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

The AA release from phospholipids is believed to be controlled by the activation of phospholipase A2 which are probably localized in the plasma membranes. And the considerable interest has been focused on the study of cells of the immune system including macrophages which metabolize arachidonic acid (AA) to prostaglandins, thromboxanes and leukotriens. Recently, it has been reported that phosphatidylinositol (PI) turnover plays an important role in the response to external stimuli in these cells. PI turnover has been accepted as being initiated by the hydrolysis of PI which is catalyzed by the phospholipase C and produced AA. Recently, we demonstrated that PI-specific phospholipase A2 in macrophage plasma membrane directly acted for AA release from PI. On the other hand, diglyceride, which is produced from PI by phospholipase C activation, is known to regulate the several cell functions with a protein kinase C activation. In this report, we examined the effect of diglyceride on phospholipase A2 activities in macrophage plasma membrane. PI-phospholipase A2 and PC-phospholipase A2 activities were stimulated by the addition of diglyceride. In contrast, PE-phospholipase A2 was not affected by diglyceride addition. The results suggested that phospholipase A2 activation was occurred with coupling the diglyceride production via the phospholipase C pathway.

It is known that the peak distribution of the power spectrum seen in the clicking sounds of the temporomandibular joints appears in the vicinity of 1 KHz in a high rate. Based on the findings that this marginal zone corresponds to speech range, the authors have performed masking experiment by narrow band noise on 20 ears in 10 normal persons and 27 ears in 19 patients with noise as subjects to assess the influence exerted by mechanical stimulation on the condition of hearing ability in speech range. The results in normal persons were 14.8dB (S.D. 13.7) at 500Hz. 27.0dB (S.D. 11.1) at 1,000Hz and 21.3dB (S.D. 10.4) at 2,000Hz. The results in abnormal persons were 12.2dB (S.D. 9.9) at 500Hz, 20.6dB (S.D. 6.6) at 1,000Hz and 15.9dB (S.D. 4.4) at 2,000Hz. A significant difference was observed in the masking level between the two groups at 1,000Hz band with a risk rate of 5%. From the above, it was suggested that the sound constituent of TMJ clicking sound exerts influence on the specific auditory level in the patients with noise.

Chemosensitivity of human head and neck tumor was evaluated by human tumor clonogenic assay. Among eight of head and neck tumors seven squamous cell carcinomas such as tongue, gingiva, maxillary sinus, pharynx and one malignant fibrous histiocytoma (MFH) of maxillary sinus and four anti-cancer agents BLM, CDDP, 5-FU and MMC were used. Five of eight tumors were succeeded to evaluate the sensitivity. Positive rates except MFH were BLM 100% (3/3), CDDP 25% (1/4), 5-FU 33% (1/3). These results are similar to recent clinical experiments except CDDP.

A recombinant plasmid, pYA724, containing an 8.45-kb DNA fragment encoding surface protein antigen A (spaA) from Streptococcus sobrinus 6715 was used to examine the DNA homology of the spaA gene with chromosomal DNA of Streptococcus sobrinus B13N. Restriction endonuclease BamHI-digested pYA724 DNA was 32P radio-labeled by nick-translation, and a Southern blot DNA-DNA hybridization experiment was carried out. pYA724 DNA hybridized with a BamHI fragment of B13N chromosomal DNA, and the size of this fragment was larger than 8.45 kb. The chromosomal DNA was digested with BamHI-Pst I, BamHI-Hind III, and BamHI-Sal I, and analyzed by Southern blot DNA hybridization. pYA724 DNA hybridized with different sizes and numbers of DNA fragments of B13N chromosomal DNA; however, the sizes were not identical to those of internal fragments expected from the pYA724 restriction map. SpaA gene clone derivative plasmids, pYA745 and pYA756, were digested with EcoRI and Hinc II, respectively, and electrophoresed together with the digested B13N chromosomal DNA on the same gel; then Southern blot analysis was carried out. Fragments with sizes corresponding to the EcoRI or HincII internal fragments of pYA745 and pYA756 were not observed among the B13N fragments. These data indicate that serotype d S. sobrinus B13N has DNA homologous with the spaA gene from serotype g strain 6715, although within the same biotype strain has a diversity of arrangement within the chromosome.

Deep body temperature in central part (thorax) and peripheries (dorsum of foot and hand) were determined, in order to observe the changes in body temperature occurring due to long or short duration of surgical operation in dental or oral surgery. The results obtained are as follows. Subjects selected were 49 cases including 32 males and 17 females, aged 17-43 years, of less surgical risk and without any disorders in respiratory and circulatory systems. They were classified into five groups on the basis of operation time: 10 cases for two hours or less group, 10 for two to three hours or less, 11 for three to four hours or less, 9 for four to five hours or less and 9 for five hours or more. The measured value in each measured site obtained when anesthesia started and at 30, 60, 120, 180, 240, 300 and 360 min. after when anesthesia started. The difference between central (thorax) deep body temperature and peripheral (dorsums pedis and manus) one was determined as delta T. 1. Changes of deep body temperature in each measured site Central (thorax) deep body temperature decreased temporarily at 30 and 60 min. and increased after 180 min. Peripheral (dorsums of foot and hand) deep body temperature increased till 60 min. and decreased after 120 min. 2. Changes in difference between central (thorax) and peripheral (dorsums of pedis and manus) deep body temperature (delta T). Both differences in deep body temperature, i.e., thorax VS dorsum pedis (delta T1) and thorax VS dorsum of manus (delta T2) became smaller with time from when anesthesia started to 120 minute.(ABSTRACT TRUNCATED AT 250 WORDS)

The subjective contrast including the density component of radiograph as well was aimed at. In relation to the intraoral radiographs (18 cases) of the left first molar of the mandible and its surrounding tissue taken using tube voltage of 60-90 kV, the radiographs were evaluated based on the mean of the extracted subjective contrast values, resulting in the following findings: 1. A tendency was observed in the enamel and dentine of the central portion of crown, for the mean of the extracted subjective contrast values using tube voltage of 70 kV to be lower than that with 60 kV. 2. A tendency was found in the dentine on the cement side of the mesial and distal cervical portion and the periodontal membrane space of the cervical portion, for the mean of the extracted subjective contrast values to generally become larger as the tube voltage was increased. 3. A tendency was recognized in the alveolar lamina dura of the mesial and distal marginal alveolar portion, for the mean of the extracted subjective contrast values to become larger as the tube voltage was increased. From intraoral radiographs of teeth, the findings mentioned above have proved that good radiographs will be created using a tube voltage of 70 kV for enamel and dentine, and using 60 kV for dentine and cement in the area of the cervical portion or in case of the periodontal tissue.

Maxillary invaginated incisor teeth have been pathomorphologically investigated and some results have been obtained as follows: 1) The classification used in this study is as follows. That is, class I: Invagination is limited within the enamel. class II: Invagination extends toward the pulp chamber in a manner of pipe. class III: Invagination seen in class II expends at its end in the fashion of drop. class IV: Invagination occludes the whole coronal pulp chamber or extends toward the root apex beyond the cervical line. Frequent enamel-lined cavities of invaginated teeth were found to contain the contents (72.7%). Solid contents were found with considerable frequency in the cavities of the class I invaginated teeth of the author's classification (80.1%). On the other hand, the solid contents were rare in cavities of class III or IV (27.3%). In most cases, contents were found in limited areas of the cavity of class III or IV (72.7%). Any invagination corresponding to class II is not seen in this research. 2) The tissue composing the contents in the cavity of invaginated tooth was not clarified by the light microscopic observations of ground sections and film replicas. In class IV, poor hypomineralization was partly found in the inner enamel, and the dentin around the cavity was sclerotic. 3) As for the measurements of microhardess, the Vickers hardness number of contents in the cavities of invaginated teeth was approximately 1/4 of that of inner enamel. 4) The contents gave a higher radiolucency than the inner enamel by means of contact microradiography. 5) Electron microscopy revealed that the cavity contents of invaginated teeth was composed of poor inorganic elements resulting in a smooth aspect, and that, in most cases, a rod-having enamel was found in the surface layer of the contents and the rest of contents was composed of rodless enamel. An organic continuation of the tissue was observed between inner enamel and the contents. The results of electron microscopy, microhardness measurement, and contact microradiography, may indicate that the contents is composed of a hypomineralized enamel. 6) Caries incidence were found at a rate of 40.9% at cavity walls of invaginated teeth. Thus, it was suggested that cavity walls were susceptible of caries. In the contents of invaginated cavity, there was found primary caries appeared there.

The radiosensitivity and radio-chemosensitivity of 3 series of human cancer cell lines were evaluated by human tumor clonogenic assay. The sources of cell lines were gingiva carcinoma (Ca9-22), uterus carcinoma (Hela) and gastric carcinoma (MKN-45). BLM and CDDP were used, and chemosensitivity of gingiva carcinoma tended to be higher than other cell lines. Radiosensitivity was same as MKN-45. Isobologram were employed for quantitation of the interaction between the irradiation and anti-cancer agents. In Ca9-22, the interaction of between gamma-rays, BLM and CDDP was supra-additive. Hela was also supra-additive, but in MKN-45, the interaction of between gamma-rays and BLM was sub-additive.

The purpose of the present study is to clarify in vitro toxicity of surface sonic extracts from Bacteroides intermedius (B. intermedius) ATCC25611, B. intermedius ATCC 33563 and Bacteroides gingivalis (B. gingivalis) 381 against mouse splenic lymphocyte. Especially the surface extracts from B. intermedius ATCC 25611 were fractionated by high performance liquid chromatography (HPLC) on a column of DEAE. The following results were obtained: 1) The surface extracts from B. gingivalis 381 and B. intermedius ATCC 25611 presented remarkable lymphotoxicity, but B. intermedius ATCC33563 did not have it. 2) The surface extracts from B. intermedius ATCC 25611 was separated to 6 fractions by HPLC. 3) Two fractions isolated from B. intermedius ATCC 25611 surface extracts observed remarkable lymphotoxicity, and the one of their fractions, possibly including fimbriae showed a remarkably higher toxicity against mouse splenic lymphocyte.

Certain species of bacteria have been implicated in the etiology and pathogenesis of periodontal diseases. It has been reported that Actinomyces viscosus (A. viscosus) is associated with gingivitis. On the other hand, it is known that prostaglandin (PG) E2 is one of potent mediators of bone resorption and macrophage is PGE2 producing cell. It has been reported that a number of macrophage is increased in inflamed gingival tissues and that A. viscosus (T14V strain) cells significantly stimulated the arachidonic acid (AA) release and the secretion of PGE2 and thromboxane (TX) B2. Furthermore, the level of PGE2 in inflamed gingival tissues was 18 times higher than that of normal gingiva. In general, it is believed that the rate-limiting step in the production of PGs and TXs is dependent on the release of AA from phospholipids in the cell membrane. However, recent papers suggested that the produced levels of PGE2 and TXB2 were not completely dependent on the amounts of released AA, and the mechanism of rate limiting step and the PGE2 production are still remains to be elucidated. It is known that glucocorticoid, anti-inflammatory steroid, inhibits the AA release from phospholipids of cell membrane. In the present study, in order to clarify the mechanism of PGE2 and TXB2 production by the A. viscosus cells, the effect of addition of glucocorticoid on the levels of PGE2 and TXB2 production were studied. The effects of ionophore A 23187 and zymosan, which were known as agents of macrophage activation but having different action manner, on the relation between the AA release and productions of PGE2 and TXB2 were also comparatively studies.(ABSTRACT TRUNCATED AT 250 WORDS)