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Biomedical subjects

K Nagae

Publications and source records attributed to K Nagae.

At least 37 records · Page 2Linked to original sources

Echocardiographic features of bioprosthetic valve endocarditis.

Abnormal echocardiographic findings in seven cases of bioprosthetic valve endocarditis were confirmed in six at operation. The echocardiograms showed three cases with thickening and increased echo intensity (group 1) and four (group 2) in which vegetations were seen initially without either of the two features in group 1. Two patients in group 1 had vegetations, the causative organism being a streptococcus. Staphylococcus epidermidis was the causative organism in three of the four cases in group 2; in two of these rapidly growing vegetations were detected. The large vegetations obstructed the ostium of the bioprosthetic valve. Thus if vegetations are detected in cases in which staphylococci are the causative bacteria surgery should be performed as soon as possible. In patients who develop a fever after bioprosthetic valve replacement and especially in those with evident bacteraemia echocardiography should be repeated frequently so that lesions may be detected early.

Adult↗

Motor innervation of the mole and shrew snout muscles by means of horseradish peroxidase technique.

The axonal transport method of the horseradish peroxidase (HRP) was used for defining the anatomical background of the snout movements in 54 Japanese shrew-moles, Urotrichus talpoides, 4 Temminck's moles, Mogera wogura, and 21 big-clawed shrews, Sorex unguiculatus. Either snout muscle or proximal stump of the facial nerve on one side was exposed to HRP. The results obtained from this experimental study were as follows: HRP-containing cells were found either ipsilaterally or bilaterally in the facial motor nucleus in both the moles and shrews. The HRP-containing cells were grouped into 4 subnuclei: ventrolateral, ventromedial, dorsal and accessory. In case of the snout muscle being exposed to the HRP were the HRP-containing cells found in the ventral groups. A HRP-positive fiber bundle was found at the genu of the facial motor root extending toward the median raphe, when the proximal stump of the facial nerve was exposed to the HRP.

Animals↗

[Mitral regurgitation in hypertrophic cardiomyopathy: an analysis with two-dimensional ultrasonic Doppler echocardiography].

Intracardiac blood flow pattern in the left ventricle and left atrium was noninvasively studied by the ultrasonic pulsed Doppler flowmeter incorporated with a real-time, phased array two-dimensional echocardiography in 28 cases of hypertrophic cardiomyopathy. Emphasis was placed on the incidence and characteristic features of mitral regurgitation in this condition. The relationship of mitral regurgitation with an early systolic murmur was also studied. The results were as follows: 1) A mitral regurgitant signal by Doppler technique was noted in all cases of hypertrophic obstructive cardiomyopathy and in half of the cases of hypertrophic nonobstructive cardiomyopathy. 2) The Doppler signal of mitral regurgitation began immediately after the first heart sound. 3) The mitral regurgitant flow spread over the left atrium or directed toward the posterior half of the left atrium in the obstructive cases. However, it was localized in the vicinity of the mitral orifice in the nonobstructive cases. These findings were different from those in rheumatic mitral regurgitation or idiopathic mitral valve prolapse. 4) The findings on mitral regurgitation by the Doppler technique exhibited a satisfactory correspondence to those by left ventriculography. 5) The early part of the systolic murmur in hypertrophic cardiomyopathy was considered to be more closely related to mitral regurgitation than a turbulent forward flow due to outflow obstruction. Therefore, mitral regurgitation might have some contribution in causing a murmur in the latter period of systole.

Adult↗

Changes of ventricular monophasic action potential duration by stellate ganglion stimulation in dogs.

Left or right stellate ganglion stimulation resulted in changes of ST segments and T waves of electrocardiogram. The present experiments were performed in an attempt to elucidate alpha-and beta-adrenergic actions, and calcium action on the monophasic action potential duration (APD), that is, the repolarizing phase of myocardium. During experiments in open-chest dogs, right ventricular pacing was performed for avoiding the acceleration of heart rate by stellate ganglion stimulation. Administration of phentolamine, propranolol or D600 prolonged APD, while hydrazine shortened it. However, stellate ganglion stimulation caused a prolongation of APD after infusion of propranolol or hydrazine, and a shortening of APD after infusion of phentolamine, D600 or hydrazine. These results indicate that alpha-and beta-adrenergic actions as well as calcium ions can be related to APD in the ventricular myocardium of dogs; apparently, alpha-adrenergic action prolongs APD and beta-adrenergic action shortens it.

Action Potentials↗

Horseradish peroxidase-labelled cells in cervical sympathetic and trigeminal nervous systems after injection of HRP into tooth pulp in monkeys and tree shrews (a preliminary report).

The neurons that project to the tooth pulp were examined by the HRP-retrograde transport technique, using 4 monkeys (3 Japanese monkeys and a crab-eating monkey) and 6 tree shrews. The present investigation showed that a large number of sympathetic cervical ganglion neurons, small and medium in size, project to the molar teeth from the superior, middle and inferior ganglia and a small number of Gasserian gangilon neurons (small in size) to the molar teeth ipsilaterally.

Animals↗