The dynamics of mesenchymal cells in transplantation of vital pulp tissues and dentin matrices, as well as the origin of new odontoblasts which participate in the formation of the dentin bridge, based upon our experiments and recent literature, are described.
Experiments involving implantation of pulp and treated dentin matrix were performed to emphasizethe capability of these cells and matrices to produce hard tissue and were compared with those of implantedperiosteum, perichondrium and treated bone matrix. Light and electron microscopic and autoradiographicstudies were carried out to clarify the origin of replacement odontoblasts. It appears thatthe pulp cells, endothelial cells, and pericytes become undifferentiated mesenchymal cells following pulpexposure. These mesenchymal cells differentiate into odontoblasts, which subsequently produce a dentinmatrix. Pulp tissues auto-grafted to non-pulpal sites, elaborated the bone (or osteodentin) matrix, butdid not produce to the tubular dentin. An experiment on dentin bridge formation, using germ-free rats, demonstrated that the pulp tissue has intrinsic healing potential. Therefore, it was concluded that theability of pulp tissues depends on its micro-environment as inductive agents. This conclusion may notcontradict the idea induced by our experiments on implantation of periosteum, perichondrium and treatedbone matrices.

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Vesicles in the nerve terminals of the taste buds were studied quantitatively using earlypostnatal (1-14 days) and adult mice. The mean number of large dense-cored (70-100nm in diameter) and small clear (30-60 nm) vesicles per nerve terminal gradually increased, reached a peak at 7 daysand decreased to only half of the number at 7 days. The mean number of both vesicles per unit area (1 um2) of the nerve terminals already showed a high level at 4 days and decreased by one-third from4 days to adulthood. The nerve terminals which made afferent synaptic contacts with the type-III (gustatory) cells contained numerous vesicles, and especially at 7 and 14 days the mean number ofvesicles showed a high level of three-fold of adult mice. The relative numbers of large dense-coredand small clear vesicles were 3: 7 throughout the experimental period, and small clear vesicles occurredmore frequently. The nerve terminals from 4 to 14 days of early postnatal period, when the tastebud cells rapidly differentiated and developed, contained more vesicles than those of adult mice. Theresults suggest that those vesicles might contain a neurotrophic factor responsible for the differentiationand maintenance of taste bud cells.

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The mercury contents in the brains, livers and kidneys of rats given an amalgam powderdiet were investigated in this study.
The rats were divided into 5 groups of four rats. Group 1 (control) was given distilled water. Groups 2 and 3 received 10 ppm and 20 ppm mercurous nitrate solutions, respectively. Group 4 was feda 10% amalgam powder diet and group 5 received 20%. The rats were killed after four weeks ofan experimental period and mercury in the tissues of the 5 groups was measured with a flameless atomicabsorption photometer using quartz tube combustion-gold amagamation. A histological examination wasalso performed on the tissues.
In groups 2 and 3, mercury contents were higher in the kidneys than in the brains and livers. Contents of mercury in the brains and livers were almost the same. In groups 4 and 5, the contentsof mercury were the highest in the kidneys, intermediate in the brains and lowest in the livers. Histologically, none of the rats showed any pathological changes in their tissues.

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Mycoplasmas require a sterol for growth. To meet this requirement, horse serum (HS) has been used most frequently in mycoplasma media. In this study, chicken egg yolk extract (EY) was tested as an HS substitute.
The tested strains were Mycoplasma salivarium ATCC 23064, Mycoplasma orate ATCC 15539 and Ureaplasma urealyticum ATCC 27816.
The growth-promoting (g. p.) ability of EY in liquid medium: EY medium (PPLO broth incorporatedwith 10% EY) and HS medium (mycoplasma or ureaplasma media consisting of PPLO broth, HS and yeast extract) were inoculated with tested strains, and viable counts (v. c.) were measuredperiodically. M. orale grew better in EY than HS medium. The maximum (m.) v. c. in EY mediumwere 10 to 100 times those in HS medium. The growth of M. salivarium in EY medium was nearlycomparable to that in HS medium, although m. v. c. in HS medium were approximately 10 timesthose in EY medium. Ureaplasma did not grow in EY medium.
The g. p. ability of EY in agar medium: The liquid medium was supplemented with 1% agarand plated. M. salivarium and M. orale produced almost the same number of colonies on EY and HS medium. But the size of the colonies was considerably smaller on EY than HS medium. U. urealyticum did not grow on EY medium, but grew well on the medium enriched with 10% yeastextract.
Based on the results, it was concluded that HS can be replaced by EY in mycoplasma mediafor cultivation of laboratory strains of M. salivarium and M. orate for some limited purposes, although EY is a little inferior to HS in g. p. ability.

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The acids produced in the oral cavity are well known to be responsible for dental caries. Thebases produced therein neutralize these acids and make the surroundings in habitable for oral microorganisms. It is important to investigate the relation between the base production by oral microorganismsand oral diseases.
This investigation deals with the production of putrescine from several precursors by salivary microorganisms. Whole saliva was collected from 9 persons. Three kinds of mixed saliva containingthe same volume of salivas collected from three persons were incubated at 37°C for 48 hours underaerobic (unshaken) condition with deionized water or 25m M precursors (ornithine, arginine, citrulline, agmatine and glutamic acid). Putrescine produced and agmatine remained were determined by isotachophoresis.
Putrescine was produced from saliva containing ornithine, arginine or citrulline but was notdetected isotachop horetically in saliva containing deionized water, agmatine or glutamic acid during 48 hours of incubation. The largest amount of putrescine was produced from ornithine. The amountof putrescine produced from arginine was less than a half of the putrescine produced from ornithineand that from citrulline was quite smaller than the putrescine produced fromarginine. It was confirmedthat agmatine was not produced from arginine in saliva and the agmatineadded in saliva was notdecomposed during 48 hours of incubation. It has been considered that putrescine is produced from argininevia the arginine dihydrolase pathway followed by ornithine decarboxylation by oral microorganisms. However, it was suggested from our experiment that salivary microorganisms produced putrescine fromarginine by the pathway comprising arginase and ornithine decarboxylaseother than via the argininedihydrolase pathway.
pH of saliva containing putrescine-producing amino acids increased with incubation but the pH was not in parallel with the amount of putrescine. The rise of pH was the highest in saliva incubated with arginine and it was due to the volatile base (ammonia) produced with putrescine.

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In order to separate the metabolic factors (MF) in human centrifugated salivary supernatant, acetone was added to the salivary supernatant to make final concentrations of 10, 30, 40, 50, 70, 90%.
These were divided into acetone soluble and insoluble fractions.
The test medium (total volume, 3 ml) containing acetone treated fractions, salivary sediment and 0.02 M glucose solution, was incubated at 37°C for 2 hours by the tube-culture method under aerobiccondition.
The glucose content was measured by the glucose oxidase method.
Most of the MF was detected in the soluble fractions at acetone concentrations of 10, 30, 40% and showed ninhydrin positive reaction.
The acetone separation method is considered to be most effective in the isolation of MF.

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The purpose of this study was to elaborate on the effect of hydrocortisone on the differentiated phenotype of chondrocytes and the proliferation of chondrocytes from rabbit craniofacial complexin culture. Hydrocortisone stimulated glycosaminoglycan (GAG) synthesis, a characteristic of cartilagephenotype, of rabbit nasal septal chondrocytes (NSC) in culture. Hydrocortisone also stimulated incor-poration of PFUJ serine into proteoglycan. The stimulation of GAG synthesis by hydrocortisone wasdose-dependent and maximal at a physiological concentration of 10-7M. Hydrocortisone also stimulated GAG synthesis in mandibular condylar chondrocytes (MCC) and sphenooccipital synchondrosal chondrocytes (SOS) in culture. The magnitude of the increase of GAG synthesis in response to hydro cortisonewas the largest in MCC, medium in SOS and smallest in NSC. Hydrocortisone stimulated DN Asynthesis in NSC dose-dependently. Hydrocortisone also stimulated DNA synthesis in MCC and SOS.

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We found Plasminogen Activator (it could not degradate fibrin and could only convertplasminogen to plasmin) and Fibrinolytic enzyme (it could degradate fibrin directly) in the submaxillaryglands of rats. We elucidated some characteristics of these enzymes as compared with other known proteasesexisting in the submaxillary glands of rats.
(1) The molecular weight of Plasminogen Activator (referred to as “Activator”) and Fibrinolyticenzyme was 28, 000 and 30, 000 respectively.
(2) These enzymes possessed amidase activities. Activator did not show protease activity (substrate: fibrin, casein, and albumin), and Fibrinolytic enzyme showed higher specific activity to fibrin than tocasein and albumin.
(3) The activities of these enzymes were inhibited with DFP and Soy Bean Trypsin Inhibitor but didnot be affected by TLCK.
(4) These enzymes did not increase the permeability of blood vessels.
(5) These characteristics of Activator resembled these of the Kallikrein-like peptidase, and the charcteristicsof Fibrinolytic enzyme resembled those of Salivain.

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In forensic examination of saliva and saliva stains, the author tried to detect only humansalivary amylase by ELISA. The results obtained were as follows:
Rabbit anti-human salivary amylase antibody absorbed by human red cells was diluted 1: 200 in PBS containing 1% horse serum. It was effective in differentiating human saliva from human body fluidsand animal saliva except monkeys.
By ELISA high amylase activity saliva with the same dilution ratio tended to show darker hue thanlow activity saliva.
Attempts at detection of human salivary amylase were performed on various saliva stains and humanbody fluid stains after they were incubated 24 hours under room temperature. It was possible to detecthuman salivary amylase in human saliva stain samples which were the size of 2×2 mm (about 0.5μlsaliva samples had been attached). Negative results were obtained, however, from all animal saliva stainsamples and human body fluid samples except human saliva stain samples.
Human saliva stain samples preserved under various conditions were periodically examined. It wasrecognized that human salivary amylase preserved under low temperature was more detectable for along time.
Amylase was detected from old saliva stains which had been preserved in the room for two years. The amylase detection was possible from the samples with high amylase activity saliva

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The cortical projection area (layer) of tooth pulp input was studied by recording surface and deep potentials in cats anesthetized with ketamine and immobilized with pancronium bromide. Cortical surface potentials evoked by stimulation of the contra- and ipsilateral upper canine tooth pulps were recorded with silver ball electrodes at 80 points on the surface of the cortex including somatosensory cortex and the intracortical deep ones with glass coated tungsten micro-electrodes. Lesions where the largest deep negative (N_D) potentials could be recorded were verified histologically. Contralateral tooth pulp stimulation evoked the largest intracortical deep negative (N_D) wave at depth of about 0.6mm in the adjacent area to the lateral branch of the ansate sulcus, at depth of 2.0-2.5mm in the middle part of the coronal gyrus, and at depth of 1.0-1.5mm in the anterior part of the coronal gyrus. On the other hand, ipsilateral one evoked the largest N_D wave at depth of 1.0-1.5mm in the anterior part of the coronal gyrus. Therefore, the following points were concluded. 1. The major cortical projection area from the contralateral tooth pulp was localized separately in the adjacent area to the lateral branch of the ansate sulcus (posterior projection area: PPA) and in the anterior and middle parts of the coronal gyri (anterior projection area: APA). 2. The intracortical projection layers of the contralateral tooth pulp input where the largest N_D could be recorded were found to be located in superficial (laminae An) of area 2 and 5a of PPA and in deep layers (laminae IV-V) of area 3a and 3b of APA. 3. The ipsilateral tooth pulp projection area was found to be located in the antero-ventral part of APA and the intracor-tical projection layer from ipsiliateral one was at a deep layers (laminae IV-V) of area 3a and 3b.

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Various methods for identification of osteoid matrix in decalcified bone were comparatively examined, using autoptic bone tissues from monkey and human. The osteoid volume in their sections measured morphometrically was also compared with that in the undecalcified control sections from the same materials.
Both methods of Meyer, and Ralis and Ralis were very easy to handle, since decalcified sections can be prepared without special pretreatment of bone tissue and then stained in routine manner. They were however extremely unreliable for identification of osteoid matrix. Tripp and MacKay method which is based on von Kossa staining consists of incubation of bone tissue in a silver nitrate solution before decalcification, followed by decalcification and sectioning of the tissue. They showed clear identification of osteoid matrix, but the section made by this method sometimes brought about the remaining of the region without silver precipitation at the center of the calcified trabeculae, confusing it with the osteoid matrix. Yoshiki method consists of cyanuric chloride treatment of bone tissue before decalcification, then decalcification and sectioning of the tissue. It could easily obtain large decalcified sections from any bone tissues in routine manner and yielded high quality results for identification of osteoid matrix in the sections, resulting in easy application in any laboratory.

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Different from most of other proteinases such as proteinase A, D and P in the mouse submandibular gland, proteinase F is rich in the gland of female mice. The in vivo biosynthesis of proteinase F was inhibited by androgen in males but not in females. The lack of response to androgen in adult females seemed to be due to the lack of the exposure against unknown factor (s) supposed to be secreted from the testis of new born mice. The in vivo inhibition of proteinase F biothynthesis by androgen in adult males appeared to require the presence of the thyroid gland, which may secrete some inhibitory factor (s) in response to androgen: whereas the pituitary gland may secrete certain substances (Pituitary factors) which stimulate the proteinase F biosynthesis.
The androgen stimulated the biosynthesis of proteinase F in the hypophysectomized mice which are also hypothyroid. Therefore, androgen is thought to be stimulatory in the absence of both the pituitary factor (s) and thyroid factor (s).

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The effect of modified neurolept analgesia method (used droperidol-pentazocine) on dopamine metabolism in rat was studied by measuring the quantity of DA, DOPAC and HVA in each dopamine neuron system using High Performance Liquid Chromatography.
Appearance of catalepsy and the analgesic effect was also studied in rat.
As a result, dopamine metabolism was accelerated by droperidol, but not changed by pentazocine. The acceleration effect of dopmine metabolism on the combined group, which was admininstered droperidol and pentazicine, was similar to the droperidol group.
Catalepsy did not appear in the pentazocine group, but appeared in the droperidol group and combined group.
Analgesic effect did not appear in the droperidol group, but appeared in the pentazocine group and combined group.
Moreover, in comparing the combined group with pentazocine group, the combined group has a greater analgesic effect than the pentazocine group. Thus, the acceleration effect of dopamine metabolism is dependent on droperidol.
The acceleration effect on dopamine metabolism and appearance of catalepsy by droperidol were not influenced by pentazocine, but analgesic effect of pentazocine was reinforced by adding droneridol.

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The cytochemical localization of endogenous peroxidase was demonstrated in the acinar cells of new-born and adult Mongolian gerbil submandibular glands in order to investigate a peroxidase synthetic pathway in an acinar cell. The secretory granules in the acinar cells were seen to be packed with dense substances. The more densely stained part of the granule showed a strong peroxidase activity. The present study focussed on the Golgi area to demonstrate the transportation of the enzyme protein of peroxidase from the rough endoplasmic reticulum to the secretory granule in the acinar cell, by means of the Graham and Karnovsky DAB method (1966). The transport vesicles formed by budding from the endoplasmic reticulum showed evidence of peroxidase activity. Reaction products were also seen in the cisternae of the endoplasmic reticulum, the nuclear envelope, immature secretory granules and in the condensing vacuoles situated away from the Golgi stack. A positive DAB reaction, however, was not found in the Golgi cisternae and in the adjoining immature condensing vacuoles. The peroxidase enzyme in the acinar cells of Mongolian gerbil submandibular gland therefore appears to be tr ansported from the rough endoplasmic reticulum to the condensing vacuoles via transport vesicles in the periphery of the Golgi complex.

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Vascularization of the enamel organ was studied in the developing molar teeth of the rat with light and electron microscopy. Capillaries were first observed in the enamel organ at the embryonic age of 21 days. Differentiation of mesenchymal cells of the dental papilla into odontoblasts had taken place by that time, but deposition of inorganic substances had not started. The occurrence of capillaries before the nutritional supply from the dental papilla is interrupted by deposition of dentin may possibly be due to high nutritional requirement of ameloblasts following differentiation from the inner enamel epithelium.
In addition to the basal lamina of the capillary endothelia, another basal lamina was recognized around the cells in contact with the endothelia. The findings indicate that, although indistinguishable from cells of the stellate reticulum because of the tendency to flatten and widen the intercellular spaces, the latter cells are the constituents of the outer enamel epithelium. The assumption was further supported by the presence of half-desmosomes characteristic cf the basal lamina of the outer enamel epithelium in the basal lamina of these cells. It is concluded, therefore, that the capillaries in the enamel organ result from indentation or invagination of the outer enamel epithelium in association with their growth and are not the result of direct invasion into the stellate reticulum by penetration through the layer of the outer enamel epithelium.
The capillaries on the surface of the outer enamel epithelium at the embryonic age of 19 days maintained the continuity of endothelia, but they became fenestrated with the growth into the enamel organ and their endothelia contained many pinocytotic and coated vesicles. This may be regarded as a change to enable rapid and sufficient supply of metabolic substances needed for amelogenesis.

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We investigated the solubilization of bone tissue by macrophages, in terms of lactate production in vitro using bone particles which could not be engulfed by macrophages. The conditions during contact to bone tissue and phagocytosis were observed ultrastructurally. The results indicated that macrophages have soluble action to bone tissue when in contact with the tissue, as suggested by release of Ca, lactate production, rise of lactate dehydrogenase-activity and glucose consumption by macrophages. Significant correlation was also found between production of lactate by macrophages and Ca releases from bone tissue. Electron microscopic observation suggests that macrophages can dissolve bone particles which can then be phagocytized following destruction and solubilization of bone tissue.

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The correlation between histological changes of secretory granules in granular convoluted tubule (GCT) cells, immunohistochemically detected EGF and NGF and binding patterns of PNA (Dgalactose binding lectin) and SBA (N-acetyl-D-galactosamine binding lectin) lectins were examined in mice submandibular gland under secretagogues administration. Morphometry of GCT in tissue sections and EGF contents by RIA were examined and compared to histologic and histochemical features.
The secretion from GCT cells started immediately after administration of phenylephrine and methoxamine, and maximum degranulation in GCT cells was seen at 6 hours after administration. Accumulation of small sized secretory granules appeared in apical cytoplasms of GCT cells as a recovery sign at 12 hours after the administration.
The GCT cell seemed to be mainly regulated by a-receptor. Effects of β-receptor may extend to the secretion of GCT since degranulation accompanied by reduced stainings of EGF, NGF and PNA, SBA lectins occurred after administration of isoproterenol. It was suggested that obvious correlation should be present between such changes of secretory granules and staining of EGF, NGF and PNA, SBA lectins.
The PIA-EGF concentrations revealed an approximate 25% decrease in the male, 60% in the female from 1 to 6 hours after a-stimulation. Sexual dimorphism could be demonstrated objectively by the use of morphometry. The GCT area to the total was 45.8±4.08% in the male gland, 8.3±2.16% in the female. In the male, the value quickly decreased after a-stimulation and the lowest was 22.0±2.02% at 6 hours after administration.

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In the present study, the initial dentine forming areas were stained with ruthenium hexam-mine trichloride (RHT) and examined under an electron microscope, consequently, the following conclusions were obtained.
1) Basal lamina had a marked affinity for RHT, in particular, and lamina lucida reacted intensely rather than lamina densa.
2) The intercellular spaces between preodontoblasts were filled with electron opaque materials which were intensely stained with RHT and appeared almost homogeneous. On the other hand, RHT-positive granules, approximately 30 nm in diameter, from which faint filamentous structures extended radially, were scattered in the predentine matrix. Some of them were situated on the surface of collagen fibrils in the periodic array.
3) Large amounts of RHT-positive materials were attached to the outer surface membrane of matrix vesicles.

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The effects of mutastein, a glucosyltransferase inhibitor, on caries development were examined using male S.D. rats (ca. 40g) which were inoculated with Streptococcus mutans 6715 and fed a cariogenic diet containing no mutastein (control), 0.04% or 0.4% mutastein for 57 days.
The value of the plaque index was in the order as follows: control group ≈0.04% mutastein group≥0.4% mutastein group. The appearance of proximal lesions was null in all the three groups. The caries score of sulcal lesions decreased in the order, control group, 0.04% mutastein group, 0.4% mutastein group, whereas that of smooth surface lesions decreased in the reverse order. However, summing up the caries score of both sulcal and smooth surface lesions, it was revealed that mutastein added to the cariogenic diet at 0.4% exhibited 34% suppression of caries development caused by S. mutans infection. Moreover, it was shown by colony counting that the number of S. mutans cells adhering to teeth in 0.4% mutastein group decreased prominently during the 5th to 8th week after inoculation. This decrease may be one of the causes for the suppression by mutastein of caries development. No toxic effects of mutastein on rats were observed under experimental conditions used in this study. These results suggest that mutastein has a potential of controlling dental caries.

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Amylase (AM), lactoferrin (LF), lysozyme (LY), and secretory component (SC) were studied in 61 cases of malignant salivary gland tumors (acinic cell tumor 3, mucoepidermoid tumor 13, adenoid cystic carcinoma 18, adenocarcinoma 7, malignant mixed tumor 4, malignant myoepithelioma 2, and undifferentiated carcinoma 14) using the peroxidase-antiperoxidase method.
Since LF and SC were frequently detected in most tumor types other than undifferentiated carcinoma and malignant myoepithelioma, often in corresponding tubular cells in serial sections, it was suggested that the combined findings of these two markers might represent a universal indication for glandular differentiation of the malignant tumor cells, particularly toward the intercalated duct. AM was revealed in abundance not only in acinic cell tumor but also in mucoepidermoid tumor and less frequently in some other tumor types, and was regarded as a useful marker for serous cell differentiation of the tumor cells. These three secretory proteins were also demonstrated in a few cells of undifferentiated carcinoma, suggesting functional differentiation of the morphologically undifferentiated cells toward secretory epithelium.
In conclusion, an immunohistochemical demonstration of AM, LF and SC seems to provide helpful information for estimation of secretory epithelial differentiation of the neoplastic cells in malignant salivary gland tumors. It is also likely that this approach can be useful for diagnosis and/or subclassification of such a group of salivary gland tumors showing an undifferentiated morphological pattern.

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Tooth replacement in bony fishes is more complicated than postulated by the Zahnreihe concept by Edmund (1960). In this paper, the growth and replacement of teeth on the maxillary and dentary in abult amago salmon, Oncorhynchus rhodurus is described. The present study is based upon 20 male ranging from 33cm to 40cm in standard length (SL), 20 female from 25cm to 30cm SL, fully matured amago salmon, and 20 young from 5.5cm to 6.5cm SL. All of specimens were stained with alizarin red S, and upper and lower jaws of adult fish were radiographed. The position of toothgerms, functional teeth and traces of lost teeth in the tooth row on the maxillary and dentary were determined in these stained specimens.
When the toothgerm appeared at the nth-tooth position, the frequencies of the appearance of toothgerms were 20.2-20.3% at the (n+1) th tooth position, 53.8-58.7% at the (n+2) th, 19.8-20.2% at the (n+3) th and 1.6-4.3% at the (n+4) th in the tooth row on the dentary, and were 11.8-19.4% at the (n+l) th tooth position, 38.9-44.3% at the (n+2) th and 26.0-36.1% at the (n+3) th on the maxillary of the adult fish. But, in the young fish, when the toothgerm appeared at the nth-tooth position, the frequencies of appearance of toothgerms was 42.5% at the (n+1) th tooth position and 53.9% at the (n+2) th in the tooth row on the dentary, and, 41.6% at the (n+l) th and 45.5% at the (n+2) th on the maxillary. The findings on the adult amago salmon may support Osborn's hypothesis (1971), but those on the young fish may not support the hypothesis. Furthermore, the shedding of functional teeth may produce a condition which stimulates a development of the teeth around them on the dentary and maxillary in amago salmon.

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The experiments were designed to induce odontogenic tumors by administration of Nmethylnitrosourea (MNU) to suckling Sprague-Dawley rats. MNU was administered by gastric intubation 2, 3 and 9 times at semiweekly intervals to 7, 9, 10 and 11 day-old rats. Histologically, seven odontogenic tumors were identified in five of a total of 28 rats. The tumors were detected in one of four 7-day-old rats given 2 mg of total doses of MNU 2 times and one of five 9-day-old rats given 2 mg of total doses of MNU 2 times. Furthermore, the tumors were induced in three of ten 11 day-old rats which had received 24 mg of total doses of MNU 9 times. All of the tumors inducedin male rats were located in the jaw ; five tumors were in the mandible and only one in the maxilla, five in the right and one in the left.
Microscopically, the tumors had many teeth-like structures, epithelial elements with marked keratinization and dental papilla-like elements. The histopathological features of these tumors resembled those of the human odonto-ameloblastoma (ameloblastic odontoma).
It is concluded that the present experimental methods were useful to induce odontogenic tumors in rats.

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In the submandibular gland of intact mice, there is a sex diffecence in cytosol androgen receptor level, being higher in females. The exchange assay using mersalyl and monothio-glycerol revealed that cytosol androgen receptor in both sexes is mostly unoccupied. To understand the action of androgen via androgen receptor in the submandibular gland, cytosol androgen receptor level and androgen-dependent N-tosyl-L-arginine methyl ester esterase (TAMEase) activity, being higher in males were determined under endocrine manipulations. In males, castration elevated unoccupied cytosol androgen receptor level and reduced the TAMEase activity. Injection of testosterone decreased unoccupied cytosol androgen receptor level and increased TAMEase activity in females, whereas injection of estradiol exerted no effects on cytosol androgen receptor level and TAMEase activity in males.

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The granular duct cells in the submandibular glands of house shrew (Suncus murinus riukivanus) and dsinezumi shrew (Crocidura dsinezumi) were studied by light and electron microscope. Their ducts showed similar structures and were better developed in the male than in the female of both animals. The myoepithelia associated with the duct cells showed a characteristic distribution, that is, they were ranged not only as proximal granular duct segment but also as distal striated duct segment. Various sized secretory granules in the duct cells of both animals contained neutral glyco-proteins in histochemistry and those of dsinezumi shrew showed more dense matrix than those of house shrew in ultrastructure. Characteristic myelin-like bodies were also contained in the granular duct cells of both animals. It was suggested that they were derived with granular endoplasmic reticulum and successively formed to be discharged into the lumen of the granular ducts as a component of saliva.

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The quantitative properties of the parameter m and a new parameter of maximum slope in the spectrophotometric aggregation assay were examined to analyze the interaction between different aggregating substances such as salivary agglutinins and glucosyltransferase (GTF). Agglutinins of parotid saliva partially purified by Sephacryl s-1000 column chromatography and GTF of S. mutans strain 6715 with sucrose aggregated cells of S. mutans strain TH 16. The parameters m and the maximum slope were directly proportional to the amount of aggregating substances and their correlation coefficients were statistically significant. Moreover, correlations between parameters m and the maximum slope were also statistically significant and each parameter was highly directly proportional to the other in both cases of salivary agglutinins and GTF.
These results suggest that both of the parameters m and the maximum slope are quantitative and useful to analyze the interaction between different aggregating substances such as salivary agglutinins and GTF.

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The effects of salivary agglutinins, calcium chloride, glucosyltransferase and sucrose in different combinations on the aggregation of S. mutans serotype c strain TH16 were examined using a new parameter of maximum slope for the quantitation of aggregating activity, and the interactions among them were statistically analyzed by the four-way analysis of variance. Salivary agglutinins, sucrose, calcium chloride and glucosyltransferase were concerned in the aggregation of S. mutans TH16 and the contribution of each factor was statistically significant. The interactions between these factors were additive except the synergetic interaction between sucrose and glucosyltransferase. Moreover, the contribution of glucosyltransferase and sucrose in the aggregation of S. mutans TH16 was 8 times as much as that of salivary agglutinins and calcium chloride.
According to these results it is suggested that glucosyltransferase may play an important role as a dominant aggregating factor for S. mutans TH16 when sucrose exists, and its additive interaction with salivary agglutinins will become negligible.

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The three-dimensional ultrastructures of the taste bud cells and the nerve fibers in the mouse were investigated by means of electron microscopy using serial ultra-thin sections.
Most of the taste bud cells were spindle-shaped and smooth in outline, but a few of type-II cells protruded in cytoplasmic processes from the basal portions. The nerve fibers entering the taste buds through the basal lamina, branched several times, the terminals were formed repeatedly, and then, they narrowed and back to slender, finally ending in the form of a teminal. The number of nerve fibers and terminals which innervate a single taste bud cell differed among the cell types. Each type of cell came in contact with the following per cell, type- I and basal cells with 1-2 nerve fibers, type- II cells with 1-4 nerve fibers, and type-DI (gustatory) cells with 2-4 nerve fibers. The number of nerve terminals in contact with each type of cell was 1-2 per cell in type- I and basal cells, 2-4 type-il and 3-6 in type-III. The nerve fibers which came in contact with type-III cells always formed several (mean number of 8 per cell) afferent synapses. A single nerve fiber innervated 4-14 (mean number of 9) taste bud cells which were composed of different cell types. Seven of nine nerve fibers innervated both type-DI cells and other types of cells. This uggests that most of the nerve fibers in the taste bud not only transmit gustatory stimulus but also have other functions, such as the trophic effect on the taste bud cells.

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Characteristics of androgen receptor were investigated in male and female rat submandibular glands.[³H] Methyltrienolone binding to the androgen receptor was displaced by methyltrienolone > testosterone = 5α-dihydrotestosterone ≥ progesterone. The apparent dissociation constant of [³H] rnethyltrienolone binding is 1.1-1.2 nM. The androgen receptor could be interacted with DNA following heat, salt or ATP treatment, which was accompanied by the change of sedimentation coefficient of androgen receptor from 8-9 S to 4 S. These results indicate that the androgen receptor in females is identical to that in males and functions similarly to that in males. On the other hand, the concentration of cytosol androgen receptor was over 2-fold higher in females than in males.

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Histological examinations of tooth germs in juvenile dog salmon (chum salmon), Oncorhynchus keta, were carried out by transmission electron micoscopy in order to observe fine structures of initial calcification sites in dental matrix and to determine the relationship between electron-dense fibrous substances and matrix vesicles reported by Igarashi (1983). A number of matrix vesicles round or oval in shape and 300-700 Å in diameter appeared in the apical dental matrix around the odontoblasts during the stage of matrix formation and about half of them contained more electron-dense crystal-like structures. On the other hand, matrix vesicles relatively decreased in number, but electron-dense fibrous substances consisting of flocculent substances and fine granular substances became well-developed and longer and increased in number in the apical dental matrix distant from the odontoblasts. These fibrous substances also contained more electrondense crystal-like structures. The stereophotographs showed that the fibrous substances exhibited filmy structures in three dimensions and continued to more electron-dense crystal-like structures. Moreover, the electron-dense fine granular substances would seem to attach to these filmy structures in parts. It seems that these filmy structures are the initial form of crystal. A number of matrix vesicles existed near the fibrous substances and some came into contact with the fibrous substances. A state indicative of the unit membrane of these matrix vesicles having broken and part of the contents disappeared was often obtained. It seems that these fibrous substances appeared later than matrix vesicles because of the observation in the early stage of matrix formation. These observations lead us to the conclusion that the fibrous substances derived from the contents of matrix vesicles. Fibrous substances indicated a positive reaction with ruthenium red staining. No fibrous substances appeared in the basal dental matrix during the stage of matrix formation in the basal portion in spite of the appearance of a number of matrix vesicles and small aggregates of crystal-like structures. It seems that this difference is closely concerned with the fact that the apical dental matrix is the initial portion to begin the calcification of tooth.

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The rat mandibular gland is known to contain two major types of secretory cells: acinar cells and cells in granular convoluted tubules. Abe and Dawes have postulated in their electrophoretic study of submandibular saliva that some kinds of characteristic proteins found in the saliva in response to β-adrenergic and cholinergic agonists are primarily derived from the acinar cells, whereas proteins specific for α-adrenergic agonist stimulus are mainly derived from the granular convoluted tubules.
In the previous study, glycoprotein species in parenchymal components dissociated from submandibular glands of normal adult rats were analysed micro-electrophoretically and it was shown that acini and granular convoluted tubules differ markedly in the number of glycoprotein species and in the amount of glycoprotein per protein. In addition, we reported that characteristic glycoproteins which were secreted in response to a cholinergic agent, pilocarpine, were primarily derived from acinar cells.
The present study was designed to elucidate the action site of some α- and β-adrenergic agents on the rat submandibular gland by following up characteristic glycoprotein species found in acini and granular convoluted tubules with the aid of SDSmicro electrophoretic techniques. The results described here support the view that β-adrenergic agents act on acinar cells and α-adrenergic ones on granular convoluted tubules.

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Osteocytes have been generally interpreted as cells in which osteoblasts with abundant organelles in relation to collagen synthesis were buried within the unmineralized bone matrix formed by osteoblasts themselves during the stage of bone matrix formation. Dudley et al. named the osteocyte immediately after impaction within the bone matrix as “osteoid osteocyte” and found their resemblances with formative osteoblast organelles. Some of the isolated osteocytes accompanying bone mineralization show a little decrease in the amount of organelles thereby, which were named “young osteocyte” by Baud, and Jande described them as “formati ve osteocyte” because unmineralized fibrillar structures were contained within pericellular zone of osteocyte lacuna in spite of mineralization of matrix around their lacuna. For the purpose of demonstrating such osteocytes and pericellular matrix on three dimensional views, by means of our modified method based on the osmium-dimethyl sulfoxide-osmium method (the ODO method) devised by Tanaka et al., we examined in detail with a high resolution scanning electron microscope.

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