Male Wistar rats, six-week-old corresponding to the human school age were used, and the effect of high calcium diet intake on bone formation in the mandibular condyle at the growing stage was investigated. The results were as follows : 1. Body weght The rats, 6-week old, were divided into their respective groups and maintained to 11-week old. As a result, no significant differences (p<0.01) were found among the groups. 2. Hematologic findings No changes were found in electrolyte in blood serum and in biochemical examinations among the groups. 3. Histopathological findings Calcium deficient food group, as compared with the controls, showed decrease in calcified matrix enclosing hypertrophic layer and in chondroclasts resorbing calcified matrix. Calcium-low diet group, especially Unical^[○!R] diet group, showed increase in chondroclasts and in invasion of calcified matrix around, which continued with densely arranged bone trabeculae where bone formation was identified active by increased osteoblasts and osteoclasts. The group showed marked findings of recovery of bone architecture and approximated the control group. 4. Scanning electron microscopic findings Calcium deficient food group, as compared with the controls, showed decrease in calcified matrix in cartilage lacuna. Calcium-low diet group showed increased calcified matrix in cartilage lacuna. Particularly Unical^[○!R] diet group showed active bone formation while bone formation and resorption areas mixed. From the above results, calcium facilitated bone formation in rat's condylar cartilage. Dietary treatment itself could not help with recovery of bone tissue from calcium deficiency in weaning age ; while the restoration and promotion of bone matrix formation were revealed in school childhood, where bone loss from calcium insufficiency was followed by continuing balanced dietary therapy. The action was thought to be related to the activity of hormones regulating bone metabolism

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Lingual papillae of four Japanese raccoon dogs (Nyctereutes procyonoides viverrinus) were invesigated by scanning electron microscopy. A well-developed Lyssa, running parallel to the long axis of the tongue, was observed in the middle portion of the anterior part of the tongue. Four types of distinct papillae could be distinguished on the dorsal lingual surface. These were filiform, fungiform, foliate and circumvallate papillae. Among them, circumvallate papillae, 5-7 in number, were located in the root of the tongue and were the largest among the papillae. Remak's ganglion cells and mechanosensory nerve corpuscles were frequently appeared in the lamina propria of the circumvallate papillae. Further, taste buds of circumvallate papillae were examined by transmission electron microscopy. Taste bud was composed of four distinct cell types, type I, type II, type III and type IV cells as well as nerve terminals. Most characteristic features of type III cells was the presence of numerous dense-cored granules, ranging from 80 to 120nm in diameter, and synaptic type vesicles in the cytoplasm. This type of cells made synaptic contacts with adjoining nerve terminals and was considered to be gustatory transducing cells. Type III cells of racoon dog taste buds occasionally contained well-developed smooth endoplasmic reticulum which arranged in the form of concentric circles. At the fringes of these structures, the smooth endoplasmic reticulum were sometimes in direct continuity with the rough endoplasmic reticulum. Type I cells were dark in appearance and contained numerous secretory granules in the apical portion of the cytoplasm, and were considered to be exocrine cells. Whereas, type II cells were light cells and characterized by the presence of smooth endoplasmic reticulum throughout the cytoplasm and special contacts with nerve terminals. Taste bud cells occasionally contained unusual nuclear inclusions. Further, they sometimes showed condensed and fragmentary nuclei suggesting the occurrence of cell death by apoptosis. It is tempting to speculate that there might exist multiple cell lines in cell lineage of taste bud cells.

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The influence of diet therapy on bone matrix formation was examined in the tibial metaphysis by endochondral ossification. Eight-week-old male Wistar rats corresponding to humans during adolescence were fed a calcium-deficient diet (0.01mg/100mg) or a low-calcium diet (144mg/100g) for 6 weeks, or the same diet for 3 weeks to induce a fragile state, followed by a standard diet for 3 weeks as a diet regimen. The following results were obtained. 1. Histopathologic findings showed a wider chondrocyte layer, decreased calcified matrix, and reduced erosion of the calcified matrix in the thickened zone chondrocytes and columnar gaps, particularly in the group fed a calcium-deficient diet compared with those in the control group. In the group fed low-calcium and standard diets, the width of the chondrocyte layer was reduced, and the calcified matrix and erosion of the calcified matrix in the columnar gaps were increased, which were findings similar to those in the control group, indicating facilitation of bone matrix formation by endochondral ossification. 2. In enzymohistochemical findings, ALP-positive cells indicating osteoblasts on the surface of the osseous beam continuing from the new osseous beam toward the lower part in the group fed low-calcium and standard diets were similar to those in the control group. TRAP-positive cells indicating osteoclast-like cells in the group fed low-calcium and standard diets were similar to those in the control group. 3. Histomorphometric findings demonstrated that the number of osteoclasts per unit area of the secondary cancellous bone was significantly increased in the order of the group fed a low-calcium diet<the group fed calcium-deficient and standard diets<the group fed a calcium-deficient diet, compared with that in the control group. However, there was no significant difference between the group fed low-calcium and standard diets and the control group. This study performed histopathologic examination, enzymohistochemical examination, and measured the number of osteoclast-like cells concerning bone resorption of bone metastasis as histomorphometry for quantification, to concretely examine the effects of diet therapy by administering calcium for bone in a fragile state on bone matrix formation. Consequently, bone that had been in a fragile state during adolescence, particularly in the group fed low-calcium and standard diets, showed almost the same findings as those in the control group after balanced diet therapy with calcium, demonstrating recovery of bone matrix formation by endochondral ossification.

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The genesis of temporomandibular joint disorders are not clear since there are many complicated factors involved. The purpose of this study is to investigate the morphology of the mandibular fossa. The focus will be on the radiological evaluation between ancient and modern Japanese who experienced different life styles and dietary habits. The specimens used in this study are the possession of the Graduate School of Social and Cultural Studies at Kyushu University. There are 19 specimens (males : 10, females : 9) from the Jomon period, 202 specimens (males : 87, females : 115) from the Yayoi period, and 206 specimens (males : 118, females : 88) from the modern period. The radiographs of the mandibular fossa, using the modified Schuller technique, were studied. The length, depth, and area of the mandibular fossa and the angulation of the frontal slope of the mandibular fossa on the radiographs were automatically computed. The results obtained were as follows : 1. The length of the mandibular fossa of the right side was significantly different from that of the left in the male skulls of the Yayoi period and the human skulls of the Modern period. The differences in the length between the right and left sides became progressively larger between the Yayoi and Modern periods. 2. There were no significant differences in the right and left side depth of the mandibular fossa within and between periods. 3. The area of the mandibular fossa of the right side was significantly different from that of the left side in the male skulls Yayoi period and the human skulls of the Modern period. The differences in area between the right and left sides became progressively larger between the Yayoi and Modern periods. 4. The angulation of the frontal slope of the mandibular fossa of the left side was significantly larger than that of the right side in the Modern period male and female skulls. The angulation of the anterior slope of the mandibular fossa in the Modern period was smaller than that in other periods. However, the differences between the right and left sides in the angulation of the anterior slope progressively increased between the Yayoi and Modern periods. The differences between the right and left sides in anterior slope angulation in the Modern period caused the asymmetry of the mandibular fossa. From the above results, it was shown that the morphology of the mandibular fossa is changed and the asymmetry of the mandibular fossa morphology is increased between the Yayoi and Modern periods. It may be speculated that this change of the morphology of the mandibular fossa in the Modern period is the result of the increase of the temporomandibular joint disorders.

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Bone mineral content increases with age in developing children and it has been reported that peak bone mass is obtained around 17-20 years of age. Therefore, the accumulation of adequate bone mass in this period is a key determinant in prevention of osteoporosis. Rats aged 5 weeks, corresponding to schoolchildren in human, were used in the present study. The effects of dietary therapy rich in calcium content on mandibular osteoporosis produced by calcium deficiency were investigated, using computed X-ray densitometry and cephalometry. The results were as follows. 1. Weight Calcium deficient animals exhibited significantly lower weight than control animals 4 weeks post-experimentally (p<0.05). The difference disappeared, however, after the animals were fed standard diet for 8 weeks. 2. Densitometry No significant differences were identified between the control and experimental groups in bone density of mandibular angle, condylar and coronoid processes. 3. Cephalometry A. Coordinate analysis The experimental groups exhibited significantly lower values than control group in mandibular angle, condylar and coronoid processes (p<0.05). However, no significant differences were found between the experimental and control groups in mandibular body and alveolar process. B. Distance measurement The experimental groups showed significantly shorter mandibular border, ramus, and coronoid process than the control animals (p<0.05). C. Area measurement The experimental groups showed significantly less area of mandibular angle and condylar process than the control animals (p<0.05). From the foregoing results, dietary therapy rich in calcium content showed a nagetive result for recovery of mandibular osteoporosis in school childhood with cephalometric investigation, but gave a positive result measured by computed X-ray densitometry.

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D-aspartate oxidase (EC 1.4.3.1) is a flavoprotein that catalyzes the oxidative deamination of dicarboxylic D-amino acids by O_2 with the production of H_2O_2, NH_3, and corresponding α-keto acids. The presence of D-aspartate oxidase has been reported in many mammalian tissues, showing that the enzyme differs from D-amino acid oxidase (EC 1.4.3.3), and is located in the peroxisomes of mammalian liver and kidney. However, there is no report on the properties of D-aspartate oxidase in mammalian oral glands. D-aspartate oxidase activity was detected in the homogenate of rat submandibular gland. Subcellular distribution of D-aspartate oxidase of the tissue was examined by sucrose-density gradient centrifugation. D-aspartate oxidase was found to be present in the peroxisomes with the same densities as those of mammalian liver and kidney ; the enzyme was located in the peroxisomal membrane or core. The peroxisomal enzyme was highly specific towards N-methyl-D-aspartate (NMDA) and D-aspartate out of 19 D-amino acids tested. The same results were obtained in other salivary glands (sublingual gland and parotid gland) with respect to the subcellular distribution and substrate specificity of D-aspartate oxidase. On the other hand, D-amino acid oxidase activity was not detected in the salivary glands, showing that D-aspartate oxidase is used as a peroxisomal marker in the salivary glands.

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A novel dihydropyridine Ca^<2+> channel blocker, cilnidipine has been shown to serve as an Ca^<2+> antagonist to L- and N-type Ca^<2+> channels and an anti-nociceptive drug. However, there are no reports to show anti-nociceptive action of cilnidipine, and also whetrher cilnidipine inhibits Ca^<2+> channel or not in the spinal cord is unclear. We evaluated the modulatony effect of intrathecal administration of cilnidipine on the flinching behavior and CSF-glutamate release, which was analyzed with microdialysis, caused by formalin injection into the rat paw. The effects were compared with those of ω-conotoxin, a N-type Ca^<2+> channel blocker, and nimodipine, a L-type Ca^<2+> chennel blocker. Cilnidipine in a dose of 100ng significantly attenuated biphasic increases in flinching behavior after formalin injection, and this attenuating effect was not reversed by intrathecal coadministration of 100ng BAY-K8644, L-type Ca^<2+> channel activator. Intrathecal 300ng ω-conotoxin also blocked both the first and second phase of flinchings by formalin injection, but nimodipine was much less effective to both the first and second phase of flinching. The increase in CSF-glutamate release evoked by formalin was inhibited by cilnidipine and ω-conotoxin. These results suggested that intrathecal cilnidipine provokes antinociceptive effect via the pre-synaptic action, that is, suppression of spinal glutamate release, implying cilnidipine produces analgesia by inhibiting N-type Ca^<2+> channels rather than L-type Ca^<2+> channels.

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Serotonin (5-HT) is one of the well known monoamine neurotransmitters, mitogen, and hormones, which mediate a wide variety of physiological effect, including peripheral and central actions. The large variety of 5-HT functions is paralleled by the pharmacological complexity of 5-HT receptors which can be classified into different families depending on their signalling pathways. A study by 5-HT2B antagonists showed 5-HT and 5-HT2B receptor function in development of tooth germ. To elucidate the role of them, I have examined the localization of 5-HT immunohistochemically and the expression of 5-HT2B subtype receptor by in situ hybridization in rat tooth germ. At the bud stage both 5-HT and 5-HT2B mRNA were not detected in incisors and molars. At the cap stage both 5-HT and 5-HT2B mRNA were detected in the enamel organ and dental papilla. 5-HT were intensely localized at the inner enamel epithelium. Otherwise 5-HT2B mRNA were intensely expressed in the mesenchymal cells of the dental papilla. At 1 day postnatal presence of 5-HT and 5-HT2B mRNA were also shown in the tooth germ of incisor and molar. However their intensity were decreased gradually in the process of differentiation of ameloblasts and odontoblasts. These results indicate that 5-HT and 5-HT2B play a role in tooth development.

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The mechanisms of pathological pain processes including hyperalgesia and allodynia after peripheral nerve injury have not been fully understood. Several recent studies have suggested that neuronal plasticity of spinal neuronal transmission such as glutamatergic nerve activation and its related chemical cascades may be responsible for developing pain sensitization. Therefore, it is reasonable to determine whether apoptosis results from gulutamatergic activation via acceleration of intracellular and nuclear signaling processes. Sarpogrelate HCl (MCI) is newly produced compound and that affects on Serotoninergic neurons (5-HT_<2A>). The present study was designed to investigate the response to thermal stimuli in relation to histopathological changes after chronic construction injury (CCI) in rats. In addition, the present study was evaluated whether seroninergic neurons located in peripheral site may regulate neuropathic pain produced by CCI. The left sciatic nerve of SD rat were ligated under pentobarbital anesthesia. Paw withdrawal latency (PWL), response to thermal stimuli, was measured by using the plantar testing apparatus before CCI and at 6, 8, and 10th days after CCI. Immunohistchemical stainig for apoptosis (TUNEL) and early degeneration (H-E) was performed with light microscope at the corresponding days. TUNEL stain score was counted positive neurons and HE stain score was obtained as 0 : normal neuron to 3 : more than 50% neuronal degeneration. In addition, rat was divided into the three series of study by drug administration ; 1) Saline 0.5ml i.p., 2) MCI 10mg/kg i.p. and 3) MCI+α-methyl-5HT 10mg/kg i.p., 5-HT_<2A> agonist. The hyperalgesia evoked at 6 day after sciatic nerve ligation in rats. In these rats, the apoptosis development was found more at 6 than 10 day. In contraction, the neuronal degeneration occurred more at 10 day. By administration of MCI, pain behavier, apoptosis, and neuronal degeneration was inhibited significantly. The present results demonstrate that apoptosis development was firstly found in the superficial layer of spinal cord in early state of hyperalgesia. This may be suggested that sciatic nerve injury leads to increased ascending inputs or glutamatergic nerve activation followed by derangement of intracellular signaling-intranuclear process (c-fos exprerssion) in the spinal cord which causes apoptosis leading to pain behaviour. It is also suggested that the delayed appearance of neuronal degeneration in the laminae III-IV causes dysfunction of inhibitory interneurons located in this regions and this neuronal damaged is sufficient to develop the sustained pain behaviour. In addition, MCI adoministration provokes antinociceptive effect on neuropathic pain produced by CCI and this effect was reversed by 5-HT_<2A> receptor agonist. It is suggested that the serotoninergic activation take a part of neuropathic pain, the inhibition of this activation is very important of treatment of neuropathic pain.

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TGF-β has been shown to have the potential to stimulate bone formation. The purpose of this study is to examine the role of TGF-β in bone formation in the extraction cavity after tooth extraction in mice. First, the enzyme-positive area was examined histochemically for alkaline phosphatase (ALP) and tartrate resistant acid phosphatase (TRAP) was examined in the sections of the decalcified tooth and periodontal tissue of mice from the first day to the 14th day of tooth extraction. The TRAP-positive areas remained at a low level during the first 5 days, rapidly increased on 7th day, and remained at a high level thereafter. The ALP-positive areas increased similarly, but with a log of 3 days. Anti-TGF-β neutralizing antibodies were injected in the submucosal tissue near the extraction cavity on an appropriate day between the first and the 14th day after tooth extraction. The effect of anti-TGF-β antibodies on trabecular bone area, ALP-positive area, or TRAP-positive area in the extraction cavity was examined using frozen sections from the decalcified periodontal tissues of the mice 12 days after tooth extraction. In the case of ALP staining, the enzyme-positive area significantly increased in sections from the mice injected with the antibodies 3 days or 7 days after tooth extraction. The ALP-positive area appeared to involve a decreasing tendency in the case of injection on the 5th day after tooth extraction. In the case of TRAP staining, the enzyme-positive area appeared to involve be a decreasing tendency in the sections from the mice injected with the antibodies 10days after tooth extraction. The trabecular bone area was significantly decreased in the sections from the mice injected with the antibodies 3 days after tooth extraction compared to those injected with saline on the same day. There was no significant difference between the other sections described above in the antibody injection group and those in the saline injection group. Thus, the above results suggest that the role of TGF-β in bone formation depends on the number of day after tooth extraction.

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The postoperative findings of the unilateral vertical ramus elongation using intraoral vertical ramus osteotomy (IVRO) were studied experimentally. Adult Japanese monkeys (macaca fuscata) were used for the experiments. Changes of the postoperative proximal segment of the monkeys including their TMJs were examined radiographicaliy and histopathologicaliy. Thirteen Japanese monkeys with permanent teeth were used. Study groups were made up of a sham group (4 animals), an experimental group (8 animals) and a control (1 animal). Bilateral IVRO was performed on the animals of the experimental group. After osteotomy, metal splints were cemented to the left lower molar teeth to elongate the rami 10mm vertically. The animals of the sham group underwent only osteotomy, and the rami were not elongated. The control animal did not undergo any operations. The following results were obtained. 1. Postoperative occlusion of the sham group and the experimental group was as stable as the occlusion at the time of operation. In the experimental group, relapses were not observed during 12 postoperative months in spite of 10mm of elongation. 2. Radiographically, the left proximal segment of the experimental group monkeys were rotated backward immediately after the operation until the 1st postoperative month. This backward rotation decreased after the 3rd postoperative month and returned to the preoperative position after the 6th postoperative month. 3. Histopathologically, the cartilaginous layer of the mandibular condyle was thick from the center to the rear at the 1st postoperative month at the elongated side of the experimental group. This thickness decreased at the 3rd postoperative month. Bleeding, which was probably due to the stress of IVRO, was observed in the superior joint cavity until the 3rd postoperative month. In the no-elongated side of the experimental group, the thickness of the cartilaginous layer of the mandibular condyle had become thinner than in the elongated side, and adhesions were observed between the articular disk and joint surface until the 3rd month. Degenerative changes were not found in any of the groups. After the 6th postoperative month, the histopathological findings of the TMJ of the experimental group and the sham groups were similar to those of the control. These results suggest that the effect of unilateral vertical ramus elongation using IVRO for the proximal segment and for the TMJ did not continue for a long time, because of production of a more functional articular disk-condyle relationship by repositioning of the proximal segment and the condyle and/or remodeling of the condyle.

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Spinally delivered adenosine receptor agonists and its analogs have recently been shown to have antinociceptive effects. However, the mechanisms by which adenosine produces antinociception are not clear. Therefore, the present study evaluated the modulating effect of adenosine A_1 receptor agonist, R-PIA injected intrathecally (I. T.) on the tactile-allodynia, associated with cerebrospinal fluid (CSF)-glutamate release induced by injection of gammna amino butyric acid. The microdialysis probe and polyethylene tube (PE-10) was intrathecally implanted into lumbar segment under halothane anesthesia in fourty-three Sprague-Dawley rats. After three days, rats were divided into three groups ; i) Control (saline, I. T.) ; ii) R-PIA at doses of 1nM, 3nM, and 10nM, and iii) 10nM R-PIA plus 300nM aminophylline. The tactile-allodynia was evaluated by touch-evoked agitation (TEA) which was scored 0 (no response to hair touching at lumbar level) to 3 (strong agitation appeared). Using an intrathecal microdialysis, glutamate concentration in cerebrospinal fluid (CSF-Glu) was periodically (10min intervals) determined simultaneously by a HPLC-ECD. Intrathecal BIC injection evoked a transient strong agitation (TEA score : 4.7 at 10min, 1.0 at 30min), associated with increased CSF-glu (70% at 10min.). R-PIA attenuated such increases of TEA and CSF-glu dose-dependently (3nM : 1.2 and 0.3, 10nM : 0.3 and 0.1). Such action of R-PIA (10nM) was reversed by codeliverly of aminophylline (300nM). Based on the present study, it is clearly demonstrated that R-PIA can prevents allodynia in a dose-dependent manner. This attenuating effect was reversed by adenosine A_1 receptor antagonist, suggesting R-PIA has a potent anti-allodynic effect via inhibiting adenosine A_1 receptor activity at spinal cord. In addition, the microdialysis study demonstrated that R-PIA attenuates increased spinal glutamate release evoked by allodynia through presynaptic inhibition of primary afferent input.

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The neuropathic pain developed following peripheral nerve injury may be mediated by upregulated synaptic transmission of spinal cord. N-type Ca^<2+> channel localized in pre-synaptic terminals has been shown to modulate the release of neurotransmitter. Previous studies have demostrated that N-type Ca^<2+> channel blockers suppress peripheral nerve neuroplasticityinduced neuropathic pain. Cilnidipine is a newly synthesized 1, 4-dihydropyridine (DHP)-type Ca^<2+> channel blocker. This study analyzed that effect of intrathecal infusion of cilnidipine on the response to thermal stimulation and histo-pathological changes after chronic constriction injury (CCI) in rats. Male Sprague-Dawley rats was implanted with intrathecal (I.T.) catheters under 2&acd;3% halothane anesthesia according to the modified method of Yaksh and Rudy (1976). The left sciatic nerve of rats was ligated under 2&acd;3% halothane anesthesia. Paw withdrawal latency times (PWL) of response to thermal stimulation were measured in these rats by using the planter test equipment before CCI (pre) and at 3, 5, 6, 8, and 10 days after CCI. Rats were separated into three groups. : 1) saline 10μl 2) L-, N-type Ca^<2+> channel blocker cilnidipine 100ng/10μl 3) L-type Ca^<2+> channel activater BayK8644 100ng/10μl+cilnidipine 100ng/10μl. Each drug group was injected by I.T. catheter, everyday from 5 days after CCI. Histochemical analysis for apoptosis (TUNEL stain) and neuronal degeneration (HE stain) in the laminae I-II, III-IV in spinal cord (L3-5) in rats was performed with light microscope (40 and 400 times) at the 6 and 10 days after CCI, respectively. The left paw withdrawal latency time was significantly increased on thermal stimulation by intrathecal infusion of cilnidipine than saline. Apoptic and necrotic neuronal degeneration was significantly decreased at the lamine I-II and III-IV by intrathecal infusion of cilnidipine than saline. The present results clearly demonstrated that cilnidipine prevents the sensitization evoked by thermal stimulation which is associated with effect on apoptotic and necrotic neuronal degeneration. This effects were not antago-nized by giving L-type Ca^<2+> channel agonist, BayK-8644. These results showed that cilnidipine may regulate pain sensitization produced by sciatic nerve ligation, suggesting that cilnidipine has beneficial effect in developing thermal neuropatic pain via mechanism by inhibiting N-type Ca^<2+> channel.

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It was demonstrated in the previous report that the consistency, setting time, film thickness and compressive strength of the luting cements were significantly changed by the variation of mixing time and P/L ratio within the dispensational errors. In this report, the questionnaire on the aspects of usage of the cements in private dental offices was performed to 47 practicioners in our study circle in order to analyze and improve the storage and manipulation of luting cements in practice. The reply to the questionnaire came to hand from 34 dentists out of 47 (72.3%), the glassionomer cements are most widely used (73.5% of offices) and the adhesive resin cements are the next (70.6%). The choice of the type and/or product of the material is mainly based on a "adhensiveness" (97.1%), "little or no irritation to pulp" (70.6%) and "high strength" (52.9%). Mixing of the cements follows the recommendation of the manufacturer in most offices. Although some offices pay careful attention to the storage condition, the temperature of the mixing instruments is little controlled. The cement powder and liquid are usually dispensed just before mixing in many offices. However, the dispensed materials are sometimes unintentionally left on the mixing pad for less than 5 minutes for certain reasons with other works, or at most 10 minutes during the busiest time.

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