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Biomedical subjects

Y Tamura

Publications and source records attributed to Y Tamura.

At least 703 records · Page 39Linked to original sources
PubMed1981

[Effect of alpha-(p-thenoylphenyl)-propionic acid (TN-762) on acute inflammatory reactions and prostaglandin biosynthesis].

A series of compounds with the general structure of phenylpropionic acid was originally synthesized for anti-inflammatory screening. The title compound, TN-762, showed marked anti-inflammatory and analgesic activities and was less toxic. This compound was the same as suprofen which was reported by Janssen to have potent anti-inflammatory and anti-writhing activities. Effects of TN-762 on acute inflammatory reactions and prostaglandin biosynthesis were investigated in animal models and findings compared to those of ketoprofen and indomethacin. TN-762 showed a dose-dependent inhibition at low doses of 5-20 mg/kg, p.o. on an increased vascular permeability induced by histamine in rats and by acetic acid in mice and carrageenin-induced paw edema in rats. The anti-inflammatory activity of TN-762 was much the same as that of ketoprofen and indomethacin. The inhibitory effect of TN-762 on carrageenin-induced paw edema was not affected by successive administration for 14 days and/or by adrenalectomy. The compound was more active than the two reference compounds in inhibiting ultraviolet erythema in guinea pigs. TN-762 inhibited markedly the arachidonic acid potentiation of carrageenin-induced edema in rat paw, the sudden death following intraveneous administration of arachidonic acid to rabbits and the diarrhea produced by endotoxin in mice, all considered to be induced by biosynthetic prostaglandins. The activities of TN-762 were the same or were more potent than those of ketoprofen and indomethacin. On the contrary, the ulcerogenic activity of TN-762 on the gastrointestinal tract in rats was significantly less than that of ketoprofen and indomethacin. From the above results, TN-762 proved to be a potent inhibitor of acutely-induced inflammation and of prostaglandin biosynthesis, however, the ulcerogenic effects were comparatively diminished.

Animals↗
PubMed1981

[Phonocardiographic and ultrasonocardiographic findings in seven cases of coronary artery fistula (author's transl)].

The diagnosis possibility of the involved arteries as well as drained site was studied in 7 cases of coronary artery fistula by pharmacodynamic phonocardiography and echocardiography. All cases had a continuous murmur, which was decreased soon after the inhalation of amyl nitrite but increased thereafter. These characteristic changes were diagnostic for coronary artery fistula. Two-dimensional echocardiograms could easily disclose the fistulous coronary artery with proximal dilatation, but not that without dilatation. The 2.4 and 3.5 mHz transducer used in this study revealed the fistulous coronary artery of 5 mm diameter confirmed by the angiocardiogram. However, the visualization depended on the anatomical relation to the aorta. In cases with drainage into the pulmonary artery, the fistulous coronary artery passed usually upwards near the aorta, so that it could be detected with the beam direction focussing to the anterior and posterior walls of the aorta. In these cases, the passage of the fistulous artery originating from the right coronary artery was easily recognized and the involved coronary artery was inferred. But it was difficult to follow the passage when originating from the left coronary artery.

Adolescent↗
PubMed1980

Sex-dependent difference in aryl hydrocarbon hydroxylase activity in mouse liver.

Sex difference was observed in the aryl hydrocarbon hydroxylase (AHH) activity of liver in the C3H/He strain of mice. Treatment with estradiol showed an increase in AHH activity in gonadectomized female mice, but not in males. Testosterone, however, lowered AHH activity in both the gonadectomized male and female. Following treatment with either estradiol or testosterone in neonatal stages, AHH activity increased in males, but not in females. A sex difference was observed also in the activity of NADPH-cytochrome c reductase, which was higher in the female, but not in the levels of cytochrome P-450 and benzo[a]pyrene (BP)-induced spectral changes.

Animals↗
PubMed1980

Effects of antibody to renal plasma membrane on urinary excretion of adenosine 3',5'-monophosphate and phosphate induced by parathyroid hormone infusion in rats.

Studies were made on the effects of pretreatment of rats with antibody to renal cortical plasma membrane (anti-RPM) on the urinary excretion of cAMP and phosphate induced by infusion of parathyroid hormone (PTH). With PTH infusion, the increase in the urinary excretion of cAMP and phosphate were not parallel. Infusion of 1-40 mg anti-RPM inhibited PTH-induced increase in urinary phosphate excretion but not the increase in urinary cAMP. Infusion of 100 mg of anti-RPM inhibited PTH-induced increases in the excretion of both substances. Infusion of nonimmunized rabbit immunoglobulin (IgG; normal IgG) did not affect PTH-induced increases in the excretion of either cAMP or phosphate. In vitro in isolated renal tubules, with 10 mg/ml anti-RPM, the increases in cAMP content induced by PTH were significantly less than those seen with lower concentrations of this antibody or with normal IgG.

Animals↗
PubMed1980

Biochemical studies on energy metabolism in the conduction system of bovine heart.

The conduction system of bovine heart was studied to clarify the characteristics of its energy metabolism. Results showed that its mitochondrial oxygen uptake was much lower than that of ordinary heart muscle with succinate as substrate but similar to that of ordinary heart muscle with glutamate + malate as substrate. The activity of succinate dehydrogenase was lower than that in ordinary heart muscle. The total activity of isozymes of lactate dehydrogenase was lower in the specialized heart muscle than in ordinary heart muscle. The main isozyme of lactate dehydrogenase in the specialized heart muscle was LDH 1 (H4). The cytoplasmic NAD+/NADH ratio as much higher in the specialized heart muscle than in ordinary heart muscle. These results suggest that in the specialized heart muscle energy is mainly derived from aerobic metabolism.

Animals↗
PubMed1980

[Pharmacological studies of new sulfhydryl compounds 2-mercapto-2-methylpropanoyl-L-cysteine (SA96). I. Evaluation of anti-rheumatic action (author's transl)].

Oral administration of 2-mercapto-2-methylpropanoyl-L-cysteine (SA 96), a newly synthesized sulfhydryl compound, showed protective and curative effects on adjuvant-induced arthritis in rats similarly to those seen with D-penicillamine (D-PA). However, the effects of these compounds were not dose-dependent, and the maximum effects of SA96 were observed at 10 mg/kg/day. On the contrary, SA96 and D-PA had little effect on the various acute and subacute inflammatory responses induced in rat and mice. Formation of hemolytic plaque forming cells in the spleen of mice immunized with 5 X 10(8) sheep red blood cells was potentiated by the oral administration of both compounds. These stimulatory effects of SA96 and D-PA on the humoral immune responses were also not dose-dependent, and the maximum effects of SA96 were observed with 10 mg/kg/day, as in the case of adjuvant-induced arthritis in rats. In in vitro experiments, the inactivation of rheumatoid factor and the inhibition of collagenase and bone alkaline phosphatase activities were observed with both compounds, but these effects of SA96 were more potent than those of D-PA. As there is a similarity in the pharmacological profiles of SA96 and D-PA, SA96 may prove to be clinically effective for rheumatoid arthritis.

Acute Disease↗
PubMed1979

An apparatus for the assembly of a combined single barrel recording electrode and a multibarrelled micropipette.

In order to impale cells lying in deeper structures of the brain with 'parallel' multibarrelled electrode, we designed a new apparatus for the assembly of a multibarrelled micropipette and a single barrel recording electrode. This device greatly simplifies the procedure of constructing electrodes with shafts of approximately 15-20 mm in length even if the multibarrelled micropipettes are pulled with a slightly curved shaft and the bend made near the base of the shaft is not exactly to the specified angle. Electrodes of this type greatly improve the size and stability of the extracellularly recorded units from the caudate nucleus.

Electrophysiology↗
PubMed1979

Effect of calcium administration on renal responsiveness to parathyroid hormone in pseudohypoparathyroidism type I and II -- in comparison with normals, idiopathic and surgical hypoparathyroidism.

A 31-year-old man and a 12-year-old girl were diagnosed as pseudohypoparathyroidism (PHP) Type I because of a failure to respond to the administration of parathyroid hormone (PTH) with increased urinary excretion of phosphate and cyclic adenosine-3', 5'-monophosphate (cAMP). A 22-year-old woman was diagnosed as PHP Type II because there was no increase in the urinary excretion of phosphate despite of a marked increase in urinary cAMP excretion. With the combined calcium-PTH infusion or PTH infusion after vitamin D therapy, renal response was improved in these patients. Also dibutyryl adenosine-3'-5'-cyclic monophosphate (dbcAMP) infusion evoked an increased urinary phosphate excretion in all of the patients. The metabolic defect of our patients with PHP Type I may be caused not by a lack or defective form of PTH-sensitive receptor adenylate cyclase complex but rather by an abnormal conformation in the plasma membrane-associated receptor adenylate cyclase enzyme complex in kidney. In the patient with PHP Type II, as cAMP generation is intact, the metabolic defect might be related to a defect of calcium mobilization in renal tubular cells in response to PTH.

Adult↗
PubMed1979

Comparative study of cyclic AMP-generation system, steroid biosynthesis and lipid metabolism in vitro in ACTH responsive and unresponsive adrenal tumors.

The responses of the cyclic AMP-generation system and corticosteroids biosynthesis to ACTH and angiotensin II and cholesterol and other lipid contents in adrenal tissues were estimated in the in vitro experiments in 3 cases of Cushing's syndrome due to ACTH-responsive and unresponsive adenomas, one case of Cushing's disease (diffuse hyperplasia), one case of primary aldosteronism and one normal subject. The responses of cAMP accumulation and corticosteroids production to ACTH in in vitro studies were quite in good agreement with the in vivo responses of plasma cortisol by ACTH infusion test. The adenylate cyclase activity decreased and the phosphodiesterase activity increased in the case of hyperplasia and in one case of ACTH-responsive adenoma, whereas the basal cyclic AMP content was slightly more in ACTH-responsive adenoma and maximal in hyperplasia compared with that of the normal adrenal tissue. The characteristic features observed in ACTH-unresponsive adenoma were the largest amount of the basal corticosteroids production and esterified cholesterol content, and the lowest content cAMP. These results indicate that there was not always the consistent correlation between the cAMP-generation system, corticosteroids and aldosterone production, and conversion of cholesterol to pregnenolone by the stimulation of ACTH and angiotensin II in adrenal tumors.

Adenoma↗