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Biomedical subjects

S Kikuchi

Publications and source records attributed to S Kikuchi.

At least 559 records · Page 31Linked to original sources

Comparison of the hypotensive and diuretic effects of 1,4-dimorpholino-7-phenylpyrido[3,4]pyridazine (DS-511) and hydrochlorothiazide in Doca, renal and spontaneously hypertensive rats.

The hypotensive and diuretic activities of a new diuretic, 1,4-dimorpholino-7-phenylpyrido[3,4-d] pyridazine (DS-511), were compared with those of hydrochlorothiazide (HC) in DOCA, renal and spontaneously hypertensive rats. The results obtained were: 1. During the developing stage of DOCA-hypertension the daily treatment of rats with DS-511 and HC showed significant hypotensive action. During this period the diuretic activity of both agents was clear. 2. During the equilibrium stage of DOCA-hypertension the hypotensive action of DS-511 was indistinct despite its diuretic activity. The hypotensive and diuretic action of HC was not clear. 3. In renal-hypertensive rats the daily treatment of DS-511 and HC caused significant, but weaker hypotension than that in the developing stage of DOCA-hypertension. In these animals the diuretic activity of both agents was clear. 4. In spontaneously hypertensive rats the daily treatment with DS-511 and HC exhibited a similar hypotensive and diuretic action. 5. In all three kinds of hypertensive rats the diuretic activity of DS-511 was similar to that of HC in the excretion of urine and sodium, but the former was less kaliuretic than the latter.

Animals↗

The structure and innervation of the sinu-atrial node of the mole heart.

The sinu-atrial node in the heart of the mole, Mogera wogera, contains myocytes which are devoid of atrial specific granules and which may be classified into two types: electron-lucent (majority) and dark (minority). Numerous unmyelinated axon terminals, containing synaptic vesicles, face the nodal myocyte surface with interspaces of less than 300 nm. There are about 6 terminals per myocyte profile and about 10 per profile at nuclear levels. Of a total of 2717 of these terminals 85.2% are 50-200 nm from the nodal myocytes, and 9.6% form closer neuromuscular junctions, with less than 50 nm interspace and some membrane specialization. Such specilizations are almost exclusively found in relation to the dark, minority-type of nodal myocyte. Myelinated nerve fibers are also numerous within the mole SA node, and may terminate almost directly on a nodal myocyte. A few nerve fibers contain many mitochondria and may represent afferent endings. Nodal capillaries are smaller and fewer than capillaries in the juxtanodal myocardium, probably indicating a lesser blood supply to the SA node than to the ordinary myocardium.

Animals↗

Clinical investigation on abnormal glucose tolerance in liver cirrhosis.

The changes of blood glucose, serum insulin, serum free fatty acid and its fatty acid composition following oral glucose load were observed in twenty-nine cirrhotic patients. The insulin secretory response was significantly lower in the cirrhotic patients with overt diabetes than in those without overt diabetes. There were no definite relation between serum free fatty acid level or its composition and glucose intolerance. These results suggest that the diabetic state in most of the cirrhotic patients with overt diabetes is due to essential diabetes and that serum free fatty acid livel and its composition are not important factors contributory to the glucose intolerance in liver cirrhosis.

Adult↗

Metaphysial dysostosis (Jansen type). Report of a case with long follow-up.

A case of the Jansen type of metaphysial dysostosis, followed for fifteen years from childhood to the age of nineteen, is reported. Radiographs taken at five years revealed the characteristic metaphysial changes in all the tubular bones, especially those of the hands and feet. The acetabular and glenoid areas, the costochondral junctions and the sternal ends of the clavicles were also involved. Radiographs taken at nineteen years, however, showed only marked deformities, which shows that the involvement of the metaphyses can regress by the end of growth. Biopsy of the lower end of radius at the age of twelve revealed changes in the growth plate or physis, especially in the zone of resting cartilage. This finding suggests that cellular function in this zone is disturbed by some unknown mechanism. Hence, the term physial dysostosis may be more accurate than metaphysial dysostosis.

Adult↗

Biosynthesis of formycin. Incorporation and distribution of labeled compounds into formycin.

1. Two carbons, carbon-2 and one of carbons-3 to -5, of lysine seemed likely to be incorporated into one of carbon of the chromophore moiety of formycin. 2. From the results of radioisotopic studies with glutamate, gamma-amino-n-butyrate or organic acids related to tricarboxylic acid cycle, the important role of glutamate in the biosynthesis of formycin was strongly suggested. 3. The incorporation of nitrogen(s) of lysine into three nitrogens, including two nitrogens of pyrazole ring, of formycin was suggested by mass spectroscopy. 4. Ribose was estimated as a direct precursor moiety of formycin, whereas the biosynthesis of ribose was shown to occur via the pathway other than hexose monophosphate shunt or glucuronate pathway. 5. In replacement culture, the salvage synthesis of formycin from its chromophore moiety was not observed and it was also evident that the chromophore moiety or pyrazofurin (pyrazomycin) inhibited the biosynthesis of formycin.

Adenine↗