Kokubyo Gakkai zasshi. The Journal of the Stomatological Society, Japan最新文献

It has been reported that hyaluronan tetrasaccharide (HA4) has an ability to accelerate the healing process of spinal cord injuries and to mitigate the symptoms of experimental autoimmune encephalitis (EAE) in animal models. However, the precise mechanisms of the effect of HA4 are unclear. This study examined the in vitro effects of HA4 on the differentiation of PC12 cells and neuronal progenitor cells from mouse embryo. The effect of HA4 on the proliferation and differentiation of rat oligodendrocyte precursor cells was examined. HA4 upregulated neurite-outgrowth of cultured PC12 cells in the presence of Nerve Growth Factor (NGF), which induces neuronal differentiation in PC12. HA4 also upregulated beta III-tubulin positive cells and increased the expression of neurofilament M, two of the marker proteins of nerve differentiation. The activation was observed in an HA4 dose-dependent manner, and the effect was observed at levels as low as femtogram/L. Furthermore, the enhancement of neurite-outgrowth was not observed in the presence of hyaluronan disaccharide, hexasaccharide, 12 mer or high molecular weight hyaluronan. Upregulation of neurite-outgrowth was observed only in the presence of NGF. While HA4 accelerated neurite-outgrowth of primary mouse neural progenitor cells, it did not enhance the proliferation or differentiation of oligodendrocyte precursor cells derived from rat primary neuronal progenitor cells in culture. These results suggest that the effects of HA4 alleviating some neuronal diseases may be ascribable, at least in part, to its capacity to enhance differentiation of neurons.

Unlabelled: The Fas-associated death domain containing protein, FADD, is an adaptor for relaying apoptotic signals. However, recent studies have shown that FADD also plays an important role in the growth and regulation of the cell cycle, and FADD gene amplifications were observed in oral squamous cell carcinoma (OSCC). The purpose of this study was to elucidate the role of FADD in oral leukoplakia, known as potentially malignant disorder.

Methods: The gene amplifications of FADD from the fresh-frozen tissues and the formalin-fixed paraffin-embedded tissues of 51 patients who underwent biopsy or surgical resection of oral leukoplakia were detected: singleplex and multiplex assays were employed.

Results: The gene amplifications of FADD were detected in the samples of 3 patients who were diagnosed pathologically with severe epithelial dysplasia or early invasive carcinoma.

Conclusion: Because the gene amplifications of FADD were observed in early invasive carcinoma rather than precancerous lesions, the FADD gene amplification was not useful for the predictive marker of cancerization and is possibly related to the malignancy of OSCC including metastatic potential.

A functional endocannabinoid system is present in several mammalian organs and tissues. The endogenous cannabinoid anandamide (AEA) is a bioactive lipid neurotransmitter that is present in a variety of tissues and has multiple functions. Recently, this cannabinoid system was reported to play important roles in osteoblastic and osteoclastic cells. Human periodontal ligament (hPDL) cells modulate alveolar bone remodeling by producing cytokines when stimulated by many factors. The aim of this study was to investigate the AEA level in periodontal regions and the osteogenic effect of AEA on hPDL cells. The levels of AEA in the gingival crevicular fluid (GCF) of periodontitis patients were measured using liquid chromatography/mass spectrometry (LC/MS). Expressions of cannabinoid receptor mRNA were detected by RT-PCR in hPDL cells and expression of the transient receptor potential cation channel subfamily V member 1 (TRPV1) was observed by confocal laser scanning microscope (CLSM). IL-11 production from hPDL cells was measured using an ELISA, with or without AEA in the presence or absence of capsazepine, a selective TRPV1 antagonist AEA secreted into GCF was detected, but there was no correlation between the probing pocket depth (PPD) and AEA level. TRPV1 mRNA was detected in hPDL cells and the TRPV1 expression was observed by CLSM. IL-11 production from hPDL cells was significantly enhanced by AEA stimulation and this IL-11 production was suppressed by capsazepine. Our findings indicate that this endogenous cannabinoid system has a possible role in bone metabolism in periodontitis through TRPV1.

Calcifying cystic odontogenic tumors are benign tumors, characterized by the presence of ghost cells and calcified materials. We evaluated clinical characteristics of calcifying cystic odontogenic tumors in 21 cases at the Maxillofacial Surgery, Tokyo Medical and Dental University Hospital, between January 1979 and December 2006. Of the 21 lesions that were studied, 12 were observed in male patients, and 9 in female patients. The median age was 13.0 years (range, 4-69 years). Of the 21 lesions, 11 were located in the maxilla (intraosseous), 9 in the mandible (intraosseous), and 1 in the lower gingiva (extraosseous). Radiographically, 18 lesions appeared as unilocular radiolucencies, and 2 lesions as multilocular radiolucencies. Impacted teeth were observed in 15 cases. In 20 cases, the lesions were treated by enucleation. The follow-up duration ranged from 2 years, 5 months to 28 years, 8 months, and in 1 case, the lesion recurred and showed a malignant transformation 2 years 10 months after the treatment. Histopathologically, the lining epithelium consisted of cuboidal or columnar odontogenic cells. Ghost cells were frequently calcified, and the tissue was hardened. In 14 cases, the tumor was associated with odontoma.

Cranial neural crest cells migrate to the craniofacial primordia and differentiate into skeletal tissues of the jaw such as Meckel's cartilage. It has not been clearly demonstrated how neural crest cells are committed to differentiate into these tissues. In this study, the conditions that are required for the formation of Meckel's cartilage were investigated. In situ hybridization in chick embryos indicated that Fgf8 and Shh involved in the pattern formation of limb cartilages were expressed in the neural tube of the midbrain-hindbrain border, the buccopharyngeal membrane and the oro-proximal site of the 1st branchial arch (oro-proximal BA1). Cell-tracing with DiI confirmed that the neural crest cells derived from both the posterior midbrain and rhombomere 1 migrated to the buccopharyngeal membrane, which subsequently forms oro-proximal BA1, by passing through the mesenchyme lateral to the midbrain-hindbrain boundary. Based on the above results, we carried out two types of ectopic transplantation experiments by chick-quail chimera The graft of oro-proximal BA1, the complex of epithelium and mesenchyme, formed a Meckel's cartilage-like structure in a self-differentiation manner, whereas neither epithelium only nor mesenchyme formed any elongated cartilage. The ectopic transplant of the buccopharyngeal membrane into the mesenchyme lateral to the neural tube of the mid-hindbrain border in which neural crest cells were migrating formed a Meckel's cartilage-like structure. These results suggest that the cranial neural crest cells derived from the mid-hindbrain region are committed to the cell fate during migration, and receive further signaling to differentiate into Meckel's cartilage in their destination.

For a better understanding of the structures comprising the human body and in view of the possible need for future revision of anatomical nomenclature, Latin anatomical names of skeletal fossa in Terminologia Anatomica were analyzed and classified, and compared with the corresponding Japanese anatomical names. The words following Fossa indicated: 1) the form of the fossa, 2) the structure to which the fossa belongs, 3) the position of the fossa, 4) the structure that exists near the fossa, 5) the structure that the fossa contains, 6) the structure attached to the fossa, 7) the structure that transmits the fossa, or 8) the structure with which the fossa articulates. The analysis of Latin names and comparison with Japanese names clarified some characteristics of both names and revealed some problems in them.

This study examined the association between masticatory movement and occlusal curvature in dentate adults. Forty-six subjects (mean age : 25.0 years) with complete permanent dentition except for their third molars participated in this study. A mandibular cast mounted on the lower member of an articulator was fixed to a three-dimensional measuring gauge (QM-Measure 353). Approximate spheres were calculated from the measurements according to the Broadrick Occlusal Plane Analyser. Subjects were asked to chew raw carrot, cheese, fish paste, boiled beef and gummy candy prepared to the size of 10 x 10 x 20 mm. Three-dimensional chewing movements of the mandibular central incisor point were measured using a Gnatho-analyzer. The Pearson correlation coefficient and multiple regression analysis were used to test the relationship between the occlusal curvature and masticatory movement. Significant correlations were found between masticatory movement and occlusal curvature in dentate adults (p < 0.01). Regression analysis found that subjects with larger occlusal curvature showed greater maximum velocity, larger vertical range and shorter cycle duration (p < 0.05). These results suggest that occlusal curvature is associated with masticatory movements.

Light-based oral cancer screening aids have been developed in identifying potentially malignant and malignant lesions of oral cavity at their earliest stage. The VELscope system is a simple hand-held device that facilitates the direct visualization of oral-cavity fluorescence for the detection of precancerous and cancerous lesions. Some published reports have shown that this system can assist in the detection of precancerous and cancerous lesions, but there is no evidence that it can distinguish between them. We studied whether objective discrimination criteria can be set for this system when observing oral mucosal lesions. We examined 74 cases with biopsy-confirmed oral mucosal lesions; 37 squamous cell carcinoma lesions, 14 moderate to severe epithelial dysplasia lesions, 13 mild epithelial dysplasia lesions and 10 lichen planus lesions. Lesions were examined macroscopically under the conventional overhead light, and then, examined by this device. Each examination was recorded with a digital camera. We contrasted findings with histopathological manifestation, and calculated the attenuation score. It is found that several conditions and sites, such as keratinization and the degree of inflammatory cell infiltration, were associated with detection sensitivity using this device. Based on the attenuation scores, a significant difference was seen between squamous cell carcinoma and epithelial dysplasia. It is suggested that this device might be a valuable adjunct in the early detection of potentially malignant and malignant lesions of the oral cavity.