We investigated the expression of p53 and the localization of Ki-67-positive cells in oral squamous cell carcinomas, and the correlation between these factors, tumor differentiation and invasion. p53 appeared in almost all of the cases examined (28/30), and was localized around cancer nests and in nearly half of the tumor cells in well differentiated carcinomas. In addition, p53 appeared in almost all tumor cells of moderately and poorly differentiated carcinomas. The correlation between differentiation and the average number of Ki-67-positive cells was 27.2% in well, 31.7% in moderately, and 35.6% in poorly differentiated carcinomas. The correlation between mode of tumor invasion and the average number of Ki-67-positive cells was 23.2% in Grade 2 (9/30), 28.3% in Grade 3 (11/30), 30.5% in Grade 4C (7/30), and 38.7% in Grade 4D (3/30).
      These results indicate that p53 is responsible for carcinogenesis in oral squamous cell carcinomas, and that the expression of p53 tends to occur in poorly differentiated and high grade carcinomas. The proliferative ability of tumor cells tended to be high in poorly differentiated, code-like increased Grade 4C, and diffuse-like increased Grade 4D carcinomas.

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We investigated the relationship between the mandibular symphysis and measurement points on the craniofacial skeleton used in orthodontic diagnosis and treat-ment by surveying the area of the symphysis and analyzing cephalograms of 120 patients with high developmental skeletal values. The subjects were divided into three groups, each containing 20 males and 20 females. The O, L and P groups had openbite, low angle Class II, and progenia, respectively.
      We found a close relationship between the height of the symphysis and total anterior facial height, and simultaneously between of the height of the mandibular body and lower anterior facial height. Evaluation of the height of the symphysis indicated an increase in the FMA and Gonial angle for the P and O groups, and a decrease for the L-group. Although the inclination of the mandibular incisors was proportional to that of the alveolar region, the site of the mandibular symphysis was unaffected. The total symphysis area was proportional to the total length of the mandibular body. The area of cortical and spongy bone tended to be larger in the L group. We found that the symphysis could be divided into alveolar and mandibular regions.

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We attempted to clarify the condition of the lateral pterygoid muscle, which holds mandibular position, by quantitatively analyzing the relation between the position of the condylar and incisor points and the resulting muscle electromyography (EMG) activity when the mandibular position is experimentally moved in horizontal and vertical directions. In the first experiment, the subjects were asked to hold mandibular positions arbitrarily along the protrusive, contralateral, and habitual opening and closing paths of movement. n the second experiment, they were asked to move mandibular position slightly from intercuspal position (ICP) and maintained it there.
      We found that when the mandibular position was gradually moved protrusive, contralateral, and along the habitual opening and closing path, the lateral pterygoid muscle EMG activity increased significantly in propotion to the distance the condylar and incisor points moved. The pattern for the increase in lateral pterygoid muscle EMG activity at the condylar point was similar for the three directions of movement. When the subject maintained a mandibular position near ICP, an area was found where there was no significant activity in the lateral pterygoid muscle. This area was located 1.25 mm in the protrusive direction and 0.96 mm in the downward direction, for a total distance of 1.20 mm.
      As the results, when holding mandibular in positions, EMG activity of lateral pterygoid muscle relates strongly with variable of condylar point at there.

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We conducted clinical tests of Hybrid Ceramics (HCC-4S), a newly developed crown material, by observing the clinical course of patients immediately after placement, at one week and at three months.
      Forty-seven subjects, 10 males and 37 females, were selected from patients visiting the Fixed Prosthodontics Clinic at Osaka Dental University Hospital. The restoration sites included one anterior tooth, 22 premolars and 24 molars. Three of the patients had spontaneous pain, pain to cold water and pain to percussion in the abutment teeth. Although one had complained of sensitivity to cold water preoperatively, the symptoms disappeared upon restoration of the tooth. Symptoms in the other two cases were attributed to hypersensitivity throughout the oral cavity in one, and to postoperative pain secondary to infected root canal treatment in the other. The condition of the gingival margins generally improved after placement, with very few patients showing a worsening of the condition. Although occlusal wear of the crowns was almost nonexistent, shiny spots were noticed in two cases. Three of the crowns fractured, two during temporary fitting and one after placement. Although there was no attrition macroscopically of the opposing teeth, shiny spots were found in two patients.
      We concluded that the Hybrid Ceramic (HCC-4S) is appropriate for the coronal restoration of posterior teeth. It has excellent strength, biocompatibility and esthetic properties.

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We investigated the minimum bactericidal concentrations of aqua oxidation water and three disinfectants used as controls to 8 methicillin-resistant staphylococci and 4 standard strains of Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli and Candida albicans. Undiluted aqua oxidation water was effective against all strains tested, although it allowed growth of S. aureus and C. albicans at 4-fold dilution, and S. aureus at 2-fold dilution. The three disinfectants used as controls were effective against almost all strains tested.
      These results suggest that the bactericidal activity of undiluted aqua oxidation water is equal to or greater than that of the three disinfectants used as controls.

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We investigated the minimum inhibitory concentrations (MIC) of 5 germicidal agents used on hospital equipment to 16 methicillin-resistant staphylococci (MRS) isolated from Osaka Dental University Hospital. The MIC for sodium hypochlorite, benzalkonium chloride, glutaraldehyde and alkyldiaminoethylglycine against all MRS strains tested were within concentrations recommended for disinfection. However, the MIC of chlorhexidine gluconate for two of the MRS strains tested indicated the need for an elevated concentration for disinfection. These results suggest that all the disinfectants except chlorhexidine gluconate are appropriate for preventing nosocomial MRS infections in Osaka Dental University Hospital.

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We studied the biological characteristics and nuclear DNA measurements of ascites Tawa sarcoma in the 2,001st through 2,700th transplant generations. On average, the take ratio was 98.3% and host survival was 5.97 days. The volume of tumorous ascitic fluid was generally between 6.1 and 10.0 ml, and metastasis was usually marked in the liver. The tumor cells were mainly composed of near-diploid DNA and the proportion of S-phase cells was higher than normal rat spleen cells. We found that the transplantability of ascites Tawa sarcoma could be maintained up to the 2,700th generation.

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We cloned and sequenced the dextranase (1, 6-α glucanhydrolase, EC 3. 2. 1. 11) gene from Streptococcus salivarius strain M-33. Recombinant clones from an S. salivarius genomic library specifying dextranase activity were identified as colonies surrounded by transparent halos on blue dextran plates. One of the clones had a 4.3-kb kpn I fragment containing the gene coding for an 826 amino acid polypeptide with a molecular weight of 87.9kDa, which corresponds well to that o f the native dextranase from cultured supernatant of S. salivarius. However, the dextranase of recombinant clones was about 100kDa. This is a fusion polypeptide of S. salivarius dextranase and E. coli-β galactosidase.

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We investigated the minimum bactericidal concentrations of aqua oxidation water and three disinfectants used as controls to 8 methicillin-resistant staphylococci and 4 standard strains of S. aureus, S. epidermidis, E. coli and Candida albicans. Undiluted aqua oxidation water was effective against al1 strains tested, although it allowed growth or S. aureus and Canadida albicans at 4-fold dilution, and S. aureus at 2-fold dilution. The three disinfectants used as controls were effective against almost all strains tested. These results suggest that the bactericidal activity of undiluted aqua oxidation water is equal to or greater than that of the three disinfectants used as controls.

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We investigated morphological characteristics in the craniofacial complex of adult Japanese by carrying out Enlow's counterpart analysis on 100 cephalograms each of selected Class I, Class II, and Class III malocclusion cases. Classes I and II were classified as either type A or B depending on whether point A or B was protrusive in the functional occlusal plane. We found that the craniofacial patterns of the B group were different from the A group, and that both Class I A and B had a Class II tendency. Compensatory effects generally failed in the Class II type A and Class III groups. However, a composite compensatory result was produced in the Class I type B group. Both Class I type B and Class II type B had an underlying Class III character in many regional anatomical relationships. These characteristic features may be the basis for the higher incidence of Class III type malocclusions in Japanese.

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We established two different cat models of cerebral venous congestion: one in which the pathway for brain venous return was physically obstructed, and another in which the head was tilted downward. We compared the pressure-volume relationship of the cranial cavity and cerebrospinal fluid dynamics of the two models. Morphological changes in the pial vessel were also investigated. We found that the two models had different indices of intracranial pressure dynamics, and different responses of the pial vessel. These results suggest that the cerebrovascular bed is related to pathophysiological differences.

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We examined the expression of the γ1 and γ2 subunit mRNAs of the γ-aminobutyric acid (GABA)_A receptor in the trigeminal ganglion (TG). Most TG cells expressed both γ1 and γ2 mRNAs simultaneously. Furthermore, expression of the γ1 subunit in the primary sensory afferents were confirmed at the protein level by immunohistochemistry using antiserum against the γ1 subunit. These findings indicate that primary sensory afferents receive GABAergic input axo-axonically via GABA_A receptors expressing γ1 and γ2 subunits. We demonstrated that a few neurons projecting to the thalamus in the TNC (trigeminal nucleus caudalis) were labeled by antiserum that recognizes the GluR1 and GluR2/3 subunits of the AMPA type glutamate receptor. However, expression of the γ1 and γ2 subunits of the GABA_A receptors indicated that several neurons projecting to the thalamus in the TNC receive GABAergic input via GABA_A receptors that at least contain γ1 and γ2 subunits.

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We investigated neuropeptide Y (NPY)-ergic innervation of the rat submandibular gland by immunohistochemical techniques and revealed the origin and properties of NPY-immunoreactive (IR) nerve fibers. NPY-IR nerve fibers, which were also immunoreactive for tyrosine hydroxylase (TH), were detected only around vessels in the lobular area. There was coexistence of NPY with TH in many cells of the superior cervical ganglion (SCG). Almost all of the NPY/TH-IR nerve fibers disappeared after SCG extirpation, although a few NPY-IR nerve fibers remained. These results suggest that most NPY-IR nerve fibers in the submandibular gland are adrenergic fibers originating from the SCG. A few of the NPY-IR nerve fibers that remained after SCG extirpation were cholinergic fibers originating from submandibular ganglion cells.

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We investigated sequential changes in the rat tongue after unilateral transection of the hypoglossal nerve by carrying out gross inspection and blood flux of the dorsum, and by studying microcorrosion casts of the capillary loops in the filliform papillae. Initial signs of histological changes were edema and musculature atrophy. Edema created a scalloped edge on the lateral margin of the tongue and depressions on the dorsal surface. At five weeks, the affected half of the tongue swelled, elongated forward and allarge, curved median groove was formed. Various changes occurred in the capillary loops, such as twisting, bulging, coiling and curving. These changes became more complicated at 7 weeks. Blood flux diminished very slowly after a slight increase, and was generally proportional to complex changes in the loops.

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I studied the relationship between the shape of titanium dental implants and bone formation. I installed implants in laboratory animals under simulated clinical conditions, and prepared microvascular casts utilizing the plastic injection method described by Ohta et al. I then observed three-dimensional chronological changes in the peri-implant tissues using scanning electron and light microscopic observations. New bone formation around the implant began in the middle region and proceeded towards the apex. These results indicate that the shape of the threaded implant is suitable for gaining initial stabilization, receiving occlusal loads, and resisting rotation.

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