Journal of Hard Tissue Biology
Online ISSN : 1880-828X
Print ISSN : 1341-7649
ISSN-L : 1341-7649
21 巻, 3 号
選択された号の論文の17件中1~17を表示しています
Original
  • Go Nakayama, Yukiko Aida, Yusuke Watanabe, Kazuhiro Honda, Shihoko Tan ...
    2012 年 21 巻 3 号 p. 217-230
    発行日: 2012年
    公開日: 2012/08/23
    ジャーナル フリー
    Both mechanical stress and inflammatory cytokines play key roles in amplifying and perpetuating inflammation of the temporomandibular joint (TMJ), although the relationship between these conditions and arthritis at this site is unclear. The present study examined the effects of compressive force and interleukin-1β (IL-1β) on the metabolism of extracellular matrix (ECM) cartilage. Chondrocytes derived from human normal femoral cartilage were treated with or without different magnitudes of compressive force and/or 100 (U) units/mL IL-1β. The expression of chondrocyte-related genes and proteins (type II collagen, type X collagen, aggrecan core, and link protein), matrix metalloproteinases (MMPs), and tissue inhibitor of metalloproteinases (TIMPs) were estimated at the mRNA level using real-time polymerase chain reaction (PCR) and at the protein level using enzyme-linked immunosorbent assay (ELISA). The gene and protein expression levels of MMPs and ECM proteins were significantly higher in compressive force-treated cells than in control cells. MMP gene expression in compressive force- plus IL-1β-treated cells was markedly higher than that in compressive force-treated cells. By contrast, gene expression of ECM proteins in compressive force- plus IL-1β-treated cells was significantly lower than that in compressive force treated-cells. These results suggest that compressive force stimulates metabolism of ECM proteins and enhances protein degradation in the presence of IL-1β.
  • Akemi Kimura, Takayuki Kawato, Tomoko Katono-Tani, Kumiko Nakai, Sakur ...
    2012 年 21 巻 3 号 p. 231-236
    発行日: 2012年
    公開日: 2012/08/23
    ジャーナル フリー
    Hydrogen sulfide (H2S), which is the main component of the volatile sulfur compounds (VSCs) produced by putrefactive bacteria, plays a role in not only oral malodor, but also the initiation and progress of periodontitis. The loss of alveolar bone associated with periodontitis appears to be related to local factors that change the balance between bone formation and resorption. Previous studies have indicated that VSCs, including H2S, induce bone resorption by stimulating the differentiation and activation of osteoclasts; however, there is little information about the effect of VSCs on bone formation by osteoblasts. Therefore, we examined the effect of H2S on cell proliferation, alkaline phosphatase (ALPase) activity, non-collagenous extracellular matrix protein (ECMP) expression, and mineralized nodule formation using ROS17/2.8 cells as osteoblasts. Cells were cultured with 0 (control), 10-4, 10-3, or 10-2 M sodium hydrogen sulfide (NaHS; H2S donor). Mineralized nodule formation was detected by alizarin red staining. The expression of non-collagenous ECMP, including bone sialoprotein (BSP) and osteopontin (OPN), was examined at the mRNA and protein levels using real-time PCR and Western blotting, respectively. Cell proliferation was suppressed by the addition of 10-2 M NaHS, but was unaffected by 10-3 and 10-4 M NaHS. ALPase activity and the expression of BSP and OPN at the mRNA and protein levels were decreased when cells were cultured with 10-4 and/or 10-3 M NaHS. In addition, mineralized nodule formation was strongly inhibited by 10-4 and 10-3 M NaHS. These results suggest that H2S suppresses mineralized nodule formation by decreasing ALPase activity and the production of BSP and OPN by osteoblasts.
  • Kayo Kuyama, Satoshi Iwai, Naomi Ogura, Takashi Eda, Toshirou Kondoh, ...
    2012 年 21 巻 3 号 p. 237-244
    発行日: 2012年
    公開日: 2012/08/23
    ジャーナル フリー
    The purpose of this study was to examine the histopathological and immunohistochemical characteristics of the dental follicle (DF) attached to impacted tooth. A total of 38 cases of DF diagnosed histopathologically between 2000 and 2011 at the Department of Oral Pathology, Nihon University School of Dentistry, Matsudo City, Japan were used in the study. Among the 38 cases, 10 cases which did not undergo decalcification were selected for immunohistochemistry. Histologically, the DF was composed of inner and outer layers. In the inner layer, myxoid tissue, dilated capillaries and peripheral nerve were observed in 100%, 83.3% and 26.3% of the cases respectively. Vessel density in the inner layer is 11 times more than in the outer layer. Capillary dilatation in the inner layer was observed in 83.3% with 107.8 ±124.0μm2 but was not observed in the outer layer with 3.4±2.4 μm2 in average, either. Lymph vessel density in the inner layer is more frequent than in the outer layer. Odontogenic epithelial islands and calcification were more prominent in the inner layer (55.3%, 31.6%) compared to those in the outer layer (2.9%, 2.6%). The mesenchymal cells in the inner layer were positive to Vimentin and α-SMA but only weakly positive to FGF-2 and VEGF. Cells positive to CD68 were scattered and cells focally positive to Runx2 were observed near the region of inflammatory cell infiltration. The odontogenic epithelial islands were positive to FGF-2 and p63. The results suggest that the ectomesenchymal cells in the inner layer of the DF are concerned with abundant vascular formation. Further, inflammatory irritation to the inner layer might have caused osteoblastic differentiation.
  • Shizuka Suzuki, Hiroshi Nakada, Toshiro Sakae, Yasuhiro Tanimoto, Yasu ...
    2012 年 21 巻 3 号 p. 245-256
    発行日: 2012年
    公開日: 2012/08/23
    ジャーナル フリー
    Ovariectomized (OVX) rats are accepted models for screening potential therapeutic agents for osteoporosis. A low-mineral diet accelerates bone loss in OVX rats. This study aimed to determine changes in bone quality caused by ovariectomy or by combined ovariectomy and a mineral-deficient diet. Forty-eight female Wistar rats, aged 19 weeks, were distributed into 3 groups (n = 16 per group): Group 1: (control) subjected to a sham operation and administered a normal diet, Group 2: OVX rats fed a normal diet, and Group 3: OVX rats fed a low-mineral diet. The rats were sacrificed after 4, 8, 16, and 24 weeks. The density distribution and volume of the femur mid-shaft were evaluated to assess bone quality using micro-computed tomography and polarized microscopy. Bone strength was evaluated using a 3-point bending test. Bone density distribution, bone volume, and strength were the lowest for Group 3 and the highest for Group 1 at all times. Using a polarized microscope, we found that the tubular structures of the Haversian and Volkmann’s canals were decreased in Group 3 compared with those of Groups 1 and 2. Positive correlations were noted between fracture load and bone density, fracture load and bone volume, and bone volume and bone density in Group 3, and between bone density and volume, and bone volume and fracture load in Groups 2 and 3. We conclude that estrogen deficiency (ovariectomy) and mineral deficiency had separate as well as combined effects on bone quality.
  • Mitsuo Kakei, Toshiro Sakae, Masayoshi Yoshikawa
    2012 年 21 巻 3 号 p. 257-266
    発行日: 2012年
    公開日: 2012/08/23
    ジャーナル フリー
    The purpose of the present study was to investigate whether fluoride (F) ions are really capable of the repair (remineralization) of damaged crystals and useful for reinforcing the quality (i.e. modify the crystal structure) of tooth enamel using transmission electron microscopy and Raman microprobe analysis. Additionally, carbonic anhydrase activity was measured in immature enamel tissue to compare the harmfulness of F ions to that of cadmium (Cd) ions during the process of crystal nucleation by means of differential gas pressure analysis. Electron micrographs indicated no signs of remineralization of artificially damaged crystals after incubation in a remineralizing solution and further revealed that treatment with acidulated phosphate fluoride (APF) gel caused crystal dissolution rather than crystal improvement. Regarding crystal structure modification, Raman microprobe analysis revealed that no up-shift of PO43-ν1 band assigned to human sound enamel crystals occurred when APF gel was used. Furthermore, fluorapatite crystals were not generated by daily intake of F ions in developing rat tooth enamel. A differential gas pressure method demonstrated that the harmfulness of F exposure during the nucleation process of calcified hard tissues was much greater than that of Cd exposure. These results demonstrate that F treatments have no effect on improving crystal quality or remineralization and are inconsistent with the purpose of public health.
  • Hung-Ta Lin, Ujjial K Bhawal, Takao Watanabe, Wei-Jen Chang, Sheng-Ya ...
    2012 年 21 巻 3 号 p. 267-272
    発行日: 2012年
    公開日: 2012/08/23
    ジャーナル フリー
    Microfibril-associated glycoprotein-1 (MAGP1) is a small molecular weight, ubiquitous component of the fibrillin-rich microfibrils that found in the extracellular matrix. Inactivation of MAGP1 results in a bleeding diathesis and an altered wound healing response in bone and skin. Beta-tricalcium phosphate (β-TCP) is widely used in clinical orthopedic surgery due to its high biodegradability, osteoconductivity, easy manipulation and lack of histotoxicity. In this study, we aimed to understand the differential expression of MAGP1 in bone tissue implanted with β-TCP. Following the extraction of premolars and subsequent bone healing,β-TCP was implanted into the artificial osseous defect of dog mandibles. Bone tissue specimens were collected at 4 and 7 days after implantation. Total RNA was isolated from bone tissue, and gene expression profiles were analyzed using microarray technology. MAGP1 mRNA was up-regulated at days 4 and 7 in β-TCP-implanted tissues compared to the controls. Real-time PCR was used to confirm the mRNA levels. Immunohistochemical analysis revealed a higher expression in MAGP1 protein at day 7 in b-TCP-implanted tissues compared to the control. These results suggest that MAGP1 might be involved in the early stage of β-TCP enhanced bone regeneration.
  • Suqian Zhao, Yuetong Qian, Hong Liu, Lingling Jiang, Li Zhou
    2012 年 21 巻 3 号 p. 273-278
    発行日: 2012年
    公開日: 2012/08/23
    ジャーナル フリー
    This paper is intended to offer a theoretical basis for clinical appliance of preheating by comparing the properties of six different resin composites at room temperature and pre-heated temperature.
    The experiment is divided into two groups: one at room temperature (20°C), the other at preheated temperature (60°C). At room temperature, the six resin composites were exposed to a LED light for 20 seconds. While in the other group, the resins were firstly put into an incubator which is elevated to 60°C, and then taken out. After 60 seconds, they were exposed to LED light for 20 seconds. In each group, the compressive strength, micro Vickers hardness and the degree of conversion of six resin composites were tested. After being filled with resin composites, the extracted teeth were dyed and sliced. The microleakage of the restoration was observed and then recorded. All the data was analyzed by statistical analyses. Preheating has no apparent effect on compressive strength, hardness and degree of conversion of FiltekTMZ350, Surefil, Solitaire2, ESTELITEΣ, BRILLIANT New Line, but significantly improved the compressive strength and the hardness of GRADIA DIRECT. And preheating also reduces the microleakage of resins, especially for Surefil and Solitaire2. Preheating has effect on the properties of resin composites, and different resins differ in the sensitivity to preheating due to their different components and contents. In clinical, we ought to fully consider the value of preheating according to requirement in order to obtain the benefit.
  • Masanobu Wakami, Kayo Kuyama, Yan Sun, Miyuki Morikawa, Masahiro Aida, ...
    2012 年 21 巻 3 号 p. 279-284
    発行日: 2012年
    公開日: 2012/08/23
    ジャーナル フリー
    The purpose of this study was to investigate the histopathological and immunohistochemical characteristics of so-called “denture fibroma” and related stromal reaction. The tissues were histologically classified into inflammatory granulation type, matured fibrous type and myxoid type. Tenascin, LOX, fibrinogen and COX were strongly detected in inflammatory granulation type whereas a weak expression was detected in matured fibrous type. LOX was remarkably expressed by spindle shaped cells/fibroblastic cells and endothelial cells while tenascin was relatively expressed by monocytes in myxoid type. Despite strong expressions of tenascin, fibrinogen, COX-2 and LOX, their expressions decreased towards the deep part of the connective tissue. The greatest number of vessels was obtained in inflammatory granulation type and the least number of vessels was obtained in myxoid type which might contribute to hypoxic condition.
    The results suggest that the so-called “denture fibroma” is a consequence of acute inflammatory reaction leading to the formation of inflammatory granulation followed by the state of fibrosis which gradually was replaced by matured collagen fibers. Furthermore, myxoid degeneration occurred when blood vessels decreased which lead to hypoxic condition.
  • Lina Wang, Wei Yin, Ming Dong, Jianbo Zheng, Qiyi Song, Jiyao Li, Weid ...
    2012 年 21 巻 3 号 p. 285-290
    発行日: 2012年
    公開日: 2012/08/23
    ジャーナル フリー
    Enterococcus faecalis has a high detection rate in root canals with failed endodontic treatment. The previous studies had shown the relationship between biofilm formation and expression of virulence factors in digestive disease. In this study, we want to find out the relationship between biofilm formation and expression of virulence factors, like enterococcus surface protein (esp), collagen-binding protein (ace), haemolysin activator(cylA), of E.faecalis recovered from root canals undergoing orthograde retreatment. Fifty clinical patients were recruited. All of them complained at least one of the following symptoms: spontaneous pain, pain of occlusion (apical shadow), sensitive to percussion, parulis and fistula. Most isolates successfully formed biofilms. After 24h of cultivation, the expression of ace, cylA, esp in the biofilm-positive groups were higher than that of biofilm- negative groups (P‹ 0.05). The expressions of esp and ace were higher than that of cylA in patients with pain of occlusion (P‹ 0.05). The results indicated patients with six clinical symptoms we studied had higher expression level of virulence factors than those without these symptoms.
  • Yukari Ueda, Zenei Taira
    2012 年 21 巻 3 号 p. 291-298
    発行日: 2012年
    公開日: 2012/08/23
    ジャーナル フリー
    Calcium is an essential mineral, and its deficiency causes several diseases such as osteoporosis. The absolute bioavailability of calcium using modern pharmacokinetic methods has not been determined even though the relative bioavailability of calcium from various calcium salts has been examined using classic kinetics and pharmacokinetics. The serum calcium concentrations of three calcium salts, calcium chloride, calcium acetate and calcium ascorbate, were measured at various times after intravenous (i.v.) and oral administrations in mice, and the pharmacokinetic behaviors of the salts were investigated using a non-compartmental model. The degree of dissociation of the calcium salts was determined based on the extent of freezing-point depression. The pharmacokinetic parameters, MRT, Vdss, CLtot and AUC for i.v. administration of calcium at 15 and 30 mg/kg from three calcium salts indicated that all three may undergo similar mechanisms of calcium metabolism. The pharmacokinetic process was linear due to a first-order reaction. The pharmacokinetic parameters of calcium after oral administration at 150 mg/kg indicated that the calcium absorption was significantly different among the three calcium salts. The absolute calcium bioavailability of calcium ascorbate and calcium acetate was 2.6 and 1.5-fold, respectively, greater than that of calcium chloride. The mean residence time, MRTab, for absorption of calcium from calcium ascorbate was longer than those from calcium chloride and calcium acetate. Furthermore, it was estimated that calcium absorbed by passing through the intestinal membrane was the dissociated form because of higher degrees of apparent dissociation for the three salts. The calcium absorbability from calcium ascorbate via the intestinal track is significantly higher than those of calcium chloride and calcium acetate.
  • Haitao Zhao, Weili Yuan, Xukai Wang, Xingjun Qin, Lei Xue
    2012 年 21 巻 3 号 p. 299-306
    発行日: 2012年
    公開日: 2012/08/23
    ジャーナル フリー
    It is known that the progression of dermal hemangioma is highly related with apoptosis of vascular endothelial cell. Researches more and more attached importance to study some apoptosis related factors on affacting the proliferation and involution of dermal hemangioma. The bcl-2 family is a group of evolutionary conserved pro- and antiapoptotic proteins that play a pivotal role in the regulation of the mitochondrial-mediated apoptotic pathway. The expression of bcl-2 family members in hemangioma is controversial. Some think that the expression of bcl-2 in hemangioma is inherent and different. The other consider that skin hemangioma do not express bcl-2. In order to illustrate the apoptotic mechanism of dermal hemangioma through the mitochondrail pathway, immunohistochemistry method and in situ hybridization were used to detect the expression of bax, bcl-2,bcl-xl and caspase9 mRNA in hemangioma, including proliferative hemangioma, involutional hemangioma and normal skin tissue. The expression of bcl-2 and bcl-xl in proliferating hemangioma were markedly stronger than that in involuting hemangioma (P‹0.01).On the contrary, the expression of bax and caspase9 mRNA in involuting hemangioma were significantly higher than that in proliferating hemangioma (P‹0.01, P‹0.05, respectively).There were no positive expression of these apoptotic related factors in normal skin tissue.
  • Hideo Kiba, Noboru Kuboyama, Ryoichiro Uchida, Tsutomu Ishizaki, Norih ...
    2012 年 21 巻 3 号 p. 307-314
    発行日: 2012年
    公開日: 2012/08/23
    ジャーナル フリー
    In this study, effects from pore size of the tube on the bone ingrowth and on the calcification of new bone permeated into the pore tube were examined through implantation of porous hydroxyapatite (HAp) in the lateral epicondyle in rabbits.The bone integration speed was strongly dependent on the pore size of the porous HAp. The 150-μm HAp provided a faster bone integration speed into the cylindrical tube than the 375-μm. However, when the pore size of the cylindrical tube in porous HAp was reduced to 20 μm, the bone integration speed into the cylindrical tube became slow. However, when the implanted period was prolonged to 8 weeks, the bone contact ratio into the 20-μm cylindrical tube dramatically increased and the bone density reached to74.0%. However, most new bones were remained as an osteoid bone. In contrast, the new bones formed inside of the 150-μm and 375-μm sized cylindrical tubes were calcified within the tube. It was concluded that the osteointegration into for the porous HAps and the calcification of osteoid formed were different with the pore size of the cylindrical tube. The optimum size of cylindrical tube was 150 μm.
  • Yasuo Miake, Nobuhiko Hiruma, Shinya Asada, Akira Katakura
    2012 年 21 巻 3 号 p. 315-320
    発行日: 2012年
    公開日: 2012/08/23
    ジャーナル フリー
    Calcified seaweed contains abundant quantities of calcium, magnesium, phosphate, sodium and fluorine ions. The objective of this study was to investigate the effect of chewing gum containing calcified seaweed on the remineralization and aciduric properties of enamel. For intraoral experiments, enamel blocks prepared from third molars were attached to an appliance. Each block was covered with acid-resistant nail varnish, except for a window measuring 6 x 4 mm. A caries-like lesion was artificially prepared in the window. Participants attached the appliance and chewed gum for 20 min, 4 times a day. The intraoral experiment period was 2 weeks. Half of each window was re-covered with nail varnish. In the aciduric experiment, these blocks were immersed in demineralizing solution. After demineralization, the blocks were embedded in polyester resin and prepared in ground sections. Contact microradiograms of these ground sections were obtained. A high degree of remineralization occurred at the surface and at a deep layer in the remineralized enamel area. In the aciduric experiment area, further demineralization was observed beneath the original demineralized layer, and overall depth of demineralization increased. A thin, highly mineralized layer was observed between the two demineralized layers. The degree of remineralization and aciduric rate with calcified seaweed treatment was higher than that with non-calcified seaweed treatment (p‹0.05). These results suggest that chewing calcified seaweed-containing gum significantly enhances the remineralization and acid resistance of enamel by exposure to fluorine ions.
  • Toshihisa Harada, Keisuke Nakano, Hirokazu Matsuda, Rina Muraoka, Maki ...
    2012 年 21 巻 3 号 p. 321-328
    発行日: 2012年
    公開日: 2012/08/23
    ジャーナル フリー
    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.
  • Pao-Li Wang, Noritaka Obana
    2012 年 21 巻 3 号 p. 329-332
    発行日: 2012年
    公開日: 2012/08/23
    ジャーナル フリー
    Because of the awareness of people to good hygiene in recent years, there are now many people who are more concern about halitosis or commonly known as ‘bad breath’. Therapeutic or prophylactic agents for the suppression of halitosis have increased. Zinc chloride has been recognized to affect volatile sulfur oxide which is the main substance that has been traditionally known to cause halitosis. In this study, we compared the inhibitory effect of bismuth oxychloride and zinc chloride in vitro on hydrogen sulfide and methyl mercaptan sulfur which are volatile substances. As a result, both bismuth oxychloride and zinc oxide have the same inhibitory effect on hydrogen sulfide. On the other hand, bismuth oxychloride’s inhibitory effect on methyl mercaptan is significantly higher than zinc chloride.
  • Hiroyuki Okada, Masaaki Suemitsu, Saori Yasuoka, Mami Nakadai, Yumi Us ...
    2012 年 21 巻 3 号 p. 333-336
    発行日: 2012年
    公開日: 2012/08/23
    ジャーナル フリー
    Raman spectroscopy is based on Raman scattering of light form molecules, and Raman spectra provide highly useful information about molecular composition and its circumstances. The micro FT-Raman spectra both of ghost cells in calcifying cystic odontogenic tumor and keratinocytes of the gingiva showed a broad beak centered around 850 cm-1.
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