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Biomedical subjects

M Tamura

Publications and source records attributed to M Tamura.

At least 973 records · Page 54Linked to original sources
PubMed1981

Permanent pacemaker implantation in patients over 80 years of age.

During the past five years, 150 pacemaker implantations have been done at Hiroshima Prefectural Hospital for the treatment of atrioventricular block, sick sinus syndrome, or slow heartbeat with atrial fibrillation. The patients were divided into two groups by age: the older group of 18 patients over 80 years of age and the younger group of 132 patients under 79 years of age. A comparative study of these two groups was undertaken with respect to pre- and postoperative courses, underlying diseases, cardiac output at variable pacing rate, capture threshold, and prognosis. The older group has as satisfactory a course as the younger group. Seventeen patients out of 18 (94%) in the older group are leading normal productive lives at this writing, and 119 out of 132 (89%) in the younger group are also doing well. In the light of this five-year comparative study, it can be concluded that it is safe and rewarding to implant prosthetic cardiac pacemakers in symptomatic patients over 80 years of age.

Adolescent↗
PubMed1981

[Unilateral exophthalmos - diagnostic and therapeutic procedure (author's transl)].

Unilateral exophthalmos related to orbital diseases was analyzed in 37 cases. Thirty-four out of 37 cases were operated on and histologically verified. The cases included five pseudotumors, five intracranial tumors invading the orbit, four carotid-cavernous fistulas, three mucoceles, two lacrimal gland tumors, two cavernous angiomas, two osteomas, two histiocytomas, two fibrous dysplasias, one neurinoma, one meningioma, one embryonal rhabdomyosarcoma, one metastatic tumor, one venous malformation, one orbital meningoencephalocele, one infraclinoid internal carotid giant aneurysm, three mass lesions not verified operatively. The location of mass lesions in the orbit was diagnostically significant and was certified by CT scan. Mucocele and osteoma occurred at the medial site of the orbit. Lacrimal gland tumors were located anterolaterally in the orbit. Pseudotumors, cavernous angiomas, and the neurionoma were situated posterior to the orbital bulb. As for age distribution, meningoencephalocele, venous angioma, fibrous dysplasia, histiocytoma and embryonal rhabdomyosarcoma occurred in infancy and childhood. The onset and course of the orbital mass lesions were characteristic in the disease process: carotid-cavernous fistula and infraclinoid internal carotid giant aneurysm occurred suddenly. Malignant tumors, such as adenoid cystic carcinoma, embryonal rhabdomyosarcoma and metastatic tumor, revealed rapidly progressive exophthalmos. Benign tumors and mucocele were slowly progressive. Orbital meningoencephaloceles were observed at birth and no remarkable change thereafter. Pseudotumors were progressive at the initial disease process and later became stationary or regressive. Venous malformation showed intermittent exophthalmos. The frontozygomatic operative approach for orbital mass lesions was applied when the tumors were large enough and located laterally in the orbit.

Adolescent↗
PubMed1980

Formation of porphyrin pi cation radical in zinc-substituted horseradish peroxidase.

Zinc-substituted horseradish peroxidase is oxidized by K2IrCl6 to a characteristic state which retains one oxidizing equivalent more than the zinc peroxidase. The oxidized enzyme gives an optical absorption spectrum similar to that of compound I of peroxidase and catalase, and a g = 2 electron paramagnetic resonance signal which has an intensity corresponding to the porphyrin content. It is reduced back to the zinc peroxidase by a stoichiometric amount of ferrocyanide or by a large excess of K3IrCl6. From the equilibrium data, the value of E0' for the zinc peroxidase couple is estimated to be 0.74 V at pH 6. The oxidized zinc peroxidase is also formed by the addition of H2O2 or upon illumination with white light. The rate constants for the oxidation by K2IrCl6 and H2O2 at pH 8.0 are 8 x 10(5) and 8 x 10(2) M-1 s-1, respectively. No essential spectral change can be observed when K2IrCl6 is added to the metal-free peroxidase (protoporphyrin--apoperoxidase complex) or to zinc-substituted sperm whale myoglobin.

Cations↗
PubMed1980

A kinetic study on the diffusion-coupled reaction of a basic horseradish peroxidase adsorbed on the carboxymethylcellulose membrane.

The rate of reactions of a basic horseradish peroxidase adsorbed on the carboxymethylcellulose membrane was measured spectrophotometrically by monitoring the state of the enzyme. For the reactions with hydrogen peroxide and cyanide dissolved in media the diffusion process was rate limiting both in the static and flowing media, and kinetic features of the enzyme were masked. The rate of CO recombination of the ferrous enzyme was measured by flash photolysis in the static media containing varying amounts of CO. Apparently, the initial rate of CO recombination was no more affected by the diffusion factor, and the second order rate constant could be measured for the reaction of the enzyme adsorbed on the membrane. The value was about 70% of that obtained from the enzyme in solution and exhibited the same pH dependence as did the value for the enzyme in solution. The difference of the reaction pattern between the enzymes on the membrane and in solution became distinct when flash photolysis was applied to the reaction system without free CO in the medium. The kinetic data were analyzed by computer simulation.

Carbon Monoxide↗
PubMed1980

Airway obstruction in achalasia.

A man with a mediastinal mass shadow detected on chest roentgenogram was diagnosed as having achalasia by barium swallowing study. Megaesophagus caused by achalasia produced airway obstruction. Maximum expiratory-inspiratory flow volume curve identified that peak flow rate decreased in early expiration, and the ratio of expired to inspired flow at 50 percent of vital capacity was below 0.9, aggravated by 250 ml water intake. Deformation of the tracheal shape was proved easily.

Adult↗