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Biomedical subjects

T Sakamoto

Publications and source records attributed to T Sakamoto.

At least 1,117 records · Page 62Linked to original sources
PubMed1983

[Aerosol administration of dibekacin--the sputum concentration].

Serum concentrations of dibekacin (DKB), sisomicin (SISO) and gentamicin (GM) were measured in 3 rabbits after intratracheal administration through the transtracheal teflon tube. The peak serum levels (average) were 106 micrograms/ml (administrated 100 mg DKB for injection), 148 micrograms/ml (administrated 100 mg DKB solution), 166 micrograms/ml (administrated 100 mg SISO solution) and 80 micrograms/ml (administrated 80 mg GM solution). Serum concentrations and urine excretions of DKB were measured in 3 volunteers after aerosol administration using ultrasonic nebulizer. The peak serum levels (average) were 4.6 micrograms/ml (administrated 100 mg DKB for injection) and 3.1 micrograms/ml (administrated 100 mg DKB solution). The urine excretions (average) were 3.7 mg and 4.3 mg respectively during 6 hours. Before and after administration of DKB aerosol the spirogram and flow-volume curve were examined in the volunteers. But the examinations showed no changes. Sputum concentrations were measured in 1 patient with chronic bronchobronchiolitis after administration of DKB aerosols using the ultrasonic nebulizer. The highest sputum concentration was acquired immediately after nebulization and the sputum levels decreased gradually while time passed. Six patients with the lower respiratory tract infections were treated with DKB aerosol therapy and the utility rate was 80%.

Adult↗
PubMed1983

[Detection of coronary sinus by parasternal two-dimensional echocardiography and the clinical significance].

To investigate the potential of a new method for detecting coronary sinus (CS), two-dimensional (2-D) echocardiography was satisfactorily performed on 80 consecutive cases, of which the coronary sinus was detected in 74 by adopting parasternal three-chamber approach. These 74 cases were classified into four groups; 25 normal individuals, 7 patients with atrial septal defect (ASD) but without tricuspid insufficiency (TI), 13 with TI and 29 with other cardiac diseases. We measured diastolic maximum diameter of CS on 2-D echocardiograms. The mean diameter of the CS was significantly increased in ASD (9.0 mm) and TI (12.4 mm) comparing with normal control (6.7 mm). The enlargement of CS seemed to correlate with right-sided volume overload. Although there were three exceptional cases, we could observe the CS during the whole cardiac cycle only in patients with TI. We conclude that CS is excellently detected in over 90% of cases by a new parasternal approach and that the diameter of CS would be a new screening index of right-sided volume overload.

Adolescent↗
PubMed1983

[Generalized lentigo in a case of hypertrophic cardiomyopathy with right ventricular outflow tract obstruction].

A case was reported in which generalized lentigo was associated with hypertrophic cardiomyopathy and right ventricular outflow tract obstruction. A 34-year-old man was admitted to our hospital for cardiac evaluation. He had been noted to have a heart murmur since his childhood and had had a diagnosis of pulmonary stenosis in his high school age. Physical examination revealed precordial murmurs and numerous lentigines over his whole body surface including palms and soles. Two-dimensional and M-mode echocardiography disclosed asymmetric septal hypertrophy, systolic anterior motion of the mitral valve (SAM) and systolic semiclosure of both semilunar valves. A systolic turbulent flow was recorded at the outflow tracts of both ventricles by pulsed Doppler technique. Cardiac catheterization demonstrated a pressure gradient of 13 mmHg across the right ventricular outflow tract. We considered that the present case was an atypical LEOPARD syndrome with predominant right ventricular outflow tract obstruction which was precisely evaluated by noninvasive techniques.

Adult↗
PubMed1982

Immature precursor catalase in subcellular fractions of rat liver.

Dialysis of the peroxisomal extract, microsomal extract and cytosol fraction of rat liver against a solution containing 44 mM acetate buffer, pH 4.1, and 22% ethanol resulted in elimination of immature and enzymatically inactive catalase as insoluble precipitates, leaving mature and active catalase in solution. These catalase molecules in the three different subcellular compartments were doubly labeled with injected radioactive amino acids, for 30 min with [3H]leucine and for 90 min with [14C]leucine. The specific radioactivities of peroxisomal catalase remained unchanged upon the dialysis described above. This was also the case with microsomal catalase, however, the values were much higher than those of peroxisomal catalase. On the other hand, cytosol catalase showed remarkably decreased radioactivities after the dialysis, which were comparable to those of peroxisomal catalase, and the immature and inactive catalase which had been removed by this treatment was estimated to be as highly radioactive as the microsomal catalase. By affinity chromatography using anticatalase antibody both the microsomal extract and cytosol fraction were found to contain enzymatically inactive and probably immature catalase, which did not occur in peroxisomal extracts. However, when examined by SDS-polyacrylamide gel electrophoresis, the catalases in the three different subcellular fractions gave identical single bands corresponding to the monomer subunit of this enzyme protein, and no other larger molecule was detected. It was also found that the peroxisomal mature catalase did not migrate in polyacrylamide gel electrophoresis the same as that in microsomes and in cytosol, the latter two exhibiting the same mobility. Based on these results and others previously obtained, intracellular events in the maturation and transfer of newly synthesized catalase are discussed.

Animals↗
PubMed1982

Detection of tricuspid regurgitation by contrast echocardiography.

Contrast echocardiography with simultaneous M-mode echocardiography was performed in 77 cases of tricuspid regurgitation (TR) and 168 cases having no TR (non-TR). The echocardiographical characteristics of TR were as follows: 1) By the subxiphoid approach, a contrast appeared in the inferior vena cava during systole. In some cases of non-TR, a similar appearance was noted but limited to the atriosystolic or late systolic-to-early diastolic phases. Such confusing cases should be excluded by the simultaneous observation of the M-mode contrast echogram. 2) By apical four-chamber view, a negative contrast echo above the tricuspid valve and subsequent back and forth movements of the contrast across the valve were useful. This movement, however, may be misleading on two-dimensional echo and the M-mode echocardiogram was also necessary to obtain the exact timing and the direction of regurgitant flow. 3) Presence of the dilated inferior vena cava. The sensitivity of this method was extremely high, and the specificity was also excellent for TR.

Adult↗
PubMed1982

Pacing echocardiography: regional wall motion, left ventricular dimension and R wave amplitude in patients with angina pectoris.

In view of the fact that stable echocardiograms are easily obtained during atrial pacing, pacing echocardiography was performed to evaluate the usefulness for detecting regional wall motion abnormalities during pacing-induced ischemia and to investigate the relationship between changes in the R wave and left ventricular dimension. The patients were 12 cases of angina pectoris (10 of coronary artery disease; CAD, and 2 of coronary patent aortic valvular disease; AVD) and 6 control cases. Simultaneous recording of two-dimensional and M-mode echocardiograms and electrocardiograms was done before, during and after the atrial pacing at increasing heart rate until angina appeared or the heart rate of at least 140/min was reached. In 12 angina cases, angina and ST depression were induced in 10 and 11, respectively. Excursion of the interventricular septum (IVS) decreased during pacing-induced ischemia in 6 of 7 CAD cases, in which the left anterior descending coronary artery was significantly stenosed (more than 75%). Excursion of the left ventricular posterior wall (LVPW) decreased during pacing-induced ischemia in 4 of 7 CAD cases, in which the vessels giving rise to posterior descending coronary artery were significantly stenosed (more than 75%). In 2 AVD cases, excursion of both IVS and LVPW decreased during ischemia. Left ventricular end-diastolic dimension (LVEDD) increased in only 2 angina cases, although R wave amplitude increased in 6 angina cases.

Adult↗
PubMed1982

Effects of acute changes in left ventricular size on surface potential in man.

Effects of cardiac size on surface potential magnitude were investigated by induction of acute changes in ventricular dimensions by rapid atrial pacing in 17 cases with ischemic heart disease (IHD) and in 15 cases without IHD. Left ventricular end-diastolic dimensions (LVDd), estimated by echocardiography, decreased along with certain changes in surface potential magnitude during atrial pacing in each case. A positive correlation between LVDd and the amplitudes of RV5, RX, and the maximum spatial QRS magnitude was observed in most of the cases and might be explained by changes in distance between the heart and the chest electrode and/or the Brody effect. However, an inverse correlation was observed in 4 of 17 cases with IHD, and could not be explained by these factors. Other factors, such as changes in the ventricular activation sequence, should be considered as the mechanism.

Adult↗