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Biomedical subjects

T Takata

Publications and source records attributed to T Takata.

At least 181 records · Page 10Linked to original sources
PubMed1987

Undifferentiated tumours of salivary glands. Immunocytochemical investigations and differential diagnosis of 22 cases.

22 undifferentiated tumours of the Salivary Gland Register (University of Hamburg) were studied by conventional light microscopical and immunocytochemical methods to elucidate the heterogeneity of this tumour group. The following observations were made in this collective: 18 tumours displayed one or more markers for the epithelial character and were classified as carcinomas. 10 carcinomas were considered as primary ones and 8 were considered as secondary ones (metastatic or invasive "per continuitatem"). Primary carcinomas were subclassified as poorly differentiated variants of a distinctive type of salivary gland tumours, as follows: 6 cases of carcinoma in pleomorphic adenoma, and one case each of mucoepidermoid tumour, adenocarcinoma, salivary duct carcinoma and epidermoid carcinoma. Secondary carcinomas were subclassified as follows: 3 epidermoid carcinomas, 3 nasopharyngeal carcinomas and 2 bronchial carcinomas. One tumour positive for S-100 protein and NSE (Neuron-specific enolase) was classified as a metastatic melanoma. Another tumour positive for vimentin and actin was classified as a rhabdomyosarcoma of the periglandular tissue. Two tumours lacked any markers studied here and were regarded as a malignant paraganglioma and an undifferentiated lymphoma, respectively. The differential diagnosis of the undifferentiated tumours of salivary glands and the special problems of this tumour group are discussed.

Adenoma, Pleomorphic↗
PubMed1987

Reduced chronotropic reserve to the metabolic requirement during exercise in advanced heart failure with old myocardial infarction.

We studied the metabolic and cardiac responses to exercise by expiratory gas analysis in 40 patients with old myocardial infarction and 33 normal sedentary males. On the basis of exercise energy metabolism, the elevation of the respiratory quotient (RQ; RQ = VCO2/VO2) during exercise is caused by the increase of blood lactate due to the augmented anaerobic metabolism. Functional aerobic impairment (FAI) in our study was significantly advanced in the control group and the NYHA functional class I, class II and class III groups, that is, -2.3 +/- 11.2%, +14.8 +/- 10.4%, +27.8 +/- 13.8% and +49.4 +/- 2.8%, respectively. The delta RQ values were similar among all groups; 0.29 respectively. The delta RQ values were similar among all groups; 0.29 +/- 0.06, 0.28 +/- 0.07, 0.27 +/- 0.07 and 0.29 +/- 0.09, respectively. Functional chronotropic impairment (FCI) for the same groups was -0.9 +/- 7.0%, +1.4 6.1%, +3.8 +/- 4.8% and +8.7 +/- 6.0%, and that of the class III group was significantly larger than that of the control group. Thus, in the class III congestive heart failure group, the chronotropic response to the metabolic requirement was impaired in comparison to the control group. It was concluded that the reduced chronotropic reserve was present in NYHA class III patients with old myocardial infarction, and that this mechanism might contribute to a decrease in the pump reserve of the heart, resulting in further impairment of physical capacity in these patients.

Adult↗
PubMed1987

[Experimental study on the development of acute gastric ulcer after hepatectomy in liver cirrhosis--mainly changes in the gastric wall protection mechanism].

Gastric wall blood flow, gastric mucosal noradrenalin (NA), gastric mucosal prostaglandin E2 (PGE2) and gastric mucosal energy metabolism were studied after partial hepatectomy in thioacetamide (TAA) --induced cirrhotic rats and these were also tested by loading water immersion restraint on the 3rd day after partial hepatectomy. Furthermore, the preventive effects of PGE2 on ulcers were also examined. Liver cirrhosis rats were prepared with an abdominal administration of TAA three times a week for 10 weeks, after which 70% partial hepatectomies were performed. The results of these tests showed that the gastric mucosa after partial hepatectomy in liver cirrhosis rats had significantly lower gastric wall blood flow, gastric mucosal NA and gastric mucosal energy and reduced gastric mucosal PGE2. The water immersion restraint stress loaded on the 3rd day to these rats after partial hepatectomy caused a noticeable and an earlier reduction in gastric wall blood flow and gastric mucosal PGE2 than to the normal group, and the ulcer index was high. PGE2 administration also appeared to be effective for the prevention of development of acute ulcers after partial hepatectomy in liver cirrhosis rats.

Acute Disease↗
PubMed1986

Initial bone-implant interfaces of submergible and supramergible endosseous single-crystal sapphire implants.

Three types of bone-single-crystal sapphire implant interfaces were histologically determined in submergible and supramergible implant: direct bone apposition (type I), thin connective tissue with poor collagen fibers (type II), and dense fibrous connective tissue (type III). Type I interface was predominant and type III interface was sparsely seen in submergible implants. In contrast to these findings, type III interfaces frequently appeared in supramergible implants, primarily at the apical region. These differences were considered to occur by the biomechanical variable of postoperative healing.

Aluminum↗
PubMed1986

Histologic evaluation of myoepithelial participation in salivary gland tumors.

To evaluate the myoepithelial participation in various salivary gland tumors, 40 cases were studied using the tannic acid--phosphomolybdic acid--Levanol fast cyanine 5RN (TPL) method directly correlated with ultrastructural observation. The TPL positivity corresponded to cytofilaments, especially microfilaments within the cells showing myoepithelial features. This approach allowed categorization of the examined tumor types into the following 4 groups according to the degree of myoepithelial participation: tumors with major myoepithelial, epithelial-myoepithelial (biphasic), minor myoepithelial, and no myoepithelial participation. It is suggested that the first 2 categories form a spectrum with myoepithelioma and basal cell adenoma at the extremes, in which neoplastic myoepithelial cells assume an active and integral constitutive rôle. The present findings indicate that the TPL method offers a very reliable marker for the screening of neoplastic myoepithelium in salivary gland tumors and thus may help in subclassification on a histogenetic basis for these tumors.

Adenoma↗
PubMed1986

Ultrastructure of regenerated junctional epithelium after surgery of the rat molar gingiva.

To elucidate the ultrastructure of reconstructed dentogingival junction and cytological details of regenerated junctional epithelium (RJE) and to discuss the functional aspects of RJE through comparing its fine structure with normal structure, molar gingivae of 15 Wistar rats were examined by electron microscopy at 6, 8 and 12 weeks after electrosurgical gingivectomy. As early as 6 weeks after surgery, the epithelial architecture of dentogingival junction was reestablished at the light microscopic level, and RJE showed the ultrastructure indistinguishable from that before surgery. The cytoplasmic vacuoles, characteristic of rat JE, displayed the morphology, distribution and intimate relationship with lysosomes, all of which were quite identical to those in controls, and were regarded to represent "phagosomes." Since various findings specific to JE are apparently reproduced in RJE, it seems that those peculiar structures would be an expression due to the environment rather than to the predetermined nature. RJE also might play a defensive function through the endocytic-vacuolar system as suggested for normal JE. The presence of two types of cuticular structures, which were not conspicuous in normal JE, was also revealed between RJE and the tooth.

Animals↗
PubMed1986

[Experimental study on the pathogenesis of acute ulceration in obstructive jaundice--with reference to gastric mucosal blood flow].

We prepared obstructive jaundice models in rats in order to study the mechanism of acute ulceration in obstructive jaundice centering on impediments to gastric wall blood flow and changes in gastric mucosal NA and PGE2 when the rats were subjected to water immersion restraint stress. The results were: In the obstructive jaundice 2 weeks group, when subjected to water immersion restraint stress, gastric mucosal NA reached a dried up stage from the incipient stage, causing gastric mucosal impediments at the same time, showing a significant decrease of gastric mucosal PGE2. Intragastric pH was at a similar level of excessive acidity in all groups; gastric acid is believed to be a secondary factor promoting ulceration. Gastric mucosal PGE2 showed a significant decrease coinciding with the increase in ulceration index, being a possible factor of ulceration; it is also presumed to regulate gastric wall blood flow alternatively with gastric mucosal NA. Pre-treatment with PGE2 prior to loading stress resulted in a decrease in gastric wall blood flow being significantly controlled. The administration of PGE2 brought about an improvement in gastric wall blood flow and a consequent increase in gastric mucosal NA, being judged effective for acute ulceration in obstructive jaundice.

Acute Disease↗
PubMed1984

Gas-chromatographic determination of environmental gases with the application of thermal desorption from charcoal disk.

Direct measurement of the gases adsorbed on charcoal disk was examined by the gas-chromatograph with thermal desorption devices to improve the inadequacies of the common passive monitor. Since the most satisfactory values were obtained by a preliminary experiment with toluene vapor, the experiments were done with concentrations of 20, 40 and 80 ppm, respectively to get a linear relationship between the mean adsorption per piece and the concentration of toluene. Adsorption on the charcoal disk, and its extraction by carbon disulfide without degeneration, are the necessary conditions for the measurement of gas concentration. Methanol was selected as typical from among the gases for which the common passive monitor is inapplicable. The experiment on methanol was carried out in a manner similar to that done on toluene. In conclusion, our method was found to be satisfactory for the analysis of toluene, and, if the conditions are appropriate, for methanol.

Adsorption↗
PubMed1983

Effects of zinc on cadmium-induced alterations in hepatic functions and blood glucose of rats.

The role of zinc (Zn) in preventing cadmium (Cd)-induced alterations of liver function and carbohydrate metabolism was studied in female rats. The animals were divided into four groups. To the diet for Group I was added 200 micrograms Cd/g of diet, to that for Group II was added 200 micrograms Zn/g of diet, and to that for Group III were added 200 micrograms Cd/g and 200 micrograms Zn/g of diet. Group IV was the control group fed normal diet. At the 11th, 26th, and 40th week of exposure, one-third of each group of animals were sacrificed and serum GPT and ALP activities, and glucose and insulin levels were measured. At the 26th and 40th week, serum GPT activity of Group I was significantly higher compared with those of Groups III and IV, and the serum glucose value of Group I was lower than that of Group III. At the 40th week, the serum insulin value of Group I was significantly higher than that of Group III. From these results, it is suggested that orally administered Zn prevents Cd-induced alterations of liver functions and the regulation of blood glucose in rats.

Alanine Transaminase↗