Heat Shock Protein Overexpression-Mediated Periodontal Ligament Regeneration: A Fundamental Approach to Generate a Potential Biomaterial.

The periodontal ligament (PDL) is a cell-rich fibrous connective tissue supporting the tooth roots. The tissue helps to maintain homeostasis and exhibits regenerative and repairing ability, which is mediated by the heat shock protein (HSP). Here, we experimentally created PDL tissue with notable ability to regenerate hard tissue and evaluated it as a potential biomaterial. We immunohistochemically examined the mechanical load-induced HSP overexpression in mouse PDL. Following mechanical load application and release, HSP70 localization in the PDL was altered immediately, suggesting that the HSP70 function may differ with the timing of its expression in PDL. HSP70 expressed in the cytoplasm and nucleus of fibroblasts in PDL on the tension side not only participated in periodontium repair, but also functioned as a molecular chaperone during protein expression involved in osteogenesis to restructure injured tissue. This study highlights the potential of artificially created highly functional PDL tissues as biomaterials.

Notch Signaling Affects Oral Neoplasm Cell Differentiation and Acquisition of Tumor-Specific Characteristics.

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.

The Role of Bone Marrow-Derived Cells during Ectopic Bone Formation of Mouse Femoral Muscle in GFP Mouse Bone Marrow Transplantation Model.

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.

Migration and Differentiation of GFP-transplanted Bone Marrow-derived Cells into Experimentally Induced Periodontal Polyp in Mice.

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.

Functional Role of HSP47 in the Periodontal Ligament Subjected to Occlusal Overload in Mice.

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.

Pathological Analysis of Cell Differentiation in Cholesterol Granulomas Experimentally Induced in Mice.

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.

Notch as a Possible Cell Differentiation Factor in Pleomorphic Adenomas.

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.

Histological Evaluation of Periodontal Ligament in Response to Orthodontic Mechanical Stress in Mice.

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.

Cytological Kinetics of Periodontal Ligament in an Experimental Occlusal Trauma Model.

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.

Role of extracytoplasmic function sigma factors in biofilm formation of Porphyromonas gingivalis.

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.

Wnt signaling as a possible promoting factor of cell differentiation in pleomorphic adenomas.

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 ß-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 ß-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, ß-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 ß-catenin. Therefore, Wnt signaling through ß-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.

Heat shock protein27 expression and cell differentiation in ameloblastomas.

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.

Promotion of transplanted bone marrow-derived cell migration into the periodontal tissues due to orthodontic mechanical stress.

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.

Differential expression of canonical and non-canonical Wnt ligands in ameloblastoma.

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.

Immunohistochemical expression of heat shock protein27 in the mouse dental pulp after immediate teeth separation.

AIM: After immediate teeth separation, expression of HSP27 in the mouse dental pulp was examined. Immunohistochemistry was performed to examine the incidence of HSP27 expression. MATERIALS AND METHODS: A total of 36 8-week-old ddY mice were used as experimental subjects and a wedge was inserted in between maxillary right molars. The wedge was removed 30 min or 3 h after insertion. Animals were immediately sacrificed after the removal of wedge or until 1 week later and serial sections from paraffin-embedded tissues were prepared. Immunohistochemistry was carried out to examine the expression of HSP27. The untreated side served as the control. RESULTS: In the control group, the endothelial cells and some pulp fibroblasts weakly expressed HSP27 suggesting that the expression is due to mechanical stress brought about by physiological masticatory force and pressure from the tongue. In both 30 min and 3 h experimental groups, HSP27 expression was highest at 24 h after wedge removal and the expression remained the same or started to decrease thereafter. The expression decreased at the same level as that of the control group 1 week after wedge removal. CONCLUSION: HSP27 may serve as an indicator of stimulus strong enough to show its expression.

Notch signaling and ghost cell fate in the calcifying cystic odontogenic tumor.

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.

Immunohistochemical expression of hard tissue related factors in the mouse dental pulp after immediate teeth separation.

We examined change of Runx2 and ALP expression in mouse tooth pulp which exposed to teeth separation experiment by immunohistochemistry as a model for conservative dentistry treatment. 8-week-old 36 male ddY mice were used and wedge was inserted between upper 1st and 2nd molars. The wedge was removed 30 minutes as well as 3 hours after the insertion and the samples were prepared extending up to 1 week of time period for regular histopathological and immunohistochemical examinations for ALP and Runx2 expression. The opposite sides without wedge insertion were taken as controls. In the control group pulp, weak expressions of Runx2 and ALP in the vessel endothelial cells as well as the pulp cells were revealed, suggesting the appearance of these genes upon mechanical stress induced by mastication and tongue pressure etc. On the other hand in the experiment group, Runx2 expression increased both in 30-minute and 3-hour teeth separation group. The expression became maximum at 24 hours. Then it gradually decreased and became similar level with the control group at 1-week after the wedge insertion. Similarly ALP expression increased after the wedge insertion and was maximum at 24 hours and then gradually decreased to the levels similar with the control group. These results suggest that when immunohistochemical expression of Runx2 as well as ALP was used as an index, no severe damage occur upon clinical application of wedge insertion.

Strawberry gingivitis as the first presenting sign of Wegener's granulomatosis: report of a case.

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.

Comparative examination of subcutaneous tissue reaction to high molecular materials in medical use.

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.

Immunohistochemical localization of Notch signaling molecules in ameloblastomas.

We examined Notch signaling molecules, Notch1 and Jagged1, in serial large cases of typical solid/multicystic ameloblastoma. In general, Notch positive staining products were frequently detected in the cytoplasms of the cells. In the same cells, Jagged positive staining were also frequently observed, while only occasionally positive in peripheral cells, especially in cuboidal cells. The results showed that these morphogenesis regulation factors are closely related to cytological differentiation in neoplastic cells of ameloblastoma. The Notch and Jagged positive-cell ratios were frequently positive, and the ratios were nearly the same between the varied histopathological, cytological patterns. However, the less-differentiated cells were fewer in number than that of well-differentiated cells.