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Biomedical subjects

Y Yazawa

Publications and source records attributed to Y Yazawa.

At least 91 records · Page 5Linked to original sources
PubMed1983

Progression of Wenckebach type A-V block to high degree A-V block in aged man.

This case report describes a 60 years old male with Wenckebach A-V block which progressed to high degree A-V block. Syncope and dizzy attacks were attributed to high degree A-V block in the study of ambulatory ECG (Holter). Wenckebach point was low; 90 bpm when the right atrium was paced. At 140 bpm, 2:1 A-H block with intermittent alternating and high degree A-H block were induced. Furthermore, a very wide His potential was recorded during the electrophysiological study. He received a permanent pacemaking. Since Wenckebach type A-V block is usually regarded as benign, this case seems to be rare.

Atrioventricular Node↗
PubMed1983

[Effect of regional phase delay on left ventricular performance studied by radionuclide angiography].

When cardiac hypokinesis in myocardial infarction is analyzed by means of phase analysis of radionuclide (RI) angiography, there are some cases in which the amount of regional wall movement of the left ventricle does not so decline, but the phase delay of regional wall movement is great. Hence, a simulation experiment was performed with a computer to evaluate the influences of regional phase delay on cardiac work. It was assumed that the radius of the model of the left ventricle varies from 3 cm in the late diastolic phase to 2 cm in the late systolic phase, and that in the initial 1/3 time of diastole, the radius alters by 90% of the change. One cardiac cycle (360 degrees) was divided into 60 fractions (1 fraction = 6 degrees), 0 degree being the end of diastole and 180 degrees the end of systole. An ischemic area was supposed to cover S% of the whole volume of the left ventricle, its amount of regional wall movement being P% of the normal area, and the phase delay being R degrees. By varying S, P and R, and taking weighted means of volume curves and normal ones, their assumed volume curves of the left ventricle were computed. Stroke volume (SV) and ejection fraction (EF) obtained from these curves were compared to those obtained from the normal curves, and were expressed in percentage (%SV, %EF). The influences of the changes of S, P and R on the volume curve and on the cardiac work were examined. Then the count curves of the left ventricle (LV) were obtained by gated RI angiography in 22 cases of myocardial infarction and 8 healthy controls, and LV regional wall movements were examined by means of the Fourier analysis. The circular volume was partitioned from the center into eight sections on the LV image of LAO 45 degrees, and the amount of wall movement and the phase delay of each section were evaluated from the count curves of each section. The following results were obtained. %SV and %EF declined with sole occurrence of regional phase delay. Occurrence of the regional phase delay flattened the slope of the volume curve of the initial diastolic phase and formed shoulders on this curve. This was observed also on the count curves actually determined from cases with myocardial infarction. When regional wall movement was markedly decreased, the influence of the regional phase delay on the pattern of the volume curve was slight even if the phase delay was extensive.(ABSTRACT TRUNCATED AT 400 WORDS)

Aged↗
PubMed1983

[Characteristic findings of mitral valve and mechanism of mitral valve prolapse in Marfan syndrome].

To elucidate the mechanism of generation of mitral valve prolapse (MVP) in Marfan syndrome, we studied the relations of the length of the anterior mitral leaflet to the diameter of the mitral ring. In 13 cases of Marfan syndrome associated with MVP (Group I), 21 of isolated MVP (Group II), and 24 controls free from valvular disease (Group C), the maximal length of the anterior mitral leaflet (L) and the end-diastolic and end-systolic diameters of the mitral ring (Rd and Rs) were measured in the long-axis views on two-dimensional echocardiograms. In addition, the measurements were corrected with the body surface area; designated as L(c), Rd(c) and Rs(c), respectively. Furthermore, L/Rd and L/Rs, and the percentage of shortening of the mitral ring in systole, (Rd-Rs)/Rd X 100, were obtained. The body surface area in Group I was greater than that in Group II (p less than 0.05), but there was no significant difference between Groups II and C. The L was obviously different between Groups I and II or C (p less than 0.001, respectively). Similarly, there was a significant difference in L(c) between Groups I and II (p less than 0.02) or C (p less than 0.001), indicating the remarkably long anterior mitral leaflet in Group I. The Rd in Group I and II was greater than that in Group C (p less than 0.01 and p less than 0.02, respectively), while there was no significant difference in the Rd(c) among the 3 groups. There was also no statistical difference in either Rs or Rs(c) among the 3 groups. Both L/Rd and L/Rs in Group I were remarkably higher than those in Groups II and C (p less than 0.001, respectively), whereas these parameter did not differentiate Group II from Group C. (Rd-Rs)/Rd X 100 was higher in Group I than that in Groups II and C (p less than 0.05 and p less than 0.01, respectively), but it was not significantly different between Groups II and C. These results suggested that one of the probable mechanisms of generation of MVP in Marfan's syndrome is the redundant mitral valve resulting from a remarkably long leaflet and increased systolic shortening of the enlarged mitral ring.

Adolescent↗
PubMed1983

[Mitral valve prolapse in the heart with pressure overload of the right ventricle].

The prevalence of mitral valve prolapse (MVP) was examined in 16 patients with right ventricular pressure overload with a peak systolic pressure ranged from 60 to 204 mmHg (Group 1; 9 cases of primary pulmonary hypertension and 7 cases of pulmonary valve stenosis), and the clinical and echocardiographic data were compared to those of 12 patients with idiopathic MVP (Group 2) and 10 healthy persons (Group 3). MVP was defined when either or both of the mitral valve leaflets protruded into the left atrium beyond the plane of the mitral ring, and "gap" was defined as positive when one of the leaflets of the mitral valve slipped 3 mm or more without prolapse toward the left atrium than the other leaflet. Eccentricity of the left ventricle was obtained from the cross-sectional view of the left ventricle at the mid-ventricular level: the ratio of the internal diameter (S) passing through the mid-point of the interventricular septum (IVS) and perpendicular to the IVS divided by the longest internal diameter (L) parallel to the IVS, at end-diastole (S/L(d] and at end-systole (S/L(s], respectively. The following results were obtained. MVP was found in seven cases of 16 patients (43.8%) of Group 1. Two cases had positive "gap" (12.5%). Eccentricity of the left ventricle in Group 1 (S/L(d) 0.81 +/- 0.12, S/L(s) 0.78 +/- 0.15) was more marked than that of Group 2 (S/L(d) 0.98 +/- 0.09, S/L(s) 1.02 +/- 0.06) or of Group 3 (S/L(d) 1.03 +/- 0.08, S/L(s) 1.00 +/- 0.04) (p less than 0.001 in each).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1983

[Left ventricular regional wall motion after correction of tetralogy of Fallot].

Cardiac function and left ventricular regional wall motion were examined using two-dimensional echocardiography in 40 post-operative patients of tetralogy of Fallot (TOF) of an average of 13 years after the correction. From the data of treadmill exercise test and cardiac catheterization, patients were classified into two groups; cases with complete ability for treadmill test (Group A, n = 22), and disabled for the test and the right ventricular systolic pressure above 50 mmHg (Group B, n = 18). Compared with the control group (n = 10), the patient groups had greater cardiothoracic ratios (CTR) and right/left ventricular dimensions (RVd/LVd) (p less than 0.001), and Group B had a greater CTR and RVd/LVd than Group A (respectively p less than 0.001). Compared with the control group, the patient groups had no significant differences in corrected ejection time, fractional shortening and mean velocity of circumferential fiber shortening, and no difference was noted between Group A and Group B. Left ventricular regional wall was divided into 12 segments around the left ventricular circumference on the two-dimensional short-axis view and the regional wall motion was evaluated on the basis of [(diastolic-systolic)/diastolic left hemiaxial length X 100%] values. In Group B, akinetic or dyskinetic wall motion was visualized at the interventricular septum and left ventricular posterior wall, but there was no abnormal motion in the control group and Group A. We concluded that even in postoperative patients with preserved cardiac function at rest, some of them had abnormal left ventricular regional wall motion due to the persistent right ventricular overload or corrective patch, resulting in low exercise capacity.

Adolescent↗
PubMed1981

Light chains of abalone myosin. UV absorption difference spectrum and resensitization of desensitized scallop myosin.

1. Abalone myosin consisted of one kind of heavy chain and two kinds of light chain according to SDS gel electrophoresis. The molecular weights of the light chains were estimated as 16,600 daltons (Light Chain-1: LC-1) and 14,500 daltons (Light Chain-2: LC-2). 2. The amino acid composition of LC-2 was not appreciably different from that of LC-1 except that the valine residue was 1 mol per mol of LC-2. 3. both LC-1 and LC-2 showed a calcium-induced UV absorption difference spectrum through the apparent binding constants for Ca2+ were low (2.5 x 10(-3) M for LC-1 and 3.2 x 10(-4) M for LC-2). 4. The modification of carboxyl groups of LC-2 by 1-ethyl-3(3-dimethylaminopropyl)carbodiimide caused the disappearance of the calcium-induced UV absorption difference spectrum. 5. Manganese ion could also induce a UV absorption difference spectrum with these light chains although the concentration of Mn2+ required to produce the difference spectrum was very high. 6. Abalone LC-2 bound to desensitized scallop myosin and restored the calcium sensitivity of the myosin but LC-1 did not.

Actomyosin↗
PubMed1981

Electron microscopic studies of the endolymphatic sac in Ménière's disease.

Five specimens of the endolymphatic sac taken from patients with Ménière's disease during epidural drainage surgery were examined under the electron microscope. The clinical history and histopathological findings are presented. The most common and prominent finding was perisaccular fibrosis of the endolymphatic sac which appears to disturb the free absorption of endolymph in the endolymph in the endolymphatic sac resulting in endolymphatic hydrops. Well-preserved epithelial cells of the endolymphatic sac could only be found in one of the specimens.

Aged↗
PubMed1981

[Regional wall motion of the left ventricle in congestive cardiomyopathy: in comparison with progressive muscular dystrophy of Duchenne type (author's transl)].

The features of regional wall motion abnormalities of the left ventricle were analysed in 11 patients of congestive cardiomyopathy (CCM) in comparison with 22 patients of progressive muscular dystrophy (DMD) of Duchenne type who showed an abnormal motion of the left ventricle by echocardiography. Real time two-dimensional echocardiographic study demonstrated the following results: I) In CCM, (1) only 2 or less of 11 cases preserved a normal motion in each left ventricular segment, and the depression of wall motion of the left ventricle were thought to be generalized; (2) there were 9 cases with segmental wall motion abnormalities and 3 of them demonstrated ventricular aneurysms, and (3) the localizations of the segmental abnormalities varied in each case, and there was no apparent accumulation to any segments. II) In DMD, (1) all the cases showed depressed motions and 8 of them demonstrated a ventricular aneurysm in the posterior wall of the left ventricle (LVPW), (2) while, there was no case showing ventricular aneurysm in the segments other than LVPW, and about one third of all cases showed normal motion in those segments. From these results, we concluded as follows: 1) Although the depression of a wall motion of the left ventricle was generalized in CCM, this was not always uniform and the segmental abnormalities of a wall motion were frequently observed. The localization of the most severely disturbed segment varied in each case. 2) On the other hand, in DMD, the wall motion was disturbed more frequently and more severely in LVPW than in other ventricular segments.

Adolescent↗
PubMed1979

Bilateral Meniere's disease.

A survey of 265 Japanese patients with Meniere's disease revealed bilateral involvement in approximately 29% of all these patients. Somatic and psychiatric aspects of bilateral Meniere's disease were as follows. (1) The duration of the disease in cases of bilateral involvement was significantly longer than cases of unilateral involvement. (2) An abnormal general condition, a more extensive degree of hearing loss and neurotic type were frequently diagnosed in cases of bilateral involvement. Based on these results, it was concluded that psychiatric management and prevention of aggravation of deafness should be part of the management of treatment in bilateral Meniere's disease.

Female↗
PubMed1976

An autopsy case of liposarcoma with granulocytic leukemoid reaction.

A 57-year-old female with a large retroperitoneal tumor was atutopsied. She showed through the entire course of illness marked leukocytosis with the appearance of immature marrow cells, and this finding was hematologically interpreted as granulocytic leukemoid reaction. An intermittent pyrexia was also seen without infective etiology. The histologic diagnosis of the tumor was liposarcoma of the pleomorphic type. The tumor showed extensive necrosis, but no metastatic invasion was found. So-called leukemoid reaction appears sometimes together with malignant neoplasms. The majority of these tumors show widespread bone marrow metastases, and without bone marrow invasion they only rarely induce this reaction. Besides it is not common for leukemoid reaction to be evoked by the development of malignant mesenchymal tumors except for malignant lymphomas. The pathophysiologic process of the present of the present case is thought to be a rare occurrence.

Autopsy↗
PubMed1975

Low molecular weight components (g-chains) of myosin from rabbit skeletal muscle. Separation, amino acid compositions and contents in myosin.

Low molecular weight components (g1, g2, and g3) were isolated from rabbit skeletal muscle myosin and their amino acid compositions were analyzed. One mole tryptophan was found in g1 and in g2, but none in g3. One mole of acetic acid was found per mole of each g-chain and it was concluded that the N-terminal groups of all three g-chains are acetylated. The minimum molecular weight of the g-chains were estimated from their amino acid compositions. It was estimated by SDS-disc electrophoresis that 1 mole of myosin contained 0.90, 1.7, and 0.63 moles of g1, g2, and g3, respectively. Similar values were obtained with psoas muscle myosin, but in heavy meromyosin prepared from skeletal muscle myosin the content of g2 was much lower, and that of g3 was much higher.

Amino Acids↗