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Biomedical subjects

T Takata

Publications and source records attributed to T Takata.

At least 163 records · Page 9Linked to original sources
PubMed1990

[Epidural morphine and buprenorphine for postoperative pain relief after hepatectomy].

Postoperative pain relief with epidural morphine and buprenorphine was studied in 33 patients following hepatectomy. Morphine 2mg or buprenorphine 0.06mg in 10ml of normal saline was administered through an epidural catheter inserted at the Th10-11 or L3-4 interspace. Morphine injected at the lumbar level, as well as that injected at the thoracic level produced excellent and long-lasting (20.8 +/- 8.6 hours) pain relief. Respiratory rate decreased significantly following epidural morphine at the L3-4, but PaCO2 did not change. Buprenorphine injected at the thoracic level produced good and long-lasting (22.6 +/- 9.9 hours) pain relief, although buprenorphine injected at the lumbar level produced incomplete analgesia. The epidural administration of morphine 2mg at L3-4 or buprenorphine 0.06mg at Th10-11 may be recommended for postoperative analgesia following hepatectomy.

Adult↗
PubMed1989

Sebaceous carcinoma of the parotid gland. An immunohistochemical and ultrastructural study.

Sebaceous carcinoma of salivary gland origin is extremely rare and, because of its rarity, the clinicopathological characteristics and the histogenesis are not fully understood. We present a case of sebaceous carcinoma of the parotid gland which brings the total number of reported cases to 22. The tumor showed epithelial cell nests which were mainly composed of sebaceous cells with marked cellular atypia. In most of the nests, glandular spaces lined by ductal epithelium were present. Scattered mucous cells and flattened eosinophilic cells at the periphery of the nests were also seen. Ultrastructural and immunohistochemical observations of the tumour revealed coexistence of sebaceous and glandular differentiations in some tumour cells. Tumour cells with lipid granules often participated in the formation of glandular structures or exhibited intracytoplasmic lumina, and immunohistochemical localization of lactoferrin and secretory component, the functional markers of ductal epithelium of salivary gland, was demonstrated not only in duct-forming tumour cells but also in many sebaceous tumour cells. It seems likely that sebaceous carcinoma originates from pluripotential duct cells which can differentiate into sebaceous, ductal and mucous cells.

Adenocarcinoma↗
PubMed1989

Correlation between clinical and histological evaluations of the peri-implant gingiva around the single-crystal sapphire endosseous implant.

The correlation between clinical periodontal parameters and histological structure of the gingiva around a single-crystal sapphire implant has been evaluated in two volunteer subjects. The implants had functioned after 6 years as the distal abutment of implant bridges in the Kennedy class II mandible. First, clinical evaluation was performed (gingival bleeding index, crevicular fluid volume, plaque index and probing depth) of the gingiva around the implant and natural teeth abutments and then a small piece of peri-implant gingiva was excised from the lingual site of the implant of each subject for histological evaluation. The clinical evaluation using the periodontal parameter indices corresponded with the histological evaluation of the peri-implant gingiva. The result suggests that it is possible for such parameters to be used in practice for judging the success of an implant.

Adult↗
PubMed1989

[A case of lung metastasis of thyroid cancer with endobronchial polypoid growth].

A case of a 73-year-old woman, complaining of exertional dyspnea and hemoptysis, is reported. About twenty years earlier, she had been diagnosed as having a thyroid carcinoma and had undergone a partial thyroidectomy. Bronchoscopic findings showed an endobronchial polypoid tumor which obstructed the intermediate bronchus almost completely. The polyp was about 3cm in length and protruded from the entrance of the middle lobe bronchus. The histologic findings revealed it to be a metastasis of the papillary thyroid carcinoma. After a polypectomy, the hypoxemia and dyspnea showed remarkable improvement.

Aged↗
PubMed1989

[Effect of dopamine on lidocaine metabolism in patients after partial liver resection--a pharmacokinetic analysis].

Pharmacokinetic changes in plasma lidocaine after bolus injection (1mg.kg-1) with or without dopamine infusion (3 micrograms.kg-1.min-1) were studied on patients who had a partial resection of the liver under enflurane-nitrous oxide anesthesia. Dopamine infusion was started in 10 minutes after endotracheal intubation. Serum concentrations of lidocaine and MEGX were measured by HPLC. The areas under the plasma lidocaine time-concentration curves were calculated after the administration of the drug into the peripheral vein or portal vein. The liver's extraction rate of lidocaine was evaluated by an equation based on the areas under the two time-concentration curve. The average extraction rate in the group with dopamine infusion was significantly higher than that in the group without dopamine. No significant difference was found in the ratio of AUC of MEGX to that of lidocaine between the group to which dopamine was administered and the control group.

Dopamine↗
PubMed1988

Effect of dietary eicosapentaenoic acid on azoxymethane-induced colon carcinogenesis in rats.

The effects of eicosapentaenoic acid (EPA, n-3 polyunsaturated fatty acid) and linoleic acid (n-6 polyunsaturated fatty acid) on azoxymethane-induced colon carcinogenesis in rats were studied. Male Donryu rats were given two types of semipurified diet containing 4.7% EPA plus 0.3% linoleic acid and 5% linoleic acid. The rats were given s.c. injection of azoxymethane (7.4 mg/kg body weight once a week for 11 weeks) and sacrificed 15 weeks after the last injection of azoxymethane. The tumor incidence and tumor yields (tumors per rat) of the colon were significantly lower in rats on the EPA diet compared to those on the linoleic acid diet; i.e., 33%, 0.41 +/- 0.61 and 69%, 1.66 +/- 1.69, respectively. In the analysis of phospholipid fatty acid composition, the colon tumor showed higher levels of arachidonic acid and lower levels of linoleic acid than those in the normal colon mucosa in both diet groups. Despite the increase of arachidonic acid in colon tumor, the EPA diet suppressed the excessive production of prostaglandin E2, which may be accompanied with neoplastic formation, whereas linoleic acid diet caused a marked increase in the tumor content of prostaglandin E2 compared to normal colon mucosa. These results suggest that EPA exerts its inhibitory effect on colon carcinogenesis by modulating lipid metabolism and inhibiting prostaglandin E2 synthesis in tumor cells.

Animals↗
PubMed1988

The hemodynamic and metabolic basis for decreased aerobic capacity in the supine exercise compared with the upright exercise in coronary artery disease.

To elucidate the mechanism of reduced exercise tolerance in the supine position, 14 patients with coronary artery disease were studied by both supine ergometer exercise and upright treadmill exercise. Maximal oxygen consumption in the supine position amounted to 80% of that in the upright position (1110 +/- 453 vs 1387 +/- 470 ml/min; p less than 0.001). Maximal cardiac output was identical in both positions (12.07 +/- 4.44 vs 12.55 +/- 4.49 l/min; ns). Maximal arteriovenous oxygen difference in the supine position amounted to 83% of that in the upright position (9.22 +/- 1.92 vs 11.14 +/- 1.88 vol%; p less than 0.01). Thus, the lower maximal oxygen consumption in the supine position was not caused by the decreased cardiac output but by the impaired augmentation of arteriovenous oxygen difference. Lactate concentration at the same oxygen consumption was higher in the supine position, which means early augmentation of anaerobic metabolism. We concluded that the aerobic capacity in the supine position was significantly lower than that in the upright position in patients with coronary artery disease, and the impaired utilization of transported oxygen was considered to be one of the mechanisms of the decreased aerobic capacity in the supine position.

Adult↗
PubMed1988

Effects of platelet-activating factor on rat airways.

Effects of platelet-activating factor (PAF) on the rat airways were investigated. Male Wistar rats were anesthetized, and PAF was inhaled into the lungs through a tracheal cannula for 5 min using an ultrasonic nebulizer. The bronchomotor response was measured with a modified Konzett-Rössler method in rats immobilized with decamethonium bromide. The inhalation of PAF caused a marked bronchoconstriction, dose-dependently, in a concentration range of 0.0001 to 0.01%. The bronchoconstrictor potency of PAF was about ten times higher than that of ACh. On the other hand, histamine inhalation gave only a slight bronchoconstriction even at the high concentration of 0.1%. The bronchomotor response to PAF was accompanied by a marked, sustained decrease in systemic blood pressure, in a dose-dependent manner. Repeated inhalations of PAF (0.001%) at an interval of 60 min resulted in a pronounced tachyphylaxis in the bronchoconstrictor response, but not in the hypotensive response. Combined inhalations of PAF with ACh or histamine did not produce a potentiation by PAF of the bronchoconstrictor responses to ACh and histamine. These findings show that PAF is a strong bronchoconstrictor agent in rats and that there is no interaction between PAF and other mediators in the acute bronchoconstrictor response.

Acetylcholine↗
PubMed1988

Penetration and uptake of colloidal gold-labeled concanavalin A in the junctional epithelium of the rat.

A complex of colloidal gold and concanavalin A (CG-Con A) with various biological properties and high ultrastructural resolution was applied into the sulcus of rat molar gingiva and traced with an electron microscope for three hours to examine the cytological changes occurring in the cells of the junctional epithelium (JE) during penetration of extrinsic irritants, and to determine the roles of JE cells in such a circumstance. While the penetration of CG-Con A was impeded on the surface of keratinized oral gingival/sulcular epithelium, CG-Con A penetrated swiftly through JE into the connective tissue. In the process of penetration, CG-Con A was taken up by lysosomal and vacuolar structures of JE cells in which degenerative changes were often provoked. Degeneration of JE cells was seen selectively in the second and/or third cell layers from the innermost cell layer of JE. It was assumed that JE cells by their phagocytic activity might participate in the first line of defense against extrinsic irritants. On the other hand, the phagocytic activity of JE cells seems also to be involved in tissue destruction, if the amount and/or toxicity of irritants exceed the dissimilating capacity of JE cells.

Animals↗
PubMed1988

The mechanism of pocket formation. A light microscopic study on undecalcified human material.

Two hundred eighteen human teeth with surrounding periodontal tissues in different stages of pathogenesis were studied under light microscopy using the "sawing and grinding" technique. This was done without decalcification and with special emphasis on the dentogingival junction area so as to study the mechanism of pocket formation. Thirty early, 133 established, and 214 advanced lesions were included. No initial lesion was seen. Pocket formation, provoked by microbacterial plaque, seemed to be initiated by the degenerative changes in the second or third cell layers from the innermost cells in the most coronal part of the junctional epithelium facing the microbial plaque. Consequently, an intraepithelial cleavage was formed followed by the degeneration and desquamation of the cells lining the split. This resulted in a deep crevice and gingival pocket formation in both early and established lesions. In advanced lesions, the deep pocket epithelium was exposed for such a long distance adjacent to the plaque and calculus, that the epithelium could be directly affected by toxic bacterial products and mechanical irritation of calculus. Finally, the epithelium became very thin and ulcerated, and a typical periodontal pocket was formed. The disruption of the epithelial barrier along with the concomitant penetration of bacteria and/or their toxic products were considered to be the most significant factors related to the conversion of an established lesion to an aggressive lesion.

Epithelial Attachment↗