We investigated cytokeratin (CK) expression biochemically and immunohistochemically in well-differentiated human gingival (GK-1) and poorly-differentiated rhinopharyngeal (KB-N) squamous cell carcinoma xenograft lines in nude mice. GK-1 expressed CKs 1, 5, 6, 8,10, 11, 14, 18 and 19, and KB-N expressed CKs 5, 6, 7, 8, 10, 13, 14, 17, 18 and 19. Western blotting analysis produced expression of various molecular sizes of CK 18 in both xenograft lines, and of CK 19 in GK-1. Immunohistochemical studies indicated that, compared with GK-1, KB-N reacted strongly and widely with antiCK 8 (34 βH 11), 18 (DC 10) and 19 (RCK 108) antibodies. CK 8 of GK-1 showed a stronger reaction in the peripheral cells of the cancer nest, while CK 19 expression was stronger in large cancer nests.
These results suggest that expression of CKs 1, 8, 18 and 19, and chemical changes in CK protein have a strong correlation with growth and invasion of head and neck primary cancer. Shika lgaku (J Osaka Odontol Soc) 1996 Dec; 59 (4): 281− 291.

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We evaluated the effectiveness of fluoride mouth rinses for preventing multiple radiation caries. Between 1995 and 1996, we treated 28 patients with 0.1% NaF mouth rinses who had received radiation therapy for head and neck cancer. Twelve of the patients had nasopharyngeal carcinoma, 10 oropharyngeal carcinoma, and 6 tongue carcinoma. The patients had been treated with external radiation therapy or interstitial brachytherapy at the Department of Therapeutic Radiology, The Center for Adult Diseasesi Osaka, or at the Department of Radiology, Osaka University Medical School.
We found that treatment with fluoride mouth rinses significantly reduced increases in the decayed, missing and filled teeth (DMFT) index. From the above results, we concluded that mouth rinses with 0.1% NaF should be recommended to reduce the incidence of multiple caries for patients who have received radiation therapy for head and neck cancer. Shika lgaku (J Osaka Odontol Soc) 1996 Dec; 59(4): 292− 300.

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Phagocytic cells play an important role in host defense mechanisms against bacterial infection. Gram negative bacteria are often isolated from periodontal pockets of patients with periodontal disease. Changes in the function of polymorphonuclear leukocytes (PMN) and macrophages (Mφ), which may be induced by lipopolysaccharide (LPS) and bacterial components, contribute to the pathogenesis of periodontal disease. There are also phagocytic cells in the gingival pockets of patients with periodontal disease. The hypoxic condition of these pockets promotes increases in the number of gram negative anaerobes.
I investigated the effect of LPS and dissolved oxygen concentration (DO) on the chemotaxis and phagocytosis of mouse PMN and MΦ. Using the hot-phenol water method, I extracted LPS derived from Porphyromanas gingivalis, Capnocytophaga ochrachea, Fusobacterium nucleatum and Actinobacillus actinomycetemcomitans. DO was adjusted to 0.87, 1.35, 2.28 and 3.78 ppm in Dulbecco's modified eagle medium. LPS and decreases in DO significantly inhibited the function of PMN and Mφ. These results suggest that LPS and decreases in gingival pocket DO affect the functions of PMN and Mφ, and promote the pathogenesis of periodontal disease. Shika lgaku (J Osaka Odontol Soc)1996 Dec; 59(4): 301-312.

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I examined the effect of fabrication procedures on the physical, metallurgical and biological properties of Co-Cr alloys. I studied four casting and treatment combinations with casting at either 100 or 250°C higher than the liquidus temperature (LT), followed by either cooling in air (CA) or immediate water quenching (IWQ). The tensile strength, yield strength, and hardness were greatest with casting at 100°C higher than LT followed by CA, while there was elongation with casting at 250°C higher than LT followed by IWQ. Five of the alloys had a brittle fractures, while one that contained 50% nickel showed a ductile fracture. Carbide formation increased with casting at 100°C higher than LT followed by CA. However, none of the fabrication procedures produced metal dissolution, and cell viability was not affected when tested by the neutral red method, 3-(4, 5-dimetylthiaidl-2 yl)-2, 5-diphenyl tetrazolium bromide method, or by heat shock protein synthesis. The fabrication procedures affected the mechanical and metallurgical properties, but not the biological properties.
These findings provide a better understanding of the physical and biological properties that fabrication procedures produce in base alloys. Shika lgaku (J Osaka Odontol Soc) 1996 Dec; 59(4): 313-332.

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Previous studies have shown that a purified hemagglutinin (25 kDa) from non-fimbriated Prevotella intermedia strain E 18 is a protein-polysaccharide complex in nature. We attempted to clarify the relation between hemagglutinin, hemolysin and various enzymes produced by this strain. Both hemagglutinating and hemolytic activities were present together in fractions (FB and FC) after first peak on Sepharose CL-4 B column. The active fraction (FB₂ and FC₂) of FB and FC was eluted from an Arginine Sepharose 4 B column using 1 M arginine, respectively. Both hemagglutinating and hemolytic activities of FB₂ and FC₂ decreased by 50% with heat treatment at 50°C for 10 min, and were lost completely with treatment at 60°C for 10 min. Hemagglutinins of FB₂ and FC₂ were sensitive to trypsin, protease, lysozyme, β-galactosidase, β-glucosidase and hyaluronidase. Hemolytic activities of FB₂ and FC₂ were affected by protease, but enhanced by lysozyme, β-glucosidase and hyaluronidase. These results suggest that active sites of hemagglutinating and hemolytic activity in FB₂ and FC₂ are different each other. Both hemagglutinating and hemolytic activities of FB₂ and FC₂ were gradually lost over time, however, addition of L-cysteine caused an increse of hemagglutinating activity of FB₂ and FC₂, indicating that hemagglutinins of FB₂ and FC₂ were O₂-instable. FB₂ produced alkaline phosphatase strongly and acid phosphatase, phosphoamidase, α-glucosidase and α-fucosidase weakly, while, FC₂ produced alkaline phosphatase, acid phosphatase, phosphoamidase and α-fucosidase strongly and α-glucosidase moderately. However, both fractions did not show protease, caseinase, gelatinase, chitinase, lecithinase and IgG protease activities. Therefore, we examined the sensitivity of FB₂ and FC₂ to alkaline phosphatase, acid phosphatase, α-glucosidase and αfucosidase. As a result, hemagglutinating activities of both fractions was inhibited by α-fucosidase, but not by other enzymes.
These results collectively suggest that FB₂ and FC₂ (25 kDa protein) contains hemagglutinin, hemolysin and α-fucosidase-like substance and this enzyme cause the decrease of their own hemagglutinating activity gradually. Shika igaku (J Osaka Odont Soc) 1996 Dec; 59(4): 333-343.

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In order to study the genetics of methicillin-resistant, coagulase-negative staphylococci (MRCNS), we examined and identified MRCNS strains by DNA-DNA hybridization, analysed chromosomal DNA, and examined the existence of the mec A gene, plasmid DNA and bacteriophages. In DNA-DNA hybridization, 60% of the MRCNS strains tested were identified as Staphylococcus epidermidis. Chromosomal DNA analysis by pulsed-field gel electrophoresis indicated that all of the strains could be classified as 14 chromosomal DNA fragment patterns. The same chromosomal DNA fragment patterns were found in the medical staff and operating rooms. We detected the mec A gene by enzymatic detection of polymerase chain reaction in 16 of the 17 strains. All except one strain possessed several plasmid DNAs, and each plasmid profile was different. Bacteriophages with morphology similar to the lambda phage were detected in 7 of 17 strains, and 31% of the MRCNS strains tested produced β-lactamase.
These results indicate that most of the MRCNS strains isolated from MRSA screening agar possess various genotypic characteristics including chromosomal DNA with mec A gene and plasmid DNA. Shika Igaku ( J Osaka Odontol Soc) 1996 Dec; 59(4): 344--355.

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A mandible removed from a dog was fixed in super hard plaster so that the long axis of the first molar was perpendicular to the surface of the foundation, loads were imparted at various angles to the lingual of the first molar, and displacements of the tooth and the surface of the mandibular bone were observed with holography. The load was imparted in the horizontal plane at angles of 30, 45, 60 and 90 degrees to the buccal surface of the first molar, which corresponds to the mesiodistal direction of the tooth. For each of these four angles, the load was imparted in the vertical plane at 30, 45 and 60 degrees with respect to the long axis of the first molar. Thus, the load was imparted from a total of 12 directions.
A fringe of straight lines in the first molar running from the distal/superior to mesial/inferior direction appeared that showed a larger displacement in the mesial than in the distal region. As the direction of the load moved towards the distal, the inclination of the fringe tended to become greater. This indicates there was rotational displacement of the tooth. Furthermore, when the angle with the long axis of the tooth decreased from 60 to 30 degrees, that is, as the direction of the load moved towards the horizontal, there was an increase in the number of fringe lines. This shows that forces from the horizontal direction caused marked displacement in the tooth.
A primary fringe of circular arcs first appeared on the surface of the mandibular bone in a location corresponding to the tips of the roots. As the direction of the load moved towards the horizontal, the fringe moved towards the cervical region, and a secondary fringe appeared where the primary fringe had first been observed. This effect became more pronounced as the direction of the load moved towards the horizontal.
From the above experiments, we were able to obtain displacement patterns for the teeth and mandibular bone that resulted from lateral forces. Shika lgaku (J Osaka Odontol Soc) 1996 Dec; 59(4): 356-364.

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Some strains of Prevotella intermedia isolated from oral infections show resistance to β-lactam antibiotics, and produce β-lactamase. We examined the induction of P. intermedia β-lactamase by various β-lactam antibiotics frequently administered for oral infections using P. intermedia MA1-V2 from a closed dentoalveolar abscess. β-Lactamase activity for the substrates cefazolin (CEZ) and ampicillin (ABPC) was 2.27 and 0.42 U/mg protein after exposure without drugs (control), respectively. After exposure to 1/8〜1/128 MIC of ten β-lactam antibiotics for 4h, enzyme activity of CEZ with treatment of latamoxef and cefaclor (CCL) was increased to the value without drugs, and for 15h, this activity of CEZ with exposure of cephalexin (CEX), piperacillin and imipenem was higher than that of the control. Enzyme activity for ABPC was increased after exposure to penicillin G, ABPC and CEX for 15h compared with no drug exposure. These results suggest that P. intermedia β-lactamase was induced by oral drugs such as ABPC, CCL and CEX.

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We did an in vivo study with weekly observations of the relationship between toothbrush bristle wear and brushing force, as well as an in vitro study of the relationship between bristle wear and the removal of experimental plaque. In the in vivo study, we found that the brushing forces employed by the subjects tended to increase as the bristles became worn. In the in vitro study, we found that hardness of the bristles decreased with the number of brushing strokes and that the actual area cleansed decreased as the toothbrush became older for all values of brushing force. These results indicate that the average person should replace his toothbrush every 4 weeks for maximum plaque removal effect.

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We examined the optimal timing for intravenous administration of anticancer agents during cryosurgery by measuring the tissue concentration of the drug. There was high uptake concentration and trapping of PEP in frosted and surrounding marginal tissues when the drug was administered 15 minutes before cryosurgery. When CDDP was administered before cryosurgery, its concentration remained high in the surrounding marginal tissues for 10 days, ranging from 0.1〜0.2mcg/g. The remarkable uptake of anticancer agents in the affected tissue was not observed in the group where the drug was administered after cryosurgery.

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