Oral Science International
Online ISSN : 1881-4204
Print ISSN : 1348-8643
Volume 2, Issue 2
Displaying 1-8 of 8 articles from this issue
REVIEW ARTICLE
  • Kanemitsu Shirasuna
    2005 Volume 2 Issue 2 Pages 69-79
    Published: 2005
    Released on J-STAGE: July 13, 2007
    JOURNAL FREE ACCESS
    Adenoid cystic carcinoma (AdCC) is one of the most common malignant tumors of the salivary glands and has unique clinical features and behavior. AdCC grows slowly, but spreads relentlessly into adjacent tissues, with a proclivity for invading nerve and endothelial sheaths. Moreover, the frequency of recurrence and distant metastasis of AdCC is very high. In vivo and in vitro, AdCC produces a large amount of extracellular matrix (ECM), including basement membrane (BM) components, elastin, and mucopolysaccharides. The accumulation of ECM components in intercellular spaces results in the formation of a pseudocyst, which is the characteristic architecture of AdCC. AdCC cells degrade considerable amounts of mesenchymal-elaborated ECM through the urokinase-type plasminogen activator (uPA)-plasmin system. By contrast, tumor-produced ECM is resistant to degradation, because it contains plasminogen activator inhibitor type 1 (PAI-1). The migration response of AdCC cell lines to ECM, especially type I and type IV collagens, is much stronger than that of oral squamous cell carcinoma (SCC) cell lines, while both cell types generally show similar patterns of integrin subunit expression. The AdCC cell response to collagens is largely and exclusively inhibited by anti-α2 integrin antibody. Surface uPA receptor (uPAR) expression by AdCC cell lines is greater than that by SCC cell lines and increases in response to collagen stimulation. This is accompanied by the assembly of numerous focal adhesions, consisting of the adapter proteins uPAR, α2 integrin, vinculin, and paxillin. A role for uPAR in cell migration and assembly of adaptor proteins was also demonstrated by transfecting AdCC cells with an antisense uPAR RNA, which strongly reduced both responses. Therefore, the proclivity of AdCC cells to migrate to type I and IV collagens might be due to the overexpression of uPAR, which also plays a key role in focal adhesion assembly. In conclusion, the invasiveness of AdCC cells might be regulated by the interaction of uPA-uPAR with integrin.
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ORIGINAL ARTICLES
  • Kaoru Kusano, Yoshihiro Abiko, Michiko Nishimura, Toshiya Arakawa, Mai ...
    Article type: Others
    Subject area: information
    2005 Volume 2 Issue 2 Pages 80-84
    Published: 2005
    Released on J-STAGE: July 13, 2007
    JOURNAL FREE ACCESS
    Human β-defensin (hBD) 2 is an epithelial antimicrobial peptide. We studied single-nucleotide polymorphisms in the gene of hBD-2 in a Japanese population, and estimated the effect of a polymorphism in the promoter/enhancer region on the transcriptional activity. By sequencing the hBD-2 gene of 50 unrelated individuals, we detected one SNP in exon 2 and nine SNPs in the promoter/enhancer region. The SNP in the coding region at the +1765 position is synonymous [CCC (Pre)→CCT (Pre)]. One SNP in the promoter region (-1029) is located at the consensus sequence for NF-IL6 binding. By luciferase reporter assay and electrophoretic mobility shift assay, the wild-type (G) of -1029 showed significantly lower transcriptional activity than did the variant-type (A). The SNP at position -1029 may influence the hBD-2 expression and cause genetic variations in susceptibility to infectious diseases.
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  • Zhiyong Zhang, Hiroshi Kurita, Hiroichi Kobayashi, Kenji Kurashina
    Article type: Others
    Subject area: information
    2005 Volume 2 Issue 2 Pages 85-95
    Published: 2005
    Released on J-STAGE: July 13, 2007
    JOURNAL FREE ACCESS
    To determine the effect of material factors on Ca-P biomaterial-induced osteogenesis, six kinds of biphasic calcium phosphate (BCP) ceramics with different HA to TCP ratio (HA/TCP 2-8, 7-3) and different porous structure (micro-, macro- and micro/macro- porous structures) were implanted intramuscularly in rabbits. Different tissue response was detected histologically and microradiographically after the ceramic samples were implanted in the dorsal muscles of rabbits for 3 and 6 months. Obvious bone formation was found in two kinds of ceramics with the same micro/macro-porous structure at both 3 and 6 months. In contrast, no bone formation or host tissue invasion was detected in two other kinds of ceramics with only micro-porous structure, even after 6 months implantation. Some bone formation was found occasionally in two kinds of ceramics with only macro-porous structure at 6 months. Bone tissue was usually formed in direct contact with the pore surface and was only located in non-dissolved porous regions. Osteocyte lacunae were seen and no pathological calcifications were observed. These results indicate that micro- and macro-porous structure play an important role in the osteoinduction with Ca-P ceramics. Furthermore, the results showed that the osteoinductive capacity of BCP ceramics was influenced by the different dissolution rate through changing HA/TCP ratio.
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  • Nobuyuki Y. Watanabe, Yoichi Nakagawa, Satonari Akutsu, Akira Yamane
    Article type: Others
    Subject area: information
    2005 Volume 2 Issue 2 Pages 96-103
    Published: 2005
    Released on J-STAGE: July 13, 2007
    JOURNAL FREE ACCESS
    Secretory immunoglobulin A (sIgA) plays an important role in mucosal immunity, and salivary levels change in response to social, psychological and physical stress. However, little is understood about how surgical stress affects salivary sIgA. The results of the present study showed that mouse salivary IgA concentration was significantly elevated immediately after surgery and returned to pre-surgical levels after 24 h. Thus, the surgery did not suppress IgA secretion under our experimental conditions, suggesting that mucosal immunity was not perturbed. Since the role of α-adrenergic receptors involved in IgA secretion has remained unclear under surgical stress, we further examined the effects of either α1-adrenergic (prazosin) or α2-adrenergic antagonist (yohimbine) on the salivary sIgA. Yohimbine, but not prazosin, antagonized the surgically induced salivary IgA enhancement, indicating mediation by α2-receptor stimulation. The mRNA for IgA was not altered in the salivary gland after surgery, suggesting that surgical stress did not stimulate IgA synthesis in the salivary gland cells. In conclusion, it is suggested that the surgical stress does not perturb mucosal immunity in our experimental model, although a transient increase of concentration of salivary IgA was observed immediately after surgical insult.
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  • Yoko Kamiya, Tomoko Ohshima
    Article type: Others
    Subject area: information
    2005 Volume 2 Issue 2 Pages 104-117
    Published: 2005
    Released on J-STAGE: July 13, 2007
    JOURNAL FREE ACCESS
    There is no consensus on the relationship between variations in TP53 mutations and tumor properties in oral squamous cell carcinoma (OSCC). To further the basic research required to eventually develop individualized (order-made) treatments and prognoses for OSCC, we established six human OSCC lines from patients within our department. Together with another nine cell lines derived from donations by other organizations, we determined the TP53 mutation and single nucleotide polymorphism (SNP) of codon 72 in a total of 15 cell lines, and examined in vitro cell invasion activity and anti-cancer drug sensitivity. The missense mutation at codon 248 was most abundant, and was noted in four cell lines, but other diverse mutation variations were also revealed. The cells which expressed the mutated p53 protein (the p53 (+) group) showed slightly higher invasion activity than did the p53 (-) group. In p53 (+) group, the 72R of SNP (72P/R) was higher than the 72P in invasion activity, although the difference was not significant. Surprisingly, an anti-cancer drug sensitivity test with four different types of drugs showed that the p53 (-) group was more resistant in other than CDDP, and that 72R was more sensitive than 72P in the p53 (+) group. To clarify the characteristics of the R248Q mutation, which is the most abundant missense mutation, the gene was introduced with an expression plasmid vector into a TP53 null Saos-2 cell. The transformant of R248Q mutation gained higher activity of invasion, while its anti-cancer drug sensitivity also increased. Our findings suggest that it may be possible to estimate oral cancer cell characteristics and the malignancy level based on differences in the TP53 mutation.
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  • Tadashige Nozaki, Masaharu Takeyasu, Akinori Hirao, Mitsuko Shinohara, ...
    Article type: Others
    Subject area: information
    2005 Volume 2 Issue 2 Pages 118-125
    Published: 2005
    Released on J-STAGE: July 13, 2007
    JOURNAL FREE ACCESS
    The in vitro differentiation potential of rat dental pulp-derived cells into an osteoblastic lineage was examined. Induction was carried out under in vitro osteogenesis-inducing conditions used for mesenchymal stem cells from human bone marrow. We previously reported that the level of mineralization was high at 6 weeks after induction, as determined by von Kossa staining. In the present study, we quantitatively measured the alkaline phosphatase (ALP) activity after induction. The ratios of ALP-positive cells to total cells were 44.4 ± 1.0, 46.9 ± 0.9, 40.5 ± 0.5 and 21.0 ± 1.8% at 1, 2, 3 and 6 weeks after induction, respectively. The level of ALP activity was significantly decreased at 6 weeks after induction (p < 0.05). The stem cell markers STRO-1, SSEA-1, Nanog and Oct-3/4 were expressed in a subset of the cells, suggesting that stem cells were present. To elucidate gene regulation in the osteoblastic lineage of the cells, quantitative gene expression analyses were carried out using real-time RT-PCR. Col1a2 (collagen type I) and Bglap (osteocalcin) were up-regulated by about 1.7-fold and 1.3-fold, respectively, at 6 weeks after induction compared with their corresponding levels at 1 week. These results indicate that the cells differentiated into an osteoblastic lineage in parallel with decreasing ALP activity during induction. Moreover, the expressions of Col1a2 and Bglap were inversely correlated with Alpl (ALP) expression after induction, which was correlated with Bmp2 (bone morphogenetic protein 2) expression. Taken together, the findings indicate that these molecules contribute to the differentiation of rat dental pulp-derived cells into an osteoblastic lineage.
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  • Junichi Ishii, Masashi Yamashiro, Masashi Yamane, Hitoshi Ishikawa, Hi ...
    Article type: Others
    Subject area: information
    2005 Volume 2 Issue 2 Pages 126-130
    Published: 2005
    Released on J-STAGE: July 13, 2007
    JOURNAL FREE ACCESS
    To estimate the prognosis of bilateral cervical metastases from tongue carcinoma, we studied twelve patients (24-72 years old) who underwent neck dissections at our hospital to judge whether we should have performed radical treatment or not for those patients of tongue carcinoma who had bilateral metastatic nodes.
    The five-year survival rate of bilateral neck metastasis patients was 58% (the Kaplan-Meier method). On the other hand, the five-year survival rate of patients with only unilateral neck metastases of squamous cell carcinoma of the tongue was 56%. Thus, there was no statistical significant difference in survival rate.
    We conclude that even if a patient has metastatic lymph nodes on both sides of the neck, radical therapy should be done.
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CASE REPORT
  • Yasumitsu Kodama, Marta Miyazawa, Jun-ichi Fukuda, Akihiko Iida, Kazuh ...
    Article type: Others
    Subject area: information
    2005 Volume 2 Issue 2 Pages 131-135
    Published: 2005
    Released on J-STAGE: July 13, 2007
    JOURNAL FREE ACCESS
    Progressive hemifacial atrophy (PHA) is a self-limited atrophy of subcutaneous tissues (and less frequently of hard tissues) on one side of the face. It is a sporadic, slowly progressing disease whose pathogenesis is still unknown. As a rule the asymmetry caused by PHA (usually of soft tissue) is treated by volume augmentation that involves free tissue grafting or a pedicled flap transfer.
    We describe a rare case of hard tissue PHA. The atrophic changes occurred in the left molar tooth, maxilla and mandible and were associated with moderate soft tissue atrophy. The left side of the patient's mouth was higher on the right side, and the occlusal plane was severely inclined in spite of normal occlusion. After no alteration and no progression of the atrophy were established, the patient was treated with orthodontic surgery. To correct the inclined occlusal plane and asymmetry profile, we performed a Le Fort I and intraoral vertical ramus osteotomy. In the 3-year follow-up, there were good occlusal balance and improved symmetrical profile without relapse or recurrence of the atrophy. Thus, orthodontic surgery was effective as a first procedure to treat hard tissue atrophy that appeared with moderate soft tissue atrophy.
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