Nichidai koku kagaku = Nihon University journal of oral science最新文献

The purpose of this study is to clarify the most suitable position and method to investigate bone formation in the mid-palatal suture after rapid palatal expansion in the rat. 10 of 8 week-old Wistar rats were employed to observe the structure of the normal mid-palatal suture at the line connecting the incisors, the anterior end of the anterior palatine foramen, the line bisecting the anterior palatine foramina, and the line of the 1st molars. A mid-palatal suture of 8 week-old Wistar rats was expanded laterally for 6 days by means of maxillary incisor expansion apparatus with a spring of 60 g load. After beheading, soft X-ray picture of the skull was taken to observe the suture. The maxilla was removed and decalcified sections (frontal section) were prepared. They were stained with hematoxylin and eosin for microscopy. The mid-palatal suture was observed at 4 levels to the lines drawn as follows; the line running through the centers of incisors (A), the line running the anterior ends of the anterior palatine foramen (B), the line running through the center of the anterior palatine foramen (C), and the line running through the centers of the 1st molars (D). At the opposing margins of A and B, the suture was composed of two layers; the layer of osteoblasts and the layer of interconnecting Sharpey's fibers. At C, the suture was curved and the layer of Sharpey's fibers were made up with longitudinal as well as transverse fibers.(ABSTRACT TRUNCATED AT 250 WORDS)

The frequency of occurrence of anomalous cusps or tubercles on human lower first molars was investigated in three racial populations: Japanese, Australian Aboriginals and Dutch white. The technique used was moiŕe contourography, which permits the three-dimensional measurement of minute cusps. Four tubercles investigated were 6th cusp, 7th cusp, deflecting wrinkle and transverse ridge. The frequencies of four traits were all highest in Australian Aboriginals among three, especially those of 6th cusp and deflecting wrinkle were significantly higher than other two populations. Japanese and Dutch showed comparatively low frequencies of four traits, but the 6th cusp in the former occurred significantly higher than that in the latter. There was no significant differences of the frequency in all the traits between sexes. It was suggested that high frequency of these traits in Australian Aboriginals demonstrates the primitive morphology of the lower molar of this population.

Twenty nine cases of oral hemangiomas composed of capillary hemangioma, cavernous hemangioma and pyogenic granuloma were examined with lectin histochemistry using ulex europaeus agglutinin I, ricinus communis agglutinin I, wheat germ agglutinin, concanavalin A, dolichos biflorus agglutinin, soybean agglutinin and peanut agglutinin, and immunohistochemistry using anti von Willebrand factor antibody in order to understand the nature of each endothelial cell. The following results were obtained; 1. UEA-I that specifically bound alpha-L-fucose was observed mainly in the endothelial cells of capillary hemangioma and hemangioma of granulation tissue type. 2. RCA-I which had specific affinity to beta-D-galactose was so identified in all endothelial cells of all type hemangiomas and normal blood vessels that it was supposed to be a useful marker of the cells. 3. WGA with specific affinity to N-acetyl-glucosamine was also found in various endothelial cells. 4. Con A which had specific affinity to alpha-D-mannose was not observed in various endothelial cells. 5. DBA, SBA and PNA that were specific bound up with N-acetyl-galactosamine were seen in the normal micro-vessels, especially in subepithelial regions. 6. Immunohistochemically, von Willbrand factor was identified chiefly in the endothelial cells of normal blood vessels and cavernous hemangioma, but it was not found in the cells of capillary hemangioma and pyogenic granuloma which had no differentiation in the functional point of view.

Thirty-three strains of methicillin-resistant Staphylococcus aureus (MRSA, MIC for methicillin greater than or equal to 16.0 micrograms/ml) isolated from sputum were examined for their susceptibilities against 8 antimicrobial agents. Ampicillin (ABPC), methicillin (DMPPC), cefazolin (CEZ), minocycline (MINO), erythromycin (EM), tobramycin (TOB), refampicin (RFP), and ofloxacin (OFLX) were used as the antimicrobial agents. The production of beta-lactamase was also determined. The results are as follows: 1) The highest susceptibility was given by RFP, and followed by MINO, and OFLX. All strains were resistant against EM and TOB. 2) The percentage of beta-lactamase-positive strains was 75.8%, which was distributed nearly identical among each MIC to DMPPC (72.0-77.8%). 3) Since the beta-lactamase-positive strains were found among the sensitive strains to ABPC, it was suggested that the use of beta-lactam antimicrobial agents might bring into the higher MIC value to ABPC. 4) Since there were beta-lactamase-negative strains among the resistant strains to ABPC, it was indicated that penicillin binding protein-2' might be produced by giving beta-lactam antimicrobial agents.

Ampicillin is widely used for the treatment and prevention of infection. When ampicillin is administered for the prevention of postoperative infection, the target tissue is a surgical wound. Since the surgical wound differs from the normal tissue, the distribution of ampicillin into the surgical wound might be affected. Thus, the present investigation was undertaken to compare with the amount of ampicillin in surgical wound and normal tissue. The vascular permeability and water content in the surgical wound were also determined. Wistar strain SPF male rats, 12 weeks old were used. Ampicillin.Na (50 mg/kg) was administered intravenously. Each rat head skin was incised 30 seconds after administration of ampicillin.Na. Specimens of serum, incised skin (surgical wound), and intact skin (normal tissue) were collected at 0.25, 0.50, 0.75, 1.0, 1.5, 2.0, 3.0, 4.0, 6.0 and 8.0 hours after incision. Amount of ampicillin in serum and skins were assayed by a thin layer disc plate method. Vascular permeability was determined by a dye diffusion method. Water content was obtained by subtracting the dry tissue weight from the wet tissue weight. The results are as follows: 1. The amount of ampicillin in serum at 0.25 hours after incision was 78.37 +/- 16.15 micrograms/ml. Ampicillin level was rapidly decreased during 0.25 to 1.0 hours after incision, and then gradually decreased to reach 0.04 +/- 0.02 micrograms/ml at 8.0 hours. 2. The amount of ampicillin in incised skin was significantly higher than that of intact skin during 0.50 to 8.0 hours after incision (t-test, p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Serum antibody titers to lipopolysaccharide from Bacteroides intermedius (B. intermedius) and Bacteroides gingivalis (B. gingivalis) were measured by enzyme-linked immunosorbent assay in serum samples from subjects with healthy gingiva and patients with periodontitis. The IgG antibody titers to LPS from B. gingivalis were significantly higher in the patients group, compared with healthy controls. No such difference was found between IgG activity to LPS from B. intermedius in the healthy and the periodonitis. Likewise, no significant difference in specific IgA level was found between the group with healthy gingiva and the patients group, both in LPS from B. intermedius and B. gingivalis. The IgM antibody levels to LPS from B. intermedius and B. gingivalis were low in subjects of patients and controls.

In order to investigate the mechanism of eruption, the rabbit lower incisors under the influence of controlled eruption were examined. The first experiment was carried out by repeated resection of the incisal edges of both upper and lower incisors so that the rate of eruption was accelerated. The second experiment was to crown the incisors for the purpose of inhibiting the eruption. In the control group, the periodontal ligament was made up of three layers. Fibers of the inner layer were continuous to the Sharpey's fibers of the cementum, and those of the outer layer were to the alveolar bone. Fibers of the middle layer ran parallel to the tooth axis. In the repeated resection group, the distance between the root end and the bottom of socket was increased, indicating the extrusion of the tooth took place. The odontogenic tissue showed increased frequency of mitosis, and the formative end of the enamel as well as the cementum shifted cervically. The eruption rate measured by the movement of metal bead embedded in the dentin, demonstrated that the rate was increased about 2 times in the repeated resection group, while the rate of growth measured by the Tetracycline method remained 1.6 times of the control group. This discrepancy was supposed to be due to the extrusion of the tooth. In case of the crowing group, the opposite was observed; the rate of eruption was reduced to about a third. Whereas the rate of growth to about a half, probably due to the intrusion of the tooth. In the crowing group, the distance between the root end and the bottom of socket was reduced, resulting the resorption of the bone tissue, and the root became sinuous, particularly at the labial side. In the lingual side, mitotic figures of the odontogenic tissue were rarely observed. The middle layer of the periodontal ligament increased in breadth in the repeated resection group, while it reduced in breadth in the crowing group. Indicating the middle layer plays an important part to the mechanism of eruption.

The relationship between the structure of monomers with amide groups and their adhesiveness to tooth was investigated. The monomers used were methacrylamide (MA), p-methacryloxybenzamide (p-MBA), and 3,5-dimethacryloxybenzamide (3,5-DMBA). MA was commercially available. p-MBA and 3,5-DMBA were prepared from the reaction of methacryloyl chloride with p-hydroxybenzamide or 3,5-dihydroxybenzamide, respectively, in acetonitrile. The bovine enamel and dentin were etched with 10% citric acid -3% FeCl3 solution. The monomers were dissolved in MMA, and TBB-O was used as a polymerization initiator. The test samples were immersed in 37 degrees C water for 1 day, 1 month, or 3 months. Then the tensile bond strengths were measured. The bond strengths to enamel were almost the same, irrespective of the kinds of monomers after 1 day immersion. Although the bond strengths of MA (1.0%) and 3,5-DMBA (3.0%) decreased after 1 month immersion, those of MA (0.5%) and p-MBA (0.5%) did not decrease after 3 months immersion. There was no relationship between the bond strengths to enamel and the bending strengths of the resins. The bond strengths of 3,5-DMBA (1.0%) and 3,5-DMBA (3.0%) to dentin were about 5-7 MPa. The bond strengths of MA (0.5%) or MA (1.0%) decreased after 3 months or 1 month immersion, respectively. The bond strength of p-MBA (0.5%) did not decrease after 3 months immersion.

A test was carried out to investigate the effect of aging in smokers and non-smokers on respiratory function, for which forced vital capacity (FVC), % forced vital capacity (%FVC), % forced expiratory volume in one second (FEV1.0%) and peak expiratory flow volume (PF) were studied. The results obtained were as follows. Subjects selected were 560 adult male smokers (smoking group) and 282 male adults with no smoking habit (non-smoking group) who were aged 22 to 59 years and with no anamnesis of serious heart disease and respiratory disorders. A total a mount of smoking was calculated using Brinkman Index (BI). 1. Each measured value index. Measured values including FVC, FEV1.0% and PF were decreased with aging together with the increase in Brinkman Index (BI). Each measured value showed a low level in smoking group as compared to that in non-smoking group. A significant decrease, in particular, of FEV1.0% shown in those aged 25 to 44 years suggested that air way obstructive ventilatory impairment resulting from smoking is manifested itself in younger generation. 2. Correlation among aging, FEV1.0% and PF. The correlation was as follows, i.e., in non-smoking group Y = -0.354X + 95.83 (r = -0.708) and Y = -0.069X + 10.82 (r = 0.720) in FEV1.0% and in PF respectively. Negative correlation also was observed in smoking group, that is, Y = -0.306X + 90.48 (r = 0.467) and Y= -0.084X + 10.93 (r = -0.594) in FEV1.0% and PF respectively. These indicate the decrease in values with aging, in particular, in smoking group that showed a marked lowering in PF.(ABSTRACT TRUNCATED AT 250 WORDS)