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Biomedical subjects

A Azuma

Publications and source records attributed to A Azuma.

At least 163 records · Page 9Linked to original sources
PubMed1989

[Evaluation of transient dilation of the left ventricle on exercise thallium-201 scintigraphy].

We have noted that some patients with ischemic heart disease have a pattern of transient dilation of the left ventricle on the immediate post exercise images as compared with 3 hour redistribution images. We assessed correlation between transient dilation of the left ventricle and coronary arteriographic findings in 32 patients with ischemic heart disease and 15 controls. Initial and delayed conventional short axis tomographic images were obtained after reconstruction of 20 projections acquired over 180 degrees. Thirty six radii by every 10 degrees were generated from the center of the middle myocardial images of the short axis. An area surrounded by thirty six points of maximal count on each radius was calculated in initial and delayed images. Transient Dilation Index (TDI) as an index of dilation was determined by dividing an area in initial image by an area in delayed image. There was no difference in TDI between patients with 1 vessel disease and controls, but TDI in patients with two vessel disease and patients with three vessel disease was larger than that in controls. Thus, transient dilation of the left ventricle on exercise Tl scintigraphy was likely to be related to number of stenotic vessel. We concluded that TDI as a simple quantitative index of transient dilation of the left ventricle was useful for detecting multi vessel stenosis.

Cardiomyopathy, Dilated↗
PubMed1989

Cinevideodensitometric quantification of relative coronary arterial stenosis: application to evaluating candidates for percutaneous transluminal coronary angioplasty.

As an alternative to visual interpretations of subjects' angiograms, coronary arteries dilated by percutaneous transluminal coronary angioplasty (PTCA) were evaluated using cinevideodensitometry, and the results were compared with those obtained by the edge detection method. Coronary arteriograms were obtained in various projections and suitable frames were selected for analysis. The frames were transformed to digitized images (512 X 512 X 8 bits) with an image analyzer (MIPRON 1), and cinevideodensitometric and edge detection analyses were performed. Phantom models of various shapes were opacified with contrast medium and were used to test our system. The cineangiograms of 58 patients with ischemic heart disease, 28 of whom had underwent PTCA, were analyzed. A highly linear correlation was observed between the cross-sectional areas of the phantoms and the summed gray levels measured using cinevideodensitometry. Percent area stenosis evaluated by the two methods was accurate and reproducible in measuring the symmetrical stenosis models. However, for the model of asymmetrical stenosis, the measurement by the edge detection method differed according to various projections. Similar results were obtained measuring asymmetrical stenosis in the right coronary artery in vivo in various projections. Based on these experimental results, coronary stenoses dilated by PTCA were evaluated. Prior to PTCA, coronary arterial stenosis measured using the two methods closely approximated each other. However, following PTCA, there were discrepancies between the measurements by the two methods in six cases. This can be accounted for by asymmetrical changes in a luminal cross-section, which cannot be accurately assessed using the edge detection method in single plane projection. In conclusion, cinevideodensitometric measurements of relative coronary arterial stenosis were objective, accurate, and reproducible. According to cinevideodensitometric analysis, eccentric lesions can be measured using a single projection, and tracing arterial borders is unnecessary. It is a useful means in measuring quantitatively the degree of dilatation of coronary arterial stenosis accomplished by PTCA.

Angiography↗
PubMed1989

[Ultrasonic tissue characterization by spectral analysis of myocardial textural pattern].

Based on the fact that ultrasonic myocardial textural patterns are more irregular in the pathological myocardium than in the normal, evaluation of the myocardial tissue character was attempted in vivo using spectral analysis. Parasternal left ventricular long-axis echocardiograms were obtained from five patients with old myocardial infarction diagnosed by history, electrocardiography and coronary angiography. These echocardiograms were transferred to an image analyzer and digitized (256 x 256 x 8). The waveforms of the gray-scale-changes from the normal myocardium showed periodicity in each 8-pixel cycle, but those from the infarcted myocardium did not. To quantify pattern changes in gray-scale values in the ultrasound beam direction, spectral analysis was performed by the maximum entropy method (MEM). There were four peaks in the MEM spectra both in the normal and infarcted myocardia, but there was a great significance in these patterns: with high, steep peaks in normal MEM spectra, and low, blunt peaks in infarcted ones. By discriminatory analysis of these four peak values, normalized by the whole spatial frequencies as multivariate, the misclassification rate was 4.8-22.7% in anteroseptal infarctions and 5.0-20.0% in posterior infarctions. Thus, spectral analysis of the myocardial textural pattern has advantages for analyzing routine echocardiograms without corrections by any absolute ultrasonic references. Furthermore, the misclassification rate is so low that we are able to characterize myocardial tissue.

Echocardiography↗
PubMed1989

[Evaluation of right ventricular systolic and diastolic properties using 81mKr scintigraphy with continuous infusion].

To evaluate right ventricular (RV) systolic and diastolic properties in patients with various heart diseases, RV volume curves obtained from 81mKr scintigraphy with continuous infusion were analyzed. The data were acquired in right anterior oblique position for five minutes, and from RV time activity curve and its first derivative curve, ejection fraction and peak ejection rate as systolic indices, and peak filling rate, time to peak filling and 1/3 mean normalized diastolic filling rate as diastolic indices were calculated. Ejection fraction in patients with dilated cardiomyopathy was lower than that in controls, but there was no difference in systolic indices among controls and patients with the other heart diseases. However, diastolic indices in patients with hypertrophic cardiomyopathy, patients with hypertensive heart disease, patients with dilated cardiomyopathy, patients with inferior myocardial infarction, and some patients with anteroseptal myocardial infarction were lower than those in controls. In conclusion, analysis of RV time activity curve by 81mKr scintigraphy with continuous infusion provides RV systolic and diastolic indices, which may permit evaluation of RV systolic and diastolic properties in various heart diseases.

Female↗
PubMed1989

[Effect of mexiletine on human atrial vulnerability].

The effect of mexiletine on human atrial vulnerability was investigated in 14 subjects (8 with paroxysmal atrial fibrillation, 2 with paroxysmal atrial tachycardia, 2 with ventricular tachycardia, 1 with sick sinus syndrome and 1 with Wolff-Parkinson-White syndrome). During the electrophysiologic study, after 8 consecutive stimuli (A1) were delivered through the electrode catheter positioned at high right atrium, premature stimulus (A2) was introduced, and following measurements were made; 1) Aw: atrial activity width of A1, 2) maximum atrial fragmentation (MAF): the longest atrial activity width of A2, which was expressed by the relative value against Aw, 3) fragmented atrial activity zone (FAZ): the zone of the coupling interval (A1A2) with the prolongation of the atrial activity width at A2 more than 150% against Aw, 4) conduction delay zone (CDZ): the zone of A1A2 with the prolongation more than 20 msec of the intraatrial conduction time at A2 from high right atrium to coronary sinus or low right atrium against the intraatrial conduction time at A1, and 5) right atrial effective refractory period (RAERP). These measurements were repeated after the intravenous administration of mexiletine (2 mg/kg/10 min). 3 cases (case 12, 13 and 14), whose FAZ and CDZ were 0 msec, were excluded from the following evaluation. Mexiletine showed little effect on Aw and RAERP, but significantly shortened MAF and FAZ (p less than 0.001 and p less than 0.05, respectively). CDZ were also reduced in 3 cases and remained unchanged in 6 cases, though no statistical difference of CDZ was recognized between before and after the administration of mexiletine.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

[Nuclear cardiological examination for evaluation of hypertrophic cardiomyopathy with midventricular obstruction and apical aneurysm: a case report].

Midventricular hypertrophy (MVO) is a rare and complicated myocardial disease. Its pathophysiology and prognosis remain unknown, and few nuclear cardiological findings for MVO were reported. On a 44-year old man with MVO, thallium-201 (Tl) myocardial scintigraphy and gated blood pool scintigraphy (GPS) were performed to evaluate their usefulness. GPS revealed a characteristic hour-glass deformity of the left ventricular cavity, apical aneurysm and asynchrony due to obliteration of the midventricle. Anteroseptal hypertrophy in midventricle and myocardial damage in apico-inferior region were detected by Tl. Thus, nuclear cardiological studies are proved to be useful and essential in not only diagnosis but also evaluating pathophysiology and observing natural history noninvasively.

Adult↗
PubMed1988

[Transmitral blood flow velocity patterns evaluated by pulsed Doppler echocardiography in diagnosing transient myocardial ischemia].

To evaluate the influences of transient myocardial ischemia on transmitral blood flow velocity patterns, pulsed Doppler echocardiography was performed during coronary artery occlusion in 10 anesthetized open-chest dogs, and also during esophageal pacing or the administration of dipyridamole in 79 patients with coronary artery disease (CAD), and in 19 control subjects. During occlusion of the coronary artery, an abrupt decrease in the peak velocity of the rapid filling wave (R) was noted within one min simultaneously with rapid decrease of % wall thickening in the ischemic regions. The peak velocity of atrial filling was augmented compensatorily. Although the transmitral blood flow velocity pattern did not change in the controls with esophageal pacing, changes similar to those which were obtained during experimental studies were demonstrated in CAD patients. There were no significant differences between transmitral blood flow velocity patterns of patients with multivessel disease and those with single vessel disease. Ischemic changes in transmitral blood flow velocity patterns were not demonstrated in patients with mitral regurgitation. Sublingual nitroglycerin normalized post-pacing abnormal blood flow velocity patterns. In contrast, after the intravenous administration of 0.56 mg/kg of dipyridamole, R and A were increased and the A/R ratio was unchanged both in CAD patients and the control groups. Deceleration time, or the half time, was prolonged during both provocation tests in CAD patients, and these changes were transient and were restored within several min. Furthermore, they were noted more frequently than was the development of ST depression on ECG, or chest pain. These findings indicate that the transmitral blood flow velocity patterns obtained by pulsed Doppler echocardiography are useful for detecting transient myocardial ischemia, though they have limitations in diagnosing the extent of coronary artery disease.

Animals↗
PubMed1987

[An autopsy case of Paget's disease of the scrotum with general metastasis].

An autopsy case of genital Paget's disease with a widespread metastases is reported. A 69-year-old man with redness, itching and swelling of the scrotum obtained dermatological consultation and underwent tumor resection for Paget's disease. At 8 months after discharge, he suffered from a costal fracture because of carcinomatosis of the bone marrow. In laboratory data the serum level of alkaline phosphatase and carcinoembryonic antigen was shown to be high. Four months later, he died of severe congestive edema of the lung with diffuse micrometastases. An autopsy revealed a widespread metastases in various organs and lymph nodes. The Paget cells were positive in carcinoembryonic antigen.

Aged↗
PubMed1987

[Analysis of drug sensitivity by successive colony-forming assay].

It is difficult to predict the adequate doses of effective drugs which must be administered in cancer chemotherapy. We have developed a successive colony-forming assay in order to analyze changes of drug sensitivity in human cancer cell lines, and it is used as a model of cancer chemotherapy. Presently, widely used methods include the clonog ceni assay as in vitro sensitivity test established by Salmon and Hamberger et al., for revealing effective drugs. However, formation of a second colony using initial colony-forming cells has not yet been performed. We therefore analyzed the changes occurring in drug sensitivity in 2nd and 3rd colony-forming assays. Using a human lung adenocarcinoma cell line PC-9 (established by Hayata at the Surgical Department in Tokyo Medical School), we measured the changes in sensitivity to CDDP and its derivatives. After picking up the colony-forming cells by micropipette and culturing them in culture medium, we tried to incubate them for 1 hour with the anticancer drug, and then replate them in soft agar. This technique is called "2nd colony-forming assay". We were able to carry this out three times. The results obtained showed that the anti-tumor effect of 254S was the same as that of CDDP, whereas that of CBDCA was less than either of them. Although these tendencies were noticeable even in the 2nd colony-forming assay, the sensitivities to CDDP and its derivatives were diminished in the 3rd colony-forming assay.

Adenocarcinoma↗
PubMed1987

[Evaluation of right ventricular function in severe left ventricular failure: comparison of old myocardial infarction with dilated cardiomyopathy].

To evaluate right ventricular (RV) function in severe left ventricular (LV) failure, we measured RV and LV ejection fractions (EF) in 18 patients with old myocardial infarction (OMI) and in 18 with dilated cardiomyopathy (DCM) using cardiac blood pool scintigraphy. In patients with OMI, RVEF was significantly greater in stage II LV failure than in stage III (functional class of the New York Heart Association, 47 +/- 8% and 28 +/- 12%, respectively: p less than 0.01), and this correlated well with exercise tolerance by bicycle ergometer and mean pulmonary artery pressure (r = 0.83 and r = -0.71, respectively). In patients with DCM, however, there was no correlation between RVEF and these indexes. After the oral administration of denopamine (beta 1 effector), both RVEF and LVEF increased in patients with OMI (35 +/- 13% to 45 +/- 12%, and 27 +/- 9% to 30 +/- 10%: p less than 0.01), but they did not change significantly in patients with DCM. These results indicate that RVEF in patients with OMI correlates well with subjective symptoms, exercise tolerance and RV afterload, but these correlations were not apparent in patients with DCM. We concluded that RV function in cases of severe LV failure has a different meaning between OMI and DCM.

Adult↗
PubMed1981

Clinical features of 53 cases with pustulotic arthro-osteitis.

We have described clinical features of 53 cases with pustulotic arthro-osteitis. Anterior chest wall symptoms such as intersterno-costoclavicular or manubriosternal lesions were observed in all of 53 cases. Spondylitis or spondylodiscitis was found in 18 cases. Sacroiliitis resembling ankylosing spondylitis was seen in 7 cases. Peripheral inflammatory arthritis was seen in 14 cases, which were of nonerosive, of oligoarthritis type, and cured within 1 to 2 months, leaving no residue. HLA B27 was never found, and RAW factor was negative. Histological examinations revealed nonspecific chronic inflammation of bone and soft tissue. Pustulotic arthro-osteitis is apparently distinct from known rheumatic diseases such as rheumatoid arthritis, ankylosing spondylitis, psoriatic arthritis, and Reiter's disease. We have proposed that this condition should be classified as a member of the "seronegative spondylo-arthritis' group as designated by Wright and Moll.

Adult↗
PubMed1981

Incidence of arthro-osteitis in patients with pustulosis palmaris et plantaris.

Arthro-osteitis at the anterior chest wall was found in 12 (9.4%) out of 128 consecutive patients with pustulosis palmaris et plantaris. This finding indicates that the concomitance of arthro-osteitis with PPP is not incidental but is based on some common aetiological factor. We propose a term ;pustulotic arthro-osteitis' for this condition.

Adult↗