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T Takata

Publications and source records attributed to T Takata.

At least 145 records · Page 8Linked to original sources
PubMed1992

Enhanced collagen phagocytosis by rat molar periodontal fibroblasts after topical application of lipopolysaccharide--ultrastructural observations and morphometric analysis.

To investigate the effect of lipopolysaccharide (LPS) on phagocytic activity of collagen fibrils by periodontal fibroblasts, we studied rat molar gingival connective tissue and periodontal ligament under light and electron microscopy after topical application of LPS (5 mg/ml in physiological salt solution (PS)) on the gingival sulcus. Phagocytic activity of collagen fibrils by fibroblasts was evaluated by counting the number of collagen-containing vacuoles inside fibroblasts that were present within a defined area (1200 microns2). Values obtained from fibroblasts in the subepithelial connective tissue, the region near the alveolar crest, and the middle region of periodontal tissue were compared. Periodontal ligament fibroblasts showed increased phagocytosis of the collagen fibrils from 3 hours to 1 day after topical LPS application, but no differences were observed in the gingival tissue. The intracytoplasmic vacuoles containing collagen fibrils were of various sizes and shapes, showing positive for acid phosphatase and/or alkaline phosphatase reaction. Collagen phagocytic activity of the fibroblasts in the middle region of the periodontal ligament also increased after PS treatment. However, this was significantly less than that observed in LPS-treated animals (p less than 0.01). This study indicates that LPS may enhance the degradation of collagen by stimulating the phagocytic activity of the periodontal ligament fibroblasts.

Animals↗
PubMed1992

Isolation of nonchemotactic mutants of Campylobacter jejuni and their colonization of the mouse intestinal tract.

Three nonchemotactic mutants (D54, Y14, and N74) of Campylobacter jejuni were isolated from wild-type strain FUM158432 by either the negative swarming or liquid gradient method with brucella broth as the attractive substance. Strains D54 and Y14 were isolated after mutagenesis with methyl methanesulfonate, and N74 was isolated from a nonmutagenized culture. These mutants all failed to swarm on a semisolid medium and did not show any chemotactic behavior in the hard-agar plus assay method for any of the chemicals which act as attractants for the wild-type strain. They had intact flagella and were actively motile. Swimming behavior examined by a video tracking technique showed that the mutants swim only straight, without any tumbling. When suckling mice were challenged orally with approximately 10(5) CFU of these mutant strains, all of the mutants were cleared from the intestinal tract by 48 h. In contrast, the wild-type strain colonized the intestinal tracts of all mice challenged with 10(2) CFU. We concluded that chemotactic movement is important for colonization of the intestinal tract of suckling mice by C. jejuni.

Animals↗
PubMed1992

Effect of exogenously applied prostaglandin E2 on alveolar bone loss--histometric analysis.

The effect of prostaglandin E2 (PGE2) on alveolar bone resorption was examined in 8-week old Wistar rats by histometric analysis. One mg/ml PGE2 topically applied to gingival sulcus induced a marked increase in osteoclasts. The number of osteoclasts increased progressively and reached a maximum at 12 hours. Ultrastructurally, these osteoclasts were in active form with well developed ruffled borders and clear zones. The changes in numbers of osteoclasts after application of various concentrations of PGE2 were dose-dependent (0.001 to 1.0 mg/ml), but higher concentrations of PGE2 (2 mg/ml) were less effective. In addition, the number of osteoclasts in groups treated with both PGE2 and endotoxin was higher than those that received PGE2 only. These results indicate that bone resorption caused by PGE2 depends on activation and increase of osteoclasts, and suggests that endogenous PGE2 production by host cells stimulated by plaque-associated bacterial endotoxin may be an important pathogenetic factor in periodontal disease.

Alveolar Bone Loss↗
PubMed1991

Spindle cell squamous carcinoma of the oral region. An immunohistochemical and ultrastructural study on the histogenesis and differential diagnosis with a clinicopathological analysis of six cases.

Six cases of spindle cell squamous carcinoma (SCSC) of the oral cavity were studied clinicopathologically, immunohistochemically and ultrastructurally to summarize the clinicopathological features of this rare neoplasm and to discuss the debatable histogenesis of the sarcomatoid component and the differential diagnosis of SCSC. The mean age of the patients was 72 years and the female to male ratio was 1:2. Four of them had a history of irradiation for pre-existing squamous cell carcinoma. One patient died of SCSC. While clinical and histological prognostic factors of SCSC could not be determined, it was shown that radical surgery resulted in good prognosis. The epithelial nature of the sarcomatoid component of SCSC was clearly revealed by a combination of immunohistochemical staining for keratins and electron microscopic demonstration of tonofilament-like filaments and/or desmosome-like structures. Together with electron microscopic evaluation of the tumour cells, immunohistochemical characterization of tumour cells using antibodies to keratin, vimentin, glial fibrillary acidic protein and S-100 protein is very helpful in differentiating SCSC from true spindle cell sarcoma, melanoma and malignant myoepithelioma. In the immunohistochemical differential diagnosis of SCSC, it is important to remember that SCSC should not be ruled out of the differential diagnosis by a positive reaction for vimentin in sarcomatoid tumour cells. Absence of staining for keratin in the sarcomatoid tumour cells does not always exclude SCSC, because some SCSCs show immunoreactivity of keratin in their sarcomatoid components only with some anti-keratin antibodies. Different kinds of anti-keratin antibodies should be applied in the differential diagnosis of SCSC.

Aged↗
PubMed1991

Clear cell tumors of minor salivary gland origin. An immunohistochemical and ultrastructural analysis.

Three cases of monophasic glycogen-rich clear cell tumors of palatal gland origin were examined immunohistochemically and ultrastructurally in attempts to characterize their cellular composition. Despite their histologic resemblances, the clear cells from each case showed different immunohistochemical features. In case 1 the extensive positivity for vimentin and S-100 protein, in addition to the focal expression of actin and glial fibrillary acidic protein, strongly suggested that the clear cells were myoepithelial in nature. In contrast, the clear cells from case 2 exhibited both keratin and epithelial membrane antigen positivity, as well as ultrastructural features that suggested that they were glandular epithelial in nature. In case 3 no special markers except for keratin could be detected, indicating the less differentiated nature of the clear cells. These results show the heterogeneity of the clear cell tumor group of minor salivary glands.

Actins↗
PubMed1991

Effects of Eicosapentaenoic Acid on Lipid Metabolism in Obesity Treatment.

In this study, we investigated the hypolipidemic action of eicosapentaenoic acid (EPA) and its mechanism. Three types of 5% fat diets (stearic acid, linoleic acid, and EPA) were prepared in our laboratory. Rats that weighed 170-190 g were fed one of these diets for 20 weeks at an equivalent calorie value (groups S, L, and E). Weight gain occurred in the following order: group E < group S < group L. Serum levels of total cholesterol, triglycerides, phospholipids and total lipids were significantly lower in group E than in the other groups. Analysis of the fatty acid composition of adipose tissue showed that the level of C18:1 was significantly higher in group S, that of C18:2 was significantly higher in group L, and that of C16:0 was significantly higher in group E than in the other groups. These results indicated that EPA had a hypolipidemic action, higher ketogenicity, and lower lipogenicity than the other fatty acids. Inclusion of EPA in the diet of hyperlipidemic subjects may thus help in the primary prevention of hyperlipidemia and, in turn, morbid obesity.

Journal Article↗
PubMed1990

A triazine dye, cibacron blue 3G-A induces Staphylococcus aureus to form giant clusters.

Cibacron blue 3G-A (CB), one of the triazinyl dyes commonly used as a ligand for affinity chromatography, induced staphylococci to form giant clusters without affecting cell viability. It was demonstrated that the cluster formation was not a mechanical aggregation of cells by CB, but a consequence of its biological effect on staphylococcal growth. Clusters induced by CB did not form a regular arrangement, and were different from clusters induced by SDS or polyanethole sulfonate.

Cell Division↗
PubMed1990

Association of hepatocellular carcinoma and a hyperplastic nodule after phosphate diethylstilbestrol therapy.

We treated a patient in whom a hepatocellular carcinoma and a hyperplastic nodule of the liver concomitantly grew in association with long term phosphate diethylstilbestrol therapy for a carcinoma of the prostate. A 72-year-old Japanese man was admitted for investigation of hepatic masses. A diagnosis of prostate carcinoma had been made seven years ago and phosphate diethylstilbestrol 200 mg daily had been prescribed. A small mass was first detected in the liver four years later and another mass appeared three years after the appearance of the first mass. Histology of the excised tissue showed the former mass to be a hyperplastic nodule and the latter one hepatocellular carcinoma. Findings of cirrhosis, hepatitis or fibrosis were nil but fatty metamorphosis of the hepatocytes was apparent. These histological changes were considered to be associated with long-term phosphate diethylstilbestrol therapy therefore careful follow-up using amazing diagnosis is recommended for patients on phosphate diethylstilbestrol therapy.

Aged↗
PubMed1990

Spitz nevus of the palate. Report of a case.

A 4-year-old Japanese girl with a nonpigmented nodule on the anterior portion of the palate since birth is described. The overall microscopic appearance of the lesion was very similar to that of Spitz nevus of the skin. Diagnosis of Spitz nevus (mixed epithelioid cell and spindle cell nevus) was made on the basis of the clinical and histologic criteria for differentiating this lesion from malignant melanomas and common compound nevi. Positive immunostaining of epithelioid and spindle cells for S-100 protein and neuron-specific enolase was also indicative of their nevocellular nature. Review of the cases of Spitz nevus from the literature revealed that the present case most probably represents the first reported instance of this type of nevus in the oral cavity.

Biomarkers, Tumor↗
PubMed1990

The cellular composition of basal cell adenoma of the parotid gland: an immunohistochemical analysis.

Four cases of basal cell adenoma of the parotid gland were examined immunohistochemically to characterize their cellular composition. In all cases epithelial membrane antigen and keratin were detected in the inner luminal cells; some cells also showed positive staining for secretory functional markers, indicating their differentiation toward secretory epithelium. In tubular and trabecular types the outer cells consistently displayed an intense staining for vimentin and some were also positive for actin, indicating their myoepithelial nature. In the solid type, most tumor cells resembled the ductal cells or basal cells of larger ducts in normal gland with regard to their immunoreactivity. Our results may suggest that the proportion and arrangement of heterogeneous tumor cells are responsible for different histologic patterns of the salivary basal cell adenoma.

Adenoma↗
PubMed1990

Specific inhibitory effect of dietary eicosapentaenoic acid on N-nitroso-N-methylurea-induced mammary carcinogenesis in female Sprague-Dawley rats.

We have investigated the effects of two qualitatively different types of unsaturated fatty acids on N-nitroso-N-methylurea (NMU)-induced mammary carcinogenesis in female Sprague-Dawley rats. Semipurified diets containing 4.7% eicosapentaenoic acid (EPA) plus 0.3% linoleic acid or 5% linoleic acid were prepared. Animals maintained on these diets were given an i.v. injection of NMU (50 mg/kg body wt) at 50 days of age and killed 20 weeks later. Both tumor incidence and tumor number per rat were significantly lower in the EPA diet group (60.0% and 2.3 +/- 2.5 versus 93.3% and 5.1 +/- 4.5 respectively) for the 5% linoleic acid diet. Furthermore, the average weight of tumor material (total) per rat was significantly lower in the EPA as compared to linoleic acid diet group (2.9 +/- 4.2 g and 11.4 +/- 12.2 g respectively). Analysis of phospholipid fatty acids in the mammary tumors in the EPA diet group showed a higher proportion of C16:0, C18:2, omega-3 fatty acids C20:5 and C22:6 and a lower proportion of C20:4. Furthermore, mammary tumors in rats fed the EPA diet demonstrated significant reduction in prostaglandins. The results thus suggest that inhibition by EPA of NMU-induced mammary carcinogenesis may be mediated via the modulation of lipid metabolism and associated reduction in prostaglandin synthesis.

Animals↗
PubMed1990

Ultrastructural and immunohistochemical observations of a true malignant mixed tumor (carcinosarcoma) of the tongue.

True malignant mixed tumor (TMMT) of salivary glands, with both carcinomatous and sarcomatous components, is exceedingly rare. We offer a case of TMMT in a 79-yr-old man, which may represent the first report example of this unusual neoplasm arising in the tongue. The carcinomatous component was mainly of solid basaloid carcinoma with focal glandular differentiation, while the sarcomatous component was composed of pleomorphic elements such as chondrosarcoma, myxosarcoma and fibrosarcoma. Carcinoma cells at the periphery of solid nests occasionally merged into these sarcomatous elements. Immunohistochemically, basaloid carcinoma cells showed positive reaction for both low molecular weight cytokeratin and S-100 protein, whereas carcinoma cells lining ductal spaces were positive for a wide spectrum of keratin and EMA. The sarcomatous elements revealed the presence of vimentin and S-100 protein. Ultrastructurally, basal lamina-like material and/or mucoid precipitates often accumulated separating the tumor cells from each other singly or into a few cell group. Some sarcomatous cells assumed the myoepithelial features, such as the presence of microfilament bundles with dense bodies and pinocytotic vesicles along the cell periphery. These findings may indicate that TMMT shares a common histogenesis with pleomorphic adenoma.

Actin Cytoskeleton↗
PubMed1990

Lectin binding of rat gingival epithelia.

Oral gingival epithelium (OGE), oral sulcular epithelium (OSE) and junctional epithelium (JE) were examined histochemically by using different lectins as markers for epithelial differentiation. The staining pattern of gingival epithelia was compared with that of the buccal and palatal epithelia. Binding of WGA had a uniform distribution in all the epithelia examined. A positive reaction was found in all the basal and spinous layers, but not in the cornified layer of the epithelia. BPA binding was seen in the lower spinous layer of OGE, OSE, buccal and palatal epithelia, and in most of the JE. The basal layer and the cells directly attached to the tooth surface at the apical part of JE were nonreactive with BPA. GS-I reacted with the basal and suprabasal layers of each epithelium and with the cells attached to the tooth at the apical part of JE. UEA-I reacted with the upper spinous layer of OGE, OSE and epithelia of hard palate, but not with any of the cells of the JE. Our results agree with previous data suggesting that OGE and OSE exhibit squamous differentiation similar to that of the masticatory epithelium of hard palate. Furthermore, our results suggested that the JE cells undergo differentiation equivalent to that of the suprabasal and lower spinous cells of OGE. The cells along the tooth surface at the apical part of JE, however, form a distinct population of cells with basal nature.

Animals↗
PubMed1990

[Relative weight and mortality during a five-year follow-up study in an aged population--a study of aged inhabitants of a rural area in Japan].

The present study, a follow-up study for 669 aged examinees of a health check performed in July 1983 in a rural area in Fukushima Prefecture, was conducted to clarify the relationship between relative weight and mortality among aged individuals living in a Japanese rural area. Using the standard body weights calculated from Japanese mean body weights by sex, age class (60-69 and 70 or more) and height cited from the data of the Ministry of Health and Welfare from 1966, mortalities during the five year follow-up were compared among four groups different in relative weight at baseline. The results are as follows. 1) The mortalities in the group of 'Relative weight less than or equal to -10% the leanest group among the four groups, were highest in both sexes, 52.8 per 1000 person-years for males and 33.2 per 1000 person-years for females. On the other hand, those in the group of '+10% less than or equal to Relative weight less than +20%' were lowest in both sexes, 23. 1 per 1000 person-years for males and 7.0 per 1000 person-years for females. In females, the difference in the mortality between these two groups was statistically significant at the 0.05 level, provided age structures in both groups were taken into consideration. 2) In both sexes, the mortalities of cancer and cerebrovascular disease in the group of 'Relative weight less than or equal to -10%' were highest among the four groups, whereas such mortalities in the group of '+10% less than or equal to Relative weight less than +20%' were lowest.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗