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Biomedical subjects

C Tanaka

Publications and source records attributed to C Tanaka.

At least 415 records · Page 23Linked to original sources

Treatment of angina pectoris patients with niludipine a new calcium antagonistic drug.

The antianginal effectivity of niludipine (Bay a 7168), a new calcium antagonistic drug, was investigated in angina pectoris patients, selected for admission to the trials by pre-determined strict criteria. Oral administration of from 60--120 mg niludipine daily for 4--8 weeks, resulted in the following: 1. Number of anginal attacks significantly reduced. 2. Nitrate consumption markedly lowered. 3. Investigating physicians assessed globally the clinical results of niludipine treatment on the basis of the reduction of the number of anginal attacks, nitrate consumption, improved physical ability and reports by the patients as to their subjective evaluation of the test drug. Niludipine was judged clinically effective in 21 out of 27 patients (77.8%). 4. Full records of ECGs, a necessary item for assessment, were obtained from 24 out of 27 patients. Ischemic ECGs were improved or normalized in 6 out of 24 patients (25%). 5. In the investigators' final overall assessment, including the evaluation of ECG changes, niludipine was rated effective for 20 out of 27 patients (74.1%). 6. Tolerance to the test drug was excellent. Only one patient complained of transient, mild nausea. After reduction of the daily dose, the patient completed the trial without any further appearance or complaints of side effects. Results suggest that niludipine is a useful antianginal drug in the management of coronary artery disease patients. Further clinical investigations with a larger number of patients should be conducted.

Aged↗

[Assessment of hypertrophic cardiomyopathy by ECG gated cardiac computed tomography (author's transl)].

The applicability of ECG gated cardiac computed tomography (CT) in 12 patients with hypertrophic cardiomyopathy was examined. Six of the 12 patients had hypertrophic obstructive cardiomyopathy, including one patient with mid-ventricular obstruction. Three of the 12 patients had hypertrophic non-obstructive cardiomyopathy, and three had apical hypertrophic cardiomyopathy. The diagnosis of hypertrophic cardiomyopathy was confirmed by the angiocardiogram in all patients. Cardiac CT was performed after intravenous administration of contrast media usually given as a bolus injection. The gantry was set with positive 20 degree tilt angle. In all patients with hypertrophic obstructive cardiomyopathy except for mid-ventricular obstruction, the hypertrophied interventricular septum in the basal and mid portions was observed, and the left ventricular cavity was narrowed in systole. In a patient with mid-ventricular obstruction, the marked hypertrophied interventricular septum and antero-lateral papillary muscle were observed. In diastole, the left ventricular cavity was narrow and divided into two parts. The apical cavity was completely disappeared in systole. In all patients with hypertrophic non-obstructive cardiomyopathy, the diffuse hypertrophied interventricular septum was observed in diastole. In systole, the apical portion of the left ventricular cavity was markedly narrow and anterio-lateral papillary muscle was hypertrophic. In all patients with apical hypertrophic cardiomyopathy, the marked apical hypertrophy of the left ventricular wall was observed in diastole. It is concluded that ECG gated cardiac CT could estimate myocardial wall motion and thickness and differentiate the types of hypertrophic cardiomyopathy each other.

Adult↗

[Nuclear magnetic resonance studies on brain edema--time course of 1H-NMR relaxation times (author's transl)].

1. The state of water in normal and edematous brain tissue was studied by measurement of proton longitudinal (T1) and transverse (T2) relaxation times using pulsed nuclear magnetic resonance (NMR) technique. 2. In control rats, T1 and T2 of water showed one component, which was more fast in white matter. Those values displayed 1.07-1.18 sec. of T1 and 75-76 msec. of T2. 3. When rat brain was injured by cold, T1 was observed to become more longer (1.18-1.27 sec.), and T2 was observed to be separated into two components, the faster T2 (45-50 msec.) and slower T2 (100-105 msec.), in body gray and white matter of the injured side. 4. In triethyltin (TET) induced brain edema, elongation of T1 (1.2 sec.) and remarkable separation of T2, faster T2 (75 msec.) and slower T2 (400-450 msec.), were observed in white matter. 5. In both cold and TET induced edema, slower T2 fraction is suggested to be the extracellular space and faster T2 fraction, intracellular. 6. T2 changes precede the water content changes in cold injury, and parallel in TET induced edema. Those changes of relaxation times are reversible. 7. T2 changes of water is more sensitive than the T1 for the detection of production and disappearance of brain edema. 8. These results disclose the dynamic movements of water during the course of brain edema and offered significant information of the clinical application of NMR-CT.

Animals↗

[Application of two dimensional echocardiography for the intracardiac manipulation: the evaluation of atrial septal movement before and after balloon atrial septostomy (author's transl)].

Two-dimensional echocardiography was applied to intracardiac catheter manipulation (especially balloon atrial septostomy: BAS) in 6 babies with complete transposition of the great arteries and 2 with total anomalous pulmonary venous drainage. Under the usual roentgenoscopic investigation, intracardiac catheter manipulation was observed by two-dimensional echocardiography directly representing the right atrium, left atrium, atrial septum, right ventricle, left ventricle and interventricular septum by the subcostal approach. Also, formation and movement of the atrial septum and intra-atrial shunt before and after BAS was evaluated by contrast echocardiography. 1. It was confirmed that the catheter tip was inserted into the left atrium from the right atrium. 2. It was clearly demonstrated that the balloon was expanding in the left atrium. 3. When the balloon was pulled out to the right atrium from the left atrium, the movement of the atrial septum and the balloon was observed. 4. The formation and movement of atrial septal defect by BAS was demonstrated and the shunt of this site was estimated by using contrast echocardiography. The relation between the catheter tip and the intracardiac structures can be judged more correctly by two-dimensional echocardiography than roentgenoscopic investigation. Also the structural and hemodynamic changes by BAS can be clearly estimated by the observation of the atrial septum by two-dimensional echography.

Cardiac Catheterization↗

[Clinical usefulness of RI angiography using amplitude image and phase image by Fourier analysis for the detection of anteroseptal myocardial infarction (author's transl)].

In 19 patients with anteroseptal myocardial infarction, the wall motion of interventricular septum was analyzed by RI angiography using the amplitude image and the phase image. Both images were obtained from ECG gated blood pool data by Fourier analysis. Namely, from the first harmonic in the Fourier series, the heart motion was detected as the amplitude and phase of time-activity curve in each pixel. The distribution of the amplitudes and phases were displayed in color scale, and then both the amplitude and phase images were acquired. Those images allowed us visualization of the ischemic area, even if the scar was parallel to the detector. Moreover, we were able to assess the wall motion of the entire interventricular septum and to distinguish hypokinetic region and dyskinetic region from the hypokinetic region with shift of phase estimated by conventional method. Abnormal region detected by those images closely corresponded with the region of decreased radioisotope concentration in thallium-201 myocardial scintigram.

Adult↗

[Evaluation of myocardial infarction by ECG gated cardiac computed tomography (author's transl)].

ECG gated cardiac computed tomography (cardiac (T) was performed in 9 cases with old myocardial infarction. Seven of these had anterio-septal infarction, one had inferior wall infarction and the remaining one had posterior wall infarction. All were investigated by left ventriculography and coronary arteriography. Cardiac CT was performed after intravenous administration of contrast medium usually given as a bolus injection. The infarcted myocardium was thin and showed abnormal wall motion in cardiac CT, but the motion did not always coincide with left ventricular cineangiographic findings. In 3 cases, mural thrombi at the left ventricular apex were observed by cardiac CT, and in 2 of which the thrombi were confirmed by left ventriculography. In 2 cases, cardiac CT showed stasis of contrast medium and aneurysmal formation in the left ventricular cavity and the aneurysms were confirmed by left ventriculography. Sequential 8 mm thick non-ECG gated cardiac CT scans from the cardiac apex to the base were performed in 7 cases with anterio-septal infarction, and the infarcted area were observed in the anterior interventricular septum in 6 cases. We concluded that cardiac CT was a useful noninvasive method to detect abnormal wall motion, abnormally thin wall, mural thrombus and left ventricular aneurysm in old myocardial infarction.

Adult↗

Immunohistochemical localization of cyclic nucleotides in guinea pig lip.

The cellular localization of cAMP and cGMP in the guinea pig lip was investigated with an indirect immunofluorescence technique. cAMP was distributed both in cell membranes and cytoplasmic elements with coarse and granular intranuclear fluorescence, while cGMP was localized in nuclear sites including nuclear membranes as well as cell membranes and cytoplasm. In the basal portion, both cAMP and cGMP fluorescence was weaker in cytoplasm and cell membranes than seen in the upper portion.

Animals↗

Adrenergic innervation in the Eustachian tube of guinea pigs.

We have succeeded in demonstrating for the first time adrenergic innervation in the Eustachian tube of guinea pigs. The approach was histochemical using the fluorescence method with glyoxylic acid. There was an apparent regional variation with a greater number of axon terminals in the pharyngeal area of the Eustachian tube as compared to the tympanic area.

Adrenergic Fibers↗

Significance of central noradrenergic system on harmaline induced tremor.

Since there is degeneration of substantia nigra concomitant with that of locus coeruleus (LC) in patients with Parkinson's disease, the study was performed to determine the role of central norepinephrine (NE) on harmaline induced tremor. The duration of harmaline (10 mg/kg IP) induced tremor was significantly reduced by intraventricular administration of L-thero-3,4-dihydroxyphenylserine (200 micrograms/rat) and 1-NE (50 micrograms/rat) was increased NE levels in the cerebral cortex, striatum, diencephalon, cerebellum and brain stem. Electrical stimulation of bilateral LC suppressed harmaline-induced 10-12/sec EMG activities in the neck muscle. Bilateral LC lesion upon electrocoagulation and 6-hydroxydopamine treatment resulted in a significant prolongation of the duration of harmaline induced tremor, reducing NE levels in the brain. These data suggest that central NE originating in the LC neurons has an inhibitory effect on the development of the tremor induced by harmaline.

Alkaloids↗

Cyclic adenosine 3',5'-monophosphate levels in response to norepinephrine in rectum of postnatal rats.

Age-related changes in cyclic adenosine 3',5'-monophosphate levels in response to norepinephrine (NE) in the rectum of postnatal rats and the localization of cyclic AMP in the rectum were studied. During the first 2 weeks after birth, the basal levels of cyclic AMP were high, NE responses to cyclic AMP contents were minimal and thereafter, the basal cyclic AMP levels rapidly declined, while NE response significantly increased compared to those seen in tissues from adult rats. Furthermore, cyclic AMP immunofluorescence was visualized in smooth muscle and postganglionic neurons of the myenteric plexus. NE application produced an increase of cyclic AMP immunofluorescence in smooth muscle. These results indicate that NE response to cyclic AMP levels in rat rectum is age-dependent and suggest that the majority of beta-adrenoceptors associated with cyclic AMP generating system are localized in the smooth muscle of rat rectum.

Adrenergic beta-Antagonists↗

Presystolic pulmonary valve opening in constrictive pericarditis.

Right heart pressure tracings were studied in 5 cases with constrictive pericarditis. The pressure of the A-wave in the right atrium of these cases was higher than the pulmonary arterial diastolic pressure. In addition, a presystolic wave appeared in the pulmonary arterial and the right ventricular pressure tracings, in coincidence with atrial systole. The pressure of this presystolic wave was similar to that of the right atrial A-wave. This suggests that the pulmonary valve opens following atrial systole, and then the blood flows into the pulmonary artery in the presystolic phase in patients with constrictive pericarditis. In 2 cases, pulmonary valve echograms were recorded. The a-dip in these 2 cases was as deep as 8.4 mm and 9.6 mm (1.8-4.1 mm with a mean of 2.80 mm for normal men), and its duration was prolonged to 0.17 sec and 0.18 sec (0.10-0.13 sec with a mean of 0.115 sec for normal men). In conclusion, such a deep and prolonged a-dip on pulmonary valve echogram is presumably a sign of presystolic pulmonary valve opening.

Adult↗

Adrenergic innervation and cyclic adenosine 3':5'-monophosphate levels in response to norepinephrine in stomach of postnatal rats.

Changes in receptor function, innervation and cyclic adenosine 3':5'-monophosphate (cAMP) levels in response to norepinephrine were investigated in the stomach of postnatal developing rats. We found that although the beta adrenergic receptor function and responsiveness of cAMP-generating system to norepinephrine are present in the early postnatal stage (3-day-old), these systems are not fully developed at birth and that increase in sensitivity comes with age. Adrenergic innervation is present at birth in Auerbach's plexus but not in smooth muscle, during the 1st postnatal week. Direct adrenergic innervation to smooth muscle appears 1 week after birth and matures during the first 4 weeks. This maturation of direct adrenergic innervation runs in parallel with the increased sensitivity of beta receptors and is accompanied by an elevated responsiveness of the cAMP-generating system to norepinephrine.

Acetylcholine↗