Faculty Profiles - NAGATSUKA Hitoshi

Papers - NAGATSUKA Hitoshi

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Immunolocalization of notch signaling protein molecules in a maxillary chondrosarcoma and its recurrent tumor

C. H. Siar, K. O. Ha, L. O. Aung, K. Nakano, H. Tsujigiwa, H. Nagatsuka, K. H. Ng, Toshiyuki Kawakami

European Journal of Medical Research 15 ( 10 ) 456 - 460 2010.10

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

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

Usefulness of MRI and dynamic contrast-enhanced MRI for differential diagnosis of simple bone cysts from true cysts in the jaw International journal

Yoshinobu Yanagi, Jun Ichi Asaumi, Teruhisa Unetsubo, Masakazu Ashida, Toshihiko Takenobu, Miki Hisatomi, Hidenobu Matsuzaki, Hironobu Konouchi, Naoki Katase, Hitoshi Nagatsuka

Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology and Endodontology 110 ( 3 ) 364 - 369 2010.9

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

Introduction. It can be difficult to differentiate simple bone cysts (SBCs) from true cysts in the jaw when these lesions appear unilocular. The present study reports the MR imaging of subjects with SBCs and describes the diagnostic value of the MRI findings. Materials and methods. Ten subjects with SBCs in the jaw were examined using MRI. T1- and T2-weighted images (T1W1, T2WI) were obtained, and contrast-enhanced images and dynamic contrast-enhanced MRI (DCE-MRI) were acquired. Results. In all cases, the contrast-enhanced TIWI acquired approximately 6 minutes after the administration of GdDTPA showed marked enhancement of the margin and slight enhancement of the inner part of the cyst cavity. In all cases, the time-signal intensity (SI) curves show a gradual increase in the SI until approximately 15 minutes after the administration of Gd-DTPA. These findings might not be observed on the DCE-MRIs of the other true cysts with epithelial lining that show no enhancement in a cavity. MRI, especially DCE-MRI, can provide useful information for distinguishing SBCs from other cysts. © 2010 Published by Mosby, Inc.

DOI： 10.1016/j.tripleo.2010.05.001

Immunohistochemical analysis of Dkk-3 expression in head and neck squamous cell carcinoma

Fujii M, Katase N, Lefeuvre M, Tsujigiwa H, Kubota M, Sathi GSA, Matsuda H, Nagatsuka H

Journal of Hard Tissue Biology 19 ( 3 ) 208 2010.9

口腔扁平上皮癌における1p36領域のLOH解析(LOH analysis of 1p36 region in oral squamous cell carcinoma)

Lefeuvre Mathieu, 片瀬直樹, 玉村亮, 辻極秀次, 長塚仁

Journal of Oral Biosciences 52 ( Suppl ) 141 - 141 2010.9

Immunohistochemical Expression of Notch Signaling in Calcifying Cystic Odontogenic Tumor Reviewed

Kawakami T, Siar C. H, Nakano K, Tomida M, Matsuura S, Tsujigiwa H, Nagatsuka H

ORAL DISEASES 16 ( 6 ) 517 - 518 2010.9

Differential expression of Notch receptors and their ligands in desmoplastic ameloblastoma International journal

Chong Huat Siar, Keisuke Nakano, Phuu Pwint Han, Hitoshi Nagatsuka, Kok Han Ng, Toshiyuki Kawakami

Journal of Oral Pathology and Medicine 39 ( 7 ) 552 - 558 2010.8

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. © 2010 John Wiley & Sons A/S All rights reserved.

DOI： 10.1111/j.1600-0714.2009.00871.x

Preferential up-regulation of heparanase and cyclooxygenase-2 in carcinogenesis of Barrett's oesophagus and intestinal-type gastric carcinoma International journal

Ryotaro Sonoda, Yoshio Naomoto, Yasuhiro Shirakawa, Yasuhiro Fujiwara, Tomoki Yamatsuji, Kazuhiro Noma, Shunsuke Tanabe, Munenori Takaoka, Mehmet Gunduz, Hidetsugu Tsujigiwa, Hitoshi Nagatsuka, Nobuya Ohara, Tadashi Yoshino, Kaiyo Takubo, Michael Vieth, Noriaki Tanaka

Histopathology 57 ( 1 ) 90 - 100 2010.7

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

Aims: Metaplastic changes secondary to chronic inflammation at the gastro-oesophageal junction and at the pyloric antrum are recognized as the premalignant conditions of Barrett's oesophageal adenocarcinoma and intestinal-type gastric carcinoma (GC), respectively. Heparanase (HPSE) and cyclooxygenase (COX)-2 have been proved to play critical roles in inflammation as well as in cancer. The aim was to examine the meaning of their expression in inflammation-related carcinogenesis. Methods and results: First, expression of HPSE and COX-2 in 78 clinical tissues of Barrett's oesophagus was examined by immunohistochemistry and in situ hybridization. Their expression was increased during the metaplasia-dysplasia sequence with increased neovascularization. Successively, their expression in Barrett's dysplasia was compared with that of GC (22 cases of diffuse-type and 10 of intestinal-type). Interestingly, the expression pattern in Barrett's dysplasia was similar to that in intestinal-type GC, which mainly arises from chronic inflammation. Furthermore, cultured cell lines isolated from differentiated GC tissues, which are often found to be of intestinal-type, revealed up-regulated mRNA expression of HPSE and COX-2. Conclusions: HPSE and COX-2 are preferentially up-regulated in Barrett's oesophagus and intestinal-type GC. These molecules may play an important role during the development of inflammation-related adenocarcinoma of the upper gastrointestinal tract. © 2010 Blackwell Publishing Limited.

DOI： 10.1111/j.1365-2559.2010.03594.x

Expression and mutation analysis of her2 in head and neck squamous cell carcinoma International journal

Mahmoud Al Sheikh Ali, Mehmet Gunduz, Esra Gunduz, Ryo Tamamura, Levent Bekir Beder, Naoki Katase, Omer Faruk Hatipoglu, Kunihiro Fukushima, Noboru Yamanaka, Kenji Shimizu, Hitoshi Nagatsuka

Cancer Investigation 28 ( 5 ) 495 - 500 2010.5

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

We analyzed mutation and expression status of human epidermal growth factor receptor 2 (Her2) in head and neck squamous cell carcinoma (HNSCC) using single strand conformation polymorphism (SSCP) mutation analysis and immunohistochemistry (IHC). Mutations were absent in all 85 cases. Out of 57 cases available for IHC, Her2 protein expression was negative (0) in 40 tumors (70). Seventeen tumors (29.8) expressed Her2, among these 13 tumors (22.8%) showed a weak (+1) expression and 4 (7%) showed a moderate expression (+2), none showed a strong (+3) expression. There was not a significant association between expression and any of the patients' clinical variables or prognosis. Our results suggest that Her2 may not be useful as a molecular target in HNSCC. Copyright © 2010 Informa Healthcare USA, Inc.

DOI： 10.3109/07357900903476778

Effect of CaTiO<inf>3</inf>-CaCO<inf>3</inf> prepared by alkoxide method on cell response International journal

Andrea P. Rodriguez, Miho Inoue, Toshiyuki Tanaka, Michihiro Miyake, Ana M. Sfer, Etsuo Kishimoto, Hidetsugu Tsujigiwa, Rosario S. Rivera, Hitoshi Nagatsuka

Journal of Biomedical Materials Research - Part A 93 ( 1 ) 297 - 303 2010.4

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

In recent years, calcium titanate (CaTiO3) and carbon-containing materials have gained much attention in a number of biomedical material researches. To maximize the advantages of both materials, we developed a novel alkoxide method to get "calcium titanate with calcium carbonate" (CaTiO3-CaCO3). The objective was to evaluate the crystallinity and elemental composition of CaTiO3-CaCO3 prepared by alkoxide method, CaTiO3-aC elaborated by modified thermal decomposition method, commercially-prepared CaTiO3, and the effect of these materials on the bone marrow stromal cell. Hydroxyapatite was used as positive control material. We examined the cellular proliferation, osteoblastic differentiation, and mineralization of KUSA/A1 cells cultured with the materials. The results showed that CaTiO3-CaCO3 and CaTiO3-aC contained evidence of calcium carbonate enhancing cell proliferation, osteoblastic differentiation, and mineralization. On the contrary, the commercially-prepared CaTiO3 revealed absence of calcium carbonate with lower cell response than the other groups. The results indicated that calcium carbonate could play a key role in the cell response of CaTiO3 material. In conclusion, our findings suggest that CaTiO 3-CaCO3 could be considered an important candidate as a biomaterial for medical and dental applications. © 2009 Wiley Periodicals, Inc.

DOI： 10.1002/jbm.a.32551

Squamous odontogenic tumor of the mandible: A case report demonstrating immunoexpression of Notch1, 3, 4, Jagged1 and Delta1

C. H. Siar, Keisuke Nakano, K. H. Ng, M. Tomida, H. Nagatsuka, T. Kawakami

European Journal of Medical Research 15 ( 4 ) 180 - 184 2010.4

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. Histopathological 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. © I. Holzapfel Pubishers 2010.

DOI： 10.1186/2047-783x-15-4-180

An unsuspected ameloblastoma in the subpontic region of the mandible with consideration of pathogenesis from the radiographic course

C. H. Siar, Keisuke Nakano, P. I. Chelvanayagam, K. H. Ng, H. Nagatsuka, T. Kawakami

European Journal of Medical Research 15 ( 3 ) 135 - 138 2010.3

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

The purpose of this report is to document a case of unsuspected ameloblastoma involving the right mandibular subpontic region in a 38-year-old Cambodian female patient. This lesion was purportedly preceded by multiple radiolucencies which were diagnosed as radicular cysts and treated a few times in the past years by enucleation followed by endodontic therapy of the affected teeth. Bridgework restoration of the partially edentulous area was performed. This case report demonstrates radiographic changes that occurred in the periods before and after the diagnosis of ameloblastoma. The case may represent an example of radicular cysts and ameloblastoma occurring as a collision phenomenon, or the ameloblastoma may have arisen as a result of neoplastic transformation of the lining epithelium in an inflammatory odontogenic epithelial cyst. © I. Holzapfel Publishers 2010.

DOI： 10.1186/2047-783x-15-3-135

Effect of a new titanium coating material (CaTiO<inf>3</inf>-aC) prepared by thermal decomposition method on osteoblastic cell response International journal

Miho Inoue, Andrea P. Rodriguez, Tohru Takagi, Naoki Katase, Midori Kubota, Noriyuki Nagai, Hitoshi Nagatsuka, Masahisa Inoue, Noriyuki Nagaoka, Shin Takagi, Kazuomi Suzuki

Journal of Biomaterials Applications 24 ( 7 ) 657 - 672 2010.3

Language：English Publishing type：Research paper (scientific journal) Publisher：SAGE PUBLICATIONS LTD

Titanium and hydroxyapatite (HA) are widely used as biomaterials for dental and medical applications. HA-coated titanium implants have excellent biocompatibility and mechanical properties. However, the adherence of HA film formed on titanium substrate is weak because of the lack of chemical interaction between HA and titanium. A solution to this problem is to form an intermediate film on titanium substrate, which provide excellent adherence to both titanium substrate and HA. We developed a novel biomaterial called calcium titanate-amorphous carbon (CaTiO3-aC) coating prepared by modified thermal decomposition method. The purpose of this study was to evaluate the effect of CaTiO3-aC and HA coating (positive control), and Ti (negative control) on osteoblastic (MT3T3-E1) cell responses. An increased cellular proliferation was observed in CaTiO3-aC coating compared to HA coating. The maximum expressions of ALP activity, Col I and ALP mRNA were higher and achieved in shorter period of time in CaTiO3-aC coating compared to others. These results demonstrated that CaTiO3-aC promoted better cell attachment, cellular proliferation, and osteoblastic differentiation compared with HA. In conclusion, we suggested that CaTiO 3-aC could be considered as an important candidate as a coating material.

DOI： 10.1177/0885328209340334

A case of malignant fibrous histiocytoma of the maxillary sinus International journal

Yoshinobu Yanagi, Jun Murakami, Miki Hisatomi, Naoki Katase, Hitoshi Nagatsuka, Jun ichi Asaumi

Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology and Endodontology 109 ( 3 ) E99 - E104 2010.3

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

Malignant fibrous histiocytoma (MFH) is recognized as one of the most common soft tissue sarcomas arising in late adulthood. Most MFHs arise from the extremities and the retroperitoneum, thus the incidence of head and neck MFH is relatively low. Because of its rare incidence, there are very few reports focusing on the imaging features of MFH arising in the maxillary sinus. A case of MFH of the maxillary sinus in a 67-year-old male patient is reported including imaging and pathological features. © 2010 Mosby, Inc. All rights reserved.

DOI： 10.1016/j.tripleo.2009.11.032

Central Adenoid Cystic Carcinoma of the Mandible With Multiple Bone Metastases: Case Report International journal

Takamitsu Mano, Noriko Wada, Kenichiro Uchida, Yukoh Muraki, Hitoshi Nagatsuka, Yoshiya Ueyama

Journal of Oral and Maxillofacial Surgery 68 ( 2 ) 446 - 451 2010.2

Frequent allelic loss of Dkk-1 locus (10q11.2) is related with low distant metastasis and better prognosis in head and neck squamous cell carcinomas International journal

Naoki Katase, Mehmet Gunduz, Levent Bekir Beder, Esra Gunduz, Mahmoud Al Sheikh Ali, Ryo Tamamura, Kursat Oguz Yaykasli, Noboru Yamanaka, Kenji Shimizu, Hitoshi Nagatsuka

Cancer Investigation 28 ( 1 ) 103 - 110 2010

Language：English Publishing type：Research paper (scientific journal) Publisher：TAYLOR & FRANCIS INC

Head and neck squamous cell carcinoma (HNSCC) is a frequently occurring cancer worldwide. Dickkopf (Dkk)-1 gene is suggested to function as tumor suppressor gene (TSG) in several kinds of malignancies. In this study, we performed loss of heterozygosity (LOH) analysis of Dkk-1 and examined the correlation between LOH status and clinicopathological parameters for the first time. A pretty high LOH ratio (50) was detected. Interestingly, in the cases with Dkk-1 retention group showed less distant metastasis and a tendency of longer disease free survival. These results indicate that Dkk-1 can play a role in HNSCC carcinogenesis and it may also be related to distant metastasis.

DOI： 10.3109/07357900903095680

Notch4 overexpression in ameloblastoma correlates with the solid/multicystic phenotype International journal

Chong Huat Siar, Hitoshi Nagatsuka, Kee Seng Chuah, Rosario Santos Rivera, Keisuke Nakano, Kok Han Ng, Toshiyuki Kawakami

Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology and Endodontology 110 ( 2 ) 224 - 233 2010

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. © 2010 Mosby, Inc.

DOI： 10.1016/j.tripleo.2010.03.009

Allelic loss of the ING gene family loci is a frequent event in ameloblastoma International journal

Silvia S. Borkosky, Mehmet Gunduz, Levent Beder, Hidetsugu Tsujigiwa, Ryo Tamamura, Esra Gunduz, Naoki Katase, Andrea P. Rodriguez, Akira Sasaki, Noriyuki Nagai, Hitoshi Nagatsuka

Oncology Research 18 ( 10 ) 509 - 518 2010

Language：English Publishing type：Research paper (scientific journal) Publisher：COGNIZANT COMMUNICATION CORP

Ameloblastoma is the most frequently encountered odontogenic tumor, characterized by a locally invasive behavior, frequent recurrences, and, although rare, metastatic capacity. Loss or inactivation of tumor suppressor genes (TSGs) allows cells to acquire neoplastic growth. The ING family proteins are tumor suppressors that physically and functionally interact with p53 to perform important roles in apoptosis, DNA repair, cell cycle regulation, and senescence. TP53 genetic alterations were reported to infrequently occur in ameloblastoma. Considering that other TSGs related to TP53 could be altered in this tumor, we focused our study on the ING family genes. We analyzed the loss of heterozygosity (LOH) status of the ING family (ING1-ING5) chromosomal loci in a group of ameloblastomas by microsatellite analysis, and correlated the ING LOH status with clinicopathological characteristics. By using specific microsatellite markers, high frequency of LOH was found at the loci of each ING gene family member (33.3-72.2%). A significant relationship was shown between LOH of D2S140 (ING5 locus) and solid tumor type (p = 0.02). LOH of ING3MS (ING3 locus) was also high in solid type tumors, showing a near significant association. In addition, a notable tendency toward higher LOH for half of the markers was observed in recurrent cases. LOH of ING family genes appears as a common genetic alteration in solid ameloblastoma. The current study provides interesting novel information regarding the potential prognostic significance of the allelic loss of the ING gene family loci in ameloblastoma tumorigenesis. Copyright © 2010 Cognizant Comm. Corp. All rights reserved.

DOI： 10.3727/096504010X12704916124864

Immunohistochemical study of notch signaling proteins in the calcifying epithelial odontogenic tumor (Pindborg tumor)

Chong Huat Siar, Kee Seng Chuah, Keisuke Nakano, Rosario Santos Rivera, Hidetsugu Tsujigiwa, Hitoshi Nagatsuka, Kok Han Ng, Toshiyuki Kawakami

Journal of Hard Tissue Biology 19 ( 3 ) 167 - 174 2010

Language：English Publishing type：Research paper (scientific journal) 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. © 2010 The Hard Tissue Biology Network Association Printed in Japan, All rights reserved.

DOI： 10.2485/jhtb.19.167

Immunohistochemical observation of notch signaling in a case of calcifying cystic odontogenic tumor

Keisuke Nakano, Chong Huat Siar, Mihoko Tomida, Sachiko Matsuura, Hidetsugu Tsujigiwa, Hitoshi Nagatsuka, Toshiyuki Kawakami

Journal of Hard Tissue Biology 19 ( 3 ) 147 - 152 2010

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

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

The effect of calcium hydroxide removal and the influence on the sealing ability of root canals

Ying Li, Mengyu Zhou, Mathieu Lefeuvre, Hitoshi Nagatsuka, Weidong Niu

Journal of Hard Tissue Biology 19 ( 3 ) 161 - 166 2010

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

The aims of this study are to evaluate the effectiveness of calcium hydroxide removal by using different irrigation regimens and the effect of the canal seals influenced by debris in root canal. 200 human premolar teeth were prepared, and divided randomly into two groups. Group A was filled with chemical calcium hydroxide and group B was filled with finished product calcium hydroxide. Each group was divided into 6 subsets and the calcium hydroxide in the root canal was removed in different ways: Group A1 and B1 by injection syringe and distilled water Ggroup A2 and B2 by injection syringe and 2.5% sodium hypochlorite; group A3 and B3 by injection syringe, 2.5% sodium hypochlorite and 17% EDTA; group A4 and B4 by ultrasonic and distilled water; group A5 and B5 by ultrasonic and 2.5% sodium hypochlorite; group A6 and B6 by ultrasonic, 2.5% sodium hypochlorite and 17% EDTA. Then, 8 teeth were randomly selected from each subset group and observed by scanning electron microscope. The other specimens were obturated by lateral condensation of cold gutta-percha, stained by Indian ink and then made into transparent teeth models. The results showed that in the same irrigation regimen, there was no significant difference between group A and group B; the result of groups associated with ultrasonic was better than that with injection syringe, which was of significant difference. The rinse solution of EDTA was the best, while distilled water was the worse. The length of dye staining had no significant difference among all groups. The conclusions are that ultrasonic is better than injection syringe; association of sodium hypochlorite and EDTA is the best rinse solution to remove the calcium hydroxide. However, none of these methods or rinse solutions can remove all the calcium hydroxide. The calcium hydroxide remains exert no remarkable influence on the root canal sealer. © 2010 The Hard Tissue Biology Network Association Printed in Japan, All rights reserved.

DOI： 10.2485/jhtb.19.161

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