandibular third molar extraction (1,040 males, 1,473 females) performed at a single medical facility in Kobe, Japan from January 2014 to May 2022. The predictive variables were categorized as patient attributes, health status, and anatomic, pathological, and operative variables that may be associated with post-extraction infection.
View Article and Find Full Text PDFBackground: Cisplatin (CDDP) plays a central role in chemotherapy for head and neck squamous cell carcinoma (HNSCC), but drug resistance in HNSCC chemotherapy remains a problem, and the mechanism of CDDP resistance is unclear. We investigated CDDP-resistance mechanisms mediated by extracellular vesicles (EVs) and ATPase copper transporting beta (ATP7B) in HNSCC.
Methods: We established CDDP-resistant sublines of HNSCC cells and verified their ATP7B expression.
Objectives: Rab11(Rab11a and Rab11b) localizes primarily along recycling endosomes in cells and is involved in various intracellular trafficking processes, including membrane receptor recycling and secretion of exosomes or small extracellular vesicles (EVs). Although Rab11 is closely associated with the progression and metastasis of various cancer types, little is known about Rab11' role in head and neck squamous cell carcinoma (HNSCC). In this study, we investigated the roles of Rab11a and Rab11b in HNSCC.
View Article and Find Full Text PDFBackground: Plasminogen serves as the precursor to plasmin, an essential element in the fibrinolytic process, and is synthesized primarily in the liver. Plasminogen activation occurs through the action of plasminogen activator, converting it into plasmin. This conversion greatly enhances the fibrinolytic system within tissues and blood vessels, facilitating the dissolution of fibrin clots.
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- The study focuses on using convolutional neural networks (CNNs) to analyze histopathological images of oral squamous cell carcinoma, aiming to enhance diagnostic accuracy.
- Histopathological samples were processed into images and labeled, with CNN models like VGG16 and ResNet50 evaluated for performance using various optimization techniques.
- Results showed that VGG16 with spectral angle mapper achieved the highest accuracy (86.22%) and significantly improved the diagnostic performance of oral pathologists when the model’s results were integrated into their assessments.
A crucial regulator in melanoma progression and treatment resistance is tumor microenvironments, and Hedgehog (Hh) signals activated in a tumor bone microenvironment are a potential new therapeutic target. The mechanism of bone destruction by melanomas involving Hh/Gli signaling in such a tumor microenvironment is unknown. Here, we analyzed surgically resected oral malignant melanoma specimens and observed that Sonic Hedgehog, Gli1, and Gli2 were highly expressed in tumor cells, vasculatures, and osteoclasts.
View Article and Find Full Text PDFObjectives: Cetuximab (Cmab) is a molecularly targeted monoclonal antibody drug for head and neck squamous cell carcinoma (HNSC), although cetuximab resistance is a serious challenge. Epithelial cell adhesion molecule (EpCAM) is an established marker for many epithelial tumors, while the soluble EpCAM extracellular domain (EpEX) functions as a ligand for epidermal growth factor receptor (EGFR). We investigated the expression of EpCAM in HNSC, its involvement in Cmab action, and the mechanism by which soluble EpEX activated EGFR and played key roles in Cmab resistance.
View Article and Find Full Text PDFMesenchymal stem cell (MSC) therapy is a promising approach to curing bone diseases and disorders. In treating genetic bone disorders, MSC therapy is local or systemic transplantation of isolated and in vitro proliferated MSC rather than bone marrow transplantation. Recent evidence showed that bone marrow MSC engraftment to bone regeneration has been controversial in animal and human studies.
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- Bone marrow regeneration is challenging due to its complex structure, but a study developed a honeycomb-shaped tricalcium phosphate (TCP) scaffold to promote bone marrow formation.
- The study tested two versions of the TCP, 300μm and 500μm pore diameters (300TCP and 500TCP) in rats, finding that 300TCP promoted a larger area of bone marrow structure with more blood vessels and hematopoietic cells.
- Results indicated that 300TCP effectively supported a niche for hematopoietic stem cells, suggesting it may be the optimal scaffold design for promoting bone marrow regeneration.
Polymeric Materials, Advances and Applications in Tissue Engineering: A Review.
Bioengineering (Basel)
February 2023
Tissue Engineering (TE) is an interdisciplinary field that encompasses materials science in combination with biological and engineering sciences. In recent years, an increase in the demand for therapeutic strategies for improving quality of life has necessitated innovative approaches to designing intelligent biomaterials aimed at the regeneration of tissues and organs. Polymeric porous scaffolds play a critical role in TE strategies for providing a favorable environment for tissue restoration and establishing the interaction of the biomaterial with cells and inducing substances.
View Article and Find Full Text PDFBackground: There are few reports on the treatment of carotid artery stenosis after arterial vessel replacement. We report and discuss an illustrative case of carotid artery stenting (CAS) performed for stenosis after carotid artery replacement.
Case Description: A woman in her 20s experienced injury to the right carotid artery during an operation for removal of a carotid body tumor 6 years before presentation.
To determine the effects of heat acclimation on gastrointestinal (GI) damage and the gastric emptying (GE) rate following endurance exercise in a hot environment. Fifteen healthy men were divided into two groups: endurance training in hot (HOT, 35 °C, = 8) or cool (COOL, 18 °C, = 7) environment. All subjects completed 10 days of endurance training (eight sessions of 60 min continuous exercise at 50% of the maximal oxygen uptake (V·O2max).
View Article and Find Full Text PDFTumor angiogenesis is one of the hallmarks of solid tumor development. The progressive tumor cells produce the angiogenic factors and promote tumor angiogenesis. However, how the tumor stromal cells influence tumor vascularization is still unclear.
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- Pleomorphic adenoma (PA) is the most common benign tumor found in salivary glands, but cases occurring on the lip are quite rare, making preoperative diagnosis challenging due to their small size and similarity to other lip lesions.
- In a 20-year study of oral region PAs, 11.8% were found on the lip, with an average size of about 1.5 cm, and a variety of imaging techniques were used to aid in diagnosis prior to surgical excision.
- While no recurrences or malignant transformations were observed after excision, the rarity and challenges of identifying lip PAs highlight the importance of thorough surgical removal and follow-up care.
Article Synopsis
- The study investigates how stromal cells from gum (G-SCs) and periodontal ligament (P-SCs), as well as dermal fibroblasts (HDFs), influence bone resorption and osteoclast activity in the context of oral squamous cell carcinoma (OSCC).
- G-SCs were found to enhance bone invasion and activate osteoclasts, while P-SCs inhibited bone resorption and promoted osteoclast proliferation but had a limited effect on activation.
- The research also highlighted that G-SCs significantly affected several protein expressions related to bone invasion, while P-SCs had a more subdued impact, suggesting distinct regulatory mechanisms in bone invasion driven by these different stromal cells
Article Synopsis
- The study evaluated how accurately deep learning can determine the relationship between the inferior alveolar canal and mandibular third molars using a dataset of 1279 digital radiographs.
- The researchers specifically focused on two types of analysis: contact (presence or absence of contact between the molar and canal) and continuity (bone continuity as seen on CT scans).
- Results showed that the ResNet50v2 model using sharpness-aware minimization (SAM) performed well in contact analysis (accuracy 0.860, AUC 0.890), but the models struggled with continuity analysis, showing limited effectiveness.