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The present study provides scientific evidence that a new chemical treatment process using calcium phosphate slurry promotes bone regeneration on titanium (Ti) implants. The material's surface modified by the treatment was analyzed using microscopic observation and the bone regeneration efficacy was evaluated both in vitro and in vivo. Formation of a thin hydroxyapatite layer with a thickness of about 50 nm and an increase of surface roughness were confirmed by microscopic observations. Histological evaluation of rat femora implanted with the specimens showed that the areas of the specimens directly attached to bone tissue were significantly more extensive than those implanted with control Ti at 2 and 8 weeks. Likewise, on the treated Ti, ALP activity, osteopontin, osteocalcin, and calcium contents of rat bone marrow stromal cells were significantly higher than on the control Ti. Furthermore, reverse transcription polymerase chain reaction showed greater expression of messenger ribonucleic acid encoding Cbfa1 and collagen type1 on the treated Ti at 2 weeks. Based on these results, we concluded that the new process was effective to enhance the osteoconductivity of Ti. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 2716-2724, 2018.

The present study provides scientific evidence that a new chemical treatment process using calcium phosphate slurry promotes bone regeneration on titanium (Ti) implants. The material's surface modified by the treatment was analyzed using microscopic observation and the bone regeneration efficacy was evaluated both in vitro and in vivo. Formation of a thin hydroxyapatite layer with a thickness of about 50 nm and an increase of surface roughness were confirmed by microscopic observations. Histological evaluation of rat femora implanted with the specimens showed that the areas of the specimens directly attached to bone tissue were significantly more extensive than those implanted with control Ti at 2 and 8 weeks. Likewise, on the treated Ti, ALP activity, osteopontin, osteocalcin, and calcium contents of rat bone marrow stromal cells were significantly higher than on the control Ti. Furthermore, reverse transcription polymerase chain reaction showed greater expression of messenger ribonucleic acid encoding Cbfa1 and collagen type1 on the treated Ti at 2 weeks. Based on these results, we concluded that the new process was effective to enhance the osteoconductivity of Ti. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 2716-2724, 2018.

The development of photosensitizers and light sources has enabled the use of antimicrobial photodynamic therapy (aPDT) in various dental therapies. In the present study, we compared the antibacterial and cytotoxic effects of Au clusters photoexcited by blue and white LED irradiation. We fabricated novel photosensitizers, captopril-protected gold (Capt-Au) clusters and lysozyme-stabilized gold (Lyz-Au) clusters, for aPDT. Au clusters were then photoexcited by two kinds of light sources, blue high-power and white low-power light-emitting diodes (LEDs). Since white LED contains a wide spectrum of light (400–750 nm), white LED would be relevant for aPDT even if using a low-power source. The turbidity and viability of Streptococcus mutans were assessed following application of Capt-Au clusters (500 μg/mL) or Lyz-Au clusters (1,000 μg/mL) photoexcited by a blue high-power LED (1,000 mW/cm2) or white low-power LED (80 mW/cm2). In addition, the cytotoxicity of Au clusters and LED irradiation was evaluated in NIH3T3 and MC3T3-E1 cells. Au clusters photoexcited by the white low-power LED equally decreased the turbidity and viability of S. mutans compared with blue high-power LED. However, Au clusters photoexcited by white LED irradiation caused decreased cytotoxicity in mammalian cells compared with those photoexcited by blue LED irradiation. In conclusion, white LEDs possess biosafe properties for aPDT using Au clusters.

This article discusses a case of bilateral multiple cervical lymph node metastases of oncocytic carcinoma—an extremely rare neoplasm of the salivary glands—that was found in a 71-year-old Japanese female patient who presented with a painless swelling in the bilateral submandibular regions. Computed tomography demonstrated enlarged bilateral multiple lymph nodes. Multiple metastases to bilateral cervical lymph nodes were clinically suspected, and bilateral neck dissections were performed. The tumor tissue adjoined the submandibular gland with a thin fibrous connective tissue capsule. Histologically, the tumor was predominantly composed of large, round to polyhedral cells with fine granular eosinophilic cytoplasm, which were arranged in solid sheets, islands and cords. Ultrastructural analysis revealed numerous mitochondria with abnormal shapes packed in the cytoplasm of the neoplastic cells. The tumor was diagnosed as oncocytic carcinoma of the submandibular gland with bilateral multiple cervical lymph node metastases. The tumor developed neither recurrence nor distant metastasis for eight years after the operation.

We developed a porous chitosan/ hydroxyapatite (HAp) composite, in which the HAp nanocrystals align along the chitosan molecules, and examined the biocompatibility, osteoinductive activity, and the ability to act as a carrier of recombinant human bone morphogenetic protein-2 (rhBMP-2) of this novel biomaterial. The composite was subcutaneously implanted into the backs of 11-week-old SD rats, with or without rhBMP- 2 (5 µg). At 2 and 8 weeks after the implantation, the composite was explanted for morphohistological evaluation. In the presence of rhBMP-2, ectopic bone formation was found at 2 weeks and maturation of the newly formed bone around the composite at 8 weeks. Chitosan/HAp composite alone caused little inflammation, and new blood vessel growth and multinucleated giant cells were found around the composite, accompanied with roughening of the surface due to degradation at 2 weeks; however, neither cartilage nor bone formation was found around the composite. With rhBMP-2, the bioabsorption of the composite was accelerated as the rhBMP- 2-induced bone matured. Histomorphometrical analysis showed that the mean value of the composite areas with rhBMP-2 was significantly smaller than that without rhBMT-2 at 2 and 8 weeks after the implantation. These results suggested that the novel chitosan/ HAp composite was an effective bioabsorbable material as a carrier of rhBMP-2.

Objective: To evaluate whether fibroblasts derived from periodontal ligament retain the ability to differentiate into putative vascular cells and construct vascular cell-specific marker-positive blood vessel structures. We also evaluated the morphological features of the structure and investigated the intracellular molecular mechanism underlying the angiogenic activity of these cells. Methods: Single cell-derived cultures (SCDCs) were established from primary rat ligament fibroblast cultures, and their expression of ligament cell-, mesenchymal stem cell- and vascular cell-specific markers was evaluated by RT-PCR and immunocytochemistry. The ability of the cells to construct a blood vessel structure was evaluated in a three-dimensional type I collagen scaffold. The morphological and immunohistological characteristics of the structure were then evaluated. Results: Each SCDC expressed endothelial cell (EC)-specific and smooth muscle cell-specific markers, in addition to mesenchymal stem cell- and ligament cell-specific markers. SCDC2 cells, which abundantly expressed the EC markers Flk-1 and Tie-2, vigorously constructed a blood vessel structure in a phosphoinositide 3-kinase activation-dependent manner. Conclusion: Periodontal ligament fibroblasts have the potential to construct an EC marker-positive blood vessel-like structure. Consequently, the fibroblastic lineage in ligament tissue could be a candidate precursor for construction of a vascular system around damaged ligament tissue to facilitate its regeneration.

We fabricated novel chitosan/hydroxyapatite (HAp) nanocomposites with porous structure by the co-precipitation and porogen leaching method. SEM observation confirmed that the porous chitosan/HAp nanocomposites with 60.6% and 87.1% porosity showed the interconnective pores with pore diameters in the range of 100-200 mum. The composites were found to be mechanically flexible and could be easily formed into any desired shape. The mechanical strength was enhanced by the heat treatment with saturated steam, which was ascribed to the formation of hydrogen bonds between chitosan molecules. The composites subcutaneously implanted in the backs of SD rats for 3 weeks caused little inflammation, and new blood vessel growth and giant cells were found around the composite accompanied with roughening of the surface due to degradation, showing good biocompatibility and biodegradation.

Histological and histometric evaluations were done to investigate the effects of streptozotocin-induced diabetes on peri-implant tissue after osseointegration in the rat maxilla. Titanium screw implants were immediately inserted into the sockets after extraction of left upper first molars of 4-week-old male Wistar rats. Rats were divided into three groups. Rats in group I and group It were sacrificed at 4 and 8 weeks after implantation, respectively, and rats in group DM, in which streptozotocin was injected intraperitoneally at 4 weeks after implantation, were sacrificed at 8 weeks after implantation. Histological and histometric evaluations were carried out for decalcified specimens with EDTA and undecalcified ground specimens. Newly formed bone contacted the implant surface directly in the three groups. No significant difference in the bone-implant contact rate was found among the three groups. However, moderate inflammatory cell invasion and dilatation of capillaries were observed in the proper lamina around the implants. The bone height was significantly less in the DM group than in group I, while significance was not found between group DM and group It. These results suggested that hyperglycemia for 4 weeks after osseointegration affected the marginal bone level, whereas it did not influence the bone-implant contact rate.

The purpose of this study was to investigate the effect of the duration of hyperglycemia on the osseointegration and bone formation around titanium implants. Rats were divided in to three groups, the short-term-hyperglycemia group (group S), the long-term-hyperglycemia group (group L), and the control group. In groups S and L, hyperglycemia was induced with streptozotocin 2 and 6 weeks before implantation, respectively. Rats received titanium implants in their femora, and were sacrificed 1, 2, 4, and 8 weeks after implantation. In the control group, the newly formed bone that directly contacted the implant surface increased with time. In groups S and L, fibrous connective tissue was observed on some parts of the implants. There were significant differences in bone-implant contact among the three groups at 4 weeks after implantation. Newly formed bone including the bone fragments scattered by surgery was remodeled, becoming thinner with time in the control group, whereas it remained immature, away from the implant in groups S and L. Although there were significant differences in the number of TRAP-positive cells between the control group and the hyperglycemia groups, there was no significant difference between groups S and L. It is suggested that the duration of hyperglycemia affected osseointegration around titanium implants.

2006; 11: 89-96, ISSN 1342-0984In the present study, rat bone marrow (RBM) cells were cultured on dental implants. Afterprimary culture, RBM cells were cultured on dental implants for 2 weeks with and withoutosteogenic factors. DNA, alkaline phosphatase activity, osteocalcin and osteopontin weremeasured. Biochemical analyses revealed that, on the dental implants, RBM cell differentiationinto osteoblasts was induced by osteogenic factors. Dental implants with and without culturedRBM cells were implanted in the subcutaneous tissue or on the femur in syngeneic rats.Osteogenesis in the subcutaneous tissue and more extensive and faster bone formation aroundthe femur were observed for the implants combined with cells cultured with osteogenic factors.These results demonstrated that dental implants combined with osteoblasts differentiated fromRBM cells with osteogenic factors were effective for osseointegration and bone formation.

Reactive oxygen species (ROS) may contribute to aging and osteoporosis resulting from marked decreases in plasma antioxidants in aged osteoporotic women. On the other hand, high-dose vitamin K2 (menaquinone-4: menatrenone, MK-4) supplementation has been reported to reduce ovariectomy-induced bone loss in rats and to decrease osteoporotic fracture in postmenopausal women. However, the mechanism by which vitamin K2 prevents osteoporosis is unclear. Recently, vitamin K2 has been suggested to preserve antioxidant activity as a novel function. Therefore, we investigated the effect of vitamin K2 on the osteoporosis of aged rats by evaluating the relationships between serum antioxidant levels and bone metabolism. Aged female rats exhibited significantly lower serum alkaline phosphatase activity and osteocalcin level, together with lower serum levels of antioxidants such as 17beta-estradiol, macrophage migration inhibitory factor (MIF) and glutathione peroxidase (GPx) activity, as compared with young female rats. On the other hand, vitamin K2 supplementation (500 mg/kg, food intake) for 98 days led to a significantly increased serum vitamin K2 level (3,045+/-915 ng/ml in the vitamin K2 supplemented group vs. 4.6+/-3.4 ng/ml in the control diet group; P

A 13-year-old female with facial asymmetry and fibrous dysplasia on the right side of the mandible complained of cross bite and facial asymmetry due to a shift of the mandible to the left. The problems were: 1. Cross bite of the left side and scissors bite of the right side; 2. A 9.0 degree tilt of the occlusal plane; 3. Spaced dental arch of the right molar region of the mandible; 4. Facial asymmetry; and 5. Fibrous dysplasia of the mandible.Orthodontic treatment followed by surgical procedures was performed. Before the orthognathic surgery, the upper arch was aligned in two segments; one segment, including canine, premolars, and molars of the right side, was prepared for alveolar segmental osteotomy. After alignment of the upper and lower dental arches, the posterior maxillary alveolar segmental osteotomy on the upper right segment and SSRO were performed. The upper right segment was moved to the planned position to enable expansion and elongation, and the mandible was also moved to enable a mandibular shift. Post-operatively, detailing and finishing were performed in the orthodontic treatment, after which the fibrous dysplasia of the mandible was reduced by operation, and the final result was an improved occlusion.

The expression of GnT-V has been shown to correlate with tumor invasion, metastasis and poor prognosis in several tumors. We examined the expression of glycosyltransferases, N- acetylglucosaminyltransferase V (GnT-V) in 40 cases of human tongue squamous cell carcinoma (SCC) and its relationship to clinicopathological characteristics. Twenty-six of the 40 cases of SCC showed positive expression of GnT-V in cytoplasm of tumor cells by imunohistochemistry, whereas none of the 4 premalignant lesions showed positive signals for GnT-V. High expression of GnT-V was positively correlated with big tumor size (T category), infiltrative invasion pattern (vs. expansive), high histological malignancy (differentiation), and cervical lymph node metastasis. Furthermore, in the early clinical stage of SCC, the subsequent metastatic rate was significantly higher in SCCs that were GnT-V positive than in SCCs that were GnT-V negaive. All SCC cases examined showed increased GnT-V mRNA levels in comparison to normal tongue tissues by real-time PCR. Contrastively, GnT-V expression was not enhanced in premalignant lesions. These findings suggest that GnT-V expression is closely correlated with tongue SCC progression and the malignant phenotype.

Purpose The study goal was to investigate the adequacy of marginal resection of the mandibular bone in cases of squamous cell carcinomas of the lower alveolus and gingiva where the radiologically detected bone defect does not extend beyond the mandibular canal. Patients and methods Sixty-two patients who have had a mandibulectomy performed with or without preoperative radiotherapy and chemotherapy were the study subjects. This retrospective study investigated the correlation between the preoperative radiographic appearance and histopathologic findings of the excised tissue. The results of the treatments were evaluated. Results In the cases with erosive bone defects, the extent of the bone involvement did not exceed the extent of the radiographically detected bone defects. However, in 7 (36.8%) of the cases with moth-eaten type bone defects, the extent of bone involvement exceeded the bone defects detected by radiography. Further, 10 of the 16 cases with no apparent bone defect showed apparent bone involvement by the tumors histologically. There were no differences in the 5-year cumulative survival rate between the marginal resection and segmental groups. Conclusions Marginal resection was effective in controlling mandibular alveolus and gingival cancers when radiologically detected erosive bone defects did not extend beyond the mandibular canal. Marginal resection was inadequate when moth-eaten defects were radiologically detected, except when the bone defects were confined to the alveolar bone.

Reliable variables to predict the radiosensitivity of each tumor have not been identified. Recent studies have demonstrated that specific regions of mutations within the core domain of p53 protein correlate with responses to chemotherapy and radiotherapy in some tumor types. In this study, we evaluated the relationship between specific p53 mutations and radiosensitivity in 49 patients with oral squamous cell carcinomas (SCCs) who underwent preoperative radiotherapy. Exons 5 through 8 of the p53 gene were examined by polymerase chain reaction-single-strand conformation polymorphism and direct sequencing. We detected p53 mutations in 27 (55.1%) cases. DNA contact mutations were detected in 11 (40.7%) of these 27 cases in L3 loop, loop-sheet-helix motif, and zinc-binding residues. Tumors containing p53 DNA contact mutations had significantly poorer responses to radiation than the other tumors, although no statistically significant difference between tumors with and without p53 mutations was found. These data indicate that DNA contact mutation of p53 could be a useful marker to predict the radioresistance of oral SCCs.

We report an osteoma in the right maxillary sinus that was removed by means of a fiberscopeassisted operation. The patient was a 33-year-old man. His chief complaint was dull pain in the right cheek region. Computed tomography showed a lesion with an ossified rim in the right maxillary sinus. A fiberscopic operation was performed using a 0.8-mm rod-lens fiberscope. Fiberscopic examination of the lesion revealed that the mass was covered by mucosa of the maxillary sinus and that the mass had bony pedicles on the sinus wall. The mass was removed with the patient under local anesthesia. The pathological diagnosis was osteoma. After operation, the pain and swelling were slight. The prognosis remains good 10 months after the operation, with no signs of recurrence. In conclusion, the surgical procedure we used is considered useful since it is minimally invasive.

一歯のみに外傷性咬合を引き起こしたときの顎関節の組織変化について明らかにすることを目的に, 次の実験を行った. 7週齢の雄性Wistar系ラットを用い, 上顎左側第一臼歯の咬合面にレジンを2mm築盛し, 外傷性咬合を付与した. レジンを築盛した群を実験群とし, 左側を処置側, 右側を無処置側とし, 無処置の群を対照群とした. 実験期間は外傷性咬合付与後3日から56日で, 通法に従い前頭断連続切片標本を作製し, 顎関節の変化について, 組織学的ならびに組織計量学的に比較検討した. 下顎頭では実験側, 無処置側ともに7日後に軟骨層で萎縮性の変化がみられたが, その後BrdU陽性細胞数の増加や軟骨層の肥厚がみられ, これらの値は対照群と比較して高値で, 14日目には最大値を示し, 28日後では対照群と同様の組織像を示した. 以上の所見より, 一歯のみの外傷性咬合の場合, 下顎頭の変化には両側で同様の組織学的変化が生じることが明らかになった.

The osteopetrosis (op) mutation in mice is characterized by generalized skeletal sclerosis; reduced numbers of osteoclasts, macrophages, and monocytes; and failure to be cured by bone marrow transplantation. This mutation has been shown to result from an absence of colony-stimulating factor-1 (CSF-1) and reported to be cured by treatment with CSF-1. Macrophage polykaryons are known to be formed by fusion of mononuclear precursors and the presence of subcutaneous implants can elicit the formation of macrophage polykaryons. In order to determine if recruitment of foreign body giant cells is also impaired in osteopetrotic mice, tissue reactions to subcutaneously implanted polyvinyl sponges were studied and compared with normal mice. Our result showed that, in the op mouse, recruitment of macrophages and foreign body giant cells in response to the implants was quantitatively not different from that of normal mice. However, these cells were smaller and did not migrate as deeply into the implant as those seen in normal littermates. In contrast, resident macrophages obtained by peritoneal lavage were significantly reduced in op mice. These data indicate that there is a deficiency in the ability of op mice to mount a foreign body giant cell response to an implanted sponge characterized by a deficiency in the recruitment of precursor cells that are capable of either full development and spreading or migration into the implanted sponge. These data add to the emerging appreciation of the regional differences among macrophage populations in their dependence on CSF-1 for differentiation and survival.

Oral ulcers are caused by several different mechanisms. Sometimes the cause is unknown in elderly patients. We present the case of a patient with multiple persistent oral ulcers of unknown cause. A 74-year-old man was referred to our department for evaluation and treatment of multiple oral ulcers. The largest ulcer measured 38 × 19mm and was located on the tongue. The muscle was exposed. There was no systemic disease, and laboratory studies revealed no abnormalities. Incisional biopsy was done because of suspected malignant lymphoma, but no tumor tissue was found. The ulcers healed within 1 month in response to treatment with steroid ointment and instructions on mouth hygiene and nutrition at our hospital. Since some oral ulcers are caused by local factors whereas others are due to systemic problems, it is important to treat ulcers of unknown cause with multidisciplinary and complementary approaches and to continue long-term follow-up even after cure.

A case of squamous cell carcinoma of the tongue with metastasis to the lateral lingual lymphnodes is reported. Preoperative computed tomography and magnetic resonance imaging revealed a mass0.5cm in diameter with heterogenous enhanced signal intensity outside of the left genioglossus muscle.Radical neck dissection, partial left glossectomy, and reconstruction with a forearm flap were performedin a pull-through manner after external radiation and chemotherapy. Histopathologically, the mass had alymph-node structure with small cancer nests at the margin.

本研究では, 糖尿病がosseointegration獲得後のチタンインプラント周囲の骨組織に与える影響について, streptozotocin誘発糖尿病ラットを用いて組織学的, 組織計量学的に検討を加えた. ラット大腿骨にチタンンプラントを埋入し, 8週後にstreptozotocinを腹腔内に投与することにより糖尿病を誘発させ, 4週後に安楽死させた. 対照はチタンインプラント埋入後8週および12週のラットとした. 骨-インプラント体の接触率は, 糖尿病ラットと対照群のラットの間に有意差は認められず, 糖尿病ラットではインプラント体周囲の新生骨量が有意に低い値を示した. 以上の結果から, 4週間の高血糖状態は, 獲得されたosseointegrationを破壊することはなく, インプラント周囲の骨形成を抑制することが示された.

The effects of coffee on bone metabolism are still controversial, although several studies have suggested that caffeine and/or heavy coffee consumption is associated with a significant increase in risk of fracture, osteoporosis, and periodontal disease. Therefore, we sought to clarify the relationship between coffee consumption and bone metabolism using male Wistar rats. Forty-eight male Wistar rats were assigned to three treatment groups including a control-diet group (control, n = 16, coffee-free diet), a 0.62% coffee-diet group (low caffeine, n = 16, diet supplemented with 6.2 g/kg of the control diet), and a 1.36% coffee-diet group (high caffeine, n = 16, diet supplemented with 13.6 g/kg of the control diet), and animals were maintained on an experimental diet for 140 days. Although caffeine in serum was not detected in rats fed the control diet, low-intake coffee for 140 days led to an increase in caffeine concentration to 0.53 +/- 0.11 microg/mL and high-intake coffee led to an increase of 1.77 +/- 0.22 microg/mL. No significant differences in body weight change, serum and urinary biochemical markers of bone metabolism, and bone histomorphometry were found between the coffee-diet groups and the control-diet group, except that urinary phosphorus excretion after 140 days of both coffee diets was significantly increased compared with controls (p0.05). In addition, the coffee diets were not associated with differences in tumor necrosis factor-alpha and interleukin-6, which have been implicated in the pathogenesis of bone loss together with interleukin-1beta. In conclusion, the present study strongly indicates that coffee does not stimulate bone loss in rats.

Mutations of the p53 tumor suppressor gene have been found in about 50% of all human cancers.The relation of p53 status to clinicopathological variables and prognosis has been evaluated; however, it remains controversial in most cancers. Recent studies suggest that malignant potential and biological properties may depend on the region of mutation. It has also been demonstrated that specific regions of mutations within the core domain of p53 protein correlate with poor prognosis in breast cancer, esophageal cancer and colon cancer. To clarify the correlation between mutations within the DNA binding surface regions of p53 and clinical outcome in patients with oral cancer, we analyzed p53 mutations in 91 fresh primary, resected specimens of oral squamous cell carcinomas (SCCs) by polymerase chain reaction-singlestrand conformation polymorphism (PCR-SSCP) and a yeast functional assay.p53 mutations were detected in 36 of 91 (40%) cases. No correlation was found between overall mutations in the p53 gene and clinicopathological variables, clinical outcome, or survival rate. The five-year cumulative survival rate of 18 patients with tumors that had p53 mutations within DNA-binding surface regions (L2, L3, LSH) was significantly lower (52.5%) than that of the 73 other patients (p=0.004). Multivariate analysis, showed that mutations within these regions were independent prognostic factors (p

Metastasis to the lateral retropharyngeal lymph nodes frequently occurs in nasopharyngeal cancers; however, it is very rare in oral carcinomas. This report describes a case of recurrent carcinoma of the lower alveolus with metastasis to retropharyngeal lymph nodes. The patient was an 84-year-old woman who underwent radical neck dissection with marginal resection of the right side of the mandible for a squamous cell carcinoma arising in the lower gingiva (T 2 N 1 M 0). Twenty-five months after the operation, she complained of a mass with ulceration in the floor of the mouth. A smear of the ulcer proved tumor recurrence. Computed tomography and magnetic resonance imaging showed that the mass invaded the tongue, with metastasis to the submental and bilateral metastases to the retropharyngeal lymph nodes. The patient and her family refused salvage treatment. She died of tumor 6 months after recurrence.

This study compares the effects of disocclusion and overloading occlusion on dental lesions. Ten-day-old Syrian hamsters were divided into 4 groups: group I, untreated animals; group II, animals whose hemilateral incisors were disoccluded; group III, N- methylnitrosourea (MNU)-treated animals; and group IV, MNU-treated animals whose hemilateral incisors were disoccluded. The ipsilateral maxillary and mandibular incisors were repetitively cut with diamond discs. The hamster is easier to anesthetize. Animals received a 0.2% solution of MNU (10 mg/kg body weight) intragastrically twice a week for 16 wk. All the cut mandibular incisors and the MNU-treated uncut mandibular incisors showed lack of iron deposition on the enamel surface. The eruption rate was significantly higher in the cut disoccluded incisors of groups II and IV (p < 0.05) and significantly lower in the uncut overloaded incisors of groups II and IV (p < 0.05). In the cut mandibular incisors of group IV, the degree of the disturbance of odontogenesis and the atypical proliferation of odontogenic epithelium were more prominent (p < 0.02), and the dental lesions occurred earlier. Histologically, the disturbed Hertwig's epithelial sheath and the Hertwig's epithelial sheath-like transformed U-shaped part and enamel organ seemed to lead to disturbances of amelogenesis and detinogenesis as well as to atypical proliferation of odontogenic epithelium nests. Thus, this method of disocclusion of the incisors of rodents may represent a useful model for the investigation of the effects of various agents on tooth formation over a short experimental period.

Macrophage migration inhibitory factor (MIF), a putative cytokine involved in inflammatory and immune responses, was identified in rat peritoneal macrophages by Western blot analysis and its secretion into culture medium by enzyme-linked immunosorbent assay. To clarify the possibility of vitamin E as an immune modulator, we investigated the effect of vitamin E on MIF production in macrophages in response to calcium ionophore A23187 and lipopolysaccharide (LPS). Intraperitoneal injections of vitamin E (5 mg per rat) for 6 successive days resulted in a significant increase of alpha-tocopherol content in peritoneal macrophages. Alpha-tocopherol content of macrophages in vitamin E-treated rats was 478.3 +/- 90.7 ng/10(6) cells, whereas in control rats it was 1.5 +/- 0.5 ng/10(6) cells. For the control macrophages, total MIF content of the medium (2.5 x 10(6) cells/18 ml) without stimulation was 40.7 +/- 3.6 ng after 14 h culture, whereas stimulation with calcium ionophore A23187 (400 nM) and LPS (5.0 microg/ml) induced the elevation of MIF content to 65.9 +/- 7.5 ng and 74.3 +/- 10.4 ng, respectively (p < 0.05, n = 3). On the other hand, vitamin E-enriched macrophages without stimulation showed less MIF content (14.0 +/- 4.2 ng) than the control (p < 0.05, n = 3). Similarly, the increase of MIF of vitamin E-treated macrophages was significantly suppressed after stimulation with calcium ionophore A23187 or LPS, compared with the control macrophages (p < 0.01, n = 3). From analysis of intracellular MIF content by Western blot, we found no alteration of intracellular MIF content of vitamin E-macrophages, in contrast to the decreased content of control stimulated-macrophages, showing that vitamin E suppressed MIF secretion into the culture medium. Taken together, these results indicate that vitamin E may contribute to the regulation of inflammatory and immune responses through regulation of MIF secretion, possibly by modulating macrophage-membrane architecture.

To predict indicators of occult neck metastasis, we evaluated clinico-pathological findings in N O cases of squamous cell carcinoma of the tongue by the quantification theory type II. The number of N O cases without local failure from 1974 through 1995 was 88. Biopsy specimens were evaluated pathologically after treatment of the primary lesion alone. Cervical lymph node metastasis subsequently developed in 18 cases. Data analysis, in which occult neck metastasis was considered a dependent variate and clinico-pathological findings as an independent variate, indicated that the invasion pattern was the most significant predictor of cervical lymph node metastasis. The presence or absence of occult cervical lymph node metastasis was correctly predicted in 76.1% of the cases.On analysis by the Anneroth classification, the contribution of morphologic variables to metastasis diminished in the following order: mode of invasion, number of mitoses, degree of keratinization, stage of invasion, lymph-plasmocytic infiltration, and nuclear polymorphism. On analysis of the total score derived from the correlation coefficients, occult neck metastasis was not found in patients with a score of 9 or less. The higher the total score, the higher was the incidence of cervical metastasis.

Oral squamous-cell carcinoma (SCC) is the most common neoplasm in Sri Lanka, accounting for approximately 30% of all cancers in males. Epidemiologic evidence indicates that there is an unequivocal relationship between betel chewing and oral carcinogenesis, suggesting that there may be specific genetic targets of betel-quid ingredients. The p53 gene has been indicated to be a tumor-suppressor gene that is found in mutated form in common human cancers; however, there are few reports about "carcinogen-specific" p53 mutation. Because of this background, primary resected specimens from 23 oral SCCs, 7 leukoplakias and 2 oral submucous fibrosis were collected from oral SCC patients in Sri Lanka and were used for p53 mutation analysis. Exons 5 through 8 of the p53 gene were examined by polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) and direct sequencing. Mutations in the p53 gene were frequent (10/23) in oral SCC specimens from Sri Lanka. Moreover, the mutations clustered significantly in exon 5 (7/10) of the p53 gene, and small deletions and inclusions other than point mutations were observed. These results indicate that 1) betel-quid chewing may cause specific genetic changes, including mutation in the p53 gene; 2) mutations in the p53 gene are not rare events in SCC patients who are betel-quid chewers, which contrasts with other reports; 3) exon 5 of the p53 gene could be one of the specific targets for some betel-quid ingredients; and 4) betel-quid chewing may be a critical environmental factor in the development of oral SCC.

Our objective was to show the presence of nitric oxide synthase (NOS) in the mammary glands of lactating rats and to determine the role that nitric oxide plays in lactation of humans. We used the nicotinamide adenine dinucleotide phosphate (NADPH) diaphorase reaction and immunostaining on fresh frozen breast tissue obtained from lactating Wistar rats (13-18 wk old, 320-380 g, 3-4 d after parturition, first pregnancy). The breast tissues positive for NADPH diaphorase staining were the mammary gland, muscle, sebaceous gland, epidermis, and endothelium of the lactiferous ducts and blood vessels. These findings corresponded to tissues that were NOS-immunoreactive. The NOS detected in the mammary glands was the constitutive NOS. The finding of positive anti-NOS immunoreactivity and of positive NADPH diaphorase activity in the cells of the rat mammary glands leads us to conclude that nitric oxide is synthesized in mammary glands of rats. The high nitric oxide activity in the human breast was previously reported by measuring the total concentration of nitrite plus nitrate, biopterin, and neopterin in human milk. These results suggest that nitric oxide plays a role in the secretion of human breast milk.

Received 14 July 2005; accepted 14 July 2005Summary Polymorphous low-grade adenocarcinoma (PLGA) occurs almostexclusively in minor salivary glands, and there are only a few reports of majorsalivary gland origin. We herein report a case of de novo PLGA arising in asubmandibular gland and discuss preoperative findings of magnetic resonanceimaging.

During the voluntary contraction of target muscles, a silent period is observed immediately after the motor evoked potential (MEP) is elicited by transcranial magnetic stimulation. In this study, the silent period was recorded from bilateral abductor digiti minimi (ADM) and abductor hallucis (AH) in 30 normal healthy subjects (120 extremities) and 30 patients with cervical myelopathy (120 extremities). In normal subjects, the silent period was 142.3 ± 41.0ms (mean ± SD) for ADM, and 83.6 ± 42.3 ms for AH. When stimulus intensity was increased from 60% to 95%, the length of the silent period increased, reaching almost maximal level. The length of the silent period correlated with stimulus intensity, but not with the contraction force of voluntary muscles. In patients with cervical myelopathy, the silent period was 69.2 ± 27.8 ms (mean ± SD) for ADM and 48.3 ± 17.0ms for AH, significantly shorter than in the normal subjects. We believe that the length of the silent period can be a useful parameter for indicating the function of the spinal inhibitory system.

Ameloblastoma is the most frequent odontogenic tumour. It occurs mainly in the mandible and grows expansively. The treatment of ameloblastoma, which influences the prognosis, is decided in consideration of many factors, especially the age and size of the tumour. Conservative treatment sometimes leads to the recurrence of tumours and poor prognosis, but the relationships between the prognosis and the cytological features of tumour cells are still unclear. In the present study, we examined the immunohistochemical detection of proliferating cell nuclear antigen (PCNA) in 23 cases of ameloblastoma and evaluated the correlation between the positive index of PCNA and the clinical and histological character. Our results revealed the higher the age of the patient the greater was the incidence of a positive index of PCNA. It was also shown that the mean positive PCNA index in the follicular type (34.56 +/- 14.00 S.D.) was higher than that of the plexiform type (24.436 +/- 15.74 S.D., P0.10). The cystic type showed a low positive PCNA index (14.75 +/- 8.41 S.D.). In the follicular type, the localisation of PCNA-positive cells was different according to the histological patterns of tumours. Additionally, the positive indices of the same patient differed at different periods of treatment.

1967年8月から1992年7月までの25年間に, 北海道大学歯学部口腔外科において経験した口腔の小唾液腺腫瘍157例の治療ならびに経過について検討し以下の結果を得た。1.良性腫瘍の94例の治療は, 切除70例, 摘出23例, 凍結手術1例であった。2.良性腫瘍の治療の結果では, 多形性腺腫50例中3例に再発が見られた。3.悪性腫瘍の63例の治療は, 手術単独41例, 手術+放射線11例, 手術+放射線+化学療法1例, 放射線単独7例, 放射線+化学療法3例であった。4.悪性腫瘍の累積生存率は5年, 10年, 15年, 20年がそれぞれ76.9%, 63.6%, 44.0%, 32.1%であった。5.悪性腫瘍の1次症例59例の10年累積生存率は, stage別ではstage I: 90.0%, stage II: 69.2%, stage III: 50.0%, stage IV: 42.6%, 全体では62.3%, 部位では口底83.9%, 頬粘膜71.4%, 口蓋60.1%, 日後部50.0%, 歯槽部25.0%, 組織型では腺様嚢胞癌70.3%, 粘表皮癌68.2%, 悪性多形性腺腫66.7%, 腺癌20.0%, 治療法では手術単独76.1%, 手術+放射線と手術+放射線+化学療法72.7%, 放射線単独と放射線+化学療法10.0%であった。6.悪性腫瘍の1次症例59例において経過中頸部リンパ節転移, 遠隔転移を認めたものはそれぞれ15例, 18例 (肺15例) であった。1次治療後再発, 腫瘍の残存がそれぞれ11例, 3例に見られた。遠隔転移, 再発, 腫瘍の残存の発生率は腺様嚢胞癌で高かった。

下顎骨エナメル上皮腫24例の臨床・組織所見および治療法と予後の関連について検討した。24例のX線像は単胞型12例, 多胞型9例および蜂巣状3例で, 前方部症例 (前歯一小臼歯部) 9例中6例が多胞型または蜂巣状であるのに対して, 後方部症例 (大臼歯―下顎枝部) 15例では9例が単胞型であった。一方, 埋伏粛を伴う比率は後方部症例 (10/15) の方が前方部症例 (2/9) に比べて高かった。WHO分類による組織型はfollicular type6例, plexiform type16例, acanthomatous type1例で, 後方部症例は大部分がplexiform typeであった。治療法は2例に下顎骨辺縁切除術が行われ, これらは再発もなく経過良好であった。摘出掻爬術は21例に施行され, 4例に再発がみられた。再発率は多胞型または蜂巣状X線像を示すもの (3/12) およびfollicular type (3/6) の方が単胞型 (1/12) やplexiform type (1/16) に比べて高かった。免疫染色が可能であった12例のPCNA陽性率は3.3～42.1%に分布し, その平均値は22.3%であったが, 陽性率と再発の有無に関連はみられなかった。

A 69-y-old man with a history of hepatitis C since May 1985 and his 6 healthy immediate relatives were examined for hemagglutination inhibition antibodies against 2009 pandemic influenza A/H1N1 virus. This patient had a hemagglutination inhibition antibody titer of 640 against 2009 pandemic influenza A/H1N1 virus in a serum sample collected on July 4, 1999, and the antibody titers fluctuated between 40 and 320 in serum samples collected after 1999. The fluctuations in hemagglutination inhibition antibody titers against pandemic 2009 influenza A/H1N1 virus were not consistent with his history of seasonal influenza, and our results suggest a relationship to his vaccination with seasonal trivalent inactivated influenza vaccine. This patient as well as three relatives showed cross-reactive antibody titers of 10 or more against 2009 pandemic A/H1N1 influenza virus in serum samples taken after June 1999. From these results we conclude that the cross-reactivity to pandemic 2009 A/H1N1 influenza virus emerged after June 1999.

1967年8月から1992年7月までの25年間に, 北海道大学歯学部口腟外科で病理組織学的に小唾液腺腫瘍と診断された166症例について臨床的に検討し以下の結果を得た。1.良性腫瘍は60.8%, 悪性腫瘍は39.2%であった。2.部位では口蓋に最も多く, 全体の62.7%を占めていた。3.組織型では多形性腺腫が最も多く, 全腫瘍の59.0%, 良性腫瘍の97.0%を占めていた。4.悪性腫瘍では, 粘表皮癌, 腺様嚢胞癌が多く, 両者で全体の31.4%, 悪性腫瘍の80.0%を占めていた。5.良性腫瘍は男性 (39.6%) に比べ女性 (60.4%) に多く, 悪性腫瘍でも男性 (41.5%) に比べ女性 (58.5%) が多かった。6.平均年齢は良性腫瘍では44.2歳, 悪性腫瘍では53.7歳で, 良性では各年代にほぼ均等に分布していたが, 悪性では中高年齢層に多かった。7.疼痛, 潰瘍, 大きさ (≧41mm) が悪性腫瘍では頻度が高かった。8.口底, 日後部, 歯槽部, 舌に生じたものは悪性の比率が高かった。

One of the osteopetrotic mutations in the rat, incisors-absent (ia), exhibits generalized skeletal sclerosis and failure or delay of tooth eruption, characteristics of other osteopetrotic mutations. Osteopetrosis in ia rats is known to be due to a reduction in bone resorption, the result of the inability of ia osteoclasts to elaborate a ruffled border. During healing of extraction wounds, especially the initial period, osteoclastic resorption of alveolar bone is considered to be a significant feature, followed by new bone formation. We have studied extraction wound healing in osteopetrotic (ia) rats histologically in order to determine if their systemic reduction in bone resorption changes the sequence or rate of alveolar bone healing within and outside the socket after tooth extraction, In ia rats, the healing process was delayed in comparison to that of normal rats. Many osteoclasts were observed on the surface of alveolar bone, but there was little evidence of resorption. Bone formation in the socket following bone resorption was reduced and the newly formed trabeculae were irregular. In contrast, the quantity of resorption-independent (periosteal) new bone formation outside the socket was exaggerated compared to normal animals. These data indicate that the disturbance of new bone formation in the socket is probably related to the reduction in osteoclastic bone resorption.

A case of spindle cell lipoma of the tongue is presented. The patient, a 71-year-old man, had a painless swelling of the tongue. Physical examination revealed two discrete, tender masses in the left ridge of the tongue. These masses were removed surgically. Histopathologically, they consisted of small groups of mature lipocytes separated by spindle cells and of stroma to composed of bundles of collagen fibers and mucinous materials. The spindle cells had a single fusiform nucleus. The histopathological diagnosis was spindle cell lipoma. Spindle cell lipoma commonly arises in the posterior neck, upper back, and shoulders and is extremely rare in the oral cavity. Only nine cases have been reported in the literature.

A 26-year-old woman was referred to our clinic on December 22, 1993, because of limited mandibular movement. Minor restriction of mouth opening was first noticed at 10 years of age, during a dental health examination. The patient became aware of pain and swelling of the right masseter region with decreased jaw movement at the end of November 1993.Clinically, the patient had a square face with prominent masseter muscles and mandibular angles. The interincisal opening was 22mm, with limitated lateral and anteroposterior mobility. A dense band of tissue, which became taut on maximal opening, was palpable along the anterior border of each masseter muscle.The clinical diagnosis was restricted mouth opening due to bilateral hyperplasia of the masseter muscle aponeuorses. Masseter muscle myotomy with aponeurectomy was performed bilaterally by an intraoral approach on May 18, 1995. The aponeuroses extended for three quarters of the length of the masseter muscles, down to the inferior borders of the mandible. The mouth opening improved to 46mm on incision of the aponeuroses.An examination of the patient 3 years after surgery revealed an interincisal opening of 38mm without strain.

A case of an odontogenic tumor which invaded the intracranial space from the mandible is reported. Judging from the radiographic images it was similar to a malignant tumor. The patient died 17 years after the first visit. According to the final pathological diagnosis, it was malignant odontogenic mixed tumor of low grade which did not belong to any of the WHO classification.

A case of unilateral enlargement of the coronoid process of the mandible is presented. The patient, a 37-year-old woman complained of restricted mandibular movement and swelling in the left zygomatic region. Coronoidectomy was performed intraorally, producing improved mandibular movement. The specimen consisted of a large amount of cartilage and mature bone. Most of the cartilage showed a marked disturbance in endochondral ossification. The histopathological diagnosis was osteochondroma. A review of the basic nature of the disease in the reported cases is presented. The value of computed tomography in deciding on a surgical procedure is briefly mentioned.

A case of non-Hodgkin's lymphoma occurred in the right mandible of 7-year-old boy is presented. He consulted the dental hospital, Hokkaido University with a chief complaint of swelling of the mandible. Histopathological and immunohistochcmical investigations showed that the lesion was malignant lymphoma, lymphoblastic (WF) or diffuse lymphoma, lymphoblastic type (LSG), and T cell phenotype. The clinical classification was stage IIIE, and radiotherapy and chemotherapy were performed. He is still alive without tumor for 6 years from the clinical onset of the disease.

Odontogenic ghost cell tumor, considered to be a solid type of calcifying odontogenic cyst, is a rare entity, and only a few cases have been reported in the English and Japanese literature. Here, we report a case of odontogenic ghost cell tumor in a 59-year-old man. The patient presented with a painless swelling in the mandible. The swelling extended from the first right molar region to the ramus. Radiography revealed a relatively well defined radiolucent lesion containing some irregularly-shaped radiopaque masses and an impacted third molar. Segmental resection and reconstruction with an iliac cancellous bone graft and a titanium mesh plate were performed. Histopathologically, there was evidence of tumor invasion of the periphelial cortical bone, areas consisting of large amounts of calcifying flaky keratin close to masses of ghost cells, and dysplastic dentinoid matrix adjacent to epithelial cell nests. Atypical mitosis was not found. A final diagnosis of “central odontogenic ghost cell tumor” was made. Three years after operation, the patient is well with no signs of recurrence.

Background. The purpose of this study was to investigate the incidence and clinical significance of genetically diagnosed lymph node micrometastasis for patients with oral squamous cell carcinoma (SCC). Methods. A total of 495 lymph nodes obtained from 21 patients with primary oral SCCs that had p53 mutations were examined for corresponding p53 mutations in lymph nodes using mutant allele–specific amplification (MASA). Results. Among 476 histologically negative nodes, 44 were scored as positive for metastasis by MASA. All 19 histologically positive lymph nodes were genetically positive. Four of the 10 pN0 cases and nine of the 11 pN-positive cases had genetically positive micrometastases. Four patients who had five or more genetically positive lymph nodes located in three or more levels, three with disease staged as pN0 or pN1, died of cancer. Conclusions. These results indicate that a high rate of micrometastasis in cervical lymph nodes of oral SCCs and patients with multiple or lower neck spread of micrometastases have a poor prognosis; they should be treated with postoperative adjuvant therapy. © 2005 Wiley Periodicals, Inc. Head Neck27: XXX–XXX, 2005

Five infants exhibited an exclusively facial rash associated with Gianotti-Crosti syndrome(GCS). On all patient cheeks, multiple erythematous papules were seen symmetrically. All patients tested positive for the immunoglobulin (Ig)M antibody against the Epstein-Barr viral capsid antigen, suggesting that a primary Epstein-Barr virus (EBV) infection caused localized facial rash, an alternative clinical picture of GCS.

Osteoporosis is associated with many etiological causes such as nutrition, cytokines, hormones, and aging. Recently, reactive oxygen species (ROS) are considered to be responsible for the aging process and osteoporosis. We investigated the relationship between ROS and bone metabolism in young female and postmenopausal rats, by using dietary iron overload and several indices including bone metabolic markers, oxidative stress and antioxidant markers, and cytokines. Postmenopausal rats exhibited significant decreases in serum alkaline phosphatase activity and the level of osteocalcin as bone formation markers compared with young female rats; however, urinary excretion of deoxypyridinoline, a bone resorption marker, did not change. On the other hand, a 5% iron lactate diet for 4 weeks in postmenopausal rats led to significantly increased excretion of urinary deoxypyridinoline and 8-hydroxy-2'-deoxyguanosine (8-OHdG) but not serum alkaline phosphatase activity. Interestingly, the diet induced significant increases of serum osteopontin and TGF-beta1, augumenting osteoclast-mediated bone resorption through the RANK/RANKL pathway [J. Clin. Invest. 112 (2003) 181]. TGF-beta1 showed a negative correlation with serum glutathione peroxidase (GPx) activity (r = -0.674, P < 0.003), but a positive correlation with the serum iron level (r = 0.836, P < 0.0001). Taken together, these results suggest for the first time that oxidative stress could be involved in the pathogenesis of metabolic bone diseases such as osteoporosis as demonstrated by analysis of the relationship between bone metabolism and oxidative stress.