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Biomedical subjects

T Higa

Publications and source records attributed to T Higa.

At least 127 records · Page 7Linked to original sources

Possible alpha-adrenoceptor blocking activity of arotinolol (S-596), a new beta-adrenoceptor blocking agent in isolated dog coronary artery.

Effects of arotinolol on dog coronary arteries were investigated in vitro. In distal portions of left circumflex coronary arteries contracted with 3 X 10(-2)M KCl, norephinephrine relaxed the strips in a concentration-dependent fashion. Propranolol (10(-6)M) converted the norepinephrine-induced relaxations to contractions, and arotinolol (10(-6)-10(-5)M) inhibited the relaxations induced by norepinephrine in a concentration-dependent manner. In proximal portions of the strips after potassium-contracture, norephinephrine produced concentration-dependent contractions which were augmented by propranolol (10(-6)M) and inhibited by arotinolol (10(-6)-10(-5)M). These results suggest that arotinolol has an alpha-adrenoceptor blocking activity in addition to a beta-adrenoceptor blocking action in dog coronary arteries.

Adrenergic alpha-Antagonists↗

Effects of an antihypertensive agent, nipradilol, on isolated coronary artery of the dog.

Effects of nipradilol on proximal, middle and distal portions of left coronary arteries of the dog were investigated in vitro. Nipradilol (10(-7)-10(-3) M) produced a concentration-dependent relaxation in helical strips of isolated coronary artery under potassium contracture. The relaxation in the middle portions was most pronounced, it was 10% of the equimolar concentrations of nitroglycerin and significantly greater than that of propranolol. In the proximal portions of the coronary arteries, nipradilol (3 X 10(-8)-3 X 10(-7) M) showed a tendency to augment the contractile responses to norepinephrine; in the middle portions it reversed the relaxant responses to norepinephrine into contractile effects in a concentration-dependent manner. In distal portions, nipradilol significantly decreased the relaxant responses of the strips to norepinephrine. The findings demonstrate direct vasodilating and beta-adrenoceptor blocking actions of nipradilol in isolated coronary arteries of the dog.

Adrenergic beta-Antagonists↗

[Evaluation of cefotaxime for postoperative infection in surgery].

Cefotaxime (CTX) was microbiologically and clinically studied in surgery. CTX shows excellent antibacterial activity in vitro against Gram-negative bacilli including E. coli. Klebsiella spp., and Proteus spp. in comparison with cefmetazole (CMZ) and cefazolin (CEZ). Antibacterial activity of CTX is found to be superior to that of CEZ and equal to that of CMZ against Gram-positive bacteria (S. aureus and S. epidermidis). The antibacterial activity of CTX against anaerobic bacteria exceeds that of CEZ and almost equal to that of CMZ. It also showed minimum inhibitory concentration values which, clinically speaking, offer great expectation. CTX is also superior to CMZ and CEZ in its antibacterial activity against P. aeruginosa. Clinical studies were carried out in the group A for which CTX was administered a drug of first choice for postoperative infections in surgery, and in the group B for which CTX was administered as a drug of second choice since the antibiotic of first choice had been ineffective for these cases. As a result, high effective rates were obtained in both groups (80.3% for the group A, and 77.1% for the group B). With reference to the group B, an effectiveness rate of 100% was obtained for the cases in which CEZ had been ineffective and 55.6% was obtained for 10 cases in which mainly combination of CMZ had been ineffective. Side effects appeared in 3 cases (1 case each of tinnitus and malaise, vomiting and nausea, and fever) with an incidence rate of 1.46%. Abnormal clinical laboratory findings appeared in 4 cases (1 case each of leukopenia and increase in GOT and GPT; eosinophilia; increases in platelet and monocyte; and increases in GOT, GPT and A1-P) with an incidence rate of 1.95%.

Adolescent↗

Krypton-81m single photon emission tomography and the collateral circulation in carotid occlusion: the role of the circle of Willis and leptomeningeal anastomosis.

Cerebral perfusion images were investigated in patients with carotid artery occlusion, using single photon emission computed tomography with the infusion of krypton-81m into the internal, common carotid and vertebral arteries. The contribution of the circle of Willis and cerebral cortical anastomoses to the maintenance of adequate blood supply into the involved hemisphere was analysed. It was concluded that the cerebral perfusion image is superior to angiography in evaluating collateral circulation, and in the case of carotid occlusion, the circle of Willis is important in preventing infarction in the territory of the perforating arteries, while the cerebral cortex mainly receives its blood supply through the cortical leptomeningeal anastomoses, illustrating the major role of the leptomeningeal anastomosis as a collateral channel.

Adult↗

Superimposition of Krypton-81m single photon emission CT and X-ray CT images for cerebral blood flow evaluation.

Selective arteriographic infusion of krypton-81m was used to obtain cerebral single photon emission computed tomograms. These were then superimposed on X-ray computed tomograms to assess topographically the perfusion of the entire brain. This method enhances the detecting capability for abnormal perfusion areas and has been used in 21 patients with various brain diseases.

Carotid Artery Thrombosis↗