The temperature distribution of the lateral half of the facial skin was thermographically evaluated in 6 male subjects. The dimensions of areas on the facial image which revealed increase in temperature of (1) more than 1.4°C (Area 2 H) and (2) more than 2.1°C (Area 3 H) were compared before, during and after gum-chewing effort of 5 minutes under a constant room temperature (26°C). Areas 2H and 3H increased by 15.2 and 15.0 % after 5 minutes gum-chewing, respectively. The increment of the dimension was remarkable in the skin area overlying the masseter muscle. Two patterns were noted in the change of temperature distribution after cessation of the gum-chewing effort, i. e., one is that the area decreased immediately after cessation of gum-chewing and the other is that the change was not significant at least 5 minutes after the cessation. It should also be noted that open/close mouth movements for 5 minutes without chewing gum revealed no significant change in the temperature distribution. The present study is the first report which quantitatively determined significant change in facial temperature distribution in accordance with chewing efforts. The obtained results suggest possible use of thermograph in indirect measurement of masticatory muscle activity, particularly the jaw-closing muscle activity.

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A leukotoxin (LT) was purified from the Actinobacillus actinomvcetemcomitans JP2 strain and its leukotoxic mechanism was investigated.
PMN destruction began 5min. after the addition of LT and more than 80% of the PMNs were destroyed after 20min. The cytotoxicity of LT was completely abolished by and LT IgG. The binding of LT to the receptors of PMN occurred within 5 min. and was not reversible. Inhibition assays using phospholipids and metabolic inhibitors revealed that the membrane phospholipid could be the receptor of LT and that the cytotoxicity was not directly related to the metabolism of PMN. On the other hand, the influx of Ca^_??_ into PMN enhanced the cytotoxicity of LT.
These results suggest that Ca^_??_ influx followed by the activation of Ca^_??_ dependent phospholipase A₂ might be the initial process of the cytotoxicity of LT.

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We have studied the postnatal alterations of the neurotransmitter receptors in rat parotid gland, and found that the number of β-adrenoceptors in the tissues and their affinity for the β-agonists increased significantly during development and that these changes were coupled with amylase secretion by β-agonist from the tissues. In this experiment, developmental changes in the adenylate cyclase in rat parotid gland cells were studies by using forskolin or isoproterenol.
Forskolin produced the rapid increases in cyclic AMP contents in the parotid tissues of 8 weeks old rats and caused amylase secretion from the tissues. The increases in cyclic AMP contents by forskolin were potentiated by 3-isobutyl-1-methylxanthine (IBMX). Calcium had an important role in the secretion of amylase by forskolin. Tolbutamide blocked the amylase secretion by forskolin at the concentration which inhibited cyclic AMP dependent protein kinase activity.
The content of cyclic AMP accumulated by forskolin (10 μM) in parotid tissues of 1 week old rats was 10 fold higher than that in the tissues of 8 weeks old rats. These changes in the contents of cyclic AMP accumulated by forskolin during development were coupled with amylase secretion from the tissues. The changes in the response of the tissues to forskolin were clearly observed in the tissues of rats between 2 and 4 weeks after birth. On the other hand, cyclic AMP contents accumulated by isoproterenol (1 μM) in parotid tissues of 1 week old rats were very low, but those increased markedly in the rat tissues of 4 and 8 weeks after birth. Isoproterenol potentiated the accumulation of cyclic AMP by forskolin in the tissues from 1 to 8 weeks old rats.
These results indicate that the response of adenylate cyclase of rat parotid tissues to forskolin decreases markedly during development, but that of β-adrenoceptors of the tissues to isoproterenol increased significantly during the same period.

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The purpose of this investigation was to reveal the physiological bone remodeling mechanism by means of cellular interaction phenomenon between osteoblasts (OB) and bone marrow cells (BM) in vitro. When OB (1×10⁵ cells) originated from newborn mouse calvaria and BM (1×10⁶ cells) obtained from 4 weeks old mouse long bones were co-cultivated by using millicell as a separator in a CO₂ incubator for 14 days, the number of BM was increased and the markedly high incorporation of ³H-thymidine into the cellular DNA of BM was recognized after 3 days incubation. However, the number of BM and uptake of ³H-thymidine into BM did not increase in only the BM cultivation. The increased BM were identified to have surface antigens of Mac-1 and LFA-1 by FACS analysis. However, ALPase activity of OB co-cultivated with BM was remarkably suppressed after 3 days incubation and reduced to one half of that of the control after 5 days incubation. These results clearly indicate that both OB and BM produced some differential factors of the clonal growth of Mac-1 and LFA-1 positive cells from BM cells and the suppression of ALPase of OB in co-cultivation with OB and BM. It is suggested that the factors produced from the interaction between OB and BM might regulate the mechanism of physiological bone remodeling.

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Differentiation of group AB saliva stains from mixed stains of group A and B saliva, and the quantitative determination of blood group antigen in the saliva stains were investigated by sandwich ELISA method.
γ-globulin fractions of rabbit anti-A serum and goat anti-B serum were used as the primary antibody: monoclonal anti-A and anti-B reagents as the secondary antibody, and goat anti-mouse IgM horseradish peroxidase conjugate as the tertiary antibody.
In mixed stains of group A and B, only A blood group antigen was detected in the rabbit anti-A-coated plate and only B blood group antigen was detected in the goat anti-B-coated plate. While, in group AB saliva stains, approximately the same amount of A and B blood group antigens were detected in the anti-A- and anti-B-coated plates. These results were observed both in secretor and non-secretor samples.
From the above it was possible to differentiate of group AB saliva stains from mixed stains of group A and B saliva clearly.
By the use of monoclonal antibodies as the secondary antibody, background levels in the ELISA were extremely low.
By the use of a computer system and calibration curves of A and B blood group substances, it was possible to quantify automatically the levels of blood group antigens in the saliva stains.

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Age changes of the terminal pulpal capillaries were studied in the upper first molar teeth of rats from 30 to 100 days after birth with transmission electron microscopy.
At 30 days, terminal capillaries were observed in the odontoblastic layer close to the predentin and exhibited many endothelial fenestrations. The number of fenestrated capillaries and the density of the fenestrations decreased and many capillaries were continuous after 40 days. At 60 days, they began to withdraw and were located in the subodontoblastic layer by 100 days.
Coupled with our previous work (Yoshida et al. 1988), the present results show that positional changes of the terminal capillaries are closely related to dentinogenesis. However, the fenestrated capillaries appear after the beginning and disappear before the end of dentinogenesis. The presence of the fenestrations corresponds temporally with the maturation of enamel. It is therefore suggested that pulpal capillaries may play some role in enamel maturation.

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The aim of this study was to evaluate the function of the primary afferent nerve innervating the temporomandibular joint (TMJ). Fiber constitution, conduction velocity and primary afferent nerve responses were examined in the nerve branches of the auriculotemporal nerve of the nembutalanesthetized cats. The auriculotemporal nerve was subdivided into seven branches. Each receptive field of the seven branches was identified clearly. The branch innervating the TMJ consisted of Aβ fibers, Aδ fibers and C fibers. The primary afferent responses elicited following mechanical stimuli to the TMJ capsule were classified into three types: as the sustained type, adapting very slowly, the transient type, adapting very rapidly and the intermediate type, adapting slowly. Furthermore, an “on-off” responce pattern which occurred at both the onset and the end of mechanical stimulus were observed in the transient type and the intermediate type. Receptive fields of primary afferent fibers were localized in the posterolateral region of the TMJ capsule. The location, size of receptive fields and the umber of units were recorded differently among three types. The sustained type produced the largest receptive field and number. The transient type showed the smallest size of receptive field. These results suggest that the TMJ has primary afferent neurons which have differentiated fiber endings functionally and morphologically.

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Bone Gla protein (BGP) is one of the major noncollagenous proteins in bone and dentin. Conformational changes of the amino-terminal segment of this protein upon calcium binding was investigated through alterations in intrinsic fluorescence and proton nuclear magnetic resonance (NMR). Fluorescence of tryptophan-5 was quenched by calcium binding, indicating secondary effect of the major conformational change in the helical region. The quenching was further enhanced by the presence of phosphate ions. A slight change in chemical shift was observed by proton-NMR in histidine-35, which is present in the calcium-dependent helical region.

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The structural and mineral content of human cervical cementum exposed in the oral cavi-ty and changes following a 30% phosphoric acid etching were investigated with scanning electron microscopy, electron-probe microanalysis, and atomic absorption spectrometry. Ca and P concentrations, and the Ca/P molar ratio of the exposed cementum were significantly higher than in the unexposed cervical cementum. However, there was no significant difference in the amounts of Ca dissolved from the exposed and the unexposed cementum by acid etching. These results indicate that the amounts of dissolved Ca may be affected by the amounts of organic fibrous material in the cementum. The acid etching strongly marked the ends of the extrinsic Sharpey's fibers in the exposed cementum, whereas in the unexposed cementum these structures were more or less difficult to differentiate from the intrinsic matrix following polishing and acid etching. The acid-influenced surface layers were divided into two zones; a completely demineralized surfaces zone showing organic fibrous structures and a partially demineralized subsurface zone, although the surface zone of the exposed cementum was covered with an organic felt-like sheath.

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