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Biomedical subjects

S Hashimoto

Publications and source records attributed to S Hashimoto.

At least 1,135 records · Page 63Linked to original sources
PubMed1986

[Effect of age on left ventricular relaxation: pulsed Doppler echocardiographic evaluation].

There is no noninvasive index to assess the left ventricular relaxation property during the isovolumic relaxation period except for the isovolumic relaxation time, which is derived from M-mode echocardiography or phonocardiography. The intracardiac blood flow can now be precisely observed using pulsed Doppler echocardiography. We evaluated the left ventricular relaxation property and studied the effect of age on the relaxation property using this method. Cardiac catheterization and pulsed Doppler echocardiography were performed for 27 patients with various heart diseases, none of whom had wall motion abnormalities on left ventriculography, to determine the relationships between invasive and noninvasive parameters. The effects of age were examined in 25 normal healthy persons ranging in age from 26 to 69 years. In all cases, the intracardiac blood flow during the isovolumic relaxation period (isovolumic relaxation flow) as obtained by pulsed Doppler echocardiography was laminar, and directed from the base toward the apex of the left ventricle. The duration of this flow (the time interval from the beginning to the end of this flow; IRT), the acceleration time (the time interval from the beginning to the peak velocity; ACT) and the acceleration rate (the slope of the beginning to the peak velocity; AcR) were measured, and IRT, ln AcT (natural logarithm of AcT) and ln AcR (natural logarithm of AcR) were compared with the parameters obtained by cardiac catheterization. The time constant T of the fall in left ventricular pressure during the isovolumic relaxation period, which was proposed as an index of the left ventricular relaxation property, correlated well with IRT (r = 0.82, p less than 0.001), ln AcT (r = 0.69, p less than 0.001) and ln AcR (r = -0.77, p less than 0.001), but there were no significant correlations with maximum blood pressure, left ventricular ejection fraction, maximal positive dp/dt or the left ventricular end-diastolic volume index. Age and these three Doppler indexes in normal healthy persons correlated significantly as follows; IRT (r = 0.80, p less than 0.001), ln AcT (r = 0.60, p less than 0.001) and ln AcR (r = -0.61, p less than 0.01).(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1986

[The role of computed tomography in the diagnosis and treatment of malignant tumors of the nasal cavity, paranasal sinuses and nasopharynx].

We studied the value of computed tomography (CT) in diagnosis and treatment of primary malignant tumors of the sinonasal cavities and nasopharynx, and reached the following conclusions. 1) In maxillary carcinomas, bone destruction is always seen on CT. When bone destruction is not apparent despite invasion to the adjacent site, malignant lymphoma or plasmacytoma is suggested. 2) In defining the tumor extent of maxillary SCC, CT is more reliable than maxillotomy, and is equal to maxillectomy. However, clouding of the sinus without bone destruction remains a problem, since this finding can be caused by either tumor invasion or obstructive sinusitis. 3) In maxillary and nasopharyngeal SCC, CT frequently reveals tumors to be more extensive than previously suspected following physical and conventional x-ray examinations. Therefore, the T-stages of these tumors are often upstaged to more advanced ones. 4) CT is of great help in identifying candidates for surgery in maxillary SCC, and in planning radiation therapy for nasopharyngeal and sinonasal tumors. Dose distribution curves displayed directly on the CT slices are becoming essential tools for radiation oncologists. After the introduction of CT, treatment results in cases of nasopharyngeal SCC have improved, probably due to better definition of the tumor volumes. 5) CT is also used for observing tumor response after therapy and for follow-up. In summary, CT is now indispensable in the management of malignant tumors of these sites.

Diagnosis, Differential↗
PubMed1986

Assessment of mucociliary clearance in patients with tracheobronchoplasty using radioaerosol.

To assess mucociliary clearance in patients with tracheobronchoplasty, radioaerosol inhalation scanning was performed in 14 patients. The unilateral total lung clearance curve was fitted into two compartmental curves, fast and slow, by least-squares techniques in order to assess mucociliary clearance of the bronchial tree quantitatively. Half-time (T 1/2) of the curve resulting from the subtraction of the slow compartment curve from the fast compartment curve was calculated. The mucociliary clearance of the bronchial tree post so-called lobectomy (N = 5) was intact (T 1/2; 13.1 +/- 7.3 min). On the other hand, the mucociliary clearance of the bronchial tree postreconstruction (N = 14) was prolonged (T 1/2; 28.3 +/- 10.6 min), compared with that of the control bronchial tree (N = 15, T 1/2; 11.9 +/- 3.9 min) (p less than 0.01). However, the mucociliary clearance of the bronchial tree postreconstruction showed improvement with the passage of time, and the original clearance was regained 5 to 12 mo after the operation. Radioaerosol inhalation studies revealed both the degree of impairment and the recovery time of mucociliary clearance in patients post-tracheobronchoplasty.

Adult↗
PubMed1986

Species difference in the muscarinic receptors of thoracic aorta.

Muscarinic receptors in rabbit aortic membranes were characterized by binding assays using I-[3H]quinuclidinyl benzilate, and compared with muscarinic receptors in dog and bovine aortas. In the rabbit aortic membranes, I-[3H]quinuclidinyl benzilate specifically bound with high affinity (KD = 28.1 pM) to a single class of sites (maximum number of binding sites = 57.2 fmol/mg of protein) which have characteristics of muscarinic receptors. Drug competition curves indicated a single class of binding sites for antagonists (e.g., K1 = 160 nM for pirenzepine), but suggested the presence of two affinity binding sites (or states) for agonists (e.g., K1 = 8.29 nM and K2 = 0.32 microM for oxotremorine, respectively). I-[3H]quinuclidinyl benzilate also bound to a single class of sites in the membranes of dog and bovine aortas, with similar affinities to the case of rabbit aorta. But the maximum number of binding site values were significantly lower than the value in the rabbit aorta. Furthermore, bovine aorta exhibited a higher affinity (K1 = 8.7-22.3 nM) for pirenzepine, but a lower affinity (K1 = 0.62-1.46 microM) for oxotremorine, as compared with rabbit and dog aortas. Accordingly, muscarinic receptors in the aorta are different between animal species, regarding its density and interactions with muscarinic agents. The receptors in bovine aorta may be M1-subtype but receptors in rabbit and dog aortas may be relatively M2-subtypes.

Animals↗
PubMed1986

[A survey of clinical applications of the remote afterloading machine in Japan].

This survey was performed to ascertain how usefully the remote afterloading machine with small radiative sources has been applied. The following results were obtained through questionaires sent to 147 hospitals in Japan: These machines are mainly used for the treatment of uterine cervix cancer, and the three channels of 60Co sources are mostly used with high dose-rate. The frequency of the treatment is 50-200 times per year in 60% of the hospitals. In only 15 hospitals is this machine routinely used for malignant tumors of the nasopharynx, paranasal sinuses, esophagus and bile tract as well as uterine cervix cancer. It is important to develop various kinds of accessories for the remote afterloading machine with high dose rate, in order to its extend the applications.

Brachytherapy↗
PubMed1986

[Isovolumic relaxation flow patterns evaluated by pulsed Doppler echocardiography: comparison with invasive parameters].

Left ventricular relaxation property was evaluated by pulsed Doppler echocardiography. The indices obtained from Doppler signals within the left ventricle (LV) during the isovolumic relaxation period (IRF) were compared with the hemodynamic parameters obtained from cardiac catheterization studies. Subjects of this study were four patients with hypertrophic cardiomyopathy, four with hypertensive heart disease, three with angina pectoris, and seven normal subjects. All of them had no wall motion abnormalities and their ejection fractions were more than 0.60. The three indices of IRF were the time interval from the start of IRF to the time immediately before the rapid filling flow (isovolumic relaxation time; IRT), the time interval from the start to the peak (acceleration time; AcT), and the slope from the start to the peak (acceleration rate; AcR). The peak pressure (peak P) was measured at the same time. The positive and negative deflections of the first derivative of left ventricular (LV) pressure (+dp/dt and -dp/dt) and the time constant of LV pressure fall (time constant T) were calculated from LV pressure using a micromanometer-tipped angiocatheter. The end-diastolic volume index (EDVI), end-systolic volume index (ESVI), and ejection fraction (EF) were calculated from the LV angiogram. There were no significant correlations between the three IRF indices (IRT, AcT and AcR) and the hemodynamic parameters (peak P, EDVI, +dp/dt and -dp/dt). However, the time constant T, which is a good index of LV relaxation property and which is relatively free from afterload and preload, correlated well with IRT (r = 0.75, p less than 0.001), AcT (r = 0.60, p less than 0.01), and AcR (r = -0.66, p less than 0.01). It was concluded that the indices obtained from the blood flow patterns of the left ventricle during isovolumic relaxation were useful for estimating left ventricular relaxation property non-invasively and quantitatively.

Adult↗
PubMed1986

[A clinical study of primary hyperparathyroidism].

Eight cases of primary hyperparathyroidism (P-HPT) confirmed pathohistologically, between April, 1974 and January, 1986 at our department, were reviewed. The patients consisted of three males and five females, ranging in age from 38 to 62 years old with an average of 50.3 years. All the cases belonged to the urolithiasis type and seven patients were recurrent or/and multiple stone-formers. Positive rates of the laboratory values studied in relation with P-HPT were 100% in serum Ca, C terminal parathyroid hormone, and % TRP, 87.5% in urine Ca, 75% in serum Cl/P ratio, alkaliphosphatase, 50% in serum Cl, 37.5% in serum P and 0% in urine P. Seven cases had clinically apparent hypercalcemia, while one was a so-called borderline P-HPT with intermittent hypercalcemia. The correct diagnosis of the localization was obtained preoperatively in two cases by angiography and one by C.T and Tl-Tc subtraction scintigraphy. Histological findings of the tumors extirpated by the cervical operation were parathyroid adenomas in six cases and hyperplasia in two. During the course of the postoperative follow up, hypercalcemia and urolithiasis did not recur in any case including two of hyperplasia.

Adult↗