Effect of an i.p. injection of diazepam on the jaw opening reflex evoked by electrical stimuli applied to the tooth pulp innervated by mainly high threshold afferents and the lower lip innervated by low threshold afferents was investigated using Wistar albino rats. Small doses of diazepam, less than 2.5 mg/kg, suppressed to the same degree the jaw opening reflexes evoked by stimulation of tooth pulp or lower lip. However, when larger doses than 5.0 mg/kg were administered, the suppression of tooth pulp evoked jaw opening reflex was greater than that of lower lip-evoked one. In this case, the period of suppression of tooth pulp-evoked jaw opening reflex was longer than that of lower lip evoked one. It is concluded that (1) the pain relieving effect of diazepam appears only when larger doses than 5.0 mg/ kg are administered and that (2) the pain-relieving effect lasts longer than muscle-relaxative effect of diazepam.
Labial salivary gland biopsy specimens from 111 patients evaluated for Sjögren’s syndrome (SjS) were examined histopathologically with particular attention to the degree of lymphoid cell infiltration with or without the formation of epimyoepithelial islands, fibrosis and atrophy with fatty replacement. These cases were divided into groups, and the histological findings were compared. In definite cases, “positive” findings of more than one focus of lymphoid cells per lobule were seen in about 80%, this value closely coinciding with the reports in Europe and America. Epimyoepithelial islands and hyaline like substance were also found in the cases with severe lymphoid cell infiltration. Cases of probable SjS, connective tissue disease and some other conditions showed lymphoid cell infiltration to a lesser degree. It seems likely that fibrosis and atrophy with fatty replacement are not closely related to SjS.
In several cases of definite SjS, labial salivary gland examinations after more than a one year interval were perform ed on two occasions, and the clinical and histopathologic al changes were investigated.
The ultrastructural changes of the labial salivary glands, in which was demonstrated light microscopically the characteristic appearance of Sjögren’s syndrome, were investigated in 12 cases. The significance of the following findings in this syndrome was discussed.
The infiltrating cells were chiefly composed of small and medium sized lymphocytes and plasma cells. There were also found large lymphocytes with mitosis and morphologically regarded as T-lymphocytes. A small number of histiocytes and other mononuclear cells scattered among them. The remaining secretory cells were degenerated with disturbance of the secretory process. Degeneration, destruction, squamous metaplasia and proliferation of the duct epithelial cells were associated with mononuclear cell infiltration, and these changes were more conspicuous in the intercalated regions. The basal laminae of the acini and ducts were in part markedly thickened with high electron density. The epimyoepithelial islands in varying forms and sizes were composed of morphologically different kinds of cells which were probably derived from the duct cells. Only a few myoepithelial cells were located in the peripheral portion of the epimyoepithelial islands and there was no proliferation of myoepithelial cells. The hyaline-like substance, occasionally appearing in and around the epimyoepithelial islands, was an accumulation of fine fibrillar substance. Virus-like or tubuloreticular structures were found in the endothelial cells in 1 case.
Cell proliferation characteristic of human malignant tumors has been related to the responses of tumors to various therapeutic means. The present study mainly concerns a routine method to measure cell kinetic parameters in human solid tumors.
Proposed for this aim is the in vitro double labeling method under hyperbaric condition. For assessment of the method, two steps were taken. First, cell cycle parameters were compared in a mouse squamous cell carcinoma between this in vitro method and the in vivo percent labeled mitoses method. Second, the in vitro method was applied to eight cases of human squamous cell carcinomas. The results indicate that two sets of the cell cycle parameters of mouse squamous cell carcinoma measured by the two methods are in good agreement within an experimental error. DNA synthesis time, labeling index and cell cycle time of human squamous cell carcinoma varied among cases with a dispersion of 2 to 3-fold, that is, with ranges of 4.1-14.0 h, 14.3-28.7% and 21.2-52.9 h, respectively.
The relationship between the eruption of mandibula r first permanent molar and growth changes of the adjacent structures was statistically investigated on 16 children during the active eruption of the tooth. Semiannual records of 45-degree oblique cephoalgrams and dental casts were used as materials. The factor analysis with orthogonal rotation was applied and the pattern of associations was revealed by the following six factors:
Factor 1. Proximity factor. With larger mesiodistal tooth diameter, the tooth tends to be more mesially positioned.
Factor 2. Eruption factor. The tooth erupts rapidly, nearing the distal surface of mandibular second deciduous molar more quickly and simultaneously widening the space posterior to the dental arch more rapidly.
Factor 3. Root development factor. As the root develops faster, the interdental space tends to close more rapidly.
Factor 4. Eruption rate factor. As the tooth nea1s the occlusal plane, the rate of eruptive movement decreases.
Factor 5. Tooth uprighting factor. With more amount of space posterior to the dental arch, the subsequent uprighting of the long axis of the tooth can be expected.
Factor 6. Tooth inclination factor. Inclination of the long axis of the tooth crown is relatively independent from the variables examined.
Sixty-two strains of anaerobic, gram-positive, pleomorphic rods were isolated from the gingival crevice of individuals clinically free from periodontal disease, and examined for biochemical characteristics, cellular and colonial morphology, and acid end-products from glucose fermentation. None of them produced indole, hydrogen sulfide, or catalase, but all hydrolysed esculin. Seven, 10, and 45 of 62 strains were identified as Bifidobacterium, Actinomyces naeslundii, and Actinomyces israelii, respectively, on the basis of biochemical characteristics.
A typical gram-positive pleomorphic aerobe is Rothia dentocariosa. However, there exist many organisms having similar characteristics (Rothia-like organisms). The purpose of this study is to isolate Rothia dentocariosa and Rothia-like organisms from the healthy and diseased sites of the oral cavity and to clarify the characteristics of those organisms. A total of 342 strains were isolated in this study, and 188 strains were identified as gram-positive pleomorphic rods. Seventy-seven typical strains of 188 isolates were examined physiologically and biochemically, and they were classified as follows: 1) 20 strains of A. viscosus; 2) 3 strains of A. naeslundii; 3) 26 strains of Rothia dentocariosa; 4) 2 strains of Bacterionema matruchotii; 5) 15 strains of Corynebacterium; 6) 7 strains of Nocardia; and 4 unknown strains. The strains of Rothia dentocariosa were mainly isolated from the dental plaque (24 of 26 isolates), and they had the ability to adhere on to the glass surface, and 5 of 26 strains of Rothia dentocariosa showed the ability of gelatin liquefaction.