The purpose of the present study was to evaluate periodontal wound healing and the regenerative nerve responses following the implantation of different sized porous Hydroxyapatite granules (HAP) (large size : 600 to 1000μm, small size : 100-400μm) in the experimental periodontal defects of 21 mongrel dogs. Three-wall bone defects (3mm×3mm×3mm) were prepared at the second and the fourth premolars for this experiment following a healing period of 3 months after extracting the bilateral 3rd premolars in the mandible. Either the large or small sized HAP granules were implanted in the left and the right side alternatively. Thereafter, the dogs were sacrificed at 1 day, 3 days, 1 week, 2 weeks, 1 month, 3 months and 6 months postoperatively. The sections were examined with hematoxylin-eosin stain and Ungewitter's silver nitrate method based on the modification of Powers, and they were also observed by a light microscopic analysis. In addition, a histomorphometrical analysis was carried out for the period from 1 month to 6 months. The results were as follows : 1. The healing process was similar in both groups. 2. A long junctional epithelial attachment was observed in both groups. There was no difference on the length of epithelial attachment in both groups. 3. In new bone formation the HAP granules were observed to conjugate with each other in the new bone. In addition, the HAP granules were suggested to have such osteogenic activities as osteoconduction and osteoinduction. 4. Regarding the histomorphometrical analysis, the small size group showed a larger amount of new bone formation than the large size group. 5. Ankylosis formed between the tooth and new alveolar bone. The new ligament was found to be different from the normal structure. 6. The regenerative nerve innervation was influenced by the new bone formation and also showed a difference between the small and large size groups. 7. The regenerative nerve (inferior alveolar nerve) terminals were observed to come in contact with the undifferentiated mesenchymal cells and multinucleated giant cells that adhered to the HAP granules in both groups. As a result, the nerves may possibly be related to the bone formation. As described in the above study, in order to accurately evaluate bioactive materials for application in periodontal therapy, the use of neurohistological studies are indispensable.

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In the present study, we fed thirty young Wistar rats that were in the secondary sexual characteristic period on calcium deficient diet so the osteoporotic mandible, which was thought as a reason for the declining of masticatory force and masticatory ability, was resulted in. After that we researched the effect of dietary therapy on the matrix formation of these osteoporotic mandible. The high calcium diet was made from sea shell, called UNICAL^[○!R]. The results were shown as follows. 1. Microphotometric findings Significant differences were observed between the control group, calcium deficient・standard diet group, calcium deficient・UNICAL^[○!R] group and low calcium・UNICAL^[○!R] group (p<0.01). And significant differences were also observed between control group and low calcium・standard diet group (p<0.05). 2. X-ray microanalysis of Ca and P By surface microanalysis, it has been found that density of calcium was higher than phosphorus in any group. Significant differences were found in quantitative analysis which was done by calculating the calcium and phosphorus relative proportion against control group, showed as Ca/[Ca]c and P/[P]c. The results of Ca/[Ca]c were calcium deficient・standard diet group<calcium deficient・UNICAL^[○!R] group<low calcium・UNICAL^[○!R] group<low calcium・standard diet group<control group, while P/[P]c showed as control<calcium deficient・standard diet group<calcium deficient・UNICAL^[○!R] group<low calcium・standard diet group<low calcium・UNICAL^[○!R] group. 3. Histopathological findings As contrasted with control group, the enlargement of bone marrow space, the number and thickness of trabeculae decreasing were obvious in calcium deficient・standard diet group. Bone osteopenia were obviously seen such as decrease of the number of lamellae and lacunae. Compared with calcium deficient standard diet group, the calcium deficient・UNICAL^[○!R] group showed that bone marrow space decreased and bone remolding was active, but the number of lacunae decreased obviously yet and bone still fell into osteopenia when compared with control group. Thicker new bone was seen in low calcium・standard diet group than in calcium deficient・UNICAL^[○!R] group, the number of Haversian system and lacunae increased too. In low calcium・UNICAL^[○!R] group the formation of bone matrix was the same as what was seen in control group.

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Just as long bones, the craniofacial bones develop and grow all through the suckling, the infant (primary sexual characteristic period), the school age, the puberty (secondary sexual characteristic period) and the adulthood. Now in dental field, dentists pay more attention to the mandible because it is a special bone that is affected by masticatory force and serves as a support for teeth. From our serial studies, it has been seen that dietary calcium and bone hormone have great effects on bone mass. In the present study, we used thirty adult rats and divided them into three groups : control group (standard diet), calcium deficient group and low calcium (30%) group. After the mandible debility having been fallen into by the low or deficient calcium diet, we gave them standard diet and then study the dietary therapy effect on it. The results were shown as follows. 1. Body weight No significant differences were observed between the control and experimental groups. 2. Radiographic findings No differences among the three groups were found by naked eyes. 3. Microdensitometric finds There were no significant differences of mandible microdensitometry between the three groups. 4. X-ray microanalysis of Ca and P By surface microanalysis, it has been found that density of calcium was higher than phosphorus in any group. 5. Hematological findings No significant differences were found among the control and experimental groups in serum electrolyte levels. 6. Histopathological findings As contrasted with control group, reduction of lacunae and enlargement of marrow cavities were observed in calcium deficient group, the bone remodeling was also seen in this group. Compared with calcium deficient group, the reduction of marrow and increase of lacunae were seen in low calcium group, and resorption was rarely seen. These findings were equivalent to that of control group. From the above results, it is suggested that bone loss in adult rats can be well restored by dietary therapy, particularly in the low calcium group. We think that balance food is able to have bone recovered from debility. The reasons for the recover are thought as balance diet and bone hormone take great part in this process based on sufficient bone mass having formed till adult hood.

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Protein phosphorylation and dephosphorylation have been recognized as an essential mechanism in the regulation of cellular metabolism and functions in various tissues. cDNA cloning revealed the existence of at least four isoforms of PP1 catalytic subunit, termed PP1 α, PP1γ1, PP1γ2, and PP1δ. PP1 targeting subunit is thought to localize to specific subcellular component and to modulate the activity of the enzyme at these sites. In the present study, we examined the cytolocalization of PP1 isozymes and expression of these proteins in MG63 cells by immunofluorescent technique and Western blot analysis, respectively. PP1α and PP1δ antibodies recognized 38 kDa and 37 kDa proteins, respectively, present in the nuclear and nucleolar regions of MG63 cells, whereas PP1γ1 antibody interacted with 36 kDa protein in cytosolic fraction. This differential distribution of PP1s suggests that these isozymes may act in a sequential fashion on modulating the activity of this enzyme in MG63 cells. Nucleolin is an abundantly expressed nucleolar phosphoprotein and is located mainly in nucleolus. Nucleolin is directly involved in the regulation of ribosome biogenesis and maturation. Staining pattern of nucleolin in MG63 cells is similar to that of the PP1δ. PP1δ and nucleolin were specifically stained as dots in the nucleus. The multiple fluorescence image revealed that PP1δ and nucleolin represent same localization in nucleolus. To examine the interaction of PP1δ and nucleolin, whole cell lysates were immunoprecipitated with PP1δ antibody. The immunoprecipitant was analyzed by Western blotting using anti-nucleolin antibody. The anti-nucleolin antibody interacted with the protein which molecular weight was estimated as 100 kDa indicating. However, the sample precipitated with the normal rabbit serum was not stained with anti-nucleolin antibody. These results indicate that PP1δ associate with nucleolin directly at cellular nucleolus. MG 63 cells were treated with actinomycin D to inhibit r-RNA synthesis. In the actinomycin D-treated cells, subcellular localization of PP1δ and nucleolin were changed. The amount of PP1δ increased whereas the level of and dephosphorylated nucleolin increased. MG63 cells were also blocked in G1/S and G2/M phase by exposing them to hydroxyurea and nocodazole, respectively, and followed by immunoblotting. The intensity of immunoreaction of PP1α, PP1δ and PP1γ1 were different between the proteins prepared from the cells at G1/S and G2/M phase. PP1α increased at G1/S and G2/M phase, PP1δ increased at G1/S and G2/M phase with the intensity was higher at G2/M phase. However, the level of PP1γ1 increased only at G1/M phase. The present results indicate that nucleolin is one of the candidate of PP1δ substrate. The present results also indicate that PP1 is involved in r-RNA synthesis and in cell cycle regulation.

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To determine whether protein phosphorylation and dephosphorylation can affect apoptosis in oral epithelial cells, we examined the effects of protein phosphatase (PP) inhibitors, okadaic acid and calyculin A, on induction of apoptosis in oral squamous carcinoma cell line, SCC-25 cells. After reaching subconfuluence, these cells were treated with varying concentrations of okadaic acid and calyculin A. Both reagents induced cell death in SCC-25 cells in dose-dependent fashions as determined by phase-contrast microscopy and WST-1 cell viability assay. By using the Hoechst 33342 staining, marked nuclear condensation and fragmentation of chromatin were observed. Both inhibitors also induced DNA ladder formation in SCC-25 cells in dose-dependent manners with the maximal effective concentrations being 20 nM okadaic acid and 2 nM calyculin A, respectively. Okadaic acid also induced DNA ladder formation in other human oral SCC cell line SCCKN and SCCTF. To further determine if new gene transcription and protein synthesis are required for okadaic acid-induced apoptosis in SCC-25 cells, the cells were treated for 48h with varying concentrations of cycloheximide under the presence of 20 nM okadaic acid. Cycloheximide did not protect the cells against okadaic acid-induced cytotoxicity and DNA ladder formation. The present results indicate that the pathway of the apoptosis in the cultured oral SCC cells is regulated by protein phosphatase type 1 and type 2A, and also that newly synthesized proteins are not involved in okadaic acid-induced apoptosis in SCC-25 cells. Cytolocalization of PP1 isozymes in cultured SCC-25 cells was examined. The results revealed that PP1s are differentially localized in SCC-25 cells. PP1α and PP1δ antibodies recognized proteins with estimated molecular weight of 38 kDa and 37 kDa, respectively, present in the nuclear regions of SCC-25 cells, whereas PP1γ1 interacted with the 36 kDa proteins in cytoplasm. It is quite interesting that PP1δ was specifically distributde in the nucleolus-like bodies of cultured SCC-25 cells.

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The purpose of this research is to clarify the traits of head, face and dental arch form of Evenks tribe by comparing with seven other tribes living in the northeastern China and Japan : Mongol, Man, Han, Xibo, Hui, Dafurs and Japanese. The somatological measurements of Evenks' head and face, and the casts of the dental arches were recorded from the 146 subjects of Evenks' young adults (68 males and 78 females) that inhabit at Hailaer city of China as of September, 1996. T-test was used to compare and assess the following respective items. The results obtained in this study were as follows : 1. Comparison of the male and the female on the mean values of head and face measurements. 1) Maximum head length was 178.53±8.20 mm im the male and 173.13±5.81 mm in the female. Both the male and the female belonged to the Middle type. In the male, Evenks tribe had a mean greater than Mongol and Han tribes, but smaller than Japanese. In the female, Evenks tribe had a mean greater than Man and Han tribes, but smaller than Japanese. 2) Maximum head breadth was 154.93±5.54 mm in the male, which belonged to the Middle type, and 151.68±5.07 mm in the female, which belonged to the Wide type. In the female, Evenks tribe had a mean greater than Japanese. 3) Bizygomatic breadth was 126.69±6.24 mm in the male, which belonged to the Very Narrow type, and 122.79±6.11 mm in the female, which belonged to the Narrow type. In the male, Evenks tribe had a mean greater than Mongol tribe, but smaller than Man, Han and Japanese. In the female, Evenks tribe had a mean greater than Man and Han tribes, but smaller than Japanese. 4) Morphological facial height was 122.53±7.38 mm in the male, which belonged to the Middle type, and 117.24±6.16 mm in the female, which belonged to the High type. In the male, Evenks tribe had a mean greater than Mongol and Man tribes, but smaller than Japanese. In the female, Evenks tribe had a mean greater than Man and Han tribes, but smaller than Mongol tribe and Japanese. 5) Cephalic index was 86.96±5.05 in the male, and 87.64±3.89 in the female, which belonged to the Hyperbrachycephalic type in both the male and female. In the male, Evenks tribe tended to be longer and shorter in values than Man tribe, and Japanese, but similar to Mongol and Han tribes. In the female, Evenks tribe tended to be longer in values than Man and Han tribes, and Japanese, but similar to Mongol tribe. 6) Morphological facial index was 96.77±4.67 in the male, which belonged to the Mesoprosopic type, and 95.62±5.42 in the female, which belonged to the Hyper Leptoprosopic type. Evenks tribe had an index significantly narrower than Man, Han tribes and Japanese, but similar to Mongol tribe in both sexes. 2. Comparison of Evenks tribe and four other tribes on the mean values of dental arch measurements. The shape of upper jaw in the male of Evenks tribe is slightly shorter than that in Mongol tribe, and the shape of lower jaw in the female of Evenks tribe is slightly shorter than Han tribe. 3. According to the cluster analysis, Evenks tribe is the closest to Mongol and Dafurs tribes among the seven east Asian populations.

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Sweating in exercise causes a loss of the body fluid and an increase of the plasma osmolality. Then we feel thirst. In general, people understand from their own experience that salivary secretion may decrease under such conditions. However, there is little evidence to show how the hyperosmosis induces a decreased salivary secretion. In this review, we clarify the control mechanism of salivary secretion by osmotic stimulation on the basis of our recent studies.

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Maxillary deformity is a disorder deriving from either a maxillofacial deformity or displeasing nonesthetic features caused by an abnormality of the maxillomandibular morphology, position or relationship with the maxilla. It has been reported that each type of deformity associated with this disease can be rectified by means of surgical correction. Accordingly, we conducted an evaluation of the outcome of corrective surgery in terms of the mandibular joint, mastication function, esthetic improvement and the psychological effects of surgical correction. Our findings revealed that although a long period of time is required, the masticatory function can be improved, and that esthetic improvement leads to marked psychological changes resulting in a raised level of the subject's social adaptability.

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