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Biomedical subjects

M Shimono

Publications and source records attributed to M Shimono.

At least 91 records · Page 5Linked to original sources
PubMed1989

Ultrastructure of basal cell adenoma in the parotid gland.

Basal cell adenoma of the parotid gland was studied with electron microscopy. The cells constituting this tumor were divided into three types of epithelial cells; ductal, myoepithelial, and squamous cells. The ductal cells, which were polygonal and cuboidal in shape, formed a sometimes distinct lumen. Glycogen were recognized in the cytoplasm of these cells. The myoepithelial cells appeared as plasmacytoid cells which contained abundant microfilaments. The squamous cells were characterized by the presence of well-developed tonofilaments and desmosomes. However, no secretory cells could be found, although small, electron dense granules were detected in the cytoplasm of the ductal cells. The granules were unlike secretory granules in their size, number and location. In consideration of the presence of secretory and myoepithelial cells, we reviewed previously reported literature and discussed the identification of secretory granules. From our and other reported results, we tentatively concluded that the electron dense granules described as secretory granules are not intrinsic secretory granules. Further, we suggested that the cell types and the histogenesis of basal cell adenoma are analogous to those of both pleomorphic and clear cell adenomas.

Adenoma↗
PubMed1989

An experimental study of osteogenesis in explants of rat dental pulp, periodontal ligament, bone marrow and muscle cells in vitro.

Cells of dental pulp, periodontal ligament, bone marrow and muscle derived from the same rat were cultured in vitro. Outgrowth of cells from these four explants were examined using phase-contrast microscope, light microscope and scanning electron microscope. Furthermore, cell lengths were measured randomly from SEM photographs and growth curves were plotted by calculating cell numbers. These cells had different morphology in both shape and length. The bone marrow cells showed the most rapid proliferation rate followed by muscle, periodontal ligament and most slowly in dental pulp cells.

Animals↗
PubMed1989

Regeneration of periodontal tissues following experimentally induced periodontitis in rats: a comparison of sucrose-rich and conventional diets.

The purpose of the present study is to elucidate influences of diet on periodontal regeneration following experimental periodontitis in rats. S-D rats were divided into two groups, which were fed either a conventional diet (group A) or a sucrose-rich diet (group B). Experimental periodontitis was produced by placement of elastic bands between maxillary molar teeth. After one week, the elastic bands were removed and the animals were sacrified by perfusion fixation with formalin immediately, 1, 3, or 5 days, or 1, 2, 3, 4, 6, or 8 weeks after the removal. Sections of the teeth and surrounding tissue were examined by light microscopy. Three days after the removal, in both groups, granulation tissues with many inflammatory cells were covered by epithelial cells; the attachment site to the root surface was located more apically than the cemento-enamel junction. Distinct periodontal pockets were formed by five days after the removal in group A. In group B, the infiltrations of inflammatory cells were more prominent than in group A. Six weeks after the removal in both groups, an epithelium which resembled long junctional epithelium rather than pocket epithelium became thicker. Eight weeks after the removal, the findings were similar to those of six weeks in group A. However, a severe inflammatory cell concentration was found in group B. These results suggest that periodontal wound healing is markedly influenced by diet, and that this experimental system is useful for studying dynamic changes in both pocket and long junctional epithelia.

Animals↗
PubMed1989

[Statistical study of epulis, especially in general pathology].

This report contains a statistical study of 874 cases of epulis diagnosed by the Department of Pathology of Tokyo Dental College from 1966 to 1986. 1. Of the 874 cases, 344 were epulis fibrosa, 217 were epulis granulomatosa, 78 were epulis fibromatosa, 74 were epulis fibrosaosteoplastica, 51 were epulis hemangiomatosa, 43 were epulis fibrosa teleangiectaticum, 15 were epulis cementoplastica, 14 were epulis osteomatosa, 3 were congenital epulis, 2 were giant cell epulis, and 1 was epulis cementomatosa. 2. As has been reported in other literature, there is a marked tendency for this condition to occur in females (331 male cases and 539 female cases). 3. Our data indicate a higher occurrence rate in people in their fifties, although the occurrence rates were similar in people in their twenties and in people in their sixties. 4. The epulis was observed most frequently in the maxillary incisor region.

Adolescent↗
PubMed1989

[A statistical study of autopsies performed on cases of oral cancer: with reference to distant metastasis in tongue cancer].

1. A statistical survey of oral-cancer (tongue, maxilla, and mandible) patients on which autopsies were performed by the 2nd. Department of Pathology of Tokyo Dental College from 1964 to 1987 was carried out. Of a total of 18 autopsies in cases in which death resulted from tongue carcinoma, 11 subjects were male and 7 female. Average age was 63.4 years. This cancer occurred most frequently in individuals in the age group of 60 to 69 years. The lung was the most common (50%) site of distant organic metastasis; the next most common sites were the liver, the thyroid gland, and the diaphragm (11.1% each). Submandibular and cervical lymph nodes were the most common sites of lymphatic metastasis in cases of tongue cancer. These data were similar to those in previous reports. 2. An autopsy on a 57-year-old man who died of tongue cancer revealed a number of distant metastases in both organs and lymph nodes were reported. 3. The report includes a review of literature on distant metastasis in cases of tongue cancer.

Aged↗
PubMed1987

Study of the selectivity of the impregnation of neurons by the Golgi method.

The selectivity of the impregnation of neurons by the Golgi method was examined by comparing Nissl-stained specimens with Golgi-stained specimens in terms of the somatic orientation, cross-sectional area, and long and short axes of the soma in the ventromedial hypothalamic nucleus (VMH) and lateral hypothalamic area (LHA) of 5-week-old rats. With regard to somatic orientation, we made comparisons directly between the Nissl distribution pattern and the Golgi pattern. The two distribution patterns did not differ significantly in either VMH or LHA (Smirnov test, P greater than 0.05). For somatic cross-sectional area and diameter (long and short), a mean value of every 10% of the total frequency was estimated for each histogram; the histogram was segmented into 10 percentile frequency domains, and a mean value for each domain was estimated. A linear regression was calculated between Golgi mean values and Nissl's at the same place. By use of the linear regression, all of the observed values on Nissl sections for somatic cross-sectional area and diameter were transformed into their corresponding Golgi values. The frequency distribution of these transformed Nissl values was compared with that of the actually observed Golgi values. There was a high degree of similarity between the two distribution patterns in all regions examined for long and short diameters as well as cross-sectional area of the soma (Smirnov test, P greater than 0.05). These findings suggest that the sampling of VMH and LHA neurons in the Golgi method used in the present study is similar to the corresponding sampling in Nissl preparation.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

Morphological changes of intercellular junctions in the rat submandibular gland treated by long-term repeated administration of isoproterenol.

Long-term repeated administration of isoproterenol (IPR) 2 mg/100 g bw, once daily for ten days, resulted in morphological changes in the intercellular junctions of rat submandibular glands, which were investigated by means of the freeze-fracture technique. A significantly increased number of tight-junctional strands was present. These junctional strands extended much deeper toward the basal membrane than those in normal acinar cells. The basal frontier strands that branched from the networks of tight junctions were elongated and had either free-endings or terminal loops, which were more frequently observed in the IPR-treated acinar cells than in untreated acinar cells. Some of the strands of tight junctions were connected to small gap junctions. The diameters of gap junctions were not significantly different from those of control acinar cells. However, smooth areas devoid of particles were found intermingling with the usual packed particles in irregularly shaped small gap junctions. There was no significant difference between the desmosomes of IPR-treated and untreated acinar cells, in terms of either morphology or distribution. These changes in junctional morphology in the IPR-treated acinar cells resemble those seen in salivary glands during development, and in some experimental conditions including tumorous changes.

Animals↗
PubMed1986

Nodular fascitis of the mandible in a child.

Nodular fascitis is an unusual, tumor-like, proliferative, fibroblastic lesion with infiltrative properties. We describe a case of nodular fascitis appearing in the mandible of a 2-year-old boy. A brief review of the literature on this lesion arising from intra or perioral regions, and the importance of differential diagnosis for this lesions are discussed.

Child, Preschool↗
PubMed1986

Kimura's disease and its relation to angiolymphoid hyperplasia with eosinophilia: report of three cases and review of the literature.

Kimura's disease, eosinophilic granuloma of soft tissues, is a chronic inflammatory condition and appears as subcutaneous tumor-like nodules in the head and neck regions. Histopathologically, it is characterized by the presence of lymphoid follicles, marked infiltration of eosinophils, fibrosis and vascular proliferation. This disease occurring in the orofacial region is relatively rare, only 14 cases having been previously reported. We describe 3 additional cases of Kimura's disease and discuss these in relation to angiolymphoid hyperplasia with eosinophilia.

Adolescent↗