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S Yanagida

Publications and source records attributed to S Yanagida.

31 records · Page 2Linked to original sources
PubMed1990

[Diagnosis of left ventricular aneurysm by exercise thallium-201 myocardial single photon emission computed tomography].

To diagnose and characterize post-infarction left ventricular aneurysms, we performed exercise thallium-201 myocardial single photon emission computed tomography (SPECT) combined with selective coronary angiography and left ventriculography. The subjects consisted of 79 patients with acute myocardial infarction; 42 with anteroseptal, three with both anterior and inferior, 29 with inferior and five with posterior infarction. Visual classification of ventricular wall morphology by either a horizontal or a vertical long-axis image was designed into convergent (C), parallel (P) and divergent (D) types, according to the interrelationship between either septal and lateral wall or anterior and inferior wall, respectively. This method was applied in post-stress and delayed images, and these patients were divided into five groups (Group A-E) in accordance with varying morphological types from the post-stress to the delayed as follows: C-C (Group A, 36 patients), P-C (Group B, 8), P-P (Group C, 7), D-P (Group D, 5) and D-D (Group E, 23). A high incidence (21/23) of a left ventricular aneurysm by left ventriculography was recognized in Group E patients in comparison with other Groups. Provided that either Group D or E (all patients had anterior infarction) had left ventricular aneurysms, the diagnostic sensitivity, specificity and accuracy were 89%, 92% and 86%, respectively. Two of three patients with false negative diagnosis had only apical involvement. Furthermore, these two Groups had significantly larger defect scores as calculated by polar maps than did the other three Groups. When patients with anterior infarction with defect scores of 200 or greater were defined positive, the sensitivity, specificity and accuracy of ventricular aneurysms were 96%, 75% and 86%, respectively. One false negative case was apical infarction, and one of the two false positive cases were extensive anteroseptal infarction involving the apex. These results suggest that a left ventricular aneurysm which is important in predicting prognostic sequence could be diagnosed only by exercise SPECT, and that it could be characterized by extensive and severe apicoanterior infarction and a divergent-type ventricular wall arrangement on a post-stress SPECT image.

Exercise Test↗
PubMed1989

Effects of calcium antagonists and free radical scavengers on myocardial ischemia and reperfusion injury: evaluation by 31P-NMR spectroscopy.

The Langendorff perfused rat heart was used to investigate whether myocardial damage during ischemia and reperfusion could be protected by free radical scavengers, calcium antagonist and adenosine. Myocardial high energy phosphates were measured by phosphorus-31 NMR spectroscopy during normal perfusion, 20 min of ischemia and 20 min of reperfusion. In hearts, which were treated both with free radical scavengers (FRS) (Superoxide dismutase): 24 IU/ml and catalase 22 IU/ml) and verapamil (10(-7) M), beta-ATP was significantly higher than that of FRS at the end of ischemia. However, beta-ATP recovered only to 83% of baseline value at the end of reperfusion. In view of myocardial metabolism, verapamil treated hearts were good for recovery of creatine phosphate (PCr) but not ATP at the end of reperfusion. Hearts which were treated with only adenosine did not differ from control hearts. However, when hearts were treated with both verapamil and adenosine (10(-4) M), recovery of both ATP and PCr content was significantly greater than that of control hearts. These results suggested that pretreatment with both verapamil and adenosine before and after global ischemia could protect ischemic myocardium, but, further studies are necessary to clarify the precise mechanism of protection.

Adenosine↗
PubMed1988

[Quantitation of the severity of coronary artery disease using thallium-201 tomographic scores].

To evaluate coronary artery disease, a new quantitative thallium-201 (201T1)-tomographic scintigraphic score (TSS: modified Massie's score) using oxygen consumption (METS) was developed and compared with coronary angiographic score (CAG-S) in 27 patients (eight patients with normal coronary angiograms, and five, eight and six patients with one, two and three vessel disease, respectively) without previous myocardial infarction. All patients received both coronary angiography and the treadmill exercise test using 201T1-myocardial single photon emission computed tomography (SPECT) within two weeks. The redistribution area (RA) and washout rate area (WA) were derived from the circumferential profile analysis using apical (A), midventricular (M) and basal (B) short-axis images. To obtain TSS values, the sum of these values was divided both by percentage of the age-predicted maximal heart rate (%PMHR) and the METS value as follows: TSS = [RA (A, M, B) + WA (A, M, B)]/(%PMHR x METS). The results were as follows: 1. TSS values were 6.4 +- 1.6, 9.4 +/- 2.2, 24.2 +/- 12.0 and 30.6 +/- 5.0 (mean +/- SD) in normal, one, two and three vessel disease groups, respectively. Significant differences were found among each group except between two and three vessel disease groups. 2. The detectability of significant coronary artery disease was 89% (17/19) except in two patients with one vessel disease. 3. A high correlation coefficient was found between TSS (X) and CAG-S (Y), i.e., Y = 0.8X - 3.5 (r = 0.944, p less than 0.001). It was concluded that the tomographic scintigraphic score (TSS) is useful not only for detecting, multivessel disease but also for totally-evaluating its severity, extent and influence on collateral supply, and could be used for analyzing prognosis and the selection of therapeutic interventions.

Aged↗
PubMed1982

[Heart rates in male Wistar rats reared under different conditions of the weaning period and social housing (author's transl)].

The electrocardiogram (ECG) was recorded from unrestrained rats reared under the 6 conditions: weaned on the 14th, 18th or 28th postnatal day and thereafter housed in isolation (14I, 18I and 28I) or grouped with littermates (14G, 18G and 28G). The heart rate (HR) was measured on a 30 second sample of the ECG recorded from the 5th to the 20th week of age. For all rearing conditions, HR was confirmed to follow the normal distribution in respective weeks, and changes in HR through development were investigated. (a) HRs of 14G and 18G were significantly higher at the 5th week, and were later to reach the stabilized HR than 28G and isolated rats. (b) The variability between individuals (Vbi) reduced markedly at the 7th week in 18G and 28G, this may be attributed to the reduction in the variance within litter (Vwl) due to the interactions among littermates. In isolated rats, it was a relative low value in Vbi perhaps because of a low value in the variance between litters (Vbl). Contrary to isolated rats, in 14G Vbi was high, Vbl was high as well, but Vwl was low owing to the early separation from the mother and long periods of group housing.

Animals↗
PubMed1982

[Heart rates in male Wistar rats reared under different conditions of the weaning period and social housing].

A prior study reported the developmental changes in heart rate (HR) in male rats. In this paper, we carried out more laborious analyses to check and compare the differences among effects of the rearing conditions. In group-housed rats, the earlier the weaning periods, the lower the variance within litter, but the higher the variance between litters. In contrast to this, high values within litter were maintained in the earlier weaned isolates On the occasion, 18 G was close to 28 G in changes in the variance, and 18 I showed the same trends as 14 I, thus indicating the different significance of the periods of 14-18 days after birth and 18-28 days concerning the interaction of mother and offspring. The rats that interacted with both littermates and mother as 18 G and 28 G, showed the marked reduction in the variance between individuals along with age as opposed to 14 I, 18 I and 14 G in which the infantile form of higher variances were maintained after the 10 th week. A dynamic model of HR was led, which showed two distinct phases according to the changes in the variance. These phases corresponded to the development and aging stages. In addition, the implications of "intrinsic process", "immaturity" and "enriched environments" were discussed.

Aging↗
PubMedDate not supplied

Imaging techniques for measuring adipose-tissue distribution in the abdomen: a comparison between computed tomography and 1.5-tesla magnetic resonance spin-echo imaging.

Eight subjects were examined both by abdominal X-ray computed transverse axial tomography (CT) and magnetic resonance imaging (MRI) (SE) (TR/TE, 200 ms/15 ms); another eight volunteers were subjected to three MRI scans to test the reliability of repeated measures. Correlations between fat area measures obtained by CT and by MRI for subcutaneous fat, total fat, and visceral vs. subcutaneous-fat ratio were highly significant (r = 0.93, 0.91, and 0.94, respectively; p < 0.01), and the standard errors of estimation were 9.99, 23.87, and 0.0047. The average errors of the method for different fat areas were 2.20 cm2 (intra-examination variance) and 3.75 cm2 (inter-examination variance) for visceral and 0.82 cm2 (intra-examination variance) and 1.29 cm2 (inter-examination variance) for subcutaneous fat areas, respectively. These results suggest that SE MRI is a practical approach to evaluate body fat distribution without the exposure to radiation. The reproducibility of SE MRI for the determination of fat areas is high; variation is small and acceptable. However, it is difficult to determine which estimate of fat area should be accepted when there is a discrepancy between MRI and CT measures.

Adipose Tissue↗