A human oral flagellated protozoon, Trichomonas tenax, was examined for antigenic proteins by immunoblotting analysis using the rabbit polyclonal antisera against the whole trichomonad cells including gram negative, facultative aerobic, motile bacteria as contaminants. Two stains of T. tenax were different from two strains of T. vaginalis, a common pathogen of a human urogenital tract, in terms of Coomassie brilliant blue-stained protein profiles on the SDS-polyacrylamide gels, the agglutination reactions, and the immunoblotting reactions. The major T. tenax protein antigens recognized by the antiserum which had been absorbed with the accompanying bacteria had molecular weights of 32KDa, 36KDa, 45 KDa, 51 KDa, 66 KDa, and 86 KDa.

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Although hydroxyapatite has been widely applied in the field of dental medicine, there is the argument about clinical complaints due to infection and inflammation after its implantation. In the present study I have attempted to establish a useful in vitro system to evaluate the biocompatibility of hydroxyapatite and other biomaterials.
I have firstly established a human gingival fibroblast line designated as HGF-22 by clonal selection techniques and two human gingival epithelial cell lines designated as HGE-15·I and HGE-15·II, respectively, by transfection of SV 40-T genes. All these established cells grow actively and maintain their cellular characteristics with stability. HGE-15·I cells conserve much higher activity to synthesize keratin molecules than HGE-15·II cells.
Using HGF-22 and HGE-15·I cells I have quantitatively analyzed their activities represented by cell adhesion, spreading, growth and differentiation when cultured on the surface of a hydroxyapa-tite disc, which is thin enough to observe their living conditions by a phase contrast microscope, and on the plastic surface of commercial cell culture dishes.
From results obtained it is possible to conclude that the established cell lines can provide highly useful experimental tools for basic studies of clinically used biomaterials such as hydroxyapatite.

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Elastic system fibers (ESFs) of the mandibular condyle were studied by histochemical methods, light and electron microscopy and quantitative techniques. Three different types of fibers were observed: oxytalan, elaunin and elastic fibers. The fine oxytalan fibers appeared at 16 days inse-mination age and completed their distribution at 18 days insemination age, then the elaunin fibers appeared. However, the elastic fibers were not observed until 1 day after birth. The fibers formed a fibrillar network at the lateral aspect of the mandibular disc, and became continuous with the epimysium of the external pterygoid muscle medially. Quantitatively the elastic fibers of the disc increased mark-edly in the lactation, and after the weaning period the fibers decreased. Furthermore, distribution of the elastic fibers changed with that of collagen fibers by the time mice reached physiological maturity.

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To investigate differences between the cementocytes and osteocytes located in the lacunar and canalicular spaces of tissue fluid transport pathways, we intravenously injected either microperoxidase (MP) or horseradish peroxidase (HRP) into the jugular veins of 6-to-7-week-old Sprague-Dawley rats.
In the cellular cementum, HRP was detected throughout all lacunae and canaliculi containing cementocytes, and MP was found in most of these lacunae and canaliculi. MP and HRP were also detected within the organelles (micropinocytotic vesicles, phagosomes, multivesicular bodies and denseb odies) of nearly all cementocytes. However, the uptake of MP was more prominent in young cementocytes than in mature cementocytes, while there was no significant difference between young and mature cementocytes in HRP uptake.
In the alveolar bone, MP and HRP infiltrated all lacunae and canaliculi containing osteocytes and were also detected within the same organelles in osteocytes as those in cemento cytes. HRP was particularly deposited along the innermcst edge of the mineralized bone matrix and was extensi vely taken up by osteocytes.
These results suggest that the main transport pathways for tissue fluids within cementu m and bone are located in the external areas of the pericellular spaces, and that cementocytes are engaged in metabolic activities similar to those of osteocytes.

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We have constructed a bovine gingival cDNA library consisting of approximately 9×10⁶λgt10 clones, from 20g of gingival tissue powder which was prepared by freezing and pulverization in liquid nitrogen. One hundred clones or more were isolated randomly from the library, and their insert cDNA's were analyzed by polymerase chain reaction (PCR). Agarose gel electrophoresis of the PCR-amplified products revealed that most of the analyzed clones harbored insert cDNA's of lengths ranging from 300 to 1100 in base-pairs.
Our library will be useful for exploring the structure of various genes expressed in gingiva, and mechanisms which may control the expression of the genes in health and disease.

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The wall of the blood vessels in rat incisor pulp were investigated by the scanning electron microscopy of the HCl-collagenase method. The central arteries were covered by two or more compact layers of the smooth muscle cells. They were spindle-shaped or starlike and circularly oriented. There were two types of the surface contours in these central arteries. One was the type of the smooth contour and the other was rough like a screw. The arterioles (10-15μm in diameter) were covered by one or two compact layers of the spindle -shaped or starlike smooth muscle cells which were circularly oriented. The capillaries were studded with the pericytes having a few processes less than 10μm in length. The venules were studded with the pericytes having longitudinally oriented primary processes more than 20μm in length. These processes had many secondary processes which were circulary oriented. The central veins were covered by the loose net consisting of the spidery pericytes. These pericytes were in grooves of the endothelial cells.

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The ultrastructure of crystal formation in vitro associated with matrix vesicles (MV) isolated from rat incisor pulp was studied in BGJb medium supplemented with an organic phosphate, Na-β-glycerophosphate (BGP). MV were isolated from basal regions of the pulps using a collagenase digestion and ultracentrifugation method. Membrane structures of the isolated MV were well preserved. Incubation of MV in BGJb medium in the presence of BGP caused the development of granular structures associated with MV after 6 hours. These preceded needle-like crystal deposition which was observed in the culture medium after 18 hours. Incubation of MV in BGJb medium in the absence of BGP caused the development of granular structures associated with MV after 18 hours. The appearance of MV even after 24 hours of exposure to the reaction mixture containing levamisole in the presence or absence of BGP was similar to that of freshly isolated MV. Electron diffraction patterns of newly formed needle-like crystals revealed a pattern consistent with hydroxyapatite (HAP). Present study indicates that high calcium (Ca) X inorganic phosphate (Pi) ion product in the original medium and supplemented organic phosphate produce early mineral deposits associated with MV, and that the formation of amorphous calcium phosphate (ACP) precedes nucleation of HAP in the present culture conditions.

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A cystatin induced by chronic isoproterenol (IPR) administration was isolated from rat submandibular saliva by two steps involving native polyacrylamide gel electrophoresis and Immobilinecanal isoelectric focusing. The partial amino acid sequence result of N-terminal region showed that the purified cystatin was identical with the rat salivary cystatin-3 (RSC-3). Immobiline-canal isoelectric focusing was a powerful tool for the separation and purification of the proteins different in charge but not in size.

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Jaw and orofacial motor representation in the orbital cortex was studied by intracortical microstimulation (ICMS) in lightly anesthetized cats. ICMS of the posterior portion of the the orbital gyrus produced movements of facial muscles, whereas stimulation of the anterior portion of the orbital gyrus produced more generalized movement of facial, jaw and tongue muscles. The region producing jaw movements was more restricted than the regions producing tongue and facial movements. Repetitive stimulation of the anterior orbital gyrus produced either rhythmic jaw movements or sustained jaw opening. Cytoarchitectonically, the posterior portion of the orbital gyrus was restricted to area 43 and the anterior portion to areas 43 and 6aβ.

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The expression of ras p 21 and its histological localization on 13 ameloblastomas has been immunohistochemically studied using monoclonal antibody NCC-RAS-001 as the primary antibody. The ras p 21 was detected in 10/13 (76.9%) ameloblastomas; 3/5 (60.0%) were of the follicular and 7/8 (87.5%) of the plexiform type. In addition, ras p 21 was also detected in the cytoplasm of metaplastic squamous cells. The result suggested that ras p21 may be closely related to the proliferation and the development of tumor cells in ameloblastoma.

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