Language：Japanese   Publisher：(一社)日本口腔診断学会  

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Language：Japanese   Publisher：(一社)日本口腔診断学会  

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Language：English   Publishing type：Research paper (scientific journal)  

The cancer stroma regulates bone invasion in oral squamous cell carcinoma (OSCC). However, data on normal stroma are limited. In the present study, the effects of gingival and periodontal ligament tissue-derived stromal cells (G-SCs and P-SCs, respectively) and human dermal fibroblasts (HDFs) on bone resorption and osteoclast activation were assessed using hematoxylin and eosin and tartrate-resistant acid phosphatase staining in a cell line-derived xenograft model. The results demonstrated that G-SCs promoted bone invasion and osteoclast activation and inhibited osteoclast proliferation following crosstalk with the human OSCC HSC-3 cell line, whereas P-SCs inhibited bone resorption and promoted osteoclast proliferation in vitro but had a minimal effect on osteoclast activation both in vitro and in vivo following crosstalk with HSC-3 cells. Furthermore, the effects of G-SCs, P-SCs and HDFs on protein expression levels of matrix metalloproteinase (MMP)-9, membrane type 1 MMP (MT1-MMP), Snail, parathyroid hormone-related peptide (PTHrP) and receptor activator of NF-κB ligand (RANKL) in HSC-3 cells in OSCC bone invasion regions were assessed using immunohistochemistry. The results demonstrated that G-SCs had a more prominent effect on the expression of MMP-9, MT1-MMP, Snail, PTHrP, and RANKL, whereas P-SCs only promoted RANKL and PTHrP expression and exerted a minimal effect on MMP-9, MT1-MMP and Snail expression. The potential genes underlying the differential effects of G-SCs and P-SCs on bone invasion in OSCC were evaluated using a microarray, which indicated that cyclin-dependent kinase 1, insulin, aurora kinase A, cyclin B1 and DNA topoisomerase II alpha underlaid these differential effects. Therefore, these results demonstrated that G-SCs promoted bone invasion in OSCC by activating osteoclasts on the bone surface, whereas P-SCs exerted an inhibitory effect. These findings could indicate a potential regulatory mechanism for bone invasion in OSCC.

DOI： 10.3892/ol.2022.13502

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Language：English   Publishing type：Research paper (scientific journal)  

Tumor 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. In the present study, we evaluated the effects of oral squamous cell carcinoma (OSCC) stromal cells on tumor vascularization. The tumor stromal cells were isolated from two OSCC patients with different subtypes: low invasive verrucous squamous carcinoma (VSCC) and highly invasive squamous cell carcinoma (SCC) and co-xenografted with the human OSCC cell line (HSC-2) on nude mice. In comparison, the CD34+ vessels in HSC-2+VSCC were larger than in HSC-2+SCC. Interestingly, the vessels in the HSC-2+VSCC expressed vascular endothelial cadherin (VE-cadherin), indicating well-formed vascularization. Our microarray data revealed that the expression of extracellular superoxide dismutase, SOD3 mRNA is higher in VSCC stromal cells than in SCC stromal cells. Moreover, we observed that SOD3 colocalized with VE-cadherin on endothelial cells of low invasive stroma xenograft. These data suggested that SOD3 expression in stromal cells may potentially regulate tumor vascularization in OSCC. Thus, our study suggests the potential interest in SOD3-related vascular integrity for a better OSCC therapeutic strategy.

DOI： 10.3390/biomedicines10112729

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Language：English   Publishing type：Research paper (scientific journal)  

In this study, the accuracy of the positional relationship of the contact between the inferior alveolar canal and mandibular third molar was evaluated using deep learning. In contact analysis, we investigated the diagnostic performance of the presence or absence of contact between the mandibular third molar and inferior alveolar canal. We also evaluated the diagnostic performance of bone continuity diagnosed based on computed tomography as a continuity analysis. A dataset of 1279 images of mandibular third molars from digital radiographs taken at the Department of Oral and Maxillofacial Surgery at a general hospital (2014-2021) was used for the validation. The deep learning models were ResNet50 and ResNet50v2, with stochastic gradient descent and sharpness-aware minimization (SAM) as optimizers. The performance metrics were accuracy, precision, recall, specificity, F1 score, and area under the receiver operating characteristic curve (AUC). The results indicated that ResNet50v2 using SAM performed excellently in the contact and continuity analyses. The accuracy and AUC were 0.860 and 0.890 for the contact analyses and 0.766 and 0.843 for the continuity analyses. In the contact analysis, SAM and the deep learning model performed effectively. However, in the continuity analysis, none of the deep learning models demonstrated significant classification performance.

DOI： 10.1038/s41598-022-21408-9

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Publishing type：Research paper (scientific journal)   Publisher：AME Publishing Company  

DOI： 10.21037/gs-22-308

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Language：English   Publisher：硬組織再生生物学会  

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Language：English   Publishing type：Research paper (scientific journal)  

The use of sharpness aware minimization (SAM) as an optimizer that achieves high performance for convolutional neural networks (CNNs) is attracting attention in various fields of deep learning. We used deep learning to perform classification diagnosis in oral exfoliative cytology and to analyze performance, using SAM as an optimization algorithm to improve classification accuracy. The whole image of the oral exfoliation cytology slide was cut into tiles and labeled by an oral pathologist. CNN was VGG16, and stochastic gradient descent (SGD) and SAM were used as optimizers. Each was analyzed with and without a learning rate scheduler in 300 epochs. The performance metrics used were accuracy, precision, recall, specificity, F1 score, AUC, and statistical and effect size. All optimizers performed better with the rate scheduler. In particular, the SAM effect size had high accuracy (11.2) and AUC (11.0). SAM had the best performance of all models with a learning rate scheduler. (AUC = 0.9328) SAM tended to suppress overfitting compared to SGD. In oral exfoliation cytology classification, CNNs using SAM rate scheduler showed the highest classification performance. These results suggest that SAM can play an important role in primary screening of the oral cytological diagnostic environment.

DOI： 10.1038/s41598-022-17602-4

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We analyzed the rate of patients with hepatitis B virus (HBV), hepatitis C virus (HCV), or human immunodeficiency virus (HIV) infection diagnosed by pre-operative screening and estimated its cost. We retrospectively analyzed patients who underwent elective surgery at our maxillofacial surgery department between April 2014 and March 2022. We compared the number of patients with each infection identified by pre-operative screening and a pre-operative questionnaire. We also compared the prevalence of infections with varying age, sex, and oral diseases, and calculated the cost of screening per positive result. The prevalence of HBV, HCV, and HIV was 0.39% (62/15,842), 0.76% (153/15,839), and 0.07% (10/12,745), respectively. The self-reported rates were as follows: HBV, 63.4% (26/41); HCV, 50.4% (62/123); HIV, 87.5% (7/8). Differences in sex were statistically significant for all infectious diseases; age significantly affected HBV and HCV rates. There was no association between the odds ratio of oral disease and viral infections. The cost per positive result was $1873.8, $905.8, and $11,895.3 for HBV, HCV, and HIV, respectively. Although self-assessment using questionnaires is partially effective, it has inadequate screening accuracy. Formulating an auxiliary diagnosis of infectious diseases with oral diseases was challenging. The cost determined was useful for hepatitis, but not HIV.

DOI： 10.3390/healthcare10071348

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Language：English   Publishing type：Research paper (scientific journal)  

Bone-modifying agents (BMA) such as bisphosphonates and denosumab are frequently used for the treatment of bone metastases, osteoporosis, and multiple myeloma. BMA may lead to anti-resorptive agent-related osteonecrosis of the jaw (ARONJ). This study aimed to clarify the risk factors for and probabilities of developing ARONJ after tooth extraction in patients undergoing BMA therapy. In this study, the records of 505 target sites of 302 patients undergoing BMA who presented with mandibular fractures at the Department of Oral and Maxillofacial Surgery, Kagawa Prefectural Central Hospital, from March 2014 to January 2022, were retrospectively analyzed for the onset of ARONJ after tooth extraction. The following variables were investigated as attributes: anatomy, health status, and dental treatment. The correlation coefficient was calculated for the success or failure of endodontic surgery for each variable, the odds ratio was calculated for the upper variable, and the factors related to the onset of ARONJ were identified. The incidence rate of ARONJ was found to be 3.2%. Hypoparathyroidism was an important factor associated with ARONJ development. Thus, systemic factors are more strongly related to the onset of ARONJ after tooth extraction than local factors.

DOI： 10.3390/healthcare10071332

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Authorship：Lead author,　Corresponding author   Language：Japanese   Publishing type：Research paper (scientific journal)  

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Language：Japanese   Publisher：(NPO)日本口腔科学会  

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Language：Japanese   Publisher：日本がん免疫学会  

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Language：Japanese   Publisher：日本がん免疫学会  

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Language：English   Publishing type：Research paper (scientific journal)  

Tumor‑associated macrophages (TAMs) are linked to the progression of numerous types of cancer. However, the effects of the tumor microenvironment (TME) of oral squamous cell carcinoma (OSCC), particularly the cancer stroma on TAMs, remains to be elucidated. In the present study, the effects of verrucous SCC‑associated stromal cells (VSCC‑SCs), SCC‑associated stromal cells (SCC‑SCs) and human dermal fibroblasts (HDFs) on the differentiation, proliferation and migration of macrophages in vitro was assayed using Giemsa staining, and immunofluorescence, MTS and Transwell (migration) assays, respectively. The combined results suggested that both VSCC‑SCs and SCC‑SCs promoted the differentiation of macrophages into M2 type TAMs, as well as the proliferation and migration of macrophages following crosstalk with HSC‑3 cells in vitro. Moreover, the SCC‑SCs exerted a more prominent effect on TAMs than the VSCC‑SCs. Immunohistochemical staining was used to examine the expression of CD34, CD45, CD11b and CD163 to assay the effects of VSCC‑SCs, SCC‑SCs and HDFs on microvessel density (MVD) and the infiltration of CD45(+) monocytes, CD11b(+) TAMs and CD163(+) M2 type macrophages. The results suggested that both VSCC‑SCs and SCC‑SCs promoted MVD and the infiltration of CD45(+) monocytes, CD11b(+) TAMs and CD163(+) M2 type TAMs into the TME of OSCC following crosstalk with HSC‑3 cells in vivo. The SCC‑SCs exerted a more prominent promoting effect than the VSCC‑SCs. Finally, the potential genes underlying the differential effects of VSCC‑SCs and SCC‑SCs on the infiltration of TAMs were investigated using microarray analysis. The results revealed that interleukin 1β, bone morphogenetic protein 4, interleukin 6 and C‑X‑C motif chemokine ligand 12 had great potential to mediate the differential effects of VSCC‑SCs and SCC‑SCs on TAM infiltration. On the whole, the findings presented herein, demonstrate that both VSCC‑SCs and SCC‑SCs promote the infiltration of TAMs into the TME of OSCC following crosstalk with HSC‑3 cells; the SCC‑SCs were found to exert a more prominent promoting effect. This may represent a potential regulatory mechanism for the infiltration of TAMs into the TME of OSCC.

DOI： 10.3892/ijo.2022.5368

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Language：English   Publishing type：Research paper (scientific journal)  

This retrospective study clarified the success rate of endoscopic endodontic surgeries and identified predictors accounting for successful surgeries. In this retrospective study, 242 patients (90 males, 152 females) who underwent endoscopic endodontic surgery at a single general hospital and were diagnosed through follow-up one year later were included. Risk factors were categorized into attributes, general health, anatomy, and surgery. Then, the correlation coefficient was calculated for the success or failure of endodontic surgery for each variable, the odds ratio was calculated for the upper variable, and factors related to the surgical prognosis factor were identified. The success rate of endodontic surgery was 95.3%, showing that it was a highly predictable treatment. The top three correlation coefficients were post, age, and perilesional sclerotic signs. Among them, the presence of posts was the highest, compared with the odds ratio, which was 9.592. This retrospective study revealed the success rate and risk factors accounting for endoscopic endodontic surgeries. Among the selected clinical variables, the presence of posts was the most decisive risk factor determining the success of endodontic surgeries.

DOI： 10.3390/ma15093353

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Language：English   Publishing type：Research paper (scientific journal)  

Osteoporosis is becoming a global health issue due to increased life expectancy. However, it is difficult to detect in its early stages owing to a lack of discernible symptoms. Hence, screening for osteoporosis with widely used dental panoramic radiographs would be very cost-effective and useful. In this study, we investigate the use of deep learning to classify osteoporosis from dental panoramic radiographs. In addition, the effect of adding clinical covariate data to the radiographic images on the identification performance was assessed. For objective labeling, a dataset containing 778 images was collected from patients who underwent both skeletal-bone-mineral density measurement and dental panoramic radiography at a single general hospital between 2014 and 2020. Osteoporosis was assessed from the dental panoramic radiographs using convolutional neural network (CNN) models, including EfficientNet-b0, -b3, and -b7 and ResNet-18, -50, and -152. An ensemble model was also constructed with clinical covariates added to each CNN. The ensemble model exhibited improved performance on all metrics for all CNNs, especially accuracy and AUC. The results show that deep learning using CNN can accurately classify osteoporosis from dental panoramic radiographs. Furthermore, it was shown that the accuracy can be improved using an ensemble model with patient covariates.

DOI： 10.1038/s41598-022-10150-x

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Stromal cells in the tumor microenvironment (TME) can regulate the progression of numerous types of cancer; however, the bone invasion of oral squamous cell carcinoma (OSCC) has been poorly investigated. In the present study, the effect of verrucous SCC‑associated stromal cells (VSCC‑SCs), SCC‑associated stromal cells (SCC‑SCs) and human dermal fibroblasts on bone resorption and the activation of HSC‑3 osteoclasts in vivo were examined by hematoxylin and eosin, AE1/3 (pan‑cytokeratin) and tartrate‑resistant acid phosphatase staining. In addition, the expression levels of matrix metalloproteinase (MMP)9, membrane‑type 1 MMP (MT1‑MMP), Snail, receptor activator of NF‑κB ligand (RANKL) and parathyroid hormone‑related peptide (PTHrP) in the bone invasion regions of HSC‑3 cells were examined by immunohistochemistry. The results suggested that both SCC‑SCs and VSCC‑SCs promoted bone resorption, the activation of osteoclasts, and the expression levels of MMP9, MT1‑MMP, Snail, RANKL and PTHrP. However, SCC‑SCs had a more prominent effect compared with VSCC‑SCs. Finally, microarray data were used to predict potential genes underlying the differential effects of VSCC‑SCs and SCC‑SCs on bone invasion in OSCC. The results revealed that IL1B, ICAM1, FOS, CXCL12, INS and NGF may underlie these differential effects. In conclusion, both VSCC‑SCs and SCC‑SCs may promote bone invasion in OSCC by enhancing the expression levels of RANKL in cancer and stromal cells mediated by PTHrP; however, SCC‑SCs had a more prominent effect. These findings may represent a potential regulatory mechanism underlying the bone invasion of OSCC.

DOI： 10.3892/or.2022.8292

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Language：Japanese   Publisher：(一社)日本病理学会  

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Language：Japanese   Publisher：(一社)日本病理学会  

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Authorship：Lead author,　Corresponding author   Language：Japanese  

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Language：English   Publishing type：Research paper (scientific journal)  

Pell and Gregory, and Winter's classifications are frequently implemented to classify the mandibular third molars and are crucial for safe tooth extraction. This study aimed to evaluate the classification accuracy of convolutional neural network (CNN) deep learning models using cropped panoramic radiographs based on these classifications. We compared the diagnostic accuracy of single-task and multi-task learning after labeling 1330 images of mandibular third molars from digital radiographs taken at the Department of Oral and Maxillofacial Surgery at a general hospital (2014-2021). The mandibular third molar classifications were analyzed using a VGG 16 model of a CNN. We statistically evaluated performance metrics [accuracy, precision, recall, F1 score, and area under the curve (AUC)] for each prediction. We found that single-task learning was superior to multi-task learning (all p < 0.05) for all metrics, with large effect sizes and low p-values. Recall and F1 scores for position classification showed medium effect sizes in single and multi-task learning. To our knowledge, this is the first deep learning study to examine single-task and multi-task learning for the classification of mandibular third molars. Our results demonstrated the efficacy of implementing Pell and Gregory, and Winter's classifications for specific respective tasks.

DOI： 10.1038/s41598-021-04603-y

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Language：English   Publishing type：Research paper (scientific journal)  

Attention mechanism, which is a means of determining which part of the forced data is emphasized, has attracted attention in various fields of deep learning in recent years. The purpose of this study was to evaluate the performance of the attention branch network (ABN) for implant classification using convolutional neural networks (CNNs). The data consisted of 10191 dental implant images from 13 implant brands that cropped the site, including dental implants as pretreatment, from digital panoramic radiographs of patients who underwent surgery at Kagawa Prefectural Central Hospital between 2005 and 2021. ResNet 18, 50, and 152 were evaluated as CNN models that were compared with and without the ABN. We used accuracy, precision, recall, specificity, F1 score, and area under the receiver operating characteristics curve as performance metrics. We also performed statistical and effect size evaluations of the 30-time performance metrics of the simple CNNs and the ABN model. ResNet18 with ABN significantly improved the dental implant classification performance for all the performance metrics. Effect sizes were equivalent to "Huge" for all performance metrics. In contrast, the classification performance of ResNet50 and 152 deteriorated by adding the attention mechanism. ResNet18 showed considerably high compatibility with the ABN model in dental implant classification (AUC = 0.9993) despite the small number of parameters. The limitation of this study is that only ResNet was verified as a CNN; further studies are required for other CNN models.

DOI： 10.1371/journal.pone.0269016

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Tumor stromal components contribute to tumor development and invasion. However, the role of stromal cells in the contribution of bone marrow-derived cells (BMDCs) in oral squamous cell carcinoma (OSCC) invasion is unclear. In the present study, we created two different invasive OSCC patient-derived stroma xenografts (PDSXs) and analyzed and compared the effects of stromal cells on the relation of BMDCs and tumor invasion. We isolated stromal cells from two OSCC patients: less invasive verrucous OSCC (VSCC) and highly invasive conventional OSCC (SCC) and co-xenografted with the OSCC cell line (HSC-2) on green fluorescent protein (GFP)-positive bone marrow (BM) cells transplanted mice. We traced the GFP-positive BM cells by immunohistochemistry (IHC) and detected matrix metalloproteinase 2 (MMP2) expression on BM cells by double fluorescent IHC. The results indicated that the SCC-PDSX promotes MMP2-positive BMDCs recruitment to the invasive front line of the tumor. Furthermore, microarray analysis revealed that the expressions of interleukin 6; IL-6 mRNA and interleukin 1 beta; IL1B mRNA were higher in SCC stromal cells than in VSCC stromal cells. Thus, our study first reports that IL-6 and IL1B might be the potential stromal factors promoting the contribution of MMP2-positive BMDCs to OSCC invasion.

DOI： 10.3390/cancers14010137

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Publishing type：Research paper (scientific journal)   Publisher：American Society for Clinical Investigation  

DOI： 10.1172/jci.insight.148960

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Language：Japanese   Publisher：岡山歯学会  

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Language：English   Publishing type：Research paper (scientific journal)  

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：MDPI  

Background: We investigated and compared the osteogenic potential and bone regeneration capacities of dedifferentiated fat cells (DFAT cells) and adipose-derived stem cells (ASCs). Method: We isolated DFAT cells and ASCs from GFP mice. DFAT cells were established by a new culture method using a mesh culture instead of a ceiling culture. The isolated DFAT cells and ASCs were incubated in osteogenic medium, then alizarin red staining, alkaline phosphatase (ALP) assays, and RT-PCR (for RUNX2, osteopontin, DLX5, osterix, and osteocalcin) were performed to evaluate the osteoblastic differentiation ability of both cell types in vitro. In vivo, the DFAT cells and ASCs were incubated in osteogenic medium for four weeks and seeded on collagen composite scaffolds, then implanted subcutaneously into the backs of mice. We then performed hematoxylin and eosin staining and immunostaining for GFP and osteocalcin. Results: The alizarin red-stained areas in DFAT cells showed weak calcification ability at two weeks, but high calcification ability at three weeks, similar to ASCs. The ALP levels of ASCs increased earlier than in DFAT cells and showed a significant difference (p < 0.05) at 6 and 9 days. The ALP levels of DFATs were higher than those of ASCs after 12 days. The expression levels of osteoblast marker genes (osterix and osteocalcin) of DFAT cells and ASCs were higher after osteogenic differentiation culture. Conclusion: DFAT cells are easily isolated from a small amount of adipose tissue and are readily expanded with high purity; thus, DFAT cells are applicable to many tissue-engineering strategies and cell-based therapies.

DOI： 10.3390/ijms222212392

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Language：Japanese   Publisher：(一社)歯科基礎医学会  

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Language：English   Publisher：硬組織再生生物学会  

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Language：English   Publisher：硬組織再生生物学会  

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Language：English   Publishing type：Research paper (scientific journal)  

The stromal cells in the tumor microenvironment (TME) can influence the progression of multiple types of cancer; however, data on oral squamous cell carcinoma (OSCC) are limited. In the present study, the effects of verrucous squamous cell carcinoma‑associated stromal cells (VSCC‑SCs), squamous cell carcinoma‑associated stromal cells (SCC‑SCs) and human dermal fibroblasts (HDFs) on the tumor nest formation, proliferation, invasion and migration of HSC‑3 cells were examined in vitro using Giemsa staining, MTS, and Transwell (invasion and migration) assays, respectively. The results revealed that both the VSCC‑SCs and SCC‑SCs inhibited the tumor nest formation, and promoted the proliferation, invasion and migration of OSCC cells in vitro. Furthermore, the effects of VSCC‑SCs, SCC‑SCs and HDFs on the differentiation, proliferation, invasion and migration of OSCC cells in vivo were evaluated by hematoxylin and eosin staining, tartrate‑resistant acid phosphatase staining, immunohistochemistry and double‑fluorescent immunohistochemical staining, respectively. The results demonstrated that the VSCC‑SCs promoted the differentiation, proliferation, invasion and migration of OSCC cells, while the SCC‑SCs inhibited the differentiation, and promoted the proliferation, invasion and migration of OSCC cells in vivo. Finally, microarray data were used to predict genes in VSCC‑SCs and SCC‑SCs that may influence the progression of OSCC, and those with potential to influence the differential effects of VSCC‑SCs and SCC‑SCs on the differentiation of OSCC. It was found that C‑X‑C motif chemokine ligand (CXCL)8, mitogen‑activated protein kinase 3 (MAPK3), phosphatidylinositol‑4,5‑bisphosphate 3‑kinase catalytic subunit alpha (PIK3CA), C-X-C motif chemokine ligand 1 (CXCL1) and C‑C motif chemokine ligand 2 (CCL2) may be involved in the crosstalk between VSCC‑SCs, SCC‑SCs and OSCC cells, which regulates the progression of OSCC. Intercellular adhesion molecule 1 (ICAM1), interleukin (IL)1B, Fos proto‑oncogene, AP‑1 transcription factor subunit (FOS), bone morphogenetic protein 4 (BMP4), insulin (INS) and nerve growth factor (NGF) may be responsible for the differential effects of VSCC‑SCs and SCC‑SCs on the differentiation of OSCC. On the whole, the present study demonstrates that both VSCC‑SCs and SCC‑SCs may promote the progression of OSCC, and SCC‑SCs were found to exert a more prominent promoting effect; this may represent a potential regulatory mechanism for the progression of OSCC.

DOI： 10.3892/ijo.2021.5252

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：MDPI AG  

Background and Objectives: A few deep learning studies have reported that combining image features with patient variables enhanced identification accuracy compared with image-only models. However, previous studies have not statistically reported the additional effect of patient variables on the image-only models. This study aimed to statistically evaluate the osteoporosis identification ability of deep learning by combining hip radiographs with patient variables. Materials andMethods: We collected a dataset containing 1699 images from patients who underwent skeletal-bone-mineral density measurements and hip radiography at a general hospital from 2014 to 2021. Osteoporosis was assessed from hip radiographs using convolutional neural network (CNN) models (ResNet18, 34, 50, 101, and 152). We also investigated ensemble models with patient clinical variables added to each CNN. Accuracy, precision, recall, specificity, F1 score, and area under the curve (AUC) were calculated as performance metrics. Furthermore, we statistically compared the accuracy of the image-only model with that of an ensemble model that included images plus patient factors, including effect size for each performance metric. Results: All metrics were improved in the ResNet34 ensemble model compared with the image-only model. The AUC score in the ensemble model was significantly improved compared with the image-only model (difference 0.004; 95% CI 0.002–0.0007; p = 0.0004, effect size: 0.871). Conclusions: This study revealed the additional effect of patient variables in identification of osteoporosis using deep CNNs with hip radiographs. Our results provided evidence that the patient variables had additive synergistic effects on the image in osteoporosis identification.

DOI： 10.3390/medicina57080846

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Publishing type：Research paper (scientific journal)   Publisher：MDPI AG  

Lymphoepithelial carcinoma (LEC) of the tongue is a rare subtype of squamous cell carcinoma. Histologically, it is an undifferentiated carcinoma with rich lymphocyte and plasma cell infiltration. The most common location for LEC in the head and neck is the salivary glands, and LEC of the oral cavity is extremely rare. The second case report of LEC in the lateral tongue is presented. In addition, a review of the literature was performed, and the relationship between LEC and Epstein–Barr virus infection was considered.

DOI： 10.3390/reports4030024

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Language：English   Publishing type：Research paper (scientific journal)  

Normal stromal cells surrounding the tumor parenchyma, such as the extracellular matrix (ECM), normal fibroblasts, mesenchymal stromal cells, and osteoblasts, play a significant role in the progression of cancers. However, the role of gingival and periodontal ligament tissue-derived stromal cells in OSCC progression is unclear. In this study, the effect of G-SCs and P-SCs on the differentiation, proliferation, invasion, and migration of OSCC cells in vitro was examined by Giemsa staining, Immunofluorescence (IF), (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium) (MTS), invasion, and migration assays. Furthermore, the effect of G-SCs and P-SCs on the differentiation, proliferation, and bone invasion by OSCC cells in vivo was examined by hematoxylin-eosin (HE) staining, immunohistochemistry (IHC), and tartrate-resistant acid phosphatase (TRAP) staining, respectively. Finally, microarray data and bioinformatics analyses identified potential genes that caused the different effects of G-SCs and P-SCs on OSCC progression. The results showed that both G-SCs and P-SCs inhibited the differentiation and promoted the proliferation, invasion, and migration of OSCC in vitro and in vivo. In addition, genes, including CDK1, BUB1B, TOP2A, DLGAP5, BUB1, and CCNB2, are probably involved in causing the different effects of G-SCs and P-SCs on OSCC progression. Therefore, as a potential regulatory mechanism, both G-SCs and P-SCs can promote OSCC progression.

DOI： 10.3390/cancers13143491

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Language：Japanese   Publisher：(NPO)日本口腔科学会  

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Language：Japanese   Publisher：(NPO)日本口腔科学会  

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Language：English   Publishing type：Research paper (scientific journal)  

In recent years, there has been increasing interest in the treatment of bone defects using undifferentiated mesenchymal stem cells (MSCs) in vivo. Recently, dental pulp has been proposed as a promising source of pluripotent mesenchymal stem cells (MSCs), which can be used in various clinical applications. Dentin is the hard tissue that makes up teeth, and has the same composition and strength as bone. However, unlike bone, dentin is usually not remodeled under physiological conditions. Here, we generated odontoblast-like cells from mouse dental pulp stem cells and combined them with honeycomb tricalcium phosphate (TCP) with a 300 μm hole to create bone-like tissue under the skin of mice. The bone-like hard tissue produced in this study was different from bone tissue, i.e., was not resorbed by osteoclasts and was less easily absorbed than the bone tissue. It has been suggested that hard tissue-forming cells induced from dental pulp do not have the ability to induce osteoclast differentiation. Therefore, the newly created bone-like hard tissue has high potential for absorption-resistant hard tissue repair and regeneration procedures.

DOI： 10.3390/ma14123409

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The purpose of this study was to investigate the bone healing properties and histological environment of a u-HA/PLLA/PGA (u-HA-uncalcined and unsintered hydroxyapatite, PLLA-Poly L-lactic acid, PGA-polyglycolic acid) composite device in humans, and to understand the histological dynamics of using this device for maxillofacial treatments. Twenty-one subjects underwent pre-implant maxillary alveolar ridge augmentation with mandibular cortical bone blocks using u-HA/PLLA or u-HA/PLLA/PGA screws for fixation. Six months later, specimens of these screws and their adjacent tissue were retrieved. A histological and immunohistochemical evaluation of these samples was performed using collagen 1a, ALP (alkaline phosphatase), and osteocalcin. We observed that alveolar bone augmentation was successful for all of the subjects. Upon histological evaluation, the u-HA/PLLA screws had merged with the bone components, and the bone was directly connected to the biomaterial. In contrast, direct bone connection was not observed for the u-HA/PLLA/PGA screw. Immunohistological findings showed that in the u-HA/PLLA group, collagen 1a was positive for fibers that penetrated vertically into the bone. Alkaline phosphatase was positive only in the u-HA/PLLA stroma, and the stroma was negative for osteocalcin. In this study, u-HA/PLLA showed a greater bioactive bone conductivity than u-HA/PLLA/PGA and a higher biocompatibility for direct bone attachment. Furthermore, u-HA/PLLA was shown to have the potential for bone formation in the stroma.

DOI： 10.3390/ma14123286

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It is necessary to accurately identify dental implant brands and the stage of treatment to ensure efficient care. Thus, the purpose of this study was to use multi-task deep learning to investigate a classifier that categorizes implant brands and treatment stages from dental panoramic radiographic images. For objective labeling, 9767 dental implant images of 12 implant brands and treatment stages were obtained from the digital panoramic radiographs of patients who underwent procedures at Kagawa Prefectural Central Hospital, Japan, between 2005 and 2020. Five deep convolutional neural network (CNN) models (ResNet18, 34, 50, 101 and 152) were evaluated. The accuracy, precision, recall, specificity, F1 score, and area under the curve score were calculated for each CNN. We also compared the multi-task and single-task accuracies of brand classification and implant treatment stage classification. Our analysis revealed that the larger the number of parameters and the deeper the network, the better the performance for both classifications. Multi-tasking significantly improved brand classification on all performance indicators, except recall, and significantly improved all metrics in treatment phase classification. Using CNNs conferred high validity in the classification of dental implant brands and treatment stages. Furthermore, multi-task learning facilitated analysis accuracy.

DOI： 10.3390/biom11060815

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PATIENT: A 54-year-old woman presenting with anterior alveolar ridge resorption was submitted to a connective tissue graft (CTG) for esthetic improvement before rehabilitation with a fixed partial denture. Palate-harvested connective tissue was used as a graft after extra-oral removal of the epithelium. Unexpectedly, complete wound healing was not observed. Moreover, 6 months post-surgery, a white discharge was detected at the grafted site. The adjacent tooth showing a root fracture was initially associated with the symptoms and was then extracted. Concomitantly, the unhealed tissue at the grafted site was also excised, leading to temporary symptom resolution. However, the white discharge reappeared after 2 months. The excision area was expanded to remove the grafted tissue entirely, and the wound was completely healed. Since the alveolar ridge resorption had become larger compared to the preoperative condition, the patient was subjected to a second CTG, now using a connective tissue harvested from the palate by a single incision technique. The wound healed uneventfully, and the final prosthesis was delivered 6 months after soft tissu e stabilization. The patient has been followed-up for more than 28 months without any recurrence of white discharge. DISCUSSION: Histopathological and cytological examination detected keratinized epithelial tissues and cells, respectively, in excised tissues and white discharge specimens. Consequently, a possible relationship between white discharge and residual epithelium in the harvested graft was strongly suspected. CONCLUSIONS: Success of the CTG procedure requires careful method selection for tissue transplantation and treatment execution.

DOI： 10.2186/jpr.JPR_D_20_00115

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Language：Japanese   Publisher：(公社)日本臨床細胞学会  

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Language：Japanese   Publisher：(株)文光堂  

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Language：Japanese   Publisher：(一社)日本病理学会  

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Publishing type：Research paper (scientific journal)   Publisher：MDPI AG  

Spindle cell carcinoma (SCSCC) with osteoid and/or cartilage formation in the head and neck is rare; only one case was reported in the tongue. Herein, we report an SCSCC with osteoid and cartilage formation of the tongue developed in an 85-year-old man, and then review the report.

DOI： 10.3390/reports4010005

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Primordial odontogenic tumor (POT) is a rare odontogenic tumor characterized by a variably cellular loose fibrous tissue with areas similar to the dental papilla and covered by cuboidal to columnar epithelium. We herein report a case of POT in a 14-year-old boy. Computed tomography (CT) exhibited a round cavity with a defined cortical border circumscribing the tooth of the second molar. However, the gross finding was a solid mass, not a cyst. Histologically, the tumor consisted of dental papillalike myxoid connective tissue covered by columnar epithelium. Therefore, although the clinical diagnosis was dentigerous cyst (DC), we diagnosed POT based on histologic findings. Clinical findings of POT resemble DC, but the clinical behavior of POT is different to DC, such as cortical expansion and root resorption of teeth. Therefore, histological differentiation of POT from DC is critical for accurate diagnosis.

DOI： 10.3390/reports4010004

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Diagnostic utility of a homeobox transcription factor, engrailed homeobox 1 (En1) in the histopathology of salivary gland neoplasms was studied. The expression of En1 was immunohistochemically examined in 51 cases of adenoid cystic carcinoma (AdCC) and 143 cases of other salivary gland neoplasms. In all 51 AdCCs, En1 was expressed in 30-100% of tumor cells. In eight of nine polymorphous adenocarcinomas (PACs), En1 was expressed in 40-100% of tumor cells. Less than 5% of tumor cells expressed En1 in three of 12 epithelial-myoepithelial carcinomas, one of 17 basal cell adenomas (BCAs), and one of 34 pleomorphic adenomas (PAs). Among 55 other carcinoma cases, 1-30% of tumor cells expressed En1 in three salivary duct carcinomas (SDCs) ex PA. None of the myoepitheliomas and Warthin tumors expressed En1. When the cut-off value of the percentage of En1-expressing cells was set to 25%, all 51 AdCCs, eight of nine PACs and one SDC ex PA were En1-positive and the others were En1-negative. En1 is expressed consistently in AdCCs, frequently in PACs, but rarely in other salivary gland neoplasms. En1 is a possible diagnostic marker for AdCC and PAC in the histopathology of salivary gland neoplasms.

DOI： 10.1111/pin.13050

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Language：Japanese   Publisher：(株)文光堂  

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DOI： 10.1016/j.radonc.2020.12.007

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Publishing type：Research paper (scientific journal)   Publisher：Medknow  

DOI： 10.4103/ams.ams_370_20

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Language：English   Publishing type：Research paper (scientific journal)  

Myeloid-derived suppressor cells (MDSCs) are a heterogeneous population of immature myeloid cells with immunosuppressive functions; these cells play a key role in infection, immunization, chronic inflammation, and cancer. Recent studies have reported that immunosuppression plays an important role in the healing process of tissues and that Treg play an important role in fracture healing. MDSCs suppress active T cell proliferation and reduce the severity of arthritis in mice and humans. Together, these findings suggest that MDSCs play a role in bone biotransformation. In the present study, we examined the role of MDSCs in the bone healing process by creating a bone injury at the tibial epiphysis in mice. MDSCs were identified by CD11b and GR1 immunohistochemistry and their role in new bone formation was observed by detection of Runx2 and osteocalcin expression. Significant numbers of MDSCs were observed in transitional areas from the reactionary to repair stages. Interestingly, MDSCs exhibited Runx2 and osteocalcin expression in the transitional area but not in the reactionary area. And at the same area, cllagene-1 and ALP expression level increased in osteoblast progenitor cells. These data is suggesting that MDSCs emerge to suppress inflammation and support new bone formation. Here, we report, for the first time (to our knowledge), the role of MDSCs in the initiation of bone formation. MDSC appeared at the transition from inflammation to bone making and regulates bone healing by suppressing inflammation.

DOI： 10.7150/ijms.51946

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Recently, dental pulp has been attracting attention as a promising source of multipotent mesenchymal stem cells (MSCs) for various clinical applications of regeneration fields. To date, we have succeeded in establishing rat dental pulp-derived cells showing the characteristics of odontoblasts under in vitro conditions. We named them Tooth matrix-forming, GFP rat-derived Cells (TGC). However, though TGC form massive dentin-like hard tissues under in vivo conditions, this does not lead to the induction of polar odontoblasts. Focusing on the importance of the geometrical structure of an artificial biomaterial to induce cell differentiation and hard tissue formation, we previously have succeeded in developing a new biomaterial, honeycomb tricalcium phosphate (TCP) scaffold with through-holes of various diameters. In this study, to induce polar odontoblasts, TGC were induced to form odontoblasts using honeycomb TCP that had various hole diameters (75, 300, and 500 μm) as a scaffold. The results showed that honeycomb TCP with 300-μm hole diameters (300TCP) differentiated TGC into polar odontoblasts that were DSP positive. Therefore, our study indicates that 300TCP is an appropriate artificial biomaterial for dentin regeneration.

DOI： 10.3390/ma13225155

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This study considers the use of deep learning to diagnose osteoporosis from hip radiographs, and whether adding clinical data improves diagnostic performance over the image mode alone. For objective labeling, we collected a dataset containing 1131 images from patients who underwent both skeletal bone mineral density measurement and hip radiography at a single general hospital between 2014 and 2019. Osteoporosis was assessed from the hip radiographs using five convolutional neural network (CNN) models. We also investigated ensemble models with clinical covariates added to each CNN. The accuracy, precision, recall, specificity, negative predictive value (npv), F1 score, and area under the curve (AUC) score were calculated for each network. In the evaluation of the five CNN models using only hip radiographs, GoogleNet and EfficientNet b3 exhibited the best accuracy, precision, and specificity. Among the five ensemble models, EfficientNet b3 exhibited the best accuracy, recall, npv, F1 score, and AUC score when patient variables were included. The CNN models diagnosed osteoporosis from hip radiographs with high accuracy, and their performance improved further with the addition of clinical covariates from patient records.

DOI： 10.3390/biom10111534

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：MEDICINA ORAL S L  

Background: This study investigated the causes of dental implant removal due to complications, and examined whether patients who had dental implant removal desired re-implant prosthesis treatments.Material and Methods: A retrospective case-control study was conducted on patients who had their dental implants removed. We investigated whether the removed dental implant was replaced with other implant prostheses. Age, sex, diabetes, smoking, implant site distribution, reason for implant removal, and blade and root-form implants were categorized as predictive variables. The outcome variable was desire for re-implantation or use of other prosthetic methods after implant removal. A logistic regression model was created to identify patient factors that could predict the re-implantation of dental prostheses after implant removal.Results: A total of 215 dental implants were removed from 143 patients. The most common reason for implant removal was peri-implantitis that was identified in 165 implants. After implant removal, re-implantation was performed in 98 implants (45.6%) Bivariate analyses showed that age, diabetes, implant type, and reason for implant removal were associated with the desire for re-implanted prostheses. The multiple regression model revealed that age, implant type, and reason for implant removal were associated with an increased desire for re-implant prostheses after implant removal.Conclusions: Re-implantation of prostheses after the removal of dental implants was desired by patients who were younger, had implants placed in the root form, and had implants removed due to prosthetic-related complications.

DOI： 10.4317/medoral.23789

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The effect of the geometric structure of artificial biomaterials on skull regeneration remains unclear. In a previous study, we succeeded in developing honeycomb β-tricalcium phosphate (β-TCP), which has through-and-through holes and is able to provide the optimum bone microenvironment for bone tissue regeneration. We demonstrated that β-TCP with 300-μm hole diameters induced vigorous bone formation. In the present study, we investigated how differences in hole directions of honeycomb β-TCP (horizontal or vertical holes) influence bone tissue regeneration in skull defects. Honeycomb β-TCP with vertical and horizontal holes was loaded with BMP-2 using Matrigel and Collagen gel as carriers, and transplanted into skull bone defect model rats. The results showed that in each four groups (Collagen alone group, Matrigel alone group, Collagen + BMP group and Matrigel + BMP-2), vigorous bone formation was observed on the vertical β-TCP compared with horizontal β-TCP. The osteogenic area was larger in the Matrigel groups (with and without BMP-2) than in the Collagen group (with and without BMP-2) in both vertical β-TCP and horizontal β-TCP. However, when BMP-2 was added, the bone formation area was not significantly different between the Collagen group and the Matrigel group in the vertical β-TCP. Histological finding showed that, in vertical honeycomb β-TCP, new bone formation extended to the upper part of the holes and was observed from the dura side to the periosteum side as added to the inner walls of the holes. Therefore, we can control efficient bone formation by creating a bone microenvironment provided by vertical honeycomb β-TCP. Vertical honeycomb β-TCP has the potential to be an excellent biomaterial for bone tissue regeneration in skull defects and is expected to have clinical applications.

DOI： 10.3390/ma13214761

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Solid tumors consist of the tumor parenchyma and stroma. The standard concept of oncology is that the tumor parenchyma regulates the tumor stroma and promotes tumor progression, and that the tumor parenchyma represents the tumor itself and defines the biological characteristics of the tumor tissue. Thus, the tumor stroma plays a pivotal role in assisting tumor parenchymal growth and invasiveness and is regarded as a supporter of the tumor parenchyma. The tumor parenchyma and stroma interact with each other. However, the influence of the stroma on the parenchyma is not clear. Therefore, in this study, we investigated the effect of the stroma on the parenchyma in oral squamous cell carcinoma (OSCC). We isolated tumor stroma from two types of OSCCs with different invasiveness (endophytic type OSCC (ED-st) and exophytic type OSCC (EX-st)) and examined the effect of the stroma on the parenchyma in terms of proliferation, invasion, and morphology by co-culturing and co-transplanting the OSCC cell line (HSC-2) with the two types of stroma. Both types of stroma were partially positive for alpha-smooth muscle actin. The tumor stroma increased the proliferation and invasion of tumor cells and altered the morphology of tumor cells in vitro and in vivo. ED-st exerted a greater effect on the tumor parenchyma in proliferation and invasion than EX-st. Morphological analysis showed that ED-st changed the morphology of HSC-2 cells to the invasive type of OSCC, and EX-st altered the morphology of HSC-2 cells to verrucous OSCC. This study suggests that the tumor stroma influences the biological characteristics of the parenchyma and that the origin of the stroma is strongly associated with the biological characteristics of the tumor.

DOI： 10.3390/ijms21207714

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BACKGROUND: This study was conducted to compare the histological diagnostic accuracy of conventional oral-based cytology and liquid-based cytology (LBC) methods. METHODS: Histological diagnoses of 251 cases were classified as negative (no malignancy lesion, inflammation, or mild/moderate dysplasia) and positive [severe dysplasia/carcinoma in situ (CIS) and squamous cell carcinoma (SCC)]. Cytological diagnoses were classified as negative for intraepithelial lesion or malignancy (NILM), oral low-grade squamous intraepithelial lesion (OLSIL), oral high-grade squamous intraepithelial lesion (OHSIL), or SCC. Cytological diagnostic results were compared with histology results. RESULTS: Of NILM cytology cases, the most frequent case was negative [LBC n = 50 (90.9%), conventional n = 22 (95.7%)]. Among OLSIL cytodiagnoses, the most common was negative (LBC n = 34; 75.6%, conventional n = 14; 70.0%). Among OHSIL cytodiagnoses (LBC n = 51, conventional n = 23), SCC was the most frequent (LBC n = 31; 60.8%, conventional n = 7; 30.4%). Negative cases were common (LBC n = 13; 25.5%, conventional n = 14; 60.9%). Among SCC cytodiagnoses SCC was the most common (LBC n = 16; 88.9%, conventional n = 14; 87.5%). Regarding the diagnostic results of cytology, assuming OHSIL and SCC as cytologically positive, the LBC method/conventional method showed a sensitivity of 79.4%/76.7%, specificity of 85.1%/69.2%, false-positive rate of 14.9%/30.7%, and false-negative rate of 20.6%/23.3%. CONCLUSIONS: LBC method was superior to conventional cytodiagnosis methods. It was especially superior for OLSIL and OHSIL. Because of the false-positive and false-negative cytodiagnoses, it is necessary to make a comprehensive diagnosis considering the clinical findings.

DOI： 10.1186/s13000-020-01027-6

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Language：Japanese   Publisher：(一社)日本医用画像工学会  

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Language：Japanese   Publisher：(一社)日本医用画像工学会  

インプラントには多くのブランドがあり,メーカーごとに独自に開発されている.患者のインプラントのメンテナンスをする際にはブランドを特定する必要があるが,一人に対して異なるブランドのインプラントが異なる歯科医によって埋入されることが頻繁にあり,歯科医の間で共有される情報がなく特定するのは困難である.歯科パノラマX線画像からは特定に必要な情報を得ることができるが,これを行うには歯科医の努力と経験が必要になる.本研究の目的は,深層学習を用いて歯科パノラマX線画像からインプラントの分類を行い,歯科医や患者の負担軽減に寄与することである.畳み込み層が6つのCNNと,VGG16とVGG19の転移学習及びファインチューニングモデルでの分類精度を評価した.5つのモデルのうちVGG16のファインチューニングが94%と最も高い精度を示し,インプラントの分類において深層学習が有用である可能性が示唆された.(著者抄録)

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Language：Japanese   Publisher：(NPO)日本口腔科学会  

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Language：Japanese   Publisher：(NPO)日本口腔科学会  

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Language：Japanese   Publisher：(一社)日本医用画像工学会  

インプラントには多くのブランドがあり,メーカーごとに独自に開発されている.患者のインプラントのメンテナンスをする際にはブランドを特定する必要があるが,一人に対して異なるブランドのインプラントが異なる歯科医によって埋入されることが頻繁にあり,歯科医の間で共有される情報がなく特定するのは困難である.歯科パノラマX線画像からは特定に必要な情報を得ることができるが,これを行うには歯科医の努力と経験が必要になる.本研究の目的は,深層学習を用いて歯科パノラマX線画像からインプラントの分類を行い,歯科医や患者の負担軽減に寄与することである.畳み込み層が6つのCNNと,VGG16とVGG19の転移学習及びファインチューニングモデルでの分類精度を評価した.5つのモデルのうちVGG16のファインチューニングが94%と最も高い精度を示し,インプラントの分類において深層学習が有用である可能性が示唆された.(著者抄録)

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Language：Japanese   Publisher：(一社)日本医用画像工学会  

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Osteosynthesis resorbable materials made of uncalcined and unsintered hydroxyapatite (u-HA) particles, poly-L-lactide (PLLA), are bioresorbable, and these materials have feasible bioactive/osteoconductive capacities. However, their strength and stability for fixation in mandibular condylar head fractures remain unclear. This in vitro study aimed to assess the biomechanical strength of u-HA/PLLA screws after the internal fixation of condylar head fractures. To evaluate their biomechanical behavior, 32 hemimandible replicas were divided into eight groups, each consisting of single-screw and double-screw fixations with titanium or u-HA/PLLA screws. A linear load was applied as vertical and horizontal load to each group to simulate the muscular forces in condylar head fractures. Samples were examined for 0.5, 1, 2, and 3-mm displacement loads. Two screws were needed for stable fixation of the mandibular condylar head fracture during biomechanical evaluation. After screw fixation for condylar head fractures, the titanium screws model was slightly more resistant to vertical and horizontal movement with a load for a small displacement than the u-HA/PLLA screws model. There was no statistically significant difference with load for large displacements. The u-HA/PLLA screw has a low mechanical resistance under small displacement loading compared with titanium within the limits of the mandibular head fracture model study.

DOI： 10.3390/ma13143153

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Language：English   Publishing type：Research paper (scientific journal)  

In this study, we used panoramic X-ray images to classify and clarify the accuracy of different dental implant brands via deep convolutional neural networks (CNNs) with transfer-learning strategies. For objective labeling, 8859 implant images of 11 implant systems were used from digital panoramic radiographs obtained from patients who underwent dental implant treatment at Kagawa Prefectural Central Hospital, Japan, between 2005 and 2019. Five deep CNN models (specifically, a basic CNN with three convolutional layers, VGG16 and VGG19 transfer-learning models, and finely tuned VGG16 and VGG19) were evaluated for implant classification. Among the five models, the finely tuned VGG16 model exhibited the highest implant classification performance. The finely tuned VGG19 was second best, followed by the normal transfer-learning VGG16. We confirmed that the finely tuned VGG16 and VGG19 CNNs could accurately classify dental implant systems from 11 types of panoramic X-ray images.

DOI： 10.3390/biom10070984

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Publishing type：Research paper (scientific journal)  

PURPOSE: This study aimed to examine the relationship between post-operative mandibular fractures and its predictable risk factors in patients with marginal mandibular resection. Additionally, the timing of post-operative mandibular fractures was assessed. PATIENTS AND METHODS: Records of 37 patients with mandibular gingival carcinoma who underwent marginal mandibular resection at the Department of Oral and Maxillofacial Surgery, Kagawa Prefectural Central Hospital, from April 2011 to March 2019 were retrospectively analyzed. The following variables were investigated: age, sex, location of carcinoma, tumor size, mandibular height on the surgical and healthy sides, surgical approach, number of residual teeth, post-operative radiotherapy, chemotherapy, and the presence or absence of diabetes and osteoporosis. Various risk factors for post-operative mandibular fractures were statistically investigated. RESULTS: Post-operative mandibular fracture was observed in 5 (13.5%) of the 37 mandibular marginal resection cases. The average residual mandibular height in patients with post-operative mandibular fracture was 8.5 mm. A significant difference in residual mandibular height (P = 0.013) was observed between patients with post-operative mandibular fracture and those with no fracture. The average time to post-operative fracture of the mandible was 305.4 days, and it was found to be correlated to the remaining height of the mandibular body. CONCLUSIONS: A decrease in mandibular height below 9 mm results in post-operative mandibular fracture. Furthermore, a correlation between the height of the mandibular bone and the period until the post-operative mandibular fracture was noted in this study. These findings contribute to the prediction and management of mandibular fractures after mandibular margin resection.

DOI： 10.1097/SCS.0000000000006636

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The authors examined the timing and causes of titanium miniplate removal after maxillofacial trauma surgery. The authors performed a retrospective study of maxillofacial fracture patients in whom maxillofacial osteosynthesis miniplates were inserted or removed at the Kagawa Prefectural Central Hospital, between 2008 and 2017. Predictive variables were age, sex, fracture site distribution, and time to miniplate removal with or without complications in relation to primary outcome variables. Among 185 patients, 440 miniplates were inserted and 272 miniplates were removed. In total, 116 patients (73.4%) had 282 miniplates (64.1%) removed, of which 4.8% fracture sites and 5.7% miniplates were removed because of complications. The mean time to miniplate removal was 630.9 and 258.0 days in patients with and without complications, respectively. There was a statistically significant difference in miniplate removal and miniplate retention relative to age and sex. This difference was not related to the presence or absence of sex- or age-related complications. The miniplates as osteosynthesis material were safe and useful for a long period of time with relatively few complications. Because complications requiring miniplate removal occurred within 1 or after 5 years postoperatively, osteosynthesis miniplate treatments should be decided while considering the patient's age and sex. Long-term follow-up is recommended for miniplates that remain implanted for >1 year.

DOI： 10.1097/SCS.0000000000006352

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Language：Japanese   Publisher：(NPO)日本口腔科学会  

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Language：Japanese   Publisher：(NPO)日本口腔科学会  

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：LIPPINCOTT WILLIAMS & WILKINS  

Purpose: This study aimed to examine the relationship between post-operative mandibular fractures and its predictable risk factors in patients with marginal mandibular resection. Additionally, the timing of post-operative mandibular fractures was assessed. Patients and methods: Records of 37 patients with mandibular gingival carcinoma who underwent marginal mandibular resection at the Department of Oral and Maxillofacial Surgery, Kagawa Prefectural Central Hospital, from April 2011 to March 2019 were retrospectively analyzed. The following variables were investigated: age, sex, location of carcinoma, tumor size, mandibular height on the surgical and healthy sides, surgical approach, number of residual teeth, post-operative radiotherapy, chemotherapy, and the presence or absence of diabetes and osteoporosis. Various risk factors for post-operative mandibular fractures were statistically investigated. Results: Post-operative mandibular fracture was observed in 5 (13.5%) of the 37 mandibular marginal resection cases. The average residual mandibular height in patients with post-operative mandibular fracture was 8.5 mm. A significant difference in residual mandibular height (P = 0.013) was observed between patients with post-operative mandibular fracture and those with no fracture. The average time to post-operative fracture of the mandible was 305.4 days, and it was found to be correlated to the remaining height of the mandibular body. Conclusions: A decrease in mandibular height below 9 mm results in post-operative mandibular fracture. Furthermore, a correlation between the height of the mandibular bone and the period until the post-operative mandibular fracture was noted in this study. These findings contribute to the prediction and management of mandibular fractures after mandibular margin resection.

DOI： 10.1097/SCS.0000000000006636

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：LIPPINCOTT WILLIAMS & WILKINS  

The authors examined the timing and causes of titanium miniplate removal after maxillofacial trauma surgery. The authors performed a retrospective study of maxillofacial fracture patients in whom maxillofacial osteosynthesis miniplates were inserted or removed at the Kagawa Prefectural Central Hospital, between 2008 and 2017. Predictive variables were age, sex, fracture site distribution, and time to miniplate removal with or without complications in relation to primary outcome variables. Among 185 patients, 440 miniplates were inserted and 272 miniplates were removed. In total, 116 patients (73.4%) had 282 miniplates (64.1%) removed, of which 4.8% fracture sites and 5.7% miniplates were removed because of complications. The mean time to miniplate removal was 630.9 and 258.0 days in patients with and without complications, respectively. There was a statistically significant difference in miniplate removal and miniplate retention relative to age and sex. This difference was not related to the presence or absence of sex- or age-related complications. The miniplates as osteosynthesis material were safe and useful for a long period of time with relatively few complications. Because complications requiring miniplate removal occurred within 1 or after 5 years postoperatively, osteosynthesis miniplate treatments should be decided while considering the patient's age and sex. Long-term follow-up is recommended for miniplates that remain implanted for >1 year.

DOI： 10.1097/SCS.0000000000006352

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Language：Japanese   Publisher：(NPO)日本口腔科学会  

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Language：Japanese   Publisher：(NPO)日本口腔科学会  

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Language：Japanese   Publisher：(株)文光堂  

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Publishing type：Research paper (scientific journal)   Publisher：MDPI AG  

Secretory carcinoma (SC) is a recently described salivary gland tumor reported in the fourth edition of World Health Organization classification of head and neck tumors. SC is characterized by strong S-100 protein, mammaglobin, and vimentin immunoexpression, and harbors a t(12;15)(p13;q25) translocation which leads to ETV6-NTRK3 fusion product. Histologically, SC displays a lobulated growth pattern and is often composed of microcystic, tubular, and solid structures with abundant eosinophilic homogenous or bubbly secretion. SC is generally recognized as low-grade malignancy with low-grade histopathologic features, and metastasis is relatively uncommon. In this case, we described a SC of hard palate that underwent high grade transformation and metastasis to the cervical lymph node in a 54-year-old patient. In addition, this case showed different histological findings between primary lesion and metastasis lesion. Therefore, the diagnosis was confirmed by the presence of ETV6 translocation. Here, we report a case that occurred SC with high-grade transformation in the palate, and a review of the relevant literature is also presented.

DOI： 10.3390/reports3020006

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Language：Japanese   Publisher：(公社)日本薬学会  

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Language：Japanese   Publisher：(一社)日本病理学会  

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Language：Japanese   Publisher：(一社)日本病理学会  

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Language：Japanese   Publisher：(一社)日本病理学会  

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Language：Japanese   Publisher：(一社)日本病理学会  

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Language：Japanese   Publisher：(一社)日本口腔診断学会  

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Language：Japanese   Publisher：(一社)日本口腔診断学会  

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Language：Japanese   Publisher：(一社)日本口腔診断学会  

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Publishing type：Research paper (scientific journal)  

Background: This study investigated the causes of dental implant removal due to complications, and examined whether patients who had dental implant removal desired re-implant prosthesis treatments. Material and Methods: A retrospective case–control study was conducted on patients who had their dental implants removed. We investigated whether the removed dental implant was replaced with other implant prosthe-ses. Age, sex, diabetes, smoking, implant site distribution, reason for implant removal, and blade and root-form implants were categorized as predictive variables. The outcome variable was desire for re-implantation or use of other prosthetic methods after implant removal. A logistic regression model was created to identify patient factors that could predict the re-implantation of dental prostheses after implant removal. Results: A total of 215 dental implants were removed from 143 patients. The most common reason for implant removal was peri-implantitis that was identified in 165 implants. After implant removal, re-implantation was performed in 98 implants (45.6%). Bivariate analyses showed that age, diabetes, implant type, and reason for implant removal were associated with the desire for re-implanted prostheses. The multiple regression model revealed that age, implant type, and reason for implant removal were associated with an increased desire for re-implant prostheses after implant removal. Conclusions: Re-implantation of prostheses after the removal of dental implants was desired by patients who were younger, had implants placed in the root form, and had implants removed due to prosthetic-related complications.

DOI： 10.4317/medoral.23789

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Language：Japanese   Publisher：(一社)日本口腔内科学会  

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The stroma affects the properties and dynamics of the tumor. Previous studies have demonstrated that bone marrow-derived cells (BMDCs) possess the capability of differentiating into stromal cells. However, the characteristics and roles of BMDCs in oral squamous cell carcinoma remain unclear. The current study therefore investigated their locations and features by tracing green fluorescent protein (GFP)-labeled BMDCs in a transplantation mouse model. After irradiation, BALB-c nu-nu mice were injected with bone marrow cells from C57BL/6-BALB-C-nu/nu-GFP transgenic mice. These recipient mice were then injected subcutaneously in the head with human squamous cell carcinoma-2 cells. Immunohistochemistry for GFP, Vimentin, CD11b, CD31 and α-smooth muscle actin (SMA), and double-fluorescent immunohistochemistry for GFP-Vimentin, GFP-CD11b, GFP-CD31 and GFP-α-SMA was subsequently performed. Many round-shaped GFP-positive cells were observed in the cancer stroma, which indicated that BMDCs served a predominant role in tumorigenesis. Vimentin(+) GFP(+) cells may also be a member of the cancer-associated stroma, originating from bone marrow. Round or spindle-shaped CD11b(+) GFP(+) cells identified in the present study may be macrophages derived from bone marrow. CD31(+)GFP(+) cells exhibited a high tendency towards bone marrow-derived angioblasts. The results also indicated that spindle-shaped α-SMA(+) GFP(+) cells were not likely to represent bone marrow-derived cancer-associated fibroblasts. BMDCs gathering within the tumor microenvironment exhibited multilineage potency and participated in several important processes, such as tumorigenesis, tumor invasion and angiogenesis.

DOI： 10.3892/ol.2019.11045

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Language：Japanese   Publisher：(一社)日本口腔内科学会  

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Language：Japanese   Publisher：(一社)日本口腔内科学会  

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Language：Japanese   Publisher：岡山歯学会  

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Language：Japanese   Publisher：岡山歯学会  

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Sonic hedgehog (SHH) and its signaling have been identified in several human cancers, and increased levels of SHH expression appear to correlate with cancer progression. However, the role of SHH in the tumor microenvironment (TME) of oral squamous cell carcinoma (OSCC) is still unclear. No studies have compared the expression of SHH in different subtypes of OSCC and focused on the relationship between the tumor parenchyma and stroma. In this study, we analyzed SHH and expression of its receptor, Patched-1 (PTCH), in the TME of different subtypes of OSCC. Fifteen endophytic-type cases (ED type) and 15 exophytic-type cases (EX type) of OSCC were used. H&E staining, immunohistochemistry (IHC), double IHC, and double-fluorescent IHC were performed on these samples. ED-type parenchyma more strongly expressed both SHH and PTCH than EX-type parenchyma. In OSCC stroma, CD31-positive cancer blood vessels, CD68- and CD11b-positive macrophages, and α-smooth muscle actin-positive cancer-associated fibroblasts partially expressed PTCH. On the other hand, in EX-type stroma, almost no double-positive cells were observed. These results suggest that autocrine effects of SHH induce cancer invasion, and paracrine effects of SHH govern parenchyma-stromal interactions of OSCC. The role of the SHH pathway is to promote growth and invasion.

DOI： 10.3390/ijms20225779

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We studied human bone healing characteristics and the histological osteogenic environment by using devices made of a composite of uncalcined and unsintered hydroxyapatite (u-HA) and poly-L-lactide (PLLA). In eight cases of fixation, we used u-HA/PLLA screws for maxillary alveolar ridge augmentation, for which mandibular cortical bone block was used in preimplantation surgery. Five appropriate samples with screws were evaluated histologically and immunohistochemically for runt-related transcription factor 2 (RUNX2), transcription factor Sp7 (Osterix), and leptin receptor (LepR). In all cases, histological evaluation revealed that bone components had completely surrounded the u-HA/PLLA screws, and the bone was connected directly to the biomaterial. Inflammatory cells did not invade the space between the bone and the u-HA/PLLA screw. Immunohistochemical evaluation revealed that many cells were positive for RUNX2 or Osterix, which are markers for osteoblast and osteoprogenitor cells, in the tissues surrounding u-HA/PLLA. In addition, many bone marrow-derived mesenchymal stem cells were notably positive for both LepR and RUNX2. The u-HA/PLLA material showed excellent bioactive osteoconductivity and a highly biocompatibility with bone directly attached. In addition, our findings suggest that many bone marrow-derived mesenchymal stem cells and mature osteoblast are present in the osteogenic environment created with u-HA/PLLA screws and that this environment is suitable for osteogenesis.

DOI： 10.3390/ma12223681

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Language：Japanese   Publisher：(一社)歯科基礎医学会  

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Language：Japanese   Publisher：(公社)日本臨床細胞学会  

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Language：Japanese   Publisher：(一社)歯科基礎医学会  

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Language：English   Publisher：硬組織再生生物学会  

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Language：English   Publisher：硬組織再生生物学会  

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：UNIV KEBANGSAAN MALAYSIA  

Ameloblastoma, the most clinically significant odontogenic epithelial tumor, is a locally-invasive and destructive lesion in the jawbones. However, the nature of this infiltrativeness and destructive behavior remains ill-understood. To address this, we established an in vitro three-dimensional (3D) co-culture system to simulate an amelobastoma disease model aimed at investigating the interactions between tumor cells and osteoblasts. Osteoblastic cell lines (KUSA/A1 and mc3T3-E1) and one stromal cell line (ST2) were separately co-seeded with ameloblastoma-derived cell line (AM-1) in a collagen scaffold (representing the extracellular bone matrix) and incubated with mineralization medium. Inununohistochemistry, double immunofluorescence and mineralization assay were performed. Only Am-1/KUsA-A1 co-culture showed a significant increase in Am-1 cell count, suggesting that heterotypic cell-cell interaction promotes tumoral cell growth, while formation of visible Am-1 epithelial nest-like structures resembling ameloblastoma cells in their native state, suggest morphodffferentiation. A RANK-high, RANKL-low and osteoprotegerin-low immunoprofile in co-culture AM-1 cells implies deregulated osteoclastogenesis. Mineralization assays showed diminished calcification in Am-1/KUSA-A1 co-culture extracellular matrix suggesting an altered local bone metabolism. In contrast, KUSA/A1 monocultures showed abundant extracellular matrix calcification. Taken together, these results suggest that a 3D co-culture system as an amelobastoma disease model provides insights that bidirectional ameloblastoma-osteoblastic interactions might play a role in modulating tumor growth and osteoclastogenesis.

DOI： 10.17576/jsm-2019-4808-15

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CXCR4 is a chemokine receptor crucial in tumor progression, although the angiogenic role of CXCR4 in oral squamous cell carcinoma (OSCC) has not been investigated. Here we show that CXCR4 is crucial for tumor angiogenesis, thereby supporting tumor survival in OSCC. Immunohistochemistry on human clinical specimens revealed that CXCR4 and a tumor vasculature marker CD34 were co-distributed in tumor vessels in human OSCC specimens. To uncover the effects of CXCR4 inhibition, we treated the OSCC-xenografted mice with AMD3100, so-called plerixafor, an antagonist of CXCR4. Notably, we found a unique pathophysiological structure defined as tumor angiogenic inhibition triggered necrosis (TAITN), which was induced by the CXCR4 antagonism. Treatment with AMD3100 increased necrotic areas with the induction of hypoxia-inducible factor-1α in the xenografted tumors, suggesting that AMD3100-induced TAITN was involved in hypoxia and ischemia. Taken together, we demonstrated that CXCR4 plays a crucial role in tumor angiogenesis required for OSCC progression, whereas TAITN induced by CXCR4 antagonism could be an effective anti-angiogenic therapeutic strategy in OSCC treatment.

DOI： 10.3390/cells8070761

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Language：Japanese   Publisher：(NPO)日本口腔科学会  

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Osteosynthesis absorbable materials made of uncalcined and unsintered hydroxyapatite (u-HA) particles, poly-l-lactide (PLLA), and u-HA/PLLA are bioresorbable, and these plate systems have feasible bioactive osteoconductive capacities. However, their strength and stability for fixation in mandibular subcondylar fractures remain unclear. This in vitro study aimed to assess the biomechanical strength of u-HA/PLLA bioresorbable plate systems after internal fixation of mandibular subcondylar fractures. Tensile and shear strength were measured for each u-HA/PLLA and titanium plate system. To evaluate biomechanical behavior, 20 hemimandible replicas were divided into 10 groups, each comprising a titanium plate and a bioresorbable plate. A linear load was applied anteroposteriorly and lateromedially to each group to simulate the muscular forces in mandibular condylar fractures. All samples were analyzed for each displacement load and the displacement obtained by the maximum load. Tensile and shear strength of the u-HA/PLLA plate were each approximately 45% of those of the titanium plates. Mechanical resistance was worst in the u-HA/PLLA plate initially loaded anteroposteriorly. Titanium plates showed the best mechanical resistance during lateromedial loading. Notably, both plates showed similar resistance when a lateromedially load was applied. In the biomechanical evaluation of mandibular condylar fracture treatment, the u-HA/PLLA plates had sufficiently high resistance in the two-plate fixation method.

DOI： 10.3390/ma12091557

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Histopathological findings of oral neoplasm cell differentiation and metaplasia suggest that tumor cells induce their own dedifferentiation and re-differentiation and may lead to the formation of tumor-specific histological features. Notch signaling is involved in the maintenance of tissue stem cell nature and regulation of differentiation and is responsible for the cytological regulation of cell fate, morphogenesis, and/or development. In our previous study, immunohistochemistry was used to examine Notch expression using cases of odontogenic tumors and pleomorphic adenoma as oral neoplasms. According to our results, Notch signaling was specifically associated with tumor cell differentiation and metaplastic cells of developmental tissues. Notch signaling was involved in the differentiation of the ductal epithelial cells of salivary gland tumors and ameloblast-like cells of odontogenic tumors. However, Notch signaling was also involved in squamous metaplasia, irrespective of the type of developmental tissue. In odontogenic tumors, Notch signaling was involved in epithelial-mesenchymal interactions and may be related to tumor development and tumorigenesis. This signaling may also be associated with the malignant transformation of ameloblastomas. Overall, Notch signaling appears to play a major role in the formation of the characteristic cellular composition and histological features of oral neoplasms, and this involvement has been reviewed here.

DOI： 10.3390/ijms20081973

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Language：Japanese   Publisher：(一社)日本病理学会  

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Language：Japanese   Publisher：(一社)日本病理学会  

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：JOURNAL HARD TISSUE BIOLOGY  

In order to evaluate the biocompatibility and mineral repair capacity, mineral trioxide aggregate (MTA), portland cement normal setting (PCn) and fast setting (PCt) and calcium hydroxide-based paste (Calen) filled silicone tube were implanted into the dorsal subcutaneous connective tissues of 25 Wistar rats. Animals were euthanized at 24, 72 hours, 7, 15 and 30 days. Implants with surrounding tissues were fixed with 10% buffer formaldehyde and processed for histological routine techniques. Slides (5 pm serial cuts) were stained with H&E and Von Kossa stains for morphological, qualitative and quantitative analysis by light microscopy. Calen showed severe and moderate inflammatory response and granulomatons reaction with psammoma body-like formation. PCn and MTA have similar behavior, with mild inflammatory reaction from 8% and 4%, respectively. Even though, PCn and MTA demonstrated analogous biological reaction, MTA developing thick artificial mineral precipitation (p = 0,007). All sealers demonstrated a similar inflammatory response at all time periods studied (p = 0.678).

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：JOURNAL HARD TISSUE BIOLOGY  

To investigate the influence of occlusal support and the presence and position of mandibular third molars on the incidence of mandibular condylar fractures. Records of 222 patients who presented with mandibular fracture at the Department of Oral and Maxillofacial Surgery, Kagawa Prefectural Central Hospital, from 2006 to 2019 were retrospectively analyzed. The following variables were investigated: age, sex, cause of fracture, the presence and state (impaction and angulation) of mandibular third molars, the site of mandibular fracture, and the presence of occlusal support for molars. Various risk factors for mandibular condylar head and subcondylar fractures were investigated. The majority of fractures were caused by a fall. The risk of mandibular subcondylar fractures was significantly higher in patients with occlusal support and mandibular third molars. The risk of mandibular condylar head fractures was significantly higher in patients without occlusal support or mandibular third molars. The position and angulation of mandibular third molars did not show significant difference between occurrences of head or subcondylar fractures. This study demonstrated that occlusal support and the presence of mandibular third molars significantly increased the risk of subcondylar fractures. One the contrary, their absence increased the risk of condylar head fractures.

DOI： 10.2485/jhtb.28.377

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Background: Yes-associated protein (YAP) is a candidate oncogene in various human cancers, and recently, it has been reported that YAP expression and its activity was enhanced by ΔNp63. However, the role of YAP and ΔNp63 expression in carcinogenesis and progression of oral squamous cell carcinoma (OSCC) has been unknown. Therefore, we investigated how YAP and ΔNp63 influence carcinogenesis and progression of OSCC. Methods: We performed immunohistochemical analyses in whole tissue samples to investigate YAP and ΔNp63 expression in normal oral mucosa, epithelial hyperplasia, oral epithelial dysplasia (OED; low/high grade), carcinoma in situ (CIS), and OSCC. Furthermore, in OSCC, we analyzed clinical significance by using Kaplan-Meier survival analysis. Results: In normal oral mucosa and epithelial hyperplasia, YAP expression was primarily confined to the basal and parabasal layers, but YAP expression was elevated in OED, CIS, and OSCC. In OED, YAP and ΔNp63 expression levels were markedly higher in high grade than in low grade. In OSCC groups, YAP and ΔNp63 expression patterns tended to differ according to histopathological differentiation of OSCC. Furthermore, the YAP high expression group, which showed YAP staining in >50% positive cells with strong cytoplasmic staining or >10% positive cells with nuclear reactivity, showed a tendency to have a poor survival rate. Conclusion: YAP and ΔNp63 expression levels correlated with grade of oral OED. Additionally, YAP expression was associated with OSCC survival rate. Our results suggested that YAP and ΔNp63 expression might serve as predictive markers to distinguish OSCC development and progression.

DOI： 10.7150/ijms.29995

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Purpose: We aimed to document the clinical usefulness of uncalcined and unsintered hydroxyapatite (u-HA) particles and poly-L-lactide (PLLA) composite materials and their advantageous properties. Methods: Between April 2016 and March 2018, five patients required anterior maxillary alveolar ridge augmentation using fixation with u-HA/PLLA screws for an onlay block bone graft harvested from the mandibular ramus at our institute. Bone biopsies were obtained from the dental implantation site following bone healing for histomorphometric and immunohistochemical (IHC) measurements. Results: Many stromal cells were positive for Osterix, RUNX2, and SOX9 but were negative for CD68. On cell counting, based on IHC staining for Osterix, RUNX2, SOX9 and CD68 from peripheral u-HA/PLLA screw or bone areas, both areas consistently showed no significant difference in terms of Osterix, RUNX2, and SOX9. Hematoxylin-eosin staining revealed direct bone connection to the biomaterials, and no inflammatory cells infiltrated the areas surrounding the bone or artificial material. Area between the bone and u-HA/PLLA screw was seamless with no boundary. Round small cells and immature fibroblasts were noted. The new bone showed the presence of bone lamellae, normal osteocytes, and osteoblasts. Conclusion: The u-HA/PLLA materials showed excellent biodegradability and bioactive osteoconductivity. In addition, this material induced no apparent inflammatory or foreign body reactions following implantation, and it directly bonded to the human bone. Therefore, this u-HA/PLLA material seems ideal and most suitable for use as a substitute for osteosynthesis.

DOI： 10.7150/ijms.27986

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In order to evaluate the biocompatibility and mineral repair capacity, mineral trioxide aggregate (MTA), portland cement normal setting (PCn) and fast setting (PCf) and calcium hydroxide-based paste (Calen) filled silicone tube were implanted into the dorsal subcutaneous connective tissues of 25 Wistar rats. Animals were euthanized at 24, 72 hours, 7, 15 and 30 days. Implants with surrounding tissues were fixed with 10% buffer formaldehyde and processed for histological routine techniques. Slides (5 µm serial cuts) were stained with H&E and Von Kossa stains for morphological, qualitative and quantitative analysis by light microscopy. Calen showed severe and moderate inflammatory response and granuloma-tous reaction with psammoma body-like formation. PCn and MTA have similar behavior, with mild inflammatory reaction from 8% and 4%, respectively. Even though, PCn and MTA demonstrated analogous biological reaction, MTA developing thick artificial mineral precipitation (p = 0,007). All sealers demonstrated a similar inflammatory response at all time periods studied (p = 0.678).

DOI： 10.2485/jhtb.28.1

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Language：English   Publisher：硬組織再生生物学会  

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Language：English   Publisher：硬組織再生生物学会  

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Members of matrix metalloproteinase (MMP) family promote cancer cell migration, invasion, and metastasis through alteration of the tumor milieu, intracellular signaling pathways, and transcription. We examined gene expression signatures of colon adenocarcinoma cell lines with different metastatic potentials and found that rapidly metastatic cells powerfully expressed genes encoding MMP3 and MMP9. The non-proteolytic PEX isoform and proteolytic isoforms of MMPs were significantly expressed in the metastatic cells in vitro. Knockdown of MMP3 attenuated cancer cell migration and invasion in vitro and lung metastasis in vivo. Profound nuclear localization of MMP3/PEX was found in tumor-stroma marginal area. In contrast, MMP9 was localized in central area of subcutaneous tumors. Overexpression of the PEX isoform of MMP3 promoted proliferation and migration of the rapidly metastatic cells in vitro. Taken together, the non-proteolytic PEX isoform of MMPs locating in cell nuclei involves proliferation, migration, and subsequent metastasis of aggressive adenocarcinoma cells.

DOI： 10.1002/jcb.27040

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Language：Japanese   Publisher：日本がん免疫学会  

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Using the experimental system of GFP (Green florescence Protein) bone marrow transplanted rats, we implanted the Vicryl absorbable suture thread in subcutaneous tissue and examined the formation of foreign body granuloma histopathologically. We also compared the main cellular components, namely, the macrophage and foreign body giant cell immunohistochemically using GFP to confirm their origin. Histologically, the disintegrated suture thread was observed as a circular in void surrounded by the proliferation of macrophages and foreign body giant cells. Fibrous connective tissue including the fibroblasts was interposed among large masses. Even after 6 months, some clusters considered to be residues of macrophages that grew on the suture were still remained. Immunohistochemical examination of GFP showed that all proliferated macrophages and foreign body giant cells were GFP-positive. However, the relatively thin fibrous tissues formed on the outermost layer of the granulation tissue growth were mostly GFP-negative. Based on the results of the experiment, the macrophages and foreign body giant cells that are GFP-positive were derived from the mesenchymal tissue of transplanted bone marrow tissues.

DOI： 10.19070/2377-8075-18000126

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Journal of Clinical and Diagnostic Research  

Basal Cell Adenoma (BCA) is an extremely rare benign salivary gland tumour that usually arises in the parotid gland. The incidence of BCA is 1%-3% of all salivary gland tumours. Here, we report an extremely rare case of BCA arising in the minor salivary gland of the hard palate of a young man.

DOI： 10.7860/JCDR/2018/32765.11364

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Background: The tumor microenvironment and its stromal cells play an important role in cancer development and metastasis. Bone marrow-derived cells (BMDCs), a rich source of hematopoietic and mesenchymal stem cells, putatively contribute to this tumoral stroma. However their characteristics and roles within the tumor microenvironment are unclear. In the present study, BMDCs in the tumor microenvironment were traced using the green fluorescent protein (GFP) bone marrow transplantation model. Methods: C57BL/6 mice were irradiated and rescued by bone marrow transplantation from GFP-transgenic mice. Lewis lung cancer cells were inoculated into the mice to generate subcutaneous allograft tumors or lung metastases. Confocal microscopy, immunohistochemistry for GFP, α-SMA, CD11b, CD31, CD34 and CD105, and double-fluorescent immunohistochemistry for GFP-CD11b, GFP-CD105 and GFP-CD31 were performed. Results: Round and dendritic-shaped GFP-positive mononuclear cells constituted a significant stromal subpopulation in primary tumor peripheral area (PA) and metastatic tumor area (MA) microenvironment, thus implicating an invasive and metastatic role for these cells. CD11b co-expression in GFP-positive cells suggests that round/dendritic cell subpopulations are possibly BM-derived macrophages. Identification of GFP-positive mononuclear infiltrates co-expressing CD31 suggests that these cells might be BM-derived angioblasts, whereas their non-reactivity for CD34, CD105 and α-SMA implies an altered vascular phenotype distinct from endothelial cells. Significant upregulation of GFP-positive, CD31-positive and GFP/CD31 double-positive cell densities positively correlated with PA and MA (P<0.05). Conclusion: Taken together, in vivo evidence of traceable GFP-positive BMDCs in primary and metastatic tumor microenvironment suggests that recruited BMDCs might partake in cancer invasion and metastasis, possess multilineage potency and promote angiogenesis.

DOI： 10.7150/ijms.24370

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Multipotential ability of bone marrow-derived cells has been clarified, and their involvement in repair and maintenance of various tissues has been reported. However, the role of bone marrow-derived cells in osteogenesis remains unknown. In the present study, bone marrow-derived cells during ectopic bone formation of mouse femoral muscle were traced using a GFP bone marrow transplantation model. Bone marrow cells from C57BL/6-Tg (CAG-EGFP) mice were transplanted into C57BL/6 J wild type mice. After transplantation, insoluble bone matrix (IBM) was implanted into mouse muscle. Ectopic bone formation was histologically assessed at postoperative days 7, 14, and 28. Immunohistochemistry for GFP single staining and GFP-osteocalcin double staining was then performed. Bone marrow transplantation successfully replaced hematopoietic cells with GFP-positive donor cells. Immunohistochemical analyses revealed that osteoblasts and osteocytes involved in ectopic bone formation were GFP-negative, whereas osteoclasts and hematopoietic cells involved in bone formation were GFP-positive. These results indicate that bone marrow-derived cells might not differentiate into osteoblasts. Thus, the main role of bone marrow-derived cells in ectopic osteogenesis may not be to induce bone regeneration by differentiation into osteoblasts, but rather to contribute to microenvironment formation for bone formation by differentiating tissue stem cells into osteoblasts.

DOI： 10.7150/ijms.24605

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Public Library of Science  

Ability to form cellular aggregations such as tumorspheres and spheroids have been used as a morphological marker of malignant cancer cells and in particular cancer stem cells (CSC). However, the common definition of the types of cellular aggregation formed by cancer cells has not been available. We examined morphologies of 67 cell lines cultured on three dimensional morphology enhancing NanoCulture Plates (NCP) and classified the types of cellular aggregates that form. Among the 67 cell lines, 49 cell lines formed spheres or spheroids, 8 cell lines formed grape-like aggregation (GLA), 8 cell lines formed other types of aggregation, and 3 cell lines formed monolayer sheets. Seven GLA-forming cell lines were derived from adenocarcinoma among the 8 lines. A neuroendocrine adenocarcinoma cell line PC-3 formed asymmetric GLA with ductal structures on the NCPs and rapidly growing asymmetric tumors that metastasized to lymph nodes in immunocompromised mice. In contrast, another adenocarcinoma cell line DU-145 formed spheroids in vitro and spheroid-like tumors in vivo that did not metastasize to lymph nodes until day 50 after transplantation. Culture in the 3D nanoenvironment and in a defined stem cell medium enabled the neuroendocrine adenocarcinoma cells to form slowly growing large organoids that expressed multiple stem cell markers, neuroendocrine markers, intercellular adhesion molecules, and oncogenes in vitro. In contrast, the more commonly used 2D serum-contained environment reduced intercellular adhesion and induced mesenchymal transition and promoted rapid growth of the cells. In addition, the 3D stemness nanoenvironment promoted secretion of HSP90 and EpCAM-exosomes, a marker of CSC phenotype, from the neuroendocrine organoids. These findings indicate that the NCP-based 3D environment enables cells to form stem cell tumoroids with multipotency and model more accurately the in vivo tumor status at the levels of morphology and gene expression.

DOI： 10.1371/journal.pone.0191109

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The effect of CaTiO3 compounded with different amounts of CaCO3 on osteoblastic KUSA/A1 cells was evaluated. CaTiO3-CaCO3 composites were obtained by alkoxide method, a simple, low-cost and reproducible technique used for large-scale production of material. The content of CaCO3 in our samples was controlled by varying the sintering time of the overall process. Composite morphology was assessed by scanning electron microscopy (SEM) showing particles with sizes ranging from100 to 500 nm. The presence of CaCO3 was revealed by XRD and thermogravimetric analyses, which suggested that samples treated at 650ºC for 30 min contained higher amounts of CaCO3 than samples treated for 2 and 10 h. Additionally, in vitro studies demonstrated that CaTiO3–CaCO3 composites sintered for 30 min induced augmented cell proliferation and mineralization in comparison to composites sintered for longer periods of time. Hence, our findings clearly suggest that the amount of CaCO3 within CaTiO3-CaCO3 composites exerts a critical effect on osteoblastic cells response. Enhanced bone regeneration could be achieved by increasing the content of CaCO3 within the composites, thus establishing CaTiO3-CaCO3 as a promising material for bone augmentation procedures in dental field.

DOI： 10.2485/jhtb.27.250

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Aims: Immunohistochemistry of PD-L1 has been recently established as a surrogate method to predict if immunotherapy targeting PD-L1/PD-1 has a significant effect on suppression of cancers such as lung non-small cell carcinoma, melanoma, and renal cell carcinoma. Here we performed immunohistochemistry for PD-L1 expression in squamous cell carcinoma (SCC) of the tongue to investigate the potential correlation between PD-L1 expression and clinicopathological factors and whether PD-L1 expression would be associated with prognosis. Methods: Tissue microarray cores of paraffin-embedded blocks from 135 cases with surgically resected tongue SCC were immunohistochemically analysed for PD-L1 expression. Results: We observed a positive correlation between PD-L1 expression and tongue SCC pT1 and pT2 tumours, but a negative correlation with pT2, pT3 and pT4 tumours. We also observed a positive correlation with lymph node metastasis. However, no positive correlation was demonstrated between PD-L1 expression and overall survival. Conclusions: PD-L1 tends to be overexpressed at the early stage of tongue SCC, showing a close correlation with initial development of tongue. However, PD-L1 expression may not affect prognosis.

DOI： 10.7150/ijms.27860

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A number of biomaterials have been developed, some of which already enjoy widespread clinic use. We have devised a new honeycomb tricalcium phosphate (TCP) containing through-and-through holes of various diameters to control cartilage and bone formation. However, the way in which the geometric structure of the honeycomb TCP controls cartilage and bone tissue formation separately remains unknown. In addition, an association has been reported between bone formation and angiogenesis. Therefore, in the present study, we investigated the relationship between angiogenesis and various hole diameters in our honeycomb TCP over time in a rat ectopic hard tissue formation model. Honeycomb TCPs with hole diameters of 75, 300, and 500 μm were implanted into rat femoral muscle. Next, ectopic hard tissue formation in the holes of the honeycomb TCP was assessed histologically at postoperative weeks 1, 2, and 3, and CD34 immunostaining was performed to evaluate angiogenesis. The results showed that cartilage formation accompanied by thin and poor blood vessel formation, bone marrow-like tissue with a branching network of vessels, and vigorous bone formation with thick linear blood vessels occurred in the TCPs with 75-μm, 300-μm, and 500-μm hole diameters, respectively. These results indicated that the geometrical structure of the honeycomb TCP affected cartilage and bone tissue formation separately owing to the induced angiogenesis and altered oxygen partial pressure within the holes.

DOI： 10.7150/ijms.28452

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Language：English   Publisher：硬組織再生生物学会  

症例は12歳の女児で、上顎左側臼歯部の萠出障害を主訴に矯正歯科を受診し当院へ紹介された。理学的所見では顔面の腫脹と非対称を認め、口腔内診察からは上顎左側臼歯部の圧痛と、同部位の第1生歯としての第1、第2臼歯の未萠出が示された。パノラマX線およびCTから同部位に20×15mm大、辺縁不整で内部に点状石灰化像を示す透亮病変が存在し、上顎洞を圧迫していることが明らかになった。局所麻酔下で核出術を施行した。骨増大術の必要は無く、また上顎洞への穿通は見られなかった。核出検体の病理組織学的検索から、病変組織は歯芽様の泡巣と歯堤様の歯原性上皮とを含む軟組織成分、および不整形な象牙質様構造物やエネメル基質といった石灰化成分から構成されていることが示された。免疫組織化学では主に腫瘍巣でWnt1とβ-カテニンの陽性反応が認められた。以上の所見から当症例はエナメル上皮線維歯牙腫と診断された。術後2年までの経過観察において再発は見られなかった。

DOI： 10.2485/jhtb.26.425

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：JOURNAL HARD TISSUE BIOLOGY  

The aim of this work is to evaluate the antibacterial effect and biocompatibility of zinc oxide (ZnO) nanopaticles and graphite-type carbon (Gt) microparticles commercial powders. SEM analysis was performed to assess particles morphology. The antibacterial behavior was studied against Staphylococcus aureus (Staph. Aureus) (bacterial strain ATCC 29213) and TEM analysis of bacteria was performed to determine ultrastructural alterations; in addition, biocompatibility was evaluated in subcutaneous tissue of Wistar rats at 3, 7 and 28 d. ZnO and Gt powders exhibited antibacterial activity while TEM images of Staph. aureus showed membrane disruption followed by the release of internal content. Also, an electron-light region within the cytoplasm was observed for microorganisms treated with ZnO. Regarding biocompatibility, Gt samples induced a foreign body reaction response with presence of giant cells whereas ZnO samples showed fibroblastic connective tissue with chronic inflammatory cells and new small vessels. Also, collagen fibers and lack of capsule was observed by Trichome Masson stain. Thus, ZnO improved wound healing by enhancing tissue regeneration in contrast with calcium hydroxide control sample response which showed a fibrous tissue scar. Hence, ZnO nano-powder seems to be a potential material in the regenerative endodontic field.

DOI： 10.2485/jhtb.26.311

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Language：English   Publisher：硬組織再生生物学会  

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Language：Japanese   Publisher：(一社)歯科基礎医学会  

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Language：Japanese   Publisher：(一社)歯科基礎医学会  

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：JOURNAL HARD TISSUE BIOLOGY  

The cervical lymph node metastasis of Oral Squamous Cell Carcinoma (OSCC) has been considered to be the main causes of death. The aim of our study was to clarify the expression pattern of ABCG2 and podoplanin in OSCC tissues and corresponding cervical lymph node, and evaluate the diagnostic value of ABCG2 and podoplanin in OSCC for tumorigenesis, histological stage and clinical prognosis. ABCG2 showed a mixed membranous and cytoplasmic pattern of staining in specific regions of stratum corneum and the center of well differentiated cancer nest, while only expressed in cytoplasm of poorly differentiated tumor nests. Podoplanin showed strong staining in LV endothelia, the periphery of well differentiated cancer nests, and tumor stromal fibroblasts surrounding tumor nests. The expression of ABCG2, especially cytoplasmic ABCG2, and podoplanin protein showed significantly higher tendency to lymph node metastasis (P&lt;0.05). Meanwhile, podoplanin positive rate increased with the decreasing degree of histological differentiation (P&lt;0.05). ABCG2 and podoplanin expression pattern is correlated with lymph node metastasis of OSCC. This result suggested that cytoplasmic ABCG2 with podoplanin have clinical potential in reliable molecule diagonsis for OSCC.

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BACKGROUND: Tumor parenchyma-stromal interactions affect the properties of tumors and their dynamics. Our group previously showed that secreted frizzled related protein (sFRP)-2 impairs bone formation and promotes bone invasion in ameloblastoma. However, the effects of the secreted growth factors CCN2, TGF-β, and BMP4 on stromal tissues in ameloblastoma remain unclear. MATERIALS AND RESULTS: Thirty-five paraffin-embedded ameloblastoma cases, ameloblastoma-derived cell lines (AM-1), and primary cultures of ameloblastoma stromal fibroblasts (ASF) were used. Immunohistochemistry, MTT assay, Western blotting, and RT-PCR were performed on these samples. Parenchyma-stromal CCN2 overexpression correlated significantly with fibrous-type stroma, but not with myxoid-type stroma, suggesting a role of CCN2 in fibrosis (P < 0.05). Recombinant CCN2 induction of enhanced ASF proliferation in AM-1 medium supports this view. Conversely, BMP4 and TGF-β were expressed in myxoid-type fibroblasts, but little expression was found in parenchyma. RANKL-positive and CD68-positive stromal cell populations were significantly greater in myxoid-type tumor areas than in fibrous-type tumor areas, while a higher Ki-67 labeling index was recorded in ameloblastoma with fibrous-type stroma. These data suggest that stromal properties influence bone resorption-related activities and growth rates, respectively. CONCLUSIONS: These results suggest that the effects of secreted growth factors are governed by ameloblastoma parenchyma-stromal interactions. CCN2 promotes fibrogenesis independent of TGF-β signaling. Absence of CCN2 expression is associated with a phenotypic switch to a myxoid-type microenvironment that is conducive for TGF-β/BMP4 signaling to promote osteoclastogenesis.

DOI： 10.1111/jop.12467

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Language：English   Publisher：硬組織再生生物学会  

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Language：English   Publisher：硬組織再生生物学会  

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Language：Japanese   Publisher：(一社)歯科基礎医学会  

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Publishing type：Research paper (scientific journal)   Publisher：Univ. of Malaya  

DOI： 10.22452/adum.vol23no1.1

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：IVYSPRING INT PUBL  

Perforation of floor of the dental pulp is often encountered during root canal treatment in routine clinical practice of dental caries. If perforation were large, granulation tissue would grow to form periodontal polyp. Granulation tissue consists of proliferating cells however their origin is not clear. It was shown that the cells in granulation tissue are mainly from migration of undifferentiated mesenchymal cells of the bone marrow. Hence, this study utilized GFP bone marrow transplantation mouse model. The floor of the pulp chamber in maxillary first molar was perforated using ½ dental round bur. Morphological assessment was carried out by micro CT and microscopy and GFP cell mechanism was further assessed by immunohistochemistry using double fluorescent staining with GFP-S100A4; GFP-Runx2 and GFP-CD31. Results of micro CT revealed alveolar bone resorption and widening of periodontal ligament. Histopathological examination showed proliferation of fibroblasts with some round cells and blood vessels in the granulation tissue. At 2 weeks, the outermost layer of the granulation tissue was lined by squamous cells with distinct intercellular bridges. At 4 weeks, the granulation tissue became larger than the perforation and the outermost layer was lined by relatively typical stratified squamous epithelium. Double immunofluorescent staining of GFP and Runx2 revealed that both proteins were expressed in spindle-shaped cells. Double immunofluorescent staining of GFP and CD31 revealed that both proteins were expressed in vascular endothelial cells in morphologically distinct vessels. The results suggest that fibroblasts, periodontal ligament fibroblasts and blood vessels in granulation tissue were derived from transplanted-bone marrow cells. Thus, essential growth of granulation tissue in periodontal polyp was caused by the migration of undifferentiated mesenchymal cells derived from bone marrow, which differentiated into fibroblasts and later on differentiated into other cells in response to injury.

DOI： 10.7150/ijms.15671

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We carried out an experiment to induce traumatic occlusion in mice periodontal tissue and analyzed the expression of HSP47. Continuous traumatic occlusion resulted to damage and remodeling of periodontal ligament as well as increase in osteoclasts and bone resorption. Four days after traumatic occlusion, osteoclasts did not increase but Howship's lacunae became enlarged. That is, the persistent occlusal overload can destroy collagen fibers in the periodontal ligament. This was evident by the increased in HSP47 expression with the occlusal overload. HSP47 is maintained in fibroblasts for repair of damaged collagen fibers. On the other hand, osteoclasts continue to increase although the load was released. The osteoclasts that appeared on the alveolar bone surface were likely due to sustained activity. The increase in osteoclasts was estimated to occur after load application at day 4. HSP47 continued to increase until day 6 in experiment 2 but then reduced at day 10. Therefore, HSP47 appears after a period of certain activities to repair damaged collagen fibers, and the activity was returned to a state of equilibrium at day 30 with significantly diminished expression. Thus, the results suggest that HSP47 is actively involved in homeostasis of periodontal tissue subjected to occlusal overload.

DOI： 10.7150/ijms.14129

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In this study, cholesterin was implanted in the subcutaneous tissue in mice to induce the formation of cholesterol granuloma. Histological examination was carried out to determine the type and source of cells. The tissue surrounding the embedded cholesterin was examined histologically within the period of 6 months. Cell differentiation in cholesterol granulomas was investigated using ddY mice and GFP bone marrow transplanted mice. Cholesterin was embedded in mice subcutaneously and histopathological examination was carried out in a period of 6 months. Results showed that at 2 weeks, cholesterin was replaced partly by granulation tissues. The majority of cells in the granulation tissues were macrophages and foreign body giant cells and the center consists of small amount of fibroblasts, collagen fibers and capillaries. At 3 months, more granulation tissue was observed compared to 2 weeks. Similar cells were observed, however, there were more fibroblasts, collagen bundles and capillaries present compared to 2 weeks. At 6 months, the cholesterin was mostly substituted by fibrous tissues consisting mainly of fibroblasts and collagen fibers with some macrophages and foreign body giant cells. Specifically, the outer part of the tissue consists of fibroblasts, collagen bundles and capillaries and the inner portion is filled with collagen bundles. Immunohistochemistry revealed that macrophages and foreign body giant cells were positive to GFP and CD68 although the fibroblasts and capillaries in the outer portion of cholesterol granulomas were GFP negative. Some spindle shape fibroblasts were also GFP positive. Immunofluorescent double staining revealed that cells lining the blood vessels were both positive to GFP and CD31 indicating that those were endothelial cells and were actually derived from the transplanted bone marrow cells. The results suggest that macrophages, foreign body giant cells as well as fibroblasts and capillary endothelial cells are bone marrow derived mesenchymal cells.

DOI： 10.7150/ijms.13853

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The mechanism in the formation of periodontal polyp has been established in several histological studies but details on cell differentiation and/or proliferation have not been elucidated. In the present study, we established a convenient and possible experimental system using ddY mice. Briefly, pentobarbital sodium (Somnopentyl) was injected into the abdominal cavity of the mouse followed by access cavity preparation on maxillary first molar using low speed 1/2 round bur (Merufa Inc), exposing the pulp and then allowed to perforate the floor of the pulp chamber. Observation was done over time until 6 months using micro CT (m_CT) image photography. Results with transmission image using m_CT showed the expansion in the width of the periodontal ligament in the furcation area. The lesion was excised as one mass and examined histopathologically. The granulation tissue was covered with stratified squamous epithelium. The present experimental technique has been confirmed to be effective in analyzing the formation of periodontal polyp induced by mechanical perforation.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：BIOMED CENTRAL LTD  

BACKGROUND: Porphyromonas gingivalis has been implicated as a major pathogen in the development and progression of chronic periodontitis. P. gingivalis biofilm formation in the subgingival crevice plays an important role in the ability of the bacteria to tolerate stress signals outside the cytoplasmic membrane. Some bacteria use a distinct subfamily of sigma factors to regulate their extracytoplasmic functions (the ECF subfamily). The objective of this study was to determine if P. gingivalis ECF sigma factors affect P. gingivalis biofilm formation. METHODS: To elucidate the role of ECF sigma factors in P. gingivalis, chromosomal mutants carrying a disruption of each ECF sigma factor-encoding gene were constructed. Bacterial growth curves were measured by determining the turbidity of bacterial cultures. The quantity of biofilm growing on plates was evaluated by crystal violet staining. RESULTS: Comparison of the growth curves of wild-type P. gingivalis strain 33277 and the ECF mutants indicated that the growth rate of the mutants was slightly lower than that of the wild-type strain. The PGN_0274- and PGN_1740-defective mutants had increased biofilm formation compared with the wild-type (p < 0.001); however, the other ECF sigma factor mutants or the complemented strains did not enhance biofilm formation. CONCLUSION: These results suggest that PGN_0274 and PGN_1740 play a key role in biofilm formation by P. gingivalis.

DOI： 10.1186/1472-6831-15-4

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The expression of Notch in 30 cases of pleomorphic adenoma was examined by immunohistochemistry. Comparing the results of our study with previous literatures, from the partial CK7 expression and substantial Notch expression in ductal epithelial cells as well as the Notch expression in solid tumor nests, it can be inferred that Notch is involved in cell differentiation. CK13 expression was observed in cells undergoing squamous metaplasia and Notch expression was seen in the nucleus of basal and squamous cells. The intense Notch expression in basal cells and weak expression in squamous cells suggests that Notch is involved in the differentiation from basal to squamous cell. Moreover, the loss of nuclear expression on the inner layer would signify that differentiation is about to end or has been terminated. Notch was expressed in the cytoplasm of cartilage cells and in the cell membrane of mucous cells but not in the nucleus indicating that differentiation has been concluded. Notch involvement is suspected in cell differentiation in areas showing ductal structures and squamous metaplasia. In summary, Notch is involved in cell differentiation of ductal cells in PA. Nuclear expression was shown in tumor cells in solid nests and surrounding structures. Moreover, Notch is expressed by basal cells undergoing squamous metaplasia suggesting the participation of Notch in cell differentiation in PA.

DOI： 10.7150/ijms.12882

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：IVYSPRING INT PUBL  

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.

DOI： 10.7150/ijms.12883

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Using a model of experimental occlusal trauma in mice, we investigated cytological kinetics of periodontal ligament by means of histopathological, immunohistochemical, and photographical analysis methods. Periodontal ligament cells at furcation areas of molar teeth in the experimental group on day 4 showed a proliferation tendency of periodontal ligament cells. The cells with a round-shaped nucleus deeply stained the hematoxylin and increased within the day 4 specimens. Ki67 positive nuclei showed a prominent increase in the group on days 4 and 7. Green Fluorescent Protein (GFP) positivity also revealed cell movement but was slightly slow compared to Ki67. It indicated that restoration of mechanism seemed conspicuous by osteoclasts and macrophages from bone-marrow-derived cells for the periodontal ligament at the furcation area. It was suggested that the remodeling of periodontal ligament with cell acceleration was evoked from the experiment for the group on day 4 and after day 7. Periodontal ligament at the furcation area of the molar teeth in this experimental model recovered using the cells in situ and the bone-marrow-derived cells.

DOI： 10.7150/ijms.12217

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：JOURNAL HARD TISSUE BIOLOGY  

Mouse subcutaneous tissue reaction to an embedded calcium hydroxide-based root canal filling material was analyzed histopathologically. After the material was placed within the mouse dorsal subcutaneous tissues, we performed examinations using histopathological, histochemical and immunohistochemical techniques. Two weeks after embedment, the proliferation of granulation tissue had already begun to surround the calcification. Most of the cells observed were macrophages. Likewise, multinucleated giant cells increased significantly. The multinucleated giant cells were observed as two types. In one, the centers of the giant cells were vacuoles, while in the others there were deeply stained calcifications with hematoxylin. Twelve weeks after embedment of the materials, further growth of multinucleated giants cells were sighted. Histochemically, von Kossa-stain-positive granules were observed within the macrophages and multinucleated giant cells as black fine granules. According to the TRAP stained specimens, the multinucleated giant cells especially reacted strongly at 4 weeks. However, the reaction became very weak at 12 weeks. CD68 immunohistochemical staining showed positive reactions in the cytoplasm of the proliferating macrophages and multinucleated giant cells. These results suggest that multinucleated giant cells are present in the surrounding tissues due to implantation of the calcium hydroxide-based root canal filling material, and that the presence of ACP in the cells is due to ingested calcium during active phagocytosis, which would disappear later on.

DOI： 10.2485/jhtb.23.435

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Language：English   Publisher：硬組織再生生物学会  

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：JOURNAL HARD TISSUE BIOLOGY  

The aim of this study was to establish a model, which can be used to investigate the response of periodontal tissues to excessive occlusal loading in mice by observing histopathological changes. The experiment was performed on ten 7-week-old ddY male mice. Under general anesthesia by intraperitoneal injection pentobarbital sodium, a micro-plus-screwpin (head part, 1.7mm in diameter, thickness 0.5mm thickness) was screwed into the pulp cavity of the upper-left-first molar. R_mCT images of the experimental site indicated the occlusal contact position between the upper- and lower-left-first molars during the experimental periods. A micro-plus-screwpin was maintained at a constant position on the occlusal surface throughout the experimental period. Histopathological changes of the periodontal ligament at the furcation lesion of the lower-left-first molar and its surrounding periodontal tissues were observed under a light microscope. The densities of deeply dyeing cells in hematoxylin staining with a round-shaped nucleus were increased in the periodontal ligament, with a peak effect of day 4. Multinucleated giant cells appeared in the central lesion of the periodontal ligament on day 7. The distribution of resorption on the surface of both of the cementum and the alveolar bone was accompanied by multinucleated giant cells, which expanded rapidly from day 7 to day 14. These results showed that histopathological changes of periodontal tissues to excessive occlusal load were observed at the furcation area of molar teeth. The present method confirmed the effectiveness of the experimental model to examine the occlusal trauma on periodontal tissues produced by excessive occlusal load.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：IVYSPRING INT PUBL  

There are well known that Wnt signaling was some roles of cell differentiation at the development tissues, especially the oral and maxillofacial regions of some developmental stages. Therefore, to determine Wnt signaling in the pleomorphic adenoma tissues, we examined. The expression of Wnt1 and β-catenin as well as the distribution of various cytoskeletal proteins CK7 and CK13 was examined in 30 cases of pleomorphic adenoma by immunohistochemistry. Wnt1 was detected in almost all tumor cells. The peripheral columnar cells in squamous metaplasia and small cuboidal cells in duct-like structures were strongly positive to Wnt1. Although β-catenin was clearly localized on the cell membrane of tumor cells, nuclear translocation was observed in small cuboidal cells and in some basaloid cells. The immunofluorescent staining pattern of Wnt1 and CK7 as well as Wnt1 and CK13 was consistent with IHC results. Thus, in pleomorphic adenoma, Wnt is involved in tumor cell differentiation of peripheral columnar cells forming solid nests and small peripheral columnar cells forming duct-like structures. Moreover, among the three currently known Wnt pathways, β-catenin is the suggested pathway working during cell differentiation. Furthermore, peripheral columnar cells in solid tumor nests and in squamous metaplasia are governed by another Wnt pathway other than β-catenin. Therefore, Wnt signaling through β-catenin pathway may be involved in the 'mixed' differentiation characteristic of pleomorphic adenoma although another pathway may also be possibly working in other parts of the tumor tissue.

DOI： 10.7150/ijms.9453

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Although studies on the formation of apical periodontitis have somehow been carried out but detailed cellular dynamics remain unclear. We recently established an experiment that could easily be performed using ddY mice. First, under general anesthesia using isoflurane inhalation, the coronal portion of the maxillary first molar was penetrated using a round bur and drill with water irrigation causing pulp exposure until the root apex. Micro computed tomography (R_mCT) was taken over time during observation. Four weeks later, R_mCT confirmed the presence of a radiolucent image at the apex of the tooth, which was then removed for histological examination. The results showed that granulation tissue with fibrosis had gradually formed at the periphery of the abscess. The present method confirmed the effectiveness of the experimental mode to exmine the formation of chronic inflammatory lesions at the root apex.

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The expression of TRAF6 protein and TRAF6 mRNA during different stages of deciduous tooth root physiological absorption was observed. Deciduous teeth with physiological absorption period were divided into 3 groups according to the length of deciduous tooth root absorption: early stage of deciduous tooth root physiological absorption (I group), intermediate stage of deciduous teeth roots' physiological absorption (II group), final stage of deciduous tooth root physiological absorption (III group). TRAF6 antibody and TRAF6 hybridization in situ agent were used to detect the expression of TRAF6 protein and TRAF6 mRNA of odontoclasts of deciduous teeth with different physiological absorption stages. Im-pro-plas 6.0 analytical system software was used to measure the optical density of odontoclasts stained in three groups. SPSS13.0 software was used to analyze the regularity of expression. Optical density value of TRAF6 immunohistochemistry stain and TRAF6 mRNA in situ hybridization stain of odontoclasts was larger in I and II group compared with the value in III group. It indicated that odontoclasts in early and intermediate stages showed more activity than in the final stage. Expression of TRAF6 protein and TRAF6 mRNA during different stages of deciduous tooth root physiological absorption was consistent with the activity of odontoclast.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Ivyspring International Publisher  

BACKGROUND: Bone marrow-derived cells (BMCs) have abilities of cell migration and differentiation into tissues/organs in the body and related with the differentiation of teeth or periodontal tissue including fibroblasts. Then, we examined the effect of orthodontic mechanical stress to the transplanted BMC migration into periodontal tissues using BMC transplantation model. MATERIAL AND METHOD: BMC from green fluorescence protein (GFP) transgenic mice were transplanted into 8-week-old female C57BL/6 immunocompromised recipient mice, which had undergone 10 Gy of lethal whole-body-irradiation. Five mice as experimental group were received orthodontic mechanical stress using separator between first molar (M1) and second molar (M2) 1 time per week for 5 weeks and 5 mice as control group were not received mechanical stress. The maxilla with M1 and M2 was removed and was immunohistochemically analyzed using a Dako Envision + Kit-K4006 and a primary anti-GFP-polyclonal rabbit antibody. Immunohistochemically stained was defined as positive area and the pixel number of positive area in the periodontal tissue was compared with the previously calculated total pixel number of the periodontal tissue. RESULTS: The immunohistochemistry revealed that GFP positive cells were detected in the periodontal tissues, both in the experimental and control specimens. The ratio of pixel number in the examination group showed 5.77 ± 3.24 % (mean ± SD); and that in the control group, 0.71 ± 0.45 % (mean ± SD). The examination group was significantly greater than that of control group (Mann-Whitney U test: p<0.001). CONCLUSION: These results suggest that orthodontic mechanical stress accelerates transplanted BMC migration into periodontal tissues.

DOI： 10.7150/ijms.6631

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The expression of HSP27 and some CKs were examined the 40 cases of typical solid/multicystic ameloblastoma using immunohistochemical techniques. In order to examine the relevance of HSP in cell differentiation, we focused on the cytoskeletal expression of CK. CK19 is a marker of typical odontogenic epithelium widely observed in follicular and plexiform types of ameloblastomas. Since staining with CK14 is one of the measures of the differentiation potential of squamous cells and is extensively expressed in both follicular and plexiform types, it implies that squamous differentiation of each type can occur. CK8 was strongly detected in tumor nests in plexiform type but weakly detected in follicular type. It was considered that the expression of HSP27 in plexiform type correlated with the expression of CK8 suggesting that HSP27 might have regulated the expression of CK8.

DOI： 10.7150/ijms.6597

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We examined the change of HSP70 expression in the mouse dental pulp which was exposed to experimental teeth separation by immunohistochemistry as a model for conservative dental treatment. Eight week-old 18 male ddY mice were used and a wedge was inserted between upper 1st and 2nd molars for 3 hours. In the experimental group, HSP70 expression increased in the dental pulp tissues. The expression was the greatest at 24 hours after which it gradually decreased to become similar to the level of the control group at 1 week. These results suggest that when immunohistochemical expression of HSP70 is used as an index, almost no severe damage occurs upon clinical application of a wedge insertion. © 2013 The Hard Tissue Biology Network Association Printed in Japan, All rights reserved.

DOI： 10.2485/jhtb.22.7

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DOI： 10.1097/00007890-201211271-01071

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY  

BACKGROUND: Canonical and non-canonical Wnt signaling pathways modulate diverse cellular processes during embryogenesis and post-natally. Their deregulations have been implicated in cancer development and progression. Wnt signaling is essential for odontogenesis. The ameloblastoma is an odontogenic epithelial neoplasm of enamel organ origin. Altered expressions of Wnts-1, -2, -5a, and -10a are detected in this tumor. The activity of other Wnt members remains unclarified. MATERIALS AND METHODS: Canonical (Wnts-1, -2, -3, -8a, -8b, -10a, and -10b), non-canonical (Wnts-4, -5a, -5b, -6, 7a, -7b, and -11), and indeterminate groups (Wnts-2b and -9b) were examined immunohistochemically in 72 cases of ameloblastoma (19 unicystic [UA], 35 solid/multicystic [SMA], eight desmoplastic [DA], and 10 recurrent [RA]). RESULTS: Canonical Wnt proteins (except Wnt-10b) were heterogeneously expressed in ameloblastoma. Their distribution patterns were distinctive with some overlap. Protein localization was mainly membranous and/or cytoplasmic. Overexpression of Wnt-1 in most subsets (UA = 19/19; SMA = 35/35; DA = 5/8; RA = 7/10) (P < 0.05), Wnt-3 in granular cell variant (n = 3/3), and Wnt-8b in DA (n = 8/8) was key observations. Wnts-8a and -10a demonstrated enhanced expression in tumoral buddings and acanthomatous areas. Non-canonical and indeterminate Wnts were absent except for limited Wnt-7b immunoreactivity in UA (n = 1/19) and SMA (n = 1/35). Stromal components expressed variable Wnt positivity. CONCLUSION: Differential expression of Wnt ligands in different ameloblastoma subtypes suggests that the canonical and non-canonical Wnt pathways are selectively activated or repressed depending on the tumor cell differentiation status. Canonical Wnt pathway is most likely the main transduction pathway while Wnt-1 might be the key signaling molecule involved in ameloblastoma tumorigenesis.

DOI： 10.1111/j.1600-0714.2011.01104.x

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Orthodontic mechanical stress was exposed on mouse molars and histopathological changes as well as the expressions of HSP27 and p-HSP27 in the periodontal tissues were examined after removal of mechanical stress. The increased in mechanical stress up to 3 hours led to pathological changes that caused a space in between stretched periodontal ligament fibrous bundles and fibroblasts as well as narrowing of the periodontal ligament space. Degenerative changes were also occurred in the pressure side. Pathological changes did not only occur due to mechanical stress but also at the time of the release of mechanical stress exposure which increased over time. In the control group, both HSP27 and p-HSP27 were negative in the pressure side after mechanical stress was released 3 hours later. On the other hand, the tension side showed a strong positive reaction. The proteins were also expressed after 20 min, 1 hour, 3 hours and 9 hours. The strongest expression was observed 24 hours. A decreased in the intensity of expression was observed 3 days and 1 week later. The results suggest that HSP27 plays an important role in the recovery of injured cells in the periodontal tissues.

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Early changes of Osterix expression were examined by immunohistochemistry (IHC) and fluorescent immunohistochemistry (FIHC) in mouse periodontal ligament exposed to experimentally induced orthodontic mechanical stress. Eight-week-old ddY mice were used as experimental animals. To provide continuous orthodontic mechanical stress on the periodontal ligament, a rubber dam sheet was placed between the upper molars of the mice. At 20 min, 1 h, 3 h, 9 h and 24 h after the insertion, related parts of the animal tissues were evaluated by IHC and FIHC regarding Osterix and Runx2 expressions. In the 3-h and 9-h experimental groups, orthodontic tension sites reacted positively. The positive reactions became weak in the experimental group at 24-h. The results suggest that Osterix acts as one of the key factors of osteogenic cell differentiation, which expresses the following after the expression of Runx2, down-steam of Runx2. © 2012 The Hard Tissue Biology Network Association Printed in Japan, All rights reserved.

DOI： 10.2485/jhtb.21.321

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We examined expression of Heat Shock Protein 27 (HSP27) molecules, in 10 cases of typical solid/multicystic ameloblastoma, by means of immunohistochemistry. In general, HSP27 and pHSP27 positive staining products were frequently detected in the cytoplasms of the neoplastic cells. The expression pattern and/or strength are slightly different according to the cytological features of ameloblastomas. The immunohistochemical staining results suggest that the expression of HSP27 and pHSP27 is considered to be involved in neoplastic transformation of odontogenic epithelial cells.

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Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：JOURNAL HARD TISSUE BIOLOGY  

We examined immunohistochemical expressions of HSP70 and p-HSP70 in the orthodontic periodontal tissues. In the control group, the HSP70 and p-HSP70 expression was observed in the periodontal ligament fibroblasts and that was kept in low levels. In the experimental group, the strong expression of HSP70 was detected according to over time. However, p-HSP70 expression was a bit delayed. The data suggests that HSP70 has been closely involved in the repair of tissue to maintain homeostasis of the periodontal tissues by the activation of periodontal ligament fibroblasts. Farthermore, the data also suggests that HSP70 act as a molecular chaperone of osteogenesis through an activation of osteoblasts.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：I HOLZAPFEL VERLAG GMBH  

We aimed to evaluate the subcutaneous tissue reaction to a newly-developed MgO Sealer for root canals. We injected the experimental material and three existing control materials into the dorsal area of 43 male ddY mice. One week and 12 weeks after embedding, the tissue surrounding the embedding sites was removed and histopathological examination was performed. The results demonstrate that the basic histopathological reaction is the formation of fibrous capsules consisting of granulation tissue around the experimental and control embedded materials. Based on our results, we believe that the newly-developed MgO Sealer is as safe as the existing control materials and can be considered for dental use as a root canal sealer.

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Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：JOURNAL HARD TISSUE BIOLOGY  

We examined immunohistochemical expression of Chromogranin A (CgA) in the mouse dental pulp and the periodontal tissues, which exposed to 3 hours immediate teeth separation. In the experimental group, CgA positive staining products were frequently detected in the periodontal fibroblasts and endothelial cells, and also detected in the dental pulp cells. The positive reactions were stronger than that of control specimens. The data suggests that induced expression was due to the mechanical stress of wedge insertion.

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Wegener's granulomatosis is a rare multi-system disease characterized by the classic triad of necrotizing granulomas affecting the upper and lower respiratory tracts, disseminated vasculitis and glomerulonephritis. Oral lesions as a presenting feature are only encountered in 2% of these cases. Hyperplastic gingival lesions or strawberry gingivitis, is a characteristic sign of Wegener's granulomatosis. The latter consists of reddish-purple exophytic gingival swellings with petechial haemorrhages thus resembling strawberries. Recognition of this feature is of utmost importance for timely diagnosis and definitive management of this potentially fatal disease. A case of strawberry gingivitis as the first presenting sign of Wegener's granulomatosis affecting a 50-year-old Malay male is reported here. The differential diagnosis of red lesions that may present in the gingiva is discussed.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：I HOLZAPFEL VERLAG GMBH  

We aimed to evaluate the subcutaneous tissue reaction to a newly developed adhesive silicone denture relining material, SG, (Neo Dental Chemical Products Co., Ltd. Tokyo, Japan). We embedded the experimental material SG and another existing control material, Roeko Seal (RS), in the dorsal area of 22 male ddY mice. One week and 12 weeks after the embedding, the tissues surrounding the embedded materials were removed and a histopathological examination was performed. The results demonstrate that the basic histopathological aspects are the formation of granulation tissue and the change of the tissue to fibrous capsule over time. The results suggests that the newly-developed SG is safe as compared with the control RS, whose composition is similar.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：I HOLZAPFEL VERLAG GMBH  

Polypropylene (PP), Polyethylene (PE) and polytetrafluoroethylene (FE) are high molecular materials in medical use. They are also used as the negative control materials for ISO 10993-6 international standard biological evaluation of medical devices. We examined tissue reactions to these materials embedded subcutaneously in the dorsal area of male ddY mice. One week and 12 weeks after embedding, the tissue surrounding the embedding site was removed and then histopathological examination was performed. Our results demonstrate that the basic histopathological reaction is the formation of fibrous capsule consisting of granulation tissue around the embedded materials. Based on our results, we believe that the high molecular materials such as, PP, PE and FE, can be considered for medical use as a biomaterials within the body.

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Teeth are important structures for masticatory and phonetic purposes. Loss of teeth decreases these functions leading to impaired quality of life. Missing teeth replaced by tooth regeneration may be possible with emerging advances in stem cell biology and tissue engineering. Recent investigations have demonstrated that bone marrow derived cells (BMDC) can differentiate into cells other than blood cells. In the present study, the ability of BMDC to differentiate into tooth forming tissues was investigated using bone marrow transplantation model. BMDC from green fluorescent protein (GFP) transgenic mice were transplanted into 8-week old, C57BL/6 immunocompromised mice, which underwent 10-Gy whole body lethal irradiation. Immunohistochemical analysis revealed that bone marrow cells are positive to GFP, confirming successful bone marrow transplantation. Diffusedly GFP-positive cells were observed within the dental pulp of mouse incisor. GFP-positive cells in the dental pulp have arborescent processes resembling dendritic cell-like cells. Some odontoblast-like cells were also positive to GFP. Cells positive to GFP were observed in the cervical loop region and periodontal ligament. Langerhans cells in the oral epithelium, stromal fibroblasts, blood vessels and osteoclasts were also positive to GFP. These results indicate that BMDC have the ability to differentiate into tooth, bone and connective tissues. © 2011 The Hard Tissue Biology Network Association.

DOI： 10.2485/jhtb.20.147

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Oxide film was obtained on a NiTi shape memory alloy by a chemical method. In vitro bioactivity of the oxidized NiTi shape memory alloy was studied. Cell culture showed that both non-oxidized and oxidized NiTi shape memory alloy did not have cell toxicity while the oxidized displayed higher cell viability. More L929 cells were found to adhere and proliferate on the oxidized samples surface than that on the non-oxidized. Cell number increased slowly for the test alloy samples'. Oxidized NiTi shape memory alloy possesses equal cell-activating properties to the pure titanium. More intercellular substance was observed for the cells on the oxidized NiTi alloy. The oxidized NiTi alloy shows better cell response than the non-oxidized. Surface oxidation improves the bioactivity of NiTi shape memory alloy. © 2011 The Hard Tissue Biology Network Association.

DOI： 10.2485/jhtb.20.53

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-BLACKWELL  

BACKGROUND: In mammals, the Notch gene family encodes four receptors (Notch1-4), and all of them are important for cell fate decisions. Notch signaling pathway plays an essential role in tooth development. The ameloblastoma, a benign odontogenic epithelial neoplasm, histologically recapitulates the enamel organ at bell stage. Notch has been detected in the plexiform and follicular ameloblastoma. Its activity in the desmoplastic ameloblastoma is unknown. METHOD: Notch1-4 and their ligands (Jagged1, Jagged2 and Delta1) were examined immunohistochemically in 10 cases of desmoplastic ameloblastoma. RESULTS: Ameloblastoma tumor epithelium demonstrated positive expression for Notch1 (n = 5/10), Notch3 (n = 8/10), Notch4 (n = 10/10), Jagged1 (n = 6/10) and Delta1 (n = 5/10), but no reactivity for Notch2 (n = 10/10) and Jagged2 (10/10). Expression patterns were distinct with some overlap. Positive activity was detected largely in the cell membrane and cytoplasm of peripheral and central neoplastic epithelial cells, and sometimes in the nucleus. Staining score was highest for Notch4. Stromal components namely endothelial cells and fibroblasts showed overexpression for Notch4 but were mildly or non-reactive for the other Notch members and their ligands. CONCLUSIONS: These findings suggest that Notch receptors and their ligands may play differing roles during the development of the desmoplastic ameloblastoma with Notch4 probably playing a greater role in the acquisition of tissue-specific cellular characteristics in the desmoplastic ameloblastoma.

DOI： 10.1111/j.1600-0714.2009.00871.x

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：MOSBY-ELSEVIER  

OBJECTIVE: Notch signaling has been implicated in cell fate decisions during odontogenesis and tumorigenesis of some odontogenic neoplasms; however, its role in solid/multicystic (SA), unicystic (UA), and recurrent (RA) ameloblastoma remains unclear. The aim of this study was to determine Notch receptor and ligand expressions in these subtypes and to speculate on their significance. METHODS: Notch receptors (Notch1, 2, 3, 4) and ligands (Jagged1, 2, and Delta1) were examined immunohistochemically in SA (n = 23), UA (n = 22), and RA (n = 19). RESULTS: Notch4 overexpression in SA (n = 19/23; 82.6%) compared with UA (n = 1/22; 4.5%) or RA (n = 10/19; 52.6%) (P < .05) suggests positive correlation between Notch4 signaling and ameloblastomas with a solid/multicystic phenotype. Ligand (Jagged1 and Delta1) underexpression compared with their receptors (Notch1, 3, 4) (P < .05) and nonreactivity for Notch2 and Jagged2 in all 3 subsets suggests that ameloblastoma epithelium belongs to an earlier stage of differentiation (equivalent to inner enamel epithelium of developing tooth germ) before lineage commitment. CONCLUSION: Present findings suggest that Notch signaling molecules may play differing roles in the acquisition of different ameloblastoma phenotypes.

DOI： 10.1016/j.tripleo.2010.03.009

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：I HOLZAPFEL VERLAG GMBH  

BACKGROUND: Squamous odontogenic tumor (SOT) is a rare benign odontogenic epithelial neoplasm. A slow-growing painless expansive swelling is the common presenting symptom. Histopathologically, SOT can be easily misdiagnosed as an acanthomatous ameloblastoma. Although Notch receptors and ligands have been shown to play a role in cell fate decisions in ameloblastomas, the role of these cell signaling molecules in SOT is unknown. CASE REPORT: This paper describes a case of SOT affecting the anterior mandible of a 10-year-old Indian female. The patient was treated by local surgical excision and there has been no follow-up clinical record of recurrence 5 years after primary treatment. Histo?pathological examination revealed a solid, locally-infiltrative neoplasm composed of bland-looking squamatoid islands scattered in a mature fibrous connective tissue stroma and the diagnosis was SOT. Immunohistochemical evaluation showed positive reactivity of varying intensity in the neoplastic epithelial cells for Notch1, Notch3, Notch4, and their ligands Jagged1 and Delta1. Expression patterns showed considerable overlap. No immunoreactivity was detected for Notch2 and Jagged2. CONCLUSIONS: Present findings suggest that Notch receptors and their ligands play differential roles in the cytodifferentiation of SOT.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：JOURNAL HARD TISSUE BIOLOGY  

Using Waldo's method in mice, we examined the immunohistochemical expression of Runx2 and alkaline phosphatase (ALP) appearing in dental pulp cells, especially in odontoblasts, just after receiving experimental orthodontic mechanical stress, using Waldo's method in mice. The examination results demonstrated that some dental root pulp cells, especially some odontoblasts, expressed the Runx2 and ALP in a comparatively short time after receiving the stress. The results suggest that the stress may cause odontoblast activity up-regulation.

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Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：JOURNAL HARD TISSUE BIOLOGY  

The purpose of this examination was to in vestigate the expression of BMP-2 and -4 in mouse orthodontic periodontal tension sides exposed orthodontic mechanical stress using the method of Waldo Immnohistochemically, in the experimental group. strong expression of BMP-2 and -4 were observed in the periodontal tension sides at 20minutes The results strongly suggested that the BMP-2 and -4 promoted the Runx2 expression for osteoblastic differention in the orthodontic periodontal tension sides at the early stage after receiving of the mechanical stress

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Using immunohistochemical techniques, we examined the expression of heat shock protein (HSP) appearing in murine dental pulp cells after the application of experimental orthodontic mechanical stress We used Waldo's method, and the results demonstrate that the dental root pulp cells expressed HSP in a comparatively short time after stress The results suggest that FISP works as one of the mechanisms to maintain homeostasis

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Development of the tooth is a complex and fascinating set of processes which require a sequential integration of numerous biological steps. For dental doctors, interest is particularly high, because the tooth is mainly composed of surface ectodermal epithelium and neural crest derived neuroectodermal mesenchyma, and formed by epithelial-mesenchymal interactions. There are many different types of odontogenic neoplasms. In general, proliferation, development and cytological differentiation of the neoplastic cells reflect the normal physiological development of the outbreak mother cells and/or tissues. There would appear to be a relationship between the cytological differentiation of odontogenic neoplastic cells and the physiological development and differentiation of tooth germ. We describe some morphogenesis regulation factors, such as Notch signaling, in the odontogenic neoplastic cells, in both well-differentiated and poorly-differentiated neoplasms. Our results suggest that these factors play some role in cytological differentiation or acquisition of tissue-specific characteristics in neoplastic cells. © 2008 The Hard Tissue Biology Network Association Printed in Japan, All rights reserved.

DOI： 10.2485/jhtb.17.79

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Development of the oral and craniofacial region is a complex and fascinating set of processes which require a sequential integration of numerous biological steps. For medical and dental doctors, interest is particularly high in this region, because it is composed of three blastoderms - ectoderm, mesoderm, and endoderm - as well as neural crest cells. There are many different types of neoplasms in this region. In general, proliferation, development and cytological differentiation of the neoplastic cells reflect the normal physiological development of the outbreak mother cells and/or tissues. Collected human neoplasm cases, such as osteosarcoma appearing in the oral and craniofacial region, are examined regarding the immunohistochemical expression of some morphogenesis regulation factors. Furthermore, examination of Notch signaling is also conducted for some odontogenic neoplasms. This chapter mainly describes the examination results of some morphogenesis regulation factors, such as Notch signaling, in the neoplastic cells originating in the oral and craniofacial region, especially in the odontogenic neoplasms, in both well-differentiated and poorly-differentiated neoplasms of tooth germ enamel organ-derived neoplasm. In general, these morphogenesis regulation factors are responsible for cytological regulation of cell fate, morphogenesis and/or development. The results suggest that these factors play some role in cytological differentiation or acquisition of tissue specific characteristics in neoplastic cells. Furthermore, there would appear to be a relationship between the cytological differentiation in the oral and craniofacial neoplastic cells and the physiological development and differentiation of their originating mother cells and tissues of the oral and craniofacial region. © 2007 by Nova Science Publishers, Inc. All rights reserved.

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Language：English   Publisher：The Society of Hard Tissue Biology  

DOI： 10.2485/jhtb.16.147

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Other Link： http://search.jamas.or.jp/link/ui/2008174255

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Ivyspring International Publisher  

Histopathological and immunohistochemical examinations were carried out in a case of pleomorphic adenoma with bone formation, occurring in the chin of a 34-year-old Japanese man. Examination results showed the modified neoplastic myoepithelial cells reacted positively to S-100 protein. The S-100-positive modified neoplastic myoepithelial cells were proliferated in the closely related area of the bone tissue. Furthermore, positive reaction was detected in the bone forming cells: osteoblasts and osteocytes. These cells also reacted positively to Runx2 as a marker of bone forming cells. These results suggest that the origin of the bone forming cells in this case of pleomorphic adenoma was modified neoplastic myoepithelial cells.

DOI： 10.7150/ijms.4.264

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Wnt genes encode a large family of secreted cysteine-rich signaling molecules involved in cell growth, differentiation and tumorigenesis. Wnt5a, a non-transforming member of the Wnt family behaves as a putative oncogene in many cancers including melanomas. The aim of our study was to determine Wnt5a expression in primary oral mucosal melanomas (OMM) and correlate it with tumor thickness. Archival tissues from 18 OMM cases were subjected to immunohistochemical detection of Wnt5a by the streptavidin-biotin method. These were categorized into tumors of <4 mm (thin and intermediate thickness lesions) and >4 mm (thick lesions) thickness. Most OMM cases (17/18; 94.4%) stained positive for Wnt5a, though heterogeneously. Seven thick (7/11; 64%) and one intermediate thickness (1/7, 14%) OMM demonstrated strongly positive Wnt5a staining (P<0.05). The only Wnt5a-negative case was a thick OMM without local recurrence after treatment. Strong Wnt5a expression at tumor advancing sites suggests a role in local tumor spread. Identification of pleomorphic epithelioid and spindle cells as melanoma cell populations with the most pronounced Wnt5a staining suggests that Wnt5a overexpression influences cellular phenotype. These results taken together suggest that Wnt5a is upregulated in OMM and may play a role in tumor progression. © 2007, THE SOCIETY FOR HARD TISSUE REGENERATIVE BIOLOGY. All rights reserved.

DOI： 10.2485/jhtb.16.79

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DOI： 10.2485/jhtb.16.23

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DOI： 10.2485/jhtb.15.6

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Pleomorphic adenoma is the most common epithelial tumor in the salivary glands. This tumor frequently exhibits "mesenchyme"-like components, including myxoid or chondroid areas. Recently, using immunohistochemical techniques, we reported that cartilage-specific matrix protein, chondromodulin-I (ChM-I), was deposited on the inter-territorial matrix of the chondroid area in salivary pleomorphic adenomas and that ChM-I, which is also a strong angio-inhibitory factor, plays an important role in the avascular nature of the chondroid area and the chondroid formation in this type of tumor. To elucidate which cells express ChM-I mRNA in pleomorphic adenomas, we examined the expression and localization of ChM-I mRNA in this type of tumor using an in situ hybridization technique. Immunoreactivity for ChM-I was observed in the inter-territorial matrix of the chondroid area, especially around the lacunae, and in the cytoplasm of neoplastic myoepithelial cells of the myxoid element of pleomorphic adenomas. On in situ hybridization analysis, strong signals for ChM-I mRNA were detected in the cytoplasm of the lacuna cells of the chondroid element, and moderate to marked signals were observed in the cytoplasm of the neoplastic myoepithelial cells of the myxoid element. Signals for ChM-I mRNA were also seen in the cytoplasm of the spindle-shaped neoplastic myoepithelial cells in the transitional areas between the myxoid and chondroid elements of this tumor. Signals for ChM-I mRNA were not seen in the inner ductal cells or the fibrous element. These findings indicate that lacuna cells and neoplastic myoepithelial cells express ChM-I mRNA and that mature ChM-I, which lacuna cells and neoplastic myoepithelial cells translate, is deposited in the chondroid matrix of pleomorphic adenomas. In conclusion, lacuna cells and neoplastic myoepithelial cells express ChM-I mRNA ectopically in pleomorphic adenoma, and this plays an important role in chondroid formation and hypovascularity in this type of tumor.

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BACKGROUND: The morphology and contents of melanosomes are important features for differentiating melanocyte-derived melanotic lesions such as melanosis and malignant melanoma. METHODS: In this study, we attempted to elucidate the structure of melanin and sulphur content in oral melanosis and malignant melanomas by ultrastructural analysis. RESULTS: In oral melanosis, the essential pathological findings were overproduction of eumelanin and discharge of melanin into keratinocytes. In malignant melanoma in situ, pleomorphic and ellipsoid abnormal melanosomes with an increase in sulphur content and alkali elution rate were detected. In invasive malignant melanoma, the irregular ellipsoid and spheroid melanosomes existing either as discrete bodies or compound melanosomes with furtherly increased sulphur content and alkali elution were detected. CONCLUSIONS: Our findings suggest that abnormal melanosome morphology and high sulphur content are predictive markers for assessment of early or precancerous melanotic lesions and malignant melanoma.

DOI： 10.1034/j.1600-0714.2002.00010.x

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BACKGROUND: Type IV collagen, a heterotrimeric molecule that exists in six genetically distinct forms, alpha1(IV)-alpha6(IV) is a major structural component of basement membrane (BM) and acts as a scaffold for other BM constituents. METHODS: Indirect immunofluorescence using alpha chain-specific monoclonal antibodies was employed to clarify basement membrane (BM) collagen IV distribution in two ameloblastoma, and for comparison, on oral mucosa and tooth germ. RESULTS: Ameloblastoma BM expressed five of six genetically distinct forms of collagen IV: alpha1(IV), alpha2(IV), alpha5(IV) and alpha6(IV) chains occurred as intense linear stainings without disruption around neoplastic epithelium, and this expression pattern was fundamentally similar to oral mucosa BM; alpha4(IV) expression was rare and occurred around nests of primitive tumor cells or potentially invasive sites. The tooth germ demonstrated a stage- and position-specific collagen IV distribution: the inner enamel epithelium BM expressed alpha1(IV), alpha2(IV), and alpha4(IV) except in the cuspal predentine region; and the outer enamel epithelium BM expressed alpha1(IV), alpha2(IV), alpha5(IV), and alpha6(IV) chains. CONCLUSIONS: Results suggest that collagen IV alpha chain distribution in ameloblastoma BM plays an important role in tumor cytodifferentiation and progression.

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The dental basement membrane (BM) putatively mediates epithelial-mesenchymal interactions during tooth morphogenesis and cytodifferentiation. Type IV collagen α chains, a major network-forming protein of the dental BM, was studied and results disclosed distinct expression patterns at different stages of mouse molar germ development. At the dental placode and bud stage, the BM of the oral epithelium expressed α 1, α 2, α 5 and α 6 chains while the gubernaculum dentis, in addition to the above four chains, also expressed α 4 chain. An asymmetrical expression for α 4, α 5 and α 6 chains was observed at the bud stage. At the early bell stage, the BM associated with the inner enamel epithelium (IEE) of molar germ expressed α 1, α 2 and α 4 chains while the BM of the outer enamel epithelium (OEE) expressed only α 1 and α 2 chains. With the onset of dentinogenesis, the collagen α chain profile of the IEE BM gradually disappeared. However from the early to late bell stage, the gubernaculum dentis consistently expressed α 1, α 2, α 5 and α 6 chains resembling fetal oral mucosa. These findings suggest that stage- and position- specific distribution of type IV collagen α subunits occur during molar germ development and that these changes are essential for molar morphogenesis and cytodifferentiation.

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Language：Japanese   Publisher：Japanese Society of Oral Implantology  

Hydroxyapatite (HAP) is considered one of the best bioactive ceramics because of high bone conduction/induction in osteogenic tissue. Although it has several characteristics of an ideal bone substitute, it does not have bone induction in heterogenous tissue. On the other hand, partially-purified bone morphogenetic protein (BMP), which contains BMP-2 and can induce differentiation of mesenchymal cells into osteoblast, was extracted from bovine bone matrix. In this study, porous HAP-BMP complex was inserted into the bone defect in case of HAP-coated implant, an integral implant system for the dog mandible.<br/> The results showed significant increases in the height and the area of the new bone in the porous HAP-BMP complex experimental group as compared with the control group. From the results above, it was considered that porous HAP-BMP composite maintains the thickness of regenerated tissue of the bone defect around implant.

DOI： 10.11237/jsoi.10.272

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Language：Japanese   Publisher：日本硬組織研究技術学会  

A modofied method was established to extracted BMP from bovine bone. SDS-PAGE and Westen blotting were apllied to analize the components of this partially purified BMP. In addition the amino acid sequence was studied using protein sequencer to analyze the unknown bands. Type I collagen derived from bone was used as a carrier whose properties and advantages were studied. The following conclusions are made from this study. 1. The limitation of molecluar weight in tbe early step of BMP purification procedure improves purification efficiency and stability, which makes the applicadon of BMP in big animalos possible. 2. In this method the purified BMP product also contains histone H3, histone 2B and other unknown proteins as well as BMP-2. 3. The atelocollagen derived from bone has proved to be an useful carrier for BMP. This carrier shows characteristics of self absorption and recalcification when embedded in tissues. 4. The minimun bone induction dose of BMP at each step (G-Ext:500μg, Hep:30μg, S200:50μg) and the optimal bone induction dose(G-Ext:5.0mg, Hep:2.0mg, S200:0.3mg) are determined, which makes the applicalion of BMP in cellular biology possible.

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Language：Japanese   Publisher：日本硬組織研究技術学会  

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Total pages：xxii, 740p   Language：Japanese

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Language：Japanese   Publisher：(NPO)日本口腔科学会  

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The calcifying epithelial odontogenic tumor (CEOT) is a benign but locally-invasive odontogenic neoplasm believed to take origin from the stratum intermedium of the developing tooth germ. Bone morphogenetic proteins (BMPs) are multifunctional signaling molecules that regulate diverse cellular processes including epithelial-mesenchymal interactions during odontogenesis. Aberrant BMP activity has been enumerated in the ameloblastoma but information about its distribution in the CEOT remains limited. The aim here was to investigate BMP expression in CEOT and to speculate on its significance. Immunolabelling for BMP-2 and BMP-7 was performed on archival tissues of six CEOT cases and the level of expression was quantified as negative (0), mild (+), moderate (2+) and strong (3+). Results disclosed that CEOT epithelium demonstrated co-expression of BMP-2 and -7 suggesting upregulation of these proteins at sites of tumor differentiation. Distribution patterns were distinct with some overlap. Their localizations were largely membranous and/or cytoplasmic. Amyloid-like materials strongly expressed BMP-7 but were nonreactive for BMP-2, implicating that these signaling proteins play differential roles in the formation of these extracellular products. Mineralized substances including Liesegang rings were mostly negative for both BMPs suggesting that calcification process is associated with repression of these molecules. Stromal endothelium and fibroblasts were stained variably positive. BMP was heterogeneously detected in the CEOT epithelium at the tumor advancing front suggesting their upregulation at active sites and downregulation in quiescent areas. Present findings suggest that BMP-2 and BMP-7 most likely play differential roles in the cellular differentiation and progression of CEOT. BMP-7 accumulation within amyloid-like protein is a novel finding.

DOI： 10.2485/jhtb.20.125

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We examined the transplanted bone marrow-derived cell migration into periodontal tissues. Bone marrow cells from green fluorescent protein (GFP) transgenic mice were transplanted. The immunohistochemistry (IHC) revealed that GFP-positive cells were detected in the periodontal tissues. The GFP-positive cells histopathologically differentiated into some cell types. The fluorescence IHC and TRAP staining techniques demonstrated these cells were detected as osteoclasts and macrophages. Furthermore, GFP-positive cells gathered adjacent blood vessels. The data suggest that GFP-positive bone marrow-derived cell migrate into periodontal tissues and differentiate periodontal tissue component-cells. © 2011 The Hard Tissue Biology Network Association.

DOI： 10.2485/jhtb.20.301

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Notch signaling is an evolutionarily conserved mechanism that enables adjacent cells to adopt different fates. Ghost cells (GCs) are anucleate cells with homogeneous pale eosinophilic cytoplasm and very pale to clear central areas (previous nucleus sites). Although GCs are present in a variety of odontogenic lesions notably the calcifying cystic odontogenic tumor (CCOT), their nature and process of formation remains elusive. The aim of this study was to investigate the role of Notch signaling in the cell fate specification of GCs in CCOT. Immunohistochemical staining for four Notch receptors (Notch1, Notch2, Notch3 and Notch4) and three ligands (Jagged1, Jagged2 and Delta1) was performed on archival tissues of five CCOT cases. Level of positivity was quantified as negative (0), mild (+), moderate (2+) and strong (3+). Results revealed that GCs demonstrated overexpression for Notch1 and Jagged1 suggesting that Notch1-Jagged1 signaling might serve as the main transduction mechanism in cell fate decision for GCs in CCOT. Protein localizations were largely membranous and/or cytoplasmic. Mineralized GCs also stained positive implicating that the calcification process might be associated with upregulation of these molecules. The other Notch receptors and ligands were weak to absent in GCs and tumoral epithelium. Stromal endothelium and fibroblasts were stained variably positive. © I. Holzapfel Publishers 2011.

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Language：English   Publisher：JOURNAL HARD TISSUE BIOLOGY  

Notch signaling pathway mediates diverse biological processes including cell fate decisions during odontogenesis. Dysregulation of Notch has been implicated in the tumorigenesis of some odontogenic neoplasms but its role in the calcifying epithelial odontogenic tumor (CEOT) remains unclarified. The aim here was to investigate Notch expression in CEOT and to speculate on its significance. Receptors Notch1-4 and their ligands (Jagged1, Jagged2 and Delta1) were examined immunohistochemically in six CEOT cases. Expression levels were quantified according to the percentage of positive tumor cells, amyloid-like proteins and calcifications: (-), negative staining; (+), mild and focal positivity <25%; (++), moderate positivity in significant areas 25-50%; (+++), strong positivity in predominant areas >50%. CEOT epithelium demonstrated variable expression levels for Notch1, 3, 4, Jagged1 and Delta1 suggesting upregulation of these molecules at sites of tumor differentiation. Distribution patterns were distinct with some overlap. Their localizations were largely membranous and/or cytoplasmic. Notch2 and Jagged2 were absent. Amyloid-like materials strongly expressed Jagged1 but variably Notch1, 3 and Delta1 implicating that these signaling proteins maybe competitive substrates with CEOT amyloid-like proteins for proteolysis. Notch2, 4 and Jagged2 were absent. Mineralized substances including Liesegang rings were negative for Notch receptors and ligands suggesting that calcification process is associated with downregulation of these molecules. Stromal endothelium and fibroblasts were stained variably positive. Taken together, current data suggest that Notch receptors and their ligands may play differing roles in the acquisition of cell fates in CEOT. Notch accumulations within amyloid-like protein suggest impaired proteolysis.

DOI： 10.2485/jhtb.19.167

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Odontogenesis is a complex biological process both with epithelial and mesenchymal tissues, and this process directly reflects the development of odontogenic neoplasms. Therefore, we have examined Notch signaling in a case of calcifying cystic odontogenic tumor, with ameloblastic fibroma and odontogenic myxoma cases as controls. In these specimens, Notch-positive-products were present both in the epithelial and ectomesenchymal components in the calcifying cystic odontogenic tumor and the ameloblastic fibroma case, but negative in the odontogenic myxoma case, having no odontogenic epithelial islands to IHC and ISH examinations. Therefore, the examination results suggest that Notch signaling plays some important roles in cytological differentiation or acquisition of tissue-specific characteristics between odontogenic epithelium and odontogenic ectomesenchymal tissues. © 2010 The Hard Tissue Biology Network Association Printed in Japan, All rights reserved.

DOI： 10.2485/jhtb.19.147

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Background: Notch receptors are critical determinants of cell fate in a variety of organisms. Notch signaling is involved in the chondrogenic specification of neural crest cells. Aberrant Notch activity has been implicated in numerous human diseases including cancers; however its role in chondrogenic tumors has not been clarified. Method: Tissue samples from a case of primary chondrosarcoma of the maxilla and its recurrent tumor were examined immunohistochemically for Notch 1-4 and their ligands (Jagged1, Jagged2 and Delta1) expression. Results: Both primary and recurrent tumors were histopathologically diagnosed as conventional hyaline chondrosarcoma (WHO Grade I). Hypercellular tumor areas strongly expressed Notch3 and Jagged1 in spindle and pleomorphic cells suggesting up-regulation of these protein molecules at sites of tumor proliferation. Expression patterns were distinct with some overlap. Differentiated malignant and atypical chondrocytes demonstrated variable expression levels of Jagged1, and weak to absent staining for Notch1, 4 and Delta1. Protein immunolocalization was largely membranous and cytoplasmic, sometimes outlining the lacunae of malignant chondrocytes. Hyaline cartilage demonstrated a diffuse or granular precipitation of Jagged1 suggesting presence of soluble Jagged1 activity at sites of abnormal chondrogenesis. No immunoreactivity for the other Notch members was observed. Calcified cartilage was consistently Notch-negative indicating down-regulation of Notch with cartilage maturation. Stromal components namely endothelial cells and fibroblasts variably expressed Notch1, 3 and Jagged1 but were mildly or non-reactive for the other members. Conclusions: Results indicate that Notch signaling pathway may participate in cellular differentiation and proliferation in chondrosarcoma. Findings implicate Notch3 and Jagged1 as key molecules that influence the differentiation and maturation of cells of chondrogenic lineage. © I. Holzapfel Publishers 2010.

DOI： 10.1186/2047-783x-15-10-456

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Statement of the problem: Dysplasia, the morphological yardstick of epithelial precursor lesions, is the collective term for a variety of architectural and cytological changes within the altered oral epithelium. Angiogenic squamous dysplasia (ASD), a distinct morphological characteristic in pre-invasive bronchial lesions, describes the presence of capillary tufts that are closely juxtaposed to and projecting into the dysplastic bronchial epithelium. Objective: To determine whether ASD-like phenomenon occurs in oral epithelial precursor lesions, and to speculate on its relevance. Methods: Twenty cases each of mild, moderate and severe oral dysplasia (inclusive of carcinoma-in-situ), and 10 normal oral mucosa (normal controls) were serial sectioned for H and E staining, and for microvessel density (MVD) scoring with CD31, CD34 and CD105. Microcapillary pattern images were digitally captured for 3-D reconstruction. Results: Oral ASD foci consisting of CD31- and CD34-positive capillary loops abutting onto the overlying dysplastic oral epithelium (and causing it to assume an irregular or papillary surface configuration) were identified in moderate (3/20; 15%) and severe dysplasia (13/20; 65%), but not in normal oral mucosa and mild dysplasia. MVD score demonstrated increasing vascularity as epithelium progressed from normal to severe dysplasia (p<0.05). CD105 demonstrated increase neovascularization in all dysplasia grades (p<0.05). Conclusions: These preliminary findings taken together suggest that: 1. ASD-like phenomenon may be an important intermediary biomarker in oral precursor lesions; and 2. architectural alterations of the entire disturbed mucosa may be a more useful pre-malignancy index. © I. Holzapfel Publishers 2009.

DOI： 10.1186/2047-783x-14-7-315

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Wingless-type protein (Wnt) is a family of 19 secreted glycoproteins that function as signaling transducers for cell-cell interaction, cell growth and differentiation. Wnt-1, a highly transforming member, has been implicated in tumorigenesis. The aim of this study was to elucidate the role of this cell signaling molecule in the development and progression of primary ameloblastoma and their recurrent tumors. Wnt-1 expression patterns were examined immunohistochemically in 22 primary and 14 recurrent ameloblastomas. These collectively consisted of the following subtypes: conventional (CA) (n=22), desmoplastic (DA) (n=2) and unicystic (UA) (n=12) ameloblastoma. Results demonstrated that CA (n=20/22; 90.9%), DA (n =2/2; 100%) and UA (11/12; 91.7%) showed high Wnt-1 expression percentages. Strong staining intensity for Wnt-1 was observed more frequently in primary CA (n =10/13; 76.9%) than in their recurrent counterparts (n= 2/9; 22.2%) (p<0.05). Conversely, in UA, recurrent tumors (n=3/5; 60.0%) tend to stain strongly for Wnt-1 more frequently than their primary lesions (n=3/7; 42.9%) (p>0.05). Keratinizing cells in areas of squamous metaplasia also expressed Wnt-1 more intensely compared to their surrounding polyhedral stellate reticulum-like cells. Tumor islands containing granular cells were also Wnt-1 positive. Present findings confirmed that the Wnt signaling pathway is activated in ameloblastoma. Strong Wnt-1 expression in primary conventional and recurrent unicystic ameloblastoma suggests that Wnt-1 plays a more critical role in these subtypes. Positive expression of Wnt-1 in keratinizing ameloblastomatous tumor epithelium and granular cells complies with the anti-apoptotic properties of Wnt-1. Negative reactivity for Wnt-1 in 3 cases of ameloblastoma suggests that the development and progression of ameloblastoma may occur independent of this cell signaling molecule. © The Hard Tissue Biology Network Association.

DOI： 10.2485/jhtb.18.63

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Expression pattern of Jagged2 gene in mandibular condylar cartilage was examined by means of in situ hybridization (ISH) technique. At E14, Jagged2 mRNA signals appeared in cytoplasm of proliferating chondrocytes. From E15 to E19, Jagged2 mRNA was detected throughout almost all cytoplasm in all layers. However, the distribution pattern was not uniform. These results suggest that Jagged2 plays an essential role for mandibular condylar cartilage morphogenesis and development. © I. Holzapfel Publishers 2008.

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The basic principle of bone tissue engineering is to use seeded stem cells in porous scaffold. Stem cells can proliferate and differentiate into various types of mature cells. A kind of stem cell called KUSA/A1 is a marrow stromal cell, capable of differentiating into three mesenchymal phenotypes: osteocyte, adipocyte, and myocyte by treating with 5-azacytidine in cell culture. Moreover, it has been reported that the mechanism of bone induction by KUSA/A1 cells is similar to intramembranous ossification. In order to clarify the origin of osteoblasts implicated in new bone formation, KUSA/A1 cells alone and combined with Honeycomb carrier were implanted in Transgenic Green Fluorescent Protein mice (GFP) mice. The presence of GFP positive host cells with osteoblastic morphology as well as GFP negative cells, clearly of KUSA/A1 cells in origin were observed around the bony trabeculae. These results indicated that the new bone was not only produced by KUSA/A1 cells but also by host cells from the surrounding connective tissues. To our knowledge, this is the first study to describe that host cells play an important role in ectopic bone induced by implanted marrow stromal cells, which would need special attention in bone tissue engineering. © 2007, THE SOCIETY FOR HARD TISSUE REGENERATIVE BIOLOGY. All rights reserved.

DOI： 10.2485/jhtb.16.75

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Objective: The purpose of this study was to investigate the expression pattern of Notch signaling in mandibular condylar cartilage, as a type of secondary cartilage. Methods: Mandibular condyle of ddY mice were fixed from embryonic day 14 (E14) through just after birth (equivalent to E19). Samples were cut into 4 μ serial sections through the central area of the mandibular condyle at the sagittal plane. Serial sections were examined using histological, immunohistochemical (IHC) and in situ hybridization (ISH) techniques. Results: At E14, there were no developmental features of mandibular condyle. At the distal upper portion of developmental mandibular bone, mesenchymal cell proliferation and condensation without metacholomatic reaction to toluidine blue (TB) were seen. At E15, mandibular condylar cartilage was clearly evident, as TB metacholomasia. In IHC specimens at E14, expression of Notchl intracellular domain (NICD) was observed in the nuclei of coagulating mesenchymal cells. After E15, NICD appeared in the nuclei and the cytoplasms of cells. In ISH examination at E14, expressions of Notch1 mRNA appeared in cytoplasm of proliferating chondrocytes. From E15 to E19, Notch1 mRNA was detected throughout almost all cytoplasm in all layers. Conclusion: These IHC and ISH results suggest that Notch signaling plays an essential role for mandibular condylar cartilage morphogenesis and development. © I. Holzapfel Publishers 2007.

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The morphogenesis and morphological development of molar are regulated by the interaction between odontogenic epithelium and mesenchymal tissues. And Type IV collagen molecules, the major component of the dental basement membrane, are composed of three alpha chains. Using indirect immunofluorescence on cryosections, we characterized the changes in protein localization of alpha 1 to 6 chains of type IV collagen during molar development in mice molar and human tooth germ. ICR mouse embryos (detection of vaginal plug: day 0) and newborn mice were used. Human tooth germ was kindly provided by Dr. Yamamoto of Ohu University. Rat monoclonal antibodies recognizing type IV collagen alpha chains were raised against synthetic peptides of non-consensus amino acid sequences of the human and mice alpha (IV) chains. These monoclonal antibodies were kindly provided by Shigei medical research institute. Both mice and human tooth germ, we detected conversions in localization and composition of type IV collagen alpha chains working with tooth germ development. These results imply that there are time and site specificity, which may be involved in tooth morphogenesis and the tooth germ development, in type IV collagen alpha chains. © 2005, THE SOCIETY FOR HARD TISSUE REGENERATIVE BIOLOGY. All rights reserved.

DOI： 10.2485/jhtb.14.124

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We examined the expression of HSP70 in acute lung injury induced by lipopolysaccharide (LPS), in order to explore the mechanism of HSP70 in acute lung injury. Using an acute lung injury model in Wistar rats, we observed the in vivo HSP70 expression by immunohistochemistry and Western blot. After exposure to LPS, the level of HSP70 increased above the control level at 1 hour, reached the maximum level at 2 hours, and returned to the control level by 6 hours. Our study suggested that the expression of HSP70 is involved in the protection of acute lung injury induced by LPS.

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DOI： 10.2485/jhtb.14.235

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Angiogenesis is an essential process in the progression of malignant tumors. However, little is known of the angioarchitecture in primary oral malignant melanoma. We sought to determine this by the use of periodic acid-Schiff (PAS) stain, endothelial markers (CD34, CD105) and laminin, and by transmission electron microscopy in two cases. The results demonstrated that endothelium-lined vessels dominated the tumor microvasculature and these stained positively for PAS, laminin, and endothelial markers. Mosaic and tumor-lined vessels were infrequently encountered. Most PAS-positive patterned networks and loops ultrastructurally represented intratumor microhemorrhages that probably arose secondary to tumor vessel leakiness. Vascular channels of the vasculogenic mimicry type were rare. They stained for laminin but not for endothelial markers.

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Type IV collagen, the major component of basement membrane (BM), demonstrates a stage- and position-specific distribution of its isoforms during tooth development. To determine its localization in BM of odontogenic neoplasms, immunohistochemistry using six anti-alpha(IV) chain-specific monoclonal antibodies was performed. Results disclosed that BM demonstrated an irregular alpha(IV) chain profile in malignant odontogenic tumors as compared to benign odontogenic neoplasms. No alpha3(IV) chains were detected. Expression of alpha1(IV)/alpha2(IV) and alpha5(IV)/alpha6(IV) chains was stronger in desmoplastic ( n=3) than in ordinary (n=5) ameloblastomas. The adenomatoid odontogenic tumor ( n=2) distinctly expressed these chains in BM of cribriform areas and hyaline materials (which was also alpha4(IV)-positive), but weakly around epithelial whorls/rosettes/nests and mineralized foci. These five chains also stained BM and tumor cells of ameloblastic fibroma ( n=3) and ameloblastic fibro-odontosarcoma (n=1), but not the inductive hard tissues. Ameloblastic carcinoma ( n=2) showed specific alpha1(IV)/alpha2(IV) chain loss, while primary intraosseous carcinoma ( n=1) demonstrated a discontinuous alpha1(IV)/alpha2(IV) and alpha5(IV)/alpha6(IV) staining pattern. The present results suggest that modification and remodeling of BM collagen IValpha chains occur during odontogenic neoplasms' progression.

DOI： 10.1007/s00428-002-0658-1

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Abnormal amplification of epidermal growth factor receptor (EGFR) gene has been reported widely in various human tumors. However, the status of amplification of this gene in the process of carcinogenesis is not clearly defined. We used competitive polymerase chain reaction (PCR) to study whether EGFR gene is amplified and the degree of amplification in pre-malignant and malignant oral epithelial lesions, and also examined the relationship between EGFR gene aberration and the development of squamous cell carcinoma (SCC). Genomic DNA was extracted from paraffin sections of 17 cases of oral epithelial dysplasia (ED), four cases of carcinoma in situ (CIS), and 20 cases of untreated primary SCC. The extracted DNA was subjected to competitive PCR to amplify EGFR gene. Amplification of the EGFR gene was observed in three cases (17%) of ED, one case of CIS and four cases (20%) of SCC. In cases showing EGFR gene amplification, the degree of amplification was low in ED and CIS cases, whereas it was extremely high in SCC cases. These results suggest that amplification of EGFR gene occurs in the relatively early stage of the development of oral SCC. However, a high level of EGFR gene accumulation probably plays an important role in the progression to invasive cancer. © 2001 Elsevier Science Ltd. All rights reserved.

DOI： 10.1016/S1368-8375(01)00051-3

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Language：English   Publisher：Japanese Society for Oral Pathology  

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A mixture of heparin-Sepharose-purified bovine bone morphogenetic protein (BMP) and type I atellocollagen was implanted in the subcutaneous tissues of 4-week, 10-month and 18-month-old rats. The implants were removed at 7, 14 and 21 days after implantation. The effects of rat age on ectopic bone formation were evaluated on the explants using H and E staining, morphometric analysis, alkaline phosphatase (ALP) activity and calcium (Ca) content determination, as well as immunohistochemical staining of type IV collagen present in the basement membrane of blood vessels. On day 14 and 21, bone was observed in 4-week and 10-month-old rats but the amount of bone formed in the later was less than in the former. In 18-month-old rats, bone was first found focally in very limited regions of the explants on day 21 and the amount of bone was much less than in 4-week-old rats. At all periods ALP activity was higher in younger rats. On day 7, there were more blood vessels in the explants of 4-week-old rats than in those of 10- or 18-month-old rats. On day 14 and 21, more blood vessels were found in the central regions of the explants in 4-week-old rats than in the same regions in 10- or 18-month-old rats. The findings in the present study indicated that the rate and quantity of ectopic bone formation were reduced, and that the difference in blood vessel distribution might be related to the reduction in ectopic bone formation in aged rats, and suggest that the difference in blood vessel distribution is related to ectopic bone formation. Magnetism can stimulate ectopic bone formation induced by BMP. Copyright (C) 2000 Elsevier Science Ireland Ltd.

DOI： 10.1016/S0928-4680(00)00036-5

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First lower molar dental papillae, isolated from day-17 mouse embryos, were embedded in 10 E l of BGJ-b medium including fetal calf serum and 0.5% agar. Two E1 of BMP solution at the different dose of BMP were added to the medium before getting. The papillae embedded in the semi-solidmedium were deposited on Millipore filters, and cultured for 6 days. This BMP fraction promoted functional differentiatioun of odontoblast-like cells and stimtulated the matrix secretion, dependent on the concentration of BMP.

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Gene expressions of bone and cartilage matrix protein during the ectopic hard tissue formation induced by BMP were investigated using in situ hybridization method. The gene expressions of type I and II as well as type X and osteocalcin, which is not able to be seen in normal chondral ossification, were observed in chondrocyte-like cells. The results indicate that chondrocyte-like cells in ectopic bone formation may have both characters of chondrocytes and osteoblasts.

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The distribtution of amelogenin mRNA was investigated in ameloblastoma and adenomatoid odontogeznic tumor (AOT). Digoxygenin(DIG) labeled RNA probe was prepared from human plexiform type amelobastoma. Sections of rat incisors human ameloblastoma and ACT were hybridized with the above-mentioned probe, and immuno-detection of the hybridized probe was performed with the DIG Ntucleic Acid Detection Kit. In the rat incisor, amelogenin mRNA was detected in the preameloblast and ameloblast. Amelogeuuin mRNA was detected mainly in the high columutar cells of the amelobastoma. Amelogenin mRNA was also detected in many duct-like and solid strtuctture tumor cells of AOT.

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The composite of recombinant bone morphogenetic protein 2 (rhBMP-2) and type I atelocollagen fibers was implanted under the calvarial periosteum of wistar rats of 8 months old. Each composite was removed at 2, 4, 6, and 8 weeks after implantation, and evaluated histologically as an onlay bone graft substitute in a calvarial model. The results demonstrated that the composite of BMP and collagen was an effective material with osteoindtnctivity as an onlay bone graft substitute even in matured rats.

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The histological differential diagnosis between cemento-ossifying fibroma and ossifying fibroma is still controversial since distingushing bone from cementum and non-specific calcification tissue by routine methods shows little reliabi11ty. Here we studied one case of each lesion by CPC treatment, immunohistochemical detection of collagen type I and III, and electron microscopy. We round that the distinction among bone, cementum and non-specific calcirication tissues might be greatly improved by these means, leading, therefore,to a more accurate differential diagnosis between cemento-ossirying and ossifying fibroma. The tissue origin in both cases is also discussed.

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