Kanagawa shigaku. The Journal of the Kanagawa Odontological Society最新文献

It has long been thought that the process of bone remodeling is regulated by the chain reactions of bone cells involving chemical mediators, growth factors and synthesis of extracellular matrix proteins etc. In this context, it has also been recognized that physical stimulation is an important factor in the regulation of bone remodeling. Thus, it is vitally important to understand whether the physical stimulation can induce the cellular events regarding autocrine regulation of protein synthesis. This study was conducted to examine the effects of hydrostatic intermittent compressive force (ICF) on the synthesis of the transforming growth factor beta (TGF-beta) and matrix phosphoproteins which may play an important role in the process of bone remodeling. The rat osteosarcoma cells (ROS 17/2.8) were cultured with DMEM containing 10% FCSP. ICF was applied to sub-confluent cells at 130 mb, 15/min cycle for 48h. ICF increased TGF-beta activity of the conditioned medium. This was assessed by its capacity to promote anchorage independent growth of NRK 49F cells and to inhibit the growth of human hepatoma cells (Hep-3B). Furthermore, ICF stimulated the synthesis of the phosphoproteins with Mr. 75 KDa by about 1.4 fold which was visualized by SDS-PAGE on 5-15% gradient gel. Immunoprecipitation of the phosphoproteins with rat osteopontin antibody revealed that the 75 KDa phosphoprotein was identical to osteopontin. The 75 KDa osteopontin synthesis was inhibited by the addition of TGF-beta antibody in a dose dependent manner. These results suggested that ICF stimulated the synthesis of TGF-beta and osteopontin in ROS 17/2.8 cells and that the osteopontin synthesis could be regulated by TGF-beta.

This study was conducted to perform mechanical evaluations of crown restorations by Laser Holographic Interferometry (LHI). However, in an application of LHI, the Fujinon Holox FHLX-II system (He-Ne Gas Laser GLG-5700, NEC Co.) to this experiment, it was mandatory to do some modifications for loading and measuring evaluations, thereby a whole sequence of this system could be successfully carried out. The experiments were conducted in the following manner: Ten pieces of full cast crowns were constructed by a conventional procedure with 12% Au-Ag-Pd alloy and each test-piece was cemented alternately by zinc phosphate cement on a master die (stainless steel) with a chamfer margin. Successive vertical loadings (0kg-30kg) were applied for each test-piece and holograms were taken for crown restorations under loadings of both 15Kg & 30Kg with an accuracy of 0.3 micron. Three-dimensional measurements of nine points on surface of a testpiece were obtained through interference fringes, which were converted into mathematical values and statistical comparisons were performed for mean values under loadings of both 15 Kg & 30 Kg. The following results were obtained from this experiment. 1. It was successfully performed that an application of Laser Holographic Interferometry (a real time) became an efficient method with some modifications for mechanical evaluations of crown restorations. 2. Besides modification for rigid fixation of a test-piece, it made possible to conduct the loading experiment under Kg unit, which was impossible in previous studies. 3. Three-dimensional measurements were also made possible by an application of mathematical calculations, thereby a total system of experimental procedures was established. 4. Reference points were marked on surface of a test-piece, and this made possible to compare with the displacement values of other test-pieces. 5. Displacements of experimental crowns with both 15 Kg & 30 Kg under areas of loadings showed remarkably and they were gradually spread out toward the outer directions of restorations with slight displacements. From this experiment, it was proved that a cemented crown showed a certain deformational behavior under loadings. Therefore, this system contributes to become an efficient method evaluating mechanical features of crown restorations for further studies.

The development and expansion of antimicrobial agents has made a remarkable improvement. Recently we began to use newqinolon agents, furthermore we began to use the third generation of oral cephem agents. We anticipate we will have a large change of trends in the use of antimicrobial agents. We investigated the trends in the use of antimicrobial agents between April 1st, 1983 to March 31st, 1988, to prepare for the trends in the future. 1) A total use of antimicrobial agents in Kanagawa Dental College, Hospital has increased 19% over the last five year. 2) Trends in the use of injection of antimicrobial agents has decreased over the same period of time, otherwise trends in the use of oral antimicrobial agents has increased tremendously 3) The use of newqinolon agents were less than 0.07% in one year.

In daily practice, cases of unilateral free-end saddle involving loss of two teeth are apt to cause problems such as a loss of function and injury on the abutment teeth due to instability of the dentures. In attempting to remedy these problems, a variety of prosthesis have been used and their dynamics analyzed. Nevertheless, dynamics during function, one basis for judging the relative worth of prostheses, remain unclear. In this study, modal analysis and linear-value analysis were used to derive values for the dynamics of the denture during function of a cone telescopic denture, an attachment denture and a clasp denture as well as impact on the abutment teeth. The following results were obtained: 1. Characteristic frequency and observation of animation showed that: (a) Mode #1 is the vibration mode for the entire system including the denture. (b) Mode #2 is the vibration mode for the abutment tooth itself. (c) Mode #3 is the mode for the resin or the metal frame of the denture. 2. In the direction of the tooth axis, the tendency for displacement of the abutment tooth decreased in the following order: unilateral clasp denture greater than bilateral clasp denture greater than cone telescopic denture greater than attachment denture. 3. In a bucco-labial direction, the order was as follows: unilateral clasp denture greater than bilateral clasp denture greater than cone telescopic denture greater than attachment denture. 4. In a mesio-distal direction, the order was as follows: unilateral clasp denture greater than attachment denture greater than cone terescpic denture greater than bilateral clasp denture. 5. A comparison with the clasp denture in terms of attenuation hints at the possibility that the design is superior with the cone telescopic denture and the attachment denture in cases of free-end saddle.

MRL/1 mice, reported by Murphy and Roths, are lupus mice in which monogenic mutation has occurred. They are characterized by the expression of massive lymphoadenopathy, splenomegaly, arthritis and glomerulonephritis. These specific characters are attributable to the proliferation of abnormal T cells governed by an autosomal recessive gene, which is called a lymphoproliferative (lpr) gene. In this study, the author has studied the pathology of various organs in MRL/1 mice in relation to their ages. Investigated the pathogenesis of spontaneous submaxillaritis in MRL/1 mice and mechanism of its occurrence. Based on the immunological abnormalities in MRL/1 mice studied thus far, the mechanism of onset of submaxillaritis is believed to be as follows; (1) expression of the lpr gene leads to proliferation of T cells accompanied by focal lymphocyte infiltration in the submandibular gland; (2) the helper T function of these proliferating T cells induces polyclonal B cell activation (PBA); (2) PBA leads to the formation of numerous autoantibodies and anti-gp70 antibody whose antigen is the glycoprotein of endogenous retrovirus, resulting in the massive formation of immune complexes; (4) the immune complexes are deposited on the vascular wall, resulting in activation of the complement system; (5) infiltration of neutrophils and macrophages is induced; and (6) the lysosomal enzymes, released from these cells, effects as a cytotoxic mediator and damages the vascular wall. In brief, submaxillaritis accompanied by granulomatous vasculitis can be regarded as a Type III allergic response caused by immunological abnormalities which are genetically determined by the lpr gene; it is thought to be a subtype of immune complex disease.

The chemical structure and immunomodulating activities of the cell wall peptidoglycans isolated from Actinobacillus actinomycetemcomitans were investigated. Peptidoglycans were isolated from A. actinomycetemcomitans strains Y4 and ATCC 29522 by boiling in 4% sodium dodecyl sulfate and by digestion with pronase, trypsin and alpha-amylase. Analysis of amino acids and amino sugars of the peptidoglycans revealed that glucosamine, muramic acid, D-glutamic acid, D-alanine, and meso-2, 6-diaminopimelic acid (A2pm) were the principal components. Serine and glycine were not found. Dinitrophenylation method revealed that about half of A2pm residue had a free aminogroup, and analysis by hydrazinolysis showed that a small part of alanine and A2pm located at the C-terminal. The above results indicate that one of the amino groups of A2pm residue at one strand of the stem peptide subunit crosslinked to the carboxyl group of alanine of the neighboring strand. It was thus revealed that the peptidoglycans of A. actinomycetemcomitans belonged to the Al gamma type of the classification by Schleifer and Kandler. Peptidoglycans isolated from A. actinomycetemcmitans strain Y4 and ATCC 29522 were found to be definitely adjuvant-active in induction of delayed type hypersensitivity against ovalbumin when administered to guinea pigs as water-in oil emulsion and stimulation of increase serum antibody levels was found in both peptidoglycans. Regarding mitogenicity on splenocytes of BALB/c and BALB/c nu/nu mice, peptidoglycans from two strains of A. actinomycetemcomitans were markedly enhanced the uptake [3H] thymidine in dose of 10 micrograms/10(5) cells, however thymocytes were not reactive. Stimulation effects on peritoneal macrophages from a guinea pig to incorporation of 14C-glucosamin were not exhibited on addition of 100 micrograms of both peptidoglycans. These findings indicate that peptidoglycan of A. actinomycetemcomitans might eventually be responsible for destruction of periodontal tissue by host mediated activities.

To define the role of calmodulin in Ca2+ fluxes behavior of canine masseter muscle sarcoplasmic reticulum (SR) vesicles, the effect of condensation product of N-methyl-p-methoxy-phenethylamine with formaldehyde (compound 48/80), a selective and powerful inhibitor of calmodulin-regulated function, on Ca(2+)-ATPase activity, oxalate-supported Ca2+ uptake velocity, and on interaction with Ca2+ permeability and Ca2+ loading at steady-state were evaluated. Compound 48/80, at concentrations of 10 to 100 micrograms/ml, reduced oxalate-supported Ca2+ uptake velocity without affecting Ca(2+)-ATPase activity. In the presence of 10 micrograms/ml compound 48/80, there was a shift of pH- or temperature-response curve of oxalate-supported Ca2+ uptake velocity, but not of Ca(2+)-ATPase activity, down. It was found that Arrhenius plots of the Ca(2+)-ATPase activity show a break at about 21 degrees C in the presence or absence of 10 micrograms/ml compound 48/80, and that compound 48/80 has no effect on Arrhenius plots of the oxalate-supported Ca2+ uptake velocity. Furthermore, Ca2+ loading at steady-state, but not passive Ca2+ permeability, was decreased by compound 48/80 at low concentrations (1-2 micrograms/ml). The results of this study suggest that calmodulin-dependent process plays a functional role in the coupling of ATP hydrolysis and Ca2+ accumulation, perhaps through regulation of Ca2+ release channels in masseter muscle SR membrane. Calmodulin-dependent component of Ca2+ fluxes in the SR vesicles may be directly modified by compound 48/80, thereby diminishing Ca2+ accumulation without affecting the Ca2+ uptake mechanism.

The cytomorphologic changes associated with acinar cell recovery in the rat submandibular glands were examined by light and electron microscopic observation and immunohistochemical test using anti-bromodeoxyuridine antibody. Ligation of excretory ducts caused morphological disorganization of the gland parenchyma, with resultant disappearance of the acini, dilation of the ducts, pronounced fibrosis and infiltration of the inflammatory cells. At seven days after obstruction, the acinar cells shrunk and destroyed partly. However, the intercalated duct cells and the myoepithelial cells were unaffected by ligation. Immunohistochemically, bromodeoxyuridine (BrdU) labeled cells existed scatteringly in the original ducts through the period of duct ligation and unligation studied. In the glands after recanalization following 7 days of the duct ligation, the duct-like structures were recognized a progressive increase. There structures were significantly developed in number from 7 to 14 days after the unligation. However, the BrdU-containing nuclei were not almost found in the duct-like structures. At twenty one days after the removal of the obstruction, the regeneration of acinar cells was striking. At 28 days, the acini were almost normal size. In the unligated glands at 21 and 28 days, a variable number of BrdU-positive cells was found in acini. At this stage, the constituent cells of the duct-like structures occurred many vacuoles and a decrease in their secretory granules was marked. These cells were transformed into intercalated duct cells. These results suggest that the constituent cells of the duct-like structures are altered for intercalated duct cells. The regeneration of acinar cells is the result of cell recovery, not the result of de novo cell differentiation.

To characterize the route of calcium permeability, the effect of intravesicular and extravesicular calcium concentration on the permeability from sarcoplasmic reticulum (SR) vesicles isolated from canine masseter muscle was determined by measuring net efflux of calcium after stopping pump-mediated fluxes. The apparent permeability, calculated as the net efflux divided by the total intravesicular calcium, depended on calcium load. When the intravesicular bound calcium was taken into account, net calcium efflux was found to be linearly related to the difference in calcium concentration across the SR membrane. The first order rate constant of calcium permeability was nearly identical when efflux was initiated by the addition of EGTA or glucose plus hexokinase to quench calcium pump by lowering activator calcium or by converting substrate ATP to ADP and glucose 6-phosphate, respectively. Extravesicular calcium concentration between 0.001 microM and 33.9 microM had no great effect on calcium permeability. The results suggest that some minimal calcium gradient may be required in order to observe a substantial passive calcium efflux, and the passive calcium efflux is not carrier mediated. It is also postulated that passive route of efflux during calcium accumulation is relatively small and that physiological calcium release during excitation-contraction coupling does not occur through this route.

The effects of testosterone and estradiol-17 beta on the protein components, amino acid compositions and trypsin-like protease activities in the secretory granules of granular duct cells of rat submandibular glands were assayed. Male and female adult rats were divided into 4 groups, non treatment (control), castrated, testosterone injected and estradiol-17 beta injected groups. The castrated rats were received 5 injections of 5 mg/kg testosterone or 500 micrograms/kg estradiol-17 beta every other day 3 weeks after the castration. The secretory granules of submandibular gland obtained from each group were prepared using centrifugal fractionation with sucrose step gradient. The protein components of secretory granule were separated by 5-15% SDS-PAGE, and the SDS-PAGE revealed the characteristic proteins of MW 39,000 in male and MW 37,000 in female. The MW 39,000 and the MW 37,000 protein was disappeared by testectomy and ovaryectomy, respectively. The MW 39,000 protein was reappeared in the castrated male rat treated by testosterone and shown in castrated female rat treated by the same steroid. Similary the MW 37,000 protein was found in the castrated male and female rats treated by estradiol-17 beta. From the results of amino acid composition analysis, abundant Asp, Ser, Glu and Gly were revealed in the MW 39,000 protein and MW 37,000 protein. Trypsin-like protease activity located in secretory granule was reduced by castration in both male and female, however, the enzyme activities were elevated by testosterone or estradiol-17 beta injection, revealing rather higher activities than control. It was demonstrated that the secretory granule of rat submandibular gland contained the testosterone dependent protein having a MW of 39,000 and the estradiol-17 beta dependent protein having a MW of 37,000 and that the trypsin-like protease activities in the granules were sensitive to both testosterone and estradiol-17 beta.