[Show abstract][Hide abstract]ABSTRACT: Sonic hedgehog (SHH) and its signaling have been identified in several human cancers, and increased levels of its expression appear to correlate with disease progression and metastasis. However, the role of SHH in bone destruction associated with oral squamous cell carcinomas is still unclear. In this study we analyzed SHH expression and the role played by SHH signaling in gingival carcinoma-induced jawbone destruction. From an analysis of surgically resected lower gingival squamous cell carcinoma mandible samples, we found that SHH was highly expressed in tumor cells that had invaded the bone matrix. On the other hand, the hedgehog receptor Patched and the signaling molecule Gli-2 were highly expressed in the osteoclasts and the progenitor cells. SHH stimulated osteoclast formation and pit formation in the presence of the receptor activator for nuclear factor-κB ligand (RANKL) in CD11b+ mouse bone marrow cells. SHH upregulated phosphorylation of ERK1/2 and p38 MAPK, NFATc1, tartrate-resistant acid phosphatase (TRAP), and Cathepsin K expression in RAW264.7 cells. Our results suggest that tumor-derived SHH stimulated the osteoclast formation and bone resorption in the tumor jawbone microenvironment.
[Show abstract][Hide abstract]ABSTRACT: Nowadays, soft tissue restoration techniques are mainly focused on volume regeneration instead of function recovering. So far, autologous fat transplant has been the most popular method although its multiple reported problems like volume and function loss. Adipose tissue engineering therefore emerges as a solution for development of biological substitutes for soft tissue which promotes not only volume regeneration but also function restoration with minimal consequences. Here we tested fibrous-structured atelocollagen (FSA) scaffolds and honeycomb atelocollagen (HCA) scaffolds for their ability to induce adipogenesis in vivo. Implants were subjected to histological and immunohistochemical assessment after 1, 2, and 4 weeks of implantation. Our studies showed that FSA scaffolds induced in vivo a markedly adipogenic response, whereas an acute inflammatory process was observed at HCA scaffolds without tissue regeneration detected within them. Our histological findings concerning FSA scaffolds clearly showed the presence of adipose-like tissue surprisingly composed by a mixture of brown-like and white-like adipocytes at week 2 whereas only white-like adipocytes at week 4. Subsequent positive Pax7 immunostaining at weeks 1 and 2 suggested the existence of a common myogenic progenitor shared by brown-like and white-like adipocytes observed. Then, in this work we present FSA scaffolds as a promising structure for brown and white adipose tissue engineering.
[Show abstract][Hide abstract]ABSTRACT: Cell migration and invasion through interstitial tissues are dependent upon several specialized characteristics of the migratory cell notably generation of proteolytic membranous protrusions or invadopodia. Ameloblastoma is a benign odontogenic epithelial neoplasm with a locally infiltrative behaviour. Cortactin and MMT1-MMP are two invadopodia proteins implicated in its local invasiveness. Other invadopodia regulators, namely N-WASP, WIP and Src kinase remain unclarified. This study addresses their roles in ameloblastoma. Eighty-seven paraffin-embedded ameloblastoma cases (20 unicystic, 47 solid/multicystic, 3 desmoplastic and 17 recurrent) were subjected to immunohistochemistry for expression of cortactin, N-WASP, WIP, Src kinase and F-actin, and findings correlated with clinicopathological parameters. Invadopodia proteins (except Src kinase) and F-actin were widely detected in ameloblastoma (cortactin: n = 73/87, 83.9%; N-WASP: n = 59/87; 67.8%; WIP: n = 77/87; 88.5%; and F-actin: n = 87/87, 100%). Protein localization was mainly cytoplasmic and/or membranous, and occasionally nuclear for F-actin. Cortactin, which functions as an actin-scaffolding protein, demonstrated significantly higher expression levels within ameloblastoma tumoral epithelium than in stroma (P < 0.05). N-WASP, which coordinates actin polymerization and invadopodia-mediated extracellular matrix degradation, was overexpressed in the solid/multicystic subtype (P < 0.05). WIP, an upstream regulator of N-WASP, and F-actin were significantly upregulated along the tumour invasive front compared to tumour centres (P < 0.05). Except for males with cortactin overexpression, other clinical parameters (age, ethnicity and anatomical site) showed no significant correlations. Present results suggest that local invasiveness of ameloblastoma is dependent upon the migratory potential of its tumour cells as defined by their distribution of cortactin, N-WASP and WIP in correlation with F-actin cytoskeletal dynamics.
No preview · Article · Jan 2016 · Journal of Oral Pathology and Medicine
[Show abstract][Hide abstract]ABSTRACT: The purpose of the study was to determine the cell dynamics in periodontal ligament in response to mechanical stress during orthodontic movement. Following Waldo's method, a square sheet of rubber dam was inserted in between the first and second maxillary molars in 10 ddY mice leaving the stress load for 3 hours. After 3 days and at 1 week, cell count on pressure and tension sides of the periodontal ligament was determined. Furthermore, the type of cell present after mechanical stress was identified using GFP bone marrow transplantation mouse model. Immunohistochemistry was carried out at 0 min (immediately after mechanical stress), 24 hours, 1 week, 2 weeks and 6 months. Temporal changes in the expression of GFP-positive bone marrow derived cells were examined. Moreover, double immunofluorescent staining was performed to determine the type of cell in the periodontal ligament. Cell count on the tension side tremendously increased 3 days after mechanical stress. At 1 week, spindle and round cell count increased compared to the control group. These changes were observed on both tension and pressure sides. Cell count on pressure side at 3 days (22.11+/-13.98) and at 1 week (33.23+/-11.39) was higher compared to the control group (15.26+/-8.29). On the tension side, there was a significantly increased at 3 days (35.46+/-11.85), but decreased at 1 week (29.23+/-13.89) although it is still higher compared to the control group (AD+/-SD: 10.37+/-8.69). Using GFP bone marrow transplantation mouse model, GFP positive cell count increased gradually over time in 6 months. GFP positive cells were also positive to CD31, CD68 and Runx2 suggesting that fibroblasts differentiated into osteoclasts and tissue macrophages. In conclusion, mechanical stress during orthodontic movement promoted the increase in the number of cells in the periodontal ligament on both tension and pressure sides. The increase in the number of cells in the periodontal ligament is believed to be due to the migration and cell division of undifferentiated mesenchymal cells.
No preview · Article · Aug 2015 · International journal of medical sciences
[Show abstract][Hide abstract]ABSTRACT: Objective: 1,4-Dihydroxy-2-naphthoic acid (DHNA) is the main component of the metabolic products after fermentation by Propionibacterium freudenreichii ET-3. In this study, DHNA, vitamin K2 (VK2), and risedronate (Ris) were administered to ovariectomized (OVX) mice to ascertain their suppressive effects on bone mass reduction. Methods: Fifty mice were divided into five groups: Sham, OVX, DHNA, VK2, and Ris groups. The drugs were administered daily for 8 weeks. Subsequently, blood was collected from the orbital venous plexus. The bilateral femurs and L5 lumbar vertebra were excised. To determine the effects of the drugs, we performed histomorphometric analyses of the left femur and L5 by micro-CT, biochemical analyses of serum samples, and histological analyses of the right femur. Results: The results for the total bone mineral density, bone volume density, trabecular thickness, trabecular number, trabecular separation, and histological analyses showed that bone resorption was improved in the DHNA and Ris groups compared with the OVX group. Furthermore, the biochemical analyses revealed that the production of inflammatory cytokines was suppressed in the DHNA and Ris groups. Conclusions: The present findings show that DHNA suppresses the bone mass reduction in OVX mice, suggesting that it could be an alternative treatment for postmenopausal osteoporosis.
[Show abstract][Hide abstract]ABSTRACT: Maxillary anterior implants are associated with the risk of nasopalatine canal damage. Here we present the case of a 37-year-old man who developed a nasopalatine duct cyst after maxillary implant placement. The patient received an implant 3 months after the extraction of a fractured maxillary right central incisor. At a maintenance visit 9 years after the procedure, he complained of swelling and mild pain in the palatal region of the implant. A panoramic radiograph and computed tomography (CT) scan revealed a large, well-circumscribed, periapical radiolucency surrounding the apical portion of the implant and extending to the nasopalatine duct. We removed the entire lesion without removing the implant. Histopathologic examination of the resected specimen revealed a nasopalatine duct cyst. Accidental contact with the nasopalatine canal during implant surgery may have led to the development of the nasopalatine duct cyst. Careful planning using a preoperative CT scan prior to implant placement may prevent such complications.
[Show abstract][Hide abstract]ABSTRACT: Osteosynthetic bone fixation devices made from composites of uncalcined and unsintered hydroxyapatite (u-HA) particles and poly-L-lactide (PLLA) are widely adopted for clinical use because of their bioresorbability and osteoconductive properties. However, how the plate systems constituting these devices change during long-term use in vivo is unknown. In this study, we present cases of two patients fitted with u-HA/PLLA devices for >5 years after surgery and evaluate the resorption process on the basis of the residual versus the resorbed material. In both cases, the majority of the degraded plates and screws had been replaced by bone. In post-operative three-dimensional (3D) CT imaging, plate and screws were maintained until two years after surgery, and then they were degraded and replaced to bone in 4-6 years after surgery. Examination of the aggregation of hydroxyapatite and decrease in molecular weight suggested that the residual material was in the final stages of resorption. The plate system examined demonstrated stable degradation without foreign body reactions in vivo. Although complete resorption is a lengthy process, it is possible to follow its progress using CT.
Preview · Article · Apr 2015 · Journal of Hard Tissue Biology
[Show abstract][Hide abstract]ABSTRACT: In recent years, calcium titanate (CaTiO3) and carbon-containing materials have gained much attention in a number of biomedical material researches. To maximize the advantages of both materials, we developed a novel alkoxide method to get ‘‘calcium titanate with calcium carbonate’’ (CaTiO3–CaCO3). Thus, our previous result indicated that calcium carbonate could play a key role in the cell response of CaTiO3 material. In the present study we evaluated the effect of sintering time of CaTiO3–CaCO3 in osteoblastic response of KUSA/A1 cells. We examined the material characterization as well as cellular proliferation and mineralization of KUSA/A1 cells cultured with the materials. The results showed that Ca-TiO3–CaCO3 material sintered during 30 min, has better influ-ence on the bone marrow stromal cells for their proliferation and mineralization compared to CaTiO3-CaCO3 sintered at 2 and 10 h. These results suggest that sintering time could be directly related to the amount of carbon within CaCO3 being crucial in cell response. In conclusion, our preliminary find-ings indicate that CaTiO3–CaCO3 could play a more dominant and favorable effect on cell response when sintered for 30 minutes.
No preview · Article · Jan 2015 · IFMBE proceedings
[Show abstract][Hide abstract]ABSTRACT: Mineralization is one of the most important processes in normal bone tissue development and in disease condition. Developing a novel and standardized in vitro model system that can readily monitor both cellular dynamics and mineralization is crucial for better understanding the bone tissue development and growth. Recent studies indicated that the mechanical environment is critical condition in mineralization. We hypothesized that hydrogel with different mechanical stiffness can provide a biomimetic mechanical environment that can modulate bone tissue growth and mineralization. A femur of mouse embryo (E16) was embedded in agarose hydrogel (2-60 kPa) and cultured in osteogenic medium for a week. Micro computed tomography (µCT) results revealed the enhanced mineralization was detected in femur head cultured in the gel condition, while no mineralization in the femur head cultured in control (floating culture) condition. The mineralized region was corresponding to the region of secondary ossification center. Both histological and quantitative analyses indicated that the mineralized region of femur head cultured in 10 kPa gel condition was the highest and the mineralized area was significantly larger than that cultured in 2, 40 and 60 kPa gel condition. Immunofluorescence results indicated that the enhanced mineralization caused by the higher chondrogenic differentiation at that region. This enhancement mainly relating to the mechanical forces not to the oxygen tension was also confirmed. Since this system enhances and shorten the mineralization procedure compared to the conventional 2D or 3D cell culture system, this hydrogel system would be one of the unique models for better understanding the mineralized tissue development.
No preview · Article · Nov 2014 · Tissue Engineering Part C Methods
[Show abstract][Hide abstract]ABSTRACT: Objective:
This study examined whether the occurrence of late neck metastasis in early tongue squamous cell carcinoma can be predicted by evaluating HMGB1 (high mobility group box 1) expression in the primary lesion.
A case-control study was conducted. The cases comprised 10 patients with late neck metastasis. The controls consisted of 16 patients without recurrence. All were examined immunohistochemically for HMGB1 protein expression. The odds ratio for late neck metastasis in relation to HMGB1 was estimated.
RESULTS for HMGB1 were dichotomised into positive staining scores (score, 5-7) and negative scores (0-4). Six cases (60 per cent) and four controls (25 per cent) were HMGB1-positive. Although no significant result was seen, compared with HMGB1-negative patients the odds ratio for late neck metastasis in HMGB1-positive patients was 3.8 (95 per cent confidence interval, 0.6-26.5) after adjusting for other factors.
In the present study, immunohistochemical study of HMGB1 in early tongue squamous cell carcinoma did not appear to be very useful for predicting occult neck metastasis. Further study is necessary to clarify the relationship between HMGB1 expression and late neck metastasis in early tongue squamous cell carcinoma.
No preview · Article · Sep 2014 · The Journal of Laryngology & Otology
[Show abstract][Hide abstract]ABSTRACT: Conclusion:
In tongue squamous cell carcinoma (SCC), high levels of regulatory T-cell (Treg) infiltration in tumor nests are observed in the cases with poor prognosis.
The role of Tregs in head and neck cancers remains unclear. The aim of this study was to observe the distribution of Tregs in different stages of tongue SCC and estimate the effects on prognosis.
Thirty-four cases with tongue SCC were examined immunohistochemically for CD4, CD8, and Forkhead box P3 (Foxp3). Immunoreactive cells were counted in cancer stroma and nest regions, and relationships between cell numbers and disease-free survival rates were analyzed.
In the 34 cases, univariate analysis for disease-free survival indicated high-level infiltration of Tregs (CD4(+)Foxp3+) into both cancer nests and stroma and presence of helper T (CD4(+)Foxp3-) cells in cancer stroma as potential predictors of significantly worse prognosis. In early-stage cases (stage I/II), high-level infiltration of Tregs in cancer nests correlated significantly with poor disease-free survival rate. Multivariate analysis for disease-free survival found no independent variables.
No preview · Article · Jun 2014 · Acta Oto-Laryngologica
[Show abstract][Hide abstract]ABSTRACT: Adenoid cystic carcinoma (ACC) is one of the most common salivary gland malignant tumors with a high risk of recurrence and metastasis. Current studies on cancer stem cells (CSCs) have verified that CSCs are the driving force behind tumor initiation and progression, suggesting that new cancer therapies may be established by effectively targeting and killing the CSCs. The primary goal of this study is to investigate the expression patterns of ABCG2, CD133, and podoplanin in ACC of minor salivary glands by immunohistochemistry analysis. We found that ABCG2 was weakly expressed in normal looking salivary gland tissues. A significant upregulation of ABCG2 expression in ACC was observed with a similar expression pattern of Ki-67. CD133 was detected in apical membrane of epithelial cells and podoplanin was expressed positively in myoepithelial cells of both normal looking tissue and ACC. However, no significant difference was found of the expression pattern of CD133 and podoplanin between normal looking tissues and ACC. Our observations suggest that CSCs may exist in quiescent cells with ABCG2 positive staining, which are surrounded by cells with positive expression of ABCG2 and Ki-67 in ACC, and costaining with ABCG2 and Ki-67 may help predict the location of CSCs.
[Show abstract][Hide abstract]ABSTRACT: Dexmedetomidine, a highly selective agonist of α2-adrenoceptors, is a commonly used sedative; however, a potent anti-inflammatory effect has also been found. In the present study we evaluated the inhibitory effect of locally injected dexmedetomidine on inflammatory responses in the injected region.
Local inflammation was induced in the hindpaws of male mice (aged 6-8 weeks) by intraplantar injection of lambda-carrageenin. To offset the central effect of tested agents, different agents were blindly injected into the left and right paws in the pairs of comparison. The effect of dexmedetomidine on edema (increase in paw volume), the accumulation of leukocytes, and production of tumor necrosis factor-α (TNF-α) and cyclooxygenase-2 (COX-2) were evaluated after carrageenin injection, using water displacement plethysmometry, histological imaging, immunohistochemistry, and Western blotting analysis. Furthermore, we also evaluated the effect of yohimbine, a full antagonist of α2-adrenoceptors, and phenylephrine, an agonist of the α1-adrenoceptor, on dexmedetomidine's action on inflammatory responses.
Paw volume and amount of leukocytes in the injected region significantly increased after the injection of carrageenin. Similarly, TNF-α and COX-2 production was found in the subcutaneous region injected with carrageenin, 4 hours after injection. Dexmedetomidine significantly inhibited all increases in paw volume, leukocytes, and production of TNF-α and COX-2. Furthermore, yohimbine significantly antagonized the anti-inflammatory effects of dexmedetomidine, whereas phenylephrine did not significantly alter them.
The findings suggest that locally injected dexmedetomidine exhibits an anti-inflammatory effect against local acute inflammatory responses, mediated by α2-adrenoceptors.
No preview · Article · Feb 2014 · Anesthesia and analgesia
[Show abstract][Hide abstract]ABSTRACT: Angiosarcoma is a malignant tumor of endothelial cells. It is a fatal disease because of the high risk of hematogenous metastasis. Angiosarcoma metastatic to the oral and maxillofacial region is extremely rare because angiosarcoma itself is rare. We report a case of angiosarcoma of the scalp that metastasized to the maxillary gingiva with a review the literature. A 72-year-old man was referred to our department in August 2009 because of a hemorrhagic mass in the right maxillary gingiva. The patient had been admitted to our hospital to receive treatment for an angiosarcoma of the scalp. He was aware that the mass was gradually growing during the past 2 months. Intraoral examination revealed a reddish-brown mass, approximately 20 mm in diameter, at the premolar region of the right maxillary gingiva. An X-ray film showed no resorption of the alveolar bone. A biopsy of the mass led to a diagnosis of angiosarcoma of the scalp metastatic to the maxillary gingiva. However, it was impossible to treat the oral metastatic lesion because of deterioration of the lung metastases. Two months later, he died of respiratory insufficiency.
Preview · Article · Jan 2014 · Nippon Koku Geka Gakkai zasshi
[Show abstract][Hide abstract]ABSTRACT: We previously reported that dynamic contrast-enhanced MRI parameters and time–signal intensity curves (TICs; also known as contrast index curves) are useful for the differential diagnosis of jawbone lesions. In particular, odontogenic fibroma and ossifying fibroma, which possess similar histopathological features (i.e., a mixture of hard and soft tissue components), display unique TIC patterns, and we consider that the TIC patterns of these lesions reflect their hard and soft tissue components. Therefore, fibrous dysplasia, which contains fibrous tissue and immature isolated trabeculae composed of woven bone, is expected to display an interesting TIC. The purpose of this study was to assess the utility of TICs for differentiating between the abovementioned lesions, which have similar histopathological components.