The occurrence of minor variants of the dental crown have been studied with a view to elucidating the degree of genetical control goveming their expression. The dental casts of samples taken from 17 Hindu families residing in Lucknow and their models examined for 5 dental traits; double shovelling of the central incisor, shovelling incisors, Carabelli's trait, interstitial tubercle and accesscry cusp of mandibular premolars. The interfamily concordance values showed that, for Carabelli's trait of the first upper molar and shovelling of the lateral incisors, the sib-sib concordance values were higher than the parent-child concordance.
The interfamily correlations were not uniformly high, but a significant correlation was found for Carabelli's trait of the upper molar in the mother-child and double shovelling in the father-child. The offspriag of various mating types for each trait were tabulated. In the case of shovelling of central incisors, all recessive homozygotes are produced from the mating of like homozygotes. In the case of Carabelli's trait of the upper first molar, all homozygotes are produced from the mating of like homozygotes and matings of unlike homozygotes do not produce recessive homozygotes. In the case of the interstitial tubercles and accessory cusp, matings of heterozygotes do not produce dominant homozygotes.
The results suggest that these dental traits probably renect the interplay between a genetical factor and a nongenetical factor.

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The basal cells of the main excretory duct of rat submandibular glands were examined using a method of serial sectioning and electron microscopy.
60% of all basal cells had the primary cilia. Various sizes of ciliated basal cells were present between epithelial cells.
Therefore, the basal cells were divided into three types (S, M, L) according to their size. Incidence and the projection direction of the cilia in every type of cell were examined.
1 Type S cell: These cells were the smallest cells of all and had numerous free-ribosomes in their cytoplasm. Only 8% of S cells had primary cilia which projected into vacuoles in the cytoplasm toward the lumen.
2 Type M cell: These cells were intermediate in size and had a moderate electron density of their cytoplasm. About 79% of M cells had primary cilia which projected in random directions.
3 Type L cell: Type L cells were the largest of all. Their form was similar to that of epithelial cells. About 92% of L cells had primary cilia. Many primary cilia of these cells projected toward the basal portion of the cell. Only a small number of the cilia were oriented parallel with the luminal surface. No cilia directed towards the lumen were observed in the L cells.
Therefore, it seems that as these cells grow, the primary cilia are formed and the direction of projection of the cilia is changed from towards the lumen to the basal portion of the cell.

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To elucidate collagen metabolism during the healing process of inflammation, the relationship between a fibrinolytic system and the activation of latent collagenase was studied in vitro and in vivo using carrageenin-induced granulation tissue in rats.
A protease that activated latent collagenase was found in the insoluble fraction of granulation tissue. This enzyme activity was inhibited by aprotinin and also by anti-rat plasminogen IgG antibody. Thus, this strongly suggested that plasmin activated the latent collagenase in granulation tissue in vitro.
When fibrinolysis was inhibited by the administration of tranexamic acid to rats, the ratio of latent collagenase to active collagenase in granulation tissue increased, though the activity of active collagenase decreased. This result again indicates that the activation of latent collagenase in the healing tissue of rat depends on a fibrinolytic system.
The above facts provide evidence that plasmin plays a role as an activator of latent collagenase in granulation tissue.

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The object of this study aimed to investigate the adsorptive properties of a cariogenic Streptococcus mutans including six serotypes and a non-oral bacillus Escherichia coli using an apparatus designed for the measurement of bacterial adsorption to electrostatically charged platinum electrodes in vitrc. Quantitative estimation of the bacterial adsorption by electron microscopy and the conditions affecting the bacterial adsorption to platinum electrodes were examined. Morphological differences in the materials adsorbed to the platinum electrodes which had been inserted into a human oral cavity were also examined as an in vivo experimental system.
The bacterial cells used were adsorbed more abundantly to positive electrodes than to negative electrodes. The number of S. mutans strain HS6 (serotype a) adsorbed to the positive electrodes increased with bacterial concentrations and current intensities up to 300μA. The bacterial adsorption to the positive electrodes was promoted by heating the bacterial cells and pretreatment of the electrodes with whole saliva. The bacterial cells of S. mutans adsorbed on the positive electrode were desorbed with time from this surface, when the polarity was changed. Scanning electron microscopy showed that in the human mouth the quantity of materials adsorbed on the positive electrodes placed was larger than those on the negative.
Results otained from in vitro and in vivo experiments strongly suggest that adsorption of the cario-genic bacterium S. mutans to positively charged surfaces of restorative materials or tooth surfaces may play a role in producing the dental plaque associated with dental caries and periodontal disease.

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The fundamental properties of monoamine oxidase (MAO) in rat parotid and sublingual glands were investigated. There was no significant difference between the specific activity of MAO in the two salivary glands, and the activities were highest on serotonin, intermediate toward tyramine and dopamine and lowest toward β-phenylethylamine which were used as substrates the relative activities when the activity with serotonin was taken as 100 were about 80, 60 and 25-30 toward tyramine, dopamine and β-phenylethylamine, respectively. More than 80% of the total enzyme activities were attributed to the type A of MAO in the two salivary glands. The activity per unit weight and per unit weight of protein were about 1.8-and 1.2-fold higher in the parotid gland than those in the sublingual gland. Unilateral duct ligation for a period of two-weeks caused a decrease in the MAO total activity to an average of about 10% in the parotid gland, and about 23% in the sublingual gland (unoperated side was used as the control). The activity toward serotonin decreased most lowly in each salivary gland.
Unilateral two-week long denervation produced to decrease in the activity in each salivary gland. The properties of MAO in the mitochondorial and microsomal fractions were abso investigated.

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A study of the age-related change in arteries was made on the tongues from Senescence Accelerated Mouse-Prone/2.The tongues from SAM-R/2 and ddY-strain mice were used as controls. The tissues from three sites of the tongue were examined histologically and electronmicroscopically.
A fine granular substance (FGS) was found in the wall of tongue arteries of the SAM -P/2 while no FGS was revealed in the control groups except in a few 12-month-old mice.Histologically the FGS was found to be present in the media of the tongue artery. Because of its varying quality in some staining methodes, it was considered that the FGS might consist of various stages of the maturation of lipofuscin from ceroid. With ageing of the SAM-P/2 there was a tendency for an increase in the quantity of the FGS. Electron microscopy revealed that the FGS was localized in the cytoplasm of a large cell distributed between the smooth muscle cells in the media of tongue artery.
The authors considered that an accumulation of the FGS in the wall of arteries might show the early stage of spontaneous atherosclerosis in the tongue arteries of SAM-P/2.

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In order to identify and characterize osteoclasts morphologically, bone marrow cells were isolated from the long bones of neonatal rats and suspended in Hepes-buffered 199 medium containing 0.1% bovine serum albumin. The cell suspensions were plated on coverslips settled in petri dishes and incubated at 37°C in a humidified air containing 5% CO2. At intervals after incubation, the adherent cells were stained with May-Gruwald-Giemsa solution and then observed morphologically under the microscope.
In this bone marrow culture, osteoclasts were identified as multinucleated giant cells, and could be classified into two different types by the characteristic morphology of their cytoplasm: the cells with a cytoplasm showing only typical lamellipodia (L-type), those with a lamellipodia, lobopodia, polarity and ruffling activity (P-type).
Almost all osteoclasts which were cultured by this method were dead within 24 hours.

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The three-dimensionl architecture of the terminal portion of transverse muscle fibers of the tongue in C-57-BL mice was studied by scanning electron microscopy. The proximal and distal portion of the transvers muscle fibers possessed finger-like processes (0.2 to 0.4pm in width) and inter-process grooves (0.01to 0.15pm in width).In the proximal portion, many finger-like processes (1 to 4pm in length) and inter-process grooves (1.3 to 5.8 pm in length) were found on the terminal end. The distal portion of the muscle fibers possessed several cornshaped processes (1 to 2.5 pm in width).The finger-like processes (2 to 5 pm in length) were mainly seen on the cornshaped processes.These structural differences between the proximal and distal portions are caused by the difference of the junctional area between the fiber's ends and the connective tissue. In the distal portion of the muscle fibers, some of the pores (0.2 to 0.5pm in width) and the basal furrows were found at the base of the finger-like processes. Moreover, mesh-like structures covered the corn-shaped processes. These structures consisted of many, short longitudinal grooves (0.15 to 0.8pm in length).There were some shallow grooves between the short longitudinal grooves. An intermediate form between the finger-like process and the corn-shaped process was also found in the distal portion of the muscle fibers. These results indicate that the mesh-like structures are formed by the fusion of the finger-like processes on the corn-shaped process.

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In the present study, the precipitate formed in situ by the antimonate -osmium mixed fixative was examined using both energy dispersive X-ray microanalysis (EDX) and electron energy- loss spectroscopy (EELS) in order to elucidate its chemical composition. EDX spectrum from the antimonate reaction product suggested the presence of complex Ca and Sb.However, since the peaks of Ca and Sb overlap considerably, it was difficult to identify both simultaneously. On the other hand, EELS spectrum clearly indicated the presence of Ca (L2, 3, 350, 346eV) and Sb (M4, 5, 537, 528eV) in the electron dense precipitate within secretory granules of preodontoblasts and on the inner face of the plasma membrane of preameloblasts.Thus, EELS analysis is very useful to confirm the presence of Ca and Sb in the antimonate reaction product.

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Morphological and biochemical studies were made to examine whether and rogen is responsible for the properties of submandibular tumor. The tumor was induced with carcinogenic hydrocarbon, 9, 10-dimethyl-1, 2-benzanthrasen, in Fisher rats. Alkaline esteroprotease and 5α-reductase were biochemically measured and the morphological observations made with a light microscope.
The histological structure of all of the experimental submandibullar gland tumors showed the pattern of a well differentiated squamous cell carcinoma with keratin being formed with in the neoplasm. Neither adenocarcinoma nor metastic lesions are created under the conditions of the present experiments. Alkaline esteroprotease from the tumor was very lower in activity than that from the control, when measured in tissue homogenates.Microsomal 5α-reductase activity in the tumor was conversely much grater than that in the control.
These results suggest the possibility that and rogen may play a role for the growth of the carcinogeninduced rat submandibular gland tumor.

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The blood supply of the trigeminal ganglion in the Macaca irus and dog was summarized by surveying many vascular specimens utilizing the acryl plastic injection method. On the basis of the findings obtained, the present study was made and discussed whether the external or internal carotid system might play a principal route as the supply source for the ganglion in the respective species. The ganglion of the Macaca irus was situated on the anterior surface of the temporal petrosa being close to the brain site, but in the dog on the base of the greater ala of the sphenoid bone at a short distance from the brain site.The main source of the ganglionic branches in the Macaca irus can be said to be the internal carotid (such as the marginal and basal tentotrial, the anterior petrosal and the trigeminal nerve branches) with accessory routes from the basilar artery (pontine branch) and the external carotid (the accessory meningeal branch). Conversely, that in the dog can be said to be the external carotid (such as the middle meningeal artery, the anastomotic, the petrosal, the accessory meningeal branches and the anastomotic artery) with accessory routes from the internal carotid (direct branches.)

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Langerhans cells functioning as epidermal macrophages are known to contain S-100 protein, a peculiar brain-derived protein. The present study demonstrates the occurrence and ultrastructure of S-100-immunoreactive dendritic cells in normal and inflamed gingiva in human subjects. A few S-100-immunopositive cells were found scattered in the normal gingival epithelium, but these greatly increased in number in the inflamed gingiva. By electron microscopical observation, the S-100-immunopositive cells in the normal gingiva were confirmed as containing Birbeck granules characteristic of Langerhans cells, while the cells multiplying in the inflamed gingiva corresponded to indeterminate dendritic cells, which have been regarded as immature Langerhans cells in the skin. The close juxtaposition of lymphocytes to the S-100-immunopositive indeterminate dendritic cells was frequently recognized in the inflamed gingiva, a finding which suggests that these cells, and not the typical Langerhans cells, may function as antigen-presenting cells.

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