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Biomedical subjects

T Sakamoto

Publications and source records attributed to T Sakamoto.

At least 1,153 records · Page 64Linked to original sources
PubMed1982

[Recurrent multiple cardiac myxomas: report of a case].

A case of recurrent multiple cardiac myxomas was presented. The patient was a 27-year-old housewife. Four years ago, she underwent urgent resection of a left atrial myxoma and replacement of the interatrial septum with a patch graft by right atrial approach. The tumor was very friable and a part of the tumor dropped into cardiac chambers during the operation, and immediately saline lavage and aspiration were performed. The recovery was uneventful. On March, 1981, she was readmitted to our hospital because of increasing dry cough. Two-dimensional echocardiography demonstrated abnormal masses in the right atrium, right ventricle, and left atrium. Open heart surgery revealed three independent tumors, which were successfully removed. All tumors were benign myxomas histologically. The patient returned to full-time housework again. A case of recurrent multiple myxomas has not been previously reported. The recurrence of the myxoma in our case is thought to be caused by implantation of tumor cells during the initial operative procedure. Our case will suggest the malignant potentiality of cardiac myxoma. The necessity of radical excision and gentle handling of the tumor during the operation are reemphasized. Postoperative follow-up study is also mandatory for early detection of the recurrence of this potentially malignant neoplasm.

Adult↗
PubMed1982

[Phonoechocardiographic study on the genesis of the initial low-frequency component of the first heart sound].

The high-frequency vibrations of the first heart sound (S1) have been reported to be associated with the closure of atrioventricular valves. However, the genesis of the low-frequency component (LFC) preceding S1 remains controversial. In order to investigate the genesis of the production of this LFC, we recorded phonocardiograms simultaneously with M-mode echocardiograms in 10 healthy subjects and 26 patients with various diseases including mitral valve replacement. The apical phonocardiograms were recorded using a 100 Hz/12 dB high-pass filter and a commercially available acceleration microphone. Patients with rheumatic mitral valve disease and bundle branch block were excluded from this study. The electrocardiograms demonstrated sinus rhythm in 23, atrial fibrillation in nine, complete atrioventricular block in two and atrial flutter in two. The P-R interval in sinus rhythm ranged from 130 to 200 msec. The LFC occurred an average of 24 msec after the QRS complex, but 38 msec before the first high-frequency component of S1. The final fast closing movement of the mitral valve echogram started following the onset of LFC in sinus rhythm or the arrhythmias. Coaptation of the mitral valve leaflets was coincident with the first high-frequency S1. In 23 cases with the visible tricuspid valve, the valve closure occurred 28 msec after that of the mitral valve. The onset of the LFC was almost synchronous in timing with, or very close (10 msec or less) to the initial upstroke of apex cardiograms simultaneously recorded in 10 cases. The amplitude of the LFC was constantly smaller than that of S1 in all cases, but it was variable in atrial fibrillation or complete atrioventricular block. The LFC became loudest after a short RR interval and then ventricular systole was coincided in time with the rapid filling of the left ventricle, or when atrial systole was very close in time to an expected time of ventricular systole. It is certain that antegrade mitral blood flow was decelerated at that time, though the mitral valve was in the rapidly closing process. We conclude that the LFC is produced by the vibration of cardiohemic system, or the acceleration of the left ventricular mass plus the deceleration of blood flow, and that atrial activity and atrioventricular valve tension are not prerequisite to the production of this soft apical vibration preceding S1.

Adolescent↗
PubMed1981

Effective timing for the application of orthopedic force in the skeletal class III malocclusion.

The purpose of this study was to investigate the most effective treatment timing with the chin cup in the treatment of the skeletal Class III malocclusion. The materials consisted of sixty-one cephalometric roentgenograms of seventeen males and forty-four females treated with the chin cup. Ages of children in the sample ranged from 3 years 11 months to 12 years 8 months at the beginning of active treatment. The A-B differences before and after treatment were measured to analyze the skeletal change that occurred. although the anterior cross-bite was corrected in all cases, the final values of the A-B differences were dependent upon the age treatment was started and the level of disharmony before treatment. The final values showed more improvement in the younger age group in the group with milder disharmony before treatment.

Age Factors↗
PubMed1981

Folic acid in serum and cerebrospinal fluid of chronic alcoholics and methamphetamine addicts.

The folic acid (FA) levels in serum and cerebrospinal fluid (CSF) of 39 chronic alcoholics, 15 methamphetamine addicts and 18 control subjects were determined using the technique of Lactobacillus casei assay. Twelve of the 39 alcoholics developed delirium tremens (DT) after determination of the FA level. The serum FA level of the alcoholics with DT was significantly lower than that of the controls, and showed a tendency to be lower than in the alcoholics without DT. The CSF FA of the DT group was significantly lower than that of the control group and of the alcoholics without DT. In the methamphetamine addicts, although the serum FA was significantly lower than that of the controls, the CSF FA remained unchanged. All the methamphetamine addicts demonstrated psychological dependence and tolerance development as did the alcoholics, but they did not show any physical dependence. From these results, a mechanism underlying the development of symptoms of physical dependence such as DT was discussed in relation to the CSF FA.

Adult↗
PubMed1981

Postural changes of vectorcardiogram in defect of the left pericardium.

Effects of postural changes upon the vectorcardiograms (VCGs) of four cases with a defect of the left pericardium (three complete and one partial) were compared to those of 115 control cases. Changes in the direction of a given instantaneous vector brought about by postural changes were significantly larger in cases with a pericardial defect than in controls. By turning to the left lateral position, the magnitude of the maximum leftward force decreased in all cases with complete defect, and increased in the case with partial defect and in 96% of controls. These findings were considered to reflect the increased mobility of the heart in cases with pericardial defect due to the lack of the restraining function of the pericardium.

Adolescent↗
PubMed1981

[Effects of bilateral mammillary bodies destruction on lever pressing for food reward in the rabbit (author's transl)].

Effects for continuous reinforcement (CRF) learning and differential reinforcement of low rate (DRL) learning for food in the rabbit by bilateral mammillary bodies destruction were examined with the Skinner box. There was no marked changes in general behavior, except a tendency to freezing by a sign of somebody and sounds. In CRF learning a delay in the start of bar pressing was thought to be due to a decrease in exploratory behavior and a decrease of the number of bar pressing may be due either to a delay of adaptation to a new environment, or to an impediment of learning by the decrease in rewarding effects. The acquisition of DRL learning was affected, but the retention of that was not. DRL learning has been generally remarked to be chiefly consisted of motivation and temporal discrimination. In our study, however, there was no remarkable changes in motivation itself and temporal discrimination was not affected at all. It was concluded that the impediment of acquisition depended upon a general decrease in cerebral rewarding effects.

Animals↗
PubMed1981

[Echocardiographic study of left ventricular motion in cases with acute left ventricular diastolic volume overload(author's transl)].

M-mode and two-dimensional echocardiography were performed to investigate the motion of the interventricular septum (IVS) and posterior wall (PW) in cases with pure mitral (MI) or aortic (AI) insufficiency. Subjects were classified into four groups; 15 cases with chorda rupture or floppy mitral valve (acute MI), four with AI of acute onset (acute AI), 17 with chronic MI including rheumatic MI, mitral valve prolapse syndrome, and 11 with chronic AI. There wee no differences of left ventricular dimension (LVDI), stroke volume (SV), ejection fraction (EF) and cardiac output (CI) between acute and chronic MI, and between acute and chronic AI, although LVDI and CI were increased in all groups. The ratio of the amplitude of IVS to PW excursion was significantly increased in cases with LV dilation due to acute MI or AI, compared with that in chronic MI or AI. This ratio had a linear relationship with LVDI in acute volume overload, but in chronic volume overload, it was constantly 1.0 or less. The mechanism of the increased septal motion in acute MI or AI is still unknown, but it appears to reflect the intact and contractile septum which adapts to volume overload more readily than the posterior wall. It is probably because the posterior wall is prevented from distension by the pericardium. On the other hand, in chronic MI or AI, vigorous septal motion would not be observed because of the occasional presence of relative tricuspid insufficiency, the effects of the long standing burden on the septal myocardium, and compensatory distension of the posterior wall and pericardium.

Adolescent↗
PubMed1981

[Jugular foramen neurinoma--report of a case (author's transl)].

A case of jugular foramen neurinoma was presented in detail with a review of fifty-seven cases reported in the literature. A thirty-six-year old man was admitted to the hospital with complaints of tinnitus and hearing loss in the right side with vertigo. Neuro-otological examination revealed the definite sensorineural hearing loss and the disturbance of vestibular function on the right. Cranial nerve palsy was not revealed except for the right eighth nerve. Craniotomogram and axial view showed enlargement of the right jugular foramen. CT, vertebral angiogram and pneumoencephalotomogram demonstrated a space taking lesion at the right cerebellopontine angle. By suboccipital craniectomy a walnut-size tumor was disclosed at the jugular foramen with total removal. However, the origin of the tumor was not confirmed. The post-operative course was uneventful and hearing loss was gradually improved.

Adult↗