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Biomedical subjects

Y Tamura

Publications and source records attributed to Y Tamura.

At least 595 records · Page 33Linked to original sources
PubMed1987

[Preoperative radiotherapy of carcinoma of the stomach and breast].

Sixty-one patients with gastric cancer and thirty-seven with breast cancer who had undergone preoperative radiotherapy were analysed retrospectively for assessment of various radiotherapeutic effects and prognosis. Most of the sixty-one patients with gastric cancer were found to be stage III or more with borderline operable lesions on admission. Of the sixty-one patients, sixteen were evaluated postoperatively to be stage I by histopathological examination. The 3-year survival rate in these sixteen patients was an admirable 60%. Of the thirty-seven patients with breast cancer, the 3-year survival rate among twenty-four in Stage III exceeded 90%. This survival rate is very high in comparison with other reports. For radiotherapy we adopted a less-fractionated irradiation method with a large dose instead of the conventional fractionated one. This irradiation method has not only a direct radiotherapeutic effect, but also produces a favorable effect on the host's immunocompetence. For gastric cancer, twice weekly treatment with 5 Gy and 3 Gy per week, and irradiation twice with 20 Gy and 10 Gy for breast cancer were very suitable preoperative irradiation doses.

Breast Neoplasms↗
PubMed1986

High-performance liquid chromatographic analysis of arachidonic acid metabolites by pre-column derivatization using 9-anthryldiazomethane.

Arachidonic acid (AA) metabolites produced by washed human platelets and rat macrophages were analyzed by high-performance liquid chromatography (HPLC) using a pre-column derivatization method. The reagent, 9-anthryldiazomethane, used in this study and AA metabolites derivatized by the reagent were purified by gel permeation chromatography (PG-pak C column), prior to normal-phase HPLC analysis. A sample containing eleven derivatives (12-, 15- and 5-hydroxyeicosatetetraenoic acid, 12-L-heptadecatrienoic acid, leukotriene B4, prostaglandins B2, D2, E2 and F2 alpha, thromboxane B2 and 6-keto-prostaglandin F1 alpha) was separated on a normal-phase column (PG-pak B); the detection limit is better than 100 pg for all components.

Animals↗
PubMed1986

Comparison of the in vitro effect of eicosapentaenoic acid (EPA)-derived lipoxygenase metabolites on human platelet function with those of arachidonic acid.

Eicosapentaenoic acid (EPA) has been reported to have a potent anti-aggregatory activity and to be efficiently metabolized by 12-lipoxygenase, not by cyclooxygenase in platelets. In vitro effect of 12-lipoxygenase metabolites of EPA on platelet function was studied and compared with those of arachidonic acid (AA). The 12-lipoxygenase metabolites of AA and EPA; 12-hydroperoxyeicosatetraenoic acid (12-HPETE) and 12-hydroperoxyeicosapentaenoic acid (12-HPEPE), and their hydroxy derivatives, 12-hydroxyeicosatetraenoic acid (12-HETE) and 12-hydroxyeicosapentaenoic acid (12-HEPE) were prepared enzymatically using human platelet lysate. These compounds were purified by high performance liquid chromatography and identified by gas chromatography mass spectrometry. 12-HPETE and 12-HPEPE inhibited dose-dependently washed human platelet aggregation and serotonin (5-HT) release induced by AA and collagen. The potency of 12-HPEPE was almost equal to that of 12-HPETE. Their hydroxy derivatives, 12-HETE and 12-HEPE were less potent. 12-hydroperoxy derivatives of AA and EPA were the most potent in inhibiting platelet aggregation and 5-HT release among 5-, 12- and 15-hydroperoxy isomers of AA and EPA. The inhibitory effects of 12-HPETE and 12-HPEPE on platelet aggregation were additive.

12-Hydroxy-5,8,10,14-eicosatetraenoic Acid↗
PubMed1986

Endogenous kallikrein inhibitor in rat kidney cortex-effect of glucocorticoid administration.

Kallikrein inhibiting proteins with two different molecular weight (6-8 X 10(4), 8-9 X 10(4) respectively) were observed in adrenalectomized rat kidney cortical soluble fraction. The larger one was observed in the kidneys of the adrenalectomized rats only when they had received chronic administration of excess amount of dexamethasone, and its kallikrein inhibitory activity was not lost with treatment with trypsin. This protein appears to be induced by chronic administration of glucocorticoid and might participate in the process of glucocorticoid regulating renal kallikrein kinin system.

Adrenalectomy↗
PubMed1986

Distribution of light chains and ATPase activity of myosin in the atrioventricular conducting tissue of bovine heart.

The relations of the light chains of myosins of the atria, ventricles, and atrioventricular conducting tissue (specialized myocardial tissue) and the distribution of the light chains of myosin in different regions of the atrioventricular conducting tissue in bovine heart were examined. Two-dimensional gel electrophoresis showed that the atrial and ventricular myosins each had two light chains (LC1 and LC2). Ventricular LC1 differed from atrial LC1, but ventricular LC2 corresponded to atrial LC2. The specialized myocardial tissue myosin had three light chains (named here SL1, SL2, and SL3). SL1 comigrated with ventricular LC1, SL2 with atrial LC1, and SL3 with ventricular LC2 and atrial LC2. The compositions of the three light chains of myosins in various regions of the atrioventricular conducting tissue were determined by sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis. The percentage proportion of SL1 decreased in the order--atrioventricular node (AVN), right and left bundle branches (RLBB), His bundle (HIS), false tendon (FT) myosin; while the percentage proportion of SL2 decreased in the order--FT and HIS, RLBB, AVN myosin. The percentages of SL3 in these four regions were similar. The Ca2+-activated ATPase activity of myosin was highest in the AVN and lowest in the FT. The activities in the HIS and RLBB were intermediate between those in the AVN and FT. Thus, the composition of the light chains and the Ca2+-activated ATPase activity were different in various regions of the atrioventricular conducting tissue.

Adenosine Triphosphatases↗
PubMed1986

Clinical and epidemiological studies of eicosapentaenoic acid (EPA) in Japan.

From 1950 to 1980, the gross alteration in dietary habit in Japan was noted. Intake of total calories has markedly increased. This could be most likely due to a remarkable increase in intake of fat, especially animal fat, egg and milk products. A marked decrease of mortality rate due to cerebral hemorrhage and in contrast a marked increase of mortality rate due to cerebral infarction and ischemic heart disease were noted. An epidemiological study of the intake of fish meat (EPA intake) and the mortality rate of adult diseases was performed in a fishing area and in a farming area in Chiba Prefecture. Intake of fish meat (EPA) by the residents of the fishing area was 2-3 times higher than by the residents of the farming area. The mortality rate due to ischemic heart disease and cerebral vascular diseases tended to be lower in the fishing area than in the farming area. EPA manufactured from sardine oil was orally given to normal subjects and to patients with cerebro- and cardiovascular diseases for 4-16 weeks. Significantly decreased platelet aggregation, decreased platelet retention, lowered whole blood viscosity, prolonged bleeding time, increased erythrocyte deformability, improvement of hyperlipidemia, and clinical improvement in some patients were noted. 12-Lipoxygenase metabolites of EPA (12-HPEPE) and arachidonic acid (12-HPETE) have an equipotent inhibitory action on platelet function.

Arachidonate 12-Lipoxygenase↗
PubMed1986

Study of chronic alcoholic pancreatitis by means of serial pancreozymin-secretin tests.

Fourteen patients with suspected chronic alcoholic pancreatitis (CAP) and 21 patients who had been shown to have the disease were followed up by the pancreozymin-secretin test in order to clarify the serial changes in exocrine pancreatic function in alcoholic pancreatitis. The initial and final test data for secretory volume, maximal bicarbonate concentration, bicarbonate output (BO), and amylase output (AmO) of exocrine secretion were compared in these two groups. Patients with suspected CAP showed a significant serial decrease only in AmO; definite CAP developed in 3 of them during the follow-up period. In definite CAP, a significantly progressive decrease in BO as well as AMO was observed. It is suggested that in the earlier stage of CAP, AMO is initially affected, whereas decreased secretion of both bicarbonate and enzyme becomes apparent in the later stage.

Adult↗
PubMed1986

Evidence for decreased activity of guanine nucleotide binding protein in adenylate cyclase of cell membranes in human ACTH-unresponsive adrenocortical carcinoma.

The present investigation was performed in order to study the properties of abnormal membrane function related to ACTH receptor-adenylate cyclase system interaction in human ACTH-unresponsive adrenocortical cancer. Two tissues of adrenocortical cancer obtained from a patient with Cushing's syndrome (CS) and a case presenting no abnormal endocrinological findings (NF) were used for in vitro studies, comparing with three normal adrenal tissues. The addition of ACTH alone and ACTH plus 10(-6) M GppNHp did not enhance the adenylate cyclase (AC) activity in the CS and NF tissues. Relative insensitivity of AC to GTP, GppNHp, and cholera toxin was observed for the NF tissue, while the rate of response to GppNHp for the CS tissue which also showed relative insensitivity to GTP and cholera toxin was similar to that for the normal tissues. Forskolin which is reported to directly activate the catalytic unit of the AC complex increased the AC activity of both CS and NF tissues as well as that of the normal tissues. Therefore, the function of the catalytic unit itself may be rather well preserved in these tumor tissues. These results suggest that the lack of ACTH receptor at the cell membrane surface might be responsible for ACTH-unresponsiveness in the CS tissue, although an accelerated degradation of GTP could contribute to decreased activity of GTP-binding protein.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenylyl Cyclases↗
PubMed1986

[Carcinoid of the papilla of Vater-somatostatinoma--a case report].

A 46-year-old woman was referred to our hospital because of liver dysfunction. She had been suffering from right hypochondralgia for two months. On admission, Laboratory data indicated extrahepatic cholestasis. Both X-ray and endoscopic examinations confirm a submucosal tumor of the papilla of Vater, and surgical diagnosis was performed. Histologically, the tumor was diagnosed as carcinoid, and a further immunohistochemical study by the PAP method using antisomatostatin serum indicated somatostatinoma. Electron microscopically, the tumor cells were found to contain numerous intracellular granules, which looked like D cells in the pancreatic islet. Somatostatinoma in the intestinal tract has been reported in only 13 cases, in only one of which was it located in the papilla of Vater. That means that, this is the second case so far.

Adenoma, Islet Cell↗
PubMed1986

Hypotensive effects of eicosapentaenoic acid (EPA) and its influence on eicosanoid metabolism in spontaneously hypertensive rats.

Oral administration of pure eicosapentaenoic acid (EPA) ethyl ester caused a reversible hypotensive effect in spontaneously hypertensive rats. Treatment with EPA also lowered the platelet response to ADP and inhibited the conversion of leucotrienes (LTs) A4 and LTB4 and other sulphidopeptide leucotrienes. Therefore, diet supplemented with EPA may lower blood pressure in hypertensive rats and affect cardiovascular functions which may be mediated through eicosanoid metabolism.

Animals↗
PubMed1986

[Long-term vasodilator therapy of chronic refractory heart failure in patients with dilated cardiomyopathy].

The effect of long-term vasodilator therapy (hydralazine, ecarazine or budralazine + isosorbide dinitrate) were evaluated for 20 patients with chronic congestive heart failure due to dilated cardiomyopathy (DCM) resistant to conventional therapy. There were 16 men and four women whose ages ranged from 30 to 74 years (mean 52 years). Fifteen patients were in NYHA class III, and five in class IV. All patients continued their previous therapeutic regimens during this study. Hemodynamic measurements were performed with a triple lumen flow-directed balloon-tipped catheter for 15 patients to evaluate the effects of vasodilator therapy. In the other five patients, heart rate, blood pressure, chest radiography for heart size (CTR) and M-mode echocardiography were monitored. The hemodynamic responses to the combined vasodilator therapy for 15 patients showed significant decreases in afterload and preload concomitant with an increase in cardiac output. The noninvasive evaluations of combined vasodilator therapy in five patients resulted in significant improvement in heart size and ejection fraction. In all 20 patients, symptoms were significantly improved. Side effects and drug toxicity were uncommon during vasodilator therapy. It is concluded that combined vasodilator treatment is the most ajunctive therapy for the management of severe refractory heart failure due to DCM. In addition, long-term nonparenteral vasodilators can be administered even in an outpatient clinic without hemodynamic monitoring.

Adult↗
PubMed1986

Study on ectopic calcification in bone marrow of rat tibia caused by vinblastine.

Contact microradiographic study and histological study were performed to investigate the sequential changes in the bone marrow after a large dose of vinblastine or colchicine administration. Rats were injected intravenously with various dose of vinblastine or colchicine. The following dynamic histological changes were noted in the bone marrow in the vinblastine 2.0 mumol/kg and colchicine 2.5 mumol/kg-injected groups: Necrosis of the bone marrow cells was observed in the early stage and the necrotic bone marrow cells were replaced by many fibroblast-like cells. After that, the fibroblast-like cells disappeared and the network-like calcified tissue replaced the region where the fibroblast-like cells existed previously. The osteoblasts were lined on the surface of the ectopic calcified tissue and then the osteoblasts were replaced by the typical osteoclasts. In consequence of this dynamic alteration of the cells, the ectopic calcified tissue decreased and the normal bone marrow cells increased in the bone marrow cavity. The ectopic calcification could hardly be observed in the area where the fibroblast-like cells had not appeared. These findings suggested that the markedly proliferated fibroblast-like cells in the marrow cavity after the administration of vinblastine or colchicine may differentiate to osteoblasts and that the osteoclasts may be derived from the bone marrow cells which had already recovered from the toxic effect of the drugs. The mechanism of the dynamic histological changes in the bone marrow remains to be investigated.

Animals↗