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Biomedical subjects

Y Takeuchi

Publications and source records attributed to Y Takeuchi.

At least 1,045 records · Page 58Linked to original sources

Surgical experience with anatomically corrected malposition of the great arteries without subpulmonary conus.

A three-year-old boy was operated on with the diagnosis of anatomically corrected malposition of the great arteries (S,D,L), ventricular septal defect, and mitral regurgitation. During the operation, it was found that the subpulmonary conus was absent. Ventricular septal defect was patch-closed, and the mitral valve was repaired. The patient was well after the surgery. This is the first case report to our knowledge of the successful surgical repair in anatomically corrected malposition of the great arteries without subpulmonary conus. Anatomically corrected malposition of the great arteries does not always have bilateral conus as once proposed, and the importance of the differentiation from the corrected transposition of the great arteries is emphasized.

Child, Preschool↗

Immunohistochemical studies on the processes of serotonin neurons and their ramification in the central nervous system--with regard to the possibility of the existence of Golgi's rete nervosa diffusa.

Using various vertebrates from teleost to macacus, we studied, by the modified PAP method, the serotonin neurons that are distributed mainly in the raphe nuclei area, focussing on their process ramifications, and obtained the following results. 1. The shapes of serotonin neurons were varied. They were multipolar with many long, thick dendrites. In most of the neurons, more than two axons originated either from the stem of a dendrite or from its tip. 2. The axons contained spherical or spindle-shaped varicosities of varied sizes (diameter 0.5-6 micron). On a few occasions, they became large, Herring body-like droplets. 3. The axons were classified into four groups according to the shape and size of the varicosities they contained: stem fibers, A-fibers (tract fibers), B-fibers (branching fibers) and C-fibers (ground fibers). 4. The axon not only branched frequently, but formed a true network by way of frequent anastomosis at the level of B- and C-fibers. Serotonin fibers do not have endings that correspond to telodendrons, but conduct impulses through "en passant" type synapses. 5. A supraependymal plexus is formed over large areas of the ventricular system. This vast network is considered to be formed by the syncytial continuity of axonal reticulum of many serotonin neurons. 6. Serotonin neurons, and probably noradrenaline neurons as well, should be classified as a third type of neuron, which belong to neither the Deiters type nor the Golgi type neuron. Their characteristic feature is the long, reticular axons, and it is highly probable that this neuron system forms the "rete nervosa diffusa" proposed by GOLGI.

Animals↗

Electron microscopic investigation of monoaminergic terminals to alpha-motoneurons in the anterior horn of the cat spinal cord.

In the anterior horn of the cat thoracic cord, networks of the monoaminergic fibers surrounding the alpha-motoneurons were investigated by fluorescent microscopy and submicroscopically. Monoaminergic terminals were recognized by the administration of 5-OHDA electron microscopically. These terminals could be classified morphologically into three types. The physiological significance of monoaminergic control of alpha-motoneurons was discussed. Type I of the labeled terminals did not show any typical synaptic specialization, such as aggregation of synaptic vesicles or thickening of the pre- and postsynaptic membranes. This type did not have synaptic contact with the alpha-motoneurons. Type II showed typical synaptic contact and asymmetrical synaptic type membranous thickening. A large number of small dense-cored vesicles were accumulated in the vicinity of the presynaptic membranes. Type III contained a large number of small and large dense-cored vesicles and a few flattened small vesicles. This type had synaptic contact with the presynaptic nerve ending in which a large number of agranular vesicles were contained. This study demonstrated that alpha-motoneurons in the anterior horn receive supraspinal monoaminergic control in three ways: modulator control through Type I, monosynaptic direct control through Type II, and inhibitory control through Type III.

Adrenergic Fibers↗

Early and late postoperative studies in coronary arterial lesions resulting from Kawasaki's disease in children.

From October, 1976, to February, 1980, eight children with coronary arterial lesions resulting from Kawasaki's disease underwent surgical treatment--aorta-coronary bypass, aorta-coronary bypass combined with right coronary aneurysmectomy, and aorta-coronary bypass combined with left ventricular aneurysmectomy. The autogenous saphenous vein was used for the bypass grafts. Selective angiography preformed 1 month after the operation revealed an early patency rate of 85%. Seven patients are now leading a normal school life, but one patient died suddenly during relatively strenuous exercise 3 years after the operation. Angiography performed in five patients 1 to 3 years after the operation and autopsy examination in one decreased patient revealed the late patency rate to be 56%. The relatively higher attrition rate of the grafts in the later stage might be ascribed to the smaller caliber of the coronary artery and saphenous vein, to possible inflammatory changes in both the graft and coronary arteries, or to unknown metabolic differences between children and adults.

Adolescent↗

[Compared studies of antimicrobial agents against E. coli, Klebsiella, Citrobacter and Proteus isolated from urinary tract infections].

In vitro activities of antibacterial agents against E. coli, Klebsiella, Citrobacter and Proteus which were isolated from patients urinary tract infections at 8 hospitals in Japan, were investigated by agar dilution method from July to October in 1979. The summarized results are as follows. 1. Among oral antibacterial agents, MPC and PPA have showed potent antibacterial activities against E. coli and Klebsiella. Among parenteral antibiotics, CTM was the most active against E. coli and Klebsiella. However, ABPC-resistant E. coli and Klebsiella have appeared to occupy about 40% and 96% of bacteria isolated from urinary tract infections, respectively. 2. In vitro activities of antibacterial agents against Proteus and Citrobacter showed not so potent. 3. Causative organisms in female patients with simple urinary tract infections were mainly E. coli and Klebsiella. 4. Among oral antibacterial agents, PPA have shown similar antimicrobial activities against E. coli isolated from simple and complicated urinary tract infections. ABPC and MPC have been influenced in some degree by these factors. However, parenteral antibiotics are not influenced by these factors. On the other hand, in vitro activities of antibacterial agents against Klebsiella isolated from simple and complicated urinary tract infections were similar.

Adult↗